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CN117940764A - An improved surface analysis method and device - Google Patents

An improved surface analysis method and device Download PDF

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Publication number
CN117940764A
CN117940764A CN202280060187.7A CN202280060187A CN117940764A CN 117940764 A CN117940764 A CN 117940764A CN 202280060187 A CN202280060187 A CN 202280060187A CN 117940764 A CN117940764 A CN 117940764A
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ozone
hydrogen
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xps
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P·库普森
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Optoelectronic Intellectual Property Co ltd
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Abstract

A method for producing an x-ray photoelectron spectrum of a sample, comprising the steps of: generating a plurality of different oxidation states of a sample at a surface of a sample surface by exposing the sample surface to an agent configured to change the oxidation state of the sample surface; placing a sample in an x-ray photoelectron spectrometer; obtaining an x-ray photoelectron spectrum for each of a plurality of oxidation states of the sample surface; the material in the sample is identified by analyzing the plurality of spectra.

Description

一种改进的表面分析方法和装置An improved surface analysis method and device

技术领域Technical Field

使用x射线光电子光谱对材料进行化学和物理分析。Chemical and physical analysis of materials using X-ray photoelectron spectroscopy.

背景技术Background technique

在分析实验室中,经常需要对小样品进行化学表征。x射线光电子光谱(XPS)1和二次离子质谱(SIMS)等技术可以提供表面顶部几纳米的出色化学表征。参见图1中的XPS仪器示例,以及图2中透过视窗看到的XPS仪器的视图。图15显示了典型商用XPS仪器的横截面示意图。In analytical laboratories, chemical characterization of small samples is often required. Techniques such as X-ray Photoelectron Spectroscopy (XPS) 1 and Secondary Ion Mass Spectrometry (SIMS) can provide excellent chemical characterization of the top few nanometers of a surface. See an example of an XPS instrument in Figure 1 and a view of an XPS instrument through the viewing window in Figure 2. A schematic cross-section of a typical commercial XPS instrument is shown in Figure 15.

在本文件中,当提及x射线光电子(XPS)光谱时,我包括x射线诱导的俄歇峰(Augerpeaks),其出现在来自XPS仪器的相同光谱中。这里提出的发明对于阐明这些俄歇峰的化学成分应该同样有价值,就像解释为严格的光电子峰一样。术语“样品”和“样本”在全文中可互换使用。In this document, when referring to x-ray photoelectron (XPS) spectra, I include the x-ray induced Auger peaks that appear in the same spectrum from an XPS instrument. The invention presented here should be as valuable in elucidating the chemical composition of these Auger peaks as it would be if interpreted as strictly photoelectron peaks. The terms "sample" and "specimen" are used interchangeably throughout the text.

在XPS中,能量分辨率通常受限于实验室仪器(例如与同步加速器相比)。在过去的二十年中,XPS中出现了单色x射线源的趋势,因此,尽管简单的阳极x射线源在20世纪80年代很流行,但几乎所有新的XPS仪器都有单色仪来提高能量分辨率,尽管这种单色仪很昂贵。In XPS, energy resolution is usually limited by laboratory instruments (compared to synchrotrons, for example). In the last two decades, there has been a trend towards monochromatic X-ray sources in XPS, so that although simple anode X-ray sources were popular in the 1980s, almost all new XPS instruments have a monochromator to improve energy resolution, although such monochromators are expensive.

分析师需要更高能量分辨率的原因是为了区分样品中核级峰(core-levelpeaks)的不同化学状态。最近在LinkedIn社交网络上进行的一项民意调查(结果如表1所示)中,XPS用户将峰拟合(即分辨XPS峰中的不同化学状态)列为他们在XPS中遇到的最大问题。The reason analysts need higher energy resolution is to distinguish different chemical states in core-level peaks in a sample. In a recent poll conducted on the LinkedIn social network (the results are shown in Table 1), XPS users listed peak fitting (i.e., distinguishing different chemical states in XPS peaks) as the biggest problem they encounter in XPS.

表1:LinkedIn对2021年XPS用户的投票结果Table 1: LinkedIn poll results for XPS users in 2021

提高能量分辨率有助于最大限度地减少核级峰的峰重叠,并且多年来一直在进行技术改进,以使商业仪器更容易做到这一点。然而,在许多情况下它是无法避免的。为了提高半球形电子能量分析器中的能量分辨率,必须选择大型分析器(这是昂贵的)和/或在该分析器中转移到较低的通过能量,这降低了计数率并可能导致噪声谱。操作XPS系统的大部分技巧在于为通过能量(eV)、光谱通道间隔(eV)和通道停留时间(秒,s)选择正确的参数,以获得具有所需分辨率的光谱来解析峰值,同时显示良好的光谱信噪比。Improving energy resolution helps minimize peak overlap of nuclear-level peaks, and technology improvements have been made over the years to make this easier to do with commercial instruments. However, in many cases it cannot be avoided. To improve energy resolution in a hemispherical electron energy analyzer, one must choose a large analyzer (which is expensive) and/or move to a lower pass energy in that analyzer, which reduces the count rate and can result in a noisy spectrum. Much of the skill in operating an XPS system lies in choosing the correct parameters for pass energy (eV), spectral channel spacing (eV), and channel dwell time (seconds, s) to obtain a spectrum with the required resolution to resolve peaks while displaying a good spectral signal-to-noise ratio.

尽管如此,在许多情况下峰无法被解析,这在表面分析界被认为是一个大问题。近年来,这个问题已在文献中详细讨论过,例如Baer等人2。基于对409篇已发表论文的广泛审查,Major等人3表示,“超过65%的显示XPS光谱的论文也显示了一定程度的拟合,这是大多数错误的来源”。这是规模庞大的国际分析界面临的最重大问题:除非分析人员熟练地选择峰参数和关联,否则XPS允许错误的峰归属和强度测量。Major等人4指出,“过渡金属的高分辨率光谱是最具挑战性的峰拟合光谱之一。事实上,过渡金属的峰拟合过于简单地将峰分配给单个化学物质,从而导致对结果的错误解释是很常见的”。然而,过渡金属在技术上极其重要,像Hf和Ta这样的元素在半导体表面分析中非常重要,这些元素中的许多元素在电池技术中也很重要。在图21中,我展示了(摘自维基百科)过渡金属的氧化态。实心点显示常见的氧化态,空心点显示可能但不太可能的状态。该图非常清楚地表明,过渡金属可以在许多可能的化合物中以多种氧化态存在,这些过渡金属元素的核级光谱,在XPS光谱中,以除了对最熟练的分析师之外的人来说非常混乱的方式重叠。Nevertheless, there are many cases where peaks cannot be resolved, which is considered a major problem in the surface analysis community. This problem has been discussed in detail in the literature in recent years, for example by Baer et al. 2 . Based on an extensive review of 409 published papers, Major et al. 3 stated that “over 65% of papers showing XPS spectra also show some degree of fitting, which is the source of most errors”. This is the most significant problem facing the large international analytical community: unless the analyst is skilled in choosing peak parameters and correlations, XPS allows for erroneous peak assignments and intensity measurements. Major et al. 4 stated that “high-resolution spectra of transition metals are among the most challenging spectra to peak fit. In fact, it is common for peak fits of transition metals to oversimplify the assignment of peaks to individual chemicals, leading to incorrect interpretations of the results”. However, transition metals are extremely important technologically, and elements like Hf and Ta are very important in semiconductor surface analysis, and many of these elements are also important in battery technology. In Figure 21, I show (taken from Wikipedia) the oxidation states of transition metals. Solid dots show common oxidation states, and open dots show possible but unlikely states. This figure shows very clearly that transition metals can exist in a wide variety of oxidation states in many possible compounds, and that the core-level spectra of these transition metal elements overlap in an XPS spectrum in a way that is very confusing to all but the most skilled analyst.

许多具有适度技能的分析人员尽了最大努力,但对这些解析度较差的峰进行峰拟合在文献中经常被批评为错误和误导。Many analysts with moderate skills do their best, but peak fitting of these poorly resolved peaks is often criticized in the literature as being erroneous and misleading.

在窄XPS光谱中出现多个未解析峰的通常原因是表面含有一种或多种元素或化合物的多个氧化态。原则上,人们可以把一种元素所有化学状态的结合能列表。这是一个很好的第一步指南,分析人员在处理特定要素时经常查看NIST数据库5。然而,专门使用这种方法是真正的挑战,因为;The usual reason for multiple unresolved peaks in a narrow XPS spectrum is that the surface contains multiple oxidation states of one or more elements or compounds. In principle, one can tabulate the binding energies of all chemical states of an element. This is a good first step guide, and analysts often consult the NIST database when dealing with a specific element5 . However, using this approach exclusively is a real challenge because;

1.一些元素的某些氧化态不在数据库中。1.Some oxidation states of some elements are not in the database.

2.结合能是在很长一段时间内,由许多不同的人使用许多不同的仪器获取的,他们的结合能校准过程可能不确定。2. The binding energies were obtained over a long period of time by many different people using many different instruments, and their binding energy calibration process may be uncertain.

3.峰(比如说一个位于光谱中另外两个峰之间的未解析峰)的结合能的小误差会导致这三个峰的相对强度的大误差。即使结合能出现0.1eV的误差(这是目前即使通过重复且昂贵的校准步骤也能达到的绝对极限)也会导致光谱中相邻未解析峰的相对强度出现很大的不确定性。3. A small error in the binding energy of a peak (say an unresolved peak located between two other peaks in the spectrum) can lead to large errors in the relative intensities of the three peaks. Even an error of 0.1 eV in the binding energy (which is currently the absolute limit that can be achieved even with repeated and expensive calibration steps) can lead to large uncertainties in the relative intensities of adjacent unresolved peaks in the spectrum.

因此,某种“内部”参考或方法将非常有用。换句话说,改变不同未解析峰的相对强度使其远离标称值的某种方法。有时这可以通过倾斜样本来实现——如果不同的化学状态存在于不同的深度,就可以实现这一点。通常它们不会出现在不同的深度,因为样品表面相当均匀。此外,在配有大型样品架6的现代仪器中,倾斜通常并不容易。此外,倾斜会改变峰下的非弹性背景,这增加了峰拟合的复杂性。Therefore, some kind of “internal” reference or method would be very useful. In other words, some way to change the relative intensities of the different unresolved peaks away from the nominal values. This can sometimes be achieved by tilting the sample - this can be done if different chemical states exist at different depths. Usually they do not appear at different depths, because the sample surface is quite uniform. Moreover, tilting is not usually easy in modern instruments with large sample holders6 . In addition, tilting changes the inelastic background under the peaks, which increases the complexity of peak fitting.

一种证明有用的技术是用高能离子轻微或短暂地溅射表面(大多数XPS系统都安装离子枪以允许溅射深度剖析)。这带来了损害,通常会去除表面附近的一些氧化物质,或化学还原其他物质的氧化态。比较这种短暂溅射前后包含重叠化学状态的窄扫描光谱可能是有用的。然而,这有局限性;溅射枪运行时间过长,表面的所有化学状态将被清除,留下受损的散装材料的光谱。这很容易做到,因为这些枪旨在快速去除材料。更糟糕的是,如果表面上几乎没有可被化学还原的物质,那么通过溅射进一步还原它几乎不会改变光谱,也不会告诉有关存在峰的信息(人们会希望改为氧化)。One technique that has proven useful is to lightly or briefly sputter the surface with energetic ions (most XPS systems are fitted with ion guns to allow sputter depth profiling). This introduces damage, typically removing some oxidized species near the surface, or chemically reducing the oxidized state of other species. Comparing narrow scan spectra containing overlapping chemical states before and after such a brief sputtering can be useful. However, this has limitations; run the sputtering gun too long and all chemical states on the surface will be removed, leaving a damaged spectrum of the bulk material. This is easy to do because these guns are designed to remove material quickly. Worse, if there is little chemically reducible species on the surface, then reducing it further by sputtering will do little to change the spectrum and tell you nothing about the presence of peaks (which one would expect to be oxidized instead).

然而,短暂的溅射通常是有用的,并且可以在XPS分析室本身中快速完成。在某种意义上,这是与本发明相反的过程,因此两者可以有效地结合,实际上,来自两者的光谱可以在相同的主成分分析7(PCA)、奇异值分解8(SVD)或非负矩阵分解(NMF)方法中有效地分析。However, brief sputtering is often useful and can be done quickly in the XPS analysis chamber itself. In a sense, this is the reverse process to the present invention, so the two can be effectively combined, and indeed spectra from both can be effectively analyzed in the same principal component analysis7 (PCA), singular value decomposition8 (SVD), or non-negative matrix factorization (NMF) method.

具有讽刺意味的是,随着商业XPS系统速度的提高,每年产生的光谱越来越多,但只有有限数量的熟练人员能够解释它们。XPS分析的成本正在从仪器时间成本转移到解释成本(在许多情况下涉及峰拟合)。这里描述的本发明的特征之一是(通过产生更多的光谱,消除了仅记录一个光谱时存在的模糊性),它使用额外的仪器时间(这是便宜的)来减少分析人员花费在解释上的时间(这是昂贵的),并提高结果的可靠性和提高向分析报告和科学出版物的读者证明已经得出正确结论的能力。Ironically, as the speed of commercial XPS systems increases, more and more spectra are produced each year, but only a limited number of skilled personnel are able to interpret them. The cost of XPS analysis is shifting from the cost of instrument time to the cost of interpretation (involving peak fitting in many cases). One of the features of the invention described here is that (by producing more spectra, eliminating the ambiguity that exists when only one spectrum is recorded) it uses the extra instrument time (which is cheap) to reduce the time the analyst spends on interpretation (which is expensive) and to improve the reliability of the results and the ability to demonstrate to readers of analytical reports and scientific publications that correct conclusions have been drawn.

使用紫外光和臭氧氧化样品表面可以提供比仅从“原样(as-received)”状态的光谱中获得更多的表面化学信息(特别是XPS峰形)。对于许多类型的样本来说,这种方法非常有效。对于某些样本,尤其是XPS取样深度内的材料已经处于或接近其最高氧化态的样本,暴露于紫外光和臭氧几乎不会改变这些氧化态。因此,在本发明中,我将氧化和还原都描述为样品表面的选项,因此即使是这种最初氧化的样品的XPS光谱也可以通过上述多变量方法来阐明。Oxidation of the sample surface using UV light and ozone can provide more surface chemical information (particularly XPS peak shapes) than can be obtained from spectra of the "as-received" state alone. This approach works very well for many types of samples. For some samples, especially those where the material within the XPS sampling depth is already at or close to its highest oxidation state, exposure to UV light and ozone will hardly change these oxidation states. Therefore, in this disclosure, I describe both oxidation and reduction as options for the sample surface, so that even the XPS spectrum of such an initially oxidized sample can be elucidated by the multivariate approach described above.

尽管用于本发明的目的不同,但已经使用XPS证实9了在氢气氛围中使用UV辅助还原氧化铜,并且在合适的时间尺度内作为一种分析方法应用于一系列样品类型,在这种情况下,在氢存在下比单独使用254nmUV曝光快约10倍。氧化石墨烯的UV辅助还原已被证实10用于本发明的不同目的,但仍然表明样品表面的UV辅助还原在XPS中对于过渡金属以及碳质材料可能是有用的。Although used for different purposes in the present invention, the use of UV-assisted reduction of copper oxide in a hydrogen atmosphere has been demonstrated using XPS9 and applied as an analytical method to a range of sample types within suitable time scales, in this case approximately 10 times faster in the presence of hydrogen than using 254 nm UV exposure alone. UV-assisted reduction of graphene oxide has been demonstrated10 for different purposes in the present invention, but still suggests that UV-assisted reduction of sample surfaces may be useful in XPS for transition metals as well as carbonaceous materials.

有证据表明,UV暴露会导致不寻常的氧化物(即,即使在室温下长时间放置或在空气中升高温度后通常也不会出现的氧化物)(例如镍或半导体表面12)的形成11,从而取代其他氧化物,这对于解释XPS中的峰结构非常有帮助。There is evidence that UV exposure can lead to the formation of unusual oxides (i.e., oxides that are not normally present even after prolonged exposure to room temperature or elevated temperatures in air ) such as on nickel or semiconductor surfaces1211 , replacing other oxides, which is very helpful in explaining the peak structure in XPS.

US7875857描述了一种用于表面分析的x射线光电子光谱分析系统及其方法。US7875857 describes an x-ray photoelectron spectroscopy system and method for surface analysis.

US7420163描述了使用光电子光谱来确定层厚度。US7420163 describes the use of photoelectron spectroscopy to determine layer thicknesses.

US5315113描述了一种使用扫描和高分辨率x射线光电子光谱和成像进行表面分析的仪器。US5315113 describes an instrument for surface analysis using scanning and high resolution x-ray photoelectron spectroscopy and imaging.

发明内容Summary of the invention

根据本发明的第一方面,提供了一种用于产生样品的x射线光电子光谱的方法,包括以下步骤:According to a first aspect of the present invention, there is provided a method for producing an x-ray photoelectron spectrum of a sample, comprising the following steps:

通过将样品表面暴露于配置成改变所述样品表面的氧化态的试剂,在其表面产生样品的多种不同氧化态;generating a plurality of different oxidation states of the sample at its surface by exposing the sample surface to a reagent configured to change the oxidation state of the sample surface;

将样品置于x射线光电子光谱仪中;placing the sample in an x-ray photoelectron spectrometer;

获得所述样品表面的多种氧化态中每一个的x射线光电子光谱;obtaining an x-ray photoelectron spectrum of each of a plurality of oxidation states of the sample surface;

通过分析多个光谱来识别样品中的材料。Identify materials in a sample by analyzing multiple spectra.

优选地,样品连续多次暴露于配置为改变样品的所述表面的氧化态的试剂,其中在样品随后的每次暴露于试剂中时,样品表面的氧化态相对于由之前暴露于配置为改变所述样品表面的氧化态的试剂所导致的样品表面的氧化态而改变。Preferably, the sample is exposed to a reagent configured to change the oxidation state of the surface of the sample multiple times in succession, wherein at each subsequent exposure of the sample to the reagent, the oxidation state of the sample surface changes relative to the oxidation state of the sample surface caused by the previous exposure to the reagent configured to change the oxidation state of the sample surface.

样品可以被分成多个子样品,每个子样品具有子样品表面,并且其中对于每个子样品产生子样品表面的不同氧化态。The sample may be divided into a plurality of subsamples, each subsample having a subsample surface, and wherein a different oxidation state of the subsample surface is produced for each subsample.

配置成改变样品表面氧化态的试剂可以是气态试剂。The reagent configured to change the oxidation state of the sample surface may be a gaseous reagent.

配置为改变样品表面氧化态的试剂可以是以下一种或多种:紫外光、臭氧和氢气。The reagent configured to change the oxidation state of the sample surface may be one or more of the following: ultraviolet light, ozone, and hydrogen gas.

有利地,紫外光由至少一个紫外(UV)灯提供,其中从至少一个UV灯发射的UV光被导向所述样品表面。Advantageously, the ultraviolet light is provided by at least one ultraviolet (UV) lamp, wherein UV light emitted from the at least one UV lamp is directed towards said sample surface.

至少一个UV灯发射的UV光可以在200nm至300nm的波长范围内。The at least one UV lamp may emit UV light in the wavelength range of 200 nm to 300 nm.

为了氧化样品表面,臭氧是必要的。波长范围为200nm至300nm的可选UV可加快氧化速度。对于许多样品材料来说,如果在真空中进行,单独使用波长范围为200nm至300nm的UV可以缓慢地实现样品表面的还原,如果有氢气存在,还原速度大约快10倍。Ozone is necessary to oxidize the sample surface. Optional UV in the wavelength range of 200nm to 300nm can accelerate the oxidation rate. For many sample materials, the reduction of the sample surface can be achieved slowly using UV in the wavelength range of 200nm to 300nm alone if performed in vacuum, and about 10 times faster if hydrogen is present.

优选地,UV灯是汞蒸汽灯。Preferably, the UV lamp is a mercury vapor lamp.

臭氧可由臭氧产生装置提供,该装置在所述样本周围的气体中产生的臭氧气体浓度在为百万分之0.01至百万分之20。Ozone may be provided by an ozone generating device that generates ozone gas at a concentration of 0.01 ppm to 20 ppm in the gas surrounding the sample.

该方法可包括通过控制以下一项或多项来控制所述样品表面的氧化态变化程度的步骤:所述样品表面暴露于试剂的时间;试剂的浓度;以及试剂的波长和/或频率。The method may include the step of controlling the extent of the change in oxidation state of the sample surface by controlling one or more of: the time the sample surface is exposed to a reagent; the concentration of the reagent; and the wavelength and/or frequency of the reagent.

通过分析多个光谱来识别样品中的材料的步骤可以包括执行多变量分析,例如主成分分析或非负矩阵分解。The step of identifying materials in the sample by analyzing the plurality of spectra may include performing a multivariate analysis, such as principal component analysis or non-negative matrix factorization.

根据本发明的第二方面,提供了一种用于捕获x射线光电子光谱(XPS)的装置,包括:According to a second aspect of the present invention, there is provided an apparatus for capturing x-ray photoelectron spectroscopy (XPS), comprising:

样品架;Sample rack;

试剂源,其配置为改变保持在样品架中的样品的表面的氧化态;a reagent source configured to change the oxidation state of a surface of a sample held in the sample holder;

控制样品表面暴露于配置为改变所述表面的氧化态的试剂的装置;和means for controlling exposure of a sample surface to a reagent configured to change the oxidation state of said surface; and

能够记录多个XPS光谱的x射线光电子能谱仪,每个XPS光谱对应样品表面的一种氧化态。An x-ray photoelectron spectrometer capable of recording multiple XPS spectra, one for each oxidation state of the sample surface.

该装置还可以包括配置为执行主成分分析的数据处理器。The apparatus may further include a data processor configured to perform a principal component analysis.

优选地,该装置的样品架包含在外壳(enclosure)中。Preferably, the sample holder of the device is contained in an enclosure.

配置为改变样品表面的氧化态的试剂可以是气态试剂。The reagent configured to change the oxidation state of the sample surface may be a gaseous reagent.

配置为改变样品表面的氧化态的试剂可以是以下一种或多种:紫外光、臭氧和氢气。The reagent configured to change the oxidation state of the sample surface may be one or more of: ultraviolet light, ozone, and hydrogen gas.

紫外光可以由至少一个紫外(UV)灯提供,其中至少一个UV灯发射的UV光被引导至所述样品表面。The ultraviolet light may be provided by at least one ultraviolet (UV) lamp, wherein UV light emitted by the at least one UV lamp is directed to the sample surface.

优选地,从至少一个UV灯发射的UV光在200nm至300nm的波长范围内。Preferably, the UV light emitted from the at least one UV lamp is in the wavelength range of 200 nm to 300 nm.

该至少一个UV灯可以是汞蒸汽灯。The at least one UV lamp may be a mercury vapor lamp.

该装置还可以包括臭氧发生器,该臭氧发生器配置成在位于样品架中的样品周围释放臭氧。The apparatus may also include an ozone generator configured to release ozone around the sample positioned in the sample holder.

臭氧发生器可以是发射波长范围为100nm至300nm的UV灯。The ozone generator may be a UV lamp emitting in the wavelength range of 100 nm to 300 nm.

有利的是,臭氧发生器的UV灯可以发射185nm和/或254nm的紫外光。有利的是,臭氧发生器的UV灯是汞蒸汽灯。Advantageously, the UV lamp of the ozone generator can emit ultraviolet light at 185 nm and/or 254 nm. Advantageously, the UV lamp of the ozone generator is a mercury vapor lamp.

该装置还可以包括氢源,该氢源配置成在样品架中的样品周围释放氢。The apparatus may also include a hydrogen source configured to release hydrogen around the sample in the sample holder.

有利的是,氢源是至少一个锌空气电池。Advantageously, the source of hydrogen is at least one zinc-air battery.

优选地,锌空气电池在无氧条件下运行,例如在部分真空中运行。Preferably, the zinc-air battery is operated in the absence of oxygen, such as in a partial vacuum.

样品架可以适于保持多个子样品,每个子样品具有不同氧化态的表面,并且其中x射线光电子光谱仪配置为记录每个子样品的XPS谱。The sample holder may be adapted to hold a plurality of subsamples, each subsample having a surface in a different oxidation state, and wherein the x-ray photoelectron spectrometer is configured to record an XPS spectrum of each subsample.

附图说明BRIEF DESCRIPTION OF THE DRAWINGS

在图示本发明的优选实施例的附图中,附图是示例性的:In the accompanying drawings which illustrate preferred embodiments of the present invention, which are exemplary:

图1是典型的商业XPS仪器。请注意不锈钢超高真空(UHV)室和端口。此处未显示运行该系统的计算机;Figure 1 is a typical commercial XPS instrument. Note the stainless steel ultra-high vacuum (UHV) chamber and ports. The computer that runs the system is not shown here;

图2是类似于图1所示系统的视口的典型视图;FIG2 is a representative view of a viewport similar to that of the system shown in FIG1 ;

图3是一种类型的商业样品架和安装在其中的盘形样品“柱(stub)”的计算机辅助设计视图;FIG3 is a computer-aided design view of one type of commercial sample holder and a disc-shaped sample "stub" mounted therein;

图4另一个市售样品架,这次来自Thermo KAlpha XPS仪器。在正常操作中,该样品块在超高真空(UHV)下通过仪器传输到分析位置;Figure 4 Another commercially available sample holder, this time from a Thermo KAlpha XPS instrument. In normal operation, this sample block is transported through the instrument under ultra-high vacuum (UHV) to the analysis position;

图5是本发明中UV/臭氧或UV/氢气暴露装置的一个实施方案的示意图;FIG5 is a schematic diagram of an embodiment of a UV/ozone or UV/hydrogen exposure device according to the present invention;

图6示意图显示了在UV/臭氧清洗过程中,氧化物质是如何产生并与样本(基底)表面发生反应的;FIG6 is a schematic diagram showing how oxidative species are generated and react with the sample (substrate) surface during UV/ozone cleaning;

图7使用本发明的光谱采集用法的一般过程;UV/臭氧选项FIG. 7 General process of using the spectrum acquisition method of the present invention; UV/ozone option

图8表面碳质污染物的UV/臭氧暴露-随暴露时间增加的XPS光谱;Fig. 8 UV/ozone exposure of surface carbonaceous contaminants - XPS spectra with increasing exposure time;

图9说明了在结合能为1.5、2.5和3.5eV时具有三个相同组分峰的合成光谱;FIG9 illustrates a synthetic spectrum having three identical component peaks at binding energies of 1.5, 2.5, and 3.5 eV;

图10示出了从(a)到(f)的UV/臭氧暴露步骤数量增加时的合成光谱;FIG10 shows the synthetic spectra as the number of UV/ozone exposure steps increases from (a) to (f);

图11示出了图10所示光谱的奇异值分解(SVD)结果;FIG11 shows the singular value decomposition (SVD) result of the spectrum shown in FIG10 ;

图12示出了如图9所示的三个合成组分峰,但能量间隔减少。这些是2eV,2.5eV和3eV,但是如果不知道这一点,就很难判断这个包络线下到底有多少峰以及它们可能具有什么能量或宽度;Figure 12 shows the three synthetic component peaks as in Figure 9, but with reduced energy spacing. These are 2eV, 2.5eV and 3eV, but without knowing this it is difficult to tell exactly how many peaks there are under this envelope and what energies or widths they might have;

图13示出了基于图12所示的三个紧密分离的峰的模型的合成光谱;FIG13 shows a synthetic spectrum based on a model of the three closely separated peaks shown in FIG12 ;

图14示出了应用于图13所示光谱的奇异值分解(SVD)的结果。数字标签表示相应峰的中心,通过用抛物线拟合最大值周围的五个值来测量;Figure 14 shows the results of singular value decomposition (SVD) applied to the spectra shown in Figure 13. The numerical labels indicate the center of the corresponding peak, measured by fitting a parabola to five values around the maximum;

图15示出了用于本发明的典型商业XPS仪器的配置;FIG15 shows the configuration of a typical commercial XPS instrument used in the present invention;

图16示出了本实验的一种配置,其中样品在空气中从XPS系统移动到包含UV/臭氧或UV产生灯和氢气(1620)的外壳(1610);FIG16 shows one configuration for this experiment, where the sample is moved in air from the XPS system to an enclosure (1610) containing a UV/ozone or UV generating lamp and hydrogen (1620);

图17示出了本发明的另一种配置,其中包含UV/臭氧的外壳与XPS系统入口锁集成在一起。这需要在所述入口锁上的UV透明窗口和回填气瓶(1700)包含氧气或含氧气体混合物(例如空气);Figure 17 shows another configuration of the present invention, where the housing containing the UV/ozone is integrated with the XPS system entry lock. This requires a UV transparent window on the entry lock and the backfill gas cylinder (1700) contains oxygen or an oxygen-containing gas mixture (e.g., air);

图18示出了典型的GTL3型的UV灯;Figure 18 shows a typical GTL3 type UV lamp;

图19所示为发射波长约为270nm的典型高功率LED的UV发射器。这些被出售用于水池和浴池中的水消毒;A typical high power LED UV emitter emitting at a wavelength of about 270 nm is shown in Figure 19. These are sold for water disinfection in pools and baths;

图20示出了臭氧的哈特利吸收带。请注意,低压汞蒸气灯的254nm发射接近臭氧光谱中这一吸收特征的顶端;The Hartley absorption band for ozone is shown in Figure 20. Note that the 254 nm emission from the low-pressure mercury vapor lamp is near the top of this absorption feature in the ozone spectrum;

图21示出了原子序数逐渐增加的元素的氧化态。实心圆圈代表常见的氧化态,而空心圆圈代表不常见的氧化态;Figure 21 shows the oxidation states of elements with increasing atomic numbers. Solid circles represent common oxidation states, while open circles represent uncommon oxidation states;

图22示出了沉积在两种不同绝缘聚合物(a)和(b)上的电势标记颗粒(EPMP)在Ti2p区域的XPS光谱。尽管这些光谱是在同一台(Thermo k-Alpha型号)仪器上仅几分钟内拍摄获得的,但请注意,由于在两种情况下建立了略有不同的电荷平衡电位,较大的Ti2p3/2峰相对于仪器能量标度具有略有不同的表观能量;Figure 22 shows XPS spectra in the Ti2p region of potential marker particles (EPMP) deposited on two different insulating polymers (a) and (b). Although these spectra were acquired within just a few minutes on the same instrument (Thermo k-Alpha model), note that the larger Ti2p 3/2 peak has slightly different apparent energies relative to the instrument energy scale due to the slightly different charge equilibrium potentials established in the two cases;

图23是示出电势标记粒子(EPMP)如何通过离子束溅射沉积的示意图;FIG23 is a schematic diagram showing how electric potential marker particles (EPMP) are deposited by ion beam sputtering;

图24示出了使用本发明的光谱采集用途的一般过程,用于还原样品表面。当充满氢气时,此处的“含氢室”与文中讨论的样品外壳相同;FIG24 shows the general process of using the spectrum acquisition application of the present invention for reducing the sample surface. When filled with hydrogen, the "hydrogen-containing chamber" here is the same as the sample housing discussed in the text;

图25示出了在结合能为1.5、2.5和3.5eV时具有三个相同组分峰的合成光谱;FIG25 shows a synthetic spectrum with three identical component peaks at binding energies of 1.5, 2.5, and 3.5 eV;

图26示出了从(a)到(f)的UV/氢气暴露步骤数量增加时的合成光谱;FIG26 shows the synthetic spectra as the number of UV/hydrogen exposure steps increases from (a) to (f);

图27示出了图26中光谱的奇异值分解(SVD)结果;FIG27 shows the singular value decomposition (SVD) results of the spectrum in FIG26 ;

图28示出了如图25所示的三个合成组分峰,但能量间隔减少。这些是2eV,2.5eV和3eV,但是如果不知道这一点,就很难判断这个包络线下到底有多少峰以及它们可能具有什么能量或宽度;Figure 28 shows the three synthetic component peaks as in Figure 25, but with reduced energy spacing. These are 2eV, 2.5eV and 3eV, but without knowing this it is difficult to tell exactly how many peaks there are under this envelope and what energies or widths they might have;

图29示出了基于图28所示的三个紧密分离的峰的模型的合成光谱;FIG29 shows a synthetic spectrum based on a model of the three closely separated peaks shown in FIG28;

图30示出了应用于图29所示光谱的奇异值分解(SVD)的结果。数字标签表示相应峰的中心,通过用抛物线拟合最大值周围的五个值来测量;Figure 30 shows the results of singular value decomposition (SVD) applied to the spectra shown in Figure 29. The numerical labels indicate the center of the corresponding peak, measured by fitting a parabola to five values around the maximum;

图31是来自Varta公司的两款制氢“纽扣”电池的产品概述;Figure 31 is a product overview of two hydrogen-producing "button" batteries from Varta;

图32(a)和32(b)示出了制氢设备的一个实施例。在(a)中,开关打开,钮扣电池720没有产生氢气,或者氢气没有通过密封的钯/钯合金管730。在可编程逻辑控制器750的控制下,如果开关闭合(如(b)所示),则电流流过由电阻器R的值预先确定的电池,从而产生氢气。氢气渗透通过所述密封的Pd/Pd合金管;Figures 32(a) and 32(b) show an embodiment of a hydrogen production device. In (a), the switch is open, the button cell 720 does not produce hydrogen, or the hydrogen does not pass through the sealed palladium/palladium alloy tube 730. Under the control of the programmable logic controller 750, if the switch is closed (as shown in (b)), current flows through the cell predetermined by the value of the resistor R, thereby producing hydrogen. Hydrogen permeates through the sealed Pd/Pd alloy tube;

图33示出了电池外壳的一个可能的简单实施例B;FIG33 shows a possible simple embodiment B of a battery housing;

图34(a)和34(B)示出了B型电池外壳的一个可能实施例的示意图(包括减压阀)。标有“外壳内部”的空间是样品外壳,而930是电池外壳。在该图中,示出了(a)休眠和(b)产氢状态;和Figures 34(a) and 34(B) show schematic diagrams of a possible embodiment of a B-type battery housing (including a pressure relief valve). The space labeled "housing interior" is the sample housing, and 930 is the battery housing. In this figure, (a) dormant and (b) hydrogen production states are shown; and

图35示出了样品被分成子样品的实施例。FIG. 35 shows an embodiment in which a sample is divided into sub-samples.

图36示出了本发明的另一种配置,其中包含产生UV灯和氢气的外壳与XPS系统入口锁集成在一起。特别地,这里显示了可选的制氢电池(1780)。Figure 36 shows another configuration of the present invention, where the housing containing the UV lamps and hydrogen generation is integrated with the XPS system entry lock. In particular, the optional hydrogen generation cell (1780) is shown here.

具体实施方式Detailed ways

本发明通过化学方式修改被分析的表面的氧化或还原,提高了XPS峰拟合的可靠性和准确性。氧化在含氧气体(例如实验室空气)的存在下使用紫外光和/或臭氧,从而改变表面不同化学状态的比例,例如通过增加高度氧化态的比例。还原采用暴露于紫外光和任选的氢气。通过比较在该步骤之前和之后记录的XPS光谱(以及任选地多于一个这样的还原/氧化步骤),其在计算机中数值提取光谱中的组分峰,例如使用多元统计方法(在一些实施方案中,主成分分析(PCA)、非负矩阵分解(NMF)或奇异值分解(SVD))。该UV/臭氧暴露/氢气暴露/XPS光谱采集循环在短时间内完成并使用相同的XPS设置,因此XPS能量标度的漂移可以忽略不计。The present invention modifies the oxidation or reduction of the analyzed surface by chemical means, thereby improving the reliability and accuracy of XPS peak fitting. Oxidation uses ultraviolet light and/or ozone in the presence of an oxygen-containing gas (e.g., laboratory air) to change the ratio of different chemical states on the surface, such as by increasing the ratio of highly oxidized states. Reduction is exposed to ultraviolet light and optional hydrogen. By comparing the XPS spectra recorded before and after this step (and optionally more than one such reduction/oxidation step), it numerically extracts the component peaks in the spectrum in a computer, such as using multivariate statistical methods (in some embodiments, principal component analysis (PCA), non-negative matrix decomposition (NMF) or singular value decomposition (SVD)). The UV/ozone exposure/hydrogen exposure/XPS spectrum acquisition cycle is completed in a short time and uses the same XPS settings, so the drift of the XPS energy scale can be ignored.

本发明的装置可以包括;The device of the present invention may include:

1.由紫外光和臭氧不易侵蚀的材料组成的外壳(如金属、玻璃)。它有易于打开和关闭的门或盖,当门或盖关闭时,它在很大程度上(尽管不一定完全)是气密的。当门或盖打开时,允许插入样品架。1. An enclosure composed of a material that is not easily attacked by UV light and ozone (e.g., metal, glass). It has a door or cover that can be easily opened and closed and is largely (though not necessarily completely) airtight when the door or cover is closed. When the door or cover is open, it allows the insertion of a sample holder.

2.一种样品架,在一些实施例中,该类型的样品架被设计成保持在电子显微镜和表面分析中使用的常见样品柱类型。2. A sample holder, in some embodiments, of the type designed to hold common sample column types used in electron microscopy and surface analysis.

3.一个或多个紫外光源位于所述外壳内,或者从外部通过紫外透射窗指向外壳内部,优选至少一个紫外光源能够发射足够短波长的显著辐射,以在室温和大气压下在空气中产生臭氧。在一些实施例中,这些是汞蒸汽灯13,而在其他实施例中是短波发光二极管(LED)或两者的组合。3. One or more UV light sources are located within the housing, or directed from the outside through a UV-transmitting window into the housing, preferably at least one UV light source capable of emitting significant radiation of sufficiently short wavelength to produce ozone in the air at room temperature and atmospheric pressure. In some embodiments, these are mercury vapor lamps 13 , and in other embodiments are short-wave light emitting diodes (LEDs) or a combination of the two.

4.电子电路,其接通光源一段预定的时间,或达到预定的臭氧浓度,或直到达到样品架对UV和/或臭氧的预定暴露量;4. An electronic circuit that turns on the light source for a predetermined period of time, or to a predetermined ozone concentration, or until a predetermined exposure of the sample holder to UV and/or ozone is reached;

5.外壳内产生的臭氧和/或UV水平足以对样本表面进行化学改性,因此XPS光谱中看到的化学状态包络线会因暴露而发生变化,但该水平足够低,不会完全去除任何元素(甚至碳)。5. The levels of ozone and/or UV generated within the enclosure are sufficient to chemically modify the sample surface so that the chemical state envelope seen in the XPS spectrum changes as a result of the exposure, but the levels are low enough not to completely remove any element (even carbon).

6.可选地,用于测量所述外壳内的UV和/或臭氧浓度的传感器。这些允许将UV和臭氧水平报告给用户,以便在一些实施例中,甚至在闭环(例如比例-积分-微分或PID)控制下,也能使得样本对UV和臭氧的暴露可重复且可再现。6. Optionally, sensors for measuring UV and/or ozone concentrations within the housing. These allow UV and ozone levels to be reported to the user so that, in some embodiments, exposure of samples to UV and ozone can be made repeatable and reproducible, even under closed loop (e.g., proportional-integral-derivative or PID) control.

7.可选地,在样品不是良好的电导体的情况下,使用电势标记粒子(EPMP)进行精确的电荷参考。7. Optionally, in case the sample is not a good electrical conductor, use electric potential marker particles (EPMP) for accurate charge referencing.

8.一种x射线光电子光谱(XPS)仪器,能够记录通常用于XPS峰拟合的XPS窄扫描光谱。8. An x-ray photoelectron spectroscopy (XPS) instrument capable of recording XPS narrow scan spectra typically used for XPS peak fitting.

9.通过多变量方法(如奇异值分解、非负矩阵分解或主成分分析)对所得XPS光谱进行计算机处理,以确定光谱中一起变化的成分。9. Computer processing of the resulting XPS spectra by multivariate methods such as singular value decomposition, non-negative matrix factorization, or principal component analysis to determine components that vary together in the spectra.

所述外壳可以与真空系统完全分离,或者形成真空系统的一部分(例如XPS系统的入口锁,使得样品块永远不会离开XPS仪器的自动样品处理系统)。使用小型汞灯产生紫外(UV)和臭氧。任选地,从外部臭氧发生器增加臭氧。臭氧是通过用非常短波长的UV光照射空气中的双原子氧原位产生的,在一个实施方案中,该UV光为来自汞蒸气灯的185nm辐射。通过用较长波长的UV照射所包含的空气来破坏臭氧以允许打开容器,在一个实施例中,UV光为来自汞蒸汽灯的254nm辐射(其中较短的185nm辐射被玻璃外壳或过滤器阻挡)。图5示意性示出了本发明这一部分的一个实施例。The housing can be completely separated from the vacuum system, or form part of the vacuum system (e.g., an entry lock for an XPS system so that the sample block never leaves the automatic sample handling system of the XPS instrument). Ultraviolet (UV) and ozone are generated using a small mercury lamp. Optionally, ozone is added from an external ozone generator. Ozone is generated in situ by irradiating diatomic oxygen in the air with very short wavelength UV light, which in one embodiment is 185nm radiation from a mercury vapor lamp. Ozone is destroyed by irradiating the contained air with longer wavelength UV light to allow the container to be opened, which in one embodiment is 254nm radiation from a mercury vapor lamp (wherein the shorter 185nm radiation is blocked by a glass housing or filter). Figure 5 schematically shows an embodiment of this part of the invention.

在图5中,电池或主电源(630)向标有A和B的两个UV灯(640)之一提供能量。在该实施例中,两个灯都是汞蒸汽灯。两者都在185nm和254nm的UV下发射能量。灯B覆盖有滤光器(610),使得只有这两个波长中较长的波长到达样品周围的空气。可编程定时器控制哪个灯(如果有的话)接收电源。在每种情况下,都需要一个“镇流器”组件(620)(对于大多数放电灯和荧光灯而言),以在灯开始工作时将灯的电压和电流控制在可接受的范围内——通常最初施加高电压来建立放电,然后施加较低的电压和电流来维持放电。在该实施例中,可编程定时器给灯A供电(用紫外光照射样品并在其周围形成臭氧),然后关闭灯A并打开灯B(只有254nm的辐射能够到达样品周围的空间,分解剩余的臭氧),最后关闭两个灯。这可确保所有臭氧迅速从外壳中排出,以便样品可以快速安全地放入XPS分析室。在一些实施例中,样品在缓慢旋转的台上,以便均匀暴露于UV和臭氧。In FIG. 5 , a battery or mains power source (630) provides energy to one of two UV lamps (640) labeled A and B. In this embodiment, both lamps are mercury vapor lamps. Both emit energy at 185nm and 254nm UV. Lamp B is covered with a filter (610) so that only the longer of these two wavelengths reaches the air around the sample. A programmable timer controls which lamp (if any) receives power. In each case, a "ballast" component (620) is required (for most discharge lamps and fluorescent lamps) to control the voltage and current of the lamp within an acceptable range when the lamp begins to operate - usually a high voltage is initially applied to establish the discharge, and then a lower voltage and current are applied to maintain the discharge. In this embodiment, the programmable timer powers lamp A (which illuminates the sample with UV light and forms ozone around it), then turns lamp A off and turns on lamp B (only the 254nm radiation is able to reach the space around the sample, breaking down the remaining ozone), and finally turns both lamps off. This ensures that all ozone is quickly exhausted from the enclosure so that the sample can be quickly and safely placed in the XPS analysis chamber. In some embodiments, the samples are on a slowly rotating stage to allow for even exposure to UV and ozone.

表层的还原Surface restoration

本发明的另一方面通过使用紫外光和/或氢气对被分析的表面进行化学改性,从而改变表面上不同化学状态的比例,例如通过降低高度氧化态的比例,来提高XPS峰拟合的可靠和准确性。通过比较在UV和/或氢气暴露步骤(以及可选地多于一个这样的氧化还原步骤)之前和之后记录的XPS光谱,其在计算机中以数字方式提取光谱中的组分峰,例如使用多元统计方法(在一些实施例中,主成分分析(PCA)、非负矩阵分解(NMF)或奇异值分解(SVD))。该UV/氢气暴露/XPS光谱采集循环在短时间内完成(通常不到一天),并使用相同的XPS设置,因此XPS能量标度的漂移能忽略不计。Another aspect of the present invention is to improve the reliability and accuracy of XPS peak fitting by chemically modifying the analyzed surface using ultraviolet light and/or hydrogen, thereby changing the ratio of different chemical states on the surface, for example, by reducing the ratio of highly oxidized states. By comparing the XPS spectra recorded before and after the UV and/or hydrogen exposure step (and optionally more than one such redox step), the component peaks in the spectrum are digitally extracted in a computer, for example, using multivariate statistical methods (in some embodiments, principal component analysis (PCA), non-negative matrix decomposition (NMF) or singular value decomposition (SVD)). The UV/hydrogen exposure/XPS spectrum acquisition cycle is completed in a short time (usually less than a day) and uses the same XPS settings, so the drift of the XPS energy scale can be ignored.

本发明的装置可以包括:The device of the present invention may include:

1.由紫外光和氢气不易侵蚀的材料(如适当的金属、玻璃)组成的样品外壳。它有易于打开和关闭的门或盖,当门或盖关闭时,它在很大程度上(尽管不一定完全)是气密的。当门或盖打开时,允许插入样品架。1. A sample enclosure composed of a material that is not easily attacked by ultraviolet light and hydrogen (e.g., appropriate metal, glass). It has a door or cover that can be easily opened and closed and is largely (though not necessarily completely) airtight when the door or cover is closed. When the door or cover is open, it allows the insertion of the sample holder.

2.一种样品架,在一些实施例中,该类型的样品架被设计成保持在电子显微镜和表面分析中使用的常见样品柱类型。2. A sample holder, in some embodiments, of the type designed to hold common sample column types used in electron microscopy and surface analysis.

3.在所述外壳内,或在样品外壳外但通过光学窗口导入其中的一个或多个UV光源,优选其中至少一个能够发射足够短波长的显著辐射,以有助于在氢气存在下光催化还原样品表面。在一些实施例中,这些是汞蒸汽灯13或其他种类的放电灯,例如氙灯,而在其他实施例中是短波发光二极管(LED)或它们的组合。3. One or more UV light sources within the enclosure, or outside the sample enclosure but directed therein through an optical window, preferably at least one of which is capable of emitting significant radiation of sufficiently short wavelength to facilitate photocatalytic reduction of the sample surface in the presence of hydrogen. In some embodiments, these are mercury vapor lamps 13 or other types of discharge lamps, such as xenon lamps, and in other embodiments are short-wavelength light emitting diodes (LEDs) or combinations thereof.

4.从样品外壳中去除氧气,可选地通过将空气从样品外壳中抽出以达到低于10-3毫巴的压力范围,优选低于10-6毫巴。可选地,可以用氮气或氩气等惰性气体吹扫样品外壳。4. Remove oxygen from the sample enclosure, optionally by pumping air out of the sample enclosure to a pressure range below 10 −3 mbar, preferably below 10 −6 mbar. Optionally, the sample enclosure may be purged with an inert gas such as nitrogen or argon.

5.将氢气引入样品外壳,可选地从后面描述的一个或多个氢气产生单元引入,或者可选地从外部氢气瓶引入。5. Introduce hydrogen into the sample enclosure, optionally from one or more hydrogen generation units described below, or optionally from an external hydrogen cylinder.

6.可选地,一个或多个锌空气(或类似)电池(形成电池)可以固定在可渗透氢的电池外壳14(例如钯或钯合金管)内,该外壳允许氢离开电池并穿过可渗透氢的电池外壳的壁,但防止其他物质(例如水蒸气)穿过。任选地,所述可渗透电池外壳可以被加热15,例如通过使电流流过该外壳导致焦耳加热,以增加氢通过其壁向外扩散到包含样品的样品外壳内的主要空间中的速率。如下所述,可以使用不可渗透的电池外壳和减压阀装置来代替可渗透氢的电池外壳。6. Optionally, one or more zinc air (or similar) cells (forming a cell) may be secured within a hydrogen permeable cell housing 14 (e.g., a palladium or palladium alloy tube) that allows hydrogen to leave the cell and pass through the walls of the hydrogen permeable cell housing, but prevents other substances (e.g., water vapor) from passing through. Optionally, the permeable cell housing may be heated 15 , such as by passing an electric current through the housing to cause Joule heating, to increase the rate at which hydrogen diffuses outwardly through its walls into the primary space within the sample housing containing the sample. As described below, an impermeable cell housing and pressure relief valve arrangement may be used in place of the hydrogen permeable cell housing.

7.可选地,电子电路,其接通通过所述锌空气或类似金属-空气电池的电流一段预定的时间,或者预定的总电荷通过或达到预定的氢浓度,或者直到达到样品架对UV和/或氢的预定暴露量。7. Optionally, electronic circuitry that switches current through said zinc air or similar metal-air battery for a predetermined period of time, or a predetermined total charge passed or a predetermined hydrogen concentration is reached, or until a predetermined exposure of the sample holder to UV and/or hydrogen is reached.

8.样品外壳内产生的氢气和/或紫外光水平足以对样品表面进行化学改性,因此XPS光谱中看到的化学状态包络线会因暴露而发生变化,因为更多还原的化学状态在表面变得更加常见。8. The levels of hydrogen and/or UV light generated within the sample enclosure are sufficient to chemically modify the sample surface, so the chemical state envelope seen in the XPS spectrum will change as a result of the exposure as more reduced chemical states become more common at the surface.

9.可选地,用于测量所述样品外壳内的UV和/或氢气浓度的传感器。这允许向用户报告UV和氢气水平,在一些实施例中甚至在闭环(例如比例-积分-微分PID)控制下,能使得样本对于UV和氢气的暴露是可重复且可再现。9. Optionally, sensors for measuring UV and/or hydrogen concentration within the sample housing. This allows reporting of UV and hydrogen levels to the user, and in some embodiments even under closed loop (e.g., proportional-integral-derivative PID) control, enabling sample exposure to UV and hydrogen to be repeatable and reproducible.

10.可选地,在样品不是良好的电导体的情况下,使用电势标记粒子(EPMP)进行精确的电荷参考。10. Optionally, in case the sample is not a good electrical conductor, use electric potential marker particles (EPMP) for accurate charge referencing.

11.一种x射线光电子光谱(XPS)仪器,能够记录通常用于XPS峰拟合的XPS窄扫描光谱。11. An x-ray photoelectron spectroscopy (XPS) instrument capable of recording XPS narrow scan spectra typically used for XPS peak fitting.

12.通过多变量方法(如奇异值分解(SVD)、非负矩阵分解(NMF)或主成分分析(PCA)对所得XPS光谱进行计算机处理,以识别一起变化的光谱成分。12. Computer processing of the resulting XPS spectra by multivariate methods such as singular value decomposition (SVD), non-negative matrix factorization (NMF), or principal component analysis (PCA) to identify spectral components that vary together.

所述样品外壳可以与真空系统完全分离,或者形成真空系统的一部分(例如XPS系统的入口锁,使得样品块永远不会离开XPS仪器的自动样品处理系统)。在一个实施例中,使用小型汞灯产生紫外(UV)光,和氢气则来自(在一个实施例中)锌空气(或类似的金属-空气)电池。任选地,氢气从外部氢气供应源或气瓶增加。The sample housing may be completely separate from the vacuum system, or form part of the vacuum system (e.g., an entry lock to an XPS system so that the sample block never leaves the automated sample handling system of the XPS instrument). In one embodiment, ultraviolet (UV) light is generated using a small mercury lamp, and hydrogen comes from (in one embodiment) a zinc air (or similar metal-air) cell. Optionally, hydrogen is added from an external hydrogen supply or cylinder.

使用锌空气电池而不是氢气瓶的一个优点是,只需要非常少量的氢气以(电)可控的方式输送,减少了在处理大量氢气时可能出现的安全问题。大多数XPS设施没有在附近放置氢气瓶(尽管有一些设施会这样做)。因此,通过使用锌空气电池或其他金属空气电池,将氢气安全输送到样品表面的成本大大降低。One advantage of using zinc-air batteries rather than hydrogen cylinders is that only very small amounts of hydrogen need to be delivered in an (electrically) controllable manner, reducing the safety issues that can arise when handling large amounts of hydrogen. Most XPS facilities do not have hydrogen cylinders nearby (although some do). Therefore, the cost of safely delivering hydrogen to the sample surface is greatly reduced by using zinc-air batteries or other metal-air batteries.

图36示意性示出了本发明一部分的一个实施例。Figure 36 schematically shows an embodiment of a portion of the present invention.

图32(a)和(b)显示了由锌空气电池供应氢气的实施例。在图32中,制氢电池720由使用开关或继电器的所述定时器或PLC控制,使得当开关“接通”并且电流经由限流电阻器R流过电池时,所述电池以由所述电阻器R的值确定的已知的预先计划的速率产生氢气,如图32(b)所示。该电阻器的典型值为100至300欧姆,但该值并不十分关键,关键量是允许通过的总电荷,它决定了释放的氢气总量。Figures 32(a) and (b) show an embodiment of hydrogen supply by a zinc air cell. In Figure 32, the hydrogen production cell 720 is controlled by the timer or PLC using a switch or relay so that when the switch is "on" and current flows through the cell via a current limiting resistor R, the cell produces hydrogen at a known pre-programmed rate determined by the value of the resistor R, as shown in Figure 32(b). The typical value of this resistor is 100 to 300 ohms, but this value is not very critical, the key quantity is the total charge allowed to pass, which determines the total amount of hydrogen released.

与现有技术的比较Comparison with existing technologies

多年来,XPS仪器有时配备有紫外光源,但这要么是为了(a)允许紫外光电子光谱(UPS)在真空中进行,而不是像本发明中那样在空气中修饰表面,要么是为了(b)使用特定类型的紫外光(无氢气)以特定的化学方式(例如Sun等人16)来修饰特定的表面,例如365nm左右的长波UV。这项早期工作的目的不是为了识别本发明所述的化学状态而改变表面的化学状态,而是为了研究特定UV照射在特定样本材料中诱发的特定化学反应。Over the years, XPS instruments have sometimes been equipped with UV sources, but this was either to (a) allow UV photoelectron spectroscopy (UPS) to be performed in a vacuum rather than modifying the surface in air as in the present invention, or (b) to modify a specific surface in a specific chemical way (e.g., Sun et al. 16 ) using a specific type of UV light (without hydrogen), such as long-wave UV around 365 nm. The purpose of this early work was not to change the chemical state of the surface in order to identify the chemical state as described in the present invention, but rather to study the specific chemical reactions induced in a specific sample material by a specific UV exposure.

UV/臭氧清洁设备:为什么本发明与这些不同,以及不同的目的如何产生差异UV/Ozone Cleaning Equipment: Why This Invention is Different and How the Different Purposes Make a Difference

紫外光/臭氧清洁设备已经使用了几十年,例如因J R Vig17的工作而普及,集中在使用汞蒸汽灯。低压汞灯在UV中有两个主要发射波长,分别为185nm和254nm。185nm的UV线分解氧分子并原位合成臭氧O3。254nm的UV线分解臭氧并产生高能O*(活性氧)。这些高氧化性物质会与表面上的含碳污染物(事实上,表面上任何可能被氧化的物质)相互作用。最终,结合直接UV暴露(通过Norrish型化学过程与C=O官能团强烈相互作用),有机物质被氧化和/或降解为挥发性化合物,主要是CO2,这些化合物从表面扩散开来。图6示意性地显示了这一过程。UV/ozone cleaning equipment has been used for decades, popularized for example by the work of JR Vig 17 , focusing on the use of mercury vapor lamps. Low-pressure mercury lamps have two main emission wavelengths in the UV, at 185 nm and 254 nm. The 185 nm UV light decomposes oxygen molecules and synthesizes ozone O 3 in situ. The 254 nm UV light decomposes ozone and produces high-energy O* (reactive oxygen species). These highly oxidizing species interact with carbon-containing contaminants on the surface (in fact, anything on the surface that can be oxidized). Ultimately, in combination with direct UV exposure (which interacts strongly with C=O functional groups through Norrish-type chemistry), the organic matter is oxidized and/or degraded to volatile compounds, primarily CO 2 , which diffuse away from the surface. Figure 6 schematically illustrates this process.

商用UV/臭氧清洁器是大功率设备,旨在尽快清除所有含碳污染物。它们通常不需要测量和报告UV或臭氧水平,而是简单地设计为提供非常高的UV或臭氧水平,以便快速清除污染物。如果试图进行表面化学改性,而不是完全去除含碳污染物(例如澄清XPS中的化学位移),那么由于UV/臭氧清洁器的设计目标,很容易“过头”并将其全部去除。出于不同的目的,商用UV/臭氧清洁器和本发明在设计上还存在进一步的差异。通常,商用UV/臭氧清洁器设计用于大型物体,如直径为200mm或更大的硅片。我们目前需要的是更低的功率,这样核级峰会被修改,但不会完全从XPS光谱中移除,这可能需要经过几个越来越激烈的氧化步骤。以及需要更小的样品空间,使得装置可以靠近XPS样品入口锁放置,用于快速暴露,然后将样品返回到XPS系统真空中,使暴露于大气污染的时间最短。UV/臭氧清洁仅适用于含碳污染物(因为它以气态氧化物的形式离开表面),而本发明旨在使用UV和/或臭氧来氧化任何样品材料,以保留用于随后的XPS分析。此外,UV强度和臭氧浓度的测量有助于确保不同位置测量的再现性,因此内置UV和臭氧监测器在XPS峰拟合应用中非常有用——即它们是可选的,但作为本发明的一部分非常有用。Commercial UV/ozone cleaners are high power devices designed to remove all carbonaceous contaminants as quickly as possible. They are not usually required to measure and report UV or ozone levels, but are simply designed to provide very high UV or ozone levels in order to quickly remove contaminants. If one is trying to perform surface chemical modification rather than complete removal of carbonaceous contaminants (e.g. clarifying chemical shifts in XPS), then it is easy to "overdo it" and remove it all due to the design goals of the UV/ozone cleaner. There are further differences in the design of commercial UV/ozone cleaners and the present invention for different purposes. Typically, commercial UV/ozone cleaners are designed for large objects, such as silicon wafers with a diameter of 200mm or more. What is currently needed is lower power so that the nuclear peaks are modified but not completely removed from the XPS spectrum, which may require several increasingly intense oxidation steps. And a smaller sample space is needed so that the device can be placed close to the XPS sample entry lock for rapid exposure and then the sample is returned to the XPS system vacuum to minimize exposure to atmospheric contamination. UV/ozone cleaning is only suitable for carbonaceous contaminants (since it leaves the surface as gaseous oxides), whereas the present invention is intended to use UV and/or ozone to oxidize any sample material to preserve it for subsequent XPS analysis. In addition, measurement of UV intensity and ozone concentration helps ensure reproducibility of measurements at different locations, so built-in UV and ozone monitors are very useful in XPS peak fitting applications - i.e. they are optional, but very useful as part of the present invention.

说了这么多,我过去已经成功地改进了UV/臭氧清洁设备,为暴露在UV/臭氧中的样品生成光谱。通常,这是通过修改仪器、以某些方式禁用仪器(例如,几秒钟后按下“紧急停止”按钮以避免过度暴露于紫外光/臭氧中)或拆卸以取出组件(例如灯)然后将这些组件放入不同的外壳中来实现的。事实上,导致本发明的大部分工作是通过修改商业UV/臭氧装置来实现其设计目的。Having said all that, I have successfully modified UV/ozone cleaning equipment in the past to generate spectra for samples exposed to UV/ozone. Typically, this was accomplished by modifying the instrument, disabling it in some way (e.g., pressing an "emergency stop" button after a few seconds to avoid overexposure to UV/ozone), or disassembling to remove components (e.g., lamps) and then placing those components into different enclosures. In fact, much of the work leading to this invention was accomplished by modifying commercial UV/ozone units to achieve what they were designed to do.

本发明的使用过程(氧化)Use process of the present invention (oxidation)

图7示出了本发明如何进行光谱采集的流程图。在某些情况下,用户将有足够的信息来提前设置UV/臭氧暴露水平/时间,而无需应用该流程图中的问题,给出一系列预定长度的暴露步骤。否则,计算机可以,例如,对该点采集的光谱进行PCA分析,并建议在下一步增加曝光,以更有可能在光谱中观察到差异。FIG7 shows a flow chart of how the present invention performs spectrum acquisition. In some cases, the user will have enough information to set the UV/ozone exposure level/time in advance without applying the questions in this flow chart, given a series of exposure steps of predetermined lengths. Otherwise, the computer can, for example, perform a PCA analysis of the spectrum acquired at that point and recommend increasing the exposure in the next step to make it more likely that a difference will be observed in the spectrum.

图8显示了使用UV/臭氧曝光和XPS识别金属碳质层的XPS光谱中哪个化学状态对应于哪个峰(有时能量无法分辨)的结果。这些窄扫描光谱显示了C1s峰周围的区域。作为该分析的结果,平滑线是根据这一分析事后添加的。注意,由于这些光谱是在几个小时内在同一台仪器上获得的,因此能量标度和能量分辨率可以认为是稳定的。Figure 8 shows the results of using UV/ozone exposure and XPS to identify which chemical state corresponds to which peak in the XPS spectra of a metallic carbonaceous layer (sometimes the energy cannot be resolved). These narrow scan spectra show the region around the C1s peak. As a result of this analysis, the smoothing line was added post hoc based on this analysis. Note that since these spectra were acquired on the same instrument over a period of several hours, the energy scale and energy resolution can be considered stable.

因此,UV/臭氧暴露会导致峰成分的高度发生变化,但它们不会在能量尺度上移动。无论UV/臭氧照射导致什么新的峰高,它们被改变的事实使它们可以从一组这样的光谱中提取出来。例如,在图8(a)中,碳的不同氧化态最初很难解析。然而,(b)、(c)和(d)显示了这些状态的强度变化,并且(d)甚至显示了新的碳化物状态。这与C*-H峰具有几乎相同的结合能,如果不是作为一组光谱(a)、(b)、(C)和(d)其中峰强度在变化,可能会被误解为C*-H(这更常见)。在该过程结束时,在(a)中看到的四个初始状态的结合能和强度被明确确定。Thus, UV/ozone exposure causes the heights of the peak components to change, but they do not shift on the energy scale. Whatever new peak heights result from UV/ozone exposure, the fact that they are altered allows them to be extracted from a set of such spectra. For example, in Figure 8(a), the different oxidation states of carbon are initially difficult to resolve. However, (b), (c), and (d) show the intensity changes of these states, and (d) even shows a new carbide state. This has almost the same binding energy as the C*-H peak, and could have been misinterpreted as C*-H (which is more common) if it were not for being a set of spectra (a), (b), (c), and (d) where the peak intensity is changing. At the end of the process, the binding energies and intensities of the four initial states seen in (a) are clearly determined.

图9至14示出了证明本发明有效性的数值模拟结果。在图9中,从图8所示的真实数据中提取出合成光谱,该光谱由三个相距1eV的峰值组成。这些可以在现代光谱仪中很容易地分辨出来,因此查看包络光谱(图9中的连续线)可以清楚地看到这里至少有三个峰值。请注意,因为XPS中的C1s峰通常位于相当平坦的背景上,所以我包含了峰高20%的背景,并且它随能量保持不变。Figures 9 to 14 show numerical simulation results demonstrating the effectiveness of the present invention. In Figure 9, a synthetic spectrum has been extracted from the real data shown in Figure 8, which consists of three peaks 1 eV apart. These can be easily resolved in a modern spectrometer, so looking at the envelope spectrum (continuous line in Figure 9) it is clear that there are at least three peaks here. Note that because the C1s peak in XPS is usually located on a fairly flat background, I included a background of 20% of the peak height, and it remains constant with energy.

图10显示了在图7所示过程的零次迭代(a)、一次迭代(b)、两次迭代(c)等之后的模拟光谱。因此,10(b)至10(f)中的每一个都显示了比前一个更多的UV/臭氧暴露的影响。随着我们在这个系列中的进展,一些状态(即峰值)的强度下降得比其他状态更快。更快移除的状态是处于高结合能还是低结合能并不重要,简单地说,在光谱中产生峰值的原子可以在下一个光谱中以不同的化学状态重新出现(或者一起离开,例如作为高度氧化的气体,如CO2)。Figure 10 shows simulated spectra after zero iterations (a), one iteration (b), two iterations (c), etc. of the process shown in Figure 7. Thus, each of 10(b) to 10(f) shows the effect of more UV/ozone exposure than the previous one. As we progress through this series, some states (i.e., peaks) decrease in intensity faster than others. It does not matter whether the states that are removed faster are at high or low binding energies, simply that the atoms that create a peak in a spectrum may reappear in the next spectrum in a different chemical state (or leave all together, e.g., as a highly oxidized gas such as CO2 ).

图11显示了图10所示模拟光谱的数值处理结果。11(a)是如图9所示的峰值及其包络的提示。图11(b)显示了该模型产生的初始光谱,纵轴为计数,并添加了泊松(Poisson)噪声。图11(c)和11(d)示出了通过使用奇异值分解(SVD)从图10所示的集合中提取的第二和第三组分。第一个组分不是很有用,因为它只是类似于图10所示的光谱的平均值。第二个和第三(在其他实际情况下也包括更高的成分)显示了重要的峰结构。在这里,我将这些组分的负部分反转,并绘制成一条完整的线。我用虚线画出了正部分。SVD告诉我们,在图11(c)中,指示了UV/臭氧诱导过程,该过程从约3.56eV处的峰值移除强度并将其添加到1.51eV处的峰值。峰值能量的这些数字标签是通过对峰值最高点周围的5个点拟合抛物线来计算的。当然,该过程是UV/臭氧暴露的某个方面,但关键是该成分揭示了组成初始光谱(b)的两个峰,并相当准确地给出了这些峰的能量(与真实值相差在0.06eV以内)。图11(d)中所示的第三组分揭示了在约2.53eV处的另一个峰(在真实峰所在位置的0.03eV范围内),并且再次揭示了在1.53eV处的先前确定的峰之一,该峰与先前确定的1.51eV足够接近,以确保它是相同的化学状态。因此,图9至11向我们展示了本发明的UV/臭氧效应将允许唯一识别状态的数量及其能量(以及它们的宽度的相当好的估计)。Figure 11 shows the results of numerical processing of the simulated spectrum shown in Figure 10. 11(a) is a hint of the peak and its envelope shown in Figure 9. Figure 11(b) shows the initial spectrum produced by the model, with counts on the vertical axis and Poisson noise added. Figures 11(c) and 11(d) show the second and third components extracted from the set shown in Figure 10 by using singular value decomposition (SVD). The first component is not very useful because it is just an average of the spectrum similar to that shown in Figure 10. The second and third (and higher components in other practical cases) show important peak structure. Here I have reversed the negative parts of these components and plotted them as a full line. I have drawn the positive parts with a dotted line. The SVD tells us that in Figure 11(c), a UV/ozone induced process is indicated, which removes intensity from the peak at about 3.56 eV and adds it to the peak at 1.51 eV. These numerical labels for the peak energies are calculated by fitting a parabola to 5 points around the highest point of the peak. Of course, this process is an aspect of the UV/ozone exposure, but the key is that this component reveals the two peaks that make up the initial spectrum (b), and gives the energies of these peaks fairly accurately (within 0.06 eV of the true value). The third component shown in Figure 11(d) reveals another peak at about 2.53 eV (within 0.03 eV of where the true peak is), and again reveals one of the previously identified peaks at 1.53 eV, which is close enough to the previously identified 1.51 eV to ensure that it is the same chemical state. Thus, Figures 9 to 11 show us that the UV/ozone effect of the present invention will allow the number of states and their energies to be uniquely identified (as well as a fairly good estimate of their widths).

有人可能会说这是一个简单的问题,因为图9中所示的峰值已经分离得相当好。它们重叠,但有三个明显的峰值可见,即使用眼睛也可以估计它们的能量为1.5eV、2.5eV和3.5eV。现在考虑图12所示的情况,我通过给予2eV、2.5eV和3eV的能量来减少峰的分离。它们现在重叠得如此之多,以至于包络线(图12中的实线)只有一个局部最大值。没有经验的分析人员可能会试图用单个峰值或少量具有不同能量和强度的峰值来拟合该曲线。许多可选模型在统计学意义上相当合适,但在化学意义上完全不合适。这是上文背景部分讨论的已发表峰拟合中许多误差的来源。One might say that this is a simple problem because the peaks shown in Figure 9 are already fairly well separated. They overlap, but there are three distinct peaks visible, and even by eye one can estimate their energies to be 1.5 eV, 2.5 eV, and 3.5 eV. Now consider the situation shown in Figure 12, where I have reduced the separation of the peaks by giving them energies of 2 eV, 2.5 eV, and 3 eV. They now overlap so much that the envelope (solid line in Figure 12) has only one local maximum. An inexperienced analyst might be tempted to fit this curve with a single peak, or a small number of peaks with varying energies and intensities. Many of the alternative models fit reasonably well in a statistical sense, but are completely inappropriate in a chemical sense. This is the source of many of the errors in published peak fits discussed in the Background section above.

图13显示了UV/臭氧清洁对光谱的影响,如图10对于分离良好的峰所做的那样。图13中的光谱可能会让刚接触XPS的人感到非常困惑,我所知道的经验不足的分析师会将这种系列的光谱解释为单峰结合能的变化、充电效应(甚至是导电表面)或仪器中的电压不稳定等仪器问题。然而,应用于图14中数据集的SVD给出了有用且稳健的答案;初始光谱在大约2.07eV、3.07eV和2.54eV处具有峰值,所有这些都非常接近2、3eV和2.5eV的真实值。鉴于这些能量值,传统的XPS峰拟合变得很容易-这种拟合的起始数据非常有价值,并消除了可能使XPS新手感到困惑的模糊之处。Figure 13 shows the effect of UV/ozone cleaning on the spectrum, as Figure 10 did for the well-separated peaks. The spectra in Figure 13 can be very confusing to someone new to XPS, and less experienced analysts I have known will interpret this series of spectra as a change in the binding energy of a single peak, a charging effect (even for a conductive surface), or an instrument problem such as voltage instability in the instrument. However, the SVD applied to the data set in Figure 14 gives a useful and robust answer; the initial spectrum has peaks at approximately 2.07eV, 3.07eV, and 2.54eV, all of which are very close to the true values of 2, 3eV, and 2.5eV. Given these energy values, conventional XPS peak fitting becomes easy - the starting data for such fits is very valuable and removes ambiguities that can confuse someone new to XPS.

本发明的使用过程(还原)The use process of the present invention (reduction)

图24给出了使用本发明的光谱采集用法的一般过程。当充满氢气时,此处的“含氢室”与文中讨论的样品外壳相同。The general process of using the spectrum acquisition method of the present invention is shown in Figure 24. When filled with hydrogen, the "hydrogen containing chamber" here is the same as the sample enclosure discussed in the text.

图24示出了本发明如何进行光谱采集的流程图。在某些情况下,用户将有足够的信息来提前设置紫外光/氢气暴露水平/时间,而无需应用该流程图中的问题,给出一系列预定长度的暴露步骤。否则,计算机可以,例如,对该点采集的光谱进行PCA分析,并建议在下一步增加曝光,以更有可能在光谱中观察到差异。FIG24 shows a flow chart of how the present invention performs spectrum acquisition. In some cases, the user will have enough information to set the UV light/hydrogen exposure level/time in advance without applying the questions in this flow chart, given a series of exposure steps of predetermined lengths. Otherwise, the computer can, for example, perform a PCA analysis of the spectrum acquired at that point and recommend increasing the exposure in the next step to make it more likely that a difference will be observed in the spectrum.

图25至30示出了证明本发明有效性的数值模拟结果。图25显示了一个合成光谱,由三个相距1eV的峰组成。这些可以在现代光谱仪中很容易地解析,因此查看包络光谱(图25中的连续线)可以清楚地看到这里至少有三个峰值。请注意,因为XPS中的C1s峰通常位于相当平坦的背景上,所以我包含了峰高20%的背景,并且它随能量保持不变。Figures 25 to 30 show numerical simulation results that demonstrate the effectiveness of the present invention. Figure 25 shows a synthetic spectrum consisting of three peaks 1 eV apart. These can be easily resolved in a modern spectrometer, so looking at the envelope spectrum (the continuous line in Figure 25) it is clear that there are at least three peaks here. Note that because the C1s peak in XPS usually sits on a fairly flat background, I included a background of 20% of the peak height, and it remains constant with energy.

图26显示了图24所示过程的零次迭代(a)、一次迭代(b)、两次迭代(c)等之后的模拟光谱。因此,26(b)至26(f)中的每一个都显示出比前一个更多的UV/氢气暴露的影响。随着我们在这个系列中的进展,一些状态(即峰值)的强度下降得比其他状态更快。更快被移除的状态是处于高结合能还是低结合能并不重要,重要的是在光谱中产生峰值的原子可以在下一个光谱中以不同的化学状态重新出现(例如,在与氢反应生成H2O后完全消失)。Figure 26 shows simulated spectra after zero iterations (a), one iteration (b), two iterations (c), and so on, of the process shown in Figure 24. Thus, each of 26(b) to 26(f) shows the effect of more UV/hydrogen exposure than the previous one. As we progress through this series, some states (i.e., peaks) decrease in intensity faster than others. It does not matter whether the states that are removed faster are at high or low binding energies; what matters is that the atoms that create the peaks in a spectrum can reappear in the next spectrum in a different chemical state (e.g., disappear completely after reacting with hydrogen to produce H2O ).

图27显示了图26所示模拟光谱的数值处理结果。图27(a)是图25所示峰值及其包络的提示。图27(b)显示了该模型产生的初始光谱,纵轴为计数,并添加了泊松(Poisson)噪声。图27(c)和27(d)示出了通过使用奇异值分解(SVD)从图26所示的集合中提取的第二和第三组分。第一个组分不是很有用,因为它只是类似于图26所示的平均光谱。第二个和第三(在其他实际情况下也包括更高的组分)显示了重要的峰结构。在这里,我将这些组分的负部分反转,并绘制成一条完整的线。我用虚线画出了正部分。SVD告诉我们,在图27(c)中,指示了UV/氢诱导过程,该过程从约3.56eV处的峰值移除强度并将其添加到1.51eV处的峰值。这些数字标签是通过峰值最高点周围的5个点拟合抛物线来计算的。当然,该过程是UV/氢气暴露的某个方面,但关键是该成分揭示了组成初始光谱(b)的两个峰,并相当准确地给出了这些峰的能量(与真实值相差在0.06eV以内)。图27(d)中所示的第三组分揭示了在约2.53eV处的另一个峰(在真实峰所在位置的0.03eV范围内),并且再次揭示了在1.53eV处的先前确定的峰之一,该峰与先前确定的1.51eV足够接近,以确保它是相同的化学状态。因此,图25至27向我们展示了本发明的UV/氢效应将允许唯一识别状态的数量及其能量(以及对其宽度的相当好的估计)。Figure 27 shows the results of numerical processing of the simulated spectrum shown in Figure 26. Figure 27(a) is a hint of the peaks shown in Figure 25 and their envelopes. Figure 27(b) shows the initial spectrum produced by the model, with counts on the vertical axis and Poisson noise added. Figures 27(c) and 27(d) show the second and third components extracted from the set shown in Figure 26 by using singular value decomposition (SVD). The first component is not very useful because it is just similar to the average spectrum shown in Figure 26. The second and third (and higher components in other practical cases) show important peak structure. Here, I have reversed the negative parts of these components and plotted them as a full line. I have drawn the positive parts with dotted lines. SVD tells us that in Figure 27(c), a UV/hydrogen induced process is indicated, which removes intensity from the peak at about 3.56 eV and adds it to the peak at 1.51 eV. These numerical labels are calculated by fitting a parabola at 5 points around the highest point of the peak. Of course, this process is an aspect of the UV/hydrogen exposure, but the key is that this component reveals the two peaks that make up the initial spectrum (b), and gives the energies of those peaks fairly accurately (within 0.06 eV of the true value). The third component shown in Figure 27(d) reveals another peak at about 2.53 eV (within 0.03 eV of where the true peak is), and again reveals one of the previously identified peaks at 1.53 eV, which is close enough to the previously identified 1.51 eV to ensure that it is the same chemical state. Thus, Figures 25 to 27 show us that the UV/hydrogen effect of the present invention will allow unique identification of the number of states and their energies (as well as a fairly good estimate of their widths).

有人可能会说这是一个简单的问题,因为图25中所示的峰值已经分离得相当好。它们重叠,但有三个明显的峰值可见,即使用眼睛也可以估计它们的能量为1.5eV、2.5eV和3.5eV。现在考虑图28所示的情况,我通过给予2eV、2.5eV和3eV的能量来减少峰的分离。它们现在重叠得如此之多,以至于包络线(图28中的实线)只有一个局部最大值。没有经验的分析人员可能会试图用单个峰值或少量具有不同能量和强度的峰值来拟合该曲线。许多可选模型在统计学意义上相当合适,但在化学意义上完全不合适。这是上文背景部分讨论的已发表峰拟合中许多误差的来源。One might say that this is a simple problem because the peaks shown in Figure 25 are already fairly well separated. They overlap, but there are three distinct peaks visible, and even by eye one can estimate their energies to be 1.5 eV, 2.5 eV, and 3.5 eV. Now consider the situation shown in Figure 28, where I have reduced the separation of the peaks by giving them energies of 2 eV, 2.5 eV, and 3 eV. They now overlap so much that the envelope (solid line in Figure 28) has only one local maximum. An inexperienced analyst might try to fit this curve with a single peak, or a small number of peaks with varying energies and intensities. Many of the alternative models fit reasonably well in a statistical sense, but are completely inappropriate in a chemical sense. This is the source of many of the errors in published peak fits discussed in the Background section above.

图29显示了UV/氢气暴露对光谱的影响,如图26对于分离良好的峰所做的那样。图29中的光谱可能会让刚接触XPS的人感到非常困惑,我所知道的经验不足的分析师会将这种系列的光谱解释为单峰结合能的变化、充电效应(甚至是导电表面)或仪器中的电压不稳定等仪器问题。然而,如图30所示,应用于图29中数据集的SVD给出了有用且稳健的答案;初始光谱在大约2.07eV、3.07eV和2.54eV处具有峰值,所有这些都非常接近2、3和2.5eV的真实值。鉴于这些能量值,传统的XPS峰拟合变得很容易-这种拟合的起始数据非常有价值,并消除了可能使XPS新手感到困惑的模糊之处。Figure 29 shows the effect of UV/hydrogen exposure on the spectrum, just as Figure 26 did for the well-separated peaks. The spectra in Figure 29 can be very confusing to someone new to XPS, and less experienced analysts I have known have interpreted this series of spectra as a change in the binding energy of a single peak, a charging effect (even for a conductive surface), or an instrument problem such as voltage instability in the instrument. However, as shown in Figure 30, the SVD applied to the data set in Figure 29 gives a useful and robust answer; the initial spectrum has peaks at approximately 2.07 eV, 3.07 eV, and 2.54 eV, all of which are very close to the true values of 2, 3, and 2.5 eV. Given these energy values, traditional XPS peak fitting becomes easy - the starting data for such fits is very valuable and removes ambiguities that can confuse someone new to XPS.

样品的额外离子束溅射Additional ion beam sputtering of samples

在UV/臭氧/氢气暴露之前和/或之后,对样品表面进行可选的离子束溅射,可以提供额外的光谱,这些光谱对于包括在PCA或机器学习数据集中非常有用。这是因为非常短的溅射处理,可以使用单原子氩离子在低动能(100到1000eV)下进行,主要是在去除氧的意义上是还原的,但在产生在原样材料中罕见的化学状态的意义上也是有害的。我们可以看到,一些样本在接收到时可能已经高度氧化,因此我们需要分析信息。进一步氧化(通过UV/臭氧)几乎不改变窄扫描XPS光谱。然而,在这种氧化之前和/或之后的光溅射可以提供更宽范围的光谱,这允许通过使用例如PCA更好地定义存在的化学状态的光谱。Optional ion beam sputtering of the sample surface before and/or after UV/ozone/hydrogen exposure can provide additional spectra that are very useful for inclusion in PCA or machine learning datasets. This is because very short sputtering treatments, which can be performed using monatomic argon ions at low kinetic energies (100 to 1000 eV), are primarily reductive in the sense of removing oxygen, but can also be detrimental in the sense of creating chemical states that are rare in the as-received material. We can see that some samples may already be highly oxidized as received, so we need this information for analysis. Further oxidation (by UV/ozone) hardly changes the narrow scan XPS spectrum. However, photo sputtering before and/or after such oxidation can provide a wider range of spectra, which allows the spectra of the chemical states present to be better defined by using, for example, PCA.

可能的实施例和配置(表面层的氧化)Possible embodiments and configurations (oxidation of the surface layer)

图15显示了典型商用XPS仪器的垂直截面示意图。有一个名义上处于超高真空(UHV)的分析室(1500),带有半球形电子能量分析器(1510)。泵(1505)保持系统各部分的真空。阀门(1520)被打开和关闭以允许样品从入口锁(1525)进入分析室。转移臂(1535)用于在所述分析室和所述入口锁之间移动样品。当从系统中提取样品时,通过允许气体(通常为氮气)从气瓶(1515)进入,使得入口锁恢复至大气压力。所述入口锁通常具有透明玻璃窗(1530)。FIG15 shows a schematic vertical cross-section of a typical commercial XPS instrument. There is an analysis chamber (1500) nominally in ultra-high vacuum (UHV) with a hemispherical electron energy analyzer (1510). A pump (1505) maintains vacuum in various parts of the system. A valve (1520) is opened and closed to allow a sample to enter the analysis chamber from an entry lock (1525). A transfer arm (1535) is used to move the sample between the analysis chamber and the entry lock. When a sample is extracted from the system, the entry lock is restored to atmospheric pressure by allowing gas (usually nitrogen) to enter from a gas cylinder (1515). The entry lock typically has a transparent glass window (1530).

图16示出了本发明的一种配置,其中XPS系统和外壳(如上所述)是分开的但非常靠近。样品在空气中从XPS系统移动到包含UV/臭氧产生灯(1620)的所述外壳(1610),并在UV/臭氧暴露后再次返回,完成图7所示的重复循环。这些转移可以使用小型空气侧机械臂或类似设备自动进行,但最有可能由操作员手动完成。Figure 16 shows a configuration of the invention in which the XPS system and enclosure (described above) are separate but in close proximity. The sample is moved in air from the XPS system to the enclosure (1610) containing the UV/ozone generating lamp (1620) and back again after UV/ozone exposure, completing the repetitive cycle shown in Figure 7. These transfers can be automated using a small air-side robot or similar device, but are most likely to be done manually by an operator.

图17示出了本发明的另一种配置,其中包含产生UV/臭氧的灯的外壳与XPS系统入口锁集成在一起。这需要在所述入口锁上使用UV透明窗口而不是通常的玻璃窗(1530),并且回填气瓶(1700)需要包含氧气或含氧气体混合物(例如干燥空气)而不是纯氮气。UV穿过所述UV透明窗口并在入口锁自身内产生臭氧。FIG17 shows another configuration of the present invention, where the housing containing the UV/ozone generating lamp is integrated with the XPS system entry lock. This requires the use of a UV transparent window on the entry lock instead of the usual glass window (1530), and the backfill gas cylinder (1700) needs to contain oxygen or an oxygen-containing gas mixture (e.g. dry air) instead of pure nitrogen. The UV passes through the UV transparent window and generates ozone within the entry lock itself.

当样品存在于入口锁中时,它因此暴露于UV和臭氧中,并且可以被移回到分析室中用于下一次光谱采集,如图7中的流程图所述。这种配置充分利用了自动化样品处理、灯和阀门控制;例如,图7中描述的整个序列可能在计算机控制下作为自动序列运行,而不需要操作人员在场。例如,它可以通宵运行,充分利用原本难以充分利用的仪器时间。早上,操作者回来发现图10和13所示类型的一整套光谱,并且图11和14所示类型的计算结果已经完成(因为计算不需要操作者的知识或干预)。When the sample is present in the entry lock, it is thus exposed to UV and ozone, and can be moved back into the analysis chamber for the next spectral acquisition, as described in the flow chart of Figure 7. This configuration takes full advantage of automated sample handling, lamp and valve control; for example, the entire sequence described in Figure 7 may be run as an automatic sequence under computer control without the need for an operator to be present. For example, it can be run overnight, making full use of instrument time that would otherwise be difficult to fully utilize. In the morning, the operator returns to find a complete set of spectra of the type shown in Figures 10 and 13, and calculation results of the type shown in Figures 11 and 14 have been completed (because the calculations do not require the operator's knowledge or intervention).

关于这种应用中可能使用的UV灯,我使用图18所示的小型“GTL3”UV灯取得了良好的效果,尽管许多其他型号可能也同样适用。我操作过这种只有一个33欧姆镇流电阻和24V电源电压的灯(交流和直流都可以工作,不过交流可能会延长灯的寿命)。在操作中,这些灯在10V时消耗大约3W的功率(剩余功率通过镇流电阻器产生压降)。这种灯有臭氧发射型和非臭氧发射型(它们分别具有不同的玻璃配方来透射或阻挡185nm辐射),因此它们可以用作图5中的灯A和灯B中的一个或两个。这些具有E17标准螺丝底座,因此易于安装在有限的空间内。Sankyo-Denki GTL3是一款3W灯,UV输出功率为0.16W。制造商规定的典型寿命为2000小时。该灯有一个E17螺丝底座,尺寸为直径20mm x长63mm的透明T7管。该产品产自日本,通常可从Ushio、Fisher Scientific、Eiko、Hikari、美国UV等公司购买,零件号为GTL3W、PO300-0350、29-258-23、GRM0036、3000022Regarding the UV lamps that might be used in this application, I have had good results using the small "GTL3" UV lamp shown in Figure 18, although many other models may be equally suitable. I have operated this lamp with only a 33 ohm ballast resistor and a 24V supply voltage (both AC and DC will work, although AC may extend the life of the lamp). In operation, these lamps consume about 3W of power at 10V (the remainder is dropped across the ballast resistor). This lamp is available in ozone-emitting and non-ozone-emitting types (they have different glass formulations to transmit or block 185nm radiation, respectively), so they can be used as one or both of lamps A and B in Figure 5. These have an E17 standard screw base, so they are easy to install in limited spaces. The Sankyo-Denki GTL3 is a 3W lamp with a UV output power of 0.16W. The typical life is specified by the manufacturer as 2000 hours. The lamp has an E17 screw base and the dimensions are a 20mm diameter x 63mm long clear T7 tube. This product is made in Japan and can usually be purchased from companies such as Ushio, Fisher Scientific, Eiko, Hikari, and American UV. The part numbers are GTL3W, PO300-0350, 29-258-23, GRM0036, 3000022

这些GTL3灯通常用于杀菌应用,例如洗衣机或牙刷消毒剂。它们相当便宜,通常不到10美元。它们在电气方面不是很有效,尤其是在使用33欧姆镇流电阻的情况下,但在这种应用中这并不是真正的问题。它们没有足够的发射功率用于表面的UV/臭氧清洁。相反,更大的汞网格灯通常用于此目的。但是如上所述,对于我们的应用而言,如果我们希望温和且渐进地氧化或还原表面,则这些GTL3灯在距离样品约10cm的范围内就足够了。根据规范,这些灯在距离灯泡3cm处测得的发射波长为254nm,紫外强度≥450x10-6W/cm2。虽然我找不到任何更短波长发射的规格,但毫无疑问是在185nm,这些灯能产生臭氧。These GTL3 lamps are often used in germicidal applications, such as washing machine or toothbrush sanitizers. They are fairly cheap, usually less than $10. They are not very efficient electrically, especially with a 33 ohm ballast resistor, but that is not really a problem in this application. They do not emit enough power for UV/ozone cleaning of surfaces. Instead, larger mercury grid lamps are often used for this purpose. But as mentioned above, for our application, if we want to oxidize or reduce a surface gently and gradually, these GTL3 lamps are more than adequate at a distance of about 10cm from the sample. According to the specifications, these lamps have an emission wavelength of 254nm measured at 3cm from the bulb, with a UV intensity of ≥450x10-6 W/ cm2 . While I can't find any specifications for shorter wavelength emission, there is no doubt that at 185nm these lamps are capable of producing ozone.

波长较长的灯B的替代灯是短波发光二极管(LED),如图19所示。目前这些灯的可用的波长低至约270nm,因此不能用作臭氧发生灯,但可以用作臭氧破坏灯,或用于在氢气存在下照射样品。参考图20,该图显示了臭氧的哈特莱(Hartley)吸收带,可以看出汞蒸汽在254nm的发射接近臭氧的最大吸收(因此使其迅速返回到双原子氧),而270nm的LED发射器速度较慢,因此在时间方面效率较低-如果光子强度相似,则效率约为慢两倍,但在使用的电功率方面效率更高,可能还有灯的寿命更长。An alternative to the longer wavelength lamp B is the short wave light emitting diode (LED), shown in Figure 19. These lamps are currently available at wavelengths down to about 270nm and therefore cannot be used as ozone generating lamps, but can be used as ozone destroying lamps, or for irradiating samples in the presence of hydrogen. Referring to Figure 20, which shows the Hartley absorption band for ozone, it can be seen that the emission of mercury vapor at 254nm is close to the maximum absorption of ozone (thus causing it to return quickly to diatomic oxygen), while the 270nm LED emitter is slower and therefore less efficient in terms of time - about twice as slow if the photon intensity is similar, but more efficient in terms of electrical power used and possibly longer lamp life.

在本申请中,操作距离或范围(灯到样品)在理论上很难决定,因为紫外光灯发出的两种竞争波长185nm和254nm分别18产生和破坏臭氧,因此臭氧浓度随着离灯距离的增加呈非线性下降。对于复杂的外壳几何形状,这最好通过臭氧和UV测量装置进行实验确定,并且这些测量可以专门应用于特定的外壳和UV灯型号。In this application, the operating distance or range (lamp to sample) is difficult to determine theoretically because the two competing wavelengths emitted by the UV lamp, 185nm and 254nm, respectively, produce and destroy ozone, so the ozone concentration decreases nonlinearly with increasing distance from the lamp. For complex housing geometries, this is best determined experimentally using ozone and UV measurement setups, and these measurements can be applied specifically to the specific housing and UV lamp model.

可能的实施例和配置(表面层的还原)Possible embodiments and configurations (reduction of the surface layer)

释氢元素Release hydrogen

许多操作XPS仪器的实验室都有高纯度氢气。其他的一些实验室则没有。在任何情况下,当处理大量氢气时,执行安全过程的成本通常很高,即使实际使用的数量(如在本应用中)非常少。Many laboratories that operate XPS instruments have access to high purity hydrogen. Others do not. In any case, the cost of enforcing safe procedures is often high when handling large quantities of hydrogen, even if the quantities actually used (as in this application) are very small.

因此,可选地,在一些实施例中,我们利用由锌空气电池或类似电池在样品外壳内原位产生的氢气。这些可能是市售的“纽扣”电池,用于助听器等设备,取代了20年前常见的汞电池。事实上,这种电池的变体已经可以用于生产氢气。Thus, optionally, in some embodiments, we utilize hydrogen generated in situ within the sample housing by a zinc air battery or similar cell. These may be commercially available "button" cells, used in devices such as hearing aids, replacing the mercury cells that were common 20 years ago. In fact, variations of such cells are already available for the production of hydrogen.

因此,为了提供高纯度氢气的简单来源,可选地,所述锌空气或其他金属-空气类型的电池(应当理解为一个电池或多个电池)位于样品外壳内,具有通过该电池的电流的外部控制。当在没有氧气的情况下对锌空气电池施加电阻负载时,电池会以相当可控的速率20产生19氢气。在一个实施例中,这可以通过在电池两端串联外部开关和电阻器来实现,使得接通将导致电阻器限制的电流通过电池。Therefore, to provide a simple source of high purity hydrogen, optionally, the zinc air or other metal-air type battery (which should be understood as a battery or multiple batteries) is located within the sample housing with external control of the current through the battery. When a resistive load is applied to the zinc air battery in the absence of oxygen, the battery will produce 19 hydrogen at a fairly controllable rate 20. In one embodiment, this can be achieved by connecting an external switch and resistor in series across the battery, so that turning on will cause the resistor-limited current to pass through the battery.

众所周知,这种锌空气电池会释放出少量氢气,与通过电池的总电荷大致成比例。这允许氢气被输送到被分析表面周围的区域,达到约10-3mb或更高的分压,该分压大于样品外壳中其他活性物质(例如潜在的氧化性物质,如氧气、水等)的压力。Such zinc-air batteries are known to release small amounts of hydrogen gas, roughly proportional to the total charge passing through the cell. This allows hydrogen gas to be delivered to the area surrounding the surface being analyzed, reaching partial pressures of about 10-3 mb or more, which is greater than the pressure of other active species (e.g., potentially oxidizing species such as oxygen, water, etc.) in the sample envelope.

可以使用专门为制氢而设计的含锌电池(如Varta公司生产21的电池)——这些电池实际上是作为精密氢气发生器销售的锌空气电池的改进型。关键的考虑因素是,在这种应用中只需要少量的氢气,在远低于大气压的压力下填充样品外壳的小体积,因此锌空气电池在其寿命期间产生大约150cm3的氢气就足够了。四个这样的电池组成的电池组在其寿命期间将能够提供600cm3的氢气,可能足以在需要更换之前在UV下进行500次以上的低压H2样品还原循环。Zinc-containing cells designed specifically for hydrogen production can be used (such as those produced by Varta21 ) - these are actually modified versions of zinc-air cells sold as precision hydrogen generators. The key consideration is that only small amounts of hydrogen are required in this application, filling the small volume of the sample enclosure at pressures well below atmospheric pressure, so it would be sufficient for a zinc-air cell to produce about 150 cm3 of hydrogen over its lifetime. A battery of four such cells would be able to provide 600 cm3 of hydrogen over its lifetime, probably enough for more than 500 cycles of low-pressure H2 sample reduction under UV before needing replacement.

图31显示了Varta公司两款专为制氢设计的电池单元产品的产品概况。Figure 31 shows a product overview of Varta's two battery cell products designed specifically for hydrogen production.

这些电池不能在真空室(样品外壳)中无密封使用,如XPS仪器入口锁,因为它们含有水溶液电解质。在干燥条件下,这会蒸发,而真空是一个非常干燥的环境。因此,电池必须由样品外壳内的容器(电池外壳)封闭,该容器允许氢气在需要时排出,但在XPS仪器的工作温度下至少保留水的分压,例如在20℃时约为18mmHg。These cells cannot be used without a seal in a vacuum chamber (sample housing), such as the XPS instrument entry lock, because they contain an aqueous electrolyte. Under dry conditions, this would evaporate, and a vacuum is a very dry environment. Therefore, the cell must be closed by a container inside the sample housing (cell housing) that allows hydrogen to vent when required, but retains at least the partial pressure of water at the operating temperature of the XPS instrument, for example about 18 mmHg at 20°C.

至少有两个可能的实施例可以实现这种电池外壳;There are at least two possible embodiments for implementing such a battery housing;

可能的电池外壳实施例A;电池周围的密封管由透氢(但不透水)材料制成,如钯或钯合金。图3示出了这种布置的示意图,这是一个可选实施例,其中四个这样的电池在密封的钯(或钯合金)管内形成电池组,该密封的钯管允许氢气渗透出。可选地,Possible battery housing embodiment A: The sealed tube around the battery is made of a hydrogen permeable (but water impermeable) material, such as palladium or a palladium alloy. Figure 3 shows a schematic diagram of this arrangement, which is an optional embodiment, where four such batteries form a battery pack within a sealed palladium (or palladium alloy) tube that allows hydrogen gas to permeate out. Optionally,

可能的电池外壳实施例B;电池周围的密封管通过常闭减压阀连接到入口锁或其他样品外壳的主空间,当内部压力(由电池产生的氢气引起)超过该温度下水的蒸气压的预定值时,减压阀打开。例如,在样品外壳中,当样品外壳内部压力高于外部压力0.2atm时,弹簧加载的安全阀将打开。每次阀门打开时,都会有一些水蒸气逸出,但在阀门处于常闭状态时,在使用实例的许多小时内,电池不会变干。Possible cell housing embodiment B; The sealed tube surrounding the cell is connected to the main space of the inlet lock or other sample housing through a normally closed pressure relief valve, which opens when the internal pressure (caused by hydrogen produced by the cell) exceeds a predetermined value of the vapor pressure of water at that temperature. For example, in the sample housing, when the pressure inside the sample housing is 0.2atm higher than the external pressure, the spring-loaded safety valve will open. Each time the valve opens, some water vapor will escape, but when the valve is in the normally closed state, the cell will not dry out during many hours of use of the example.

图32示意性示出了本发明的渗透式氢释放元件的一个可能的实施方案A,图32(a)是未选择操作的,图32(b)是选择进行操作并释放氢的。FIG. 32 schematically shows a possible embodiment A of the permeable hydrogen releasing element of the present invention, FIG. 32( a ) is not selected for operation, and FIG. 32( b ) is selected for operation and releases hydrogen.

图33显示了电池外壳的简单实施例类型B的示意图。在图33中,预先选择的漏斗1030中的球1020的重量允许电池外壳1010内的压力超过装置工作温度(通常为室温或稍高)下水的饱和蒸汽压,即使样品外壳压力(不要与电池外壳混淆)可能是真空。这确保了电池720不会变干。瞬间按压按钮使电容器放电,从而当释放按钮时,电流流过电池,产生氢气,直到电容器充满电,释放由电容值C的选择预先确定的固定量的氢气。电池外壳1010内的氢气压力高于其周围的样品外壳内的压力,然后瞬间移动球1020,将少量、固定和预定量的纯氢气释放到样品外壳中样品周围的区域中,用于还原或UV辅助还原样品表面。FIG33 shows a schematic diagram of a simple embodiment of a battery housing, Type B. In FIG33, the weight of the ball 1020 in the funnel 1030 is pre-selected to allow the pressure within the battery housing 1010 to exceed the saturated vapor pressure of water at the operating temperature of the device (typically room temperature or slightly higher), even though the sample housing pressure (not to be confused with the battery housing) may be a vacuum. This ensures that the battery 720 does not dry out. A momentary press of the button discharges the capacitor so that when the button is released, current flows through the battery, producing hydrogen gas until the capacitor is fully charged, releasing a fixed amount of hydrogen gas predetermined by the selection of the capacitance value C. The hydrogen pressure within the battery housing 1010 is higher than the pressure within the sample housing surrounding it, and the ball 1020 is then moved momentarily to release a small, fixed and predetermined amount of pure hydrogen gas into the area surrounding the sample in the sample housing for reduction or UV-assisted reduction of the sample surface.

图34示意性地显示了处于(a)休眠和(B)产氢状态的电池外壳类型B的稍微更复杂的可能实施例。这里,控制制氢的开关是常开的,如(a)所示,并且可以是在可编程逻辑控制器(PLC)750控制下的继电器或类似开关。由于由弹簧960、调节螺钉970和“提升阀”950形成的减压阀,电池外壳930内的电池720周围的压力高于样品外壳内的压力(不要与电池外壳930混淆)。如(b)所示,当PLC闭合开关时,直流电流(由电阻器R限制以限制氢气产生速率)通过电池720。电池释放氢气,直到提升阀上的压力足以克服弹簧960的力,并且氢气逃逸到样品外壳中。在该实施例中,由PLC执行的计算机代码可以选择开关闭合的不同持续时间,从而将不同量的氢气释放到样品周围的区域中,用于后续的还原或UV辅助还原样品表面。FIG34 schematically shows a slightly more complex possible embodiment of a cell housing type B in (a) dormant and (b) hydrogen production states. Here, the switch controlling hydrogen production is normally open, as shown in (a), and can be a relay or similar switch under the control of a programmable logic controller (PLC) 750. Due to the pressure relief valve formed by spring 960, adjustment screw 970 and "poppet valve" 950, the pressure around the cell 720 in the cell housing 930 is higher than the pressure in the sample housing (not to be confused with the cell housing 930). As shown in (b), when the PLC closes the switch, a direct current (limited by resistor R to limit the rate of hydrogen production) passes through the cell 720. The cell releases hydrogen until the pressure on the poppet valve is sufficient to overcome the force of the spring 960 and the hydrogen escapes into the sample housing. In this embodiment, the computer code executed by the PLC can select different durations of switch closure to release different amounts of hydrogen into the area around the sample for subsequent reduction or UV-assisted reduction of the sample surface.

图15显示了典型商用XPS仪器的垂直截面示意图。有一个名义上处于超高真空(UHV)的分析室(1500),带有半球形电子能量分析器(1510)。泵(1505)保持系统各部分的真空。阀门(1520)被打开和关闭以允许样品从入口锁(1525)进入分析室。转移臂(1535)用于在所述分析室和所述入口锁之间移动样品。当从系统中提取样品时,通过允许气体(通常为氮气或干燥空气)从气瓶(1515)进入,将入口锁恢复至大气压力。所述入口锁通常具有透明玻璃窗(1530)。Figure 15 shows a schematic vertical cross-section of a typical commercial XPS instrument. There is an analysis chamber (1500) nominally in ultra-high vacuum (UHV) with a hemispherical electron energy analyzer (1510). A pump (1505) maintains vacuum in various parts of the system. A valve (1520) is opened and closed to allow samples to enter the analysis chamber from an entry lock (1525). A transfer arm (1535) is used to move samples between the analysis chamber and the entry lock. When a sample is extracted from the system, the entry lock is restored to atmospheric pressure by allowing gas (usually nitrogen or dry air) to enter from a gas cylinder (1515). The entry lock typically has a transparent glass window (1530).

图16显示了本发明的一种配置,其中XPS系统和样品外壳(如上文段落中所述)是分开的,但非常靠近。样品在空气中从XPS系统移动到包含UV产生灯(1620)的所述样品外壳(1610),并在UV/氢气暴露后再次返回。氢气可通过气瓶或其他“管道”供应方式供应给样品外壳1610,或者通过上述和图10、11或12中描述的实施例之一的产氢电池供应。这些转移可以使用小型空气侧机械臂或类似设备自动进行,但最有可能由操作员手动完成。Figure 16 shows a configuration of the invention in which the XPS system and sample housing (as described in the paragraph above) are separate but in close proximity. The sample is moved in air from the XPS system to the sample housing (1610) containing the UV generating lamp (1620), and back again after UV/hydrogen exposure. Hydrogen can be supplied to the sample housing 1610 via a cylinder or other "pipeline" supply, or via a hydrogen producing cell of one of the embodiments described above and in Figures 10, 11, or 12. These transfers can be automated using a small air-side robotic arm or similar device, but are most likely to be done manually by an operator.

图36显示了本发明的另一个实施例,其中包含产生UV的灯的样品外壳与XPS系统入口锁集成在一起。这需要在所述入口锁上具有UV透明窗口(该窗口的位置在图13中为1530)。回填气瓶(1700)可用于向样品附近供应氢气,或者在其自身电池外壳1780中的氢发射电池可供应氢气(未示出电连接和安全阀)。UV光穿过所述UV透明窗口进入入口锁本身。FIG36 shows another embodiment of the invention, wherein a sample housing containing a UV generating lamp is integrated with an XPS system entry lock. This requires a UV transparent window on the entry lock (the location of the window is 1530 in FIG13 ). A backfill gas cylinder (1700) can be used to supply hydrogen near the sample, or a hydrogen emission cell in its own cell housing 1780 can supply hydrogen (electrical connections and safety valve not shown). UV light passes through the UV transparent window into the entry lock itself.

当样品存在于入口锁中时,它因此暴露于UV和氢气中,并可被移回到分析室中进行下一次光谱采集,如以上流程图中所述。这种配置充分利用了自动化样品处理、灯和阀门控制;例如,整个序列可以在计算机(和/或PLC)控制下运行,而不需要操作人员在场。例如,它可以通宵运行,充分利用原本难以充分利用的仪器时间。早上,操作员回来时会发现一整套光谱。When the sample is present in the entry lock, it is thus exposed to UV and hydrogen and can be moved back to the analysis chamber for the next spectrum acquisition, as described in the flow chart above. This configuration takes full advantage of automated sample handling, lamp and valve control; for example, the entire sequence can be run under computer (and/or PLC) control without the need for an operator to be present. For example, it can be run overnight, making full use of instrument time that would otherwise be difficult to fully utilize. In the morning, the operator returns to find a complete set of spectra.

关于这种应用中可能使用的UV灯,我使用图16所示的小型“GTL3”UV灯取得了良好的效果,尽管许多其他型号可能也同样适用。我操作过这种只有一个33欧姆镇流电阻和24V电源电压的灯(交流和直流都可以工作,不过交流可能会延长灯的寿命)。在操作中,这些灯在10V时消耗大约3W的功率(剩余功率通过镇流电阻器降低)。这些灯具有E17标准螺丝底座,因此易于安装在有限的空间内。Sankyo-Denki GTL3是一款3W灯,UV输出功率为0.16W。制造商规定的典型寿命为2000小时。该灯在20mm直径x63mm长的透明T7管上有一个E17螺丝底座。该产品产自日本,通常可从Ushio、Fisher Scientific、Eiko、Hikari、美国Ultraviolet等公司购买,零件号为GTL3W、PO300-0350、29-258-23、GRM0036、3000022。Regarding the UV lamps that might be used in this application, I have had good results using the small "GTL3" UV lamp shown in Figure 16, although many other models may be equally suitable. I have operated this lamp with only a 33 ohm ballast resistor and a 24V supply voltage (both AC and DC will work, although AC may extend the life of the lamp). In operation, these lamps consume approximately 3W of power at 10V (the remaining power is reduced by the ballast resistor). These lamps have an E17 standard screw base, so they are easy to install in limited spaces. The Sankyo-Denki GTL3 is a 3W lamp with a UV output power of 0.16W. The typical life is specified by the manufacturer as 2000 hours. The lamp has an E17 screw base on a 20mm diameter x 63mm long clear T7 tube. This product is produced in Japan and can usually be purchased from companies such as Ushio, Fisher Scientific, Eiko, Hikari, and Ultraviolet in the United States. The part numbers are GTL3W, PO300-0350, 29-258-23, GRM0036, and 3000022.

根据规范,这些灯在距离灯泡3cm处测得的发射波长为254nm,紫外强度≥450x10- 6W/cm2According to the specification, these lamps have an emission wavelength of 254nm and a UV intensity ≥450x10 - 6 W/cm 2 measured at a distance of 3cm from the bulb.

这些GTL3灯通常用于杀菌应用,例如洗衣机或牙刷消毒剂。它们相当便宜,通常不到10美元。它们在电气方面不是很有效,尤其是在使用33欧姆镇流电阻的情况下,但在这种应用中这并不是真正的问题。事实上,这些灯产生的废热可以用来加热透氢气瓶或膜,以增加其透氢性。These GTL3 lamps are often used in germicidal applications, such as washing machine or toothbrush sanitizers. They are fairly cheap, usually less than $10. They are not very efficient electrically, especially with a 33 ohm ballast resistor, but that is not really a problem in this application. In fact, the waste heat from these lamps can be used to heat hydrogen permeable gas bottles or membranes to increase their hydrogen permeability.

UV灯的另一种灯是短波发光二极管(LED)。目前这些产品的可用波长低至约270nm。Another type of UV lamp is the short-wave light emitting diode (LED). Currently these products are available with wavelengths down to about 270nm.

闭环控制Closed-loop control

使用来自样品附近的氢气或压力传感器的信号,可以通过接通通过锌空气(或类似)电池的电流来自动控制氢气水平,使其保持在所需的值。Using a signal from a hydrogen or pressure sensor near the sample, the hydrogen level can be automatically controlled by switching on a current through a zinc-air (or similar) cell to keep it at the desired value.

主成分分析、NMF或奇异值分解结果的解释Interpretation of PCA, NMF or SVD results

当通过PCA或SVD算法处理一组光谱(在样品逐渐暴露于越来越多的UV/臭氧或UV/氢气之后)时,这可以被视为从该数据中提取纯组分光谱的一个步骤。例如,通过应用这些组分的组合所具有的约束;When a set of spectra is processed by a PCA or SVD algorithm (after the sample has been gradually exposed to more and more UV/ozone or UV/hydrogen), this can be seen as a step to extract the pure component spectra from this data. For example, by applying constraints that the combination of these components has;

1.没有负向特征,或仅有非常小的负向特征,和1. No negative features, or very small negative features, and

2.光谱的总曲率被最小化2. The total curvature of the spectrum is minimized

人们可以自动获得在UV/臭氧处理过程中产生和去除的纯化学成分(例如典型的几种金属氧化物)的光谱。不实施或实施非常小的负向特征会导致非负矩阵分解或NMF。One can automatically obtain spectra of pure chemical components (typically several metal oxides, for example) generated and removed during UV/ozone treatment. Not implementing or implementing very small negative features leads to non-negative matrix factorization or NMF.

然而,现在还有更有用的数据。人们可以将这些主要成分中的每一个视为代表在UV/臭氧或UV/氢气暴露下发生的化学过程。例如,聚合物可能显示出在烃的结合能C-C*-C处具有负峰、在结合能C*-OH处具有正峰的组分。这可以解释为代表一种化学氧化反应。然而这种反应的速度首先取决于碳的化学环境。在具有不同分子(例如作为聚合物主链一部分的O或N)的样本中,可以预期该反应的速率不同,因此UV/臭氧处理样本光谱的顺序不同,因此主要成分的类型(或排序)不同。因此,这使我们能够获得单个XPS光谱无法提供的更多信息;例如,我们也许能够区分具有以下SMILES代码的分子;However, there is now even more useful data. One can think of each of these major components as representing a chemical process that occurred upon UV/ozone or UV/hydrogen exposure. For example, a polymer might show a component with a negative peak at the binding energy C-C*-C of the hydrocarbon and a positive peak at the binding energy C*-OH. This could be interpreted as representing a chemical oxidation reaction. However the rate of this reaction depends first and foremost on the chemical environment of the carbon. In samples with different molecules (e.g. O or N as part of the polymer backbone) one would expect the rate of this reaction to be different, and therefore the order of the UV/ozone treated sample spectrum to be different, and therefore the type (or ordering) of major components to be different. This therefore allows us to get more information that a single XPS spectrum cannot provide; for example we might be able to distinguish between molecules with the following SMILES codes;

CCCCNCCCCCCCCNCCCC

…与具有以下SMILES代码的分子...with a molecule having the following SMILES code

CCCC(N)CCCCCCCC(N)CCCC

…尽管在UV/臭氧照射前观察光谱中的化学变化很难或不可能做到这一点。机器学习算法,如神经网络模型或“深度学习”在应用于本文所述的逐步UV/臭氧和/或UV/氢气暴露的样本光谱时将特别有用,即使相同的算法在仅应用于单独来自(未UV/臭氧处理的)样本的光谱时揭示很少。…even though it may be difficult or impossible to observe chemical changes in the spectra prior to UV/ozone exposure. Machine learning algorithms such as neural network models or “deep learning” will be particularly useful when applied to spectra of samples exposed to stepwise UV/ozone and/or UV/hydrogen as described herein, even though the same algorithms reveal little when applied to spectra from (non-UV/ozone treated) samples alone.

闭环控制Closed-loop control

使用来自样品附近的臭氧传感器的信号,通过打开灯A(产生臭氧)和灯B(破坏臭氧),可以自动控制臭氧水平保持在所需的值,如图5所示。这可以方便地使用光吸收或化学臭氧传感器和比例积分微分(PID)控制器来开关灯(或者在能够使用LED设备的情况下,调制它们的功率输出或占空比)。控制臭氧水平可以通过提高臭氧水平来缩短一些较晚的较长臭氧暴露步骤的时间。Using signals from an ozone sensor near the sample, the ozone level can be automatically controlled to remain at a desired value by turning on lamp A (producing ozone) and lamp B (destroying ozone), as shown in Figure 5. This can be conveniently done using a light absorption or chemical ozone sensor and a proportional integral derivative (PID) controller to switch the lamps on and off (or, in the case of LED devices, modulate their power output or duty cycle). Controlling the ozone level can shorten the duration of some later, longer ozone exposure steps by increasing the ozone level.

非导电样品Non-conductive samples

非导电样品存在一个特殊的问题,为此我开发了一种特殊的方法来克服这个问题。Non-conductive samples present a special problem, for which I developed a special method to overcome this.

在常规XPS仪器操作中,通常使用“漫射枪(flood gun)”从非导电样品中获得良好的光谱。这种枪用低能电子有时也用离子“漫射(flood)”样品,这样样品表面积累的电荷就会被这些带电物质中和。实现了电荷平衡,由此离开表面的光电子留下正电荷,然后被漫射枪发射的带电粒子中和。这种电荷平衡不一定使表面精确地回到地电位,但会使该电位稳定在接近地电位的某个位置。表面电位的稳定性对于光谱的获取是最重要的。XPS操作员很快就能识别出在电荷平衡稳定性未达到的情况下的光谱,因为XPS光谱中的峰在一定能量范围内模糊不清,有时看起来根本不像峰。In routine XPS instrument operation, a "flood gun" is often used to obtain good spectra from non-conductive samples. This gun "floods" the sample with low energy electrons and sometimes ions so that the charge accumulated on the surface of the sample is neutralized by these charged species. Charge balance is achieved, whereby photoelectrons leaving the surface leave behind a positive charge that is then neutralized by the charged particles emitted by the diffuse gun. This charge balance does not necessarily return the surface to exactly ground potential, but it stabilizes that potential to somewhere close to ground potential. The stability of the surface potential is of utmost importance for the acquisition of spectra. XPS operators quickly recognize spectra where charge balance stability has not been achieved because the peaks in the XPS spectrum are smeared over a certain energy range and sometimes do not look like peaks at all.

当应用此处描述的UV/臭氧或UV/氢气暴露方法时,非导电样品的问题是连续暴露会轻微改变表面化学性质,从而改变电荷平衡电位。这意味着样品组分的峰似乎发生了偏移。The problem with non-conductive samples when applying the UV/ozone or UV/hydrogen exposure methods described here is that continued exposure slightly changes the surface chemistry and thus the charge balance potential. This means that the peaks of the sample components appear to be shifted.

为了消除电荷平衡漂移的问题,我成功地使用了沉积在样品表面的离子束溅射粒子,这种粒子可以称为电势标记粒子(EPMP)。它们由一种可以溅射(使用几乎所有XPS系统内置的离子枪通过离子束溅射)的材料组成,以小颗粒簇覆盖样品表面的一小部分(可能1%至5%)。这在连续暴露于UV/臭氧或UV/氢气之前进行一次。然后这些颗粒出现在样品表面的所有XPS光谱中。选择EPMP的化学成分以提供尖锐的峰,然后用于标记表面电势的任何变化。To eliminate the problem of charge balance drift, I have had success using ion beam sputtered particles deposited on the sample surface, which can be called electrical potential marker particles (EPMPs). They consist of a material that can be sputtered (by an ion beam using the ion gun built into almost all XPS systems) to cover a small portion (perhaps 1% to 5%) of the sample surface with small clusters of particles. This is done once before continuous exposure to UV/ozone or UV/hydrogen. These particles then appear in all XPS spectra of the sample surface. The chemical composition of the EPMP is chosen to give sharp peaks, which are then used to mark any changes in the surface potential.

离子束溅射可以用于多种材料,因此原则上可以使用许多不同的材料来提供EPMP。此外,在这种应用中溅射材料的数量很少,因此没有真正的成本限制-如果性能良好,即使最昂贵的贵金属也是可以接受的。所以我们必须仔细观察元素的化学性质,看看哪种元素最适合作为EPMP。Ion beam sputtering can be used for a wide range of materials, so in principle many different materials could be used to provide an EPMP. Also, the amount of sputtered material is small in this application, so there is no real cost limit - even the most expensive precious metals are acceptable if the properties are good. So we have to look carefully at the chemistry of the elements to see which would be best suited as an EPMP.

显然,一个糟糕的材料选择是那些会在暴露于更多臭氧时发生氧化的材料,特别是如果其氧化物峰几乎无法解析,那么渐进氧化似乎会移动监测到的EPMP XPS峰的位置。例如,这使得Cu成为一个糟糕的选择。Obviously, a poor material choice is one that will oxidize when exposed to more ozone, especially if its oxide peak is barely resolvable, so that the progressive oxidation appears to shift the position of the monitored EPMP XPS peak. This makes Cu, for example, a poor choice.

理想情况下,用作溅射靶以提供EPMP的元素X在整个渐进的UV/臭氧或UV/氢气暴露过程中应具有单一、恒定的氧化态。这可以通过确保以下几点来实现:Ideally, the element X used as a sputtering target to provide the EPMP should have a single, constant oxidation state throughout the progressive UV/ozone or UV/hydrogen exposure. This can be achieved by ensuring the following:

1.X很容易氧化到其最高氧化态XOy,或1. X is easily oxidized to its highest oxidation state XO y , or

2.X非常贵重,根本不会氧化,尽管暴露在臭氧中,它仍以金属状态存在作为EPMP,2.X is so precious that it does not oxidize at all. Despite exposure to ozone, it still exists as EPMP in a metallic state.

3.X具有接近C1s和O1s峰的XPS峰,这在大多数绝缘体的分析中通常是最重要的。能量上的接近意味着在少量XPS扫描中更容易捕获,并降低了能量尺度漂移导致重大误差的可能性。3.X has XPS peaks close to the C1s and O1s peaks, which are usually the most important in the analysis of most insulators. The closeness in energy means that they are easier to capture in a small number of XPS scans and reduces the possibility of significant errors caused by energy scale drift.

图21很有启发性。为了形成尽可能最好的EPMP,贵金属(例如金)还不够“高贵”。暴露于臭氧时,由于表面的金氧化物(有时是氮化物),Au 4f峰有可测量的表观位移。相反,我们应该关注那些氧化态很少且容易氧化的元素。Sc,Ti,Ni,Zn,Y,Cd,Lu,Hf可能是合理的候选元素。有些可能难以从安全角度证明处理的合理性(如Cd)。易于操作也是有用的,因此广泛可得且易于操作和延展的箔是一个优势。Figure 21 is instructive. To form the best possible EPMP, noble metals (such as gold) are not "noble" enough. When exposed to ozone, there is a measurable apparent shift of the Au 4f peak due to gold oxides (and sometimes nitrides) on the surface. Instead, we should focus on elements that have few oxidation states and are easily oxidized. Sc, Ti, Ni, Zn, Y, Cd, Lu, Hf are likely reasonable candidates. Some may be difficult to justify handling from a safety perspective (such as Cd). Ease of handling is also useful, so widely available foils that are easy to handle and stretch are an advantage.

我使用钛作为溅射靶以沉积EPMP的应用中取得了良好的成功。钛满足上述标准1,很容易被氧化到最高氧化态。以至于如果试图获得Ti金属的XPS光谱,即使在含氧物质(通常是水)浓度非常小的“超高真空”条件下,表面氧化物的出现也通常会使人沮丧。事实上,钛正是出于这一原因被用于XPS中的升华泵,因为它对捕获含氧物质具有亲和力和高粘附系数。钛箔有各种不同的厚度,很容易弯曲成合适的形状。Ti的最强XPS峰,Ti 2p峰,在能量上大约位于C1s和O1s之间的中间位置,这是理想的。I have had good success in applications using titanium as a sputtering target to deposit EPMP. Titanium satisfies criterion 1 above and is easily oxidized to its highest oxidation state. So much so that if one attempts to obtain an XPS spectrum of Ti metal, even under "ultra-high vacuum" conditions where the concentration of oxygen-containing species (usually water) is very small, the appearance of surface oxides is often discouraging. In fact, titanium is used for sublimation pumps in XPS for this very reason, as it has an affinity for trapping oxygen-containing species and a high adhesion coefficient. Titanium foil comes in a variety of thicknesses and is easily bent into the appropriate shape. The strongest XPS peak for Ti, the Ti 2p peak, is energetically approximately midway between C1s and O1s, which is ideal.

Ti 2p3/2XPS峰的峰位置可以通过许多方法精确确定。我使用了20世纪90年代开发的多项式拟合方法22,效果非常好。在固定的UV/臭氧或UV/氢气暴露后,从样本记录的所有光谱随后被移动,以确保EPMP峰精确重合,包括对整数个移动的通道进行插值。The peak position of the Ti 2p 3/2 XPS peak can be determined accurately by a number of methods. I have used a polynomial fit method developed in the 1990s22 which works very well. All spectra recorded from the sample after a fixed UV/ozone or UV/hydrogen exposure are then shifted to ensure that the EPMP peaks coincide accurately, including interpolation of an integer number of shifted channels.

EPMP在样品表面的沉积Deposition of EPMP on sample surface

如图23所示,一小片箔片(在一个实施例中为钛,如上所述)被折叠成具有大约110°的内角。离子束(通常是氩,适当时可以是团簇或单原子)用于首先清洁箔溅射靶。然后使用这个或另一个离子枪将单原子氩离子聚焦在靶箔表面,并将原子从箔溅射到样品上。图23示意性地示出了该溅射沉积步骤(横截面),其中继续形成EPMP的颗粒从靶2310(通常为Ti金属箔)溅射到被分析的绝缘样品2320上。As shown in Figure 23, a small piece of foil (in one embodiment, titanium, as described above) is folded to have an internal angle of approximately 110°. An ion beam (typically argon, which can be cluster or monatomic as appropriate) is used to first clean the foil sputtering target. This or another ion gun is then used to focus monatomic argon ions on the target foil surface and sputter atoms from the foil onto the sample. Figure 23 schematically illustrates this sputter deposition step (cross section), where particles that continue to form EPMP are sputtered from a target 2310 (typically a Ti metal foil) onto an insulating sample 2320 being analyzed.

通常溅射沉积需要1到2分钟的离子枪操作时间。Ti 2p3/2峰应至少为光谱中其他最强峰的5%。如果没有达到这个水平(如在样本的宽扫描光谱中所测量的),那么当然可以返回来从靶2310溅射更多,直到达到为止。Typically sputter deposition requires 1 to 2 minutes of ion gun operation time. The Ti 2p 3/2 peak should be at least 5% of the other strongest peaks in the spectrum. If this level is not reached (as measured in a wide scan spectrum of the sample), then of course you can go back and sputter more from target 2310 until it is reached.

图35示出了本发明的一个实施例,其中样品被分成多个子样品s1至s9。这在样品材料特别均匀的情况下可能是有用的,例如半导体材料的晶片。每个子样品的氧化态变化量不同。虽然可以单独分析每个样品,但如图35所示,可以同时分析多个子样品。FIG. 35 shows an embodiment of the invention in which a sample is divided into a plurality of sub-samples S1 to S9 . This may be useful in cases where the sample material is particularly uniform, such as a wafer of semiconductor material. Each sub-sample has a different amount of change in oxidation state. Although each sample may be analyzed individually, as shown in FIG. 35, multiple sub-samples may be analyzed simultaneously.

引文列表Citation List

1Fred A Stevie and Carrie L Donley,Introduction to x-rayphotoelectron spectroscopy,J.Va.Sci.Technol.A38,063204(2020)doi:10.1116/6.0000412 1 Fred A Stevie and Carrie L Donley, Introduction to x-ray photoelectron spectroscopy, J.Va. Sci. Technol. A38, 063204 (2020) doi: 10.1116/6.0000412

2D R Baer et al,Practical guides for x-ray photoelectronspectroscopy:First steps in planning,conducting and reporting XPSmeasurements,,J.Va.Sci.Technol.A37(3),May/Jun 2019,031401-1 2 DR Baer et al, Practical guides for x-ray photoelectron spectroscopy: First steps in planning, conducting and reporting XPS measurements,, J.Va.Sci.Technol.A37(3), May/Jun 2019, 031401-1

3G H Major et al,Assessment of the frequency and nature of erroneousx-ray photoelectron spectroscopy analyses in the scientific literature,J.Va.Sci.Technol.A38,061204(2020)doi:10.1116/6.0000685 3 GH Major et al, Assessment of the frequency and nature of erroneous x-ray photoelectron spectroscopy analyses in the scientific literature, J.Va.Sci.Technol.A38,061204(2020)doi:10.1116/6.0000685

4G H Major et al,Practical Guide for curve fitting in x-rayphotoelectron spectroscopy,J.Vac.Sci.Technol.A38,061203(2020);doi:10.1116/6.0000377. 4 GH Major et al, Practical Guide for curve fitting in x-ray photoelectron spectroscopy, J. Vac. Sci. Technol. A38, 061203 (2020); doi: 10.1116/6.0000377.

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6F A Stevie et al,J.Vac.Sci.Technol.A38,063202(2020);doi:10.1116/6.0000421 6 FA Stevie et al, J. Vac. Sci. Technol. A 38, 063202 (2020); doi: 10.1116/6.0000421

7Kevin M McEvoy,Michel J.Genet and Christine Dupont,PrincipalComponent Analysis:A Versatile Method for Processing and Investigation of XPSSpectra,September 2008,Analytical Chemistry 80(19):7226-38 7 Kevin M McEvoy, Michel J. Genet and Christine Dupont, Principal Component Analysis: A Versatile Method for Processing and Investigation of XPS Spectra, September 2008, Analytical Chemistry 80(19): 7226-38

8https://en.wikipedia.org/wiki/Singular_value_decomposition 8 https://en.wikipedia.org/wiki/Singular_value_decomposition

9T.H.Fleisch,G.J.Mains,Reduction of copper oxides by UV radiation andatomic hydrogen studied by XPS,Applications of Surface Science,Volume 10,Issue 1,1982,Pages 51-62,ISSN 0378-5963,https://doi.org/10.1016/0378-5963(82)90134-9. 9 TH Fleisch, G J Mains, Reduction of copper oxides by UV radiation and atomic hydrogen studied by XPS, Applications of Surface Science, Volume 10, Issue 1, 1982, Pages 51-62, ISSN 0378-5963, https://doi.org/10.1016/0378-5963(82)90134-9.

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13 Waymouth,John(1971).Electric Discharge Lamps.Cambridge,MA:TheM.I.T.Press.ISBN 978-0-262-23048-3. 13 Waymouth, John (1971). Electric Discharge Lamps. Cambridge, MA: The M. ITPress. ISBN 978-0-262-23048-3.

14 H Amandusson,L.-G Ekedahl,H Dannetun,Hydrogen permeation throughsurface modified Pd and PdAg membranes,Journal of Membrane Science,Volume193,Issue 1,2001,Pages 35-47,ISSN 0376-7388,https://doi.org/10.1016/S0376-7388(01)00414-8. 14 H Amandusson, L.-G Ekedahl, H Dannetun, Hydrogen permeation through surface modified Pd and PdAg membranes, Journal of Membrane Science, Volume 193, Issue 1, 2001, Pages 35-47, ISSN 0376-7388, https://doi.org/10.1016/S0376-7388(01)00414-8.

15 A.G.Knapton,Palladium Alloys for Hydrogen Diffusion Membranes,Platinum Metals Rev.,1977,21,(2)p44-50 15 AG Knapton, Palladium Alloys for Hydrogen Diffusion Membranes, Platinum Metals Rev., 1977, 21, (2) p44-50

16 Xueni Sun et al,Persistent adsorptive desulfurization enhancementof TiO2 after one-time ex-situ UV-treatment,Fuel 193(2017)pp95-100 16 Xueni Sun et al, Persistent adsorptive desulfurization enhancement of TiO2 after one-time ex-situ UV-treatment, Fuel 193(2017)pp95-100

17 John R.Vig,"UV/ozone cleaning of surfaces",Journal of VacuumScience&Technology A 3,1027-1034(1985)https://doi.org/10.1116/1.573115 17 John R. Vig,"UV/ozone cleaning of surfaces",Journal of Vacuum Science & Technology A 3,1027-1034(1985)https://doi.org/10.1116/1.573115

18 The photodissociation of ozone in the Hartley band:A theoreticalanalysis,J.Chem.Phys.123,074305(2005);https://doi.org/10.1063/1.2001650,Z.-W.Qu,H.Zhu,S.Yu.Grebenshchikov,and R.Schinke 18 The photodissociation of ozone in the Hartley band:A theoretical analysis, J. Chem. Phys. 123, 074305(2005); https://doi.org/10.1063/1.2001650, Z.-W. Qu, H. Zhu, S. Yu. Grebenshchikov, and R. Schinke

19 Shangwei Huang et al 2020 J.Electrochem.Soc.167 090538 19 Shangwei Huang et al 2020 J.Electrochem.Soc.167 090538

20 Jeong,B.J.;Jo,Y.N.A Study on the Self-Discharge Behavior of Zinc-Air Batteries with CuO Additives.Appl.Sci.2021,11,11675.https://doi.org/10.3390/app112411675 20 Jeong, BJ; Jo, YNA Study on the Self-Discharge Behavior of Zinc-Air Batteries with CuO Additives. Appl. Sci. 2021, 11, 11675. https://doi.org/10.3390/app112411675

21 For example,Varta type V 150 H2 MF,see 21 For example, Varta type V 150 H2 MF, see

https://www.varta-ag.com/en/industry/product-solutions/hydrogenhttps://www.varta-ag.com/en/industry/product-solutions/hydrogen

22 Peter J.Cumpson,M.P.Seah and S.J.Spencer,Simple Procedure forPrecise Peak Maximum Estimation for Energy Calibration in AES and XPS,September 1996,Surface and Interface Analysis 24(10):687-694 DOI:10.1002/(SICI)1096-9918(19960930)24:103.0.CO;2-Q 22 Peter J. Cumpson, MP Seah and SJ Spencer, Simple Procedure for Precise Peak Maximum Estimation for Energy Calibration in AES and XPS, September 1996, Surface and Interface Analysis 24(10): 687-694 DOI: 10.1002/(SICI)1096-9918(19960930)24: 103.0.CO;2-Q

Claims (25)

1.一种用于产生样品的x射线光电子光谱的方法,包括以下步骤:1. A method for producing an x-ray photoelectron spectrum of a sample, comprising the steps of: 通过将样品表面暴露于配置为改变所述样品表面的氧化态的试剂,在其表面产生样品的多种不同氧化态;generating a plurality of different oxidation states of the sample at its surface by exposing the sample surface to a reagent configured to change the oxidation state of the sample surface; 将样品置于x射线光电子光谱仪中;placing the sample in an x-ray photoelectron spectrometer; 获得所述样品表面的多种氧化态中每一个的x射线光电子光谱;obtaining an x-ray photoelectron spectrum of each of a plurality of oxidation states of the sample surface; 通过分析多个光谱来识别样品中的材料。Identify materials in a sample by analyzing multiple spectra. 2.根据权利要求1所述的方法,其中所述样品连续多次暴露于配置为改变所述样品表面的氧化态的试剂,其中在样品随后每次暴露于所述试剂中时,样品表面的氧化态相对于由之前暴露于配置为改变所述样品表面的氧化态的试剂所导致的样品表面的氧化态而改变。2. A method according to claim 1, wherein the sample is exposed to a reagent configured to change the oxidation state of the sample surface multiple times in succession, wherein at each subsequent exposure of the sample to the reagent, the oxidation state of the sample surface changes relative to the oxidation state of the sample surface caused by the previous exposure to the reagent configured to change the oxidation state of the sample surface. 3.根据权利要求1的方法,其中样品分成多个子样品,每个子样品具有子样品表面,并且其中对于每个子样品产生子样品表面的不同氧化态。3. The method according to claim 1, wherein the sample is divided into a plurality of subsamples, each subsample having a subsample surface, and wherein a different oxidation state of the subsample surface is generated for each subsample. 4.根据前述权利要求中任一项所述的方法,其中配置为改变样品表面的氧化态的试剂是气态试剂。4. A method according to any one of the preceding claims, wherein the reagent configured to change the oxidation state of the sample surface is a gaseous reagent. 5.根据前述权利要求中任一项所述的方法,其中,配置为改变样品表面氧化态的试剂包括以下一种或多种:紫外光、臭氧和氢气。5. The method of any one of the preceding claims, wherein the reagent configured to change the oxidation state of the sample surface comprises one or more of: ultraviolet light, ozone and hydrogen. 6.根据权利要求5所述的方法,其中紫外光由至少一个紫外(UV)灯提供,其中至少一个UV灯发射的UV光被引导至所述样品表面。6. The method of claim 5, wherein the ultraviolet light is provided by at least one ultraviolet (UV) lamp, wherein UV light emitted by the at least one UV lamp is directed to the sample surface. 7.根据权利要求6所述的方法,其中至少一个UV灯发射的UV光的波长范围为200nm至300nm。7. The method of claim 6, wherein the at least one UV lamp emits UV light having a wavelength in the range of 200 nm to 300 nm. 8.根据权利要求6或7所述的方法,其中所述UV灯是汞蒸汽灯。8. The method of claim 6 or 7, wherein the UV lamp is a mercury vapor lamp. 9.根据权利要求5所述的方法,其中臭氧由臭氧产生装置提供,所述臭氧产生装置在所述样本周围的气体中产生的臭氧气体浓度范围为百万分之0.01至百万分之20。9. The method of claim 5, wherein ozone is provided by an ozone generating device, the ozone generating device generating ozone gas in a concentration range of 0.01 ppm to 20 ppm in the gas surrounding the sample. 10.根据前述权利要求中任一项所述的方法,包括通过控制以下一项或多项来控制所述样品表面的氧化态变化程度的步骤:所述样品表面暴露于试剂的时间;试剂的浓度;以及试剂的波长和/或频率。10. A method according to any preceding claim, comprising the step of controlling the extent of the change in oxidation state of the sample surface by controlling one or more of: the time the sample surface is exposed to a reagent; the concentration of the reagent; and the wavelength and/or frequency of the reagent. 11.根据前述权利要求中任一项所述的方法,其中通过分析多个光谱来识别样品中的物质的步骤包括执行多变量分析,例如主成分分析或非负矩阵分解。11. A method according to any one of the preceding claims, wherein the step of identifying substances in the sample by analysing a plurality of spectra comprises performing a multivariate analysis, such as principal component analysis or non-negative matrix factorisation. 12.一种用于捕获x射线光电子光谱(XPS)的装置,其配置为执行权利要求1至11中任一项的方法,包括:12. An apparatus for capturing x-ray photoelectron spectroscopy (XPS) configured to perform the method of any one of claims 1 to 11, comprising: 样品架;Sample rack; 试剂源,其配置为改变保持在样品架中的样品表面的氧化态;a reagent source configured to change the oxidation state of a surface of a sample held in a sample holder; 控制样品表面暴露于配置为改变所述表面的氧化态的试剂的装置;和means for controlling exposure of a sample surface to a reagent configured to change the oxidation state of said surface; and 能够记录多个XPS光谱的x射线光电子光谱仪,每个XPS光谱对应样品表面的一种氧化态。An x-ray photoelectron spectrometer capable of recording multiple XPS spectra, one for each oxidation state of the sample surface. 13.根据权利要求12所述的装置,还包括数据处理器,其配置为执行主成分分析或非负矩阵分解。13. The apparatus of claim 12, further comprising a data processor configured to perform principal component analysis or non-negative matrix factorization. 14.根据权利要求12或13所述的装置,其中,所述样品架包含在外壳中。14. The device of claim 12 or 13, wherein the sample holder is contained in a housing. 15.根据权利要求12至14中任一项所述的装置,其中,配置为改变样品表面的氧化态的试剂是气态试剂。15. The apparatus of any one of claims 12 to 14, wherein the reagent configured to change the oxidation state of the sample surface is a gaseous reagent. 16.根据权利要求12至15中任一项所述的装置,其中,配置为改变样品表面的氧化态的试剂的来源是以下的一种或多种:紫外光、臭氧和氢气。16. The apparatus of any one of claims 12 to 15, wherein the source of the reagent configured to change the oxidation state of the sample surface is one or more of: ultraviolet light, ozone, and hydrogen. 17.根据权利要求16所述的装置,其中所述紫外光由至少一个紫外(UV)灯提供,其中至少一个UV灯发射的UV光被引导至所述样品表面。17. The apparatus of claim 16, wherein the ultraviolet light is provided by at least one ultraviolet (UV) lamp, wherein UV light emitted by at least one UV lamp is directed toward the sample surface. 18.根据权利要求17所述的装置,其中,至少一个UV灯发出的UV光的波长范围为200nm至300nm。18. The apparatus of claim 17, wherein the at least one UV lamp emits UV light having a wavelength in the range of 200 nm to 300 nm. 19.根据权利要求17或18所述的装置,其中所述至少一个UV灯是汞蒸汽灯。19. The apparatus of claim 17 or 18, wherein the at least one UV lamp is a mercury vapor lamp. 20.根据权利要求16至19中任一项所述的装置,进一步包括臭氧发生器,所述臭氧发生器配置为在位于所述样品架中的样品周围释放臭氧。20. The apparatus of any one of claims 16 to 19, further comprising an ozone generator configured to release ozone around a sample located in the sample holder. 21.根据权利要求20所述的装置,其中所述臭氧发生器是在样品周围的空气中以100nm-300nm区域发射的至少一个UV灯。21. The apparatus of claim 20, wherein the ozone generator is at least one UV lamp emitting in the 100 nm - 300 nm region in the air surrounding the sample. 22.根据权利要求21所述的装置,其中所述至少一个UV灯发射185nm和/或254nm的紫外光。22. The device of claim 21, wherein the at least one UV lamp emits ultraviolet light at 185 nm and/or 254 nm. 23.根据权利要求16至19所述的装置,还包括氢源,所述氢源配置为在样品架中的样品周围释放氢。23. The apparatus of claims 16 to 19, further comprising a hydrogen source configured to release hydrogen around a sample in the sample holder. 24.根据权利要求23所述的装置,其中所述氢源是至少一个锌空气电池。24. The apparatus of claim 23, wherein the hydrogen source is at least one zinc air battery. 25.根据权利要求12至24中任一项所述的装置,其中所述样品架适于保持多个子样品,每个子样品具有不同氧化态的表面,并且其中所述x射线光电子光谱仪配置为记录每个子样品的XPS光谱。25. Apparatus according to any one of claims 12 to 24, wherein the sample holder is adapted to hold a plurality of sub-samples, each sub-sample having a surface in a different oxidation state, and wherein the x-ray photoelectron spectrometer is configured to record an XPS spectrum of each sub-sample.
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