TWI794252B - Spatially resolved optical emission spectroscopy (oes) in plasma processing - Google Patents
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Abstract
Description
本發明係關於使用電漿光放射光譜術(OES)在半導體電漿處理中量測化學物種濃度的方法、電腦方法、系統及設備。具體而言,本發明係關於判定電漿光放射的二維分布,由其得以判定化學物種濃度之二維分布。 The present invention relates to a method, computer method, system and apparatus for measuring the concentration of chemical species in semiconductor plasma processing using plasma optical emission spectroscopy (OES). More specifically, the present invention relates to determining the two-dimensional distribution of plasma light emission, from which the two-dimensional distribution of chemical species concentration can be determined.
本申請案為2014年10月31日提交的案名為「SPATIALLY RESOLVED OPTICAL EMISSION SPECTROSCOPY(OES)IN PLASMA PROCESSING」(參考編號TTI-242)之美國專利申請案第14/530,164號的部分延續案,在此藉由參照該案之全部內容而引入,該案係根據2013年11月1日提交的案名為「SPATIALLY RESOLVED OPTICAL EMISSION SPECTROSCOPY(OES)IN PLASMA ETCHING」(參考編號TTI-242PROV)之美國臨時專利申請案第61/898,975號,並主張其權利和優先權。 This application is a continuation-in-part of U.S. Patent Application Serial No. 14/530,164, filed October 31, 2014, entitled "SPATIALLY RESOLVED OPTICAL EMISSION SPECTROSCOPY (OES) IN PLASMA PROCESSING" (Reference No. TTI-242), INCORPORED HEREBY BY REFERENCE, IN ENTIRE TIGHT, OF THE UNITED STATES OF SPATIALLY RESOLVED OPTICAL EMISSION SPECTROSCOPY (OES) IN PLASMA ETCHING, filed November 1, 2013 (Reference No. TTI-242PROV) Provisional Patent Application No. 61/898,975, and claim and priority thereto.
半導體元件、顯示器、太陽能電池等之生產係以一連串的步驟進行,而各步驟具有為了最大元件良率而最佳化的參數。電漿處理中,電漿的化學性質為受控之參數中強烈影響良率者,特別係在電漿環境內、鄰近受處理之基板的局部電漿化學性質,亦即各種化學物種的局部濃度。某些物種(特別係 諸如自由基之暫態化學物種)對電漿的處理結果有著重大的影響,並且已知該等物種的偏高局部濃度可能產生較快處理的區域,其可能在處理步驟中且最終在產出的元件上導致不均勻性。 The production of semiconductor devices, displays, solar cells, etc. is carried out in a series of steps, each step having parameters optimized for maximum device yield. In plasma processing, the chemical properties of the plasma are the ones that strongly affect the yield among the controlled parameters, especially the local plasma chemical properties in the plasma environment, adjacent to the substrate being processed, that is, the local concentration of various chemical species . certain species (especially Transient chemical species such as free radicals) have a significant impact on plasma processing results, and it is known that high local concentrations of these species may create regions of faster processing, which may be in the processing steps and ultimately in the output causes non-uniformity on the components.
電漿製程的化學性質係憑藉對諸多製程變因的控制、以直接或間接的方式所控制,該等製程變因例如用以激發電漿而供應的一或更多射頻(RF)或微波電力、供應至電漿處理腔室的氣體流及氣體種類、電漿處理腔室內的壓力、受處理之基板的種類、輸送至電漿處理腔室的泵送速率、及其他更多變因。光放射光譜術(OES)已證明其在製程開發及電漿處理之監測為一有用的工具。在光放射光譜術中,特別受關注的某些化學物種(如自由基)之存在及濃度可由取得的電漿之光學(亦即光線)放射頻譜推論而得,其中某些光譜線的強度及其比例係與化學物種的濃度相關。此技術的詳細說明可於如G.Selwyn的「Optical Diagnostic Techniques for Plasma Processing,AVS Press,1993」中得到,在此為簡潔之目的不予重述。 The chemistry of the plasma process is controlled, either directly or indirectly, by virtue of the control of process variables such as one or more radio frequency (RF) or microwave power supplied to excite the plasma , the gas flow and type of gas supplied to the plasma processing chamber, the pressure in the plasma processing chamber, the type of substrate being processed, the pumping rate delivered to the plasma processing chamber, and many more variables. Optical emission spectroscopy (OES) has proven to be a useful tool in process development and monitoring of plasma processing. In photoemission spectroscopy, the presence and concentration of certain chemical species of particular interest (such as free radicals) can be inferred from the optical (that is, light) emission spectrum of the plasma obtained, in which the intensity of certain spectral lines and their The proportionality system is related to the concentration of the chemical species. A detailed description of this technique can be found, for example, in "Optical Diagnostic Techniques for Plasma Processing, AVS Press, 1993" by G. Selwyn and will not be repeated here for the sake of brevity.
儘管光放射光譜術的使用已變得相對普遍,特別係在電漿處理腔室內部的電漿製程開發,但光放射光譜術通常藉由自電漿內部的單一狹長體積取得光放射光譜所完成。此體積的精確形狀及尺寸由用於自電漿收集光放射的光學系統所決定。此光放射信號的收集本質上導致電漿光放射光譜沿著此狹長體積之長度(亦稱之為射線)的均分,因此關於電漿光放射光譜之局部變異及化學物種濃度之局部變異的所有資訊大體都遺失了。 Although the use of photoemission spectroscopy has become relatively common, especially with the development of plasma processes inside plasma processing chambers, photoemission spectroscopy is usually performed by taking photoemission spectra from a single elongated volume inside the plasma . The precise shape and dimensions of this volume are determined by the optics used to collect light emissions from the plasma. The collection of this photoemission signal essentially results in an equal division of the plasmon photoemission spectrum along the length of this elongated volume (also referred to as a ray), so the local variation in the plasma photoemission spectrum and the local variation in the concentration of chemical species All information is largely lost.
在電漿製程開發中,且事實上甚至在新式及改良式的電漿處理系統開發中,獲知受處理之基板上方受關注的化學物種二維分布甚為有用,例如因此而得以做出系統設計及/或製程參數的改變,以最小化基板各處之處理結 果的變異。電漿光放射光譜技術的進一步應用在於藉由監測存在電漿中之化學物種的演變及不連續變化來決定電漿處理步驟的終止點,該演變及不連續變化係與例如到達一基板層的一蝕刻步驟有關,該基板層的化學成分不同於蝕刻製程期間受蝕刻之化學成分。可決定整個基板表面的電漿處理步驟之終止點的能力對提高的元件良率有所貢獻,因為電漿處理步驟不會過早終止。 In plasma process development, and indeed even in the development of new and improved plasma processing systems, it is useful to know the two-dimensional distribution of chemical species of interest above the substrate being processed, e.g. to enable system design and/or changes in process parameters to minimize process junctions across the substrate fruit variation. A further application of plasma photoemission spectroscopy is to determine the termination point of a plasma treatment step by monitoring the evolution and discontinuity of chemical species present in the plasma, which is related, for example, to the arrival of a substrate layer. In connection with an etching step, the chemical composition of the substrate layer is different from that etched during the etching process. The ability to determine the termination point of the plasma treatment step over the entire substrate surface contributes to improved device yield because the plasma treatment step is not terminated prematurely.
一種由已知的積分測量法沿著橫貫關注區域的複數射線以判定一變數之空間分布而廣泛用於其他科技領域(例如X射線層析成像)的技術,乃係使用Abel轉換或Radon轉換的層析成像反運算。然而,為獲得有效結果,此技術要求極大的資料獲取量,亦即大量的射線,其在具受限電漿光通道的半導體處理設備中是不切實際的,其中該電漿光通道係通過嵌裝於電漿處理腔室壁之一或少數光窗或光埠。層析成像通常亦為計算非常密集的技術。吾人亦已發現化學物種濃度的局部差異具有大體平滑變化的本質,而在徑向或甚至在圓周方向(即方位角方向)兩者並無任何不連續的梯度。因此,具有能在沒有OES量測法之層析成像方法中涉及的操作負擔之情況下獲得電漿光放射光譜二維分布之簡單、快速、相對低成本的電漿光放射光譜術之技術及系統將甚有優勢。 A technique widely used in other scientific fields (such as X-ray tomography) to determine the spatial distribution of a variable along complex rays traversing a region of interest by the known method of integral measurement, using the Abel or Radon transform Tomography inverse operation. However, to obtain effective results, this technique requires an extremely high data acquisition volume, i.e., a large number of rays, which is impractical in semiconductor processing equipment with confined plasmonic channels through Embedded in one of the walls of the plasma processing chamber or a few light windows or light ports. Tomography is also generally a very computationally intensive technique. We have also found that the local differences in the concentrations of chemical species are of a generally smoothly varying nature without any discontinuous gradients either in the radial or even in the circumferential direction (ie, the azimuthal direction). Therefore, there is a technique of simple, fast, relatively low-cost plasma photoemission spectroscopy capable of obtaining a two-dimensional distribution of the plasma photoemission spectrum without the operational burden involved in the tomography method of OES measurements and The system will be very advantageous.
最為明顯的是,如同一些先前技術所認為的,雖然圓周方向上的變異可能微小,但其並非不存在,而理想的技術及系統將仍須可確實獲得此等變異。 Most obviously, while variations in the circumferential direction may be small, as some prior art has suggested, they are not non-existent, and ideal techniques and systems would still have to be able to reliably achieve such variations.
本發明的一態樣包含用於光放射量測之設備,該設備包含一收集系統,用於透過設置在電漿處理腔室之壁部的一光窗收集電漿光放射光譜。 該收集系統包含一鏡件,其係配置以掃描橫越該電漿處理腔室之複數非重合射線;以及一遠心耦合器,用於自電漿收集一光信號,並將該光信號導引至一光譜儀以量測該電漿光放射光譜。 An aspect of the present invention includes an apparatus for light emission measurements that includes a collection system for collecting a plasma light emission spectrum through a light window disposed in a wall of a plasma processing chamber. The collection system includes a mirror configured to scan a plurality of non-coincident rays across the plasma processing chamber; and a telecentric coupler for collecting an optical signal from the plasma and directing the optical signal to a spectrometer to measure the plasmonic emission spectrum.
另一實施例包含一種電漿光放射量測系統,其包含一電漿處理腔室;一光窗,其係設置在該電漿處理腔室之壁部上;一收集系統,用於透過該光窗收集電漿光放射光譜;耦接於該收集系統的一光譜儀,用於量測該電漿光放射光譜。該收集系統包含一鏡件,其係配置以掃描橫越該電漿處理腔室之複數非重合射線,以及一遠心耦合器,用於自電漿收集一光信號,並將該光信號導引至該光譜儀。 Another embodiment includes a plasma optical emission measurement system comprising a plasma processing chamber; a light window disposed on a wall of the plasma processing chamber; a collection system for transmitting light through the plasma processing chamber. The light window collects the plasma light emission spectrum; a spectrometer coupled to the collection system is used to measure the plasma light emission spectrum. The collection system includes a mirror configured to scan a plurality of non-coincident rays across the plasma processing chamber, and a telecentric coupler for collecting an optical signal from the plasma and directing the optical signal to the spectrometer.
本發明的又另一實施例包含一種用於光放射量測之方法,其包含將一光窗設置在一電漿處理腔室之壁部;設置一收集系統,以透過該光窗收集電漿光放射光譜,該收集系統包含一鏡件及一遠心耦合器;使用該鏡件掃描橫越該電漿處理腔室的複數非重合射線;透過該遠心耦合器自電漿收集一光信號;以及將該光信號導引至一光譜儀,以量測該電漿光放射光譜。 Yet another embodiment of the present invention includes a method for light emission measurement comprising disposing a light window in a wall of a plasma processing chamber; and disposing a collection system to collect plasma through the light window optical emission spectroscopy, the collection system comprising a mirror and a telecentric coupler; scanning a plurality of non-coincident rays across the plasma processing chamber using the mirror; collecting an optical signal from the plasma through the telecentric coupler; and The optical signal is guided to a spectrometer to measure the plasmonic emission spectrum.
10:電漿處理系統 10: Plasma treatment system
15:電漿光放射光譜(OES)系統 15: Plasma Optical Emission Spectroscopy (OES) System
20:電漿處理腔室 20: Plasma treatment chamber
30:基板支架 30: Substrate support
40:基板 40: Substrate
50:電漿 50: Plasma
60:光偵測器 60: Light detector
65:空間 65: space
70:光窗 70: light window
80:控制器 80: Controller
100:射線 100: ray
300:光學系統 300: optical system
300A-E:光學系統 300A-E: Optical system
305:射線 305: ray
305A-E:射線 305A-E: rays
310:光譜儀 310: spectrometer
320:光纖 320: optical fiber
320A-E:光纖 320A-E: Optical fiber
350:自選孔洞 350: optional holes
360A:收光透鏡 360A: Light collecting lens
360B:收光透鏡 360B: Light collecting lens
370A:耦合透鏡 370A:Coupling lens
370B:耦合透鏡 370B:Coupling lens
390:端口 390: port
400:掃描鏡 400: scanning mirror
410:檢流計台/步進馬達 410: Galvanometer table/stepper motor
800:鏡系統 800: mirror system
802:傳送鏡 802: teleportation mirror
804:折鏡 804:folding mirror
902:第一收光透鏡 902: The first receiving lens
904:耦合透鏡 904:Coupling lens
906:耦合透鏡 906:Coupling lens
908:遠心孔 908: Telecentric hole
1102:三合透鏡 1102: triplet lens
1104:耦合三合透鏡 1104:Coupling triplet lens
1106:耦合三合透鏡 1106:Coupling triplet lens
1108:罩孔 1108: cover hole
1110:遠心孔 1110: Telecentric hole
1202:折鏡 1202: folding mirror
1204:線弧台 1204: arc table
1302:繪圖 1302: Drawing
1304:繪圖 1304: Drawing
1306:繪圖 1306: Drawing
1308:繪圖 1308: Drawing
1310:繪圖 1310: Drawing
1312:繪圖 1312: Drawing
1400:方法 1400: method
1402:操作 1402: Operation
1404:操作 1404: Operation
1406:操作 1406: Operation
1408:操作 1408: Operation
1410:操作 1410: Operation
參照其後的詳細說明,特別係隨同所附圖式加以考慮時,本發明之更完整察知及其諸多伴隨的優點即變得顯而易知,在圖式中: A fuller appreciation of the invention and its many attendant advantages will become apparent with reference to the detailed description which follows, particularly when considered in conjunction with the accompanying drawings in which:
根據一實施例,圖1為裝配有光放射光譜術(OES)量測系統的電漿處理系統概要側視圖。 1 is a schematic side view of a plasma processing system equipped with an optical emission spectroscopy (OES) measurement system, according to one embodiment.
根據一實施例,圖2為裝配有OES量測系統的電漿處理系統概要俯視圖。 According to one embodiment, FIG. 2 is a schematic top view of a plasma processing system equipped with an OES measurement system.
根據一實施例,圖3為使用OES量測系統所獲得的範例電漿光放射光譜。 According to an embodiment, FIG. 3 is an exemplary plasmonic emission spectrum obtained using an OES measurement system.
根據一實施例,圖4為用於OES量測系統的光學系統概要圖。 According to an embodiment, FIG. 4 is a schematic diagram of an optical system for an OES measurement system.
根據另一實施例,圖5為用於OES量測系統的光學系統概要圖。 According to another embodiment, FIG. 5 is a schematic diagram of an optical system for an OES measurement system.
根據一實施例,圖6為光學系統之一實施例的概要展開圖。 According to an embodiment, FIG. 6 is a schematic expanded view of an embodiment of an optical system.
根據一實施例,圖7為使用OES量測系統及其相關方法所測得的範例電漿光放射二維分布。 According to an embodiment, FIG. 7 is an exemplary two-dimensional distribution of plasma light emission measured using an OES measurement system and related methods.
根據另一實施例,圖8為用於OES量測系統的光學系統概要圖。 According to another embodiment, FIG. 8 is a schematic diagram of an optical system for an OES measurement system.
根據另一實施例,圖9為光學系統之一實施例的概要展開圖。 According to another embodiment, FIG. 9 is a schematic expanded view of an embodiment of an optical system.
圖10為裝配有圖8之光學系統的電漿處理系統概要俯視圖。 FIG. 10 is a schematic top view of a plasma processing system equipped with the optical system of FIG. 8 .
根據另一實施例,圖11為光學系統之一實施例的概要展開圖。 According to another embodiment, FIG. 11 is a schematic expanded view of an embodiment of an optical system.
根據另一實施例,圖12為用於OES量測系統的光學系統概要圖。 According to another embodiment, FIG. 12 is a schematic diagram of an optical system for an OES measurement system.
圖13為顯示光放射強度之重建圖案之範例結果的概要圖。 FIG. 13 is a schematic diagram showing exemplary results of reconstructed patterns of light emission intensity.
根據一範例,圖14為顯示光放射量測之方法的流程圖。 According to an example, FIG. 14 is a flowchart showing a method of light emission measurement.
在以下的說明中,為促進本發明的透徹理解及為達解釋而非限制的目的而列舉出特定細節-例如電漿光放射光譜(OES)系統之特定幾何外觀及各種零部件與程序之說明。然應當理解,本發明仍可實施於偏離該等特定細節的其他實施例中。 In the following description, specific details are set forth to facilitate a thorough understanding of the invention and for purposes of explanation and not limitation - such as specific geometrical aspects of a plasmonic optical emission spectroscopy (OES) system and descriptions of various components and procedures . It should be understood, however, that the invention may be practiced in other embodiments that depart from these specific details.
在以下的說明中,代表受處理之工件的詞語「基板」與如半導體晶圓、液晶顯示器(LCD)面板、發光二極體(LED)、太陽能(PV)元件控制板等的詞語可相互交替使用,所有此等項目的處理均落於所請發明的範疇。 In the following descriptions, the term "substrate" representing the workpiece being processed is used interchangeably with terms such as semiconductor wafers, liquid crystal display (LCD) panels, light emitting diodes (LEDs), solar (PV) element control panels, etc. use, the processing of all such items falls within the scope of the claimed invention.
遍及本說明書中參照「某一實施例」或「一實施例」意指與該實施例相關而說明的特定特性、結構、材料或特徵係包含於本發明的至少一實施例中,但並不代表其存在於每一實施例中。因此,遍及本說明書各處「某一實施例中」或「一實施例中」的詞語之出現未必意指本發明的相同實施例。此外,特定的特性、結構、材料或特徵可在一或更多實施例中以任何適當的方式結合。 Reference throughout this specification to "an embodiment" or "an embodiment" means that a particular feature, structure, material, or characteristic described in connection with that embodiment is included in at least one embodiment of the invention, but is not intended to represents its presence in each example. Thus, appearances of the phrase "in an embodiment" or "in an embodiment" throughout this specification do not necessarily mean the same embodiment of the invention. Furthermore, the particular properties, structures, materials or characteristics may be combined in any suitable manner in one or more embodiments.
各種操作以最有助於了解本發明的方式而將其描述為多個不連續的依序操作。然描述的次序不應理解為隱喻該等操作必須依賴此次序。特別係,此等操作毋需以其呈現的次序運行。所說明的操作可依照有別於所述實施例的次序而運行。各種額外的操作可予以運行,且/或所說明的操作可在額外的實施例中予以省略。 Various operations are described as multiple discrete, sequential operations in a manner that is most helpful in understanding the invention. However, the order of description should not be understood as implying that such operations are necessarily dependent on this order. In particular, these operations need not be run in the order in which they are presented. The illustrated operations may be performed in an order different from that of the described embodiment. Various additional operations may be performed, and/or illustrated operations may be omitted in additional embodiments.
圖1顯示裝配有電漿光放射光譜(OES)系統15之電漿處理系統10的實施例。電漿處理系統10包含電漿處理腔室20,其內部設置有用於接收待處理之基板40的基板支架30(例如靜電夾具)。射頻(RF)及/或微波電力(圖未示)供應至電漿處理腔室20以在基板40的附近激發電漿50並維持之,其中來自電漿50的高能化學物種係用於在基板40上進行電漿處理步驟。處理氣體(圖未示)流入電漿處理腔室20,並設置一泵浦系統(圖未示)以將電漿處理腔室20內的真空狀態保持在需要的製程壓力。電漿處理步驟的範例包括電漿蝕刻、電漿輔助化學
氣相沉積(PECVD)、電漿輔助原子層沉積(PEALD)等等。於此所說明的系統及方法可適用於任何類型的電漿處理。
FIG. 1 shows an embodiment of a
電漿光放射光譜(OES)系統15係用以透過至少一光偵測器60獲得電漿光放射光譜,光偵測器60將獲得的電漿光放射光譜傳遞至控制器80並由其控制。控制器80可為通用用途的電腦,且可位於電漿處理系統10的鄰近處或位於遠端,並經由內部網路或網際網路聯結而連接至光偵測器60。
The plasma optical emission spectroscopy (OES)
光偵測器60具有光學元件,此(等)光學元件以可使光偵測器60自電漿50內一狹長、大致為筆型體積的空間65收集電漿光發射的方式所設置。電漿處理腔室的光通道由光窗70所提供。取決於應用及電漿50之化學侵略性的程度多寡,光窗70可包含如玻璃、石英、熔融矽石或藍寶石的材料。之後稱為「射線」65的體積65定義出由其中收集電漿光放射光譜的一空間部分,而所收集的光譜代表對收集自位於沿著射線65並在射線65內部的所有空間點之電漿光放射光譜之貢獻部份的積分。應當注意,取決於光偵測器60的幾何形狀與結構,在射線65範圍內之每一空間點的貢獻部份將不會均等,而係由光效率(將於之後更詳細論述)所加權及影響。在一典型的結構中,射線65定位為實質上平行於基板40表面的方向,並與基板40的表面保持一微小距離以減少來自基板表面的光學干擾,然而仍需保持足夠靠近基板40以對鄰近於基板的電漿化學性質進行取樣。
如前所述,控制器80係用於控制電漿光放射光譜系統15,且亦用於:(1)計算作為空間位置及波長之函數的電漿光強度分布,以及用於(2)由所計算的電漿光強度分布計算受關注之化學物種的空間分布。此資訊可在之後用
於製程開發、電漿處理設備開發、電漿製程就地監控、電漿製程錯誤偵測、電漿製程終止點偵測等等。
As previously mentioned, the
圖1顯示橫越位於電漿處理腔室20內部之電漿50、鄰近受處理之基板40的一射線65。本發明的一實施例中,複數射線100可用於對電漿光放射光譜進行取樣,如顯示例如圖1之電漿處理系統10的概要俯視圖之圖2所示。在圖2的範例實施例中,兩個光偵測器60用以各由7條射線100收集電漿光放射光譜。射線100必須是非重合的,以利在基板40的上方自電漿50獲得最大量的空間資訊。每一光偵測器60之射線100的數目可自2變動至9、或更高。又,在其中電漿處理腔室20之光通道僅由單一光窗70所提供的另一實施例中,單一光偵測器60可伴隨與其相關的射線100之扇形使用。或者,可使用各具有與其相關之射線扇形的第三或更多光偵測器。各個射線100的角度係相對於其光偵測器60的中心線定義為θi。在電漿處理腔室內部的每一點可由其極座標(即(r,θ))所定義,如圖2所示。
FIG. 1 shows a
如同稍後將更為詳細說明的,取決於光偵測器60的配置,所有來自相關之射線100扇形的電漿光放射光譜可同時予以收集。此適用於具有複數個光學系統及通道、容許自所有射線100同步收光之光偵測器60的實施例。另種方式地,電漿光放射光譜可沿著與光偵測器60有關的射線100相繼地取得。後者的方法適用於掃描式的實施例,其中電漿光放射光譜隨著射線100由一角度θi掃描至另一角度而收集。可理解地,此掃描及取得必須發生得足夠快,而使得整體基板各處之電漿化學性質的急遽變化得以偵測。
As will be described in more detail later, depending on the configuration of the
圖3顯示使用光偵測器60在角度θi自一射線100所獲得的範例電漿光放射光譜。此光譜中,收集了M個波長的光強度,其波長範圍通常自約
200nm至約800nm。使用於光放射光譜術中之一般光譜儀的電荷耦合元件(CCD)具有在此波長範圍內的4096個畫素,但取決於應用和收集之光譜所需的解析度,畫素的數目可在低如256且高如65536的範圍內變動。
FIG. 3 shows an example plasmonic photoemission spectrum obtained from a
由光偵測器60自其相關的射線100扇形所收集的電漿光放射光譜傳遞至控制器80,此控制器80用於進一步處理所傳遞的數據以計算電漿光放射的空間分布,然後由此計算化學物種濃度的空間分布。本發明的一態樣係用於快速計算各波長之電漿光放射空間分布的演算法,此演算法可提供用於終止點偵測、錯誤偵測等等的電漿製程就地監測。
The plasmonic light emission spectrum collected by the
圖4顯示光偵測器60的一實施例,其中單一多頻道光譜儀310用於自射線305A-E同步收集電漿光放射光譜。為清楚的目的,呈現於此的本範例實施例具有5條射線305A-E,但其數目可自2變動至9,甚至高於9。光偵測器60包含供各射線305A-E所用的光學系統300A-E,並全數位於安裝在電漿處理腔室20壁上之光窗70的鄰近處。射線305A-E以放射狀方式排列,以便涵蓋基板40(圖未示)的有關部分。所收集的電漿光放射光譜自光學系統300A-E經由各自的光纖320A-E而進入多頻道光譜儀310。光學系統300A-E將於之後更詳細地描述。由於圖4實施例的「同步收集電漿光放射光譜」能力,故此實施例適用於快速判斷。
FIG. 4 shows an embodiment of
圖5顯示使用了一單頻道光譜儀310的另一可選實施例,且當電漿光放射光譜透過單一光學系統300由該光譜儀310獲得的時候,射線305A-E由受控制地掃掠射線305A-E的掃描鏡400所形成,此將在之後更詳細的說明。此實施例適用於電漿光放射光譜的依序收集,亦因此更適於較緩演變的電漿製程判斷。掃描鏡400可安裝於一檢流計台410上並由其致動。另一可選地,掃描鏡
400可安裝於步進馬達410上並藉其掃描。射線305A-E的數目於此顯示為5,但實際上此數目係由用於控制檢流計台或步進馬達410之控制器軟體的設定所決定。
FIG. 5 shows an alternative embodiment using a single-
為確保對一精準的空間體積進行抽樣檢測,圖4的光學系統300A-E及圖5的光學系統300需加以設置,使得射線305A-E為準直的,其具有對於光學系統的既定目標成本而言所能達成之盡可能微小的發散角。
To ensure sampling of an accurate volume of space, the
光學系統300A-E及300的範例實施例顯示於圖6。光學系統300A-E(又稱遠心耦合器)負有從電漿50之範圍內、由射線305A-E所界定的空間體積中收集電漿光放射光譜,並導引所收集的電漿光放射光譜至光纖320A-E或320之端口390的任務,因此所收集的電漿光放射光譜即可發送至圖4或圖5之實施例中的光譜儀310。射線305A-E的直徑由形成於板上的自選孔洞350所界定。在另一可選的實施例中,例如透鏡的其他光學元件可用於界定射線305A-E的直徑。一範例的射線直徑為4.5mm,但其取決於應用而可自約1mm變動至20mm。所收集的射線305A-E通過收光透鏡360A及360B的組合,該等透鏡與自選孔洞的組合界定出射線305A-E。用於射線305A-E之收光系統的數值孔徑通常很低,例如大約0.005,而作為最後結果的射線305A-E是具有最小發散角度的實質準直光。在光學系統300A-E或300的另一端係另一對透鏡,亦即耦合透鏡370A及370B,此等耦合透鏡370A及370B用於將所收集的光放射光譜聚焦至光纖320A-E或320的端口390上。用於本系統中的所有透鏡較佳為消色差的,或為了更嚴苛條件的應用甚至為複消色差的,其確保每一透鏡的焦距不隨波長變化,使得光學系統300A-E或300在一大範圍波長內(通常係自200nm至800nm,但在某些
情況下則可能低至150nm)可良好地運作。為了光譜的紫外光(UV)部分(亦即350nm以下)中的較佳運作,應針對所有光學元件使用UV等級的材料。
Example embodiments of
對於每一光學硬體配置而言,獲知適用於射線305A-E範圍內所有位置點之權重係數的光效率w至為重要,其中電漿光放射光譜由射線305A-E獲得。光效率w可使用光學設計軟體而由模擬決定,或可藉由實驗而決定,該實驗使用經校準光源並移動該等經校準光源穿越及沿著射線305A-E來決定自射線305A-E之內部一給定位置至光纖端口390的光耦合效率。光效率w將用於供判定電漿光放射之空間分布所用的演算法。
For each optical hardware configuration, it is important to know the optical efficiency w applicable to the weighting factors for all points within the range of
如前所述,電漿光放射(OES)系統15的任務係針對M個測得波長λ之每一者判定電漿光放射的二維強度分布。
As previously stated, the task of the plasmonic optical emission (OES)
對於圖2的每一射線100(由下標i數學性地標注的射線),所收集的光偵測器輸出D i 可界定為:
在具有N個光偵測器與射線、或具有射線100之N個掃描位置的電漿光放射光譜系統15中,對於M個測得波長λ之每一者有N個收集到的強度。因此,為重建在一波長λ下的電漿光放射之空間分布,需假設具有N個參數的函
數形式。在給定有限的參數數目N的條件下,需對用於電漿光放射分布的基底函數做出審慎的選擇。選定的基底函數須隨著徑向座標r及圓周座標θ兩者變化,使其得以良好地重現電漿放射在基板40各處的圓周方向變化。
In a plasmonic
特別適合於此任務的基底函數集合為Zernike多項式Z P (r,θ)。Zernike多項式由一項相依於徑座標r之一項及相依於圓周座標θ之一項的乘積所定義,亦即Z P (r,θ)=R(r)G(θ) A set of basis functions particularly suitable for this task is the Zernike polynomial Z P ( r, θ). Zernike polynomials are defined by the product of a term dependent on the radial coordinate r and a term dependent on the circumferential coordinate θ , that is, Z P ( r, θ)=R( r ) G ( θ )
表格1羅列了前18階的Zernike多項式,在此使用通用的數學符號
表示。 Table 1 lists the Zernike polynomials of the first 18 orders, using common mathematical symbols here express.
一般而言,其他的基底函數亦可予以選擇用於此應用,只要其如同本情況之Zernike多項式一樣為正交並且只要其微分在單位圓各處為連續。然而,由於Zernike多項式的「可使用相對少的項數來描述函數在極座標(徑向方向與圓周方向兩者)上之相當複雜的變化」的性質,因而此應用中以Zernike多項式為佳。 In general, other basis functions can also be chosen for this application as long as they are orthogonal like the Zernike polynomials in this case and as long as their differentials are continuous around the unit circle. However, Zernike polynomials are preferred for this application due to their property that a relatively small number of terms can be used to describe fairly complex variations of functions in polar coordinates (both radial and circumferential).
將Zernike多項式Z P (r,θ)代換至所收集的偵測器輸出結果
既然收集的偵測器輸出Di根據選定的基底函數、擬合參數與光效率而界定,則確定Di之擬合參數ap的問題可簡化為最小化下列式子,亦即解最小平方的問題:
圖7顯示以根據本發明之一實施例的方法所測定的電漿光放射強度分布範例。儘管為相對少數的項數(N=18),繪製的分布圖仍清楚地顯示出對電漿光發射強度在徑向與圓周方向兩者之變化的良好紀錄。 FIG. 7 shows an example of the intensity distribution of plasma light radiation measured by the method according to an embodiment of the present invention. Despite the relatively small number of entries (N=18), the plotted distribution clearly shows a good record of the variation of the plasmonic light emission intensity in both radial and circumferential directions.
圖8顯示使用單一頻道光譜儀310的另一實施例。射線305A-E由掃描鏡400及鏡系統800所形成,其中鏡系統800將射線305A-E的旋轉中心從與掃描鏡400相關的步進馬達410位置移動至光窗70或實質上靠近光窗70,如圖8中之點C所示(亦即,點C顯示旋轉中心)。光窗70通常係微小的(直徑為一英吋),因此為了掃掠射線305A-E橫越電漿50(例如,電漿處理腔室20之中心軸的角度θmax=25°),在光窗70處射線305A-E具有最小偏移。因此,射線305A-E之旋轉中心係配置為實質上靠近或位在光窗70。利用本文所述構造的情況下,使用具有68.5mm×8mm或更大的尺寸的窗部係可能的。窗部尺寸(上限)受限於例如下列因素:汙染、腔室UV與RF洩漏、及電漿處理腔室20之壁部處的可用空間。在一實施例中,窗部可具有矩形外形、且其平面中之大尺寸對應於射束之掃描平面。此具有在滿足洩漏及空間需求的同時最小化窗部尺寸的優點。
FIG. 8 shows another embodiment using a
掃描鏡400係利用步進馬達410而可控地掃描,藉以掃掠射線305A-E,同時該光譜儀310經由單一光學系統300而獲得電漿光放射光譜。
The
鏡系統800可包含傳送鏡802及折鏡804。所收集之各射線305A-E或65(亦即,透過所收集之射線305自電漿收集的光信號)係由傳送鏡802所傳送,傳送鏡802反射所收集之射線305、並將所收集之射線305傳送至折鏡804。折鏡804將所收集之射線305由水平(方位角方向)反射為垂直同心、並將所收集
之射線305傳送至掃描鏡400,掃描鏡400將所收集之射線305反射至光學系統300。鏡系統800與光學系統300為靜止的。可將鏡系統800、掃描鏡400、光學系統300、及光譜儀310裝設於電漿處理腔室20附近。
當掃掠掃描鏡400時,獲得高空間解析度的化學物種濃度之空間分布。例如,可緩慢掃掠掃描鏡400,同時獲得電漿光放射光譜。所獲得的電漿光放射光譜係與-θmax°至+θmax°之間的任一位置相關。因此,利用本文所述之掃描配置,可獲得相當精確的空間解析度。
When scanning the
圖9為依據實施例之圖8的光學系統300的一實施例之概要展開圖。光學系統300負有從電漿50之範圍內、由所收集之射線305所界定的空間體積中收集電漿光放射光譜,並導引所收集的電漿光放射光譜至光纖320之端口390的任務,因此所收集的電漿光放射光譜即可發送至本文先前所描述的光譜儀310。光學系統300包含具有小數值孔徑的遠心耦合器。所收集之掃描射線尺寸在直徑方面沿收集路徑可在約3mm至5mm間變動。
FIG. 9 is a schematic expanded view of an embodiment of the
所收集之射線305(從掃描鏡400被反射)通過第一收光透鏡902。接著,可使射線通過遠心孔908(例如,具有600μm之直徑)。然後,兩個耦合透鏡904與906用於使所收集之光放射光譜聚焦於光纖320的端口390上。在一範例中,光纖320具有600μm之直徑。光學系統300亦可包含位在兩個耦合透鏡904與906之間的選用性的濾光片。
Collected rays 305 (reflected from scanning mirror 400 ) pass through
光學系統300的數值孔徑非常低,例如0.005。透鏡902、904、及906為分別具有30mm、12.5mm、與12.5mm之有效焦距、及12.5mm、6.25mm、與6.25mm之直徑的消色差透鏡。
The numerical aperture of
參照回圖8,掃描鏡400可具有至少10mm×10mm的尺寸。傳送鏡802可為球面鏡。掃描鏡400及傳送鏡802可具有鋁塗層、一氧化矽(SiO)保護膜、或在鋁上方之介電質多層膜,以增加某些波長區域(例如UV)下的反射率。傳送鏡802之半徑可介於100mm至120mm之間。在一實施例中,傳送鏡802之半徑為109.411mm。可將傳送鏡802定位於與光窗70之外緣相距68.4mm處。可將折鏡804定位於與掃描鏡400之平面相距71.5mm處。
Referring back to FIG. 8 , the
光譜儀310可為具有0.4nm之光譜解析度、及介於200nm至1000nm之波長範圍的超寬帶(UBB)高解析度光譜儀。
The
圖10為配備有圖8之光學系統的電漿處理系統之概要俯視圖。電漿處理腔室20可配備有兩個圖8之光學系統。該光學系統被稱為掃描模組。可將各掃描模組配置為從X至Y個射線位置收集資料。在一實施例中,可將各掃描模組配置為從提供較佳精確度的5至50個射線位置收集資料,以利用高空間解析度偵測事件。圖10中,顯示射線305之一位置。如本文先前所述,射線305的掃描角度可在-θmax°至+θmax°之間變化(例如,θmax=25°或30°)。如本文先前所述而處理來自光譜儀310的資料,以獲得二維(2D)OES強度分布。各模組可包含單一頻道光譜儀310、或者具有兩個頻道的單一光譜儀可用於兩個掃描模組。亦可使用額外的掃描模組以提供更高的空間解析度。光窗70(即各掃描模組的光窗70)可位在電漿處理腔室20之彼此垂直或實質垂直的側壁上。依據電漿處理腔室20的構造,光窗70可為石英、熔融矽石或藍寶石,其取決於應用及電漿之化學侵略性的程度多寡。
10 is a schematic top view of a plasma processing system equipped with the optical system of FIG. 8 . The
圖11為圖5或圖8之光學系統300的實施例之概要展開圖。光學系統300負有將經反射的所收集之電漿光放射光譜從掃描鏡400導引至光纖320之
端口390的任務,因此所收集的電漿光放射光譜即可發送至本文先前所描述的光譜儀310。使所收集之射線305通過收光透鏡,該收光透鏡可為三合透鏡1102(例如具有40mm之有效焦距)。可使所收集之射線305通過選用性的罩孔1108(例如具有7mm之直徑)。可將罩孔1108定位於掃描鏡400與三合透鏡1102之間。接著,可使所收集之射線305通過選用性的遠心孔1110(例如,具有1.20mm之直徑)。在另一實施例中,諸如透鏡之其他光學元件可用於界定射線305的直徑。
FIG. 11 is a schematic expanded view of the embodiment of the
兩個耦合三合透鏡1104與1106用於使所收集之光放射光譜聚焦於光纖320的端口390上。在一實施例中,耦合三合透鏡1104與1106可為具有15mm之有效焦距的三合透鏡。耦合三合透鏡1104與1106之有效焦距為光纖320之類型及直徑的函數。
Two
用於本系統中的所有透鏡較佳為消色差的,或為了更嚴苛條件的應用甚至為複消色差的,其確保每一透鏡的焦距不隨波長變化,使得光學系統300A-E或300在一大範圍波長內(通常係自200nm至800nm,但在某些情況下則可能低至150nm)可良好地運作。為了光譜的紫外光(UV)部分(亦即350nm以下)中的較佳運作,應針對所有光學元件使用UV等級的材料,例如石英、熔融矽石、氟化鈣(CaF2)。
All lenses used in this system are preferably achromatic, or even apochromatic for more demanding applications, which ensures that the focal length of each lens does not vary with wavelength such that
圖12為使用單一頻道光譜儀310之另一實施例的概要圖。可依序使用一或兩個模組以獲得電漿光放射光譜。各模組可包含線弧台1204。光譜儀310、光學系統300、及折鏡1202係裝設於線弧台1204上。將折鏡1202定位以從電漿處理腔室20接收所收集之射線305、並將所收集之射線305反射至光學系統300。線弧台1204係可控地掃描,藉以掃掠所收集之射線305,同時該光譜儀
310經由單一光學系統300而獲得電漿光放射光譜。可經由控制器80控制線弧台1204。圖12中的點C顯示線弧台1204的旋轉中心。單一光學系統300可為圖9或圖11所顯示及描述的單一光學系統。在一實施例中,線弧台1204可具有85°的掃描角度及163.2mm的長度。線掃描速度可在0.35m/s至2.2m/s間變動。因此,可依據電漿光放射光譜系統15之應用,調整掃描速度以使空間解析度與速度之間的取捨問題最佳化。
FIG. 12 is a schematic diagram of another embodiment using a
在圖6、9、及11之光學系統300的進一步實施例中,可使用其他光學元件(例如鏡、稜鏡、透鏡、空間光調變器、數位微鏡裝置等),以使所收集之射線305轉向。圖4至6、及圖8至12的光學系統300之配置及元件佈置未必需要完全如圖4至6、及圖8至12所示,而係可藉由額外的光學元件將所收集之射線305折疊和轉向,以便於將電漿光放射光譜系統15裝入適合裝設在電漿處理腔室20之壁部上的緊湊包裝中。
In further embodiments of the
發明人進行了若干實驗以重建光放射分布的圖案、並將所重建的圖案與蝕刻圖案進行比較。 The inventors performed several experiments to reconstruct the pattern of the light emission distribution and compared the reconstructed pattern with the etched pattern.
圖13為顯示光放射強度之重建圖案之示例性結果的概要圖。放射線(亦即氯化矽之522.45nm)的強度顯示氯化矽(SiCl)之濃度,而氯化矽(SiCl)之濃度又與基板40上局部蝕刻之強度相關。圖13顯示實際蝕刻速率與由本文所述電漿OES系統15所獲得之光放射在522.5nm的實際分布之間的比較。繪圖1302、1304、及1306顯示在各種電漿處理條件下之各種樣本的實際蝕刻速率。繪圖1308、1310、及1312各別顯示與繪圖1302、1304、及1306相關之樣本的重建光放射分布。
FIG. 13 is a schematic diagram showing exemplary results of reconstructed patterns of light emission intensity. The intensity of the radiation (ie, 522.45 nm of silicon chloride) indicates the concentration of silicon chloride (SiCl), which in turn is related to the intensity of the local etching on the
可使用本文所述之設備及方法以監視蝕刻均勻性。例如,可在製程開發期間使用該設備以監視各種電漿處理條件下之蝕刻均勻性,而無需將基板轉移至另一設備,其使得各種製程的開發更加快速。 The apparatus and methods described herein can be used to monitor etch uniformity. For example, the device can be used during process development to monitor etch uniformity under various plasma processing conditions without transferring the substrate to another device, which enables faster development of various processes.
結果顯現蝕刻厚度與涉及電漿蝕刻的物種(包括反應物及產物兩者)之重建OES分布之間的強關聯。OES分布之均勻性與氧化物蝕刻輪廓遵循相同的趨勢,例如繪圖1302與繪圖1308相比。具有較佳蝕刻均勻性的基板顯現與OES分布之較低關聯(例如繪圖1306與繪圖1302相比)。
The results show a strong correlation between etch thickness and the reconstructed OES distribution of species involved in plasma etching, including both reactants and products. The uniformity of the OES distribution follows the same trend as the oxide etch profile, eg
圖14為顯示依據一範例之光放射量測的方法1400的流程圖。在1402,在處理腔室(例如,電漿處理腔室20)之壁部設置一光窗。在1404,設置一收集系統,以透過光窗收集電漿光放射光譜。收集系統可包含鏡件及遠心耦合器。遠心耦合器可包含至少一收光透鏡(例如,收光透鏡360A與360B)及至少一耦合透鏡(例如,圖9之耦合透鏡904與906)。在1406,使用鏡件以掃描橫越電漿處理腔室的複數非重合射線。可透過控制器80以控制該掃描。在1408,透過遠心耦合器自電漿收集光信號。在步驟1410,將光信號導引至光譜儀,以量測電漿光放射光譜。
FIG. 14 is a flowchart showing a
熟悉相關技術的人員可根據上述之教示而察知到有諸多改良與變化係為可行。熟悉相關技術的人員將理解到顯示於圖中之各種元件的等效組合與替換。因此,本發明之範疇並非意欲由此詳細說明書所限制,而是由附加於此的申請專利範圍所限制。 Those who are familiar with related technologies can realize that many improvements and changes are possible based on the above teachings. Those skilled in the relevant art will understand equivalent combinations and substitutions of the various elements shown in the figures. Accordingly, it is intended that the scope of the invention be limited not by this detailed description, but by the claims appended hereto.
以上揭示內容亦包含下列實施例。 The above disclosure also includes the following examples.
(1)一種用於光放射量測之方法,其包含將一光窗設置在一電漿處理腔室之壁部;設置一收集系統,以透過該光窗收集電漿光放射光譜,該收 集系統包含一鏡件及一遠心耦合器;使用該鏡件掃描橫越該電漿處理腔室的複數非重合射線;透過該遠心耦合器自電漿收集一光信號;以及將該光信號導引至一光譜儀,以量測該電漿光放射光譜。 (1) A method for measuring light emission, which includes arranging a light window on the wall of a plasma processing chamber; setting a collection system to collect the plasma light emission spectrum through the light window, the collection The collection system includes a mirror and a telecentric coupler; using the mirror to scan a plurality of non-coincident rays across the plasma processing chamber; collecting an optical signal from the plasma through the telecentric coupler; and guiding the optical signal to lead to a spectrometer to measure the plasmonic light emission spectrum.
(2)如特徵(1)之方法,其中該遠心耦合器包含至少一收光透鏡;以及至少一耦合透鏡。 (2) The method according to feature (1), wherein the telecentric coupler includes at least one light-collecting lens; and at least one coupling lens.
(3)如特徵(2)之方法,其中該至少一收光透鏡或該至少一耦合透鏡為消色差透鏡。 (3) The method according to feature (2), wherein the at least one light-collecting lens or the at least one coupling lens is an achromatic lens.
(4)如特徵(2)之方法,其中該遠心耦合器更包含:一孔洞,其係設置於該至少一收光透鏡與該至少一耦合透鏡之間,以界定該複數非重合射線的直徑。 (4) The method of feature (2), wherein the telecentric coupler further includes: a hole, which is arranged between the at least one light-collecting lens and the at least one coupling lens, to define the diameter of the plurality of non-coincident rays .
(5)如特徵(1)至(4)之任一者之方法,其中該鏡件為一掃描鏡。 (5) The method according to any one of features (1) to (4), wherein the mirror is a scanning mirror.
(6)如特徵(5)之方法,其中該掃描鏡係裝設於一檢流計掃描台上並藉由該檢流計掃描台掃描。 (6) The method according to feature (5), wherein the scanning mirror is mounted on a galvanometer scanning table and scanned by the galvanometer scanning table.
(7)如特徵(5)之方法,其中該掃描鏡係裝設於一步進馬達上並藉由該步進馬達掃描。 (7) The method according to feature (5), wherein the scanning mirror is mounted on a stepping motor and scanned by the stepping motor.
(8)如特徵(5)之方法,其中該收集系統更包含一鏡系統,用於將該複數非重合射線之旋轉中心移動至該光窗或該光窗附近。 (8) The method according to feature (5), wherein the collection system further includes a mirror system for moving the rotation center of the plurality of non-coincident rays to the light window or near the light window.
(9)如特徵(8)之方法,其中該鏡系統包含一傳送鏡;一折鏡;以及其中該傳送鏡係配置以將所收集之該信號傳送至該折鏡,且該折鏡係配置以將所收集之該信號傳送至該鏡件。 (9) The method of feature (8), wherein the mirror system includes a transmission mirror; a folding mirror; and wherein the transmission mirror is configured to transmit the collected signal to the folding mirror, and the folding mirror is configured to transmit the collected signal to the mirror.
(10)如特徵(1)之方法,其中該遠心耦合器包含一收光三合透鏡,其係配置以自該鏡件收集該光信號;以及兩個耦合三合透鏡,其係配置以使所收集之該信號聚焦至耦接於該光譜儀的光纖之端口中。 (10) The method of feature (1), wherein the telecentric coupler includes a light-receiving triplet lens configured to collect the optical signal from the mirror; and two coupling triplet lenses configured so that The collected signal is focused into a port of an optical fiber coupled to the spectrometer.
(11)如特徵(1)之方法,更包含利用一第二收集系統以透過設置在該電漿處理腔室之該壁部的一第二光窗收集該電漿光放射光譜。該第二光窗之中心軸係垂直於該光窗之中心軸。 (11) The method of feature (1), further comprising using a second collecting system to collect the plasma light emission spectrum through a second light window disposed on the wall of the plasma processing chamber. The central axis of the second light window is perpendicular to the central axis of the light window.
(12)如特徵(1)之方法,其中該收集系統更包含一線弧台,其固持該鏡件、該遠心耦合器、及該光譜儀,該線弧台係配置以相對於該光窗之中心軸而徑向移動,使得該複數非重合射線掃描橫越該電漿處理腔室。 (12) The method of feature (1), wherein the collection system further includes a linear arc stage holding the mirror, the telecentric coupler, and the spectrometer, and the linear arc stage is configured relative to the center of the optical window The shaft is moved radially such that the plurality of non-coincident beams are scanned across the plasma processing chamber.
(13)如特徵(12)之方法,其中該鏡件為一折鏡。 (13) The method according to feature (12), wherein the mirror element is a folding mirror.
(14)如特徵(1)至(13)之任一者之方法,其中該複數非重合射線係掃描該光窗中心軸之25°橫越該電漿處理腔室。 (14) The method according to any one of features (1) to (13), wherein the plurality of non-coincident rays scan across the plasma processing chamber at 25° of the central axis of the optical window.
(15)如特徵(1)至(14)之任一者之方法,其中該光譜儀為一超寬帶高解析度光譜儀。 (15) The method according to any one of features (1) to (14), wherein the spectrometer is an ultra-broadband high-resolution spectrometer.
(16)如特徵(1)至(15)之任一者之方法,其中該收集系統具有低數值孔徑。 (16) The method of any one of features (1) to (15), wherein the collection system has a low numerical aperture.
(17)如特徵(1)至(14)之任一者之方法,其中該光信號係自21個非重合射線收集。 (17) The method of any one of features (1) to (14), wherein the optical signal is collected from 21 non-coincident rays.
20‧‧‧電漿處理腔室 20‧‧‧plasma treatment chamber
60‧‧‧光偵測器 60‧‧‧light detector
70‧‧‧光窗 70‧‧‧light window
300A-E‧‧‧光學系統 300A-E‧‧‧optical system
305A-E‧‧‧射線 305A-E‧‧‧ray
310‧‧‧多頻道光譜儀 310‧‧‧Multi-channel spectrometer
320A-E‧‧‧光纖 320A-E‧‧‧optical fiber
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