KR101056592B1 - Mask Blanks and Photomasks - Google Patents

Abstract

A large mask and mask blank for FPDs are provided for making FPD devices suitable for multicolor wave exposure. A mask blank having a light shielding film at least composed of a lower layer having a light shielding function and an upper layer having a reflection preventing function on a light-transmissive substrate, the light shielding film having a wavelength band extending from at least i rays to g rays emitted from an ultra-high pressure mercury lamp, It is a film | membrane controlled so that the fluctuation range of a film surface reflectance may exist in less than 1% of range.

Light-transmissive substrate, light-shielding film, mask blank, patterning, photomask, wavelength band, reflectance, equal exposure exposure treatment

Description

Mask Blanks and Photomasks {MASK BLANK AND PHOTO MASK}

The present invention relates to mask blanks and photomasks, in particular mask blanks (blanks for photomasks) for manufacturing FPD devices, photomasks (transfer masks) manufactured using such mask blanks, and the like.

In recent years, in the field of a large sized FPD mask, an attempt has been made to reduce the number of masks using a gray tone mask having a semi-transmissive region (so-called gray tone portion) (Non-Patent Document 1).

Here, as shown in FIGS. 5 (1) and 6 (1), the gray tone mask includes a light blocking portion 1, a transmitting portion 2, and a gray tone portion that is a semi-transmissive region on a transparent substrate. Has (3). The gray tone part 3 has a function of adjusting the transmission amount, for example, as shown in Fig. 5 (1), a region in which a semi-transmissive film (half transmissive film) 3a 'for a gray tone mask is formed, or As shown in Fig. 6 (1), as the region in which the gray tone pattern (the fine light shielding pattern 3a and the fine transmission portion 3b below the resolution limit of the large LCD exposure machine using the gray tone mask) is formed, these are formed. It is formed for the purpose of reducing the amount of light transmitted through the region and reducing the amount of irradiation by the region to control the reduced film thickness after development of the photoresist corresponding to this region to a desired value.

In the case where the large-scale gray tone mask is mounted on a large-scale exposure apparatus of a mirror projection method or a lens system using a lens, the exposure light passing through the gray tone part 3 becomes insufficient in overall exposure amount. The positive photoresist exposed through) remains only on the substrate with a thin film thickness. That is, since the difference in the solubility with respect to a developing solution arises in the part corresponding to the normal light-shielding part 1 and the part corresponding to the gray tone part 3 by a difference in an exposure amount, the resist shape after image development is shown in FIG. 2) and part 2 'corresponding to the normal light shielding part 1, for example, about 1 micrometer and the part 3' corresponding to the gray tone part 3, as shown to (2) of FIG. ) Is, for example, about 0.4 to 0.5 占 퐉, and the portion corresponding to the transmission portion 2 is the portion 2 'having no resist. Then, a first etching of the substrate to be processed is performed in the portion 2 'having no resist, and the resist of the thin portion 3' corresponding to the gray tone portion 3 is removed by ashing or the like, and the second etching is performed in this portion. By performing the process, the mask number of masks is reduced by performing the process of two conventional masks with one mask.

Non-Patent Document 1: Monthly FPD Intelligence, p.31-35, May 1999

Non-Patent Document 2: "The Story of Photomask Technology", Isao Tanabe, Norimoto Morihisa, Hiroshi Takana, Industrial Research Society, "Chapter 4. The Reality of LCD Photomasks," pp. 151-180

By the way, the LSI mask for manufacturing a semiconductor device such as a microprocessor, a semiconductor memory, or a system LSI is relatively small at a maximum of about 6 inches, and is mounted in a reduced projection exposure apparatus by a stepper (short-step exposure) method. It is often used. In such a mask for LSI, a silicon wafer is used as the substrate to be transferred, and is cut into a plurality of chips as a final form. In such a mask for LSI, shortening of the exposure wavelength is aimed at breaking the resolution limit determined by the exposure wavelength. Here, in the mask for LSI, monochromatic exposure light (a single wavelength of exposure light) is used from the viewpoint of eliminating chromatic aberration by the lens system and thereby improving resolution. The shortening of the monochromatic exposure wavelength with respect to this LSI mask proceeds with g line (436 nm), i line (365 nm), KrF excimer laser (248 nm), and ArF excimer laser (193 nm) of an ultrahigh pressure mercury lamp. Coming. Further, the minimum line width of the mask pattern formed on the LSI mask is about 0.26 m (the minimum line width of the pattern formed on the wafer is about 0.07 m).

In contrast, when a large-sized mask for an FPD (flat panel display) is mounted and used in an exposure apparatus of a mirror projection (equivalent projection exposure by a scanning exposure method) system, (1) exposure through a mask is performed only by the reflective optical system. Therefore, chromatic aberration generated based on the interposition of a lens system such as an LSI mask does not become a problem, and (2) the effect of multicolor wave exposure (multi-wavelength exposure having a plurality of wavelengths) in the phenomenon (transmitted light or reflected light based on Compared with monochromatic wave exposure (single wavelength exposure), it is advantageous in terms of overall production, rather than examining the influence of interference, chromatic aberration, etc.). In the case of mounting and using, the polychromatic wave exposure is performed using the broad wavelength band of i line | wire to g line | wire of ultra-high pressure mercury lamp from what was described in said (2), etc. have.

In the large-sized mask blank for FPD, the larger the substrate size is, the smaller the substrate size is, compared to the factors of the limit plane (limit plane derived from the manufacturing method or the manufacturing apparatus) on the manufacturing principle, and variations in the manufacturing conditions (process variation). On the basis of the factors of), variations in various properties (film composition, film quality, transmittance, reflectance, optical density, etching characteristics, other optical properties, film thickness, etc.) are likely to occur between the in-plane and the substrate. There is a feature that it is difficult to make a large amount of uniform properties. Such a characteristic tends to be extended as the FPD becomes larger and higher in definition.

Here, when the fluctuation of the overall characteristics between the in-plane and the substrate is large, there are the following problems.

(1) A product with a large variation in characteristics is not a high quality product due to a large variation, and may not be said to be good in terms of performance.

(2) When the variation in general characteristics is large, it is very difficult to enter the standard, and it is difficult to manufacture a large amount of the material within the standard, and it is difficult to make it.

(3) Since the fluctuation of the general characteristics is large, the thing out of the standard comes out and the productivity (yield) is bad.

(4) If the fluctuations in characteristics are large, it is necessary to loosen the standard accordingly. Therefore, high standardization cannot be pursued and it is difficult to cope with high standardization.

In addition, the minimum line width of the pattern formed on the large sized mask for FPD is about 1 μm or less, and the minimum line width of the pattern formed on the large sized glass substrate for use is about 2 to 3 μm, which is larger than the minimum line width of the uppermost LSI. . However, FPD is used as one FPD product with large area, and the final shape is large compared to LSI, and it is necessary for all of many devices to function. Therefore, defects that hinder the operation of all devices and defects other than the standards that are considered to be impaired are not allowed. As such, there is a need to realize that there are no defects in the large area of the FPD product.In the case of large variation in characteristics between in-plane and the substrate in the large mask blank for FPD, high quality of the large mask for FPD and the large area FPD product And the improvement of yield etc. are difficult. Such a characteristic tends to be extended as the FPD becomes larger and higher in definition.

As described above, in the large size mask for FPD, a characteristic that is not required for the LSI mask (that is, does not need to be examined) is required (that is, needs to be examined) based on the difference in the mask use environment, the difference in mask size, or the like. I can say)

With respect to the required characteristics peculiar to the large-sized mask for FPD, which occur based on such differences in the use environment of such a mask, the inventors have focused on multicolor wave exposure.

By the way, the advantage of the exposure (multicolor wave exposure) process by a some wavelength can make an exposure light intensity larger than the case of exposure by a single wavelength (mono wave exposure). For example, the exposure light intensity is higher for exposure with light of a wavelength band including the h line and extending from the i line to the g line as compared with the monochromatic wave exposure of only the i line or only the g line. For this reason, the productivity of a device can be improved.

For example, large display devices such as FPD devices are often manufactured using an equal magnification exposure method. Compared with the reduced exposure method used in the manufacture of LSI devices and the like, the incident light intensity of the exposure light irradiated onto the device surface is small in the equal exposure method, so that the incident intensity of the exposure light irradiated onto the device surface is compensated by using a plurality of wavelengths. Advantages can be obtained.

On the other hand, in the case of performing exposure processing using a plurality of wavelengths, since the exposure light intensity is large, it is necessary to sufficiently suppress the reflectance of the mask surface.

A part of the exposure light irradiated to the device surface is reflected, and the light (returned light from the device surface side) incident on the mask surface from the device surface side is also light having a plurality of wavelengths of reflected light reflected from the mask surface, and the light This is because the incident light is incident on the device surface together with the exposure light, so that proper patterning is inhibited.

For example, in a large display device such as an FPD device, since it has a large area, in particular, it is required to perform exposure processing uniformly over the surface, but in a multi-wavelength exposure using a plurality of wavelengths, the light intensity of the reflected light is large and sufficiently restrained. Since this is difficult, it has become an impediment factor in terms of supplying high quality products (for example, FPD devices).

In addition, in the case of a gray tone mask, since the reflected light of the mask surface by the return light of the device side by two places of a gray tone part and a light shielding part enters into a device side, manufacturing difficulties may arise.

An object of the present invention is to find a problem associated with polychromatic wave exposure and to devise a countermeasure.

Means for solving the problem

Based on the research of the present inventors, it has been found that these problems can be solved as long as the reflectance of the mask surface is suppressed in a wide band over the wavelength band of the exposure light used for exposure processing.

Further, based on the research of the present inventors, a mask in which a lower layer portion having a light shielding function and an upper layer portion having an antireflection function formed on the lower layer portion are laminated on the light-transmissive substrate, and the composition of the portion adjacent to the lower layer portion and the upper layer portion is When it has a composition gradient which transitions continuously from the said lower layer part toward the said upper layer part, it turned out that it is suitable for solving these problems.

In addition, based on the research of the present inventors, such a composition inclined structure has a lower layer portion having a light shielding function and an upper layer portion having an antireflection function on the lower layer portion, and is formed from the lower layer portion to the upper layer portion using an inline sputtering method or the like. It turned out that it can form preferably by continuous forming process over.

Moreover, this inventor paid attention to the polychromatic wave exposure peculiar to a large sized mask for FPD, and studied the required characteristic peculiar to a large sized mask for FPD suitable for this polychromatic wave exposure.

As a result, the followings were found.

(1) The exposure light intensity (relative intensity) of i line | wire, h line | wire, and g line | wire radiated | emitted from the ultrahigh pressure mercury lamp which is an exposure light source is almost the same. In more detail, the exposure light intensity (relative intensity) of i line | wire, h line | wire, and g line | wire is substantially the same, but the intensity | strength of the center h line | wire is slightly low compared with the intensity | strength of i line | wire and g line of both ends (refer FIG. 1).

That is, i-line, h-line, and g-line should all be equally important in terms of relative intensity, and the action expressed according to relative intensity during exposure through a mask, for example, the film surface reflectance by an anti-reflection film, etc. It is thought that all of them need to be equally important.

Here, considering the film surface reflectance of the antireflection film during the action expressed by the relative intensities of i, h and g lines, the spectral curve of the film surface reflectivity R by the antireflection film of any film thickness (spectral reflectance line, Reflectance curve) is expressed as R = 1 (λ) as a function of wavelength λ. The spectral curve of this film surface reflectance R is mainly determined by a film material, a film composition, a film quality, a manufacturing condition, a manufacturing apparatus, and the like. On the other hand, the film surface reflectance R is related to the wavelength? / 4 and the film thickness, and changes according to these changes.

Regarding the film surface reflectance R, there is no problem in the performance and the standard of the antireflection when it is below a certain value. Therefore, even if the fluctuation range (difference between the maximum reflectance and the minimum reflectance of the reflectance at each wavelength) of the spectral curve of the film surface reflectance R in the wavelength band of the i-g line is large (even if the curve of the spectroscopic curve is severe), i-g-g If the maximum value of the film surface reflectivity R within the wavelength band of a line is below a fixed level, there is no problem in the performance of antireflection.

However, considering that the exposure light intensities of i-line, h-ray, and g-ray are almost equal, it is thought that it is desirable to realize a film surface low reflectance (low film-surface reflectance) that is substantially equivalent to any of i-line, h-ray, and g-ray. I could see.

(2) A film having a film surface reflectance (e.g., a mutual difference between the reflectances of i-line, h-ray, and g-ray less than 1%) substantially equal to i-ray, h-ray, and g-ray can be actually manufactured. Could know.

(3) In the large FPD mask used in the multi-color wave exposure, such fluctuation ranges are actually applied to the mask blank and the mask having a film surface reflectance that is substantially equivalent to i-line, h-ray, and g-ray, which are almost equal in relative intensity. Compared to the case where this large film is applied, it is easy to make a large amount of uniform film surface reflectivity between in-plane and substrate, thus contributing to the improvement of the quality of the mask blank and the improvement of yield, and the improvement of the quality of the large-area FPD product or the yield. I could see that I could contribute.

(4) In relation to (1) and (3) above, for example, as shown in Fig. 3, a film surface reflectance optically designed and manufactured to have a film surface reflectance almost equal to at least i-line, h-line, and g-line. A film having a small fluctuation range of (e.g., a fluctuation range of less than 1%), preferably a film having a small fluctuation range in reflectance (e.g., a wavelength of 350 nm to In the case where the variation in the film surface reflectance in the wavelength band over 450 nm is optically designed and manufactured with less than 2%), the variation in manufacturing conditions (process variation), the variation in the film composition and the film thickness accompanying this, Even if the spectral curves (spectral reflectance lines and reflectance curves) are shifted up, down, left and right, the spectral reflectance (reflectance at each wavelength) does not greatly fluctuate by this, and the spectral reflectance (at each wavelength Reflectance) Il is good. Therefore, it turned out that the uniformity of spectral reflectance (reflectance in each wavelength) is easy to manufacture in large quantities, and it is easy to manufacture the mask blank and mask which fall within the specification k in large quantities with good yield.

On the other hand, for example, as shown in Fig. 3, when the fluctuation range H 'of the spectral reflectance (reflectance at each wavelength) is large in the wavelength band, a very small variation in the manufacturing conditions (process fluctuation) or Since the spectral curve (spectral reflectance line, reflectance curve) shifts up and down and left and right, and the spectral reflectance (reflectance at each wavelength) is fluctuate | varied in response to the fluctuation | variation of a film composition, a film thickness, etc. accompanying, The uniformity of the reflectance (reflectance at each wavelength) is deteriorated, and the ratio of becoming out of the standard k also increases due to the shift of the spectral curve (spectral reflectance line, reflectance curve). Therefore, as compared with the case where the fluctuation range H is small in reality, it turns out that it cannot manufacture with high productivity unless the specification k is relaxed.

(5) As described above, even if the fluctuation range of the spectral curve of the film surface reflectance R is large in the wavelength bands of the i-g line, the reflection prevention is prevented if the maximum value of the film surface reflectivity R in the wavelength band of the i-g line is less than or equal to a certain level. There is no problem in performance. However, for example, as shown in FIG. 4, the fluctuation range of the spectral reflectance (reflectance at each wavelength) in the wavelength band is small and falls within the standards k and k 'covering the wavelength band (upper and lower limits). In the case where the wavelength band management is possible at the standard values k and k ', it is found that it is preferable because it serves as one criterion of whether or not the same film is produced, as compared with the case where such fluctuation range is large.

(6) In addition, in relation to the above (2), it was found that the film having a film surface reflectance almost equal to the i-line, h-line, and g-line was found in the process of finding out that it could be actually manufactured.

(i) If it is an antireflection film of a chromium oxide film system (e.g., a CrO film monolayer or the like), in order to have a function as an antireflection film, O is contained in the film (since there is a lot of O in the film). Wavelengths in the wavelength band, and in the broader wavelength bands encompassing these wavelength bands, are basically deep curves of the spectral curves (spectral reflectance lines, reflectance curves), or wavelengths that become the minimum reflectance of the spectral curves (spectral reflectance lines, reflectance curves). It turned out that the width | variety of a band becomes small and there exists a tendency for the fluctuation range of spectral reflectance (reflectance in each wavelength) to become large.

Here, it is conceivable that the anti-reflection film of the chromium oxide film system (e.g., CrO film or the like) is made into a multilayer to reduce the variation in the spectral reflectance (reflectance at each wavelength) in the wavelength band. This complicates the process and increases membrane defects.

(ii) In the antireflection film of the chromic acid nitride film system (e.g., CrON film), compared with the antireflection film of the chromium oxide film system, spectroscopy is basically performed in the wavelength band of i line to g line, and also in the wider wavelength band including such wavelength band. Although the curves of the curves (spectral reflectance lines and reflectance curves) are smooth and flat, for the purpose of achieving high quality mask blanks and FPDs themselves, or to make more uniform ones easier to manufacture in large quantities, etc. The antireflection film of any chromium nitride film system is not suitable for the achievement of this object. Furthermore, no light shielding film of the lower layer of the chromic nitride nitride film system is suitable for the achievement of this purpose. Accordingly, it has been found that it is necessary to find and use an antireflection film and a light shielding film of a chromic acid nitride film system that satisfy certain conditions suitable for achieving the above object. That is, even if the film material is the same chromic acid nitride film system, adjustment of the film composition, selection and control of the manufacturing conditions, manufacturing apparatus, etc., control of the film quality by these, materials of the light-shielding film, etc., the position of the bottom peak, the difference of the film structure, etc. It has been found that there is a case where a predetermined condition is met and a case where the predetermined condition is not satisfied.

The method of this invention has the following structures.

<Configuration 1> As a mask blank which has a light shielding film comprised at least by the lower layer part which has a translucent function, and the upper layer part which has a reflection prevention function on a transparent substrate,

The light-shielding film is a mask blank for manufacturing an FPD device, wherein the film is controlled so that the fluctuation range of the reflectivity of the film surface is within a range of less than 1% in a wavelength band extending from at least i to g rays emitted from an ultra-high pressure mercury lamp. .

<Configuration 2> The mask blank for manufacturing the FPD device according to Configuration 1, wherein the light shielding film is a film controlled so that the minimum reflectance at which the film surface reflectance is minimized is in a wavelength range of 380 nm to 430 nm.

<Configuration 3> The light shielding film is composed of a lower layer of a chromium carbide system having a light shielding function and an upper layer of a chromium oxynitride system having an antireflection function, and the lower layer and the upper layer are optically designed and manufactured to satisfy the above requirements. The mask blank for manufacturing the FPD device of the structure 1 or 2 characterized by the above-mentioned.

<Configuration 4> The light shielding film is composed of a chromium nitride base layer, a lower layer of chromium carbide series having a light shielding function, and an upper layer of chromium oxynitride series having an antireflection function, and includes the base layer, lower layer, and upper layer. The mask blank for manufacturing the FPD device of the structure 1 or 2 which is optically designed and manufactured so as to satisfy the said requirement.

<Configuration 5> In the mask blank in which the light transmissive substrate, the lower layer part which has the light-shielding function formed on this board | substrate, and the upper layer part which has the antireflection function formed on this lower layer part were laminated | stacked, the said mask blank is the said lower layer part and the said upper layer part patterning. A mask blank for a photomask that is subjected to exposure processing by exposure light containing a plurality of wavelengths when the device is processed to become a photomask, and the reflectance curve of the mask blank is convex downward with respect to the wavelength of light. And a minimum reflectance portion of the reflectance curve is in a wavelength band corresponding to the exposure light.

<Configuration 6> The mask blank according to Configuration 5, wherein the mask blank is minimized in a wavelength band within an i-line wavelength or more and a g-line wavelength.

<Configuration 7> The mask blank according to Configuration 5 or Configuration 6, wherein the mask blank is substantially minimized at the h-ray wavelength.

<Configuration 8> The mask blank according to any one of Configurations 5 to 7, wherein the maximum reflectance in the wavelength band corresponding to the exposure light does not exceed 13%.

<Configuration 9> The mask blank for photomasks corresponding to the exposure machine which performs the equal magnification exposure process as the mask blank in any one of structures 5-8.

<Configuration 10> A photomask for producing an FPD device, which is manufactured using the mask blank according to Configurations 1 to 4.

<Configuration 11> A photomask manufactured by using the mask blank according to any one of Configurations 5 to 9.

Effect of the Invention

According to the present invention, it is possible to provide a large size mask and a mask blank for FPD suitable for multicolor wave exposure.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

In mask blanks and masks for manufacturing FPD devices according to the invention,

The light shielding film composed at least of the lower layer portion having the light shielding function and the upper layer portion having the antireflection function has a variation in the film surface reflectivity within a range of less than 1% in a wavelength band extending from at least i to g rays emitted from an ultra-high pressure mercury lamp. It is characterized by being a controlled membrane (configuration 1).

In the present invention, the light-shielding film that satisfies the above requirements is selected after a film material that is considered to be capable of meeting the above requirements (suitable to satisfy the above requirements), and furthermore, adjustment of film composition, manufacturing conditions, manufacturing apparatus, and the like. It is obtained by confirming that it is possible to satisfy the above requirements by the position of the bottom peak, the film structure, etc., such as the selection and control of the film, the control of the film quality by these, the material of the light-shielding film, and the like. In addition, even if the film materials are the same, bottom peaks (spectral curves (reflectivity curves, spectral reflectance lines), such as adjustment of film composition, selection and control of manufacturing conditions, manufacturing apparatuses, control of film quality by these, materials of light-shielding film, etc. The above requirements may or may not be met depending on the position of the minimum reflectance portion), the difference in film structure, and the like.

In the present invention, the light-shielding film has a fluctuation range of the film surface reflectance within a range of less than 1% in at least a wavelength range from i-line to g-line radiated from an ultra-high pressure mercury lamp under the above circumstances, i-line, It is an optical film designed and manufactured so that the film surface reflectance with respect to h line | wire and g line | wire may become substantially equal regardless of a wavelength.

In addition, in the present invention, the lower layer portion having the light shielding function is a portion that expresses most or all of the light shielding performance required as the part having the high light shielding performance. Moreover, the upper layer part which has an antireflection function is a part formed on the lower layer part which has a light shielding function, and reduces the reflectance of the lower layer part which has a light shielding function, and expresses an antireflection function.

In the mask blank and mask for manufacturing the FPD device according to the present invention, it is preferable that the light shielding film is a film controlled such that the minimum reflectance at which the film surface reflectivity is minimized is in the wavelength range of 380 nm to 430 nm (constitution). 2).

The reason is that the film controlled such that the minimum reflectance (that is, the position of the bottom peak) at which the film surface reflectance is minimized is within the wavelength range of 380 nm to 430 nm is used for the shift in the up, down, left and right directions of the spectral curve accompanying the process variation. This is because the spectral reflectance (reflectance at each wavelength) rarely varies greatly, and the uniformity of the spectral reflectance (reflectance at each wavelength) is good. In addition, even when the manufacturing conditions (film forming conditions) during the film formation of the light-shielding film are varied, the spectral reflectance (reflectance at each wavelength) is rarely changed, whereby a mask blank or a mask falling within the standard can be manufactured with good yield. have.

In a mask blank and a mask for manufacturing an FPD device according to the present invention, the light shielding film is formed of a chromium oxynitride having an antireflection function and a lower layer portion of a chromium carbide system (a material system containing chromium and carbon) having a light shielding function. It is preferable that the upper layer is composed of an upper layer of a system (a material system containing chromium, oxygen, and nitrogen), and the lower layer and the upper layer are optically designed and manufactured so as to meet the above requirements (constitution 3).

The reason for this is that a film made of these materials (for example, a film made of a CrC light-shielding layer (lower layer) -CrON antireflection layer (upper layer), etc.) has a higher film composition adjustment, manufacturing conditions, and production than the film of other materials. By the selection and control of an apparatus and the like, the control of the film quality by these, the location of the bottom peak such as the material of the light-shielding film, the film configuration, and the like, the variation of the film surface reflectance in the wavelength range of the i-line to g-line is less than 1%. This is because it is easy to obtain what is in the range.

Moreover, the film | membrane which consists of these material systems (for example, the film | membrane which consists of a CrC light-shielding layer (lower layer part) -CrON antireflection layer (upper layer part), etc.) is compared with the film | membrane of other material system, and is adjusted of a film composition, manufacturing conditions, a manufacturing apparatus, etc. In the wavelength band over a wavelength of 350 nm to 450 nm due to the selection and control of the film, the control of the film quality, the control of the film quality, the material of the light-shielding film, the position of the bottom peak, the film configuration, and the like. A film controlled to be in a range is easily obtained, whereby the spectral reflectance (reflectance at each wavelength) does not fluctuate significantly with respect to the left and right shift of the spectral curve accompanying process variation, and thus the spectral reflectance (at each wavelength Good reflectivity). On the other hand, for example, when the spectral curve (spectral reflectance line, reflectance curve) rises rapidly in the wavelength band at both ends even if the fluctuation range of the film surface reflectance is small in the wavelength band including i-g line, the spectral curve ( It is conceivable that the spectroscopic reflectance line) will be out of the standard by slightly shifting in the horizontal direction.

Moreover, the film | membrane which consists of these material systems (for example, the film | membrane which consists of CrC light-shielding layer (lower layer part) -CrON antireflection layer (upper layer part), etc.) adjusts a film composition, selection and control of manufacturing conditions, a manufacturing apparatus, etc., by these Based on the control of the film quality, the material of the light-shielding film, the position of the bottom peak, the film structure, and the like, the bottom peak of the film surface reflectance is determined by the h line (the center of the wavelength band of the i line to the g line, as shown by the A line and the C line of FIG. 2). 405 nm) can be produced in accordance with 400 ± 10 nm, whereby the spectral reflectance (reflectance at each wavelength) fluctuates significantly with respect to the shift in the up, down, left and right directions of the spectral curve accompanying the process variation. Without this, it is possible to obtain a film having good uniformity of spectral reflectance (reflectance at each wavelength).

In a mask blank and a mask for manufacturing an FPD device according to the present invention, the light shielding film is formed of a base layer of chromium nitride (based on chromium and nitrogen) and a chromium carbide (chromium and carbon) having a light shielding function. And an upper layer of a chromium oxynitride system (a material containing chromium, oxygen, and nitrogen) having an antireflection function, and the base layer, the lower layer, and the upper layer meet the above requirements. It is preferable that it is designed and manufactured (Configuration 4).

The reason for this is that in a film made of these materials (for example, a film made of a CrN base layer-CrC light-shielding layer (lower layer part) -CrON antireflection layer (upper layer), etc.), the base layer is included and continuously by an inline sputtering apparatus. By forming, the spectral curve of the film surface reflectivity is subtly changed, whereby the bottom peak of the film surface reflectance (1) h line (405 nm) is almost the center of the wavelength band of i line to g line as shown by line A in FIG. Spectral curves of the film surface reflectivity in the vicinity and (2) almost symmetrical around the bottom peak, and (3) the spectrum having the maximum value of the film surface reflectance in the wavelength band from i to g line is 12% or less. This is because a curve is obtained. These results in a film having a smaller variation in spectral reflectance (reflectance at each wavelength) and a better uniformity of spectral reflectance (reflectance at each wavelength) with respect to the shift in the up, down, left, and right directions of the spectral curve accompanying the process variation. It is possible to obtain. In addition, in a film made of a CrN base layer ＼CrC light shielding layer (lower layer) ＼CrON antireflection layer (upper layer), which is formed continuously by an inline sputtering apparatus, since an oxide layer is not formed on the surface of each film, optical characteristics (reflectivity, etc.) ), It becomes easier to control strictly.

As the ultra-high pressure mercury lamp in the present invention, for example, those having the characteristics shown in FIG. 1 are exemplified, but the present invention is not limited thereto.

Moreover, as a transparent substrate, board | substrates, such as a synthetic quartz, soda-lime glass, an alkali free glass, are mentioned.

In the present invention, mask blanks and masks for manufacturing FPD devices include mask blanks and masks for manufacturing FPD devices such as LCD (liquid crystal display), plasma display, organic EL (electroluminescence) display, and the like. .

Here, the mask for manufacturing LCD includes all the masks necessary for manufacturing LCD, and for example, TFT (thin film transistor), especially TFT channel part or contact hole part, low temperature polysilicon TFT, color filter, reflecting plate (black matrix), etc. A mask for forming is included. Other masks for manufacturing display devices include all masks necessary for manufacturing organic EL (electroluminescence) displays, plasma displays and the like.

Further, in the mask blank and the mask according to the present invention, the mask blank formed with the light-transmissive substrate, the lower layer portion having the light shielding function formed on the light-transmissive substrate, and the upper layer portion having the anti-reflection function formed on the lower layer portion is the lower layer portion and the A mask blank for a photomask that is exposed by exposure light containing a plurality of wavelengths when the upper layer portion is patterned to become a photomask, and when manufacturing a device, the reflectance curve of the mask blank is lower than the wavelength of light. And a minimum reflectance portion of the reflectance curve is within a wavelength band corresponding to the exposure light (Configuration 5).

Here, the minimum reflectance portion refers to a region from the smallest reflectance (minimum reflectance) to 0.5% higher reflectance in the reflectance curve of the mask blank. By making the minimum reflectance part of this reflectance curve into the wavelength band corresponding to exposure light, even when the manufacturing conditions (film forming conditions) in the film formation of a light shielding film change, when a spectral reflectance (reflectance in each wavelength) changes by this There is little, and the mask blanks and mask which fall in a specification can be manufactured with high yield. In addition, the film controlled in this way rarely fluctuates greatly in spectral reflectance (reflectance at each wavelength) with respect to the shift in the up, down, left, and right directions of the reflectance curve accompanying the process variation. Good uniformity Since the reflectance of the mask blank and the mask surface is suppressed in the optical wavelength band, appropriate patterning is not hindered when the device is manufactured by the exposure process.

In addition, the mask blank and the mask according to the present invention are preferably configured to have a minimum reflectance in the wavelength band of i-line wavelength (365 nm) or more and g-line wavelength (436 nm) or less (structure 6), and more preferably. Preferably, it is preferable to set the structure in which the reflectance of the mask blank is minimized at the h line wavelength (405 nm) (Configuration 7). Here, substantially h line wavelength means the wavelength band of 405 nm +/- 10 nm.

In addition, the mask blank and the mask according to the present invention do not exceed 13% of the maximum reflectance in the wavelength band with respect to the exposure light (constitution 8), so that more appropriate patterning can be performed when fabricating a device by exposure processing. have. Preferably, the maximum reflectance in the wavelength band (specifically, i-line wavelength to g-line wavelength) with respect to exposure light is 12% or less, More preferably, it is 11.5% or less, More preferably, it is 11% or less.

In addition, the mask blank and mask of this invention are suitable as a mask blank and a photomask (constitution 9) corresponding to the exposure machine to perform the equal exposure exposure process.

Moreover, the mask blank and mask which concern on this invention are mask blanks which comprised the lower layer part which has a light shielding function on the translucent board | substrate, and the upper layer part which has an anti-reflective function above this lower layer part, and is a part of the part adjacent to the said lower layer part and the said upper layer part. It is preferable that a composition has a composition gradient which continuously transitions from the lower layer portion toward the upper layer portion.

Moreover, the structure which has the composition gradient which made the main component of the said upper layer part and the said lower layer part the same element, and made the content content of an additional element continuously transition to the film thickness direction is more preferable. For example, the element of the main component can be a metal element. Transition metals, such as chromium and tantalum, are mentioned as a metal element, Especially, chromium is preferable. Moreover, as an addition element, the element which has an antireflection function is mentioned, Especially, nitrogen or oxygen is preferable. As a preferred embodiment, for example, the lower layer portion is composed of chromium as a main component, and the upper layer portion is composed of chromium and a material containing nitrogen and / or oxygen, and at the boundary between the lower layer portion and the upper layer portion, nitrogen and / or oxygen The mask blank and mask which have a structure in which content increases continuously in the film thickness direction are preferable.

Moreover, the mask blank and mask which concern on this invention are suitable as a mask blank and a mask corresponding to the exposure apparatus in which the illumination optical system was comprised by the reflection optical type.

In addition, the mask blank and mask which concern on this invention are suitable as a large mask 330 mmx450 mm square or more, and the large mask blank corresponding to this mask. As a use of such a large size mask, the mask for display device manufacture, for example, the photomask for FPD device manufacture, etc. are mentioned.

Moreover, this invention is suitable as a mask blank corresponding to a gray tone mask.

The photomask for manufacturing the FPD device according to the present invention is characterized by being manufactured using the mask blank for manufacturing the FPD device according to the present invention (Configurations 10 and 11).

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail based on an Example.

&Lt; Example 1 >

On a large glass substrate (synthetic quartz (QZ) 10 mm thick, size 850 mm x 1200 mm), using a large inline sputtering device, the base layer, the lower layer having a light shielding function, and the upper layer having an antireflection function The light shielding film to be formed was formed. For film formation, a Cr target is placed in each space (sputtering chamber) continuously arranged in a large in-line sputtering apparatus, and first, Ar and N ₂ gas are used as sputtering gases, for the purpose of enhancing adhesion to the CrN layer (glass). Base layer) to 150 Angstrom, followed by Ar gas and CH ₄ 650 angstroms of CrC layer (lower layer having light shielding function) using gas as sputtering gas, and 250 angstroms of CrON layer (upper layer having antireflection function) using Ar gas and NO gas as sputtering gas. Was produced. Each film was a composition gradient film. In addition, the CrC layer (lower layer part having a light shielding function) is N ₂ used during the film formation of the CrN base layer or the CrON layer (upper layer part having an antireflection function). N (nitrogen) was contained by gas and NO gas, and both Cr and N were contained in the said base layer, CrC layer (lower layer part with light shielding function), and CrON layer (upper layer part with antireflection function).

The spectral curve (spectral reflectance line, reflectance curve) of the said sample is shown to A of FIG. In addition, the spectral reflectance was measured with the spectral reflectometer.

In the spectral curve A (spectral reflectance line and reflectance curve) A shown in FIG. 2, the fluctuation range of the film surface reflectance is within a range of less than 1% (0.8%) in the wavelength band from at least i to g rays emitted from an ultra-high pressure mercury lamp. It was. In detail, the fluctuation range of the film surface reflectance was 0.8%, falling within the range of less than 1%. In addition, the maximum value of the film surface reflectance in such a wavelength band was 12.0% or less.

In addition, in the spectral curve A (spectral reflectance line and reflectance curve) A shown in FIG. 2, the fluctuation range of the film surface reflectance was within a range of less than 2% (1.8%) in the wavelength band over the wavelength of 350 nm to 450 nm. In detail, the fluctuation range of the film surface reflectance was 1.8%, falling within the range of less than 2%. In addition, the maximum value of the film surface reflectance in such a wavelength band was 12.8%.

Similar investigations were carried out with respect to the in-plane (nine equal places) for a plurality of sheets (between boards: 100 sheets), and it was confirmed that all of them were within the range of the fluctuation range of the film surface reflectance.

<Example 2>

On a large glass substrate (synthetic quartz (QZ) 10 mm thick, size 850 mm x 1200 mm), using a large inline sputtering device, the base layer, the lower layer having a light shielding function, and the upper layer having an antireflection function The light shielding film to be formed was formed. In film-forming, Cr targets are each arrange | positioned in each space (sputtering chamber) arrange | positioned continuously in a large-scale inline sputtering apparatus, and Ar gas and N2 are _{first performed.} Using a gas as a sputtering gas, the CrN layer (the base layer for enhancing adhesion to glass) is 150 angstrom, followed by Ar gas and CH _4. 540 angstroms of CrC layer (lower layer with light shielding function) using gas and He gas as sputtering gas, followed by 250 angstroms of CrON layer (upper layer with antireflection function) using Ar gas and NO gas as sputtering gas. A mask blank was produced. Each film was a composition gradient film. In addition, the CrC layer (lower layer part having a light shielding function) is N ₂ used during the film formation of the CrN base layer or the CrON layer (upper layer part having an antireflection function). N (nitrogen) was contained by gas and NO gas, and both Cr and N were contained in the said base layer, CrC layer (lower layer part with light shielding function), and CrON layer (upper layer part with antireflection function). In addition, the CrC layer (lower layer part which has a light shielding function) was a layer containing He.

The spectral curve (spectral reflectance line, reflectance curve) of the sample is shown in FIG. 2B. In addition, the spectral reflectance was measured with the spectral reflectometer.

In the spectral curve B (spectral reflectance line and reflectance curve) B shown in FIG. 2, the fluctuation range of the film surface reflectance is within the range of less than 1% (0.8%) in the wavelength band from at least i to g rays emitted from an ultra-high pressure mercury lamp. It was. In detail, the fluctuation range of the film surface reflectance was 0.8%, falling within the range of less than 1%. In addition, the maximum value of the film surface reflectance in such a wavelength band was 12.7%.

In addition, in the spectral curve (spectral reflectance line, reflectance curve) B shown in FIG. 2, the fluctuation range of the film surface reflectance was within a range of less than 2% (1.3%) in the wavelength band over the wavelength of 350 nm to 450 nm. In detail, the fluctuation range of the film surface reflectance was 1.3%, falling within the range of less than 2%. In addition, the maximum value of the film surface reflectance in such a wavelength band was 13.2%.

A plurality of sheets (between boards: 100 sheets) were similarly examined for in-plane (nine equal places), and it was confirmed that all of them were within the range of the fluctuation range of the film surface reflectance.

<Example 3>

On a large glass substrate (synthetic quartz (QZ) 10 mm thick, size 850 mm x 1200 mm), using a large inline sputtering device, a light shielding film composed of a lower layer having a light shielding function and an upper layer having an antireflection function The film formation was performed. The film formation, a large batch in-line sputtering apparatus Cr target in each space (sputtering chamber) arranged in series and in each, first Ar gas and CH ₄ Using a gas as a sputtering gas, 500 angstroms of CrC layer (lower layer having light shielding function) and a 500 angstrom of CrON layer (upper layer having antireflection function) were formed using Ar gas and NO gas as sputtering gas to form a mask blank. Produced. Each film was a composition gradient film. In addition, the CrC layer (lower layer part having a light shielding function) contains N (nitrogen) by the NO gas used during the formation of the CrON layer (upper layer part having an antireflection function), and the CrC layer (lower layer part having a light shielding function). ) And Cr were contained in both the CrON layer (upper layer portion having an antireflection function).

The spectral curve (spectral reflectance line, reflectance curve) of the said sample is shown to C of FIG. In addition, the spectral reflectance was measured with the spectral reflectometer.

In the spectral curve (spectral reflectance line, reflectance curve) C shown in FIG. 2, the fluctuation range of the film surface reflectance is within the range of less than 1% (0.3%) in the wavelength band from at least i to g rays emitted from an ultra-high pressure mercury lamp. It was. In detail, the fluctuation range of the film surface reflectance was 0.3%, falling within the range of less than 1%. In addition, the maximum value of the film surface reflectance in such a wavelength band was 12.2%.

In addition, in the spectral curve (spectral reflectance line, reflectance curve) C shown in FIG. 2, the fluctuation range of the film surface reflectance was in the range of less than 2% (0.7%) in the wavelength band which covers wavelength 350nm-450nm. In detail, the fluctuation range of the film surface reflectance was 0.7%, falling within the range of less than 1%. In addition, the maximum value of the film surface reflectance in such a wavelength band was 12.6%.

A plurality of sheets (between boards: 100 sheets) were similarly examined for in-plane (nine equal places), and it was confirmed that all of them were within the range of the fluctuation range of the film surface reflectance.

Comparative Example 1

On the large glass substrate (10 mm thick of synthetic quartz (QZ), size 850 mm x 1200 mm), a base film, a light shielding film, and an antireflection film were formed using a large inline sputtering apparatus. The film formation, a large batch in-line sputtering each space arranged in series in the apparatus in the Cr target (sputtering chamber), respectively, first Ar gas and CO ₂ The gas is used as a sputtering gas and the CrO film (glass surface antireflection film) is 300 angstroms, and then the Ar film is used as the sputtering gas, and the Cr film (light shielding film) is 950 angstroms, followed by Ar gas and CO _2. A 300-angstrom continuous CrO film (film surface antireflection film) was formed into a film by using gas as a sputtering gas, and the mask blank was produced.

The spectral curve (spectral reflectance line, reflectance curve) of the sample is shown in FIG. In addition, the spectral reflectance was measured with the spectral reflectometer.

In the spectral curve (spectral reflectance line and reflectance curve) D shown in FIG. 2, the fluctuation range of the film surface reflectance was greater than 2% (2.3%) in the wavelength band from at least i to g rays emitted from an ultra-high pressure mercury lamp. In detail, the fluctuation range of the film surface reflectance was 2.3%, exceeding 2%. In addition, the maximum value of the film surface reflectance in such a wavelength band was 13.6%.

In addition, in the spectral curve (spectral reflectance line, reflectance curve) D shown in FIG. 2, the fluctuation range of the film surface reflectance was more than 3% (3.3%) in the wavelength band which spans wavelength 350nm-450nm. In detail, the fluctuation range of the film surface reflectance was 3.3%, exceeding 3%. In addition, the maximum value of the film surface reflectance in such a wavelength band was 14.57%.

A plurality of sheets (between boards: 100 sheets) were similarly inspected for in-plane (nine equal places), whereby a slight process variation caused the spectral curve (spectral reflectance line, reflectance curve) C to be shifted up, down, left and right, As a result, it was found that the reflectance greatly changed.

<Example 4>

On a large glass substrate (synthetic quartz (QZ) 10 mm thick, size 850 mm x 1200 mm), using a large inline sputtering device, the base film, the lower layer having a light shielding function, and the upper layer having an antireflection function A light shielding film was formed into a film. The film formation, placing a Cr target in each space (sputtering chamber) arranged in series in a large inline sputtering apparatus, respectively, first Ar and N ₂ Using the gas as a sputtering gas, the CrN layer (the base layer for enhancing adhesion to glass) is 150 angstroms, followed by Ar and CH ₄ Gas and N ₂ Using a gas as a sputtering gas, a CrCN layer (lower layer having a light shielding function) is 620 angstroms, and then a CrON layer (upper layer having an antireflection function) is 230 angstroms using a sputtering gas of Ar gas and NO gas as a mask blank. Produced. About the obtained film | membrane, composition analysis of the film thickness direction of the light-shielding film | membrane was performed by the gauze electron spectroscopy. The result is shown in FIG. As shown in FIG. 7, at the boundary between the CrCN layer in the lower layer and the CrON layer in the upper layer, a composition gradient film in which oxygen and nitrogen continuously increased in the surface direction of the light shielding film was formed. Moreover, the composition inclination film which chromium, carbon, oxygen, and nitrogen which comprise a light shielding film continuously transitioned to the film thickness direction was carried out over the base layer, the lower layer part, and the upper layer part. Moreover, it was the film | membrane which chromium and nitrogen contained in all the base layer, lower layer part, and upper layer part.

When the reflectance of the film surface of the light-shielding film was measured by a spectroscopic reflectometer, the fluctuation range of the film surface reflectance was 0.8% in the wavelength band from at least i to g rays emitted from an ultrahigh pressure mercury lamp (ultra high pressure mercury lamp). It was in the range of less than 1%. In addition, similarly to Examples 1 to 3, the minimum reflectance portion with the smallest reflectance was almost near the h line (405 nm). In addition, the maximum value of the film surface reflectance in such a wavelength band was 11.0% or less. Moreover, in the wavelength band which spans wavelength 350nm-450nm, the fluctuation range of the film surface reflectance was 1.5% and was in the range of less than 2%. In addition, the maximum value of the film surface reflectance in such a wavelength band was 11.7%.

A plurality of sheets (between boards: 100 sheets) were similarly examined for in-plane (nine equal places), and it was confirmed that all of them were within the range of the fluctuation range of the film surface reflectance.

<Mask making>

The light shielding film was patterned using the mask blank produced by the said Example 1-Example 4 and the comparative example 1, and the large sized mask for FPD was produced.

As a result, it was confirmed that the film of Examples 1 to 4 was beneficial in the quality improvement of the mask, the yield improvement, etc., compared with the case of using the film of Comparative Example 1.

As mentioned above, although this invention was demonstrated based on a preferable Example, this invention is not limited to the said Example.

BRIEF DESCRIPTION OF THE DRAWINGS The figure which shows the spectral distribution of the ultrahigh pressure mercury lamp which is an exposure light source.

2 is a diagram showing spectral curves (spectral reflectance lines and reflectance curves) of light-shielding films having antireflection functions prepared in Examples 1 to 3 and Comparative Example 1. FIG.

3 is a diagram for explaining an aspect of a spectral curve (spectral reflectance line, reflectance curve) of a light shielding film having an antireflection function.

4 is a diagram for explaining a preferred embodiment of a spectral curve (spectral reflectance line, reflectance curve) of a light shielding film having an antireflection function.

5 is a view for explaining a gray tone mask having a translucent film, in which (1) is a partial plan view, and (2) is a partial sectional view.

Fig. 6 is a view for explaining a gray tone mask having a fine light shielding pattern below a resolution limit, where (1) is a partial plan view and (2) is a partial sectional view.

FIG. 7 is a diagram showing the results of a composition analysis of the light-shielding film of Example 4 in the depth direction of the film by OWE electron spectroscopy; FIG.

<Explanation of symbols for the main parts of the drawings>

1: shading part

2: transmission part

3: gray tone

3a: fine shading pattern

3b: fine permeable part

3a ': translucent film

Claims (13)

A mask blank having a light shielding film having a structure in which a lower layer portion having a light shielding function and an upper layer portion having an antireflection function are laminated on a light transmitting substrate, A portion where the lower layer portion and the upper layer portion of the light shielding film are adjacent to each other is inclined in composition toward the upper layer portion from the lower layer portion, The light-shielding film is a mask blank for manufacturing an FPD device, wherein the film is controlled so that the fluctuation range of the reflectivity of the film surface is within a range of less than 1% in a wavelength band extending from at least i to g rays emitted from an ultra-high pressure mercury lamp. . The method of claim 1, The light shielding film is a mask blank for manufacturing an FPD device, characterized in that the film is controlled such that the minimum reflectance at which the film surface reflectance is minimized is in a wavelength range of 380 nm to 430 nm. The method according to claim 1 or 2, The light shielding film is a mask blank for manufacturing an FPD device, comprising a lower layer of a chromium carbide system having a light shielding function and an upper layer of a chromium oxynitride system having an antireflection function. The method according to claim 1 or 2, The light shielding film is composed of a chromium nitride base layer, a lower layer of a chromium carbide system having a light shielding function, and an upper layer of a chromium oxynitride system having an anti-reflective function, and comprises a mask blank for manufacturing an FPD device. . The method according to claim 1 or 2, The lower layer part is made of a material containing chromium, The upper layer is made of a material containing chromium and nitrogen or oxygen, A mask blank for manufacturing an FPD device, wherein the boundary between the lower layer portion and the upper layer portion has a composition gradient in which the nitrogen or oxygen content continuously increases toward the surface direction of the light shielding film. The method according to claim 1 or 2, And said light shielding film is formed by continuous processing from said lower layer portion to said upper layer portion using an inline sputtering method. The method according to claim 1 or 2, The light shielding film is a mask blank for manufacturing an FPD device, wherein the light shielding film is a film controlled to have a variation in film surface reflectance in a range of less than 2% in a wavelength band spanning from 350 nm to 450 nm. The method of claim 1, The mask blank is a mask blank for a photomask which is exposed by light emitted from the ultra-high pressure mercury lamp when the device is manufactured after the lower and upper layers of the light-shielding film are patterned to form a photomask. The reflectance curve of the light-shielding film is configured to draw a convex curve downward with respect to the wavelength of light emitted from the ultra-high pressure mercury lamp, and the FPD is configured so that the minimum reflectance portion of the reflectance curve is within a wavelength band corresponding to the light. Mask blanks for manufacturing the device. The method of claim 8, The light shielding film is a mask blank for manufacturing an FPD device, characterized in that the reflectance is minimized in a wavelength band within an i-line wavelength or more and a g-ray wavelength. The method of claim 8, The light shielding film is mask blank for manufacturing an FPD device, wherein the reflectance is substantially minimized at the h-ray wavelength. The method according to claim 1 or 2, The light shielding film is a mask blank for manufacturing an FPD device, wherein a maximum reflectance in the wavelength band from i to g lines does not exceed 13%. The method of claim 8, The mask blank is a mask blank for manufacturing an FPD device, characterized in that the mask blank for a photomask corresponding to an exposure machine subjected to an equal exposure exposure process. A photo mask for manufacturing an FPD device, characterized by using the mask blank of claim 1.

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