Phase shift mask blank, phase shift mask, producing method

Abstract

To achieve both chemical resistance and shortening of etching time.SOLUTION: A phase shift mask blank having a mask layer that serves as a phase shift mask, and having a phase shift layer laminated on a transparent substrate, wherein the phase shift layer contains molybdenum, silicon, and nitrogen, and the average value of the ratio Si / Mo of the atomic percentage of silicon to the atomic percentage of molybdenum is in the range of 2.2 to 3.2.SELECTED DRAWING: Figure 13

Description

[Technical Field]

[0001] The present invention relates to a phase shift mask blank, a phase shift mask, and a technique suitable for use in a manufacturing method thereof. [Background technology]

[0002] In the manufacture of FPDs (flat panel displays) such as liquid crystal displays and organic EL displays, or in the manufacture of semiconductor devices, edge-enhancing phase shift masks are sometimes used in addition to masks using conventional light-shielding films.

[0003] A phase shift mask may be formed by forming a phase shift layer of a silicide film on a quartz substrate as a mask layer. The phase shift layer is set to have a transmittance of 5% or 20% for the i-line (wavelength 365 nm), for example, and a phase of about 180°. For this reason, the optical constants and film thickness of the phase shift layer must be adjusted in advance.

[0004] When a phase shift layer using molybdenum silicide is formed as a phase shift mask, wet etching with a specific etching solution (etchant) is used to form the desired pattern, and a cleaning solution such as an alkali is used for cleaning. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 7381374 Summary of the Invention [Problem to be solved by the invention]

[0006] The tolerance range for the optical properties of each layer in a photomask is extremely narrow. This limits the degree of freedom in the optical density and film thickness of each layer. Furthermore, to accommodate narrower widths, stricter cross-sectional perpendicularity is required. Furthermore, because even slight changes in film thickness are critical for each layer of the mask layer, high chemical resistance to etching or cleaning solutions is also required. However, layers with high chemical resistance require longer etching times, which can adversely affect exposed areas other than the target area. For example, this can cause surface roughness on the glass substrate, unexpected changes in film thickness, and poor cross-sectional shape due to poor etching. For this reason, there is also a demand for shortening the etching time.

[0007] Wet etching of a molybdenum silicide film requires the use of an etching solution containing hydrofluoric acid. Therefore, during over-etching of the molybdenum silicide, the glass substrate is etched by the etching solution containing hydrofluoric acid. If the wet etching time for the phase shift film is long, the over-etching time inevitably becomes long. This can cause damage to the transparent substrate, such as glass, during pattern formation, potentially causing the optical characteristics of the phase shift mask to deviate from the specified range. Therefore, it is desirable to keep the wet etching time as short as possible.

[0008] Furthermore, there is a trade-off between shortening the wet etching time and chemical resistance, and the use of a phase shift film with a short wet etching time results in a deterioration in chemical resistance to alkaline solutions. Since alkaline solutions are used in the cleaning process during mask fabrication, poor chemical resistance can cause changes in the phase shift mask characteristics during the cleaning process.

[0009] The present invention has been made in view of the above circumstances, and aims to achieve the following objects. 1. In the phase shift phase, shortening of etching time and improvement of chemical resistance are simultaneously realized. 2. Achieve patterning accuracy while maintaining optical properties simultaneously. 3. Simultaneously reduce the roughness of the glass substrate surface and reduce defects. [Means for solving the problem]

[0010] Generally, in phase shift masks and phase shift mask blanks, film formation conditions such as film thickness and film composition are set to control the accuracy of patterning and the accuracy of optical properties. Conventionally, the following control concepts have been used for molybdenum silicide films. In order to improve chemical resistance, the following measures are taken: Increase the nitrogen (N) content in the film composition. Reduce oxygen (O) in the film composition. Reduce carbon (C) in the film composition. · Reduce the amount of molybdenum (Mo) in the film composition. Increase the substrate temperature during film formation. - Reduce the deposition pressure during deposition. One or more of these methods can be selected to improve chemical resistance, but any of these methods will result in a longer etching time.

[0011] Conversely, in order to shorten the etching time, the following measures are adopted. Reduce nitrogen (N) in the film composition. Increase the oxygen (O) content in the film composition. Increase the carbon (C) content of the film. · Increase the amount of molybdenum (Mo) in the film composition. - Lower the substrate temperature during film formation. Increase the deposition pressure during deposition. One or more of these methods can be used to shorten the etching time. However, using any of these methods reduces chemical resistance. Furthermore, the inclusion of oxygen (O) in the film composition leads to poor defect quality.

[0012] Conventionally, in order to form a film with the required optical properties (optical density, refractive index, transmittance, etc.), the above-mentioned methods have been combined and adjusted, but with this conventional method, there is a trade-off between chemical resistance and shortening the etching time. In response to this, the inventors of the present invention have conducted extensive research and discovered the following facts.

[0013] As mentioned above, the etching time is usually shortened when oxygen (O) is mixed into the molybdenum silicon film. However, it was found that the etching time is longer for molybdenum silicon films (MoSi7.0 to MoSi15.0) that contain a high proportion of silicon (Si). Furthermore, while adding CO2 gas during deposition of molybdenum silicon films typically shortens the etching time, in the case of molybdenum silicon films (MoSi7.0 to MoSi15.0) that contain a high proportion of silicon (Si), adding even a small amount of CO2 gas during deposition makes etching impossible. Here, the "7.0" in MoSi7.0 indicates the ratio of silicon to molybdenum.

[0014] Generally, when the film composition of a molybdenum silicon film contains a large amount of molybdenum (Mo) and a small amount of silicon (Si), wet etching proceeds and the etching time becomes shorter. On the other hand, if the film composition of the molybdenum silicon film contains less molybdenum (Mo) and more silicon (Si), the wet etching will not proceed well and the etching time will be longer. This is thought to be because the ease of etching the molybdenum silicon film changes depending on the ratio of molybdenum trioxide, which is easily dissolved by wet etching, to silicon oxide, which is not easily dissolved by wet etching. The inventors of the present invention have found that the boundary value at which the ease of etching of the molybdenum silicon film changes is near Mo:Si=1:7.0 (MoSi7.0).

[0015] In general, mixing nitrogen (N) into a molybdenum silicon film increases the etching time, and also increases the transmittance. In contrast, in the case of molybdenum silicon films (MoSi7.0 to MoSi15.0) with a high silicon (Si) content, transmittance can be increased because the molybdenum (Mo) content is low. Therefore, in the case of molybdenum silicon films (MoSi7.0 to MoSi15.0) with a high silicon (Si) content, transmittance does not decrease even if the nitrogen (N) content is reduced.

[0016] The inventors of the present application have found that when forming a molybdenum silicon film (approximately MoSi7.0 to MoSi15.0) with a high proportion of silicon (Si), if the film formation gases supplied are Ar gas and N2 gas, a transmittance of 5% at I-line can be satisfied even if the amount of N2 gas is reduced relative to Ar gas and the gas ratio Ar / N2 is increased. At this time, the amount of nitrogen (N) in the film composition of the molybdenum silicon film is reduced, which shortens the etching time of the molybdenum silicon film (MoSi7.0-MoSi15.0). Also, since there is no need to add oxygen (O), the amount of molybdenum trioxide does not increase, which improves the chemical resistance of the molybdenum silicon film (MoSi7.0-MoSi15.0).

[0017] In the past, the substrate was heated during the deposition of molybdenum silicon films, but we found that deposition without heating the substrate shortened the etching time. The mechanism behind this is unclear, but it is thought that etching was inhibited by film properties (film density, degree of oxidation) caused by heating.

[0018] Furthermore, the etching time was shortened by forming the molybdenum silicon film at high pressure, but in this case, the trade-off was that chemical resistance was deteriorated. The present inventors have discovered that, under certain conditions, the chemical resistance of the molybdenum silicon film can be improved by low-pressure film formation, and at the same time, the etching time can be shortened even with low-pressure film formation.

[0019] In summary, the inventors of the present application have found that by using only Ar gas and N2 gas as deposition gases to form molybdenum silicon films (MoSi7.0 to MoSi15.0) with a high proportion of silicon (Si), increasing the Ar gas ratio and using a supply gas that does not contain oxygen (O), nitriding but not oxidizing, and depositing under conditions of low deposition pressure and no substrate heating, it is possible to shorten the etching time and, at the same time, find a range within which chemical resistance can be maintained while maintaining a short etching time. This has made it possible to achieve both high chemical resistance and a short etching time in a molybdenum silicon film, thereby completing the present invention.

[0020] (1) A phase shift mask blank according to one aspect of the present invention, A phase shift mask blank having a mask layer that serves as a phase shift mask, a phase shift layer made of a metal silicide laminated on a transparent substrate; the phase shift layer contains nitrogen, molybdenum, and silicon, and the average ratio of the silicon composition ratio (atm%) to the molybdenum composition ratio (atm%), Si / Mo, is in the range of 2.2 to 3.2; This solved the above problem. (2) The phase shift mask blank of the present invention, in the above (1), a light-shielding layer containing chromium laminated on the phase shift layer; It is possible. (3) The phase shift mask blank of the present invention, in the above (1), The phase shift layer has an average ratio N / Si of nitrogen composition (atm%) to silicon composition (atm%) in the range of 0.50 to 0.65. It is possible. (4) The phase shift mask blank of the present invention, in the above (1), The phase shift layer has an average value of a ratio Si / (Mo+N) of a silicon composition ratio (atm%) to a sum of a molybdenum composition ratio (atm%) and a nitrogen composition ratio (atm%) in the range of 1.00 to 1.13. It is possible. (5) The phase shift mask blank of the present invention, in the above (1), The phase shift layer has an average ratio N / (Mo+Si) of the nitrogen composition ratio (atm%) to the sum of the molybdenum composition ratio (atm%) and the silicon composition ratio (atm%) in the range of 0.35 to 0.50. It is possible. (6) The phase shift mask blank of the present invention, in the above (1), The phase shift layer has an average ratio N / Mo of the nitrogen composition ratio (atm%) to the molybdenum composition ratio (atm%) in the range of 1.4 to 1.75. It is possible. (7) The phase shift mask blank of the present invention, in the above (1), The phase shift layer has an average sum of the molybdenum composition ratio (atm%), the silicon composition ratio (atm%), and the nitrogen composition ratio (atm%), Mo+Si+N, which is greater than 90. It is possible. (8) The phase shift mask blank of the present invention, in the above (1), The phase shift layer has an average ratio O / Si of the oxygen composition ratio (atm%) detected by Auger electron spectroscopy to the silicon composition ratio (atm%) in the range of 0.01 to 0.15. It is possible. (9) Another aspect of the present invention provides a method for producing a phase shift mask blank, comprising the steps of: 1. A method for producing a phase shift mask blank according to any one of claims 1 to 9, When forming the phase shift layer, the ratio of molybdenum to silicon is 7.0≦Si / Mo≦15.0 Sputtering is performed using a target having a composition set to It is possible. (10) The method for producing a phase shift mask blank of the present invention is the method for producing a phase shift mask blank of the present invention described above in (9), When forming the phase shift layer, sputtering is performed by supplying argon gas and nitrogen gas. It is possible. (11) Another aspect of the present invention is a method for manufacturing a phase shift mask, A phase shift mask is manufactured by patterning the phase shift mask blank manufactured by the method for manufacturing a phase shift mask blank according to (10) above, by wet etching. It is possible. (12) A phase shift mask according to another aspect of the present invention comprises: Manufactured by the method for manufacturing a phase shift mask according to (11) above. It is possible.

[0021] (1) A phase shift mask blank according to one aspect of the present invention, A phase shift mask blank having a mask layer that serves as a phase shift mask, a phase shift layer made of a metal silicide laminated on a transparent substrate; the phase shift layer contains nitrogen, molybdenum, and silicon, and the average ratio of the silicon composition ratio (atm%) to the molybdenum composition ratio (atm%), Si / Mo, is in the range of 2.2 to 3.2; This solved the above problem.

[0022] In the above configuration, the phase shift layer is a layer made of molybdenum, silicon, and nitrogen, and does not contain oxygen, thereby improving chemical resistance. Since the phase shift layer does not contain oxygen, the etching time should be long, but by setting the molybdenum to silicon ratio within the above range, the etching time can be shortened. Since the phase shift layer does not contain oxygen but does contain nitrogen, the transmittance can be increased and set to about 5% for I-line.

[0023] Furthermore, the phase shift layer has a significantly higher silicon content than molybdenum, which prevents etching from progressing.The phase shift layer has a significantly higher silicon content than molybdenum, and does not contain oxygen, which suppresses the occurrence of defects and increases transmittance. Therefore, it is possible to achieve both high chemical resistance and a short etching time in the phase shift layer.

[0024] (2) The phase shift mask blank of the present invention, in the above (1), a light-shielding layer containing chromium laminated on the phase shift layer; It is possible.

[0025] In the above configuration, the chemical resistance of the surface of the phase shift layer can be maintained. The etching time for the phase shift layer can be shortened. The pattern formation shapes of the phase shift layer and the light-shielding layer can be optimized. The fluctuation in film thickness of the phase shift layer due to hydrofluoric acid can be suppressed. The phase shift characteristics of the phase shift layer are not changed. All of these can be achieved simultaneously.

[0026] Furthermore, the etching rate of the phase shift layer, which is a molybdenum silicide film, can be increased, making it possible to form a phase shift pattern by fast etching. As a result, even when a phase shift layer is etched with an etching solution containing hydrofluoric acid when a phase shift mask is manufactured from a phase shift mask blank, i.e., when a phase shift pattern is formed from the phase shift layer, the etching time required can be shortened.

[0027] Even when the phase shift layer is etched with an etching solution containing hydrofluoric acid, over-etching can be suppressed. The effects of etching with hydrofluoric acid on a transparent substrate, such as a glass substrate (quartz substrate), can be reduced. The phase shift characteristics are not changed by etching the glass substrate. Since the defect quality of the phase shift layer does not deteriorate, problems such as pattern formation not occurring when forming a phase shift pattern from the phase shift layer do not occur. Furthermore, the surface of the phase shift layer maintains high chemical resistance, and the film thickness can be prevented from being changed by a cleaning solution such as an alkali in the cleaning process.The phase shift characteristics of the phase shift layer are not changed. These can be achieved simultaneously.

[0028] (3) The phase shift mask blank of the present invention, in the above (1), The phase shift layer has an average ratio N / Si of nitrogen composition (atm%) to silicon composition (atm%) in the range of 0.50 to 0.65. It is possible.

[0029] In the above configuration, the phase shift layer has a nitrogen to silicon ratio within the above range and does not contain oxygen, thereby improving chemical resistance. Since the phase shift layer does not contain oxygen, the etching time should be long, but by setting the nitrogen to silicon ratio within the above range, the etching time can be shortened. Since the phase shift layer does not contain oxygen but does contain nitrogen, the transmittance can be increased and set to about 5% for I-line.

[0030] Furthermore, by setting the nitrogen to silicon ratio in the above range, the phase shift layer can prevent etching from progressing. The phase shift layer contains a large amount of silicon, the nitrogen to silicon ratio is set in the above range, and oxygen is not added, so that the occurrence of defects can be suppressed and the transmittance can be increased. Therefore, it is possible to achieve both high chemical resistance and a short etching time in the phase shift layer.

[0031] (4) The phase shift mask blank of the present invention, in the above (1), The phase shift layer has an average ratio Si / (Mo+N) of the silicon composition ratio (atm%) to the sum of the molybdenum composition ratio (atm%) and the nitrogen composition ratio (atm%) in the range of 1.00 to 1.13. It is possible.

[0032] In the above configuration, the phase shift layer is a layer in which the ratio of silicon to the sum of nitrogen and molybdenum is within the above range, and oxygen is not added, thereby improving chemical resistance. Since the phase shift layer does not contain oxygen, the etching time should be long, but by setting the ratio of silicon to the sum of nitrogen and molybdenum to the above range, the etching time can be shortened. Because the phase shift layer does not contain oxygen but does contain nitrogen, the transmittance is increased and can be set to about 5% for I-line.

[0033] Furthermore, by setting the ratio of silicon to the sum of nitrogen and molybdenum in the phase shift layer within the above range, etching can be prevented from progressing. The phase shift layer contains a large amount of silicon, and the ratio of silicon to the sum of nitrogen and molybdenum is set within the above range, and no oxygen is added, so that the occurrence of defects can be suppressed and transmittance can be increased. Therefore, it is possible to achieve both high chemical resistance and a short etching time in the phase shift layer.

[0034] (5) The phase shift mask blank of the present invention, in the above (1), The phase shift layer has an average ratio N / (Mo+Si) of the nitrogen composition ratio (atm%) to the sum of the molybdenum composition ratio (atm%) and the silicon composition ratio (atm%) in the range of 10.35 to 0.50. It is possible.

[0035] In the above configuration, the phase shift layer is a layer in which the ratio of nitrogen to the sum of silicon and molybdenum is within the above range, and oxygen is not added, thereby improving chemical resistance. Since the phase shift layer does not contain oxygen, the etching time should be long, but by setting the ratio of nitrogen to the sum of silicon and molybdenum within the above range, the etching time can be shortened. Because the phase shift layer does not contain oxygen but does contain nitrogen, the transmittance can be increased and set to about 5% for I-line.

[0036] Furthermore, by setting the ratio of nitrogen to the sum of silicon and molybdenum in the phase shift layer within the above range, etching can be prevented from progressing. The phase shift layer contains a large amount of silicon, has the ratio of nitrogen to the sum of silicon and molybdenum in the above range, and does not contain oxygen, so it is possible to suppress the occurrence of defects and increase transmittance. Therefore, it is possible to achieve both high chemical resistance and a short etching time in the phase shift layer.

[0037] (6) The phase shift mask blank of the present invention, in the above (1), The phase shift layer has an average ratio N / Mo of the nitrogen composition ratio (atm%) to the molybdenum composition ratio (atm%) in the range of 1.4 to 1.75. It is possible.

[0038] In the above configuration, the phase shift layer has a nitrogen-to-molybdenum ratio within the above range and does not contain oxygen, thereby improving chemical resistance. Since the phase shift layer does not contain oxygen, the etching time should be long, but by setting the nitrogen-to-molybdenum ratio within the above range, the etching time can be shortened. Since the phase shift layer does not contain oxygen but does contain nitrogen, the transmittance can be increased and set to about 5% for I-line.

[0039] Furthermore, by setting the ratio of nitrogen to molybdenum in the phase shift layer within the above range, etching can be prevented from progressing. The phase shift layer contains a large amount of silicon, has the ratio of nitrogen to molybdenum in the above range, and does not contain oxygen, so it is possible to suppress the occurrence of defects and increase transmittance. Therefore, it is possible to achieve both high chemical resistance and a short etching time in the phase shift layer.

[0040] (7) The phase shift mask blank of the present invention, in the above (1), The phase shift layer has an average sum of the molybdenum composition ratio (atm%), the silicon composition ratio (atm%), and the nitrogen composition ratio (atm%), Mo+Si+N, which is greater than 90. It is possible.

[0041] In the above configuration, the phase shift layer is a layer in which the sum of the ratios of silicon and nitrogen is within the above range, and oxygen is not added, thereby improving chemical resistance. Since the phase shift layer does not contain oxygen, the etching time should be long, but by setting the sum of the ratios of silicon and nitrogen within the above range, the etching time can be shortened. Since the phase shift layer does not contain oxygen but does contain nitrogen, the transmittance can be increased and set to about 5% for I-line.

[0042] Furthermore, by setting the sum of the ratios of silicon and nitrogen in the phase shift layer within the above range, etching can be prevented from progressing. The phase shift layer contains a large amount of silicon, has the sum of the ratios of silicon and nitrogen within the above range, and does not contain oxygen, so that the occurrence of defects can be suppressed and transmittance can be increased. Therefore, it is possible to achieve both high chemical resistance and a short etching time in the phase shift layer.

[0043] (8) The phase shift mask blank of the present invention, in the above (1), The phase shift layer has an average ratio O / Si of the oxygen composition ratio (atm%) detected by Auger electron spectroscopy to the silicon composition ratio (atm%) in the range of 0.01 to 0.15. It is possible.

[0044] In the above configuration, the phase shift layer is a layer in which the ratio of detected oxygen to silicon is within the above range, and since oxygen is not added, chemical resistance can be improved. Since the phase shift layer does not contain oxygen, the etching time should be long, but by setting the ratio of detected oxygen to silicon within the above range, the etching time can be shortened. Since the phase shift layer does not contain oxygen but contains nitrogen, transmittance can be increased and set to about 5% for I-line.

[0045] Furthermore, by setting the ratio of detected oxygen to silicon in the phase shift layer to the above range, etching can be prevented from progressing. The phase shift layer contains a large amount of silicon, and the ratio of detected oxygen to silicon is set to the above range, and oxygen is not added, so that the occurrence of defects can be suppressed and transmittance can be increased. Therefore, it is possible to achieve both high chemical resistance and a short etching time in the phase shift layer. It is believed that oxygen was detected in the analysis using Auger electron spectroscopy due to the atmosphere of the sample, moisture and other adhering matter on the sample, impurities mixed in during the analysis, and the like.

[0046] (9) Another aspect of the present invention provides a method for producing a phase shift mask blank, comprising the steps of: 1. A method for producing a phase shift mask blank according to any one of claims 1 to 9, When forming the phase shift layer, the ratio of molybdenum to silicon is 7.0≦Si / Mo≦15.0 Sputtering is performed using a target having a composition set to It is possible.

[0047] In the above configuration, by using the above target, it is possible to deposit a phase shift layer in which the average ratio of silicon composition ratio (atm %) to molybdenum composition ratio (atm %), Si / Mo, is in the range of 2.2 to 3.2.

[0048] (10) The method for producing a phase shift mask blank of the present invention is the method for producing a phase shift mask blank of the present invention, wherein the method comprises the steps of: When forming the phase shift layer, sputtering is performed by supplying argon gas and nitrogen gas. It is possible.

[0049] In the above configuration, by setting the gases supplied during the deposition of the phase shift layer as described above, the phase shift layer contains nitrogen, molybdenum, and silicon, and the average value of the ratio of the silicon composition ratio (atm%) to the molybdenum composition ratio (atm%), Si / Mo, is in the range of 2.2 to 3.2, the average value of the ratio of the nitrogen composition ratio (atm%) to the silicon composition ratio (atm%), N / Si, is in the range of 0.50 to 0.65, the average value of the ratio of the silicon composition ratio (atm%) to the sum of the molybdenum composition ratio (atm%) and the nitrogen composition ratio (atm%), Si / (Mo+N), is in the range of 1.00 to 1.13, and the average value of the ratio of the nitrogen composition ratio (atm%) to the sum of the molybdenum composition ratio (atm%) and the silicon composition ratio (atm%), N / (Mo+Si), is in the range of 1.00 to 1.13. a phase shift layer can be formed in which the average value of the ratio N / Mo of the nitrogen composition ratio (atm%) to the molybdenum composition ratio (atm%) is in the range of 0.35 to 0.50, the average value of the ratio N / Mo of the nitrogen composition ratio (atm%) to the molybdenum composition ratio (atm%) is in the range of 1.4 to 1.75, the average value of the sum of the molybdenum composition ratio (atm%), the silicon composition ratio (atm%), and the nitrogen composition ratio (atm%) is in the range of more than 90, and the average value of the ratio O / Si of the oxygen composition ratio (atm%) to the silicon composition ratio (atm%) detected by Auger electron spectroscopy is in the range of 0.01 to 0.15.

[0050] (11) Another aspect of the present invention is a method for manufacturing a phase shift mask, A phase shift mask is manufactured by patterning the phase shift mask blank manufactured by the method for manufacturing a phase shift mask blank according to (10) above, by wet etching. It is possible.

[0051] In the above configuration, by using a phase shift mask blank having a phase shift layer that can achieve both high chemical resistance and short etching time, it is possible to produce a high-quality phase shift mask with accurate pattern formation and reduced damage to the transparent substrate.

[0052] (12) A phase shift mask according to another aspect of the present invention comprises: Manufactured by the method for manufacturing a phase shift mask according to (11) above. It is possible. [Effects of the Invention]

[0053] According to the present invention, a phase shift mask blank is provided having a phase shift layer that can achieve both high chemical resistance and short etching time, and it is possible to simultaneously achieve a reduction in the roughness of the glass substrate surface and a reduction in defects, thereby simultaneously achieving patterning accuracy and maintaining optical properties. [Brief explanation of the drawings]

[0054] [Figure 1] 1 is a cross-sectional view showing a first embodiment of a phase shift mask blank according to the present invention. [Figure 2] 1 is a cross-sectional view showing a first embodiment of a method for producing a phase shift mask blank according to the present invention. [Figure 3] 1A to 1C are cross-sectional views showing the steps of a first embodiment of a method for manufacturing a phase shift mask according to the present invention. [Figure 4] 1A to 1C are cross-sectional views showing the steps of a first embodiment of a method for manufacturing a phase shift mask according to the present invention. [Figure 5] 1A to 1C are cross-sectional views showing the steps of a first embodiment of a method for manufacturing a phase shift mask according to the present invention. [Figure 6] 1A to 1C are cross-sectional views showing the steps of a first embodiment of a method for manufacturing a phase shift mask according to the present invention. [Figure 7] 1A to 1C are cross-sectional views showing the steps of a first embodiment of a method for manufacturing a phase shift mask according to the present invention. [Figure 8] 1A to 1C are cross-sectional views showing the steps of a first embodiment of a method for manufacturing a phase shift mask according to the present invention. [Figure 9] 1 is a cross-sectional view showing a first embodiment of a phase shift mask according to the present invention. [Figure 10] 1 is a schematic diagram showing a film formation apparatus in a first embodiment of a method for producing a phase shift mask blank according to the present invention. [Figure 11] 1 is a schematic diagram showing a film formation apparatus in a first embodiment of a method for producing a phase shift mask blank according to the present invention. [Figure 12] 10 is a graph showing the results of Auger analysis of N in a phase shift layer in an experimental example according to the present invention. [Figure 13] 10 is a graph showing the results of Auger analysis of O in a phase shift layer in an experimental example according to the present invention. [Figure 14] 10 is a graph showing the results of Auger analysis of Si in a phase shift layer in an experimental example according to the present invention. [Figure 15] 10 is a graph showing the results of Auger analysis of Mo in a phase shift layer in an experimental example according to the present invention. [Figure 16] 10 is a graph showing the results of Auger analysis of Si / Mo in a phase shift layer in an experimental example according to the present invention. [Figure 17] 10 is a graph showing the results of Auger analysis of Si / (Mo+N) in a phase shift layer in an experimental example according to the present invention. [Figure 18] 10 is a graph showing the results of Auger analysis of N / (Mo+Si) in a phase shift layer in an experimental example according to the present invention. [Figure 19] 10 is a graph showing the results of Auger analysis of N / Mo in a phase shift layer in an experimental example according to the present invention. [Figure 20]10 is a graph showing the results of Auger analysis of O / Si in a phase shift layer in an experimental example according to the present invention. [Figure 21] 10 is a graph showing the results of Auger analysis of O / Mo in a phase shift layer in an experimental example according to the present invention. [Figure 22] 10 is a graph showing the results of O / N Auger analysis of a phase shift layer in an experimental example according to the present invention. [Figure 23] 10 is a graph showing the results of Auger analysis of (O+N) / Si in a phase shift layer in an experimental example according to the present invention. [Figure 24] 10 is a graph showing the results of Auger analysis of Mo+Si+N in a phase shift layer in an experimental example according to the present invention. [Figure 25] 10 shows data showing the results of Auger analysis of a phase shift layer in an experimental example according to the present invention. [Figure 26] 10 is data showing a change in transmittance in a phase shift layer in an experimental example according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0055] A first embodiment of a phase shift mask blank, a phase shift mask, and a manufacturing method thereof according to the present invention will be described below with reference to the drawings. Fig. 1 is a cross-sectional view showing a phase shift mask blank in this embodiment. Fig. 2 is a cross-sectional view showing a phase shift mask blank in this embodiment. In the figure, reference numeral 10B denotes a phase shift mask blank.

[0056] The phase shift mask blank 10B according to this embodiment is intended to be used as a phase shift mask (photomask) for use with exposure light having a wavelength in the range of approximately 365 nm to 436 nm, or approximately 290 to 380 nm. As shown in FIG. 1, the phase shift mask blank 10B according to this embodiment is composed of a glass substrate (transparent substrate) 11, a phase shift layer 12 formed on this glass substrate 11, and a light-shielding layer 13 formed on the phase shift layer 12.

[0057] The phase shift layer 12 is formed directly on the surface of the glass substrate 11. The light-shielding layer 13 is provided at a position farther away from the glass substrate 11 than the phase shift layer 12. The light-shielding layer 13 is formed on the surface of the phase shift layer 12. The phase shift layer 12 is sandwiched between the glass substrate 11 and the light-shielding layer 13. Phase shift layer 12 and light-shielding layer 13 have the optical properties required for a photomask. Phase shift layer 12 and light-shielding layer 13 constitute a mask layer, which is a phase shift film that can shift the phase of exposure light by approximately 180°.

[0058] The mask blank 10B according to this embodiment may also have a photoresist layer 15 formed thereon in advance, as shown in FIG.

[0059] In addition to the phase shift mask blank 10B according to this embodiment, the mask layer may be configured by laminating an antireflection layer, an adhesion layer, a chemical-resistant layer, a protective layer, an etching stopper layer, etc. in addition to the phase shift layer 12 and the light-shielding layer 13. Furthermore, in the phase shift mask blank 10B according to this embodiment, a photoresist layer 15 may be formed on these laminated films.

[0060] The glass substrate (transparent substrate) 11 is made of a material having excellent transparency and optical isotropy. For example, a quartz glass substrate is used as the glass substrate 11. The size of the glass substrate 11 is not particularly limited. The size of the glass substrate 11 is appropriately selected according to the substrate to be exposed using the phase shift mask. The substrate to be exposed using the phase shift mask is, for example, a substrate for an FPD such as an LCD (liquid crystal display), a plasma display, or an organic EL (electroluminescence) display.

[0061] The glass substrate 11 can be a rectangular substrate with a side of about 100 mm. The glass substrate 11 may be a rectangular substrate with a side of more than 100 mm. The glass substrate 11 can be a rectangular substrate with a side of 2000 mm or more. The glass substrate 11 can be a substrate with a thickness of 1 mm or less. The glass substrate 11 can be a substrate with a thickness of more than 1 mm. The glass substrate 11 can be a substrate with a thickness of several mm. The glass substrate 11 can also be a substrate with a thickness of 10 mm or more.

[0062] Furthermore, the surface flatness of the glass substrate 11 may be reduced. The surface flatness of the glass substrate 11 is reduced by polishing the surface. The flatness of the glass substrate 11 can be reduced to, for example, 20 μm or less. Reducing the surface flatness of the glass substrate 11 increases the depth of focus of the mask. Reducing the surface flatness of the glass substrate 11 can greatly contribute to the formation of fine and highly accurate patterns. Furthermore, the surface flatness of the glass substrate 11 can be reduced to 10 μm or less. It is preferable that the surface flatness of the glass substrate 11 is reduced.

[0063] The phase shift layer 12 is a metal silicide film containing silicon and a metal such as Ta, Ti, W, Mo, or Zr, or an alloy of these metals. The phase shift layer 12 is a molybdenum silicide film. The phase shift layer 12 contains O (oxygen). The phase shift layer 12 contains N (nitrogen). The phase shift layer 12 contains C (carbon). The phase shift layer 12 is MoSi X (X≧2) film. Phase shift layer 12 is a MoSi2 film. Phase shift layer 12 is a MoSi3 film. Phase shift layer 12 is a MoSi4 film.

[0064] The phase shift layer 12 has predetermined optical characteristics. The phase shift layer 12 must have the optical characteristics required for use as a phase shift mask. For this reason, the composition and film thickness are set within predetermined ranges. For example, the phase shift layer 12 is set to have a transmittance of approximately 5% at a wavelength of approximately 365 nm. Alternatively, the phase shift layer 12 may be set to have a refractive index of approximately 2.4 to 3.1 and an extinction coefficient of 0.3 to 2.1 in a wavelength range of approximately 365 nm to 436 nm. The optical characteristics of the phase shift layer 12 are not limited to the above values. The composition ratio and film thickness of phase shift layer 12 are set depending on the optical characteristics required for phase shift mask 10 to be manufactured.

[0065] Phase shift layer 12 is a molybdenum silicide film containing nitrogen (N). Phase shift layer 12 preferably does not contain oxygen (O) or carbon (C). Phase shift layer 12 is a MoSiN film. The phase shift layer 12 has a silicon composition ratio higher than the molybdenum composition ratio and the nitrogen composition ratio. The phase shift layer 12 has a molybdenum composition ratio and a nitrogen composition ratio that are approximately the same. The phase shift layer 12 may contain impurities other than silicon, molybdenum, and nitrogen. The phase shift layer 12 has a composition ratio of elements other than silicon, molybdenum, and nitrogen that is less than 10 atm%.

[0066] The phase shift layer 12 has a nitrogen composition ratio (atm %) in the range of 25 atm % to 30 atm %. The phase shift layer 12 has a silicon composition ratio (atm %) in the range of 45 atm % to 50 atm %. The phase shift layer 12 has a molybdenum composition ratio (atm %) in the range of 15 atm % to 20 atm %.

[0067] In the phase shift layer 12, the average ratio of the silicon composition ratio (atm %) to the molybdenum composition ratio (atm %), Si / Mo, is in the range of 2.2 to 3.2. In the phase shift layer 12, the average ratio N / Si of the nitrogen composition ratio (atm %) to the silicon composition ratio (atm %) is in the range of 0.50 to 0.65. In the phase shift layer 12, the average value of the ratio Si / (Mo+N) of the silicon composition ratio (atm %) to the sum of the molybdenum composition ratio (atm %) and the nitrogen composition ratio (atm %) is in the range of 1.00 to 1.13.

[0068] In the phase shift layer 12, the average value of the ratio N / (Mo+Si) of the nitrogen composition ratio (atm %) to the sum of the molybdenum composition ratio (atm %) and the silicon composition ratio (atm %) is in the range of 0.35 to 0.50. In the phase shift layer 12, the average ratio N / Mo of the nitrogen composition ratio (atm %) to the molybdenum composition ratio (atm %) is in the range of 1.4 to 1.75. In the phase shift layer 12, the average value of the sum of the molybdenum composition ratio (atm %), the silicon composition ratio (atm %), and the nitrogen composition ratio (atm %) is in the range of 90 or more.

[0069] Here, the average value of each ratio means the value of the composition ratio, excluding measurement variations, in the region where the composition ratio value is constant in the film thickness direction of the graph, as described below. Specifically, the arithmetic average can be calculated by excluding the maximum and minimum values ​​from the multiple measured values ​​in the region corresponding to the phase shift layer 12. Alternatively, the arithmetic average can be calculated by excluding the maximum value and the next largest value, and the minimum value and the next smallest value from the multiple measured values. Alternatively, the arithmetic average can be calculated by excluding the maximum value, a predetermined number of values ​​larger than the maximum value, the minimum value, and a predetermined number of values ​​smaller than the minimum value from the multiple measured values.

[0070] When the composition of the phase shift layer 12 is measured using Auger electron spectroscopy, oxygen and carbon, which were not added during film formation, are detected, as described below. While the cause of this is largely unknown, it means that oxygen and carbon are detected as unavoidable impurities during composition measurement using Auger electron spectroscopy. The detection of oxygen and carbon as unavoidable impurities is thought to be due to external factors, such as insufficient removal in the film formation equipment, adhesion after film formation, or contamination after film formation, which are contained in the molybdenum silicide film, or insufficient removal before measurement or contamination into the measurement atmosphere.

[0071] The oxygen composition ratio (atm %) of the phase shift layer 12, as detected by Auger electron spectroscopy, is in the range of 0 atm % to 5 atm %. In the phase shift layer 12, the average value of the ratio O / Si of the oxygen composition ratio (atm %) to the silicon composition ratio (atm %) detected by Auger electron spectroscopy is in the range of 0.01 to 0.15. In the phase shift layer 12, the average value of the ratio O / N of the oxygen composition ratio (atm %) to the nitrogen composition ratio (atm %) detected by Auger electron spectroscopy is in the range of 0.01 to 0.3.

[0072] In the phase shift layer 12, the average ratio O / Mo of the oxygen composition ratio (atm %) to the molybdenum composition ratio (atm %) detected by Auger electron spectroscopy is in the range of 0.01 to 0.3. In the phase shift layer 12, the average ratio (O+N) / Si of the oxygen composition ratio (atm%) and the nitrogen composition ratio (atm%) relative to the silicon composition ratio (atm%) detected by Auger electron spectroscopy is in the range of 0.6 to 0.75.

[0073] The phase shift layer 12 has a composition ratio (atm %) of impurities other than nitrogen, silicon, molybdenum, and oxygen detected by Auger electron spectroscopy in the range of 0 atm % to 5 atm %. Specifically, the impurity may be carbon (C). In the phase shift layer 12, the composition ratio (atm%) of impurities other than nitrogen, silicon, molybdenum, and oxygen detected using Auger electron spectroscopy is approximately equal to the composition ratio (atm%) of oxygen detected using Auger electron spectroscopy, or the composition ratio (atm%) of oxygen is slightly smaller, ranging from 0.54 to 0.55.

[0074] The phase shift layer 12 may have a composition that varies along the thickness direction.

[0075] The thickness of the phase shift layer 12 is set in the range of 100 nm to 200 nm. The thickness of the phase shift layer 12 is set in the range of 120 nm to 150 nm. The thickness of the phase shift layer 12 is set in the range of 135 nm to 145 nm.

[0076] The light-shielding layer 13 contains Cr (chromium) as a main component. The light-shielding layer 13 contains O (oxygen) as a main component. The light-shielding layer 13 contains C (carbon). The light-shielding layer 13 contains N (nitrogen). The light-shielding layer 13 can also be formed by laminating one or more materials selected from chromium oxide, chromium nitride, chromium carbide, chromium oxynitride, chromium carbonitride, and chromium oxycarbonitride.

[0077] The light-shielding layer 13 contains Cr (chromium) and O (oxygen) as main components, and may further contain C (carbon) and N (nitrogen). In this case, the light-shielding layer 13 may be formed by laminating one or more materials selected from oxides, nitrides, carbides, oxynitrides, carbonitrides, and oxycarbonitrides of Cr. Furthermore, the light-shielding layer 13 may have a composition that varies in the thickness direction. For example, the light-shielding layer 13 may have a configuration in which the nitrogen concentration or oxygen concentration is graded in the thickness direction.

[0078] Furthermore, the light-shielding layer 13 may have a composition that varies in the thickness direction. For example, the light-shielding layer 13 may have a nitrogen concentration that varies in the thickness direction. The light-shielding layer 13 may have an oxygen concentration that varies in the thickness direction. The light-shielding layer 13 may have a carbon concentration that varies in the thickness direction.

[0079] As will be described later, the thickness and composition ratio (atm %) of Cr, N, C, O, Si, etc. of the light-shielding layer 13 are set so as to obtain predetermined adhesion (hydrophobicity) and predetermined optical characteristics. The concentrations (composition ratio; atm %) of chromium, nitrogen, carbon, oxygen, etc. of light-shielding layer 13 are set so as to obtain predetermined optical characteristics. The film thickness of light-shielding layer 13 is set so as to obtain predetermined optical characteristics. The film characteristics of light-shielding layer 13 vary depending on the composition ratio of chromium, nitrogen, carbon, oxygen, etc. The film thickness of light-shielding layer 13 can be set particularly depending on the optical characteristics required for phase shift mask 10.

[0080] By setting the film thickness and composition of the light-shielding layer 13 as described above, adhesion to the photoresist layer 15, for example, made of chromium, is improved during patterning by photolithography, and penetration of the etching solution at the interface with the photoresist layer 15 does not occur, resulting in a good pattern shape and enabling the formation of a desired pattern.

[0081] If the light-shielding layer 13 is not set to the above conditions, it is undesirable because overhangs are formed at the interface between the phase shift layer 12 and the light-shielding layer 13 by etching during mask pattern formation. If the light-shielding layer 13 is not set to the above conditions, it is undesirable because the mask pattern has a non-perpendicular cross-sectional shape. Furthermore, if the light-shielding layer 13 is not set to the above conditions, it is difficult to set the optical characteristics of the photomask to the desired conditions, which is undesirable.

[0082] The refractive index of the light-shielding layer 13 can be reduced by increasing the oxygen concentration in the chromium compound. The extinction coefficient of the light-shielding layer 13 can be reduced by increasing the oxygen concentration in the chromium compound. The refractive index of the light-shielding layer 13 can be reduced by increasing the nitrogen concentration in the chromium compound. The extinction coefficient of the light-shielding layer 13 can be reduced by increasing the nitrogen concentration in the chromium compound. The refractive index of the light-shielding layer 13 can be increased by lowering the oxygen concentration in the chromium compound. The extinction coefficient of the light-shielding layer 13 can be increased by lowering the oxygen concentration in the chromium compound. The refractive index of the light-shielding layer 13 can be increased by lowering the nitrogen concentration in the chromium compound. The extinction coefficient of the light-shielding layer 13 can be increased by lowering the nitrogen concentration in the chromium compound.

[0083] In the phase shift mask blank 10B of this embodiment, the phase shift layer 12 can improve chemical resistance. The phase shift layer 12 can shorten the etching time. The phase shift layer 12 can be set to have an I-line transmittance of about 5%. The phase shift layer 12 can prevent etching from progressing. The phase shift layer 12 can suppress the occurrence of defects and increase the transmittance. The phase shift layer 12 can achieve both high chemical resistance and a short etching time.

[0084] The method for manufacturing a phase shift mask blank according to this embodiment will be described below with reference to the drawings.

[0085] FIG. 3 is a cross-sectional view showing the manufacturing process for phase shift mask blanks and phase shift masks in this embodiment. FIG. 4 is a cross-sectional view showing the manufacturing process for phase shift mask blanks and phase shift masks in this embodiment. FIG. 5 is a cross-sectional view showing the manufacturing process for phase shift mask blanks and phase shift masks in this embodiment. FIG. 6 is a cross-sectional view showing the manufacturing process for phase shift mask blanks and phase shift masks in this embodiment. FIG. 7 is a cross-sectional view showing the manufacturing process for phase shift mask blanks and phase shift masks in this embodiment. FIG. 8 is a cross-sectional view showing the manufacturing process for phase shift mask blanks and phase shift masks in this embodiment. FIG. 9 is a cross-sectional view showing a phase shift mask in this embodiment. FIG. 10 is a schematic diagram showing a manufacturing apparatus for phase shift mask blanks in this embodiment.

[0086] The method for manufacturing a phase shift mask blank in this embodiment includes a film-forming step of forming a mask layer on glass substrate 11. In the film-forming step, phase shift layer 12 is formed on glass substrate 11, and then light-shielding layer 13 is formed. The phase shift mask blank 10B in this embodiment is manufactured by a manufacturing apparatus (film forming apparatus) S10 shown in FIG.

[0087] The manufacturing apparatus S10 is an inter-back sputtering apparatus as shown in Fig. 10. The manufacturing apparatus S10 has a load chamber S11, an unload chamber S16, and a film formation chamber (vacuum processing chamber) S12.

[0088] The load chamber S11 has a transfer mechanism S11a and an exhaust mechanism S11f. The transfer mechanism S11a transfers the glass substrate 11 carried in from the outside to the film formation chamber S12. The exhaust mechanism S11f roughly evacuates the inside of the load chamber S11. The exhaust mechanism S11f is a rotary pump or the like. The load chamber S11 is connected to the film formation chamber S12 via a sealing mechanism S17.

[0089] The unloading chamber S16 has a transfer mechanism S16a and an exhaust mechanism S16f. The transfer mechanism S16a transports the glass substrate 11, which has been transferred from the film forming chamber S12 and on which film formation has been completed, to the outside. The exhaust mechanism S16f roughly evacuates the inside of the unloading chamber S16. The exhaust mechanism S16f is a rotary pump or the like. The unloading chamber S16 is connected to the film forming chamber S12 via a sealing mechanism S18.

[0090] The film formation chamber S12 includes a substrate holding mechanism S12a, a film formation mechanism S13, a film formation mechanism S14, and a gas barrier S12g. The film formation chamber S12 is a mechanism capable of two-stage film formation processing with the two film formation mechanisms S13 and S14.

[0091] The substrate holding mechanism S12a receives the glass substrate 11 transported by the transport mechanism S11a. The substrate holding mechanism S12a holds the glass substrate 11 inside the film formation chamber S12. The substrate holding mechanism S12a holds the glass substrate 11 so that it faces the target S13b of the film formation mechanism S13 and the target S14b of the film formation mechanism S14 during film formation. The substrate holding mechanism S12a transports the glass substrate 11 inside the film formation chamber S12. The substrate holding mechanism S12a hands over the glass substrate 11 to the transport mechanism S16a. During film formation, the substrate holding mechanism S12a can apply bias power to the glass substrate 11. During film formation, the substrate holding mechanism S12a can set the temperature of the glass substrate 11.

[0092] The film formation mechanism S13 is disposed inside the film formation chamber S12 and adjacent to the load chamber S11. The film formation mechanism S13 performs the first stage of the two-stage film formation process. The film formation mechanism S13 supplies film formation materials for the first stage of the film formation process. The film forming mechanism S13 includes a target S13b, a cathode electrode (backing plate) S13c, a power source S13d, a gas introducing mechanism S13e, and a high-vacuum exhaust mechanism S13f.

[0093] The target S13b supplies the first-stage film forming material. The target S13b is attached to the cathode electrode S13c. The power supply S13d applies a negative sputtering voltage to the backing plate S13c. The gas introduction mechanism S13e introduces the first-stage film formation gas into the film formation chamber S12. The gas introduction mechanism S13e introduces the first-stage film formation gas into the film formation mechanism S13. The gas introduction mechanism S13e introduces the film formation gas mainly near the cathode electrode S13c. The high-vacuum exhaust mechanism S13f evacuates the inside of the film formation chamber S12. The high-vacuum exhaust mechanism S13f draws a high vacuum mainly near the cathode electrode S13c. The high-vacuum exhaust mechanism S13f is a turbomolecular pump or the like. The film forming mechanism S13 may include a magnetron magnetic circuit, which forms a predetermined magnetic field on the target S13b.

[0094] The film formation mechanism S14 is disposed inside the film formation chamber S12 at a position adjacent to the unload chamber S16. The film formation mechanism S14 performs the second-stage film formation process of the two-stage film formation process. The film formation mechanism S14 supplies film formation materials for the second-stage film formation process. The film formation mechanism S14 has the same configuration as the film formation mechanism S1 for the second-stage film formation process.

[0095] The film formation mechanism S13 and the film formation mechanism S14 are adjacent to each other inside the film formation chamber S12. The gas barrier S12g is disposed inside the film formation chamber S12. The gas barrier S12g is disposed between the film formation mechanism S13 and the film formation mechanism S14. The gas barrier S12g separates the film formation gases in the film formation mechanism S13 and the film formation mechanism S14. The gas barrier S12g is disposed so that the film formation gases do not mix in the film formation mechanism S13 and the film formation mechanism S14. The gas barrier S12g suppresses the flow of the film formation gas between the film formation mechanism S13 and the film formation mechanism S14. The gas barrier S12g is configured so that the substrate holding mechanism S12a can move between the film formation mechanism S13 and the film formation mechanism S14.

[0096] The film formation mechanisms S13 and S14 have the configurations necessary for performing the two-stage film formation processes, respectively. The film formation mechanisms S13 and S14 can implement the conditions necessary for performing the two-stage film formation processes, respectively. The film formation mechanism S13 corresponds to the formation of the phase shift layer 12. The film formation mechanism S14 corresponds to the formation of the light-shielding layer 13.

[0097] In the film forming mechanism S13, the target S13b has a composition necessary for forming the phase shift layer 12. The material of the target S13b is molybdenum silicide. In the film formation mechanism S13, a gas introduction mechanism S13e supplies process gas and sputtering gas necessary for forming the phase shift layer 12. The gas introduction mechanism S13e can supply argon and nitrogen gas. The gas introduction mechanism S13e does not supply oxygen-containing gas or carbon-containing gas.

[0098] The gas introduction mechanism S13e and the high-vacuum exhaust mechanism S13f set gas partial pressures required for depositing the phase shift layer 12. The gas introduction mechanism S13e and the high-vacuum exhaust mechanism S13f can change the supply gas conditions in the thickness direction of the phase shift layer 12. The gas introduction mechanism S13e and the high-vacuum exhaust mechanism S13f set conditions required for depositing the etching time shortening layer 12a, the intermediate layer 12b, and the surface layer 12c, respectively.

[0099] In the film formation mechanism S13, the power supply S13d sets a sputtering voltage corresponding to the formation of the phase shift layer 12. The power supply S13d sets conditions required for forming the etching time shortening layer 12a, the intermediate layer 12b, and the surface layer 12c, respectively.

[0100] In the film forming mechanism S14, the target S14b has a composition necessary for forming the light-shielding layer 13. The target S14b is made of a material containing chromium. In the film formation mechanism S14, the gas introduction mechanism S14e supplies gases necessary for forming the light-shielding layer 13. The gas introduction mechanism S14e can supply process gases containing carbon, nitrogen, oxygen, etc. The gas introduction mechanism S14e can supply sputtering gases such as argon gas and nitrogen gas.

[0101] The gas introduction mechanism S14e and the high-vacuum exhaust mechanism S14f set the gas partial pressure required to form the light-shielding layer 13. The gas introduction mechanism S14e and the high-vacuum exhaust mechanism S14f can change the supply gas conditions in the film thickness direction of the light-shielding layer 13. In the film-forming mechanism S14, the power supply S14d sets a sputtering voltage corresponding to the formation of the light-shielding layer 13.

[0102] When manufacturing the phase shift mask blank 10B in the manufacturing apparatus S10, as a preparation step, the glass substrate 11 is carried into the load chamber S11. The glass substrate 11 is transported from the load chamber S11 to the film formation chamber S12 by the transport mechanism S11a. The glass substrate 11 is transported inside the film formation chamber S12 by the substrate holding mechanism S12a. Inside the film formation chamber S12, the glass substrate 11 undergoes two-stage sputtering film formation as a film formation process. After film formation is completed, the glass substrate 11 is transported from the film formation chamber S12 to the unload chamber S16 by the substrate holding mechanism S12a. The glass substrate 11 is then carried out to the outside by the transport mechanism S16a.

[0103] The film forming process includes a phase shift layer forming process and a light blocking layer forming process.

[0104] In the phase shift layer forming step, a phase shift layer 12 is formed on a glass substrate 11. The phase shift layer forming step is performed in a film forming mechanism S13. In the phase shift layer forming step, the film forming mechanism S13 supplies a process gas and a sputtering gas from the gas introduction mechanism S13e. In the phase shift layer forming step, the film forming mechanism S13 applies a sputtering voltage from the power supply S13d. In the phase shift layer forming step, the magnetron magnetic circuit may form a predetermined magnetic field on the target S13b.

[0105] In the phase shift layer forming process, the film forming mechanism S13 generates plasma near the target S13b. The plasma excites ions of the sputtering gas. The ions of the sputtering gas collide with the target S13b, releasing particles of the film forming material. The particles of the film forming material released from the target S13b combine with the reactive gas and then adhere to the glass substrate 11. This forms a phase shift layer 12 on the surface of the glass substrate 11.

[0106] In the phase shift layer formation process, gases are supplied from the gas introduction mechanism S13e. The supplied gases are Ar gas and N2 (nitrogen gas). This forms a film containing nitrogen, molybdenum, and silicon. The gas introduction mechanism S13e supplies each gas at a predetermined partial pressure as the film thickness increases. Alternatively, the gas introduction mechanism S13e may control the partial pressure of each gas as the film thickness increases. In this case, in the phase shift layer formation process, the composition of the phase shift layer 12 can be adjusted to a concentration range that varies in the film thickness direction by controlling the gas partial pressure. In the phase shift layer forming step, the deposition atmosphere for the phase shift layer 12 can be set to a low pressure of 1.0 Pa or less, about 0.1 to 0.5 Pa, preferably about 0.1 to 0.3 Pa, about 0.2 Pa.

[0107] The phase shift layer forming step comprises forming a phase shift layer having a molybdenum to silicon ratio of: 7.0≦Si / Mo≦15.0 In particular, a target containing more than 9.0 times as much silicon as molybdenum can be used.

[0108] In the phase shift layer forming step, the power supply S13d applies a plasma generating power to the cathode electrode S13c within a predetermined range.In the phase shift layer forming step, the power supply S13d applies a plasma generating power to the cathode electrode S13c within a predetermined range. In the phase shift layer forming step, the substrate holding mechanism S12a may apply bias power to the glass substrate 11. Furthermore, in the phase shift layer forming step, the temperature of the glass substrate 11 supported by the substrate holding mechanism S12a is maintained at a low temperature. Specifically, in the phase shift layer forming step, the temperature of the glass substrate 11 can be set to 100° C. or less, 50° C. or less, or approximately room temperature during film formation. In this case, the substrate holding mechanism S12a does not need to actively heat the glass substrate 11. The substrate holding mechanism S12a may cool the glass substrate 11.

[0109] In the light-shielding layer forming step, the light-shielding layer 13 is formed on the glass substrate 11. In the light-shielding layer forming step, the light-shielding layer 13 is laminated on the phase shift layer 12. The light-shielding layer forming step is performed in a film-forming mechanism S14. In the light-shielding layer forming step, the film-forming mechanism S14 supplies a process gas and a sputtering gas from the gas introduction mechanism S14e. In the light-shielding layer forming step, the film-forming mechanism S14 applies a sputtering voltage from the power supply 14d. In the light-shielding layer forming step, the magnetron magnetic circuit may form a predetermined magnetic field on the target S14b.

[0110] In the light-shielding layer forming process, the film-forming mechanism S14 generates plasma near the target S14b. The plasma excites ions of the sputtering gas. The ions of the sputtering gas collide with the target S14b, releasing particles of the film-forming material. The particles of the film-forming material released from the target S14b combine with the reactive gas and then adhere to the surface of the phase shift layer 12. As a result, the light-shielding layer 13 is deposited on the surface of the phase shift layer 12.

[0111] In the light-shielding layer forming step, a target S14b containing chromium is used. In the light-shielding layer forming step, a target S14b made of chromium is used. In the film formation of the light-shielding layer 13, the target S14b can be replaced as needed. In the light-shielding layer forming step, the power supply S14d applies a plasma-forming power to the cathode electrode S14c within a predetermined range.In the light-shielding layer forming step, the power supply S14d applies a plasma-forming power to the cathode electrode S14c within a predetermined range. In the light-shielding layer forming step, the substrate holding mechanism S12a may apply bias power to the glass substrate 11. In the light-shielding layer forming step, the sputtering power applied from the power source S14d and the bias power applied from the substrate holding mechanism S12a may be changed according to the film thickness of the light-shielding layer 13.

[0112] In the light-shielding layer forming process, gas is supplied from the gas introduction mechanism S14e. The supplied gas may be a sputtering gas, a carbon-containing gas, a nitrogen-containing gas, an oxygen-containing gas, or the like. The gas introduction mechanism S14e may supply each gas at a predetermined partial pressure as the film thickness increases. Alternatively, the gas introduction mechanism S14e may be switched to control the partial pressure of each gas as the film thickness increases. In this way, in the light-shielding layer forming process, the composition of the light-shielding layer 13 is adjusted to a set concentration range in the film thickness direction by controlling the gas partial pressure.

[0113] The light-shielding layer forming step may vary the composition of the light-shielding layer 13 in the film thickness direction. In this case, the light-shielding layer forming step varies the partial pressure of each gas in the atmospheric gas according to the thickness of the formed film. The light-shielding layer forming step may keep the composition of the light-shielding layer 13 constant in the film thickness direction. In this case, the light-shielding layer forming step maintains the partial pressure of each gas in the atmospheric gas constant according to the thickness of the formed film.

[0114] Examples of oxygen-containing gases include CO2 (carbon dioxide), O2 (oxygen), NO (nitrous oxide), NO (nitric oxide), and CO (carbon monoxide). Examples of carbon-containing gases include CO2 (carbon dioxide), CH4 (methane), CH6 (ethane), and CO (carbon monoxide). Examples of nitrogen-containing gases include N2 (nitrogen gas), NO (nitrous oxide), NO (nitric oxide), NO (nitrous oxide), and NH3 (ammonia).

[0115] The method for manufacturing a phase shift mask blank may include, in addition to the phase shift layer forming step and the light-shielding layer forming step, a lamination step for laminating an etching stop layer, a protective layer, an adhesion layer, a chemical-resistant layer, an anti-reflection layer, etc., to the phase shift mask blank 10B. In this case, the film can be formed by sputtering under sputtering conditions such as a corresponding target and gas, or by stacking the film by other film forming methods to form the phase shift mask blank 10B of this embodiment.

[0116] The phase shift mask blank 10B shown in FIG. 1 is manufactured by the method for manufacturing a phase shift mask blank according to this embodiment. As shown in FIG. 9, phase shift mask (photomask) 10 in this embodiment is formed by forming a pattern on phase shift layer 12 and light-shielding layer 13 which are laminated as mask blank 10B.

[0117] A manufacturing method for manufacturing the phase shift mask 10 from the mask blank 10B of this embodiment will be described below.

[0118] In the resist pattern formation step, as shown in FIG. 2, a photoresist layer 15 is formed on the outermost surface of a phase shift mask blank 10B. Alternatively, a phase shift mask blank 10B may be prepared with a photoresist layer 15 formed on its outermost surface in advance. The photoresist layer 15 may be either positive or negative. The photoresist layer 15 is suitable for etching so-called chromium-based materials and molybdenum silicide-based materials. A liquid resist is used as the photoresist layer 15.

[0119] Subsequently, the photoresist layer 15 is exposed and developed to form a resist pattern 15P1 outside the light-shielding layer 13. The resist pattern 15P1 functions as an etching mask for the phase shift layer 12 and the light-shielding layer 13.

[0120] The shape of the resist pattern 15P1 is determined appropriately according to the etching pattern of the phase shift layer 12 and the light-shielding layer 13. As an example, the resist pattern 15P1 is set to a shape having an opening width corresponding to the opening width dimension of the light-transmitting region 10L (see FIGS. 4 to 9) to be formed.

[0121] Next, in the light-shielding pattern forming step, the light-shielding layer 13 is wet-etched using an etching solution through the resist pattern 15P1 to form the light-shielding pattern 13P1 as shown in FIG. As an etching solution for the light-shielding pattern formation process, an etching solution containing cerium diammonium nitrate can be used as an etching solution for chromium-based materials, and it is preferable to use, for example, cerium diammonium nitrate containing an acid such as nitric acid or perchloric acid.

[0122] Next, in the phase shift pattern forming step, the phase shift layer 12 is wet-etched using an etching solution through the light-shielding pattern 13P1 and the resist pattern 15P1 to form a phase shift pattern 12P1 as shown in FIG. The etching solution used in the phase shift pattern formation step is preferably one that can etch the phase shift layer 12 made of molybdenum silicide and contains at least one fluorine compound selected from hydrofluoric acid, hydrosilicic acid, and ammonium bifluoride, and at least one oxidizing agent selected from hydrogen peroxide, nitric acid, and sulfuric acid.

[0123] In this case, since the phase shift layer 12 has the above composition ratio, the etching rate (ER) of the phase shift layer 12 with respect to a molybdenum silicide-based etching solution becomes high, but the etching time does not become too long. Furthermore, the etching rate (ER) of the phase shift layer 12 with respect to a molybdenum silicide-based etching solution becomes small, and the etching time of the entire phase shift layer 12 can be shortened. Furthermore, the occurrence of defects in the phase shift layer 12 is suppressed.

[0124] This shortens the etching time and makes it possible to suppress the influence (over-etching) of the etching solution on the glass substrate 11. 4, it is possible to form light-transmitting region 10L in which the surface of glass substrate 11 is exposed. After light-shielding pattern 13P1 and phase shift pattern 12P1 are formed by etching, it is possible to obtain a favorable cross-sectional shape of phase shift mask 10 that is close to vertical.

[0125] After the phase shift pattern forming step is completed, a cleaning step is carried out as necessary. The cleaning step is a resist removal step in which the resist pattern 15P1 is removed. The cleaning process uses a sodium hydroxide solution, a potassium hydroxide solution, and a tetramethylammonium hydroxide (TMAH) solution as cleaning solutions. Because the phase shift layer 12 has the above composition ratio, it has high chemical resistance, and cleaning with an alkaline solution in the cleaning process does not change the film thickness of the phase shift pattern 12P1.

[0126] In the resist pattern forming step, as shown in Fig. 5, the photoresist layer 15 is exposed and developed to form a resist pattern 15P2 outside the light-shielding pattern 14P1 as shown in Fig. 6. The resist pattern 15P2 functions as an etching mask for the light-shielding pattern 13P1.

[0127] The resist pattern 15P2 is appropriately shaped depending on the etching pattern with the light-shielding pattern 14P1. For example, the resist pattern 15P2 is set to have an opening width corresponding to the opening width dimensions of the exposure region 10P1 and the phase shift region 10P2 (see FIGS. 7 to 9) to be formed.

[0128] Next, in the light-shielding pattern forming step, the light-shielding pattern 13P1 is wet-etched using an etching solution through the resist pattern 15P2 to form the light-shielding pattern 13P2 as shown in FIG. As a result, it is possible to form an exposure region 10P1 where the surface of the phase shift pattern 12P1 is exposed, and a light-shielding pattern 13P2 corresponding to the phase shift region 10P2.

[0129] Similarly, as an etching solution for a chromium-based material in the light-shielding pattern formation process, an etching solution containing cerium diammonium nitrate can be used, and for example, it is preferable to use cerium diammonium nitrate containing an acid such as nitric acid or perchloric acid.

[0130] Next, in the phase shift pattern forming step, the phase shift pattern 12P1 is wet-etched using an etching solution through the resist pattern 15P2 and the light-shielding pattern 13P2 to form a phase shift pattern 12P2 as shown in FIG.

[0131] This makes it possible to shorten the etching time and suppress the influence of the etching solution on the glass substrate 11 exposed in the light-transmitting region 10L. As a result, as shown in FIG. 8, an exposed region 10P1 where the surface of the glass substrate 11 is exposed and a phase shift region 10P2 where the phase shift pattern 12P2 remains and is exposed can be formed.

[0132] Next, in a resist removal step, resist pattern 15P2 is removed to produce phase shift mask 10 as shown in FIG.

[0133] The film characteristics of the phase shift layer 12 in this embodiment will be described below.

[0134] Phase shift mask blank 10B has a mask layer formed on glass substrate 11. The mask layer is formed using a method such as sputtering. The mask layer is first formed as a phase shift layer 12. Phase shift layer 12 is formed from a molybdenum silicide compound. The molybdenum silicide compound formed here is a film containing molybdenum, silicon, and nitrogen. The composition of the molybdenum, silicon, and nitrogen contained in the film and the film thickness corresponding to the composition are controlled. This allows phase shift layer 12 to have the desired transmittance, phase, etching rate, chemical resistance, and defect quality.

[0135] After the formation of phase shift layer 12, a chromium compound that will become light-shielding layer 13 is formed, whereby phase shift mask blank 10B for forming phase shift mask 10 can be constructed. This phase shift mask blank 10B is used to form a phase shift mask 10. By forming a resist pattern on the formed phase shift mask blank 10B and etching the phase shift mask blank 10B, the phase shift mask 10 can be formed.

[0136] As a result of intensive research by the inventors, it was found that in order to simultaneously increase the chemical resistance and etching rate of the phase shift layer 12 and improve the accuracy of patterning, it is important to form the phase shift layer 12 from a molybdenum silicide film with a high silicon concentration (composition ratio) and to incorporate only nitrogen. As a result, it was discovered that a phase shift layer 12 with short etching time, high chemical resistance, and good defect quality can be formed by a method different from the conventional idea of ​​lowering the silicon concentration and further controlling the film characteristics of the phase shift layer by controlling the concentrations (composition ratios) of oxygen, carbon, etc.

[0137] When phase shift layer 12 is formed of a molybdenum silicide film, it is necessary to etch it with an etching solution containing hydrofluoric acid when forming phase shift mask 10. Therefore, in order to reduce the influence of etching on glass substrate 11, it is desirable to use a molybdenum silicide film with as fast an etching rate as possible.

[0138] By using a target in which the molybdenum to silicon composition ratio falls within the above-mentioned range as the molybdenum silicide composition ratio, the silicon concentration in the molybdenum silicide film is increased. This has been found to increase the etching rate (ER) of the molybdenum silicide film. It is possible to form a molybdenum silicide film with an etching rate that maintains a state in which etching of the glass substrate 11 is suppressed. This has made it possible to manufacture a phase shift mask blank 10B that is suitable for production and has reduced effects of defects.

[0139] A target having a molybdenum to silicon composition ratio within the above range was used when forming a molybdenum silicide film as phase shift layer 12. At the same time, when forming a molybdenum silicide film as phase shift layer 12, the flow rates of argon and nitrogen were changed during film formation. Acidic or alkaline chemicals are usually used in forming patterns in the manufacturing process of phase shift mask 10. It is necessary to suppress changes in phase shift angle, film thickness, and transmittance during these processes.

[0140] It was found that the resistance to acid and alkali chemicals was improved by setting the nitrogen concentration of the molybdenum silicide film within the above range. This shows that it is important to set the nitrogen concentration range of the molybdenum silicide film in order to improve the resistance to chemicals.

[0141] Furthermore, the oxygen and carbon concentrations in the molybdenum silicide film were measured by changing the gas conditions used when depositing the molybdenum silicide film. The relationship between the etching rate and the ratio of oxygen concentration (O concentration) to carbon concentration (C concentration) for this molybdenum silicide film was investigated. These results show that the etching rate of the molybdenum silicide film can be increased by keeping the oxygen and carbon concentrations extremely low. It can also be seen that reducing the oxygen and carbon concentrations in the molybdenum silicide film can suppress the occurrence of defects to an extremely low level. At the same time, it can also be seen that the chemical resistance of the molybdenum silicide film is improved.

[0142] Based on these results, the concentration distribution (composition ratio) in the phase shift layer 12 is set. Specifically, the phase shift layer 12 contains molybdenum, silicon, and nitrogen in the proportions: Mo=0.15~0.2 Si=0.45~0.50 approx. N=0.25~0.30 approx. It is preferable to set the above formula. More preferably, Mo=1 or so Si=2.6 approx. N=1.6 approx. Furthermore, the phase shift layer 12 can be formed by adding the remainder other than molybdenum, silicon, and nitrogen to the molybdenum, silicon, and nitrogen components in the ratios as follows: Mo=0.15~0.2 Si=0.45~0.50 approx. N=0.25~0.30 approx. Remainder = about 0~0.10 More preferably, Mo=18 approx. Si=48 approx. N=27 approx. Remaining amount = about 7 It is preferable to set the following.

[0143] As a phase shift mask used for a display, a phase shift mask 10 having a transmittance of 5% or more at a phase of 180° at a wavelength of 365 nm (I-line) is used. [Example]

[0144] Hereinafter, examples of the present invention will be described.

[0145] <Experimental Example 1> In Experimental Example 1, a three-layer molybdenum silicide compound film was formed on a glass substrate by sputtering or the like as a phase shift layer 12. The molybdenum silicide compound film formed here contains molybdenum, silicon, and nitrogen.

[0146] Here, in the sputtering for forming the film of the molybdenum silicide compound, a target having a molybdenum to silicon ratio of Mo:Si=1:9.0 was used. The sputtering atmosphere gas was argon gas and nitrogen gas (N2) only, and the deposition pressure was 0.2 Pa. The substrate was not heated, but kept at room temperature of about 18 to 25°C, and the film was deposited while moving relative to the target.

[0147] The film formation conditions for the phase shift layer are as follows: Ar flow rate: 130sccm N2 flow rate: 45.5sccm Film thickness: 130 nm Film formation atmosphere: 0.2 Pa Glass substrate temperature: 22.0℃ Glass substrate dimensions: 850mm x 1200mm

[0148] Furthermore, the composition of the formed phase shift layer 12 was evaluated by Auger electron spectroscopy, and the results are shown in FIGS. 11 to 25, the horizontal axis represents the etching time in Auger electron spectroscopy, which corresponds to the depth in the film thickness direction. Detection was carried out for Si, Mo, N, O, and C.

[0149] <Experimental Example 2> In Experimental Example 2, a film of a molybdenum silicide compound containing oxygen and carbon was formed on a glass substrate in the same manner as in Experimental Example 1. In this case, a target having a molybdenum to silicon ratio of Mo:Si=1:2.3 was used in sputtering to form the molybdenum silicide compound film.

[0150] The film formation conditions for the phase shift layer are as follows: Ar flow rate: 130sccm N2 flow rate: 98sccm CO2 flow rate: 8.0sccm Film thickness: 130 nm Film formation atmosphere: 0.2 Pa Glass substrate temperature: 22.0℃ Glass substrate dimensions: 850mm x 1200mm

[0151] Furthermore, the composition of the formed molybdenum silicide compound film was evaluated using Auger electron spectroscopy in the same manner as in Experimental Example 1. The results are shown in FIGS.

[0152] 11, it can be seen that the average nitrogen composition ratio (atm %) N in the MoSiN film of Experimental Example 1 was in the range of 26 to 29. It can be seen that the average nitrogen composition ratio (atm %) N in the MoSiN film of Experimental Example 2 was in the range of 22 to 27.

[0153] 12, it can be seen that in the MoSiN film of Experimental Example 1, the average oxygen composition ratio (atm %) O ranges from 2 to 5. It can be seen that in the MoSiN film of Experimental Example 2, the average oxygen composition ratio (atm %) O ranges from 14 to 21.

[0154] 13, it can be seen that in the MoSiN film of Experimental Example 1, the average silicon composition ratio (atm %) Si is in the range of 45 to 50. In the MoSiN film of Experimental Example 2, it can be seen that the average silicon composition ratio (atm %) Si is in the range of 15 to 18.

[0155] 14 shows that in the MoSiN film of Experimental Example 1, the average molybdenum composition ratio (atm %) Mo is in the range of 16 to 19. In the MoSiN film of Experimental Example 2, the average molybdenum composition ratio (atm %) Mo is in the range of 26 to 31.

[0156] 15, it can be seen that the average value of the ratio of the silicon composition ratio (atm%) to the molybdenum composition ratio (atm%), Si / Mo, is in the range of 2.7 to 2.8 in the MoSiN film of Experimental Example 1. It can also be seen that the average value of the ratio of the silicon composition ratio (atm%) to the molybdenum composition ratio (atm%), Si / Mo, is in the range of 2.5 to 3.1 in the MoSiN film of Experimental Example 2.

[0157] 16, it can be seen that the average value of the ratio N / Si of the nitrogen composition ratio (atm%) to the silicon composition ratio (atm%) in the MoSiN film of Experimental Example 1 is in the range of 0.54 to 0.62, and that the average value of the ratio N / Si of the nitrogen composition ratio (atm%) to the silicon composition ratio (atm%) in the MoSiN film of Experimental Example 2 is in the range of 1.3 to 1.7.

[0158] 17, it can be seen that the average value of the ratio Si / (Mo+N) of the silicon composition ratio (atm%) to the sum of the molybdenum composition ratio (atm%) and the nitrogen composition ratio (atm%) in the MoSiN film of Experimental Example 1 is in the range of 1.00 to 1.13, and the average value of the ratio Si / (Mo+N) of the silicon composition ratio (atm%) to the sum of the molybdenum composition ratio (atm%) and the nitrogen composition ratio (atm%) in the MoSiN film of Experimental Example 2 is in the range of 0.29 to 0.34.

[0159] 18, it can be seen that the average value of the ratio N / (Mo+Si) of the nitrogen composition ratio (atm%) to the sum of the molybdenum composition ratio (atm%) and the silicon composition ratio (atm%) in the MoSiN film of Experimental Example 1 is in the range of 0.40 to 0.44, and the average value of the ratio N / (Mo+Si) of the nitrogen composition ratio (atm%) to the sum of the molybdenum composition ratio (atm%) and the silicon composition ratio (atm%) in the MoSiN film of Experimental Example 2 is in the range of 0.45 to 0.65.

[0160] 19, it can be seen that the average value of the ratio N / Mo of the nitrogen composition ratio (atm%) to the molybdenum composition ratio (atm%) in the MoSiN film of Experimental Example 1 is in the range of 1.4 to 1.75, and that the average value of the ratio N / Mo of the nitrogen composition ratio (atm%) to the molybdenum composition ratio (atm%) in the MoSiN film of Experimental Example 2 is in the range of 0.75 to 1.00.

[0161] 20, it can be seen that the average value of the ratio O / Si of the oxygen composition ratio (atm%) detected by Auger electron spectroscopy to the silicon composition ratio (atm%) in the MoSiN film of Experimental Example 1 is in the range of 0.01 to 0.15. It can also be seen that the average value of the ratio O / Si of the oxygen composition ratio (atm%) detected by Auger electron spectroscopy to the silicon composition ratio (atm%) in the MoSiN film of Experimental Example 2 is in the range of 0.5 to 1.5.

[0162] 21, it can be seen that the average value of the ratio O / Mo of the oxygen composition ratio (atm%) detected by Auger electron spectroscopy to the molybdenum composition ratio (atm%) in the MoSiN film of Experimental Example 1 is in the range of 0.1 to 0.40. It can also be seen that the average value of the ratio O / Mo of the oxygen composition ratio (atm%) detected by Auger electron spectroscopy to the molybdenum composition ratio (atm%) in the MoSiN film of Experimental Example 2 is in the range of 0.45 to 0.75.

[0163] 22, it can be seen that the average value of the ratio O / N of the oxygen composition ratio (atm%) detected by Auger electron spectroscopy to the nitrogen composition ratio (atm%) in the MoSiN film of Experimental Example 1 is in the range of 0.07 to 0.26, and that the average value of the ratio O / N of the oxygen composition ratio (atm%) detected by Auger electron spectroscopy to the nitrogen composition ratio (atm%) in the MoSiN film of Experimental Example 2 is in the range of 0.55 to 0.90.

[0164] 23, it can be seen that the average value of the ratio (O+N) / Si, which is the sum of the oxygen composition ratio (atm%) and the nitrogen composition ratio (atm%) detected by Auger electron spectroscopy relative to the silicon composition ratio (atm%), is in the range of 0.6 to 0.75 for the MoSiN film of Experimental Example 1. It can also be seen that the average value of the ratio (O+N) / Si, which is the sum of the oxygen composition ratio (atm%) and the nitrogen composition ratio (atm%) detected by Auger electron spectroscopy relative to the silicon composition ratio (atm%), is in the range of 2.3 to 2.7 for the MoSiN film of Experimental Example 2.

[0165] 24 shows that, in the MoSiN film of Experimental Example 1, the average value of the sum of the molybdenum composition ratio (atm %), nitrogen composition ratio (atm %), and silicon composition ratio (atm %), Mo+N+Si, detected by Auger electron spectroscopy, is in the range of 92 to 95. In the MoSiN film of Experimental Example 2, the average value of the sum of the molybdenum composition ratio (atm %), nitrogen composition ratio (atm %), and silicon composition ratio (atm %), Mo+N+Si, detected by Auger electron spectroscopy, is in the range of 63 to 76.

[0166] Note that some of the numerical values ​​of the molybdenum composition ratio (atm %), nitrogen composition ratio (atm %), silicon composition ratio (atm %), oxygen composition ratio (atm %), and carbon composition ratio (atm %) detected using Auger electron spectroscopy are shown in FIG. 25.

[0167] Here, the data of the composition ratios described above are average values, but this "average value" does not refer directly to the range of the actually measured composition, but rather to a range in which measurement variations have been eliminated, using a method in which the maximum and minimum values ​​from the outermost surface to the contact depth with the glass substrate are extracted (excluding) and averaged in order to eliminate the influence of contamination on the outermost surface and Si and O at the film contact position with the glass substrate surface, and corresponds to the flat portion of the graph.

[0168] Furthermore, the etching time, overetching state, chemical resistance, defect characteristics, and accuracy of patterning shape were measured for the molybdenum silicide compound films of Experimental Examples 1 and 2. The results are shown below.

[0169] The etching time was measured as follows. Using MoSi etchant (product name: PEF006) manufactured by Kanto Chemical Co., Ltd., the time until the film of the molybdenum silicide compound disappeared was measured at a constant liquid temperature of 20° C. The disappearance times for the films of the molybdenum silicide compound in Experimental Example 1 and Experimental Example 2 were respectively: Experimental example 1: 15 minutes, Experimental example 2: 40 minutes It was.

[0170] The chemical resistance was measured as follows. The temperature of the NH4OH + H2O2 solution was kept constant at 23°C, and the change in transmittance was measured every 10 minutes up to 50 minutes. The results are shown in Figure 26. In Figure 26, the vertical axis represents the change in transmittance, and the horizontal axis represents the contact time with the chemical solution. From these results, it can be seen that Example 1 has chemical resistance that is five times or more that of Example 2. The accuracy of the patterning shape was evaluated by cross-sectional SEM observation, and good cross-sectional perpendicularity was confirmed in both Experimental Examples 1 and 2.

[0171] These results demonstrate that the phase shift layer of the present invention can simultaneously achieve a short etching time, high chemical resistance, and accurate patterning. [Explanation of symbols]

[0172] 10...Phase shift mask 10B...Phase shift mask blanks 10L…Translucent area 10P...Phase shift area 11...Glass substrate (transparent substrate) 12...Phase shift layer 12P1...Phase shift pattern 13...Light blocking layer 13P...Light blocking pattern 13P1, 13P2...Light blocking pattern 15...Photoresist layer 15P1, 15P2...resist pattern

Claims

1. A phase shift mask blank having a mask layer that serves as a phase shift mask, a phase shift layer made of a metal silicide laminated on a transparent substrate; the phase shift layer contains nitrogen, molybdenum, and silicon, and the average ratio of the silicon composition ratio (atm %) to the molybdenum composition ratio (atm %), Si / Mo, is in the range of 2.2 to 3.2; A phase shift mask blank characterized by:

2. a light-shielding layer containing chromium laminated on the phase shift layer; 2. The phase shift mask blank according to claim 1.

3. the phase shift layer has an average ratio N / Si of nitrogen composition (atm %) to silicon composition (atm %) in the range of 0.50 to 0.65; 2. The phase shift mask blank according to claim 1.

4. the phase shift layer has an average ratio Si / (Mo+N) of the silicon composition ratio (atm %) to the sum of the molybdenum composition ratio (atm %) and the nitrogen composition ratio (atm %) in the range of 1.00 to 1.13; 2. The phase shift mask blank according to claim 1.

5. the phase shift layer has an average ratio N / (Mo+Si) of nitrogen composition (atm %) to the sum of molybdenum composition (atm %) and silicon composition (atm %) in the range of 0.35 to 0.50; 2. The phase shift mask blank according to claim 1.

6. the phase shift layer has an average ratio N / Mo of a nitrogen composition ratio (atm %) to a molybdenum composition ratio (atm %) in the range of 1.4 to 1.75; 2. The phase shift mask blank according to claim 1.

7. the phase shift layer has a molybdenum composition ratio (atm %), a silicon composition ratio (atm %), and a nitrogen composition ratio (atm %), and the average value of Mo+Si+N is greater than 90; 2. The phase shift mask blank according to claim 1.

8. the phase shift layer has an average ratio of oxygen composition ratio (atm %) to silicon composition ratio (atm %), O / Si, detected by Auger electron spectroscopy, in the range of 0.01 to 0.15; 2. The phase shift mask blank according to claim 1.

9. A method for producing a phase shift mask blank according to any one of claims 1 to 8, comprising the steps of: When forming the phase shift layer, the ratio of molybdenum to silicon is 7.0≦Si / Mo≦15.0 Sputtering is performed using a target having a composition set to 1. A method for producing a phase shift mask blank, comprising:

10. When forming the phase shift layer, sputtering is performed by supplying argon gas and nitrogen gas.

10. The method for producing a phase shift mask blank according to claim 9.

11. A phase shift mask is manufactured by patterning the phase shift mask blank manufactured by the method for manufacturing a phase shift mask blank according to claim 10 by wet etching.

10. A method for manufacturing a phase shift mask, comprising:

12. 12. A phase shift mask manufactured by the method of manufacturing a phase shift mask according to claim 11. A phase shift mask characterized by:

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