JP2008052120A - Mask blank, photomask, and method for manufacturing same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mask blank and a photomask suitable for a wet process in a large mask for an FPD (such as a resist stripping method, an etching method and a cleaning method). <P>SOLUTION: The mask blank for manufacturing an FPD device has at least a semi-translucent film containing Mo and Si and having a function of controlling the transmitting quantity on a translucent substrate, wherein the semi-translucent film containing Mo and Si shows 5% or less of variation in the transmittance in a wavelength band covering at least from the i line to the g line emitted from an extra-high pressure mercury lamp, after the film is in contact with an alkali aqueous solution (e.g. potassium hydroxide (KOH)) for 15 minutes, the solution to be used in a step of manufacturing or using the mask blank and the mask. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a mask blank, a photomask, and a manufacturing method thereof, and particularly relates to a mask blank for manufacturing an FPD device, a photomask manufactured using the mask blank, a manufacturing method thereof, and the like.

In recent years, in the field of large FPD masks, attempts have been made to reduce the number of masks using a gray tone mask having a semi-transparent region (so-called gray tone portion) (Non-Patent Document 1).
Here, as shown in FIGS. 13 (1) and 14 (1), the gray tone mask has a light shielding portion 1, a transmission portion 2, and a gray tone portion 3 which is a semi-transparent region on a transparent substrate. And have. The gray tone part 3 has a function of adjusting the transmission amount, for example, as shown in FIG. 13 (1), a region in which a gray-tone mask semi-transparent film (half-transparent film) 3a ′ is formed, Alternatively, as shown in FIG. 14 (1), a gray tone pattern (a fine light shielding pattern 3a and a fine transmission portion 3b below the resolution limit of a large FPD exposure machine using a gray tone mask) is formed. For the purpose of reducing the amount of light transmitted through these regions and reducing the amount of irradiation by this region, and controlling the reduced film thickness after development of the photoresist corresponding to the region to a desired value. It is formed.
When a large gray tone mask is mounted on a large exposure apparatus of a mirror projection method or a lens projection method using a lens, the exposure light passing through the gray tone portion 3 as a whole is insufficient in exposure amount. The positive photoresist exposed through the gray tone portion 3 remains on the substrate only by reducing the film thickness. That is, since the resist can have a difference in solubility in the developer at the portion corresponding to the normal light-shielding portion 1 and the portion corresponding to the gray tone portion 3 depending on the exposure amount, the resist shape after development is shown in FIG. ) And FIG. 14B, the portion 1 ′ corresponding to the normal light-shielding portion 1 is, for example, about 1 μm, and the portion 3 ′ corresponding to the gray tone portion 3 is, for example, about 0.4 to 0.5 μm. The portion corresponding to the portion 2 is a portion 2 ′ without resist. Then, the first etching of the substrate to be processed is performed in the portion 2 ′ without the resist, the resist in the thin portion 3 ′ corresponding to the gray tone portion 3 is removed by ashing or the like, and the second etching is performed in this portion. The process for two conventional masks is performed with one mask to reduce the number of masks.
Monthly FPD Intelligence, p.31-35, May 1999

By the way, an LSI mask for manufacturing a semiconductor device such as a microprocessor, a semiconductor memory, or a system LSI is relatively small at a maximum of about 6 inches square, and is reduced projection by a stepper (shot-step exposure) method. Often used in an exposure apparatus. In such an LSI mask, since the resolution limit is determined by the exposure wavelength, the exposure wavelength is shortened (for example, 248 nm and 193 nm). In the LSI mask, monochromatic exposure light (for example, 248 nm and 193 nm) is used from the viewpoint of eliminating chromatic aberration due to the lens system and improving resolution.
In addition, since a small mask blank for manufacturing an LSI mask requires high etching accuracy, a thin film formed on the mask blank is patterned by dry etching. Similarly, resist stripping or the like is often performed by dry etching.
On the other hand, a large mask for FPD (flat panel display) is relatively large from 330 mm × 450 mm to 1220 mm × 1400 mm, and uses a mirror projection (same projection exposure by scanning exposure method) method or a lens. It is often used by being mounted on a lens projection type exposure apparatus. In a large-sized mask for FPD, multicolor wave exposure is performed using a wide band of i to g lines of an ultrahigh pressure mercury lamp.
Further, in a large mask blank for manufacturing a large mask for FPD, when emphasizing cost and throughput rather than emphasizing high etching accuracy as in an LSI mask, wet etching using an etching solution is used. Thus, patterning of the thin film formed on the mask blank is performed.

  An object of the present application is to provide a mask blank and a photomask suitable for a wet process (resist stripping method, etching method, cleaning method, etc.) in a large FPD mask.

The present inventors have conducted extensive research and development on FPD large mask blanks and FPD large photomasks from the viewpoint of MoSi semitranslucent films suitable for wet etching in consideration of cost.
As a result, for both the MoSi ₂ film and the MoSi ₄ film, the etching time of the MoSi-based film with respect to the etching solution (such as an etching solution containing ammonium hydrogen fluoride and hydrogen peroxide) is about 30 seconds. Regarding the quality, the pattern dimensional accuracy and its in-plane uniformity, the pattern edge quality (no so-called jaggedness), and the cross-sectional shape quality of the pattern (cross-sectional verticality) are all good, and there is no difference between them. I understood.
Here, the MoSi ₂ film is formed by using a MoSi target of Mo: Si = 1: 2 (atomic% ratio) and using Ar as a sputtering gas. This MoSi target has a general composition and is generally widely used. It is advantageous because it is easy to obtain, stable in terms of film formation, and easy to form including film defects.
On the other hand, the MoSi ₄ film is formed by using a Si-rich MoSi target with Mo: Si = approximately 1: 4 (atomic% ratio) and using Ar as a sputtering gas. This Si-rich MoSi target is a special product. is there.
Therefore, was examined using the MoSi ₂ layer as MoSi-based semi-transparent film suitable for wet etching, MoSi ₂ film as semitransparent film is used in the mask blank and mask manufacturing processes and use step A new problem 1 has been found that the amount of change in transmittance is large depending on the chemical solution and its processing conditions, and that it is easily affected by the dissolving action depending on the chemical solution and its processing conditions. Specifically, for an alkaline aqueous solution (for example, used as a developer, a resist stripping solution, or a mask cleaning solution), the change in transmittance is 10 minutes until the contact time is 10 minutes as shown in FIGS. Although it is about 4%, it has been found that the amount of change in transmittance increases rapidly after 10 minutes (in FIGS. 4 to 6, the slope of the graph suddenly increases after 10 minutes). It was found that the amount of change in transmittance when contacted for a minute was about 8% or more. Similarly, it was found that the amount of change in transmittance when contacted with a chromium etching solution for 2 minutes was about 2% or more.
Here, in particular, in the manufacturing process of the MoSi-based semipermeable membrane underlay (front-attached) type Grayton mask shown in FIG. 11 (1), as described in detail in FIG. There is an effect because it is in contact for about 15 minutes in total at the longest. In addition to this, it is in contact with the chrome etching solution for about 2 minutes in total, and is further contacted with acidic cleaning solution several times. Since the quantity is cumulative, it has been found that it is most susceptible to the effects described above and is most prominent.
Under such circumstances, the inventors set the atomic percent ratio of Mo and Si in the MoSi film substantially composed of Mo and Si to Mo: Si = 1: _{3 to} 1:19 (hereinafter referred to as MoSi ₃ −3). ₁₉ ), an alkaline aqueous solution (for example, a developer, a resist stripping solution, and a mask cleaning solution such as potassium hydroxide (KOH) used in a mask blank and a mask manufacturing process and a use process. Before and after contact with sodium hydroxide (NaOH), and so on for 15 minutes, the amount of change in transmittance in the wavelength band from the i-line to the g-line can be reduced to 5% or less. It was found that it was a means and reached the first invention. This first invention can eliminate the phenomenon that the amount of change in transmissivity of MoSi semi-transmission increases rapidly at a contact time of 10 minutes with respect to an alkaline aqueous solution (for example, KOH). It has succeeded in greatly improving the durability characteristics against (for example, KOH).
However, in the first invention, the MoSi _3-19 film has a phenomenon that the change in transmittance increases with respect to an alkaline aqueous solution (for example, KOH) at 10 minutes as shown in FIGS. Still confirmed. When there is such a phenomenon, the amount of change in transmittance in the wavelength band extending from i-line to g-line before and after contact with the alkaline aqueous solution used in the mask blank and mask manufacturing process and use process for 15 minutes It becomes an obstacle when trying to further reduce. Moreover, when there is such a phenomenon, handling becomes complicated, for example, management of the contact time with the alkaline aqueous solution must be strictly performed. For example, handling is complicated when trying to manage the change in transmittance with a certain value of 5% or less.
Therefore, the present inventors have further studied a more effective coping means for the new problem 1, and as a result, carbon (C), hydrogen (H), nitrogen, etc. are formed on a film based on the MoSi _3-19 film. (N) By including at least one element selected from oxygen (O), before and after being contacted with an alkaline aqueous solution used in a mask blank and a mask manufacturing process or a use process for 15 minutes, from i-line The amount of change in transmittance in the wavelength band extending over the g-line can be reduced to 3% or less (further 2% or less), and it has been found that this is a very effective countermeasure against the new problem 1, and the second invention It came. In particular, the second invention can eliminate the phenomenon that the amount of change in the transmissivity of the MoSi semi-transmission increases at a contact time of 10 minutes with respect to an alkaline aqueous solution (for example, KOH). In the case where it is possible to realize a further reduction in the amount of change in transmittance, and to manage with a narrower variation range of transmittance (for example, 3% or less) based on the realization of the further reduction in the amount of change in transmittance, It is not necessary to strictly manage the contact time (for example, the contact time does not have to be concerned until the contact time is 20 minutes). Even when the above element is added to the MoSi ₂ film, the change in transmittance in the wavelength band extending from the i-line to the g-line under the same conditions as described above, that is, before and after being contacted with an alkaline aqueous solution for 15 minutes. It turned out that it was difficult to make it 3% or less.
However, in the second invention, the addition of the element increases the wet etching time of the semi-transmissive film as compared with the case where the element is not added (for example, about 10 times or more compared with the case where the element is not added). It has been found. Further, a new problem 2 has been found that when the wet etching time is increased by the addition of the above elements, the etching cannot be performed satisfactorily and a good pattern cannot be formed. That is, although the amount of change in transmittance with respect to the aqueous alkali solution is reduced by the addition of the above elements (advantageous to solving the new problem 1), the addition of the above elements increases the wet etching time (a new problem). It turned out to be disadvantageous to the solution of No. 2), and it was found that the two are in a trade-off relationship.
Therefore, the present inventor examined whether both of the problems 1 and 2 can be solved simultaneously. As a result, for both Problem 1 and Problem 2, the transmittance variation in the wavelength band from the i-line to the g-line can be reduced to 3% or less, and a good pattern can be formed by wet etching (that is, MoSi). The etching rate with respect to the etching solution is within a range of 0.3 to 5 liters / second), and the MoSi _3-19 film or the like is carbon (C), hydrogen (H), nitrogen (N), oxygen (O). It was found that it is actually possible to contain at least one or more selected from the above, that is, it was found that both Problem 1 and Problem 2 could be solved at the same time, leading to the third invention.

The method of the present invention has the following configuration.
(Configuration 1) A mask blank for manufacturing an FPD device having at least a semi-transparent film containing Mo and Si having a function of adjusting a transmission amount on a translucent substrate,
The translucent film containing Mo and Si is formed from at least i rays emitted from an ultra-high pressure mercury lamp before and after being brought into contact with an alkaline aqueous solution used in a mask blank and a mask manufacturing process and a use process for 15 minutes. A mask blank for manufacturing an FPD device, characterized in that a change in transmittance in a wavelength band extending over a line is 5% or less.
(Configuration 2) The translucent film containing Mo and Si is substantially composed of Mo and Si, and the atomic% ratio of Mo to Si in the film is Mo: Si = 1: 3 to 1: A mask blank for manufacturing the FPD device according to Configuration 1, wherein the mask blank is 19.
(Configuration 3) A mask blank for manufacturing an FPD device having at least a semi-transparent film containing Mo and Si having a function of adjusting a transmission amount on a translucent substrate,
The translucent film containing Mo and Si is formed from at least i rays emitted from an ultra-high pressure mercury lamp before and after being brought into contact with an alkaline aqueous solution used in a mask blank and a mask manufacturing process and a use process for 15 minutes. An FPD device comprising a film containing at least one element selected from carbon, hydrogen, nitrogen, and oxygen so that a change in transmittance in a wavelength band extending over a line is 3% or less. Mask blank for manufacturing.
(Configuration 4) A mask blank for manufacturing an FPD device having at least a semi-transparent film containing Mo and Si having a function of adjusting a transmission amount on a translucent substrate,
The semi-transparent film has an atomic percent ratio of Mo and Si in the semi-transparent film so that the etching rate of the MoSi-based material with respect to the etchant is within a range of 0.3 to 5 Å / sec. It is selected from Mo: Si = 1: 3 to 1:19, and / or a film containing at least one element selected from carbon, hydrogen, nitrogen and oxygen in the semi-transparent film. A mask blank for manufacturing an FPD device.
(Structure 5) A mask for manufacturing an FPD device according to any one of Structures 1 to 4, wherein a light-shielding film made of a material containing chromium is formed on the semi-translucent film. blank.
(Structure 6) The semi-translucent film is formed from at least i rays emitted from an ultrahigh pressure mercury lamp before and after being brought into contact with an etching solution of a chromium-based material used for patterning the light-shielding film for 2 minutes. 6. A mask blank for manufacturing an FPD device according to any one of configurations 1 to 5, wherein a change in transmittance in a wavelength band extending over g-line is 1.5% or less.
(Configuration 7) A photomask for manufacturing an FPD device manufactured using the mask blank according to configurations 1 to 6.
(Configuration 8) A mask blank manufacturing method for manufacturing an FPD device having at least a semi-transparent film containing Mo and Si having a function of adjusting a transmission amount on a translucent substrate,
The translucent film containing Mo and Si is
Using a target in which the atomic percent ratio of Mo to Si is Mo: Si = 1: 3 to 1:19, and
The amount of change in transmittance in the wavelength band extending from at least i-line to g-line emitted from the ultrahigh pressure mercury lamp is 3 before and after contact with the alkaline aqueous solution used in the mask blank and mask manufacturing process and use process for 15 minutes. %, A film containing at least one element selected from carbon, hydrogen, nitrogen, and oxygen as a sputtering gas, and forming a film as a sputtering gas so as to be less than or equal to%, a mask for manufacturing an FPD device Blank manufacturing method.

  ADVANTAGE OF THE INVENTION According to this invention, the mask blank and photomask suitable for the wet process (resist peeling method, an etching method, a washing | cleaning method, etc.) in the large sized mask for FPD can be provided.

Hereinafter, the present invention will be described in detail.
A mask blank and a mask for manufacturing the FPD device according to the first invention are:
A mask blank and a mask for manufacturing an FPD device having at least a semi-transparent film containing Mo and Si having a function of adjusting a transmission amount on a translucent substrate,
The translucent film containing Mo and Si is “at least from i-line radiated from an ultrahigh pressure mercury lamp before and after being contacted with an alkaline aqueous solution used in a mask blank and a mask manufacturing process and a use process for 15 minutes. It is characterized in that “amount of change in transmittance in a wavelength band extending over g-line” (hereinafter referred to as “the above-mentioned amount of change in transmittance”) is 5% or less (Configuration 1).
Here, when the amount of change in the predetermined transmittance exceeds 5%, it is difficult to adjust (push in) the transmittance within the set value ± 1% when applied to an actual mask manufacturing process. In addition, it is difficult to manufacture a product that satisfies the transmittance setting value ± 1%.
On the other hand, if the change amount of the predetermined transmittance is 5% or less, the increase amount S of the transmittance in the actual mask manufacturing process is estimated in advance, and the set value (final required value) of the transmittance is estimated. A blank having a translucent film having a transmittance of S by a low value is prepared, and through a mask manufacturing process, it is possible to adjust the transmittance to within a set value ± 1%. Production of a product that satisfies the rate setting value ± 1% is practically possible.

In the first invention, the translucent film containing Mo and Si whose predetermined transmittance change amount is 5% or less is substantially composed of Mo and Si, and the atomic% of Mo and Si. This can be realized by a translucent film containing Mo and Si in which the ratio Mo: Si is 1: 3 to _1:19 (MoSi _3-19 ) (Configuration 2).
In the semitranslucent film containing Mo and Si in which the atomic percent ratio Mo: Si is less than 1: 3, it is difficult to set the change amount of the predetermined transmittance to 5% or less.
In the present invention, the Mo: Si ratio Mo: Si is 1: 4 to 1: 9 (MoSi _4-9 ) and is a semi-transparent film containing Mo and Si. More preferable for reasons of controllability of the pattern shape.

The second invention is a mask blank for manufacturing an FPD device having at least a semi-transparent film containing Mo and Si having a function of adjusting a transmission amount on a translucent substrate,
The translucent film containing Mo and Si is formed from at least i rays emitted from an ultra-high pressure mercury lamp before and after being brought into contact with an alkaline aqueous solution used in a mask blank and a mask manufacturing process and a use process for 15 minutes. A film containing at least one element selected from carbon, hydrogen, nitrogen, and oxygen so that the amount of change in transmittance in the wavelength band extending over the line is 3% or less (Configuration 3) .
In the second aspect of the present invention, the translucent film containing Mo and Si in which the amount of change in transmittance in the predetermined wavelength band is 3% or less before and after contact with the alkaline aqueous solution for 15 minutes is, for example, the configuration 2 described above. the _{MoSi 3 to 19} film film was based, as the amount of change in the transmittance is 3% or less, at least selected from carbon (C), hydrogen (H), nitrogen (N), oxygen (O) This can be realized by a film containing one element.
In addition, even if these elements are contained in the translucent film containing Mo and Si in which the ratio Mo: Si is less than 1: 3, the change in transmittance is 3% or less. That is difficult.
In the second aspect of the invention, when the change amount of the predetermined transmittance is 3% or less, it is easy to adjust the transmittance to within the set value ± 1%, and the transmittance set value ± Production of a product satisfying 1% is practically possible.
In the second aspect of the invention, carbon (C), hydrogen (H), nitrogen (N), and oxygen (O) are contained so that the change in the predetermined transmittance is 3% or less.
The content of these elements is preferably such that the predetermined change in transmittance is 2% or less, more preferably 1.5% or less, and even more preferably 1.0% or less.
In the second aspect of the invention, in addition to an embodiment containing carbon (C), hydrogen (H), nitrogen (N), and oxygen (O) alone, an embodiment containing a plurality of elements such as CH, NO, CHN, CHO, and CHNO. Is included.

The third invention is a mask blank for manufacturing an FPD device having at least a semi-transparent film containing Mo and Si having a function of adjusting a transmission amount on a translucent substrate,
The semi-transparent film so that a good pattern can be formed by wet etching, that is, the etching rate with respect to the etching solution of the MoSi-based material is within a range of 0.3 to 5% / second.
(1) The atomic% ratio of Mo and Si in the semi-translucent film is selected from Mo: Si = 1: 3 to 1:19, and / or
(2) The semitranslucent film is a film containing at least one element selected from carbon (C), hydrogen (H), nitrogen (N), and oxygen (O). (Configuration 4).
As described above, although the amount of change in transmittance with respect to the aqueous alkali solution is reduced by the addition of the above elements (which is advantageous for solving the new problem 1), the wet etching time is increased by the addition of the above elements ( Although it is disadvantageous for the solution of the new problem 2), both are in a trade-off relationship, but according to the third invention having the requirements (1) and (2), the problem 1 and the problem 2 Both can be solved simultaneously.
In addition, even if these elements are contained in the translucent film containing Mo and Si in which the ratio Mo: Si is less than 1: 3, both of the above problems 1 and 2 can be solved simultaneously. It is difficult to do.
In the third invention having the requirement (1), the atomic percentage ratio of Mo and Si in the semi-translucent film is selected from Mo: Si = 1: 3 to 1:19. It has been found that the etching rate with respect to the etching solution can be in the range of 0.3 to 5 Å / second, and as a result, a good pattern can be formed by wet etching.
The third invention having the above requirement (2) is a semi-transparent film containing Mo and Si so that the etching rate of the MoSi-based material with respect to the etching solution is in the range of 0.3 to 5 Å / sec. It is actually possible to contain at least one element selected from carbon (C), hydrogen (H), nitrogen (N), and oxygen (O). As a result, a good pattern can be formed by wet etching. It has been found that.

As described above, in the second invention, the addition of the above element increases the wet etching time, and the semi-permeable film cannot be etched well, and a new pattern may not be formed. 2 is produced.
Specifically, in a large mask blank for FPD, when the wet etching time of the semipermeable membrane becomes long, the cross-sectional shape of the semipermeable membrane pattern deteriorates, that is, the shape controllability deteriorates, and as a result, the CD accuracy deteriorates. Cause.
According to the third aspect of the invention, the cross-sectional shape of the semi-permeable membrane pattern is deteriorated, that is, the shape controllability is deteriorated due to the long wet etching time of the semi-permeable membrane, and the resulting CD accuracy is deteriorated. Thus, a mask blank and a photomask can be provided.

In the present invention, examples of the alkaline aqueous solution used in the mask blank and mask manufacturing process and use process include an alkaline aqueous solution used as a developer, a resist stripper, a mask or mask blank cleaning liquid, and the like. Examples of the alkali component include potassium hydroxide (KOH) and sodium hydroxide (NaOH).
The alkaline aqueous solution is brought into contact with the translucent film and the upper surface of the pattern in the manufacturing process and use process of the mask blank and the mask. Since the etching solution for the MoSi-based film is protected by the etching mask during etching, it is not in contact with the semi-transparent film or the upper surface of the pattern.

The present invention includes a mask blank in which a light-shielding film made of a material containing chromium is formed on the semi-transparent film (Configuration 5).
Thus, in a mask blank having a semi-transparent film and a light-shielding film made of a material containing chromium, the semi-transparent film is a chromium-based material used when patterning the light-shielding film. Before and after contact with the etching solution of the material for 2 minutes, it is preferable that the amount of change in transmittance in the wavelength band extending from at least the i-line to the g-line emitted from the ultrahigh pressure mercury lamp is 1.5% or less (Configuration 6) ).
Examples of the etching solution for the chromium-based film include an etching solution containing ceric ammonium nitrate and perchloric acid.
As will be described later, the alkaline aqueous solution and the chromium-based film etching solution are chemicals used in the manufacturing process of a semi-transparent film-laying (pre-attached) type gray tone mask.

  In the present invention, the contact with the alkaline aqueous solution and the chromium-based film etching solution means exposure to these solutions such as spraying, spraying and dipping.

In the present invention, the reason why “transmittance in the wavelength band extending from at least i-line to g-line emitted from at least an ultra-high pressure mercury lamp” is a particular problem is that in the large-sized mask for FPD, This is because multi-color wave exposure is performed using a wide band, and the exposure light intensity (relative intensity) of i-line, h-line, and g-line radiated from the ultra-high pressure mercury lamp as the exposure light source is almost equal. This is because the i-line, h-line, and g-line need to be equally important in terms of relative intensity (see FIG. 9).
In the present invention, before and after contact with the alkaline aqueous solution used in the mask blank and mask manufacturing process and use process for 15 minutes, “the change in transmittance at a wavelength of 300 to 600 nm is 5% or less”. Further preferred. This is because exposure light having a high relative intensity is distributed over the region (see FIG. 10).
In the present invention, examples of the ultra-high pressure mercury lamp include those having the characteristics shown in FIG. 10, for example, but the present invention is not limited to this.

  In the present invention, examples of the translucent substrate include substrates such as synthetic quartz, soda lime glass, and non-alkali glass.

In the present invention, mask blanks and masks for manufacturing FPD devices include mask blanks and masks for manufacturing FPD devices such as LCD (liquid crystal display), plasma display, and organic EL (electroluminescence) display. .
Here, the LCD manufacturing mask includes all masks necessary for LCD manufacturing. For example, TFTs (thin film transistors), particularly TFT channel portions and contact hole portions, low-temperature polysilicon TFTs, color filters, reflectors ( A black matrix), and the like. Other display device manufacturing masks include all masks necessary for manufacturing organic EL (electroluminescence) displays, plasma displays, and the like.

The mask blank and the mask for manufacturing the FPD device according to the present invention include a mode in which at least the gray-tone mask semi-transparent film and the light-shielding film are arranged in any order on the translucent substrate. That is, a mode in which a light-shielding film is formed for the purpose of blocking the exposure wavelength separately from the translucent film is included. Specifically, for example, as shown in FIG. 11 (1), a gray-tone mask semi-transparent film 11 and a light-shielding film 12 are formed in this order on a translucent substrate 10. As shown in FIG. 11 (2), a semi-transparent film underlay type in which a gray-tone mask semi-transparent film pattern and a light-shielding film pattern are formed. A light-shielding film and a gray-tone mask semi-transparent film are formed in this order on the substrate, and these films are patterned to form a light-shielding film pattern and a gray-tone mask semi-transparent film pattern. Examples include a semi-transparent film-mounted type that is formed. The MoSi-based semi-transparent film for gray tone mask is suitable for the semi-transparent film underlay type shown in FIG.
In the present invention, as the material of the light-shielding film, for example, a material different from the etching characteristics of the light translucent film is preferable, and includes at least one of chromium, chromium nitride, chromium carbide, chromium fluoride, and the like. Material is preferred.

  A photomask for manufacturing the FPD device according to the present invention is manufactured using the mask blank for manufacturing the FPD device according to the present invention, and is subjected to patterning of a thin film formed on the mask blank by wet etching. A mask pattern is formed and manufactured (Configuration 7).

Hereinafter, an example of a manufacturing process for manufacturing a semi-transparent film underlay type gray tone mask using a semi-transparent film underlay type large-size FPD mask blank will be described with reference to FIG.
First, a mask blank 20 is formed by performing a process of sequentially forming a semi-transparent film 17 and a light-shielding film 18 on the surface of the translucent substrate 16 (FIG. 12A).
Here, the semi-transparent film 17 can be formed by sputtering film formation using, for example, a MoSi-based sputtering target containing Mo and Si. The film thickness is appropriately selected depending on the required transmissivity of the semipermeable membrane. Next, the light shielding film 18 is a single layer or multi-layered film (for example, a light shielding film with an antireflection film) by reactive sputtering using a reactive gas such as nitrogen, oxygen, methane, and carbon dioxide using a chromium target, for example. ) Can be formed.
The semi-transparent film 17 and the light shielding film 18 have resistance to mutual etching in the manufacturing process of the gray tone mask 10. That is, the semi-transparent film 17 is resistant to the chromium etching solution. Further, the light shielding film 18 is resistant to the MoSi etching solution.
The etching solution for MoSi includes at least one fluorine compound selected from hydrofluoric acid, hydrosilicofluoric acid, and ammonium hydrogen fluoride, and at least one oxidizing agent selected from hydrogen peroxide, nitric acid, and sulfuric acid. Things.

Next, a resist film (a positive resist film or a negative resist film) is formed on the light shielding film 18 of the mask blank 20, and this resist film is exposed using an electron beam or a laser drawing apparatus, Development is performed with a developer to form a first resist pattern 21 (FIG. 12B). The first resist pattern 21 is formed in a shape having the light transmitting portion 14 of the manufactured gray-tone mask 10 as an opening region. In addition, as the resist for forming the first resist pattern 21, a novolak resist can be used.
The mask blank 20 on which the first resist pattern 21 is formed is immersed in a chromium etching solution, and the light shielding film 18 of the mask blank 20 is wet etched using the chromium etching solution with the first resist pattern 21 as a mask. (FIG. 12C). By this etching, a light shielding film pattern 22 is formed on the light shielding film 18.
After the formation of the light shielding film pattern 22, the first resist pattern 21 remaining on the light shielding film pattern 22 is removed with a resist stripping solution of an alkaline aqueous solution (FIG. 12D).
After the first resist pattern 21 is peeled off, the mask blank 20 on which the light shielding film pattern 22 is formed is immersed in an etching solution for MoSi, and this MoSi etching solution is used to make a semi-transparent film using the light shielding film pattern 22 as a mask. 17 is wet-etched to form a semi-transparent film pattern 23 (FIG. 12E). The light-transmitting portion 14 is formed by the light shielding film pattern 22 and the semi-transparent film pattern 23.
After forming the semi-transparent film pattern 23 as described above, a step of removing portions other than the desired portions of the light shielding film 18 constituting the light shielding film pattern 22 is performed. That is, a resist film is formed on the light-shielding film pattern 22 and the light-transmitting substrate 16 and this resist film is exposed and developed in the same manner as described above to form the second resist pattern 24 (FIG. 12F). ). The second resist pattern 24 is formed in a shape having the gray tone portion 15 as an opening region. Next, using the second resist pattern 24 as a mask, the light shielding film 18 constituting the light shielding film pattern 22 is further wet-etched using the chrome etching solution (FIG. 12G).
Thereafter, the remaining second resist pattern 24 is stripped with a resist stripping solution of an alkaline aqueous solution, and the light-shielding portion 13 formed by laminating the gray tone portion 15 made of the semi-transparent film 17, the light-shielding film 18 and the semi-transparent film 17 is formed. The gray tone mask 30 having the same is manufactured (FIG. 12H).

Hereinafter, the present invention will be described in more detail based on examples.
(Example 1)
A semi-transparent film for a gray tone mask was formed on a large glass substrate (synthetic quartz (QZ) 10 mm thick, size 850 mm × 1200 mm) using a large in-line sputtering apparatus. Specifically, a gray tone composed of molybdenum and silicon using a target of Mo: Si = 20: 80 (atomic% ratio) (input current 0.27 A) and Ar (100%) as a sputtering gas (flow rate 56 sccm). A semi-transparent film (MoSi ₄ ) for mask was formed with a film thickness of 40 Å. The spectral transmittance at a wavelength of 300 to 600 nm at this stage (before contact with the aqueous alkali solution (KOH)) was measured. The spectral transmittance was measured with a spectrophotometer (manufactured by Hitachi, Ltd .: U-4100). As shown in FIGS. 1 to 3, the transmittance at the wavelength of the exposure light source before contact with the alkaline aqueous solution (KOH) (the contact time and the number of treatments are both zero) is 64.4% at 365 nm and 66. 7%, 68.3% at 436 nm.
Next, each stage (each processing number of 1 to 4 times) immersed for 5 minutes, 10 minutes, 15 minutes, and 20 minutes in an alkaline aqueous solution (KOH) used in the mask blank and mask manufacturing process and use process, respectively. In step), the spectral transmittance at a wavelength of 300 to 600 nm was measured. 1-3 show the change in transmittance at each stage at wavelengths of 365 nm (i-line), 406 nm (h-line), and 436 nm (g-line).
In addition, as the alkaline aqueous solution, potassium hydroxide (KOH) was used at room temperature.
1-3, the increase in the transmittance before and after immersion for 15 minutes in the wavelength band extending from i-line to g-line is 5% or less, more specifically, the transmittance at the wavelength of the exposure light source after immersion for 15 minutes. Was 66.7% at 365 nm, 68.7% at 406 nm, and 69.9% at 436 nm, and the maximum increase in transmittance before and after immersion for 15 minutes in the band was 2.3%. Further, it was confirmed that the increase in transmittance before and after immersion for 15 minutes in the wavelength band of 300 to 600 nm can be reduced to 5% or less.

(Example 2)
A semi-transparent film for a gray tone mask was formed on a large glass substrate (synthetic quartz (QZ) 10 mm thick, size 850 mm × 1200 mm) using a large in-line sputtering apparatus. Specifically, a target of Mo: Si = 20: 80 (atomic% ratio) was used (input current 0.41 A), Ar (88.5%) and CH ₄ (11.5%) were sputtered (flow rate). 66 sccm), a gray-tone mask semi-transparent film (MoSi ₄ C) containing molybdenum, silicon, and carbon was formed to a thickness of 50 Å. The spectral transmittance at a wavelength of 300 to 600 nm at this stage (before contact with the aqueous alkali solution (KOH)) was measured. The spectral transmittance was measured with a spectrophotometer (manufactured by Hitachi, Ltd .: U-4100). As shown in FIGS. 1 to 3, the transmittance at the wavelength of the exposure light source before contact with the alkaline aqueous solution (KOH) (the contact time and the number of treatments are both zero) is 65.3% at 365 nm and 68. 39.9% at 436 nm.
Next, each stage (each processing number of 1 to 4 times) immersed for 5 minutes, 10 minutes, 15 minutes, and 20 minutes in an alkaline aqueous solution (KOH) used in the mask blank and mask manufacturing process and use process, respectively. In step), the spectral transmittance at a wavelength of 300 to 600 nm was measured. 1-3 show the change in transmittance at each stage at wavelengths of 365 nm (i-line), 406 nm (h-line), and 436 nm (g-line).
In addition, as the alkaline aqueous solution, potassium hydroxide (KOH) was used at room temperature.
1 to 3, the increase in transmittance before and after immersion for 15 minutes in the wavelength band extending from i-line to g-line is 3% or less, more specifically, the transmittance at the wavelength of the exposure light source after immersion for 15 minutes. Was 65.6% at 365 nm, 68.4% at 406 nm, and 70.0% at 436 nm, and the maximum increase in transmittance before and after immersion for 15 minutes in the band was 0.3%. It was also confirmed that the increase in transmittance before and after immersion for 15 minutes in the wavelength band of 300 to 600 nm could be 3% or less.

(Example 3)
A semi-transparent film for a gray tone mask was formed on a large glass substrate (synthetic quartz (QZ) 10 mm thick, size 850 mm × 1200 mm) using a large in-line sputtering apparatus. Specifically, using a target of Mo: Si = 20: 80 (atomic% ratio) (input current 0.87 A), Ar (70%) and N ₂ (30%) as sputtering gas (flow rate 56 sccm), A gray-tone mask translucent film (MoSi ₄ N) made of molybdenum, silicon, and nitrogen was formed to a thickness of 81 Å. The spectral transmittance at a wavelength of 300 to 600 nm at this stage (before contact with the aqueous alkali solution (KOH)) was measured. The spectral transmittance was measured with a spectrophotometer (manufactured by Hitachi, Ltd .: U-4100). As shown in FIGS. 1 to 3, the transmittance at the wavelength of the exposure light source before contact with the alkaline aqueous solution (KOH) (both the contact time and the number of treatments is zero) is 63.5% at 365 nm and 66. 9%, 68.8% at 436 nm.
Next, each stage (each processing number of 1 to 4 times) immersed for 5 minutes, 10 minutes, 15 minutes, and 20 minutes in an alkaline aqueous solution (KOH) used in the mask blank and mask manufacturing process and use process, respectively. In step), the spectral transmittance at a wavelength of 300 to 600 nm was measured. 1-3 show the change in transmittance at each stage at wavelengths of 365 nm (i-line), 406 nm (h-line), and 436 nm (g-line).
In addition, as the alkaline aqueous solution, potassium hydroxide (KOH) was used at room temperature.
1 to 3, the increase in transmittance before and after immersion for 15 minutes in the wavelength band extending from i-line to g-line is 3% or less, more specifically, the transmittance at the wavelength of the exposure light source after immersion for 15 minutes. Was 64.7% at 365 nm, 67.9% at 406 nm, and 69.7% at 436 nm, and the maximum increase in transmittance before and after immersion for 15 minutes in the band was 1.2%. It was also confirmed that the increase in transmittance before and after immersion for 15 minutes in the wavelength band of 300 to 600 nm could be 3% or less.

Example 4
A semi-transparent film for a gray tone mask was formed on a large glass substrate (synthetic quartz (QZ) 10 mm thick, size 850 mm × 1200 mm) using a large in-line sputtering apparatus. Specifically, using a target of Mo: Si = 20: 80 (atomic% ratio) (input current 1.01 A), Ar (85%) and O ₂ (15%) as sputtering gas (flow rate 66 sccm), A gray-tone mask translucent film (MoSi ₄ O) made of molybdenum, silicon, and oxygen was formed to a thickness of 205 Å. The spectral transmittance at a wavelength of 300 to 600 nm at this stage (before contact with the aqueous alkali solution (KOH)) was measured. The spectral transmittance was measured with a spectrophotometer (manufactured by Hitachi, Ltd .: U-4100). As shown in FIGS. 1 to 3, the transmittance at the wavelength of the exposure light source before contact with the alkaline aqueous solution (KOH) (the contact time and the number of treatments are both zero) is 65.2% at 365 nm and 68. 7% and 70.5% at 436 nm.
Next, each stage (each processing number of 1 to 4 times) immersed for 5 minutes, 10 minutes, 15 minutes, and 20 minutes in an alkaline aqueous solution (KOH) used in the mask blank and mask manufacturing process and use process, respectively. In step), the spectral transmittance at a wavelength of 300 to 600 nm was measured. 1-3 show the change in transmittance at each stage at wavelengths of 365 nm (i-line), 406 nm (h-line), and 436 nm (g-line).
In addition, as the alkaline aqueous solution, potassium hydroxide (KOH) was used at room temperature.
1 to 3, the increase in transmittance before and after immersion for 15 minutes in the wavelength band extending from i-line to g-line is 3% or less, more specifically, the transmittance at the wavelength of the exposure light source after immersion for 15 minutes. Was 65.9% at 365 nm, 69.3% at 406 nm, and 71.2% at 436 nm, and the maximum increase in transmittance before and after immersion for 15 minutes in the band was 0.7%. It was also confirmed that the increase in transmittance before and after immersion for 15 minutes in the wavelength band of 300 to 600 nm could be 3% or less.

(Comparative Example 1)
A semi-transparent film for a gray tone mask was formed on a large glass substrate (synthetic quartz (QZ) 10 mm thick, size 850 mm × 1200 mm) using a large in-line sputtering apparatus. Specifically, a gray tone composed of molybdenum and silicon using a target of Mo: Si = 30: 70 (atomic% ratio) (input current 0.28 A) and Ar (100%) as a sputtering gas (flow rate 56 sccm). A mask translucent film (MoSi ₂ ) was formed with a film thickness of 38 Å. The spectral transmittance at a wavelength of 300 to 600 nm at this stage (before contact with the aqueous alkali solution (KOH)) was measured. The spectral transmittance was measured with a spectrophotometer (manufactured by Hitachi, Ltd .: U-4100). As shown in FIGS. 4 to 6, the transmittance at the wavelength of the exposure light source before contact with the alkaline aqueous solution (KOH) (the contact time and the number of treatments are both zero) is 62.0% at 365 nm and 63.3% at 406 nm. 74.5% at 436 nm.
Next, each stage (each processing number of 1 to 4 times) immersed for 5 minutes, 10 minutes, 15 minutes, and 20 minutes in an alkaline aqueous solution (KOH) used in the mask blank and mask manufacturing process and use process, respectively. In step), the spectral transmittance at a wavelength of 300 to 600 nm was measured. FIGS. 4 to 6 show changes in transmittance at each stage at wavelengths of 365 nm (i line), 406 nm (h line), and 436 nm (g line).
In addition, as the alkaline aqueous solution, potassium hydroxide (KOH) was used at room temperature.
4 to 6, the increase in transmittance before and after immersion for 15 minutes in the wavelength band extending from i-line to g-line is 8% or more, and more specifically, the transmittance at the wavelength of the exposure light source after immersion for 15 minutes. Was 70.7% at 365 nm, 71.8% at 406 nm, and 72.5% at 436 nm. The increase in transmittance before and after immersion for 15 minutes in the band was 8.7% at the maximum.

(Examples 5 to 8 and Comparative Example 2)
In Examples 1 to 4 and Comparative Example 1, it was the same as Examples 1 to 4 and Comparative Example 1 except that the etching solution for the chromium-based film was used as a chemical instead of the alkaline aqueous solution (KOH).
Note that an etching solution containing ceric ammonium nitrate and perchloric acid was used at room temperature as an etching solution for the chromium-based film.
In addition, Example 5 is MoSi ₄ target: Ar gas, Example 6 is MoSi ₄ target: Ar + CH ₄ gas, Example 7 is MoSi ₄ target: Ar + N ₂ gas, Example 8 is MoSi ₄ target: Ar + O ₂ gas, comparison Example 2 is MoSi ₂ target: Ar gas.
FIGS. 7 to 9 show changes in transmittance at each stage at wavelengths of 365 nm (i-line), 406 nm (h-line), and 436 nm (g-line) in Examples 5 to 8 and Comparative Example 2, respectively. In these figures, the horizontal axis represents the number of treatments (1 time: 2 minutes), and the vertical axis represents the transmittance (%).
From FIG. 7 to FIG. 9, the amount of increase in transmittance before and after 8-minute immersion in the wavelength band extending from i-line to g-line is 1.6% or less in Examples 5 to 8 (= 1.5% or less of claim 6). In Comparative Example 2, it was found to be as large as 3.3% or more.

(Manufacture of large mask for FPD)
In the same manner as in Examples 1 to 4 and Comparative Example 1, a semi-transparent film for a gray tone mask was formed on a large glass substrate.
Next, a Cr-based light-shielding film was formed on the gray-tone mask translucent film, and a large mask blank for FPD was produced. Specifically, the CrN film is 150 angstroms using Ar and N ₂ gas as sputtering gas, the CrC film is 650 angstrom using Ar and CH ₄ gas as sputtering gas, and then the CrON film is 250 using Ar and NO gas as sputtering gases. An angstrom film was continuously formed.
Next, a mask was manufactured in accordance with the above-described semi-translucent underlay type gray tone mask manufacturing process shown in FIG. At that time, potassium hydroxide (KOH) was used at room temperature as a developer, a resist stripping solution, and a mask cleaning solution, respectively, and the contact time was within 15 minutes in total. An etching solution containing ceric ammonium nitrate and perchloric acid was used at room temperature as a chromium-based film etching solution, and the contact time (etching time) was within 2 minutes in total.
As a result, the transmittance change amount in the translucent film pattern 15 before and after mask fabrication (after mask blank fabrication and after mask fabrication) is as small as 3% or less when the mask blank according to Examples 1 to 4 is used. However, when the mask blank which concerns on the comparative example 1 was used, it was as large as 8% or more.
Moreover, when the mask blank which concerns on Examples 1-4 was used, the pattern cross section was perpendicular | vertical and the favorable MoSi type semipermeable membrane pattern was able to be formed.

  While the present invention has been described with reference to the preferred embodiments, the present invention is not limited to the above embodiments.

It is a figure which shows the change of the transmittance | permeability in wavelength 365nm (i line | wire) when it is made to immerse about 0 to 20 minutes in alkaline aqueous solution (KOH) about the semi-transparent film | membrane created in Examples 1-4. . It is a figure which shows the change of the transmittance | permeability in wavelength 406nm (h line | wire) when it is made to immerse 0-20 minutes in alkaline aqueous solution (KOH) about the semi-transparent film | membrane created in Examples 1-4. . It is a figure which shows the change of the transmittance | permeability in wavelength 436nm (g line) when it is made to immerse for 0 to 20 minutes in alkaline aqueous solution (KOH) about the semi-transparent film | membrane created in Examples 1-4. . It is a figure which shows the change of the transmittance | permeability in wavelength 365nm (i line | wire) when the semi-transparent film | membrane produced in the comparative example 1 was immersed in alkaline aqueous solution (KOH) for 0 to 20 minutes at intervals of 5 minutes. It is a figure which shows the change of the transmittance | permeability in wavelength 406nm (h line) when making the translucent film | membrane produced in the comparative example 1 immersed in alkaline aqueous solution (KOH) for 0 to 20 minutes at intervals of 5 minutes. It is a figure which shows the change of the transmittance | permeability in wavelength 436nm (g line | wire) when the semi-transparent film | membrane produced in the comparative example 1 was immersed in alkaline aqueous solution (KOH) for 0 to 20 minutes at intervals of 5 minutes. About the translucent film | membrane created in Examples 5-8 and the comparative example 2, the change of the transmittance | permeability in wavelength 365nm (i line) when immersed in the etching liquid of a chromium-type film | membrane for 0 to 8 minutes at intervals of 2 minutes FIG. About the translucent film | membrane created in Examples 5-8 and the comparative example 2, the change of the transmittance | permeability in wavelength 406nm (h line) when immersed in the etching liquid of a chromium-type film | membrane for 0 to 8 minutes at intervals of 2 minutes FIG. About the translucent film | membrane created in Examples 5-8 and the comparative example 2, the change of the transmittance | permeability in wavelength 436nm (g line) when immersed in the etching liquid of a chromium-type film | membrane for 0 to 8 minutes at intervals of 2 minutes FIG. It is a figure which shows the spectral distribution of the ultra high pressure mercury lamp which is an exposure light source. It is a figure for demonstrating the aspect of the large sized gray tone mask for FPD. It is a figure for demonstrating the manufacturing process which manufactures a semi-translucent film | membrane underlay type gray tone mask. It is a figure for demonstrating the gray tone mask which has a translucent film | membrane, (1) is a fragmentary top view, (2) is a fragmentary sectional view. It is a figure for demonstrating the gray-tone mask which has a fine light-shielding pattern below a resolution limit, (1) is a fragmentary top view, (2) is a fragmentary sectional view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light-shielding part 2 Transmission part 3 Gray tone part 3a Fine light-shielding pattern 3b Fine transmission part 3a 'Semi-transmissive film 10 Translucent substrate 11 Semi-transmissive film 12 Light-shielding film

Claims (8)

A mask blank for manufacturing an FPD device having at least a semi-transparent film containing Mo and Si having a function of adjusting a transmission amount on a translucent substrate,
The translucent film containing Mo and Si is formed from at least i rays emitted from an ultra-high pressure mercury lamp before and after being brought into contact with an alkaline aqueous solution used in a mask blank and a mask manufacturing process and a use process for 15 minutes. A mask blank for manufacturing an FPD device, characterized in that a change in transmittance in a wavelength band extending over a line is 5% or less.   The translucent film containing Mo and Si is substantially composed of Mo and Si, and the atomic% ratio of Mo to Si in the film is Mo: Si = 1: 3 to 1:19. A mask blank for manufacturing the FPD device according to claim 1. A mask blank for manufacturing an FPD device having at least a semi-transparent film containing Mo and Si having a function of adjusting a transmission amount on a translucent substrate,
The translucent film containing Mo and Si is formed from at least i rays emitted from an ultra-high pressure mercury lamp before and after being brought into contact with an alkaline aqueous solution used in a mask blank and a mask manufacturing process and a use process for 15 minutes. An FPD device comprising a film containing at least one element selected from carbon, hydrogen, nitrogen, and oxygen so that a change in transmittance in a wavelength band extending over a line is 3% or less. Mask blank for manufacturing. A mask blank for manufacturing an FPD device having at least a semi-transparent film containing Mo and Si having a function of adjusting a transmission amount on a translucent substrate,
The semi-transparent film has an atomic percent ratio of Mo and Si in the semi-transparent film so that the etching rate of the MoSi-based material with respect to the etchant is within a range of 0.3 to 5 Å / sec. It is selected from Mo: Si = 1: 3 to 1:19, and / or a film containing at least one element selected from carbon, hydrogen, nitrogen and oxygen in the semi-transparent film. A mask blank for manufacturing an FPD device.   The mask blank for manufacturing the FPD device according to claim 1, wherein a light-shielding film made of a material containing chromium is formed on the semi-transparent film.   The semi-translucent film extends from at least i-line to g-line emitted from an ultra-high pressure mercury lamp before and after being brought into contact with an etching solution of a chromium-based material used when patterning the light-shielding film for 2 minutes. The mask blank for manufacturing the FPD device according to any one of claims 1 to 5, wherein a change in transmittance in a wavelength band is 1.5% or less.   A photomask for manufacturing an FPD device manufactured using the mask blank according to claim 1. A mask blank manufacturing method for manufacturing an FPD device having at least a semi-transparent film containing Mo and Si having a function of adjusting a transmission amount on a light-transmitting substrate,
The translucent film containing Mo and Si is
Using a target in which the atomic percent ratio of Mo to Si is Mo: Si = 1: 3 to 1:19, and
The amount of change in transmittance in the wavelength band extending from at least i-line to g-line emitted from the ultrahigh pressure mercury lamp is 3 before and after contact with the alkaline aqueous solution used in the mask blank and mask manufacturing process and use process for 15 minutes. %, A film containing at least one element selected from carbon, hydrogen, nitrogen, and oxygen as a sputtering gas, and forming a film as a sputtering gas so as to be less than or equal to%, a mask for manufacturing an FPD device Blank manufacturing method.

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