JP2003107677A - Photomask, its manufacturing method and photomask material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photomask having sheet film such as a Cr layer as a light shielding layer, for preventing reflection of light when the photomask is used, for enabling exposure with high resolution and by which occurrence of a void defect such as a pin hole due to cleaning, etc., is suppressed. SOLUTION: The photomask having the light shielding layer including at least one kind of metals and metal oxide on the surface of a transparent substrate, is characterized by having a protection layer on the light shielding layer. The protection layer has a film thickness equal to or less than 5 μm, and reflection ratio of short wavelength light with a wavelength equal to or less than 440 nm (especially below 405 nm) is equal to or less than 35%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly relates to a photomask for forming an image by laser exposure and a method for manufacturing the same.
Further, regarding the photomask material used for manufacturing, in detail, flat panel displays such as PDP, FED or LCD, shadow masks for CRTs, printed wiring boards,
The present invention relates to a photomask suitably used in a photolithography process in the fields of packages, semiconductors, etc., a method for manufacturing the same, and a photomask material used for the manufacturing.

[0002]

2. Description of the Related Art As a photomask used in a photolithography process in the fields of flat panel displays, shadow masks for CRTs, printed wiring boards, semiconductors, etc., "Photofabrication" (published by the Japan Photofabrication Association, Educational Society) Hen, 67-
As described in page 80, June 1992), a Cr mask provided with a metal chromium layer (Cr layer) and an Em mask provided with a silver halide emulsion layer (emulsion mask) are known. .

Of the above, the Cr mask is formed by forming a Cr layer on a transparent substrate such as quartz or glass by a sputtering method, and then providing an etching resist on the Cr layer, exposing it by a HeCd laser (442 nm), and the like.
It is produced by patterning an etching resist by development with an alkaline aqueous solution, etching chromium, and peeling the etching resist.

The Cr mask can repair defects such as pinholes, and has the advantages of high resolution and high durability.
That is, since the Cr layer of the Cr mask is a thin film of 0.1 to 0.5 μm, a very high resolution of about 1 μm can be obtained, and the durability (scratch resistance) and the cleaning property are also extremely excellent. Regarding the defect correction of the Cr mask, when foreign matters and the like are present in the white portion (translucent portion when used as a photomask) of the photomask, it can be removed by ablation using a YAG laser or the like. On the other hand, black area (light-shielding area when used as a photomask)
When a blank defect such as a pinhole occurs in the defect, it is possible to form a Cr layer again in the defective portion and correct it by etching using the photolithography.

However, Cr provided with the above-mentioned metallic chromium layer
The mask has the following problems. That is, firstly, in a Cr mask provided with a metal chromium layer, the reflectance of the surface of the metal chromium layer is about 60 to 70.
% (435 nm), and when the Cr mask is used for exposure in the photolithography process, the light reflected from the object to be exposed during the exposure is further reflected by the chromium metal layer of the Cr mask. There is a problem that the resolution decreases due to scattered light. On the other hand, as a means for avoiding such reflection, a multilayer structure of chromium / chromium oxide or the like is widely adopted, but the cost becomes high. Secondly, in the Cr mask provided with the metal chrome layer, as described above, the metal chrome layer itself has high film strength and excellent durability, but the layer thickness is generally as thin as about 0.1 μm. There is a problem in that white defects such as pinholes frequently occur due to contact with hard foreign matter during the process or exposure.

[0006]

As described above, in the photomask having the metal thin film such as the metal chromium layer,
Although high resolution and high durability of the photomask itself can be achieved by forming a thin film of the light shielding layer, there is no light reflection when used as a photomask and high-resolution exposure is possible, and pinholes are possible. The current situation is that a photomask that is less likely to cause white spot defects is not yet provided.

An object of the present invention is to solve the above-mentioned problems in the prior art and achieve the following objects. That is, the present invention is a photomask having a metal thin film such as a metal chrome layer as a light-shielding layer, which can prevent light reflection during use of the photomask and can be exposed at high resolution, and can be used for pinhole cleaning. It is an object of the present invention to provide a high quality photomask in which the occurrence of white spot defects such as the above is suppressed. Further, the present invention is suitable for manufacturing the photomask of the present invention, which is patterned with high resolution and has a wavelength of 440 nm.
The following (especially less than 405 nm) low photoreflectance is used in the method for producing a photomask capable of producing a high-quality photomask without white spot defects, and the photomask producing method of the present invention, which has a wavelength of 405 nm or more. It is an object of the present invention to provide a photomask material capable of forming a high-quality photomask which can be imaged by the above light and has a low light reflectance at a wavelength of 440 nm or less (particularly less than 405 nm) and has no white spot defect.

[0008]

Means for solving the above-mentioned problems are as follows. That is, <1> In a photomask having a light-shielding layer containing at least one of a metal and a metal oxide on the surface of a transparent substrate, a film thickness of 5 μm or less and a wavelength of 440 nm or less (particularly, on the light-shielding layer). A photomask having a protective layer having a reflectance of 35% or less for short wavelength light (less than 405 nm). <2> The photomask according to <1>, wherein the protective layer contains a coloring material and is cured by light and / or heat.

<3> A light shielding layer containing at least one of a metal and a metal oxide can be formed on the surface of a transparent substrate with light having a wavelength of 405 nm or more, and a short wavelength of 440 nm or less (particularly less than 405 nm). A photomask material having, in this order, a photosensitive layer capable of forming a protective layer having a light reflectance of 35% or less is used, and the photosensitive layer of the photomask material is exposed to light having a wavelength of 405 nm or more. It is the photomask according to <1> or <2> above.

<4> A light-shielding layer containing at least one of a metal and a metal oxide can be formed on the surface of a transparent substrate with light having a wavelength of 405 nm or more, and a short wavelength of 440 nm or less (particularly less than 405 nm). Forming a photomask material having, in this order, a photosensitive layer capable of forming a protective layer having a light reflectance of 35% or less; and forming an image of the photosensitive layer of the photomask material with light having a wavelength of 405 nm or more. Similarly exposed and developed, the wavelength is 440 nm or less (especially 4
A step of forming a protective layer having a reflectance of 35% or less of short wavelength light (less than 05 nm) of 35% or less, and a step of etching to remove the light shielding layer in the region where the photosensitive layer has been removed by the developing treatment. A method of manufacturing a photomask characterized by having.

<5> On the surface of the temporary support, a protective layer capable of forming an image with light having a wavelength of 405 nm or more and having a reflectance of 35% or less for short wavelength light having a wavelength of 440 nm or less (particularly less than 405 nm) is formed. The photosensitive layer of the photosensitive transfer material having a photosensitive layer and the light shielding layer of the transparent substrate having the light shielding layer are laminated in contact with each other, and the temporary support is peeled off to form the photosensitive layer. Forming a photomask material by transferring it onto the light-shielding layer;
Imagewise exposure with light of wavelength of nm or more, development processing,
A step of image-forming a protective layer having a reflectance of 35% or less for short-wavelength light having a wavelength of 440 nm or less (particularly less than 405 nm), and etching to remove the light-shielding layer in the region where the photosensitive layer has been removed by development processing. The method of manufacturing a photomask, comprising:

<6> On the surface of the temporary support, a protective layer capable of forming an image with light having a wavelength of 405 nm or more and having a reflectance of 35% or less for light having a short wavelength of 440 nm or less (particularly less than 405 nm) is formed. A photosensitive transfer layer having a photosensitive layer and a light-shielding layer of a transparent substrate having a light-shielding layer in contact with each other to form a photomask material; 405nm photosensitive layer
Imagewise exposure with light of the above wavelengths, peeling off the temporary support and developing treatment, and a wavelength of 440 nm or less (especially 405 nm or less).
(less than nm), a step of forming a protective layer having a reflectance of 35% or less of short-wavelength light of not more than image, and a step of removing the light-shielding layer in the region where the photosensitive layer has been removed by the developing treatment by etching. A method of manufacturing a photomask characterized by having.

<7> A photomask obtained by the method for producing a photomask according to any one of <4> to <6>. <8> A light-shielding layer which is used in the method for producing a photomask according to any one of <4> to <6> above, and which includes at least one of a metal and a metal oxide on the surface of the transparent substrate,
An image can be formed with light having a wavelength of 5 nm or more and a wavelength of 440
A photomask material having a photosensitive layer capable of forming a protective layer having a reflectance of 35% or less for short-wavelength light of nm or less (particularly less than 405 nm) in this order.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION In the photomask of the present invention, a short-wavelength light having a film thickness of 5 μm or less and a wavelength of 440 nm or less (particularly less than 405 nm) is provided on a light-shielding layer made of a metal thin film such as a metal chromium layer. A layer having a reflectance of 35% or less is provided as a protective layer. Further, in the method for producing a photomask of the present invention, an image can be formed with light having a wavelength of 405 nm or more, and a protective layer having a reflectance of 35% or less for short wavelength light having a wavelength of 440 nm or less (particularly less than 405 nm) is formed. Using a photomask material having a photosensitive layer
The photomask of the present invention is produced. The photomask material of the present invention is used in the method for producing a photomask of the present invention. The photomask of the present invention will be described below in detail, and the photomask manufacturing method and photomask material of the present invention will also be described in detail through the description.

<Photomask> In the photomask of the present invention, at least a light-shielding layer and a protective layer are laminated in this order on the surface of a transparent substrate, and other layers may be formed. The protective layer is formed in at least one layer in the same pattern as the light-shielding layer formed in an image-like manner to avoid generation of pinholes and the like in the light-shielding layer, and to prevent light having a short wavelength of 440 nm or less (particularly less than 405 nm). Since the reflectance is 35% or less, when used as a photomask, it is possible to effectively suppress reflection of light generated when light is irradiated between the photomask and the object to be irradiated.

(Light-shielding layer) The light-shielding layer is composed of a metal film mainly composed of at least one of metal and metal oxide. Examples of the metal film include a chromium film, a low reflection chromium / chromium oxide two-layer film, an aluminum film, and an iron oxide film. The metal film can be formed by, for example, a sputtering method, an EB vapor deposition method, coating or the like.

The thickness of the light shielding layer is preferably about 0.05 to 0.5 μm from the viewpoint of improving the resolution of the photomask itself.

As described above, by forming the light-shielding layer as a metal film, a light-shielding layer having excellent film strength and durability can be formed. However, as described above, in the thin film state in the above range, defects such as pinholes are likely to occur due to cleaning at the time of manufacturing the photomask, and the reflectance of the light-shielding layer made of a metal film is, for example, a chromium film. 70%
Since it is about (435 nm), light is reflected, and the resolution at the time of irradiating light through a photomask to form an image is likely to be lowered. Therefore, the following protective layer is further laminated on the light shielding layer.

(Protective Layer) The protective layer contains at least a photosensitive composition constituting a photomask material described later or a curing component thereof, and the wavelength in the layer is 440 nm.
The reflectance of the following short wavelength light is 35% or less, and the film thickness thereof is 5 μm or less. That is, as will be described later, the protective layer contains a photosensitive composition and has a short wavelength light of 440 nm or less (particularly less than 405 nm) after image formation by light having a wavelength of 405 nm or more and curing if necessary. Of a photosensitive layer that constitutes a photomask material and can have a reflectance of less than 35%. The method of forming the protective layer according to the present invention will be described in detail in the section of the photomask manufacturing method described later.

In the present invention, a protective layer which absorbs short wavelength light having a wavelength of 440 nm or less and has a reflectance of 35% or less is further provided on the light shielding layer of the photomask. If the reflectance exceeds 35%, for example, when used as a photomask for exposure in a process such as photolithography and exposed, it is not possible to sufficiently prevent reflection of light generated between the irradiation object and the photomask, and It is not possible to avoid a reduction in the resolution of the image formed on the irradiated object. Above all, the reflectance is preferably 20% or less, and more preferably 10% or less, from the viewpoint of reducing the reflection of light in a range that does not affect the deterioration of resolution.

The reflectance is the amount of light h incident on the protective layer.
For ^one of the light refers to the ratio of the amount of light reflected by the protective layer without being absorbed ^{(h 2) (h 2 /} h 1 × 100), for example, a spectrophotometer (UV-3100S ((Ltd.) Shimadzu Corporation)
Etc.) and the like. In the above description, the object to be irradiated refers to an object that is irradiated with light from a light source through a photomask.

Now, the photosensitive composition (photosensitive layer) will be described. The photosensitive composition can form an image in response to light having a wavelength of 405 nm or more, and absorbs short-wavelength light having a wavelength of 440 nm or less (particularly less than 405 nm) after exposure, development, and curing as necessary. And a photopolymerizable curable photosensitive composition containing a colorant. From the environmental point of view, the photosensitive composition is preferably an alkali developing type, either a negative type in which an exposed portion is cured and insolubilized in an alkaline developing solution, or a positive type in which the exposed portion is soluble in an alkaline developing solution. It may be. In the case of the negative type, for example, a photosensitive composition containing at least an alkali-soluble polymer binder, an addition polymerizable monomer having an ethylenically unsaturated double bond, a photopolymerization initiation system, and at least one coloring material. And the photosensitive composition can be preferably used.

The components constituting the negative photosensitive composition will be described below. -Alkali-soluble polymer binder-As the alkali-soluble polymer binder, a polymer having a carboxylic acid group in a side chain, for example, JP-A-59-44 is used.
615, Japanese Patent Publication No. 54-34327, Japanese Patent Publication No. 58-1
No. 2577, Japanese Patent Publication No. 54-25957, and Japanese Patent Laid-Open No. 59-
53836, JP-A-59-71048, methacrylic acid copolymers, acrylic acid copolymers, itaconic acid copolymers, crotonic acid copolymers,
There are maleic acid copolymers, partially esterified maleic acid copolymers and the like, and examples thereof include cellulose derivatives having a carboxylic acid group in the side chain. In addition, a polymer having a hydroxyl group and a cyclic acid anhydride added thereto is also useful. Particularly preferred is a copolymer of benzyl (meth) acrylate and (meth) acrylic acid described in U.S. Pat. No. 4,139,391, or a multicomponent copolymer of benzyl (meth) acrylate, (meth) acrylic acid and other monomers. Can be mentioned.

The content of the alkali-soluble polymer binder is 5 to 50 of the total solid content (mass) of the photosensitive composition.
Mass% is preferable, and 10-40 mass% is more preferable.
When the content is less than 5% by mass, the strength of the film of the photosensitive layer may be weakened, and when it exceeds 50% by mass, the developability may be deteriorated.

-Addition Polymerizable Monomer Having Ethylenically Unsaturated Double Bond- As the addition polymerizable monomer having an ethylenically unsaturated double bond, at least one addition-polymerizable ethylenically unsaturated monomer in the molecule is used. A compound having a group and having a boiling point of 100 ° C. or higher at normal pressure is preferable. For example, monofunctional acrylates and monofunctional methacrylates such as polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, phenoxyethyl (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, Trimethylolethane triacrylate, trimethylolpropane triacrylate, trimethylolpropane diacrylate, neopentyl glycol di (meth) acrylate, pentaerythritol tetra (meth) acrylate,

Pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, hexanediol di (meth) acrylate, trimethylolpropane tri (acryloyloxypropyl) ether, tri ( Acryloyloxyethyl) isocyanurate, tri (acryloyloxyethyl) cyanurate, glycerin tri (meth) acrylate, trimethylolpropane,

A polyfunctional alcohol such as glycerin which is subjected to an addition reaction of propylene oxide with ethylene oxide and then converted into (meth) acrylate, JP-B-48-417.
08, Japanese Examined Patent Publication No. 50-6034, and Japanese Patent Laid-Open No. 51-371.
No. 93, urethane acrylates described in JP-A-48-64183, JP-B-49-43191, JP-B-52-30490, and epoxy acrylates and (meth) acrylics. Examples thereof include polyfunctional acrylates and methacrylates such as epoxy acrylates which are reaction products of acids.

Of these, trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate and dipentaerythritol penta (meth) acrylate are preferred.

The content of the addition-polymerizable monomer having an ethylenically unsaturated double bond is preferably 5 to 50% by mass, and 10 to 4% by mass based on the total solid content (mass) of the photosensitive composition.
0 mass% is more preferable. If the content is less than 5% by mass, problems such as deterioration of developability and reduction in sensitivity may occur, and if it exceeds 50% by mass, the tackiness of the photosensitive layer may become too strong.

-Photopolymerization initiation system-As the photopolymerization initiation system, since the laser wavelength of the laser plotter used during image formation of the photomask material is in the visible region, a combination of a sensitizing dye that absorbs laser light and a polymerization initiator is used. The use of a combined photopolymerization initiation system is desirable. Examples of the photopolymerization initiation system in which a sensitizing dye and a polymerization initiator are combined include:
A combination of a coumarin-based dye such as 3,3′-carbonylbis (7-diethylaminocoumarin) and the following compound (2), a combination of the following compounds (1) and (2), or a compound (3) below is further added thereto. And the like. Further, a compound group described in JP-A 2000-39712 can be mentioned.

[0031]

[Chemical 1]

The content of the photopolymerization initiation system is preferably 5 to 20% by mass, and more preferably 7 to 15% by mass based on the total solid content (mass) of the photosensitive composition.

In the present invention, an image can be formed by being sensitive to light having a wavelength of 405 nm or more at the time of producing a photomask, and a protective material that absorbs short wavelength light of 440 nm or less, particularly less than 405 nm when used as a photomask. From the viewpoint of functioning as a layer, it is preferable that the photosensitive composition (photosensitive layer) contains a colorant. That is, the wavelength range of light to be shielded is 440 nm or less (especially 405 nm).
Of less than) (light-shielding light) is large, and the absorption of light having a wavelength of 405 nm or more (image-forming light) in the wavelength region of light for image formation is small (photosensitive layer). And

In order to enable image formation at the time of producing a photomask, the photosensitive layer before exposure and development is an image forming layer which is light having a wavelength of 405 nm or more from the viewpoint of efficiently photopolymerizing the entire photosensitive layer. It is desirable that the absorbance be small in the wavelength region of the light. However, as described later, if the sensitivity of image forming light is high and the photosensitive layer can be sufficiently photopolymerized, the absorbance does not need to be particularly small.

Specifically, the absorbance is 2.4.
It is preferably less than 2.0, more preferably 2.0 or less, and particularly preferably less than 1.0. For example, an 488 nm Ar ion laser and a 532 nm ND-YAG laser have relatively low sensitivity. Therefore, when using these laser beams, the photosensitivity in a wavelength region near 500 nm longer than 480 nm, particularly at 488 nm or 532 nm is used. It is desirable that the absorbance of the layer is low.

As the light for image formation, light having a wavelength of 405 nm or more, particularly laser light is used. For example, ND-YAG laser (532 nm), Ar ion laser (488 nm), He-Cd laser (442).
nm), Kr ion laser (413 nm), and the like, but are not limited thereto.

In addition, depending on the type of laser light (for example, Kr ion laser of 413 nm, He-Cd laser of 442 nm), the absorbance is somewhat large (the absorbance in the case of the laser light is 0.3 to 4. In this case, there is no need to make the absorbance particularly small, because there are some that can obtain a predetermined sensitivity. Therefore, the absorbance of light having a wavelength for forming an image can be appropriately determined in consideration of sensitivity.

In addition, when used as a photomask, 4
When the protective layer absorbs short wavelength light of 40 nm or less, particularly less than 405 nm, the absorbance of the photosensitive layer in the short wavelength region is preferably 1.05 or more,
It is more preferably 1.5 or more.

Here, examples of the light (light to be shielded by the photomask) to be used during use as a photomask include light from an extra-high pressure mercury lamp used in an aligner or other exposure device. In this case, in the photosensitive layer (protective layer) according to the present invention, g of 435 nm
It is desirable that the absorbance of the X-ray, the h-line of 405 nm, and the i-line of 365 nm is large.

In order to obtain the photosensitive layer having the above-mentioned characteristics, the photosensitive layer is colored such that the light absorption characteristic of the light having the wavelength of the image forming light is smaller than the light absorption characteristic in the short wavelength band of 440 nm or less. It is preferable to include a material (however, as described above, the absorbance for the wavelength of the laser light does not have to be particularly small depending on the type of the laser light that is the image forming light). Further, when the shielded light contains ultraviolet rays, it is possible to increase the absorbance in the ultraviolet region by adding an ultraviolet absorber.

The absorbance of the photosensitive layer varies depending on not only the kind of the coloring material but also the content of the coloring material in the layer, the film thickness of the layer, etc. It is necessary to consider factors.

When a photomask is manufactured using a photomask material having such a photosensitive layer, light having a wavelength of 405 nm or more, which is exposed to light at the time of manufacturing the photomask, particularly 4
Light with a wavelength of 80 nm or more passes sufficiently into the deep portion of the photosensitive layer, and it is not necessary to increase the light energy or to irradiate the light for a long time, and the sensitivity becomes high, while the reflectance of short wavelength light with a wavelength of 440 nm or less. Is as low as 35% or less, high resolution can be achieved when used as a photomask.

As the coloring material, for example, carbon black can be used alone, but it is also possible to use a combination of dyes or pigments such as blue, green, red, yellow, or violet. For higher sensitivity, absorption of light having a wavelength range of light to be exposed at the time of manufacturing a photomask, that is, light having a wavelength of 405 nm or more (for example, near 500 nm) is small, and irradiation at the time of using the photomask is 440 nm or less, particularly 405 nm.
Pigments having a light absorption efficiency of less than nm and having a high light absorption efficiency are preferable. For example, it is preferable to use blue or green pigments alone or to use a mixture of a blue pigment or a green pigment and a yellow pigment in combination.

Examples of the pigment include, for example, Victoria
Pure Blue BO (C.I. 42595), Auramine (C.I. 41000), Fat Black HB
(C.I.26150), Monolight Yellow GT
(C.I. Pigment Yellow 12), permanent
Yellow GR (C.I. Pigment Yellow 17),
Permanent Yellow HR (C.I. Pigment Yellow 83), Permanent Carmin FBB (C.I.
I. Pigment Red 146), Hoster Balm Red ESB (CI Pigment Violet 19),
Permanent Ruby FBH (CI Pigment Red 11) Fastel Pink B Supra (CI Pigment Red 81) Monastral First Blue (CI Pigment Blue 15), Monolite
First Black B (C.I. Pigment Black 1), Carbon, C.I. I. Pigment Red 97,
C. I. Pigment Red 122, C.I. I. Pigment Red 149, C.I. I. Pigment Red 16
8, C.I. I. Pigment Red 177, C.I. I. Pigment Red 180, C.I. I. Pigment Red 1
92, C.I. I. Pigment Red 215, C.I. I. Pigment Green 7, C.I. I. Pigment Green 36, C.I. I. Pigment Blue 15: 1, C.I. I.
Pigment Blue 15: 4, C.I. I. Pigment Blue 15: 6, C.I. I. Pigment Blue 22, C.I.
I. Pigment Blue 60, C.I. I. Pigment Blue 64 and the like. The colorants may be used alone or in combination of two or more.

The content of the coloring material is determined in consideration of the density of the photomask, the sensitivity at the time of manufacturing the photomask, the resolution and the like, and it varies depending on the kind of the coloring material, but it is generally a photosensitive composition. 10 to 50 mass% of the solid content (mass) is preferable, and 15 to 35 mass% is more preferable.

-Other Components-In addition to the above, the following other components may be added. For the purpose of improving the strength of the cured film, an alkali-insoluble polymer such as an epoxy resin or a melamine resin can be added within a range that does not adversely affect the developability and the like. The content of the polymer is 0.2 to 5 of the total solid content (mass) of the photosensitive composition.
0 mass% is preferable, and 1 to 30 mass% is more preferable.
If the content is less than 0.2% by mass, the effect of improving the cured film strength may not be observed, and if it exceeds 50% by mass, the developability may deteriorate.

For the purpose of increasing the absorbance in the ultraviolet region, U
V absorber, metal, metal oxide such as titanium oxide and the like may be added at the same time. As the UV absorber, JP-A-9
The compound described in JP-A-25360, which exhibits strong absorption in the ultraviolet region by heat treatment, can also be used. It is also preferable to add a thermal polymerization inhibitor as an additive. Examples of the thermal polymerization inhibitor include hydroquinone, p-methoxyphenol, di-t-butyl-p-
Cresol, pyrogallol, t-butylcatechol, benzoquinone, 4,4'-thiobis (3-methyl-6-t
-Butylphenol), 2,2'-methylenebis (4-
(Methyl-6-t-butylphenol), 2-mercaptobenzimidazole, phenothiazine and the like.
Further, known additives such as a plasticizer and a surfactant can be added, if necessary.

The layer thickness of the protective layer is 5 μm or less, preferably 2 μm or less, and 0.3 to 1.2.
μm is more preferable. If the layer thickness of the protective layer exceeds 5 μm, the resolution deteriorates. If it is less than 0.3 μm, it may be difficult to make the layer thickness uniform. Therefore, by setting the layer thickness within the above range, a protective layer having a uniform thickness and high resolution can be provided.

-Transparent Substrate- Examples of the transparent substrate include glass plates such as quartz, soda glass and non-alkali glass, and transparent plastic films such as polyethylene terephthalate. The thickness of the transparent substrate varies depending on its use, but is generally 1 to 7 mm.

<Photomask Manufacturing Method> The photomask manufacturing method of the present invention basically comprises a step of forming a photomask material having a light-shielding layer and a photosensitive layer on the surface of a transparent substrate (hereinafter, referred to as "photomask material"). Sometimes referred to as "material forming process".)
And a step of imagewise exposing and developing the photosensitive layer of the photomask material having a light-shielding layer and a photosensitive layer in this order with light having a wavelength of 405 nm or more (hereinafter, may be referred to as “image forming step”). .) And a step of removing the light-shielding layer in the region where the photosensitive layer has been removed by the developing treatment by etching (hereinafter, sometimes referred to as “etching step”). It may have other steps such as a heat treatment step. The above-described photomask of the present invention can be suitably manufactured by the following photomask manufacturing method of the present invention, and specifically, the manufacturing methods of the first to third aspects shown below may be used.

The first aspect of the method for producing a photomask of the present invention comprises, as a material forming step, a light-shielding layer containing at least one of a metal and a metal oxide on the surface of a transparent substrate;
An image can be formed with light having a wavelength of 05 nm or more, and a wavelength of 44
A step of forming a photomask material having, in this order, a photosensitive layer capable of forming a protective layer having a reflectance of short wavelength light of 0 nm or less (particularly less than 405 nm) of 35% or less, and a photomask as an image forming step The photosensitive layer of the material is imagewise exposed to light having a wavelength of 405 nm or more and developed to form a protective layer having a reflectance of 35% or less for short wavelength light of 440 nm or less (particularly less than 405 nm). And a step of etching the light shielding layer in the region where the photosensitive layer has been removed by the developing process.

The second aspect of the method for producing a photomask of the present invention is to form a material on the surface of the temporary support in a 4 step.
An image can be formed with light having a wavelength of 05 nm or more, and a wavelength of 44
Of a photosensitive transfer material having a photosensitive layer capable of forming a protective layer having a reflectance of 35% or less for short-wavelength light of 0 nm or less (particularly less than 405 nm), and a transparent substrate having a light-shielding layer. A step of forming a photomask material by stacking in contact with the light shielding layer, peeling off the temporary support to transfer a photosensitive layer onto the light shielding layer, and the image forming step of the first aspect. A similar image forming step and an etching step similar to the first aspect are included as the etching step.

The third aspect of the method for producing a photomask of the present invention is to form a material on the surface of the temporary support in a 4 step.
An image can be formed with light having a wavelength of 05 nm or more, and a wavelength of 44
Of a photosensitive transfer material having a photosensitive layer capable of forming a protective layer having a reflectance of 35% or less for short-wavelength light of 0 nm or less (particularly less than 405 nm), and a transparent substrate having a light-shielding layer. A step of forming a photomask material by stacking the light shielding layer in contact with each other, and a step of imagewise exposing the photosensitive layer of the photomask material with light having a wavelength of 405 nm or more (exposure step) And a step of peeling off the temporary support and subjecting to development processing to form an image-like protective layer having a reflectance of 35% or less for short-wavelength light of 440 nm or less (particularly less than 405 nm), and the etching step, The etching process is the same as that of the first aspect.

Each step of the photomask manufacturing method of the present invention will be described. <Material forming step> In the material forming step in the first aspect, a light-shielding layer containing at least one of a metal and a metal oxide can be formed on the surface of the transparent substrate, and an image can be formed with light having a wavelength of 405 nm or more. 440nm or less (especially 405n
A photomask material having a photosensitive layer capable of forming a protective layer having a reflectance of short wavelength light (less than m) of 35% or less in this order is formed. Here, the details of the component constitution of the light-shielding layer, the forming method and the like are the same as in the case of the photomask of the present invention described above, and the details of the component constitution of the photosensitive layer are the same as those described above. Like the protective layer of the photomask of the invention, it can be formed by including the above-mentioned photosensitive composition.

The specific method of forming the photomask material is not particularly limited, and for example, a method of coating and forming the above-mentioned photosensitive composition on the light-shielding layer of the transparent substrate provided with the light-shielding layer may be used. A method of forming a photosensitive layer on a substrate using a transfer material having a photosensitive layer may be used, and other methods can be appropriately selected. Among them, in the present invention, the photosensitive layer which finally becomes the protective layer can be formed to have a uniform thickness, for example, in the case of a large-sized substrate, and this step can be simplified,
The latter method is preferable, and specifically, a transfer method of forming a photosensitive layer on a substrate by using a transfer material having a photosensitive layer (material forming step of the second aspect), having a photosensitive layer A laminating method of laminating a transfer material on a base material to form a laminated body (the material forming step of the third aspect) is particularly preferable. That is,

In the material forming step in the second aspect, the photosensitive layer of the photosensitive transfer material having a photosensitive layer on the surface of the temporary support and the light shielding layer of the transparent substrate on which the light shielding layer is formed. After they are brought into contact with each other and laminated, the temporary support is peeled off before exposure and the photosensitive layer is transferred onto the light-shielding layer to form a photomask material.

The above-mentioned photosensitive transfer material comprises at least a photosensitive layer containing the above-mentioned photosensitive composition on the surface of a temporary support and, if necessary, a layer containing an alkali-soluble resin (release layer). ), An intermediate layer, and a cover sheet. The photosensitive layer can be formed by directly applying a solution of the photosensitive composition using a spin coater, a slit spin coater, a roll coater, a die coater, a curtain coater or the like. The solution of the photosensitive composition can be prepared by dissolving and dispersing the above-mentioned photosensitive composition in a solvent, and examples of the solvent include methyl ethyl ketone and
Examples include PEGMEA and cyclohexanone.

The layer containing the alkali-soluble resin (alkali-soluble resin layer) contains at least the alkali-soluble resin and functions as an oxygen barrier layer or a peeling layer. Examples of the alkali-soluble resin include polymers having a carboxylic acid group in the side chain, for example, JP-A-59-44615 and JP-B-54-3432.
No. 7, JP-B-58-12577, JP-B-54-259
57, JP-A-59-53836, JP-A-59-71.
The methacrylic acid copolymer, the acrylic acid copolymer, the itaconic acid copolymer, the crotonic acid copolymer, the maleic acid copolymer, the partially esterified maleic acid copolymer and the like described in each publication of 048 are cited. Further, a cellulose derivative having a carboxylic acid group in its side chain can be mentioned. Further, a polymer having a hydroxyl group and a cyclic acid anhydride added thereto is also useful. Among them, particularly, a copolymer of benzyl (meth) acrylate and (meth) acrylic acid described in U.S. Pat. No. 4,139,391, and a multidimensional copolymerization of benzyl (meth) acrylate, (meth) acrylic acid and other monomers Preference is given to coalescence and the like.

Further, as another aspect of the alkali-soluble resin layer and an intermediate layer, JP-A-4-208940 is used.
JP-A-5-80503, JP-A-5-173320
Nos. 5,27,724 and JP-A-5-72724, examples thereof include a separation layer (having an oxygen barrier property and a peeling property), an alkali-soluble thermoplastic resin layer, and an intermediate layer.

A thin cover sheet is preferably provided on the photosensitive layer of the photosensitive transfer material for the purpose of protecting it from contamination and damage during storage. The cover sheet may be made of the same or similar material as the temporary support, but it is necessary that it can be easily separated from the photosensitive layer. From this point, the cover sheet material is, for example, silicone paper. ,
Polyolefin, polytetrafluoroethylene sheet and the like are suitable. The thickness of the covering sheet is about 5
100 μm is preferable. Particularly preferably, 10 to 30 μ
It is an m-thick polyethylene or polypropylene film. These cover sheets are peeled off before being laminated.

As the temporary support, for example, a thin sheet of Teflon (R), polyethylene terephthalate, polycarbonate, polyethylene, polypropylene or the like, or a laminate thereof is preferable. The thickness of the temporary support is appropriately 5 to 300 μm, preferably 2
It is 0 μm to 150 μm.

Further examples of photosensitive transfer materials are described in Examples of JP-A-4-208940, JP-A-5-80503, JP-A-5-173320, and JP-A-5-72724. It is also possible to use a photosensitive transfer material having an alkali-soluble thermoplastic resin layer, an intermediate layer and a photosensitive layer in this order on a temporary support.

A suitable method for laminating the photosensitive transfer material on the surface of the transparent substrate is, for example, a method using a heat roll laminator under normal pressure or reduced pressure.

In the material forming step of the third aspect, the photosensitive layer of the photosensitive transfer material having a photosensitive layer on the surface of the temporary support and the light-shielding layer of the transparent substrate provided with the light-shielding layer are provided. A photomask material is formed by stacking and contacting each other. Therefore, unlike the material forming step in the second aspect, the temporary support is not peeled after being laminated, but the temporary support or the transparent substrate is exposed to light, and the temporary support is peeled off after development after the exposure. To do. Details of the photosensitive transfer material, its layer structure, components and forming method, and examples of the photosensitive transfer material are the same as in the case of the second embodiment.

<Image Forming Step> In the image forming step in the first and second embodiments, the photosensitive layer of the photomask material is imagewise exposed with light having a wavelength of 405 nm or more,
After development, a protective layer having a reflectance of 35% or less for short wavelength light having a wavelength of 440 nm or less (particularly less than 405 nm) is formed imagewise. That is, the patterned protective layer can be formed by exposing the photosensitive layer to a desired image and developing it. The protective layer is composed of the above-mentioned photosensitive layer, and is 3 for short-wavelength light of 440 nm or less.
Since it has a reflectance of 5% or less, when used as a photomask, it is possible to effectively prevent reflection of light and perform exposure with high resolution.

In this step, light having a wavelength of 405 nm or more can be simply and safely exposed without using radiation such as ultraviolet rays or X-rays.
There is no particular limitation as long as it is a light source that emits light having a wavelength of 405 nm or more, and it is possible to appropriately select from known methods and perform imagewise exposure. It is also possible to select the exposure wavelength by incorporating a bandpass filter into an ultraviolet exposure device such as an ultra-high pressure mercury lamp. Of these, a laser that emits light having a wavelength of 405 nm or more is preferable, for example, 442.
A HeCd laser of nm, an argon laser of 488 nm and the like are particularly preferable.

Examples of the developer include hydroxides, carbonates, hydrogen carbonates of alkali metals or alkaline earth metals,
Examples thereof include aqueous ammonia and an aqueous solution of a quaternary ammonium salt. Of these, sodium carbonate aqueous solution is particularly preferable.
The developing method is also not limited, and a method of contacting or immersing in a developing solution, a method of spraying the developing solution in a spray form, and the like can be appropriately selected. The temperature of the developing solution during development is preferably 20 to 40 ° C.

In the image forming step of the third aspect, the photosensitive layer of the photomask material is 405 nm thick.
A step of imagewise exposure with light of the above wavelength, and a process of peeling off the temporary support and performing a development treatment, and a wavelength of 440 nm or less (especially 40 nm or less)
The protective layer having a reflectance of short-wavelength light (less than 5 nm) of 35% or less is formed imagewise. That is, after the photosensitive layer is exposed in a desired image pattern in the state of a laminated body in which a transparent substrate and a photosensitive transfer material are laminated, the temporary support is peeled and removed, and a development treatment is performed to form a pattern. Can be a protective layer. Also in this embodiment, 405n is obtained without being affected by radiation such as ultraviolet rays or X-rays.
Since it can be simply and safely exposed to light having a wavelength of m or more, and the protective layer is composed of the above-described photosensitive layer and exhibits a reflectance of 35% or less for short wavelength light of 440 nm or less. When used as a photomask, it is possible to effectively prevent reflection of light and perform exposure with high resolution. Here, the details of the light source, the developing solution, the developing method, the developing temperature and the like are the same as in the case of the second aspect.

<Etching Step> In the etching step,
In any of the embodiments, the light-shielding layer in the region can be removed and the light-shielding layer can be imagewise patterned by etching the region where the photosensitive layer has been removed by the development treatment. Etching can be performed by a conventional method,
Examples of the etching solution at the time of etching include a mixed acid aluminum etching solution, an etching solution containing ceric ammonium nitrate and perchloric acid, and the like.

In the photomask manufacturing method of the present invention, as described above, after the etching, the photosensitive layer on the light-shielding layer is left as a protective layer without being removed, so that it is caused by cleaning in the manufacturing process. Defects such as pinholes can be avoided, and short wavelength light having a wavelength of 440 nm or less is absorbed, and the reflectance thereof is 35% or less, so that it exhibits an excellent function as a photomask.

After the etching step, the protective layer formed in a pattern may be subjected to heat treatment to harden the film and increase the film strength. The temperature of the heat treatment is preferably 120 to 250 ° C. If the temperature is lower than 120 ° C., the effect of heat treatment may not be obtained, and if it exceeds 250 ° C., the material may be decomposed, and conversely, the film may be brittle and weak. The heat treatment time is appropriately 15 to 60 minutes, and as the heat treatment method, for example, a known method using a dry oven, a hot plate or the like can be used.

In the photomask manufacturing method of the present invention, when the manufactured photomask has a defect,
The defect can be corrected as follows. In the case of a black portion, the defect of the photomask means a defect that transmits light such as a white spot mainly in the black portion, for example, a pinhole, and in the case of a white portion, for example, a transparent base material of a portion that should originally become a white portion. A defect in which the light transmittance is reduced due to the adhesion of foreign matter or a photosensitive layer on it.

When a blank portion is generated in the black portion of the photomask, the solution for forming the photosensitive layer described above is applied to the peripheral portion of the defect, or the photosensitive transfer material described above is partially applied by the laminator or the like. Affixed to, for example HeCd
Defects can be corrected by exposing with a laser or the like and developing to remove the unnecessary photosensitive layer. Also,
Instead of exposing and developing with HeCd laser etc., YAG
It is also possible to remove unnecessary portions of the photosensitive layer with a laser by ablation.

On the other hand, if a defect occurs in the white part of the photomask, it can be removed by ablation using a YAG laser or the like. In this case, unlike the Em mask, there is no organic component such as the photosensitive layer in the white portion, and therefore no new defect is generated due to laser abrasion.

Further, from the viewpoint of further improving the film strength, a protective film such as a thermosetting epoxy resin can be further provided on the image-like protective layer after the etching process is completed. In the above description, the negative type photosensitive layer was mainly described, but in the present invention, it is also possible to use a positive type photosensitive layer in which the exposed portion is solubilized in an alkaline aqueous solution.

<Photomask Material> As described above, the photomask material of the present invention comprises a light-shielding layer containing at least one of a metal and a metal oxide on the surface of a transparent substrate and 405 nm.
An image can be formed with light having the above wavelength, and the reflectance of short wavelength light having a wavelength of 440 nm or less (especially less than 405 nm) is 35%.
A photosensitive layer capable of forming a protective layer that is composed of the following in this order, if necessary, an alkali-soluble resin layer,
It may have other layers such as an intermediate layer and is suitably used in the method for producing a photomask of the present invention. The photosensitive layer is configured so that an image can be formed with light having a wavelength of 405 nm or more, and a reflectance of short wavelength light having a wavelength of 440 nm or less (particularly less than 405 nm) is 35% or less. So, finally, the wavelength of 440nm on the light shielding layer.
It is possible to obtain a photomask on which a protective layer having the following short-wavelength light reflectance of 35% or less is laminated. The details of the light-shielding layer, the photosensitive layer, the transparent base material, the alkali-soluble resin layer, and the intermediate layer, which constitute the photomask material, are as described above.

[0077]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. Hereinafter, "parts" in the examples mean "parts by mass".

Example 1 Material Forming Step (1) Preparation of Photosensitive Transfer Material Formation of Alkali-Soluble Resin Layer (Release Layer) A PET (polyethylene terephthalate) film having a thickness of 100 μm was prepared as a temporary support. On the surface of the PET film, an alkali-soluble resin layer coating solution having the following composition was applied by a whiler to a dry film thickness of 0.8 μm and dried to form an alkali-soluble resin layer as a release layer. The drying was performed at 100 ° C. for 2 minutes.

[0079] [Composition of coating solution for alkali-soluble resin layer]   ・ Methyl methacrylate / 2-ethylhexyl acrylate / benzylmethac Relate / methacrylic acid copolymer: 15 parts   (Copolymerization ratio (molar ratio) = 55 / 28.8 / 11.7 / 4.5,     Weight average molecular weight 90000)   ・ Polypropylene glycol diacrylate ... 6.5 parts   (Weight average molecular weight 822)   ・ Tetraethylene glycol dimethacrylate ... 1.5 parts   ・ P-toluenesulfonamide: 0.5 part   ・ Benzophenone ... 1.0 part   ・ Methyl ethyl ketone ... 30 parts

Formation of Intermediate Layer Subsequently, a coating solution for an intermediate layer having the following composition was applied onto the alkali-soluble resin layer (release layer) formed as described above by a whiler so that the dry film thickness was 1.6 μm. Then, it was dried and the intermediate layer was laminated. [Composition of coating liquid for intermediate layer] -Polyvinyl alcohol ... 130 parts (PVA-205 (saponification rate = 80%) manufactured by Kuraray Co., Ltd.)-Polyvinylpyrrolidone ... 60 parts (PVP K-90, GAF Corporation) Fluorine surfactant: 10 parts (Surflon S-131, manufactured by Asahi Glass Co., Ltd.) Deionized water: 3350 parts

Formation of Photosensitive Layer Subsequently, a coating solution for a photosensitive layer having the following composition was further coated on the above intermediate layer by a whiler so as to have a dry film thickness of 1.2 μm, dried and then 12 μm. A thick polypropylene film was laminated to obtain a photosensitive transfer material. The drying was performed at 100 ° C. for 3 minutes.

[0082] [Composition of coating liquid for photosensitive layer]   ・ Green pigment dispersion: 51.3 parts   ・ Yellow pigment dispersion ... 13.45 parts   * 3,3'-Carbonylbis (7-diethylaminocoumarin)                                                         … 0.6 copies   -Allyl methacrylate / methacrylic acid copolymer ... 5.71 parts     (Copolymerization ratio (molar ratio) = 80/20, weight average molecular weight = 40,000)   ・ Hydroquinone monomethyl ether ... 0.004 parts   ・ DPHA (manufactured by Nippon Kayaku Co., Ltd.) ... 7.75 parts   ・ Irgacure 784 ... 1.16 copies     (Ciba Specialty Chemicals Co., Ltd.)   ・ Megafuck F-176P ... 0.06 part     (Fluorine-based surfactant, manufactured by Dainippon Ink and Chemicals, Inc.)   ・ Cyclohexanone 27.39 parts   ・ Methyl ethyl ketone ... 36.83 parts

The green pigment dispersion is 98 parts of green pigment (Pigment Green 7) and cardo resin (V259).
MB, 18 parts by Nippon Steel Chemical Co., Ltd., and PEGMEA
This is a dispersion liquid prepared by mixing and dispersing 884 parts. The yellow pigment dispersion is a yellow pigment (Pigment Yellow 13
9) A dispersion liquid prepared by mixing 148 parts, 57 parts of cardo resin (V259MB, manufactured by Nippon Steel Chemical Co., Ltd.), and 795 parts of PEGMEA.

(2) Preparation of Photomask Material After peeling off the polypropylene film of the photosensitive transfer material obtained as described above, the surface of the photosensitive layer of the photosensitive transfer material and a chromium layer (light-shielding) having a thickness of 0.11 μm were formed by sputtering. Layer) provided in a state of being in contact with the surface of the chromium layer of the glass substrate having a thickness of 2 mm, pressurization (0.8 kg / cm ² ) with a fast laminator (VP-200, manufactured by Taisei Laminator Co., Ltd.). ) And heating (130 ° C.) conditions to bond them to prepare a photomask material.

-Image forming step- Next, the temporary support of the photomask material obtained above was peeled off at the boundary with the alkali-soluble resin layer. Then, through the alkali-soluble resin layer, laser plotter (Mas
k White 800 (He-Cd laser having a wavelength of 442 nm, laser output 180 mW, manufactured by Gerber) was used for exposure at an output of 70%. After the exposure, the film is immersed in an alkaline developer (10% aqueous solution of TCD (manufactured by Fuji Photo Film Co., Ltd.), 28 ° C.) for 35 seconds for development treatment, further washed with water and dried to form a protective layer in a pattern. did. Here, the exposure sensitivity of the photosensitive layer was about 5 mJ / cm ² .

-Etching Step- Next, the chromium layer (light-shielding layer) was etched under the conditions of 20 ° C. and 90 seconds using an etching solution containing 360 g / l of ceric ammonium nitrate. After washing with water and drying, heat treatment was performed at 180 ° C. for 30 minutes to obtain a photomask of the present invention having a chromium layer (light-shielding layer) and a protective layer on the glass substrate. The obtained photomask is line /
The space had a resolution of 8 μm / 8 μm.

In the photomask of the present invention obtained as described above, the reflectance of light having a wavelength of 435 nm of the protective layer is U.
As a result of measurement by V-3100S (manufactured by Shimadzu Corporation), it was about 15%. Further, the number of pinholes having a size of 2 to 10 μm in the photomask was visually measured, and as a result, the number was 0.012 / m ² . further,
No increase in pinholes was observed even after the photomask was subjected to 10 minutes of IPA ultrasonic cleaning five more times. As described above, in this embodiment, a high-quality photomask capable of preventing reflection of light when the photomask is used and performing exposure with high resolution and suppressing generation of defects such as pinholes due to cleaning is provided. I was able to get it.

(Example 2) -Material forming step-In Example 1, the glass provided with an aluminum layer (light-shielding layer) having a thickness of 0.3 μm by a sputtering method in place of the glass substrate provided with the chromium layer. A photomask material having an aluminum layer, a photosensitive layer, an intermediate layer, an alkali-soluble resin layer and a temporary support on a glass substrate was obtained in the same manner as in Example 1 except that the substrate was used.

—Image Forming Step / Etching Step— Then, in the same manner as in Example 1, the temporary support was peeled off, and then exposed, developed, further washed with water and dried to form a protective layer in a pattern. Formed. Then, the aluminum layer (light-shielding layer) was etched at 22 ° C. for about 8 minutes using a mixed acid aluminum etching solution (manufactured by Kanto Chemical Co., Inc.).
After further washing with water and drying, heat treatment was carried out at 180 ° C. for 30 minutes to obtain a photomask of the present invention in which an aluminum layer as a light shielding layer and a protective layer were provided on a glass substrate. The resulting photomask has a line / space of 7μ
It had a resolution of m / 7 μm.

In the photomask of the present invention obtained as described above, the reflectance of light having a wavelength of 435 nm of the protective layer is U.
As a result of measurement by V-3100S (manufactured by Shimadzu Corporation), it was about 5.8%. Further, the number of pinholes having a size of 2 to 10 μm in the photomask was visually measured, and as a result, the number was 0.022 / m ² . further,
No increase in pinholes was observed even after the photomask was subjected to 10 minutes of IPA ultrasonic cleaning five more times. As described above, in this embodiment, a high-quality photomask capable of preventing reflection of light when the photomask is used and performing exposure with high resolution and suppressing generation of defects such as pinholes due to cleaning is provided. I was able to get it.

(Comparative Example 1) In Example 1, the chromium layer was etched, washed with water and dried, and then heat-treated (180 ° C) was not performed, and the protective layer was treated with N-methyl-pyrrolidone (alkaline agent). Was removed to obtain a photomask of a comparative example in which the chrome layer (light-shielding layer) was exposed. The obtained photomask was measured in the same manner as in Example 1 to measure the light reflectance (435n).
m) was about 44%. The number of pinholes measured in the same manner as in Example 1 was 0.024 / m ² , and after the IPA ultrasonic cleaning performed in the same manner as in Example 1, 0.047 pinholes / m 2. ^Was increased to ² .
As described above, the reflection of light generated when used as a photomask cannot be sufficiently suppressed, and it can be said that it is difficult to achieve high resolution with this photomask. Moreover, many pinholes were generated due to cleaning, and the quality was inferior.

(Comparative Example 2) In Example 1, after etching the aluminum layer, further washing with water and drying, heat treatment (180 ° C) was not carried out, and the protective layer was treated with N-methyl-pyrrolidone (alkaline agent). Removed, chrome layer (light shielding layer)
A photomask of a comparative example in which is exposed was obtained. The obtained photomask was measured for light reflectance (4
(35 nm) was about 78%. The number of pinholes measured in the same manner as in Example 1 was 0.017 / m ² , but after the IPA ultrasonic cleaning performed in the same manner as in Example 1, 0.03 pinholes / m ² were obtained. It was increased to m ² . As described above, the reflection of light generated when used as a photomask cannot be sufficiently suppressed, and it can be said that it is difficult to achieve high resolution with this photomask. Moreover, many pinholes were generated due to cleaning, and the quality was inferior.

[0093]

According to the present invention, a photomask having a metal thin film such as a metal chrome layer as a light-shielding layer can be exposed at a high resolution by preventing reflection of light when the photomask is used. Moreover, it is possible to provide a high-quality photomask in which the occurrence of white defects such as pinholes due to cleaning is suppressed. Further, according to the present invention, a high-quality photomask which is suitable for manufacturing the photomask of the present invention and which is patterned with high resolution and has a low light reflectance at a wavelength of 440 nm or less and has no white spot defect is manufactured. And a photomask manufacturing method of the present invention, which can be imaged with light having a wavelength of 405 nm or more, has a low light reflectance of 440 nm or less, and has no white spot defect. A photomask material which can form a high-quality photomask can be provided.

Claims (8)

[Claims] 1. A photomask having a light-shielding layer containing at least one of a metal and a metal oxide on the surface of a transparent substrate, wherein the light-shielding layer has a film thickness of 5 μm or less and a wavelength of 4 μm or less.
A photomask having a protective layer having a reflectance of 35% or less for short wavelength light of 40 nm or less. 2. The photomask according to claim 1, wherein the protective layer contains a coloring material and is cured by light and / or heat. 3. A light-shielding layer containing at least one of a metal and a metal oxide can be formed on the surface of a transparent substrate with light having a wavelength of 405 nm or more, and a reflectance of short wavelength light having a wavelength of 440 nm or less is 35. % Of a photomask material having a photosensitive layer capable of forming a protective layer in this order, and the photosensitive layer of the photomask material is exposed by light having a wavelength of 405 nm or more. The photomask according to 1 or 2. 4. A light-shielding layer containing at least one of a metal and a metal oxide can be formed on the surface of a transparent substrate with light having a wavelength of 405 nm or more, and a reflectance of short-wavelength light having a wavelength of 440 nm or less is 35. % Or less of a photosensitive layer capable of forming a protective layer in this order, and forming a photomask material having a photosensitive layer of 405 nm.
Imagewise exposure with light having the above wavelength and development treatment to imagewise form a protective layer having a reflectance of 35% or less for short wavelength light having a wavelength of 440 nm or less, and a photosensitive layer by development treatment. And a step of removing the light-shielding layer in the region where the is removed by etching. 5. A photosensitive layer capable of forming a protective layer capable of forming an image on the surface of a temporary support with light having a wavelength of 405 nm or more and having a reflectance of 35% or less for light having a short wavelength of 440 nm or less. The photosensitive layer of the photosensitive transfer material having the same and the light shielding layer of the transparent substrate having the light shielding layer are brought into contact with each other to be laminated, and the temporary support is peeled off to transfer the photosensitive layer onto the light shielding layer. A step of forming a photomask material, and imagewise exposing the photosensitive layer of the photomask material with light having a wavelength of 405 nm or more, and developing it so that the reflectance of short wavelength light having a wavelength of 440 nm or less is 35% or less. And a step of removing the light-shielding layer in a region where the photosensitive layer has been removed by a developing process by etching, the method for producing a photomask. 6. A photosensitive layer capable of forming a protective layer on the surface of a temporary support capable of forming an image with light having a wavelength of 405 nm or more and having a reflectance of 35% or less for light having a short wavelength of 440 nm or less. Forming a photomask material by bringing the photosensitive layer of the photosensitive transfer material and the light shielding layer of a transparent substrate having a light shielding layer into contact with each other to form a photomask material; Imagewise exposure with light having a wavelength
It has a step of imagewise forming a protective layer having a reflectance of 35% or less for light having a short wavelength of 0 nm or less, and a step of etching to remove the light shielding layer in the region where the photosensitive layer has been removed by the development treatment. A method for manufacturing a photomask, which is characterized by the above. 7. A photomask obtained by the method for producing a photomask according to claim 4. 8. The method for producing a photomask according to claim 4, wherein the transparent substrate has a surface,
A light-shielding layer containing at least one of a metal and a metal oxide,
An image can be formed with light having a wavelength of 405 nm or more and a wavelength of 4
A photomask material comprising a photosensitive layer capable of forming a protective layer having a reflectance of short wavelength light of 40 nm or less of 35% or less in this order.