JP2000010257A - Mask for exposure and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mask for exposure which can be easily manufactured and a process for producing the same. SOLUTION: The mask for exposure and the process for producing the same are characterized in that the light shielding film of the mask for exposure for forming circuit patterns formed by disposing the light shielding film on a transparent substrate has a laminated structure composed of at least a metallic film and a silver film which is obtd. by dissolving a silver halide and receiving image by physical development nuclei at the time of development. The mask for exposure is characterized in that the mask has a org. oxide layer or org. metal compd. layer between the transparent substrate and the metallic film and the physical development nuclei are held by the metal oxide or org metal compd.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an exposure mask for forming a circuit pattern and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventional exposure masks include Isao Tanabe and
According to Yoichi Takehana and Morihisa Homoto, "Story of Photomask Technology," Industrial Research Committee (1996), a photographic emulsion containing silver halide (emulsion mask) or a metal thin film such as chrome (emulsion mask) on a transparent substrate such as a film or glass. A hard mask) is used to form a light-shielding film. The emulsion mask irradiates a photosensitive layer containing silver halide such as silver iodide with light and develops the same to form a blackened image. Such emulsion masks use silver salt photography, which is a highly sensitive and simple method, but has the disadvantage of poor heat resistance and ultraviolet light resistance due to the use of gelatin as the binder in the photosensitive layer. There is.

On the other hand, in the hard mask, the light-shielding film is a metal thin film, so that it has excellent heat resistance and ultraviolet light resistance.
In order to obtain a high-density exposure mask directly using a laser light source, the demand for which has been rapidly increasing in recent years, the process of forming a resist film using a photopolymer is rate-determining. Has not been reached.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide an exposure mask capable of easily producing an exposure mask and a method of manufacturing the same.

[0005]

As a result of investigations by the present inventors, in an exposure mask for forming a circuit pattern in which a light-shielding film is provided on a transparent substrate, the light-shielding film is at least a metal film. The above problem has been solved by an exposure mask characterized in that it has a laminated structure of a silver film obtained by dissolving silver halide and receiving an image by physical development nuclei during development. Also, at least a metal film on a transparent substrate,
A layer containing a physical development nucleus and a photosensitive layer containing a silver halide emulsion are sequentially laminated, and the silver halide in the light-irradiated part is developed in the photosensitive layer, and at the same time, the silver halide in the unirradiated part is dissolved, An image is received at the physical development nucleus portion during development to form a silver film, and the photosensitive layer, the layer containing the physical development nucleus, and the metal film in the portion where the silver film is not formed are removed. The above problem has been solved by a mask manufacturing method.

Furthermore, a light-shielding film is provided on a transparent substrate,
In an exposure mask for forming a circuit pattern,
The light shielding film has a laminated structure of at least a metal film and a silver film obtained by dissolving silver halide and receiving an image by a physical development nucleus during development, wherein the physical development nucleus on the metal film is a metal oxide. The above problem has been solved by an exposure mask characterized in that the exposure mask is held by the method. Further, in an exposure mask for forming a circuit pattern formed by providing a light-shielding film on a transparent substrate, the light-shielding film is formed by dissolving at least a metal film and silver halide and receiving an image by a physical development nucleus during development. The object has been solved by an exposure mask having a laminated structure with a silver film obtained by the above method, wherein a physical development nucleus is held on the metal film by an organometallic compound.

Further, a light shielding film is provided on a transparent substrate.
In an exposure mask for forming a circuit pattern,
The light-shielding film has a laminated structure of at least a metal film and a silver film obtained by dissolving silver halide and receiving an image by a physical development nucleus during development, wherein a metal oxide film is formed between the metal film and the transparent substrate. The above object has been attained by an exposure mask characterized in that a substance containing layer is provided. Further, in an exposure mask for forming a circuit pattern formed by providing a light-shielding film on a transparent substrate, the light-shielding film is formed by dissolving at least a metal film and silver halide and receiving an image by a physical development nucleus during development. The above problem has been solved by an exposure mask having a laminated structure of a silver film obtained by the above method, wherein a layer containing an organometallic compound is provided between the metal film and the transparent substrate.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
In the present invention, first, a silver film is formed on a metal film of a transparent substrate having at least a metal film by the principle of a silver complex salt diffusion transfer method (hereinafter, referred to as a DTR method). The DTR method is described in U.S. Pat. No. 2352014 or "Photographic S
ilver Halide Diffusion Processes, '' Andre Rott, Ed
As described in The Focal Press (1972) by ith Weyde, unexposed silver halide dissolves and is converted into a soluble silver complex compound, which diffuses through the silver halide emulsion layer and undergoes physical development. Developed at the location of the nucleus to form a silver film. On the other hand, the silver halide in the exposed portion has a latent image nucleus formed by light irradiation, and the silver halide is developed in the emulsion layer by the latent image nucleus.

Next, when the silver halide emulsion layer is removed with, for example, hot water, only the silver film formed on the physical development nuclei in the unexposed area remains on the transparent substrate coated with the metal film to form an image. . On the other hand, a transparent substrate has at least a metal film as an ultraviolet absorbing or reflecting film for baking an electronic circuit pattern. However, when the generated silver film is used as a resist film and the metal film is removed, an exposure mask is used. Available as

In general, a light-shielding film made of a silver film can be formed in an unexposed area by the above method. However, when a latent image nucleus is formed in advance in silver halide and an electron-accepting substance is used in combination around silver halide, It is also possible to form a silver film which is invertible to exposure by forming a silver film on at least a metal film of a transparent substrate having a metal film, such as by oxidizing and eliminating latent image nuclei only in the exposed portion. is there.

As the transparent substrate, soda lime glass such as soda lime and white crown, low expansion glass such as borosilicate, alkali-free, aluminosilicate, synthetic quartz glass, polyester film, etc. can be used. Considering the ultraviolet properties, a transparent substrate using an inorganic glass is appropriate.

As the metal film, nickel, chromium, aluminum, bismuth, tin, zinc, silicon, indium,
A metal film or a metal alloy film of iron, an iron-nickel alloy, a magnesium-aluminum alloy, a nickel-aluminum alloy, a calcium-silver alloy, or the like can be used. In addition, metal oxides such as zinc oxide and iron oxide can be used because they serve as a light shielding film against ultraviolet light. These films are formed on a transparent substrate by an evaporation method or a plating method.
The thickness of the metal film is about 1 nm to 1 μm, preferably 10 nm.
It is used in a range from nm to 0.8 μm.

Physical development nuclei include sulfides of heavy metals, for example, sulfides of antimony, bismuth, cadmium, cobalt, lead, nickel, palladium, platinum, gold, silver, zinc and the like. Further, salts such as selenide, polyselenide, polysulfide, mercaptan and tin (II) halide, heavy metals, preferably silver, gold, platinum, palladium, mercury and the like are used. Further preferred physical development nuclei for use in the present invention are palladium sulfide nuclei having an average diameter of less than 6 nm as described in EP-A-546598.

As the silver halide used in the present invention, silver chloride, silver bromide, silver iodide and the like can be used. These are synthesized by reacting silver ions and halogen ions in gelatin, and silver halides having various crystal structures such as a plate-like or core-shell type can be used. It is generally said that the larger the diameter of silver halide, the higher the sensitivity and the smaller the diameter, the lower the sensitivity.
It is used in the range of 00 μm.

The surface condition of silver halide grains can be controlled by adding iridium or rhodium-containing compounds during the reaction of silver ions or halogen ions. These additive compounds are 10 ^-8 per mole of silver.
To 10 ^-3 mol, preferably about 10 ^-7 to 10 ^-6 mol. Further, additives such as a chemical sensitizer, a spectral sensitizer, and an antistatic agent can be used.

Silver halide is synthesized by reaction in gelatin, but ionic impurities in gelatin tend to affect the photographic characteristics of silver halide, and thus must be sufficiently removed. In addition, an emulsion stabilizer may be mixed during the synthesis in order to impart dispersion stability in a gelatin aqueous solution of silver halide. Preferred stabilizers include azaindenes and heterocyclic mercapto compounds. In the present invention, a material containing these silver halide, gelatin, additive compound, dispersion stabilizer and the like is called a silver halide emulsion, and a layer formed on a transparent substrate is called a photosensitive layer. The photosensitive layer contains silver halide at about 10 to 90% of its weight,
It is maintained at about 5 to 20 μm, preferably about 2 to 15 μm.

To dissolve silver halide, mesoionic compounds represented by alkanolamines, thioethers and triazolium thiolates, sulfites, amines,
-Mercaptobenzoic acid, cyclic imide compounds, alkyl sulfones and the like can be used. Also, two or more kinds of 4,6-dihydroxypyrimidine and other silver halide solvents can be used in combination. These are used in addition to the developing solution.

Examples of the developer include hydroquinone,
P- such as methylhydroquinone and chlorohydroquinone
Examples include dihydroxybenzenes such as sodium, potassium or ammonium thiosulfate, sodium, potassium or ammonium thiocyanate. These are used in addition to the developer.

The metal oxide for holding the physical development nucleus in the present invention is, for example, a metal oxide such as colloidal silica, colloidal alumina, titanium oxide, zinc oxide, zirconium oxide or a hydroxide thereof. Colloidal silica is a colloidal material of amorphous silicic anhydride,
In addition to unmodified, modified colloidal silica in which the silica surface is modified with ions or compounds such as ammonia, calcium, and alumina to change the behavior of particles against ionicity and pH fluctuation is also included. Colloidal alumina is an amorphous or pseudo-boehmite (including boehmite in a broad sense) alumina hydrate in the form of a colloid having a dispersed shape such as a feather-like, fibrous, or plate-like shape.

Further, natural clay minerals such as smectites such as saponite, hectorite and montmorillonite, vermiculites, kaolinite-serpentine such as kaolinite and halosite, and sepiolites, for example, fluorophlogopite, fluorine tetrasilicic mica, Fluorine mica such as teniolite and synthetic inorganic polymers such as synthetic smectite can also be used.

These metal oxides or hydroxides are finely dispersed in a solvent containing water, mixed with a physical development nucleus, and then coated and held on at least a metal film of a transparent substrate having a metal film. You. The particle diameter of the finely dispersed metal oxide or hydroxide is about 1 nm to 100 μm. Since the physical development nucleus to be retained is 6 nm or less, if the metal oxide is too large, the physical development nucleus is buried in the metal oxide. Used in degrees.

After being applied onto the gold film of a transparent substrate having at least a metal film, and dried, the metal oxide particles are coated with a metal oxide film to increase the bonding strength between the particles and the base material.
It may be heated to 0 ° C. or more. However, since heating to 600 ° C. or more causes particle growth of the metal oxide, heating at 150 ° C. to 400 ° C. is preferable.

As the organometallic compound, tetraethoxysilane, vinyltriethoxysilane, γ-chloropropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N- (β-aminoethyl) -γ-aminopropylmethyldimethoxysilane , Γ-mercaptopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, aluminum isopropoxy , Aluminum acetate, indium acetyl acetate, zinc acetyl acetate, zinc stearate, tetraethyl orthotitanate, tetraisopropyl orthotitanate, tetrabutyl orthotitanate, It may be an organic metal compound such as barium.

In some cases, these organometallic compounds can be combined with metal chlorides such as dimethyldichlorosilane, diphenyldichlorosilane, dimethylphenylchlorosilane, aluminum chloride and titanium tetrachloride. These organometallic compounds improve the retention and adhesion between the metal film on the transparent substrate and the physical development nuclei, and eventually improve the adhesion between the silver film finally formed. The organometallic compound is mixed with the physical development nucleus, applied on the metal film on the transparent substrate, forms fine particles of the metal oxide by heating or hydrolysis, and is further heated to increase the bonding force between the fine particles, Physical development nuclei are firmly held on the metal film.

[0025] Even on a metal surface, when a thin oxide film is formed on a metal film having a surface hydroxyl group remaining, for example, a substitution reaction of an alkoxy group such as an organosilicon compound or an organotitanium compound causes an organometallic compound. The compound can be chemically bonded to the surface. In the case of an organosilicon compound, a functional group such as an amino group, a thiol group, or a glycidyl group can be introduced to the substrate surface to improve the retention of physical development nuclei. In the case of an organic titanium compound, it is possible to improve the acid resistance and the alkali resistance of the surface of the metal film to improve the retention of physical development nuclei. These can be used alone or in combination.

In the present invention, a layer containing a metal oxide containing a metal chloride or an organometallic compound can be formed between a transparent substrate and a metal film. These layers improve the adhesion between the transparent substrate and the metal film, and during development after image reception of the silver film,
Alternatively, when the photosensitive layer, the layer containing physical development nuclei, and the metal film are removed from the transparent substrate, the image reproducibility of the remaining light-shielding film can be significantly improved. These layers are used in a range from a thickness of one molecular scale to about 100 μm,
Preferably it is about 0.4 nm to about 10 μm.

The amount of physical development nuclei held on the metal film on the transparent substrate is in the range of 0.4 mg / m ^{2 to} 25 mg / m ² , preferably in the range of 1 mg / m ² to 20 mg / m ² . It is. If retained by the gelatin layer,
For example, when a hardening agent such as triazine trichloride is used in combination,
The film strength is increased and a strong shielding film is obtained. When a metal oxide or an organometallic compound is used, the amount thereof is 0.01 to 10000 based on the amount of physical development nuclei.
It is used in a weight ratio of about 0, preferably in a weight ratio of about 1 to 10,000. When using titanium oxide or zinc oxide, it must be used as thinly as possible on a transparent substrate because it itself absorbs ultraviolet rays.

[0028]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but it should not be construed that the invention is limited thereto without departing from the spirit of the present invention.

Example 1 Preparation of Metal Film Nickel was deposited on a glass substrate at a thickness of 0.2 μm by vapor deposition.
To give a substrate.

Preparation of Physical Development Nucleus Solution First, a 1% by weight aqueous solution of photographic gelatin (manufactured by Nitta Gelatin) was prepared, and 200 parts by weight of this aqueous solution was further added with distilled water.
800 parts by weight, 1.77 parts by weight of palladium chloride, 3.16 parts by weight of sodium thiosulfate at 30 ° C.
0.39 parts by weight of sodium sulfide was added to obtain palladium sulfide as a physical development nucleus. At this time, the core diameter of palladium sulfide was 1.5 nm on average.

Preparation of physical development nucleus layer 10 parts by weight of 1% by weight of photographic gelatin prepared above was added to
Triazine trichloride was mixed in an amount of 0.01 part by weight, and a physical development nucleus solution was further added in an amount of 10 parts by weight.
Dried and heated.

Preparation of photosensitive layer 70 parts by weight of silver chloride, 30 parts by weight of photographic gelatin (manufactured by Nitta Gelatin), 300 parts by weight of distilled water, containing a trace amount of rhodium chloride and iridium chloride and having an average particle size of 0.2 μm A silver chloride emulsion was prepared by heating the emulsion to 40 ° C., coating it on a physical development nucleus layer by a spinner, quenching it, and drying it at 25 ° C. with cold air for 12 hours. Was prepared. The preparation, coating, and drying steps of the emulsion were all performed in a dark room.

Preparation of Developer Solution Carboxymethylcellulose 4.0 parts by weight Sodium hydroxide 22.5 parts by weight Anhydrous sodium sulfite 120.0 parts by weight Hydroquinone 20.0 parts by weight 1-phenyl-3-pyrazolinone 6.0 parts by weight Bromide 0.8 parts by weight of potassium 8.0 parts by weight of anhydrous sodium thiosulfate 2.0 parts by weight of tetrasodium ethylenediaminetetraacetate A solution of 1000.0 parts by weight of distilled water was prepared and used as a developer.

Exposure, development and preparation of exposure mask Four 10 W fluorescent lamps are arranged, and a part of the
Light was irradiated from a distance of 30 cm for 30 seconds. Thereafter, the film was immersed in a developer at 25 ° C. for 30 seconds to perform development by the DTR method.
Next, the photosensitive layer was removed with warm water at 35 ° C. to obtain a silver image on the substrate. Next, this substrate was immersed in 0.1 N hydrochloric acid to remove the nickel portion, thereby obtaining an exposure mask.

Example 2 Preparation of Metal Film A glass substrate was coated with tetraisopropyl orthotitanate diluted with dehydrated methyl ethyl ketone, heated to 60 ° C. in dry air, and left for 20 minutes. Thereafter, the substrate was washed with acetone and heated at 250 ° C. for 30 minutes to form a titanium oxide layer of about 2 nm. Next, 0.16 by evaporation method
A μm nickel film was formed to obtain a substrate 2.

Preparation of Physical Developing Layer γ-Mercaptopropyltrimethoxysilane was dissolved in dehydrated methyl ethyl ketone, applied on the substrate 2, heated to 60 ° C. in dry air, and left for 1 hour. Then, after washing with acetone, the substrate was left in methyl ethyl ketone in which palladium acetate was dissolved for 3 hours to form physical development nuclei on the surface.

Next, the photosensitive layer prepared in Example 1 was applied to a thickness of 4 μm, exposed and developed in the same manner as in Example 1 to form a silver film on the nickel film. Furthermore, by removing the photosensitive layer,
The nickel film was removed in 0.1 N hydrochloric acid to obtain an exposure mask. The obtained exposure mask reproduced the exposed image well, and the image did not deteriorate even after being left at 120 ° C. for 6 hours.

Example 3 γ-glycidoxypropylmethyldimethoxysilane was dissolved in dehydrated methyl ethyl ketone, applied on a glass substrate, and left at 60 ° C. for 1 hour in dry air. Further, nickel was vapor-deposited at a thickness of 0.2 μm to prepare a base material 3. On this substrate 3, 30: 10: 0.1: tetraethyl orthosilicate, tetrabutyl orthotitanate, palladium acetate, and bismothiol in dehydrated methyl ethyl ketone were used.
Mix at a molar ratio of 0.2, apply and dry to about 30 nm
Was prepared.

Next, a photosensitive layer was formed in the same manner as in Example 1, exposed and developed, and the photosensitive layer was removed. Further, the nickel film was removed in 0.5N hydrochloric acid to prepare an exposure mask. The obtained exposure mask reproduces the exposed image well,
The image did not deteriorate even after being left at 6 ° C. for 6 hours.

[0040]

As described above, according to the present invention,
An exposure mask having good image reproducibility and heat resistance was easily obtained.

Claims (6)

[Claims] 1. An exposure mask for forming a circuit pattern, comprising a light-shielding film provided on a transparent substrate, wherein the light-shielding film is formed by dissolving at least a metal film and silver halide. An exposure mask, which has a laminated structure with a silver film obtained by receiving an image by the above method. 2. A method according to claim 1, wherein at least a metal film, a layer containing physical development nuclei, and a photosensitive layer containing a silver halide emulsion are sequentially laminated on a transparent substrate, and the silver halide in a light-irradiated portion is developed in the photosensitive layer. At the same time, the silver halide in the unirradiated portion is dissolved, and an image is received in the physical development nucleus portion during development to form a silver film, and the photosensitive layer, the layer containing the physical development nucleus, and the silver film are not formed. A method for manufacturing an exposure mask, comprising removing a portion of a metal film. 3. An exposure mask for forming a circuit pattern, comprising a light-shielding film provided on a transparent substrate, wherein the light-shielding film is formed by dissolving at least a metal film and silver halide and developing a physical development nucleus during development. An exposure mask, wherein the physical development nuclei on the metal film are held by a metal oxide. 4. An exposure mask for forming a circuit pattern, comprising a light-shielding film provided on a transparent substrate, wherein the light-shielding film is formed by dissolving at least a metal film and silver halide, and developing a physical development nucleus during development. An exposure mask having a layered structure with a silver film obtained by receiving an image, wherein a physical development nucleus is held on said metal film by an organometallic compound. 5. An exposure mask for forming a circuit pattern, comprising a light-shielding film provided on a transparent substrate, wherein the light-shielding film is formed by dissolving at least a metal film and silver halide, and developing a physical development nucleus during development. An exposure mask, comprising a layered structure of a silver film obtained by receiving an image according to the present invention, wherein a metal oxide-containing layer is provided between the metal film and the transparent substrate. 6. An exposure mask for forming a circuit pattern, comprising a light-shielding film provided on a transparent substrate, wherein the light-shielding film is formed by dissolving at least a metal film and silver halide, and developing a physical development nucleus during development. An exposure mask, which has a laminated structure of a silver film obtained by receiving an image according to the present invention, wherein a layer containing an organometallic compound is provided between the metal film and the transparent substrate.