JPS6115420B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image forming method, and more particularly to an image forming method for easily obtaining a heat-resistant, chemical-resistant and/or durable image.

Conventionally, photographic materials in which a silver halide emulsion is provided on a support (for example, a glass plate) are subjected to image exposure, development, and
The silver image obtained by fixing has low heat resistance (the binder becomes colored due to thermal decomposition at 150 to 200°C) and low chemical resistance (for example, the silver image may dissolve with acid, and the binder may become colored with alkali). Also, the emulsion layer was mechanically weak and easily scratched during handling (that is, its durability was low).

To overcome these drawbacks, forming images with materials that are highly heat resistant, chemical resistant, and durable (eg, chromium) has been practiced in the field of microelectronic construction manufacturing. For example, a thin layer of chromium (e.g.
(approximately 800 Å) by vacuum evaporation or sputtering, a photoresist layer is applied on top of it to form a photosensitive material, and after imagewise exposure using ultraviolet light,
The photoresist layer is developed with a developer to remove exposed or unexposed areas of the resist layer to expose the underlying chromium layer, and the exposed chrome thickness is then chemically etched with an etchant. The chrome image is obtained by removing the remaining resist layer if necessary. In this field, what is thus obtained is called a chrome mask, and the chrome layer is called the mask layer. In the present invention, it will be referred to as an image forming layer because it is used for a wider range of purposes than a mask. For the mask layer, chromium oxide (Cr ₂ O ₃ ), iron oxide (Fe ₂ O ₃ ), chromium monoxide, silicon, silicon oxide (SiO), germanium, silicon-germanium, etc. are used instead of chromium. .

In the process of obtaining the chrome mask mentioned above,
A photoresist is used, but since the photoresist has very low photosensitivity, it cannot be subjected to image exposure using a special device called a pattern generator. Therefore, for the pattern generator,
A photographic light-sensitive material in which a silver halide emulsion is coated on the glass substrate described above is used. However, as mentioned above, the obtained silver image has low durability and chemical resistance, so this silver image is closely attached to a photosensitive material in which the above-mentioned photoresist is coated on a chrome mask layer and exposed to ultraviolet light. The photoresist layer is then developed and the chromium layer is etched as described above to obtain a chrome mask. The chrome mask thus obtained is called a chrome reticle, and is used as a master image for a special device called a step-and-repeat camera. The reticle pattern is usually 1/1 by step-and-repeat camera.
The exposure is reduced to 10. As mentioned above, due to the low sensitivity of photoresist, two types of photosensitive materials have to be used to obtain a chrome reticle, thus increasing the material cost and the number of processes that make it difficult to obtain a chrome reticle. This method has the disadvantage that a large number of defects occur.

Therefore, a photosensitive material for a chrome reticle with high sensitivity has been desired, and for example, a photographic photosensitive material described in US Pat. No. 3,674,492 has been proposed. (1st
figure). This photographic light-sensitive material has a mask layer 11 on a glass substrate 10, a photoresist layer 12 on top of that, and a silver halide emulsion layer 1 on top of that.
3. First, the emulsion layer 13 is imagewise exposed and developed and fixed to form a silver image, then the photoresist layer 12 is uniformly exposed to ultraviolet light, the emulsion layer is removed, the photoresist layer is further developed, and then the mask layer is formed. A durable mask is obtained by etching and finally removing the resist.

However, in this photographic material, a silver halide emulsion (hydrophilic) is coated on a photoresist (oleophilic), so in reality, unless a hydrophilic undercoat layer is provided on top of the photoresist, the emulsion layer and photo The drawback is that the adhesion of the resist layer is poor. Therefore, the layer structure is complicated and the material is expensive. Furthermore, the process is still complex.

If a silver halide emulsion could be used in place of a photoresist, the materials and process would be much simpler, but the emulsion layer would allow aqueous solutions to freely pass through it and would not act as a resist for aqueous etching solutions. be. However, we have discovered several methods for making an emulsion layer act as a resist, and have proposed a photographic material in which a silver halide emulsion layer is coated on a mask layer without a photoresist layer, and a process suitable therefor.

One of the new processes that we have proposed that is suitable for such photographic materials is the method described in JP-A-52-87034. According to one embodiment of this method, a masking layer (e.g. 0.1μ
After forming a silver image by exposing, developing and fixing a photographic light-sensitive material on which a chromium thin layer of about m thickness is provided, and further a halide photographic silver emulsion layer is provided thereon,
Etch bleaching is performed to remove the emulsion layer in the silver image area and expose the mask layer in that area. Then, by plasma etching this material, the exposed mask layer is selectively etched using a binder relief pattern (usually a gelatin relief pattern) corresponding to the emulsion layer in the unexposed area as a resist, and a mask image is formed. It is complete.

According to another embodiment of this method, after imagewise exposure and development (without fixing) is carried out on the above-mentioned photographic light-sensitive material, the obtained silver image is tanned and bleached to re-halogenate, and then the entire surface is The emulsion layer is irradiated with uniform light and then developed to blacken the entire emulsion layer. Then,
Etch bleaching is performed in the same manner as in the above embodiment to remove the emulsion layer in non-image exposed areas and expose the mask layer in those areas. Then, by subjecting this material to plasma etching in the same manner as in the above embodiment, a mask image is formed by selectively etching the exposed mask layer using the silver-binder relief pattern corresponding to the emulsion layer in the image-exposed area as a resist. It will be done.

However, when implementing these embodiments, the width of the portion of the mask layer removed by etching becomes narrower than the desired etching width (as a result, the width of the portion of the mask layer that is not etched, i.e., It was found that the formed image area becomes thicker. It has also been found that the edges of the formed mask pattern are granularly disturbed.

The present inventors have discovered that the reason for the above-mentioned defects is due to trace amounts of silver particles, sometimes silver halide particles, or a mixture of silver and silver halide particles remaining at the edges of the relief pattern.

This will be explained in detail below with reference to FIGS. 2 to 4.

That is, according to one embodiment of the above method, a mask layer (for example, a thin chromium layer (about 0.1 μm) provided by vacuum deposition) is formed on a transparent support (for example, a glass plate).
A photographic light-sensitive material (see Figure 1) on which a silver halide emulsion layer is provided is exposed, developed and fixed to form a silver image (see Figure 2), and then etched by bleaching. The emulsion layer in the silver image area is removed (see Figure 3).

In FIG. 2, reference numeral 20 denotes a photographic material, which consists of a transparent support 21, a mask layer 22, and an emulsion layer 23. 24 is a silver image area, and 25 is an emulsion layer in a non-image area. In FIG. 3, reference numeral 30 indicates an area where the emulsion layer 24 in the silver image area is removed by etch bleaching and the mask layer in that area is exposed. 32 is a binder relief pattern (usually a gelatin relief pattern) corresponding to the emulsion layer 25 in the non-exposed area of FIG. It was found that 31 is a trace amount of silver particles remaining at the edge of the relief pattern, and sometimes they are silver halide particles, and sometimes silver and silver halide particles are mixed. The particle layer was found to have a width of about 1 to about 5 microns and a thickness of about 0.1 microns. Even if such a small amount of particles (i.e., at most 1/200 to 1/100th of the thickness of the relief pattern 31) exists, they will not be removed during the next gas plasma etch. It has been found that the mask layer under this particle layer is difficult to be etched, and even if the mask layer in the part without the particle layer is completely etched, it remains almost unetched. (See FIG. 4) In FIG. 4, reference numeral 40 indicates a portion from which the mask layer has been removed by plasma etching. In order to completely remove the mask layer under the particle layer 31, plasma etching must be performed for a very long time, which is impractical (for example, if there was no particle layer, it would only take 5 to 6 minutes, but (It takes 30-40 minutes to remove the mask layer underneath). Furthermore, the presence of a particle layer has the disadvantage that the edges of the mask pattern become grainy after plasma etching.

If the line width of the mask image obtained in this manner differs from that of the desired mask image, or if the edges of the mask image become grainy, the resultant semiconductor device may be affected, especially in the case of photomasks used in the field of microelectronic construction. This is not preferable because it lowers the yield rate.

As mentioned above, the present inventor found that these defects were caused by silver particles and/or silver halide particles remaining at the edges of the mask pattern, and as a result, the above-mentioned silver particles and/or silver halide particles were After removing it and gas plasma etching,
It has been discovered that the above-mentioned drawbacks (the resulting mask image tends to be thick, the etching time is long to completely remove it, and the edges of the pattern become grainy) can be solved.

The above explanation is about photomasks,
The method of the present invention is not limited to photomasks, but can be used as a method for creating images in general. for example,
It is also possible to form a chemical-resistant precious metal pattern such as gold or palladium on a plastic film (for example, a polyethylene terephthalate film), or to form a pattern of chromium or iron oxide on a ceramic (for example, white alumina porcelain).
It is also possible to obtain permanent images that are heat resistant, chemical resistant, and durable.

Accordingly, an object of the present invention is to provide a new and simple process suitable for photographic materials having an image forming layer on a support and a silver halide emulsion layer thereon.

Another object of the invention is that in the above process,
It is possible to obtain an image of an accurate size in a short etching time, and furthermore, an image with sharp edges of the pattern obtained is provided.

The object of the present invention is achieved by the following configuration.

(1) After image exposure and development of a photographic light-sensitive material having an image forming layer on a support and a silver halide emulsion layer thereon and fixing if necessary, the emulsion layer in the silver image area is removed by etching bleaching. In this method, the exposed image forming layer is removed by gas plasma etching. 1. A method for forming an image, comprising the step of removing residual silver and/or silver halide by treatment with a solvent.

(2) A photographic light-sensitive material having an image forming layer on a support and a silver halide emulsion layer thereon is exposed and developed to form a silver image without fixing, and then the silver image is tanned. After bleaching and re-halogenation, the entire emulsion layer is blackened with a developer, and then only the emulsion layer in the non-image exposed area is removed by etch bleaching to expose the image forming layer in that area, and the exposed image is formed. In a method of removing a layer by gas plasma etching,
Formation of an image characterized by comprising the step of treating the material with a silver or/and silver halide solvent between the etch bleaching and gas plasma etching to remove residual silver and/or silver halide. Method.

Hereinafter, the present invention will be explained in more detail with reference to FIGS. 2 to 6.

The support 21 used in the present invention may be transparent or opaque, and may be hard or flexible. Specifically, glass, quartz, sapphire, plastic films (e.g. polyethylene terephthalate, polystyrene, cellulose acetate, etc.), ceramics (alumina porcelain, titanium porcelain, etc.), metals (nickel, cobalt, chromium, titanium, nickel-chromium alloy, iron) - Nickel alloys, iron-chromium alloys, iron-cobalt alloys, iron-nickel-chromium alloys, etc.), semimetals (e.g. silicon, germanium, etc.), metals with an oxide film on their surfaces (e.g. aluminum anodized) material), enamel, etc. are used.

The image-forming layer 22 used in the present invention is provided by depositing an image-forming substance by vacuum deposition, sprinkling, ion blating, plasma, CVD, chemical plating, or other methods. Image forming substances include metal oxides (e.g. silicon oxide (SiO), chromium oxide (Cr ₂ O ₃ ), iron oxide (Fe ₂ O ₃ , Fe ₃ O ₄ ), copper oxide (Cu ₂ O), etc.); Metals (chromium, aluminum, silver, titanium, cobalt, tungsten, nickel, iron-nickel alloy, iron-chromium alloy, iron-cobalt alloy, iron-nickel-chromium alloy), semimetals (e.g. silicon, germanium), these Combinations (for example, Cr-Cr ₂ O ₃ in which chromium oxide is added to chromium, Si-SiO ₂ , a mixture of silicon and germanium, etc.), and others are used.

Although the thickness of the image forming layer 22 cannot be clearly defined as it varies depending on the application, it is generally in the range of 0.01 to 10 μm, preferably in the range of 0.05 to 1.5 μm. If it is too thin, the image density will be low, and if it is too thick, the etching time will be long.

When the image forming layer 22 is lipophilic, an undercoat layer such as gelatin, which is hydrophilic and can be attacked by an etch bleach solution to be described later, is provided between the image forming layer 22 and the silver halide emulsion layer 23. , the closeness between the two can be improved. The thickness of the undercoat layer is preferably as small as possible, 0.01 to 1 μm,
Preferably it is in the range of 0.05 to 0.5 μm. Furthermore, for the same purpose, the silver halide emulsion layer 23 can be provided after a very small amount of a hydrophilic metal (for example, chromium, etc.) is deposited on the surface of the image forming layer 22 by means such as vapor deposition.

The silver halide emulsion 23 coated on the image forming layer 22 is obtained by dispersing silver halide in a water-soluble binder, and a known silver halide emulsion is used, but a fine grain emulsion is particularly preferred. For example, a so-called Lippmann emulsion in which the average grain size of silver halide is 0.1 μm or less is desirable. The weight ratio of silver halide and water-soluble binder is approximately 1:6 ~
The ratio is approximately 8:1.

Examples of the silver halide include silver chloride, silver bromide, silver iodide, silver chlorobromide, silver iodobromide, silver chloroiodide, silver chloroiodobromide, and the like.

Examples of water-soluble binders include gelatin, albumin, casein, cellulose derivatives, agar, sodium alginate, sugar derivatives, polyvinyl alcohol, polyvinylpyrrolidone, polyacrylamide, and others. Compatible mixtures of two or more of these binders may be used if desired.

The thickness of the silver halide emulsion layer after drying is approximately 0.1~
A range of approximately 10 μm is preferred.

In the first embodiment of the present invention, after the emulsion layer is imagewise exposed, developed and, if necessary, fixed, the silver image area of the emulsion layer is removed using an etch bleach solution to remove the underlying image forming layer. The exposed image-forming layer is exposed to form a binder relief pattern corresponding to the emulsion layer in the unexposed areas, and then trace amounts of silver and/or silver halide remaining at the edges of the relief pattern are removed, and then the exposed image-forming layer is removed. is removed using gas plasma.

Developers for forming the silver image in the first aspect of the invention are generally well known in the art, such as hydroquinone, pyrogallol, 1-phenyl-3-pyrazolidone, p-aminophenol, ascorbic acid, etc. There is.

The developer may contain an alkaline agent (e.g., sodium hydroxide, sodium carbonate), a PH adjusting or buffering agent (e.g., acetic acid, boric acid), an antifoggant (e.g., potassium bromide), and a preservative (e.g., sodium sulfite) as necessary. Known compounds and compositions such as these can be added.

On the other hand, the fixing agent for silver halide is any well-known silver halide solvent (e.g., sodium thiosulfate, sodium thiocyanate), and the solution containing the fixing agent may optionally contain a preservative (e.g., sodium sulfite). , PH buffer (e.g. boric acid),
PH regulators (eg, acetic acid), chelating agents, and the like can be included.

A silver image is thus formed in the emulsion layer by a known method. In the unexposed areas, silver halide remains or has been fixed and removed. FIG. 2 shows a photographic material with a silver image 24 formed in the exposed area. Halogen silver may remain in the unexposed portions of the emulsion layer 25, or may be removed by fixing.

The emulsion layer is then treated with a conventional etch bleach solution to remove the silver image area of the emulsion layer and expose 30 the imaging layer below the silver image area 24, as shown in FIG. Etch bleaching is a phenomenon in which when an emulsion layer containing a silver image is treated with an etch bleaching solution, silver image areas of the emulsion layer fall off.

Known etch bleaching liquids can be used, for example, TAGA Proceedings, pp. 1-11 (1967); PSA Technical Quarterly.
Examples include those described in Nov. 1955, pages 130-134. Specific examples include cupric chloride, an aqueous solution containing citric acid and hydrogen peroxide, an aqueous solution containing copper nitrate, potassium bromide, lactic acid and hydrogen peroxide, ferric nitrate, potassium bromide, lactic acid and hydrogen peroxide. , an aqueous solution containing ferric nitrate, potassium bromide and lactic acid, and an aqueous solution containing tin chloride and potassium bromide.

The photographic material in which the silver image areas of the emulsion layer have been removed to expose the imaging layer in that area 30 is then processed by a gas plasma etch to select the exposed imaging layer, as shown in FIG. Although the thickness of the emulsion layer 32 in the unexposed areas is reduced by plasma treatment, it remains without being completely removed, and as a result, an image is formed by the image forming layer in the unexposed areas. Even if etch bleaching is performed, trace amounts of silver grains and/or silver halide grains as shown at 31 in FIG.
The width of the particle layer is about 1 to about 5 μm and the thickness is 0.1 μm.
It remains around m. This thickness is only 1/200 to several 100 times the thickness of the relief pattern 31, but even if such a small amount of particles is present, the next gas plasma etch will be difficult. Even if the portion of the image forming layer where there is no particulate layer is completely etched, the image forming layer below this particulate layer remains largely unetched, as shown in FIG. In FIG. 4, reference numeral 40 indicates a portion from which the image forming layer has been removed by plasma etching.
In order to completely remove the image forming layer under the particle layer 31, plasma etching must be performed for a very long time, which is not practical (for example, if there was no particle layer, it would only take 5 to 6 minutes). , once there is a particle layer, it takes as much as 30-40 minutes to remove the imaging layer underneath). Furthermore, if there is a particle layer, the edges of the pattern after plasma etching will become granular.

Therefore, the inventor added a new step to remove the silver and/or silver halide mentioned above before gas plasma etching. That is, when silver and/or silver halide grains are removed, a very small amount of binder 51 remains at the edge of the relief pattern where the grain layer was, as shown in FIG. 5, but this is removed by plasma etching. It is easily removed and a pattern identical to the relief pattern is obtained in the imaging layer as shown in FIG. Due to the presence of a small amount of binder 51, the etching time is
Although the time required to etch only the image forming layer is longer, it is at most twice as long.

The reason why the particle layer 31 is formed is not clear, but it may be because the particles in the silver image area that have been removed re-adhere to the edges, or because the silver image density at the edge areas is low.
It is thought that either the edge portion was not completely removed. In either case, the remaining grains are normally silver, but if the etch bleach time is long, they become silver halide. Therefore, the particles can be considered to be composed of silver and/or silver halide.

When the grains consist only of silver, they are dissolved and removed by a silver solvent, and when the grains consist only of silver halide, they are dissolved and removed by a silver halide solvent. When the grains are a mixture of silver grains and silver halide grains, they can be dissolved and removed using both silver and silver halide solvents (one solution), or silver can be dissolved and removed using a silver solvent, and then the silver halide grains can be removed by dissolving and removing them. Silver halide is dissolved and removed by a solvent. This order may be reversed.

Silver solvents used are those known in the photographic industry as silver bleaching solutions, such as potassium dichromate, sodium dichromate, ammonium dichromate, potassium permanganate, ammonium persulfate, and ceric sulfate. A mixed aqueous solution of at least one oxidizing agent such as oxidizing agents such as sulfuric acid, sodium hydrogen sulfate, acetic acid, etc. is used. The most commonly used examples include potassium dichromate (approximately 1 g
~50g/), sulfuric acid (approximately 1ml~50ml/), and ceric sulfate (5~50g/) and sulfuric acid (approximately 5~50ml/).

As the solvent for silver halide, all those used as fixing solutions in the photographic industry, such as the above-mentioned fixing agents, can be used.

Furthermore, as a solvent for both silver and silver halide, any solvent used as a whitening fixer in the photographic industry can be used.

The gas of the gas plasma used in the gas plasma etching performed after silver and/or silver halide is removed is appropriately selected depending on the material of the image forming layer. For example, when the image forming layer is made of chromium or chromium oxide, carbon tetrachloride or a mixed gas of carbon tetrachloride and air is preferable;
In the case of germanium mixtures, fluorocarbons (CF ₄ , CCl ₂ F ₂ etc.) are preferred. Other known gases can also be used.

Materials are removed by gas plasma (etching)
It is well known that, for example,
“Automatic Plasma Machines for Stripping
"Photoresist", Richard L. Bersin, Solid State
Technology, June 1970, 13 (6), pp. 39-45;
Plasma Oxidation Process for Removing
Photoresist Films”, Stephen M. Irving, Solid
State Technology, June 1971, 14 (6), pages 47-51. Substances are removed by gas plasma by both radicals generated by gas plasma combining with the substance and gasifying it, and ions in the gas plasma colliding with the substance and scattering the substance (so-called sputtering). It is thought that this is due to When the gas pressure is high (0.01 to 1 Torr), the kinetic energy of the ions is small, so the sputtering effect is small.
It is thought that the main chemical effect is due to the combination of radicals and substances.

Once the exposed imaging layer has been removed by the gas plasma, the remaining emulsion layer is optionally removed. The removal of the emulsion layer can be similarly carried out by gas plasma or by a removal liquid. When removing by gas plasma, oxygen, air, etc. are suitable as the gas. As the removal liquid, an aqueous solution of acid, alkali or salt is used. Specifically, sulfuric acid,
Aqueous solutions such as hydrochloric acid and nitric acid, aqueous solutions such as sodium hydroxide and potassium hydroxide, sodium hypochlorite,
An aqueous solution of potassium hypochlorite is used.

In the above explanation, a silver image is formed in the image-exposed area, and the emulsion layer in that area is removed by etch bleaching. However, if a reversal emulsion is used or reversal development is performed, a silver image is formed in the non-image-exposed area. Then, the emulsion layer in non-image exposed areas is removed by etch bleaching.

A particularly advantageous embodiment of the present invention includes the following method. That is, after the image is exposed and developed (without fixing), the silver image is tanned and bleached with a bleaching solution containing hexavalent chromium ions and halogen to re-halogenate it. The emulsion layer is then exposed to uniform light and developed again, forming silver in the imagewise exposed and unexposed areas. Next, when etch bleaching is performed, the emulsion layer in the image-exposed areas is not removed, but only the emulsion layer in the non-image-exposed areas is removed, and the image forming layer underneath is exposed.
Thereafter, removal of the exposed imaging layer by gas plasma and, if necessary, removal of the remaining emulsion layer is carried out as described above.

In this case as well, fine particles of silver and/or silver halide may remain around the emulsion relief pattern formed by etch bleaching in the image-exposed area, causing the above-mentioned problem. It has been discovered that even in such cases, very good results can be obtained by removing the remaining particles with the solvent as described above and then performing plasma etching.

Tanning bleaching is a phenomenon in which the binder in the silver image area is hardened when the silver image is bleached (re-halogenated in the case of the present invention). Tanning bleaches and liquid compositions are described in P. Glafkidis, Photographic Chemistry, Vol. 2666-667 (Fountain Press, London, 1958).

In this embodiment, the negative/positive relationship is reversed from the above case. The advantage of this example is that the resolution is extremely high. Normally, when the relief of the emulsion layer is formed by etching bleaching, the resolution is 5.
~10μm, but according to this method, 1~10μm
2 μm lines are also resolved. Moreover, this effect requires that the whitening solution contains halogens other than hexavalent chromium ions, that the bleached area must be rehalogenated (e.g., potassium dichromate and hydrochloric acid), and that it is usually reversal development or tanning bleach. This effect cannot be achieved with the bleaching solution used in the industry, which consists of an aqueous solution of potassium dichromate and sulfuric acid.

The method of the present invention will be explained in more detail with reference to Examples below.

Example 1 1400 ml of silver bromide emulsion using 50 g of gelatin and 188 g of silver bromide (average grain size of silver bromide is approximately 0.06μ)
m) was prepared. This emulsion was subjected to physical ripening according to a conventional method, and sodium thiosulfate and gold chloride () were added to the emulsion.
After adding acid and chemically ripening, 0.15 g of 5-[2-(3-methylthiazolinylidene)ethylidene]-3-carboxymethylrhodanine was added to give a 510 nm-
After optically sensitizing to 560nm, chromium was vacuum-deposited to a thickness of about 0.1μm on a chromium layer of a soda lime glass plate so that the emulsion layer after drying was about 2μm thick, dried and photographed. A photosensitive material was obtained. This photographic light-sensitive material was imagewise exposed, developed with a developer having the following composition (24°C, 5 minutes), fixed with a fixer (20°C, 2
) A silver image was obtained.

Developer 1-phenyl-3-pyrazolidone 0.5 g Sodium sulfite 50 g Hydroquinone 12 g Sodium carbonate (monohydrate) 60 g Potassium bromide 2 g Benzotriazole 0.2 g 1-Phenyl-5-mercaptotetrazole
5 mg phenazine-2-carboxylic acid 1 g Add water to make 1.

Fixer 70% ammonium thiosulfate aqueous solution 200c.c. Sodium sulfite 15g Boric acid 8g Glacial acetic acid 16c.c. Aluminum sulfate 10g Sulfuric acid 2c.c. Add water to make 1.

After washing with water for 2 minutes, the photographic material was immersed in an etch bleach solution having the following composition at 20°C for 2 minutes, washed with water and dried to expose the chromium layer in the silver image area.

Etch bleaching solution A solution Cupric chloride 10g Citric acid 10g Add water to make 1 solution B solution 3% hydrogen peroxide aqueous solution (When using, mix A and B in a volume ratio of 1:1. After rinsing with water for 5 minutes and drying, the photographic material was placed in a plasma etch device (manufactured by TEGAL Corporation, model "PLASMOD") for plasma etching of the exposed chromium layer.

Plasma etching conditions Frequency: 13.56MHz High frequency output: 50W Gas: Air saturated with carbon tetrachloride Gas pressure: Approximately 0.1 Torr When plasma etched for 5 minutes, the exposed chromium layer was removed, but detailed observation revealed that It was found that the edge portion of the pattern remained unetched with a width of several microns. Even when the plasma etch time was increased to 30 minutes, the chromium on this edge was still not completely removed.

On the other hand, using the same photographic material as above, perform image exposure, development, fixing, and etch bleaching in the same manner as above, and then use a bleaching solution with the following formulation (to remove silver particles remaining near the relief pattern). After being immersed in a solution for 1 minute, washed with water for 5 minutes, and further dried, plasma etching was performed in the same manner as above.

Bleach solution Potassium dichromate 9.5 g Concentrated hydrochromic acid 12 ml Add water to make 1 After plasma etching for 5 minutes, a slight amount of chromium remained on the edge of the pattern, but
After plasma etching for 1 minute, the chromium at the edges was completely removed, and a chrome pattern completely corresponding to the gelatin relief pattern was obtained.

Example 2 After developing in exactly the same way as in Example 1, without fixing, apply 20% of the tanning bleach solution prescribed below.
℃ for 1 minute.

Tanning Bleach Liquid Potassium Dichromate 10g Concentrated Hydrochloric Acid 10ml Add water to make 1 After washing for 4 minutes, apply to a 100W tungsten light bulb.
The entire surface was exposed to light for 1 minute at a distance of 20 cm, and developed for 5 minutes using the developer of Example 1 to turn the entire surface into blackened silver.

Next, etch bleaching was performed in the same manner as in Example 1 to remove only the emulsion layer in the non-image exposed area, exposing the chromium layer in that area, washing with water for 5 minutes, drying, and plasma etching in the same manner as in Example 1. As a result, the exposed chromium layer was etched away in 5 minutes, but unetched chromium remained at the edge with a width of several μm. This is because trace amounts of silver halide grains and silver grains remain in the edge portions.

Therefore, using the same material as the above-mentioned photographic light-sensitive material, a photographic light-sensitive material that had been treated up to etch bleach in exactly the same manner as above was immersed in the fixing solution of Example 1 for 1 minute to remove the silver halide. After washing with water for 2 minutes, it was immersed in the bleach solution of Example 1 for 1 minute to remove silver, washed with water, dried, and then plasma etched in the same manner as in Example 1. was also completely etched.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a conventional photographic material, FIGS. 2, 3, 5, and 6 are cross-sectional views showing the steps of the present invention, and FIG. 4 is a cross-sectional view showing a conventional method. . 20: Photographic material, 21: Support, 22: Image forming layer, 23: Silver halide emulsion layer.

Claims (1)

[Scope of Claims] 1. A photographic light-sensitive material having an image forming layer on a support and a silver halide emulsion layer thereon is imagewise exposed and developed, and if necessary, after fixing, it is processed by etching bleaching. In an image forming method in which the emulsion layer in the silver image area is removed to expose the image forming layer in this area, and the exposed image forming layer is removed by gas plasma etching, the The material is silver or/
and a step of removing residual silver and/or silver halide by treating with a silver halide solvent. 2 A photographic light-sensitive material having an image forming layer on a support and a silver halide emulsion layer thereon is exposed and developed to form a silver image without fixing, and then the silver image is tanned and bleached. After the entire emulsion layer is blackened with a developer, only the non-image exposed portion of the emulsion layer is removed by etch bleaching to expose the image forming layer in that portion, and the exposed image forming layer is In an image forming method in which the image is removed by gas plasma etching,
A method for forming an image, comprising the step of treating the material with a silver or/and silver halide solvent between the etch bleaching and gas plasma etching to remove residual silver and/or silver halide. .