JPS63153575A - Production of relief hologram - Google Patents

Abstract

PURPOSE:To form a relief hologram not to be peeled from a base even at the time of low exposure by constituting the developing process of a process for executing development by means of an aq. alkaline solution and a process for executing dipping processing by means of dioxane. CONSTITUTION:A pattern is exposed to a negative photoresist layer formed on a base and capable of being developed with the aq. alkaline solution, dipped into an aq. alkaline developing solution, and then dipped into dioxane. A solution obtained by dissolving unexposed photoresist is used as the aq. alkaline developing solution and a component having no dissolving function is preferable for a polymer part bridged by exposure. In the dipping processing, a relief hologram formed in a low exposure area separated from the base is left and the depth of the relief hologram can be increased. Thus, the relief hologram not to be peeled from the base can be formed even at the low exposure and a sufficiently satisfied result for the diffraction grating which is essential characteristics for the hologram can be obtained.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for producing a relief hologram.

More specifically, the present invention relates to a method for producing a relief hologram using a negative photoresist.

[Conventional technology]

Various types of image forming materials for relief holograms have been reported, but relief holograms using photoresist have the advantage of being able to easily reproduce large quantities of relief holograms, so the holograms that have actually begun to penetrate the printing field are , all made using photoresist.

There are two types of photoresists, negative type and positive type, but image forming materials for relief holograms are currently limited to positive type photoresists. The reason is A.
ppl, Opticm, 13.129 (1974
), negative-tone photoresists may require sufficient exposure to prevent the relief hologram from peeling off from the substrate during development, but hologram imaging is usually low. This is because the ultra-fine relief hologram easily falls off the substrate during development because it has to be done with a certain amount of exposure, making it impossible to leave the interference fringes recorded by the radar light as a relief.

Therefore, positive photoresists that do not cause such problems are widely used. However, the sensitivity of the 4-di photoresist is low, and the general-purpose laser, Alco-9 (
The disadvantage is that the sensitivity to Ar) is extremely low. Therefore, there is a strong desire for a photoresist that has high resolution and is highly sensitive to Ar laser, and a method for producing a relief hologram using the photoresist.

[Problems to be solved by the present invention]

Therefore, the problem to be solved by the present invention is that in a method for manufacturing a relief hologram using a photoresist that has high resolution and is highly sensitive to Ar radiation, it is difficult to remove the hologram from the substrate even at a low exposure dose. It is an object of the present invention to provide a new method that can form a relief hologram that does not peel off and can also obtain sufficiently satisfactory results regarding diffraction efficiency, which is an essential characteristic of holograms.

[Means for solving problems]

That is, the present inventors have developed a method in which a relief hologram is produced by exposing a photoresist layer formed on a substrate and developable with a hydrotactic alkaline developer in a pattern of a certain amount, and then developing it. (1) a first step of developing with an aqueous alkaline developer;
(2) The above-mentioned problems have been solved by providing a method for producing a relief hologram, which is characterized by comprising a second step of immersion treatment in dioxane.

The present invention will be explained in detail below.

Regarding a negative photoresist that can be developed with an aqueous alkaline developer containing a polymer containing a phenylene cyacrylate group and/or a cinnamic group in the main chain or chain, for example, JP-A-60-165646 Publications, JP-A-61-15860 and JP-A-61-55643
It is described in Japanese Patent Publication No. 2003-110033, and has been partially put into practical use as a photosensitive material for 18th edition.

The present inventors investigated the suitability of a negative photoresist as an image forming material for relief holograms, and as a result of studying a method for recording interference fringes using a three-beam interference system, we found that transparent image areas with a rain-like shine was obtained, but the diffraction efficiency was! It didn't reach good.

Therefore, as a result of various studies to improve the diffraction efficiency, we found that the first method: After exposing the negative photoresist layer that can be developed with an aqueous alkaline developer formed on the substrate by 4 turns, After development by immersion, by further immersion treatment in dioxane, or, more preferably, in the second method: immersion treatment in an organic solvent, followed by immersion in an aqueous alkaline developer. After development, a drastic improvement in diffraction efficiency was observed by further immersion treatment in dioxane, leading to the completion of the present invention.

The aqueous alkaline developer used in the present invention is preferably one that dissolves the unexposed negative photoresist and does not dissolve a portion of the polymer crosslinked by exposure. Examples of alkalinizing agents include sodium silicate, potassium silicate, and sodium metasilicate.

Sodium carbonate, potassium carbonate, sodium bicarbonate, tribasic sodium phosphate, tribasic potassium phosphate.

Inorganic alkalis such as tertiary ammonium phosphate, dibasic sodium phosphate, and organic amines such as monoethanolamine, jetanolamine, triethanolamine, 2-diethylaminoethanol, and ethylenediamine are used alone or in combination. It can also be used as a mixture of more than one species.

A suitable amount of a surfactant and other water-soluble organic solvents may also be added to this aqueous alkaline developer for the purpose of promoting dissolution or swelling of the photoresist layer.

As the surfactant, anionic surfactants, nonionic surfactants, amphoteric surfactants, etc. can be used, and the water-soluble organic solvent preferably has a solubility in water of 3 or more. Furthermore, additives such as antifoaming agents and wetting agents can also be included as necessary.

In the immersion treatment using an organic solvent in the second method of the present invention, it is not necessarily necessary to form a Lely 7 hologram that is visible to the naked eye, and when the resist coating surface is actually measured after development treatment, almost no surface irregularities are observed. .

However, this immersion treatment has a remarkable effect on leaving relief holograms formed in the low exposure range, which would easily detach from the substrate using conventional methods, and furthermore, it is possible to increase the depth of the relief holograms. The effects are tremendous, such as making it possible to Although the reason for this effect is not clear, by dipping treatment using an organic solvent, the relatively low molecular weight uncrosslinked components remaining between the crosslinked polymers are extracted from between the crosslinked 4-rimers. This is considered to be effective in improving the developer resistance of the crosslinked polymer portion when developed with an aqueous alkaline developer and in improving the developability of the unexposed area.

The organic solvent used in the second method of the present invention is preferably a solvent that is a poor solvent for the negative type 7t) resist, and a mixed solvent of a poor solvent and a good solvent may also be used. Further, the mixing ratio can also be changed in consideration of the development time. In this case, in order to minimize the influence of residual solvent on the photoresist layer, it is preferable that the boiling point of the solvent is 135° C. or lower. Preferred solvents include, but are not limited to, methyl isobutyl ketone, isopropyl alcohol, a mixture of methyl isobutyl ketone and isopropyl alcohol, a mixture of dioxane and isopropyl alcohol, and the like.

Hereinafter, the present invention will be specifically explained using examples.

"Parts" and "ts" in the examples are based on weight.

(Assembling of optical system) An air-cooled argon laser was used as the output light source, and the optical system was assembled so that the object beam:reference beam was divided at a ratio of 1:2, the intersection angle was 20°, and the total output was 88 μW/crn2.

(Production of photosensitive resin) Zoethyl p-phenylene diacrylate 54.89 (
ethylene oxide (6.2 mol) adduct of bisphenol A (1 mol) and bisphenol A (1 mol) 1 aa, 2p (0
, 266 mol) and the catalyst (sibutyltin oxide 600 mol).
rn9) and an inhibitor (phenothiazine 6011 kg) were charged into a reactor equipped with a stirring device, a nitrogen gas inlet tube, a thermometer, and a distillation tube, and the mixture was stirred under a nitrogen gas atmosphere.
The reaction was started by heating to 90°C. Thereafter, heating and stirring were continued for 3 and a half hours to completely distill off the ethanol produced by the reaction, yielding a linear polyester resin with a hydroxyl value of 46.5.

100g of the above linear polyester resin was heated to 140°C,
After stirring, 9.0 g of pyromellitic dianhydride was added, and stirring was continued for 20 minutes at normal pressure in a nitrogen atmosphere, and the acid value was 4.
A lumexyl group-containing photosensitive polyester resin with a side chain strength of 3.5 was obtained.

Example 1 The above photosensitive resin was dissolved in cyclohexane to prepare a photosensitive resin solution with a non-volatile content of 7 or more, and using a spinner (
1000 r, p, m, / 20 seconds) This solution was applied onto a glass plate and heat treated at 90°C for 10 minutes to obtain a resist dry plate.

This resist dry plate was set in a dry plate holder, and the pattern was exposed to red light for 15 seconds. The exposed dry plate was developed by immersing it in a 20° C. aqueous alkaline developer having the following composition for 10 seconds. After development.

It was washed with water and dried at 90°C for 1 minute. The diffraction efficiency of the relief hologram at this point was 0.14%. Further, this dry plate was immersed in dioxane at 20° C. for 5 seconds. Next, this dry plate was washed with water and dried, and the diffraction efficiency of the relief hologram was as follows. Note 1) Sodium tert-butylnaphthalene sulfonate anionic surfactant manufactured by Kao Atlas @) Example 2 Same as Example 1 The resist dry plate prepared above was set in a dry plate holder and exposed to laser light for 10 seconds in 4 turns. The exposed dry plate was immersed for 30 seconds in a mixed solvent of 5 parts of dioxane and 35 parts of isonorobyl alcohol at 20°C.

Next, this dry plate was dried at 90° C. for 1 minute, allowed to cool at room temperature, and then developed by immersing it in an aqueous alkaline developer having the same composition as in Example 1 at 20° C. for 10 seconds. After development, it was washed with water and dried at 90° C. for 1 minute. The diffraction efficiency of the relief hologram at this point was 0.56%.

Furthermore, this dry plate was immersed in dioxane at 20° C. for 10 seconds. Next, this dry plate was washed with water and dried, and the diffraction efficiency of the relief hologram was improved to 11.431.

〔Effect of the invention〕

According to the method for producing a relief hologram using a negative-tone photoresist of the present invention, a relief hologram that does not peel off from the substrate can be formed even at a low exposure dose, and results are sufficiently satisfactory in terms of diffraction efficiency, which is an essential characteristic of a hologram. can be obtained.

Claims (1)

[Scope of Claims] 1. A method for producing a relief hologram by exposing a pattern to a negative photoresist layer which is formed on a substrate and is developable with an aqueous alkaline developer, and then developing the resist layer. A method for producing a relief hologram, characterized in that the steps include (1) a first step of developing with an aqueous alkaline developer, and (2) a second step of immersion treatment in dioxane. 2. The method according to claim 1, wherein a polymer containing a phenylene diacrylate group and/or a cinnamic acid group in the main chain or side chain is used as the negative photoresist. 3. In a method in which a pattern is exposed to light on a negative photoresist layer developable with an aqueous alkaline developer formed on a substrate and then the resist layer is developed to produce a relief hologram, the developing step includes (1) organic (2) a second step of developing with an aqueous alkaline developer;
and (3) a third step of immersion treatment in dioxane. 4. The method according to claim 3, wherein a polymer containing a phenylene diacrylate group and/or a cinnamic acid group in the main chain or side chain is used as the negative photoresist. 5. The method according to claims 3 and 4, wherein a solvent that is a poor solvent for negative photoresist is used as the organic solvent. 6. The method according to claims 3 and 4, wherein a mixed solvent of a poor solvent and a good solvent is used for the negative photoresist as the organic solvent. 7. The method according to claims 3 to 6, wherein a solvent having a boiling point of 135° C. or lower is used as the organic solvent.