JPH0147774B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a highly sensitive positive-working photosensitive composition that can be applied as a resist for ultra-fine processing used in the production of elements such as ICs and LSIs, and as a photosensitive material used in the production of lithographic printing plates. Typical positive photosensitive materials include: 1.
There are 2-quinonediazide compounds, such as 1.2-
Regarding quinonediazide compounds, for example, West German Patent No. 938233 and J. Coser's ``Light-Sensitive Systems'' (John
Wiley & Sons, Inc.), pages 339-357, a large number of compounds are known from the many patent publications and technical literature. Furthermore, it is also known that among these known 1,2-quinocidiazide compounds, 1,2-naphthoquinone-2-diazide sulfonic acid esters of aromatic polyhydroxy compounds are particularly suitable. The photoresist currently sold by Shipley under the trademark "AZ-1350J" is the most representative one that is practically widely used in the field of ultrafine processing, and the photoresist used in the resist is Sexual substances have already been identified in the IBM report (IBM J, Res.
Develop.Vol.23, No.1, JANNARY 1979), its chemical structure was clarified.
That is, according to this IBM report, the photosensitive material of the photoresist is It has been revealed that the compound is represented by The present inventors understand that this photosensitive material represents the current practical level of positive photosensitive materials in view of the fact that it is a typical photosensitive material that is actually widely used. are doing. On the other hand, in the field of ultrafine processing, there is a strong need for a photoresist with higher sensitivity than the photoresists currently in practical use in order to further improve the current processing productivity. The present invention has been made in view of such circumstances, and its purpose is to provide a highly sensitive positive-working photosensitive composition. As a result of studying the relationship between the chemical structure and sensitivity of various photosensitive substances, the present inventors found that 1,2-naphthoquinone-2 of polyhydroxybenzophenone
- Among the group of compounds of diazito-sulfonic acid esters, it was discovered that a compound in which at least the 2-position and the 2'-position connected to the carbonyl group of the benzophenone nucleus were each substituted with a hydroxyl group had a specifically high sensitivity, and the present invention reached. That is, the present invention provides the general formula In the formula, R and R′ may be the same or different from each other,
It represents a hydrogen atom, an alkoxyl group having 1 to 2 carbon atoms, a hydroxyl group, a nitro group or an -O-D group. D is 1,2-naphthoquinone-2-diazide-
Represents a sulfonyl group. m is an integer from 0 to 3,
m' represents an integer from 0 to 4. The present invention relates to a photosensitive composition comprising a compound represented by the formula and an alkali-soluble resin. Among the compounds of formula (1), the following compounds are particularly preferred. As the alkali-soluble resin to be mixed with the compound of formula (1), various alkali-soluble resins conventionally used in the preparation of positive-working photosensitive compositions can be used. Such resins include, for example, phenol formaldehyde resin, cresol formaldehyde resin, styrene-maleic anhydride resin, and silica resin. The compound of formula (1) is preferably blended in an amount of 20 to 35% by weight based on the total solid content of the photosensitive composition. The photosensitive composition according to the present invention is dissolved in a suitable solvent and applied onto a support. Suitable solvents include, for example, methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate, cyclohexanone, dimethyl sulfoxide, dimethyl formamide, dioxane, and tetrahydrofuran, which may be used alone or in combination. As the support to which the photosensitive composition according to the present invention is coated, for example, a silicon wafer, an aluminum plate, a copper plate, a copper-clad laminate for printed wiring, etc. are used as appropriate depending on the purpose. A photosensitive layer is formed by applying the photosensitive composition according to the present invention onto a support using a suitable coating means such as a spinner or coater and drying it. The photosensitive layer is irradiated with a light beam transmitted through a transparent original image such as a patterned mask or patterned film, and then developed with an alkaline developer. Examples of alkaline developers include aqueous solutions of inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium silicate, potassium silicate, sodium triphosphate, potassium triphosphate, sodium carbonate, and potassium carbonate, and organic alkalis such as ethanolamine. and, if necessary, a surfactant,
Developers loaded with alcohol such as benzyl alcohol can be used. Hereinafter, the present invention will be explained in more detail with reference to Examples. Example 6 g of phenol novolac resin (“Plyophene” manufactured by Dainippon Ink and Chemicals) and 3 g of each photosensitive substance (note) listed in Tables 1 and 2 were dissolved in 20 ml of cellosolve acetate to make it photosensitive. A resin solution was prepared, and this solution was applied onto a silicon wafer using a spinner, and then heated and dried on a hot plate heated to 90° C. for 30 minutes to form a photoresist film. The thickness of each photoresist film was 1.2μ. (Note) Compounds (a) to (g) in Table 1 are photosensitive materials according to the present invention, and compounds (h) to (K) in Table 2 are known compounds used for comparison. A photosensitive substance,
(h) is a photosensitive material used in Shipley's photoresist "AZ-1350J", which is currently widely used in the field of ultrafine processing, as mentioned at the beginning of the specification of the present invention, and (i) ~ (K) is a compound having a similar chemical structure to the photosensitive substance according to the present invention and is described in West German Patent No. 938233. Next, each photoresist film was exposed and developed according to the exposure method described below, and the sensitivity of each photoresist film was measured. During exposure, an ultraviolet irradiation device "K-200" manufactured by Kyoei Semiconductor Co., Ltd. was used, and the amount of light on the surface of the photoresist film was set at 33 mW/cm ² . During development, an aqueous NaOH solution with a pH of 12.5 was used as a developer. In the exposure method, as shown in FIGS. 1 and 2, a photoresist film 2 formed on a silicon wafer 1 is
The hard mask 3 is divided into seven sections S0, S1, S2, S3, S4, S5 and S6 by dividing lines 1, l2, l3, l4, l5 and l6. Position it on the dividing line and press S.
Section 6 was exposed and the section was covered with hard mask 3, and the exposed photoresist film was exposed for 1 second.
Next, move the hard mask 3 to the right side of the drawing,
Its left end was positioned at the division line 15 and exposed again for 1 second. Similarly, l4, l3, l2 and l
The left end of the hard mask 3 was sequentially positioned at each dividing line of 1, and exposed for 1 second at each position. With this operation, S
Each section of 0, S1, S2, S3, S4, S5, and S6 was exposed for 0, 1, 2, 3, 4, 5, and 6 seconds, respectively. The photosensitive layer 2, in which the sections having different amounts of ultraviolet exposure were formed, was immersed in the developer for 1 minute and gently shaken, then washed with water and dried. The number of seconds of exposure in the category where the amount of ultraviolet rays was least exposed among the several sections in which the photoresist film 2 was removed by this development was defined as the sensitivity and is listed in Table 3. This development condition is a phenomenon in which the unexposed areas of the photoresist film are dissolved by the developer and the film thickness decreases (so-called film thinning).
The conditions are set so that this does not occur. When setting the development conditions, it was confirmed that no film loss occurred in the photoresist film by using a Nippon Kogaku Surf Finish Microscope.

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【table】 [Brief explanation of drawings]

The drawings are explanatory diagrams of a method of exposing a photosensitive layer, with FIG. 1 being a plan view and FIG. 2 being a sectional view. 1... Silicon wafer, 2... Photosensitive layer, 3...
...hard mask.

Claims (1)

[Claims] 1. General formula In the formula, R and R′ may be the same or different from each other,
It represents a hydrogen atom, an alkoxyl group having 1 to 2 carbon atoms, a hydroxyl group, a nitro group or an -O-D group. D is 1,2-naphthoquinone-2-diazide-
Represents a sulfonyl group. m is an integer from 0 to 3,
m' represents an integer from 0 to 4. A photosensitive composition comprising a compound represented by: and an alkali-soluble resin.