JPH0215054B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a resist material for high energy beams such as electron beams and soft X-rays. [Prior Art] Regarding resists used in the manufacture of LSIs, a method has been proposed in which the resist has a two-layer structure in order to form a pattern with high definition and a high aspect ratio. That is, after a thin resist layer is placed on the organic polymer material layer and a resist pattern is formed, the organic polymer material is etched using oxygen gas plasma using the resist pattern as a mask. This resist is required to have excellent oxygen plasma resistance, as well as high sensitivity and high resolution, and resist materials in which highly sensitive groups are introduced into silicon-containing polymers that have excellent oxygen plasma resistance are viewed as promising. However, currently known silicone resists have a glass transition temperature (Tg) lower than room temperature.
Polymers with low molecular weights are liquid, making them very difficult to handle and have poor sensitivity to high-energy radiation. In addition, when the molecular weight is high, it is rubbery and swells in a developing solvent, resulting in a decrease in resolution due to pattern waviness. Furthermore, in order to achieve even higher resolution by reducing the resist film thickness, it was necessary to improve oxygen plasma resistance. Therefore, it was necessary to significantly increase the silicon content. [Object of the invention] The object of the present invention is to
The objective is to provide a resist material with a high Tg. [Structure of the Invention] To summarize the present invention, the first invention of the present invention is an invention of a resist material, which has the following general formula: (In the formula, l, m, and n represent 0 or a positive integer, but l and m are never 0 at the same time.) And, the second invention of the present invention is an invention of another resist material, which is a resist material represented by the above general formula, in which part of the --CH ₂ Cl group in the general formula [] or All, ―CH ₂ Br, ―CH ₂ I,

【formula】

[Formula] and

It is characterized by being a compound substituted with one type of group selected from the group consisting of [Formula]. That is, the resist material of the present invention is characterized by containing oxygen plasma-resistant -Si-O- bonds, contains a ladder-shaped silsesquioxane structure with a high Tg, and has a high Tg phenyl group. This is a polysilsesquioxane resist characterized by having a sensitive group that exhibits high reactivity and resolution with respect to energy rays. The most important point in the present invention is the discovery that by introducing a sensitive group into the phenyl group of polyphenylsilsesquioxane with a high Tg, a resist material for high energy radiation with high sensitivity and high resolution can be obtained. At the point. Polyphenylsilsesquioxane is a soluble ladder polymer, and as expected from its structure, it has excellent heat resistance and mechanical strength.
However, if a part of the phenyl group is replaced with another group, it is difficult to maintain the ladder structure of the polymer; for example, in the case of a methyl group or a vinyl group, several percent
It is known that gelation is caused by the introduction of . However, polyphenylsilsesquioxane is stable even to high energy radiation and cannot be used as a resist material. On the other hand, those in which the hydrogen of the phenyl group is replaced with a halogen such as chlorine are sensitive to high-energy rays, but their sensitivity is low, so they are unsuitable as resist materials. The present inventors have discovered that by introducing a chloromethyl group into a phenyl group, a resist material for high-energy rays with high sensitivity and high resolution can be obtained. , -I or other halogens or

Acryloyl represented by [formula] ruoxy group,

A methacryloyloxy group represented by [Formula],

It has been found that polyphenyl cisequioxane substituted with a cinnamoyloxy group represented by the formula can also be used as a resist material for high energy rays. Polyphenylsilsesquioxane has a silicon content more than 1.5 times higher than polydiphenylsiloxane, which has a similar structure.
Excellent oxygen plasma resistance. Polyphenylsilsesquioxane is

〔Example〕

Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited thereto. Example 1 The high-energy ray-sensitive materials obtained in Production Examples 1 to 6 were dissolved in methyl isobutyl ketone, coated on a silicon wafer to a thickness of about 0.5 μm, and prebaked at 100° C. for 20 minutes in a nitrogen stream. After pre-baking,
Electron beam irradiation was performed at an accelerating voltage of 20KV. After irradiation, the wafer was developed with a mixed solvent of methyl ethyl ketone:isopropyl alcohol=4:1, and rinsed with isopropyl alcohol. Table 1 summarizes the electron beam irradiation amount that leaves 50% of the initial film thickness, which is a measure of sensitivity, and the γ value, which is a measure of resolution.

[Table] Table 2 also shows the minimum line width that can be resolved without whiskers or bridges when development is performed after electron beam irradiation using a line/space pattern for evaluating resolution.

[Table] As a result of measuring the Tg of these polyphenylsilsesquioxane resists, it was confirmed that all of them were 300°C or higher, which was higher than the Tg of diphenylsiloxane polymer, which was 150°C. In addition, as a result of examining oxygen plasma resistance, the etching rate was 50 Å/min for diphenylsiloxane polymer.
Since the resist material of the present invention has a high silicon content, the value was as low as 20 Å/min. Examples 2 to 4 In the method of Example 1, instead of electron beam irradiation, X
Irradiation was carried out using radiation (Example 2), deep ultraviolet light (Example 3), and ion beam (Example 4). At this time, Table 3 shows the irradiation doses of each high-energy ray that left 50% of the initial film thickness.

[Table] The high-energy ray-sensitive materials used here were those obtained in Production Examples 1 to 6. Example 5 In the method of Example 1, ultraviolet rays (365 nm wavelength) were irradiated using an ultra-high pressure mercury lamp instead of electron beam irradiation. Table 4 shows the minimum exposure amount to obtain 100% of the initial film thickness.

[Table] The resist materials obtained in Production Examples 1 to 3 had low sensitivity to ultraviolet rays, and even with an irradiation dose of 3 J/cm ² or more, the film thickness was 0% of the initial film thickness, making it impossible to form a pattern. Comparative example: Hydrolyzing chlorophenyltrichlorosilane,
Results of measuring electron beam irradiation characteristics using the same method as in Example 1 for chlorinated polyphenylsilsesquioxane obtained by dehydration condensation and polyphenylsilsesquioxane in which no high-energy ray-sensitive group has been introduced. are shown in Table 5. It can be seen that the sensitivity is lower than that of the resist material of the present invention.

〔Effect of the invention〕

As explained above, the resist material obtained by the present invention has a high energy ray-sensitive group in the benzene ring of polyphenylsilsesquioxane, so it has a high sensitivity compared to conventional silicone resists.
Tg, high sensitivity and high resolution. Furthermore, since it has a high silicon content, it has the advantage of excellent oxygen plasma resistance.

Claims (1)

[Claims] 1. The following general formula: (In the formula, l, m, and n represent 0 or a positive integer, but l and m are never 0 at the same time.) 2 General formula below: (In the formula, l, m, and n represent 0 or a positive integer, but l and m are never 0 at the same time.)
Some or all of the CH ₂ Cl groups can be replaced with -CH ₂ Br,
-CH ₂ I, [Formula] A resist material characterized in that it is a compound substituted with one type of group selected from the group consisting of [Formula] and [Formula].