JPS6362593B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a photolithographic resist material used in the manufacture of semiconductor devices, and in particular provides a resist composition that is resistant to dry etching. As semiconductor devices become faster and LSIs become more highly integrated, pattern miniaturization has become an important issue. In the manufacturing process of integrated circuit elements, in order to create fine patterns, a resist is irradiated with light or electron beams to cause decomposition or crosslinking reactions, and then developed to form a pattern.
Using this resist pattern as a mask, Si,
Methods of etching substrates such as SiO ₂ , Si ₃ N ₄ or Al have been implemented. Etching methods include wet etching, in which the sample is immersed in a liquid such as HF-HNO ₃ , NH ₄ F-HF, H ₃ PO ₄ ;
Dry etching methods using plasma or ions of CF ₄ , CCl ₄ , Ar, etc. are known.
In the case of the former wet etching, the etching progresses isotropically, resulting in side etching and underetching, making it impossible to form a fine pattern faithful to the resist mask. Further, the wet etching solution is toxic and requires a large amount of processing cost to render the waste solution harmless. On the other hand, the dry etching method is non-polluting and does not emit toxic waste liquid, and by selecting etching conditions, etching progresses anisotropically without side etching undercuts, resulting in the mask being etched. A faithful fine pattern can be obtained. However, in this method, conventional resist materials such as rubber-based negative resists, phenol novolak resin-based positive resists, polymethyl methacrylate-based positive resists, and polymethyl isopropenyl Kent-based positive resists are used. The resist material is
All of them have the drawbacks of poor dry etching resistance, such as a high film reduction rate during dry etching and a low etching selectivity with respect to the substrate. An object of the present invention is to eliminate such drawbacks and provide a resist composition with excellent dry etching resistance. The present invention is characterized in that, in the photosensitive resist composition, phenyl-β-naphthylamine, α-naphthylamine, N,N'-di-sec-butyl-P-phenylenediamine, phenothiazine, N,N'- Diphenyl-P-phenylenediamine, 2(2-hydroxy-3',5'-di-tert-butylphenyl)benzotriazole, 2(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)benzotriazole , triphenyl phosphite, amine compounds such as 2-mercaptobenzimidazole, and phosphorus compounds. The amount is 1 to 50 parts by weight per 100 parts by weight of the resist solid component.
It is practical to use parts by weight. In the present invention, CF ₄ , CCl ₄ , Ar
It has been discovered that this material has the effect of imparting durability against plasma or ion etching using, for example. The content of at least one selected from amine compounds and phosphorus compounds in the resist is preferably 1 to 50 parts by weight based on 100 parts by weight of solid components in the resist. If it is less than 1 part by weight, the effect on dry etching resistance will be small, and if it is more than 50 parts by weight, the photosensitivity properties will tend to deteriorate. EXAMPLES The present invention will be described in detail below with reference to Examples. [Example 1] Rubber-based negative resist (“KMR” manufactured by Kodatsu Co., Ltd.
-747''), polymethyl isopropenyl positive resist (hereinafter referred to as PMIP), and polymethyl methacrylate positive resist (hereinafter referred to as PMMA)
Samples of various resist compositions were obtained by adding and dissolving the amine compounds or phosphorus compounds shown in Table 1, respectively.

[Table] Each resist composition sample obtained was
It was coated on a silicon wafer with a SiO ₂ film, and after prebaking, it was exposed to ultraviolet light, far ultraviolet light, or an electron beam, and then developed and postbaked to obtain a sample with a resist pattern. . For each sample obtained, CF ₄ or
Etching was performed using CCl ₄ and the etching rate was measured. The results are shown in Table 2.

【table】

[Example 2]

Rubber-based negative resist (manufactured by Kodatsu Co., Ltd. “KMR
-747''), PMIP, phenol novolac resin positive resist (hereinafter referred to as PN), and PMIP were each applied to a silicon wafer with an Al film,
After pre-baking, the wafer was exposed to ultraviolet light, deep ultraviolet light, or an electron beam, and then developed and post-baked to obtain a wafer having a resist pattern. Next, an amine compound or a phosphorus compound was dissolved in methanol to prepare a methanol solution shown in Table 3. The wafer with the resist pattern obtained as described above was placed in these methanol.
After immersion for 10 minutes, each sample was obtained by heating and drying at 160°C for 15 minutes. For each sample obtained, CF ₄ or
Etching was performed using CCl ₄ and the etching rate was measured. The results are shown in Table 3.

【table】

[Table] As is clear from the table above, by immersing a patterned resist in a solution containing an amine compound or phosphorus compound and impregnating the resist with the amine compound or phosphorus compound,
It can be seen that the etching rate of the resist decreases. As described above, according to the present invention, dry etching resistance can be significantly improved by incorporating a specific amine compound or phosphorus compound into an ordinary photosensitive resist composition.

Claims (1)

[Claims] 1. In the photosensitive resist composition used for dry etching, phenyl-β-naphthylamine, α-naphthylamine, N,N'-di-sec-butyl-P-phenylenediamine, phenothiazine, N,N'-diphenyl- P-phenylenediamine, 2(2'-hydroxy-3',5'-di-tert-butylphenyl)benzotriazole, 2(2'-hydroxy-3'-tert-butyl-5'methylphenyl)benzotriazole, triphenyl phosphite,
and 2-mercaptobenzimidazole.