JPS61256348A - Energy sensitive resin - Google Patents

Abstract

PURPOSE:To obtain a resin advantageous for using high energy rays by using a mixture of an alkali-soluble resin and nitrocellulose for an energy sensitive resin. CONSTITUTION:The mixture of an alkali-soluble resin and nitrocellulose is used for the energy sensitive resin, and, for example, the energy sensitive resin soln. is prepared by placing o-t-butylphenol, o-cresol, and an aq. soln. of formaldehyde into a flask, adding an aq. soln. of HCl as a catalyst into it to cause reaction, reprecipitating the reaction product with water to give a white solid, dissolving the obtained alkali-soluble novolak resin of o-t-butylphenol-o-cresol- formaldehyde into ethyl cellosolve acetate to obtain a soln. [1], on the other hand, dissolving N-contg. nitrocellulose paper into amyl acetate, and mixing this soln. with the soln. [1] in a ratio of 1:1.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an energy-sensitive resin liquid used in the manufacturing process of semiconductor devices, particularly for exposure with high-energy beams such as electron beams, X-rays, and ion beams. It relates to energy sensitive resins, so-called resists.

[Prior art]

Currently, positive resists used for exposure with high-energy beams such as electron beams, It has excellent manufacturing processability and is often used.

For example, in the case of semiconductor device manufacturing, after applying a resist material, the energy rays are selectively irradiated to decompose the energy-sensitive groups at desired locations, change the solubility of the regions in the developing solution, and select unnecessary regions. and then remove the resist pattern to form a desired resist pattern. Thereafter, using this resist pattern, desired processing of the base substrate is performed.

[Problems with conventional technology]

Conventionally, a mixture of a cresol-formaldehyde-based novolak resin and a quinonediazide compound or 2-methylpentene-1-sulfone has been used as a positive sensitive material for high-energy beam pressures typified by electron beams. Especially the latter is M.J. Bowden.
den) et al. in the Journal of Electrochemical
Society (Journal of Blectro
-Chemical 5ociety) Volume 128,
As stated in June 1981 on pages 1304 to 1313 of issue 2, it has superior sensitivity of 5 μC/i compared to the former's sensitivity of 20 μC/cdK, and is widely used, such as Hitachi Chemical's Raycast-5000. has been done.

However, the shipping mechanism related to the 2-methylpentene-1-sulfone sensitivity mechanism is more susceptible to the influence of the atmosphere during energy ray irradiation, and compared to the latter, there is a problem in that the shipping mechanism remains in the fine pattern portion as a staining residue.

[Purpose of the invention]

The present invention has been made to solve the above problems, and provides an energy-sensitive resin that is advantageous for use with high-energy rays.

[Structure of the invention]

The energy-sensitive resin of the present invention is an energy-sensitive resin composed of a mixture of an alkali-soluble resin and nitrocellulose.

[Detailed explanation of the configuration]

BACKGROUND ART In lithography techniques for manufacturing semiconductor devices, the use of high-energy rays is very effective in obtaining high resolution. For its practical application, the development of energy-sensitive resin liquids, so-called resists, with high sensitivity and high dry etching resistance is an essential prerequisite.

On the other hand, as the dry etching resistance of the resist increases,
Even minute residues can affect the etching process.

As a result of intensive research, the present inventor has found that when a nitrocellulose compound is used as an energy-sensitive group, the decomposition products are gaseous such as Co, , N, etc., so the residual content is small and the sensitivity and dry resistance are improved. It was found that the requirements for etching properties were also satisfied.

(Example 1) Ortho (tertiary butyl) phenol 5F.

4fi of orthocresol and 5.8 I of an aqueous solution of 35 thiformaldehyde were placed in a flask, 8 g of O was added with a 35% aqueous solution of hydrochloric acid as a catalyst, and the mixture was reacted at 120° C. for 1 hour. Thereafter, the reaction product was reprecipitated with water to obtain 5I as a white solid. The entire structure of the obtained novolac resin consisting of ortho(tert-butyl)phenol-orthocresol-formaldehyde was confirmed by NMR.

NMR (Nuclear Magnetic Resonance Spectrum) (CD-C13
Medium) δ (ppm): 1.33 (
c(CHJ3)2.13 (-CH3
)3, sc) (-CH2-)6
．． 67-7.0 (@-T() composition ratio: ortho (tert-butyl) phenol 0.53 / ortho-cresol 0.47 Dissolve this resin in ethyl cellosolve acetate and add 20
On the other hand, nitroceltooth paper containing 15 nitrogen was dissolved in amyl acetate to prepare a 5 nitrogen solution, which was mixed in equal amounts with solution [1] to form an energy-sensitive resin solution. and I-ta.

Spin coat this solution onto silicone ueno-- and heat it to 80°C.
The resist film was baked for 30 minutes to obtain a resist film having a thickness of eoooi.

After electron beam irradiation, 0.3 N hydroxide) I) When developed with a ram aqueous solution, a 0.5 micron pattern was resolved with a sensitivity of 5 μC as shown in Figure 1, and the residue was similar to that of the conventional product. significantly decreased compared to . Furthermore, the dry etching resistance was comparable to that of currently commonly used photoresists, such as Az-2400 manufactured by Silapray.

As the alkali-soluble resin, good results can also be obtained by using ortho-cresol-formaldehyde or polyhydroxystyrene.

〔Effect of the invention〕

As described above, it has been found that the energy-sensitive resin of the present invention leaves very little residue after development and has high sensitivity. Therefore, the positive resist material of the present invention and the pattern forming method using the same are useful in the manufacturing process of semiconductor devices and the like.

[Brief explanation of drawings]

Claims (1)

[Claims] Energy-sensitive resin consisting of a mixture of alkali-soluble resin and nitrocellulose.