JP2628597B2 - Silicone compound - Google Patents

Description

The present invention relates to a silicone compound, a method for forming an insulating layer and a method for forming a resist pattern using the compound, and a method for obtaining a silicone compound having photosensitivity and excellent heat resistance. In addition, to obtain an insulating layer having excellent heat resistance as well as photosensitivity, and to form an upper resist pattern of a two-layer resist having high sensitivity to far ultraviolet rays, in particular, a vinyl group or an allyl group, and It is constituted as a silicone compound having an aryl group, and further constituted such that these silicone compounds can be used as an insulating layer or as an upper resist for a two-layer structure.

[Industrial applications]

The present invention relates to a silicone compound, a method for forming an insulating layer using the compound, and a method for forming a resist pattern.

[Problems to be solved by the prior art and the invention]

Conventionally, when forming an insulating layer of a semiconductor device, a photosensitive resist is applied on each layer for patterning,
Exposure, development, and etching of each layer are employed. Processes using these resists are very complicated and require many sub-materials.

In recent years, a process using a photosensitive insulating material has been developed to eliminate the complexity, but since the insulating material requires extremely high heat resistance in the process, it is usually used for a resist. Such photosensitive organic materials cannot be used. Recently, a process using photosensitive polyimide was developed to solve this problem.However, this heat resistance never exceeded that of conventional polyimide, and in the case of photosensitive polyimide, all the photosensitive compounds were thermally decomposed. If this is attempted, the polyimide skeleton of the main chain is also thermally decomposed, which greatly limits the semiconductor manufacturing process.

Attempts have been made to use a photosensitive heat-resistant resin as an insulating film for the purpose of simplifying the conventional insulating film forming process. However, in order to impart photosensitivity to the heat-resistant resin, a photosensitive agent must be used. However, when a photosensitive agent is used, the heat treatment after pattern formation decomposes the photosensitive agent, resulting in a hole in the film.

Further, as the integration of LSIs increases, the pattern width of the LSIs tends to be further miniaturized. The minimum line width of the current 256KDRAM is about 1.2 μm, and this pattern is formed by a reduced projection exposure using a g-line and using a positive photoresist. However, such reduced projection exposure lowers the resolution due to problems such as standing waves generated in the resist film, side reflection from wiring, and a shallow focal depth. Therefore, development of a process that solves such a problem is demanded. Currently, a two-layer resist process is being studied. As the upper resist material of the two-layer structure, a negative resist composed of a mixture of a polymer containing silicon atoms and an azide or bisazide compound, and a mixture of an alkali-soluble resin containing silicon atoms and an O-naphthoquinonediazide derivative are used. There is a positive resist. Positive resists have insufficient oxygen plasma resistance, and a pattern width shift occurs during transfer of an upper layer pattern. Negative-type resists have a problem in that the photosensitizer is an azide compound and the peak of the absorbed light is around 350 nm, so that the sensitivity to far ultraviolet rays is low. There is a demand for the development of upper layer resist materials.

Hitachi's ASTR is a conventional positive type two-layer resist.
O and NEC's SIPR and conventional positive photoresists mixed with silicon compounds have been announced. However, all of the resists have insufficient oxygen plasma resistance, and a pattern width shift occurs during transfer of the upper resist pattern.

As a conventional negative type two-layer resist, NTT's MSNR
There are NEC MAS, TRS, etc. However, since these resists use a bisazide compound as a photosensitizer, the absorption wavelength thereof is maximum at 350 to 370 nm, and the sensitivity to far ultraviolet rays is extremely low.

[Means for solving the problem]

In order to solve the above problems, the present invention has the general formula ^{_{1: SiO 1.5 R 1) l}} (SiO 1.5 R 2 m n (I) (R 1 is vinyl or an allyl group, R ² is an aryl group l, m, n are positive integers from 1 to 10,000, and n is 1
Which is a positive integer of 1010,000). This silicone compound
Further, the hydrogen atom of the silanol group present in the silicone compound of the formula I is replaced with the following group: (Wherein, R ₃ , R ₄ or R ₅ may be the same or different and independently represent C ₁ -C ₄ alkyl, C ₂ -C ₄ alkenyl, or aryl) There may be.

Such a silicone compound has excellent photosensitivity and heat resistance. Therefore, the silicone compound of the present invention can be preferably used as a resin composition for forming a recording layer of a semiconductor device or the like.

This method comprises applying the silicone compound of the formula I onto a substrate such as a semiconductor on which a wiring layer is formed, exposing and developing, and then under an inert gas atmosphere at 200 to 500 ° C. for 10 minutes to 120 minutes. It is characterized by performing a heat treatment.

The processing temperature is preferably 300 to 400 ° C., and the processing time is preferably 30 minutes to 1 hour.

That is, the present invention relates to a method for preparing a silylated polyorganosilsesquioxane having excellent heat resistance (500 ° C. or higher), crack resistance (on 3 mAl), and excellent leveling property and photosensitivity on a substrate on which a wiring layer is formed. After exposure, development and heating in an inert gas atmosphere, for example, at 350 ° C. for 1 hour.

Thus, the resin composition of the present invention has heat resistance as well as photosensitivity.

Furthermore, another method of the present invention focuses on the fact that the silicone compound has excellent oxygen plasma resistance and high sensitivity to far ultraviolet rays.
Used as an upper layer resist of a two-layer resist, the silicone compound is coated on a resin on a substrate such as a semiconductor, exposed to far ultraviolet rays, developed, and then dry-etched to form a fine resist pattern. Is what you do.

〔Example〕

Example 1 Methyl isobutyl ketone (MIBK) 100ml and pyridine 18m
l was added and cooled to -60 ° C. 13 ml of vinyltrichlorosilane, 16 ml of phenyltrichlorosilane and then 18 ml of ion-exchanged water were added dropwise thereto, and the reaction solution was gradually heated. Further, a polycondensation reaction was performed at 120 ° C. for 5 hours while performing bubbling with nitrogen gas. After completion of the reaction, the solution is
After washing with water, the MIBK layer was separated. Next, 30 ml of trimethylchlorosilane and 30 ml of pyridine were added and heated at 60 ° C. for 2 hours to silylate unreacted hydroxyl groups. Next, the reaction solution was washed ten times with water and poured into acetonitrile to precipitate and recover silylated polyorganosilsesquioxane. The obtained resin was dissolved in 50 ml of benzene and freeze-dried.

The silylated polyorganosyl selquioxane obtained by this synthesis example had _w = 5.0 × 10 ⁴ , _w / _n = 1.8.

Example 2 1 g of the silylated polyorganosilsesquioxane obtained in Synthesis Example 1 was dissolved in 9 g of MIBK to prepare a resist solution.

An MP-1350 resist (manufactured by Shipley) as a lower resist was spin-coated on the silicon substrate 1 so as to have a thickness of 2 μm, and was cured by heating at 200 ° C. for 1 hour. The film thickness after drying the resist solution on this film 2 is
Spin coating was performed to a thickness of 0.2 μm, and solvent drying was performed at 60 ° C. for 20 minutes to form a resist layer 3.

This sample was subjected to mask exposure by soft contact using far ultraviolet rays of 248 nm. Then, immerse in MIBK for 30 seconds and develop, and further apply isopropyl alcohol for 30 seconds.
A rinsing treatment was performed for seconds. Next, the substrate to be processed was set in a parallel plate type dry etching apparatus (manufactured by Nidec Anelva Co., Ltd.), etched by oxygen plasma, and the upper layer pattern was transferred to the lower layer. As a result, the sensitivity of this resist is
At 50 mJ / cm ² , a 0.5 μm line and space pattern could be resolved.

Example 3 2 g of the polyorganosilsesquioxane obtained in Example 1 was added to MIBK
It was dissolved in 8 g to obtain a resin solution.

Next, the above-mentioned resin was applied on the silicon substrate on which the Al wiring of the first layer was formed by spin coating, and dried at 120 ° C. for 30 minutes to form a film having a thickness of 0.6 μm.

Next, using a Xe-Hg lamp through a quartz mask (DNP fine line test pattern manufactured by Dai Nippon Printing Co., Ltd.), an optical filter was provided and exposed to far ultraviolet light having a maximum intensity at 250 nm.

Subsequently, the film was developed with methyl isobutyl ketone for 1 minute and rinsed with isopropyl alcohol for 30 seconds to obtain a good pattern.

The patterned membrane N ₂ atmosphere, 350 ° C., 1
The heat treatment of h was performed to obtain a patterned insulating film. This film did not show any cracks even after further heat treatment at 500 ° C. for 1 hour.

Since the present invention is configured as described below, it is possible to form a film having photosensitivity per se, and sufficient heat resistance and crack resistance. Therefore, an effect that the multilayer wiring can be easily formed can be obtained. Also, there is no need to separately use a photosensitive agent. Therefore, a uniform film can be obtained without a decrease in heat resistance.

Further, it is possible to form a submicron pattern by using the silicone compound according to the present invention as an upper layer resist of a two-layer structure resist and performing exposure to far ultraviolet rays.

[Brief description of the drawings]

FIG. 1 is a process chart in the case of using the method for forming a resist pattern of the present invention. 1 ... substrate, 2 ... organic resin layer, 3 ... resist layer.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Keiji Watanabe 1015 Uedanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Prefecture Inside Fujitsu Limited (72) Inventor Yasuhiro Yoneda 1015 Kamikodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Fujitsu Limited ( 56) References JP-A-55-125123 (JP, A) JP-A-62-227929 (JP, A)

Claims (4)

(57) [Claims] 1. A general formula ^{_{I: SiO 1.5 R 1) l}} (SiO 1.5 R 2 m n (I) (R 1 is vinyl or an allyl group, R ² is an aryl group l, m, n is Is a positive integer from 1 to 10,000, and n is 1
A positive integer of ~ 10,000). 2. The method according to claim 1, wherein the hydrogen atom of the silanol group present in the silicone compound of the formula I is Wherein R ₃ , R ₄ or R ₅ may be the same or different and independently of _one another represent C ₁ -C ₄ alkyl, C ₂ -C ₄ alkenyl or aryl. 2. The silicone compound according to item 1 above. 3. The silicone compound according to claim 2 is coated on a substrate such as a semiconductor on which a wiring layer is formed, exposed and developed, and then at 200 to 500 ° C. for 10 to 120 minutes in an inert gas atmosphere. A method for forming an insulating layer of a semiconductor device or the like, which is performed by performing a heat treatment of 4. A method for forming a resist pattern, comprising applying the silicone compound of claim 2 onto a resin on a substrate such as a semiconductor, exposing with far ultraviolet rays, developing, and then dry etching. .