JPS63101426A - Alkali-soluble ladder silicone polymer - Google Patents

Abstract

PURPOSE:To obtain the title polymer excellent in oxygen plasma resistance and useful as a functional polymer material such as a light- or radiation- sensitive material, having a specified structural formula. CONSTITUTION:A trichlorosilane or trialkoxysilane containing an organic group having a phenolic hydroxyl group protected in the form of an alkoxy group, a t-butyldimethylsiloxy group, a methylene acetal or the like is obtained by, for example, a process wherein a halide (e.g., benzyl chloride derivative) is condensed with HSiCl3 in the presence of a tert. amine. The obtained compound is subjected to a treatment which varies according to the protected hydroxyl group to eliminate the protective group. In this way, the title polymer of the formula (wherein R1 is an organic group having a phenolic hydroxyl group, R2-3 are each on organic group free of a phenolic hydroxyl group, n, m and lare integers, and n/(n+m+l)>0.4), e.g., a polymer of the formula (wherein R1 is a p-hydroxyphenylethyl group, R2 is a p-methoxyphenylethyl group and R3 is a p-trimethylsiloxyphenylethyl group) can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a novel polymer that is extremely useful as a functional polymer material such as a light- and radiation-sensitive material. More specifically, the present invention relates to an alkali-soluble ladder silicone polymer.

[Conventional technology]

For manufacturing electronic components such as semiconductor elements and integrated circuits.

Microfabrication technology by etching using light and radiation is used, and the current resist material has excellent resolution, so an alkali-developable type containing an alkali-soluble polymer such as phenolic resin or polyvinylphenol as a basic polymer is used. .

Resist materials are the mainstream. For example, a composition of novolak resin and 2-7toquinone diazides is a positive photoresist, and a composition of polyvinylphenol and bisazides is a negative photoresist. Furthermore, it is widely known that a composition of novolak resin and polyolefin sulfone is a radiation-sensitive positive resist. On the other hand, as the wiring of semiconductor devices and the like becomes finer, dry etching is increasingly being adopted in place of the conventional wet etching for etching the underlying layer after patterning the resist layer. Therefore, resist materials are required to have strong resistance to dry etching. Conventional a.

The resist material used for alkali development is based on metal or metal oxide film (e.g. aluminum, silicon, silicon oxide film, etc.)
It exhibits strong resistance to halogen-based plasma, which is used in the case of is not enough (,
There has been a strong desire to improve its characteristics. In addition, as a literature on alkali-developable resists, J. C. 5triete
r Author Kodak Microelectronics Seminar Grossing (Kodak Mioroelec)
tronios Sem1-nor procaadi
ng) 116 (1976).

[The problem that the invention attempts to solve]

The object of the present invention is to provide an alkaline solution with excellent oxygen plasma resistance, which can be used as an alternative to the basic polymer of the conventional alkali shell type resist, which has low oxygen plasma resistance.

The purpose of the present invention is to provide a polymer with the following properties.

[Means for solving problems]

Organosilicon polymers are well known as polymers with excellent oxygen plasma resistance. This is because the organosilicon polymer efficiently turns into a silicon oxide film by oxygen plasma, and this silicon oxide film functions as an oxygen plasma resistant film. On the other hand, as an alkali-soluble polymer,
Polymers having phenolic hydroxyl groups, such as novolac resins and polyvinylphenol, are known.

Therefore, in order to achieve the above purpose, the main chain is silicon.

As a result of synthesizing various polymers having a ladder silicone skeleton closest to the oxide structure and having a phenolic hydroxyl group in the side chain, it was found that an alkali-soluble ladder silicone polymer represented by the following general formula (1) is good.

(R+ 810V2)n(R2-8iOv□)m(1
'b 5to3. ), -・-(1) However, the general formula (1
), R1 is an organic group having a phenolic hydroxyl group, R2
and Rs is an organic group containing no phenolic hydroxyl group. In addition, le, m, thl are integers, and n+m+工〉
Must satisfy 0.4.

Here, R+ specifically includes, for example, an alkyl group having 1 to 6 carbon atoms (excluding the substituent carbon) having phenol or catechol as a substituent.

On the other hand, this is not accompanied by a ladder silicone skeleton.

There are no restrictions on the side chains, R2 and Ri, as long as they are -valent organic groups. To give a specific example, the hydroxyl group of the above-mentioned organic group having a phenolic hydroxyl group is replaced with an alkoxy group, t-
Examples include a butyldimethylsiloxy group, a group protected in the form of methylene acetal, an alkyl group, a vinyl group, and the like.

However, in order to achieve alkali solubility, sufficient alkali solubility can be obtained unless the organic group having a phenolic hydroxyl group is present in 40-5 or more of the total side chains.

I can't do it.

The polymer of the present invention is synthesized by first synthesizing a ladder silicone polymer with protected hydroxyl groups, and then removing the protecting groups. Trichlorosilane or trialkoxysilane corresponding to R1 with a protected hydroxyl group is
Various methods are available, such as condensation of a halide (such as a benzyl chloride derivative) with H81Cf using a tertiary amine, Grignard reaction of tetrahalogenosilane or tetraalkoxysilane, or use of a platinum catalyst with a styrene derivative. It can be synthesized by using a method of adding H8tC13. Furthermore, the polymerization reaction can be carried out under various conditions, such as a reaction using potassium hydroxide, an amine, or cesium fluoride as a catalyst after hydrolysis. Furthermore, when removing the protecting group, for example,
From an alkoxy group to a hydroxyl group, a method using trimethylsilyl iodide and sodium iodide or a method using trimethylsilyl iodide is used. From a t-butyldimethylsiloxy group, a method using tetra-butylammonium fluoride is used. From a methylene acetal, a method using tetra-butylammonium fluoride is used. This can be carried out using various reactions, such as a method using phosphorus chloride. Therefore, the synthesis method for synthesizing the polymer of the present invention is not limited.

While the polymer of the present invention is soluble in alkaline water, it is also easily soluble in general-purpose organic solvents, such as alcohol-based, ether-based, amide-based, ketone-based, ester-based, and cellosolve-based organic solvents. The film can be formed using a solution of

Therefore, similar to conventional alkaline development resists, this polymer can be used as a basic polymer and various photosensitive dissolution inhibitors or radiation-sensitive dissolution inhibitors can be selected.

This polymer can be used as a resist material for light or radiation.

On the other hand, the film of the polymer of the present invention did not erode at all in oxygen plasma and exhibited extremely high dry etching resistance. Therefore, the above-mentioned resist acts as an oxygen plasma resistant film when the underlying organic material is dry etched using oxygen plasma, and can be used, for example, as an upper layer resist in a two-layer resist method.

[Effect]

Since the polymer skeleton of the present invention is a ladder silicone skeleton that is closest to the structure of a silicon oxide film, it has high oxygen plasma resistance (and also has an organic group having a 7-enolic hydroxyl group in the side chain). It is thought that this is why it became alkali-soluble.

〔Example〕

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited to these Examples.

Example 1 Poly(P-hydroxyphenylethylsilsesquioxane-oo-p-methoxyphenylethylsilsesquioxane-ao-P-t')methylsiloxyphenylethylsilsesquioxane) 11 P-methoxyphenylethyltri Synthesis of chlorosilane 7 g of P-methoxystyrene sa (α274 md ) and 37.1 g of trichlorosilane (0,274 WLej
) into a Pyrex tube. Then, chloroplatinic acid 99
．． 4mf, l'lyl-butylamine 8tO? ? L
? Add a few drops of suspension consisting of P-methoxystyrene 11888p and P-methoxystyrene 11888p to the Pyrex tube and seal the tube. After reacting in a sealed tube in an oil bath at 80°C to 100°C, open the sealed tube and distill the contents to obtain the desired product.
o, o g (0,148°fFLσ1) was obtained. Yield 5
4%bp 84~bNMR (60MHz rC
C-1trTMS) δ1.48~t76(2
Ht? FL)! δ2.62~2.88 (2H, f
i), δ3.6゜(3H,s), δ6.61
(2H, ct, J-s, sHz) *δ 6.9
2 (2H, i, J -8,5[-12)
t2 Synthesis of Bo 1J (P-methoxyphenylethylsilsesquioxane) 2 (10WJ-Pour 3Q mA of water into a Mitsuro flask equipped with a stirrer, 1 cooling tube, 1 dropping funnel, and a hydrochloric acid trap. Dissolved in toluene 2011) P-methoxyphenylethyltrichlorosilane 2$6p (80,0 gourd 1)
was added dropwise over 15 minutes with stirring, and then aged for 11 hours. Transfer the mixture to a separatory funnel and separate the toluene layer. Toluene and water are removed by distillation.

After that, 1CM of potassium hydroxide was added to the above hydrolysis product.
Add itt% metall solution [L21p and heat at 200°C for 2 hours. The reaction mixture was dissolved in tetrahydrofuran, and insoluble matter was removed by filtration. Tetrahydrofuran was distilled off to obtain the desired product at 79 f (42 m
tnJ) Obtained. Yield 53% Number average molecule f110
00~500000NMR(60MH2pD
M S O-'a.

TMS) δ0.85 (2H,br,s), δ2.
50 (2H.

br, s ), δ3.58 (3H, br, a ) δ
6.65 (4H, br.

t3 Synthesis of poly(P-humanoQ diphenylethylsilsesquioxane) Stirrer, cooling tube 1 dropping funnel, and #! A 100 tJ Mitsuro flask equipped with an acid trap is purged with nitrogen. bo1j
(P-methoxyphenylethylsilsesquioxane)
79 g (42mmf1) in 20ml of acetonitrile
Melt it by heating and put it in a flask, then add
) '7 Add 1B, 9p (C1, 126mtL). While heating under reflux under nitrogen pressure, 13.79 (0.126 mt1) of trimethylchlorosilane is added dropwise over 15 minutes.

After aging for 24 hours, water and acetonyl are added dropwise, and heating and refluxing is continued for an additional 6 hours. After the reaction is complete.

Separate the acetonitrile layer and wash with aqueous sodium bisulfite solution. Polymer acetonitrile solution.

Drop into 20 times the amount of water, re-precipitate, and sip the polymer. The target material is dried by vacuum heating at 5.8 f (34?FL?F).
LIP & ) obtained. Yield 81% number average molecule 1i1k)0
0~30000ONMR (60MHz, DMSO-d
4, TMS) δ0.93 (2H, br, s),
δ2.60 (2H,br,a), δ6.67C4
H, br, s ), δ9.08 (I H, br, s
)1.4 BoIJ(P-hydroxyphenylethylsilsesquioxane-00-P-methoxyphenylethylsilsesquioxane-00-P-)! Synthesis of poly(p-hydroxyphenylethylsilsesquioxane) described in Section 1.3, the reaction-i [(trimethyl By reducing the amount of chlorosilane and sodium iodide (chlorosilane and sodium iodide) or shortening the aging time, methoxy groups can be left in any proportion.

I can do that. In addition, in the process of converting trimethylsiloxy groups to hydroxyl groups by hydrolysis, it is possible to shorten the aging time (
Up to about 15% of the trimethylsiloxy groups can then remain intact.

Table 1 shows BoIJ (P-human) when the aging time was changed.

Roxyphenylethylsilsesquioxane-〇〇-P
-Methoxyphenylethylsilsesquioxane-oo
--P-trimethylsiloxyphenylethylsilsesquioxane) shows the mole % of each structural unit.

Margin below.

t5 Solubility As a result of examining the solubility of the polymer of the present invention in typical general-purpose organic solvents, the present polymer containing 40% or more of water-ugly groups was found to be soluble in methanol, tetrahydrocran, N,N-dimethylacetamide, It was soluble in 2-methyl-cyclohexanone, isoamyl acetate, ethyl cellosolve, and dimethyl sulfoxide, but insoluble in toluene, hexane, and carbon tetrachloride. On the other hand, in the aqueous solution, it was dissolved in an aqueous tetramethylammonium hydroxide solution.

16 Oxygen plasma resistance An 8-layer solution of the polymer of the present invention in 2-methylcyclohexanone was coated on a silicon substrate by a spin coating method, and baked at 100°C for 30 minutes.
．． A coating film with a thickness of 2 μm was formed. Next, oxygen plasma (
Conditions: 02 pressure Q, 5 Torr + RF2O3W,
Although the polymer was exposed to a barrel-type asher for 20 minutes, the film did not peel off at all.

〔Effect of the invention〕

The polymer of the present invention is soluble in general-purpose organic solvents, so it can be formed into a film, and it is also soluble in alkaline aqueous solutions, so it can be used as a base polymer for various photosensitive dissolution inhibitors or A composition with a radiation-sensitive dissolution inhibitor can be used as a photo- or radiation-resistant resist material. On the other hand, since the present polymer has excellent oxygen plasma resistance, these resists can be used as an upper layer resist, etc. in a two-layer resist method. As described above, the polymer of the present invention is extremely useful as a functional polymer material such as a light- and radiation-sensitive material.

Representative Patent Attorney Masaru Ogawa (Male)・－／

Claims (1)

[Claims] 1. An alkali-soluble ladder silicone polymer represented by the following general formula (1). (R_2-SiO_3_/_2)_n(R_2-SiO
_3_/_2)_m(R_3-SiO_3_/_2)_
l... (1) (However, R_1 in general formula (1) is an organic group having a phenolic hydroxyl group, R_2 and R_3 are organic groups not containing a phenolic hydroxyl group. Also, n
, m, and l are integers and must satisfy (n/n+m+l)>0.4. ) 2. Claim No. 1 characterized in that R_1 in the above general formula (1) is a P-hydroxyphenylethyl group, R_2 is a P-methoxyphenylethyl group, and R_3 is a P-trimethylsiloxyphenylethyl group. The alkali-soluble ladder silicone polymer according to item 1.