JPS63141046A - Resist - Google Patents

Abstract

PURPOSE:To obtain a resist having superior resolution and sensitivity for ultraviolet rays together with high resistance to O2 plasma by incorporating a specified polysilane in the resist. CONSTITUTION:Polysilane expressed by the formula is incorporated in a resist. In the formula, R1-R3 are methyl or phenyl group; R4-R8 are H atom or methyl group, but at least one of them is methyl group; n is a positive integer; m is zero or a positive integer. The used polysilane is pref. one having >=1X10<3> mol.wt. from the viewpoint of sensitivity and glass transition point of the polymer. If the mol.wt. is >=5X10<5>, disadvantage in the formation of fine pattern is resulted because of the higher tendency for causing swelling when it is developed. It is preferred from the viewpoint of resolution that the mol.wt. distribution is as near as possible to monodisperse distribution. Since better heat resistance and resolution of the resist are obtd. when the glass transition point of the polymer is as high as possible, it is preferred that the polymer has at least 50 deg.C glass transition point.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to resists.

(Prior technology) In parallel with conventional lithography technology, ionizing radiation such as electron beam, X@, ion beam, etc. Lithography using radiation such as short wavelength ultraviolet light is being put into practical use.

Especially about 0.5μm! Or smaller micro-measuring processing E
In this case, the latter phosphorography technology is indispensable.

In recent years, as semiconductor devices have become three-dimensional, cyst patterns have been formed on semiconductor substrates with considerable steps, and fine training techniques have been developed.
There is a tendency to perform O-work. For the fourth step, it is necessary to increase the resist film thickness to some extent, but increasing the resist film thickness will result in a decrease in the inverse image quality.

Ninth, a thick flat layer 1 is formed on the semiconductor board, several layers including a thin resist pattern are formed on it, and the upper layer resist pattern is sequentially transferred to the lower layer by dry etching. Multiple resists are being used to form a resist pattern with a high ratio of 0 to 100%.
) The most commonly used is the 31 series, which forms an intermediate layer with plasma oil and forms a thin resist layer on top of it.

In this method, the dry etching process must be repeated several times to transfer the resist pattern, which tends to slow down the process and make it complicated. Therefore.

It has a resistance of 0. A two-layer resist process is being developed in which a resist pattern having plasma properties is formed on the flatness ratio layer.

Such resistance to 0. Polysilastyrene containing chloromethyl as a resist having plasma properties was disclosed in Japanese Patent Application Laid-open No. 1986-9.
It is described in Publication No. 8431.

However, this resist is difficult to use during chloromethylation reactions.

There was a problem in that it was difficult to control the reaction, resulting in poor molecular distribution due to a decrease in molecular weight, resulting in a decrease of 1140 degrees. Furthermore, there was one point that differences in properties between one synthetic lot tended to occur, and resist quality control was difficult.

Furthermore, since the sensitivity to ultraviolet rays is low, the practicality of using ultraviolet rays for photosensitive emitters is low.

(While the invention is about to reach its conclusion = M, a) As described above, the conventional resist having resistance to Ot plasma has a problem of low degree of resolution and poor sensitivity to ultraviolet rays.

The present invention was developed in view of these problems,
The object of the present invention is to provide a resist with high resistance to Ot plasma and good sensitivity to ultraviolet radiation.

[Structure of the invention]

(Means for solving one point) The present invention is based on the general formula CI below. where at least one is a methyl group, n is a positive integer, m is O
ff is a positive integer) This is a resist characterized by containing polysilane represented by:

The molecular weight of the polysilane used in the present invention is desirably 1Xl0' or more from the viewpoint of sensitivity and the glass transition point of the polymer. To become, 'i,
It is difficult to form a s-shaped pattern.

From the viewpoint of resolution, it is desirable that the molecule I distribution be as close to monodisperse as possible. The heat resistance and solubility of the resist should be at least 5.
It is desirable to have a glass transition point of 0°C or higher.

The polysilane used in the present invention is 几.

Sialgyldichlorosilane [IL] represented by 90 141 German or 几.

Amane C1-#CI　　　　　[In) 几.

It can be obtained by mixing dialkyldichlorosilane [II[) represented by t in any ratio and carrying out the reaction in a happy medium such as xylene in the presence of a dispersion of gold and tetrasodium. This method uses only Plig, and the molecular weight can be controlled by changing the reaction time, and a copolymer having an arbitrary component ratio can be synthesized by changing the amount of dialkyldichlorosilane to be mixed.

As a dialkyldichlorosilane represented by the monofunctional formula [70].

Tolylmethyldichlorosilane, tolylphenyldichlorosilane, xylylmethyldichlorosilane.

Examples include xylylphenyldichlorosilane, mesitylmethyldichlorosilane, mesiterphenyldichlorosilane, and the like. M9. As the dialkyldichlorosilane represented by the general formula [I[I], dimethyldichlorosilane,
Examples include methylphenyldichlorosilane and diphenyldichlorosilane. When polysilane is a copolymer,
A copolymer is formed by any combination of dialkyldichlorosilanes remaining from [I[)-Th and [Iff], respectively. At this time, the composition ratio of the dialkyldichlorosilane represented by [II] is preferably at least 10 molar. When the 5 composition ratio is lower than this, the sensitivity of the resist is lowered.

When this resist is made of polysilane alone, it is a negative type resist with respect to 4 radiation, and can be a positive type resist with respect to short wavelength ultraviolet rays.

Further, by adding a bisazide compound to the polysilane, a negative resist with high sensitivity to ionizing radiation and ultraviolet rays can be obtained, which is desirable.

That is, this is a negative resist according to claim 2, which is characterized in that it contains bisazidized &--. , the resist described in box gt.

The bisazide compounds used in the present invention generally have negative qv
Anything used for cysts is fine.

It is not particularly limited. For example, 3,3'-dichloro-4,4'-diazidiphenylmethane.

4.4'-diazide diphenyl ether, 4.4-diazide diphenyl disulfide, 4,4'-diazide diphenyl sulfide, 4,4'-diazide diphenyl sulfone h 4-azidocalcoy, 2s6-pis (4
'-azidocinnamylidene)-4-methylcyclohexanone, 2,6-bis(azidocinnamylidenenocyclohexanone-2s6-bis(4'-azidobenzal)-4-methylcyclohexanone, 2,6-bis(4'-azidocinnamylidene)-4-methylcyclohexanone, ′
-azidobe/zarun-cyclohexanone, 4,4'-diazidostilbene-2,2'-disulfonyl-N-(p
-methoxyphenylnoamide, 4,4'-diazidostilbene-2,2'-disulfonyl-N-(p-hydroxyethylphenyl)amide, 4,4'-diazidostilbene-2,2'-disulfonyl-N -(p-hydroxyphenylnoamide, 4,4'-diazidostilbene-2
,,2'-disulfonylamide, 4.4'-diazidobenzophenone, 4.4'-diazidostilbene, 4.4
'-Diazidochalcone, 4.4'-Diazidobenzalacetone, 6-azido-2-(4'-azidostyrene penzimidal, 1,4-bis(3'-azidosterylnobenzene, 3 .3'-diazide diphenyl sulfone,
4.4'-Diazidiphenylmethane, 1,8-diazidnaphthalene/, 2-(p-azidocinnamoyloxy)
-2-(4'-p-azidocinnamoyloxyphenyl]propane and the like can be mentioned.

When the radiation used is ultraviolet rays, the bisazide compound can be selected arbitrarily depending on the wavelength of the ultraviolet rays.

That is, by appropriately selecting the bisazide compound, it is possible to obtain a negative resist that is sensitive to ultraviolet light having a wavelength of 500 to 150 nm.

Furthermore, regarding the addition of bisazide compound t'J111k, there is no significant change in sensitivity when the amount added is in the range of 10 to 25% by weight, but when the amount added is too large, a decrease of 1 degree in reverse sensitivity occurs. Furthermore, since the oxygen plasma resistance is lowered, the amount added should be 30 or less times the polymer, preferably 0.1 to 2 Oiaii.

An example of one use of the Negajaku V cyst of the present invention will be briefly described.

First, a polymer material '#JrfI is formed on a substrate. use Hypothetically, for example, a silicon substrate doped with an impurity, or this substrate conductor, or this fI
Semiconductor substrates such as those with a polycrystalline silicon layer formed on a plate as a base material through silicon oxide 1, figures with a metal film such as gallium-arsenic, and rR layer with chromium layer or chromium oxide pattern on a transparent glass plate. For example, any organic polymer material that can be used to form a bookmark, such as polystybin, can be used as a mask substrate, etc., such as polystybin. Product name 0FP used as a glandular resist
R-800 (Tokyo 6 Kakogyo), product name HPR-204 (
(Hendt style) etc. A polymeric material solution prepared by dissolving this material in an appropriate solvent is applied using, for example, a spinner and dried to provide the polymeric material 1. This polymer material layer solution! 111i! Suitable examples of the solvent C used are, for example, toluene, xylene, ethyl acetate, and cyclohexanone.

Furthermore, each of these coatings may further contain additives such as diazidate and other additives to improve thermosetting properties. The viscosity of this solution is adjusted to 1 m, 20 to LOOcps in consideration of application using a spinner or the like. Preferably it is 60-100 C1)S.

Adjusted like this 7'? , the solution is applied onto the substrate and then subjected to baking treatment. The baking treatment conditions at this time are a temperature sufficient to evaporate the solvent and a temperature exceeding the glass transition point of the polymer material used.
0.1 to 1 hour at 00 to 250°C.

Preferably it is 0.4 to 1 hour at 150 to 200°C.

The polymer material layer formed usually has a thickness of 1.0 to 2 μIn.

If this thickness is out of the above range, the resolvability will deteriorate and flattening will not be achieved on a substrate with a step difference.

Preferably it is 1.5 to 2 μm.

Next, the present invention's negative resist layer is formed on the polymeric material layer. The above-mentioned resist formula [a polysilane or a mixture with a bisazide compound represented by 1] is dissolved in an electrolytic solvent, a solution of C is applied with a spinner, and dried. will be established. Suitable solvents for use in preparing this V-cyst bath solution include, for example, Torton and xylene. This solution may further contain additives such as octamethylcyclotetrasilazane and hexamethylcyclotrisilazane for improving coating properties and layering properties. Furthermore, the viscosity of this solution should be taken into consideration when applying it with a spinner.

Adjusted to 10-100 cps. Preferably 10~
60 cps - After the solution prepared in this way is applied onto the polymer material prraO, it is subjected to baking treatment. The baking condition at this time is a temperature sufficient to evaporate each 6X, usually 100 to 180°C.

0.1 to 0.5 hours, preferably at 120°C to 140°C. L~0.4 hours. What is the thickness of the resist layer to be formed?

The average diameter is 0.1 to 0.5 μm. If this layer thickness is out of the above-mentioned t range, the eRg plasma resistance decreases or the resolution decreases. Preferably 0.1~
It is 0.3 μm.

Nine resists are formed as described above, and then the radiation center is irradiated to expose nine patterns. Thereafter, the exposed or unexposed portions of the resist are exposed and removed, and the polymeric material layer is subsequently dry etched using plasma to form the desired 1JILKm pattern. .

Example 1 Methyl mesityl dichlorosilane in the presence of a 1111 sodium dispersion in xylene for 24 hours at 13
After carrying out the reaction at 0°C, insoluble matter was separated from P, and the reaction solution was poured into methanol to obtain stoichiometric precipitation.90 Polymerization yield: 54%
m MW-9,5X10" *Mw/Mn-2,0. IH-NM of the obtained t polymethylmesitylsilane
The results of R and elemental analysis are as follows.

')l NMR: -8i-CH,: 0.2ppm
, 3H elemental analysis: C near 4.5 ratio (74,1%) H: 9
．． 0% (8,6 units) Si: 16.5 units (17, 3 units) The values in parentheses are calculated values.Dissolve this 1 in toluene so that each degree of coalescence is 10 tons, and then Polymer 10? IC! 2,6-bis-(4'azidobenzal)-4-methylcyclohexanone 1 corresponding to 1:r! 3, and a negative resist of the present invention.

This Lee Ga-yeol V cyst is made of silicon with a thickness of 2000AiK.
To the sea urchin - the dragon cloth on top, the acceleration voltage of 201 (V a)
t-irradiation t, Ne,, methyl ethyl keto/:isoglobil alcohol-3:1 solution! Therefore, it is now 1H.
By the way, is it a negative pattern? Forming 'i#-a, m@1
When a15μC/c is drawn, the pattern is 0.25
It is possible to capture a negative pattern (μm).

Example 2: Mix methylmesityldichlorosilane and 1 mole of dimethyldichlorosilane, and use the same method as Example 1 (Kot, C, *
The reaction is carried out in the presence of a sodium fraction in a plasma chamber.%? X
I got a company. ) (by NM 3-element zero analysis) It was found that the mixture was 1:1 # of methidimesitylsilane-dimethylsilane/, heavy & t.

i ft 'IX 4%sMvvm1.5XlO'
sMw/Mn-1,9H'NMR: -8i-C
H,: 0.2ppm, 9H elemental analysis: C65,9'1
(65,51) H10,1 section (9,0 arrogant) S turtle 24.0 悌 (25,5 many) The values in parentheses are calculated values. Furthermore, 2,6- corresponding to lθ weight & 1% of the polymer
Bis-(4'azidobenzal)-4-methylcyclohexanone was added to prepare a resist of the present invention.

This resist was applied to a silicon urchin with a thickness of 2000A and irradiated with a 4-wire beam at 1 pressure of 20KV. After that, the resist was subjected to the same process as in Example 1 to form a negative pattern. Obtained. When drawn at 19.8 μC/cm” (0,2
Example 3 A negative pattern of 5 μm) can be formed.
When the film was formed to have a thickness of qX, exposed to ultraviolet light having a wavelength of 3651 m, and developed using the same developer solution as in Example 1, a negative pattern could be formed. 60mJ/using a chrome mask with a 0.5nm line and space pattern.
After exposure, the mask pattern can be transferred to the mixed film on the sea urchin.

Example 4 Apply the negative resist film of Example 2 to the sea urchin by 0.2 μm on top.
, formed in a vague thickness, subjected to quaternary ultraviolet light with a wavelength of 365 nm, and developed using the same developing solution as in Example 1.A negative pattern was obtained. I was able to form it. 65 mJ using a chrome mask with a 0.5 μm line and space pattern.
Exposure of /c-! It was possible to transfer the mask pattern to the mixed film on the wood.

Example 5 Product name HPR of resist film and hunt film in Example 1
-204 resist film was exposed to a parallel plate type dry etching device with an output cuff of 00 W and a cumulative pressure of 0.05) phosphoric acid, and dry etching was performed.
It was found that the etching resistance was 25 times that of -204. On the silicon sea urchin, a 1.5 μm HPR-204 pattern was formed as flattening 1, and the thin film of Example 1 was formed on top of it to a thickness of 0.2 μm. Form a line and space pattern with a width of 0.25 μm on the film of
The film was exposed to a parallel plate type dry etching device, and dry etched using oxygen plasma. After an etching time of 18 minutes, the pattern was completely transferred to the underlying layer of HPR-204. In this way, we were able to form a 1.7 μm thick line and space pattern.

Example 6 Resist film in Example 7 and Hunt preparation.

Product Name: HPR-204 Resist Mock - When the etching resistance was investigated using Example 5, it was found that the product name: HPR-204
It was found to be 25 times more resistant than v-cyst membrane.

1.5 μm HP as a planarization layer on silicon wafer
A 0.2 μm thick layer of Example 1 was formed on the R-204 layer, and a 0.25 μm wide line space pattern was formed on the layer of Example 1 in the same manner as in Example 1. Formed. Afterwards, the pattern was completely exposed under HPR-204 by parallel Fi-type dry etching with an output cuff of 00W)W and pressure of 0.05), followed by dry etching with oxygen plasma. 1
transcribed into. Through this process, a line and space pattern with a thickness of 1.7 μm was formed.

[Brightening effect]

According to the present invention, 0. It is possible to provide a radiation resist that has high plasma resistance, good detoxification degree, and good sensitivity to the ultraviolet region.

Claims (2)

[Claims] (1) The following general formula [I] ▲There are mathematical formulas, chemical formulas, tables, etc.▼[I] (In the formula, R_1 to R_3 represent a methyl group or a phenyl group, and R_4 to R_5 represent a hydrogen atom or a methyl group. At least one is a methyl group, n is a positive integer, and m is 0 or a positive integer. (2) The resist according to claim 1, which contains a bisazide compound.