JPH07120044B2 - Photosensitive composition and pattern forming method using the same - Google Patents

Description

The present invention relates to a photosensitive composition, and more particularly to forming a fine resist pattern when manufacturing an integrated circuit of a semiconductor device. And a photosensitive composition capable of Also,
The present invention relates to a pattern formation method by an alkaline phenomenon using such a photosensitive composition.

(Prior Art) Photosensitive compositions are widely used in the field of processes using lithographic printing such as semiconductors. As electronic devices become multifunctional and sophisticated, there is a strong demand for miniaturization of patterns in order to achieve high density and high integration.

That is, since the vertical dimension of the integrated circuit is not reduced as much as the horizontal dimension of the integrated circuit, the ratio of the height to the width of the resist pattern must be increased. Therefore, suppressing the dimensional change of the resist pattern on a wafer having a complicated step structure is
As the pattern becomes finer, it becomes more difficult. Furthermore, in various exposure methods, problems have arisen as the minimum size is reduced. For example, in the light focusing, the interference effect of the reflected light due to the step of the substrate has a great influence on the dimensional accuracy. On the other hand, in the electron beam exposure, the proximity effect caused by the backscattering of electrons causes a fine effect. It became impossible to increase the height-to-width ratio of the resist pattern.

It has been found that many of these problems are overcome by using a multilayer resist system. For multilayer resist systems, see Solid State Technology, 74 (1981) [Solid State Technology, 74 (198
The outline is published in [1)], but many other studies on this system have been published. Currently, the most commonly attempted method is a three-layer resist system, which functions as a mask for etching the lowermost layer and the lowermost layer, which have the role of flattening the steps of the substrate and preventing reflection from the substrate. And an uppermost layer as a photosensitive layer. However, this three-layer resist system has an advantage that fine patterning is possible as compared with the single-layer resist method, but has a drawback that the number of steps until pattern formation increases.

(Problems to be Solved by the Invention) As described above, conventionally, in order to obtain a fine resist pattern, a resist system having a three-layer structure has to be adopted, and therefore, the number of steps has been unavoidably increased. It was

The present invention solves the above-mentioned problems of the prior art and can apply the two-layer resist method without adopting a resist system having a three-layer structure, and a photosensitive composition capable of forming a fine pattern, and An object of the present invention is to provide a pattern forming method using the same.

[Structure of Invention]

(Means for Solving the Problem) The photosensitive composition of the present invention comprises (A) the following formula: In addition to these essential components, the polysiloxane resin having a structural unit represented by the formula (B) and a photosensitive compound (B) are contained as an essential component. It may contain a resin.

Further, the pattern forming method of the present invention is characterized in that such a photosensitive composition is applied to a substrate, and after exposure, a phenomenon is caused by using an alkaline aqueous solution.

In (I), R ₁ represents a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 14 carbon atoms, a siloxy group or a substituted siloxy group, and R _{2 to} R ₆ Is at least one of the groups is a carboxyl group or a phenolic hydroxyl group or a group containing the same, and the remaining groups are a hydrogen atom, a halogen atom, an alkyl group, or a halogenoalkyl group,
Cyanoalkyl group, substituted alkyl group such as alkoxyalkyl group, carboxyl group, alkylcarbonyl group,
An alkoxycarbonyl group, an alkoxy group, an acyloxy group, an allyl group, a substituted or unsubstituted aryl group having 6 to 14 carbon atoms, an amide or an imide, and one of R ₂ and R ₃ , R ₄ and R ₅ , It may also cooperate with one of R ₆ to form a ring.

In the formula (I), examples of the alkyl group having 1 to 10 carbon atoms include, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-
Examples thereof include a butyl group, an n-pentyl group, an n-hexyl group, an n-octyl group, an n-nonyl group and an n-decyl group. Examples of the substituted or unsubstituted aryl group include phenyl group, o-hydroxyphenyl group, p-hydroxyphenyl group, o-methylphenyl group, p-methylphenyl group, o-methoxyphenyl group, p-methoxyphenyl group. Group, p-chlorophenyl group, β-naphthyl group,
A 9-anthranyl group and the like can be mentioned.

Further, in the above formula (I), when R ₁ is a siloxy group or a substituted siloxy group, a structure in which these groups are bonded to a siloxy group or a substituted siloxy group of adjacent structural units, or Alternatively, it may have a two-dimensional or three-dimensional structure such as a structure bonded to a siloxy group or a substituted siloxy group in another molecule.

Furthermore, specific examples of the structural unit represented by the formula (I) include: And so on.

The compound represented by the above formula (I) can be produced, for example, as follows. That is, a compound having an unsaturated bond obtained by protecting phenol or carboxylic acid with a trimethylsilyl group or an alkyl ether, and trichlorosilane, monosubstituted dichlorosilane or triethoxysilane, monosubstituted diethoxysilane are used as platinum catalysts, etc. It is produced by subjecting the compound to a reaction and then performing a hydrolytic condensation.

Next, the photosensitive compound used in the present invention may be any one generally known as a photosensitizer, and examples thereof include an azide compound, a naphthoquinone diazide sulfonate, and a diazonium salt.
Specific examples of this azide compound include 4,4'-diazidochalcone, 2,6-bis (4'-azidobenzal) cyclohexanone, and 2,6-bis (4'-azidobenzal) -4.
-Methylenecyclohexanone, 1,3-bis (4'-azitobenzal) -2-propanone, 1,3-bis (4'-azidocinnamylidene) -2-propanone, 4,4'-diazidostilbene, 4, 4'-diazitobiphenyl, 4,4'-
Diazido diphenyl sulfide, 3,3'-diazido diphenyl sulfide, 4,4'-diazido diphenyl sulfone, 3,3'-diazido diphenyl sulfone and 4,4'-
Examples include diazidostilbene. In addition, Japanese Patent Laid-Open No. 50-701
No. 05, No. 50-40626, No. 49-8214, No. 48-
The compounds described in JP-A-94420 or JP-A-48-94419 are also included. Furthermore, a compound containing a naphthoquinonediazide group or a benzoquinonediazide group can also be mentioned.
This compound, for example, naphthoquinone diazide sulfonic acid chloride or benzoquinone diazide sulfonic acid chloride and a low molecular compound or a high molecular compound having a hydroxy group,
It is obtained by condensation in the presence of a weak alkali. Here, examples of the low-molecular compound include hydroquinone, resorcin, phloroglucin, 2,4-dihydroxybenzophenone, 2,3,4-trihydroxybenzophenone, gallic acid alkyl ester, catechin, quercetin, quinalizarin, purpurin, etc. Examples of the molecular compound include phenol-formaldehyde novolac resin, cresol-formaldehyde novolac resin, polyhydroxystyrene and the like.

Among these compounds, the azide compound is preferable. Even more preferred are naphthoquinone diazide sulfonates or aryl azide compounds. These may be used alone or in a mixed system.

In such a photosensitive composition of the present invention, the mixing ratio of the polysiloxane resin which is an essential component and the photosensitive compound is not particularly limited, but the polysiloxane resin 10
The amount of the photosensitive compound is usually 5 to 100 parts by weight based on 0 part by weight. If the amount is less than 5 parts by weight, the difference in alkali solubility between the unexposed part and the exposed part cannot be obtained, and a clean pattern cannot be obtained.

Furthermore, in the photosensitive composition of the present invention, the alkali-soluble resin optionally contained is not particularly limited as long as it is a resin that is alkali-soluble,
For example, poly-p-vinylphenol, poly-o-vinylphenol, poly-m-isopropenylphenol,
Poly-p-isopropenylphenol, m, p-cresol novolac resin, copolymer of p-vinylphenol and methyl methacrylate, copolymer of p-isopropenylphenol and maleic anhydride, poly-p-vinyl Partial benzoylated products of phenol, partial o-methylated products of poly-p-vinylphenol, polymethacrylic acid, polyacrylic acid and the like can be mentioned, and those having a phenolic hydroxyl group are particularly preferable. The amount of the alkali-soluble resin blended is set to about 5 to 100 parts by weight based on 100 parts by weight of the polysiloxane resin.

The photosensitive composition of the present invention contains the above-mentioned components, for example,
It can be easily obtained by using a conventional method such as dissolving in a solvent. The composition of the present invention may be a sensitizer, a dye, a surfactant, or another polymer for modifying the coating film, such as an epoxy resin, a polymethylmethacrylate resin, or propylene oxide-ethylene oxide, if necessary. A copolymer, polystyrene, silicone ladder polymer, etc. may be blended.

The formation of the pattern of the present invention will be described below. First, the composition of the present invention is dissolved in a solvent and then applied. The solvent used is not particularly limited, and examples thereof include toluene, xylene, o-dichlorobenzene, chloroform, ethanol, isopropyl alcohol, cyclopentanone, cyclohexanone, cellosolve acetate and methyl ethyl ketone. The coating method is also a conventional method, but a spin coating method is preferably used.

After applying the resin, it is dried. Drying conditions, in the case of the lower layer resin, usually 50 ~ 250 ℃, preferably 80 ~ 220 ℃,
Usually 0.5 to 120 minutes, preferably 1 to 90 minutes, in the case of a photosensitive silicone resin, usually 50 ~ 200 ℃, preferably 8
At 0 to 120 ° C, it is usually 0.5 to 120 minutes, preferably 1 to 60 minutes.

Next, the photosensitive composition layer of the present invention is exposed through a mask having a predetermined pattern. Exposure is done in the visible, infrared, and
It is performed by irradiating an energy ray such as an ultraviolet ray or an electron beam.

After exposure, the phenomenon occurs with the solvent. Phenomenon time is usually 0.5-10
Minutes, and the solvent is preferably an aqueous alkali solution. Next, it is usually dried at 50 to 200 ° C. for 0.5 to 120 minutes. Finally, the lower layer is etched using oxygen gas plasma or an appropriate solvent to obtain a predetermined resist pattern. It is preferable to etch with oxygen gas plasma. In this case, usually 1 × 10 ^-4 to 1 ×
Treat with 10 ⁻¹ Torr, 0.01 to 10 W / cm ² for 1 to 120 minutes.

(Example) Example 1 The following formula: 80 parts by weight of a polysiloxane resin having a structural unit represented by (molecular weight 5,000) and 4-azido-2'-methyl-4 '[N- (2-ethoxyethyl) as a photosensitive compound.
20 parts by weight of -N-ethyl-amino] -α-cyanostilbene was used, and these were dissolved in 200 parts by weight of cyclohexanone to prepare a photosensitive composition.

Next, a novolac-based commercial resist OFPR-800 (manufactured by Tokyo Ohka Co., Ltd.) was applied on a silicon wafer with a spinner, and 220
The lower layer was formed by drying at 0 ° C. for 1 hour. The thickness of the lower layer is 2.
It was 0 μm. Then, the photosensitive composition solution obtained above was applied thereto by a spinner and dried on a hot plate at 90 ° C. for 2 minutes to form a photosensitive coating film having a thickness of 0.5 μm. After that, it is exposed by a reduction projection exposure device (stepper) using monochromatic light with a wavelength of 436 nm,
A resist pattern was formed by causing a phenomenon with a 1.5% aqueous solution of tetramethylammonium hydroxide for 45 seconds.
After that, oxygen gas plasma (2.0 × 10 ^-2 Torr, 0.06W / c
m ² ), etching for 30 minutes, line width 0.5μ
A good pattern of m was formed.

Example 2 Example 1 above except that 1,2-naphthoquinonediazide-5-sulfonic acid ester of 2,3,4-trihydroxybenzophenone (average esterification rate 2.0) was used as the photosensitive compound. When done in the same way, the line width is 0.5 μm
A good pattern was formed.

Example 3 The following formula: 80 parts by weight of polysiloxane resin (molecular weight 7,000) with the structural unit shown by
-Naphthoquinone diazide-5-sulfonic acid ester (average esterification rate 3.0) 20 parts by weight and cyclohexanone 200
When a photosensitive composition was prepared by mixing with 1 part by weight and a pattern was formed in the same manner as in Example 1, a good pattern having a line width of 0.5 μm was formed.

Example 4 The following formula: 30 parts by weight of a polysiloxane resin having a structural unit shown in (molecular weight 3,000) and a commercially available positive resist OFPR-800
(Tokyo Ohka, solid content 30%, (m, p-cresol novolac resin, consisting of naphthoquinone diazide sulfonate ester compound of 2,3,4-trihydroxybenzophenone and a solvent)) 100 parts by weight and mixed When a photosensitive composition was prepared and a pattern was formed in the same manner as in Example 1, a good pattern having a line width of 0.5 μm was formed.

Example 5 As a polysiloxane resin, the following formula: 100 parts by weight having a structural unit represented by (molecular weight 2,500), as a photosensitive compound, naphthoquinone diazide sulfonic acid ester of quercetin (esterification rate to the -OH group 80%) 50 parts by weight and m as an alkali-soluble resin,
A photosensitive composition was prepared by mixing with 50 parts by weight of p-cresol novolac resin (molecular weight 4,000), and a pattern was formed in the same manner as in Example 1. As a result, a good pattern having a line width of 0.5 μm was formed. .

Example 6 As a polysiloxane resin, the following formula: 100 parts by weight having a structural unit shown in (molecular weight 3,000), 30 parts by weight of naphthoquinone diazide sulfonic acid ester of quercetin (80% esterification rate for -OH groups) as a photosensitive compound, and silicone ladder polymer
GR-950 (manufactured by Owens-Illinois, USA) was mixed with 30 parts by weight to prepare a photosensitive composition, and a pattern was formed in the same manner as in Example 1. A good pattern having a line width of 0.5 μm was formed. Was done.

Example 7 As a photosensitive compound, the following formula: A pattern was formed in the same manner as in Example 6 except that the compound represented by
A good pattern of 0.5 μm was formed.

〔The invention's effect〕

As is clear from the above description, the photosensitive composition of the present invention enables the formation of an extremely fine resist pattern when forming a resist pattern, without forming a conventional multilayer laminate. For example, it is useful when applied to a wide range of applications such as a manufacturing process of an integrated circuit of a semiconductor element, and its industrial value is great.

 ─────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-60-80844 (JP, A) JP-A-62-36661 (JP, A) JP-A-62-159141 (JP, A)

Claims (3)

[Claims] (A) The following formula: (In the formula, R ₁ represents a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 14 carbon atoms, a siloxy group or a substituted siloxy group, and R _{2 to} R ₆ are , At least one group of which is a carboxyl group or a phenolic hydroxyl group or a group containing the same, and the remaining groups are a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a carboxyl group,
Alkylcarbonyl group, alkoxycarbonyl group, alkoxy group, acyloxy group, allyl group, 6 to 6 carbon atoms
14 represents a substituted or unsubstituted aryl group, amide or imide, or one of R ₂ and R ₃ , and R ₄ ,
R ₅ and one of R ₆ may cooperate with each other to form a ring) and a polysiloxane resin having a structural unit represented by the following), and (B) a photosensitive compound as an essential component. A photosensitive composition comprising: 2. The photosensitive composition according to claim 1, which further contains an alkali-soluble resin. (A) The following formula: (In the formula, R ₁ represents a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 14 carbon atoms, a siloxy group or a substituted siloxy group, and R _{2 to} R ₆ are , At least one group of which is a carboxyl group or a phenolic hydroxyl group or a group containing the same, and the remaining groups are a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a carboxyl group,
Alkylcarbonyl group, alkoxycarbonyl group, alkoxy group, acyloxy group, allyl group, 6 to 6 carbon atoms
14 represents a substituted or unsubstituted aryl group, amide or imide, or one of R ₂ and R ₃ , and R ₄ ,
R ₅ and one of R ₆ may cooperate with each other to form a ring), and a polysiloxane resin having a structural unit represented by the following), and (B) a photosensitive compound containing a photosensitive compound as an essential component. A method for forming a pattern, which comprises applying a functional composition to a base material, exposing the base material, and developing the base material using an alkaline aqueous solution.