JPS60198538A - Positive type resist material - Google Patents

Abstract

PURPOSE:To impart high resolution and dry etching resisting characteristics by incorporating a polycondensate having phenol rings in the molecule and an O- nitrobenzyloxysilane deriv. represented by a specified formula. CONSTITUTION:The present positive type resist material is prepared by incorporating a polycondensate having phenol rings in the molecule and an O-nitrobenzyloxysilane deriv. represented by the formula in which R<1>, R<2>, R<3> are each H, halogen, vinyl, allyl, 1-10C alkyl, alkoxy, aryl, aryloxy, or siloxy; R<4> is H, 1-10C alkyl or phenyl; R<5>, R<6>, R<7> are each H, nitro, cyano, hydroxy, or the like; and 0<=p, q, r<=3, and 1<=p+q+r<=3.

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to positive resist materials, and more particularly to positive resist materials suitable for recording ultraviolet light, particularly deep ultraviolet light. This resist material is composed of a combination of a polymeric material having a phenol skeleton and an 0-nitrobenzyloxysilane derivative, and has good resistance, especially to plasma etching, and can be effectively used in the production of semiconductor devices.

[Technical background of the invention and its problems]

Currently, in the field of semiconductor devices, efforts are being focused on the development of microfabrication technology on the submicron order in response to the increasing degree of integration. In particular, in addition to conventional exposure systems in the visible light and ultraviolet regions, X-rays, which enable finer processing,
Development of electron beam and deep ultraviolet light systems is underway. In particular, since the far-UV exposure system is an extension of conventional technology, it has the great advantage of being able to use most of the accumulated semiconductor device manufacturing technology as is.

For this reason, the development of exposure equipment necessary for deep ultraviolet exposure systems and resist materials suitable for this system is actively underway.

Currently, polymethyl methacrylate C is used in the far ultraviolet region.
PIVIMA), polymethyl isopropenyl ketone (
Proposals include a copolymer of styrene and vinyl monomer, a resist material with an azide compound dispersed in a phenolic resin, and a diversion of quinone diazi) U, which has traditionally been used in the ultraviolet region, to the deep ultraviolet region. I came.

By the way, resist materials are required to have various properties.

Typical characteristics include (1) high sensitivity, @high resolution, θ dry etching resistance, and 0 heat resistance.

All conventional resist materials have advantages and disadvantages, and none are known that satisfy all of the required characteristics. For example, PMMA
Although PMIPK has excellent resolution, it has extremely low sensitivity and poor dry etching resistance, while phenol resin/azide and quinonediazide resist materials have excellent dry etching resistance but have drawbacks such as poor resolution. have.

[Purpose of the invention]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a resist material suitable for ultraviolet (particularly deep ultraviolet) and non-light systems, and which has high resolution and dry etching resistance.

[Structure of the invention]

The present inventors conducted extensive research on resist materials that can be applied to ultraviolet rays, especially deep ultraviolet exposure systems, provide high resolution, and have dry etching resistance properties. It has been found that a formulation containing a polycondensate having a phenol nucleus as an essential component satisfies the above object. That is, 1. When an O-nitrobenzyloxysilane derivative is blended with a polycondensate having a phenol nucleus that is originally soluble in alkaline substances, it changes to a substance that is soluble in alkalis, and when the above blend is further irradiated with deep ultraviolet rays, We have again found a development method that makes it solubilized in alkaline substances.

By the way, in order to use it as a resist material, a resist solution is first prepared by dissolving the O-nitrobenzyloxysilane derivative and the phenol nucleus-containing polycondensate in a suitable organic solvent. Thereafter, the obtained resist solution is applied onto the surface of a substrate such as a silicon wafer and dried to form a resist film. Next, the resist film is irradiated with deep ultraviolet rays in a pattern and then developed with an alkaline aqueous solution, whereby the exposed portions of the resist film are dissolved and removed, forming a blur pattern.

The present invention will be explained in detail below. A polycondensate having a phenol nucleus in its molecule is an oligomer or polymer containing a phenol nucleus, for example, the following general formula +1. t[l,
mV (where X is a hydrogen atom, an alkyl group, a halogen group,
Formalin polycondensates of phenol represented by alkoxy groups, hydroxyl groups, etc.), formalin polycondensates of cresol, or copolycondensates thereof (general formula n), or vinylphenol polymers (general formula 1), with a phenol core In the present invention, the former device is also used in combination with a polycondensate having a phenol nucleus in the molecule. 0-Nitrobenzyloxysilane derivative of general formula (I) (wherein,
R, R, and R may be the same or different, and each represents a hydrogen atom; a halogen atom; a vinyl group; an allyl group;
Unsubstituted or substituted alkyl group having 1 to 10 carbon atoms; alkoxy group having 1 to 10 carbon atoms; unsubstituted or substituted aryl group; aryloxy group; siloxy group 7, R4
represents a hydrogen atom; an unsubstituted or substituted alkyl group having 1 to 10 carbon atoms; a phenyl group; a substituted phenyl group;
,R.

R8 may be the same or different, and each
Hydrogen atom; nitro group; cyano group; hydroxy group; mercaguto group; halogen atom; acetyl group; allyl group; carbon l
v, an alkyl group having 1 to 5 carbon atoms; an alkoxy group having 1 to 5 carbon atoms; an unsubstituted or substituted aryl group; an aryloxy group, p+q+r is 0≦p+ q+r≦3, ■≦p+
Represents an integer that satisfies the condition q+r≦3. ) is a compound represented by

Examples of unsubstituted or substituted alkyl groups having 1 to 10 carbon atoms include methyl group, ethyl group, propyl group, butyl group, t-
Examples include butyl group, pentyl group, chloromethyl group, chloroethyl group, fluoromethyl group, cyanmethyl group, and examples of alkoxy groups having 1 to 1 carbon atoms include methoxy group,
Examples include ethoxy group, n-propoxy group, and n-butoxy group. As the unsubstituted or substituted aryl group,
7-g, p-methoxyphenyl g, p-rio.

Examples of the aryloxy group include a phenyl group, I)-)lifluoromethylphenyl group, and a phenoxy group.

In addition, as a silicon compound, the terminal group is an 0-nitrobenzyloxysilyl group, and the main chain is of the following formula; (wherein, n is 0
or represents an integer of 1 or more, R1 and R have the same meanings as above, x and y may be the same or different,
Each represents an oxygen atom, an alkylene group, an aryl group, etc. ) may be a compound consisting of a group represented by

Specific examples of silicon compounds having an unsubstituted or substituted 0-nitrobenzyloxy group directly bonded to a silicon atom used in the present invention include trimethyl(0-nitrobenzyloxy)silane dimethylphenyl(0-nitrobenzyloxy)silane diphenylmethyl (0-nitrobenzyloxy) silane triphenyl (0-nitrobenzyloxy) silane vinylmethylphenyl (0-nitrobenzyloxy) silane t-butylmethylphenyl (0-nitrobenzyloxy) silane triethyl (0-nitrobenzyl oxy)silane)!
j (2-chloroethyl)-〇-nitropenzyloxysilane)! J(p-toIJfluoromethylphenyl)-
〇-Ditropendyloxysilanetrimethyl[α-(0-nitrophenyl)-〇-ditropenzyloxy]silanedimethylphenyl[α-(0-nitrophenyl)-〇-
Nitrobenzyloxy]7-methylphenyldi[α-(0-nitrophenyl)-〇-
nitrobenzyloxy]silanetriphenyl(α-ethyl-〇-nitrobenzyloxy)silanetrimethyl(3-methyl-2-nitrobenzyloxy)silanedimethylphenyl(3,4,5-)dimethoxy-2-nitro benzyloxy)silanetriphenyl(4,5,6)dimethoxy-2-nitrobenzyloxy)silanediphenylmethyl(5-methyl-4-methoxy-2-nitrobenzyloxy)silanetriphenyl(4,5-dimethyl- 2-nitrobenzyloxy)silanevinylmethylphenyl(4,5-dichloro-2-nitrobenzyloxy)silanetriphenyl(2,5-dinitrobenzyloxy)furandiphenylmethyl(2,4-dinitrobenzyloxy) Silanetriphenyl(3-methoxy-2-nitrobenzyloxy)silanevinylmethylphenyl(3,4-dimethoxy-2-nitrobenzyloxy)72-dimethyl(0-nitrobenzyloxy)silanemethylphenyldi(0-nitrobenzyloxy) ) silane vinylphenyldi(0-nitrobenzyloxy)silane t-7'
tylphenyldi(0-nitrobenzyloxy)silanemethyltrim-nitrobenzyloxy)silane2-chloroethylphenyldi(0-nitrobenzyloxy)silanediphenyldi(0-nitrobenzyloxy)furandiphenyldi(3-methoxy-2 -nitrobenzyloxy)
Silane diphenyldi(3,4-dimethoxy-2-nitrobenzyloxy)silane diphenyldi(2,5-dinitrobenzyloxy)silane diphenyldi(2,4-dinitrobenzyloxy)silanemethyltri(0-nitrobenzyloxy) Silane methyl trirubis (0-nitrobenzyloxydimethylsilyl)
Benzene 1, 1, 3, l-tetraphenyl-1
, 3-di(0-nitrobenzyloxy)siloxane 1.1,3,3,5.5-hexaphenyl-1,5-di(o-nitrobenzyloxy)siloxane and 5ICl-containing silicone resin and 0-nitro Examples include silicon compounds produced by reaction with benzyl alcohol.

To prepare the resist solution, the essential components consisting of the phenol nucleus-containing polycondensate and the O-nitrobenzyloxysilane conductor may be dissolved in a suitable organic solvent. These organic solvents include ethylene glycol monoethyl ether acetate (ethyl cellosolve acetate).
, ethers such as glycol methyl ether, glycol monoethyl ether, aliphatic esters such as butyl acetate, acetone, aliphatic ketones such as methyl ethyl ketone, methyl isobutyl ketone, cyclic ethers such as dioxane, N, N- Examples include dimethylformamide.

In addition to the above-mentioned essential components, a small amount of a surface-modifying agent for the coating film, such as a surfactant, silicone oil, or a low-molecular-weight leveling agent, can be added to the resist solution. Additionally, if necessary, it is desirable to add a small amount of dye or the like to adjust the photosensitive wavelength range of the resist itself. Reflection of light on the substrate surface can be suppressed.

By the way, the blending ratio of the essential component phenol nucleus-containing polycondensate and the 0-nitrobenzylox7silane derivative is extremely important in improving the resolution of the resist pattern. This ratio depends on the type of condensate used,
Although it varies depending on the type of silane derivative, the combination of both, and the type of developer, the amount of silane derivative is 5 to so M: A part, preferably 1 to 100 parts by weight of the condensate.
0 to 40 parts by weight is common. If it is less than 10 parts by weight, a sufficient fd freshness difference cannot be obtained between the irradiated part and the unirradiated part.

As a result, a good pattern cannot be obtained. On the other hand, if the amount exceeds 40 molar parts, a large amount of energy is required for pattern formation, resulting in a disadvantage that not only the sensitivity is substantially lowered but also the resist film becomes brittle. As described above, in order to fully exhibit the effects of the present invention, the combination of the condensate and the silane derivative should be determined so that a sufficient difference in solubility for alkaline substances can be obtained between the irradiated and non-irradiated areas of the resist film, while taking sensitivity into consideration. It is necessary to reconcile.

It is not clear why the silane derivative according to the present invention changes the polycondensate to be poorly soluble in alkali. Similarly, the mechanism by which it changes to be readily alkali soluble when it is irradiated with 1% ultraviolet rays and deep ultraviolet rays is also not clear. However, it is presumed that the reaction shown in the following formula is dominant, and the main components obtained by photolysis of the 72-phosphorus derivative in this way are ξ, which is a substance that is easily soluble in alkali, and ξ, which is naturally easily soluble in alkali. In order to reproduce the properties of the condensate and to obtain a resist pattern, a resist solution composed of the above materials is applied onto a suitable substrate such as a silicon wafer, dried to form a uniform resist film, and then exposed to ultraviolet light, In particular, far ultraviolet rays are irradiated in a pattern. Thereafter, the exposed portions are removed using an alkaline developer to obtain a resist pattern. As a coating method, a spin coating method is usually used. Drying is achieved by heating the back side of the substrate with hot air or on a hot plate, and the heating conditions include 80 to 150°C for 1 to 30 minutes.

Examples of developing solutions include aqueous solutions of inorganic alkaline substances such as hydroxide, potassium hydroxide, sodium metasilicate, sodium phosphate, sodium carbonate, and sodium chloride, and organic solutions such as tetramethylammonium hydroxide and choline. An aqueous solution of an alkaline substance is used.

The energy source for decomposing the 0-nitrobenzyloxysilane derivative is ultraviolet light with a wavelength of 200 to 4 QOnm, /I? Far ultraviolet rays of 200 to 300 nm are effective for this purpose. However, as with conventional resist materials, it is of course possible to effectively utilize not only the above-mentioned ultraviolet rays but also '1-rays, X-rays, and visible light.

[Embodiments of the invention]

Specific examples of the present invention will be described below.

Examples 1 to 7 First, the following organic solvents were used to prepare a resist solution.

Solvent Ethyl cellosolve acetate 60 Capacity Thyxylene 10 l N-Butyl acetate 51 N,N-dimethylformamide 5 g To 100 ml of the obtained mixed solvent, add the phenol nucleus-containing polycondensate and O-nitrobenzyloxysilane derivative as shown in Table 1. A resist solution was prepared by dissolving it in the proportion shown. Then, the material that had passed through a 0.5 μm filter was spun onto a 5i02/St wafer at 4000 revolutions. Furthermore, it was dried on a hot plate at 90° C. for 20 minutes to form a resist film having a thickness of 1.0 to 1.5 μm.

Next, pattern exposure was performed using a deep ultraviolet exposure device. The wafer irradiated with light was then immersed in 5 ml of trisodium phosphate aqueous solution (liquid temperature: 24°C) for development. The obtained results are also listed in Table 1.

The insole values of the examples below are the amounts of ingredients added to the solvent tooml,
Unit nigerum.

Sensitivity: Canon Glojection Aligner PLA-
Using 520F/A (CM-250Mivvor),
Exposure time required to obtain the optimal pattern, in units of 2 seconds.

Resolution: Minimum pattern size at proper exposure, unit μm0 Dry etching resistance: S with Freon/oxygen mixed gas
Displayed as the etching rate ratio of SiO2 and resist film when etching iOz. O mark: 8 or more, × mark: 4 or less [Effects of the Invention] As shown in the results in Table 1, the resist material according to the present invention has dry etching resistance properties equivalent to those of conventional naphthoquinone diazide resists, and PMMA, PMIP
Much better than K. Also.

In terms of pattern resolution, it has performance comparable to PMIPK. As described above, the resist material according to the present invention satisfies the characteristics required of a resist material to a high degree, and has a resist property that is extremely advantageous for manufacturing semiconductor devices.

Agent: Patent Attorney Noriyuki Chika (1 other person)

Claims (1)

[Claims] A positive resist material containing as essential components a polycondensate having a phenol nucleus in its molecule and an 0-nitrobenzyloxysilane derivative represented by the following general formula (1); I): (In the formula, R, R, and R may be the same or different, and each represents a hydrogen atom, a halogen atom, a vinyl group, an allyl group, and an unsubstituted or substituted alkyl group having 1 to 10 carbon atoms. ; Alkoxy group having 1 to 10 carbon atoms; Unsubstituted or substituted aryl group Niaryloxy group: Represents a siloxy group, R4 is a hydrogen atom; Unsubstituted or substituted alkyl group having 1 to 10 carbon atoms; Phenyl group; Substituted phenyl group represents,
R5, R', R7゜R8 may be the same or different, and each represents a hydrogen atom; a nitro group; a cyano group;
Hydroxy group; mercapto group; halogen atom; acetyl group; allyl group; alkyl group having 1 to 5 carbon atoms; 1 to 5 carbon atoms
5 alkoxy group; unsubstituted or substituted aryl group; represents an aryloxy group; p+qyr is 0≦pr q
, r≦3.1≦p+q+r≦3. )