JPH0354334B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel material related to so-called lithography in which images are formed using radiation, and a method for forming images using this material.

Lingraphie technology is used for microfabrication, printing, photography,
It is applied in a wide range of technical fields such as semiconductors and dyeing. Although the novel material and image forming method of the present invention can be used in each of these fields, it is particularly useful as a positive resist for use in processes for manufacturing solid-state devices such as semiconductor elements and integrated circuits. In response to the recent demands for higher density, higher speed, and smaller integrated circuits, it has become necessary to form even finer patterns, and new technologies have been developed to replace conventional photolithography using visible to ultraviolet light. It has become an urgent matter. Therefore, lithography techniques using far ultraviolet light, X-rays, electron beams, etc., which have shorter wavelengths than light, are being researched. There are a wide range of performance requirements for this core resist material, including sensitivity, resolution, etching resistance, development tolerance, and stability, but conventionally developed materials and processes fully satisfy all of these performances. There was a strong desire for improved performance. For example, positive resists such as polymethyl methacrylate have good resolution, but have poor sensitivity and etching resistance, which poses practical problems. Further, negative resists such as polyglycidyl methacrylate have high sensitivity and exhibit good throughput, but have poor resolution and dry etching resistance, and improvements are strongly desired. In particular, positive resists generally have poor sensitivity, and the development of new materials has been desired.

As a result of extensive research, the present inventors discovered that a polymer containing a unique repeating unit and a process using the same exhibit excellent properties against the radiation, and thus arrived at the present invention.

That is, the gist of the present invention is the general formula () -C(R ₁ )=C(R ₂ )- () (wherein R ₁ is hydrogen or a C ₁ to C ₃ alkyl group, R ₂
represents a C ₁ to C ₁₀ alkyl group. ) A radiation-sensitive image-forming material characterized by containing a polymer containing the repeating unit represented by It is an image forming method characterized by developing with an organic solvent after image irradiation, and in particular, as the developing solvent, the general formula () (In the formula, R ₃ and R ₄ represent an alkyl group of C ₁ to F ₆ or may form an alicyclic group.) An image forming method using a solvent represented by the following as a main component, and further The image forming method consists in forming a solution using a solvent containing at least one selected from benzene, toluene, and xylene as a main component in the process of forming a thin film, and forming a film from this solution.

In the following description of the present invention, the radiation-sensitive image-forming material used in the present invention contains a polymer containing a repeating unit represented by the above general formula () as an active ingredient.

Such polymers include polymers consisting of only one type of repeating unit represented by the general formula (),
That is, poly(2-butyne), poly(2-pentyne),
Poly(2-hexyne), poly(2-heptyne), poly(2-octyne), poly(2-nonine), poly(2-decyne), poly(2-undecyne), poly(2-dodecyne), poly (2-tridecine), poly(3,3-dimethyl-1-butyne), poly(3-hexyne), poly(3-heptyne), poly(3-octyne), poly(3-nonine), poly(3-heptyne) -Decine),
poly(3-undecyne), poly(3-dodecyne),
Poly(3-tridecine), poly(3-tetradecine), poly(4-octyne), poly(4-nonine),
Poly(4-decyne), poly(4-undecyne), poly(4-dodecyne), poly(4-tridecyne), poly(4-tetradecine), poly(4-pentadecyne), etc., or the above homopolymers are formed. Copolymers of two or more monomers selected from various monomers can be mentioned. These polymers can be synthesized by polymerizing substituted acetylene using a group transition metal catalyst such as molybten chloride (MoCl ₅ ) according to a known method. Showa 58
-32608, Patent Application No. 162398 (1983)].

In the present invention, the above-mentioned polymer is generally used, preferably a polymer having a number average molecular weight of 10,000 or more (GPC method, styrene equivalent), and, if necessary, various known additives selected from benzene, toluene, and xylene. Prepare a coating solution by dissolving it in a solvent containing one or more of these as the main component, and apply it on a substrate such as a silicon wafer, glass, or printed circuit board using various methods, such as a spinner, to form a thin film of the required thickness. do. A certain amount of radiation selected from deep ultraviolet light, X-rays, electron beams, etc. is irradiated onto the image forming material in an imagewise manner depending on the purpose.

Next, it can be developed by a conventional method using a developer containing a solvent represented by the above general formula () as a main component.

As such a developer, a solvent represented by the above general formula (), ie, ascent, methyl ethyl ketone,
Methyl-n-propyl ketone, methyl-iso-propyl ketone, methyl-n-butyl ketone, methyl-iso-butyl ketone, methyl-sec-butyl ketone, methyl-t-butyl ketone, methyl 4-
Methylpentylketone, methyl-n-hexylketone, diethylketone, ethyl-n-propylketone, ethyl-n-butylketone, ethyl-iso
-butyl ketone, ethyl-n-hexyl ketone,
Di-n-propyl ketone, di-iso-propyl ketone, n-propyl-isobutyl ketone, iso-propyl-n-butyl ketone, isopropyl-iso-
Butyl ketone, n-propyl-n-pentyl ketone, n-propyl-n-hexyl ketone, di-n
-butyl ketone, di-iso-butyl ketone, n-
Butyl-n-hexyl ketone, di-n-pentyl ketone, cyclohexanone, cyclopentanone,
Examples include cycloheptanone and the like alone or a mixture of two or more selected from these. In addition, with these solvents as the main components, esters such as ethyl acetate, alcohols such as n-BnOH, cellosolves such as n-propyl cellosolve, cellosolve esters such as ethyl cellosolve acetate, etc. are mixed. It is also possible to use a However, preferred examples include acetone, methyl ethyl ketone, methyl-iso-butyl ketone, and the like.

Images formed in this way have good resolution;
Fine patterns from microns to submicrons could be reproduced.

It was also found that the sensitivity is about twice as high as that of polymethyl methacrylate, which is a commonly used positive type polymer, and exhibits extremely high performance.

EXAMPLES Next, the present invention and its effects will be explained with reference to examples, but the present invention is not limited to these in any way.

Example 1 4.9 g of poly(2-octyne) (n=7.89×10 ⁴ , w/n=1.8) polymerized using a MoCl ₅ catalyst
A solution was prepared by dissolving this in 100 ml of xylene, and spin coating was performed on a silicon wafer at a rotation speed of 4000 rpm to form a 0.9 μm thin film. Observation of the surface condition using a surface roughness meter revealed that an extremely uniform coating film could be formed.

Using a mask made of Si ₃ N ₄ as a substrate material and gold as an X-ray absorber, AlK rays are used as an X-ray source.
Irradiation was performed at 400 mJ/cm ² . After irradiation, it was immersed in methyl ethyl ketone at 20° C. for 1 minute and developed. As a result of observation using a scanning electron microscope, a fine pattern with a line width and spacing of 0.5 μm could be reproduced.

For comparison, a similar test using polymethyl methacrylate (PMMA) resulted in a distance of 800 m.
Irradiation of J/cm ² was required.

Example 2 The solution prepared in Example 1 was spin-coated onto a silicon wafer at a rotation speed of 4000 rpm.
A thin film of 0.9 μm was formed. After prebaking at 90°C for 30 minutes, a glass mask on which a resolution test pattern was formed was placed in close contact.

Next, deep ultraviolet rays were irradiated for 30 seconds using a 500WXe-Hg lamp as a light source. After irradiation, the film was developed by immersing it in methyl ethyl ketone at 20°C for 1 minute. As a result of observation using a scanning electron microscope, a sharp image of 0.8 μm was formed.

Example 3 Poly(2-decyne) (n=6.05×10 ⁴ , w/n=
1.9) and was similarly irradiated with far ultraviolet rays for 30 seconds.
As a result of developing under the same conditions, a sharp micro resist pattern was formed.

Example 4 As a result of carrying out the same lithography process using toluene as a solvent instead of xylene in Example 2,
A fine pattern almost equivalent to that of Example 2 could be reproduced.

Example 5 As a result of carrying out the same procedure as in Example 2 using acetone as a developer instead of methyl ethyl ketone, a resist image almost equivalent to that of Example 2 was reproduced.

Example 6 The same procedure was carried out using methyl isobutyl ketone as a developer instead of methyl ethyl ketone in Example 2, and as a result, a resist image almost equivalent to that of Example 2 was obtained.

Example 7 The same procedure was carried out using cyclohexanone as a developer instead of methyl ethyl ketone in Example 2, and as a result, a resist image almost equivalent to that of Example 2 was obtained.

Example 8 Poly(3,3-dimethyl-1-butyne) (n=2.18×
10 ⁴ , w/n=1.7) and was similarly irradiated with deep ultraviolet rays for 50 seconds. As a result of processing under similar conditions,
A sharp micro resist pattern was formed.

Claims (1)

[Claims] 1 General formula () (In the formula, R ₁ is hydrogen or a C ₁ to C ₃ alkyl group,
R ₂ represents a C ₁ to C ₁₀ alkyl group) A radiation-sensitive image-forming material containing a polymer having a repeating unit represented by: 2 General formula () (In the formula, R ₁ is hydrogen or a C ₁ to C ₃ alkyl group,
R ₂ represents an alkyl group from C ₁ to C ₁₀ ) A thin film is formed from a radiation-sensitive imaging material containing as an active ingredient a polymer having a repeating unit of An image forming method characterized by developing with. 3 The organic solvent has the general formula () (In the formula, R ₃ and R ₄ may represent a C ₁ to C ₆ alkyl group or may form an alicyclic group) as a main component. Image forming method 4 according to item 2: A patent claim in which the thin film is formed from a solution of a radiation-sensitive image forming material dissolved in at least one solvent selected from xylene, toluene, and benzene. The image forming method according to item 2.