JPH0332783B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an image sharpness enhancer for a differential solution rate developer and a developing composition containing the same. Currently, compounds that are sensitive to energy rays such as visible light, ultraviolet rays, far ultraviolet rays, X-rays, and electron beams are used in many fields, and are widely used in industrial applications such as printing, paints, and photoresists, especially in the printing industry. It plays an important role as a pattern forming material in the semiconductor industry. In general, these pattern-forming materials include, for example, alkyl acrylates, alkyl methacrylates, halogenoalkyl acrylates (especially fluoroalkyl acrylates), halogenoalkyl methacrylates (especially fluoroalkyl methacrylates), vinyl cinnamate, vinyl alcohol, etc. alone or Copolymers, novolak resins containing azide compounds, natural rubber, cyclized polyisoprene, silane compounds, chalcogenite glasses, etc. are being considered. These compounds are used as an aqueous or organic solution, and are coated onto the target substrate, dried, and the solvent is evaporated to obtain a film.The film is then irradiated with energy rays to draw a pattern, and then developed. By doing so, a pattern is formed on the coating of the substrate. As the developer, solvents with significantly different dissolution rates are used, taking advantage of the difference in dissolution rate between areas irradiated with energy rays and areas not irradiated with energy rays in the film of the photosensitive compound. A developer suitable for the photosensitive compound is used. However, in the recent printing industry, even greater clarity is required.Furthermore, in the semiconductor industry, patterns are becoming finer as weight reduction and capacity increases, and there is an increasing demand for faithful and clear transfer of patterns. has been done. However, with conventional developing solutions, the pattern after development is poor and scum is generated, making it difficult to meet such demands. In order to prevent the occurrence of such a state, efforts have been made to increase the developing temperature, use a strong developer, or lengthen the developing time.
However, when developing under such severe conditions, the pattern often collapses. An object of the present invention is to provide an image sharpness enhancer that enables faithful and clear transfer under normal development conditions. The present inventor has discovered that the object of the present invention can be achieved by adding a small amount of a specific compound to a developer commonly used as a dissolution rate differential developer. That is, the present invention relates to fluorine-containing carboxylic acids, ammonium salts thereof, or primary to 3 carbon atoms having 1 to 6 carbon atoms.
The present invention relates to an image sharpness enhancer for a differential solubility developer containing a class amine salt as an active ingredient. According to the present invention, particularly when obtaining a fine pattern, the pattern is excellent in sharpness, little or no scum occurs, and it is possible to perform faithful and clear transfer. Furthermore, when the remaining coating is removed from the substrate with a solvent after transfer, it has the excellent effect of not leaving traces of the coating. Examples of the fluorine-containing carboxylic acid used in the present invention include various compounds that are hydrocarbons having a COOH group or derivatives thereof, in which a portion of the hydrogen atoms are substituted with fluorine atoms. _Preferred ^specific _{examples include} ^the _{formula :} X ₍ CF _{2 ) lCOOH} CF ₂ CF ₂ O [CF (CF ₃ ) CF ₂ O] nCF (CF ₃ )
COOH (X is hydrogen, fluorine, CF ₃ CHF, (CF ₃ ) ₂ CH or (CF ₃ ) ₂ CF, R ¹ and R ² are hydrogen or carbon number 1 to
6 alkyl group, l is 1 to 10, m is 0 to 10, provided that when X is hydrogen, m is 1 to 10, n is 0 to 3, and a part of fluorine in the formula or other than COOH group A part of the hydrogen may be substituted with a halogen other than fluorine. ) can be exemplified. In addition, examples of halogens other than fluorine include chlorine and bromine. In the present invention, in addition to the above-mentioned fluorine-containing carboxylic acid, ammonium salts thereof or primary carboxylic acids having 1 to 6 carbon atoms are used.
Grade to tertiary amine salts can also be used. Examples of amines include methylamine, ethylamine, butylamine, hexylamine, dimethylamine, diisopropylamine, trimethylamine, triethylamine, and the like. In the present invention, a fluorine-containing carboxylic acid or an ammonium salt thereof or a primary to
If the amount of tertiary amine salt added is too large, it may reduce the sensitivity of the photosensitive compound film, cause the fine pattern to rise above the substrate, or cause the film to peel off, so it is necessary to keep it in a small amount. The amount added is usually about 0.001 to 4% (by weight, hereinafter the same) in the developer, preferably about 0.005 to 2%. The image sharpness enhancer of the present invention can be added to a conventionally known solution rate differential developer. Such conventional developers are comprised of various known solvents. Examples of such solvents include aqueous solutions such as alkalis;
Hydrocarbons such as cyclohexane, heptane, and toluene, halogenated hydrocarbons such as chloroform and methylene chloride, ketones such as methyl ethyl ketone and methyl isobutyl ketone, alcohols such as ethanol and isopropanol, esters such as ethyl acetate and isoamyl acetate, and ethers such as tetrahydrofuran. , and various other solvents such as dimethylformamide. These solvents can be used as a developer, either alone or as a mixture, and are appropriately selected depending on the molecular weight of the photosensitive compound, desired sensitivity, etc., and the developing temperature and time are also appropriately selected depending on the type of developer and the molecular weight of the polymer. determined. Development with the developing composition containing the image sharpness enhancer of the present invention is as follows:
The development may be carried out under the development conditions of a conventionally known dissolution rate differential developer depending on the photosensitive compound described above, or under conditions in the vicinity thereof. After development, rinse, dry,
In some cases, a desired pattern is formed by firing. Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples, but the present invention is not limited only to these Examples. Example 1 Poly-2,2,3,4,4,4- with a molecular weight of 800,000
Hexafluorobutyl methacrylate (PFBM)
An 8% methyl isobutyl ketone (MIBK) solution was used as a resist solution, and this was spin-coated onto a silicon wafer to a film thickness of 0.45 μm. Then 30 at 140℃
Prebaking was performed for a minute to evaporate the solvent and obtain a resist film. Next, an accelerating voltage was applied to the resist film using an ERE-302 electron beam lithography system (manufactured by Elionix Co., Ltd.).
An electron beam of 20 KV and a current density of 1×10 ⁻⁹ A/cm ² was irradiated with various irradiation times to draw lines and spaces of 32 μ. This sample was
(CF ₂ CF ₂ ) ₃ MIBK with 0.2% by weight of COOH added:
Develop by immersing it in a developer solution with IPA (isopropanol) at 1:150 (volume ratio) for 120 seconds, then immediately transfer it to IPA.
Dip and wash for 60 seconds. The sensitivity of the resist film was 4×10 ⁻⁷ C/cm ² and the γ value was 4.5. For comparison, a pattern (Comparative Example 1) was obtained in the same manner as in Example 1 except that H(CF ₂ CF ₂ ) ₃ COOH was not added. Examples 2 to 5 Resist patterns were obtained in the same manner as in Example 1 except that the fluorine-containing carboxylic acids listed in Table 1 were used. The characteristics of the obtained resist pattern are also shown in Table 1. All of the patterns obtained had a clearer cross section than when using a developer to which no fluorine-containing carboxylic acid was added, and almost no scum was observed. Reference Example 1 A resist pattern was obtained in the same manner as in Example 2 except that fluorine-containing alcohol (HCF ₂ CF ₂ CH ₂ OH) was used instead of fluorine-containing carboxylic acid, and its characteristics are also shown in Table 1. show. Table 1 shows the results of examining the sharpness and adhesion of the resist patterns obtained in Examples 1 to 5, Comparative Example 1, and Reference Example 1. In the table, ○ means good and ◎ means excellent.

【table】

[Table] Examples 6 to 7 Coating was carried out in the same manner as in Example 1 using a 10% methyl cellosolve solution of polymethyl methacrylate for photoresists as a resist solution. then 170
Prebaking was performed at ℃ for 30 minutes to evaporate the solvent and obtain a resist film. Next, in the same manner as in Example 1, an electron beam with an acceleration voltage of 20 KV and a current density of 1×10 ^-8 A/cm ² was irradiated with various irradiation times to draw lines and spaces of 32 μm. This sample was mixed with MIBK:IPA in a ratio of 1:1.
The resist pattern was developed by immersing it in a developer solution (volume ratio) for 120 seconds to which additives had been added, and then immediately immersing it in IPA for 60 seconds for cleaning to obtain a resist pattern. Table 2 shows the characteristics of the resist pattern obtained.

【table】

Claims (1)

[Scope of Claims] 1. An image sharpness enhancer for a dissolution rate developer containing a fluorine-containing carboxylic acid, an ammonium salt thereof, or a primary to tertiary amine salt having 1 to 6 carbon atoms as an active ingredient. _{2 Fluorine} ^{- containing} _{carboxylic acid has the formula : 3} CF ₂ CF ₂ O [CF (CF ₃ ) CF ₂ O] nCF (CF ₃ )
COOH (X is hydrogen, fluorine, CF ₃ CHF, (CF ₃ ) ₂ CH or (CF ₃ ) ₂ CF, R ¹ and R ² are hydrogen or carbon number 1 to
6 alkyl group, l is 1 to 10, m is 0 to 10, provided that when X is hydrogen, m is 1 to 10, n is 0 to 3, and a part of fluorine in the formula or other than COOH group A part of the hydrogen may be substituted with a halogen other than fluorine. ) The image sharpness enhancer according to claim 1, which is a compound represented by: