Radiation imagery chemistry: process – composition – or product th – Imaging affecting physical property of radiation sensitive... – Radiation sensitive composition or product or process of making
Reexamination Certificate
2001-07-12
2004-02-17
Baxter, Janet (Department: 1753)
Radiation imagery chemistry: process, composition, or product th
Imaging affecting physical property of radiation sensitive...
Radiation sensitive composition or product or process of making
C430S270100, C430S905000, C430S919000, C564S305000
Reexamination Certificate
active
06692897
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a positive resist composition used for lithographic printing plates, semiconductor production processes, such as IC, etc., productions of circuit substrates for liquid crystals, thermal heads, etc., and further other photofabrication processes. Particularly, the positive photoresist composition of the invention functions by high-energy radiations such as far-ultraviolet rays (including excimer laser light, etc.), electron rays, X-rays, and radiations, and are suitably used for the production of semiconductor integrated circuits.
BACKGROUND OF THE INVENTION
Hitherto, in the production processes of IC, LSI, etc., fine working by a lithography using a photoresist composition has been carried out. Recently, with the high-integration of integrated circuits, the formation of hyperfine patterns of a sub-micron region and a quarter micron region has been required. With the requirement, the light-exposure wavelength tends to become shorter wavelength such as from g line to i line and further an excimer laser light. At present, a lithography using an excimer laser light has become the important working technique in the field, and a resist suitable for such an excimer laser lithographic process, a chemically amplified type resist has been employed.
The chemically amplified type resist composition is a material of forming an acid at the exposed portions by the irradiation of radiations such as a far-ultraviolet light, etc., and by changing the solubility of the irradiated portions by the active radiation and the non-exposed portions in a developer by the reaction using the acid as a catalyst, patterns are formed on a substrate. The chemical amplified type resist has the advantages of having a high resistance and a high resolution, and capable of forming images by a compound generating an acid by the irradiation of small amount of radiations (hereinafter, the compound is referred to as “photoacid generator”).
The above-described chemically amplified resist can be largely classified into (1) a three-component system made of an alkali-soluble resin, a photoacid generator, and a dissolution-inhibiting compound to the alkali-soluble resin and having an acid-decomposing group, (2) a two-component system made of a resin having a group, which becomes alkali soluble by being decomposed by the reaction acid, and a photoacid generator, and (3) a hybrid system made of a resin having a group, which becomes alkali soluble by being decomposed by the reaction acid, a low-molecular dissolution inhibiting compound having an acid decomposing group, and a photoacid generator. In these positive-working chemically amplified resists of the two-component system, the three-component system, and the hybrid system, an acid is generated from the photoacid generator by light exposure, and after heat treatment, by developing, resist patterns are obtained.
In the lithography using the chemically amplified type resist, a photoresist excellent in the characteristics such as the sensitivity, the resolution, the profile, the coating property, the dry etching resistance, the adhesion, the substrate dependence, the stability to the environment (for example, the resist dimensional stability by the fluctuation of the setting time of the resist), the depth of focus (for example, the pattern forming property to the focus gap at the irradiation of radiation), etc., has been demanded and many means for improving the performances by additives have hitherto been proposed.
Because the chemically amplified resists has the specific reaction mechanism, it has been attempted to improve the resist characteristics, particularly the environmental stability by preventing the diffusing property of the generated acid by adding an acid scavenger. For example, it is proposed to add organic amines as disclosed in Japanese Patent Laid-Open Nos. 127369/1993, 232706/1993, 249662/1993, 289322/1993, 317902/1994, 92678/1995, 120929/1995, etc. However, there is a problem that when an amine is added, the resolution is improved but the sensitivity is lowered.
On the other hand, it has been attempted to add various kinds of compounds to the chemically amplified resist composition for the purposes of improving the sensitivity, the improvement of the resist pattern forms. For example, it is disclosed to add carboxylic acids in Japanese Patent Laid-Open Nos. 181279/1993, 92679/1995, 6002/1994, and 6003/1997, U.S. Pat. Nos. 5,955,240 and 5,948,589, European Patent 67951, etc.; it is disclosed to add aromatic polyhydroxy compounds in Japanese Patent Laid-Open Nos. 134345/1992, 217251/1992, 181680/1995, and 211597/1996, U.S. Pat. Nos. 5,688,628 and 5,972,559, etc.; and it is disclosed to add sulfonamide compounds in Japanese Patent Laid-Open Nos. 181263/1993 and 92680/1995.
Furthermore, means for improving the resist characteristics such as the resolution, the light exposure latitude, the adhesion, the substrate dependence, etc., has been provided. For example, the methods of preventing the occurrence of pattern collapsing by the addition of formamide or acetamide compounds are disclosed in Japanese Patent Laid-Open No. 5987/1997, U.S. Pat. No. 5,770,343, and European Patent 749044 and it is disclosed to improve the substrate dependence by adding nitrogen-containing compounds such as succinic acid imide, phthalimide, etc., in Japanese Patent Laid-Open No. 44950/1999. Also, the methods of improving the stability to the environment (for example, the resist dimensional stability by the fluctuation of the setting time of the resist), the resolution, the depth of focus, etc., by the addition of the compounds (photobases) lowering the basic property by light exposure are disclosed in Japanese Patent Laid-Open Nos. 232706/1993, 11835/1994, 242606/1994, 266100/1994, 333851/1995, and 333844/1995, U.S. Pat. No. 5,663,035, and European Patent 677788.
Furthermore, it is disclosed in Japanese Patent Laid-Open No. 297396/1997 to improve the resolution and the depth of focus by adding a specific low-molecular acid-decomposing dissolution-inhibiting compound to a two-component type chemically amplified resist.
However, in the photoresist composition for fat-ultraviolet light exposure, even by the techniques as described above, about the performance of a line edge roughness, there are many unsufficient points, and thus the improvement has been required. In this case, the line edge roughness is that the edges of the interface between the line pattern of a resist and a substrate fluctuates irregularly to the direction perpendicular to the line direction because of the characteristics of the resist. When the pattern is observed from right above, the edge is seen as roughness. The roughness is transferred by the etching step using the resist as a mask to deteriorate the electric characteristics, whereby the yield is lowered.
Particularly, with the resist pattern size becomes a quarter micron or smaller, the requirement of improving the line roughness has been increased but the guideline for the improvement has not yet been disclosed.
As described above, because in the known techniques of the photoresist compositions, a roughness is seen on the edge of a pattern and stable patterns are not obtained, a further improvement has been desired.
SUMMARY OF THE INVENTION
Accordingly, an object of the invention is to provide a positive resist composition capable of giving an excellent resist pattern profile wherein the edge roughness of the pattern is improved and a development defect is also improved.
As the result of intensive investigations on the materials constituting a resist composition in the positive-working amplified system, the present inventors have found that the above-described object can be attained by using a specific nitrogen-containing compound and have accomplished the present invention.
That is, the above-described object can be attained by the constitutions of the invention described below.
(1) A positive resist composition comprising:
(A) a resin having an aliphatic cyclic hydrocarbon group and increasing the solub
Fujimori Toru
Kawabe Yasumasa
Nakao Hajime
Baxter Janet
Thornton Yvette C.
LandOfFree
Positive resist composition does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Positive resist composition, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Positive resist composition will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3289348