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
2001-09-24
2004-04-27
Huff, Mark F. (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Imaging affecting physical property of radiation sensitive...
Radiation sensitive composition or product or process of making
C430S281100, C430S905000, C430S910000, C525S105000
Reexamination Certificate
active
06727039
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a positive resist composition for use in ultra-micro-lithography processes, such as the manufacture of ultra LSI (large-scale integrated circuit) and high capacitance micro chips, and in other photo-fabrication processes. More specifically, the present invention relates to a positive photoresist composition which is improved in exposure margin.
BACKGROUND OF THE INVENTION
The integration of integrated circuits has been heightened more and more in recent years, and the process of ultra-fine pattern comprising line width of half a micrometer or less has been required in the manufacture of semiconductor substrates, such as ultra LSI. For satisfying the necessity, the wavelengths used in the exposure apparatus for photo-lithography have become short waves more and more, the use of short wavelength eximer laser rays (XeCl, KrF, ArF, etc.) of far ultraviolet rays has been discussed now.
Chemically amplified resists are used for the pattern formation of lithography in the above wavelength region.
In general, chemical amplification series resist compositions can be roughly classified into three kinds of a two component system, a two and a half component system and a three component system. A two component system is comprised of a compound which generates an acid by photolysis (hereinafter referred to as a photo-acid generating agent) and a binder resin. The binder resin is a resin having a group which is decomposed by the action of acid and increases the solubility of the resin in an alkali developer (an acid-decomposable group) in the molecule. A two and a half component system is comprised of the combination of the above two component system and a low molecular weight compound having an acid-decomposable group. A three component system is comprised of a photo-acid generating agent, an alkali-soluble resin and the above-described low molecular weight compound.
The chemical amplification series resist compositions are suitably used in photoresists for ultraviolet and far ultraviolet ray irradiation, but it is further necessary to deal with the required characteristics on use. A photoresist composition comprised of a (meth)acrylate resin which is less absorptive than a partially hydroxylated styrene resin in combination with a compound which generates an acid by light is suggested as the photoresist compositions for ArF light sources.
Such photoresist compositions are disclosed, e.g., in JP-A-7-199467 (the term “JP-A” as used herein means an “unexamined published Japanese patent application”) and JP-A-7-252324. A resin having a tertiary carbon organic group bonded to the oxygen of the carboxyl group of the acrylic acid by ester bonding is disclosed in JP-A-6-289615.
Acid-decomposable resins having an acrylic ester and a fumaric ester as repeating structural units are disclosed in JP-A-7-234511, but these resins are insufficient in pattern profiling or adhesion with a substrate, therefore, satisfactory performances are not obtained yet up to the present.
Since the light having a wavelength of 193 nm is often used as the exposure radiation in a lithographic process for producing the device using design rule of 0.18 &mgr;m and 0.13 &mgr;m or less, resist polymers not containing too much ethylenic unsaturated polymers are desired. Further, a resin having incorporated alicyclic hydrocarbon moiety is proposed for the purpose of giving dry etching resistance.
Resist polymers comprising an alkali-soluble group protected with the structure containing an alicyclic group and an acid-sensitive compound containing a structural unit capable of making the alkali-soluble group dissociate by acid to thereby bring into alkali-soluble are disclosed in JP-A-9-73173, JP-A-9-90637 and JP-A-10-161313.
Resist compositions containing an acid-decomposable resin having specific lactone structure are disclosed in JP-A-9-90637, JP-A-10-207069 and JP-A-10-274852.
Although the techniques disclosed in JP-A-10-10739 and JP-A-10-307401 are improved in transparency to the light of wavelength of 193 nm, sensitivity is not necessarily high and resist performances, e.g., resolution, are insufficient in lithography of 0.13 &mgr;m or less.
A chemical amplification series resist composition containing a terpolymer having a specific repeating structural unit having a norbornene structure at the backbone chain is disclosed in JP-A-10-130340.
A resin containing a repeating structural unit having an adamantane structure at the backbone chain and a maleic anhydride as the repeating structural unit is disclosed in JP-A-11-305444.
In these chemical amplification series resist compositions, however, the further improvements of characteristics such as an adhering property, an exposure margin and the fluctuations of sensitivity with the lapse of time have been desired.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to provide a positive photoresist composition excellent in an adhering property, an exposure margin (in particular, the exposure margin of an isolated line) and the fluctuations of sensitivity with the lapse of time in the manufacture of a semiconductor device.
Another object of the present invention is to provide a positive photoresist composition excellent in storage stability.
A further object of the present invention is to provide a positive photoresist composition which hardly generates development defects.
As a result of eager investigations of the materials constituting chemical amplification series positive photoresist compositions, the present inventors have found that the above objects of the present invention can be achieved by an acid-decomposable resin having a repeating structural unit of a specific structure, thus the present invention has been attained.
That is, the above objects of the present invention can be achieved by the following means.
(1) A positive photoresist composition comprising:
(A) a resin containing a repeating structural unit represented by formula (I) below and at least one of repeating structural units represented by formulas (IIa), (IIb) and (IIc) below, the resin being capable of increasing the solubility in an alkali developer by the action of acid; and
(B) a compound capable of generating an acid by irradiation with one of an actinic ray and radiation:
wherein R
11
, R
12
, R
13
and R
14
each represents a hydrogen atom or an alkyl group; and a represents 0 or 1;
wherein R
0
represents a hydrogen atom or a lower alkyl group; A represents a single bond, or a group or combination of two or more groups selected from the group consisting of an alkylene group, a cycloalkylene group, an ether group, a thioether group, a carbonyl group and an ester group; R
1
and R
2
each represents a lower alkyl group; R
3
, R
4
, R
5
, R
6
, R
7
and R
8
each represents a hydrogen atom, a lower alkyl group, a lower alkoxyl group or a halogen atom; R
3
and R
4
, or R
5
and R
6
, may form a carbonyl group together; and R
3
and R
5
may be linked to form an alkylene chain; k and l each represents an integer of from 2 to 5; R
15
represents a lower alkyl group, a lower alkoxyl group or a halogen atom; and m represents an integer of from 0 to 3.
(2) The positive photoresist composition as described in item (1), wherein the resin (A) further contains a repeating structural unit represented by formula (III):
wherein Z
2
represents —O— or —N(R
31
)—; R
31
represents a hydrogen atom, a hydroxyl group, a haloalkyl group, or an —OSO
2
—R
32
group; and R
32
represents an alkyl group, a haloalkyl group, a cycloalkyl group or a camphor residue.
(3) The positive photoresist composition as described in item (1), wherein the resin (A) further contains a repeating structural unit represented by formula (IV):
wherein R
10
represents a hydrogen atom or a methyl group; W represents a single bond, or a group or combination of two or more groups selected from the group consisting of an alkylene group, an ether group, a thioether group, a carbonyl group and an ester group; Ra, Rb, Rc, Rd and Re each represents a hydro
Huff Mark F.
Thornton Yvette C.
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