Organic compounds -- part of the class 532-570 series – Organic compounds – Heterocyclic carbon compounds containing a hetero ring...
Reexamination Certificate
2001-05-31
2002-12-31
Solola, T. A. (Department: 1626)
Organic compounds -- part of the class 532-570 series
Organic compounds
Heterocyclic carbon compounds containing a hetero ring...
C549S273000, C549S323000, C549S328000
Reexamination Certificate
active
06500961
ABSTRACT:
This invention relates to novel lactone compounds useful as monomers to form base resins for use in chemically amplified resist compositions adapted for micropatterning lithography, and a method for preparing the same.
BACKGROUND OF THE INVENTION
While a number of recent efforts are being made to achieve a finer pattern rule in the drive for higher integration and operating speeds in LSI devices, deep-ultraviolet lithography is thought to hold particular promise as the next generation in microfabrication technology. In particular, photolithography using a KrF or ArF excimer laser as the light source is strongly desired to reach the practical level as the micropatterning technique capable of achieving a feature size of 0.3 &mgr;m or less.
The resist materials for use in photolithography using light of an excimer laser, especially ArF excimer laser having a wavelength of 193 nm, are, of course, required to have a high transmittance to light of that wavelength. In addition, they are required to have an etching resistance sufficient to allow for film thickness reduction, a high sensitivity sufficient to eliminate any extra burden on the expensive optical material, and especially, a high resolution sufficient to form a precise micropattern. To meet these requirements, it is crucial to develop a base resin having a high transparency, rigidity and reactivity. None of the currently available polymers satisfy all of these requirements. Practically acceptable resist materials are not yet available.
Known high transparency resins include copolymers of acrylic or methacrylic acid derivatives and polymers containing in the backbone an alicyclic compound derived from a norbornene derivative. All these resins are unsatisfactory. For example, copolymers of acrylic or methacrylic acid derivatives are relatively easy to increase reactivity in that highly reactive monomers can be introduced and acid labile units can be increased as desired, but difficult to increase rigidity because of their backbone structure. On the other hand, the polymers containing an alicyclic compound in the backbone have rigidity within the acceptable range, but are less reactive with acid than poly(meth)acrylate because of their backbone structure, and difficult to increase reactivity because of the low freedom of polymerization. Additionally, since the backbone is highly hydrophobic, these polymers are less adherent when applied to substrates. Therefore, some resist compositions which are formulated using these polymers as the base resin fail to withstand etching although they have satisfactory sensitivity and resolution. Some other resist compositions are highly resistant to etching, but have low sensitivity and low resolution below the practically acceptable level.
SUMMARY OF THE INVENTION
An object of the invention is to provide a novel lactone compound useful as a monomer to form a polymer for use in the formulation of a photoresist composition which exhibits firm adhesion and high transparency when processed by photolithography using light with a wavelength of less than 300 nm, especially ArF excimer laser light as the light source. Another object is to provide a method for preparing the lactone compound.
We have found that a lactone compound of formula (1) can be prepared in high yields by a simple method, that a polymer obtained from this lactone compound has high transparency at the exposure wavelength of an excimer laser, and that a resist composition comprising the polymer as a base resin is improved in adhesion.
The invention provides a lactone compound of the following general formula (1).
Herein R
1
is hydrogen or a straight, branched or cyclic alkyl group of 1 to 6 carbon atoms. R
2
is hydrogen or an acyl or alkoxycarbonyl group of 1 to 15 carbon atoms in which some or all of the hydrogen atoms on the constituent carbon atoms may be substituted with halogen atoms. Z is a divalent organic group of 1 to 15 carbon atoms which forms a lactone ring with the carbonyloxy group. The letter k is 0 or 1, and m is an integer from 0 to 5.
In another aspect, the invention provides a method for preparing a lactone compound of the following general formula (4), comprising effecting addition reaction of a metal enolate of the following general formula (3) to a carbonyl compound of the following general formula (2).
Herein k, m, R
1
and Z are as defined above, and M is Li, Na, K, MgY or ZnY wherein Y is a halogen atom.
In a further aspect, the invention provides a method for preparing a lactone compound of the following general formula (5), comprising subjecting to acylation or alkoxycarbonylation reaction the hydroxyl group on a compound of the following general formula (4).
Herein k, m, R
1
and Z are as defined above, and R
3
is an acyl or alkoxycarbonyl group of 1 to 15 carbon atoms in which some or all of the hydrogen atoms on the constituent carbon atoms may be substituted with halogen atoms.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The lactone compounds of the invention are of the following general formula (1).
Herein R
1
is hydrogen or a straight, branched or cyclic alkyl group of 1 to 6 carbon atoms. Exemplary alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, tert-amyl, n-pentyl, n-hexyl, cyclopentyl, and cyclohexyl.
R
2
is hydrogen or an acyl or alkoxycarbonyl group of 1 to 15 carbon atoms in which some or all of the hydrogen atoms on the constituent carbon atoms may be substituted with halogen atoms. Exemplary of R
2
are formyl, acetyl, propionyl, pivaloyl, methoxycarbonyl, ethoxycarbonyl, tert-butoxycarbonyl, trifluoroacetyl, trichloroacetyl, and 3,3,3-trifluoropropionyl.
Z is a divalent organic group of 1 to 15 carbon atoms which forms a lactone ring with the carbonyloxy group in formula (1). Specifically, the partial structure represented by
is exemplified by lactone structures represented by
and structures having fused to these lactone structures a hydrocarbon ring (such as cycloalkane, cycloalkene or aromatic hydrocarbon) or a heterocyclic ring containing a hetero atom.
The letter k is 0 or 1, and m is an integer from 0 to 5 (i.e., 0≦m≦5), and preferably from 0 to 3.
Illustrative, non-limiting, examples of the lactone compounds of formula (1) are given below.
The inventive lactone compounds can be prepared, for example, by the following process, although the process is not limited thereto.
As seen from the reaction scheme shown below, the desired lactone compound can be prepared by the first step of treating a lactone compound of formula (6) with a base in a solvent in an inert gas atmosphere of nitrogen, argon or the like, forming a metal enolate of formula (3). The enolate solution is then reacted with a carbonyl compound of formula (2) to form a hydroxylactone compound of formula (4).
Preferably 0.8 to 2.0 mol, especially 1.0 to 1.5 mol of the base is used per mol of the lactone compound (6), and 0.8 to 2.0 mol, especially 0.9 to 1.5 mol of the carbonyl compound (2) is used per mol of the lactone compound (6).
Herein, k, m, R
1
, R
2
and Z are as defined above, X is a hydrogen or halogen atom, M is Li, Na, K, MgY or ZnY wherein Y is a halogen atom.
When X is hydrogen, the bases used herein include metal amides such as sodium amide, potassium amide, lithium diisopropylamide, potassium diisopropylamide, lithium dicyclohexylamide, potassium dicyclohexylamide, lithium 2,2,6,6-tetramethylpiperidine, lithium bistrimethylsilylamide, sodium bistrimethylsilylamide, potassium bistrimethylsilylamide, lithium isopropylcyclohexylamide, and bromomagnesium diisopropylamide; alkoxides such as sodium methoxide, sodium ethoxide, lithium methoxide, lithium ethoxide, lithium tert-butoxide, and potassium tert-butoxide; inorganic hydroxides such as sodium hydroxide, lithium hydroxide, potassium hydroxide, barium hydroxide, and tetra-n-butylammonium hydroxide; inorganic carbonates such as sodium carbonate, sodium hydrogen carbonate, lithium carbonate and potassium carbonate; metal hydrides such as sodium hydride, lithium hydride, potassium hydride, and cal
Hasegawa Koji
Hatakeyama Jun
Kinsho Takeshi
Nakashima Mutsuo
Nishi Tsunehiro
Millen White Zelano & Branigan P.C.
Shin-Etsu Chemical Co. , Ltd.
Solola T. A.
LandOfFree
Lactone compounds having alicyclic structure and their... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Lactone compounds having alicyclic structure and their..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Lactone compounds having alicyclic structure and their... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2922755