Carboxylic acid derivatives and their synthesis method

Details Carboxylic acid derivatives and their synthesis method Carboxylic acid derivatives and their synthesis method

1999-10-25

2001-11-06

Geist, Gary (Department: 1623)

Organic compounds -- part of the class 532-570 series

Organic compounds

Cyclopentanohydrophenanthrene ring system containing

C552S555000, C552S502000, C560S116000, C560S117000, C560S118000, C560S120000, C560S129000

Reexamination Certificate

active

06313327

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to carboxylic acid derivatives and their synthesis method and more particularly, to novel carboxylic acid derivatives represented by the following formula I via introduction of some protecting group which can be easily decomposed by acid, including their synthesis method.
wherein, R
1
is an hydrogen atom, an alkyl group or an alkoxy group of 1 to 20 carbon atoms in a linear, branched or cyclic form; R
2
is a carboxy group of 1 to 40 carbon atoms in a linear, branched or cyclic form which is unsubstituted, or substituted into a hydroxy group, an ester group and an ether group.
2. Description of the Related Art
As an additive or active ingredient of a resist, an electronic material, carboxylic acid compounds serve to improve the etching resistance and pattern profile of the resist.
It has been reported that one example of such carboxylic acid derivatives introducing t-butyl group as a protecting group includes t-butyl deoxycholate or t-butyl lithocholate (
Proc. SPIE
3049, 84, 1997).
However, the resist containing such carboxylic acid derivatives has recognized some disadvantages in that the insolubility of basic aqueous solution in a unexposed area cannot be overcome and the resist cannot be easily decomposed by acid.
In consequence, when the resist is developed for the final patterning using developer, the unexposed resist area is etched and this may lead to a poor pattern profile.
SUMMARY OF THE INVENTION
Therefore, an object of this invention is to provide novel carboxylic acid derivatives which have excellent combination of properties such as an easier decomposition by acid than the conventional t-butyl ester compounds including better insolubility in basic aqueous solution, so as to improve the etching resistance and pattern profile in a resist.
Another object of this invention is to provide a method for synthesizing the carboxylic acid derivatives.
To achieve the aforementioned objective, the carboxylic acid derivatives of this invention is characterized by the following formula I.
wherein, R
1
is an hydrogen atom, an alkyl group or an alkoxy group of 1 to 20 carbon atoms in a linear, branched or cylic form; R
2
is a carboxy group of 1 to 40 carbon atoms in a linear, branched or cyclic form which is unsubstituted, or substituted into a hydroxy group, an ester group and an ether group.
Further, this invention is characterized by a method of synthesizing the carboxylic acid derivatives represented by the formula I via reaction between a halogen compound represented by the following formula II and a carboxylic acid compound represented by the following formula III in the presence of a basic catalyst.
Formula II
R
1
—CHX
2
Wherein, R
1
is the same as defined above; X is F, Cl, Br or I.
Formula III
R
2
—H
Wherein, R
2
is the same as defined above.
DETAILED DESCRIPTION OF THE INVENTION
The carboxylic acid derivatives of this invention is synthesized via one-step reaction between a halogen compound represented by the compound II and a carboxylic acid compound represented by the formula III which are dissolved in an appropriate solvent and stirred with the slow addition of the basic catalyst.
Hence, the examples of the basic catalyst includes any of the general primary, secondary or tertiary amines, pyridines, organic metals or metals. However, in consideration of the fact that the base catalyst should contain a small amount of metal impurities as an electronic material, it is preferred that amine derivatives as organic basic catalyst is employed instead of metal catalysts. The method for synthesizing the carboxylic acid derivatives of this invention can be represented by the following scheme 1:
Wherein, R
1
, R
2
and X are the same as defined above.
According to this invention, the halogen compound represented by the formula II is 1,1-dihaloalkane or 1,1-dihaloalkyl alkyl ether, as defined above. The detailed examples of the halogen compound include dibromomethane, 1,1-dibromopropane, 1,1-dichloromethyl methyl ether and 1,1-dichloromethyl 2-norbornyl ether; among them, the reactability of 1,1-dibromopropane is somewhat poor than other halogen compounds.
From the carboxylic acid represented by the formula III of this invention, a majority of the aforementioned functional groups do not affect the reaction process. The detailed examples of functional group in the carboxylic acid include a hydroxy group, ester group, ether group, amide group, epoxy group, amino group, halogen group, lactone group, anhydride group and sulfide group. One or more of the functional groups in the carboxylic acid does not affect the reaction.
Reaction is generally performed at −80 to 150° C. If the reaction temperature is extremely low, the starting materials are not well stirred. By contrast, if the reaction temperature is extremely high, some by-products may be generated.
Meantime, it is preferred that the reaction is performed for 0.5 to 15 hours.
It is preferred that 1.5 to 3.0 equivalents of the carboxylic acid represented by the formula III is employed to the halogen compound represented by the formula II, more preferably in the range of 1.8 to 2.2 equivalents.
In case of synthesizing the carboxylic acid derivatives using the halogen compound, the reaction solvents includes dichloromethane, chloroform, carbon tetrachloride. Acetonitrile, ethylacetate, ethylether, dioxane, dimethyl formamide, dimethyl acetamide, ethanol, methanol, isopropanol or acetone, among them, it is preferred that dichloromethane and dimethyl formamide are employed. Hence, if any solvent can dissolve the halogen compound represented by the formula II and carboxylic acid represented by the formula III or can be dissolved in the reaction mixture without dissolving these starting materials, there are no special restriction in using the solvent.
Based on the carboxylic acid derivatives, so synthesized by the above mentioned, a photoresist composition can be prepared using a basic resin, photo-acid generator, and some additive. Hence, the carboxylic acid derivatives serves to improve various properties such as etching resistance, adhesiveness, pattern profile, resolution and exposure energy.
From the newly synthesized carboxylic acid derivatives of this invention, the reaction mechanism of deoxycholic acid derivatives decomposed by strong acid is shown in the following scheme 2.
From the above scheme 2, the deoxycholic acid derivatives has an extremely low solubility to basic aqueous solution but the deoxycholic acid generated form the acid-decomposition has an extremely high solubility to basic aqueous solution.
Under the above principle, the deoxycholic acid derivative in a chemical-amplified resist function not only as a dissolution inhibitor on basic aqueous solution in the unexposed area but also as a dissolution promoter on basic aqueous solution in the exposed area due to formation of the deoxycholic acid.


REFERENCES:
Schaap, Formation of stable bicyclic 1,2-Dioxetanes from the addition of single oxygen to p-dioxene and 1,3-dioxole, May 1971, Tetrahedron Letters, and pp. 11757-60.*
“Limits To Etch Resistance For 193-nm Single-Layer Resists” by R.R. Kunz e al., Proc. SPIE 2724, pp. 365-376 (1996).
“Recent Advances in 193 nm Single-Layer Photoresists Based on Alternating Copolymers of Cycloolefins” by F.M. Houlihan et al., Proc. SPIE 3049, pp. 84-91 (1997).

Affiliated with

Also associated with

Rating

Carboxylic acid derivatives and their synthesis method does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Carboxylic acid derivatives and their synthesis method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Carboxylic acid derivatives and their synthesis method will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2583998