GB2398787A - Benzenesulfonyloxyalkyl (methyl)acrylate polymers - Google Patents

Abstract

Benzenesulfonyloxyalkyl (meth)acrylate anti-reflective coating polymers are suitable for use in a semiconductor device during a photolithography process for forming ultrafine patterns using ArF beam radiation. p-Toluenesulfonyloxy-alkyl (meth)acrylates are prepared by reacting p-toluenesulphonyl chloride with a hydroxyalkyl (meth)acrylate in triethylamine. Reaction of these (meth)acrylates with additional (meth)acrylate monomers in solvents such as THF with a suitable initiator yields the polymers of the invention.

Description

a, 2398787

ORGANIC ANTI-REFLECTIVE POLYMER AND PREPARATION THEREOF

i3ACKGRO-UD OF THE INVENTION

Field of the Invention

The present invention relates to an organic anti-reflective coating ("ARC") material which allows the stable formation of ultrafine patterns suitable for 64M, 256M, 1G, 4G and 16G DRAM semiconductor devices. More particularly, the present invention relates to an organic anti-reflective coating material that contains a chromophore with high absorbance at the wavelengths useful for submicrolithography. A layer of said antireflection material can prevent back reflection of light from lower layers or a surface of the semiconductor ship, as well as eliminate the standing waves in the photoresist layer, during a submicrolithographic process using a 193 rim ArF laser light sources. Also, the present invention Is concerned with an anti-reflective coating composition comprising such a material, an anti-reflective coating therefrom and a pr paragon method thereof

Description of the Prior Art

During a submicrolithographic process, one of the most Important processes for fabricating highly integrated semiconductor devices, there Inevitably occur standing waves and reflective notching of the waves due to the optical properties of lower layers coated on the wafer and to changes in the thickness of the photosensitive film applied thereon. In addition, the submicrolithographic process generally suffers from a problem of the CD (critical dimension) being altered by the diffracted light and reflected light from the lower layers.

To overcome these problems, it has been proposed to introduce a film, called an anti-reflective coating, between the substrate and the photosensitive film to prevent light reflection from the lower layer. Largely, anti-reflective coatings are classified into "organic" and "inorganic" by the materials used and into "absorbing" and "interfering" by the operation mechanisms.

An inorganic anti-reflectve coating is used mainly in the process of ultrahme-pattern fommation using i-line radiation with a wavelength of 365 nm. TiN and amorphous carbon have been widely used in light-absorbing coatings, and SiON has been used in light-interfering coatings. The SiON anti-reflective coatings are also adopted for submicrolithographic processes that use KrF light sources.

Recently, extensive and intensive research has been and continues to be directed to the application of organic anti-reflectve coatings for such submicrolithography. In view of the present development status, organic anti-reflective coatings, if they are to be useful, must satisfy the following fundamental requirements: First, during the pattern formation process, the photoresist must not be peeled from the substrate by dissolving in the solvent used in the organic anti-reflective coating. For this reason, the organic anti-reflective coating needs to be designed to form a cross-linked structure, and must not produce chemicals as a byproduct.

Second, acid or amine compounds must not migrate in or out of the antireflective coating. This is because there is a tendency for undercutting at the lower side of the pattern if an acid migrates, and for footing if a base such as an amine migrates.

Third, the anti-reflective coating must have a faster etching speed compared to the photoresist layer so that the etching process can be performed efficiently by utilizing the photoresist layer as a mask.

Finally, the organic anti-reflective coatings should be as thin as possible while playing an excellent role in preventing light reflection.

As various as anti-reflective coatings are, those which are satisfactorily applicable for submicrolithographic processes using ArF light have thus far not been found. As for inorganic anti-reflective coatings, there have been reported no materials which can control interference at the ArF wavelength, that is, 193 nm. In contrast, active research has been undertaken to develop organic materials into superb anti-reflective coatings. In fact, in most cases of submicrolithography, the coating of photosensitive layers is necessarily followed by organic anti-reflective coatings that prevent the standing waves and reflective notching occurring upon light exposure, and that eliminate the influence of the back diffraction and reflection of light from lower layers. Accordingly, the development of such an anti-reflective coating material showing high absorption properties against specific wavelengths is one of the hottest and most urgent issues in the art.

SUMMARY OF THE INVENTION

The present invention overcomes the problems encountered in the prior art and provides a novel organic compound that can be used as an antireflective coating useful for submicrolithography processes using 193 rim ArF laser.

The present invention provides a method for preparing an organic compound that prevents the diffusion and reflection caused by light exposure in submicrolithography.

The present invention further provides an anti-reflective coating composition containing such a diffusion/reflection-preventive compound and a preparation method therefor.

The present invention also provides an anti-reflective coating formed from such a composition and a preparing method thereof.

The polymers of the present invention comprise a monomer with a phenyl group having high absorbance at 193nm, so that the polymer resin absorbs 193nm wavelength light. A cross-linking mechanism using a ring opening reaction is introduced into preferred polymer resins of the invention by adding another monomer having an epoxy structure, so that a cross-linking reaction takes place when coatings of the polymer resins are "hard baked", i.e., heated at a temperature of 100-300 C for 10-1,000 seconds.

Accordingly, a great improvement can be effected in the formation, tightness and dissolution properties of the anti-reflective coatings using polymers of the present invention. Particularly, maximal cross- linking reaction efficiency and storage stability are realized by the present invention. The anti-reflective coating resins of the present invention have superior solubility in all hydrocarbon solvents, in order to form a coating composition, yet are of such high solvent resistance after hard baking that they are not dissolved in any solvent at all. These advantages allow the resins to be coated without any problem to form an anti-reflective coating which prevents undercutting and footing problems when images are formed on the overlying photosensitive layer. Furthermore, coatings made of the acrylate polymers of the invention are higher in etch rate than the photosensitive film coatings, thereby improving the etch selection ratio therebetween.

DETAILED DESCRIPTION OF THE INVENTION

Polymer resins according to the present invention are represented by the following general formula 2: ACHE-C:CH2-CCH2- C-O X C-O Y IC=0 Z 1 1 ( C)n' ICH2)n2 CH3

O OH O=S=0

(general formula 2) wherein, Ra, Rb, and Rc each represents hydrogen or methyl group; Rat represents hydrogen, hydroxy, substituted or unsubstituted, straight or branched C-Cs alkyl, cycloalkyl, alkoxyalkyl or cycloalkoxyalkyl; x, y and z each represents mole fraction of 0.01-0. 99; and n; and n2 each represents an integer of l to 4.

The polymer resins of the present invention are particularly suitable for use in the organic anti-reflective coatings since they comprise a ptosylalkylacrylate monomer having a phenyl group with excellent absorbency of 193nm wavelength radiation.

Preferred monomers comprise a monomer of the following chemical formula 3: i CH 2 =C C =0

O (CH2) o

O AS 0 C13 (general formula 3) wherein, R is hydrogen or methyl group; n is an integer of 2 or 3.

The polymers represented by general formula 2 above can be prepared in accordance with the reaction equation 2 set forth below, wherein, ptosylalkylacrylate- type monomers, hydroxyalkylacrylate-type monomers and methylacrylate-type monomers are polymerized with the aid of an initiator in a solvent. Each of the monomers has a mole fraction ranging from 0.01 to 0.99.

R. Rb Re 1 1 1 CH2=C CH2=C CH2=C 1 1 1 C=0 C=0 C=0 | + | + | general 0 0 0 formula 2 1 1 1 (CH2)n, (CH2)r CH3 1 1

O OH O=S=0

R

(reaction equation 2) wherein, Ra, Rb, and Rat each represents hydrogen or methyl group; Rat represents hydrogen, hydroxy, a substituted or unsubstituted, straight or branched Ci-C5 alkyl, cycloalkyl, alkoxyalkyl or cycloalkoxyalkyl; and no and n2 represents an integer of I to 4.

Conventional radical initiators, preferably 2,2-azobisisobutyronitrile (AIBN), acetylperoxide, laurylperoxide or t-butylperoxide, may be used for initiating the polymerization reaction forming the polymers of general formula 2. Also, conventional solvents may be used for the polymerization, preferably tetrabydrofuran, toluene, benzene, methylethylketone or dioxane. Preferably, the polymerization for the polymers of the general formula 2 is carried out at 50 - 800C.

Semiconductor devices of the present invention may be prepared as described below. The copolymer of general formula I or formula 2 may be dissolved in a suitable solvent alone, or with a cross-linker additive selected from acrolein, ! , diethylacetal and melamine-type cross linkers, at an amount of 0.1 to 30 % by weight.

The solution is filtered and coated on a wafer and then hard-baked to form a cross-linked anti-reflective coating. Semiconductor devices can then be fabricated therefrom in the conventional manner.

Conventional organic solvents may be used in preparing the antireflective coating composition, with preference given to ethyl 3ethoxypropionate, methyl 3-methoxy propionate, cyclohexanone or propyleneglycol methyletheracetate. The solvent is preferably used at an amount of 200 to 5000 % by weight based on the weight of the antireflective coating resin copolymer used.

It has been found that the anti-reflective coatings of the present invention exhibit high performance in photolithography processes for forming ultraDme- patterns using 193 rim ArF radiation. The same was also true of where 248nm KrF, 157nm F2 laser, E-beams, EWE (extremely ultraviolet) and ion beams are used as light sources.

A better understanding of the present invention may be obtained from following examples, which are set forth to illustrate, but are not to be construed to limit, the present invention. Examples I to 14 and 25 are not within the scope of the claimed invention.

EXAMPLE I: Synthesis of p-tosylethvlacrvlate monomer 0.35 mole of p-toluene sulfonylchloride are added to 0.35 mole of tnethylamine. After complete dissolution, 0.3 mole of 2- hydroxyethylacrylate are slowly added in a nitrogen atmosphere. The reaction is continued for more than 24 hours with cooling, and during the reaction, the rate of reaction is checked by TLC. After the completion of the reaction, the mixture is neutralized with IN- sulfuric acid and washed with deionized water, and then the reactant in the organic solvent layer is extracted. The water m the organic solvent is removed with MgS04 to produce the monomer represented by the following chemical formula 1. The yield is 90-95 %. it\

Cab= CH C=0 ( cow)2 o OeS O Cob (chemical formula 1) EXAMPLE 2: Synthesis of p-tosylethvlmethacrylate monomer 0.35mole of p-toluene sulfonylchloride are added to 0.35 mole of triethylamine. After complete dissolution, 0.3mole of 2- hydroxyethylmethacrylate are slowly added in a nitrogen atmosphere. The reaction is continued for more than 24 hours with cooling, and during the reaction, the rate of reaction is checked by TLC. After the completion of the reaction, the mixture is neutralized with IN- sulfuric acid and washed with deionized water, and then the reactant in the organic solvent layer is extracted. the water in the organic solvent is removed with MgS04 to produce the monomer represented by the following chemical formula 2. The yield is 90-95 %.

ICHG

CHz= 1C lc=o 1 H2)2 o O=S50 Cob (chemical formula 2) EXAMPLE III: Synthesis of p-tosvlpropylacrylate monomer The 0.35mole of p-toluene sulfonylchloride are added to 0.35 mole of triethylamine. After complete dissolution, 0.3mole of 2- hydroxypropylacrylate are slowly added in a nitrogen atmosphere. The reaction is continued for more than 24 hours with cooling and during the reaction, the rate of reaction is checked by TLC. After the completion of the reaction, the mixture is neutralized with INsulfuric acid and washed lie with deionized water, and then the reactant in the organic solvent layer is extracted. the water in the organic solvent is removed with MgS04 to produce the monomer represented by the following chemical formula 3. The yield is 90-95 %. l

Cat= ICH lC=o lo ( CFE)3 Ol O=S50 CH3 (chemical formula 3) EXAMPLE IV: SYnthesis of p-tosylpropylmethacrylate monomer The 0.35mole of p-toluene sulfonylchloride are added to 0.35 mole of triethylamine. After complete dissolution, 0.3mole of 2- hydroxypropylmethacrylate are slowly added in a nitrogen atmosphere. The reaction is continued for more than 24 hours with cooling, and during the reaction, the rate of reaction is checked by TLC. After the completion of the reaction, the mixture is neutralized with INsulfuric acid and washed with deionized water, and then the reactant in the organic solvent layer is extracted. The water in the organic solvent is removed with MgS04 to produce the monomer represented by the following chemical formula 4. The yield is 90-95 %. Ic CH2=C jC=0 1

( Cat)3 OeSO CH3 (chemical formula 4) EXAMPLE V: Synthesis of the copolymer poly (tosylethylacrylate hydroxvethylacrylate-methylmethacrylate- clycldylmethacrylate

- -

In a 500 ml round-bottom flask are placed 0.3 mole of tosylethylacrylate, 0.25 mole of hydroxyethylacrylate, 0.1 mole of methylmethacrylate, and 0. 3 mole of glycidylmethacrylate. This mixture is added to 300 g of separately prepared tetrahydrofuran (THE) with stirring and mixed completely. Thereafter, in the presence of 0.1 g - 3 g of 2,2-azobisisobutyronitnle (AIBN), the reaction mixture is subjected to polymerization at 60-75 C for 5-20 hours in a nitrogen atmosphere. After completion of this polymerization, the solution is precipitated in ethyl ether or normal-hexane and the precipitate is filtered and dried to produce poly (tosylethylacrylate- hydroxyethylacrylatemethylmethacrylate-glycidylmethacrylate) represented by the following chemical formula 5, at a yield of 65-70 %.

ECU-C - CH2-CACHE C O 0 1 O (oH2)2 (COHEN Cal Cgo So CHe (chemical formula 5) EXAMPLE VI: Synthesis of the copolymer poly (tosylethylacrylate hvdroxvethylmethacrylate-methylmethacrylate- c1 ycidylmethacrylate! In a 500 ml round-bottom flask are placed 0.33 mole of tosylethylacrylate, 0.2 mole of hydroxyethylmethacrylate, 0.15 mole of methylmethacrylate, and 0.3 mole of glycidylmethacrylate. This mixture is added to 300 g of separately prepared tetrahydrofuran (THE) with stirring and mixed completely. Thereafter, in the presence of 0.1 g - 3 g of AIBN, the reaction mixture is subjected to polymerization at 60-75 C for 5- hours in a nitrogen atmosphere. After completion of this polymerization, the solution is precipitated in ethylether or normal-hexane and the precipitate is filtered and dried to produce poly (tosylethylacry]ate-hydroxyethylmethacrylate- methylmethacrylateglycidylmethacrylate) represented by the following chemical formula 6, at a yield of 65- 70%.

ACHE-IC - CH2-7CHz-Ct ACHE-C: Coo 03 iC= .2 iC=0 0 1 C 07 1 ,0,0 H2) 2 ECHO CH3 CH2 OH jO O=S50 cH3 (chemical formula 6) EXAMPLE VII: Svnthesis of the copolymer polv (tosvlethylacrylate hydroxvpropylacrylate-methylmethacrylate- alycidylmethacrVlate) In a SOO ml round-bottom flask are placed 0.3 mole of tosylethylacrylate, 0.25 mole of hydroxypropylacrylate, 0.1 mole of methylmethacrylate, and 0. 3 mole of glycidylmethacrylate. This mixture is added to 300 g of separately prepared tetrahydrofuran (THE) with stirring and mixed completely. Thereafter, in the presence of 0.1 g - 3 g of AIBN, the reaction mixture is subjected to polymerization at 60-75 C for 5- hours in a nitrogen atmosphere. After completion of this polymerization, the solution is precipitated in ethyl ether or normal-hexane and the precipitate is filtered and dried to produce poly (tosylethylacrylate-hydroxypropylacrylate-methylmethacrylateglycidylmethacrylate) represented by the following chemical formula 7, at a yield of 65- %.

ACHE-iCH2-CH2-CCH2-ó: C=0 03 C- z5 C=0 of C= 03 (CH2)2 (CHEF CH3 CH2

OH O=S=0 CH3

(chemical formula 7) EXAMPLE VIII: Svnthesis of the copolymer polv (tosylethv!acrylate hydroxpropylmethacrylate-methylmethacrv]ateglycidylmethacrylate! In a 500 ml round-bottom flask are placed 0.3 mole of tosylethylacrylate, 0.23 mole of hydroxypropylmethacrylate, 0.1 mole of methylmethacrylate, and 0.3 mole of glycidylmethacrylate. This mixture is added to 300 g of separately prepared tetraLydrofuran (TlIF) with stirring and mixed completely. Thereafter, in the presence of 0.1 g - 3 g of AIBN, the reaction mixture is subjected to polymerization at 60-75 C for 5hours in a nitrogen atmosphere. After completion of this polymerization, the solution is precipitated in ethyl ether or normal-hexane and the precipitate is filtered and dried to produce poly (tosylethylacrylate-hydroxypropylmethacrylate- methylmethacrylateglycidylmethacrylate) represented by the following chemical formula 8, at a yield of 65- 70%.

C -C CH2- CH2-C C*- C- - 223( C 03 O o O O ( I H2)2 ( I?3 Cat Cat

OH HO O-So

CHa (chemical formula 8) EXAMPLE IX: Synthesis of the copolymer pole (tosvlethYlacrylate hvdroxybutylacrylate-methvlmethacrylateglycidVlmethacrylate! In a 500 ml round-bottom flask are placed 0.3 mole of tosylethylacrylate, 0.2 mole of hydroxybutylacrylate, 0.1 mole of methylmethacrylate, and 0.3 mole of glycidylmethacrylate. This mixture is added to 300 g of separately prepared tetrahydrofuran (THE) with sterns and mixed completely. Thereafter, in the presence of 0.1 g - 3 g of AIBN, the reaction mixture is subjected to polymerization at 60-75 C for 5hours in a nitrogen atmosphere. After completion of this polymerization, the solution is precipitated in ethyl ether or normal-hexane and the precipitate Is filtered and dried to produce poly (tosylethylacry]ate-hydroxybutylacrylate-methylmethacrylateglycidylmethacrylate) represented by the following chemical formula 9, at a yield of 65- 70%. ( )

C-O -

( I H2)2 CHz 8H3 CO' H2

OH LO

O-SO

CH3 (chemical formula 9) EXAMPLE X: Synthesis of the copolymer poly (tosylethylmethacrylate hydroxyethylacrylate-methylmethacrylateglycldylmethacrylate! In a 500 ml round-bottom flask are placed 0.3 mole of tosylethylmethacrylate, 0.25 mode of hydroxyethylacrylate, 0.15 mole of methylmethacrylate, and 0.3 mole of glycidylmethacrylate. This mixture is added to 300 g of separately prepared tekahydrofuran (THE) with stirring and mixed completely.

Thereafter, In the presence of 0.1 g - 3 g of 2,2-azobisisobutyronitrile (AIBN), the reaction mixture is subjected to polymerization at 60-75 C for 5-20 hours in a nikogen atmosphere. After completion of this polymerization, the solution is precipitated in ethyl ether or normalhexane and the precipitate is filtered and dried to produce poly (tosylethylmethacrylate-hydroxyethylacrylate-methylmethacrylateglycidylmethacrylate) represented by the following chemical formula 10, at a yield of 65-70 %.

iCH2-óWCH2-C - CH2- iCCH2-C: C=0 03 IC-O o 2s C- o IC- 03 1 1 1 1 (7HZ)2 (CH2)2 CH3 CH2 o OH to

O-S-O

CH3 (chemical formula 10) EXAMPLE XI: SYnthesis of the copolymer poly (tosylethylmethacrylate hydroxyethylmethacrylate-methylacrylateclvcidylmethacrylate! In a 500 ml round-bottom flask are placed 0.3 mole of tosylethylmethacrylate, 0.2 mole of hydroxyethylmethacrylate, 0.15 mole of ( *N methylacrylate, and 0.3 mole of glycidylmethacrylate. This mixture is added to 300 g of separately prepared tetraDydrofuran (THE) with stirring and mixed completely.

Thereafter, in the presence of 0.1 g - 3 g of AIBN, the reaction mixture is subjected to polymerization at 60-75 C for 5-20 hours in a nitrogen atmosphere. After completion of this polymerization, the solution is precipitated in ethylether or normal-hexane and the precipitate is filtered and dried to produce poly (tosyle*lylmethacrylatehydroxyethylmethacrylate-methylacrylate-glycidylmethacrylate) represented by the following chemical formula l l, at a yield of 65-70 %.

ECU-C:C-Cat Hi C: C=0 3 C=0 02 IC- Is IC- 03

O O O O

( :*)z (C)2 CH3 C*

OH LO

OUTDO

CHID (chemical formula 11) EXAMPLE XII: Synthesis of the copolymer polv (tosvlethylmethacrylate hydroxYpropYlacrYlate-methYlmethacrYlateglycidYlmethacr-Ylate! In a 500 ml round-bottom flask are placed 0.3 mole of tosylethylmethacrylate, 0.25 mole of hydroxypropylacrylate, 0.15 mole of methylmethacrylate, and 0.3 mole of glycidylmethacrylate. This mixture is added to 300 g of separately prepared tetrahydrofuran (THE) with stirring and mixed completely.

Thereafter, in the presence of 0.1 g - 3 g of AIBN, the reaction mixture is subjected to polymerization at 60-75 C for 5-20 hours in a nitrogen atmosphere. After completion of this polymerization, the solution is precipitated in ethyl ether or normal-hexane and the precipitate is filtered and dried to produce poly (tosylethylmethacrylatehydroxypropylacrylate-methylmethacrylate-glycidylmethacrylate) represented by the following chemical formula 12, at a yield of 65-70 %. (-' /

CHIT CH2-CH2_CH2-83 (O8)2 (CH2)3 CH3 8:O O=S50 CH3 (chemical formula 12) EXAMPLE XIII: Synthesis of the copolymer poly (tosylethylmethacrvlate hydroxvpropylmethacrylate-methylmethacrylate- glycidylmethacr-ylate! In a 500 ml round-bottom flask are placed 0.3 mole of tosylethylmethacrylate, 0.22 mole of hydroxypropylmethacrylate' 0.15 mode of methylmethacrylate, and 0.3 mole of glycidylmethacrylate. This mixture is added to 300 g of separately prepared tetrabydrofuran (THE? with stirring and mixed completely.

Thereafter, in the presence of 0.1 g - 3 g of AIBN, the reaction mixture is subjected to polymerization at 60-75 C for 5-20 hours in a nitrogen atmosphere. After completion of this polymerization, the solution is precipitated in ethyl ether or normal-hexane and the precipitate is filtered and dried to produce poly (tosylethylmethacrylatehydroxypropylmethacrylate-methylmethacrylate-glycidylmethacrylate) represented by the following chemical formula 13, at a yield of 65-70 %.

CH2-8 CH2-c CH2 C CH2 c t 1: C-O.3 IC=0 022 C- O IC- 3

O O O O

I H2)2 (cH2)3 Cab CH2

OH LO OS=0

cat (chemical formula 13) EXAMPLE XIV: Synthesis of the copolymer polv (tosylethvlmethacrylate hydroxYbutylacrylate-methvlmethacrylateglycidylmethacrylate! In a 500 ml round-boKom flask are placed 0.3 mole of tosylethylmethacrylate, 0.2 Rae mole of hydroxybutylacrylate, 0.1 mole of methylmethacrylate, and 0.3 mole of glycidylmethacrylate. This mixture is added to 300 g of separately prepared tetraLydrofuran (THE) with stirring and mixed completely. Thereafter, in the presence of 0.1 g - 3 g of AIBN, the reaction mixture is subjected to polymerization at 60-75 C for 5hours in a nitrogen atmosphere. After completion of this polymerization, the solution is precipitated in ethyl ether or normal-hexane and the precipitate is filtered and dried to produce poly (tosylethylmethacrylate-hydroxybutylacrylate- methylmethacrylateglycidylmethacrylate) represented by the following chemical formula 14, at a yield of 65- 70%.

ICH3 H CH3 CH3 iCH2-C:C-tC - Cat- iCC-Con C=0 03 IC=0 oz TIC- of IC=O'o

O O O O

( IH2)2 (cHz)4 CH3 CH2

OH LO

OHIO CH3

(chemical formula 14) EXAMPLE XV: Synthesis of the copolymer poly(tosylethylacr-vlate hvdroxvethylacrylate-methylmethacrvlate! In a 500 ml round-bottom flask are placed 0.3 mole of tosylethylacrylate, 0.3 mole of hydroxyethylacrylate and 0.25 mole of methylmethacrylate. This mixture is added to 300 g of separately prepared tetrahydrofuran (THE) with stirring and mixed completely. Thereafter, in the presence of 0.1 g - 3 g of AIBN, the reaction mixture is subjected to polymerization at 60-75 C for 5-20 hours in a nitrogen atmosphere. After completion of this polymerization, the solution Is precipitated in ethyl ether or normalhexane and the precipitate is filtered and dried to produce poly(tosylethylacrylate- hydroxyethylacrylate-methylmethacrylate) represented by the following chemical formula 15, at a yield of 65-70 %. it' )

ACHE-C:CH2-Cl CH2-C: C=0 3 C=0 3 C= 25 ( I H2) 2 ( 1' H2) 2 CH3 1 OH 0=5-O CH3 (chemical formula 15) EXAMPLE XVI: Synthesis of the copolymer poly (tosylethYlacrYlate hydroxyethylmethacrylate-methylmethacrylate! In a 500 ml round-bottom flask are placed 0.33 mole of tosylethylacrylate, 0.35 mole of hydroxyethylmethacrylate and 0.25 mole of methylmethacrylate. This mixture is added to 300 g of separately prepared tetrahydrofuran (THE) with stirring and mixed completely. Thereafter, in the presence of 0.1 g - 3 g of AIBN, the reaction mixture is subjected to polymerization at 60-75 C for 5-20 hours in a nitrogen atmosphere. After completion of this polymerization, the solution is precipitated in ethyl ether or normal-hexane and the precipitate is filtered and dried to produce poly(tosylethylacrylate-hydroxyethylmethacrylate-methylmethacrylate) represented by the following chemical formula 16, at a yield of 65-70 %.

ACHE- H2-C - CH C) IC=0 33 IC=0 o as Cl = as

O O O

( CHz) Z ( 1; H2) 2 CH3 0 OH O=S=0 CH3 (chemical forrnu]a 16) EXAMPLE XVII: Svnthesis of the copolymer poly(tosylethylacrYlate hydroxypropylacrylate-methylmethacrvlate! In a 500 ml round-bottom flask are placed 0.3 mole of tosylethylacrylate, 0.33 () mole of hydroxypropylacrylate and 0.22 mole of methylmethacrylate. This mixture is added to 300 g of separately prepared tetraDydrofuran (THF) with stirring and mixed completely. Thereafter, in the presence of 0.1 g - 3 g of AIBN, the reaction mixture is subjected to polymerization at 60-75 C for 5-20 hours in a nitrogen atmosphere. After completion of this polymerization, the solution is precipitated in ethyl ether or nommal- hexane and the precipitate is filtered and dried to produce poly(tosylethylaclylatehydroxypropylacrylate-methylmethacrylate) represented by the following chemical formula 17, at a yield of 65-70 %.

Nc-:c-c-ócL :=0 a Cl-O o 33 tC Z2 ( Chl2)z ( CFt) 3 cab o OH

ONTO

CH3 (chemical fommula 17) EXAMPLE XVIII: Synthesis of the copolymer polv(tosylethylacrylate hydroxypropylmethacrylate-methylmethacrylate! In a 500 ml round-bottom flask are placed 0.3 mole of tosylethylacrylate, 0.33 mole of hydroxypropylmethacrylate and 0.25 mole of methylmethacrylate. This mixture is added to 300 g of separately prepared tetrahydrofuran (THF) with stirring and mixed completely. Thereafter, in the presence of 0.1 g - 3 g of AIBN, the reaction mixture is subjected to polymerization at 60-75 (: for 5-20 hours in a nitrogen j atmosphere. After completion of this polymerization, the solution is precipitated in ethyl ether or nommal-hexane and the precipitate is filtered and dried to produce poly(tosylethylacrylate-hydroxypropylmethacrylate- methylmethacrylate) represented by the following chemical formula 18, at a yield of 65-70 %. so

I o o o

( I H2)2 ( I H2) 3 CH3

O OH O=SO CH3

(chemical formula 18) EXAMPLE XIX: Synthesis of the copolymer poly (tosylethylacrvlate hvdroxybutylacrylate-methylmethacrylate) In a 500 ml round-bottom flask are placed 0.3 mole of tosylethylacrylate, 0.3 mole of hydroxybutylacrylate and 0.3 mole of methylmethacrylate. This mixture is added to 300 g of separately prepared tetrabydrofuran (THF) with stirring and mixed completely. Thereafter, in the presence of 0.1 g - 3 g of AIBN, the reaction mixture is subjected to polymerization at 60- 75 C for 5-20 hours in a nitrogen atmosphere. After completion of this polymerization, the solution is precipitated in ethyl ether or normal- hexane and the precipitate is filtered and dried to produce poly (tosylethylacrylatehydroxybutylacrylate-methylmethacrylate) represented by the following chemical formula 19, at a yield of 65-70 %. iCH2-C:CHz-CACHE - C: H22 (COH2), 8H3

O OH O=S=0

cat (chemical formula 19) EXAMPLE XX: Synthesis of the copolymer poly(tosylethylmethacrYlate hvdroxyethylacrylate-methylmethacrvlate! In a 500 ml round-bottom flask are placed 0.3 mole of tosy]ethylmethacrylate, 0.25 mole of hydroxyethylacrylate and 0.3 mole of

- (-- )

methylmethacrylate. This mixture is added to 300 g of separately prepared tetrahydrofuran (THF) with stirring and mixed completely. Thereafter, in the presence of 0.1 g - 3 g of AIBN, the reaction mixture is subjected to polymerization at 60-75 C for 5- hours in a nitrogen atmosphere. After completion of this polymerization, the solution is precipitated in ethyl ether or norrna]-hexane and the precipitate is filtered and dried to produce poly(tosylethylrnethacrylatehydroxyethylacrylate-mef.hylrnlethacrylate) represented by the following chemical formula 20, at a yield of 65-70 %.

ACHE-óCH2-C - CH2_ó\ C=0 C=0 o Z5 C- A ( IH2)2 (COlH2)2 8

O OH

O OSLO

cat (chemical formula 20) EXAMPLE XXI: Svnthesis of the copolymer polv(tosvlethylmethacrvlate hvdroxvethvlmethacrvlate-methvlmethacrvlate! In a 500 ml round-bottom flask are placed 0.3 mole) of tosylethylmethacrylate, 0.32 mole of hydroxyethylmethacrylate and 0.3 mole of methylmethacrylate. This mixture is added to 300 g of separately prepared tetrahydrofuran (THE) with stirring and mixed completely. Thereafter, in the presence of 0.1 g - 3 g of AIBN, the reaction mixture is subjected to polymerization at 60-75 C for 5-20 hours in a nitrogen atmosphere. After completion of this polymerization, the solution is precipitated in ethy] ether or normal- hexane and the precipitate is filtered and dried to produce poly(tosylethylmethacrylate-hydroxye.hylrnethacrylate- methylmethacrylate) represented by the following chemical formula 21, at a yield of 65- 70%. ( -

ACHE-C:CH2-ó - CHZ -ó: C=0 3 IC-O c 32 C= 3

O O O

( ICH2)2 ( rH2)2 CH3

O OH O=S=0 CH3

(chemical formula 21) EXAMPLE XXII: Synthesis of the copolymer polY(tosYlethvlmethacrylate hydroxypropylacrylate-methylmethacr-ylate! In a 500 ml round-bottom flask are placed 0.3 mole of tosylethylmethacrylate, 0.33 mole of hydroxypropylacrylate and 0.3 mole of methylmethacrylate. This mixture is added to 300 g of separately prepared tetrabydrofuran (THE) with stirring and mixed completely. Thereafter, in the presence of 0.1 g - 3 g of AIBN, the reaction mixture is subjected to polymerization at 60-75 C for S- hours in a nitrogen atmosphere. After completion of this polymerization, the solution is precipitated in ethyl ether or normal-hexane and the precipitate is filtered and dried to produce poly(tosylethylmethacrylate- hydroxypropylacrylate-methylmethacrylate) represented by the following chemical formula 22, at a yield of 65-70 %.

iCH2-ccH2-ccH2 8: Coo 3 iC=0 0 33 C= 3

O O O

i H2)2 óH2 3 CH3

O OH 0=5=0 CH3

(chemical formula 22) EXAMPLE XXIII: Synthesis of the copolymer poly(tosYlethYlmethacrylate hydroxypropylmethacrvlate-methylmethacrylate! In a 500 ml round-bottom flask are placed 0.3 mole of tosylethylmethacrylate, 0.3 mole of hydroxypropylmethacrylate and 0.3 mole of

- - J

methylmethacrylate. This mixture is added to 300 g of separately prepared tetrahydrofuran (THE) with stirring and mixed completely. Thereafter, in the presence of 0.1 g - 3 g of AIBN, the reaction mixture is subjected to polymerization at 60-75 C for 5-20 hours in a nitrogen atmosphere. After completion of this polymerization, the solution is precipitated in ethyl ether or normal- hexane and the precipitate is filtered and dried to produce poly(tosylethylmethacrylate-hydroxypropylme+.hacrylatemethylmethacrylate) represented by the following chemical formula 23, at a yield of 65- 70%.

ACT-C:CH2-OC-C d o o o Oh)2 OHH2 3 Cat OS=0 CH3 (chemical formula 23) EXAMPLE XXIV: Synthesis of the copolymer poly(tosylethylmethacrylatehvdroxybutvlacrvlate-methylmethacryl ate) In a 500 ml round-bottom flask are placed 0.3 mole of tosylethylacrylate, 0.33 mole of hydroxybutylacrylate and 0.3 mole of methylmethacrylate. This mixture is added to 300 g of separately prepared tetrahydrofuran (THE) with stirring and mixed completely. Thereafter, in the presence of 0.1 g - 3 g of AIBN, the reaction mixture is subjected to polymerization at 60-75 C for 5-20 hours in a nitrogen atmosphere. After completion of this polymerization, the solution is precipitated in ethyl ether or normal- hexane and the precipitate is filtered and dried to produce poly (tosylethylmethacrylatehydroxybutylacrylate-methylmethacrylate) represented by the following chemical formula 24, at a yield of 65-70 %. - - )

t cow He C

O O O

( IIH2)2 (cH2)4 Club

O OH OS=0 chb

(chemical formula 24) EXAMPLE XXV Preparation of ARC A polymer (resin) having a chemical structure of general formula 1, as obtained in each of Examples V-XIV polymer (resin), is dissolved in 200-5,000 % (w/w) of propyleneglycolmethyletheracetate (PGMEA). This solution is filtered, coated on a wafer, and hard-baked (i.e. heated at 100-300 C for 10-l,OOO see). A photosensitive material may be applied on the anti-reflective coating thus formed, and imaged to ulkafine patterns in the conventional manner.

EXAMPLE XXVI: Preparation of ARC A polymer (resin) having a chemical structure of the general formula 2, as obtained in each of Examples XVXXIV is dissolved in 200-5,000 % (w/w) of propyleneglycolmethyletheracetate (PGMEA). This solution, alone or in combination with 0. l -30 % by weight of at least one cross-linker selected from the group consisting of acroleindmethylacetal, acroleindiethylacetal and melamine type cross-linker is filtered, coated on a wafer, and hard-baked (i.e. heated at 100-300 C for 10-1,000 see). A photosensitive material may be applied on the anti-reflective coating thus formed, and imaged to ulkafine patterns in the conventional manner.

As described hereinbefore, anti-reflective coating of the present invention, for example, coatings formed from the polymer resins of chemical formulas 5 to 24, contain phenyl groups pendant from the polymeric backbone which exhibit superior absorbency at 193nm wavelength. Thus, an anti-reflective coating of the present invention can play an excellent role in forming ultrafine patterns. For example, it can prevent the back-reflection of light from the wafer surface and lower layers as well as eliminate the standing waves in the photoresist layer itself during a submicrolithographic it-? process using a 193nm ArF laser. This results in the formation of ultrafine patterns suitable for 64M, 256M, lG, 4G, and 16 G DRAM semiconductor devices and a great improvement in the production yield. - \

Claims (29)

1. A polymer represented by the following general formula 2.

ECU-C:C-C:H2-C: c to x coo Y c=o z 0 0 0 ( in, ( ICH2)n2 Clb

O OH O=s=0

Rat (general formula 2) wherein, Ra, Rb, Rc and Rd each represents hydrogen or methyl group; Rat represents hydrogen, hydroxy, straight or branched alkyl of C-Cs alkyl, including alkoxyalkyl and cycloalkoxyalkyl; cycloalkyl; x, y and z each represents mole fraction of 0.01-0.99; and no and n2 each represents an integer of 1 to 4.

2. A polymer as set forth in claim 1 wherein Rim represents methyl.

3. A polymer as set forth in claim 1 comprising poly (tosylethylacrylate-hydroxyethylacrylate-methylmethacrylate) wherein the mole ratio of tosylethylacrylate: hydroxyethylacry]ate: methylmethacrylate is 0.3: 0.3: 0.25.

4. A polymer as set forth in claim 1 comprising poly (tosylethylacrylate-hydroxyethylmethacrylate-methylmethacrylate) wherein the mole ratio of tosyle+,ylacrylate: hydroxyethylmethacrylate: metnylmethacrylate is 0.33: 0.35: 0.25.

5. A polymer as set forth in claim I comprising poly (tosylethylacrylate-hydroxypropylacrylate-methylmethacrylate) wherein the mole ratio of tosy]ethylacrylate: hydroxypropylacrylate: methylmethacrylate is 0.3: 0.33: 0.22.

6. A polymer as set forth in claim I comprising poly (tosylethylacry]ate-hydroxypropylmethacrylate-methylmethacrylate) wherein the mole ratio of tosylethylacrylate: hydroxypropylmethacrylate: methylmethacrylate is 0.3: 0.33: 0.25.

7. A polymer as set forth in claim 1 comprising poly (tosylethylacrylate-hydroxybutylacrylate-methylmethacrylate) wherein the mole ratio of tosylethylacrylate: hydroxybutylacrylate: methylmethacrylae is 0.3: 0.3: 0.3.

8. A polymer as set forth in claim 1 comprising poly (tosylethylmethacrylate-hydroxyethylacrylate-methylmethacrylate) wherein the mole ratio of tosylethylmethacrylate: hydroxyethylacrylate: methylmethacrylate is 0.3: 0.25: 0.3.

9. A polymer as set forth in claim 1 comprising poly (tosylethylmethacrylate-hydroxyethylmethacrylate-methylmethacrylate) wherein the mole ratio of tosy]ethylmethacrylate: hydroxyethylmethacrylate: methylmethacrylate is 0.3: 0.32: 0.3.

10. A polymer as set forth in claim 1 comprising poly (tosylethylmethacrylate-hydroxypropylacrylate-methylmethacrylate) wherein the mole ratio of tosylethylmethacrylate: hydroxypropylacrylate: methylmethacrylate is 0.3: 0.33: 0.3.

11. A polymer as set forth in claim I comprising poly (tosylethylmethacrylate-hydroxypropylmethacrylate-methylmethacrylate) wherein the mole ratio of tosylethylmethacrylate: hydroxypropylmethacrylate: methylmethacrylate is 0.3: 0.3: 0.3.

12. A polymer as set forth m claim I comprising poly (tosylethylmethacrylate-hydroxybutylacrylate-methylmethacrylate) wherein the mole ratio of tosylethylmethacrylate: hydroxybutylacrylate: methylmethacrylate is 0.3: 0.33: 0.3.

13. A method for preparing a polymer of claim 1 comprising polymerizing a tosylalkylacrylate-type monomer, a hydroxyalkylacrylate-type monomer my/ and an alkylacrylate-type monomer in a solvent in the presence of an initiator as shown In the following reaction equation 2: Raw Rb Rc 1 1 1 CH 2 =C CHz =C CH2 =C 1 1 1 C=0 C=0 C=0 I I + | general O 0 formula 2 (CH2)n. (CH2)r CHa 1 1

O OH O=S=0 R'

(reaction equation 2) wherein, Ra, Rb and Rr each represents hydrogen or methyl group; Rat represents hydrogen, hydroxy, a substituted or unsubstituted, straight or branched alkyl of C-Cs, cycloalkyl, alkoxyalkyl or cycloalkoxyalkyl; and no and n2 each represents an mteger of 1 to4.

14. A method for preparing a polymer as set forth in claim 13, wherein Rat represents methyl.

15. A method for preparing a polymer as set forth in claim 13, wherein the initiator is selected from the group consisting of 2,2azobisisobutyronitrile (AIBN), acetylperoxide, laurylperoxide and tbutylperoxide.

l 6. A method for preparing a polymer as set forth in claim 13, wherein the solvent is selected from the group consisting of tetrahydrofuran, toluene, benzene, methylethylketone and dioxane.

17. A method for preparing a polymer as set forth in claim 13, wherein the polymerizing reaction is conducted at 50-8Oo C.

18. A method for preparing an anti-reflective coating, which comprises dissolving 200-5000 %(w/w) of the polymer of any of claims 1 to 12 in an organic solvent to form a coating composition; coating said composition on a wafer; and subjecting the coated wafer to hard baking for 10 to 1000 sec. at 100-30Oo C.

19. A method as set forth in claim 18, wherein the organic solvent is selected from the group consisting of ethyl 3-ethoxypropionate, methyl 3methoxypropionate, cyclohexanone and propyleneglycolmethyletheracetate.

20. An anti-reflective coating comprising the polymer of claim 1 and an additive selected from the group consisting of acroleindimethylacetal, acroleindiethylacetal and melamine-type crosslinkers.

21. A method for preparing anti-reflective coating useful in fabricating semiconductor devices which comprises dissolving 200-S000 %(w/w) of the polymer of claim I in a organic solvent; completely dissolving therein an additive selected from the group consisting of acroleindimethylacetal, acroleindiethylacetal and melamine type cross-linkers to form a coating composition; filtering said composition, coating said composition on a wafer; and subjecting the coated wafer to hard baking for 10 to 1000 sec. at 100-300 C.

22. A method as set forth in claim 21, wherein the organic solvent is selected from the group consisting of ethyl 3-ethoxypropionate, methyl 3methoypropionate, cycl oh ex anon e an d prop yl en eglycolmethyl etheracetate.

23. A method as set forth in claim 21, wherein said additive is used at an amount of 0.1 to 30 % (w/w).

24. A semiconductor device comprising an anti-reflective coating including a polymer of any of claims 1 to 12.

25. A semiconductor device comprising the anti-reflective coating of claim 20.

26. A polymer as claimed in claim I substantially as hereinbefore described.

27. An anti-reflective coating as claimed in claim 20 substantially as hereinbefore described.

28. A method of preparing an anti-reflective coating as claimed in claim 21 substantially as hereinbefore described.

29. A seminconductor device fabricated by using an anti-reflective coating as claimed in claim 20 substantially hereinbefore described.