NON-AROMATIC CHROMOPHORES FOR USE IN POLYMER ANTI-REFLECTIVE COATINGS

Abstract: An improved light attenuating compound for use in the production of microdevices is provided. Broadly, the light attenuating compound is non-aromatic and can be directly incorporated (either physically or chemically) into photolithographic compositions such as bottom anti-reflective coatings (BARC) and contact or via hole fill materials. The preferred non-aromatic compounds of the invention are conjugated aliphatic and alicyclic compounds which greatly enhance the plasma etch rate of the composition. Furthermore, the light attenuating compounds are useful for absorbing light at shorter wavelengths. In one embodiment, the inventive compounds can be polymerized so as to serve as both the polymer binder of the composition as well as the light absorbing constituent.

Description: NON-AROMATIC CHROMOPHORES FOR USE IN POLYMER ANTI-REFLECTIVE COATINGS BACKGROUND OF THE INVENTION Field of the Invention The present invention is broadly concerned with light attenuating compounds for incorporation into photolithographic compositions (e g , anti-reflective coatings and contact or via hole fill compositions) utilized in the manufacturing of microdevices More particularly, the light attenuating compounds are non-aromatic and are especially useful for absorbing light at shorter wavelengths (e g , 248 nm) The compounds can be physically incoφorated into the particular composition, or alternately, can be chemically bonded to a polymer binder already present in the composition The compounds of the invention compπse conjugated aliphatic and alicyclic moieties which meet the necessary light absorbency requirements for the composition while enhancing the plasma etch rate of the composition when compared to prior art aromatic dyes Description of the Pπor Art A frequent problem encountered by photoresists during the manufacturing of semiconductor devices is that activating radiation is reflected back into the photoresist by the substrate on which it is supported Such reflectivity tends to cause blurred patterns which degrade the resolution of the photoresist Degradation of the image in the processed photoresist is particularly problematic when the substrate is non-planar and/or highly reflective One approach to address this problem is the mcoφoration of an anti-reflective dye either into the photoresist layer, into a contact or via hole fill composition, into a bottom anti-reflective coating (BARC), or as a separate layer adjacent the photoresist layer Pπor art BARC compositions usually contain aromatic anti-reflective dyes which attenuate light that would otherwise reflect from the substrate duπng photoresist exposure For example, anthracene and naphthalene derivatives are typically the preferred dyes for use at 248 nm exposing wavelengths Dyes comprising a benzene ring with at least one conjugated substituent are widely used in BARC's which operate at 365 nm. w hile dyes comprising a benzene ring without conjugated substituents ha\ e ample absoφtivity to satisfy most 193 nm applications Aromatic dyes have been preferred for BARC applications because of their high light absorbency per unit mass as well as their wide availability, easy preparation, and high chemical stability While aromatic dyes are useful for achieving high film optical density they limit the plasma etch rate of the BARC compositions by \ irtue of their chemical stability Aromatic dyes require considerably more energy for decomposition than do the polymer binders (which are typically non-aromatic) used m the BARC compositions As a result, the composite etch rate is highly dependent on the aromatic character of the dyes U S Patent No 4,719,166 to Blevms et al discloses the use of certain butadienyl dyes in a photoresist layer, an anti-reflective layer, or a planaπzing layer for protecting photoresist elements against reflection of activating radiation from the substrate However, the dyes of the '166 patent are not attached to the backbone of a polymer binder, thus permitting them to readily solubihze in the photoresist, often leading to pattern degradation Furthermore, cuπent technology continues to require increasingly complex circuitry be imprinted on chips of decreasing size These smaller chips require shorter wavelengths (e g , 248 nm) be used during photoresist exposure The dyes of the '166 patent are useful for absorbing light only at 365 nm exposure wavelengths, making them unsuitable for use in the manufactuπng of most current microdevices There is a need for a compound which can effectively attenuate light at shorter wavelengths and which does not inhibit the etch rate of the particular BARC or contact or via hole fill composition in which it is utilized SUMMARY OF THE INVENTION The present invention fills this need by providing light attenuating compounds for BARC compositions, contact or via hole fill compositions and other ice manufactuπng compositions which do not inhibit the etch rate of the composition Furthermore, the inventive compounds are useful for absorbing light at shorter wavelengths In more detail, the light attenuating compounds are non-aromatic and can be formulated to absorb light at the desired wavelength Advantageously, the compounds are also useful for absorbing light at wavelengths of less than about 300 nm, and preferably less than about 250 nm (e g , for 248 nm applications) As used herein, non-aromatic refers to compounds or moieties of compounds which either (1) do not include a benzene ring, or (2) (a) have non-planar carbon skeletons, and (b) do not contain (4n + 2) π electrons, where n = 0 1 2, 3, etc ( I e do not obey Huckel's Rule as described in Solomons T \\ Graham, Fundamentals of Organic Chemistn 3rd ed lohn Wiley & Sons, Inc (1990)) The light attenuating compounds of the invention comprise moieties ha\ ing general structural formulas (set forth in detail below) Preferably, these compounds include one or more reactive groups selected from the group consisting of COOH, OH CONH 2 , CONHR, CH 2 X groups, and mixtures thereof, where R is selected from the group consisting of hydrogen, alkyls (preferably C,-C 4 branched and unbranched) and heteroalkyls, and X is a halogen The light attenuating compounds can be incoφorated into the particular photolithographic composition either physically (I e , as a mixture) or by chemicalh attaching the light attenuating compound to the polymer binder or resin present in the composition (either to a functional group on the binder or directly to the backbone ot the binder) In situations where the light attenuating compound is attached to the polymer binder, a linkage unit can be used as an intermediate for securing the light attenuating compound to the binder That is, the light attenuating compound can be attached to a linkage unit which m turn is attached to the polymer binder (eithei to a functional group on the binder or to the binder backbone) Examples of suitable linkage units are those which comprise a moiety selected from the group consisting of Is (preferably C r C 4 branched and unbranched), acyclic heteroalkyls, non-aromatic c\ chc alkyls (preferably C 3 -C 6 ) and non-aromatic cyclic heteroalkyls In another embodiment, the light attenuating compounds can be polymerized alone so as to directly form the polymer binder utilized in the particulai photolithographic composition while simultaneously acting as a light absorber Thus in these applications an additional polymer binder would not be necessary In applications where a polymer binder other than the light attenuating compound is present m the composition, the binder should be dissoh ed in a soh ent system (either single or multiple solvents) The particular polymer binders and soh ent systems utilized are readily ascertainable by those skilled in the art Examples ot suitable polymer binders include polyesters, polyacrylates, poKheterocychcs polyetherketones, polyhydroxystyrene, polycarbonates, polyepichlorohydnn, polyΛ m\ 1 alcohol, ohgomenc resins (such as crown ethers, cyclodextrms, resins), and mixtures of the foregoing Examples of preferred solvents for use in the solvent svstem include alcohols, ethers, glycol ethers, amides, esters, ketones, vv ater, propvlene col monomethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA), ethyl lactate, and PCBTF ( -chlorobenzotπfluoπde) Incoφorating light attenuating compounds into photolithographic compositions in accordance with the invention will not increase the etch rate of the composition as is the case with pπor art compositions compπsmg aromatic dyes Thus, when practicing the instant invention, the etch rate of the photolithographic composition will be at least about 4000 A/mmute, where a mixture of HBr and O 2 is the etchant gas DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS While the lm entive light attenuating compounds broadly include non-aromatic dyes, and particularly non-aromatic dyes which absorb light at shorter wavelengths, in preferred embodiments the compounds include one or more of the following moieties Generally speaking, the light attenuating compounds should include at least one double bond conjugation with at least one electron-withdrawing group (EWG) One such structure is shown below in Formula I Formula I Structure B where • each R, is non-aromatic and may individually be hydrogen, or an acyclic (preferably C,-C 4 branched or unbranched) or cyclic (preferably C 5 -C 6 ) alkyl or heteroalkyl, in structure A, where EWG and R 2 do not form a cyclic unit EWG is a non-aromatic electron-withdrawing group such as a carbonyl, cyano, imino. carboxyhc acid, carboxyhc ester, carboxamido, carboximido, or sulfonyl group; and R 2 is non-aromatic and may be hydrogen, an acyclic (preferably C r C 4 branched or unbranched) or cyclic (preferably C,-C ή ) alkyl or heteroalkyl, or an electron-withdrawing group such as a carbonyl, immo, cyano, carboxyhc acid, carboxyhc ester, carboxamido, carboximido, or sulfonyl group; in structure B, where EWG and R 2 form a cyclic electron- withdrawing unit, the cyclic unit preferably comprises a C=0, C=S, or a C=N at a first carbon atom, and: a C=O or a C=N attached to a carbon atom at least two carbon atoms away from the first carbon atom; or an O, S, or N as a member of the ring at least two positions away from the first carbon atom; and (1 ) and (2) refer to the respective double-bonded carbon atoms. Examples of particularly preferred structures B of Formula I where EWG and R 2 form a cyclic electron-withdrawing unit include the following: where R, is non-aromatic and may individually be hydrogen, or an acyclic (preferably C,-C 4 branched or unbranched) or cyclic (preferably C 5 -C 6 ) alkyl or heteroalkyl. In another embodiment, the light attenuating compounds include at least one EWG across a double bond from an electron donating group (EDG) as show n in Formula II. Formula II: Structure A Structure B where: • R, is non-aromatic and may individually be hydrogen, or an acyclic (preferably C,-C 4 branched or unbranched) or cyclic (preferably C 5 -C 6 ) alkyl or heteroalkyl; • EDG is an electron-donating group such as H 3 CO-, -OH, or R R y N-, where each of R x and R v is non-aromatic and may individually be hydrogen, or an acyclic (preferably C,-C 2 ) or cyclic (preferably C 5 -C 6 ) alkyl or heteroalkyl; • in structure A, where EWG and R 2 do not form a cyclic unit: EWG is a non-aromatic electron-withdrawing group such as a carbonyl, cyano, imino, carboxyhc acid, carboxylic ester, carboxamido, carboximido, or sulfonyl group; and R 2 is non-aromatic and may be hydrogen, an acyclic (preferably C,-C 4 branched or unbranched) or cyclic (preferably C 5 -C 6 ) alkyl or heteroalkyl, or an electron-withdrawing group such as a carbonyl, imino, cyano, carboxylic acid, carboxylic ester, carboxamido, carboximido, or sulfonyl group; in structure B, where EWG and R 2 form a cyclic electron- withdrawing unit, the cyclic unit preferably comprises a C=O, C=S, or a C=N at a first carbon atom, and: a C=O or a C=N attached to a carbon atom at least two carbon atoms away from the first carbon atom; or an O, S, or N as a member of the ring at least two positions away from the first carbon atom; and ( 1 ) and (2) refer to the respective double-bonded carbon atoms. Examples of particularly preferred structures B of Formula II where EWG and R 2 form a cyclic electron- withdrawing unit include the following: where R, is non-aromatic and may individually be hydrogen, or an acyclic (preferabK C r C 4 branched or unbranched) or cyclic (preferably C 3 -C 6 ) alkyl or heteroalkyl. In another embodiment, the light attenuating compounds include two conjugated double bonds in series with at least one EWG (see Formula III) or with two E WG's ( see Formula IV). The structures shown in Formulas III and IV are particularly useful at 248 nm or 365 nm wavelength applications, depending upon the selection of R and EWG. Formula III: Structure A Structure B where: each R, is non-aromatic and may individually be hydrogen, or an acyclic (preferably C r C 4 branched or unbranched) or cyclic (preferably C 5 -C 6 ) alkyl or heteroalkyl; in structure A, where EWG and R 2 do not form a cyclic unit: EWG is a non-aromatic electron-withdrawing group such as a carbonyl, cyano, imino, carboxylic acid, carboxylic ester, carboxamido. carboximido. or sulfonyl group; and R 2 is non-aromatic and may be hydrogen, an acyclic (preferably C,-C 4 branched or unbranched) or cyclic (preferably C 5 - ) alkyl or heteroalkyl, or an electron-withdrawing group such as a carbonyl, imino, cyano, carboxylic acid, carboxylic ester, carboxamido, carboximido, or sulfonyl group; in structure B, where EWG and R 2 form a cyclic electron- withdrawing unit, the cyclic unit preferably comprises a C=O, C=S, or a C=N at a first carbon atom, and: a C=O or a C=N attached to a carbon atom at least two carbon atoms away from the first carbon atom; or an O, S, or N as a member of the ring at least two positions away from the first carbon atom; and (l)-(4) refer to the respective double-bonded carbon atoms. Examples of particularly preferred structures B of Formula III where EWG and R 2 form a cyclic electron-withdrawing unit include the following: where R, is non-aromatic and may individually be hydrogen, or an acyclic (preferabK C r C 4 branched or unbranched) or cyclic (preferably C 5 -C 6 ) alkyl or heteroalkyl. Formula IV: where: each R, is non-aromatic and may individually be hydrogen, or an acyclic (preferably C,-C 4 branched or unbranched) or cyclic (preferably C 5 -C 6 ) alkyl or heteroalkyl; EWG is a non-aromatic electron-withdrawing group such as a carbonyl, cyano. imino, carboxylic acid, carboxylic ester, carboxamido, carboximido, or sulfonyl group; and ( 1 ) - (4) refer to the respective double-bonded carbon atoms. In another embodiment the light attenuating compounds include an EWG coupled with an EDG across a conjugated double bond system. An example of this structure is shown in Formula V. Formula V: Structure A Structure B where: each R { is non-aromatic and may individually be hydrogen, or an acyclic (preferably C,-C branched or unbranched) or cyclic (preferably C 5 -C 6 ) alkyl or heteroalkyl; EDG is an electron-donating group such as H 3 CO-, -OH, or R X R N-. where each of R N and R is non-aromatic and may individually be hydrogen, or an acyclic (preferably C,-C 2 ) or cyclic (preferably C -C 6 ) alkyl or heteroalkyl; in structure A, where EWG and R : do not form a cyclic unit EWG is a non-aromatic electron-withdrawing group (other than cyano groups) such as a carbonyl, imino, carboxylic acid, carboxyhc ester, carboxamido, carboximido, or sulfonyl group, and R 2 is non-aromatic and may be hydrogen, an acyclic (preferably C,-C 4 branched or unbranched) or cyclic (preferably C 5 -C 6 ) alkyl or heteroalkyl, or an electron-withdrawing group such as a carbonyl, imino, cyano, carboxylic acid, carboxylic ester, carboxamido, carboximido, or sulfonyl group; or EWG is a cyano group, and R 2 is non-aromatic and ma be hydrogen, or an acyclic (preferably C r C 4 branched or unbranched) or cyclic (preferably C 5 -C 6 ) alkyl or heteroalkyl; • in structure B, where EWG and R 2 form a cyclic electron- withdrawing unit, the cyclic unit preferably comprises a C=O. C=S, or a C=N at a first carbon atom, and: a C=O or a C=N attached to a carbon atom at least two carbon atoms away from the first carbon atom; or an O, S, or N as a member of the ring at least two positions away from the first carbon atom; and • (l)-(4) refer to the respecth e double-bonded carbon atoms. Examples of particularly preferred structures B of Formula V where EWG and R 2 form a cyclic electron-withdrawing unit include the following: where R, is non-aromatic and may individually be hydrogen, or an acyclic (preferably C,-C 4 branched or unbranched) or cyclic (preferably C 5 -C 6 ) alkyl or heteroalkyl. Of course, those skilled in the art will appreciate that light attenuating compounds in accordance with the invention can include mixtures of the foregoing Formulas I-V in the particular photolithographic composition. In another embodiment, the foregoing structures can be dimerized to form new compositions which are preferably incoφorated into photolithographic compositions to absorb light, thus minimizing or eliminating the reflectance from the substrate These dimerized structures are shown in Formulas VI-VIII Formulas VI where • each R, is non-aromatic and may individually be hydrogen, or an acyclic (preferably C r C 4 branched or unbranched) or cyclic (preferably C 5 -C 6 ) alkyl or heteroalkyl, each R-, may individually be R, or where each R, is non-aromatic and may individually be hydrogen, or an acyclic (preferably C,-C 4 branched or unbranched) or cyclic (preferably C 3 -C 6 ) alkyl or heteroalkyl, and where the (*) represents the double-bonded carbon atom (1 ) oi (4), • each EWG is a non-aromatic electron-withdra ing group such as a carbonyl, cyano, imino caiboxyhc acid, carboxylic estei, carboxamido, carboximido or sulfonyl group, • each R 2 is non-aromatic and may individually be hydrogen, an acyclic (preferably C,-C 4 blanched or unbranched) or cyclic (preferably C 5 -C 6 ) alkyl or heteroalkyl, or an electron- withdrawing group such as a carbonyl, imino, cyano, carboxylic acid, carboxylic ester, carboxamido, carboximido, or sulfonyl group; • R 4 is a divalent, non-aromatic-containing bridging group such as -(CH 2 ) n -, dimethylenecyclohexyl (-CH 2 -C 6 H 4 -CH 2 -), -CH 2 CH 2 - O-CH 2 CH 2 -, or other acyclic (preferably C C 4 , branched or unbranched) or cyclic (preferably C 5 -C 6 ) alkyls or heteroalkyls; and • ( 1 ) - (4) refer to the respective double-bonded carbon atoms. Formulas VII: where: each R, is non-aromatic and may individually be hydrogen, or an acyclic (preferably C,-C 4 branched or unbranched) or cyclic (preferably C 5 -C 6 ) alkyl or heteroalkyl; each R 2 is non-aromatic and may individually be hydrogen, an acyclic (preferably C,-C 4 branched or unbranched) or cyclic (preferably C 5 -C 6 ) alkyl or heteroalkyl, or an electron- withdrawing group such as a carbonyl, imino, cyano, carboxylic acid, carboxylic ester, carboxamido, carboximido, or sulfonyl group; • each R 3 may individually be EDG, or where each R, is non-aromatic and may individually be hydrogen, or an acyclic (preferably C,-C 4 blanched or unbranched) or cyclic (preferably C,-C 6 ) alkyl or heteroalkyl, EDG is an electron-donating group such as H 3 CO-, -OH, or R λ R>N-, where each of R and R y is non-aromatic and may individually be hydrogen, oi an acyclic (preferably C,-C 2 ) or cyclic (preferably C-C ( ) alkyl or heteroalkyl, and where the (*) l epi esents the double-bonded carbon atom ( 1 ) oi (4), • R 4 is a divalent, non-aromatic-contaimng bridging group such as -(CH 2 ) π -, dimethylenecyclohexyl (-CH 2 -C 6 H 4 -CH 2 -), -CH 2 CL - O-CH 2 CH 2 -, or other acyclic (preferably C C 4 , branched oi unbranched) or cyclic (prefei ably C 5 -C 6 ) alkyls or heteroalkyls, • each EWG is a non-aromatic electron-withdrawing group such as a carbonyl, cyano, imino, carboxyhc acid, carboxyhc ester, carboxamido, carboximido, or sulfonyl group, and • (1 ) - (4) refer to the respectiv e double-bonded carbon atoms Formula VIII Structure A Structure B where each R, is non-aromatic and may individually be hydrogen, or an acyclic (preferably C,-C branched or unbranched) or cyclic (preferably C 3 -C 6 ) alkyl 01 heteioalkyl, • where each R 3 may lndiudualK be an EWG, Structure D in structure A of Formula VIII, in situations where R 3 is an EWG or structure C (i.e., EWG and R 2 do not form a cyclic unit): each EWG is a non-aromatic electron-withdrawing group (other than cyano groups) such as a carbonyl, imino. carboxylic acid, carboxylic ester, carboxamido, carboximido, or sulfonyl group, and each R 2 is non-aromatic and may individually be hydrogen, an acyclic (preferably C,-C 4 branched or unbranched) or cyclic (preferably C 5 -C 6 ) alkyl or heteroalkyl, or an electron-withdrawing group such as a carbonyl, imino, carboxylic acid, carboxylic ester, carboxamido, carboximido, or sulfonyl group; or EWG is a cyano group, and each R 2 is non-aromatic and may individually be hydrogen, or an acyclic (preferably r C 4 branched or unbranched) or cyclic (preferably C ; - ) alkyl or heteroalkyl; • in structure B of Formula VIII. and in structure A of Formula VIII where R 3 is structure D (i.e., in situations where EWG and R 2 form a cyclic electron-withdrawing unit), the cyclic unit preferably comprises a C=O, C=S, or a C=N at a first carbon atom, and: a C=O or a C=N attached to a carbon atom at least two carbon atoms away from the first carbon atom; or an O, S, or N as a member of the ring at least two positions away from the first carbon atom; and each EDG is an electron-donating group such as -O-, -S-, or -RjN-, where R 5 is hydrogen or an acyclic (preferably C,-C 2 ) or cyclic (preferably C-C,,) alkyl or heteroalkyl; • R 4 is a divalent, non-aromatic-containing bridging group such as -(CH 2 ) n -, dimethylenecyclohexyl (-CH 2 -C 6 H -CH 2 -), -CH 2 CH 2 - O-CH 2 CH 2 -, or other acyclic (preferably C,-C 4 , branched or unbranched) or cyclic (preferably C 5 -C 6 ) alkyls or heteroalkyls; and • (1) - (4) refer to the respective double-bonded carbon atoms. Examples of particularly preferred structures A of Formula VIII where R, is structure D (i.e., so that EWG and R 2 form a cyclic electron-withdrawing unit) include the following: where each R, is non-aromatic and may individually be hydrogen, an acyclic (preferably C,-C 4 branched or unbranched) or cyclic (preferably C 5 -C 6 ) alkyl or heteroalkyl, and each R 2 is non-aromatic and may individually be hydrogen, an acyclic (preferably C,-C 4 branched or unbranched) or cyclic (preferably C -C 6 ) alkyl or heteroalkyl, or an electron-withdrawing group such as a carbonyl, imino, carboxylic acid, carboxylic ester, carboxamido, carboximido, or sulfonyl group. Examples of particularly preferred structures B of Formula VIII where EWG and R 2 form a cyclic electron- withdrawing unit include the following: where R, is non-aromatic and may individually be hydrogen, acyclic (preferably C,-C 4 branched or unbranched) or cyclic (preferably C 5 -C 6 ) alkyl or heteroalkyl, and each R 2 is non-aromatic and may individually be hydrogen, an acyclic (preferably C,-C 4 branched or unbranched) or cyclic (preferably C 5 -C 6 ) alkyl or heteroalkyl, or an electron- withdrawing group such as a carbonyl, imino, carboxylic acid, carboxylic ester, carboxamido. carboximido, or sulfonyl group. In another embodiment, a light attenuating compound is attached to a polymer binder (either directly to the backbone or via a linkage unit) via an EWG. A specific example of one such structure is shown m Formula IX. Formula IX where EWG is a non-aromatic electron-withdrawing group such as a carbonyl, cyano, imino, carboxylic acid, carboxylic ester, carboxamido, carboximido. or sulfonyl group, and each R, may individually be hydrogen or an alkyl group (and preferably a methyl group). One preferred structure of Formula IX wherein the EWG (a carboxyl group) is directly attached to a polymer backbone as shown below. Polymer Backbone In another embodiment, two R, substituents on a moiety of the light attenuating compound form a cyclic structure such as those shown in Formulas X and XI Formula X where R 2 is non-aromatic and may individually be hydrogen, an acyclic (preferably C,-C 4 branched oi unbranched) or cyclic (preferably C 5 -C 6 ) alkyl or heteroalkyl, oi an electron-withdrawing group such as a carbonyl. imino, cyano, caiboxyhc acid, carboxyhc ester carboxamido. carboximido, oi sulfonyl group, and EWG is a non- aromatic electron-withdrawing gioup such as a carbonyl. cyano, imino, carboxylic acid, carboxyhc estei carboxamido, carboximido, or sulfonyl group Formula XI where R 2 is non-aromatic and may individually be hydrogen, an acyclic (preferably C,-C 4 branched oi unbranched) or cyclic (preferably C 5 -C 6 ) alkyl or heteroalkyl, or an electron- withdrawing group such as a carbonyl, imino, cyano. caiboxyhc acid, carboxyhc ester, carboxamido, carboximido, or sulfonyl group, and EWG is a non- aromatic electron-withdrawing gioup such as a carbonyl, cyano, imino, carboxyhc acid, carboxyhc estei carboxamido, carboximido, oi sulfonyl group In yet another embodiment, the disc losed Formulas can bejoined to one another to form a polymeric structure foi use in a photolithographic composition w ithout the need for an additional polymer bmdei That is, the polymerized structures w ould act as the polymer binder as well as the light absorbing compound The structures of Formulas I-XI can by polymerized in a neai fashion by creating non-conjugated, non- aromatic linkages between two of the functional groups as shown in the table below Where (') refers to the first unit of the dimer e. and (") refers to the second unit of a dimer dye Linkage units could be utilized between the structures to form the abo\ e- described linkages. Suitable linkage units include a moiety selected from the group consisting of alkyls, acyclic heteroalkyls. non-aromatic cyclic alkyls, and non-aromatic cyclic heteroalkyls. As indicated previously, the light attenuating compound can be attached to the polymer binder backbone or to a functional group or linkage unit which is, in turn, attached to the polymer backbone. Structures E and F below illustrate these attachments. In structure E, a 365 nm dienyl dye having an amino electron-donating group is bonded to a polymer binder via a hydroxypropyl linking group. The dye is attached by a carboxylic ester electron-withdrawing group. In structure F, the ammo electron-donating group is functionalized with two hydroxyethyl substituents which are reacted with a diisocyanate to fonn a polyurethane backbone. Structure E Structuic F When used in reference to Formulas I-XI, the term "compounds" is intended to refer to the actual compound represented in the particular Formula, as well as all functional olefinic and/or diolefinic moieties thereof. For example, the "compound of structure A of Formula I," refers to the structure A shown in Formula I above as well as the structure: where "M" is a compound to which R' is bonded. Thus, "compound of structure A of Formula I" would include those moieties where any of the constituents (i.e., any of the R groups or the EWG) are bonded to another compound. Also, as used herein, "cyclic" is intended to refer to any group, compound, or moiety which includes a cyclic group as part of its structure. Thus, cyclic would include groups such as methylenecyclohexyl (-CH 2 -C 6 H 5 ) and ethylenecyclohexyl. The following table sets forth prefeπed compounds which fall into the classes described above with respect to Formulas I-XIII. EXAMPLE The following example sets forth preferred methods in accordance with the invention. It is to be understood, however, that this example is provided by way of illustration and nothing therein should be taken as a limitation upon the overall scope of the invention. Poly(glycidyl methacrylate) was reacted with 2,4-hexadienoic acid (a non- aromatic, deep ultraviolet chromophore) at 100-110°C for 24 hours with a benzyltriethylammonium chloride catalyst to form a solution of the dye-attached binder shown in Scheme A. Scheme A - 2,4-Hexadienoic Acid Attached to Poly(glycidyl methacrylate) The resulting polymer binder was combined in solution (with l-methoxy-2- propanol and ethyl lactate as the solvents) with a glycouril-formaldehyde cross-linking agent and an acid catalyst ( -toluenesulfonic acid) to form a BARC composition. The concentrations of the various compounds utilized in the composition were as follows: Compounds Parts bv Weieh Polymer Solution 14.52 Cross-Linking Agent 0.66 -toluenesulfonic acid 0.06 1 -methoxy-2-propanol 42.38 ethyl lactate 42.38 a Parts by weight based upon the total weight of all compounds taken as 100% by weight The composition was spin coated onto a silicon wafer at 1500 φ for 60 seconds followed by a hotplate bake at 175 °C for 60 seconds to form a BARC layer with a film optical density at 248 nm of 4.83/micron. The coating was then plasma etched in a commercial wafer etching tool using a mixture of HBr and O 2 as the etchant gas. The etch rate of the coating was 5815 A/mmute. For comparison puφoses, the etch rate of a BARC composition (DUV-42 for use in 248 nm photolithographic processes, available from Brewer Science, Inc , Rolla, MO) was determined The binder in DUV-42 is a copolymer of glycidyl methaciylate and 2-hydroxypropyl methacrylate in which the glycidyl groups have been reacted with 9-anthracenecarboxyhc acid (9-ACA) to form a dye-attached binder with high light absorbency at 248 nm The DUV-42 was applied to a silicon wafer and processed following the procedures set forth above with respect to the inventive composition The etch rate of the DUV-42 was 3218 Λ/minute Thus, the composition utilizing a light attenuating compound according to the invention etched 1 8 times faster than the prior art product. The comparatively low plasma etch rate of the DUV-42 was a result of the high aromatic ring content of the 9-ACA

Claims: We Claim: 1. In a curable composition for use during microlithographic processes. said composition comprising a polymer binder dissolved in a solvent system, the improvement which comprises a non-aromatic, light attenuating compound which absorbs light at wavelengths of less than about 300 nm in said composition. 2. The composition of claim 1 , wherein said light attenuating compound is bonded to the polymer binder. 3. The composition of claim 1 , wherein the polymer binder comprises a backbone, and said light attenuating compound is bonded to said backbone. 4. The composition of claim 1, wherein said light attenuating compound is bonded to a linkage unit and said linkage unit is bonded to the polymer binder. 5. The composition of claim 4, wherein said linkage unit comprises a moiety selected from the group consisting of cyclic alkyls, acyclic alkyls, acyclic heteroalkyls, and cyclic heteroalkyls. 6. The composition of claim 1 , wherein said light attenuating compound includes a moiety selected from the group consisting of COOH, OH, CONH 2 , CONHR'. CH 2 X, and mixtures thereof, wherein R' is selected from the group consisting o hydrogen, alkyls, and heteroalkyls, and wherein X is a halogen. 7. The composition of claim 1 , wherein after curing, said composition has an etch rate of at least about 4000 A/minute when utilizing an etchant gas comprising a mixture of HBr and O 2 . 8. The composition of claim 1 , wherein said light attenuating compound comprises an olefinic moiety including carbon atoms C, and C 2 double-bonded to one another, and an EWG bonded to carbon atom 9. The composition of claim 8, wherein the EWG includes a moiety selected from the group consisting of carbonyl, carboxyl, carboxamido. sulfonyl, and non-aromatic heterocyclic groups. 10. The composition of claim 8, said light attenuating compound comprising a diolefin, including carbon atoms C 3 and C 4 double-bonded to one another, and wherein C 3 is bonded to C 2 so as to form conjugated double bonds. 11. The composition of claim 10, further including an EDG bonded to C 4 . 12. The composition of claim 1 1 , wherein the EDG includes a moiety selected from the group consisting of H 3 CO, OH, and R r O-, wherein R, is non- aromatic and is selected from the group consisting of hydrogen, acyclic and cyclic alkyls, and heteroalkyls. 13. The composition of claim 10, further including a second EWG, said second EWG being bonded to C 4 . 14. The composition of claim 13, wherein the second EWG includes a moiety selected from the group consisting of carbonyl, carboxyl, carboxamido, sulfonyl, and non-aromatic heterocyclic groups. 15. In a composition for use during microlithographic processes, said composition comprising a polymer binder dissolved in a solvent system, the improvement which comprises a non-aromatic, light attenuating compound comprising a moiety selected from the group consisting of: (a) the compounds of Formula I, Formula II, Formula X, Formula XI, and mixtures thereof; (b) olefinic moieties of the compounds of Formula I, Formula II, and mixtures thereof; and (c) mixtures of (a) and (b). 16. The composition of claim 15, wherein said light attenuating compound is bonded to the polymer binder. 17. The composition of claim 16. wherein the EWG of said light attenuating compound is bonded to the polymer binder 18. The composition of claim 16. wherein at least one of R, and R 2 of said light attenuating compound is bonded to the polymer binder. 19. The composition of claim 15, wherein the polymer binder comprises a backbone, and said light attenuating compound is bonded to said backbone. 20. The composition of claim 19, w herein the EWG of said light attenuating compound is bonded to said backbone 21. The composition of claim 19. wherein at least one of R, and R 2 of said light attenuating compound is bonded to said polymer binder. 22. The composition of claim 15, wherein said light attenuating compound is bonded to a linkage unit and said linkage unit is bonded to the polymer binder 23. The composition of claim 22, wherein said linkage unit comprises a moiety selected from the group consisting of cyclic alkyls, acyclic alkyls, acyclic heteroalkyls, and cyclic heteroalkyls 24. The composition of claim 15. wherein the EWG of said light attenuating compound is selected from the group consisting of carbonyl, cyano. carbox\ l. carboxamido, sulfonyl, and non-aromatic heterocyclic groups. 25. The composition of claim 15, wherein each of R, and R 2 of said light attenuating compound is individually selected from the group consisting of hydrogen, alkyls, and heteroalkyls 26. The composition of claim 25, wherein each of R, and R 2 of said light attenuating compound is individually selected from the group consisting of cyclic alkyls and acyclic alkyls. 27 The composition of claim 15, wherein said light attenuating compound comprises a moiety selected from the group consisting of (a) the compounds of Formula II, (b) olefinic moieties of the compounds of Formula II, and (c) mixtures of (a) and (b), wherein the EDG of said light attenuating moiety comprises a group selected from the group consisting of H 3 CO, OH, R,-O-, and R x R y N groups, wherein R, is non- aromatic and is selected from the group consisting of hydrogen, acyclic and cyclic alkyls, and heteroalkyls and each of R and R y being non-aromatic and individually selected from the group consisting of hydrogen, alkyls, and heteroalkyls 28 The composition of claim 15, wherein said light attenuating compound comprises a moiety selected from the group consisting of COOH, OH, CONH,, CONHR', CH 2 X, and mixtuies thereof, wherein each R' is individually selected from the group consisting of hydi ogen, alkyls, and heteroalkyls, and wherein X is a halogen 29 In a composition for use during microhthographic processes, said composition compπsmg a polymer binder dissolved in a solvent system, the improvement which comprises a non-aromatic, light attenuating compound comprising a moiety selected from the group consisting of (a) the compounds of Formula III, Formula IV, Formula V, Fonriula IX, and mixtures thereof, (b) diolefinic moieties of the compounds of Formula III, Formula IV Formula V, and mixtures thereof, and (c) mixtuies of (a) and (b) 30 The composition of claim 29, wherein said light attenuating compound is bonded to the polymei binder 31 The composition of claim 30, wherein the EWG of said light attenuating compound is bonded to the polymer binder 32 The composition of claim 31 , wherein at least one of R, and R 2 of said light attenuating compound is bonded to the polymer binder 33 The composition of claim 29, wherein the polymer binder comprises a backbone, and said light attenuating compound is bonded to said backbone 34. The composition of claim 33, wherein the EWG of said light attenuating compound is bonded to said backbone 35. The composition of claim 33, wherein at least one of R, and R 2 of said light attenuating compound is bonded to said polymer binder. 36. The composition of claim 29, wherein said light attenuating compound is bonded to a linkage unit and said linkage unit is bonded to the polymer binder 37 The composition of claim 36. wherein said linkage unit comprises a moiety selected from the group consisting of cyclic alkyls, acyclic alkyls, acyclic heteroalkyls, and cyclic heteroalkyls. 38. The composition of claim 29, wherein the EWG of said light attenuating compound is selected from the group consisting of carbonyl, cyano, carboxy l. carboxamido, sulfonyl, and non-aromatic heterocyclic groups. 39. The composition of claim 29, wherein each of R, and R 2 of said light attenuating compound is individually selected from the group consisting of hydrogen. alkyls, and heteroalkyls 40. The composition of claim 38. wherein each of R, and R 2 of said light attenuating compound is individually selected from the group consisting of cyclic alkyls and acyclic alkyls.

Inventors: COX ROBERT, DESHPANDE SHREERAM V, FLAIM TONY D, PULIGADDA RAMA, SHAO XIE, COX, ROBERT, DESHPANDE, SHREERAM, V., FLAIM, TONY, D., PULIGADDA, RAMA, SHAO, XIE
Applicants: BREWER SCIENCE INC, BREWER SCIENCE, INC.
Application year: 2000
Main classification: G03C1
IPC codes: C08G18, C08G59, G03F7