Silacyclic Compounds and Methods for Depositing Silicon-Containing Films Using Same

Abstract

A method and composition for producing a porous low k dielectric film via chemical vapor deposition includes the steps of: providing a substrate within a reaction chamber; introducing into the reaction chamber gaseous reagents including at least one structure-forming precursor comprising an silacyclic compound, and with or without a porogen; applying energy to the gaseous reagents in the reaction chamber to induce reaction of the gaseous reagents to deposit a preliminary film on the substrate, wherein the preliminary film contains the porogen, and the preliminary film is deposited; and removing from the preliminary film at least a portion of the porogen contained therein and provide the film with pores and a dielectric constant of 3.0 or less. In certain embodiments, the structure-forming precursor further comprises a hardening additive.

1 . A method for producing a dielectric film represented by the formula Si v O w C x H y F z , wherein v+w+x+y+z=100%, v is from 10 to 35 at. %, w is from 10 to 65 at. %, x is from 5 to 40 at. %, y is from 10 to 50 at. % and z is from 0 to 15 at. %, said method comprising:
 providing a substrate within a reaction chamber;   introducing into the reaction chamber gaseous reagents comprising at least one structure-forming precursor comprising an silacyclic compound, wherein the silacyclic compound contains less than about 100 ppm of impurities; and   applying energy to the gaseous reagents in the reaction chamber to induce reaction of the gaseous reagents and thereby deposit a film on the substrate.   
     
     
         2 . The method of  claim 1  wherein the gaseous reagents further comprise a structure forming reagent comprising a hardening additive selected from tetraethoxysilane and tetramethoxysilane. 
     
     
         3 . The method of  claim 1  wherein the silacyclic compound comprises a compound having the following Formula I: 
       
         
           
           
               
               
           
         
         wherein R 1  is selected from hydrogen, a linear or branched C 1  to C 10  alkyl group, a linear or branched C 2  to C 10  alkenyl group, a linear or branched C 2  to C 10  alkynyl group, a C 3  to C 10  cyclic alkyl group, a C 3  to C 10  hetero-cyclic alkyl group, a C 5  to C 10  aryl or aralkyl_group, and a C 3  to C 10  hetero-aryl group; R 2  is selected from hydrogen, a linear or branched C 1  to C 10  alkyl group, a linear or branched C 2  to C 10  alkenyl group, a linear or branched C 2  to C 10  alkynyl group, a C 3  to C 10  cyclic alkyl group, a C 3  to C 10  hetero-cyclic alkyl group, a C 5  to C 10  aryl or aralkyl group, and a C 3  to C 10  hetero-aryl group; and R 3  is selected from a C 3  to C 10  alkyl di-radical which forms a four-membered, five-membered, or six-membered saturated or unsaturated cyclic ring with the Si atom wherein the silacyclic compound contains less than about 100 ppm of impurities. 
       
     
     
         4 . The method of  claim 3  wherein the silacyclic compound comprises at least one compound selected from the group consisting of 1-methyl-1-acetoxy-1-silacyclopentane, 1-methyl-1-propionoxy-1-silacyclopentane, 1-methyl-1-acetoxy-1-silacyclobutane, 1-methyl-1-propionoxy-1-silacyclobutane, 1-methyl-1-acetoxy-1-silacyclohexane, 1-methyl-1-propionoxy-1-silacyclohexane, 1-ethyl-1-acetoxy-1-silacyclopentane, 1-ethyl-1-propionoxy-1-silacyclopentane, 1-ethyl-1-acetoxy-1-silacyclobutane, 1-ethyl-1-propionoxy-1-silacyclobutane, 1-ethyl-1-acetoxy-1-silacyclohexane, 1-ethyl-1-propionoxy-1-silacyclohexane and combinations thereof. 
     
     
         5 . The method of  claim 4  wherein the silacyclic compound comprises 1-methyl-1-acetoxy-1-silacyclopentane. 
     
     
         6 . The method of  claim 1  wherein the method is plasma enhanced chemical vapor deposition. 
     
     
         7 . The method of  claim 1  wherein the gaseous reagents further comprise at least one oxidant selected from the group consisting of O 2 , N 2 O, NO, NO 2 , CO 2 , water, H 2 O 2 , ozone, and mixtures thereof, wherein the gaseous reagents are free of an oxidant. 
     
     
         8 . The method of  claim 1  wherein the reaction chamber in the applying step further comprises at least one gas selected from He, Ar, N 2 , Kr, Xe, NH 3 , H 2 , CO 2 , or CO. 
     
     
         9 . The method of  claim 1  further comprising an additional post deposition treatment step, which comprises at least one of a thermal treatment, a UV annealing, an e-beam treatment, and a gamma radiation treatment. 
     
     
         10 . The method of  claim 9  wherein the post deposition treatment step comprises both UV annealing and thermal treatment. 
     
     
         11 . The method of  claim 1  wherein the as deposited film includes 30 at. % or higher carbon, has an elastic modulus of 13 GPa or higher; and has a film hardness of 2.0 GPa or higher. 
     
     
         12 . The method of  claim 1  wherein the as deposited film is subsequently UV cured and the cured film includes 25 at. % or higher carbon, has an elastic modulus of 15 GPa or higher, and has a hardness of 3.0 GPa or higher. 
     
     
         13 . The method of  claim 1 ;
 wherein the gaseous reagents further comprise a porogen;   wherein the as deposited film is a preliminary film including the porogen; and wherein the method further comprises:   removing from the preliminary film at least a portion of the porogen to provide the porous dielectric film comprising pores and having a dielectric constant of 2.6 or less.   
     
     
         14 . The method of  claim 13  wherein the porogen is at least one compound selected from the group consisting of:
 cyclic hydrocarbons of the general formula C n H 2n  where n=4-14, wherein the number of carbons in the cyclic structure is between 4 and 10, and wherein one or more simple or branched hydrocarbon substituents are optionally present on the cyclic structure; 
 linear or branched, saturated, singly or multiply unsaturated hydrocarbons of the general formula C n H (2n+2)-2m  wherein n=2-20 and m=0-n; 
 singly or multiply unsaturated cyclic hydrocarbons of the general formula C n H 2n-2p  wherein p is the number of unsaturated sites in the molecule, n=4-14, the number of carbons in the cyclic structure is between 4 and 10, and wherein one or more simple or branched hydrocarbon substituents are optionally present on o the cyclic structure; 
 bicyclic hydrocarbons of the general formula C n H 2n-2  wherein n=4-14, the number of carbons in the bicyclic structure is between 4 and 12, and wherein one or more simple or branched hydrocarbon substituents are optionally present on the cyclic structure; 
 multiply unsaturated bicyclic hydrocarbons of the general formula C n H 2n-(2+2m)  wherein m is the number of unsaturated sites in the molecule, n=4-14, the number of carbons in the bicyclic structure is between 4 and 12, and wherein one or more simple or branched hydrocarbon substituents are optionally present on the cyclic structure; and 
 tricyclic hydrocarbons of the general formula C n H 2n-4  wherein n=4-14, the number of carbons in the tricyclic structure is between 4 and 12, and wherein one or more simple or branched hydrocarbon substituents are optionally present on the cyclic structure. 
 
     
     
         15 . The method of  claim 14  wherein the porogen comprises at least one compound selected from the group consisting of cyclohexane, 1,2,4-trimethylcyclohexane, 1-methyl-4-(1-methylethyl)cyclohexane, cyclooctane, methylcyclooctane, ethylene, propylene, acetylene, neohexane, 1,3-butadiene, 2-methyl-1,3-butadiene, 2,3-dimethyl-2,3-butadiene, substituted dienes, para-cymene, cyclooctene, 1,5-cyclooctadiene, cyclohexene, vinyl-cyclohexane, dimethylcyclohexene, alpha-terpinene, pinene, limonene, vinyl-cyclohexene, norbornane, spiro-nonane, camphene, norbornene, norbornadiene, 5-ethylidene-2-norbornene, decahydronaphthalene, and adamantane. 
     
     
         16 . The method of  claim 1  wherein the film structure comprises at least one of —CH 2 — methylene and —CH 2 CH 2 — ethylene bridges.