Ethyleneoxide-silane and bridged silane precursors for forming low k films

Abstract

An organosilicon precursor for vapor deposition, e.g., low pressure (<100 Torr), plasma-enhanced chemical vapor deposition (PECVD) of a low k, high strength dielectric film, wherein the precursor includes at least one of: (i) silicon-pendant oxiranyl functionality; and (ii) a disilyl moiety of the formula wherein x is an integer having a value of from 0 to 4 inclusive. These precursors are useful for the formation of dielectric films having dielectric constants on the order of ˜3 and less, and a hardness exceeding ˜1 GigaPascals.

1 . An oxiranylsilane compound of formula (I):  
     
       
         
         
             
             
         
       
       wherein:  
       m is an integer having a value of 0 to 6, inclusive;  
       n is 0 or 1;  
       x is an integer having a value of 0 to 3, inclusive; and  
       each R and R* can be the same as or different from one another and each is independently selected from the group consisting of H, C 1 -C 8  alkyl, C 1 -C 8  fluoroalkyl, C 1 -C 8  alkoxy, C 6 -C 10  cycloalkyl, C 6 -C 10  aryl, C 6 -C 10  fluoroaryl, C 2 -C 6  vinyl, and C 3 -C 6  allyl,  
       with the provisos that:  
       when m is 4, n is 0, and x is 3, all R cannot be methyl;  
       when m is 0, n is 1 and x is 1, R cannot be fluoroalkyl;  
       when m is 0, x is 2 or 3, all R cannot be methyl, methoxy, or ethoxy; and  
       when m=n=0, x is 3, and one ethoxy is present, then the remaining R cannot both be phenyl.  
     
   
   
       2 . An organosilicon precursor composition for forming a low k dielectric film, comprising: 
 (A) an oxiranylsilane compound of formula (I):                          wherein:    m is an integer having a value of 0 to 6, inclusive;    n is 0 or 1;    x is an integer having a value of 0 to 3, inclusive; and    each R and R* can be the same as or different from one another and each is independently selected from the group consisting of H, C 1 -C 8  alkyl, C 1 -C 8  fluoroalkyl, C 1 -C 8  alkoxy, C 6 -C 10  cycloalkyl, C 6 -C 10  aryl, C 6 -C 10  fluoroaryl, C 2 -C 6  vinyl, and C 3 -C 6  allyl,    with the provisos that:    when m is 4, n is 0, and x is 3, all R cannot be methyl;    when m is 0, n is 1 and x is 1, R cannot be fluoroalkyl;    when m is 0, x is 2 or 3, all R cannot be methyl, methoxy, or ethoxy; and    when m=n=0, x is 3, and one ethoxy is present, then the remaining R cannot both be phenyl; and    (B) a porogen.    
   
   
       3 . An oxiranylsilane dielectric film having a dielectric constant below about 3 and hardness above 1 GPa.  
   
   
       4 . A method of increasing hardness of a dielectric film formed from a silicon-containing precursor, said method comprising at least one of (A) and (B): 
 (A) providing in said silicon-containing precursor a disilane in which Si atoms are bridged by C 1 -C 4  alkylene, of the formula —(CH 2 ) y — wherein y is an integer having a value of from 1 to 4; and    (B) providing in said silicon-containing precursor a silane in which at least one pendant oxiranylmethylene functionality of the formula                          is bonded to a silicon atom.    
   
   
       5 . An organosilicon precursor composition for forming a low k dielectric film, comprising: 
 (I) a cyclosiloxane precursor; and    (II) at least one additional precursor selected from the group consisting of: 
 (A) disilanes in which Si atoms are bridged by C 1 -C 4  alkylene, of the formula —(CH 2 ) y — wherein y is an integer having a value of from 1 to 4;  
 (B) silanes in which at least one pendant oxiranylmethylene functionality of the formula  
                     
   is bonded to a silicon atom; and 
 (C) combinations of (A) and (B).