Method of forming trench isolation regions

Abstract

In accordance with an aspect of the invention, a method of forming a trench isolation region includes forming a trench within a substrate. A silanol layer is formed to partially fill the trench and then converted, at least some of the silanol, to a compound including at least one of SiO n and RSiO n , where R includes an organic group. An electrically insulative material is formed over the converted silanol to fill the trench. In another aspect of the invention, a method of forming a trench isolation region includes forming a trench within a substrate. A first layer of at least one of Si(OH), and (CH 3 ) y Si(OH) 4-y is formed to partially fill the trench. At least some of the Si(OH), if present is converted to SiO 2 and at least some of (CH 3 ) y Si(OH) 4-y if present is converted to (CH 3 ),SiO 2-x . Next, a layer of an electrically insulative material is formed to fill the trench.

1 . A method of forming a trench isolation region comprising: 
 forming a trench within a substrate;    forming a first layer comprising a silanol to partially fill the trench;    converting at least some of the silanol to a compound comprising at least one of SiO n  and RSiO n , where R comprises an organic group; and    forming a second layer comprising an electrically insulative material over the converted silanol to within the trench.    
     
     
         2 . The method of    claim 1    wherein the trench has sidewalls, and further comprising thermally oxidizing at least some of the trench sidewalls intermediate the converting and the forming of the second layer.  
     
     
         3 . The method of    claim 1    wherein the trench has a trench depth, the first layer filling at least 25% of the trench depth.  
     
     
         4 . The method of    claim 1    wherein the trench has a trench depth, the first layer filling 35% or less of the trench depth.  
     
     
         5 . The method of    claim 1    wherein the second layer fills the trench.  
     
     
         6 . The method of    claim 1    wherein the silanol comprises methyl silanol and R is a methyl group.  
     
     
         7 . The method of    claim 1    wherein the second layer is formed by chemical vapor deposition.  
     
     
         8 . The method of    claim 1    wherein the second layer is formed by plasma-enhanced chemical vapor deposition.  
     
     
         9 . The method of    claim 1    wherein the second layer comprises SiO 2 .  
     
     
         10 . The method of    claim 9    wherein the SiO 2  is formed by a high density plasma.  
     
     
         11 . The method of    claim 1    wherein the trench comprises sidewalls, thermally oxidizing the sidewalls prior to forming the first layer.  
     
     
         12 . The method of    claim 1    wherein the trench comprises sidewalls, thermally oxidizing the sidewalls after forming the first layer and before forming the second layer.  
     
     
         13 . The method of    claim 1    wherein the trench comprises sidewalls and the first layer adds 200 angstroms or less of layer to the sidewalls.  
     
     
         14 . The method of    claim 1    wherein prior to forming the second layer, maintaining the first layer at a temperature of at least about 300° C. and at a pressure of at least about  10  atmospheres effective to drive water from first layer.  
     
     
         15 . The method of    claim 1    wherein converting the first layer comprises exposing the first layer to ultraviolet light.  
     
     
         16 . A method of forming a trench isolation region comprising: 
 forming a trench within a substrate;    chemical vapor depositing an electrically insulating first layer to within the trench to partially fill the trench;    forming a second layer comprising a silanol over the first layer to within the trench; and    converting at least some of the silanol to a compound comprising at least one of SiO n  and RSiO n , where “R” comprises an organic group.    
     
     
         17 . The method of    claim 16    wherein the trench is formed in silicon, and wherein the chemical vapor depositing comprises substantially selectively depositing an oxide over exposed silicon within the trench.  
     
     
         18 . The method of    claim 17    wherein the substantially selectively depositing the oxide comprises flowing O 3  and TEOS to within the trench.  
     
     
         19 . The method of    claim 16    wherein the trench comprises silicon-comprising sidewalls and a silicon-comprising base, and further comprising forming an electrically insulative layer over the sidewalls and the base; anisotropically etching the insulative layer to expose silicon of the base while leaving silicon of the sidewalls covered; and the chemical vapor depositing comprising substantially selectively depositing an oxide over the exposed trench base.  
     
     
         20 . The method of    claim 19    wherein the forming of the electrically insulative layer comprises chemical vapor deposition.  
     
     
         21 . The method of    claim 19    wherein the electrically insulative material comprises silicon dioxide, and the forming of the electrically insulative layer comprises thermal oxidation.  
     
     
         22 . The method of    claim 16    wherein the trench has sidewalls, and further comprising thermally oxidizing at least some of the trench sidewalls intermediate the chemical vapor depositing and the forming of the second layer.  
     
     
         23 . The method of    claim 16    wherein the trench has a trench depth, the first layer filling at least 25% of the trench depth.  
     
     
         24 . The method of    claim 16    wherein the second layer fills the trench.  
     
     
         25 . The method of    claim 16    wherein the silanol comprises methyl silanol and R is a methyl group.  
     
     
         26 . The method of    claim 16    wherein the first layer is deposited by plasma-enhanced chemical vapor deposition.  
     
     
         27 . The method of    claim 16    wherein the first layer comprises SiO 2 .  
     
     
         28 . The method of    claim 27    wherein the SiO 2  is deposited by a high density plasma.  
     
     
         29 . The method of    claim 16    further comprising thermally oxidizing sidewalls of the trench prior to depositing the first layer.  
     
     
         30 . The method of    claim 16    further comprising thermally oxidizing sidewalls of the trench after depositing the first layer and before forming the second layer.  
     
     
         31 . The method of    claim 16    further including maintaining the second layer at a temperature of at least about 300° C. and at a pressure of at least about 10 atmospheres effective to drive water from the second layer.  
     
     
         32 . The method of    claim 16    wherein converting the second layer comprises exposing the second layer to ultraviolet light.  
     
     
         33 . A method of forming a trench isolation region comprising: forming a trench within a substrate, the trench comprising silicon-comprising sidewalls and a silicon-comprising base; 
 forming a first electrically insulative layer over the sidewalls and base;    anisotropically etching the first electrically insulative layer to expose silicon of the base while leaving silicon of the sidewalls covered; substantially selectively chemical vapor depositing a second electrically insulative layer over the exposed trench base; and    forming a third electrically insulative layer over the first and second insulative layers to within the trench.    
     
     
         34 . The method of    claim 33    wherein the third electrically insulative layer comprises a silanol, and further comprising converting at least some of the silanol to a compound comprising at least one of SiO n  and RSiO n , where R comprises an organic group.  
     
     
         35 . The method of    claim 34    wherein the silanol comprises methyl silanol and R is a methyl group.  
     
     
         36 . The method of    claim 33    wherein the substantially selectively depositing comprises flowing O 3  and TEOS to within the trench to form an oxide.  
     
     
         37 . The method of    claim 33    wherein the third electrically insulative layer comprises SiO 2 .  
     
     
         38 . The method of    claim 33    wherein the third electrically insulative layer is formed by plasma-enhanced chemical vapor deposition.  
     
     
         39 . A method of forming a trench isolation region comprising: 
 forming a trench within a substrate, and the trench comprising sidewalls and a base;    thermally oxidizing the sidewalls and base of the trench in an oxidizing environment, the oxidizing environment comprising oxygen and hydrogen and having a greater molar concentration of hydrogen than oxygen;    forming a layer comprising a silanol to within the trench; and    converting at least some of the silanol to a compound comprising at least one of SiO n  and RSiO n , where R comprises an organic group.    
     
     
         40 . The method of    claim 39    wherein the silanol comprises methyl silanol and R is a methyl group.  
     
     
         41 . The method of    claim 39    wherein the oxidizing environment further comprises maintaining the substrate at from 800° C. to 1100° C.  
     
     
         42 . The method of    claim 39    wherein the oxidizing environment further comprises maintaining the substrate within a reactor having a pressure at from 10 Torr to 760 Torr.  
     
     
         43 . The method of    claim 39    wherein the oxidizing environment further comprises maintaining the substrate within a reactor at from 800° C. to 1100° C. and a pressure at from 10 Torr to 760 Torr.  
     
     
         44 . A method of forming a trench isolation region comprising: 
 forming a trench within a substrate, and the trench comprising sidewalls and a base;    forming a layer comprising a silanol to within the trench;    converting at least some of the silanol to a compound comprising at least one of SiO n  and RSiO n , where R comprises an organic group; and    after the converting, thermally oxidizing the sidewalls and base of the trench in an oxidizing environment.    
     
     
         45 . The method of    claim 44    wherein the silanol comprises at least one of Si(OH) x  and (CH 3 ) y Si(OH) 4-y , and the converting comprises converting at least some of the Si(OH), if present to SiO 2  and at least some of (CH 3 ) y Si(OH) 4-y  if present to (CH 3 ) x SiO 2-x .  
     
     
         46 . The method of    claim 44    wherein the oxidizing environment further comprises maintaining the substrate in a reactor at from 850° C. to 1150° C. and a pressure at from 10 Torr to 760 Torr.  
     
     
         47 . A method of forming a trench isolation region comprising the following steps: 
 forming a trench within a substrate;    forming a first layer comprising at least one of Si(OH), and (CH 3 ) y Si(OH) 4-y  to partially fill the trench;    converting at least some of the Si(OH), if present to SiO 2  and at least some of (CH 3 ) y Si(OH) 4-y  if present to (CH 3 ) x SiO 2-x ; and    after the converting, forming a second layer comprising an electrically insulative material to within the trench.    
     
     
         48 . The method of    claim 47    wherein the trench has sidewalls, and further comprising thermally oxidizing at least some of the trench sidewalls intermediate the converting and the forming of the second layer.  
     
     
         49 . The method of    claim 47    wherein the trench has a trench depth, the first layer filling at least 25% of the trench depth.  
     
     
         50 . The method of    claim 47    wherein the second layer comprises SiO 2 .  
     
     
         51 . The method of    claim 50    wherein the SiO 2  is formed by a high density plasma.  
     
     
         52 . The method of    claim 47    wherein the trench comprises sidewalls, and further comprising thermally oxidizing the sidewalls prior to forming the first layer.  
     
     
         53 . The method of    claim 47    wherein the trench comprises sidewalls, and further comprising thermally oxidizing the sidewalls after forming the first layer and before forming the second layer.  
     
     
         54 . The method of    claim 47    wherein the trench comprises sidewalls and the first layer adds 200 angstroms or less of layer to the sidewalls.  
     
     
         55 . A method of forming a trench isolation region comprising the following steps: 
 forming a trench within a substrate;    forming a high density plasma proximate the substrate to deposit a first layer of material to partially fill the trench;    forming a second layer comprising at least one of Si(OH), and (CH 3 ) y Si(OH) 4-y  over the first layer to within the trench; and    converting at least some of the Si(OH), if present to SiO, and at least some of (CH 3 ) y Si(OH) 4-y  if present to (CH 3 ) x SiO 2-x .    
     
     
         56 . The method of    claim 55    wherein the trench has sidewalls, and further comprising thermally oxidizing at least some of the trench sidewalls intermediate the forming of the high density plasma and the forming of the second layer.  
     
     
         57 . The method of    claim 55    wherein the trench has a trench depth, the first layer filling at least 25% of the trench depth.  
     
     
         58 . The method of    claim 55    wherein the second layer fills the trench.  
     
     
         59 . The method of    claim 55    wherein the first layer comprises SiO 2 .  
     
     
         60 . The method of    claim 55    wherein the trench comprises sidewalls, and further comprising thermally oxidizing the sidewalls prior to forming the first layer.  
     
     
         61 . The method of    claim 55    wherein the trench comprises sidewalls, and further comprising thermally oxidizing the sidewalls after forming the first layer and before forming the second layer.  
     
     
         62 . The method of    claim 55    further including maintaining the second layer at a temperature of at least about 300° C. and at a pressure of at least about 10 atmospheres effective to drive water from second layer.  
     
     
         63 . The method of    claim 55    wherein converting the second layer comprises exposing the second layer to ultraviolet light.