Modified Facet Etch to Prevent Blown Gate Oxide and Increase Etch Chamber Life

Abstract

A modified facet etch is disclosed to prevent blown gate oxide and increase etch chamber life. The modified facet etch is a two-stage process. The first stage is a plasma sputter etch to form a facet profile. The first stage etch is terminated prior to reaching the target depth for the etching process. The second stage etch is a reactive ion etch which directionally follows the facet profile to reach the target depth.

1 . An intermediate for a semiconductor device, the intermediate comprising: 
 a substrate comprising a plurality of conductive structures, at least some of the conductive structures being placed apart to form spaces between the conductive structures;    an exposed layer of insulating material which is in direct contact with the substrate and in at least some of the spaces between the conductive structures, wherein the semiconductor device requires a facet etch to a target depth in the exposed layer; and,    a facet etch in the exposed layer having a predetermined depth which is less than the target depth.    
   
   
       2 . The intermediate of  claim 1  wherein the exposed layer comprises silicon dioxide or boron phosphosilicate glass.  
   
   
       3 . The intermediate of  claim 1  wherein the conductive structures form at least one of metal lines, interconnects and leads.  
   
   
       4 . The intermediate of  claim 1  wherein the conductive structures comprise at least one of titanium, tungsten, tantalum, molybdenum, aluminum, copper, gold, silver, nitrides thereof and silicides thereof.  
   
   
       5 . The intermediate of  claim 1  wherein the predetermined depth is no more than about 150 Å less than the target depth.  
   
   
       6 . The intermediate of  claim 1  wherein the predetermined depth is no more than about 100 Å less than the target depth.  
   
   
       7 . The intermediate of  claim 1  wherein the predetermined depth is about 50 Å less than the target depth.  
   
   
       8 . An intermediate for a semiconductor device that requires a facet etch to a target depth in an exposed layer of insulating material, the intermediate comprising: 
 a substrate comprising a plurality of conductive structures, at least some of the conductive structures being placed apart to form spaces between the conductive structures;    an exposed layer of insulating material which is in direct contact with the substrate and in at least some of the spaces between the conductive structures; and,    an intermediate facet etch in the exposed layer having a predetermined depth which is less than the target depth, wherein the intermediate facet etch was formed by a sputter etching method.    
   
   
       9 . The intermediate of  claim 8  wherein the exposed layer comprises silicon dioxide or boron phosphosilicate glass.  
   
   
       10 . The intermediate of  claim 8  wherein the conductive structures form at least one of metal lines, interconnects and leads.  
   
   
       11 . The intermediate of  claim 8  wherein the conductive structures comprise at least one of titanium, tungsten, tantalum, molybdenum, aluminum, copper, gold, silver, nitrides thereof and silicides thereof.  
   
   
       12 . The intermediate of  claim 8  wherein the predetermined depth is no more than about 150 Å less than the target depth.  
   
   
       13 . The intermediate of  claim 8  wherein the predetermined depth is no more than about 100 Å less than the target depth.  
   
   
       14 . The intermediate of  claim 8  wherein the predetermined depth is about 50 Å less than the target depth.  
   
   
       15 . The intermediate of  claim 8  wherein the sputter etching method comprises etching the exposed layer by directing a plasma beam at the exposed layer formed in at least some of the spaces between the conductive structures, wherein the plasma is of sufficient energy to sputter material from the exposed layer and the plasma is an ion of an inert gas.  
   
   
       16 . A method of making a semiconductor device that requires a facet etch to a target depth in an exposed layer of insulating material, the method comprising: 
 providing an the intermediate comprising: a substrate comprising a plurality of conductive structures, at least some of the conductive structures being placed apart to form spaces between the conductive structures; an exposed layer of insulating material which is in direct contact with the substrate and in at least some of the spaces between the conductive structures; and, an intermediate facet etch in the exposed layer having a predetermined depth which is less than the target depth, wherein the intermediate facet etch was formed by a sputter etching method;    etching the exposed layer by contacting the exposed layer with a reactive chemical gas/plasma; and    terminating the etch when the exposed layer has been etched to the target depth.    
   
   
       17 . The method of  claim 16  wherein the exposed layer comprises silicon dioxide or boron phosphosilicate glass.  
   
   
       18 . The method of  claim 16  wherein the conductive structures form at least one of metal lines, interconnects and leads.  
   
   
       19 . The method of  claim 16  wherein the conductive structures comprise at least one of titanium, tungsten, tantalum, molybdenum, aluminum, copper, gold, silver, nitrides thereof and silicides thereof.  
   
   
       20 . The method of  claim 16  wherein the predetermined depth is no more than about 150 Å less than the target depth.  
   
   
       21 . The method of  claim 16  wherein the predetermined depth is no more than about 100 Å less than the target depth.  
   
   
       22 . The method of  claim 16  wherein the predetermined depth is about 50 Å less than the target depth.