Simplified etching technique for producing multiple undercut profiles

Abstract

A process for producing multiple undercut profiles in a single material. A resist pattern is applied over a work piece and a wet etch is performed to produce an undercut in the material. This first wet etch is followed by a polymerizing dry etch that produces a polymer film in the undercut created by the first wet etch. The polymer film prevents further etching of the undercut portion during a second wet etch. Thus, an undercut profile can be obtained having a larger undercut in an underlying portion of the work piece, utilizing only a single resist application step. The work piece may be a multi-layer work piece having different layers formed of the same material, or it may be a single layer of material.

1 . A method of processing a semiconductor device, comprising: defining a non-horizontal surface of a first material within a semiconductor device; exposing the semiconductor device to a first material-etching substance; and protecting the non-horizontal surface from the first material-etching substance.  
   
   
       2 . The method in  claim 1 , wherein protecting the non-horizontal surface further comprises forming a polymer on the non-horizontal surface.  
   
   
       3 . The method in  claim 1 , wherein defining a non-horizontal surface further comprises defining a non-horizontal surface underlying a generally horizontal surface.  
   
   
       4 . The method in  claim 3 , wherein defining a non-horizontal surface further comprises defining a non-horizontal surface underlying an additional portion of the first material.  
   
   
       5 . The method in  claim 4 , wherein defining a non-horizontal surface further comprises defining a generally vertical surface.  
   
   
       6 . The method in  claim 5 , further comprising exposing the semiconductor device to the first material-etching substance a second time.  
   
   
       7 . A method of profiling a semiconductor device including a material, comprising: 
 providing a patterned mask over a material;    performing a first etch of the material while guiding the first etch with the patterned mask;    adding a polymer to an etched portion of the material; and    performing a second etch of the material while guiding the second etch with the patterned mask and the polymer.    
   
   
       8 . A method of producing multiple undercut profiles within a semiconductor device, comprising: 
 defining a plurality of levels within a semiconductor device using a plurality of etches;    generating a polymer on a side of at least one of the plurality of levels after at least one etch of the plurality of etches; and    performing at least one etch of the plurality of etches after generating the polymer.    
   
   
       9 . The method in  claim 8 , wherein defining a plurality of levels further comprises defining a plurality of levels within an insulator included as part of the semiconductor device.  
   
   
       10 . A method of forming a semiconductor device on a substrate, comprising: 
 providing a bottom portion of a dielectric over a substrate;    providing a top portion of a dielectric over the bottom portion;    exposing the top portion to a first undercutting ambient; and    exposing the bottom portion to a second undercutting ambient while protecting the top portion from the second undercutting ambient.    
   
   
       11 . The method in  claim 10 , further comprising: 
 providing a mask over the top portion of the dielectric;    exposing the top portion through an opening in the mask; and    protecting the top portion by etching the top portion.    
   
   
       12 . The method in  claim 11 , wherein exposing the bottom portion further comprises exposing the bottom portion through the opening in the mask and through an opening in the top portion; and wherein providing the top portion further comprises lining the opening in the top portion with a polymer.  
   
   
       13 . The method in  claim 10 , wherein providing a top portion of a dielectric further comprises providing a dielectric of a same type as the dielectric of the bottom portion.  
   
   
       14 . The method in  claim 10 , wherein providing a top portion of a dielectric further comprises providing a top portion discrete from the bottom portion.  
   
   
       15 . The method in  claim 14 , wherein exposing the bottom portion to a second undercutting ambient further comprises exposing the bottom portion to a second undercutting ambient of a same type as the first undercutting ambient.  
   
   
       16 . A method of etching a material included within a semiconductor device, comprising: 
 providing an etch-guiding layer over a material included within a semiconductor device;    defining a first sidewall within the material under the etch-guiding layer;    providing an etch-guiding liner on the first sidewall; and    defining a second sidewall within the material under the etch-guiding liner.    
   
   
       17 . A method of generating a plurality of etch profiles in a semiconductor device covered by a mask, comprising: 
 etching a first perimeter from a semiconductor device through a first opening in a mask;    etching a second perimeter under the first perimeter; and    generally retaining the first perimeter while etching the second perimeter.    
   
   
       18 . The method in  claim 17 , further comprising providing a lining around the first perimeter and wherein generally retaining the first perimeter further comprises protecting the first perimeter with the lining.  
   
   
       19 . A method of defining different profiles within at least one layer of a semiconductor device using a single mask over the at least one layer, comprising: generally allowing etches of at least one layer through an opening in a mask; and preventing a particular etch from affecting a particular profile.  
   
   
       20 . The method in  claim 19 , wherein preventing a particular etch from affecting a particular profile further comprises protecting the particular profile during an etch of a portion of the at least one layer that is lower than the particular profile.  
   
   
       21 . The method in  claim 20 , wherein etching the particular profile further comprises polymer etching the particular profile.  
   
   
       22 . The method in  claim 21 , wherein etching the particular profile further comprises polymer etching the particular profile.  
   
   
       23 . The method in  claim 21 , wherein etching the particular profile further comprises dry etching the particular profile.  
   
   
       24 . A method of producing a semiconductor device, comprising: 
 wet etching a semiconductor device;    reducing an effect of a subsequent wet etch on the semiconductor device; and    subsequently wet etching the semiconductor device.    
   
   
       25 . The method in  claim 24 , wherein reducing an effect of a subsequent wet etch further comprises: 
 producing a carbonaceous film on an etched portion of the semiconductor device; and    allowing the carbonaceous film to remain on the semiconductor device during the subsequent wet etch.    
   
   
       26 . The method in  claim 25 , wherein wet etching the semiconductor device further comprises defining a generally vertical sidewall from the etched portion, and producing a carbonaceous film further comprises producing a carbonaceous film on the sidewall.  
   
   
       27 . The method of  claim 26 , further comprising removing the carbonaceous film.