Technologies for selectively etching oxide and nitride materials and products formed using the same

Abstract

Technologies for selectively etching oxide and nitride materials on a work piece are described. Such technologies include methods for etching a work piece with a remote plasma that is produced by igniting a plasma gas flow. By controlling the flow rate of various components of the plasma gas flow, plasmas exhibiting desired etching characteristics may be obtained. Such plasmas may be used in single or multistep etching operations, such as recess etching operations that may be used in the production of non-planar microelectronic devices.

What is claimed is: 
     
         1 - 25 . (canceled) 
     
     
         26 . A method for selectively etching oxide and nitride on a work piece, comprising:
 exposing the work piece to a first plasma comprising reactive species of a first plasma gas flow to remove at least a portion of said oxide and nitride at a first oxide:nitride etch ratio, the first plasma gas flow comprising nitrogen trifluoride gas (NF 3 ), ammonia gas (NH 3 ), and hydrogen gas (H 2 );   exposing the work piece to a second plasma comprising reactive species of a second plasma gas flow to remove at least a portion of said oxide and said nitride at a second oxide:nitride etch ratio, the second plasma gas flow comprising NF 3 , NH 3 , and H 2 ;   wherein said first and second oxide:nitride etch ratios are different.   
     
     
         27 . The method of  claim 26 , wherein said first oxide:nitride etch ratio ranges from greater than 1:1 to about 10:1, and said second oxide:nitride etch ratio ranges from less than 1:1 to about 1:1.4. 
     
     
         28 . The method of  claim 27 , wherein said first plasma gas flow comprises said NF 3  at a flow rate ranging from about 5 to about 60 sccm, said NH 3  at a flow rate ranging from 0 to about 100 sccm, and said H 2  at a flow rate of about 100 to about 300 sccm. 
     
     
         29 . The method of  claim 28 , wherein said first plasma gas flow comprises said NF 3  at a flow rate ranging from about 5 to about 40 sccm, said NH 3  at a flow rate ranging from about 65 to about 90 sccm, and said H 2  at a flow rate of about 120 to about 150 sccm. 
     
     
         30 . The method of  claim 27 , wherein said second plasma gas flow comprises said NF 3  at a flow rate ranging from about 30 to about 60 sccm, said NH 3  at a flow rate ranging from 0 to about 100 sccm, and said H 2  at a flow rate of about 100 to about 300 sccm. 
     
     
         31 . The method of  claim 30 , wherein said first plasma gas composition comprises said NF 3  at a flow rate ranging from about 5 to about 40 sccm, said NH 3  at a flow rate ranging from about 65 to about 90 sccm, and said H 2  at a flow rate of about 120 to about 150 sccm. 
     
     
         32 . The method of  claim 26 , wherein said first and second plasma gas flows each further comprise at least one inert gas. 
     
     
         33 . The method of  claim 26 , further comprising:
 annealing said work piece to remove at least one byproduct produced by exposing said work piece to said first plasma; and   annealing said work piece to remove at least on byproduct produced by exposing said work piece to said second plasma.   
     
     
         34 . The method of  claim 26 , wherein said first plasma is generated with a first applied power and said second plasma is generated with a second applied power, and the method further comprises:
 adjusting said first applied power to adjust said first oxide:nitride etch rate; and   adjusting said second applied power to adjust said second oxide:nitride etch rate.   
     
     
         35 . The method of  claim 26 , wherein said oxide is selected from the group consisting of silicon oxide, a silicate, carbon doped oxide, spun on glass, and combinations thereof. 
     
     
         36 . The method of  claim 26 , wherein said nitride comprises at least one of a silicon nitride, a silicon oxynitride, and combinations thereof. 
     
     
         37 . The method of  claim 26 , wherein said work piece comprises at least a part of a semiconductor device, a precursor of a semiconductor device, or a combination thereof. 
     
     
         38 . The method of  claim 26 , wherein said work piece comprises:
 first and second fins laterally offset by a fin pitch of less than or equal to 50 nm, so as to define a first field there between;   a conformal oxide layer disposed on at least said first fin, said second fin;   a conformal nitride layer disposed on said conformal first oxide layer;   a sacrificial oxide material disposed on said conformal nitride layer and within said first field so as to embed said first and second fins.   
     
     
         39 . The method of  claim 38 , wherein:
 exposing said work piece to said first plasma removes at least a portion of said sacrificial oxide material from said first field and exposes at least a portion of said first and second fins; and   exposing said work piece to said second plasma removes at least a portion of said conformal oxide layer and said conformal nitride layer from said first and second fins, such that a height of the first and second fins extending above said conformal oxide and nitride layers is greater than about 35 nm.   
     
     
         40 . The method of  claim 39 , wherein after exposing said work piece to said second plasma, the conformal nitride layer remaining on said first and second fins protrudes above an upper surface of sacrificial oxide material within said first field by less than about 5 nm. 
     
     
         41 . The method of  39 , wherein:
 said work piece further comprises a third fin laterally offset from said second fin by a fin pitch of greater than 50 nm so as to define a second field between said second and third fins;   said conformal oxide layer is further disposed on at least said third fin; and   said sacrificial oxide material is further disposed on said conformal nitride layer and within said second field so as to embed said third fin.   
     
     
         42 . The method of  claim 41 , wherein:
 exposing said work piece to said first plasma removes at least a portion of said sacrificial oxide material from said first and second fields to expose at least a portion of said first, second and third fins; and   exposing said work piece to said second plasma removes at least a portion of said conformal oxide layer and said conformal nitride layer from said first, second and third fins, such that a height of the first, second and third fins extending above said conformal oxide and nitride layers is greater than about 35 nm.   
     
     
         43 . The method of  claim 42 , wherein after exposing said work piece to said second plasma, the conformal nitride layer remaining on said first and second fins protrudes above sacrificial oxide material within said first field by less than about 5 nm, and the conformal nitride layer remaining on said third fin protrudes above sacrificial oxide material within said second field by less than about 5 nm. 
     
     
         44 . A microelectronic device, comprising:
 first and second fins laterally offset by a fin pitch less than or equal to 50 nm so as to define a first field there between;   a conformal oxide layer disposed on at least a portion of said first and second fins;   a conformal nitride layer disposed on at least a portion of said first and second fins and on at least a portion of said conformal oxide layer; and   a sacrificial oxide material disposed at least within said first field;   
       wherein:
 said first and second fins extend above said conformal oxide and nitride layers by at least 35 nm; and 
 said conformal nitride layer on said first and second fins protrudes above an upper surface of said sacrificial oxide material within said first field by less than about 5 nm. 
 
     
     
         45 . The microelectronic device of  claim 44 , further comprising a third fin laterally offset from said second fin by a fin pitch greater than 50 nm so as to define a second field between said second and third fins, wherein:
 said conformal oxide layer is further disposed on said third fin;   said conformal nitride layer is further disposed on at least a portion of said third fin and on at least a portion of conformal oxide layer on said third fin;   said sacrificial oxide material is further disposed within said second field; and   said conformal nitride layer on said third fin protrudes above an upper surface of said sacrificial oxide material within said second field by less than about 5 nm.   
     
     
         46 . The microelectronic device of  claim 45 , wherein said conformal nitride layer on said first, second, and third fins protrudes above an upper surface of said sacrificial oxide material within said first and second fields by less than about 5 nm. 
     
     
         47 . The microelectronic device of  claim 46  wherein said sacrificial oxide is selected from the group consisting of silicon oxide, a silicate, carbon doped oxide, spun on glass, and combinations thereof. 
     
     
         48 . The microelectronic device of  claim 47 , wherein said nitride comprises at least one of a silicon nitride, a silicon oxynitride, and combinations thereof. 
     
     
         49 . The microelectronic device of  claim 44 , wherein said microelectronic device is a non-planar transistor. 
     
     
         50 . The microelectronic device of  claim 45 , wherein said microelectronic device is a non-planar transistor.