Method for forming trench semiconductor device having schottky barrier structure

Abstract

A method for forming a semiconductor device includes providing a region of semiconductor material. The method includes providing a trench structure having a trench extending into the region of semiconductor material from a first major surface, and a conductive material disposed within the trench and separated from the region of semiconductor material by a dielectric region. The method includes providing a Schottky contact region disposed adjacent to the first major surface and adjacent to the trench structure. In one example, providing the Schottky contact region comprises forming a layer of material comprising as-formed nickel-chrome; exposing the layer of material to a temperature in a range from about 400 degrees Celsius through about 550 degrees Celsius; and after the step of exposing, removing any unreacted portions of the layer of material.

What is claimed is: 
     
         1 . A method of forming a semiconductor device, comprising:
 providing a region of semiconductor material comprising a first major surface and a second major surface opposite to the first major surface;   providing a trench structure comprising:
 a trench extending into the region of semiconductor material from the first major surface; and 
 a conductive material disposed within the trench and separated from the region of semiconductor material by a dielectric region; 
   providing a Schottky contact region disposed adjacent to the first major surface and adjacent to the trench structure, wherein providing the Schottky contact region comprises:
 forming a layer of material disposed adjacent to the first major surface, the layer of material comprising an as-formed layer of nickel-chrome and having a first thickness; 
 exposing the layer of material to a temperature in a range from about 400 degrees Celsius through about 550 degrees Celsius; and 
 after the step of exposing, removing any unreacted portions of the layer of material. 
   
     
     
         2 . The method of  claim 1 , wherein:
 forming the layer of material comprises forming the layer of material consisting essentially of nickel-chrome.   
     
     
         3 . The method of  claim 1 , wherein:
 forming the layer of material comprises forming the layer of material consisting of nickel-chrome.   
     
     
         4 . The method of  claim 1 , wherein:
 forming the layer of material comprises forming the layer of material comprising a 40% nickel-60% chrome alloy material.   
     
     
         5 . The method of  claim 1 , wherein:
 forming the layer of material comprises providing the first thickness in a range from about 400 Angstroms through about 1300 Angstroms.   
     
     
         6 . The method of  claim 1 , wherein:
 forming the layer of material comprises providing the first thickness in a range from about 500 Angstroms through about 1100 Angstroms.   
     
     
         7 . The method of  claim 1 , wherein:
 forming the layer of material comprises providing the first thickness in a range from about 600 Angstroms through about 1000 Angstroms.   
     
     
         8 . The method of  claim 1 , further comprising:
 forming a conductive layer overlying the Schottky contact region.   
     
     
         9 . The method of  claim 1 , wherein:
 providing the trench structure comprises providing an active trench structure.   
     
     
         10 . The method of  claim 1 , wherein:
 exposing the layer of material to the temperature comprises exposing to a temperature in a range from about 400 degrees Celsius to about 500 degrees Celsius.   
     
     
         11 . The method of  claim 10 , wherein:
 exposing the layer of material to the temperature comprises exposing for a time. period from about 70 seconds to about 100 seconds.   
     
     
         12 . A method of forming a semiconductor device, comprising:
 providing a region of semiconductor material comprising a first major surface and a second major surface opposite to the first major surface;   providing a trench structure comprising:
 a trench extending into the region of semiconductor material from the first major surface; and 
 a conductive material disposed within the trench and separated from the region of semiconductor material by a dielectric region, wherein the dielectric region is disposed along opposing sidewall surfaces of the trench and disposed along a lower surface of the trench; and the dielectric region comprises a first uppermost surface. 
   providing a Schottky contact region disposed adjacent to the first major surface and adjacent to the trench structure, wherein providing the Schottky contact region comprises:
 forming a first layer of material disposed adjacent to the first major surface, the first layer of material consisting essentially of nickel-chrome and having a first thickness; 
 exposing the first layer of material to a temperature in a range from about 400 degrees Celsius through about 550 degrees Celsius; and 
 after the step of exposing, removing any unreacted portions of the first layer of material 
   
     
     
         13 . The method of  claim 12 , wherein:
 forming the layer of material comprises forming the layer of material comprising a 40% nickel-60% chrome alloy material.   
     
     
         14 . The method of  claim 12 , wherein:
 forming the layer of material comprises providing the first thickness in a range from about 400 Angstroms through about 1300 Angstroms.   
     
     
         15 . The method of  claim 12 , wherein:
 providing the trench structure comprises providing the first uppermost surface of the dielectric region extending above an upper surface of the Schottky region in a cross-sectional view.   
     
     
         16 . The method of  claim 12 , further comprising:
 forming a conductive layer overlying the Schottky contact region, wherein:   providing the trench structure comprises providing an active trench structure; and   exposing the layer of material comprises exposing for a time period of about 70 seconds to about 100 seconds.   
     
     
         17 . The method of  claim 12 , wherein:
 providing the region of semiconductor material comprises:
 providing a semiconductor substrate; and 
 providing a semiconductor layer overlying the substrate; 
   the semiconductor layer includes the first major surface; and   the semiconductor layer comprises a non-uniform dopant profile over its thickness.   
     
     
         18 . A method of forming a semiconductor device, comprising:
 providing a region of semiconductor material comprising a first major surface and a second major surface opposite to the first major surface;   providing a trench structure comprising:
 a trench extending into the region of semiconductor material from the first major surface; and 
 a conductive material disposed within the trench and separated from the region of semiconductor material by a dielectric region, wherein:
 the dielectric region is disposed along opposing sidewall surfaces of the trench and disposed along a lower surface of the trench; and 
 the dielectric region comprises a first uppermost surface; and 
 
   providing a Schottky contact region disposed adjacent to the first major surface and adjacent to the trench structure, wherein providing the Schottky contact region comprises:
 forming a conductive structure, the conductive structure being one of:
 a layer of material consisting essentially of nickel-chrome disposed adjacent to the first major surface; or 
 a first layer of material consisting essentially of titanium disposed adjacent to the first major surface and a second layer of material disposed adjacent to the first layer of material and consisting essentially of nickel-platinum; 
 
 exposing the conductive structure to an elevated temperature to form a silicide structure; and 
 after the step of exposing, removing any unreacted portions of the conductive structure. 
   
     
     
         19 . The method of  claim 18 , wherein:
 forming the conductive structure comprises:
 forming the first layer of material consisting essentially of titanium and having a first thickness; and 
 forming the second layer of material consisting essentially of nickel-platinum and having a second thickness; 
   exposing comprises exposing the first layer of material and the second layer of material to a temperature in a range from about 650 degrees Celsius through about 700 degrees Celsius; and   forming the conductive structure comprises providing a first thickness to second thickness ratio greater than or equal to 1.33:1.   
     
     
         20 . The method of  claim 18 , wherein:
 forming the conductive structure comprises:
 forming the layer of material consisting essentially of nickel-chrome and having a thickness in a range from about 500 Angstroms through about 1100 Angstroms; 
   exposing comprises exposing the layer of material to a temperature in a range from about 400 degrees Celsius through about 550 degrees Celsius.