Method for depositing refractory metal layers employing sequential deposition techniques

Abstract

A method for forming a tungsten layer on a substrate surface is provided. In one aspect, the method includes positioning the substrate surface in a processing chamber and exposing the substrate surface to a boride. A nucleation layer is then deposited on the substrate surface in the same processing chamber by alternately pulsing a tungsten-containing compound and a reducing gas selected from a group consisting of silane (SiH 4 ), disilane (Si 2 H 6 ), dichlorosilane (SiCl 2 H 2 ), derivatives thereof, and combinations thereof. A tungsten bulk fill may then be deposited on the nucleation layer using cyclical deposition, chemical vapor deposition, or physical vapor deposition techniques.

1 . A method for forming a tungsten layer on a substrate surface, comprising: 
 positioning a substrate in a process chamber;    exposing the substrate surface to a diborane soak; and    depositing a nucleation layer in the process chamber by alternately pulsing a tungsten-containing compound and a reductant selected from a group consisting of borane, diborane, silane, disilane, dichlorosilane, derivatives thereof and combinations thereof.    
     
     
         2 . The method of  claim 1 , wherein the tungsten-containing compound is selected from the group consisting of tungsten hexafluoride or tungsten hexacarbonyl.  
     
     
         3 . The method of  claim 2 , wherein the nucleation layer is deposited by alternately pulsing tungsten hexafluoride and silane.  
     
     
         4 . The method of  claim 3 , wherein the nucleation layer has a thickness of about 100 Å or less.  
     
     
         5 . The method of  claim 4 , wherein exposing the substrate surface to the diborane soak occurs for about 30 seconds or less.  
     
     
         6 . The method of  claim 5 , further comprising forming a bulk tungsten deposition film on the nucleation layer using cyclical deposition, chemical vapor deposition or physical vapor deposition techniques.  
     
     
         7 . The method of  claim 6 , wherein the bulk tungsten deposition film has a thickness from about 1,000 Å to about 2,500 Å.  
     
     
         8 . The method of  claim 7 , wherein the substrate surface comprises titanium or titanium nitride.  
     
     
         9 . A method for forming a tungsten layer on a substrate surface, comprising: 
 exposing the substrate surface comprising titanium to a soak process for about 30 seconds or less;    depositing a nucleation layer by alternately pulsing a tungsten-containing compound and a reductant; and    forming a bulk tungsten deposition film on the nucleation layer.    
     
     
         10 . The method of  claim 9 , wherein the soak process comprises a compound selected from the group consisting of borane, diborane, silane, derivatives thereof and combinations thereof.  
     
     
         11 . The method of  claim 10 , wherein the soak process and depositing the nucleation layer occurs in a first process chamber.  
     
     
         12 . The method of  claim 11 , wherein the reductant is selected from the group consisting of borane, diborane, silane, disilane, dichlorosilane, derivatives thereof and combinations thereof.  
     
     
         13 . The method of  claim 12 , wherein the nucleation layer has a thickness of about 100 Å or less.  
     
     
         14 . The method of  claim 13 , wherein the bulk tungsten deposition film has a thickness from about 1,000 Å to about 2,500 Å.  
     
     
         15 . A method for forming a tungsten layer on a substrate, comprising: 
 positioning the substrate in a process chamber;    exposing the substrate to a diborane soak;    depositing a nucleation layer in the process chamber by alternately exposing the substrate to a tungsten-containing compound and a reductant; and    forming a bulk tungsten deposition film on the nucleation layer.    
     
     
         16 . The method of  claim 15 , wherein the diborane soak occurs for about 30 seconds or less.  
     
     
         17 . The method of  claim 16 , wherein the reductant is selected from the group consisting of borane, diborane, silane, disilane, dichlorosilane, derivatives thereof and combinations thereof.  
     
     
         18 . The method of  claim 17 , wherein the tungsten-containing compound is selected from the group consisting of tungsten hexafluoride or tungsten hexacarbonyl.  
     
     
         19 . The method of  claim 18 , wherein the nucleation layer has a thickness of about 100 Å or less.  
     
     
         20 . The method of  claim 19 , wherein the bulk tungsten deposition film has a thickness from about 1,000 Å to about 2,500 Å.  
     
     
         21 . The method of  claim 20 , wherein the substrate surface comprises titanium or titanium nitride.  
     
     
         22 . A method for forming a tungsten layer on a substrate, comprising: 
 positioning the substrate in a process chamber;    exposing the substrate to a silane soak;    depositing a nucleation layer in the process chamber by alternately exposing the substrate to a tungsten-containing compound and a reductant; and    forming a bulk tungsten deposition film on the nucleation layer.