Methods for forming a metal contact in a semiconductor device in which an ohmic layer is formed while forming a barrier metal layer

Abstract

A metal contact in a semiconductor device is formed by forming an insulating layer having a contact hole therein on a silicon substrate. A cobalt layer is formed on a bottom and inner walls of the contact hole. A cobalt silicide layer is formed at the bottom of the contact hole while forming a titanium layer on the cobalt layer. A plug is formed on the titanium layer so as to fill the contact hole.

1 - 26 . (canceled)  
   
   
       27 . A method of forming a metal contact in a semiconductor device, comprising: 
 forming an insulating layer having a contact hole therein on a silicon substrate;    forming a titanium layer on a bottom and inner walls of the contact hole;    forming a cobalt layer on the titanium layer;    forming a complex silicide layer comprising titanium silicide and cobalt silicide at the bottom of the contact hole while forming a titanium nitride layer on the cobalt layer; and    forming a plug on the titanium nitride layer so as to fill the contact hole.    
   
   
       28 . The method of  claim 27 , wherein the plug comprises at least one of tungsten, titanium nitride, aluminum, and tantalum nitride.  
   
   
       29 . The method of  claim 27 , wherein the titanium nitride layer has a thickness of about 50 to 500 Å.  
   
   
       30 . The method of  claim 27 , wherein the titanium nitride layer is formed using chemical vapor deposition (CVD) at a temperature of about 400 to 750° C.  
   
   
       31 . The method of  claim 27 , wherein the titanium layer, the cobalt layer, and the titanium nitride layer are formed in situ without a vacuum break.  
   
   
       32 . The method of  claim 27 , wherein the cobalt layer has a thickness of about 5 to 200 Å.  
   
   
       33 . The method of  claim 27 , wherein the cobalt layer is formed using one of physical vapor deposition (PVD) and chemical vapor deposition (CVD).  
   
   
       34 . The method of  claim 33 , wherein the cobalt layer is formed using PVD at a temperature of about 25 to 500° C.  
   
   
       35 . The method of  claim 27 , wherein the titanium layer has a thickness of about 5 to 150 Å.  
   
   
       36 . The method of  claim 27 , wherein the titanium layer is formed using chemical vapor deposition (CVD) at a temperature of about 400 to 750° C.  
   
   
       37 . The method of  claim 27 , wherein substrate and insulating layer are cleaned after forming the insulating layer.  
   
   
       38 . A method of forming a metal contact in a semiconductor device, comprising: 
 forming an insulating layer having a contact hole therein on a silicon substrate;    forming a titanium layer on a bottom and inner walls of the contact hole;    forming a cobalt layer on the titanium layer; and    forming a complex silicide layer comprising titanium silicide and cobalt silicide at the bottom of the contact hole while forming a plug that fills the contact hole on the cobalt layer.    
   
   
       39 . The method of  claim 38 , wherein the plug comprises titanium nitride.  
   
   
       40 . The method of  claim 39 , wherein the plug has a thickness of about 20 to 3000 Å.  
   
   
       41 . The method of  claim 38 , wherein the titanium layer, the cobalt layer, and the plug are formed in situ without a vacuum break.