Method of forming a conductive contact

Abstract

Conductive contacts in a semiconductor structure, and methods for forming the conductive components are provided. The method comprises depositing a conductive material over a substrate to fill a contact opening, removing excess material from the substrate leaving the contact within the opening, and then heating treating the contact at a high temperature, preferably with a rapid thermal anneal process, in a reactive gas to remove an undesirable component from the contact, for example, thermal annealing a TiCl 4 -based titanium nitride in ammonia to remove chlorine from the contact, which can be corrosive to an overlying aluminum interconnect at a high concentration. The contacts are useful for providing electrical connection to active components in integrated circuits such as memory devices. In an embodiment of the invention, the contacts comprise boron-doped and/or undoped TiCl 4 -based titanium nitride having a low concentration of chlorine. Boron-doped contacts further possess an increased level of adhesion to the insulative layer to eliminate peeling from the sidewalls of the contact opening and cracking of the insulative layer when formed to a thickness of greater than about 200 angstroms in a high-aspect-ratio opening.

1 . A method of forming a material layer on a substrate, comprising the steps of: 
 forming the material layer on the substrate to a thickness of about 500 angstroms or greater, the material layer comprising a component capable of diffusing into and corroding an adjacent metal layer; and    heat treating the material layer using a reactive gas at a temperature of about 550° C. or greater to remove an effective amount of the component from the material layer to eliminate corrosion of said adjacent metal layer without forming substantial cracks within the material layer.    
   
   
       2 . A method of forming a material layer on a substrate, comprising the steps of: 
 forming a metal nitride layer on the substrate to a thickness of about 500 angstroms or greater, the metal nitride layer comprising a component capable of diffusing into and corroding an adjacent metal layer; and    heat treating the metal nitride layer using a reactive gas at a temperature of about 550° C. or greater to remove an effective amount of the component from the metal nitride layer to eliminate corrosion of said adjacent metal layer by said component, without forming substantial cracks within the metal nitride layer.    
   
   
       3 . A method of forming a conductive material layer on a substrate, comprising the steps of: 
 forming a layer of titanium nitride on the substrate to a thickness of about 500 angstroms or greater, the titanium nitride layer comprising chlorine; and    heat treating the titanium nitride layer using a reactive gas at a temperature of about 550° C. or greater to remove an effective amount of the chlorine from the titanium nitride layer to eliminate corrosion of an adjacent metal layer by said chlorine.    
   
   
       4 . A method of forming a conductive material layer on a substrate, comprising the steps of: 
 forming a layer of titanium boronitride on the substrate to a thickness of about 500 angstroms or greater, the titanium boronitride layer comprising chlorine;    heat treating the titanium boronitride layer using a reactive gas at a temperature of about 550° C. or greater to remove an effective amount of the chlorine from the titanium boronitride layer to eliminate corrosion of an adjacent metal layer by said chlorine.    
   
   
       5 . A method of forming a conductive material layer on a substrate, comprising the steps of: 
 forming a layer of titanium nitride on the substrate to a thickness of about 500 angstroms or greater, the titanium nitride layer comprising chlorine;    forming a layer of titanium boronitride on the titanium nitride layer to a thickness of about 500 angstroms or greater, the titanium boronitride layer comprising chlorine;    repeating the steps of forming the titanium nitride layer and the titanium boronitride layer to form the material layer to a thickness of about 500 angstroms or greater, the material layer comprising sequential layers of titanium nitride and titanium boronitride; and    heat treating the material layer in a reactive gas at a temperature of about 550° C. or greater to remove an effective amount of the chlorine from the material layer to reduce corrosion of an adjacent metal layer by said chlorine.    
   
   
       6 . A method of forming a conductive material layer on a substrate, comprising the steps of: 
 depositing a gas comprising titanium tetrachloride and ammonia onto a substrate to form a layer of titanium nitride to a thickness of about 500 angstroms or greater, the titanium nitride layer comprising chlorine; and    heat treating the titanium nitride layer using a reactive gas at a temperature of about 550° C. or greater to remove an effective amount of the chlorine from the titanium nitride layer to reduce corrosion of an adjacent metal layer by said chlorine.    
   
   
       7 . A method of forming a conductive material layer on a substrate, comprising the steps of: 
 depositing a gas comprising titanium tetrachloride, ammonia, and diborane onto a substrate to form a layer of titanium boronitride to a thickness of about 500 angstroms or greater, the titanium boronitride layer comprising chlorine; and    heat treating the titanium boronitride layer in a reactive gas at a temperature of about 550° C. or greater to remove an effective amount of the chlorine from the titanium boronitride layer to reduce corrosion of an adjacent metal layer by said chlorine.    
   
   
       8 . A method of forming a conductive material layer on a substrate, comprising the steps of: 
 depositing a first gas comprising titanium tetrachloride and ammonia onto a substrate to form a layer of titanium nitride to a thickness of about 100-500 angstroms, the titanium nitride layer comprising chlorine;    depositing a second gas comprising titanium tetrachloride, ammonia, and diborane onto the titanium nitride layer to form a layer of titanium boronitride to a thickness of about 100-500 angstroms, the titanium boronitride layer comprising chlorine;    repeating the steps of depositing the first and second gases to form the material layer to a thickness of about 500 angstroms or greater, the material layer comprising sequential layers of titanium nitride and titanium boronitride; and    heat treating the material layer in a reactive gas at a temperature of about 550° C. or greater to remove an effective amount of the chlorine from the material layer to reduce corrosion of an adjacent metal layer by said chlorine.    
   
   
       9 . A method of forming a material layer on a substrate, comprising the steps of: 
 forming a metal nitride layer on the substrate to a thickness of about 500 angstroms or greater, the metal nitride layer comprising a component capable of diffusing into and corroding an adjacent metal layer; and    heat treating the metal nitride layer using a reactive gas at a temperature of about 700° C. or greater to remove an effective amount of the component from the metal nitride layer to eliminate corrosion of said adjacent metal layer by said component, without forming substantial cracks within the metal nitride layer.    
   
   
       10 . A method of forming a fill, comprising the steps of: 
 forming a fill of about 500 angstroms or greater within an opening in a substrate, the fill comprising a component capable of diffusing into and corroding an adjacent metal layer; and    heat treating the fill using a reactive gas at a temperature of about 550° C. or greater to remove an effective amount of the component from the fill to eliminate corrosion of said adjacent metal layer by said component, without forming substantial cracks within the fill.    
   
   
       11 . The method of  claim 10 , wherein the opening has an aspect ratio of at least about 3:1.  
   
   
       12 . A method of forming a fill, comprising the steps of: 
 forming a fill of about 500 angstroms or greater within an opening in a substrate, the fill comprising metal nitride and a component capable of diffusing into and corroding an adjacent metal layer; and    heat treating the fill using a reactive gas at a temperature of about 550° C. or greater to remove an effective amount of the component from the fill to eliminate corrosion of said adjacent metal layer by said component.    
   
   
       13 . The method of  claim 12 , wherein the component comprises chlorine.  
   
   
       14 . A method of forming a fill, comprising the steps of: 
 forming a fill of about 500 angstroms or greater within an opening in a substrate, the fill comprising titanium nitride and chlorine; and    heat treating the fill using a reactive gas at a temperature of about 550° C. or greater to remove an effective amount of the chlorine from the fill to eliminate corrosion of an adjacent metal layer by said chlorine.    
   
   
       15 . A method of forming a fill, comprising the steps of: 
 forming a fill of about 500 angstroms or greater within an opening in a substrate, the fill comprising titanium boronitride and chlorine; and    heat treating the fill using a reactive gas at a temperature of about 550° C. or greater to remove an effective amount of the chlorine from the fill to eliminate corrosion of an adjacent metal layer by said chlorine.    
   
   
       16 . A method of forming a fill, comprising the steps of: 
 forming a layer of titanium nitride within an opening in a substrate to a thickness of about 500 angstroms or greater, the titanium nitride layer comprising chlorine;    forming a layer of titanium boronitride on the titanium nitride layer to a thickness of about 500 angstroms or greater, the titanium boronitride layer comprising chlorine;    repeating the steps of forming the titanium nitride layer and the titanium boronitride layer to form the fill to a thickness of about 500 angstroms or greater, the fill comprising sequential layers of titanium nitride and titanium boronitride; and    heat treating the fill in a reactive gas at a temperature of about 550° C. or greater to remove an effective amount of the chlorine from the fill to reduce corrosion of an adjacent metal layer by said chlorine.    
   
   
       17 . A method of forming a fill, comprising the steps of: 
 depositing a gas comprising titanium tetrachloride and ammonia onto a substrate within an opening to form a fill comprising titanium nitride and chlorine, the fill having a thickness of about 500 angstroms or greater; and    heat treating the fill in a reactive gas at a temperature of about 550° C. or greater to remove an effective amount of the chlorine from the fill to reduce corrosion of an adjacent metal layer by said chlorine.    
   
   
       18 . A method of forming a fill, comprising the steps of: 
 depositing a gas comprising titanium tetrachloride, ammonia, and diborane onto a substrate within an opening to form a fill comprising titanium boronitride and chlorine, the fill having a thickness of about 500 angstroms or greater; and    heat treating the fill in a reactive gas at a temperature of about 550° C. or greater to remove an effective amount of the chlorine from the fill to reduce corrosion of an adjacent metal layer by said chlorine.    
   
   
       19 . A method of forming a fill, comprising the steps of: 
 depositing a first gas comprising titanium tetrachloride and ammonia onto a substrate within an opening to form a first layer comprising titanium nitride and chlorine, the first layer having a thickness of about 100-500 angstroms;    depositing a second gas comprising titanium tetrachloride, ammonia, and diborane into the opening to form a second layer comprising titanium boronitride and chlorine, the second layer having a thickness of about 500 angstroms or greater; and    repeating the steps of depositing the first and second gases to form the fill to a thickness of about 500 angstroms or greater, the fill comprising sequential layers of titanium nitride and titanium boronitride; and    heat treating the fill in a reactive gas at a temperature of about 550° C. or greater to remove an effective amount of the chlorine from the fill to reduce corrosion of an adjacent metal layer by said chlorine.    
   
   
       20 . A conductive contact, comprising a metal nitride fill within an opening in a substrate, the fill having a thickness of about 500 angstroms or greater, and formed using a gas comprising a metal chloride gas and a nitrogen-based gas, and heat treated at a temperature of about 550° C. or greater to remove an effective amount of the chlorine from the fill to reduce corrosion of an adjacent metal layer by said chlorine.  
   
   
       21 . A conductive contact, comprising a titanium nitride fill within an opening in a substrate, the fill having a thickness of about 500 angstroms or greater, and formed using a gas comprising titanium tetrachloride and a nitrogen-based gas, and heat treated at a temperature of about 550° C. or greater to remove an effective amount of chlorine from the fill to reduce corrosion of an adjacent metal layer by said chlorine.  
   
   
       22 . A conductive contact, comprising a titanium boronitride fill within an opening in a substrate, the fill having a thickness of about 500 angstroms or greater, and formed using a gas comprising titanium tetrachloride, a nitrogen-based gas, and diborane, and heat treated at a temperature of about 550° C. or greater to remove an effective amount of chlorine from the fill to reduce corrosion of an adjacent metal layer by said chlorine.  
   
   
       23 . A conductive contact, comprising a metal nitride fill within an opening in a substrate, the fill comprising alternating layers of titanium nitride and titanium boronitride, and a thickness of about 500 angstroms or greater, the fill formed using a first gas comprising titanium tetrachloride and a nitrogen-based gas and a second gas comprising titanium tetrachloride, a nitrogen-based gas and diborane, and heat treated at a temperature of about 550° C. or greater to remove an effective amount of chlorine from the fill to reduce corrosion of an adjacent metal layer by said chlorine.  
   
   
       24 . A semiconductor device, comprising a conductive contact according to  claim 20 .  
   
   
       25 . A memory device, comprising: 
 an array of memory cells;    internal circuitry; and    a conductive contact according to  claim 20 , coupled to the memory array and the internal circuitry.    
   
   
       26 . An integrated circuit supported by a substrate, and comprising a conductive contact according to  claim 20 .  
   
   
       27 . A semiconductor device, comprising a metal nitride layer on a substrate, the metal nitride layer having a thickness of about 500 angstroms or greater, and formed using a gas comprising a metal chloride gas and a nitrogen-based gas, and heat treated at a temperature of about 550° C. or greater to remove an effective amount of the chlorine from the metal nitride layer to reduce corrosion of an adjacent metal layer by said chlorine.  
   
   
       28 . The device of  claim 27 , wherein the metal nitride layer comprises titanium nitride.  
   
   
       29 . The device of  claim 27 , wherein the metal nitride layer comprises titanium boronitride.  
   
   
       30 . The device of  claim 27 , wherein the metal nitride layer comprises alternating layers of titanium nitride and titanium boronitride, each layer about 100-500 angstroms thick.