Multi-step anneal of thin films for film densification and improved gap-fill

Abstract

A method of annealing a substrate comprising a trench containing a dielectric material, the method including annealing the substrate at a first temperature of about 200° C. to about 800° C. in a first atmosphere comprising an oxygen containing gas, and annealing the substrate at a second temperature of about 800° C. to about 1400° C. in a second atmosphere lacking oxygen. In addition, a method of annealing a substrate comprising a trench containing a dielectric material, the method including annealing the substrate at a first temperature of about 400° C. to about 800° C. in the presence of an oxygen containing gas, purging the oxygen containing gas away from the substrate, and raising the substrate to a second temperature from about 900° C. to about 1100° C. to further anneal the substrate in an atmosphere that lacks oxygen.

1 - 22 . (canceled)  
   
   
       23 . An annealing system comprising: 
 a housing configured to form an annealing chamber;    a substrate holder configured to hold a substrate within said annealing chamber, wherein the substrate comprises a trench filled with a dielectric material;    a gas distribution system configured to introduce gases into said annealing chamber; and    a heating system configured to heat the substrate,    wherein the gas distribution system introduces a first anneal gas comprising an oxygen containing gas into the chamber while the heating system heats the substrate to a first temperature of about 200° C. to about 800° C.; and    the heating system heats the substrate to a second temperature of about 800° C. to about 1400° C. in an atmosphere lacking oxygen, after a purge of the oxygen containing gas from the chamber.    
   
   
       24 . The annealing system of  claim 23 , wherein the substrate stays in the chamber as the heating system raises the temperature from the first temperature to the second temperature.  
   
   
       25 . The annealing system of  claim 23 , wherein the heating system comprises a resistive heating element.  
   
   
       26 . The annealing system of  claim 23 , wherein the heating system comprises a radiant heating lamp.  
   
   
       27 . The annealing system of  claim 23 , wherein the annealing system comprises a rapid thermal processor (RTP).  
   
   
       28 . The annealing system of  claim 23 , wherein the gas distribution system is configured to introduce a gas comprising water, nitric oxide, or nitrous oxide to the annealing chamber as the first anneal gas.  
   
   
       29 . The annealing system of  claim 23 , wherein the gas distribution system is configured to introduce hydrogen and oxygen gas into the annealing chamber as the first anneal gas, and wherein the gases react to form in-situ generated steam.  
   
   
       30 . The annealing system of  claim 23 , wherein the gas distribution system is configured to deliver a gas comprising nitrogen, hydrogen, ammonia, helium, neon, argon, krypton, or xenon to the annealing chamber as the heating system heats the substrate to the second temperature.  
   
   
       31 . The annealing system of  claim 23 , wherein the heating system is programmable to change the substrate temperature from the first temperature to the second temperature at a predefined rate.  
   
   
       32 . The annealing system of  claim 31 , wherein the predefined rate is about 4° C./min.  
   
   
       33 . A multi-stage annealing system comprising: 
 an annealing chamber;    a substrate holder configured to hold one or more substrate wafers;    a gas distribution system configured to introduce one or more first anneal gases into the chamber during a first anneal stage, and one or more second anneal gases during a second anneal stage, wherein the first anneal gases comprise an oxygen containing gas and the second anneal gases do not include oxygen; and    a heating system configured to heat the annealing chamber to about 200° C. to about 800° C. during the first anneal stage and increase the temperature at a predefine rate to about 800° C. to about 1400° C. during the second anneal stage.    
   
   
       34 . The system of  claim 33 , wherein the system further comprises a gas purging system configured to remove at least a portion of the first anneal gas before the start of the second anneal stage.  
   
   
       35 . The system of  claim 34 , wherein the second anneal gas is introduced into the annealing chamber during the removal of the first anneal gas.  
   
   
       36 . The system of  claim 34 , wherein the gas purging system removes the first anneal gas for about 60 minutes.  
   
   
       37 . The system of  claim 34 , wherein the heating system heats the annealing chamber from about 600° C. to about 700° C. during the first anneal stage, and heats the annealing chamber from about 1000° C. to about 1100° C. during the second anneal stage.  
   
   
       38 . An annealing system comprising: 
 an annealing chamber;    a substrate holder configured to hold at least one substrate wafer;    a gas distribution system configured to introduce gases into said annealing chamber; and    a heating system comprising a rapid thermal processor configured first to heat the annealing chamber to about 200° C. to about 800° C. in a first atmosphere comprising an oxygen containing gas, and then heat the chamber to about 800° C. to about 1400° C. in a second atmosphere that lacks oxygen.    
   
   
       39 . The system of  claim 38 , wherein the rapid thermal processor comprises an array of lights positioned above the substrate wafer to supply radiant energy to heat the wafer, wherein each of the plurality of lights is mounted in a light pipe.  
   
   
       40 . The system of  claim 39 , wherein the annealing chamber comprises a bottom reflecting surface to reflect a portion of the radiant energy from the lights onto a backside of the wafer.  
   
   
       41 . The system of  claim 39 , wherein the array of lights are grouped into zones that are independently controlled.  
   
   
       42 . The system of  claim 39 , wherein the array of lights are arranged in a honeycomb arrangement.  
   
   
       43 . The system of  claim 39 , wherein the rapid thermal processor comprises a plurality of temperature probes facing a backside of the wafer.  
   
   
       44 . The system of  claim 38 , wherein the gas distribution system comprises a gas inlet and gas outlet positioned opposite to the gas inlet, wherein the inlet and outlet direct a flow of the annealing gases in a direction substantially parallel to a top and bottom surface of the substrate wafer.