Temperature measurement and control of wafer support in thermal processing chamber

Abstract

The present invention provides apparatus and methods for achieving uniform heating to a substrate during a rapid thermal process. More particularly, the present invention provides apparatus and methods for controlling the temperature of an edge ring supporting a substrate during a rapid thermal process to improve temperature uniformity across the substrate.

1 . A rapid thermal processing chamber, comprising:
 a chamber body defining a chamber volume;   an edge ring to thermally couple to a substrate to be processed in the chamber, wherein the edge ring is disposed in the chamber volume;   a first heat source to heat a surface of the substrate; and   a second heat source to heat the edge ring.   
     
     
         2 . The rapid thermal processing chamber of  claim 1 , further comprising a thermal probe to measure at least one thermal property of the edge ring. 
     
     
         3 . The rapid thermal processing chamber of  claim 2 , further comprising a cooling device to reduce the temperature of the edge ring. 
     
     
         4 . The rapid thermal processing chamber of  claim 1 , wherein the first and second heat sources together comprise a lamp assembly to radiantly heat the chamber volume, and the lamp assembly has independently temperature controllable zones. 
     
     
         5 . The rapid thermal processing chamber of  claim 1 , wherein the first heat source and second heat source are disposed on opposite sides of the edge ring. 
     
     
         6 . The rapid thermal processing chamber of  claim 1 , wherein the second heat source is one of a radiant heater, a conductive heat source, a resistive heater, an inductive heater, and a microwave heater. 
     
     
         7 . A method for uniformly heating a substrate to a target temperature, comprising:
 positioning the substrate in a processing chamber, wherein the processing chamber is connected with a first heat source;   thermally coupling a periphery of the substrate to an edge ring;   heating a surface of the substrate with the first heat source; and   maintaining the edge ring at a first temperature, wherein the first temperature differs from the target temperature.   
     
     
         8 . The method of  claim 7 , further wherein maintaining the edge ring at the first temperature comprising heating the edge ring with a second heat source, wherein the first and second heat sources are independently controllable. 
     
     
         9 . The method of  claim 8 , wherein the first and second heat sources together comprise a lamp assembly having independently controllable zones. 
     
     
         10 . The method of  claim 8 , further comprising cooling the edge ring using a purge gas. 
     
     
         11 . The method of  claim 8 , further comprising:
 measuring a temperature of the edge ring using a thermal probe to determine a measured temperature; and   adjusting the second heat source according to the measured temperature.   
     
     
         12 . The method of  claim 7 , wherein the first temperature differs from the target temperature for about 10° C. to about 15° C. 
     
     
         13 . The method of  claim 7 , wherein the first temperature is higher than the target temperature. 
     
     
         14 . The method of  claim 7 , wherein the first temperature is lower than the target temperature. 
     
     
         15 . A rapid thermal processing chamber, comprising:
 a chamber body defining a processing volume;   a substrate support mechanism disposed in the processing volume;   an edge ring disposed on the substrate support mechanism, wherein the edge ring supports a substrate being processed by a peripheral edge of the substrate, and heat exchange between the edge ring and the peripheral edge of the substrate adjusts a temperature profile of the substrate near the peripheral edge;   a first heat source to rapidly heat the substrate disposed on the edge ring; and   a second heat source to heat the edge ring at a temperature different from a temperature of the substrate.   
     
     
         16 . The rapid thermal processing chamber of  claim 15 , wherein the first heat source comprises an array of heating elements. 
     
     
         17 . The rapid thermal processing chamber of  claim 16 , wherein the first heat source and the second heat source are disposed on opposite sides of the substrate. 
     
     
         18 . The rapid thermal processing chamber of  claim 17 , wherein the second heat source comprises one or more laser heaters. 
     
     
         19 . The rapid thermal processing chamber of  claim 16 , wherein the array of heating elements are lamps disposed outside the chamber body and configured to provide thermal energy through a quartz window of the chamber body, and the second heat source comprises a plurality of lamps disposed radially outwards of the first heat source. 
     
     
         20 . The rapid thermal processing chamber of  claim 15 , further comprising:
 a cooling device to reduce to temperature of the edge ring.