Temperature controlled showerhead for high temperature operations

Abstract

A temperature controlled showerhead assembly for chemical vapor deposition (CVD) chambers enhances heat dissipation to provide accurate temperature control of the showerhead face plate and maintain temperatures substantially lower than surrounding components. Heat dissipates by conduction through a showerhead stem and removed by the heat exchanger mounted outside of the vacuum environment. Heat is supplied by a heating element inserted into the steam of the showerhead. Temperature is controlled using feedback supplied by a temperature sensor installed in the stem and in thermal contact with the face plate.

What is claimed is: 
     
         1 . A temperature controlled showerhead assembly comprising:
 a heat conductive stem;   a back plate attached to the heat conductive stem;   a face plate thermally coupled to the heat conductive stem and attached to the back plate;   a heat exchanger thermally coupled to the heat conductive stem;   a temperature sensor thermally coupled to the face plate; and   a first opening extending through the heat conductive stem and the back plate, the first opening configured to receive the temperature sensor, wherein the back plate includes a feature between the first opening and the face plate, the feature being in direct contact with the face plate.   
     
     
         2 . The temperature controlled showerhead assembly of  claim 1 , wherein the temperature sensor is removably coupled to the heat conductive stem and to the back plate in the first opening. 
     
     
         3 . The temperature controlled showerhead assembly of  claim 1 , wherein the heat conductive stem, the back plate, and the first opening are manufactured out of a single piece of material. 
     
     
         4 . The temperature controlled showerhead assembly of  claim 1 , wherein each of the heat conductive stem, the back plate, and the face plate comprises a material selected from the group consisting of aluminum  6061  and aluminum  3003 . 
     
     
         5 . The temperature controlled showerhead assembly of  claim 1 , wherein heat conductive stem comprises a top surface, the first opening extending from the top surface and configured to receive the temperature sensor through the top surface. 
     
     
         6 . The temperature controlled showerhead assembly of  claim 1 , further comprising:
 a removable heating element; and   a second opening extending through the heat conductive stem, the second opening configured to receive the removable heating element.   
     
     
         7 . The temperature controlled showerhead assembly of  claim 1 , wherein the face plate and the back plate defines a gap therebetween, the feature extending into the gap between the first opening and the face plate. 
     
     
         8 . The temperature controlled showerhead assembly of  claim 7 , wherein an average size of the gap between the back plate and the face plate is between about 0.25 inches and about 0.75 inches. 
     
     
         9 . The temperature controlled showerhead assembly of  claim 1 , wherein an average thickness of the face plate is between about 0.5 inches and about 1 inch. 
     
     
         10 . The temperature controlled showerhead assembly of  claim 1 , wherein the back plate and the face plate are integrated together to form a single unified body. 
     
     
         11 . The temperature controlled showerhead assembly of  claim 1 , wherein the heat conductive stem comprises:
 a seat configured to receive the heat exchanger, the heat exchanger positioned on the seat and thermally coupled to the heat conductive stem.   
     
     
         12 . The temperature controlled showerhead assembly of  claim 1 , wherein the heat exchanger comprises a convective cooling fluid passageway configured to allow for a flow of a cooling fluid, wherein the cooling fluid is selected from the group consisting of water and a liquid antifreeze solution. 
     
     
         13 . The temperature controlled showerhead assembly of  claim 1 , wherein the back plate includes three or more stacked substantially solid disks decreasing in diameter from the attachment at the face plate to the attachment at the heat conductive stem, wherein the disk at the attachment at the face plate is configured to distribute a flow of gas to the face plate. 
     
     
         14 . The temperature controlled showerhead assembly of  claim 13 , wherein each of the stacked disks has a different thickness. 
     
     
         15 . The temperature controlled showerhead assembly of  claim 1 , wherein the face plate has a plurality of through holes configured for uniform distribution of process gases. 
     
     
         16 . A temperature controlled showerhead assembly comprising:
 a heat conductive stem;   a back plate attached to the heat conductive stem;   a face plate thermally coupled to the heat conductive stem and attached to the back plate, the face plate and the back plate defining a gap therebetween;   a heat exchanger thermally coupled to the heat conductive stem;   a removable temperature sensor thermally coupled to the face plate;   a removable heating element thermally coupled to the heat conductive stem;   a first opening extending through the heat conductive stem and the back plate from a top surface of the heat conductive stem, the first opening configured to receive the temperature sensor, wherein the back plate includes a feature between the first opening and the face plate, the feature being in direct contact with the face plate; and   a second opening extending through the heat conductive stem from the top surface of the heat conductive stem, the second opening configured to receive the heating element, wherein the heat conductive stem, the back plate, and the face plate comprises a material selected from the group consisting of aluminum 6061 and aluminum 3003.   
     
     
         17 . A Chemical Vapor Deposition (CVD) system for depositing a material on a partially manufactured semiconductor substrate, the CVD system comprising:
 a processing chamber;   a substrate support in the processing chamber, the substrate support supporting the partially manufactured semiconductor substrate;   a temperature controlled showerhead assembly over the substrate support and comprising:
 a heat conductive stem; 
 a back plate attached to the heat conductive stem; 
 a face plate thermally coupled to the heat conductive stem and attached to the back plate; 
 a heat exchanger thermally coupled to the heat conductive stem; 
 a temperature sensor thermally coupled to the face plate; and 
 a first opening extending through the heat conductive stem and the back plate, the first opening configured to receive the temperature sensor, wherein the back plate includes a feature between the first opening and the face plate, the feature being in direct contact with the face plate. 
   
     
     
         18 . The CVD system of  claim 17 , wherein the heat conductive stem, the back plate, and the first opening extending through the heat conductive stem and the back plate are manufactured out of a single piece of material. 
     
     
         19 . The CVD system of  claim 17 , wherein heat conductive stem comprises a top surface, the first opening extending from the top surface and configured to receive the temperature sensor through the top surface. 
     
     
         20 . The CVD system of claim  24 , wherein the temperature controlled showerhead further comprises:
 a removable heating element; and   a second opening extending through the heat conductive stem, the second opening configured to receive the removable heating element.