Integrated substrate temperature measurement on high temperature ceramic heater

Abstract

Embodiments described herein include integrated systems used to directly monitor a substrate temperature during a plasma enhanced deposition process and methods related thereto. In one embodiment, a substrate support assembly includes a support shaft, a substrate support disposed on the support shaft, and a substrate temperature monitoring system for measuring a temperature of a substrate to be disposed on the substrate support. The substrate temperature monitoring system includes a optical fiber tube, a light guide coupled to the optical fiber tube, and a cooling assembly disposed about a junction of the optical fiber tube and the light guide. Herein, at least a portion of the light guide is disposed in an opening extending through the support shaft and into the substrate support and the cooling assembly maintains the optical fiber tube at a temperature of less than about 100° C. during substrate processing.

What is claimed is: 
     
         1 . A method of processing a substrate, comprising:
 positioning a substrate on a substrate receiving surface of a substrate support assembly disposed in a processing volume of a processing chamber;   measuring a temperature of the substrate using an optical fiber tube, wherein the temperature of the substrate exceeds about 110° C.;   maintaining the optical fiber tube at a temperature of temperature less than about 100° C.; and   depositing a material layer on the substrate.   
     
     
         2 . The method of  claim 1 , wherein the temperature of the substrate exceeds about 250° C. 
     
     
         3 . The method of  claim 1 , further comprising:
 flowing one or more processing gases into the processing volume; and   forming a plasma of the one or more processing gases.   
     
     
         4 . The method of  claim 3 , further comprising monitoring the measured substrate temperature and changing one or more processing conditions responsive to determining that the substrate temperature exceeds a threshold value. 
     
     
         5 . The method of  claim 1 , wherein the substrate support assembly comprises:
 a support shaft;   a substrate support disposed on the support shaft; and   a substrate temperature monitoring system for measuring a temperature of a substrate to be disposed on the substrate support, comprising:
 the optical fiber tube; 
 a light guide coupled to the optical fiber tube, wherein at least a portion of the light guide is disposed in an opening extending through the support shaft and into the substrate support; and 
 a cooling assembly disposed about a junction of the optical fiber tube and the light guide. 
   
     
     
         6 . The method of  claim 5 , wherein the light guide comprises a tube having a length of at least about 400 mm and an inner diameter of at least 40 mm. 
     
     
         7 . The method of  claim 5 , wherein the light guide comprises a sapphire tube having an inner diameter of at least 40 mm. 
     
     
         8 . The method of  claim 1 , wherein measuring the temperature of the substrate comprises measuring IR radiation emitted by and/or reflected from a non-active surface of the substrate. 
     
     
         9 . The method of  claim 8 , wherein the IR radiation is directed from the non-active surface of the substrate to the optical fiber tube using a light guide coupled to the optical fiber tube. 
     
     
         10 . The method of  claim 9 , wherein maintaining the optical fiber tube at a temperature of less than about 100° C. comprises maintaining a junction of the optical fiber tube and the light guide at a temperature of less than about 100° C. 
     
     
         11 . A method of processing a substrate, comprising:
 positioning a substrate on a substrate receiving surface of a substrate support assembly disposed in a processing volume of a processing chamber;   flowing one or more processing gases into the processing volume;   forming a plasma of the one or more processing gases;   measuring a temperature of the substrate using an optical fiber tube, wherein the temperature of the substrate exceeds about 110° C.,   maintaining the optical fiber tube at a temperature of less than about 100° C.; and   depositing a material layer on the substrate.   
     
     
         12 . The method of  claim 11 , wherein the optical fiber tube is coupled to a light guide, and wherein maintaining the optical fiber tube at a temperature of less than about 100° C. comprises maintaining a junction of the optical fiber tube and the light guide at a temperature of less than about 100° C. 
     
     
         13 . The method of  claim 12 , wherein the light guide comprises a tube having an inner diameter of at least about 40 mm. 
     
     
         14 . The method of  claim 13 , wherein measuring the temperature of the substrate includes measuring IR radiation emitted by and/or reflected from a non-active surface of the substrate. 
     
     
         15 . The method of  claim 14 , wherein the IR radiation is directed from the non-active surface of the substrate to the optical fiber tube using the light guide. 
     
     
         16 . A non-transitory computer readable medium having instructions stored thereon for performing a method of processing a substrate when executed by a processor, the method comprising:
 positioning a substrate on a substrate receiving surface of a substrate support assembly disposed in a processing volume of a processing chamber;   flowing one or more processing gases into the processing volume;   forming a plasma of the one or more processing gases;   measuring a temperature of the substrate using an optical fiber tube, wherein the temperature of the substrate exceeds about 110° C.,   maintaining the optical fiber tube at a temperature of less than about 100° C.; and   depositing a material layer on the substrate.   
     
     
         17 . The method of  claim 16 , further comprising monitoring the measured substrate temperature and changing one or more processing conditions responsive to determining that the substrate temperature exceeds a threshold value. 
     
     
         18 . The method of  claim 16 , wherein measuring the temperature of the substrate comprises measuring IR radiation emitted by and/or reflected from a non-active surface of the substrate. 
     
     
         19 . The method of  claim 16 , wherein the optical fiber tube is coupled to a light guide, and wherein maintaining the optical fiber tube at a temperature of less than about 100° C. comprises maintaining a junction of the optical fiber tube and the light guide at a temperature of less than about 100° C. 
     
     
         20 . The method of  claim 19 , wherein the light guide comprises a tube having an inner diameter of at least about 40 mm.