Temperature enhanced electrostatic chucking in plasma processing apparatus

Abstract

Methods and systems for temperature enhanced chucking and dechucking of resistive substrates in a plasma processing apparatus are described herein. In certain embodiments, methods and systems incorporate modulating a glass carrier substrate temperature during a plasma etch process to chuck and dechuck the carrier at first temperatures elevated relative to second temperatures utilized during plasma etching. In embodiments, one or more of plasma heat, lamp heat, resistive heat, and fluid heat transfer are controlled to modulate the carrier substrate temperature between chucking temperatures and process temperatures with each run of the plasma etch process.

What is claimed is: 
     
         1 . A plasma processing apparatus, comprising:
 an electrostatic chuck (ESC) disposed with a plasma etch chamber to clamp a workpiece during a plasma process;   a first heat exchanger coupled to the ESC; and   a heat source to heat the workpiece to a first temperature that is greater than a setpoint of the first heat exchanger, wherein the heat source is to heat the workpiece to the first temperature until completion of a workpiece chucking sequence, and wherein the first heat exchanger is to cool the ESC to a second temperature following completion of the workpiece chucking sequence.   
     
     
         2 . The apparatus of  claim 1 , wherein the heat source is at least one of: a second heat exchanger, a lamp, an RF plasma bias power generator. 
     
     
         3 . The apparatus of  claim 2 , further comprising:
 one or more switched valves to decouple the first heat exchanger from the ESC and to couple the second heat exchanger to the ESC to cool the ESC from the first temperature to the second temperature in response to completion of a workpiece chucking sequence.   
     
     
         4 . The apparatus of  claim 3 , wherein a setpoint of the first heat exchanger is at least 35° C. higher than a setpoint of the second heat exchanger. 
     
     
         5 . The apparatus of  claim 2 , further comprising a controller to reduce a backside helium pressure while the RF plasma bias power is heating the workpiece. 
     
     
         6 . The apparatus of  claim 2 , further comprising a controller to discontinue the RF plasma bias power in response to a backside helium leak rate increase during execution of a dechucking sequence.