Multi-zone cooling of plasma heated window

Abstract

A plenum, positioned beneath a first coil and above a window disposed on a top portion of a processing chamber, has side walls and a top surface covering an upper surface of the window and has a first air inlet positioned at a center portion to receive airflow from a first air amplifier. The first air inlet includes holes to distribute the air across the window within the side walls to reduce hotspots at a center portion of the window. The plenum includes a second air inlet at an edge portion of the top surface to receive the airflow from a second air amplifier to reduce hotspots at an edge portion of the window, and a third air inlet between the center and edge portions of the top surface to receive the airflow from a third air amplifier to reduce hotspots at a middle portion of the window.

What is claimed is: 
     
         1 . A substrate processing system comprising:
 a processing chamber having a window disposed at a top portion of the processing chamber, the window covering the processing chamber;   a first coil positioned above the window, the first coil to generate electromagnetic energy to ionize processing gases in the processing chamber to generate plasma in the processing chamber;   first, second, and third air amplifiers to generate airflow when activated;   a plenum positioned beneath the first coil and above the window, the plenum having side walls and having a top surface substantially equal in area to an area of an upper surface of the window, the top surface having a first air inlet positioned at about a center portion of the top surface of the plenum to receive the airflow from the first air amplifier, the first air inlet including multiple holes to distribute the air across the window within the side walls of the plenum to reduce hotspots at a center portion of the window beneath the first coil, the plenum further including:   a second air inlet at an edge portion of the top surface of the plenum to receive the airflow from the second air amplifier to reduce hotspots at an edge portion of the window; and   a third air inlet at a middle portion of the top surface of the plenum, between the center portion and the edge portion of the top surface of the plenum, to receive the airflow from the third air amplifier to reduce hotspots at a middle portion of the window.   
     
     
         2 . The substrate processing system of  claim 1 , wherein the plenum is sized to cover all of the upper surface of the window. 
     
     
         3 . The substrate processing system of  claim 1 , wherein the plenum comprises a plurality of plenums which cover all of the upper surface of the window. 
     
     
         4 . The substrate processing system of  claim 1 , wherein the plenum has an additional air inlet at the edge portion of the top surface of the plenum, the first air amplifier to provide airflow to both the first air inlet and the additional air inlet. 
     
     
         5 . The substrate processing system of  claim 1 , further comprising an additional air amplifier, wherein the plenum has an additional air inlet, the first air amplifier to provide airflow to the first air inlet and the additional air amplifier to provide airflow to the additional air inlet. 
     
     
         6 . The substrate processing system of  claim 1 , further comprising a second coil coupled to the first coil and positioned above the plenum. 
     
     
         7 . The substrate processing system of  claim 1 , wherein the plenum has a first air outlet at the top surface. 
     
     
         8 . The substrate processing system of  claim 1 , wherein the plenum has a first air outlet in one of the side walls. 
     
     
         9 . The substrate processing system of  claim 1 , further comprising a source of air, first and second valves connected to the source of air, the first air amplifier connected to the source of air through the first and second valves, and a controller to control the source of air and the first and second valves to provide the airflow, the first and second valves providing different airflows. 
     
     
         10 . The substrate processing system of  claim 1 , further comprising:
 a plurality of temperature sensors, each of the plurality of temperature sensors to measure a temperature of a corresponding portion of the window and to output a sensed temperature; and   a controller to control the first, second, and third air amplifiers to generate the airflow based on the sensed temperatures.   
     
     
         11 . A substrate processing system comprising:
 a processing chamber having a window disposed at a top portion of the processing chamber, the window covering the processing chamber;   a plurality of coils positioned above the window to generate electromagnetic energy to ionize processing gases in the processing chamber to generate plasma in the processing chamber;   a plurality of air amplifiers to generate airflow; and   a plenum positioned beneath the plurality of coils and above the window, the plenum having side walls and having a top surface substantially equal in area to an area of an upper surface of the window, the top surface having a plurality of air inlets to receive the airflow from the plurality of air amplifiers and distribute the airflow across the window within the side walls of the plenum to reduce one or more hotspots in one or more areas of the window beneath the plurality of coils;   wherein the plurality of air inlets include:   a first air inlet positioned at about a center portion of the top surface of the plenum to receive the airflow from a first one of the air amplifiers and includes multiple holes to reduce hotspots at a center portion of the window;   a second air inlet at an edge portion of the top surface of the plenum to receive the airflow from a second one of the air amplifiers to reduce hotspots at an edge portion of the window; and   a third air inlet at a middle portion of the top surface of the plenum between the center and edge portions of the top surface of the plenum to receive the airflow from a third one of the air amplifiers to reduce hotspots at a middle portion of the window.   
     
     
         12 . The substrate processing system of  claim 11 , wherein the plenum is sized to cover all of the upper surface of the window. 
     
     
         13 . The substrate processing system of  claim 11 , wherein the plenum comprises a plurality of plenums which cover all of the upper surface of the window. 
     
     
         14 . The substrate processing system of  claim 11 , wherein the plurality of air amplifiers are equal in number to the plurality of air inlets. 
     
     
         15 . The substrate processing system of  claim 11 , wherein the plurality of air amplifiers are fewer than the plurality of air inlets, and wherein two or more of the plurality of air inlets share an air amplifier. 
     
     
         16 . The substrate processing system of  claim 11 , wherein the plenum has a first air outlet at the top surface. 
     
     
         17 . The substrate processing system of  claim 11 , wherein the plenum has a first air outlet in one of the side walls. 
     
     
         18 . The substrate processing system of  claim 11 , further comprising a source of air and a plurality of pairs of valves connected to the source of air, each of the plurality of air amplifiers connected to the source of air through one of the plurality of pairs of valves, and a controller to control the source of air and the plurality of pairs of valves to provide the airflow. 
     
     
         19 . The substrate processing system of  claim 18 , wherein a first valve in each of the plurality of pairs of valves provides relatively low airflow, and wherein a second valve in each of the plurality of pairs of valves provides relatively high airflow. 
     
     
         20 . The substrate processing system of  claim 11 , further comprising:
 a plurality of temperature sensors, each of the plurality of temperature sensors to measure a temperature of a corresponding portion of the window and to output a sensed temperature; and   a controller to control the plurality of air amplifiers based on the sensed temperatures.