Plasma processing apparatus and method

Abstract

A plasma processing apparatus comprises a first passage opened in a top of suscepter at a peripheral area thereof, a first gas supply source for supplying heat exchange gas into a small clearance between the suscepter and a wafer through the first passage, a first vacuum pump for exhausting the clearance through the first passage, a second passage opened in the top of the suscepter at a center area thereof, a second gas supply source for supplying heat exchange gas into the clearance through the second passage, a second vacuum pump for exhausting the clearance through the second passage, and a controller for controlling the first and second gas supply sources and the first and second vacuum pumps independently of the others in such a way that backpressure caused in the second passage by the second gas supply source and vacuum pump can become lower than backpressure caused in the first passage by the first gas supply source and vacuum pump.

What is claimed is: 
     
       1. A plasma processing apparatus using a heat exchange gas to increase the cooling efficiency of a substrate to be processed through a suscepter during plasma generation, comprising: a first passage open at a peripheral portion in a top of said suscepter;   first gas supply means for supplying a heat exchange gas through said first passage into a small clearance formed between the suscepter and said substrate to be processed;   a first temperature control mechanism for controlling the temperature of the heat exchange gas supplied from said first gas supply means into the first passage;   first exhaust means for exhausting the small clearance formed between the suscepter and the substrate through the first passage;   a second passage open in a central portion in the top of the suscepter;   second gas supply means for supplying a heat exchange gas into the small clearance formed between the suscepter and the substrate through said second passage;   a second temperature control mechanism for controlling the temperature of the heat exchange gas supplied from said second gas supply means into said second passage; and   second exhausting means for exhausting the small clearance formed between the suscepter and the substrate through the second passage.   
     
     
       2. The plasma processing apparatus according to claim 1, wherein each of said first and second temperature control mechanisms comprises: a temperature control member mounted within a pipe through which the heat exchange gas is supplied; and   heat exchange means .[.arranged within a.]. .Iadd.wound about an outer surface of the .Iaddend.pipe for supplying the heat exchange gas such that heat is exchanged between said heat exchange means and said heat exchange gas circulated through said pipe.   
     
     
       3. The plasma processing apparatus according to claim 2, further comprising: temperature control means for controlling the temperature of the heat exchange means;   a temperature sensor for detecting a temperature of said suscepter; and   control means for controlling the first and second gas supply means, the first and second exhausting means, and the temperature control means based on the temperature detected by the temperature sensor.   
     
     
       4. The plasma processing apparatus according to claim 2, wherein said temperature control member has a surface area which is sufficiently large compared with the volume thereof and is adapted for achieving heat exchange. 
     
     
       5. The plasma processing apparatus according to claim 4, wherein said temperature control member is formed of a porous material. 
     
     
       6. The plasma processing apparatus according to claim 4, wherein said temperature control member consists of a bundle of capillary tubes. 
     
     
       7. The plasma processing apparatus according to claim 6, wherein said capillary tube is formed of quartz. 
     
     
       8. The plasma processing apparatus according to claim 6, wherein said capillary tube is made of a metallic material. 
     
     
       9. The plasma processing apparatus according to claim 2, wherein a heat exchange medium is interposed between said heat exchange means and said pipe. 
     
     
       10. The plasma processing apparatus according to claim 1, further comprising control means for independently controlling said first and second gas supply means and said first and second exhaust means such that the backpressure generated within the second passage by the second gas supply means and the second exhaust means is lower than the backpressure generated within the first passage by the first gas supply means and the first exhaust means. 
     
     
       11. The plasma processing apparatus according to claim 1, wherein each of said first and second passages is open at a plurality of portions at the top of the suscepter to form a first group of openings positioned to form a circular arrangement and a second group of openings positioned to form a circular arrangement concentric with said circular arrangement formed by said first group of openings. 
     
     
       12. The plasma processing apparatus according to claim 1, further comprising: a third passage open at an intermediate portion between the center and the periphery in the top of the suscepter;   third gas supply means for supplying a heat exchange gas into a small clearance formed between the suscepter and the substrate to be processed through said third passage; and   third exhaust means for exhausting the small clearance formed between the suscepter and said substrate through said third passage.   
     
     
       13. A plasma processing apparatus using a heat exchange gas to increase the cooling efficiency of a substrate to be processed through a suscepter during plasma generation comprising: a first passage open at a peripheral portion in a top of said suscepter;   gas supply means for supplying a heat exchange gas through said first passage into a small clearance formed between the suscepter and said substrate to be processed;   a temperature control mechanism for controlling the temperature of the heat exchange gas supplied from said gas supply means into the first passage;   a second passage open in a central portion in the top of the suscepter; and   exhausting means for exhausting the small clearance formed between the suscepter and the substrate through the second passage.   
     
     
       14. The plasma processing apparatus according to claim 13, wherein said temperature control mechanism comprises: a temperature control member mounted within a pipe through which the heat exchange gas is supplied; and   heat exchange means .[.arranged within a.]. .Iadd.wound about an outer surface of the .Iaddend.pipe for supplying a heat exchange gas such that heat is exchanged between said heat exchange means and said heat exchange gas circulated through said pipe.   
     
     
       15. A plasma processing apparatus using a heat exchange gas to increase the cooling efficiency of a substrate to be processed through a suscepter during plasma generation, comprising: a passage open at a top of said suscepter;   gas supply means for supplying a heat exchange gas through said passage into a small clearance formed between the suscepter and the substrate to be processed; and   a temperature control mechanism for controlling a temperature of the heat exchange gas supplied from said gas supply means into said passage.   
     
     
       16. The plasma processing apparatus according to claim 15, wherein said temperature control mechanism comprises: a temperature control member mounted within a pipe through which the heat exchange gas is supplied; and   heat exchange means .[.arranged within a.]. .Iadd.wound about an outer surface of the .Iaddend.pipe for supplying a heat exchange gas such that heat is exchanged between said heat exchange means and said heat exchange gas circulated through said pipe.   
     
     
       17. The plasma processing apparatus according to claim 15, further comprising: temperature control means for controlling the temperature of the heat exchange means;   a temperature sensor for detecting the temperature of said suscepter; and   control means for controlling the first and second gas supply means, the first and second exhausting means, and the temperature control means based on the temperature detected by the temperature sensor.   
     
     
       18. A plasma processing apparatus using a heat exchange gas to increase the cooling efficiency of a substrate to be processed through a suscepter during plasma generation, comprising: a passage open at a top of said suscepter;   first and second gas supply means for supplying a heat exchange gas through said passage into a small clearance formed between the suscepter and the substrate to be processed, the heat exchange gases supplied from said first and second gas supply means differing from each other in composition.