Plasma processing apparatus and a plasma processing method

Abstract

In an oxide film etching process, a plasma having a suitable ratio of CF 3 , CF 2 , CF, and F is necessary, and there is a problem in that the etching characteristic fluctuates in accordance with a temperature fluctuation of the etching chamber. Using a UHF type ECR plasma etching apparatus having a low electron temperature, a suitable dissociation can be obtained, and by maintaining the temperature of a side wall of the etching chamber in a range from 10° C. and 120° C., a stable etching characteristic can be obtained. Since oxide film etching using a low electron temperature and a high density plasma can be obtained, an etching result having a superior characteristic can be obtained, and, also, since the side wall temperature adjustment range is low, a simplified apparatus structure and a heat resistant performance countermeasure can be obtained easily.

1 . A plasma processing method of using a plasma processing apparatus comprising a vacuum processing chamber, a sample table for mounting a sample which is processed in said vacuum processing chamber, a temperature adjustment side wall of said vacuum processing chamber and a plasma generation means for generating a plasma according to introduction of a gas which contains at least carbon and fluorine, thereby forming a gas species which contains carbon and fluorine by plasma dissociation and a plasma processing is carried out using said plasma, the plasma processing method comprising the steps of:
 generating a plasma which contains the formed gas species, of a reduced amount of F and a greater amount of CF 3 , CF 2  or CF as a ratio of the gas species, by controlling the electron temperature of said plasma generated to a range of from 0.25 eV to 1 eV, so as to perform an etching with an etching characteristic of a predetermined selection ratio and a predetermined etching speed,   etching said sample having an insulating film as a film to be processed, using said plasma, and   controlling a temperature of said temperature adjustment side wall to a range of 10° C. to 120° C., thereby adhering deposits to the temperature adjustment side wall and controlling the amount of the gas released from the deposits so as to restrain a time lapse change of the etching characteristic.   
   
   
       2 . A plasma processing method according to  claim 1 , wherein said plasma generation means is an electron cyclotron resonance system using a microwave at a frequency of from 300 MHz to 1 GHz. 
   
   
       3 . A plasma processing method according to  claim 2 , wherein a temperature-adjusted coolant medium is used as a means for controlling the temperature of said temperature of said temperature adjustment side wall so as to establish restraint of the time lapse change. 
   
   
       4 . A plasma processing method according to  claim 3 , wherein the temperature of said temperature adjustment side wall is controlled to a range of 30° C. to 50° C. 
   
   
       5 . A plasma processing method according to  claim 1 , wherein a temperature-adjusted coolant medium is used as a means for controlling the temperature of said temperature adjustment side wall so as to establish restraint of the time lapse change. 
   
   
       6 . A plasma processing method according to  claim 1 , wherein the temperature of said temperature adjustment side wall is controlled to a range of 30° C. to 50° C. so as to establish restraint of the time lapse change. 
   
   
       7 . A plasma processing method according to  claim 1 , wherein said temperature of said temperature adjustment side wall is controlled so as to restrain a time lapse change of the amount of the gas released from the deposits.