Plasma processing apparatus and plasma processing method

Abstract

In a plasma processing apparatus comprising a processing chamber arranged in a vacuum chamber, a sample stage arranged under the processing chamber and having its top surface on which a wafer to be processed is mounted, a vacuum decompression unit for evacuating the interior of the processing chamber to reduce the pressure therein, and introduction holes arranged above said sample stage to admit process gas into the processing chamber, the wafer having its top surface mounted with a film structure and the film structure being etched by using plasma formed by using the process gas, the film structure is constituted by having a resist film or a mask film, a poly-silicon film and an insulation film laminated in this order from top to bottom on a substrate and before the wafer is mounted on the sample stage and the poly-silicon film underlying the mask film is etched, plasma is formed inside the processing chamber to cover the surface of members inside the processing chamber with a coating film containing a component of Si.

1 . A plasma processing apparatus comprising:
 a processing chamber arranged in a vacuum chamber;   a sample stage arranged under the processing chamber and having its top surface on which a wafer to be processed is mounted;   a vacuum decompression unit for evacuating the interior of said processing chamber to reduce the pressure therein; and   introduction holes arranged above said sample stage to admit process gas into said processing chamber, said wafer having its top surface mounted with a film structure and said film structure being etched by using plasma formed by using said process gas, wherein   said film structure is constituted by having a resist film or a mask film, a poly-silicon film and an insulation film laminated in this order from top to bottom on a substrate and before said wafer is mounted on said sample stage and the poly-silicon film underlying said mask film is etched, plasma is formed inside said processing chamber to cover the surface of members inside said processing chamber with a coating film containing a component of Si.   
     
     
         2 . A plasma processing apparatus according to  claim 1 , wherein in the step of covering said coating film, a gas containing a component of at least one of Si or Si and O or Si and C is supplied to the interior of said processing chamber. 
     
     
         3 . A plasma processing apparatus according to  claim 1 , wherein after, following the step of covering said coating films, an aftertreatment process for forming plasma inside said processing chamber is carried out to process the surface of the coating film, said wafer is located inside said processing chamber and then an etching process is executed. 
     
     
         4 . A plasma processing apparatus according to  claim 3 , wherein said film structure has a metal film made of a metal material and interposed between said poly-silicon film and said insulation film and a cleaning process for forming plasma adapted to eliminate said metal material from said coating film is carried out.