Plasma processing apparatus capable of controlling plasma emission intensity

Abstract

An antenna electrode having a substantially circular shape, is arranged on a plane of a processing vessel, which is located opposite to a stage for mounting a sample within the processing vessel, and positioned parallel to the stage. An emission monitor monitors emission intensity of plasma present in at least 3 different points along a radial direction of the antenna electrode. A control unit adjusts an energizing current supplied to an external coil for forming a magnetic field within the processing vessel. The control unit adjusts the energizing current supplied to the external coil based upon the monitoring result obtained from the emission monitor so as to control the emission intensity of the plasma to become uniform emission intensity.

1 . A plasma processing apparatus comprising: 
 a processing vessel, the pressure of which can be lowered;    a stage for mounting a sample within said processing vessel;    an antenna electrode having a substantially circular shape, arranged on a plane of the processing vessel, which is located opposite to the stage, and positioned parallel to the stage;    gas conducting means for supplying processing gas into the processing vessel;    an external coil which forms a magnetic field within said processing vessel and produces plasma within said processing vessel due to a mutual reaction occurred between the formed magnetic field and an electromagnetic wave radiated from the antenna electrode;    an emission monitor for monitoring emission intensity of plasma present in at least  3  different points along a radial direction of said antenna electrode; and    a control unit for adjusting an energizing current supplied to said external coil; wherein:    said control unit adjusts the energizing current supplied to the external coil based upon the monitoring result obtained from said emission monitor so as to control the emission intensity of the plasma to become uniform emission intensity.    
   
   
       2 . A plasma processing apparatus as claimed in  claim 1  wherein: 
 said gas conducting means is comprised of a gas distributing plate and a shower plate, which are arranged in such a manner that both said gas distributing plate and said shower plate cover said antenna electrode; and    said emission monitor is comprised of an optical fiber which is arranged at a position where said optical fiber faces a narrow hole formed in the shower plate of said gas distributing plate.    
   
   
       3 . A plasma processing apparatus as claimed in  claim 1  wherein: 
 said emission monitor is arranged outside said processing vessel in such a manner that said emission monitor owns directivities along at least 3 different directions of a center portion, a side edge portion, and an intermediate portion of the produced plasma.    
   
   
       4 . A plasma processing apparatus as claimed in  claim 1  wherein: 
 said emission monitor is arranged outside said processing vessel in such a manner that said emission monitor owns directivities along at least 3 different directions of a center portion, a side edge portion, and an intermediate portion of the produced plasma,    said emission monitor calculates emission intensity of the plasma produced in at least said 3 different points along the radial direction of said antenna electrode based upon the monitor values of the plasma emission in the respective directions.    
   
   
       5 . A plasma processing apparatus as claimed in  claim 1  wherein: 
 said emission monitor is arranged outside said processing vessel in such a manner that said emission monitor owns directivities along at least 3 different directions of a center portion, a side edge portion, and an intermediate portion of the produced plasma,    said emission monitor is provided at a position which is higher than a surface of the sample on the side surface of the processing vessel.    
   
   
       6 . A plasma processing apparatus as claimed in  claim 1  wherein: 
 said external coil is comprised of coils of plural systems to which currents different from each other are supplied.    
   
   
       7 . A plasma processing apparatus as claimed in  claim 1  wherein: 
 a silicon member is provided on a surface of said antenna electrode on the side of said stage.    
   
   
       8 . A plasma processing apparatus as claimed in  claim 1  wherein: 
 said antenna electrode is comprised of an antenna bias power supply which applies thereto an antenna bias voltage.    
   
   
       9 . In a plasma processing apparatus comprising: 
 a processing vessel, the pressure of which can be lowered; a stage for mounting a sample within said processing vessel; an antenna electrode having a substantially circular shape, arranged on a plane of the processing vessel, which is located opposite to the stage, and positioned parallel to the stage; gas conducting means for supplying processing gas into the processing vessel; and an external coil which forms a magnetic field within said processing vessel and produces plasma within said processing vessel due to a mutual reaction occurred between the formed magnetic field and an electromagnetic wave radiated from the antenna electrode,    a plasma processing method for plasma-processing said sample by employing said plasma, comprising the steps of:    monitoring emission intensity of plasma present in at least 3 different points along a radial direction of said antenna electrode; and    adjusting an energizing current supplied to said external coil in response to a ratio of the emission intensity monitored in the respective points so as to control the emission intensity of the plasma to become uniform emission intensity.