Microwave plasma source and plasma processing apparatus

Abstract

There are provided a microwave plasma source and a plasma processing apparatus capable of improving uniformity of a plasma density distribution within a processing chamber by controlling positions of nodes and antinodes of a standing wave of microwave within the processing chamber not to be fixed. The microwave plasma source 2 includes a microwave supply unit 40. The microwave supply unit 40 includes multiple microwave introducing devices 43 each introducing microwave into the processing chamber; and multiple phase controllers 46 for adjusting phases of the microwaves inputted to the microwave introducing devices 43. Here, the phases of the microwaves inputted to the microwave introducing devices 43 are adjusted by fixing an input phase of the microwave inputted to one of two adjacent microwave introducing devices 43 while varying an input phase of the microwave inputted to the other microwave introducing device 43 according to a periodic waveform.

1 . A microwave plasma source for introducing microwave into a processing chamber capable of performing a plasma process by exciting a gas supplied into the processing chamber into plasma by the microwave, the microwave plasma source comprising:
 a microwave generator for generating microwave; and   a microwave supply unit, configured to supply the generated microwave into the processing chamber, including:   a plurality of microwave introducing devices, each introducing the microwave into the processing chamber; and   a plurality of phase controllers for adjusting phases of the microwaves input to the plurality of microwave introducing devices,   wherein the phases of the microwaves are adjusted by fixing an input phase of the microwave input to one of two adjacent microwave introducing devices while varying an input phase of the microwave input to the other microwave introducing device according to a periodic waveform, or by varying input phases of the microwaves input to both of the two adjacent microwave introducing devices according to periodic waveforms not overlapped with each other.   
     
     
         2 . The microwave plasma source of  claim 1 , wherein the periodic waveform is one of a sine waveform, a triangular waveform, a trapezoidal waveform and a waveform similar to a sine waveform. 
     
     
         3 . The microwave plasma source of  claim 1 , further comprising:
 a ceiling plate serving as a top wall of the processing chamber and configured to transmit the microwaves radiated from the plurality of microwave introducing devices,   wherein the ceiling plate includes:   a plurality of dielectric members provided at positions corresponding to the plurality of microwave introducing devices; and   a metal frame, having a honeycomb structure, for supporting the dielectric members.   
     
     
         4 . The microwave plasma source of  claim 3 ,
 wherein the frame has a gas flow path and a plurality of gas discharge holes, and   a gas used for the plasma process is discharged into the processing chamber from the gas discharge holes.   
     
     
         5 . A plasma processing apparatus comprising:
 a processing chamber for accommodating therein a processing target substrate;   a mounting table for mounting thereon the processing target substrate within the processing chamber;   a gas supply unit for supplying a gas into the processing chamber; and   a microwave plasma source as claimed in  claim 1 ,   wherein plasma is generated by microwave introduced into the processing chamber from the microwave plasma source and a process is performed on the processing target substrate by the plasma.