Plasma processing apparatus

Abstract

A plasma processing apparatus includes a processing gas supplying unit for supplying a desired processing gas to a processing space between an upper electrode and a lower electrode which are disposed facing each other in an evacuable processing chamber. The plasma processing apparatus further includes a radio frequency (RF) power supply unit for applying an RF power to one of the lower and the upper electrode to generate plasma of the processing gas by RF discharge and an electrically conductive RF ground member which covers a periphery portion of the electrode to which the RF power is applied to receive RF power emitted outwardly in radial directions from the periphery portion of the electrode to which the RF power is applied and send the received RF power to a ground line.

1 . A plasma processing apparatus comprising:
 an evacuable processing chamber;   a lower electrode for mounting thereon a substrate in the processing chamber;   an upper electrode facing the lower electrode in parallel in the processing chamber;   a processing gas supplying unit for supplying a processing gas to a processing space between the upper electrode and the lower electrode;   a radio frequency (RF) power supply unit for applying an RF power to one of the lower and the upper electrode to generate a plasma of the processing gas by RF discharge; and   an electrically conductive RF ground member which covers a periphery portion of the electrode to which the RF power is applied to receive RF power emitted outwardly in radial directions from the periphery portion of the electrode to which the RF power is applied and send the received RF power to a ground line.   
   
   
       2 . The plasma processing apparatus of  claim 1 , wherein the electrode to which the RF power is applied is the lower electrode. 
   
   
       3 . The plasma processing apparatus of  claim 2 , wherein a dielectric material is interposed between the lower electrode and the RF ground member. 
   
   
       4 . The plasma processing apparatus of  claim 2 , wherein a surface of the RF ground member is covered by an insulating film. 
   
   
       5 . The plasma processing apparatus of  claim 2 , wherein an annular gas exhaust path for connecting the processing space to a gas exhaust port provided at a bottom portion of the processing chamber is formed between the RF ground member and an inner wall of the processing chamber, and
 wherein a plurality of conductive fin members, which is electrically grounded and vertically extending, for promotion of extinction of a plasma diffused from the processing space is provided at an upper region of the gas exhaust path.   
   
   
       6 . The plasma processing apparatus of  claim 5 , wherein the plurality of fin members is seamlessly molded as a single unit with or attached to an electrically conductive exhaust ring provided annularly at the upper region of the gas exhaust path. 
   
   
       7 . The plasma processing apparatus of  claim 6 , wherein surfaces of the fin members are covered by insulating films. 
   
   
       8 . The plasma processing apparatus of  claim 5 , wherein the fin members are radially disposed at regular intervals in a circumferential direction of the gas exhaust path. 
   
   
       9 . The plasma processing apparatus of  claim 2 , wherein a dielectric material having a thickness distribution in which the dielectric material is thickest in the central portion of the lower or the upper electrode and is thinnest in an edge portion of the lower or the upper electrode is prepared at the top surface region of the lower electrode or a bottom surface region of the upper electrode. 
   
   
       10 . The plasma processing apparatus of  claim 1 , wherein the RF power has a frequency equal to or higher than 80 MHz. 
   
   
       11 . A plasma processing apparatus comprising:
 an evacuable processing chamber;   a lower electrode for mounting thereon a substrate in the processing chamber;   an upper electrode facing the lower electrode in parallel in the processing chamber;   a processing gas supplying unit for supplying a processing gas to a processing space between the upper electrode and the lower electrode;   a radio frequency (RF) power supply unit for applying an RF power to one of the lower and the upper electrode to generate a plasma of the processing gas by RF discharge; and   a grounded electrically conductive RF ground member which covers a periphery portion of a top or a bottom surface and a side surface of the electrode to which the RF power is applied.   
   
   
       12 . The plasma processing apparatus of  claim 11 , wherein the electrode to which the RF power is applied is the lower electrode. 
   
   
       13 . The plasma processing apparatus of  claim 12 , wherein the RF ground member covers a substantially entire region of the top surface of the lower electrode projecting outwardly in radial directions from the substrate. 
   
   
       14 . The plasma processing apparatus of  claim 12 , wherein a dielectric material is interposed between the lower electrode and the RF ground member. 
   
   
       15 . The plasma processing apparatus of  claim 12 , wherein a surface of the RF ground member is covered by an insulating film. 
   
   
       16 . The plasma processing apparatus of  claim 12 , wherein an annular gas exhaust path for connecting the processing space to a gas exhaust port provided at a bottom portion of the processing chamber is formed between the RF ground member and an inner wall of the processing chamber, and
 wherein a plurality of conductive fin members, which is electrically grounded and vertically extending, for promotion of extinction of a plasma diffused from the processing space is provided at an upper region of the gas exhaust path.   
   
   
       17 . The plasma processing apparatus of  claim 16 , wherein the plurality of fin members is seamlessly molded as a single unit with or attached to an electrically conductive exhaust ring provided annularly at the upper region of the gas exhaust path. 
   
   
       18 . The plasma processing apparatus of  claim 17 , wherein surfaces of the fin members are covered by insulating films. 
   
   
       19 . The plasma processing apparatus of  claim 16 , wherein the fin members are radially disposed at regular intervals in a circumferential direction of the gas exhaust path. 
   
   
       20 . The plasma processing apparatus of  claim 12 , wherein a dielectric material having a thickness distribution in which the dielectric material is thickest in the central portion of the lower or the upper electrode and is thinnest in an edge portion of the lower or the upper electrode is prepared at the top surface region of the lower electrode or a bottom surface region of the upper electrode.