Plasma etching apparatus

Abstract

In order to improve a controllability of etching characteristics by way of precisely and freely controlling a flow or a density distribution of a processing gas introduced into a processing chamber, a plasma etching apparatus includes, as a gas inlet for introducing an etching gas into a plasma generation region PS in a chamber 10 , an upper gas inlet (an upper central shower head 66 a and an upper peripheral shower head 68 a ) for introducing a gas through an upper electrode 38 ; and a side gas inlet for introducing a gas through a sidewall of the chamber 10 . The side gas inlet 104 has a side shower head 108 attached to the sidewall of the chamber 10.

1 . A plasma etching apparatus comprising: 
 a depressurizable processing chamber;    a lower electrode for mounting thereon a substrate to be processed in the processing chamber;    an upper electrode facing the lower electrode in the processing chamber with a plasma generation region formed therebetween;    a radio frequency power supply unit for applying a radio frequency power between the upper electrode and the lower electrode to thereby form a radio frequency electric field in the plasma generation region;    an upper gas inlet for introducing a first gas including etchant gas through the upper electrode into the plasma generation region; and    a side gas inlet for introducing a second gas including dilution gas through a sidewall of the processing chamber into the plasma generation region.    
   
   
       2 . The plasma etching apparatus of  claim 1 , wherein the upper gas inlet has a first mass flow control unit for independently controlling a flow rate of the first gas.  
   
   
       3 . The plasma etching apparatus of  claim 1 , wherein the first gas is a mixed gas, and the upper gas inlet has a first mixing ratio control unit for independently controlling a mixing ratio of the first gas.  
   
   
       4 . The plasma etching apparatus of  claim 1 , wherein the upper gas inlet has an upper gas injection portion provided at the upper electrode, for injecting the first gas toward the plasma generation region.  
   
   
       5 . The plasma etching apparatus of  claim 4 , wherein the upper gas inlet has a first gas supply line for supplying the first gas toward the upper gas injection portion and an upper gas buffer space for accumulating the first gas supplied through the first gas supply line in front of the upper gas injection portion.  
   
   
       6 . The plasma etching apparatus of  claim 1 , wherein the side gas inlet has a second mass flow control unit for independently controlling a flow rate of the second gas.  
   
   
       7 . The plasma etching apparatus of  claim 1 , wherein the second gas is a mixed gas, and the side gas inlet has a second mixing ratio control unit for independently controlling a mixing ratio of the second gas.  
   
   
       8 . The plasma etching apparatus of  claim 1 , wherein the side gas inlet has a side gas injection portion provided at the sidewall of the processing chamber, for injecting the second gas toward the plasma generation region.  
   
   
       9 . The plasma etching apparatus of  claim 8 , wherein the side gas injection portions are circumferentially provided at the sidewall of the processing chamber at regular intervals.  
   
   
       10 . The plasma etching apparatus of  claim 8 , wherein the side gas injection portion is made of a material selected from a group consisting of Si, SiC and quartz.  
   
   
       11 . The plasma etching apparatus of  claim 8 , wherein the side gas inlet has a second gas supply line for supplying the second gas toward the side gas injection portion and a side gas buffer space for accumulating the second gas supplied through the second gas supply line in front of the side gas injection portion.  
   
   
       12 . A plasma etching apparatus comprising: 
 a depressurizable processing chamber;    a lower electrode for mounting thereon a substrate to be processed in the processing chamber;    an upper electrode facing the lower electrode in the processing chamber with a plasma generation region formed therebetween;    a radio frequency power supply unit for applying a radio frequency power between the upper electrode and the lower electrode to thereby form a radio frequency electric field in the plasma generation region;    an upper central gas inlet for introducing a first gas including dilution gas through a central portion of the upper electrode into the plasma generation region;    an upper peripheral gas inlet for introducing a second gas including etchant gas through a peripheral portion provided at an outside of the central portion of the upper electrode along its radial direction into the plasma generation region; and    a side gas inlet for introducing a third gas including dilution gas a sidewall of the processing chamber into the plasma generation region.    
   
   
       13 . The plasma etching apparatus of  claim 12 , wherein the upper central gas inlet has a first mass flow control unit for independently controlling a flow rate of the first gas.  
   
   
       14 . The plasma etching apparatus of  claim 12 , wherein the first gas is a mixed gas, and the upper central gas inlet has a first mixing ratio control unit for independently controlling a mixing ratio of the first gas.  
   
   
       15 . The plasma etching apparatus of  claim 12 , wherein the upper central gas inlet has an upper central gas injection portion provided at the central portion of the upper electrode, for injecting the first gas toward the plasma generation region.  
   
   
       16 . The plasma etching apparatus of  claim 15 , wherein the upper central gas inlet has a first gas supply line for supplying the first gas toward the upper central gas injection portion and an upper central gas buffer space for accumulating the first gas supplied through the first gas supply line in front of the upper central gas injection portion.  
   
   
       17 . The plasma etching apparatus of  claim 12 , wherein the upper peripheral gas inlet has a second mass flow control unit for independently controlling a flow rate of the second gas.  
   
   
       18 . The plasma etching apparatus of  claim 12 , wherein the second gas is a mixed gas, and the upper peripheral gas inlet has a second mixing ratio control unit for independently controlling a mixing ratio of the second gas.  
   
   
       19 . The plasma etching apparatus of  claim 12 , wherein the upper peripheral gas inlet has an upper peripheral gas injection portion provided at an outside of the central portion of the upper electrode along its radial direction, for injecting the second gas toward the plasma generation region.  
   
   
       20 . The plasma etching apparatus of  claim 19 , wherein the upper peripheral gas injection portion has a plurality of gas injection openings disposed at regular intervals.  
   
   
       21 . The plasma etching apparatus of  claim 19 , wherein the upper peripheral gas inlet has a second gas supply line for supplying the second gas toward the upper peripheral gas injection portion and an upper peripheral gas buffer space for accumulating the second gas supplied through the second gas supply line in front of the upper peripheral gas injection portion.  
   
   
       22 . The plasma etching apparatus of  claim 12 , wherein the side gas inlet has a third mass flow control unit for independently controlling a flow rate of the third gas.  
   
   
       23 . The plasma etching apparatus of  claim 12 , wherein the third gas is a mixed gas, and the side gas inlet has a third mixing ratio control unit for independently controlling a mixing ratio of the third gas.  
   
   
       24 . The plasma etching apparatus of  claim 12 , wherein the side gas inlet has a side gas injection portion provided at the sidewall of the processing chamber, for injecting the third gas toward the plasma generation region.  
   
   
       25 . The plasma etching apparatus of  claim 24 , wherein the side gas injection portions are circumferentially provided at the sidewall of the processing chamber at regular intervals.  
   
   
       26 . The plasma etching apparatus of  claim 24 , wherein the side gas injection portion has a plurality of gas injection openings disposed at regular intervals.  
   
   
       27 . The plasma etching apparatus of  claim 24 , wherein the side gas injection portion is made of a material selected from a group consisting of Si, SiC and quartz.  
   
   
       28 . The plasma etching apparatus of  claim 24 , wherein the side gas inlet has a third gas supply line for supplying the third gas toward the side gas injection portion and a side gas buffer space for accumulating the third gas supplied through the third gas supply line in front of the side gas injection portion.  
   
   
       29 . The plasma etching apparatus of  claim 12 , further comprising a flow rate ratio control unit for controlling a flow rate ratio of the first and the third gas depending on processes.  
   
   
       30 . The plasma etching apparatus of  claim 12 , wherein the first gas contains all or most of an additive gas.  
   
   
       31 . The plasma etching apparatus of  claim 12 , wherein the second gas contains all or most of an additive gas.  
   
   
       32 . The plasma etching apparatus of  claim 1 , wherein the first and the third gas contain all or most of an additive gas.  
   
   
       33 . A plasma etching apparatus comprising: 
 a depressurizable processing chamber;    a lower electrode for mounting thereon a substrate to be processed in the processing chamber;    an upper electrode facing the lower electrode in the processing chamber with a plasma generation region formed therebetween;    a radio frequency power supply unit for applying a radio frequency power between the upper electrode and the lower electrode to thereby form a radio frequency electric field in the plasma generation region;    a first gas inlet for introducing a first gas including dilution gas through a first region containing a central portion of the upper electrode into the plasma generation region;    a second gas inlet for introducing a second gas including etchant gas through a second region of the upper electrode provided at an outside of the first region along its radial direction into the plasma generation region; and    a third gas inlet for introducing a third gas including dilution gas through a third region of the upper electrode provided at an outside of the second region along its radial direction into the plasma generation region.    
   
   
       34 . The plasma etching apparatus of  claim 33 , wherein the first gas inlet has a first mass flow control unit for independently controlling a flow rate of the first gas.  
   
   
       35 . The plasma etching apparatus of  claim 33 , wherein the first gas is a mixed gas, and the first gas inlet has a first mixing ratio control unit for independently controlling a mixing ratio of the first gas.  
   
   
       36 . The plasma etching apparatus of  claim 33 , wherein the first gas inlet has a first gas injection portion provided in the first region of the upper electrode, for injecting the first gas toward the plasma generation region.  
   
   
       37 . The plasma etching apparatus of  claim 36 , wherein the first gas inlet has a first gas supply line for supplying the first gas toward the first gas injection portion and a first gas buffer space for accumulating the first gas supplied through the first gas supply line in front of the first gas injection portion.  
   
   
       38 . The plasma etching apparatus of  claim 33 , wherein the second gas inlet has a second mass flow control unit for independently controlling a flow rate of the second gas.  
   
   
       39 . The plasma etching apparatus of  claim 33 , wherein the second gas is a mixed gas, and the second gas inlet has a second mixing ratio control unit for independently controlling a mixing ratio of the second gas.  
   
   
       40 . The plasma etching apparatus of  claim 33 , wherein the second gas inlet has a second gas injection portion provided in the second region of the upper electrode, for injecting the second gas toward the plasma generation region.  
   
   
       41 . The plasma etching apparatus of  claim 40 , wherein the second gas injection portion has a plurality of gas injection openings disposed at regular intervals.  
   
   
       42 . The plasma etching apparatus of  claim 40 , wherein the second gas inlet has a second gas supply line for supplying the second gas toward the second gas injection portion and a second gas buffer space for accumulating the second gas supplied through the second gas supply line in front of the second gas injection portion.  
   
   
       43 . The plasma etching apparatus of  claim 33 , wherein the third gas inlet has a third mass flow control unit for independently controlling a flow rate of the third gas.  
   
   
       44 . The plasma etching apparatus of  claim 33 , wherein the third gas is a mixed gas, and the third gas inlet has a third mixing ratio control unit for independently controlling a mixing ratio of the third gas.  
   
   
       45 . The plasma etching apparatus of  claim 33 , wherein the third gas inlet has a third gas injection portion provided in the third region of the upper electrode, for injecting the third gas toward the plasma generation region.  
   
   
       46 . The plasma etching apparatus of  claim 45 , wherein the third gas injection portion has a plurality of gas injection openings disposed at regular intervals.  
   
   
       47 . The plasma etching apparatus of  claim 45 , wherein the third gas injection portion is made of a material selected from a group consisting of Si, SiC and quartz.  
   
   
       48 . The plasma etching apparatus of  claim 45 , wherein the third gas inlet has a third gas supply line for supplying the third gas toward the third gas injection portion and a third gas buffer space for accumulating the third gas supplied through the third gas supply line in front of the third gas injection portion.  
   
   
       49 . The plasma etching apparatus of  claim 33 , further comprising a flow rate ratio control unit for controlling a flow rate ratio of the first and the third gas depending on processes.  
   
   
       50 . The plasma etching apparatus of  claim 33 , wherein the first gas contains all or most of an additive gas.  
   
   
       51 . The plasma etching apparatus of  claim 33 , wherein the second gas contains all or most of an additive gas.  
   
   
       52 . The plasma etching apparatus of  claim 33 , wherein the first and the third gas contain all or most of an additive gas.