Plasma processing apparatus and plasma processing method

Abstract

There is provided a plasma processing apparatus and a plasma processing method capable of carrying out a stable plasma process by way of improving plasma stabilization and also capable of increasing lifetime of a variable capacitor in a matching unit, as compared to a conventional case. The plasma processing apparatus includes a power modulation unit configured to perform a power modulation for periodically switching a high frequency power from a high frequency power supply between a first power and a second power higher than the first power. The matching unit is configured to stop a matching operation for a first power application time and for a preset time after a second power application is started.

1 . A plasma processing apparatus comprising:
 a processing chamber configured to accommodate a substrate and perform a plasma process thereon;   a processing gas supply unit configured to supply a processing gas into the processing chamber;   a pair of parallel-plate-type electrodes provided within the processing chamber and including a lower electrode serving as a mounting table configured to mount the substrate thereon and an upper electrode provided above the lower electrode;   a high frequency power supply configured to apply a high frequency power to at least one of the pair of electrodes;   a matching unit configured to perform impedance matching of the high frequency power from the high frequency power supply, the matching unit being connected to the one of the electrodes; and   a control unit configured to perform a power modulation for periodically switching the high frequency power from the high frequency power supply between a first power and a second power higher than the first power and to perform a mask control for stopping a matching operation of the matching unit for a first power application time and for a preset time after a second power application is started.   
     
     
         2 . The plasma processing apparatus of  claim 1 , wherein the high frequency power supply is a high frequency power supply for attracting ions connected with the lower electrode and configured to output a high frequency power for attracting ions, and
 the control unit performs the power modulation of the high frequency power for attracting ions and performs the mask control of the matching unit.   
     
     
         3 . The plasma processing apparatus of  claim 2 , further comprising:
 a high frequency power supply for generating plasma configured to apply a high frequency power for generating plasma to the upper electrode.   
     
     
         4 . The plasma processing apparatus of  claim 2 , further comprising:
 a high frequency power supply for generating plasma configured to apply a high frequency power for generating plasma to the lower electrode.   
     
     
         5 . The plasma processing apparatus of  claim 3 , further comprising:
 a matching unit for the high frequency power supply for generating plasma, the matching unit being configured to perform impedance matching of the high frequency power for generating plasma,   wherein the control unit stops a matching operation of the matching unit for the high frequency power supply for generating plasma according to the mask control of the matching unit.   
     
     
         6 . The plasma processing apparatus of  claim 4 , further comprising:
 a matching unit for the high frequency power supply for generating plasma, the matching unit being configured to perform impedance matching of the high frequency power for generating plasma,   wherein the control unit stops a matching operation of the matching unit for the high frequency power supply for generating plasma according to the mask control of the matching unit.   
     
     
         7 . The plasma processing apparatus of  claim 3 , further comprising:
 a matching unit for the high frequency power supply for generating plasma, the matching unit being configured to perform impedance matching of the high frequency power for generating plasma,   wherein the control unit switches the high frequency power for generating plasma between a third power and a fourth power higher than the third power in synchronization with the power modulation, and stops the matching operation of the matching unit for the high frequency power supply for generating plasma according to the mask control.   
     
     
         8 . The plasma processing apparatus of  claim 4 , further comprising:
 a matching unit for the high frequency power supply for generating plasma, the matching unit being configured to perform impedance matching of the high frequency power for generating plasma,   wherein the control unit switches the high frequency power for generating plasma between a third power and a fourth power higher than the third power in synchronization with the power modulation, and stops the matching operation of the matching unit for the high frequency power supply for generating plasma according to the mask control.   
     
     
         9 . The plasma processing apparatus of  claim 1 , wherein the high frequency power supply is a high frequency power supply for generating plasma configured to output a high frequency power for generating plasma, and
 the control unit performs the power modulation of the high frequency power for generating plasma and performs the mask control of the matching unit.   
     
     
         10 . The plasma processing apparatus of  claim 9 , wherein the high frequency power supply for generating plasma is connected with the upper electrode. 
     
     
         11 . The plasma processing apparatus of  claim 9 , wherein the high frequency power supply for generating plasma is connected with the lower electrode. 
     
     
         12 . The plasma processing apparatus of  claim 10 , further comprising:
 a high frequency power supply for attracting ions configured to apply a high frequency power for attracting ions to the lower electrode; and   a matching unit for the high frequency power supply for attracting ions, the matching unit being configured to perform impedance matching of the high frequency for attracting ions power from the high frequency power supply for attracting ions,   wherein the control unit stops a matching operation of the matching unit for the high frequency power supply for attracting ions according to the mask control of the matching unit.   
     
     
         13 . The plasma processing apparatus of  claim 11 , further comprising:
 a high frequency power supply for attracting ions configured to apply a high frequency power for attracting ions to the lower electrode; and   a matching unit for the high frequency power supply for attracting ions, the matching unit being configured to perform impedance matching of the high frequency power for attracting ions from the high frequency power supply for attracting ions,   wherein the control unit stops a matching operation of the matching unit for the high frequency power supply for attracting ions according to the mask control of the matching unit.   
     
     
         14 . The plasma processing apparatus of  claim 1 , wherein a plasma etching process is performed on the substrate. 
     
     
         15 . The plasma processing apparatus of  claim 1 , wherein the control unit controls the high frequency power supply to perform the power modulation after the plasma process is performed on the substrate for a preset time by applying a high frequency power of a certain power level from the high frequency power supply. 
     
     
         16 . A plasma processing method using a plasma processing apparatus that includes a processing chamber configured to accommodate a substrate and perform a plasma process thereon; a processing gas supply unit configured to supply a processing gas into the processing chamber; a pair of parallel-plate-type electrodes provided within the processing chamber; a high frequency power supply configured to apply a high frequency power to at least one of the pair of electrodes; and a matching unit configured to perform impedance matching of the high frequency power from the high frequency power supply, the matching unit being connected to the one of the electrodes, the method comprising:
 performing a power modulation for periodically switching the high frequency power from the high frequency power supply between a first power and a second power higher than the first power; and   performing a mask control for stopping a matching operation of the matching unit for a first power application time and for a preset time after a second power application is started.   
     
     
         17 . The plasma processing method of  claim 16 , wherein a plasma etching process is performed on the substrate. 
     
     
         18 . The plasma processing method of  claim 17 , wherein the power modulation is performed after the plasma process is performed on the substrate for a preset time by applying a high frequency power of a certain power level from the high frequency power supply.