Apparatus for Plasma Processing a Substrate and a Method Thereof

Abstract

An apparatus for processing a substrate includes a pulsed power supply that generates a waveform having a first period with a first power level and a second period with a second power level. A plasma source generates a first plasma during the first period and a second plasma during the second period. The first plasma may have higher plasma density than the second plasma. A bias voltage power supply generates a bias voltage waveform at an output that is electrically connected to a platen which supports a substrate. The bias voltage waveform having a first voltage and a second voltage may be coupled to the substrate. The first voltage may have more negative potential than the second voltage.

1 . An apparatus comprising:
 a processing chamber;   a plasma source proximate to the processing chamber;   an RF power unit configured to output to the plasma source an RF waveform having a first power level during a first period and a second power level during a second period, the first power level being less than the second power level, the plasma source being configured to generate first plasma during the first period and second plasma during the second period;   a substrate being supported by a platen; and   a bias voltage unit being configured to output to the substrate a bias voltage waveform having a first voltage during the first period and a second voltage, the first voltage having more negative potential than the second voltage.   
   
   
       2 . The apparatus of  claim 1 , wherein the bias voltage unit being further configured to output the first voltage during the second period. 
   
   
       3 . The apparatus of  claim 1 , wherein the bias voltage unit being further configured to output the second voltage during the first period. 
   
   
       4 . The apparatus of  claim 1 ,
 wherein the bias voltage waveform includes a first bias voltage pulse width and a second bias voltage pulse width, the first voltage width extending from the first period to second periods.   
   
   
       5 . The apparatus of  claim 4 , wherein the second voltage width extends from the first period to the second period. 
   
   
       6 . The apparatus of  claim 1 , wherein the second plasma has higher plasma density than the first plasma. 
   
   
       7 . The apparatus of  claim 6 , wherein each of the first and second plasma comprises ions and electrons. 
   
   
       8 . The apparatus of  claim 7 , wherein number of ions and electrons of the second plasma is greater than number of ions and electrons of the first plasma. 
   
   
       9 . The apparatus of  claim 7 , wherein ions of the first plasma are attracted to the substrate applied with first voltage and electrons of the second plasma are attracted to the substrate applied with second voltage. 
   
   
       10 . The apparatus of  claim 1 , wherein each of first plasma and second plasma comprises a plurality of charged particles, and wherein the substrate is treated with the charged particles of the first and second plasma. 
   
   
       11 . The apparatus of  claim 10 , wherein the charged particles of the first and second plasma treating the substrate have opposite charge. 
   
   
       12 . A method of processing a substrate comprising:
 inputting to a plasma source a current waveform having a first amplitude during a first period and a second amplitude during a second period to generate a first plasma during the first period and a second plasma during the second period, the second amplitude being greater than the first amplitude;   coupling a bias voltage waveform having a first voltage and a second voltage to a substrate, the first voltage having more negative potential than the second voltage; and   synchronizing the current waveform and the bias voltage waveform such that the first voltage is coupled to the substrate during the first period.   
   
   
       13 . The method of  claim 12 , further comprising synchronizing the current waveform and the bias voltage waveform such that the second voltage is coupled to the substrate during the first period. 
   
   
       14 . The method of  claim 12 , wherein the first plasma has lower plasma density than the second plasma. 
   
   
       15 . The method of  claim 14 , further comprising synchronizing the current waveform input and the bias voltage waveform input such that the second voltage is coupled to the substrate during generation of the second plasma. 
   
   
       16 . The method of  claim 12 , wherein each of the first plasma and second plasma comprises ions and electrons. 
   
   
       17 . The method of  claim 16 , further comprising attracting ions of the first plasma to the substrate. 
   
   
       18 . The method of  claim 17 , further comprising attracting electrons of the second plasma to the substrate. 
   
   
       19 . A method comprising:
 applying current to a plasma source proximate to a processing chamber during a first period to generate a first plasma;   increasing the amplitude of the current applied to the plasma source during a second period to generate a second plasma; and   coupling a first voltage of a voltage waveform having the first voltage and a second voltage to a substrate, the first voltage having greater negative potential than the second voltage.   
   
   
       20 . The method of  claim 19 , wherein the first voltage is coupled to the substrate during the first period. 
   
   
       21 . The method of  claim 19 , wherein the first voltage is coupled to the substrate during the first period. 
   
   
       22 . The method of  claim 20 , further comprising applying the second voltage to the substrate during the second period. 
   
   
       23 . The method of  claim 19 , further comprising coupling the first voltage to the substrate during the first and second periods. 
   
   
       24 . The method of  claim 19 , wherein the first plasma has higher plasma density that the second plasma. 
   
   
       25 . The method of  claim 18 , further comprising:
 attracting ions of the first plasma to the substrate and   attracting electrons of the second plasma to the substrate.