Method for processing wafer using single frequency RF power in plasma processing chamber

Abstract

A method for processing a wafer in a plasma processing chamber using single frequency RF power is provided. The method includes generating a single modulated RF power and providing a wafer over an electrostatic chuck in a plasma processing chamber. The electrostatic chuck includes a first electrode disposed under the wafer for receiving the modulated RF power, and a second electrode disposed over the wafer. The method further includes receiving the modulated RF power, by the plasma processing chamber, and generating plasma and ion bombardment energy in the plasma processing chamber for processing the wafer in response to the modulated RF power.

What is claimed is:  
     
         1 . A method for processing a wafer in a plasma processing chamber, comprising: 
 generating a single modulated RF power capable of having a varying modulation depth;    providing a wafer over an electrostatic chuck in a plasma processing chamber, the electrostatic chuck including a first electrode disposed under the wafer for receiving the modulated RF power, and the plasma processing chamber further including a second electrode disposed over the wafer;    receiving the modulated RF power, by the plasma processing chamber; and    generating plasma and ion bombardment energy in the plasma processing chamber for processing the wafer in response to the modulated RF power.    
     
     
         2 . The method as recited in  claim 1 , wherein modulated RF power is a modulated high frequency RF power adapted to produce a specified etch rate on the wafer for an anisotropic etching.  
     
     
         3 . The method as recited in  claim 2 , wherein the modulated high frequency RF power includes an average RF power and a peak RF power.  
     
     
         4 . The method as recited in  claim 2 , wherein the plasma processing chamber maintains a constant plasma density in response to the average RF power of the modulated high frequency RF power.  
     
     
         5 . The method as recited in  claim 4 , wherein the peak RF power is adapted to increase the ion bombardment energy in the plasma processing chamber for isotropic processing of the wafer.  
     
     
         6 . The method as recited in  claim 5 , wherein the modulated high frequency RF power includes a modulation frequency adapted to decouple the etch rate from the ion bombardment energy.  
     
     
         7 . The method as recited in  claim 6 , wherein the modulation frequency of the modulated high frequency RF power is greater than the time for an ion to travel from a center region of the plasma to one of the electrodes.  
     
     
         8 . The method as recited in  claim 7 , wherein the frequency of the modulated RF power is greater than 4 MHz.  
     
     
         9 . A method for processing a wafer in a plasma processing chamber, the plasma processing chamber having an electrostatic chuck that includes a first electrode disposed therein, and a second electrode disposed over the electrostatic chuck, the method comprising: 
 generating a single frequency RF power;    modulating the single frequency RF power, the modulating capable of having a varying modulation depth and defining a modulated RF power; and    generating plasma and ion bombardment energy in the plasma processing chamber for processing the wafer in response to the modulated RF power.    
     
     
         10 . A method for processing a wafer in a plasma processing chamber as recited in  claim 9 , wherein the modulated RF power is capable of defining an average RF power and a peak RF power.  
     
     
         11 . A method for processing a wafer in a plasma processing chamber as recited in  claim 10 , wherein the plasma processing chamber maintains a constant plasma density in response to the average RF power of the modulated RF power.