Methods and apparatus for controlling ion fraction in physical vapor deposition processes

Abstract

Methods and apparatus for controlling the ion fraction in physical vapor deposition processes are disclosed. In some embodiments, a physical vapor deposition chamber includes: a body having an interior volume and a lid assembly including a target to be sputtered; a magnetron disposed above the target, wherein the magnetron is configured to rotate a plurality of magnets about a central axis of the physical vapor deposition chamber; a substrate support disposed in the interior volume opposite the target and having a support surface configured to support a substrate; a collimator disposed between the target and the substrate support, the collimator having a central region having a first thickness and a peripheral region having a second thickness less than the first thickness; a first power source coupled to the target to electrically bias the target; and a second power source coupled to the substrate support to electrically bias the substrate support.

1 . A physical vapor deposition chamber, comprising:
 a body having an interior volume and a lid assembly including a target to be sputtered;   a magnetron disposed above the target, wherein the magnetron is configured to rotate a plurality of magnets about a central axis of the physical vapor deposition chamber;   a substrate support disposed in the interior volume opposite the target and having a support surface configured to support a substrate;   a collimator disposed between the target and the substrate support, the collimator having a central region having a first thickness and a peripheral region having a second thickness less than the first thickness;   a first power source coupled to the target to electrically bias the target; and   a second power source coupled to the substrate support to electrically bias the substrate support.   
     
     
         2 . The physical vapor deposition chamber of  claim 1 , wherein the central region of the collimator has a diameter equal to or greater than a diameter of a substrate to be supported. 
     
     
         3 . The physical vapor deposition chamber of  claim 1 , wherein the collimator is disposed in an upper portion of the interior volume, closer to the target than to the substrate support. 
     
     
         4 . The physical vapor deposition chamber of  claim 1 , wherein the second power source is an RF power source. 
     
     
         5 . The physical vapor deposition chamber of  claim 1 , further comprising:
 a shield disposed in the interior volume, wherein the collimator is coupled to the shield.   
     
     
         6 . The physical vapor deposition chamber of  claim 5 , wherein the shield includes an upper shield and a lower shield, and wherein the collimator is coupled to the upper shield. 
     
     
         7 . The physical vapor deposition chamber of  claim 1 , further comprising:
 an edge ring disposed on the substrate support.   
     
     
         8 . The physical vapor deposition chamber of  claim 7 , further comprising:
 a shield ring configured to mate with the edge ring.   
     
     
         9 . The physical vapor deposition chamber of  claim 1 , further comprising:
 a set of magnets disposed about the body, above a support surface of the substrate support and below the collimator.