High pressure rf-dc sputtering and methods to improve film uniformity and step-coverage of this process

Abstract

Embodiments of the invention generally provide a processing chamber used to perform a physical vapor deposition (PVD) process and methods of depositing multi-compositional films. The processing chamber may include: an improved RF feed configuration to reduce any standing wave effects; an improved magnetron design to enhance RF plasma uniformity, deposited film composition and thickness uniformity; an improved substrate biasing configuration to improve process control; and an improved process kit design to improve RF field uniformity near the critical surfaces of the substrate. The method includes forming a plasma in a processing region of a chamber using an RF supply coupled to a multi-compositional target, translating a magnetron relative to the multi-compositional target, wherein the magnetron is positioned in a first position relative to a center point of the multi-compositional target while the magnetron is translating and the plasma is formed, and depositing a multi-compositional film on a substrate in the chamber.

1 . A plasma processing chamber comprising:
 a target having a first surface that is in contact with a processing region and a second surface that is opposite the first surface;   an RF power supply coupled to the target;   a DC power supply coupled to the target;   a substrate support having a substrate receiving surface;   a magnetron disposed adjacent to the second surface of the target, wherein the magnetron comprises:
 an outer pole comprising a plurality of magnets; and 
 an inner pole comprising a plurality of magnets, wherein the outer and inner poles form an open-loop magnetron assembly. 
   
     
     
         2 . The plasma processing chamber of  claim 1 , further comprising:
 a center feed that is electrically coupled to the target and has a first surface and a second surface, wherein the RF power supply is coupled to first surface and the second surface is coupled to the target, and the center feed is positioned over the central axis of the target.   
     
     
         3 . The plasma processing chamber of  claim 1 , further comprising a center feed that is electrically coupled to the target, and having a cross-section that extends between a first surface and a second surface and is symmetric about a first axis, wherein the RF power supply is coupled to the first surface, and a diameter aspect ratio between about 0.001/mm and about 0.025/mm, and wherein the cross-section surface extends between the first surface and the second surface. 
     
     
         4 . The plasma processing chamber of  claim 1 , further comprising:
 a grounded shield that at least partially encloses a portion of the processing region and is electrically coupled to a ground;   the substrate support further comprising an electrode disposed below the substrate receiving surface;   a cover ring; and   a deposition ring disposed over a portion of the substrate support, wherein during processing the cover ring is disposed on a portion of the deposition ring, the cover ring is electrically isolated from the ground, and the deposition ring and the cover ring are disposed below the substrate receiving surface that is disposed below the target.   
     
     
         5 . The plasma processing chamber of  claim 4 , further comprising:
 a variable capacitor that is disposed between the electrode and the ground; and   a controller that is adapted to adjust the amount of capacitance of the variable capacitor during processing.   
     
     
         6 . A plasma processing chamber comprising:
 a target having a first surface that is in contact with a processing region, a second surface that is opposite the first surface and an edge;   an RF power supply coupled to the target;   a substrate support having a substrate receiving surface;   a motor having a shaft that has a rotation axis; and   a magnetron disposed adjacent to the second surface of the target, wherein the magnetron comprises:
 a cross arm that is coupled to the shaft; 
 a plate coupled to the cross arm at a pivot point, wherein the pivot point is a distance from the rotation axis; and 
 an outer pole and an inner pole that are coupled to the plate and form an open-loop magnetron assembly. 
   
     
     
         7 . The plasma processing chamber of  claim 6 , wherein the center of mass of the plate is configured to move a first distance from the rotation axis when rotated in a first direction, and the center of mass of the plate is configured to move a second distance from the rotation axis when rotated in a second direction. 
     
     
         8 . The plasma processing chamber of  claim 6 , wherein the center of mass of the plate is configured to rotate about the pivot point in a third direction when the shaft is rotated in a first direction, and the center of mass of the plate is configured to rotate in a fourth direction about the pivot axis when the shaft is rotated in a second direction that is opposite to the first direction. 
     
     
         9 . The plasma processing chamber of  claim 6 , wherein the outer pole and the inner pole form a portion of an arc. 
     
     
         10 . The plasma processing chamber of  claim 6 , further comprising:
 a grounded shield that at least partially encloses a portion of the processing region and is electrically coupled to a ground;   the substrate support further comprising an electrode disposed below the substrate receiving surface;   a cover ring; and   a deposition ring disposed over a portion of the substrate support, wherein during processing the cover ring is disposed on a portion of the deposition ring, the cover ring is electrically isolated from the ground, and the deposition ring and the cover ring are disposed below the substrate receiving surface that is disposed below the target.   
     
     
         11 . A plasma processing chamber comprising:
 a target having a first surface that is in contact with a processing region, a second surface that is opposite the first surface and an edge;   an RF power supply coupled to the target;   a substrate support having a substrate receiving surface;   a motor having a shaft that has a rotation axis; and   a magnetron disposed adjacent to the second surface of the target, wherein the magnetron comprises:
 an outer pole and a inner pole that are concentric about a first axis that extends through a center point and form a closed-loop magnetron assembly, wherein the plurality of magnets disposed in the inner and outer poles is not symmetric about a second axis that extends through the center point and is perpendicular to the first axis. 
   
     
     
         12 . The plasma processing chamber of  claim 11 , further comprising:
 a grounded shield that at least partially encloses a portion of the processing region and is electrically coupled to a ground;   the substrate support further comprising an electrode disposed below the substrate receiving surface;   a cover ring; and   a deposition ring disposed over a portion of the substrate support, wherein during processing the cover ring is disposed on a portion of the deposition ring, the cover ring is electrically isolated from the ground, and the deposition ring and the cover ring are disposed below the substrate receiving surface that is disposed below the target.   
     
     
         13 . A plasma processing chamber comprising:
 a target having a first surface that is in contact with a processing region, a second surface that is opposite the first surface;   an RF power supply coupled to the target;   a grounded shield that at least partially encloses a portion of the processing region and is electrically coupled to a ground; and   a substrate support assembly comprising:
 a support having a substrate receiving surface that is below the target; 
 a cover ring; and 
 a deposition ring disposed over a portion of the support, wherein when a substrate is disposed on the substrate receiving surface during processing the cover ring is disposed on a portion of the deposition ring, the cover ring is electrically isolated from the ground, and the deposition ring and the cover ring are disposed below the substrate receiving surface. 
   
     
     
         14 . The plasma processing chamber of  claim 13 , further comprising:
 a motor having a shaft that has a rotation axis; and   a magnetron disposed adjacent to the second surface of the target, wherein the magnetron comprises:
 an outer pole and an inner pole that are concentric about a first axis that extends through a center point and form a closed-loop magnetron assembly, wherein the plurality of magnets disposed in the inner and outer poles is not symmetric about a second axis that extends through the center point and is perpendicular to the first axis. 
   
     
     
         15 . The plasma processing chamber of  claim 13 , further comprising:
 an electrode disposed in the support;   a variable capacitor that is disposed between the electrode and the ground; and   a controller that is adapted to adjust the amount of capacitance of the variable capacitor during processing.   
     
     
         16 . The plasma processing chamber of  claim 13 , further comprising:
 a motor having a shaft that has a rotation axis; and   a magnetron disposed adjacent to the second surface of the target, wherein the magnetron comprises:
 an outer pole comprising a plurality of magnets; and 
 an inner pole comprising a plurality of magnets, wherein the outer and inner poles form an open-loop magnetron assembly. 
   
     
     
         17 . The plasma processing chamber of  claim 13 , further comprising:
 a center feed that is electrically coupled to the target and has a first surface and a second surface, wherein the RF power supply is coupled to first surface and the second surface is coupled to the target, and the center feed is positioned over the central axis of the target.   
     
     
         18 . The plasma processing chamber of  claim 13 , further comprising a center feed that is electrically coupled to the target, and having a cross-section that extends between a first surface and a second surface and is symmetric about a first axis, wherein the RF power supply is coupled to first surface, and a diameter aspect ratio between about 0.001/mm and about 0.025/mm, and wherein the cross-section surface extends between the first surface and the second surface. 
     
     
         19 . A method of depositing a thin film, comprising:
 forming a plasma in a processing region of a chamber using an RF power supply coupled to a multi-compositional target in the chamber, the multi-compositional target having a first surface that is in contact with the processing region of the chamber and a second surface that is opposite the first surface;   translating a magnetron relative to the multi-compositional target, wherein the magnetron is positioned in a first position relative to a center point of the multi-compositional target while the magnetron is translating and the plasma is formed; and   depositing a multi-compositional film on a substrate positioned on a substrate support in the chamber.   
     
     
         20 . A method of depositing a thin film on a substrate, comprising:
 delivering energy to a plasma formed in a processing region of a chamber, wherein delivering energy comprises delivering RF power from an RF power supply to a multi-compositional target and delivering DC power from a DC power supply to the multi-compositional target, the multi-compositional target having a first surface that is in contact with a processing region of the chamber and a second surface that is opposite the first surface;   translating a magnetron relative to the multi-compositional target, wherein the magnetron is positioned in a first position relative to a center point of the multi-compositional target while the magnetron is translating and the plasma is formed;   adjusting a bias voltage on an electrode disposed near a substrate receiving surface of a substrate support, wherein the bias voltage is adjusted by changing the capacitance of a variable capacitor to control the bias voltage achieved at the electrode relative to an electrical ground;   pressurizing the processing region to at least 20 mTorr; and   depositing a metal alloy film on a substrate disposed on the substrate receiving surface.