Control Of The Incidence Angle Of An Ion Beam On A Substrate

Abstract

One system includes a chamber, a chuck assembly, and an ion source. The chuck assembly includes a substrate support and a precession assembly with a center support coupled to a stationary center point of an under region of the substrate support. The precession assembly includes first and second actuators connected to first and second locations, respectively, that are in the under region off-set from the center point. The precession assembly imparts a precession motion to the substrate support when the first actuator and the second actuator move up and down relative to the center support, and the precession motion imparted to the substrate causes a rotating tilt of the substrate support without rotation of the substrate support. The rotating tilt of the substrate is configured to cause ions generated by the ion source to impinge upon a surface of the substrate in continually varying angles of incidence.

What is claimed is: 
     
         1 . A system for processing a substrate, comprising:
 a chamber;   a chuck assembly including,
 a substrate support; and 
 a precession assembly having a center support that is coupled to a center point of an under region of the substrate support, the center support being stationary, 
 wherein the precession assembly further includes a first actuator and a second actuator, the first actuator being connected to a first location in the under region off-set from the center point, the second actuator being connected to a second location in the under region off-set from the center point, 
 wherein the precession assembly is programmed to cause a precession motion to be imparted to the substrate support when the first actuator and the second actuator move up and down relative to the center support, such that the first actuator moves up and down in accordance with a first frequency and the second actuator moves up and down in accordance with a second frequency, the first frequency being independent of the second frequency; and 
   an ion source interfaced with the chamber, the ion source being directionally oriented toward the substrate support of the chuck assembly, wherein the ion source is configured to produce ions when a plasma is struck and the ions are directed toward the substrate support,   wherein the precession motion is imparted to the substrate support when the substrate is present on the substrate support, the precession motion causing a rotating tilt of the substrate support without rotation of the substrate support, the rotating tilt of the substrate being configured to cause the ions generated by the ion source to impinge upon a surface of the substrate in continually varying angles of incidence.   
     
     
         2 . The system as recited in  claim 1 , wherein the first actuator moves up and down with a first amplitude, and the second actuator moves up and down with a second amplitude, wherein the first amplitude is independently controlled from the second amplitude. 
     
     
         3 . The system as recited in  claim 1 , further including a controller, wherein the controller is in communication with the precession assembly to program the precession motion. 
     
     
         4 . The system as recited in  claim 3 , wherein the controller manages the precession motion to set an angle of incidence of the ions from the plasma to control how features on the substrate are etched. 
     
     
         5 . The system as recited in  claim 1 , wherein the precession motion is cyclical, wherein the first location is in an initial position when the substrate is loaded onto the substrate support, wherein a distance from the first location to the initial position over time changes sinusoidally. 
     
     
         6 . The system as recited in  claim 1 , wherein the first location and the second location are in a periphery of the under region, wherein the first location is separated 90 degrees from the second location with reference to the center point. 
     
     
         7 . The system as recited in  claim 1 , wherein the first location and the second location are near a periphery of the under region. 
     
     
         8 . The system as recited in  claim 1 , wherein the motions up and down of the first actuator and the second actuator are separately and independently controlled by the precession assembly to create the precession motion. 
     
     
         9 . The system as recited in  claim 1 , wherein points on a periphery of the substrate move up and down during the precession motion. 
     
     
         10 . A system for processing a substrate, comprising:
 a chamber;   a chuck assembly including,
 a substrate support; and 
 a precession assembly including a center support, a first rotating cam, and a second rotating cam, wherein the center support is stationary and coupled to a center point of a bottom surface of the substrate support, 
 wherein the first rotating cam is connected to a first location that is in the bottom surface and off-set from the center point, wherein the second rotating cam is connected to a second location that is in the bottom surface and off-set from the center point, 
 wherein the precession assembly is programmed to cause a precession motion to be imparted to the substrate support when the first rotating cam and the second rotating cam move up and down 
 the first location and the second location, wherein the first rotating cam moves independently from the second rotating cam; and 
   an ion source oriented toward the substrate support, the ion source producing ions when a plasma is struck, wherein the precession motion causes a rotating tilt of the substrate support without rotation of the substrate support, the rotating tilt of the substrate being configured to cause the ions generated by the ion source to impinge upon a surface of the substrate in continually varying angles of incidence.   
     
     
         11 . The system as recited in  claim 10 , wherein the first location moves up and down with a first amplitude, and the second location moves up and down with a second amplitude, wherein the first amplitude is independently controlled from the second amplitude. 
     
     
         12 . The system as recited in  claim 10 , further including a controller, wherein the controller is in communication with the precession assembly to program the precession motion. 
     
     
         13 . The system as recited in  claim 12 , wherein the controller manages the precession motion to set an angle of incidence of the ions from the plasma to control how features on the substrate are etched. 
     
     
         14 . The system as recited in  claim 10 , wherein the precession motion is cyclical, wherein the first location is in an initial position when the substrate is loaded onto the substrate support, wherein a distance from the first location to the initial position over time changes sinusoidally.