Method and Apparatus for Anisotropic Pattern Etching and Treatment

Abstract

Methods and apparatuses for providing an anisotropic ion beam for etching and treatment of substrate are discussed. In one embodiment, a system for processing a substrate includes a chamber, a chuck assembly, an ion source, and a grid system. The ion source includes grid system interfaces both the chamber and the ion source and includes a plurality of holes through which ions are extracted from the ion source to form an ion beam. The size of the plurality holes varies along an axis such that the ion density of the ion beam also varies along the axis. The density of the plurality of holes varies along an axis such that the ion density of the ion beam also varies along the axis. In some embodiments, the energies of a beamlet or multiple beamlets may be individual defined to adjust beam energy density.

What is claimed is: 
     
         1 . A system for processing a substrate, comprising:
 a chamber;   a chuck assembly disposed in the chamber including,
 a substrate support; 
 a tilt assembly for tilting the substrate support; and 
 a rotation assembly for rotating the substrate support; 
   an ion source coupled to the chamber and directionally oriented toward the substrate support of the chuck assembly, wherein the ion source is configured to generate ions when a plasma is struck; and   a grid system that interfaces with the chamber on one side and with the ion source on another side, the grid system includes an array of holes for extracting ions from the ion source and for forming an ion beam, the grid system is oriented so the ion beam is directed into the chamber toward the substrate support, the array of holes of the grid system is defined vertically by a y-axis and horizontally by an x-axis, wherein the array of holes is defined by hole sizes that vary vertically in the y-axis such that the ion beam is caused to have an energy density gradient that is defined vertically in the y-axis.   
     
     
         2 . The system of  claim 1 , wherein the array of holes is further defined by a hole size that does not vary horizontally in the x-axis, such that the ion beam is characterized by an energy density that does not vary horizontally. 
     
     
         3 . The system of  claim 1 , wherein the hole size of the array of holes is defined to decrease as a y-coordinate becomes more positive such that the ion beam is characterized by an energy density that decreases as the y-coordinate becomes more positive. 
     
     
         4 . The system of  claim 1 , wherein the grid system is defined by a plurality of sections that extend horizontally across a width of the grid system, the plurality of sections dividing the grid system vertically, and wherein each section defines a hole size for a plurality of holes within each section. 
     
     
         5 . The system of  claim 4 , wherein the grid system is defined by a first section and a second section, the first section is more positive in the y-axis than the second section, the first section defines a first plurality of holes and the second section defines a second plurality of holes, the second plurality of holes are defined to be larger in size than the first plurality of holes. 
     
     
         6 . The system of  claim 4 , wherein the plurality of sections defines respective hole sizes that decrease a y-coordinate associated with each of the plurality of sections become more positive. 
     
     
         7 . The system of  claim 1 , wherein the substrate support is tilted such that a first region of the substrate support is closer to the grid system than a second region of the substrate support, wherein the first region and the second region of the substrate support experience a similar energy density of the ion beam caused at least in part by the array of holes defined by hole sizes that vary vertically. 
     
     
         8 . The system of  claim 1 , wherein the ion source further includes a sectional magnetic system that induces a magnetic field gradient such that the plasma is characterized by a higher electron density the negative y direction, and a lower electron density in the positive y direction. 
     
     
         9 . A system for processing a substrate, comprising:
 a chamber;   a chuck assembly disposed in the chamber including,
 a substrate support; 
 a tilt assembly for tilting the substrate support; and 
 a rotation assembly for rotating the substrate support; 
   an ion source coupled to the chamber and directionally oriented toward the substrate support of the chuck assembly, wherein the ion source is configured to generate ions when a plasma is struck; and   a grid system that interfaces with the chamber on one side and with the ion source on another side, the grid system includes an array of holes for extracting ions from the ion source and for forming an ion beam, the grid system is oriented so the ion beam is directed into the chamber toward the substrate support, the array of holes of the grid system is defined vertically by a y-axis and horizontally by an x-axis, wherein the array of holes is defined by hole densities that vary vertically in the y-axis such that the ion beam is caused to have an energy density gradient that is defined vertically in the y-axis.   
     
     
         10 . The system of  claim 9 , wherein the array of holes is further defined by a hole density that does not vary horizontally in the x-axis, such that the ion beam is characterized by an energy density that does not vary horizontally. 
     
     
         11 . The system of  claim 9 , wherein the hole density of the array of holes is defined to decrease as a y-coordinate becomes more positive such that the ion beam is characterized by an energy density that decreases as the y-coordinate becomes more positive. 
     
     
         12 . The system of  claim 9 , wherein the grid system is defined by a plurality of sections that extend horizontally across a width of the grid system, the plurality of sections dividing the grid system vertically, and wherein each section defines a hole density for a plurality of holes within each section. 
     
     
         13 . The system of  claim 12 , wherein the grid system is defined by a first section and a second section, the first section is more positive in the y-axis than the second section, the first section defines a first plurality of holes and the second section defines a second plurality of holes, the second plurality of holes are defined to have a higher density in the grid system than the first plurality of holes. 
     
     
         14 . The system of  claim 12 , wherein the plurality of sections defines respective hole densities that decrease a y-coordinate associated with each of the plurality of sections become more positive. 
     
     
         15 . The system of  claim 9 , wherein the substrate support is tilted such that a first region of the substrate support is closer to the grid system than a second region of the substrate support, wherein the first region and the second region of the substrate support experience a similar energy density of the ion beam caused at least in part by the array of holes defined by hole densities that vary vertically. 
     
     
         16 . The system of  claim 9 , wherein the ion source further includes a sectional magnetic system that induces a magnetic field gradient such that the plasma is characterized by a higher electron density the negative y direction, and a lower electron density in the positive y direction. 
     
     
         17 . A system for processing a substrate, comprising:
 a chamber;   a chuck assembly disposed in the chamber including,
 a substrate support; 
 a tilt assembly for tilting the substrate support; and 
 a rotation assembly for rotating the substrate support; 
   an ion source coupled to the chamber and directionally oriented toward the substrate support of the chuck assembly, wherein the ion source is configured to generate ions when a plasma is struck; and   a grid system that interfaces with the chamber on one side and with the ion source on another side, the grid system includes an array of holes for extracting ions from the ion source and for forming an ion beam, the grid system is oriented so the ion beam is directed into the chamber toward the substrate support, the grid system is defined by a plurality of sections that are individual controlled for voltage, wherein an energy density of the ion beam is defined by respective voltages of the plurality of sections of the grid system.   
     
     
         18 . The system of  claim 17 , wherein the grid system is defined vertically by a y-axis and horizontally by an x-axis, and wherein the respective voltages of the plurality of sections is caused to be less positive as a y-coordinate associated with each of the sections increases such that a voltage gradient is produced for the grid system, the voltage gradient of the grid system further causes the energy density of the ion beam to decrease as the y-coordinate increases. 
     
     
         19 . The system of  claim 18 , wherein the substrate support is tilted such that a first region of the substrate support is closer to the grid system than a second region of the substrate support, wherein the first region and the second region of the substrate support experience a similar energy density of the ion beam caused at least in part by voltage gradient of the grid system. 
     
     
         20 . The system of  claim 17 , wherein the respective voltages for each of the plurality of sections is individually controlled in real time. 
     
     
         21 . The system of  claim 17 , wherein the grid system is configured such that each hole of the array of holes is associated with an individual section of the plurality of sections such that each hole is individually definable for voltage. 
     
     
         22 . The system of  claim 21 , wherein each hole is associated with a respective beamlet, wherein each respective beamlet is individually definable for beamlet energy.