System, Method and Apparatus for Generating Pressure Pulses in Small Volume Confined Process Reactor

Abstract

A method for modulating a pressure in a plasma processing volume of a chamber during a plasma processing operation is disclosed. The plasma processing volume is defined between a surface of a top electrode, a supporting surface of a substrate support and an outer region defined by a plasma confinement structure that encloses an outer perimeter of the plasma processing volume. The plasma confinement structure includes a plurality of equally distributed openings out of the plasma processing volume. The method includes supplying process gases to the processing volume during the plasma processing operation and supplying radio frequency (RF) power to the chamber to produce a plasma using the process gases and to produce gas byproducts. The method further includes controlling a position of a conductance control structure relative to the plasma confinement structure. During a first period of time of the plasma processing operation, the position of the conductance control structure is moved to increase a restriction the produced gas byproducts that flow out of the process volume through the plasma confinement structure. During a second period of time of the plasma processing operation, the position of the conductance control structure is moved to decrease a restriction the produced gas byproducts that flow out of the process volume through the plasma confinement structure. The movement of the conductance control structure functions to module the pressure during the plasma processing operation.

What is claimed is: 
     
         1 . A method of modulating a pressure in-situ in a plasma processing volume of a chamber, the plasma processing volume defined between a surface of a top electrode, a supporting surface of a substrate support and an outer region defined by a plasma confinement structure, the plasma confinement structure including at least one outlet port, the method comprising:
 injecting at least one processing gas into the plasma processing volume;   forming a plasma within the plasma processing volume; and   modulating a pressure during a period of time when the plasma is formed in the plasma processing volume, the modulating of the pressure being controlled by at least one of,
 a first outlet flow out of the plasma processing volume from the at least one outlet port, the first outlet flow being through a restricted flow path out of the at least one outlet port, or 
 a second outlet flow out of the plasma processing volume from the at least one outlet port, the second outlet flow being greater than the first outlet flow, wherein the second outlet flow being through a less restricted flow path out of the at least one outlet port than the first outlet flow. 
   
     
     
         2 . The method of  claim 1 , wherein the period of time when the plasma is formed corresponds to a processing recipe having one or more predefined pressure set points. 
     
     
         3 . The method of  claim 2 , wherein each of the predefined pressure set points corresponds to one of the first outlet flow or the second outlet flow or an outlet flow between the first outlet flow and second outlet flow. 
     
     
         4 . The method of  claim 1 , wherein the pressure in the plasma processing volume is increased when the restriction of a conductance path is increased and the pressure in the plasma processing volume is decreased when the restriction of the conductance path is decreased. 
     
     
         5 . The method of  claim 1 , further comprising changing an operational state of at least one RF source coupled to the chamber to correspond to at least one of a first pressure or a second pressure. 
     
     
         6 . A method for modulating a pressure in a plasma processing volume of a chamber during a plasma processing operation, the plasma processing volume defined between a surface of a top electrode, a supporting surface of a substrate support and an outer region defined by a plasma confinement structure that encloses an outer perimeter of the plasma processing volume, the plasma confinement structure including a plurality of equally distributed openings out of the plasma processing volume, the method comprising,
 supplying process gases to the plasma processing volume during the plasma processing operation;   supplying radio frequency (RF) power to the chamber to produce a plasma using the process gases and to produce gas byproducts;   controlling a position of a conductance control structure relative to the plasma confinement structure, wherein the controlling of the position is such that,
 during a first period of time of the plasma processing operation, the position of the conductance control structure is moved to increase a restriction of the produced gas byproducts that flow out of the plasma process volume through the plasma confinement structure; 
 during a second period of time of the plasma processing operation, the position of the conductance control structure is moved to decrease a restriction of the produced gas byproducts that flow out of the process volume through the plasma confinement structure. 
   
     
     
         7 . The method of  claim 6 , wherein during the first period of time the conductance control structure is moved closer to the plasma confinement structure to increase a blocking of the produced gas byproducts out of the processing volume, which increases a pressure within the plasma processing volume. 
     
     
         8 . The method of  claim 6 , wherein during the second period of time the conductance control structure is moved away from the plasma confinement structure to decrease a blocking of the produced gas byproducts out of the processing volume, which reduces a pressure within the plasma processing volume. 
     
     
         9 . The method of  claim 6 , wherein each one of the plurality of equally distributed openings are arranged radially around the plasma confinement structure. 
     
     
         10 . The method of  claim 6 , wherein movement of the conductance control structure is facilitated by a shift up toward the plasma confinement structure or a shift down away from the plasma confinement structure. 
     
     
         11 . The method of  claim 6 , wherein movement of the conductance control structure is facilitated rotation of the plasma confinement structure around the plasma confinement structure. 
     
     
         12 . The method of  claim 6 , further comprising,
 synchronizing the RF power to have a first operational state that corresponds to the first period of time and a second operation state that corresponds to the second period of time.   
     
     
         13 . The method of  claim 12 , wherein the first and second operational states of the RF power correspond to RF pulse states. 
     
     
         14 . The method of  claim 12 , wherein a first pressure is corresponded to the first operation state of the RF power and a second pressure is corresponded to the second operation state of the RF power.