Apparatus for controlling temperature uniformity of a showerhead

Abstract

An apparatus for controlling thermal uniformity of a substrate-facing surface of a showerhead is provided herein. In some embodiments, the thermal uniformity of the substrate facing surface of the showerhead may be controlled to be more uniform. In some embodiments, the thermal uniformity of the substrate facing surface of the showerhead may be controlled to be non-uniform in a desired pattern. In some embodiments, an apparatus for controlling thermal uniformity of a substrate-facing surface of a showerhead may include a showerhead having a substrate facing surface and one or more plenums for providing one or more process gases through a plurality of gas distribution holes formed through the substrate facing surface of the showerhead; and a plurality of flow paths having a substantially equivalent fluid conductance disposed within the showerhead to flow a heat transfer fluid.

1 . An apparatus for controlling thermal uniformity of a substrate-facing surface of a showerhead, comprising:
 a showerhead having a substrate facing surface and one or more plenums for providing one or more process gases through a plurality of gas distribution holes formed through the substrate facing surface of the showerhead; and   a plurality of flow paths having a substantially equivalent fluid conductance disposed within the showerhead to flow a heat transfer fluid.   
     
     
         2 . The apparatus of  claim 1 , further comprising:
 a plurality of inlets, each respectively coupled to a first end of a respective one of the plurality of flow paths; and   a plurality of outlets, each respectively coupled to a second end of a respective one the plurality of flow paths.   
     
     
         3 . The apparatus of  claim 2 , wherein the plurality of flow paths are symmetrically positioned within the showerhead. 
     
     
         4 . The apparatus of  claim 3 , further comprising:
 a heat transfer fluid inlet coupled to the plurality of inlets to provide in an inflow of heat transfer fluid to the plurality of inlets; and   a heat transfer fluid outlet coupled to the plurality of outlets to provide an outflow of heat transfer fluid from the plurality of outlets.   
     
     
         5 . The apparatus of  claim 3 , wherein each of the plurality of flow paths comprise a recursive symmetric pattern. 
     
     
         6 . The apparatus of  claim 1 , wherein the showerhead further comprises:
 a first plate having the plurality of flow paths disposed at least partially therein; and   a second plate disposed adjacent to the first plate, the second plate having the one or more plenums at least partially formed therein.   
     
     
         7 . The apparatus of  claim 1 , wherein the plurality of flow paths are arranged in a plurality of zones having radial symmetry with respect to a central axis of the showerhead, wherein each of the plurality of zones comprises at least two flow paths. 
     
     
         8 . The apparatus of  claim 7 , wherein each of the plurality of zones further comprises:
 an inlet coupled to the at least two flow paths; and   an outlet coupled to the at least two flow paths.   
     
     
         9 . The apparatus of  claim 8 , wherein each of the at least two flow paths are symmetrical with respect to one another. 
     
     
         10 . The apparatus of  claim 1 , wherein each of the plurality of flow paths are coupled to a common inlet and a common outlet. 
     
     
         11 . The apparatus of  claim 1 , further comprising a heat transfer fluid source configured to provide the heat transfer fluid to the plurality of flow paths and to control a temperature and a flow rate of the heat transfer fluid. 
     
     
         12 . The apparatus of  claim 1 , wherein the showerhead further comprises:
 an inner portion having a first plurality of the plurality of flow paths disposed therein; and   an outer portion having a second plurality of the plurality of flow paths disposed therein, the outer portion disposed radially outward of the inner portion with respect to a center point of the showerhead.   
     
     
         13 . The apparatus of  claim 12 , wherein each of the plurality of flow paths disposed in the outer portion of the showerhead is positioned adjacent to a respective each of the plurality of flow paths disposed in the inner portion of the showerhead. 
     
     
         14 . The apparatus of  claim 13 , wherein each of the plurality of flow paths disposed in the outer portion of the showerhead is configured to provide a flow of heat transfer fluid in an opposite direction with respect to a direction of flow of heat transfer fluid of an adjacent one of the plurality of flow paths disposed in the inner portion of the showerhead. 
     
     
         15 . The apparatus of  claim 1 , further comprising:
 at least one valve respectively coupled to the at plurality of flow paths to control a flow rate of the heat transfer fluid.   
     
     
         16 . The apparatus of  claim 15 , further comprising a controller coupled to at least one valve to control the operation thereof. 
     
     
         17 . The apparatus of  claim 1 , wherein the showerhead further comprises at least one heating element to heat the showerhead. 
     
     
         18 . The apparatus of  claim 17 , wherein the at least one heating element comprises a plurality of heating elements arranged in two or more zones. 
     
     
         19 . An apparatus for controlling thermal uniformity of a substrate-facing surface of a showerhead, comprising:
 a showerhead having a substrate facing surface and one or more plenums for providing one or more process gases through a plurality of gas distribution holes formed through the substrate facing surface of the showerhead; and   a flow path disposed within the showerhead and having an inlet and an outlet to flow a heat transfer fluid through the flow path, wherein the flow path comprises a first portion and a second portion, each portion having a substantially equivalent axial length, wherein the first portion is spaced about 2 mm to about 10 mm from the second portion, and wherein the first portion provides a flow of heat transfer fluid in a direction opposite a flow of heat transfer fluid of the second portion.   
     
     
         20 . An apparatus for controlling thermal uniformity of a substrate-facing surface of a showerhead, comprising:
 a showerhead having a substrate facing surface and one or more plenums for providing one or more process gases through a plurality of gas distribution holes formed through the substrate facing surface of the showerhead; and   a first flow path and a second flow path disposed within the showerhead, each having an inlet and an outlet to flow a heat transfer fluid through the respective flow path, wherein each flow path has a substantially equivalent axial length, and wherein the first flow path and the second flow path a inversely symmetrical about an axis that passes through a central axis of the showerhead.