Substrate support with varying depths of areas between mesas and corresponding temperature dependent method of fabricating

Abstract

A method is provided and includes: determining a temperature distribution pattern across a substrate or a support plate of a substrate support; determining, based on the temperature distribution pattern, a number of masks to apply to a top surface of the support plate, where the number of masks is greater than or equal to two; and determining patterns of the masks based on the temperature distribution pattern; and applying the masks over the top surface. The method further includes: performing a first machining process to remove a portion of the support plate unprotected by the masks to form first mesas and first recessed areas between the first mesas; removing a first mask from the support plate; performing a second machining process to form second recessed areas and at least one of second mesas or a first seal band area; and removing a second mask from the support plate.

What is claimed is: 
     
         1 . A method comprising:
 determining a temperature distribution pattern across a substrate or a support plate of a substrate support;   determining, based on the temperature distribution pattern, a number of masks to apply to a top surface of the support plate, wherein the number of masks is greater than or equal to two;   determining patterns of the masks based on the temperature distribution pattern;   applying the masks over the top surface of the support plate;   performing a first machining process to remove a portion of the support plate unprotected by the masks to form first mesas and first recessed areas between the first mesas;   removing a first one of the masks from the support plate;   performing a second machining process to form second recessed areas and at least one of second mesas or a first seal band area; and   removing a second one of the masks from the support plate.   
     
     
         2 . The method of  claim 1 , wherein, subsequent to performing the second machining process, depths of the first recessed areas are different than depths of the second recessed areas. 
     
     
         3 . The method of  claim 2 , wherein:
 the second machining process includes increasing depths of the first recessed areas; and   subsequent to performing the second machining process, the depths of the first recessed areas are greater than the depths of the second recessed areas.   
     
     
         4 . The method of  claim 1 , wherein depths of the first recessed areas are equal to depths of the second recessed areas subsequent to performing the second machining process. 
     
     
         5 . The method of  claim 1 , wherein the second mesas and the first seal band areas are formed during the second machining process. 
     
     
         6 . The method of  claim 1 , wherein heights of the first mesas, the second mesas and bands of the first seal band area are at a same level relative to a bottom of the support plate. 
     
     
         7 . The method of  claim 1 , further comprising:
 performing a third machining process to form at least one of third mesas and a second seal band area; and   removing a third one of the masks from the support plate.   
     
     
         8 . A substrate support for a substrate processing system, the substrate support comprising:
 a body; and   a plurality of mesas distributed across and extending from and in a direction away from the body and are configured to support a substrate,   wherein
 each of the plurality of mesas includes a surface area that contacts and supports the substrate, 
 each of the plurality of mesas has a same height relative to a bottom of the body, and 
 depths of areas between the plurality of mesas vary in size according to a temperature distribution pattern of the substrate or a base plate of the substrate support and experienced during processing of the substrate. 
   
     
     
         9 . The substrate support of  claim 8 , wherein the depths of the areas between the plurality of mesas decrease in size as a radial distance from a center of the substrate support increases. 
     
     
         10 . The substrate support of  claim 8 , wherein the depths of the areas between the plurality of mesas decrease in size from an area over a coolant channel inlet of the base plate to an area over a coolant channel outlet of the base plate. 
     
     
         11 . The substrate support of  claim 8 , wherein:
 the depths of the areas between the plurality of mesas decrease radially across the body from a first point along a diameter of the body to a second point along the diameter of the body; and   the second point is opposite the first point relative to a center of the body.   
     
     
         12 . The substrate support of  claim 8 , further comprising a plurality of bands defining a seal band area, wherein:
 the seal band area has a first depth; and   depths of the plurality of mesas, which are external to the seal band area, are greater in size than the first depth.   
     
     
         13 . The substrate support of  claim 12 , wherein the plurality of mesas, which are external to the seal band area, are located radially closer to a center of the body than the seal band area. 
     
     
         14 . The substrate support of  claim 8 , wherein a pattern of the depths of the plurality of mesas is arranged to account for hot spots in the base plate, such that depths of the ones of the plurality of mesas over the hot spots are smaller in size than depths of other ones of the plurality of mesas, which are not over the hot spots. 
     
     
         15 . The substrate support of  claim 8 , further comprising a first seal band area, a second seal band area, and a non-seal band area, wherein:
 the first seal band area and the second seal band area are each bounded by two bands; and   a depth of the first seal band area is different than a depth of the second seal band area or a depth of the non-seal band area.   
     
     
         16 . The substrate support of  claim 8 , further comprising
 the base plate;   a thermal bond layer disposed on the base plate; and   a support plate comprising the body and the plurality of mesas.   
     
     
         17 . A substrate processing system comprising:
 the substrate support of  claim 8 ;   a radio frequency (RF) power generator configured to generate RF power and supply the RF power to the substrate support; and   a system controller controlling operation of the RF power generator.   
     
     
         18 . A method comprising:
 determining a temperature distribution pattern across a substrate or a support plate of a substrate support;   determining, based on the temperature distribution pattern, at least one of (i) rates at which a machining tool is to pass over the support plate, or (ii) periods of time the machining tool is to spend over corresponding areas of the support plate; and   based on the determined rates or periods of time, moving the machining tool from a first position over the support plate to a second position over the support plate;   while moving the machining tool, machining a top surface of the support plate to provide mesas and a gradient in depths of recessed areas between the first position and the second position, wherein the mesas have a same height relative to a bottom of the support plate.   
     
     
         19 . The method of  claim 18 , wherein the machining tool is moved radially across the support plate from a center of the support plate to a circumferential edge of the support plate at an increasing rate, such that the machining tool machines for a maximum period of time at the center and for a minimum period of time at the edge. 
     
     
         20 . The method of  claim 18 , wherein depths decrease in size from a center of the support plate to a circumferential edge of the support plate.