Apparatus and method of aligning and positioning a cold substrate on a hot surface

Abstract

Embodiments of the invention contemplate a method, apparatus and system that are used to support and position a substrate on a surface that is at a different temperature than the initial, or incoming, substrate temperature. Embodiments of the invention may also include a method of controlling the transfer of heat between a substrate and substrate support positioned in a processing chamber. The apparatus and methods described herein generally may also provide an inexpensive and simple way of accurately positioning a substrate on a substrate support that is positioned in a semiconductor processing chamber. Substrate processing chambers that can benefit from the various embodiments described herein include, but are not limited to RTP, CVD, PVD, ALD, plasma etching, and/or laser annealing chambers.

1 . A processing chamber for processing a substrate, comprising:
 a substrate support having a substrate supporting surface that is disposed at an angle relative to the horizontal and a plurality of ports which are adapted to direct a fluid to a region formed between the substrate supporting surface and a substrate that is disposed over the substrate supporting surface;   a heating element that is in thermal communication with the substrate supporting surface and is adapted to heat the substrate disposed on the substrate supporting surface; and   two or more alignment features having a substrate contact surface, wherein the two or more alignment features are positioned to align the substrate relative to the substrate supporting surface when the substrate is disposed against the substrate contact surface of each of the two or more alignment features.   
     
     
         2 . The processing chamber of  claim 1 , wherein the heating element is adapted to heat the substrate disposed on the substrate supporting surface to a temperature greater than about 450° C. 
     
     
         3 . The processing chamber of  claim 1 , further comprising:
 an optical radiation assembly comprising an electromagnetic radiation source and optics; and   a translation mechanism that is adapted to move the optics relative to the substrate support.   
     
     
         4 . The processing chamber of  claim 1 , wherein the angle is less than about 1 degree relative to the horizontal plane. 
     
     
         5 . The processing chamber of  claim 1 , further comprising:
 one or more walls that enclose a processing region;   an exhaust system that is adapted to reduce the pressure in the processing region to a pressure below atmospheric pressure.   
     
     
         6 . The processing chamber of  claim 1 , wherein the two or more alignment features are pins that attached to the substrate support. 
     
     
         7 . A method of processing a substrate, comprising:
 heating substrate support having a substrate supporting surface;   delivering a flow of a fluid to a plurality of ports formed in the substrate support, wherein the flow of fluid creates a cushion of fluid that is adapted to support the weight of the substrate;   positioning a substrate on the cushion of fluid for a desired period of time, wherein the substrate is not in physical contact with the substrate supporting surface;   reducing the flow of fluid to allow the substrate to contact at least a portion of the substrate supporting surface; and   performing a substrate processing step on the substrate disposed on the substrate supporting surface.   
     
     
         8 . The method of  claim 7 , wherein the substrate is in physical contact with two or more alignment pins that are connected to the substrate support. 
     
     
         9 . The method of  claim 7 , wherein the flow of a fluid is between about 200 sccm and about 6 slm. 
     
     
         10 . The method of  claim 7 , wherein the processing step is a laser annealing thermal process. 
     
     
         11 . The method of  claim 7 , wherein the substrate is heated to a temperature greater than about 450° C. 
     
     
         12 . The method of  claim 7 , further comprising positioning the substrate supporting surface at an angle relative to the horizontal before positioning the substrate on the cushion of fluid. 
     
     
         13 . A method of processing a substrate, comprising:
 heating substrate support having a substrate supporting surface;   delivering a flow of a fluid to a plurality of ports formed in the substrate support, wherein the flow of fluid creates a cushion of fluid that is adapted to support the weight of the substrate;   positioning a substrate on the cushion of fluid;   aligning the substrate to the substrate support while the substrate is positioned on the cushion of fluid;   reducing the flow of fluid to allow the substrate to contact at least a portion of the substrate supporting surface; and   performing a substrate processing step on the substrate disposed on the substrate supporting surface.   
     
     
         14 . The method of  claim 13 , further comprising positioning the substrate supporting surface at an angle relative to the horizontal before positioning the substrate on the cushion of fluid. 
     
     
         15 . The method of  claim 13 , wherein aligning the substrate to the substrate support comprises waiting a desired period of time to allow the substrate disposed on the cushion of fluid to come in contact with two or more alignment features that are coupled to the substrate support. 
     
     
         16 . The method of  claim 13 , further comprising holding the substrate on the cushion of fluid for a period of time longer than the time required to align the substrate to the support. 
     
     
         17 . The method of  claim 13 , wherein the substrate is not in physical contact with the substrate supporting surface when the substrate is positioned on the cushion of fluid. 
     
     
         18 . The method of  claim 17 , wherein the substrate is in physical contact with two or more alignment pins that are connected to the substrate support. 
     
     
         19 . The method of  claim 13 , wherein the flow of a fluid is between about 200 sccm and about 6 slm. 
     
     
         20 . The method of  claim 13 , wherein the processing step is a laser annealing thermal process.