Chemical vapor deposition reactor

Abstract

A CVD reactor, such as a MOCVD reactor conducting metalorganic chemical vapor deposition of epitaxial layers, is provided. The CVD or MOCVD reactor generally comprises a flow flange assembly, adjustable proportional flow injector assembly, a chamber assembly, and a multi-segment center rotation shaft. The reactor provides a novel geometry to specific components that function to reduce the gas usage while also improving the performance of the deposition.

1 - 27 . (canceled) 
     
     
         28 . A chemical vapor deposition reactor comprising:
 a chamber assembly having a top end and a bottom end;   a flow flange assembly attached to the top end of the chamber assembly;   a wafer carrier configured to support at least one substrate wafer; and   a wafer carrier heating assembly;   wherein the chamber assembly comprises a lower flow guide that surrounds a wafer carrier.   
     
     
         29 . The chemical vapor deposition reactor according to  claim 28 , wherein the flow flange assembly comprises an upper flow guide above the wafer carrier. 
     
     
         30 . The chemical vapor deposition reactor according to  claim 29 , wherein the upper flow guide has a curved cross-sectional profile and first fluid gap formed between the an inward facing surface of the upper flow guide and an underside of a main flange body of the flow flange assembly. 
     
     
         31 . The chemical vapor deposition reactor according to  claim 28 , wherein the flow flange assembly comprises an upper flow guide connected to a main flange body, wherein a first fluid gap is positioned between the upper flow guide and the main flange body. 
     
     
         32 . The chemical vapor deposition reactor according to  claim 31 , wherein a second gap located between an upper surface of the wafer carrier and an outward facing surface of the upper flow guide is about 1 inch or less. 
     
     
         33 . The chemical vapor deposition reactor according to  claim 28 , wherein the chamber assembly comprises one or more reflectors located between the wafer carrier and the lower flow guide. 
     
     
         34 . The chemical vapor deposition reactor according to  claim 28 , wherein the lower flow guide, generally, has a conical shape, a sloped shape or a frustoconical shape. 
     
     
         35 . The chemical vapor deposition reactor according to  claim 28 , wherein a top end or surface of the lower flow guide is aligned approximately with a top surface of the wafer carrier. 
     
     
         36 . The chemical vapor deposition reactor according to  claim 28 , wherein the lower flow guide has an outer diameter that is larger than an inner diameter of the lower flow guide, and further wherein at least a portion of an outer surface of the lower flow guide is sloped or curved in a downward direction. 
     
     
         37 . The chemical vapor deposition reactor according to  claim 28 , wherein an inner diameter of the lower flow guide and an outer diameter of the wafer carrier are in close proximity and provide a narrow gap between each other. 
     
     
         38 . The chemical vapor deposition reactor according to  claim 28 , further comprising:
 one or more reflectors arranged to surround at least a portion of the wafer carrier heating assembly and angled in a downward direction.   
     
     
         39 . The chemical vapor deposition reactor according to  claim 38 , wherein the one or more reflectors is constructed of a thin piece of metal. 
     
     
         40 . The chemical vapor deposition reactor according to  claim 39 , wherein the thin piece of metal is molybdenum. 
     
     
         41 . The chemical vapor deposition reactor according to  claim 28 , wherein the lower flow guide is constructed of two or more pieces. 
     
     
         42 . The chemical vapor deposition reactor according to  claim 41 , wherein the lower flow guide comprises a first piece, located adjacent to the wafer carrier, fabricated from a first material having a first temperature tolerance and coefficient of thermal expansion about equal to a second temperature tolerance and coefficient of thermal expansion of a second material of the wafer carrier. 
     
     
         43 . The chemical vapor deposition reactor according to  claim 42 , wherein the lower flow guide comprises a second piece fabricated from a third material that is a different material than the first material of the first piece. 
     
     
         44 . The chemical vapor deposition reactor according to  claim 28 , wherein an inner diameter of the lower flow guide is the same as or larger than an outer diameter of the wafer carrier. 
     
     
         45 . The chemical vapor deposition reactor according to  claim 28 , wherein the wafer carrier rests on a top of a center rotation shaft. 
     
     
         46 . The chemical vapor deposition reactor according to  claim 45 , wherein the center rotation shaft has a flange at a proximal end located adjacent to the wafer carrier and a bottom surface of the wafer carrier rests on the flange of the center rotation shaft. 
     
     
         47 . The chemical vapor deposition reactor of  claim 45 , wherein the center rotation shaft comprises at least one shaft segment having a substantially lower thermal conductivity than remaining shaft segments of the center rotation shaft.