Chemical vapor deposition with energy input

Abstract

Methods of depositing compound semiconductors onto substrates are disclosed, including directing gaseous reactants into a reaction chamber containing the substrates, selectively supplying energy to one of the gaseous reactants in order to impart sufficient energy to activate that reactant but insufficient to decompose the reactant, and then decomposing the reactant at the surface of the substrate in order to react with the other reactants. The preferred energy source is microwave or infrared radiation, and reactors for carrying out these methods are also disclosed.

1 . A chemical vapor deposition reactor comprising:
 (a) a reaction chamber;   (b) a substrate carrier mounted within said reaction chamber for rotation about an axis of rotation extending in upstream and downstream directions, said substrate carrier being arranged to hold one or more substrates so that surfaces of said substrates face generally in the upstream direction;   (c) a flow inlet element disposed upstream of the substrate carrier, said flow inlet element having a plurality of discharge zones disposed at different locations in directions transverse to said axis of rotation, said flow inlet element being arranged to discharge different gases through different ones of said plurality of discharge zones so that said discharged gases are directed generally downstream toward said substrate carrier in substantially separate streams at different locations relative to said axis of rotation; and   (d) selective energy input apparatus arranged to supply energy selectively at locations between said flow inlet element and said substrate carrier aligned with a selected one of said substantially separate streams to thereby supply energy selectively to said gas associated with said selected one of said substantially separate streams.   
     
     
         2 . The reactor of  claim 1  wherein said selective energy input apparatus is selected from the group consisting of microwave and infrared energy generators. 
     
     
         3 . The reactor of  claim 1  wherein said selective energy input apparatus is arranged to supply said energy at a wavelength which is substantially absorbed by said gas associated with said selected one of said substantially separate streams. 
     
     
         4 . The reactor of  claim 1  wherein said energy is substantially not absorbed by the others of said substantially separate streams. 
     
     
         5 . The reactor of  claim 1  wherein said selective energy input apparatus is arranged to direct beams of said energy along one or more beam paths having components in directions transverse to said axis of rotation. 
     
     
         6 . The reactor of  claim 5  wherein said one or more beam paths are arranged to intercept said selected one of said separate streams adjacent to said surface of said substrate carrier. 
     
     
         7 . The reactor of  claim 1  wherein said selective energy input apparatus is arranged to direct beams of said energy along one or more beam paths having components in directions parallel to said axis of rotation. 
     
     
         8 . The reactor of  claim 1  wherein said selective energy input apparatus is arranged to direct beams of said energy along one or more beam paths having components in directions at an angle between about 0° and 90° with respect to said axis of rotation. 
     
     
         9 . The reactor of  claim 1  wherein said selective energy input apparatus is arranged to direct beams of said energy along one or more beam paths having components in a direction at an angle of about 90° with respect to said axis of rotation.