Defect reduction of non-polar and semi-polar iii-nitrides with sidewall lateral epitaxial overgrowth (sleo)

Abstract

A method of reducing threading dislocation densities in non-polar such as a-{11-20} plane and m-{1-100} plane or semi-polar such as {10-1n} plane III-Nitrides by employing lateral epitaxial overgrowth from sidewalls of etched template material through a patterned mask. The method includes depositing a patterned mask on a template material such as a non-polar or semi polar GaN template, etching the template material down to various depths through openings in the mask, and growing non-polar or semi-polar III-Nitride by coalescing laterally from the tops of the sidewalls before the vertically growing material from the trench bottoms reaches the tops of the sidewalls. The coalesced features grow through the openings of the mask, and grow laterally over the dielectric mask until a fully coalesced continuous film is achieved.

1 . A device having a structure that includes a lateral epitaxial overgrowth from sidewalls of a patterned substrate, wherein the lateral epitaxial overgrowth is grown in a semi-polar or non-polar direction and has a top surface that is semi-polar or non-polar, the lateral epitaxial overgrowth comprising a semi-polar or non-polar III-nitride film. 
     
     
         2 . The device of  claim 1 , wherein the lateral epitaxial overgrowth is grown in the non-polar direction and has the top surface that is non-polar, the lateral epitaxial overgrowth comprising the non-polar III-nitride film. 
     
     
         3 . The device of  claim 2 , wherein the non-polar III-nitride film comprises a threading dislocation density of 10 6  cm −2  or less. 
     
     
         4 . The device of  claim 2 , wherein the non-polar III-nitride film comprises a stacking fault density of 10 3  cm −1  or less. 
     
     
         5 . The device of  claim 2 , wherein the non-polar III-nitride film comprises a stacking fault density of 10 4  cm −1  or less. 
     
     
         6 . The device of  claim 2 , wherein the non-polar III-nitride film is substantially defect free. 
     
     
         7 . The device of  claim 1 , wherein the lateral epitaxial overgrowth is grown in the semi-polar direction and has the top surface that is semi-polar, the lateral epitaxial overgrowth comprising the semi-polar III-nitride film. 
     
     
         8 . The device of  claim 7 , wherein the semi-polar III-nitride film comprises a threading dislocation density of 10 6  cm 2  or less. 
     
     
         9 . The device of  claim 7 , wherein the semi-polar III-nitride film comprises a stacking fault density of 10 3  cm −1  or less. 
     
     
         10 . The device of  claim 7 , wherein the semi-polar III-nitride film comprises a stacking fault density of 10 4  cm −1  or less. 
     
     
         11 . The device of  claim 7 , wherein the semi-polar III-nitride film is substantially defect free. 
     
     
         12 . The device of  claim 1 , wherein the patterned substrate is an initial non-polar or semi-polar III-nitride layer and a top surface of the initial non-polar or semi-polar III-nitride layer is an epitaxially grown non-polar or semi-polar surface. 
     
     
         13 . The device of  claim 1 , wherein the device is an electronic, optoelectronic, or electromechanical device. 
     
     
         14 . The device of  claim 1 , wherein the semi-polar or non-polar III-nitride film is a fully coalesced planar film. 
     
     
         15 . The device of  claim 1 , wherein the semi-polar or non-polar III-nitride film is a planar a-plane, m-plane, or (10-1n) plane film. 
     
     
         16 . A method of fabricating a non-polar or semi-polar III-nitride device, comprising:
 performing a lateral epitaxial overgrowth from sidewalls of a patterned substrate, wherein the lateral epitaxial overgrowth is grown in a semi-polar or non-polar direction and has a top surface that is semi-polar or non-polar, the lateral epitaxial overgrowth comprising a semi-polar or non-polar III-nitride film, and the device having a structure including the lateral epitaxial overgrowth.   
     
     
         17 . The method of  claim 16 , wherein the patterned substrate is an initial non-polar or semi-polar III-nitride layer and a top surface of the initial non-polar or semi-polar III-nitride layer is an epitaxially grown non-polar or semi-polar surface. 
     
     
         18 . The method of  claim 16 , wherein the lateral epitaxial overgrowth is grown by Metal Organic Chemical Vapor Deposition (MOCVD), Hydride Vapor Phase Epitaxy (HVPE), or Molecular Beam Epitaxy (MBE). 
     
     
         19 . A non-polar or semi-polar III-nitride device, comprising:
 an initial non-polar or semi-polar III-nitride layer grown on a non-III-nitride substrate, wherein a top surface of the initial non-polar or semi-polar III-nitride layer is an epitaxially grown non-polar or semi-polar surface; and   a subsequent non-polar or semi-polar III-nitride layer grown on the initial non-polar or semi-polar III-Nitride layer, comprising a threading dislocation density of no more than 10 7  cm −2 , wherein the non-polar or semi-polar III-nitride device is grown on a non-polar or semi-polar top surface of the subsequent non-polar or semi-polar III-nitride layer.   
     
     
         20 . The device of  claim 19 , wherein the initial non-polar III-nitride layer has a top surface that is the non-polar surface and the non-polar III-nitride device is grown on the non-polar top surface of the subsequent non-polar III-nitride layer. 
     
     
         21 . The device of  claim 19 , wherein the initial semi-polar III-nitride layer has a top surface that is the semi-polar surface and the semi-polar III-nitride device is grown on the semi-polar top surface of the subsequent semi-polar III-nitride layer.