METHOD FOR ENHANCING GROWTH OF SEMIPOLAR (Al,In,Ga,B)N VIA METALORGANIC CHEMICAL VAPOR DEPOSITION

Abstract

A method for enhancing growth of device-quality planar semipolar nitride semiconductor thin films via metalorganic chemical vapor deposition (MOCVD) by using an (Al,In,Ga)N nucleation layer containing at least some indium. Specifically, the method comprises loading a substrate into a reactor, heating the substrate under a flow of nitrogen and/or hydrogen and/or ammonia, depositing an In x Ga 1-x N nucleation layer on the heated substrate, depositing a semipolar nitride semiconductor thin film on the In x Ga 1-x N nucleation layer, and cooling the substrate under a nitrogen overpressure.

What is claimed is: 
     
         1 . A device structure, comprising:
 a III-nitride nucleation or buffer layer on, above, or overlying a substrate or template; and   a semi-polar III-nitride film on, above, or overlying the III-nitride nucleation or buffer layer, wherein:   the semi-polar III-nitride film is characterized by a rocking curve having a full width at half maximum (FWHM) of less than 0.5 degrees as measured by X-ray Diffraction.   
     
     
         2 . The device structure of  claim 1 , wherein:
 the III-nitride nucleation or buffer layer is deposited on or above a major surface of a substrate; and   the semipolar III-nitride film has a planar surface area greater than 10 microns wide.   
     
     
         3 . The device structure of  claim 1 , wherein a top surface of the semipolar III-nitride film is substantially parallel to the substrate's major surface. 
     
     
         4 . The device structure of  claim 1 , wherein the III-nitride nucleation or buffer layer includes at least some indium. 
     
     
         5 . The device structure of  claim 1 , wherein the III-nitride nucleation or buffer layer comprises InGaN. 
     
     
         6 . The device structure of  claim 1 , wherein the semi-polar III-nitride film has a lower surface roughness and a reduced number of crystallographic defects as compared to a semi-polar III-nitride semiconductor film grown without the III-nitride nucleation or buffer layer. 
     
     
         7 . The device structure of  claim 1 , wherein the substrate is sapphire. 
     
     
         8 . The device structure of  claim 1 , wherein the nucleation or buffer layer is grown on Gallium Nitride. 
     
     
         9 . The device structure of  claim 1 , wherein the semi-polar III-nitride film is Gallium Nitride. 
     
     
         10 . The device structure of  claim 1 , wherein the semi-polar III-nitride film has a comprises a {11  2 2} semipolar III-nitride film. 
     
     
         11 . A method of fabricating a device structure, comprising:
 growing a III-nitride nucleation or buffer layer on, above, or overlying a substrate or template; and   growing a semi-polar III-nitride film on, above, or overlying the III-nitride nucleation or buffer layer, wherein:   growth conditions and characteristics for the nucleation or buffer layer and the semi-polar III-nitride film are such that the semi-polar III-nitride film is characterized by a rocking curve having a full width at half maximum (FWHM) of less than 0.5 degrees as measured by X-ray Diffraction.