Wafer structure and epitaxial growth method for growing the same

Abstract

A wafer structure and epitaxial growth method for growing the same. The method may include forming a mask layer having nano-sized areas on a wafer, forming a porous layer having nano-sized pores on a surface of the wafer by etching the mask layer and a surface of the wafer, and forming an epitaxial material layer on the porous layer using an epitaxial growth process.

1 . An epitaxial growth method comprising: 
 forming a mask layer having nano-sized areas on a wafer;    forming a porous layer having nano-sized pores on a surface of the wafer by etching the mask layer and a surface of the wafer; and    forming an epitaxial material layer on the porous layer using an epitaxial growth process.    
     
     
         2 . The method according to  claim 1 , further comprising: 
 annealing the epitaxial material layer.    
     
     
         3 . The method according to  claim 2 , wherein annealing of the epitaxial material layer is performed at a temperature of 850° C. or higher.  
     
     
         4 . The method according to  claim 1 , wherein the wafer is a single crystalline wafer.  
     
     
         5 . The method according to  claim 4 , wherein the single crystalline wafer is an Al 2 O 3  wafer.  
     
     
         6 . The method according to  claim 1 , wherein the epitaxial material layer is formed of a group III nitride semiconductor.  
     
     
         7 . The method according to  claim 1 , wherein the epitaxial material layer is a GaN layer.  
     
     
         8 . The method according to  claim 1 , wherein the epitaxial material layer is formed using a vapor deposition process.  
     
     
         9 . The method according to  claim 8 , wherein the vapor deposition process is one selected from the group consisting of a halide or hydride vapor phase epitaxy (HVPE) process, a metal organic chemical vapor deposition (MOCVD), and a molecular beam epitaxy (MBE) process.  
     
     
         10 . The method according to  claim 1 , wherein the mask layer is formed of a material having a lower etch rate than the single crystalline wafer.  
     
     
         11 . The method according to  claim 10 , wherein the mask layer is formed of AlN.  
     
     
         12 . The method according to  claim 11 , wherein the AlN mask layer is formed using a halide or hydride vapor phase epitaxy (HVPE) process.  
     
     
         13 . A wafer structure comprising: 
 a substrate;    a porous layer having nano-sized pores on a surface of the substrate; and    an epitaxially formed material layer on the porous layer.    
     
     
         14 . The wafer structure according to  claim 13 , wherein the wafer is a single crystalline wafer.  
     
     
         15 . The wafer structure according to  claim 14 , wherein the single crystalline wafer is an Al 2 O 3  wafer.  
     
     
         16 . The wafer structure according to  claim 13 , wherein the epitaxial material layer is formed of a group III nitride semiconductor.  
     
     
         17 . The wafer structure according to  claim 13 , wherein the epitaxial material layer is a GaN layer.  
     
     
         18 . The wafer structure according to  claim 13 , wherein the mask layer is formed of a material having a lower etch rate than the single crystalline wafer.  
     
     
         19 . The wafer structure according to  claim 18 , wherein the mask layer is formed of AlN.  
     
     
         20 . An optical device including the wafer structure of  claim 13.