Epitaxial substrate having nano-rugged surface and fabrication thereof

Abstract

The invention provides an epitaxial substrate and fabrication thereof. The epitaxial substrate according to the invention includes a crystalline substrate. In particular, the crystalline substrate has an epitaxial surface which is nano-rugged and non-patterned. The epitaxial substrate according to the invention thereon benefits a compound semiconductor material in growth of epitaxy films with excellent quality. Moreover, the fabrication of the epitaxial substrate according to the invention has advantages of low cost and rapid production.

What is claimed is: 
     
         1 . An epitaxial substrate, comprising:
 a crystalline substrate having an epitaxial surface which is nano-rugged and non-patterned.   
     
     
         2 . The epitaxial substrate of  claim 1 , wherein the crystalline substrate is formed of one selected from the group consisting of sapphire, SiC, GaN, GaAs, ZnO, Si, ScAlMgO 4 , SrCu 2 O 2 , YSZ(Yttria-Stabilized Zirconia), LiAlO 2 , LiGaO 2 , Li 2 SiO 3 , LiGeO 3 , NaAlO 2 , NaGaO 2 , Na 2 GeO 3 , Na 2 SiO 3 , Li 3 PO 4 , Li 3 AsO 4 , Li 3 VO 4 , Li 2 MgGeO 4 , Li 2 ZnGeO 4 , Li 2 CdGeO 4 , Li 2 MgSiO 4 , Li 2 ZnSiO 4 , Li 2 CdSiO 4 , Na 2 MgGeO 4 , Na 2 ZnGeO 4 , and Na 2 ZnSiO 4 . 
     
     
         3 . The epitaxial substrate of  claim 2 , wherein the epitaxial surface of the crystalline substrate has an average surface roughness (Ra) in a range from 100 nm to 400 nm. 
     
     
         4 . The epitaxial substrate of  claim 2 , wherein the epitaxial surface of the crystalline substrate has a mean peak-to-valley height (Rz) in a range from 50 μm to 350 μm.