Patent ID: 8785947
Filing Date: 2014-07-22
Classification: H01L

Abstract:
1. A semiconductor substrate for growth of an epitaxial semiconductor device thereon, said semiconductor substrate comprising: a base layer; a sacrificial layer formed on said base layer, and including a plurality of spaced apart sacrificial film regions and a plurality of first passages each of which is defined between two adjacent ones of said sacrificial film regions, each of said sacrificial film regions having a plurality of nanostructures and a plurality of second passages defined among said nanostructures, said second passages being communicated spatially with said first passages and having a width less than that of said first passages; and an epitaxial layer disposed on said sacrificial layer, wherein a selective etching ratio of said sacrificial layer to said epitaxial layer is greater than 5; and wherein said epitaxial layer does not fill said first passages.