Epitaxial layer transfer by bond and etch back of porous Si

Abstract

We demonstrate a novel method for bond and etch back silicon on insulator in which an epitaxial Si layer over porous Si is transferred onto a dissimilar substrate by bonding and etch back of porous Si. The highest etching selectivity (100 000:1) between the porous Si and the epitaxial layer is achieved by the alkali free solution of HF, H2O2, and H2O which is essential for this single etch-stop method to produce a submicron-thick active layer with superior thickness uniformity (473±14 nm) across a 5 in. silicon-on-insulator wafer.