Cleave Engineered Layer Transfer using Porous Silicon

Abstract

A Cleave-Engineered Layer Transfer (CELT) substrate was fabricated consisting of a thin InP template layer transferred, via wafer bonding and hydrogen exfoliation, onto a silicon handle wafer with a porous layer at its surface. The mechanically weak porous silicon layer enables transfer of subsequent epitaxial growth and device fabrication on the template layer by initiating cleavage through the porous layer. Structural and mechanical property changes in the porous silicon layer after various processing conditions were studied. Characterization included atomic force microscopy, high-resolution x-ray diffraction, scanning electron microscopy, and nanoindentation measurements. Atomic force microscopy and transmission electron microscopy show the template layer has high surface- and crystalline- quality for subsequent epitaxial deposition. Layer transfer capability was demonstrated on a similar structure by fracture through the porous layer.