Integration of indium phosphide thin film structures on silicon substrates by direct wafer bonding

Wafer bonding or wafer fusion is a method of combining two same or dissimilar materials, either atomically or by means of adhesive. In this paper we report a new process to bond thin film Indium Phosphide (InP) to oxidized Silicon (100) substrates at low temperatures (>250 deg. C). The treatment of InP epitaxial structures to oxygen plasma and the Si substrate to chemical treatment aids the substrates in contact bonding at room temperature. A thermal treatment at 220 deg. C, completes the wafer fusion, with uniform bonding occurring along the length and breadth of the sample. The InP substrate is removed, resulting in a thin film of two micron InP bonded to oxidized Si. The InP thin film was studied for its structural and optical quality by high-resolution scanning electron microscopy, micro-PL and micro-Raman. The thin-film exhibited excellent quality and was patterned and released to form cantilever structures, showing the process capability of integrating free-standing III-V thin-films on Si platform