Wafer Bonding and Layer Transfer Approach for Strained Silicon-On-Insulator (sSOI) Fabrication

Two different types of oxide layers (a low-temperature oxide and an ultrathin thermal oxide) were deposited on strained silicon (sSi) and bonded hydrophilically to oxidized Si(001) handle wafers. To enhance the bonding energy, the bonded wafers were annealed at 300°C for 5 h and subsequently at 500°C for 2 h. The quality of the bonded interface was assessed and the bonding energy measured after each annealing step by the crack-opening method. Using these two wafer bonding approaches and layer transfer techniques, the fabrication of SSOI wafers were demonstrated with sSi thickness of about 11 nm.