Si layer transfer to InP substrate using low-temperature wafer bonding
Using a low-temperature wafer bonding process, InP substrates are bonded to silicon-on-insulator (SOI) substrates at 220 °C. A combination of oxygen plasma and chemical treatment results in a direct contact bonding at room temperature. After the bonding process at 220 °C for 45 min, removal of the Si handle substrate by sacrificial etching of the buried oxide layer in SOI, results in a thin membrane of Si robustly bonded to InP. The thin Si membrane bonded to InP shows uniformly bonded interface under high-resolution electron microscopy. Micro-Raman analysis has also been carried out to study the bonded interface. I–V characteristics of the bonded structures suggest that such bonding and layer transfer processes are suitable for device integration.