Strain reduction in Silicon-on-Sapphire by wafer bonding

Though Silicon-on-Sapphire (SOS) has many applications for RF circuits, compressive strain in the hetero epitaxially deposited silicon film reduces the electron mobility and diminishes its high-frequency performance. To eliminate this strain, we bonded silicon films to sapphire. There has been limited work done on Bonded SOS (BSOS) up until this time. The current work has provided a mass-produced SOI technology that has device performance exceeding that of incumbent RF technologies. The BSOS films show 56% higher electron mobility than SOS and RF switch performance better than GaAs PHEMT's.