High responsivity in integrated optically controlled metal-oxide semiconductor field-effect transistor using directly bonded SiO2-InP

For the first time, high responsivity was obtained from an integrated optically controlled metal-oxide semiconductor field-effect transistor using the direct wafer bonding technique. The integrated structure of the device was composed of an absorption p-i-n photodiode region and a MOSFET. These two regions were bonded using the SiO₂-InP direct wafer bonding technique. When a laser light with a wavelength of 1.50 μm was irradiated on the absorption region, a responsivity of more than 280 A/W was obtained. This is the largest responsivity in an integrated long-wavelength photoreceiver on a Si substrate. This device modulates MOSFET´s current by changing the electric field in the absorption region.