Gate-length dependence of optical characteristics in optically controlled MOSFET

The gate-length dependencies of the optical response characteristics in an optically controlled metal oxide semiconductor field effect transistor (MOS FET) have been measured. This device was fabricated as an integrated struct ure of the absorption region anti MOSFET region using the direct wafer-bond ing technique. By reducing the gate length of the MOSFET region, the transc onductance of the FET channel was increased, and a high current modulation and responsivity was obtained by irradiation of 1.5 mu m wavelength light.