TCAD simulation of gate-enclosed MOSFET for terahertz detector

The source parasitic capacitor significantly influences the terahertz responsivity for CMOS terahertz detector. In this paper, the gate-enclosed MOSFET is used for terahertz signal detection in order to reduce the source parasitic capacitor. 3D-TCAD simulation reveals that the gate-enclosed structure improves the voltage responsivity (Rv) of the THz detectors and reduces noise-equivalent power (NEP) effectively by comparing with the equal conventional MOSFET detectors. A maximum Rv of 3 kV/W and a minimum NEP of 42pW/√Hz are achieved for the gate-enclosed nMOSFETs implemented in 0.18μm CMOS technology.