HOTMOS : a 2-D MOS device simulator for hot carrier effects

Generation of hot carriers in bulk silicon and their injection into the oxide of MOS devices has been a subject of deep concern with the device size shrinking into the sub-micron range. Simulation of hot carrier effects would be an important aid to design hot-carrier resistant devices. HOTMOS is a 2-D MOS device simulator, developed at I.I.T. Bombay, to simulate the hot carrier effects in NMOS transistors. The speciality of this simulator in comparision with the already existing ones, like MINIMOS, is that the oxide is treated as non-ideal. Hence the semiconductor equations along with trap rate equations are solved in the oxide to monitor the time evolution of trapped oxide charges and interface states. Hot carrier degradation can be predicted by simulating the substrate current and gate current besides the standard I-d - V-g and I-d - V-d device characteristics. The simulation results of this agree qualitatively with the theoretical expectations and are presented in this paper