Hot-electron currents in very short channel MOSFET´s

The behaviors of the hot-electron gate and substrate currents in very short channel devices were studied. For a test device with electrical channel length of 0.14 µm, the hot-electron substrate current can be detected at 0.9-V drain voltage which is lower than the silicon band gap. The gate current can be measured at 2.35-V drain voltage, which is lower than the oxide-silicon energy barrier for electrons. These measurements support the quasi-thermal-equilibrium approximation and suggest that the hot-electron-induced problems cannot be eliminated in future VLSI MOSFET´s of arbitrarily short channels by reducing the drain bias below some constant critical energies. An empirical relationship between the effective electron temperature and the field is found to be Te= 9.05 × 10^-3E.