Silicon nanowire tunneling field-effect transistor arrays: Improving subthreshold performance using excimer laser annealing

We have experimentally established that the inverse subthreshold slope S of a Si nanowire tunneling field-effect transistor (NW-TFET) array can be within 9% of the theoretical limit when the doping profile along the channel is properly engineered. In particular, we have demonstrated that combining excimer laser annealing with a low-temperature rapid thermal anneal results in an abrupt doping profile at the source/channel interface as evidenced by the electrical characteristics. Gate-controlled tunneling has been confirmed by evaluating S as a function of temperature. The good agreement between our experimental data and simulation allows performance predictions for more aggressively scaled TFETs. We find that Si NW-TFETs can be indeed expected to deliver S-values below 60 mV/dec for optimized device structures.