Static and Dynamic TCAD Analysis of IMOS Performance: From the Single Device to the Circuit

Impact ionization MOSFET (IMOS) is a device that enables to reach subthreshold slopes as small as 5 mV/dec. This device has an asymmetric doping profile, and only a fraction of the channel is covered by the gate. In the first part of this paper, the purpose is to investigate the impact of some geometrical parameters on the IMOS performance: the gate length, the intrinsic length, and the Si film thickness. This study simulates a p-IMOS device on silicon-on-insulator using ATLAS. It is pointed out that the increase of the ratio L
_G
/L
_IN
allows a drop of the bias voltage, but involves a degradation of the subthreshold slope. A thin Si film improves the overall device performance. In the second part, the performance of an IMOS-based inverter is investigated, and for the first time an IMOS ring oscillator is simulated