Two-dimensional analysis of a BiNMOS transistor operating at 77 Kusing a modified PISCES program

The authors present a detailed two-dimensional numerical simulation study on the steady-state and turn-on transient behavior of a BiNMOS device operating at 77 K using PISCES-2B with modified low-temperature models. It is shown that the switching speed of the BiNMOS device, which is designed for operation at room temperature, is degraded for low-temperature operation. The BiNMOS device structure and the low-temperature device models for the two-dimensional (2D) device simulator are described, following by the steady-state and the transient analysis of the BiNMOS device. The turn-on transient performance of the BiNMOS device shows that, at 77 K, the switching time, which is determined by the load-related delay and the intrinsic delay of the bipolar device, increases about 45% from its 300 K value for an output load of 0.1 pF/μm