Device-level analysis of a 1 mu m BiCMOS inverter circuit operating at 77 K using a modified PISCES program

The authors present a device-level study on the steady-state and transient behavior of a 1- mu m BiCMOS inverter circuit operating at 77 K using a modified PISCES program, where appropriate low-temperature device models with a large-scale simulation capability have been added. According to simulation results, at 77 K, the falltime is 35.2% longer than and the risetime is about identical to those at 300 K, due to a smaller output swing and a smaller non-negligible collector current in the BiNMOS transistor and a smaller BiPMOS emitter current at 77 K during pull-up transient. Circuit and device designs can be optimized to justify the low-temperature operation of BiCMOS circuits.<
>