Charge Collection and SEU in SiGe HBT Current Mode Logic Operating at Cryogenic Temperatures.

This paper investigates cryogenic temperature charge collection and single-event upset (SEU) in SiGe HBT devices and logic circuits using 3-D device simulation and circuit simulation. Cryogenic temperature circuit simulation is enabled by a new SiGe HBT compact model developed for wide temperature range operation. Incomplete ionization was found to impact charge collection below 130 K. With cooling, collector-substrate (CS) junction peak current ICS and integral charge QCS first increase, and then decrease below 130 K. Circuit SEU immunity is found to be nearly independent of temperature above 150 K and improve with further cooling, suggesting no additional hardening is required for cryogenic temperature operation. [ABSTRACT FROM AUTHOR]