Investigation of cryogenic CMOS performance

The performance of cryogenic CMOS (CRYOCMOS) operation is investigated at the device, circuit and system levels. With the exception of saturation transconductance, device parameters are monotonic functions of the ambient temperature in the 10-300K range. Direct measurements demonstrate the absence of freezeout in the channel of enhancement type MOSFET's. CRYOCMOS scaling is discussed. The speed advantage is reduced for the non-ideal scaling. However, if the gate drive and device dimensions are scaled proportionally, the performance gain of CRYOCMOS remains unchanged. The switching time is a monotonic function of temperature down to 10K. The operation of a microcomputer with a CMOS-based CPU immersed in liquid nitrogen results in speed increase of about 100% as compared with room temperature operation.