Total Ionizing Dose Effects in Silicon Bulk FinFETs at Cryogenic Temperatures

Abstract

The icy bodies of the solar system, such as Europa and Titan, are high priority targets for exploratory spacecraft missions by NASA and the world’s space agencies. Such missions would likely involve electronic payloads being subjected to harsh radiation environments while at extremely low temperatures. This work aims to characterize the effects of such an environment on the modern bulk FinFET device geometry in order to determine viability and design optimization. The operation of bulk Silicon FinFET devices at temperatures from room temperature (293 K) to 90 K is explored. The TID responses of bulk FinFET devices irradiated with protons at 89 K are compared to the responses of devices irradiated at 293 K. Experiments show that fin-width is a determining factor in device operation at lower temperatures, and in the radiation response of devices at both room temperature and cryogenic temperatures. Devices irradiated at low temperatures experienced different TID effects due to the changes in material properties at low temperatures. In particular, they experienced greater transconductance degradation and relatively greater subthreshold slope degradation.