Total ionizing dose radiation effects of RF PDSOI LDMOS transistors

The effects of total ionizing dose radiation on direct current (DC) and small-signal radio frequency (RF) performance of multi-finger RF partial deplete silicon-on-insulator lateral double diffused MOS (PDSOI LDMOS) transistors are investigated. The radiation response of the LDMOS transistors with different device structures is characterized for an equivalent gamma dose up to lMrad(Si) at room temperature. The front and back gate threshold voltages, off-state leakage, transconductance, and output characteristics are measured before and after radiation, and the results show a significant degradation of DC performance. Moreover, high frequency measurements for the irradiated transistors indicate remarkable declines of 5-parameters, cutoff frequency, and maximum oscillation frequency to lMrad(Si) exposure levels. Compared to the transistors with the BTS contact structure, the transistors with the LBBC contact do not show its excellent DC radiation hardness when the transistors operate at alternating current (AC) mode. ©2008 Chinese Institute of Electronics.