Thermal Annealing of Radiation Damage in CMOS ICs in the Temperature Range -140°C to +375°C

Annealing of radiation damage was investigated in the commercial,Z-and J-processes of the RCA CD4007A ICs in the temperature range from -140°C to +375°C. Tempering curves were analyzed for activation energies of thermal annealing, following irradiation at -140°C. It was found that at -140°C, the radiation-induced shifts in the threshold potentials were similar for all three processes. The radiation hardness of the Z-and J-processes is primarily due to rapid annealing of radiation damage at room temperature. In the region -140 to 20°C, no dopant-dependent charge trapping is seen, similar to that observed at higher temperatures. In the unbiased Z-process n-channels, after 1 MeV electron irradiation, considerable negative charge remains in the gate oxide.