Radiation induced degradation of CMOS operational amplifiers at different dose rates and temperatures
The degradation of CMOS operational amplifiers with bipolar and CMOS input stages under irradiation at different dose rates and temperatures has been investigated. We show that such circuits can be susceptible to enhanced low dose rate and temporal degradation. Moreover, some features inherent to radiation response of bipolar devices have been revealed in operational amplifiers which contained CMOS elements only, for example, an increase in degradation with the temperature applied during irradiation. This is not typical for most CMOS devices. Our results suggest that the test procedures for devices and integrated circuits containing bipolar and CMOS elements should combine existing test approaches developed for the radiation testing of bipolar and CMOS devices. We have also shown that ionizing current generated by irradiation can affect the input current of operational amplifiers with CMOS input stages as measured during testing. This current can be estimated as the difference between input currents measured during irradiation and immediately after an interruption of irradiation.