Post irradiation effects (PIE) in integrated circuits

The authors review the behavior of MOS devices and circuits in an ionizing radiation environment, with an emphasis on post irradiation effects (PIEs) and dose rate dependence of total dose response. They first recount the development of Total Dose Method 1019, and then suggest modifications and enhancements that allow the maximum utilization of 1019 for the qualification and radiation hardness assurance of parts for use in the low-dose-rate natural space environment. Examples of PIE in MOS integrated circuits show that one cannot neglect these effects, and that one must test for the possibility of post irradiation circuit failure due to rebound when the best dose rate is significantly higher than the space application dose rate. Attention is also focused on the fact that Method 1019 is often too conservative when used as a test method for the effects of trapped oxide charge (TOC) in devices to be used in the space environment. These considerations lead to a focus on two features of Method 1019: PIE testing and allowance for devices that exhibit fast annealing of TOC. The recently approved Method 1019.4 contains the PIE test prescription