Test CMOS/SOS RAM for transient radiation upset comparative research and failure analysis

The test Complementary Metal-Oxide-Semiconductor/Silicon-on-Sapphire Random Access Memory (CMOS/SOS RAM) with eight types of memory cells was designed and tested at high dose rates with a flash X-ray machine and laser simulator. The memory cell (MC) design with additional transistors and RC-chain was found to be upset free up to 2/spl times/10/sup 12/ rad(Si)/s. An "inversion" effect was discovered in which almost 100% logic upset was observed in poorly protected memory cell arrays at very high dose rates.