Effects of moisture on radiation-induced degradation in CMOS SOI transistors

The effects of moisture on radiation-induced charge buildup in the oxides of a 0.35 μm SOI technology are explored. Data show no observable effects of moisture-related aging on radiation hardness. These results are in contrast to those of previous work performed on bulk MOS technologies fabricated in the 1980s. The cause of these differences do not appear to be due to differences in final chip passivation layers. Instead, other processing variables (including the use of different implant materials and thicker overlayers) may account for these differences. In any case, the SOI technology results indicate that not all advanced technologies exposed to moisture are necessarily susceptible to significant long-term radiation-induced aging effects.