OXIDE AND INTERFACE DEGRADATION RESULTING FROM SUBSTRATE HOT-HOLE INJECTION IN METAL-OXIDE-SEMICONDUCTOR FIELD-EFFECT TRANSISTORS AT 295-K AND 77-K

Substrate hot-hole injection (SHI) induced hole trapping and interface trap generation have been characterized at 295 and 77 K. At both temperatures, the trapping is independent of the injection conditions in the silicon, and is fairly insensitive to the oxide field. Initial trapping efficiencies are about 2.5 times higher at 77 K. The experiments show that essentially the same traps are being filled at the two temperatures, and that the increase in trapping efficiency can be attributed to a larger effective cross section of the traps at 77 K. Hot-hole induced interface trap generation is observed to be independent of the injection conditions in the silicon, and to decrease with increasing oxide field magnitude. More interface traps are generated at 77 K for the same injected fluence. This is in contrast to the characteristics of irradiation-induced interface trap generation. The presence of holes at the Si-SiO2 interface is the key factor in the direct interface trap generation process acting during hot-hole injection. Following low-temperature SHI, an additional temperature-activated generation mechanism, attributed to the migration of H+, is observed in isochronal anneal experiments. This delayed mechanism is identical to the one that accounts for most of the irradiation-induced interface trap generation.