An overview of radiation-induced interface traps in MOS structures

The authors focus on radiation-induced interface traps, describing first how they fit into the overall radiation response of metal-oxide-semiconductor structures. Detailed measurements of the time, field and temperature dependences of the build-up of radiation-induced interface traps indicate three processes by which the build-up occurs. The largest of these is the slow two-stage process described by McLean and co-workers (1989) which is rate-limited by the hopping transport of hydrogen ions. Two other faster processes also contribute small interface trap build-ups in gate oxides. The processes seem to be controlled by hole transport to the Si/SiO2 interface and by neutral hydrogen diffusion respectively. They also discuss several models which fall into three classes, corresponding roughly to the three processes observed experimentally. Other topics discussed briefly are dose dependence, field oxide effects, chemical and processing dependences and scaling effects.