Interface-State Generation in Thick SiO2 Layers

Evidence is presented that interface states are produced by radiation in some MOS structures with thick SiO2 layers (e.g., field oxides) by a mechanism different from the slow two-stage process previously identified in thinner radiation-hardened gate oxides. Production of interface states by the new process occurs promptly after irradiation, is independent of oxide field and polarity, and takes place with nearequal efficiency at room temperature and 77 K.