Hydrogen-induced donor states in the mos system: Hole Traps, Slow States and Interface States

摘要

We propose that atomic hydrogen, trapped at regular network oxygen atoms, produces a hole trap, a slow state and an interface state. The overcoordinated oxygen configuration resulting from this interaction is associated with an electronic donor state. Extensive studies of the metal-oxide-silicon (MOS) system have led to a broad consensus that atomic hydrogen (H~0) plays a key role in the degradation of the system. Unfortunately, our understanding of H~0 in the MOS system still is rather limited. Cartier et al. have observed that exposure of the Si/SiO_2 system to H~0 indeed produces large numbers of interface states. However, only a fraction of these are silicon dangling bonds centers; the majority are defects with unknown microscopic structure. H~0 is also directly involved in the generation of slow states, also known as "anomalous positive charge (APC) centers" or "border traps". These slow states are related to defects in the near-interfacial region of the oxide, but like hydrogen-induced interface states their microscopic nature has not been established. McLean postulated that H° also exists as a proton in the oxide layer. If so, H~0 must be capable of trapping a hole. Apparently, H~0 is associated with an interface state, a slow state, and with a hole trap.