Detection of field-induced single-acceptor ionization in Si by single-hole-tunneling transistor

Abstract

The authors have detected the ionization of single-acceptors in the underlying p on p+ substrate of a silicon-on-insulator (SOI) wafer using a single-hole-tunneling (SHT) transistor fabricated in the top Si layer of the SOI at low temperatures. It was found that freeze-out boron atoms in the substrate are sequentially ionized from near the buried SiO2∕p-Si substrate interface to deeper positions by application of a vertical electric field, creating steplike features in the time-dependent SHT current.