Foundry Metal-Oxide-Semiconductor Field-Effect-Transistor Electrometer for Single-Electron Detection

摘要

NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato Wakamiya, Atsugi, Kanagawa 243-0198, Japan A conventional metal-oxide-semiconductor field-effect-transistor (MOSFET) fabricated by a foundry complementary metal-oxide-semiconductor (CMOS) process has been investigated for use as an electrometer. The estimation of sensitivity in the linear and subthreshold regimes shows that the sensitivity of MOSFETs is comparable to that of single-electron transistors (SETs). In the experiments, charges in an island, which is electrically isolated by two MOSFETs in the "off" state and efficiently coupled to the electrometer via a floating gate, are detected sensitively. The results show clear steps in the drain current corresponding to electrons entering the island one by one, which demonstrates that conventional foundry MOSFETs have the ability to detect single electrons.