Si complementary single-electron inverter with voltage gain

A Si complementary single-electron inverter in which two identical single-electron transistors (SETs) are packed is fabricated on a silicon-on-insulator substrate. For the fabrication, the vertical pattern-dependent oxidation method, which enables the formation of two tiny SETs aligned in parallel, is modified so that the two SETs can be connected in series to realize an inverter configuration. The resultant circuit occupies a very small area: 100 X 100 nm for each SET. For complementary operation, the electrical characteristics of one of the SETs are shifted using a side gate situated near the SET. Input-output transfer with a voltage gain larger than unity is demonstrated at 27 K.