Conductance quantization in nanoscale vertical structure silicon field-effect transistors with a wrap gate

Experimental results of quantum ballistic transport in single quantum conta ct by using vertical structure silicon field effect transistors with a wrap gate are presented. Based on dc measurement, the conductance-voltage chara cteristics show quantized plateaus at multiples of 2e(2)/h. The devices wer e prepared by electron beam lithography and by combinations of various type s of etching. The channel is fabricated by the chemical vapor deposition of amorphous silicon and solid-phase crystallization. The vertical structure allows a channel length as short as 30 nm, which is defined by the film thi ckness. The effective channel is reduced by the depletion potential, result ing in a much narrower channel width compared to the geometrical width of 6 0 nm. Thus, the effective size of the silicon transistor is smaller than th e elastic mean free path of 40 nm, resulting in the conduction quantization at 3-5 K. (C) 2000 American Institute of Physics. [S0003-6951(00)04919-6].