Comparison of electrical characteristics of back- and top-gate Si nanowire field-effect transistors

Abstract

Back- and top-gate field-effect transistors (FETs) with channels composed of p-type Si nanowires were fabricated by a conventional photolithographic process and their electrical properties were characterized by conventional current-voltage (I-V) measurements. For a representative top-gate FET, the peak transconductance was enhanced from 2.24 to 72.2 nS, the field-effect mobility from 1.7 to 3.1 cm(2)/VS, and the I-on/I-off ratio from 2.21 to 2.49 x 10(6), compared with those of a representative back-gate FET. The observed improvement of the electrical characteristics is mostly attributed to both the top-gate geometry and the relatively thin gate layer. (C) 2008 Elsevier Ltd. All rights reserved.