Channel-bias-controlled reconfigurable silicon nanowire transistors via an asymmetric electrode contact strategy

Abstract

Reconfigurable field-effect transistors (R-FETs) that can dynamically reconfigure the transistor polarity, from n-type to p-type channel or vice versa, represent a promising new approach to reduce the logic complexity and granularity of programmable electronics. Although R-FETs have been successfully demonstrated upon silicon nanowire (SiNW) channels, a pair of extra program gates is still needed to control the source/drain (S/D) contacts. In this work, we propose a rather simple single gate R-FET structure with an asymmetric S/D electrode contact, where the FET channel polarity can be altered by changing the sign of channel bias V_ds. These R-FETs were fabricated upon an orderly array of planar SiNW channels, grown via in-plane solid-liquid-solid mechanism, and contacted by Ti/Al and Pt/Au at the S/D electrodes, respectively. Remarkably, this channel-bias-controlled R-FET strategy has been successfully testified and implemented upon both p-type-doped (with indium dopants) or n-type-doped (phosphorus) SiNW channels, whereas the R-FET prototypes demonstrate an impressive high I_on/off ratio of > 10⁶ and a steep subthreshold swing of 79 mV/dec. These results indicate a rather simple, compact and generic enough R-FET strategy for the construction of a new generation of SiNW-based programmable and low-power electronics.