Converging-guiding-track design enables 100% growth deployment rate of ultrathin monocrystalline silicon nanowire channels

Abstract

A low temperature catalytic growth of orderly ultrathin silicon nanowires (SiNWs) is desirable for the construction of monolithic 3D stacked electronics but usually suffers a large diameter fluctuation and a low growth deployment rate (GDR). In this work, the ultra-confined growth dynamics of in-plane solid–liquid–solid SiNWs within narrow groove tracks has been systematically investigated, and a converging-guiding-track strategy is proposed and testified to accomplish 100% GDR of ultra-dense and uniform SiNW array, with diameter and spacing of only Dnw = 22.5±3.5 nm and 25 nm, respectively. Despite a low temperature growth at 350 °C, the SiNWs are found to be all monocrystalline and Si⟨100⟩ oriented, while prototype Schottky barrier tunneling field effect transistors built on the SiNW channels demonstrate a high Ion/off ratio and subthreshold swing of >105 and 197 mV dec−1. This new strategy complements a long-missing key capability of catalytic growth approach to serve a reliable integration technology of ultrafine high quality 1D c-Si channels, without the need of preexisting wafer substrate, for a wide range of 3D electronics, neuromorphic, and logic-in-memory functionalities.