Deterministic Single-Row-Droplet Catalyst Formation for Uniform Growth Integration of High-Density Silicon Nanowires

Abstract

Planar silicon nanowires (SiNWs), grown by using low temperature catalytic approaches, are excellent 1D channel materials for developing highperformance logics and sensors. However, a deterministic position and size control of the metallic catalyst droplets, that lead to the growth of SiNWs, remains still a significant challenge for reliable device integration. In this work, we present a convenient but powerful edge-trimming catalyst formation strategy, which can help to produce a rather uniform single-row of indium (In) catalyst droplets of D cat = 67 ± 5 nm in diameter, with an exact one-droplet-on-one-step arrangement. This approach marks a significant achievement in self-assembled catalyst formation and offers a foundation to attain a reliable and scalable growth of density SiNW channels, via an inplane solid−liquid−solid (IPSLS) mechanism, with a uniform diameter down to D nw = 35 ± 4 nm, and do not rely on high-precision lithography techniques. Prototype SiNW-based field effect transistors (FETs) are also fabricated, with a high I on /I off current ratio and small subthreshold swing of >10 7 and 262 mV•dec −1 , respectively, indicating a reliable new routine to integrate a wide range of SiNW-based logic, sensor, and display applications.

Growth Control of In-Plane Silicon Nanowires via Catalyst Size-Dependent Laser Heating for High-Performance Electronics

“…Considering the extremely small heat capacitance of the tiny catalyst droplets and droplet volume-dependent heating efficiency ∼D In (diameter of In droplet), the local temperature elevation of catalyst droplets under laser-heated mode could also be catalyst size-dependent. Different from the traditional substrate heating mode used in our previous works, where all of the droplets are heated and activated to guide the growth of SiNWs with diameters of D NW ∼ f·D In ,− (Figure b), the size-dependent heating in the laser heating mode may result in a different IPSLS SiNW growth (Figure c). However, this important aspect has never been verified experimentally.…”