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

Planar silicon nanowires (SiNWs), grown by using low temperature catalytic approaches, are excellent 1D channel materials for developing high-performance 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 in-plane 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 >10⁷ and 262 mV·dec^-1, respectively, indicating a reliable new routine to integrate a wide range of SiNW-based logic, sensor, and display applications.