Unprecedented Uniform 3D Growth Integration of 10-Layer Stacked Si Nanowires on Tightly Confined Sidewall Grooves

Nano Lett. 2020 Oct 14;20(10):7489-7497. doi: 10.1021/acs.nanolett.0c02950. Epub 2020 Oct 1.

Abstract

Bottom-up catalytic growth offers a high-yield, versatile, and powerful tool for the construction of versatile 3D nanocomplexes, while the major challenge is to achieve a precise location and uniformity control, as guaranteed by top-down lithography. Here, an unprecedented uniform and reliable growth integration of 10-layer stacked Si nanowires (SiNWs) has been accomplished, for the very first time, via a new groove-confined and tailored catalyst formation and guided growth upon the truncated sidewall of SiO2/SiNx multilayers. The SiNW array accomplishes a narrow diameter of Dnw = 28 ± 2.4 nm, NW-to-NW spacing of tsp = 40 nm, and extremely stable growth over Lnw > 50 μm and bending locations, which can compete with or even outperform the state-of-the-art top-down lithography and etching approaches, in terms of stacking number, channel uniformity at different levels, fabrication cost, and efficiency. These results provide a solid basis to establish a new 3D integration approach to batch-manufacture various advanced electronic and sensor applications.

Keywords: 3D growth integration; Si nanowire; in-plane solid−liquid−solid; stacked channels.