Quasi-one-dimensional silicon nanowires (Si NWs), fabricated via catalytic approaches, are favorable building blocks to explore a new generation of high-performance nanoelectronics for large area display and sensor applications, thanks to their high aspect-ratio and excellent electrostatic control capability. In addition, if the line-shape or geometry of these slim SiNWs is precisely designable in a deterministic manner, these 1D nanostructures can even morph into various biomimetic micro robotics, to carry out a series of dexterous finger-like maneuvers. However, it is usually difficult for the conventional catalytic growth mechanisms of SiNWs, for example via the famous vapor-liquid-solid (VLS) approach, to produce orderly array of ultrathin SiNWs as planar 1D channels for scalable electronics, not to mention achieving a programmable growth fabrication of robotic complexity out of a single run of SiNW growth.   

In this talk, we will present a relatively new in-plane solid-liquid-solid (IPSLS) growth mechanism [1-2], with metallic catalyst droplets consuming surface-coating amorphous Si (a-Si) precursor layer to produce planar crystalline SiNWs. Interestingly, this IPSLS growth can be easily guided by surface step edges or sidewall grooves, which provides a key capability to integrate ultrathin SiNWs, with CD<10 nm, into orderly high-density array on substrate surface or stacked horizontally on the vertical sidewalls [3-4]. Based on these designable SiNW channels, high performance FET devices were successfully demonstrated, with high Ion/Ioff current >10^7 and subthreshold swing <100 mV/dec. In addition, the line-shape of SiNWs can be reliably tailored into a series of flexible and functional electro-nanomechanical structures to demonstrate the smallest mechanical slingshot and accomplish dexterous finger-like robotic operations under vectorial Lorentz force driving [5].   

 

1.        Linwei Yu,^* Pere Roca i Cabarrocas et al. Physical Review Letters, 102, 125501 (2009)

2.        Ying Sun, Taige Dong, Linwei Yu^*, Jun Xu^* et al., Advanced Materials 31, 1903945 (2020) 

3.        Ruijin Hu, Junzhuan Wang*, Linwei Yu* et al., Nano Letters 20, 7489 (2020)

4.        Ruijin Hu, Linwei Yu* et al., Small 18, 2204390 (2022) 

5.        Jiang Yan, Zongguang Liu*, Linwei Yu* and et al. Nature Communications 14, 3786 (2023)