High-fidelity moulding growth and cross-section shaping of ultrathin monocrystalline silicon nanowires

Catalytic growth of ultrathin silicon nanowires (SiNWs) provides ideal 1D channel materials for the construction of high-performance field effect transistors, where the diameter, uniformity and crystalline qualities are of utmost importance. In this work, a high-fidelity moulding growth of orderly ultrathin monocrystalline SiNWs, with diameter of 17±2nm, has been accomplished within tightly confined nanogrooves. A continuous and deterministic groove-width-transition or squeezing strategy has also been developed to accomplish an effective cross-section tailoring of the as-grown SiNW channels, while enabling a close-to-unity growth filling rate within the guiding grooves. Finally, a size-dependent adatom-searching model is proposed to explain how a monocrystalline SiNWs can be obtained even at such a low growth temperature of < 350 ℃. These results indicate a feasible catalytic growth fabrication route to implement monolithic 3D integration of advanced in-memory-computing and neuromorphic electronics.