Van der Waals Epitaxial Growth of Ultrathin Indium Antimonide on Arbitrary Substrates through Low‐Thermal Budget

Abstract

AbstractIII–V semiconductors possess high mobility, high frequency response, and detection sensitivity, making them potentially attractive for beyond‐silicon electronics applications. However, the traditional heteroepitaxy of III–V semiconductors is impeded by a significant lattice mismatch and the necessity for extreme vacuum and high temperature conditions, thereby impeding their in situ compatibility with flexible substrates and silicon‐based circuits. In this study, a novel approach is presented for fabricating ultrathin InSb single‐crystal nanosheets on arbitrary substrates with a thickness as thin as 2.4 nm using low‐thermal‐budget van der Waals (vdW) epitaxy through chemical vapor deposition (CVD). In particular, in situ growth has been successfully achieved on both silicon‐based substrates and flexible polyimide (PI) substrates. Notably, the growth temperature required for InSb nanosheets (240 °C) is significantly lower than that employed in back‐end‐of‐line processes (400 °C). The field effect transistor devices based on fabricated ultrathin InSb nanosheets exhibit ultra‐high on‐off ratio exceeding 108 and demonstrate minimal gate leakage currents. Furthermore, these ultrathin InSb nanosheets display p‐type characteristics with hole mobilities reaching up to 203 cm2 V−1 s−1 at room temperatures. This study paves the way for achieving heterogeneous integration of III–V semiconductors and facilitating their application in flexible electronics.