Center of Nanoelectronics and School of Microelectronics, Shandong University , Jinan 250100, PR China.
Key Laboratory of Modern Acoustics, MOE, Institute of Acoustics, Collaborative Innovation Center of Advanced Microstructures, National Laboratory of Solid State Microstructures, Nanjing University , Nanjing 210093, PR China.
ACS Nano. 2017 Apr 25;11(4):4237-4246. doi: 10.1021/acsnano.7b01217. Epub 2017 Apr 5.
Using CMOS-compatible Pd catalysts, we demonstrated the formation of high-mobility ⟨111⟩-oriented GaSb nanowires (NWs) via vapor-solid-solid (VSS) growth by surfactant-assisted chemical vapor deposition through a complementary experimental and theoretical approach. In contrast to NWs formed by the conventional vapor-liquid-solid (VLS) mechanism, cylindrical-shaped PdGa catalytic seeds were present in our Pd-catalyzed VSS-NWs. As solid catalysts, stoichiometric PdGa was found to have the lowest crystal surface energy and thus giving rise to a minimal surface diffusion as well as an optimal in-plane interface orientation at the seed/NW interface for efficient epitaxial NW nucleation. These VSS characteristics led to the growth of slender NWs with diameters down to 26.9 ± 3.5 nm. Over 95% high crystalline quality NWs were grown in ⟨111⟩ orientation for a wide diameter range of between 10 and 70 nm. Back-gated field-effect transistors (FETs) fabricated using the Pd-catalyzed GaSb NWs exhibit a superior peak hole mobility of ∼330 cm V s, close to the mobility limit for a NW channel diameter of ∼30 nm with a free carrier concentration of ∼10 cm. This suggests that the NWs have excellent homogeneity in phase purity, growth orientation, surface morphology and electrical characteristics. Contact printing process was also used to fabricate large-scale assembly of Pd-catalyzed GaSb NW parallel arrays, confirming the potential constructions and applications of these high-performance electronic devices.
我们使用与 CMOS 兼容的 Pd 催化剂，通过表面活性剂辅助的化学气相沉积法，采用互补的实验和理论方法，实现了通过 VSS 生长形成具有高迁移率的〈111〉取向 GaSb 纳米线（NWs）。与通过传统的 VLS 机制形成的 NWs 相比，我们在 Pd 催化的 VSS-NWs 中存在圆柱形 PdGa 催化种子。作为固态催化剂，发现化学计量的 PdGa 具有最低的晶体表面能，因此在种子/NW 界面处具有最小的表面扩散和最佳的面内界面取向，有利于高效的外延 NW 成核。这些 VSS 特性导致生长出直径低至 26.9 ± 3.5 nm 的细 NWs。超过 95%的高结晶质量 NWs 在〈111〉取向生长，直径范围很宽，在 10 到 70 nm 之间。使用 Pd 催化的 GaSb NW 制造的背栅场效应晶体管（FET）表现出约 330 cm V s 的卓越峰值空穴迁移率，接近具有约 30nm 直径的 NW 沟道的迁移率极限，载流子浓度约为 10 cm。这表明 NWs 在相纯度、生长取向、表面形貌和电特性方面具有优异的均一性。接触印刷工艺也被用于制造 Pd 催化的 GaSb NW 平行阵列的大规模组装，证实了这些高性能电子器件的潜在结构和应用。
