Heteroepitaxial Writing of Silicon-on-Sapphire Nanowires

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• 作者：Mingkun Xu ; Zhaoguo Xue ; Jimmy Wang ; Yaolong Zhao ; Yao Duan ; Guangyao Zhu ; Linwei Yu ; Jun Xu ; Junzhuan Wang ; Yi Shi ; Kunji Chen ; Pere Roca i Cabarrocas
• 刊名：Nano Letters
• 出版年：2016
• 出版时间：December 14, 2016
• 年：2016
• 卷：16
• 期：12
• 页码：7317-7324
• 全文大小：690K
• ISSN：1530-6992

文摘

The heteroepitaxial growth of crystal silicon thin films on sapphire, usually referred to as SoS, has been a key technology for high-speed mixed-signal integrated circuits and processors. Here, we report a novel nanoscale SoS heteroepitaxial growth that resembles the in-plane writing of self-aligned silicon nanowires (SiNWs) on R-plane sapphire. During a low-temperature growth at <350 °C, compared to that required for conventional SoS fabrication at >900 °C, the bottom heterointerface cultivates crystalline Si pyramid seeds within the catalyst droplet, while the vertical SiNW/catalyst interface subsequently threads the seeds into continuous nanowires, producing self-oriented in-plane SiNWs that follow a set of crystallographic directions of the sapphire substrate. Despite the low-temperature fabrication process, the field effect transistors built on the SoS-SiNWs demonstrate a high on/off ratio of >5 × 10⁴ and a peak hole mobility of >50 cm²/V·s. These results indicate the novel potential of deploying in-plane SoS nanowire channels in places that require high-performance nanoelectronics and optoelectronics with a drastically reduced thermal budget and a simplified manufacturing procedure.