Wang Liming, Zhang Yichi, Sun Hao, You Jie, Miao Yuanhao, Dong Zuoru, Liu Tao, Jiang Zuimin, Hu Huiyong
Wide Bandgap Semiconductor Technology Disciplines State Key Laboratory, School of Microelectronics, Xidian University Xi'an 710071 China
School of Physics and Optoelectronic Engineering, Xidian University Xi'an 710071 China
Nanoscale Adv. 2020 Nov 19;3(4):997-1004. doi: 10.1039/d0na00680g. eCollection 2021 Feb 23.
Here, SiGeSn nanostructures were grown molecular beam epitaxy on a Si (111) substrate with the assistance of Sn droplets. Owing to the thermal effect and the compressive strain induced by a lattice mismatch, Si and Sn atoms were successfully incorporated into the Ge matrix during the Sn-guided Ge deposition process. A low growth temperature of 350 °C produced a variety of SiGeSn nanostructures of different sizes, attributed to the variation of the initial Sn droplet size. Using energy-dispersive X-ray spectroscopy, the Sn, Si and Ge contents of a defect-free SiGeSn nanoisland were approximately determined to be 0.05, 0.09 and 0.86, respectively. Furthermore, as the growth temperature increased past 600 °C, the growth direction of the nanostructure was changed thermally from out-of-plane to in-plane. Meanwhile, the stacked SiGeSn nanowires grown along the 〈112〉 direction remained defect-free, though some threading dislocations were observed in the smooth SiGeSn nanowires along the 〈110〉 direction. These results offer a novel method to grow Si-based SiGeSn nanostructures while possessing important implications for fabricating further optoelectronic devices.
在此，在锡液滴的辅助下，通过分子束外延在硅（111）衬底上生长了硅锗锡纳米结构。由于热效应和晶格失配引起的压缩应变，在锡引导的锗沉积过程中，硅和锡原子成功地掺入到锗基体中。350℃的低生长温度产生了各种不同尺寸的硅锗锡纳米结构，这归因于初始锡液滴尺寸的变化。使用能量色散X射线光谱法，确定无缺陷的硅锗锡纳米岛中的锡、硅和锗含量分别约为0.05、0.09和0.86。此外，当生长温度超过600℃时，纳米结构的生长方向从面外热转变为面内。同时，沿〈112〉方向生长的堆叠硅锗锡纳米线保持无缺陷，尽管在沿〈110〉方向的光滑硅锗锡纳米线中观察到一些位错。这些结果提供了一种生长硅基硅锗锡纳米结构的新方法，同时对制造进一步的光电器件具有重要意义。
