Non-isothermal phase-field simulations of laser-written in-plane SiGe heterostructures for photonic applications
Non-isothermal phase-field simulations of laser-written in-plane SiGe heterostructures for photonic applications
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DOI：
10.1038/s42005-021-00632-1
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发表时间：
2021-06-11
影响因子：
5.5
通讯作者：
Peacock, Anna C.
中科院分区：
文献类型：
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作者：
Aktas, Ozan;Yamamoto, Yuji;Peacock, Anna C.
先进的固体器件，包括激光器和调制器，需要半导体异质结构的纳米级工程的电子带隙和折射率。然而，现有的外延生长方法仅限于制造一层一层生长的垂直异质结构。在这里，我们报告了使用基于有限元法的相场建模和热毛细管对流来研究硅锗薄膜内平面异质结构的激光刻蚀。使用外延生长的Si0.5Ge0.5层的实验工作支持了该模型。相场模拟表明，通过调制扫描速度、功率和波束位置来控制相偏析，可以制备出具有单界面或周期界面的多种平面内异质结构。光学模拟用于证明两种器件的潜力：具有富锗（>70%）核心的渐变折射率波导和具有纳米尺度周期（100-500nm）的波导布拉格光栅。通过亚毫秒调制激光参数形成周期性异质结构，为半导体合金薄膜中平面内量子阱和超晶格的后生加工开辟了一条途径。先进半导体器件的设计和构造依赖于具有空间工程成分的纳米结构的形成。本文作者利用相场模拟结合实验数据，了解了如何通过激光加工控制和利用SiGe合金中的相偏析来制备平面内异质结构。
Advanced solid-state devices, including lasers and modulators, require semiconductor heterostructures for nanoscale engineering of the electronic bandgap and refractive index. However, existing epitaxial growth methods are limited to fabrication of vertical heterostructures grown layer by layer. Here, we report the use of finite-element-method-based phase-field modelling with thermocapillary convection to investigate laser inscription of in-plane heterostructures within silicon-germanium films. The modelling is supported by experimental work using epitaxially-grown Si0.5Ge0.5 layers. The phase-field simulations reveal that various in-plane heterostructures with single or periodic interfaces can be fabricated by controlling phase segregation through modulation of the scan speed, power, and beam position. Optical simulations are used to demonstrate the potential for two devices: graded-index waveguides with Ge-rich (>70%) cores, and waveguide Bragg gratings with nanoscale periods (100-500nm). Periodic heterostructure formation via sub-millisecond modulation of the laser parameters opens a route for post-growth fabrication of in-plane quantum wells and superlattices in semiconductor alloy films. The design and construction of advanced semiconductor devices relies on the formation of nanostructures with spatially engineered compositions. Here, the authors use phase-field simulations combined with experimental data to understand how to control and utilise phase segregation in SiGe alloys by laser processing for fabrication of in-plane heterostructures.