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 Si_0.5Ge_0.5 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 (100–500 nm). 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.

先进的固态设备，包括激光器和调制器，需要半导体异质结构来实现电子带隙和折射率的纳米级工程。然而，现有的外延生长方法仅限于制造逐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方法的相场建模与热毛细管对流来研究硅锗薄膜内平面异质结构的激光刻字。该建模得到了使用外延生长的 Si _0.5 Ge _{0.5 的}实验工作的支持层。相场模拟表明，通过调制扫描速度、功率和光束位置来控制相分离，可以制造具有单个或周期性界面的各种面内异质结构。光学模拟用于证明两种器件的潜力：具有富锗 (>70%) 芯的渐变折射率波导和具有纳米级周期 (100-500 nm) 的波导布拉格光栅。通过亚毫秒级调制激光参数形成周期性异质结构，为半导体合金薄膜中面内量子阱和超晶格的后生长制造开辟了道路。