Selective area epitaxy of GaAs: the unintuitive role of feature size and pitch
Selective area epitaxy of GaAs: the unintuitive role of feature size and pitch
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DOI：
10.1088/1361-6528/ac88d9
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发表时间：
2022-11-26
期刊：
影响因子：
3.5
通讯作者：
Morral, Anna Fontcuberta i
中科院分区：
文献类型：
--
作者：
Dede, Didem;Glas, Frank;Morral, Anna Fontcuberta i
选择性区域外延（SAE）提供了用于在设备兼容配置中可缩放地制造半导体纳米结构的路径。在当前的范例中，SAE被理解为局部外延，并且通过结合平面和自组装纳米线生长机制来建模。在这里，我们使用GaAs SAE作为一个模型系统，以提供不同的观点。首先，我们提供的退火阶段在计算的增长率的显着影响的证据。然后，通过阐明几何约束对半导体晶体生长的影响，我们证明了吸附原子的解吸和吸收的作用超出了直接碰撞和扩散限制制度。我们的理论模型解释了这些约束对增长的影响，特别是为什么SAE的增长率是高度敏感的图案的几何形状。最后，在最大间距点的模型的分歧，以不可忽略的多个吸附原子图案化的功能之间的再循环。总的来说，我们的研究结果指出了在设计SAE图案以在晶片上创建预定的纳米级结构时考虑吸附原子扩散、吸附和解吸动力学的重要性。这些结果是SAE工艺在半导体工业中可行的基础。
Selective area epitaxy (SAE) provides the path for scalable fabrication of semiconductor nanostructures in a device-compatible configuration. In the current paradigm, SAE is understood as localized epitaxy, and is modelled by combining planar and self-assembled nanowire growth mechanisms. Here we use GaAs SAE as a model system to provide a different perspective. First, we provide evidence of the significant impact of the annealing stage in the calculation of the growth rates. Then, by elucidating the effect of geometrical constraints on the growth of the semiconductor crystal, we demonstrate the role of adatom desorption and resorption beyond the direct-impingement and diffusion-limited regime. Our theoretical model explains the effect of these constraints on the growth, and in particular why the SAE growth rate is highly sensitive to the pattern geometry. Finally, the disagreement of the model at the largest pitch points to non-negligible multiple adatom recycling between patterned features. Overall, our findings point out the importance of considering adatom diffusion, adsorption and desorption dynamics in designing the SAE pattern to create pre-determined nanoscale structures across a wafer. These results are fundamental for the SAE process to become viable in the semiconductor industry.