The integration of photonic elements with nitride optoelectronic structures allows control of emitted light properties, which is advantageous for achieving, e.g., a single wavelength lasing. Positioning of the photonic structures on the top surface of GaN‐based devices is problematic, in particular, for deposition of a metal contact to p‐type top layer. In this work, custom‐shaped submicron air channels arranged periodically 150 nm below the sample surface, forming an air/GaN diffraction grating embedded within a volume of the structure is proposed and fabricated. The fabrication process includes selective area Si ion implantation, GaN regrowth using plasma‐assisted molecular beam epitaxy, ultra‐high‐pressure annealing for efficient electrical activation of implanted Si without diffusion, and electrochemical etching for the removal of selectively doped material. Embedded air/GaN diffraction gratings with periodicity of 460 and 631 nm are shown. Width of air channels ranges from 46 to 320 nm. Angle and polarization resolved reflectivity measurements combined with theoretical modeling confirm the designed optical performance of the embedded diffraction gratings in the GaN volume. The presented design and fabrication of custom‐shaped, fully integrated photonic structures buried below the surface paves the way for novel type constructions of optoelectronic devices, such as compact distributed feedback laser diodes

中文翻译：

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用于光子应用的亚微米嵌入式空气/GaN 衍射光栅


光子元件与氮化物光电结构的集成允许控制发射光特性，这有利于实现单波长激光等。光子结构在基于 GaN 的器件顶面上的定位是有问题的，特别是对于金属触点到 p 型顶层的沉积。在这项工作中，提出并制造了定制形状的亚微米空气通道，周期性地排列在样品表面以下 150 nm 处，形成嵌入结构体积内的空气/GaN 衍射光栅。制造工艺包括选择性区域 Si 离子注入、使用等离子体辅助分子束外延的 GaN 再生、用于高效电活化注入 Si 而不扩散的超高压退火，以及用于去除选择性掺杂材料的电化学蚀刻。图中显示了周期性为 460 和 631 nm 的嵌入式空气/GaN 衍射光栅。空气通道的宽度范围为 46 至 320 nm。角度和偏振分辨反射率测量与理论建模相结合，证实了 GaN 体积中嵌入式衍射光栅的设计光学性能。所提出的定制形状、完全集成的光子结构的设计和制造埋在表面以下，为新型光电器件的结构铺平了道路，例如紧凑型分布式反馈半导体激光管