CDT Compound Semiconductor Physics (PhD Progression 1+3)

人们对光子集成电路(PIC)的需求越来越大，以推动传感、数据通信和人工智能技术的发展。它们依赖于包含无源和有源化合物半导体元件的复杂光学电路，这些元件密集地封装在晶片上。PIC的效率和功能在很大程度上取决于构建块的体系结构以及它们的连接方式。这里的结构将基于磷化铟(InP)材料系统；历史上，这种材料系统被广泛用于在通信带宽上产生、检测和放大光。在这个项目中，将开发高密度PIC和复杂外延结构的制造，例如用于量子级联激光器(QCL)的那些。随着技术的成熟，制造业的规模和复杂性自然会增加。这给工艺带来了挑战，特别是对InP来说，这个项目将集中在包含高密度微/纳米结构的PIC的尺度和功能上，例如高深宽比光栅和波导，研究掺杂和成分对刻蚀轮廓的影响。对于某些部件，如激光器或光学放大器，将需要应用高/低反射率(HR/AR)的薄膜涂层，并将研究将这些薄膜作为晶片规模加工的一部分的方法。

There is an increasing need for photonic integrated circuits (PICs) to advance technologies in sensing, datacoms and AI. These rely on complex optical circuitry containing passive and active compound semiconductor components, densely packed onto a wafer. The efficiency and functionality of the PIC depends strongly on the architecture of the building blocks and how they are connected. The structures here will be based on the indium phosphide (InP) material system; historically this has been widely used for generation, detection and amplification of light at the communication bandwidths. Versatile yet robust fabrication methods are required and in this project, fabrication of high-density PICs and complex epitaxial structures such as those used in quantum cascade lasers (QCLs) will be developed. As technology matures, the scale and complexity of manufacturing naturally increases. This presents processing challenges, particularly for InP, and this project will focus on the scaling and functionality of PICs which contain a high-density of micro/nano-structures, e.g. high aspect-ratio gratings and waveguides, studying the impact of dopants and composition on etching profiles. For certain components such as lasers or optical amplifiers, the application of thin-film coatings for high/low reflectivity (HR/AR) will be required and methods to apply these films as part of wafer-scale processing will be investigated.