Ion Mixing As A Processing Technique For Monolithic And And Array Integration of Photonic Devices

由于光子器件集成对光通信系统的影响，近年来，光子器件集成已成为研究的热点。然而，由于各种光子器件的功能和操作模式的多样性，涉及光子集成的制造工艺的发展并非微不足道。由于这些要求，许多光子器件结构对单片制造的兼容性很差。有一个重要的需要，以发展更好的大规模制造工艺，以促进光子集成。我们建议研究离子混合作为由量子阱和超晶格结构组成的光子器件的平面集成过程。作为一种加工技术，离子混合具有许多优点：(i)该过程可以在足够低的温度下进行，以允许自对准过程；（ii）用于自对准目的的金属离子掩膜可以用作器件的电极；（iii）易于获得的稀有气体离子与具有相似原子质量的浅掺杂离子一样有效，可以引起无序。（iv）明智选择的离子可用于诱导无序，同时提高器件隔离。然而，在离子混合成为光子集成的有用过程之前，有几个问题需要解决。第一个问题是在微观层面上理解混合过程，以便将半导体材料的混合及其性质（如带隙、光学指数）与是否涉及应变联系起来。二是离子辐照对材料的损伤，离子辐照对材料的输运和光学性能都有影响。将这种损伤降低到光子集成可接受的水平的方法将在本研究中进行研究。第三个问题是研究离子混合如何用于形成激光波导，这是光子技术的关键组成部分。第四个问题是研究离子混合在改进异质结双极晶体管中的应用。为了解决这些问题，拟议的计划有以下目标：(i)离子混合过程控制的研究，特别是将离子辐照损伤降低到光子器件可接受的水平；（ii）如果制造平面条纹折射率制导激光器，则通过离子混合使器件平面化，其初始目标为(2)；（iii）通过离子混合实现单片器件集成，推动调制器/激光器和激光器/HBT集成。

Integration of photonic devices has been the subject of much research interest in recent years due to its implications for optical communication systems. However, the development of the fabrication processes involved in photonic integration has not been trivial due largely to the diversity in functions and consequently modes of operation of various photonic devices. Because of these requirements, many photonic device structures have poor compatibility for monolithic fabrication. There is an important need to develop better large scale manufacturable processes to facilitate photonic integration. We propose to investigate ion mixing as a process for planar integration of photonic devices made of quantum-well and superlattice structures. As a processing technique, ion mixing offers many advantages: (i) the process can be carried out at sufficiently low temperatures to allow for a self-aligned process, (ii) metallic ion masks for self-alignment purposes can serve as electrodes for devices, (iii) readily available noble gas ions are just as efficient as shallow dopant ions with similar atomic mass in causing disordering, and (iv) judiciously chosen ions can be used to induce disordering and to improve device isolation simultaneously. However, there are several issues that need to be resolved before ion-mixing becomes a useful process for photonic integration. The first issue is to understand the mixing process at a microscopic level so as to relate the intermixing of semiconductor materials and their properties such as bandgap, optical index, with or without strain involved. The second has to do with the material damage caused by ion-irradiation which can affect both the transport and the optical properties. Approaches to reduce this damage to a level acceptable to photonic integration will be investigated in this study. The third issue is to study how ion-mixing can be used in the formation of laser waveguide, a critical component of photonic technology. A fourth issue is to investigate the use of ion mixing in the improvement of heterojunction bipolar transistors. To address these issues, the proposed program has the following objectives: (i) investigation of process control of ion mixing, particularly the reduction of ion irradiation damage to a level acceptable for photonic devices, (ii) the planarization of devices by ion mixing with an initial (2) goal if fabricating planar stripe index guided lasers, and (iii) monolithic device integration by ion mixing, driving toward modulator/laser and laser/HBT integration.