Photonic integration using Laser interference structured substrates

在单个衬底上集成不同的半导体材料是未来电子和光子器件非常需要的。特别是，在工业衬底硅上集成III-V半导体将利用基于硅的低成本、大晶片尺寸和出色的可制造性的现有电子器件概念的好处，III-V材料具有优异的电子和光子性能。然而，由于晶体尺寸和其他特性的不同，材料集成多年来一直是一个挑战，这些不同的材料需要在这些材料的界面处适应而不会传播到III-V层。为了解决这个问题，我们提出了一种激进的方法，使用基于直接激光干涉的创新的硅衬底纳米结构工艺将III-V材料单片集成到硅衬底上。该方法将平面硅表面转换为高度结构化的阵列，可以适应晶体大小和类型的差异。这种新颖的方法有可能利用基于硅的平台上的III-V器件的单片集成的好处，这是下一代光子集成电路、III-V CMOS和量子器件的基本要求。这个项目是高风险-高回报的，基于对先前项目的附带观察。有一些原则上的证据，但总体方法还有待充分探索。如果成功，这可能最终解决高度不匹配的外延问题，并对行业产生转型影响，打开在行业选择的衬底上集成各种替代材料的前景。该提案寻求开发这种方法，以在硅上产生高质量的III-V缓冲层。在这些III-V层上，我们将生长、制造和测试激光和太阳能电池等光子器件。激光操作的演示是芯片外光学互连到CMOS光互连的关键设备演示，实现了单个处理器之间更快的连接，并克服了限制下一代计算性能的主要瓶颈。该多结太阳能电池结合了硅的吸收结和至少两个III-V结。半导体多结电池提供了所有光伏中最高的量子效率，有可能走得更远，超过50%。然而，目前的技术手段意味着这些电池对于消费者来说太昂贵了。我们相信，我们有潜力通过我们的现场生产的结构化衬底来提供一种成本更低的方法，如果成功，这可能会给太阳能发电带来革命性的变化。

The integration of diverse semiconductor materials on a single substrate is highly desirable for future electronic and photonic devices. In particular, the integration of III-V semiconductors on silicon, the industry substrate of choice, would leverage the benefits of existing electronic device concepts based on the low-cost, large wafer size and the excellent manufacturability of silicon with III-V materials offering superior electronic and photonic performance However materials integration has remained a challenge over many years due to dissimilarities in the crystal size and other properties which need to be accommodated at the interface of these materials without propagating into the III-V layer.To address this issue, we propose a radical method to monolithically integrate III-V materials onto silicon substrates using an innovative silicon substrate nanostructuring process based on direct laser interference. The approach transforms the planar silicon surface into a highly structured array which can accommodate the differences between crystal size and type. This novel approach has potential to leverage the benefits of the monolithic integration of III-V devices on a Si-based platform, which is an essential requirement for next-generation photonic integrated circuits, III-V CMOS, and quantum devices. The project is high risk-high reward, based on incidental observations from a previous project. Some proof of principle exists, but the overall approach is yet to be fully explored. If successful, this could finally solve the problem of highly mismatched epitaxy and have transformational impact on industry, opening the prospect of integration of a wide range of alternative materials on the substrate of industry choice. The proposal seeks to develop this approach to produce high quality III-V buffer layers onto silicon. On to these III-V layers we will grow, fabricate, and test photonic devices such as laser and solar cells. The demonstration of laser operation is a critical device demonstration for off-chip optical interconnects to CMOS enabling faster connection between individual processors and overcoming a major bottleneck which will limit next-generation computing performance. The multijunction solar cell combines absorbing junctions of silicon and at least two III-V junctions. Semiconductor multijunction cells offer the highest quantum efficiency of all photovoltaics, with potential to go further and exceed 50%. However, the current technology approach means that these cells are far too expensive for consumer use. We believe we have the potential to provide a lower cost approach through our in-situ produced structured substrates, which if successful could revolutionise solar energy generation.