New strategies for dislocation density reduction in monolithic III/V epitaxy on Si

降低 Si 上单片 III/V 族外延位错密度的新策略

• 批准号: 446180337
• 负责人: Dr. Achim Trampert
• 金额: --
• 依托单位: Abteilung für Mikrostruktur
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/446180337?language=en
• 关键词: New; strategies; dislocation; density; reduction

The combination of the Silicon technology with III-V semiconductors is expected to have a major impact for the realization of high-volume / low-cost integrated circuits. Photonic chips based on the already mature Silicon photonics capabilities together with integrated III-V lasers or photodetectors will soon be the foreground for optical-interconnects or lab-on-chip sensors. While heterogeneous integration - where the III-V device or material is bonded to the Si circuit - already showed promising results, a more direct integration scheme is highly desirable in order to improve the yield, the integration density and to decrease the cost of devices. In this context, the monolithic integration by epitaxial growth of high-quality III-V heterostructures directly on Si has been intensively pursued in the past decade. The main challenge remains a drastic reduction of the threading dislocation density (TDD). These line defects are created at the III-V/Si interface due to the large lattice-mismatch and propagate through the epilayers, severely degrading the device performance and lifetime. Despite a considerable amount of work over the past years, TDDs in the range of 109 to 1010 /cm2 are still generally present after growth of about 1 micrometer of III-V material. We propose to explore a radically new design and growth strategy with the main objective to reduce TDDs down to below 105 /cm2. The groundbreaking concept in this project is to initiate in a controlled manner the interaction between on the one hand threading dislocations and, on the other hand, other types of extended defects such as anti-phase boundaries or misfit dislocation arrays at interfaces between specially designed interlayers. These interlayers can be inserted directly at the III V/Si interface or inside the III-V buffer layer and should act as sink for the threading defects. To this end, MBE growth strategies and new structure designs will be proposed by the French group thanks to an extensive study by advanced transmission electron microscopy techniques of dedicated samples carried out by the German group. The progress made on the TDD reduction will be assessed by the fabrication and testing of lasers demonstrating the impact of the proposed project. The III-V material used here will be GaSb, which can readily serve as a starting point for many optoelectronic devices in the mid- to far-infrared. Even so, the filter design rules derived on the basis of detailed microstructure analysis as well as the growth techniques developed throughout the project are expected to be applicable to other compound semiconductor families and have consequently a major impact on a wide range of applications from data/tele-communication to sensing among others. Furthermore, the developed methodology of dynamic microscopy in three dimensions is in itself an important step towards a complete and efficient determination of the structure-function relationship which can be applied to many materials combinations.

硅技术与III-V族半导体的结合预计将对实现大批量/低成本集成电路产生重大影响。基于已经成熟的硅光子学能力的光子芯片以及集成的III-V激光器或光电探测器将很快成为光学互连或芯片实验室传感器的前景。虽然异质集成（其中III-V器件或材料接合到Si电路）已经显示出有希望的结果，但是为了提高产量、集成密度并降低器件的成本，更直接的集成方案是非常期望的。在此背景下，在过去的十年中，通过直接在Si上外延生长高质量III-V族异质结构的单片集成一直在积极追求。主要的挑战仍然是大幅减少螺纹位错密度（TDD）。由于大的晶格失配，这些线缺陷在III-V/Si界面处产生并通过外延层传播，严重降低了器件性能和寿命。尽管在过去几年中进行了大量的工作，但在生长约1微米的III-V材料之后，通常仍然存在109至1010 /cm 2范围内的TDD。我们建议探索一种全新的设计和增长策略，主要目标是将TDD降低到105 /cm 2以下。该项目的突破性概念是以受控的方式启动一方面螺纹位错和另一方面其他类型的扩展缺陷（如反相边界或特别设计的夹层之间的界面处的错配位错阵列）之间的相互作用。这些中间层可以直接插入在III-V/Si界面处或III-V缓冲层内部，并且应该充当穿透缺陷的汇。为此，法国集团将提出MBE增长战略和新的结构设计，这要归功于德国集团对专用样品进行的先进透射电子显微镜技术的广泛研究。减少TDD的进展将通过制造和测试激光器来评估，以证明拟议项目的影响。这里使用的III-V材料将是GaSb，它可以很容易地作为许多中红外到远红外光电器件的起点。即便如此，根据详细的微观结构分析以及整个项目开发的生长技术得出的滤波器设计规则预计将适用于其他化合物半导体家族，并因此对从数据/远程通信到传感等广泛的应用产生重大影响。此外，在三维动态显微镜的开发方法本身是一个重要的一步，走向一个完整的和有效的确定的结构-功能关系，可以应用于许多材料的组合。