New Avalanche Photodiodes for Fiberoptics Applications

在光纤通信系统中，检测器是 的主要组成部分。 目前，Ge和GaInAs p-i-n和 雪崩光电二极管（APD）是主要的探测器， 应用程序. 然而，雪崩增益相当的APD 并且对于Si APD的噪声系数仍然不可用。 碲镉汞， 由于其可控的低掺杂、高倍增 增益超过50，k值高（8-12，对比度0.3-2 对于Ge和GaInAs），可能是有希望的 制作高性能APD的材料。 第一阶段 该计划研究了使用液相的可行性 外延（LPE）和金属有机化学气相沉积 （MOCVD）方法来产生常规APD和阶梯APD。 结果表明，特别是LPE产生的常规APD， 超出了节目预期。 这些特征 APD不仅比最近报道的要好得多， HgCdTe APD由其他方法制成，但也具有可比性或 优于Ge和GaInAs APD的报道。 然而，在这方面， 在HgCdTe APD投入商业应用之前， 必须解决潜在的问题。 因此，在本阶段 二方案，提出解决这些问题， 生产高质量的HgCdTe APD原型用于商业 应用程序. 具体目标包括：（1）实现低 串联电阻，（2）可靠性测试，（3）增加 形成保护环 （5）分析其它器件结构。 本研究主要针对光束的转换 信息转化为可用的电信号。 这种转换 是光波通信系统的核心 它不仅是 重要的是要做到这一点，以良好的效率，但它也必须是 尽可能地减少噪音。 该特定 研究将利用一种 制造这种电转换器的特定材料 或“探测器”，其特性上级现有技术 从其他材料。

In fiberoptics communication systems, detectors are one of the major components. Currently, Ge and GaInAs p-i-n and avalanche photodiodes (APD) are the major detectors for this application. However, an APD with comparable avalanche gain and noise figure to a Si APD is still not available. HgCdTe, because of its controllable low doping, high multiplication gain of over 50, and a high k value (8-12 in contrast of 0.3-2 for Ge and GaInAs), is potentially one of the promising materials for making high performance APD. Phase I of this program investigated the feasibility of using liquid phase epitaxy (LPE) and metal-organic chemical vapor deposition (MOCVD) methods to produce conventional APD and staircase APD. The results, especially the conventional APD produced by LPE, exceeded the program expectation. The characteristics of these APD are not only much better than those recently reported on HgCdTe APD made by other methods, but are also comparable or better than those reported on Ge and GaInAs APD. However, before the HgCdTe APD is used commercially, a number of potential problems have to be solved. Therefore, in this Phase II program, it is proposed to solve these problems and to produce a prototype high quality HgCdTe APD for commercial application. The specific goals include (1) Achieving a low series resistance, (2) Reliability test, (3) Increasing the bandgap of the window layer, (4) Forming a guard ring structure, and (5) Analyzing other device structures. This research addresses the conversion of light beam information into useable electrical signals. This conversion is central to lightwave communication systems. Not only is it important to do this with good efficiency, but it must also be done with as little noise as it possible. This particular research will exploit the demonstrated characteristics of a particular material in which to make such electrical convertors or "detectors" with characteristics superior to those available from other materials.