In-situ Growth of Indium Arsenide/Antimonide Long Wavelength Photodiodes

InAsSb应变超晶格（SSL）和在硅（Si）上原位形成光电二极管的新技术具有制造可生产的长波红外（L-WIR）光电二极管的潜力，可用于各种和军事应用。在第一阶段的SBIR计划中，研究了SSL在Si上的分子束外延生长（MBE），旨在制造可生产的LWIR阵列。这是在第一阶段完成的：(1)所有与MBE系统兼容的MBE修改都已设计完成，其中一些已减少到实际应用；(2)描述了生长晶格匹配缓冲器、SSL和光结的MBE过程；(3)在Si上生长高质量缓冲层和InAsSb外延层的可行性已被大量MBE生长试验证明；(4)制定了二期工程的详细规划。所进行的MBE生长运行始终产生良好的外延生长，表现为有序的反射高能电子衍射（RHEED）模式，高生长稳定性，镜面状表面形貌和高载流子迁移率。这些运行减少了高风险因素，增加了第二期成功的可能性。第二阶段的第一个目标是优化缓冲液和InAsSb SSL的生长，以建立12微米的截止波长。第二个目标是利用MBE开发光电二极管探测器。在硅基上开发一种特殊的用于匹配缺陷阻挡的缓冲层，然后在缓冲层上生长SSL，随后建立光电二极管的原位生长。低缺陷SSL将提供高的探测器性能，生产效率和均匀性，而顺序多层生长将产生一个直接的原位光电二极管形成过程。

The new technology of strained superlattice (SSL) of InAsSb and in- situ formation of photodiode on silicon (Si) has the potential of fabricating producible long-wavelength infrared (L-WIR) photodiodes for diverse and military applications. An investigation on the molecular beam epitaxial (MBE) growth of the SSL on Si has been made in a phase I SBIR program, aimed at fabricating producible LWIR arrays. This was accomplished in phase I: (1) all required MBE modifications compatible to the MBE system have been designed and some have been reduced to practice; (2) the MBE processes for growing a lattice-matching buffer, SSL and photojunction have been delineated; (3) the feasibility of growing high quality buffer and InAsSb epitaxial layers on Si has been demonstrated by numerous MBE growth runs; and (4) a detailed plan for phase II has been established. The MBE growth runs performed have consistently produced good epitaxial growth, manifested by well-ordered reflective high energy electron diffraction (RHEED) patterns, high growth stability, mirror-like surface morphology and high carrier mobility. These runs have reduced the high risk elements and increase the probability of success of phase II. The first goal in phase II is to optimize the growth of the buffer and InAsSb SSL to establish a cutoff wavelength of 12 microns. Second goal is to develop the photodiode detector using MBE. A special buffer on Si for lattice matching an defect blocking will be developed then the growth of SSL on the buffer, followed by the in-situ growth of the photodiodes will be established. The low- defect SSL will provide high detector performance, producibility and uniformity, while the sequential multilayer growth will produce a straightforward in-situ photodiode formation process.