Abstract Compositionally-graded InAs1−ySby metamorphic buffers, grown on GaSb wafers via metal organic chemical vapor deposition and designed to serve as virtual substrates for InAs0.6Sb0.4 long wave infrared detectors, were investigated for their potential to provide low residual threading dislocation densities. Structural properties of a range of step-graded buffer designs, including surface morphology, strain relaxation, and residual threading dislocation density were investigated as a function of substrate orientation, initial layer composition (lattice mismatch), grading rate, and compositional step size and thickness, and used to guide optimization of the metamorphic buffer structure. A minimum threading dislocation density of 2 × 106 cm−2 within the InAs0.6Sb0.4 terminal layer was achieved through use of a 7-layer buffer design with a strain grading rate of −0.78% μm−1, with potential for further reduction by continued optimization and interfacial control.

中文翻译：

---

通过 MOCVD 生长的 InAs1-ySby 虚拟衬底用于长波红外探测器

摘要 通过金属有机化学气相沉积在 GaSb 晶片上生长并设计用作 InAs0.6Sb0.4 长波红外探测器的虚拟衬底的成分分级 InAs1−ySby 变质缓冲液，研究了它们提供低残留螺纹位错密度的潜力. 研究了一系列阶梯式缓冲设计的结构特性，包括表面形态、应变弛豫和残余螺纹位错密度，作为衬底方向、初始层组成（晶格失配）、分级速率以及组成步长和厚度的函数，并用于指导优化变形缓冲区结构。InAs0.6Sb0 内的最小穿透位错密度为 2 × 106 cm-2。