Abstract We report on the growth of high quality GaSb-based AlInAsSb quaternary alloy by molecular beam epitaxy (MBE) to fabricate avalanche photodiodes (APDs). By means of high resolution X-ray diffraction (HRXRD) and scanning transmission electron microscope (STEM), phase separation phenomenon of AlInAsSb random alloy with naturally occurring vertical superlattice configuration was demonstrated. To overcome the tendency for phase segregation while maintaining a highly crystalline film, a digital alloy technique with migration-enhanced epitaxy growth method was employed, using a shutter sequence of AlSb, AlAs, AlSb, Sb, In, InAs, In, Sb. AlInAsSb digital alloy has proved to be reproducible and consistent with single phase, showing sharp satellite peaks on HRXRD rocking curve and smooth surface morphology under atomic force microscopy (AFM). Using optimized digital alloy, AlInAsSb separate absorption, grading, charge, and multiplication (SAGCM) APD was grown and fabricated. At room temperature, the device showed high performance with low dark current density of ∼14.1 mA/cm 2 at 95% breakdown and maximum stable gain before breakdown as high as ∼200, showing the potential for further applications in optoelectronic devices.

中文翻译：

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数字生长的 AlInAsSb 用于高增益独立吸收、分级、电荷和倍增雪崩光电二极管

摘要 我们报告了通过分子束外延 (MBE) 生长高质量 GaSb 基 AlInAsSb 四元合金以制造雪崩光电二极管 (APD)。通过高分辨率 X 射线衍射 (HRXRD) 和扫描透射电子显微镜 (STEM)，证明了具有自然发生的垂直超晶格构型的 AlInAsSb 随机合金的相分离现象。为了在保持高结晶膜的同时克服相分离的趋势，采用具有迁移增强外延生长方法的数字合金技术，使用 AlSb、AlAs、AlSb、Sb、In、InAs、In、Sb 的快门序列。AlInAsSb 数字合金已被证明是可重复的并且与单相一致，在原子力显微镜 (AFM) 下，HRXRD 摇摆曲线上显示出尖锐的卫星峰和光滑的表面形态。使用优化的数字合金，AlInAsSb 单独的吸收、分级、电荷和倍增 (SAGCM) APD 被生长和制造。在室温下，该器件表现出高性能，在 95% 击穿时具有 ~14.1 mA/cm 2 的低暗电流密度和高达 ~200 的击穿前最大稳定增益，显示出在光电器件中进一步应用的潜力。