Abstract

Elastically strained supermultiperiod (100–1000 periods) AlGaAs/GaAs superlattices with different doping levels and slightly differing period thicknesses have been investigated. The proposed technique of characterization consisting of combined application of deep X-ray reflectometry based on a rigorous calculation method, as well as the well-known method of high-resolution X-ray reflectometry, has made it possible to investigate 100-period structures with 2-nm-wide Al_0.3Ga_0.7As barriers and 10-nm-wide GaAs wells and determine with a high accuracy the layer thicknesses and spread of interfaces. This achievement can be considered as a first step in further analysis of thick structures using bright synchrotron radiation source. The difference between the expected and obtained by the proposed method layer thicknesses is several percent, including that for samples with a high doping level (up to 10¹⁸ cm^–3). All supermultiperiod structures are characterized by sharp interfaces with a standard deviation of about 0.1 nm. Based on the obtained data on the thicknesses, one can accurately determine the layer compositions using high-resolution X-ray diffraction.

中文翻译：

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分子束外延生长量子阱的超多周期A 3 B 5结构的深X射线反射测量

摘要

研究了具有不同掺杂水平和周期厚度略有不同的弹性应变超多周期（100-1000个周期）的AlGaAs / GaAs超晶格。提出的表征技术结合了基于严格计算方法的深层X射线反射法的应用以及众所周知的高分辨率X射线反射法的方法，使得研究100周期结构成为可能。 2纳米宽Al _0.3 Ga _0.7作为势垒和10 nm宽的GaAs阱，可以高精度确定层的厚度和界面扩展。可以将这一成就视为使用明亮的同步加速器辐射源对厚结构进行进一步分析的第一步。所建议的方法层厚度与预期厚度之间的差异为百分之几，其中包括高掺杂水平（最高10 ¹⁸ cm ^–3）的样品。所有超周期结构的特征都是尖锐的界面，标准偏差约为0.1 nm。根据获得的厚度数据，可以使用高分辨率X射线衍射精确确定层组成。