Technische Physik, Physikalisches Institut, Julius-Maximilians-Universität Würzburg, Würzburg, Germany.
Nanotechnology. 2010 Nov 12;21(45):455603. doi: 10.1088/0957-4484/21/45/455603. Epub 2010 Oct 14.
This paper presents a systematic investigation of strain compensation schemes for InAs/AlSb superlattices (SLs) on GaSb substrates. Short growth interruptions (soak times) under varying arsenic and/or antimony beam equivalent pressures in InAs/AlSb SLs with exemplary dimensions of about ((2.4/2.4) ± 0.2) nm were investigated to achieve strain compensation. When using uncracked As(4), strain compensation was found to be unaccomplishable unless sub-monolayer AlAs spikes were inserted at the InAs → AlSb interface. In contrast, the supply of cracked As(2) dimers leads directly to the formation of strain compensating AlAs-like interfaces. This mechanism allows various growth sequences for strain compensated superlattices, including soak-time-free and Sb-soak-only SL growth. Each of the two latter approaches yields layers with excellent crystal quality and minimal intermixing at the heterointerfaces as verified by high resolution x-ray diffraction analysis and transmission electron microscopy.
本文系统研究了在 GaSb 衬底上的 InAs/AlSb 超晶格（SL）的应变补偿方案。研究了具有约 ((2.4/2.4) ± 0.2) nm 典型尺寸的 InAs/AlSb SL 中在不同砷和/或锑束等效压力下的短生长中断（浸泡时间），以实现应变补偿。使用未开裂的 As(4)时，除非在 InAs→AlSb 界面插入亚单层 AlAs 尖峰，否则应变补偿无法实现。相比之下，开裂的 As(2)二聚体的供应直接导致形成应变补偿的 AlAs 样界面。这种机制允许各种应变补偿超晶格的生长序列，包括无浸泡时间和仅 Sb 浸泡的 SL 生长。这两种后一种方法中的每一种都得到了具有极好晶体质量和最小异质界面混合的层，这通过高分辨率 X 射线衍射分析和透射电子显微镜得到了验证。
