GaSb基的InAs/GaSbⅡ类超晶格背景载流子浓度的测量

摘要

High-quality type-II InAs/GaSb superlattices are on lattice-matched CaSb substrates. However,since there is no commercial semi-insulating CaSb substrate,traditional Hall measurement has difficulty to obtain the carrier concentration of the InAs/GaSb superlattices. Therefore,how to accurately acquire the carrier density of epitaxial SLs is a major task in the material growth optimization. Through years of research, several techniques have been developed to measure the carrier concentration of the thin films grown on conducting substrates. In this paper we review five typical approaches: ①low-temperature Hall technique; ②variable magnetic field Hall technique and mobility spectrum analysis; ③growing an electrically isolating lattice matched AlGaAsSb buffer layer; ④the technique of removing the substrate; ?capacitance-voltage measurement. We discuss their basic principles, and comment on their advantages and disadvantages.%高质量的InAs/GaSbⅡ类超晶格(SLs)材料生长在晶格匹配的GaSb衬底上,由于GaSb衬底具有良好的导电性,传统的霍尔测量难以直接得到外延超晶格材料的载流子浓度等电学参数,所以,如何准确地获得InAs/GaSb超晶格外延材料中的载流子浓度成为了研究人员关注的焦点之一.主要介绍了InAs/GaSbⅡ类超晶格背景载流子浓度测量的四种典型的方法:低温霍尔技术；变磁场霍尔技术以及迁移率谱拟合；衬底去除技术；电容-电压技术.并给出了各种方法的基本原理,评价了每种方法的优缺点.