Smaali K, Troyon M
Laboratoire de Microscopies et d'Etude de Nanostructures, EA 3799, Université de Reims Champagne-Ardenne, 21, rue Clément Ader, F-51685 Reims Cedex 2, France.
Nanotechnology. 2008 Apr 16;19(15):155706. doi: 10.1088/0957-4484/19/15/155706. Epub 2008 Mar 12.
High resolution electron-beam-induced current (EBIC) analyses were carried out on InP and GaAs substrates with a home-made atomic force microscope (AFM) combined with a scanning electron microscope (SEM). With this scanning nano-EBIC microscope, a sample can be conventionally imaged by SEM, its local topography investigated by AFM and nano-EBIC image simultaneously obtained. In this study, we report the utilization of nano-EBIC microscopy for imaging and characterizing GaAs and InP homojunctions. I-V characteristic measurements allow understanding of the electrical behavior of the AFM tip-sample contact. The electron probe intensity must be larger than about 100 pA to be able to generate an induced current because of the surface states which act as non-radiative recombination centers. The minority carrier diffusion length of InP and GaAs is measured and compared for different electron probe currents and it is shown that the measurements are not perturbed by photon recycling, i.e. the self-absorption of photons that gives rise to an extra generation of electron-hole pairs.
利用自制的原子力显微镜（AFM）与扫描电子显微镜（SEM）相结合，对磷化铟（InP）和砷化镓（GaAs）衬底进行了高分辨率电子束诱导电流（EBIC）分析。使用这种扫描纳米EBIC显微镜，可以通过SEM对样品进行常规成像，通过AFM研究其局部形貌，并同时获得纳米EBIC图像。在本研究中，我们报告了利用纳米EBIC显微镜对GaAs和InP同质结进行成像和表征。I-V特性测量有助于了解AFM针尖-样品接触的电学行为。由于表面态充当非辐射复合中心，电子探针强度必须大于约100 pA才能产生感应电流。测量了不同电子探针电流下InP和GaAs的少数载流子扩散长度并进行了比较，结果表明测量不受光子回收（即光子的自吸收导致额外产生电子-空穴对）的干扰。
