Observation of Ga0.47In0.53As/InP Multiquantum Well Structure in Air by Scanning Tunneling Microscope

Abstract
A cross-sectional surface of Ga0.47In0.53As/InP multiquantum wells (MQWs) prepared by cleaving was observed in air by a scanning tunneling microscope (STM), and clear STM images of periodic MQW structures were obtained with nanometer resolution. The apparent height of the STM images on the surface of the GaInAs layers was 50–150 Å larger than that of the images on the surface of the InP layers. This difference between the two kinds of layers was found to be due not to a real corrugation but to some difference in surface electronic properties. It was demonstrated that STM is a useful tool for nanometer scale evaluation of fine structures of MQWs.