オージェ電子分光を備えた中速電子回折装置の開発とそれによるInP(111)B表面の温度依存性の観察

Abstract

A new medium-energy electron diffraction (MEED) apparatus combined with Auger electron spectroscopy (AES), MEED-AES, has been developed. This apparatus enables surface analyses on not only atomic structure but also atomic composition. InP(111)B surface with low melting point was used as a sample in order to investigate the changes of the surface structure and the surface composition depending on the heat treatment. It has been found by the new MEED-AES apparatus that the atomic composition of the topmost surface becomes P rich by heat treatment over about 500 C and the surface structure has two times periodicity over about 540 C. At the same time, scanning electron microscopy (SEM) combined with energy dispersive X-ray spectrometry (EDS) showed formation of droplets of In atoms. Considering the deference of sampling depth between AES and EDS, it is considered that very thin film of P atoms covers the topmost surface of each In droplet.