Influence of resonant tunneling on the imaging of atomic defects on InAs(110) surfaces by low-temperature scanning tunneling microscopy

TL;DR

This study uses low-temperature STM to examine InAs(110) surfaces, revealing atomic defects and showing how resonant tunneling affects their imaging, providing insights into impurity states in semiconductors.

Contribution

It demonstrates the impact of resonant tunneling on STM imaging of atomic defects in heavily doped InAs, highlighting the role of localized impurity states.

Findings

Identification of S dopant atoms and As vacancies as surface defects.

Bias voltage dependence explained by resonant tunneling through localized states.

Enhanced understanding of impurity imaging in semiconductor surfaces.

Abstract

We have used a low-temperature scanning tunneling microscope (STM) to study the surface of heavily doped semiconductor InAs crystals. The crystals are cleaved in situ along the (110) plane. Apart from atomically flat areas, we also observe two major types of atomic scale defects which can be identified as S dopant atoms and as As vacancies, respectively. The strong bias voltage dependence of the STM image of the impurities can be explained in terms of resonant tunneling through localized states which are present near the impurity.