Abstract
We report direct observation of individual dopant impurities (Si Ga in GaAs, S As in InAs) and Ga surface vacancies (V Ga ) on the (110) cleavage surfaces of III-V compounds. In the scanning tunneling microscopy images at low sample bias voltages, the charged dopants and surface vacancies exhibit the delocalized feature seen as protrusions or depressions extended over several lattice sites on the (110) face. This approach opens up new opportunities for studying individual defects in compound semiconductors on the atomic scale.