Temperature dependent compensation of Zn‐dopant atoms by vacancies in III–V semiconductor surfaces

Scanning tunneling microscopy is used to study the compensation of Zn‐dopant atoms by surface vacancies on InP and GaAs(110) surfaces as a function of the annealing time and temperature. An attractive interaction is observed between negatively charged Zn atoms and positively charged anion vacancies. Uncharged Zn‐vacancy defect complexes are formed and their structure is analyzed. The concentration of the complexes increases with the vacancy concentration. Simultaneously the concentration of charged Zn decreases. The total observable Zn concentration is found to be the sum of the concentration of isolated charged Zn atoms and of the concentration of the defect complexes. This sum is constant at low temperatures, but decreases at 480 K. The observations are explained by the formation of subsurface defect complexes at higher temperatures and surface complexes at low temperatures.