Heavily doped GaAs:Te layers grown by MOVPE using diisopropyl telluride as a source

Abstract

The capabilities of GaAs epitaxial layers extremely heavily doped with tellurium by metal-organic vapor-phase epitaxy using diisopropyl telluride as a source are studied. It is shown that tellurium incorporation into GaAs occurs to an atomic concentration of 10²¹ cm^–3 without appreciable diffusion and segregation effects. Good carrier concentrations (2 × 10¹⁹ cm^–3) and specific contact resistances of non-alloyed ohmic contacts (1.7 × 10^–6 Ω cm²) give grounds to use such layers to create non-alloyed ohmic contacts in electronic devices. A sharp decrease in the electrical activity of Te atoms, a decrease in the electron mobility, and an increase in the contact resistance at atomic concentrations above 2 × 10²⁰ cm^–3 are detected.