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

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 $\sim$10$^{21}$ cm$^{-3}$ without appreciable diffusion and segregation effects. Good carrier concentrations (2 $\times$ 10$^{19}$ cm$^{-3}$) and specific contact resistances of non-alloyed ohmic contacts (1.7 $\times$ 10$^{-6}$ $\Omega$ cm$^{2}$) 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 $\times$ 10$^{20}$ cm$^{-3}$ are detected.