Improvement of the Interface Properties of Fluoride/GaAs(100) Structures by Postgrowth Annealing

Abstract
The postgrowth annealing technique has been shown to be useful for improving the interface properties of fluoride films grown on GaAs(100) by molecular beam epitaxy. Annealings typically at 800°C–850°C for 1 min reduce the interface state densities of the fluoride/GaAs interface to about 5×1011/cm2eV (derived from the 1 MHz capacitance-voltage measurement) in both n- and p-type substrates. Photoluminescence intensity of the CaF2-coated GaAs was compared before and after annealing. Ambient dependency during annealing was also investigated by measuring the structural and electrical properties of the films.