Chemical Composition of Native Oxide Layers on In⁺Implanted and Thermally Annealed GaAs

Abstract

Semi-insulating GaAs wafers have been implanted with 250 keV In+ ions at a uence of 3 × 10 16 cm −2 . The samples prepared in this way were subsequently annealed at a temperature of 600• C or 800• C for 2 h. Thicknesses of the native oxide layers on implanted GaAs after samples storage in air were evaluated using the Rutherford backscattering spectrometry with the nuclear reaction O 16 (α, α)O 16 method. The chemical composition of native oxide layers on In + implanted and annealed GaAs has been studied using X-ray photoelectron spectroscopy. As2O3, As2O5, Ga2O3, GaAs, InAs and InAsO4 compounds were detected in these layers.

Chemical composition of native oxides on noble gases implanted GaAs

“…According to the Gibbs phase rule no more than three phases can coexist at equilibrium in a ternary system and therefore it is often useful to represent these phases (neglecting any solid solubility) schematically on the Gibbs triangle [24]. Our recent paper [29] on the chemical composition of native oxide layers covering the implanted and thermally annealed layer on the GaAs surface showed that the formation of Ga 2 O 3 is energetically preferred due to lower Gibbs free energy (− 998.9 kJ/mol) [30]. This is lower than the Gibbs free energies of Ga 2 O, Ga 2 O 3 , As 2 O 3 , As 2 O 5 which are equal to −314.0 kJ/mol, −998.9 kJ/mol, −576.5 kJ/mol and −782.9 kJ/mol, respectively [28].…”