Be-ion implantation in AlxGa1−x As

Abstract

The rapid thermal annealing (RTA) behavior of Be⁺‐ion‐implanted Al_xGa_1−xAs is investigated by means of Hall‐effect and photoluminescence (PL) measurements. The electrical activation in GaAs occurs from 400 °C and saturates at about 450 °C, while in Al_xGa_1−xAs alloys, the activation fractions increase gradually with increase in the annealing temperature. These fractions are evidently smaller in the Al_xGa_1−xAs alloys than in the GaAs, and larger x alloys give smaller activation fractions at any fixed temperature. PL intensity measurements indicate that annealing at 900 °C results in the maximum optical activation and lattice recovery both for GaAs and Al_xGa_1−xAs alloys. Secondary ion mass spectrometry (SIMS) analysis reveals Be accumulation at the Al_xGa_1−xAs (0≤x≤0.3) / SiO₂ encapsulant interface caused by Be out‐diffusion during RTA. SIMS and differential Hall‐effect measurements also suggest significant Be in‐diffusion in Al_xGa_1−xAs alloys especially for larger x values.