Damage and contamination-free GaAs and AlGaAs etching using a novel ultrahigh-vacuum reactive ion beam etching system with etched surface monitoring and cleaning method
I n situ monitoring and suppression of damage and contamination induced by GaAs and AlGaAs reactive-ion-beam-etching (RIBE) have been investigated to establish clean surfaces, required for fabricating III–V compound optoelectronic integrated circuits (OEIC’s). A novel ultrahigh-vacuum RIBE system with etched surface monitors and a surface cleaning gun has been developed for this purpose. Damage suppression with low energy (10–100 eV) RIBE was confirmed with an ideality factor in a Schottky diode. Removal of Cl contamination induced by Cl2 plasma was established with temperature-controlled (200 °C) RIBE or heat treatment (400 °C) after RIBE. Furthermore, it was demonstrated for the first time that both GaAs and AlGaAs native oxide layers could be successfully removed simply with irradiations of H and Cl radical beam released from the novel, compact electron-cyclotron-resonance (ECR) plasma gun.