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

Abstract

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.

Formation of Thin Germanium Dioxide Film with a High-Quality Interface Using a Direct Neutral Beam Oxidation Process

“…Note that, in this study, heating the substrate did not cause GeO desorption because of the 280 C substrate temperature. 2,3) This process of using H radicals to remove native oxide was previously used for gallium arsenide (GaAs) 21,22) and Si. 23) The results we obtained in this investigation indicate that H radical treatment is an effective process for removing the native oxide of Ge.…”

Quantum size effects in GaAs nanodisks fabricated using a combination of the bio-template technique and neutral beam etching

“…First, stacked GaAs/Al 0.3 Ga 0.7 As thin films consisting of the GaAs capping layer/Al 0.3 Ga 0.7 As/4 nmthick GaAs QW/Al 0.3 Ga 0.7 As (figure 3(a)) were grown on a GaAs substrate, which was the etching template, using MBE. Then, the native oxide on the GaAs capping layer surface was removed by the first hydrogen-radical treatment [20,21], which was conducted at 280 • C at a hydrogen flow rate of 40 sccm, a process pressure of 40 Pa, and 2.45 GHz microwave power of 190 W (figure 3(b)). The sample was then transferred to a neutral beam oxidation (NBO) chamber in a vacuum environment and sequentially oxidized to form a thin and controllable GaAs-NBO film.…”

Solution-Derived Amorphous Yttrium Gallium Oxide Thin Films for Liquid Crystal Alignment Layers

“…The conventional rubbing process involves mechanical contact with a roller, resulting in debris generation, local defects, and the accumulation of electric charge, which degrades the performance of LC devices. In contrast, IB activated ions collide with the material surface, allowing for the removal of contaminations [10], thereby overcoming a weakness of the rubbing process and yielding high-quality LC devices. In addition, IB can be used with oxide materials and may be possible to expand the range of material choices for the alignment layer.…”