Generation of two‐dimensional electron gas to normally depleted AlGaN/GaN hetero‐interface by SiO2 deposition and subsequent high‐temperature annealing

Abstract

Abstract SiO2 film deposition and subsequent high‐temperature annealing resulted in the generation of a two‐dimensional electron gas (2DEG) at Al(Ga)N/GaN hetero‐interfaces, of which the 2DEG was originally fully depleted. The obtained mobilities and sheet carrier concentrations were over 1100 cm2/Vs and 3.0 × 1012 cm–2, respectively. Surface energy lowering, which is proof of the generated 2DEG, was observed by electron state analysis using hard X‐ray photoelectron spectroscopy. This damage‐less method that selectively generates a 2DEG can contribute not only toward improving some characteristics in existing devices but also toward creating entirely novel devices.

Keywords

• Annealing processes
• Solid surface structure
• Thin film growth, structure, and epitaxy
• Fermions in reduced dimensions (condensed matter)
• Low-field transport and mobility; piezoresistance (semiconductors/insulators)
• Chemical vapour deposition