High quality Al0.15Ga0.85WGaN heterostructures have been fabricated on 6H-SiC and sapphire substrates by metalorganic vapor phase epitaxy (MOVPE). A temperature independent mobility, indicative of the presence of a two-dimensional electron gas (2DEG), was observed in all samples below 80 K. The highest low temperature 2DEG mobility, 7500 cm2/V s, was measured in AlGaN/ GaN grown on 6H-SiC; the sheet carrier density was 6×1012 cm-2. Strong, well resolved, Shubnikov-de Haas oscillations were observed in fields as low as 3 T and persisted to temperatures as high as 15 K. Hall effect measurements also revealed the presence of well-defined plateaus in the Hall resistance. The high quality 2DEG properties of the AlGaN/GaN heterostructures grown on 6H-SiC are attributed to the absence of significant parallel conduction paths in the material.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)