Thermal stability of sheet resistance in AlGaN/GaN 2DEG structure

摘要

An annealing study of an MGaN/GaN two-dimensional electron gas structure was conducted in combination with precise MGaN-thickness measurements by using reflectivity spectra. We found that the sheet resistance increases when annealing is performed below the growth temperture, and the increase depends on the AlGaN thickness and crystal quality. One possible explanation for the increase is that Si donors in low-quality MGaN layers were passivated or compensated from the top surfaces upon annealing.