Properties of Al y Ga 1– y N/Al x Ga 1– x N/AlN/GaN Double-Barrier High Electron Mobility Transistor Structure

Electrical properties of Al y Ga 1–y N/Al x Ga 1–x N/AlN/GaN structure are investigated by solving coupled Schrödinger and Poisson equation self-consistently. Our calculations show that the two-dimensional electron gas (2DEG) density will decrease with the thickness of the second barrier (Al y Ga 1–y N) once the AlN content of the second barrier is smaller than a critical value y c , and will increase with the thickness of the second barrier (Al y Ga 1–y N) when the critical AlN content of the second barrier y c is exceeded. Our calculations also show that the critical AlN content of the second barrier y c will increase with the AlN content and the thickness of the first barrier layer (Al x Ga 1–x N).