The experiential fit of the capacitance-voltage characteristicsof the AlGaN/AlN/GaN high electron mobility transistors

This paper expresses the experiential relationship between Fermi level and the density of two-dimensional electron gas, based on the capacitance voltage (C-V) characteristics of the AlGaN/AlN/GaN high electron mobility transistor (HEMT) on sapphire substrate. The expression provides important references for establishing the device charge control model and simpliying the transconductance and capacitance. Parameter α is introduced for describing the ability for the two-dimensional potential well to restrict electrons, and we believe that the smaller the value of α, the stronger the restricting ability is. A coherent fitting effect, compared with the measurement, is obtained by making use of the experiential relationship said above.