利用蓝宝石衬底的AlGaN/AlN/GaN高电子迁移率器件(HEMT)的电容电压(C-V)特性,对电子费米能级与二维电子气面密度的经验关系进行表征,其结果对器件电荷控制模型的建立,跨导及电容表达式的简化有重要意义.文章创新性地提出参数α用于表征二维势阱对沟道电子限制能力,并认为α越小则二维势阱的沟道电子限制能力越强.利用上述经验关系来拟合电容,可以获得与实测电容很好的一致性.
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.