为了优化传统AlGaN/GaNhighelectronmobilitytransistors结构表面电场分布,提高器件击穿电压和可靠性,本文利用不影响AlGaN/GaN异质结极化效应的Si3N4钝化层电荷分布,提出了一种sbN4钝化层部分固定正电荷AIGaN/GaNhighelectronmobilitytransistors新结构.SiaN4钝化层中部分固定正电荷通过电场调制效应使表面电场分布中产生新的电场峰而趋于均匀.新电场峰使得新结构栅边缘和漏端高电场有效降低,器件击穿电压从传统结构的296V提高到新结构的650V,而且可靠性改善.通过Si3N4与AlGaN界面横、纵向电场分布,说明了产生表面电场峰的电场调制效应,为设计SiaN4层部分固定正电荷新结构提供了科学依据.Si3N4钝化层部分固定正电荷的补偿作用,使沟道二维电子气浓度增加,导通电阻减小,输出电流提高.
In order to optimize the surface electric field of the traditional AlGaN/GaN high electron mobility transistor and improve the breakdown voltage and reliability, a new AlGaN/GaN high electron mobility transistor is proposed with the partial fixed positive charges in the SiaN4 passivation layer in this paper. The partial fixed positive charges of the Si3Na passivation layer do not affect the polarization effect of the A1GaN/GaN heterojunction. The surface electric field tends to the uniform distribution due to the new electric field peak formed by the partial fixed positive charges, which modulates the surface electric field by applying the electric field modulation effect. The high electric fields near the gate and drain electrode decrease due to the new electric field peak. The breakdown voltage is improved from the 296V for the traditional structure to the 650V for the new structure proposed. The reliability of the device is improved due to the uniform surface electric field. The effect of the electric field modulation is explained by the horizontal and vertical electric field distribution between the Si3Na and AlGaN interface, which provides a scientific basis for designing the new structure with the partial fixed positive charges in the Si3N4 layer. Because of the fixed positive charge compensation, the two-dimensional electron gas concentration increases, and the on-resistance decreases. So, the output current of the new structure increases compared with that of the traditional AlGaN/GaN High Electron Mobility Transistor.