为获得更高的阈值电压, 提出了一种新型栅下双异质结增强型AlGaN/GaN高电子迁移率晶体管(HEMT)。使用双异质结电荷控制模型分析了基本机理, 推导了阈值电压表达式。仿真结果表明, 器件阈值电压与调制层Al组分呈线性关系。当调制层Al组分小于势垒层时, 阈值电压增大, 反之减小。调制层厚度可加大这种调制作用。当调制层Al组分为0%、厚度为112 nm时, 器件具有2.13 V的阈值电压和1.66 mΩ·cm2的比导通电阻。相对于常规凹槽栅结构, 新结构的阈值电压提高了173%。

In order to obtain higher threshold voltage, a novel AlGaN/GaN high electron mobility transistor (HEMT) enhanced by double heterojunction under gate was proposed. The basic mechanism was analyzed by using the double heterojunction charge control model, and the threshold voltage expression was derived. The simulation results showed that the threshold voltage of the device was linear with the Al content of the modulation layer. When the Al content of the modulation layer was less than the barrier layer, the threshold voltage increased, otherwise it decreased, and the thickness of the modulation layer would increase this modulation effect. When the modulation layer Al content was 0% and the thickness was 112 nm, the device had a threshold voltage of 2.13 V and a specific on-resistance of 1.66 mΩ·cm2. Compared with the conventional fluted gate structure, the threshold voltage of the new structure was increased by 173%.