【摘要】 本研究成功制备了栅长为100 nm、具有InGaAs/InAs/InGaAs复合沟道的磷化铟基高电子迁移率晶体管（InP HEMTs）。直流测试表明，InAs沟道层的引入提升了跨导，但导致跨导峰值点在高漏压(V_ds)偏置下向低栅压(V_gs)方向偏移。峰分离分析发现直流跨导曲线由两部分构成：栅压调控的本征跨导和碰撞电离诱导的附加跨导。进一步研究表明，该异常偏移源于沟道碰撞电离强度的变化，这种变化主要由栅漏电场改变引起，而非沟道载流子浓度的变化。小信号模型中引入的两个额外电流源表征碰撞电离跨导，其数值变化趋势与峰分离结果的一致性验证了机理的正确性。射频测试证实，尽管直流跨导有所提升，但碰撞电离跨导的时间常数远大于一般跨导的时间常数，器件射频特性未能得到有效改善。这些发现为抑制碰撞电离效应及提升有效跨导提供了理论基础。更多还原

【Abstract】 In this work, 100 nm gate-length InP-based high electron mobility transistors（HEMTs） with a composite InGaAs/InAs/InGaAs channel are fabricated. DC measurements indicate that the InAs channel enhances transconductance but shifts the peak point toward lower V_gs under high V_ds bias. Peak separation analysis reveals the DC transconductance curve is composed of two components: the gate-controlled transconductance and the impact-ionization-induced additional transconductance. Further analysis demonstrates that the anomalous shift originates from the channel impact ionization intensity variation, which is caused by changes in the gate-drain electric field rather than the carrier density in the channel. Two additional current sources are introduced in the small-signal model to characterize the impact-ionization-induced transconductance, and the numerical variation trends of their parameters are consistent with the peak separation results, which validate the mechanism’s correctness. RF measurements confirm that the DC transconductance enhancement does not effectively improve RF characteristics, which is attributed to the ionization-induced transconductance having a time constant significantly larger than that of conventional transconductance components. These findings provide a theoretical foundation for controlling the impact-ionization.更多还原