不同散射机理对 Al2O3/InxGa1-xAs nMOSFET 反型沟道电子迁移率的影响

通过考虑体散射、界面电荷的库仑散射以及 Al₂O₃/In_xGa_1-xAs 界面粗糙散射等主要散射机理, 建立了以 Al₂O₃为栅介质In_xGa_1-xAs n 沟金属-氧化物-半导体场效应晶体管 (nMOSFETs) 反型沟道电子迁移率模型, 模拟结果与实验数据有好的符合. 利用该模型分析表明, 在低至中等有效电场下, 电子迁移率主要受界面电荷库仑散射的影响; 而在强场下, 电子迁移率则取决于界面粗糙度散射. 降低界面态密度, 减小 Al₂O₃/In_xGa_1-xAs 界面粗糙度, 适当提高In含量并控制沟道掺杂在合适值是提高 InGaAs nMOSFETs 反型沟道电子迁移率的主要途径. 关键词： InGaAs MOSFET 反型沟道电子迁移率 散射机理

Effects of different scattering mechanisms on inversion-channel electron mobility in Al2O3/InxGa1-xAs nMOSFET

An inversion-channel electron mobility model for In_xGa_1-xAs n-channel metal-oxide-semiconductor field-effect transistors (nMOSFETs) with Al₂O₃ as gate dielectric is established by considering main scattering mechanisms of bulk scattering, Coulomb scattering of interface charges and interface- roughness scattering of the Al₂O₃/In_xGa_1-xAs interface. The simulated results are in good agreement with the experimental data. Analyses by using the model indicate that the total electron mobility is mainly limited by the Coulomb scattering of interface charges under weak and medium effective fields and by the interface-roughness scattering under strong effective fields. Therefore, the effective approaches of enhancing the inversion-channel electron mobility are to reduce the interface-state density and roughness of the Al₂O₃/In_xGa_1-xAs interface, to properly increase the in content and control the doping concentration of the In_xGa_1-xAs channel to a suitable value.
Keywords： InGaAs MOSFET inversion-channel electron mobility scattering mechanisms