InAlAs/InGaAs调制掺杂场效应晶体管研究

Investigation of InAlAs/InGaAs Modulation Doped Field-Effect Transistor

从理论上和实验上对InAlAs/InGaAs调制掺杂场效应晶体管(MODFET)进行了研究。建立了简单的一维电荷控制模型,并进行二维数值模拟,得到了不同偏压下器件内部电势分布和电子浓度分布。在上述理论的指导下,设计了我们所需要的器件纵向和横向结构,并对设计器件的直流特性进行了计算机辅助分析。最后叙述了利用国产Ⅳ型MBE设备生长的材料制作出MODFET的工艺过程,并对器件的直流特性和射频特性进行了测试和分析。直流测试表明,器件的最大饱和电流密度为125mA/mm,最大非本征跨导达250mS/mm;射频测试得到器件(L_g=1.0～1.2βm,W_g=150μm)的特征频率f_T为26GHz,最高振荡频率f_(max)为43GHz。

InAlAs/InGaAs modulation-doped field-effect transistor (MODFET) is investigated theoretically and experimentally. An one-dimensional charge control model was suggested.By twodimensional numerical simulation, the internal potential and electron density distribution of the device in different bias were obtained. Based on the theory above,the vertical and lateral structures of the device we need were designed.For the designed device, computer-aided analysis of the DC characteristics was done. Fi- nally the process of the device using MBE-grown material and the test and analysis on DC and RF performances were presented. The DC characterization shows that the maximum saturation current density is 125mA/mm, the maximum extrinsic transconductance is 250mS/mm. The RF characterization of the current gain cutoff frequency of 26 GHz and maximum oscillation frequency of 43 GHz for the device (L_g=1.0～1.2μm, W_g=150μm) is shown.