毫米波集成电路在5G通信等许多领域中具有广阔的应用前景。但是进入毫米波频段，晶体管等非线性器件的性能显著降低，使得集成电路设计存在困难。器件的紧凑模型能够支持电路仿真，对于有效提高毫米波集成电路的性能具有关键作用。但是代工厂提供的器件模型主要针对数字和模拟应用，毫米波频段的准确性不足。在毫米波频段下，非线性器件紧凑模型的建立面临许多挑战：一是器件表现出复杂的非线性特性，模型预测非线性特性的准确性及其在电路仿真中的收敛性难以协调；二是器件的电极和衬底等寄生效应以及色散等独特物理效应开始突显，完整的器件特性难以描述；三是在片测试的寄生效应对被测器件的特性造成明显影响，准确反映器件本征特性的测试数据难以获取。本文面向毫米波集成电路设计需要，围绕主流非线性器件，针对紧凑模型建立的基本方法和关键技术开展深入研究。本文提出了基于物理的先进FinFET毫米波小信号等效电路模型及其参数直接提取方法，根据FinFET多鳍结构的分布效应，使用多条电阻-电容支路描述了栅源和栅漏导纳，利用横向和纵向电阻网络说明了栅极电阻对于鳍数的非线性缩放关系，准确预测了7nm和14nm先进FinFET直至50GHz的射频小信号特性。本文针对GaAs HEMT，折合色散效应的影响，建立了等效电路完全基于物理的Angelov毫米波大信号模型，首次提出了完整的Angelov模型参数直接提取方法，形成了更简单、更易于使用的Angelov模型形式，准确预测了70nm GaAs HEMT的直流特性、直至67GHz的射频小信号特性、30GHz下的射频大信号特性。本文针对GaN HEMT，利用双脉冲测试，首次实现了陷阱效应的精细表征和自热效应的直接表征，以等效栅压形式建立了准确反映陷阱电荷非对称充放电过程的陷阱效应模型，以功耗子电路形式建立了直接描述功耗对器件特性影响的自热效应模型，结合基于Angelov模型改进的非对称电流模型，构成了完整直流热电模型，准确预测了250nm GaN HEMT在不同陷阱和自热状态下的电流-电压特性。本文提出了第一个完整描述直流电流和射频电容特性的CMOS肖特基二极管非线性模型及其参数直接提取方法，以非线性电阻形式完整描述了热发射、隧穿、速度饱和等电流输运机制，完整考虑了杂散和衬底等寄生效应，准确预测了65nm和130nm CMOS肖特基二极管的直流特性和直至67GHz的射频小信号特性。
Millimeter-wave integrated circuits have broad application prospects in many fields, including the 5G communication. However, the performances of nonlinear devices, such as transistors, significantly degrade in millimeter-waveband, which causes difficulties in designing integrated circuits. Hence, the compact device models, which support circuit simulations, play a key role in improving the performances of millimeter-wave integrated circuits. Nevertheless, the device models provided by foundries, which are targeted mainly at digital and analog applications, have poor precisions in millimeter-waveband. Besides, in millimeter-waveband, the compact modeling for nonlinear devices faces various challenges. Firstly, the devices exhibit complicated nonlinear behaviors, which makes it hard to simultaneously guarantee the prediction accuracies and the circuit simulation convergencies of the models. Secondly, the parasitic effects, including the electrode and substrate parasitics, and the unique physical effects, such as the dispersion effect, become significant, which makes it difficult to completely take the device characteristics into account. Thirdly, the parasitics in on-wafer measurements exert a strong impact on the behaviors of the devices under test, which causes obstacles in measuring the intrinsic device characteristics. Therefore, an in-depth study on the fundamental methodology and the key technologies in compact modeling for mainstream nonlinear devices in millimeter-wave integrated circuits is carried out in this dissertation.A novel physics-based small-signal equivalent circuit model and its direct parameter extraction strategy for advanced FinFETs in millimeter-waveband are proposed. According to the distribution property of the multi-fin structure, multiple resistance-capacitance branches are introduced to account for the gate-source and gate-drain admittances, and the horizontal and vertical resistances are utilized to explain the nonlinear scalability of the gate resistance with the number of fins. The model accurately predicts the RF small-signal characteristics up to 50GHz for 7nm and 14nm advanced FinFETs.An Angelov large-signal model, in which the equivalent circuit is fully based on the physics, for GaAs HEMTs in millimeter-waveband is developed, and the complete direct parameter extraction method of the Angelov model is proposed for the first time. By transferring the influences of the dispersion effect to other components, the Angelov model is modified to be simpler and easier to use. The model precisely predicts the DC characteristics, the RF small-signal characteristics up to 67GHz, and the RF large-signal characteristics at 30GHz for 70nm GaAs HEMTs.On the basis of double-pulse measurements, the elaborate characterization of the trapping effect and the direct characterization of the self-heating effect for GaN HEMTs are realized for the first time. A trapping model in the form of the equivalent gate-source voltage, which accurately reflects the asymmetry between the charging and discharging processes of the traps, and a self-heating model in the form of the power subcircuit, which directly describes the influences of the power on the device characteristics, are established. Along with the asymmetric current model modified from the Angelov model, a complete DC electrothermal model for GaN HEMTs is formed. The model precisely predicts the current-voltage characteristics under different trapping and self-heating states for 250nm GaN HEMTs.A nonlinear model, which completely covers the DC current and RF capacitance behaviors, and its direct parameter extraction strategy for CMOS Schottky diodes are proposed. Different current transport mechanisms, including the thermionic emission, tunneling, and carrier velocity saturation effects, are counted by the nonlinear resistances, and the stray and substrate parasitic effects are also included. The model accurately predicts the DC characteristics and the RF small-signal characteristics up to 67GHz for 65nm and 130nm CMOS Schottky diodes.
