Physical modeling based on hydrodynamic simulation for the design of InGaAs/InP double heterojunction bipolar transistors

A physical model for scaling and optimizing InGaAs/InP double heterojunction bipolar transistors（DHBTs） based on hydrodynamic simulation is developed.The model is based on the hydrodynamic equation,which can accurately describe non-equilibrium conditions such as quasi-ballistic transport in the thin base and the velocity overshoot effect in the depleted collector.In addition,the model accounts for several physical effects such as bandgap narrowing,variable effective mass,and doping-dependent mobility at high fields.Good agreement between the measured and simulated values of cutoff frequency,f t,and maximum oscillation frequency,f max,are achieved for lateral and vertical device scalings.It is shown that the model in this paper is appropriate for downscaling and designing InGaAs/InP DHBTs.

High efficiency modeling of broadband millimeter-wave CMOS FETs with gate width scalability by using pre-modeled cells

Thisworkpresentsahighlyefficientapproachforbroadbandmodelingofmillimeter-waveCMOSFETs with gate width scalability by using pre-modeled cells. Only a few devices with varied gate width are required to be measured and modeled with fixed models, and later used as pre-modeled cells. Then a target device with the desired gate width is constructed by choosing appropriate cells and connecting them with a wiring network. The corresponding scalable model is constructed by incorporating the fixed models of the cells used in the target device and the scalable model of the connection wires. The proposed approach is validated by experiments on 65-nm CMOS process up to 40 GHz and across a wide range of gate widths.

Scalable modeling and comparison for spiral inductors using enhanced 1-π and 2-π topologies

Two different scalable models developed based on enhanced 1-πand 2-πtopologies are presented for onchip spiral inductor modeling.All elements used in the two topologies for accurately predicting the characteristics of spiral inductors at radio frequencies are constructed in geometry-dependent equations for scalable modeling.Then a comparison between the 1-πand 2-πscalable models is made from the following aspects：the complexity of equivalent circuit models and parameter-extraction procedures,scalable rules and the accuracy of scalable models.The two scalable models are further verified by the excellent match between the measured and simulated results on extracted parameters up to self-resonant frequency（SRF） for a set of spiral inductors with different L,R and N,which are fabricated by employing 0.18-μm 1P6M RF CMOS technology.

RF CMOS modeling:a scalable model of RF-MOSFET with different numbers of fingers

A novel scalable model for multi-finger RF MOSFETs modeling is presented.All the parasitic components, including gate resistance,substrate resistance and wiring capacitance,are directly determined from the layout.This model is further verified using a standard 0.13μm RF CMOS process with nMOSFETs of different numbers of gate fingers,with the per gate width fixed at 2.5μm and the gate length at 0.13μm.Excellent agreement between measured and simulated S-parameters from 100 MHz to 20 GHz demonstrate the validity of this model.