Study On Device Model Of InP-Based HEMT

InP-based high electron mobility transistor(HEMT)has shown extremely high electron mobility,low noise figurelow,superior power consumption and high gain performance.They are widely used in millimeter-wave monolithic integrated circuit designs and hace occupied an important position in defense and aerospace applications.Device model is the important link between fabrication and integrated circuit design.This paper studies the small signal model and large signal model of InP-based HEMT device.The details are as follows:(1)Considering the specifical device structure of InP-based HEMTs including small-signal the short gate length and gate-channel,a 16-parameter model topology of InP-based HEMTs is proposed.The gate-source resistance(Rgs)is added to characterize the gate leakage effect of the short-gate-channel distance device,and the drain-source delay factor(?ds)is added to characterize the effect of the drain voltage on the channel current.Open and short elements are used to extract peripheral parasitic parameters,and the intrinsic parameters are extracted using the de-embedded Y parameters.The parameters of the small-signal model are extracted through optimization.The results show that the introduction of Rgs and ?ds improves the fitting accuracy of S22 parameter,which reduces the model fitting error from 0.294 in the traditional topological structure to 0.266.(2)The large-signal model of the InP-based HEMT device is constructed based on the EEHEMT model.The parameter extraction of Schottky characteristics,transfer characteristics,output characteristics and AC characteristics of InP-based HEMT devices was realized.The dispersion effects caused by device surface states and traps were also considered in the model.Finally,the problem of the constant knee voltage in the EEHEMT model is improved,and the relationship between the knee voltage and the gate bias is introduced,which improves the fitting accuracy of the DC characteristics of the device.The improvement of the signal model for InP-based HEMT devices will help to guide device fabrication process,and it has good application value for high-frequency integrated circuit design and stability analysis.