Study On Nonlinear Model Of Inp-based HEMT Device

InP-based high electron mobility transistor（HEMT）has excellent electron mobility,noise,gain and power characteristics,and is one of the most competitive high-frequency semiconductor devices.It is widely used in the military and civilian space of defense aerospace,space exploration and satellite remote sensing.The device model is a bridge between the fabrication process and the practical application,which accurately predict and feasibility evaluate the circuit performance.For the application of InP-based HEMT irradiation environment,the accurate device irradiation model can correctly predict the deviation of the integrated circuit chips caused by irradiation and guide the design of anti-irradiation redundancy.In this paper,the non-linear equivalent circuit model of InP-based HEMT devices under conventional working conditions is established,and the radiation DC model of electron irradiation is established.The specific research results are as follows:1.The nonlinear equivalent model of the InP-based HEMT device was established.The channel electron concentration of the device increases as the gate bias increases,eventually reaching saturation due to the fixed doping concentration.In this paper,the hyperbolic tangent function is used to describe the knee voltage variation of the device with the gate voltage.The gate capacitance of the device increases with the gate bias before the peak and then gradually decreases due to the saturated channel current.In this paper,a piecewise function is used to describe the relationship between gate capacitance and bias voltage.A cubic polynomial is introduced to describe the trend of gate capacitance decreasing with bias voltage.Through the introduction of the variable knee voltage,the model DC characteristic fitting error(e _DC)is reduced by 1.02%.The piecewise capacitance characteristic is significant reduce the AC characteristic fitting error(e _RF).The improved model is more suitable for InP-based HEMT devices.2.The nonlinear irradiation DC model of the InP-based HEMT device was established.The corresponding irradiation model was established by studying the effects of different doses of electron irradiation on the Schottky characteristics,transfer characteristics and output current of the device.The reverse saturation current and the ideal factor of the Schottky barrier show an exponential increase with the increase of the irradiation factor.The transfer characteristics move negatively with the irradiation dose and decrease with increasing irradiation dose.As the irradiation dose increases,the kink effect of the output current characteristics is weakened.In the nonlinear semi-empirical model of InP-based HEMT devices,the exponential relationship between each parameter and the change of irradiation factor is introduced,and the Schottky and transfer characteristic models of the device are established.At the same time,the slope（M）of Kink effect under different irradiation doses was introduced into the model to establish the output current irradiation model.The model simulation and the measured data were well fitted.The establishment of a large-signal model of InP-based HEMT devices will facilitate the development of its millimeter-wave integrated circuits,and its irradiation model will promote the application of devices and related integrated circuit space.