Modeling method of Schottky barrier diode electrothermal model suitable for software simulation

Abstract

The invention discloses a Schottky barrier diode electrothermal model modeling method suitable for software simulation. The method comprises the following steps: A, manufacturing an assembly test circuit according to the structure size of a Schottky barrier diode; b, assembling the diode in an assembling test circuit, and measuring the I-V characteristics of the diode at different temperatures by using a semiconductor analyzer and a high-low temperature test box; c, according to the I-V characteristic data, extracting an ideal factor, a reverse saturation current and series resistance of the diode at each temperature by using a diode ideal equation, and performing polynomial function fitting on extracted characteristic parameters by taking the temperature as a variable; and D, defining the port voltage and the port current of the diode by using the function obtained in the step C in combination with radio frequency simulation software, and constructing a Schottky barrier diode electric heating model. According to the invention, a model of the diode relative to temperature change can be established in a high frequency band, and the working state of the Schottky barrier diode under large and small signals can be simulated at the same time.

Description

Technical Field

[0001] The invention belongs to the technical field of diode modeling, and in particular relates to a Schottky barrier diode electrothermal modeling method suitable for software simulation. Background Art

[0002] As a device made by contacting metal and semiconductor, Schottky barrier diode has high electron mobility, good high-frequency characteristics, fast reverse recovery ability and low forward turn-on voltage, simple structure and good integration, showing great potential in improving communication system performance, reducing power consumption and reducing device size. Since its introduction in 1938, Schottky barrier diode has been widely used in microwave and millimeter wave frequency bands, and has gradually become the main device for terahertz frequency band circuit design as terahertz technology has become a research hotspot.

[0003] In the circuit design related to Schottky barrier diodes, the SPICE models provided by various manufacturers are usually used to simulate the performance of the diode. As the current communication frequency band continues to develop towards higher frequencies, the chip size and device area are gradually reduced, and the problem of self-heating effect becomes more prominent, which in turn affects the ability of the chip to work under high power conditions. In actual work, the electrical conductivity, thermal conductivity and other properties of Schottky barrier diodes will change with temperature, and these properties will interact with internal parameters such as current, parasitic capacitance and parasitic resistance. This shows that parameters such as saturation current and series resistance in the Schottky diode model are not fixed, but are closely related to temperature. As the working state changes, these temperature-related intrinsic and non-intrinsic parameters will also change, which will significantly affect the IV characteristics of the diode. In the case of high frequencies, the SPICE model modeling method, as an equivalent circuit modeling method, needs to consider and introduce a large number of temperature-related parameters for modeling in order to improve the accuracy of the model. The steps are cumbersome and the accuracy is difficult to guarantee.

[0004] Symbolically-Defined Devices (SDD) is a "black box" model established by defining equations related to the model's port current, port voltage and their derivatives. It can develop and modify complex models simply and quickly. Using SDD, the behavior of nonlinear devices under large and small signals can be accurately simulated. It can not only perform detailed qualitative and quantitative analysis of the IV characteristics of the diode, but also effectively build dynamic connections between various parameters. Compared with the equivalent circuit modeling method, SDD modeling references fewer parameters in high-frequency situations, has high modeling accuracy, and is easy to integrate into commercial simulation software. At present, SDD is mainly used in the modeling of triodes, and is less used in the field of diode modeling. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a method for modeling an electrothermal model of a Schottky barrier diode suitable for software simulation, which can establish a model of the diode relative to temperature changes in a high frequency band and can simultaneously simulate the working state of the Schottky barrier diode under large and small signals.

[0006] The object of the present invention is achieved through the following technical scheme: a method for modeling a Schottky barrier diode electrothermal model suitable for software simulation, comprising the following steps:

[0007] A. Make and assemble the test circuit according to the structural dimensions of the Schottky barrier diode;

[0008] B. Assemble the diode in the assembly test circuit, and use a semiconductor analyzer and a high and low temperature test chamber to measure the IV characteristics of the diode at different temperatures;

[0009] C. Based on the IV characteristic data, the ideal factor, reverse saturation current and series resistance of the diode at each temperature are extracted using the diode ideal equation, and a polynomial function is fitted to the extracted characteristic parameters with temperature as the variable;

[0010] The ideal equation of the diode is I(V)=I0[exp(qV / nKT)-1], where I(V) is the current obtained from the actual test, V is the corresponding test voltage, I0 is the reverse saturation current, n is the diode ideal factor, q is the basic electron charge, K is the Boltzmann constant, and T represents the temperature after the high and low temperature test chamber is stabilized during the test;

[0011] The formula for solving the ideal factor n is n = qΔVlog 10 (e) / KT, ΔV is the change in junction voltage for every ten-fold current change. Substituting the ideal factor n obtained into the ideal diode equation, the reverse saturation current I0 of the diode is obtained.

[0012] Solve the series resistance R based on the part of the IV characteristic curve that deviates from linearity under high current s : R s =ΔV d / I d , where ΔV d Represents large current I d The difference in voltage deviation from linearity;

[0013] Ideality factor n, reverse saturation current I0 and series resistance R s The fitting function forms are all high-order polynomials about temperature;

[0014] D. Use the function obtained in step C to define the port voltage and port current of the diode in combination with RF simulation software, and construct an electrothermal model of the Schottky barrier diode.

[0015] In step B, the diode IV characteristics are tested over the entire temperature range that the diode can withstand, from low temperature to high temperature, and each temperature IV characteristic test is performed after the high and low temperature test chamber reaches a stable target temperature.

[0016] In the step D, the function fitted in the step C is used to correct the SDD diode model, so that the model can accurately characterize the self-heating effect of the diode in actual operation.

[0017] The beneficial effects of the present invention are as follows: by extracting the IV characteristic curves of the Schottky barrier diode at different temperatures, the established model can be associated with temperature, and the diode port voltage and current are defined by SDD, thereby overcoming the defect that the traditional equivalent circuit method diode modeling in the high frequency band relies on a large number of uncertain parameters. The modeling is simple and efficient, high-precision modeling is achieved, and it has good versatility. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram of the flow chart of the method for modeling the electrothermal model of a Schottky barrier diode of the present invention;

[0019] Figure 2 Schematic diagram of parameter extraction based on the IV characteristic curve of a Schottky barrier diode in an embodiment of the present invention;

[0020] Figure 3 The electrothermal model of the diode SDD is established by using the fitted polynomial function in the embodiment of the present invention. DETAILED DESCRIPTION

[0021] The technical solution of the present invention is further described below in conjunction with the accompanying drawings.

[0022] like Figure 1 As shown, a method for modeling a Schottky barrier diode electrothermal model suitable for software simulation of the present invention comprises the following steps:

[0023] A. Make and assemble the test circuit according to the structural dimensions of the Schottky barrier diode;

[0024] B. Assemble the diode on the assembly test circuit made in step A, and use a semiconductor analyzer and a high and low temperature test chamber to measure the IV characteristics of the diode at different temperatures; the diode IV characteristics are tested over the entire temperature range that the diode can withstand, from low temperature to high temperature, and the IV characteristics test at each temperature is performed after the high and low temperature test chamber reaches a stable target temperature.

[0025] C. Based on the IV characteristic data, the ideal factor, reverse saturation current and series resistance of the diode at each temperature are extracted using the diode ideal equation, and a polynomial function is fitted to the extracted characteristic parameters with temperature as the variable;

[0026] The IV characteristic of the diode satisfies the ideal equation: I(V) = I0[exp(qV / nKT)-1], where I(V) is the current obtained by actual test, V is the corresponding test voltage, I0 is the reverse saturation current, n is the diode ideal factor; q is the basic electron charge: 1.602176634×10 -19 C; K is the Boltzmann constant: 1.380649×10 -23 J / K; T represents the temperature value after the high and low temperature test chamber stabilizes during the test;

[0027] The formula for solving the ideal factor n is n = qΔVlog 10 (e) / KT, ΔV is the change in junction voltage for every ten-fold current change. Specifically, at this time, the IV characteristic curve is approximately linear in the region with a small current. At this time, the voltage drop on the series resistor is small, and the extracted ideal factor n data is more accurate. Then substitute the solved ideal factor n into the ideal diode equation to obtain the reverse saturation current I0 of the diode;

[0028] Solve the series resistance R based on the part of the IV characteristic curve that deviates from linearity under high current s : R s =ΔV d / I d , where ΔV d Represents large current I d The difference in voltage deviation from linearity;

[0029] Ideality factor n, reverse saturation current I0 and series resistance R s The fitting function forms are all high-order polynomials about temperature;

[0030] D. Use the function obtained in step C to define the port voltage and port current of the diode in combination with RF simulation software, and construct the electrothermal model of the Schottky barrier diode; use the function fitted in step C to correct the SDD diode model so that the model can accurately characterize the self-heating effect of the diode in actual operation.

[0031] In an optional embodiment of the present invention, step C extracts the three parameters of ideal factor, reverse saturation current and series resistance according to the diode IV characteristic curve test data combined with the diode ideal equation as shown in the schematic diagram Figure 2 As shown, the linear portion of the curve is used to extract the ideality factor and thus calculate the reverse saturation current, and the nonlinear portion of the curve is used to extract the series resistance.

[0032] In an optional embodiment of the present invention, the electrothermal model of the diode SDD obtained in the above step D is as follows: Figure 3 As shown, I[1,0] is the corrected ideal diode equation, and I[1,1] is the charge equation. Wherein, Rs is the series resistance, t is the temperature, I0 is the reverse saturation current, n is the diode ideal factor, _v1 is the diode input voltage, and Vt is the diode temperature equivalent. The modeling method of the present invention is based on the physical meaning of the diode, is consistent with the actual working state of the diode, and does not need to introduce a large number of uncertain parameters to model the model. It is simple, efficient, highly accurate, and has good versatility.

[0033] Those skilled in the art will appreciate that the embodiments described herein are intended to help readers understand the principles of the present invention, and should be understood that the protection scope of the present invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific variations and combinations that do not deviate from the essence of the present invention based on the technical revelations disclosed by the present invention, and these variations and combinations are still within the protection scope of the present invention.

Claims

1. A method for modeling a Schottky barrier diode electrothermal model suitable for software simulation, characterized in that: The following steps are involved: A. Make and assemble the test circuit according to the structural dimensions of the Schottky barrier diode; B. Assemble the diode in the assembly test circuit, and use a semiconductor analyzer and a high and low temperature test chamber to measure the IV characteristics of the diode at different temperatures; C. Based on the IV characteristic data, the ideal factor, reverse saturation current and series resistance of the diode at each temperature are extracted using the diode ideal equation, and a polynomial function is fitted to the extracted characteristic parameters with temperature as the variable; The ideal equation of the diode is I(V)=I0[exp(qV / nKT)-1], where I(V) is the current obtained from the actual test, V is the corresponding test voltage, I0 is the reverse saturation current, n is the diode ideal factor, q is the basic electron charge, K is the Boltzmann constant, and T represents the temperature after the high and low temperature test chamber is stabilized during the test; The formula for solving the ideal factor n is n = qΔVlog 10 (e) / KT, ΔV is the change in junction voltage for every ten-fold current change. Substituting the ideal factor n obtained into the ideal diode equation, the reverse saturation current I0 of the diode is obtained. Solve the series resistance R based on the part of the IV characteristic curve that deviates from linearity under high current s : R s =ΔV d / I d , where ΔV d Represents large current I d The difference in voltage deviation from linearity; Ideality factor n, reverse saturation current I0 and series resistance R s The fitting function forms are all high-order polynomials about temperature; D. Use the function obtained in step C to define the port voltage and port current of the diode in combination with RF simulation software, and construct an electrothermal model of the Schottky barrier diode.

2. The method for modeling a Schottky barrier diode electrothermal model suitable for software simulation according to claim 1, characterized in that: In step B, the diode IV characteristics are tested over the entire temperature range that the diode can withstand, from low temperature to high temperature, and each temperature IV characteristic test is performed after the high and low temperature test chamber reaches a stable target temperature.

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