CN-115392171-B - HEMT transistor charge model establishment and extraction method based on GaN technology

CN115392171BCN 115392171 BCN115392171 BCN 115392171BCN-115392171-B

Abstract

The invention discloses a method for establishing and extracting a charge model of a HEMT transistor based on a GaN technology, which comprises the steps of obtaining a gate channel voltage based on externally input gate voltage, drain potential and source potential, obtaining gate charges based on gate charge density, gate root number, gate length and width of a single gate, obtaining drain-source potential difference based on drain potential and source potential, establishing a charge model used for representing the correlation between a charge value and drain-source voltage of the transistor device after the transistor device is started based on the gate channel voltage, the gate charges and the drain-source potential difference, differentiating the charge value of the charge model, and establishing a capacitance model used for representing the correlation between gate-source capacitance, gate-source voltage and drain-source voltage. The invention supports charge/capacitance description of the HEMT transistor based on the GaN technology, in particular to the relation description of gate-source capacitance, gate-source voltage and drain-source voltage after the channel is opened, and has high model accuracy.

Inventors

CAI WENBI
ZHANG YONGMING
WEI HONGJI
LIN YISHU

Assignees

厦门市三安集成电路有限公司

Dates

Publication Date: 20260505
Application Date: 20211029

Claims (8)

1. A method for establishing a charge model of a HEMT transistor based on a GaN technology is characterized by comprising the following steps: obtaining a gate channel voltage based on the externally input gate voltage, drain potential, and source potential; Obtaining gate charge based on gate charge density, gate count, gate length, and width of a single gate; obtaining a drain-source potential difference based on the drain potential and the source potential; based on the gate channel voltage, the gate charge and the drain-source potential difference, establishing a charge model for representing the correlation between the charge value and the drain-source voltage after the transistor device is started; Differentiating the charge value of the charge model, and establishing a capacitance model for representing the correlation of gate-source capacitance, gate-source voltage and drain-source voltage; based on the gate channel voltage, the gate charge and the drain-source potential difference, a charge model for representing the correlation between the charge value and the drain-source voltage after the transistor device is started is obtained, and the charge model is specifically as follows: ; Wherein, the A charge value representing a charge model; Representing gate charge; Representing the gate channel voltage; representing the drain-source potential difference; Representing a threshold voltage; Representing a hyperbolic tangent function; Representing a first charge coefficient; representing a second charge coefficient; The knee point drain-source voltage is represented; Representing a logarithmic function.
2. The method for building a charge model of a HEMT transistor based on a GaN process according to claim 1, wherein a gate channel voltage is obtained based on a gate voltage, a drain potential and a source potential inputted from the outside, concretely comprising: ; Wherein, the Representing the gate channel voltage; A gate voltage representing an external input; representing the drain potential; representing the source potential.
3. The method for building a charge model of a HEMT transistor based on a GaN process according to claim 1, wherein the gate charge is obtained based on a gate charge density, a gate number, a gate length, and a width of a single gate, specifically as follows: ; Wherein, the Representing gate charge; Representing gate charge density; Representing the width of a single gate; Representing the number of gates; representing the gate length.
4. The method for establishing a charge model of a HEMT transistor based on a GaN process according to claim 1, wherein the drain-source potential difference is obtained based on a drain potential and a source potential, specifically as follows: ; Wherein, the Representing the drain-source potential difference; representing the drain potential; representing the source potential.
5. A GaN-process-based HEMT transistor charge model parameter extraction method is characterized by comprising the following steps: s501, acquiring a test curve of capacitance-voltage characteristics of a transistor; S502, determining a calibration value of a core parameter in a charge model of a transistor and an empirical initial value of an auxiliary parameter, wherein the core parameter is a model parameter influencing the variation trend of the capacitance-voltage characteristic, the calibration value of the core parameter is determined according to process/epitaxial setting, based on an empirical calculation formula or by testing the transistor; s503, substituting the calibration value of the core parameter and the adjustment value of the auxiliary parameter into the charge model of the transistor; S504, differentiating the charge value of the charge model of the transistor to obtain a corresponding capacitance model; s505, obtaining a simulation curve of the capacitance-voltage characteristic of the capacitance model; S506, judging whether the fitting error of the simulation curve and the test curve reaches a preset threshold value, if so, executing S507, otherwise, executing S508; s507, determining the adjustment value of the auxiliary parameter as a calibration value of the auxiliary parameter; S508, after modifying the adjustment value of the auxiliary parameter, returning to S503; The charge model of the transistor is specifically as follows: ; Wherein, the A charge value representing a charge model; Representing gate charge; Representing the gate channel voltage; representing the drain-source potential difference; Representing a threshold voltage; Representing a hyperbolic tangent function; Representing a first charge coefficient; representing a second charge coefficient; The knee point drain-source voltage is represented; Representing a logarithmic function.
6. The method according to claim 5, wherein the core parameters include a voltage core parameter and a charge core parameter, wherein the voltage core parameter includes a gate channel voltage, a drain-source potential difference, and a threshold voltage, wherein the charge core parameter includes a gate charge, and wherein the auxiliary parameter includes a first charge coefficient and a second charge coefficient.
7. The method of extracting charge model parameters of a HEMT transistor based on a GaN process according to claim 5, the gate channel voltage is expressed as follows: ; Wherein, the Representing the gate channel voltage; A gate voltage representing an external input; representing the drain potential; Representing the source potential; The gate charge is represented as follows: ; Wherein, the Representing gate charge; Representing gate charge density; Representing the width of a single gate; Representing the number of gates; Representing the gate length; the drain-source potential difference is expressed as follows: ; Wherein, the Representing the drain-source potential difference.
8. The method for extracting parameters of a charge model of a HEMT transistor based on a GaN process according to claim 5, wherein obtaining a test curve of capacitance-voltage characteristics of the transistor comprises: Acquiring a two-port S parameter matrix of a transistor; Converting the two-port S parameter matrix into a two-port Y parameter matrix; and acquiring the gate-source capacitance of the transistor device based on the two-port Y parameter matrix, and establishing a test curve of the gate-source capacitance, the gate-source voltage and the drain-source voltage.

Description

HEMT transistor charge model establishment and extraction method based on GaN technology Technical Field The invention relates to the technical field of semiconductors, in particular to a charge model building and extracting method of a HEMT transistor based on a GaN technology. Background In GAN HEMT MMIC design, an accurate GaN HEMT device model is an important guarantee for ensuring that the chip characteristics of an actual flow sheet reach design indexes. Therefore, a transistor device model based on a GaN HEMT process needs to be able to characterize the dc and ac characteristics of a real device. It is necessary to include a current model and a charge model in addition to the parasitic rc effect in the model, as shown in fig. 1, which is an equivalent circuit diagram. Currently, the Advanced SPICE Model (ASM) for gallium nitride devices, which is introduced by the compact model alliance (CMC), can be applied to the description of nonlinear charges, but the ASM model is only applicable to use on a single drain voltage, and the specific model is: The simulation result of the ASM model is shown in fig. 2, in which the abscissa represents the gate-source voltage, the curve with a circle represents the actually measured gate-source capacitance, the curve without a circle represents the simulated gate-source capacitance of the ASM model, and the multiple curves represent the actually measured gate-source capacitance or the simulated gate-source capacitance under different drain-source voltages. As can be seen from the graph, the correlation of the gate-source capacitance with the increase of the drain-source voltage in the ASM model is greatly different from that of the actual device. Disclosure of Invention The invention aims to overcome the defects of the prior art and provides a charge model building and extraction method of a HEMT transistor based on a GaN process, wherein the built charge/capacitance model of the transistor can support charge/capacitance description of the HEMT transistor based on the GaN process, particularly the relation description of gate-source capacitance, gate-source voltage and drain-source voltage after a channel is started, and the accuracy of the model is effectively improved. The technical scheme adopted for solving the technical problems is as follows: In one aspect, a method for building a charge model of a HEMT transistor based on a GaN process includes: obtaining a gate channel voltage based on the externally input gate voltage, drain potential, and source potential; Obtaining gate charge based on gate charge density, gate count, gate length, and width of a single gate; obtaining a drain-source potential difference based on the drain potential and the source potential; based on the gate channel voltage, the gate charge and the drain-source potential difference, establishing a charge model for representing the correlation between the charge value and the drain-source voltage after the transistor device is started; and differentiating the charge value of the charge model, and establishing a capacitance model for representing the correlation of the gate-source capacitance, the gate-source voltage and the drain-source voltage. Preferably, the gate channel voltage is obtained based on the externally input gate voltage, drain potential, and source potential, concretely as follows: Where V gm denotes a gate channel voltage, V g0 denotes an externally input gate voltage, psid denotes a drain potential, and psis denotes a source potential. Preferably, the gate charge is obtained based on gate charge density, gate count, gate length, and width of the individual gates, as follows: Cgq＝Cg×wg×nf×lg Where C gq represents gate charge, cg represents gate charge density, w g represents the width of a single gate, nf represents the number of gates, and l g represents the gate length. Preferably, the drain-source potential difference is obtained based on the drain potential and the source potential, specifically as follows: psids=psid-psis Wherein psids denotes a drain-source potential difference, psid denotes a drain potential, and psis denotes a source potential. Preferably, a charge model for representing the correlation between the charge value after the transistor device is turned on and the drain-source voltage is obtained based on the gate channel voltage, the gate charge and the drain-source potential difference, which is specifically as follows: Wherein Q g represents the charge value of the charge model, C gp represents the gate charge, V gm represents the gate channel voltage, psids represents the drain-source potential difference, V tv represents the threshold voltage, tanh represents the hyperbolic tangent function, lambda A represents the first charge coefficient, lambda B represents the second charge coefficient, V k represents the knee point drain-source voltage, and ln represents the logarithmic function. On the other hand, the HEMT transistor charge model parameter extr