CN-122017510-A - Gallium nitride device dynamic on threshold voltage test circuit and method

CN122017510ACN 122017510 ACN122017510 ACN 122017510ACN-122017510-A

Abstract

The invention belongs to the technical field of power device testing, and particularly relates to a gallium nitride device dynamic on threshold voltage testing circuit and method. The method solves the problems of poor stress switching instantaneity, low parameter extraction precision, difficulty in covering various working conditions and the like in the dynamic threshold voltage representation of the existing GaN device. The circuit comprises a high-voltage source circuit, a stress control switch, a drain load matching network, a threshold voltage test circuit and a threshold voltage test circuit, wherein the high-voltage source circuit is used for providing adjustable high-voltage bias and simulating high-voltage turn-off stress born by a device in practical application, the stress control switch is used for accurately controlling the time and time sequence of stress application and realizing rapid switching of a stress state and a test state, the drain load matching network is used for limiting current and protecting in an off-state drain bias stress test and providing adjustable working current for the device to be tested in a continuous switch stress test, and the threshold voltage test circuit is used for rapidly and accurately extracting dynamic threshold voltage parameters of the device to be tested in transient time after stress release.

Inventors

Duan Enchuan
TAN YUAN
HUANG SHUTING
ZHOU QI
ZHANG BO

Assignees

电子科技大学

Dates

Publication Date: 20260512
Application Date: 20260211

Claims (6)

1. The dynamic turn-on threshold voltage test circuit of the gallium nitride device is characterized by comprising a high-voltage source circuit (1), a stress control switch (2), a drain load matching network (3), a threshold voltage test circuit (4) and a device to be tested (5); the output end of the high-voltage source circuit (1) is connected to the input end of the stress control switch (2); the output end of the stress control switch (2) is connected to the first end of the drain load matching network (3); the second end of the drain load matching network (3) is respectively connected to the drain of the device (5) to be tested and the drain output end of the threshold voltage test circuit (4); the source electrode of the device to be tested is connected to the reference ground, the grid electrode of the device to be tested is connected to the driving loop through the driving resistor, and the grid electrode of the device to be tested is simultaneously connected to the grid electrode output end of the threshold voltage testing circuit (4); And the threshold voltage test circuit and the self-adaptive closed loop path are formed between the drain electrode and the grid electrode of the device to be tested and are used for transient advancing the threshold voltage of the device to be tested in the test stage.
2. The gallium nitride device dynamic on threshold voltage test circuit according to claim 1, wherein the threshold voltage test circuit (4) comprises a test control switch S3, a controlled constant current source I1, a first isolation diode D1, a second isolation diode D2 and a driving loop isolation switch S2; The test control switch S3 is connected between a test auxiliary power supply and the input end of the controlled constant current source I1; the output end of the controlled constant current source I1 is respectively connected with the anode of the first isolation diode D1 and the anode of the second isolation diode D2; the cathode of the first isolation diode D1 is connected with the drain electrode of the gallium nitride device 5 to be tested, and the unidirectional conduction direction of the first isolation diode D1 is from the anode to the cathode; The cathode of the second isolation diode D2 is directly connected with the grid electrode of the gallium nitride device (5) to be tested, and the unidirectional conduction direction of the second isolation diode D2 is from the anode to the cathode; The source electrode of the drive loop isolating switch S2 is connected with the output end of an external drive circuit, and the drain electrode is connected with the grid electrode of the gallium nitride device (5) to be tested; The stress control switch (2) is configured to be conducted in a stress applying stage and turned off in a testing stage, the driving circuit isolating switch S2 is configured to be conducted in the stress applying stage so as to be communicated with an external driving circuit and turned off in the testing stage so as to isolate the external driving circuit, and the testing control switch S3 is configured to be conducted in the testing stage so that the controlled constant current source I1 provides a testing current to a drain electrode through the first isolating diode D1 and a testing current to a grid electrode through the second isolating diode D2.
3. The circuit for testing the dynamic on threshold voltage of the gallium nitride device according to claim 1, wherein the high-voltage source circuit comprises a direct-current high-voltage source Vbus and a filter capacitor C1 with low equivalent series resistance ESR which are connected in parallel.
4. The circuit according to claim 1, wherein the stress control switch (2) is a bidirectional power switch S1 formed by connecting two power MOSFET tubes back to back, sources of the two MOSFET tubes are connected to each other and connected to a floating driving signal, and drains of the two MOSFET tubes are respectively used as an input end and an output end of the stress control switch.
5. A gallium nitride device dynamic on-threshold voltage test circuit according to claim 1, wherein the drain load matching network (3) comprises a drain load resistor R1.
6. A method for testing dynamic threshold voltage of gallium nitride device, adopting the test circuit as set forth in any one of claims 1-5, characterized in that in the initial state, the stress control switch S1, the test control switch S3 and the device to be tested are all turned off, and the drive circuit isolating switch S2 is turned on; The electric stress applying stage is to control the stress control switch (2) to be closed so that the high-voltage source circuit (1) applies electric stress to the drain electrode of the device (5) to be tested through the drain electrode load matching network (3) and simultaneously control the test control switch S3 to be opened; An electric stress releasing stage, wherein the stress control switch (2) is controlled to be disconnected; A grid isolation stage, wherein the drive circuit isolation switch S2 is controlled to be disconnected, so that the grid of the device (5) to be tested is electrically isolated from the drive circuit; A threshold voltage test stage, wherein the test control switch S3 is controlled to be closed, so that the controlled constant current source I1 injects a milliamp-level test current to the drain electrode of the gallium nitride device (5) to be tested through the first isolation diode D1, the test current enables the gate voltage of the device (5) to be tested to rise, when the gate voltage reaches a dynamic threshold voltage, the device is conducted, and the gate voltage is clamped and maintained at the dynamic threshold voltage; And the voltage acquisition step is to acquire the gate-source voltage of the device (5) to be detected through a voltage acquisition unit and use the gate-source voltage as a dynamic threshold voltage measurement value.

Description

Gallium nitride device dynamic on threshold voltage test circuit and method Technical Field The invention relates to the technical field of power device testing, in particular to a gallium nitride device dynamic on threshold voltage testing circuit and method. Background With the rapid popularization of gallium nitride (GaN) power devices in high-frequency and high-efficiency application scenarios such as consumer electronics, AI server power supply, electric traffic, etc., it is becoming a mainstream choice for replacing traditional silicon-based MOSFETs by virtue of low gate charge, high switching speed and compact physical size. However, in a practical high frequency high voltage operating environment, gaN devices (particularly schottky p-GaN gate HEMTs) face significant reliability challenges. Limited by charge storage effects in the floating p-GaN layer, interface trap charge trapping, and high-intensity electric field modulation, the threshold voltage (V TH) of the device can exhibit significant dynamic instability. Such dynamic threshold voltage shifts not only change the switching characteristics of the device, resulting in a compressed gate drive margin, but may even cause unintended erroneous conduction of the circuit, thereby threatening system-level reliability and thermal management stability. Therefore, the dynamic threshold voltage of the GaN device under the stress effect is accurately extracted, and the GaN device has extremely high engineering application value. However, existing characterization methods have significant limitations in dealing with dynamic threshold measurements. The traditional test platform is often focused on static parameter measurement or dynamic on-resistance evaluation, transient threshold fluctuation of a device under the same electric stress condition is difficult to capture, and standard test equipment is poor in real-time synchronism of stress switching and signal acquisition, and real characteristics of stress release moment are difficult to accurately restore. In view of the foregoing, there is a need for a GaN dynamic threshold voltage test solution with high response speed and capable of flexibly simulating multiple stress conditions, so as to meet the severe requirements of industry on dynamic characteristic evaluation of GaN devices. Disclosure of Invention The invention aims to solve the problems that in the existing gallium nitride (GaN) device dynamic threshold voltage testing technology, due to poor stress switching instantaneity, dependence on complex fitting of parameter extraction and single working condition simulation capability, the transient threshold voltage drift (caused by charge storage of a p-GaN layer, trapping of an interface trap and strong electric field modulation) of the device under multiple dynamic working conditions such as off-state drain bias stress or continuous switching stress cannot be accurately and efficiently captured. The invention adopts the following technical means to realize the purposes: The invention provides a gallium nitride device dynamic conduction threshold voltage test circuit, which comprises a high-voltage source circuit, a stress control switch, a drain load matching network, a threshold voltage test circuit and a device to be tested, wherein the high-voltage source circuit is connected with the stress control switch; the output end of the high-voltage source circuit is connected to the input end of the stress control switch; The output end of the stress control switch is connected to the first end of the drain load matching network; The second end of the drain load matching network is respectively connected to the drain of the device to be tested and the drain output end of the threshold voltage test circuit; The source electrode of the device to be tested is connected to the reference ground, the grid electrode of the device to be tested is connected to the driving loop through the driving resistor, and the grid electrode of the device to be tested is simultaneously connected to the grid electrode output end of the threshold voltage testing circuit; And the threshold voltage test circuit and the self-adaptive closed loop path are formed between the drain electrode and the grid electrode of the device to be tested and are used for transient advancing the threshold voltage of the device to be tested in the test stage. In the above scheme, the threshold voltage test circuit includes a test control switch S3, a controlled constant current source I1, a first isolation diode D1, a second isolation diode D2, and a driving circuit isolation switch S2; The test control switch S3 is connected between a test auxiliary power supply and the input end of the controlled constant current source I1; the output end of the controlled constant current source I1 is respectively connected with the anode of the first isolation diode D1 and the anode of the second isolation diode D2; the cathode of the first isolation diode D1 i