CN-121995189-A - Gallium nitride transistor thermal resistance measuring device and method based on laser thermal reflectivity

CN121995189ACN 121995189 ACN121995189 ACN 121995189ACN-121995189-A

Abstract

The invention provides a gallium nitride transistor thermal resistance measuring device and method based on laser thermal reflectivity, and relates to the technical field of semiconductor device testing, wherein the method is used for acquiring laser reflectivity data of gallium nitride transistors at different temperatures; calculating the distance weight of each data point of the laser reflectivity data to the target point to obtain the distance weight of each data point, carrying out local linear fitting based on the distance weight to obtain the current fitting value of the target point, carrying out residual calculation on all the data points based on the current fitting value of the target point to obtain the robust scale estimation of the residual, updating the combination weight by utilizing the robust scale estimation of the residual to obtain the next updating result, and obtaining the thermal resistance measurement result when the fitting value change of the next updating result is smaller than the preset threshold value and reaches any one of the maximum iteration times to finish the measurement of the thermal resistance of the gallium nitride transistor. The invention solves the problems of large noise and insufficient stability of the test result of the existing heat reflection temperature measurement method.

Inventors

ZHANG YAMIN
WANG SHIHAO
Cheng Haoxuan
Peng Ruikang
XIAO MENGYUE

Assignees

北京工业大学

Dates

Publication Date: 20260508
Application Date: 20260205

Claims (7)

1. The gallium nitride transistor thermal resistance measuring device based on the laser thermal reflectivity is characterized by comprising a measurement and control module, an optical path module and a bearing module; The bearing module comprises a manual three-dimensional table (10) and a constant temperature platform (9) arranged on the manual three-dimensional table (10), and the constant temperature platform (9) is used for bearing a device (8) to be tested; The measurement and control module comprises an upper computer (1), a laser driver (2), a photoelectric detection assembly (13), a data acquisition card (14) and a power supply (15), wherein the upper computer (1) is respectively and electrically connected with the laser driver (2), the data acquisition card (14) and the power supply (15), and the power supply (15) is used for supplying power to a device (8) to be measured; the optical path module comprises a laser (3), a first optical lens (4), a first spectroscope (5), a second spectroscope (6), an objective lens (7), a focusing lens (12) and a CCD camera (11); The laser driver (2) is electrically connected with the laser (3), and light beams emitted by the laser (3) are collimated by the first optical lens (4) and then are incident to the first spectroscope (5); The emergent light path of the first spectroscope (5) is coupled to the second spectroscope (6), and the emergent light path of the second spectroscope (6) is focused to a device (8) to be tested through an objective lens (7); the reflected light of the device (8) to be tested returns to the second beam splitter (6) through the objective lens (7); The second spectroscope (6) splits part of the reflected light to the CCD camera (11) for observing the spot position, and transmits or reflects the other part of the reflected light to the first spectroscope (5); the first beam splitter (5) couples the light beam from the second beam splitter (6) to a focusing lens (12); the emergent light path of the focusing lens (12) is coupled to the input end of a photodiode of the photoelectric detection component (13), and the output end of the photoelectric detection component (13) is electrically connected with the data acquisition card (14).
2. The device for measuring thermal resistance of gallium nitride transistor based on laser thermal reflectivity according to claim 1, wherein the photodetection module (13) comprises: The device comprises a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a resistor R8, a resistor R9, a resistor R10, a photodiode, a first operational amplifier, a second operational amplifier, a third operational amplifier, a fourth operational amplifier and a fifth operational amplifier, wherein the positive electrode of the photodiode is connected with the inverting input end of the first operational amplifier, the negative electrode of the photodiode is respectively connected with the positive input end of the first operational amplifier and one end of the resistor R2, the other end of the resistor R2 is respectively connected with the output end of the first operational amplifier and the positive input end of the fourth operational amplifier, the inverting input end of the fourth operational amplifier is respectively connected with one end of the resistor R6 and one end of the resistor R7, the output end of the fourth operational amplifier is respectively connected with the other end of the resistor R7 and one end of the resistor R8, the other end of the resistor R8 is respectively connected with the positive input end of the ground resistor R10 and the positive input end of the fifth operational amplifier, the other end of the resistor R6 is respectively connected with the inverting input end of the third operational amplifier and the positive end of the third operational amplifier and the other end of the resistor R5 is respectively connected with the inverting input end of the third operational amplifier, the inverting input end of the fourth operational amplifier is respectively connected with the inverting input end of the resistor R1 and the third operational amplifier is connected with the other end of the positive end of the resistor R5 and the third operational amplifier is connected with the other end of the positive end of the resistor is respectively, the negative electrode of the output end of the photoelectric detection component is grounded.
3. A method for measuring thermal resistance of a gallium nitride transistor based on laser thermal reflectivity, which is applied to the device for measuring thermal resistance of a gallium nitride transistor based on laser thermal reflectivity according to any one of claims 1-2, and comprises the following steps: s1, acquiring laser reflectivity data of a gallium nitride transistor at different temperatures; S2, calculating the distance weight of each data point of the laser reflectivity data to the target point to obtain the distance weight of each data point; s3, based on the distance weight, carrying out local linear fitting to obtain a current fitting value of the target point; s4, carrying out residual calculation on all data points based on the current fitting value of the target point to obtain a residual robust scale estimation; And S5, updating the combination weight by utilizing robust scale estimation of residual errors to obtain a next updating result, judging that the next updating result meets a preset threshold value of fitting value change and reaches the maximum iteration number, stopping iteration when the next updating result meets any one of the fitting value change smaller than the preset threshold value and the maximum iteration number, obtaining a thermal resistance measuring result, and finishing measurement of the thermal resistance of the gallium nitride transistor, otherwise, returning the updating result to S3 for iterative calculation.
4. A method for measuring thermal resistance of a gallium nitride transistor based on laser thermal reflectivity according to claim 3, wherein the expression of the distance weight is: ; ; ; Wherein, the Representation of The distance weight relative to the target data point, Representing the target data point(s), The function of the third order kernel is represented, Indicating that the i-th data point is present, Representing the local window width of the target data point, Representing the first variable.
5. A method for measuring thermal resistance of a gallium nitride transistor based on laser thermal reflectivity according to claim 3, wherein the expression of the current fitting value of the target point is: ; ; Wherein, the Representing the solved minimum intercept term, Representing the solved minimum slope term, The minimization function is represented as a function of the minimization, Representing the combination weight in the t-1 th iteration of the target data point, i representing the data point sequence number, n representing the number of data points, t representing the number of iterations, Representing the target data point(s), The observation data representing the i-th data point, The intercept term is represented as such, Represents a slope term that is representative of the slope, Indicating that the i-th data point is present, Representing the current fit value of the target data point x.
6. A method for measuring thermal resistance of a gallium nitride transistor based on laser thermal reflectivity according to claim 3, wherein the expression of the robust scale estimation is: ; Wherein, the Representing robust scale estimation in the t-th iteration, Represents the absolute deviation of the bits in the position, The residual error of the ith data point in the t-th iteration is represented, i represents the data point serial number, and t represents the iteration number.
7. A method for measuring thermal resistance of a gallium nitride transistor based on laser thermal reflectivity according to claim 3, wherein the expression of the next updated result is: ; ; ; ; Wherein, the Representing the combining weights for the ith data point in the t-th iteration, Representing the target data point(s), Representation of The distance weight relative to the target data point, The robust weight is represented as a function of the weight, A double-weighted function is represented and, Representing the residual of the ith data point in the t-th iteration, Representing robust scale estimation in the t-th iteration, Representing a second variable.

Description

Gallium nitride transistor thermal resistance measuring device and method based on laser thermal reflectivity Technical Field The invention relates to the technical field of semiconductor device testing, in particular to a gallium nitride transistor thermal resistance measuring device and method based on laser thermal reflectivity. Background Gallium nitride-based microwave power devices have shown excellent performance in the fields of high-frequency and high-power application by virtue of the characteristics of high response speed, high breakdown electric field strength, high radio frequency output power, high temperature resistance and the like. The device is a key component for microwave power amplification in radar, satellite communication, precision guidance and electronic countermeasure equipment, and is a strategic development direction which is preferentially supported in all countries of the world. However, under high-frequency and high-power working conditions, the excessive temperature of the active region of the gallium nitride microwave power device becomes a key for restricting the reliability and stability of the gallium nitride microwave power device. Therefore, measurement of the temperature distribution of the device surface and detection of the thermal resistance of each material on the device heat dissipation path are critical to the reliability of the process. Methods that can be used to characterize the temperature rise characteristics of the active region of gallium nitride-based microwave power devices include infrared thermal imaging, raman spectral thermal imaging, electrical parametric methods, and thermal reflection methods. However, they can only obtain a temperature profile on the device surface or determine the temperature of the material layer on the device heat source path. Traditional thermal reflectometry uses data acquisition by a Charge Coupled Device (CCD) camera, the shortest exposure time of which determines the minimum time resolution of the experiment. This severely limits the temporal resolution of the heat reflection method. To solve this problem, a boxcar model has been proposed by the scholars, which has only one LED pulse for each CCD camera exposure, shortens the CCD camera exposure time to the duration of the LED pulse, and shortens the time resolution to the delay time between excitation and LED pulse. However, this approach requires a high level of requirements for the CCD camera and involves complex mechanical movements, which greatly increases costs. Other scholars have improved on this basis, and in the long exposure process of the CCD camera, pulse excitation is applied to the device, and time delay exists between the LED pulse and the pulse excitation of the device, and the time resolution of the system is determined by the delay time. This approach reduces the requirements on the CCD camera, but this approach requires multiple heats of the device. However, due to the low thickness and small area of the active region of typical gallium nitride devices, the minimum thermal time constant is typically on the order of microseconds and the time to heat to steady state after packaging is typically in excess of 100 seconds. Multiple times of cyclic heating can cause device damage, and the accuracy of the experiment is affected. For this situation, photodiodes are proposed for detection, but the time resolution needs to be further improved. The traditional noise reduction method is adaptive to weak and volatile data details, and cannot meet the high-precision requirement. Disclosure of Invention Aiming at the defects in the prior art, the device and the method for measuring the thermal resistance of the gallium nitride transistor based on the laser thermal reflectivity solve the problems of large noise and insufficient stability of the test result of the traditional thermal reflection temperature measurement method. In order to achieve the aim of the invention, the technical scheme adopted by the invention is that the gallium nitride transistor thermal resistance measuring device based on laser thermal reflectivity comprises a measurement and control module, an optical path module and a bearing module; The bearing module comprises a manual three-dimensional table and a constant temperature platform arranged on the manual three-dimensional table, and the constant temperature platform is used for bearing a device to be tested; the measurement and control module comprises an upper computer, a laser driver, a photoelectric detection assembly, a data acquisition card and a power supply, wherein the upper computer is respectively and electrically connected with the laser driver, the data acquisition card and the power supply, and the power supply is used for supplying power to a device to be measured; The light path module comprises a laser, a first optical lens, a first spectroscope, a second spectroscope, an objective lens, a focusing lens and a CCD camera; The l