Research On High-precision Test Method For Wide Impedance Range Of High Power Semiconductor Devices

With the rapid development of electronic information technology,semiconductor devices,as the key element of hardware circuits,have evolved over three generations in decades.As a representative of the third-generation semiconductor devices,GaN power devices have many advantages including excellent band gap,good thermal conductivity,ultra-high electron mobility and ultra-high breakdown voltage,so it attracts many researchers in recent year.However,due to the low impedance of the GaN power device,a certain measurement error is caused by excessive port reflection during actual measurement.Therefore,it is a challenge that measuring the characteristic parameters of high-power semiconductor devices accurately in this field.This topic mainly studies the wide impedance range and high-precision test method of highpower semiconductor devices.By comparing various impedance conversion schemes,a new test method is proposed,and the accuracy of the this method is verified by ADS simulation.In addition,the main parameters of GaN power device are tested and extracted such as the S-parameters in order to test the feasibility of the verification method.The method utilizes a test fixture to achieve a fixed device under test and a signal transmission function,and the impedance conversion is achieved to some extent.This is beneficial to solve the mismatch problem caused by the low impedance of the input and output ports of the GaN power device.In the test system,the 50 ? system impedance is conversed to the input and output impedance values of the DUT.Not only the impedance test range of the test system is improved,but also the measurement accuracy.Network analyzers are the most important test instruments in modern microwave RF test systems,and network analyzer-based test systems inevitably produce measurement errors due to the undesired characteristics of instruments,cables,and test fixtures.To solve this problem,the SOLT calibration method based on 12 error models and the TRL calibration method based on 8 error models are studied to eliminate the errors generated during the actual test.Furthermore,this paper proposes the fixture de-embedding technology and calibration method for wide-impedance high-precision test methods based on the research of traditional calibration methods.Through the actual design of the test fixture,the Sparameters of the test fixture are tested and solved.Finally,the test method with wideimpedance and high precision is used to measure the S parameters extracted to the GaN power device,and the results are compared to the measured data.Through the research,simulation verification and practical test of high-impedance highprecision test method,this paper achieves the wide impedance range and high-precision test of high-power semiconductor devices represented by GaN power devices,which solves the problem of low accuracy and mearurement error.Overall,this paper provides a new method for the testing of high-power semiconductor device.It also lays a corresponding research foundation for ultra-high power and ultra-high frequency power amplifier design.