Research On Manufacturing And Testing Of Silicon Carbide JBS Device

With the application of high power and high radiation,it shows great material advantages and broad application prospects,so it is very suitable for making power electronic power devices.Compared with traditional silicon-based materials and devices,they have many superior characteristics,and these advantages will become more and more obvious in the global market in the next few years.Among them,the 4H-Si C JBS power diode is currently the most mature and fastest growing Si C power device with a certain application and research foundation.This structure includes Schottky barrier diodes and junction barrier Schottky diodes,and therefore has the superior performance of these two types of diodes.For example,it has high reverse withstand voltage,low turn-on voltage drop,low leakage current,Higher frequency characteristics and other capabilities.There have been many reports of Si C JBS diodes abroad,and there have been substantial developments in recent years,while domestic reports of Si C power devices are relatively few.This article mainly made targeted research on the package thermal resistance test of 4H-Si C JBS power diode and the electrical characteristic parameters at different operating temperatures and the parameters under different reliability tests in the following aspects.The following is the main research content:(1)The operating principles of SBD,Pi N,and JBS diodes(including forward and reverse characteristics,etc.)are systematically described.Among them,based on the operating principles of JBS diodes,the forward characteristics,reverse withstand voltage characteristics,and Temperature characteristics,etc.,provide a theoretical basis for the subsequent testing of the electrical characteristics of the diode at different temperatures.Then describes the process flow,process difficulties and main defects brought by JBS diode tape out,including triangle defects,microtubes,dislocations and so on.(2)Study the classification of device packaging,which focuses on the design,process and key factors of power device packaging,including heat sinks,solder paste,leads,and plastic packaging materials.Then test the thermal resistance of the device under test,and test the shell temperature and junction temperature of the device under test to calculate the thermal resistance.From the test results,it can be found that when the power dissipation increases,the junction and shell temperature will vary to varying degrees.As the temperature rises,the junction temperature T_J rises slowly,while the case temperature T_Crises relatively quickly.At the same time,it can also be observed that the junction-to-case thermal resistance also increases with the increase in power dissipation,but there are also some test results that deviate from its theoretical value,resulting in the deviation of some data in the image,which may be caused by the test equipment or chip A series of factors such as size.Finally,the results of our thermal resistance test are compared with the device test results of the internationally renowned company Cree and found to be consistent with our heat dissipation effect.(3)Test the electrical characteristics of the device under test,including the I_V curve test at different operating temperatures in the forward conduction characteristic and the reverse blocking characteristic,as well as the extraction of Schottky barrier height,ideal factor and on-resistance parameters And analyze the test results.Then conduct reliability tests on the device under test,including pretreatment,temperature cycling,high temperature and high pressure reverse bias test,high pressure cooking test,and measure the parameter values of the forward voltage drop and reverse leakage current of each test.The forward and reverse changes of the device under test are described.It is found that the forward characteristics are basically stable and unchanged,and the reverse characteristics are greatly affected by the test.In the pretreatment and high temperature reverse bias test,the reverse leakage current I_Rwill be Increased than before the test,especially in the high temperature reverse bias test,the increase is particularly large;and in the temperature cycle and high pressure cooking test,the reverse leakage current I_R will be lower than before the test.