Study Of The Uis Characteristics Of The Power Mosfet

The development of semiconductor technology and the deep cognition of reliability and failure mode have brought a new challenge to the power semiconductor manufacture. How to make the products more safe, reliable and long shelf life with decreasing chip size also becomes another challenge to many companies. Especially the power MOSFET switch (like communication power supply) and the automotive electronics have extensive use in special environment. UIS failure becomes one of the most vital security killer of power MOSFET. Generally the product ruggedness (UIL capability) decreases with die size. The smaller the chip size, the lower energy the chip can sustain. It is the contradiction to the decreasing chip size with the trend of semiconductor which has been mentioned in"Moore law".It will lead to the UIS which gives rise to safe problem becomes more serious.It describs DC, AC and the thermal characteristics of Power MOSFET in this thesis, unifies in these characteristics and the practical application component's breakdown characteristic, conducts the research separately from the following several aspects to the power MOSFET UIS characteristic:1 UIS electric circuit level mechanism and test method.2 UIS component physics level principle and failure mode.3 The effect of UIS to the power MOSFET electrical characteristic.4 Analysis of UIS thermal characteristics.A trench power MOSFET which is used in automobile electron domain has been selected in this thesis, it carries on the UIS test according to the actual project requirement with different test condition. Use engineering methods just like DC test, reliability test and failure analysis to carry on the analysis to UIS test result, finally it sets up a physical model of temperature distribution and provide theory analysis of junction temperature, verification test result.The engineering method in this thesis is significant to the establishment of UIS test spec and the setting of UIS test limit in mass production; This thesis provide the supplement to computational method of Tj,it is helpful to theoretically determine safe operation condition of UIS; It does research on the UIS failure mode by the physical model which has the positive influence to improve UIS characteristic of power MOSFET.