SiC MOSFET高温可靠性评估失效机理研究

Research on Failure Mechanism of High Temperature Reliability Evaluation of SiC MOSFET

碳化硅(SiC)金属-氧化物半导体场效应晶体管(MOSFET)器件具有耐高压、耐高温、开关频率高、导通电阻低等特性,但现有的封装材料、工艺在一定程度上限制了SiC MOSFET器件充分发挥其高温特性的优势。以国际主流厂商的SiC MOSFET器件为对象,进行极限高温可靠性评估。对试验后失效器件进行失效机理分析,提出导致器件失效的主要原因并非通常认为的源极键合丝接触电阻增大所致,而是由于栅极键合丝接触电阻增大导致器件沟道电阻变大,进而导致上述失效。该试验为后续相关工艺的改进提供了参考依据,有利于更好地发挥SiCMOSFET的优势。

Silicon carbide(SiC)metal-oxide-semiconductor field-effect transistor(MOSFET)devices have the charac-teristics of high voltage resistance,high temperature resistance,high switching frequency and low on-resistance.How-ever,the existing packaging materials and processes restrict the SiC MOSFET devices to give full play to their high-temperature characteristics to a certain extent.Taking the SiC MOSFET devices of international mainstream manufac-turers as the object,the reliability evaluation of extreme high temperature is carried out.The failure mechanism of the failed devices after the test is analyzed,and it is proposed that the main cause of device failure is not due to the in-crease in the contact resistance of the source bonding wire,but the channel resistance of the device due to the in-crease in the contact resistance of the gate bonding wire becomes larger,which in turn leads to the above-mentioned failure.The experiment provides a reference for the improvement of subsequent related processes,which is conducive to better exerting the advantages of SiC MOSFET.