3300V SiC MOSFET栅氧可靠性研究

Investigation on the Reliability of Gate Oxide in 3300V SiC MOSFET

碳化硅SiC(silicon carbide)功率器件因其卓越的材料性能,表现出巨大的应用前景,其中金属-氧化物-场效应晶体管MOSFET(metal oxide semiconductor field effect transistor)是最重要的器件。3300 V SiC MOSFET可应用于轨道交通和智能电网等大功率领域,能显著提高效率,降低装置体积。在这些应用领域中,对功率器件的可靠性要求很高,为此,针对自主研制的3300 V SiC MOSFET开展栅氧可靠性研究。首先,按照常规的评估技术对其进行了高温栅偏HTGB(high temperature gate bias)试验;其次,针对高压SiC MOSFET的特点进行了漏源反偏时栅氧电热应力的研究。试验结果表明,在高压SiC MOSFET中,漏源反偏时栅氧的电热应力较大,在设计及使用时应尤为注意。

The applications of silicon carbide(SiC)power devices keep growing rapidly owing to their excellent material properties,and metal-oxide-semiconductor field effect transistor(MOSFET)is one of the most important devices.3300 V SiC MOSFET can significantly improve the efficiency and reduce the volume,so it is applicable in rail traction,smart grid and other high-power fields,where high reliability of power devices is required.Based on a self-developed 3300 V SiC MOSFET,the reliability of its gate oxide was investigated.First,high temperature gate bias(HTGB)tests were carried out according to the conventional evaluation technology.Then,the electrical-thermal stress of gate oxide under reverse bias was verified by taking into account the characteristics of high-voltage SiC MOSFET.Test results show that the gate oxide in high-voltage SiC MOSFET endured a high electrical-thermal stress under reverse condition,which should be paid attention to in its design and applications.