4H-SiC外延形貌缺陷对MOSFET电学特性影响研究OA

4H-SiC metal-oxide-semiconductor field-effect transistor(MOSFET)has become one of the most promising semiconductor devices due to their excellent properties such as high breakdown voltage,fast switching,and low loss.However,the yield and reliability of MOSFET can be degraded by morphological defects formed during the epitaxial process.In this study,the influence of three types of morphological defects on the electrical characteristics of 6.5 kV MOSFET was investigated.The results show that triangle defects can lead to early breakdown of the device,with a reverse breakdown voltage not exceeding 3 V.Furthermore,the presence of these defects in the active region also induces gate control failure.In contrast,triangle-like defects and linear defects have no significant impact on the breakdown voltage of the device,but the on-resistance of device with the triangle-like defect increases by 4.56%.Although triangle-like defects exhibit smaller band-gap shrinkage compared to linear defects,they introduce higher localized stress in their morphology and have a stacking fault area five times larger than that of linear defects,resulting in increased on-resistance of the device.In addition,both triangle-like defects and linear defects exhibit leakage current when a negative voltage was applied by the conductive atomic force microscope.Although neither type of defect caused significant changes in the static characteristics of the device,this behavior remains detrimental to long-term reliability.