论文标题
了解螺纹位错在高温反向偏置应力下4H-SIC MOSFET崩溃的作用
Understanding the role of threading dislocations on 4H-SiC MOSFET breakdown under high temperature reverse bias stress
论文作者
论文摘要
在三个月的高温反向偏置（HTRB）应力后，研究了介电分解的起源，该介电分解的起源是在4H-SIC MOSFET上。对故障设备的当地检查证明了在故障位置存在螺纹位错（TD）。高级高空间分辨率探针显微镜（SPM）技术强调了介电击穿的纳米级起源。特别是，SPM揭示了TD的导电性质以及接近缺陷的少数载体浓度的局部增加。数值模拟估计孔浓度比理想的4H-SIC晶体大13个数量级。设备特定区域的孔注入解释了应力下栅极氧化物的故障。通过这种方式，明确证明了TD在4H-SIC MOSFET介电分解中的关键作用。
The origin of dielectric breakdown was studied on 4H-SiC MOSFETs that failed after three months of high temperature reverse bias (HTRB) stress. A local inspection of the failed devices demonstrated the presence of a threading dislocation (TD) at the breakdown location. The nanoscale origin of the dielectric breakdown was highlighted with advanced high-spatial-resolution scanning probe microscopy (SPM) techniques. In particular, SPM revealed the conductive nature of the TD and a local increase of the minority carrier concentration close to the defect. Numerical simulations estimated a hole concentration 13 orders of magnitude larger than in the ideal 4H-SiC crystal. The hole injection in specific regions of the device explained the failure of the gate oxide under stress. In this way, the key role of the TD in the dielectric breakdown of 4H-SiC MOSFET was unambiguously demonstrated.
