A New Trench Termination for Power Semiconductor Devices

전력소자를 위한 새로운 홈구조 터미네이션

The trench termination scheme is introduced for high voltage devices. The curvature of the depletion region at field limiting ring is critical factor to determine the breakdown voltage. The smooth curvature of the depletion junction alleviate the electric field crowding effect around this region. In the trench field limiting ring, the radius of the depletion region is smaller than conventional field limiting ring, but the distance between every trench is spaced small enough to punchthrough before initiation of local breakdown. The trench field limiting ring on silicon can ne formed by RIE followed by oxidation on side wall surface of the trench, and polysilicon filling. The combined termination of this trench floating field ring and field plate have been designed and analyzed. The breakdown simulation by 2-dimensional TCAD shows that the cylindrical junction breakdown voltage for substrate doping might be 99 percent of the ideal breakdwon voltage for substrate doping concentration of $3\times10^{14}cm^{-3}$ with about $100{\mu}m$ of lateral termination width.