具有部分超结的新型SiC SBD特性分析

Characteristics of a SiC SBD with semi-superjunction structure

提出了一种具有部分超结(super junction,SJ)结构的新型SiC肖特基二极管,命名为SiC Semi-SJ-SBD结构,通过将常规SBD耐压区分为常规耐压区和超结耐压区来减小导通电阻,改善正向特性.利用二维器件模拟软件MEDICI仿真分析,研究了不同超结深度和厚度时击穿电压(VB)和比导通电阻(Ron-sp),与常规结构的SBD比较得出,半超结结构可以明显改善SiC肖特基二极管特性,并得到优化的设计方案,选择超结宽度2W为2μm,3μm,超结深度大于5μm,可以使Ron-sp降低量大于10%,而且保持VB基本不变(降低量小于4%).

A novel SiC semi-superjunction-Schottky Barrier Diode （Semi-SJ-SBD） structure is proposed, which is the combination of super-junction （SJ） structure and conventional drift region structure. The proposed structure can significantly reduce the specific on-resistance （ Ron-sp ） and improve the forward characteristics. The breakdown voltage （ VB ） and specific on-resistance （ Ron-sp ） in different SJ depth and width are studied using two-dimensional simulator Medici and compared with conventional SiC SBD. The results show that Ron-sp is greatly reduced （greater than 10% ） with VB unchanged （less than 4% ） when the SJ width is chosen as 2--3 μm and SJ depth is deeper than 5μm.