4H-SiC沟槽型结势垒肖特基二极管仿真与实验研究.pdfVIP

中国电工技术学会电力电子学会第十四届学术年会 4H-SiC 沟槽型结势垒肖特基二极管的仿真与实验研究 吴九鹏，任娜，盛况 浙江大学电气工程学院，浙江杭州，310007 Design and Experimental Study of 4H-SiC Trenched Junction Barrier Schottky Diodes WU Jiu-peng, REN Na, SHENG Kuang (College of Electrical Engineering, Zhejiang University, Hangzhou, Zhejiang, 310007) 摘要：本文介绍了1200V 等级的4H-SiC 结势垒肖特基(JBS)二极管的仿真和实验研究。基于2 维数值仿真平台Silvaco ，研究 了不同结构参数，如p+ 区深度（X ）、p+ 区间距（S）对JBS 二极管的正反向特性的影响。实验中实现了两种不同的JBS 二极 j 管，即平面型JBS 和沟槽型JBS （TJBS ），测试了其正反向特性。由于4H-SiC 中离子注入深度的限制，平面型JBS 二极管的 p-n 结深较浅，电场屏蔽效应只有在S 较小的情况下有效，增大了工艺中对线宽控制的要求。而TJBS 二极管的p-n 结深较深， 电场屏蔽效应在 S 较大时同样有效，当 1.5μmS3.0μm 时，器件都能同时实现较好的正反向特性，从而减小了工艺中对线 宽控制的要求，提高了生产的良率。器件最高实现了1766V 的反向耐压，接近100%的耐压效率。 关键词：4H-SiC ；结势垒肖特基（JBS ）二极管；沟槽型结势垒肖特基（TJBS ）二极管 ABSTRACT : This paper presents the design, fabrication and experimental analysis of 1200V 4H-SiC junction barrier Schottky (JBS) and trenched junction barrier Schottky (TJBS) diodes. Design considerations and device performances of JBS and TJBS diodes are compared via numerical simulation and experiments. Due to the limited P+ implantation depth in SiC for planar JBS diodes,the electric field shielding effect is sufficient only for narrow junction spacing. As a result, there is a stringent requirement on obtaining a narrow photolithography line width. On the other hand, TJBS diodes have reinforced electric field shielding effects by the introduction of deeper PN junctions, which enables good reverse blocking and forward conduction capabilities at the same time . As a result, this structure puts less restriction on line width control of the fabrication process and hence can improve the device yield. The maximum breakdown voltage achieved in this paper is 1766V, close to 100% of the theoretical br