快速软恢复SiGe功率开关二极管的结构设计与特性分析  

Structure Design and Characteristics Analysis of Fast and Soft Recovery SiGe Switching Power Diodes

作　　者：马丽[1] 高勇[2] 刘静[2] 余明斌 

机构地区：[1]西安理工大学应用物理系,西安710048 [2]西安理工大学电子工程系,西安710048 [3]新加坡微电子研究所,新加坡117685

出　　处：《电子器件》2007年第4期1255-1257,1265,共4页Chinese Journal of Electron Devices

基　　金：国家自然科学基金资助(50477012);陕西省教育厅专项科研项目资助(05JK268);高等学校博士学科点专项科研基金资助(20050700006)

摘　　要：为了进一步提高SiGe/Si异质结功率开关二极管的性能,提出了一种SiGe功率开关二极管的新结构,用交替的p+、n+区形成的mosaic结构来代替原常规的n+区,关断时可同时为电子和空穴的抽取提供通道使阴极具有理想欧姆接触.该结构可大大提高开关速度,并获得很软的反向恢复特性及很低的漏电流.与常规p+(SiGe)-n--n+功率开关二极管相比,反向恢复时间缩短了近2/3,反向峰值电流降低了约1/2,漏电流降低了约1个数量级.另外,嵌镶结构中p+区的厚度对器件性能有很大影响,调整p+区的厚度可实现器件的反向耐压能力和反向恢复特性之间很好的折衷.这种性能的改进无需采用少子寿命控制技术因而很容易集成于功率IC中.A novel structure of SiGe/Si hetero-junction switching power diode is proposed in order to improve further the characteristics of SiGe diodes. The improvement is achieved by using a p^＋ -n^＋ mosaic layer as a substitute for the n^＋ region in the conventional p^＋ （SiGe）-n^- -n^＋ diode to realize an ＂ideal ohmic＂ contact for electrons and holes simultaneously. The reverse recovery characteristics of the novel SiGe diodes are much more improved. Compared with conventional SiGe diodes, there are about two thirds shorter in the reverse recovery current and a half shorter in peak reverse recovery current. Furthermore, the leakage current decreases one order of magnitude and much more soft recovery characteristics is obtained. Moreover, the p^＋ regions thickness in mosaic structure has great influence on the devices characteristics and the better trade-off between the reverse block voltage and the reverse recovery characteristic can be gotten by adjusting the p^＋ regions thickness. The performance improvement doesn＇t resort to lifetime killing technology,therefore, it can be easily integrated into power IC.

关 键 词：SIGE/SI异质结 功率二极管 快速软恢复 低漏电流 

分 类 号：TN313.4[电子电信—物理电子学]