Low specific contact resistance on epitaxial p-type 4H-SiC with a step-bunching surface

作     者：韩超 张玉明 宋庆文 汤晓燕 张义门 郭辉 王悦湖 Han Chao;Zhang Yu-Ming;Song Qing-Wen;Tang Xiao-Yan;Zhang Yi-Men;Guo Hui;Wang Yue-Hu

作者机构：School of Microelectronics Xidian University Key Laboratory of Wide Band Gap Semiconductor Materials and Devices School of Advanced Materials and Nanotechnology Xidian University 

出 版 物：《Chinese Physics B》 (中国物理B（英文版）)

年 卷 期：2015年第24卷第11期

页      面：452-459页

核心收录：

学科分类：081702[工学-化学工艺] 08[工学] 0817[工学-化学工程与技术] 

基　　金：supported by the Key Specific Projects of Ministry of Education of China(Grant No.625010101) the National Natural Science Foundation of China(Grant No.61234006) the Natural Science Foundation of Shaan Xi Province,China(Grant No.2013JQ8012) the Doctoral Fund of Ministry of Education of China(Grant No.20130203120017) the Specific Project of the Core Devices,China(Grant No.2013ZX0100100-004) 

主　　题：4H-SiC p-type ohmic contact alloying step bunching 

摘      要：This paper reports the performances of Ti/Al based ohmic contacts fabricated on highly doped p-type 4H-SiC epitaxial layer which has a severe step-bunching surface. Different contact schemes are investigated based on the AI：Ti composition with no more than 50 at.% Al. The specific contact resistance （SCR） is obtained to be as low as 2.6 × 10-6Ωcm2 for the bilayered Ti（100 nm）/Al（100 nm） contact treated with 3 rain rapid thermal annealing （RTA） at 1000 ℃. The microstructure analyses examined by physical and chemical characterization techniques reveal an alloy-assisted ohmic contact formation mechanism, i.e., a high degree of alloying plays a decisive role in forming the interfacial ternary Ti3SiC2 dominating the ohmic behavior of the Ti/Al based contact. Furthermore, a globally covered Ti3 SiC2 layer with （0001）-oriented texture can be formed, regardless of the surface step bunching as well as its structural evolution during the metallization annealing.