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

• 作者: 宋庆文 张义门 张玉明 汤晓燕 王悦湖 郭辉 韩超
• 来源期刊: 中国物理B（英文版）
• 关键词: 4H-SiC p-type ohmic contact alloying step bunching
• 年，卷（期）: 2015,（11）
• 页码范围: 117304-1-117304-8
• 页数: 1页
• 语种: 英文
• DOI: 10.1088/1674-1056/24/11/117304

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 Al:Ti composition with no more than 50 at.%Al. The specific contact resistance (SCR) is obtained to be as low as 2.6 × 10?6?·cm2 for the bilayered Ti(100 nm)/Al(100 nm) contact treated with 3 min rapid thermal annealing (RTA) at 1000?C. 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 Ti3SiC2 layer with (0001)-oriented texture can be formed, regardless of the surface step bunching as well as its structural evolution during the metallization annealing.