Vertical and bevel-structured SiC etching techniques incorporating different gas mixture plasmas for various microelectronic applications

• Published in: Scientific reports 2017-06, Vol.7 (1), p.3915-9, Article 3915
• Main Authors: Sung, Ho-Kun, Qiang, Tian, Yao, Zhao, Li, Yang, Wu, Qun, Lee, Hee-Kwan, Park, Bum-Doo, Lim, Woong-Sun, Park, Kyung-Ho, Wang, Cong
• Format: Article
• Language: English
• Subjects: 142/126; 639/166/987; 639/301/930/12; 639/766/1130; Etching; Fabrication; Humanities and Social Sciences; multidisciplinary; Science; Science (multidisciplinary); Silicon carbide
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-017-04389-y

This study presents a detailed fabrication method, together with validation, discussion, and analysis, for state-of-the-art silicon carbide (SiC) etching of vertical and bevelled structures by using inductively coupled plasma reactive ion etching (ICP-RIE) for microelectronic applications. Applying different gas mixtures, a maximum bevel angle of 87° (almost vertical), large-angle bevels ranging from 40° to 80°, and small-angel bevels ranging from 7° to 17° were achieved separately using distinct gas mixtures at different ratios. We found that SF 6 with additive O 2 was effective for vertical etching, with a best etching rate of 3050 Å/min. As for the large-angle bevel structures, BCl 3  + N 2 gas mixtures show better characteristics, exhibiting a controllable and large etching angle range from 40° to 80° through the adjustment of the mixture ratio. Additionally, a Cl 2  + O 2 mixture at different ratios is applied to achieve a small-angel bevels ranging from 7° to 17°. A minimum bevel angel of approximately 7° was achieved under the specific volume of 2.4 sccm Cl 2 and 3.6 sccm O 2 . These results can be used to improve performance in various microelectronic applications including MMIC via holes, PIN diodes, Schottky diodes, JFETs’ bevel mesa, and avalanche photodiode fabrication.