Naoya Okamoto, Toshihiro Ohki, Satoshi Masuda, Masahito Kanamura, Yusuke Inoue, Kozo Makiyama, Kenji Imanishi, Hisao Shigematsu, Toshihide Kikkawa, Kazukiyo Joshin, and Naoki Hara
Fujitsu Limited and Fujitsu Laboratories Ltd.
10-1 Morinosato-Wakamiya, Atsugi 243-0197, Japan
E-mail: naoya_okamoto@jp.fujitsu.com, Phone: +81-46-250-8242
Keywords: SiC, Backside via-hole process, ICP etching, GaN HEMT
We have demonstrated a SiC backside via-hole process for GaN HEMT MMICs using ICP etching at a high rate of about 2 μm/min, higher than any previously reported rate. We discuss pillars, microtrenches, RIE lag, loading effects and etch uniformity in high-rate ICP etching, which are significant issues related to the yield of via-hole fabrication. Finally, we describe the successful 3-inch backside via-hole process for GaN HEMT MMICs.