In this study, we have developed a technique for forming GaN through-substrate vias (TSV) using inductively coupled plasma (ICP) dry etching with a gas mixture of Cl2/BCl3. A 91 μm-deep GaN via-hole having a diameter of 80 μm was successfully formed at a high etching rate of 1.5 μm/min and a high etching selectivity of 35. We discuss pillar formation, RIE lag, loading effects and etch uniformity in high-rate ICP etching, which are critical issues related to the yield of via-hole fabrication. Finally, we investigated the effect of GaN TSVs on heat dissipation by thermal simulation.
Yusuke Kumazaki
Fujitsu Limited
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High-rate ICP Etching for GaN Through-substrate Via of GaN-on-GaN HEMTs
Keiji Watanabe, Fujitsu Laboratories Ltd.Naoya Okamoto, Fujitsu Limited and Fujitsu Laboratories Ltd.Naoya Okamoto, Fujitsu Laboratories Ltd.Atsushi Takahashi, Fujitsu Laboratories Ltd.Atsushi Takahashi, Fujitsu LimitedYuichi Minoura, Fujitsu Limited and Fujitsu Laboratories Ltd.Yuichi Minoura, Fujitsu Laboratories Ltd.Yusuke Kumazaki, Fujitsu LimitedYusuke Kumazaki, Fujitsu Laboratories Ltd.Masato Nishimori, Fujitsu LimitedMasato Nishimori, Fujitsu Laboratories Ltd.Shiro Ozaki, Fujitsu Limited and Fujitsu Laboratories Ltd.Shiro Ozaki, Fujitsu LimitedKozo Makiyama, Fujitsu Limited and Fujitsu Laboratories Ltd.Kozo Makiyama, Fujitsu LimitedToshihiro Ohki, Fujitsu Limited and Fujitsu Laboratories Ltd.Toshihiro Ohki, Fujitsu Laboratories Ltd.Norikazu Nakamura, Fujitsu Limited and Fujitsu Laboratories Ltd.Naoki Hara, Fujitsu Laboratories Ltd.Naoki Hara, Fujitsu LimitedKeiji Watanabe, Fujitsu LimitedDownload Paper