TY - JOUR
T1 - Fabrication of diamond/Cu direct bonding interface for power device applications
AU - Kanda, Shinji
AU - Shimizu, Yasuo
AU - Ohno, Yutaka
AU - Shirasaki, Kenji
AU - Nagai, Yasuyoshi
AU - Kasu, Makoto
AU - Shigekawa, Naoteru
AU - Liang, Jianbo
PY - 2020/2/1
Y1 - 2020/2/1
N2 - Direct bonding of diamond and Cu was successfully conducted by the surface activated bonding method at room temperature. The structure of the diamond/Cu bonding interface was investigated by transmission electron microscopy and electron energy-loss spectroscopy. The effect of heat treatment temperature on the interface structure was also investigated. A 4-nm-thick damaged layer was formed at the as-bonded interface, and the damaged layer's thickness decreased with an annealing temperature rise. It was found that the atomic ratio of sp2 bonding in the bonding interface was larger than that of the diamond separated from the interface by approximately 50 nm, which indicates that the damaged layer was composed of amorphous carbon or graphite and diamond. After annealing at 700 °C, a composite layer about 2 nm thick was observed at the interface. There were no nano-voids or micro-cracks observed at the interface with annealing at a temperature as high as 700 °C. These results indicate that the diamond/Cu bonding interface has high thermal stability and can withstand the temperature rise of power devices during operation.
AB - Direct bonding of diamond and Cu was successfully conducted by the surface activated bonding method at room temperature. The structure of the diamond/Cu bonding interface was investigated by transmission electron microscopy and electron energy-loss spectroscopy. The effect of heat treatment temperature on the interface structure was also investigated. A 4-nm-thick damaged layer was formed at the as-bonded interface, and the damaged layer's thickness decreased with an annealing temperature rise. It was found that the atomic ratio of sp2 bonding in the bonding interface was larger than that of the diamond separated from the interface by approximately 50 nm, which indicates that the damaged layer was composed of amorphous carbon or graphite and diamond. After annealing at 700 °C, a composite layer about 2 nm thick was observed at the interface. There were no nano-voids or micro-cracks observed at the interface with annealing at a temperature as high as 700 °C. These results indicate that the diamond/Cu bonding interface has high thermal stability and can withstand the temperature rise of power devices during operation.
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U2 - 10.7567/1347-4065/ab4f19
DO - 10.7567/1347-4065/ab4f19
M3 - Article
AN - SCOPUS:85081958209
VL - 59
JO - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
JF - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
SN - 0021-4922
IS - SB
M1 - SBBB03
ER -