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IJAT Vol.13 No.2 pp. 254-260
doi: 10.20965/ijat.2019.p0254
(2019)

Paper:

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Growth Behavior of Au Films on SiO2 Film and Direct Transfer for Smoothing Au Surfaces

Michitaka Yamamoto*,**, Takashi Matsumae*, Yuichi Kurashima*, Hideki Takagi*, Tadatomo Suga***, Toshihiro Itoh**, and Eiji Higurashi*,***,†

*National Institute of Advanced Industrial Science and Technology (AIST)
1-2-1 Namiki, Tsukuba, Ibaraki 305-8564, Japan

†Corresponding author

**Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Japan

***School of Engineering, The University of Tokyo, Tokyo, Japan

Received:
July 6, 2018
Accepted:
January 7, 2019
Published:
March 5, 2019
Creative Commons License
Keywords:
smoothing process, smooth Au surfaces, room temperature Au-Au bonding, direct transfer technique
Abstract

Direct transfer of Au films deposited on smooth SiO2 film with RMS (root mean square) surface roughness of 0.24 nm was investigated with the aim of generating smooth Au surfaces. Deposited Au films with different thicknesses were transferred to rough Au surfaces on target substrates at room temperature with a contact pressure of 50 MPa. Observation of the growth behavior of the deposited films revealed that they formed a continuous structure when their nominal film thickness was around 15 nm or above. The transfer of continuous Au films with a thickness of 20, 51, or 102 nm reduced the RMS roughness of the rough Au surfaces from 1.6 nm to 0.4 nm. In contrast, the transfer of Au films with a thickness less than 5 nm increased their surface roughness. This direct transfer technique should thus be useful for low temperature bonding.

Cite this article as:
M. Yamamoto, T. Matsumae, Y. Kurashima, H. Takagi, T. Suga, T. Itoh, and E. Higurashi, “Growth Behavior of Au Films on SiO2 Film and Direct Transfer for Smoothing Au Surfaces,” Int. J. Automation Technol., Vol.13 No.2, pp. 254-260, 2019.
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