AVS 51st International Symposium
    Surface Science Monday Sessions
       Session SS-MoP

Paper SS-MoP33
Site-selective Electroless Plating on Amino-terminated Diamond Substrate Patterned by 126 nm Vacuum Ultraviolet Light Lithography

Monday, November 15, 2004, 5:00 pm, Room Exhibit Hall B

Session: Poster Session
Presenter: A. Hozumi, National Institute of Advanced Industrial Science and Technology, Japan
Authors: A. Hozumi, National Institute of Advanced Industrial Science and Technology, Japan
N. Shirahata, National Institute of Materials Science, Japan
S. Asakura, Waseda University, Japan
A. Fuwa, Waseda University, Japan
Y. Yokogawa, National Institute of Advanced Industrial Science and Technology, Japan
T. Kameyama, National Institute of Advanced Industrial Science and Technology, Japan
Correspondent: Click to Email
The use of diamond substrates to manage heat dissipation in microelectronics has recently attracted considerable attention. Diamond metallization technique is of crucial importance in order to fabricate microelectronics devices. However, due to its excellent chemical inertness, it is hard to fabricate metal circuitry on the diamond substrates. Here we report a spatially defined metallization of copper (Cu) through an electroless plating on the amino-terminated diamond surface micropatterned by vacuum ultraviolet (VUV) photolithography. A diamond surface was first photochemically hydrophilized using VUV light of 126 nm. Due to VUV irradiation, the diamond surface became completely hydrophilic with its water-contact angle changing from 102° to 5° or less. According to X-ray photoelectron spectroscopy, polar-functional groups, such as C-O and C=O/O-C-O, were formed on the surface. Amino-terminated organosilane molecules were then chemisorbed onto the photochemically modified surface through a vapor phase. Next, the sample was exposed to 126 nm VUV light through a mesh mask, and subsequently immersed into a PdCl@sub 2@ solution kept at pH 5 for 30 min and rinsed with Milli-Q water. Finally, the substrate was immediately immersed into a commercial electroless Cu plating bath for 2 min at room temperature. Cu film with about 40 nm thick was site-selectively deposited onto the amino-terminated surface and remained free of deposits in the VUV-irradiated regions, as evidenced by an optical microscopy. The well-defined Cu microstructures were successfully formed on the diamond surface. Due to thermal treatment at 200 °C for 3 h in vacuum, a resistivity of the Cu film decreased from 17.1 µ@ohm@ cm to 13.4 µ@ohm@ cm.