Frontier Research Institute for Interdisciplinary Sciences
Tohoku University

To embody a humanity-rich-communication by innovating information-and-communication technology (ICT) for realizing sustainable, safe, secure and reliable society, we have to create human-friendly low-environmental-impact ICT devices and systems by using new electronic materials and device-technology. Science and technology for fabricating new materials and controlling nanometer-order structure should be developed and established further.

I have been expanding my study of two applications of sputter film deposition using a UHV technology: fabrication of magnetic films having high uniaxial magnetic anisotropy Ku, and development of room-temperature bonding techniques for use in fabricating wafers.

The former study is aimed mainly at realizing high-capacity magnetic storage and memory devices. My co-workers and I fabricated L11 type Co?Pt ordered alloy films, a quasi-stable phase, on glass wafers. We also fabricated high-quality L10-type ordered films at low temperatures of 200?300°C. We have been studying structural and magnetic properties of these high-Ku films and dot arrays of these films.

Atomic diffusion bonding of two flat wafers at room temperature is the latter study. Very thin metal films were fabricated on two flat wafer surfaces using sputter deposition, with subsequent bonding of the two metal films on the wafers in vacuum. The 2?4 inch wafers were bonded at room temperature over the entire bonded area using various metal films, even with films of 0.2 nm thickness. We have been investigating the potential of bonding for application to device fabrication.