Sumitomo Electric Industries, Limited

Yoko Maeda

Seiji Nakahata

Akihiro Hachigo

Fumitaka Sato

An epitaxial-deposition composite substrate, of more than about 50 mm diameter, in which a nitride-compound semiconductor first substrate is bonded together with a second substrate of either identical or different material. The first substrate is ion-implanted, and on its nitrogen-face side is coated with a special film of thickness within a predetermined range. On a bonding side of the second substrate a special coating of thickness within the predetermined range is formed. The join created by the coated nitrogen-face side of the first substrate being bonded to the coated bonding side of the second substrate occupies at least 90% of the surface area where the two substrates meet.

Composite substrate

A composite-substrate manufacturing method is provided with: a step of carrying out implantation of ions through a surface of a bulk substrate composed of the nitride compound semiconductor; a step of setting said surface of the bulk substrate against the second substrate, and bonding the bulk substrate and the second substrate together to obtain a bonded substrate; a step of elevating the temperature of the bonded substrate to a first temperature; a step of sustaining the first temperature for a fixed time; and a step of producing a composite substrate by severing the remaining portion of the bulk substrate from the bonded substrate; characterized in that a predetermined formula as for the first temperature, the thermal expansion coefficient of the first substrate, and the thermal expansion coefficient of the second substrate is satisfied.

Growing community of inventors

Itami, Japan

Yoko Maeda