Kabushiki Kaisha Kobe Seiko Sho

Rie Nakamura

Koji Kobashi

Kimitsugu Saito

Kazushi Hayashi

Kozo Nishimura

Takeshi Tachibana

A method of forming a highly oriented diamond film having a reduced thickness with a high quality at a low cost. Surface of a single crystal substrate is cleaned, and is then left in a high vacuum of 10.sup.-6 Torr or less at a temperature between room temperature and 800.degree. C. for 15 min for releasing gas molecules absorbed on the surface of the substrate. The surface of the substrate is then processed using carbon-containing plasma for forming a barrier of obstructing a carbon component within the substrate. After that, an electric field is applied across the substrate and plasma for allowing a current to flow thereacross for a specified time, to form nuclei of diamond for synthesis of a diamond film. Thus, highly oriented diamond particles or films, in which crystal orientations thereof are epitaxial to the substrate, are synthesized.

Formation of highly oriented diamond film

A surface acoustic wave device uses a highly oriented diamond film with a planar surface, increasing the propagating velocity of a surface acoustic wave, and fabricating many devices on a large area without polishing processes. The surface acoustic wave device includes the highly oriented diamond films, a piezoelectric film and electrodes which are formed on the diamond film. In the highly oriented diamond film, 80% or more of the surface area of the diamond film is composed of the (100) faces or (111) faces of diamond; and the difference {.DELTA..alpha.,.DELTA..beta.,.DELTA..gamma.} between the Euler angles {.alpha.,.beta.,.gamma.} expressing the crystal orientations of the adjacent (100) or (111) faces of the diamond film simultaneously satisfies the relations of .vertline..DELTA..alpha..vertline..ltoreq.10.degree., .vertline..DELTA..beta..vertline..ltoreq.10.degree., and .vertline..DELTA..gamma..vertline..ltoreq.10.degree..

Growing community of inventors

Kobe, Japan

Rie Nakamura