Diamond substrate for surface acoustic wave device, and surface acoustic wave device
AssigneeSumitomo Electric Industries, Ltd.
InventorsKeiji Ishibashi, Takahiro Imai, Tomoki Uemura, Daichi Kawaguchi, Hideaki Nakahata, Satoshi Fujii
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Abstract
A diamond film is deposited in the thickness of 20 μm on a silicon wafer 0.8 mm thick by filament CVD. Here the hydrogen content of the diamond film is adjusted in the range of not less than 1% nor more than 5% in atomic percent. By mechanical polishing with a grinding wheel including diamond abrasives, the diamond film is smoothed so that the arithmetic mean roughness (Ra) of the surface thereof becomes not more than 20 nm.
Claims10
A diamond substrate for surface acoustic wave device, comprising a substrate, and a diamond film formed on the substrate,
- wherein a hydrogen content of said diamond film is in the range of not less than 1% nor more than 5% in atomic percent,
- wherein an arithmetic mean roughness (Ra) of a surface of said diamond film is not more than 20 nm, and
- wherein a ratio I(220)/IT, which is a ratio of a peak intensity I(220) of the diamond crystal plane (220) to the total IT of peak intensities of the diamond crystal planes (111), (220), (311), (400), and (331) in X-ray diffraction analysis of said diamond film, is not less than 0.8.
A diamond substrate for surface acoustic wave device, comprising a substrate, and a diamond film formed on the substrate,
- wherein a hydrogen content of said diamond film is in the range of not less than 1% nor more than 5% in atomic percent,
- wherein an arithmetic mean roughness (Ra) of a surface of said diamond film is not more than 20 nm, and
- wherein said diamond film has a peak near the wave number of 1333 cm−1 in Raman spectroscopy and a half width of said peak is not less than 10 cm−1.
Dependencies are inferred from the claim text.