Patent ID: 6448688
Filing Date: 2002-09-10
Classification: C23C,H03H,Y10T

Abstract:
A SAW substrate comprising at least:a base material; a hard carbon film composed of a combined film of graphite-like diamond and carbon clusters, being mounted on the base material, wherein: (1) a crystalline structure in said combined film is continuous, that is, interstices between grains of said graphite-like diamond are filled with said carbon clusters; (2) the graphite-like diamond has a peak in the range of 1333 to 1335 cmâˆ’1 in Raman spectroscopy using an argon laser beam whose wavelength is 457.92 nm and the peak has a FWHM of 6 cmâˆ’1 or more; (3) the carbon clusters have only one peak in the range of 1500 to 1520 cmâˆ’1 in Raman spectroscopy using an argon laser beam whose wavelength is 457.92 nm, and the peak has a FWHM of 170 cmâˆ’1 or less; and (4) the hard carbon film has an Ic/Id ratio of 4 or more wherein the integrated intensity is Id when the peak by Raman spectroscopy for the graphite-like diamond, that is, the position P1=1333 to 1335 cmâˆ’1, at which the peak value exists, is integrated with respect to the range of P1Â±5 cmâˆ’1, and the integrated intensity is Ic when the peak by Raman spectroscopy for the carbon clusters, that is, the position P2=1500 to 1520 cmâˆ’1, at which peak value exists, is integrated with respect to the range of P2Â±cmâˆ’1; and a piezoelectric film mounted on the hard carbon film.