| 摘要 |
PROBLEM TO BE SOLVED: To provide a surface acoustic wave device having an aluminum electrode which is superior in stress migration resistance by aligning the crystal azimuth of an aluminum film to a certain direction and forming an electrode with a migration preventing function. SOLUTION: For example, a 33.5 deg. rotation cut crystal substrate is used as a piezoelectric substrate 1 and on the surface of this piezoelectric substrate 1, a thin Ti film, a Cr film, etc., are formed. The thin Ti or Cr film is thin enough not to impede the alignment of the aluminum film. Then the aluminum film is formed by properly controlling the vapor-deposition speed and substrate temperature in electron-beam vapor deposition. At this point, when a film forming speed is at least >=20Å/sec, an aluminum aligned film is obtained which has its crystal azimuth aligned to a certain direction. This aluminum film is processed by photolithography to form two inter-digital electrodes 2a and a grating electrode 2b on the surface of the piezoelectric substrate 1, thereby manufacturing a surface acoustic wave(SAW) resonator 3.
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