A surface acoustic wave device has superior electrical power resistance
that is obtained by improving stress migration resistance of electrodes.
In order to form at least one electrode, for example, on a .theta.
rotation Y-cut (.theta.=36.degree. to 42.degree.) LiTaO.sub.3
piezoelectric substrate, an underlying electrode layer including Ti or Cr
as a primary component is formed, and an Al electrode layer including Al
as a primary component is then formed on this underlying electrode layer.
The Al electrode layer is an oriented film grown by epitaxial growth and
is also a polycrystalline thin film having a twin structure in which a
diffraction pattern observed in an X-ray diffraction pole figure has a
plurality of symmetry centers.
