Patent ID: 7605524

Claim:
A surface acoustic wave device, comprising: a single crystal piezoelectric substrate composed of lithium tantalate (LiTaO 3 ) or lithium niobate (LiNbO 3 ); and an electrode formed on the piezoelectric substrate, wherein the electrode comprises a first film formed of titanium (Ti), and a second film formed of aluminum or aluminum alloy made by adding a small amount of metal atom to aluminum (Al), wherein the second film is formed of a crystal film including two (111) domains growing in different directions from each other, wherein both <111> directions of the two (111) domains tilt at angles within 0 to 10 degrees to the surface of the piezoelectric substrate, and wherein <11-2> directions in an in-plane of each of the (111) domains are arranged uniformly, while the <11-2> direction in the in-plane of one (111) domain and the <11-2> direction in the in-plane of the other (111) domain are 1 to 15 degrees apart from each other.