| 摘要 |
A piezoelectric substrate (1) is provided with interdigital transducer electrodes including a first electrode layer (2), a second electrode layer (3), and a third electrode layer (4) that is principally made of aluminum. The piezoelectric substrate (1) has a stepped structure on the surface of the piezoelectric substrate, the stepped structure including terraces (6) each having a width of about 50 nm or less and steps each having a width of a mono-molecular layer (e.g., about 14 ANGSTROM ). <IMAGE> |
