| 摘要 |
PURPOSE:To improve adhesive strength between electrodes and a substrate by forming a pattern group of input electrodes and output electrodes by vapor-depositing Al on one main surface of a piezoelectric substance wafer and then by carrying out a heat treatment. CONSTITUTION:One main surface of a wafer of 62mm.phi, for example, made of LiTaO3 is mirror-finished and on this mirror surface, Al is vapor-deposited to form a thin vapor-deposition film. Next, pattern groups of prescribed input electrodes 12' and output electrodes 13' are formed by photoetching. Such a wafer is thermally processed in a nitrogen atmosphere at 300-400 deg.C for 30-60min, for example. Consequently, grown seeds of about 0.7-1.5mumphi are formed on surfaces of input electrodes 12' and output electrodes 13' made of the Al-vapor-deposition films. Thus, the adhesive strength between the Al-vapor-deposition films and piezoelectric substrate 11 is improved. |
