MANUFACTURE OF ELASTIC SURFACE WAVE DEVICE

摘要

PURPOSE:To improve characteristics and yield by reducing bad conditions such as camber as much as possible by roughening the 2nd main surface of a wafer and then by etching the wafer before mirror-finishing the 1st main surface where input and output electrodes are to be formed. CONSTITUTION:An LiTaO3 signle crystal is cut into a prescribed wafer. Of this wafer, the 2nd main surface 5 opposing to the 1st main surface 2 where input and output electrodes are to be formed is roughened by manual sliding and honing work. Next, a solution having a 1:2 ratio of HF to HNO3 is used to etch the wafer at the room temperature for 15 minutes and after curvature is removed, electrodes are formed on this wafer to improve the yield while maintaining prescribed excellent characteristics. Namely, provess etching provides better results with regard to removal of camber and prevention of cracking in handling.