PIEZOELECTRIC SINGLE CRYSTAL WAFER FOR SURFACE ACOUSTIC WAVE OR PSEUDO SURFACE ACOUSTIC WAVE DEVICE AND MANUFACTURE OF THE SAME

摘要

PROBLEM TO BE SOLVED: To lower percent defective caused by a deviation between a surface acoustic wave(SAW) speed and a pseudo surface acoustic wave (LSAW) speed by lowering an X-ray rocking curve half-width of a wafer surface, which forms a transmission/reception electrode of the SAW or LSAW which is made smaller than or signal to a specified value. ;SOLUTION: An X-ray rocking curve half-width of a wafer surface which forms a transmission/reception electrode of a SAW and an LSAW is made smaller than 0.06 degree and a frequency dispersion at device manufacturing is made smaller. Also, after a polish work which uses an SiO2 colloidal polishing liquid, heat processing is performed in an atmosphere of air, oxygen, nitrogen or the like for one to five hours at 400 to 1,600°C, and piezoelectric single crystal wafer for a SAW and LSAW device can be obtained, where a deviation between a SAW speed and an LSAW speed is small for every wafer in the wafer surface. After an electrode, such as an Al, is formed on this single-crystal wafer in a specified direction, it is cut out into chip-shape to manufacture a device.;COPYRIGHT: (C)2000,JPO