| 摘要 |
PURPOSE:To improve performances and qualities of device and to improve yield, by specifically prescribing the plane of the flat of single crystal wafer of lithium tantalate having orientation flat. CONSTITUTION:The surface of single crystal water of lithium tantalate having at least one orientation flat is made (A) parallel to plane (018) of crystal or parallel to plane which is parallel to X axis and has <=15 deg. angle to the plane (018) or (B) parallel to plane which is parallel to X axis and vertical to plane (018) or to plane which has <=15 deg. angle to plane vertical to plane (018) and parallel to X axis. Since the plane (018) is diffraction crystal plane, the plane (018) can be determined by X ray diffractometer method readily, in a short time and precisely. Consequently this single crystal water has extremely high direction precision of OF. When SAW divices, etc., are manufactured from the wafer, qualities and performances of device are extremely improved in comparison with existing devices and yield is also improved. |
