摘要 |
PURPOSE:To prevent cracks and chipping and to improve the yield by applying dicing processing to a lithium niobate single crystal in the direction of a line of intersection between a line of cleavage of the crystal for an elastic surface wave filter and a wafer surface. CONSTITUTION:The 64 deg. Y-cut is applied to the wafer so that a straight line segment A rotating the Y axis to the Z axis by 64 deg. is a normal of the face of wafer on the Y-Z plane of a hexagonal unit cell of the lithium niobate single crystal. The planes of the single crystal are (-1012), (01-12) and (1-102) in this case. Then, an oriented flat plane 3 is cut so that a line of intersection between the oriented flat plane 3 and the wafer plane is in parallel with a line of intersection between the (1-102) plane and the wafer plane. The direction N is in parallel with the line of intersection between the (01-12) plane and the wafer plane. Further, the M direction is in parallel with the line of intersection between the (1-102) plane and the wafer plane. Further, the dicing processing is applied to the crystal in a direction in parallel with the directions M and N to form slots 4, 5. The single crystal element 6 is formed by slicing the crystal along the slots. |