| 摘要 |
A wafer is divided by setting the focal point of a laser beam inside the wafer at positions corresponding to division lines, thereby forming modified layers inside the wafer along the division lines. Each modified layer has a thickness ranging from the vicinity of the front side of the wafer to the vicinity of the back side of the wafer. An etching gas or an etching liquid is supplied to the wafer to erode the modified layers, thereby dividing the wafer into individual devices. The modified layers are not crushed, so fine particles are not generated in dividing the wafer. Accordingly, fine particles do not stick to the surface of each device and cause a reduction in quality. Further, since the modified layers are removed by etching, it is possible to prevent a reduction in die strength of each device due to the remainder of the modified layers. |
