Patent ID: 9130031
Filing Date: 2015-09-08
Classification: B23K,H01L

Abstract:
1. A wafer processing method of dividing a wafer into a plurality of individual optical devices along a plurality of crossing division lines, said wafer being composed of a substrate and a light emitting layer formed on a front side of said substrate, said optical devices being respectively formed in a plurality of regions partitioned by said division lines on said light emitting layer, said wafer processing method comprising: a modified layer forming step of applying a laser beam having a transmission wavelength to said substrate from a back side of said substrate along said division lines in a condition where a focal point of said laser beam is set inside said substrate, thereby forming said modified layer inside said substrate along each division line; and a wafer dividing step of applying an external force to said wafer to break said wafer from said modified layer as a division start point along each division line after performing said modified layer forming step, thereby dividing said wafer into said individual optical devices; said modified layer forming step including the steps of