Wafer processing method

A wafer processing method for dividing a wafer into a plurality of individual devices along a plurality of division lines formed on a front side of said wafer, said wafer being composed of a substrate and a functional layer formed on a front side of said substrate, said individual devices being formed from said functional layer and partitioned by said division lines, said wafer processing method comprising:

• a protective tape attaching step of attaching a protective tape having an adhesive layer to a front side of said functional layer of said wafer in a condition where said adhesive layer of said protective tape is in contact with the front side of said functional layer;
• and
• a wafer dividing step of holding said wafer processed by said protective tape attaching step on a holding surface of a chuck table in a condition where said protective tape is in contact with said holding surface, and next applying a laser beam having an absorption wavelength to said substrate and said functional layer of said wafer from a back side of said substrate along each division line to form a laser processed groove having a depth reaching said protective tape along each division line, thereby dividing said wafer into individual device chips corresponding to said individual devices,
• wherein said protective tape is closely attached to the front side of said functional layer in said protective tape attaching step in such a manner that said adhesive layer of said protective tape comes into tight contact with said devices formed from said functional layer, so as to prevent the adhesion of debris to a front side of each device, said debris being generated from said wafer along each division line by the application of said laser beam in said wafer dividing step.