Wafer processing method

A wafer processing method for dividing a wafer into individual device chips by plasma etching using a fluorine-based gas, the wafer processing method comprising:

• a frame unit forming step of positioning the wafer at an opening of an annular frame provided in a center with the opening for accommodating the wafer and attaching a dicing tape to a lower surface of the wafer and the annular frame to form a frame unit;
• a resin film coating step of coating an upper surface of the wafer with a water-soluble resin and coating the dicing tape exposed between the wafer and the annular frame with a water-soluble resin, and solidifying the water-soluble resin to form a resin film;
• a partial resin film removing step of removing the resin film from regions to be divided of the wafer to partially expose the upper surface of the wafer;
• an etching step of subjecting the regions to be divided of the wafer to plasma etching to divide the wafer into the individual device chips;
• and
• a whole resin film removing step of cleaning the frame unit to remove wholly the resin film.