Semiconductor substrate treatment method and treatment device

This invention provides a technique which, upon forming a protection film on one side (the front side) of a semiconductor wafer formed thereon with IC chip before a step of reducing the thickness of the other side (the back side) of the same semiconductor wafer, can achieve the planarization of the protection film. First, curing agent 11 for peeling is coated on the front side of a wafer W, the curing agent 11 is cured through, for example, ultraviolet irradiation, curing agent 12 used as a protection film is further coated on the curing agent 11, and the surface of the curing agent is pressurized by a pressurization member 14 formed of a glass plate. Then, the curing agent 12 is cured through, for example, ultraviolet irradiation, and the wafer W is turned over for grinding and polishing the back side of the wafer W, and holder for dicing is adhered to the back side of the wafer W. Subsequently, ultraviolet irradiation or laser irradiation is conducted on the front side of the wafer W for changing the proper