Aspects of the present disclosure provide a method for optimizing wafer shape. For example, the method can include receiving a wafer having a working surface for one or more devices to be fabricated thereon and a backside surface opposite to the working surface, measuring the wafer to identify bow measurement of the wafer, and forming a first stress-modification film on the backside surface. The first stress-modification film can be reactive to a first wavelength of light in that exposure to the first wavelength of light modifies an internal stress of the first stress-modification film. The method can further include exposing the first stress-modification film to a pattern of the first wavelength of light to modify the internal stress of the first stress-modification film. The pattern of the first wavelength of light corresponds to the bow measurement.