a wafer lithographic shielding mask for fabricating a multi - project wafer and a wafer fabrication method using the same are disclosed . the mask including a light shielding layer and at least one transparent region is used to select the layout patterns of designated chips on an mpw reticle to be exposed onto the photoresist layer on the surface of the wafer . the lithography method of fabricating mpw mainly involves disposing a wafer lithographic shielding mask for selecting the exposure regions on the mpw reticle on the light transmission path from a lithographic light source to a wafer , e . g ., between the mpw reticle and the lithographic light source or between the mpw reticle and the wafer , so as to prevent some undesired chips from being fabricated on the wafer using the mpw reticle , thereby decreasing the wafer production cost .