A method for patterning a layer on a semiconductor substrate includes forming a layer of a semiconductor substrate and exposing the layer to light. The light travels through a second pellicle that is manufactured by a method that includes determining a first transmission of a first light through a first pellicle, wherein the first light is normal to the first pellicle, determining a second transmission of a second light through the first pellicle, wherein the second light is not normal to the first pellicle, and modifying the first pellicle to form a second pellicle using the first and second transmission.