In some embodiments, a method includes wet-etching a first film layer of a plurality of film layers stacked on a semiconductor substrate, the wet-etching of the first film layer performed using a first chemical, where the first film layer is an outermost film layer stacked on the semiconductor substrate. The method further includes wet-etching a second film layer of the plurality of film layers using a second chemical. The method also includes using a mechanical grinding wheel to grind the semiconductor substrate to reduce a thickness of the semiconductor substrate.