A method includes selecting a first memory cell located along a first bit line and a first word line of a memory array. The method includes reading a word from a data stream, determining if the word should be included in a parity calculation, and including the word in the parity calculation, if the word should be included in the parity calculation, and ignoring the word otherwise. In one embodiment, the source bushing is constructed from a material having a lower electrical resistance than is currently used. The exposure processing unit includes: a mask stage that holds a mask having mask marks thereon; a second alignment microscope that detects the mask marks of the mask; and an exposure stage that holds the workpiece.