Patent ID: 7887999

Claim:
A method of making a device, comprising: forming a photoresist layer over a substrate; performing a first exposure of the photoresist layer using a first mask to form first exposed regions in the photoresist layer; performing a second exposure of the photoresist layer using a second mask to form second exposed regions in the photoresist layer; performing a third exposure of the photoresist layer using a third mask to form third exposed regions in the photoresist layer, such that each adjacent first, second and third exposed regions are approximately equidistant from each other; patterning the photoresist layer after the first, the second and the third exposures; etching the substrate using the patterned photoresist layer; forming a plurality of pillar shaped devices arranged in a substantially hexagonal pattern, wherein the substantially hexagonal pattern comprises a repeating pattern of seven nonvolatile memory cells having a central nonvolatile memory cell surrounded by six other nonvolatile memory cells arranged in a hexagonal layout around the central nonvolatile memory cell; forming a plurality of bit lines using double photoresist exposure; and and forming a plurality of word lines using double photoresist exposure.