Method for trimming a photoresist pattern line for memory gate etching

摘要

Memory gate stacks having widths of about 0.18 microns to 0.15 microns are formed by trimming a resist mask pattern, having line widths of about 0.25 microns, to a width of about 0.20 microns. An antireflective coating layer such as silicon oxynitride underlying the resist pattern is then etched to form etched silicon oxynitride pattern lines having widths of about 0.18 to 0.15 microns. The etched silicon oxynitride layer is then used for self-aligned etching of underlying layers to form the memory gate stack. Hence, a memory gate can be formed that has a width substantially less than the current photolithography limit during formation of the resist mask pattern.