A NON-CRITICAL COMPLEMENTARY MASKING METHOD FOR POLY-1 DEFINITION IN FLASH MEMORY DEVICE FABRICATION

摘要

A method [300] is disclosed for the definition of the poly-1 layer [220] in a semiconductor wafer. A non-critical mask [227] is used to recess field oxides in the periphery [216] prior to poly-1 deposition [309] by an amount equal to the final poly-1 thickness [226]. A complimentary non-critical mask [222] is used to permit CMP [223] of the core [215] to expose the tops of core oxide mesas [225] from the shallow isolation trenches [210].