Process to improve the Vss line formation for high density flash memory and related structure associated therewith

摘要

One aspect of the invention relates to a method of a NOR-type flash memory and associated structure which comprises forming a flash memory array on a semiconductor substrate in a core region of the flash memory. The flash memory array comprises a plurality of flash memory cells which each have a source region and a drain region in the semiconductor substrate. A first portion of a first dielectric layer is formed over the flash memory array, and contact holes in the first dielectric layer are formed down to source regions of flash memory cells in the core region. A trench is then formed in the first dielectric layer and extends between the two contact holes. The contact holes and trench are then filled with a conductive material, thereby electrically coupling together the source regions of the two flash memory cells. A second portion of the first dielectric layer is then formed over the first portion of the first dielectric layer and the trench, thereby embedding the source contacts and trench in within the first dielectric layer.