GUARD RING FOR MEMORY ARRAY

摘要

A device and a method for forming a device are presented. The method includes providing a substrate having an array region in which memory cells are to be formed. Storage gates of the memory cells are formed in the array region. A guard ring surrounding the array region is formed. A gate electrode layer is formed on the substrate. The gate electrode layer fills gaps between the storage gates and guard ring. The gate electrode layer is planarized to produce a planar surface between the gate electrode layer, storage gates and guard ring. The guard ring maintains thickness of the gate electrode layer in the array region such that thickness of the storage gates across center and edge regions of the array region is uniform.

主权项

1. A device comprising:
a substrate having an array region in which memory cells are disposed; a plurality of storage gates of the memory cells disposed in the array region, wherein each of the storage gates comprises a floating gate and a control gate formed over the floating gate; and a guard ring surrounding the array region, wherein the guard ring is a storage gate guard ring which includes the same gate and dielectric layers as the storage gates of the memory cells.