FLASH MEMORY ARRAY AND A METHOD AND SYSTEM OF FABRICATION THEREOF

摘要

In a first aspect of the present invention, a flash memory array is disclosed. The flash memory array comprises a substrate comprising active regions, wherein the active regions are defined by a layer of nitride, the layer of nitride including a top surface. The flash memory array further comprises shallow trenches in the substrate, each of the shallow trenches including a layer of oxide, the layer of oxide having a top surface, wherein the top surface of the layer of oxide and the top surface of the layer of nitride are on substantially the same plane and channel area wherein the occurrences of poly 1 stringers in the channel areas is substantially reduced. In a second aspect of the present invention, a method and system for fabricating a flash memory array is disclosed. The method comprises the steps of providing a layer of nitride over a substrate, forming trenches in the substrate and then growing a layer of oxide in the trenches. Finally, the layer of oxide is polished back. Through the use of the preferred embodiment of the present invention, a shallow trench isolation process is implemented as opposed to LOCOS process, thereby reducing the occurrence of poly 1 stringers in the channel area. Accordingly, the occurrence of unwanted electrical shorting paths between the adjacent regions is substantially reduced.