Patent ID: 6541339
Filing Date: 2003-04-01
Classification: H01L,Y10S

Abstract:
A method of creating floating gates for split-gate flash memory devices, comprising the steps of:providing a semiconductor substrate; creating a first layer of gate oxide over the surface of said substrate; depositing a layer of gate material that can be oxidized over the surface of said first layer of gate oxide; creating a second layer of native oxide over the surface of said layer of gate material; depositing a layer of etch stop material over the surface of said second layer of native oxide; patterning and etching said layer of etch stop material, creating openings through said layer of etch stop material exposing the surface of said second layer of native oxide, said exposed surface of said second layer of native oxide overlying surface regions of said layer of gate material where floating gates are to be created; first oxidizing the exposed surface of said second layer of native oxide, said first oxidizing further second oxidizing said layer of gate material in a pattern of said openings created through said layer of etch stop material, creating a pattern of oxidized gate material over the surface of said layer of gate material; removing said patterned and etched layer of etch stop material from the surface of said second layer of native oxide; and etching said second layer of native oxide and said layer of gate material in accordance with said pattern of oxidized gate material created over the surface of said layer of gate material.