Patent ID: 6355526
Filing Date: 2002-03-12
Classification: H01L

Abstract:
A method of manufacturing a non-volatile semiconductor memory device that includes:a semiconductor substrate including a first region and a second region; at least one memory element including a floating gate formed in said first region and a control gate formed on said floating gate; and at least one access transistor for selectively activating said memory element being formed in the second region, comprising a gate electrode; said method including the steps of; forming a first insulation layer on said semiconductor substrate; forming on the first insulation layer a first conductive layer; selectively etching said first conductive layer in said second region; forming a dielectric layer over the entire surface of said semiconductor substrate; selectively etching said dielectric layer and said first insulation layer in said second region; forming a second insulation layer on said second region; forming a second conductive layer over the entire surface of said semiconductor substrate; forming on said second conductive layer a masking layer that has a different etching rate from said first conductive layer and functions as a mask when said first conductive layer is selectively etched; selectively etching said second conductive layer by using said masking layer as a mask to form said control gate and gate electrode; forming a first resist which covers said gate electrode; selectively etching said first conductive layer by using said masking layer on said control gate as well as said first resist as masks to form said floating gate; unavoidably forming a groove section on said semiconductor substrate that is not covered by said first resist in said second region through said step of selectively etching said first conductive layer; and forming in said semiconductor substrate an impurity region which electrically connects a source/drain of said memory element to a source/drain of said access gate transistor and covers said groove section.