Flash memory device and method of fabricating the same

Abstract

A semiconductor memory device and method of fabricating the same includes a first insulation layer and a first conductive layer formed on a substrate; conductive sidewall spacers protruding upwardly on the sides of the first conductive layer; a second insulation layer formed on the substrate and covering the conductive sidewall spacers; a second conductive layer, a third insulation layer, a third conductive layer, and a fourth insulation layer sequentially formed on the second insulation layer; a contact hole formed through the second and third conductive layers and the second through fourth insulation layers; insulative sidewall spacers formed on the sidewalls of the contact hole; and a fourth conductive layer formed in the contact hole so as to be in contact with the first conductive layer. The gate structure of the semiconductor memory device effectively prevents electrons from tunneling from the fourth conductive layer (data line) to the third conductive layer (control gate) through the inter-layer insulation layer formed on the second conductive layer (floating gate) by providing a strong electrical field at the upper tips of the conductive sidewall spacers, though a low voltage is applied to the gate electrode of the semiconductor memory device.