METHOD FOR FABRICATING A FLASH MEMORY DEVICE

摘要

PURPOSE: A method for fabricating a flash memory device is provided so that a stable operation characteristic can be obtained by improving a reverse tunneling voltage. CONSTITUTION: To improve a characteristic of a reverse tunneling voltage, a polysilicon is stacked with the thickness of 200 angstrom instead of a conventional nitride layer on the resulting structure and etched by an anisotropic etching as an etch back process until the polysilicon and an oxide layer(13) do not exist on an upper surface of an oxide layer(9). Accordingly, oxide layers(11,13) are intervened between a sidewall of a pattern of a floating polysilicon(5) and a spacer(35) of thin polysilicon. At this time, oxide layers(9,11,13) do not damaged particularly in the etch back process for forming the spacer(35) by high etching selectivity between the polysilicon for constructing the spacer(35), and the oxide layers(9,11,13).