Method of fabricating poly spacer gate structure

Abstract

The present invention provides a fabrication method of devices like flash memory cells, which is used to fabricate a poly spacer as a floating gate. In the present invention, an oxide, a predefined and patterned first dielectric, a first poly silicon, and a second dielectric are formed in order on the surface of a semiconductor substrate. Next, anisotropic etch is performed to the second dielectric to form dielectric spacer around projective sides of the first poly silicon. The first poly silicon is then etched with the dielectric spacer as a mask. Subsequently, the first dielectric is removed. A poly spacer is thus completed. The poly spacer is used as a floating gate to complete a flash memory. A channel length of stability and easy control and tips useful for point discharge can thus be obtained so that repetitive control of fabrication of semiconductor devices can be achieved.