Patent attributes
A flash memory device and programming and erasing methods therewith is disclosed, to secure the programming and erasing characteristics by changing a structure of a floating gate, in which the flash memory device includes a first conductive type semiconductor substrate defined as a field area and an active area; a tunnel oxide layer on the active area of the first conductive type semiconductor substrate; a floating gate on the tunnel oxide layer, having at least first and second floating gates having different levels of energy band gap; a dielectric layer on the floating gate; a control gate on the dielectric layer; and second conductive type source/drain regions in the active area of the first conductive type semiconductor substrate at both sides of the floating gate.