Abstract: A method for fabricating a floating gate in a flash memory device includes providing a substrate, forming a first-type ion doped floating gate layer on the substrate, forming a first patterned photoresist layer on the first-type ion doped floating gate layer, dry etching the first patterned photoresist layer, wherein a dimension of the pattern of the first photoresist layer after the dry etching process is smaller than a dimension of the pattern before the dry etching process. The method further includes forming a dual-doped floating gate layer by implanting second-type ions into the first-type ion doped floating gate layer by using the first photoresist layer as a mask, wherein the first-type ions and the second-type ions have opposite charges. A flash memory device thus fabricated has a small CD and a dual-doped floating gate that provide high programming efficiency.