Method of fabricating memory device
AssigneePowerchip Semiconductor Corp.
InventorsChih-Wei Hung, Da Sung, Chien-Chih Du
Life of this patent
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Abstract
A method of fabricating a memory device. A plurality of isolation structures and a plurality of stacked gate structures are sequentially formed on a substrate. While defining the stacked gate structures, the isolation structures are over etched to form a plurality of trenches. A material layer is filled into the trenches. A patterned photoresist layer is formed on the substrate, while a part of the substrate predetermined for forming a drain region is exposed. An ion implantation step is performed to implant a dopant into the part of substrate predetermined for forming the drain region, such that a well is formed. As the trenches are filled with the material layer, the dopant cannot penetrate therethrough.
Claims15
A method of fabricating memory device, comprising:
- providing a substrate on which a plurality of isolation structures and a plurality of stacked-gate structures are formed, wherein a plurality of trenches are formed in the isolation structures due to over etching during a step for forming the stacked-gate structures;
- filling the trenches with a material layer;
- forming a patterned photoresist layer over the substrate, wherein a part of the substrate predetermined for forming a drain region is exposed;
- and
- performing an ion implantation step to implant dopant into the exposed substrate for forming a well region, wherein the dopant does not penetrate through the isolation structures.
A method of fabricating a memory device, comprising:
- providing a substrate comprising at least a plurality of isolation structures thereon, wherein the isolation structures are over etched to form a plurality of trenches therein;
- forming a material layer over the substrate;
- and
- removing the material layer out of the trenches, while the remaining material layer fills the trenches to prevent dopant implanted in an ion implantation step from penetrating through the isolation structures.
Dependencies are inferred from the claim text.