Method for manufacturing flash memory device
AssigneeHynix Semiconductor Inc.
InventorKwang Chul Joo
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Abstract
The present invention discloses a method for manufacturing a flash memory device which can minimize a hole current by impurity diffusion of floating gates, obtain a sufficient capacitance for a cell operation by increasing a breakdown voltage, and improve retention properties of a flash memory cell, by filing up an impurity on the interface between an oxide film and a polysilicon film, by forming the oxide film on the polysilicon film used as the floating gates, doping an impurity into the oxide film, and annealing the oxide film.
Claims24
A method for manufacturing a flash memory device, comprising the steps of:
- forming a tunnel oxide film and a first polysilicon film on a semiconductor substrate;
- forming an oxide film on the first polysilicon film;
- distributing an impurity along the interface between the first polysilicon film and the oxide film by doping the impurity into the oxide film and annealing the oxide film;
- forming a dielectric film on the oxide film;
- and
- forming a second polysilicon film and a tungsten silicide film over the resulting structure, and performing an etching process thereon.
A method for manufacturing a flash memory device, comprising the steps of:
- forming a tunnel oxide film and a first polysilicon film on a semiconductor substrate;
- forming an oxide film on the first polysilicon film;
- nitrifying the top surface of the oxide film by doping an impurity into the oxide film and annealing the oxide film in a nitrogen atmosphere, thereby distributing the impurity along the interface between the first polysilicon film and the oxide film;
- forming a dielectric film on the oxide film, and steam-annealing the dielectric film;
- and
- forming a second polysilicon film and a tungsten silicide film over the resulting structure, and performing an etching process thereon.
Dependencies are inferred from the claim text.