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US 2003/0119263 A1Published application
Method of manufacturing a flash memory cell
AssigneeHynix Semiconductor Inc.
InventorsSeung Cheol Lee, Sang Wook Park
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Abstract
A method of manufacturing a flash memory cell in which an ion implantation process is performed before a cleaning process for etching a protrusion of a trench insulating film to a nipple shape. As a result, the etch rate at a portion except for portions in which a moat will occur along the trench insulating film is increased. Therefore, generation of the moat in the trench insulating film can be prevented and spacing of the floating gate can be optimized.
Claims7
A method of manufacturing a flash memory cell, comprising the steps of:
- forming a pad oxide film and a pad nitride film on a semiconductor substrate;
- forming a trench in the semiconductor substrate;
- forming a trench insulating film on the entire structure and then performing a first chemical mechanical polishing (CMP) process to isolate the trench insulating film;
- removing the pad nitride film to expose a protrusion of the trench insulating film;
- performing an ion implantation process to dope the protrusion of the trench insulating film;
- performing a cleaning process to etch the protrusion of the trench insulating film by a given width;
- forming a first polysilicon layer on the entire structure and then performing a second CMP process to form an isolated floating gate;
- and
- forming a dielectric film and a second polysilicon layer on the entire structure and then performing respective etch processes to form a control gate.
6 more elements
Dependencies are inferred from the claim text.