Morgan, Lewis & Bockius LLP
Method of manufacturing flash memory device using trench device isolation process
The present invention relates to a method of manufacturing a flash memory device. The method comprises the steps of sequentially depositing a pad oxide film and a pad nitride film on a semiconductor substrate, when trenches are formed by etching the pad nitride film, the pad oxide film and the substrate using a mask for forming a device isolation film, forming trenches having a different depth in a cell region and in a peripheral by controlling an etch angle and etch target depending on the width of the trench, depositing trench insulating films on the entire surfaces to bury the trenches with the trench insulating films, performing a chemical mechanical polishing process and a strip process for the trench insulating films to form the trench insulating film upper structures of which are protruded, forming a well region through an ion implantation process, and forming a tunnel oxide film, a floating gate, a dielectric film and a control gate. Therefore, as a cell source resistance is reduced, a back-bias effect generating due to the source resistance can be prevented. As the cell current is increased, the read speed of the device can be increased.
Hynix Semiconductor Inc.
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inventional inventional inventional
Jum Soo Sung Mun
Kim Jung