Resources Contact Us Home
Browse by: INVENTOR PATENT HOLDER PATENT NUMBER DATE
 
 
Method to increase coupling ratio of source to floating gate in split-gate flash










Image Number 6 for United States Patent #7001809.

A split-gate flash memory cell having a three-dimensional source capable of three-dimensional coupling with the floating gate of the cell, as well as a method of forming the same are provided. This is accomplished by first forming an isolation trench, lining it with a conformal oxide, then filling with an isolation oxide and then etching the latter to form a three-dimensional coupling region in the upper portion of the trench. A floating gate is next formed by first filling the three-dimensional region of the trench with polysilicon and etching it. The control gate is formed over the floating gate with an intervening inter-poly oxide. The floating gate forms legs extending into the three-dimensional coupling region of the trench thereby providing a three-dimensional coupling with the source which also assumes a three-dimensional region. The leg or the side-wall of the floating gate forming the third dimension provides the extra area through which coupling between the source and the floating gate is increased. In this manner, a higher coupling ratio is achieved without an increase in the cell size while at the same time alleviating the punchthrough and junction break-down of source region by sharing gate voltage along the side-wall.








 
 
  Recently Added Patents
Adjustable high precision surveying device
Alkaline battery
Toy
Co-crystals of agomelatine, a process for there preparation and pharmaceutical compositions containing them
Power supply device
Process and intermediates for preparing lapatinib
Triazolylphenyl sulfonamides as serine/threonine kinase inhibitors
  Randomly Featured Patents
Massive parallel method for decoding DNA and RNA
Switch point guard rail
Device to remove sulfur from water systems
Data interfaces
Laminated identity card having separation-resistant laminae and method of manufacturing same
Apparatus and method for retaining screw breech block
Voltage follower and related method of regulation
Production of biologically degradable films
Transfer apparatus and image forming apparatus including the same
Secondary battery devices