Electrically erasable and programmable read only memory (EEPROM) having multiple overlapping metallization layers
First Claim
1. An Electrically Erasable and Programmable Read Only Memory (EEPROM) having an array of memory cells, each memory cell having a trench configuration and a semiconductor drain region adjacent a surface-adjoining portion of said trench, characterized in that said EEPROM is provided with at least two overlapping metallization layers overlying said memory cells separated from each other and from said trenches and said drain regions by regions of insulating material, and in that each of said overlapping metallization layers contact the drain region of at least one underlying memory cell through said insulating material.
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Accused Products
Abstract
An electrically erasable and programmable read only memory (EEPROM) includes an array of trench memory cells, with each memory cell having a semiconductor drain region adjacent a surface-adjoining portion of the trench. The EEPROM is provided with at least two overlapping metallization layers overlying the memory cells and separated from each other and from the trenches and the drain regions by regions of insulating material. The overlapping metallization layers contact the drain regions of the underlying memory cells through the insulating material. This configuration results in a memory array having a very high packing density.
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Citations
8 Claims
- 1. An Electrically Erasable and Programmable Read Only Memory (EEPROM) having an array of memory cells, each memory cell having a trench configuration and a semiconductor drain region adjacent a surface-adjoining portion of said trench, characterized in that said EEPROM is provided with at least two overlapping metallization layers overlying said memory cells separated from each other and from said trenches and said drain regions by regions of insulating material, and in that each of said overlapping metallization layers contact the drain region of at least one underlying memory cell through said insulating material.
Specification