Plug-based floating gate memory

Abstract

A device and a method of forming a floating gate memory transistor of very small area, thereby allowing a high-density integrated circuit chip, more specifically for Erasable Programmable Read-Only Memory (EPROM) or similar non-volatile devices.In a first embodiment, a method is disclosed that fabricates a programmable memory cell described as a "diffusion cut" cell where a plug-type floating gate contact hole cuts through a diffusion region and partially into a substrate region. In a second embodiment, a method is disclosed that fabricates a programmable memory cell described as an "oxide cut" cell, where the plug-type floating gate contact hole only penetrates a silicon oxide layer. This "oxide cut" cell is formed in a similar fashion except penetration does not go into the diffusion region or substrate.

Claims