Dense array structure for non-volatile semiconductor memories

Abstract

The present invention describes an array structure ( 10 ) for non-volatile semiconductor memory elements ( 14, 16 ) with a high area density. This high density is obtained by the combination of a commonly used virtual ground scheme and a 2-dimensional array of memory elements ( 14, 16 ). Wordlines ( 18, 20 ) connecting memory elements ( 14, 16 ) in a row or a column cross each other at insulated cross-points ( 22 ). Furthermore, the invention describes a possible fabrication process for such memory arrays.

Description

technical field [0001] The present invention relates to the field of a nonvolatile semiconductor memory such as a floating gate memory and a method of operation thereof. More particularly, the present invention relates to such dense array structures of memory elements, nonvolatile memory devices including such dense array structures Memories, and methods of fabricating such dense array structures. Background technique [0002] Non-volatile memory (NVM) is widely used in various commercial and military electronic devices and equipment, such as cellular phones, radio communications, and digital cameras. The market for these electronic devices still requires low voltage, low power consumption, and reduced chip size. device. [0003] Flash memory consists of a grid of columns and rows with MOSFETs at each intersection, the MOSFETs have one (or more) floating gates (FG) between the control gate (CG) and the channel region, the floating gate and The control gates are separated b...

AI Technical Summary

Problems solved by technology

[0006] A disadvantage of the above prior art cell structures is that they use zigzag patterns which inevitably lead to large cells. This is due to the photolithography process used in the fabrication of such devices: it is easier to pattern straight lines than to pattern zigzag lines .Furthermore, the zigzag pattern can lead to yield loss for large arrays because of the risk of sub-circuiting

Images