Abstract: An improved method for fabricating a three dimensional monolithic memory with increased density. The method includes forming conductors preferably comprising tungsten, then filling and planarizing; above the conductors forming semiconductor elements preferably comprising two diode portions and an antifuse, then filling and planarizing; and continuing to form conductors and semiconductor elements in multiple stories of memories. The arrangement of processing steps and the choice of materials decreases aspect ratio of each memory cell, improving the reliability of gap fill and preventing etch undercut.
Abstract: The traditional nitride-only charge storage layer of a SONOS device is replaced by a multifilm charge storage layer comprising more than one dielectric material. Examples of such a multifilm charge storage layer are alternating layers of silicon nitride and silicon dioxide, or alternating layers of silicon nitride and aluminum oxide. The use of more than one material introduces additional barriers to migration of charge carriers within the charge storage layer, and improves both endurance and retention of a SONOS-type memory cell comprising such a charge storage layer.
Type:
Grant
Filed:
September 23, 2003
Date of Patent:
March 14, 2006
Assignee:
Matrix Semiconductors, Inc.
Inventors:
Maitreyee Mahajani, Andrew J. Walker, En-Hsing Chen
Abstract: An improved method for fabricating a three dimensional monolithic memory with increased density. The method includes forming conductors preferably comprising tungsten, then filling and planarizing; above the conductors forming semiconductor elements preferably comprising two diode portions and an antifuse, then filling and planarizing; and continuing to form conductors and semiconductor elements in multiple stories of memories. The arrangement of processing steps and the choice of materials decreases aspect ratio of each memory cell, improving the reliability of gap fill and preventing etch undercut.
Abstract: An improved method for fabricating a three dimensional monolithic memory with increased density. The method includes forming conductors preferably comprising tungsten, then filling and planarizing; above the conductors forming semiconductor elements preferably comprising two diode portions and an antifuse, then filling and planarizing; and continuing to form conductors and semiconductor elements in multiple stories of memories. The arrangement of processing steps and the choice of materials decreases aspect ratio of each memory cell, improving the reliability of gap fill and preventing etch undercut.
Abstract: A thin film transistor with a channel less than 100 angstroms thick, preferably less than 80 angstroms thick, preferably less than 60 angstroms thick. The very thin channel reduces variability of threshold voltage from one TFT to the next. This is particularly advantageous for TFT memory arrays. It is possible that an extremely thin channel restricts the size of grains, forcing many small grains to be formed.
Type:
Grant
Filed:
December 31, 2002
Date of Patent:
November 1, 2005
Assignee:
Matrix Semiconductor, Inc.
Inventors:
Andrew J. Walker, S. Brad Herner, Maitreyee Mahajani, En-Hsing Chen, Roy E. Scheuerlein, Sucheta Nallamothu, Mark Clark
Abstract: A three dimensional monolithic memory comprising a memory cell allowing for increased density is disclosed. In the memory cell of the present invention, a bottom conductor preferably comprising tungsten is formed. Above the bottom conductor a semiconductor element preferably comprises two diode portions and an antifuse. Above the semiconductor element are additional conductors and semiconductor elements in multiple stones of memories. The arrangement of processing steps and the choice of materials decreases aspect ratio of each memory cell, improving the reliability of gap fill and preventing etch undercut.
Abstract: The invention provides for a vertically oriented junction diode having a contact-antifuse unit in contact with one of its electrodes. The contact-antifuse unit is formed either above or below the junction diode, and comprises a silicide with a dielectric antifuse layer formed on and in contact with it. In preferred embodiments, the silicide is cobalt silicide, and the antifuse preferably silicon oxide, silicon nitride, or silicon oxynitride grown on the colbalt silicide. The junction diode and contact-antifuse unit can be used as a memory cell, which is advantageously used in a monolithic three dimensional memory array.