Static ferroelectric memory transistor having improved data retention
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United States of America Patent
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Nov 26, 1996
Grant Date -
N/A
app pub date -
Mar 17, 1995
filing date -
Mar 17, 1995
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Abstract
An improved ferroelectric FET structure in which the ferroelectric layer is doped to reduce retention loss. A ferroelectric FET according to the present invention includes a semiconductor layer having first and second contacts thereon, the first and second contacts being separated from one another. The ferroelectric FET also includes a bottom electrode and a ferroelectric layer which is sandwiched between the semiconductor layer and the bottom electrode. The ferroelectric layer is constructed from a perovskite structure of the chemical composition ABO.sub.3 wherein the B site comprises first and second elements and a dopant element that has an oxidation state greater than +4 in sufficient concentration to impede shifts in the resistance measured between the first and second contacts with time. The ferroelectric FET structure preferably comprises Pb in the A-site. The first and second elements are preferably Zr and Ti, respectively. The preferred B-site dopants are Niobium, Tantalum, and Tungsten at concentrations between 1% and 8%.

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Patent Owner(s)
Patent Owner | Address | |
---|---|---|
SANDIA CORPORATION | P O BOX 5800 MS-0161 ALBUQUERQUE NM 87185 |
International Classification(s)
Inventor(s)
Inventor Name | Address | # of filed Patents | Total Citations |
---|---|---|---|
Evans, Jr Joseph T | 13609 Verbena Pl., N.E., Albuquerque, NM 87112 | 35 | 821 |
Tuttle, Bruce A | 12808 Lillian Pl., NE., Albuquerque, NM 87112 | 6 | 87 |
Warren, William L | 7716 Wm. Moyers Ave., NE., Albuquerque, NM 87112 | 46 | 1686 |
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Surcharge after expiration - Late payment is unavoidable | $700.00 | $350.00 | $175.00 |
Surcharge after expiration - Late payment is unintentional | $1,640.00 | $820.00 | $410.00 |
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