US5486707A
Expired / Lapsed
US
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Antifuse structure with double oxide layers
Assignee: Xilinx Inc
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Filing: 1994-01-10
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Granted: 1996-01-23
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Expires: 2014-01-10
Abstract
Abstract An antifuse for programmable integrated circuit devices is formed above a refractory metal on a thin native oxide layer and comprises an amorphous compound resulting from an PECVD deposition using a combination of silane gas and nitrogen. After formation of the amorphous antifuse layer, the layer is implanted with an atomic species such as argon. The thin oxide layer is formed on the surface of a refractory metal, therefore the process of forming the oxide is slow, the oxide is of even thickness, and the thickness can be controlled precisely. In a preferred embodiment, a second thin oxide layer is formed above the doped amorphous layer. The oxide layers significantly reduce the leakage current of an unprogrammed antifuse. Because of these thin oxide layers and the implantation step, the amorphous layer may be as thin as 200 Å.
Inventors
- 👤 Kevin T. Look
- 👤 Evert A. Wolsheimer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:07
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/064; H10W20/065; H10W20/40; H10W20/49; H10W20/491
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
73 words
An antifuse structure comprising: a first conductive layer including a refractory metal; a first oxide layer comprising an oxide of said refractory metal; an amorphous silicon layer formed on said first oxide layer; a second oxide layer comprising an oxide of said amorphous silicon layer; and a second conductive layer formed on said second oxide layer, wherein said antifuse structure provides a programming voltage range of approximately 7.5 volts to approximately 10.0 volts.
Claim 2
Dependent Claim
73 words
An antifuse structure comprising: a first conductive layer including a refractory metal; a first oxide layer comprising an oxide of said refractory metal; an amorphous silicon layer formed on said first oxide layer; a second oxide layer comprising an oxide of said amorphous silicon layer; and a second conductive layer formed on said second oxide layer, wherein said antifuse structure provides a programming voltage range of approximately 7.5 volts to approximately 10.0 volts.
Claim 3
Dependent Claim
15 words
The antifuse structure of claim 1 wherein said amorphous layer includes amorphous silicon and nitrogen.
Claim 4
Dependent Claim
25 words
The antifuse structure of claim 2 wherein said amorphous layer is implanted with atoms, wherein said atoms include: argon, silicon, arsenic, oxygen, or phosphorus atoms.
Claim 5
Dependent Claim
20 words
The antifuse structure of claim 2 wherein said amorphous layer is implanted with atoms capable of breaking up small crystals.
Claim 6
Dependent Claim
20 words
The antifuse structure of claim 1 wherein said amorphous layer has a thickness range between 200 Å and 800 Å.
Claim 7
Dependent Claim
12 words
The antifuse structure of claim 1 wherein said refractory metal includes titanium-tungsten.
Claim 8
Dependent Claim
17 words
The antifuse structure of claim 1 further comprising a field oxide region adjacent said first oxide layer.
Claim 9
Dependent Claim
17 words
The antifuse structure of claim 1 further comprising a field oxide region adjacent said second oxide layer.
Claim 10
Dependent Claim
13 words
The antifuse structure of claim 1 wherein said amorphous layer includes amorphous silicon.
Claim 11
Dependent Claim
70 words
An anti fuse structure comprising: a first conductive layer including a refractory metal; a first oxide layer formed from said refractory metal; an amorphous layer formed on said first oxide layer, wherein said amorphous layer includes amorphous silicon and nitrogen and wherein said amorphous layer has approximately 25 atomic percent nitrogen; a second oxide layer formed from said amorphous layer; and a second conductive layer formed on said second oxide.
Claim 12
Dependent Claim
70 words
An anti fuse structure comprising: a first conductive layer including a refractory metal; a first oxide layer formed from said refractory metal; an amorphous layer formed on said first oxide layer, wherein said amorphous layer includes amorphous silicon and nitrogen and wherein said amorphous layer has approximately 25 atomic percent nitrogen; a second oxide layer formed from said amorphous layer; and a second conductive layer formed on said second oxide.
Claim 13
Dependent Claim
23 words
The antifuse structure of claim 1 wherein said first conductive layer includes a base layer, said refractory metal formed on said base layer.
Claim 14
Dependent Claim
19 words
The antifuse structure of claim 11 wherein said base layer includes aluminum, an aluminum-silicon alloy, or an aluminum-silicon-copper alloy.
Claim 15
Dependent Claim
26 words
The antifuse structure of claim 6 wherein said first layer of oxide includes titanium oxide, tungsten oxide, or a combination of titanium oxide and tungsten oxide.
Claim 16
Dependent Claim
18 words
The antifuse structure of claim 1 further including a third conductive layer formed over said second conductive layer.
Claim 17
Dependent Claim
17 words
The antifuse structure of claim 14 wherein said third conductive layer includes at least one refractory metal.
Claim 18
Dependent Claim
15 words
The antifuse structure of claim 15 wherein said at least one refractory metal includes titanium.
Claim 19
Dependent Claim
15 words
The antifuse structure of claim 15 wherein said at least one refractory metal includes tungsten.
Claim 20
Dependent Claim
18 words
The antifuse structure of claim 15 wherein said third conductive layer further includes at least one non-refractory metal.
Claim 21
Dependent Claim
15 words
The antifuse structure of claim 18 wherein said at least one non-refractory metal includes aluminum.
Claim 22
Dependent Claim
13 words
The antifuse structure of claim 5 wherein said thickness is approximately 450 Å.
References Cited (Backward Citations)
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| 7.5 Years (Year 8) | 2003-01-22 | 2003-07-24 | 2004-01-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-01-22 | 2007-07-24 | 2008-01-23 | $7700.00 | Window Closed / Lapsed |