US5328865A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for making cusp-free anti-fuse structures
Assignee: NXP BV
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Filing: 1993-01-29
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Granted: 1994-07-12
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Expires: 2013-01-29
Abstract
Abstract A method for making an anti-fuse structure characterized by the steps of forming a conductive base layer; forming an anti-fuse layer over the base layer; patterning the anti-fuse layer to form an anti-fuse island; forming an insulating layer over the anti-fuse island; forming a via hole through the insulating layer to the anti-fuse island; forming a conductive connection layer over the insulating layer and within the via hole; and patterning the conductive connection layer to form a conductive contact to the anti-fuse island. Preferably, the anti-fuse island comprises amorphous silicon which can optionally be covered with a thin layer of a titanium-tungsten alloy.
Inventors
- 👤 William J. Boardman
- 👤 David P. Chan
- 👤 Kuang-Yeh Chang
- 👤 Calvin T. Gabriel
- 👤 Vivek Jain
- 👤 Subhash R. Nariani
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 07:59
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/40; H10W20/49; H10W20/491; H10W20/01; H10W20/031; H10W20/064; H10W20/065
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
174 words
A method for making an anti-fuse structure, the method comprising the steps of: forming a conductive base layer having at least one substantially planar surface portion; forming an anti-fuse layer over at least said planar surface portion of said conductive base layer such that a lower surface portion of said anti-fuse layer that is in contact with said planar surface portion of said conductive base layer is also substantially planar; patterning said anti-fuse layer to form an anti-fuse island including said lower surface portion, such that said lower surface portion of said anti-fuse island contacts essentially only said substantially planar surface portion of said conductive base layer; forming an insulating layer over said anti-fuse island; forming a via hole through said insulating layer to said anti-fuse island; forming a conductive connection layer over said insulating layer and within said via hole; and patterning said conductive connection layer to form a conductive contact to said anti-fuse island through said via hole; whereby said anti-fuse island comprises a substantially cusp-free anti-fuse structure within said via hole.
Claim 2
Independent Claim
174 words
A method for making an anti-fuse structure, the method comprising the steps of: forming a conductive base layer having at least one substantially planar surface portion; forming an anti-fuse layer over at least said planar surface portion of said conductive base layer such that a lower surface portion of said anti-fuse layer that is in contact with said planar surface portion of said conductive base layer is also substantially planar; patterning said anti-fuse layer to form an anti-fuse island including said lower surface portion, such that said lower surface portion of said anti-fuse island contacts essentially only said substantially planar surface portion of said conductive base layer; forming an insulating layer over said anti-fuse island; forming a via hole through said insulating layer to said anti-fuse island; forming a conductive connection layer over said insulating layer and within said via hole; and patterning said conductive connection layer to form a conductive contact to said anti-fuse island through said via hole; whereby said anti-fuse island comprises a substantially cusp-free anti-fuse structure within said via hole.
Claim 3
Dependent Claim
44 words
A method for making an anti-fuse structure as recited in claim 1, further comprising the step of forming a conductive protective layer over said anti-fuse layer prior to patterning said anti-fuse layer, whereby said conductive protective layer forms a part of said anti-fuse island.
Claim 4
Dependent Claim
31 words
A method for making an anti-fuse structure as recited in claim 2, further comprising the step of patterning said conductive protective layer and said anti-fuse layer to form said anti-fuse island.
Claim 5
Dependent Claim
24 words
A method for making an anti-fuse structure as recited in claim 3, further comprising the step of including amorphous silicon in said anti-fuse layer.
Claim 6
Dependent Claim
29 words
A method for making an anti-fuse structure as recited in claim 4, further comprising the step of including an alloy including titanium and tungsten in said conductive protective layer.
Claim 7
Dependent Claim
24 words
A method for making an anti-fuse structure as recited in claim 5, further comprising the step of including aluminum in said conductive base layer.
Claim 8
Dependent Claim
38 words
A method for making an anti-fuse structure as recited in claim 6, further comprising the step of including in said conductive connection layer a composite layer comprising a layer including aluminum and a layer including tungsten and titanium.
Claim 9
Dependent Claim
26 words
A method for making an anti-fuse structure as recited in claim 1, further comprising the step of patterning said base layer after patterning said anti-fuse layer.
Claim 10
Dependent Claim
32 words
A method for making an anti-fuse structure as recited in claim 1, wherein a plurality of anti-fuse islands, via holes, and conductive contacts are formed to provide a plurality of anti-fuse islands.
Claim 11
Dependent Claim
100 words
A method for making an anti-fuse structure as recited in claim 1, further comprising the step of providing as said conductive base layer a multilayer structure that comprises a first sub-layer that suppresses migration of atoms of a selected element across the first sub-layer, a second sub-layer that provides a low resistance path across the second sub-layer, and a third sub-layer that suppresses migration of atoms of a selected element across the third sub-layer, where the third sub-layer is positioned contiguous to said anti-fuse layer and said second sub-layer is positioned between and contiguous to the first and third sub-layers.
Claim 12
Dependent Claim
51 words
A method for making an anti-fuse structure as recited in claim 10, further comprising the steps of: including an alloy comprising titanium and tungsten in said first sub-layer; including an alloy comprising aluminum and copper in said second sub-layer; and including an alloy comprising titanium and tungsten in said third sub-layer.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-07-11 | 1998-01-10 | 1998-07-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-07-11 | 2002-01-10 | 2002-07-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-07-11 | 2006-01-10 | 2006-07-12 | $7700.00 | Window Closed / Lapsed |