Patent US5328865A successfully refreshed from Google Patents.
US5328865A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for making cusp-free anti-fuse structures
Assignee: NXP BV
•
Filing: 1993-01-29
•
Granted: 1994-07-12
•
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 19:07
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.
References Cited (Backward Citations)
US4419812A
Cited
EP0118158A2
Cited
US4569121A
Cited
WO1985003599A1
Cited
US4748490A
Cited
US4876220A
Cited
US4826785A
Cited
US4862243A
Cited
JPH01124240A
Cited
JPH0223654A
Cited
US5210598A
Cited
US4853347A
Cited
US4914055A
Cited
US5087957A
Cited
US5070384A
Cited
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 |