US5353246A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Programmable semiconductor antifuse structure and method of fabricating
Assignee: Lattice Semiconductor Corp
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Filing: 1993-08-18
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Granted: 1994-10-04
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Expires: 2013-08-18
Abstract
Abstract A programmable semiconductor antifuse structure and method of fabricating are provided which allow for miniaturization of components to an area of less than one micron. The cell exhibits a high pre-programmed resistance of more than 1×10 7 ohms and has an extremely low programmed cell resistance of around 50 ohms.
Inventors
- 👤 Wai M. Tsang
- 👤 Daniel C. Hu
- 👤 Dong T. Khong
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 10:08
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/064; H10W20/065; H10D; H10D48/00; H10D48/30; H10D48/38; H10D48/381
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
155 words
The method of forming an electrical programmable read only memory cell having an antifuse structure comprising the steps of: growing a first insulating layer on a silicon substrate; depositing a first semiconductor layer on said first insulating layer; doping said first semiconductor layer to a predetermined conductivity; etching said first semiconductor layer; depositing a second insulating layer over said first semiconductor layer and said first insulating layer; etching said second insulating layer to form an opening which extends to and exposes a portion of said first semiconductor layer; forming a conductive layer over said first semiconductor layer; depositing a second semiconductor layer over said second insulating layer and said conductive layer; etching said second semiconductor layer, wherein said second semiconductor layer overlies said conductive layer and a portion of said second insulating layer; depositing a metal layer on said second semiconductor layer; and etching said metal layer to form a contact to said memory cell.
Claim 2
Independent Claim
155 words
The method of forming an electrical programmable read only memory cell having an antifuse structure comprising the steps of: growing a first insulating layer on a silicon substrate; depositing a first semiconductor layer on said first insulating layer; doping said first semiconductor layer to a predetermined conductivity; etching said first semiconductor layer; depositing a second insulating layer over said first semiconductor layer and said first insulating layer; etching said second insulating layer to form an opening which extends to and exposes a portion of said first semiconductor layer; forming a conductive layer over said first semiconductor layer; depositing a second semiconductor layer over said second insulating layer and said conductive layer; etching said second semiconductor layer, wherein said second semiconductor layer overlies said conductive layer and a portion of said second insulating layer; depositing a metal layer on said second semiconductor layer; and etching said metal layer to form a contact to said memory cell.
Claim 3
Dependent Claim
26 words
A method of claim 1 further comprising: forming a passivation layer; and removing a portion of said passivation layer on the periphery of said memory cell.
Claim 4
Dependent Claim
16 words
The method of claim 2 further comprising: performing an alloy to ensure all contacts are ohmic.
Claim 5
Dependent Claim
49 words
The method of claim 1 wherein said step of forming said conductive layer comprises: sputtering a layer of titanium; performing a thermal annealing to form a layer of titanium silicide; stripping unreacted titanium and titanium nitride; and forming a layer of titanium nitride on said layer of titanium silicide.
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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) | 1997-10-03 | 1998-04-04 | 1998-10-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-10-03 | 2002-04-04 | 2002-10-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-10-03 | 2006-04-04 | 2006-10-04 | $7700.00 | Window Closed / Lapsed |