US5248632A
Expired / Lapsed
US
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Method of forming an antifuse
Assignee: Texas Instruments Inc
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Filing: 1992-09-29
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Granted: 1993-09-28
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Expires: 2012-09-29
Abstract
Abstract An antifuse (42) is formed by forming a layer of titanium tungsten (34) overlying a portion of a first metal layer (28). The titanium tungsten layer (34) is oxidized to form a film of oxide (36) on its surface. Insulating regions (30) are formed adjacent the titanium tungsten layer (34) and overlying the first metal layer (28). A second metal layer (40) is formed overlying the titanium tungsten layer (34). Applying a break down voltage across the first and second metal layers (28), (40) will break down the oxide film (36), thereby causing a connection between the first and second metal layers (28), (40).
Inventors
- 👤 Yingsheng Tung
- 👤 Scott Montgomery
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:15
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/40; H10W20/49; H10W20/491; Y; Y10; Y10S; Y10S148/00; Y10S148/055
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
61 words
A method of forming an antifuse, comprising the steps of: forming a first metal layer; forming a layer of titanium tungsten overlying at least a portion of the first metal layer; oxidizing the titanium tungsten layer to form a film of oxide on the surface of the titanium tungsten layer; and forming a second metal layer overlying the titanium tungsten layer.
Claim 2
Independent Claim
61 words
A method of forming an antifuse, comprising the steps of: forming a first metal layer; forming a layer of titanium tungsten overlying at least a portion of the first metal layer; oxidizing the titanium tungsten layer to form a film of oxide on the surface of the titanium tungsten layer; and forming a second metal layer overlying the titanium tungsten layer.
Claim 3
Dependent Claim
21 words
The method of claim 1, wherein the oxidizing step comprises exposing the titanium tungsten layer to a plasma of ionized oxygen.
Claim 4
Dependent Claim
24 words
The method of claim 1, further comprising the step of forming a barrier layer of refractive metal prior to forming the first metal layer.
Claim 5
Dependent Claim
24 words
The method of claim 1, further comprising the step of forming insulating regions adjacent the titanium tungsten layer and overlying the first metal layer.
Claim 6
Dependent Claim
47 words
The method of claim 4, wherein the step of forming insulating regions comprises the steps of: forming an interlevel oxide layer overlying the first metal layer; patterning the interlevel oxide layer; and etching the interlevel oxide layer to expose a first region of the first metal layer.
Claim 7
Dependent Claim
77 words
The method of claim 5, wherein the step of forming the layer of titanium tungsten comprises the steps of: depositing a layer of titanium tungsten overlying the interlevel oxide layer and the exposed region of the first metal layer; patterning the titanium tungsten layer; and the titanium tungsten layer to remove all except a plug of titanium tungsten overlying the first exposed region of the first metal layer and overlapping a portion of the interlevel oxide layer.
Claim 8
Dependent Claim
100 words
The method of claim 5, wherein the step of forming a second metal layer comprises the steps of: forming a via through the interlevel oxide layer to expose a second region of the first metal layer; depositing a second metal layer overlying the titanium tungsten layer, the interlevel oxide layer, and the second exposed region of the first metal layer; patterning the second metal layer; and etching the second metal layer to form a first interconnect coupled to the first metal layer through the titanium tungsten layer, and a second interconnect contacting the second exposed region of the first metal
Claim 9
Dependent Claim
52 words
The method of claim 4, wherein the step of forming insulating regions comprises the steps of: forming an interlevel oxide layer overlying the titanium tungsten layer and the first metal layer; patterning the interlevel oxide layer; and etching the interlevel oxide layer to expose the upper surface of the titanium tungsten layer.
Claim 10
Dependent Claim
98 words
The method of claim 8, wherein the step of forming a second metal layer comprises the steps of: forming a via through the interlevel oxide layer to expose a region of the first metal layer; depositing a second metal layer overlying the titanium tungsten layer, the interlevel oxide layer, and the exposed region of the first metal layer; patterning the second metal layer; and etching the second metal layer to form a first interconnect coupled to the first metal layer through the titanium tungsten layer, and a second interconnect contacting the exposed region of the first metal layer.
Claim 11
Dependent Claim
54 words
The method of claim 1, wherein the step of forming the layer of titanium tungsten comprises the steps of: depositing a layer of titanium tungsten overlying the first metal layer; patterning the titanium tungsten layer; etching the titanium tungsten layer to remove all except a cylinder of titanium tungsten overlying the first metal layer.
Claim 12
Independent Claim
201 words
A method of forming an antifuse, comprising the steps of: forming a first metal layer; forming an interlevel oxide layer overlying the first metal layer; etching the interlevel oxide layer to expose a first region of the first metal layer; depositing a layer of titanium tungsten overlying the interlevel oxide layer and the first exposed region of the first metal layer; patterning the titanium tungsten layer; etching the titanium tungsten layer to remove all except a plug of titanium tungsten overlying the first exposed region of the first metal layer and a portion of the interlevel oxide layer; oxidizing the titanium tungsten plug in a plasma of ionized oxygen to form a film of oxide on its surface; forming a via through the interlevel oxide layer to expose a second region of the first metal layer; depositing a second metal layer overlying the titanium tungsten plug, the interlevel oxide layer, and the second exposed region of the first metal layer; patterning the second metal layer; and etching the second metal layer to form a first interconnect coupled to the first metal layer through the titanium tungsten plug, and a second interconnect contacting the second exposed region of the first metal layer.
Claim 13
Independent Claim
201 words
A method of forming an antifuse, comprising the steps of: forming a first metal layer; forming an interlevel oxide layer overlying the first metal layer; etching the interlevel oxide layer to expose a first region of the first metal layer; depositing a layer of titanium tungsten overlying the interlevel oxide layer and the first exposed region of the first metal layer; patterning the titanium tungsten layer; etching the titanium tungsten layer to remove all except a plug of titanium tungsten overlying the first exposed region of the first metal layer and a portion of the interlevel oxide layer; oxidizing the titanium tungsten plug in a plasma of ionized oxygen to form a film of oxide on its surface; forming a via through the interlevel oxide layer to expose a second region of the first metal layer; depositing a second metal layer overlying the titanium tungsten plug, the interlevel oxide layer, and the second exposed region of the first metal layer; patterning the second metal layer; and etching the second metal layer to form a first interconnect coupled to the first metal layer through the titanium tungsten plug, and a second interconnect contacting the second exposed region of the first metal layer.
Claim 14
Independent Claim
185 words
A method of forming an antifuse, comprising the steps of: forming a first metal layer; depositing a layer of titanium tungsten overlying the first metal layer; patterning the titanium tungsten layer; etching the titanium tungsten layer to remove all except a cylinder of titanium tungsten overlying the first metal layer; forming an interlevel oxide layer overlying the titanium tungsten cylinder and the first metal layer; patterning the interlevel oxide layer; etching the interlevel oxide layer to expose the upper surface of the titanium tungsten cylinder; oxidizing the titanium tungsten cylinder in a plasma of ionized oxygen to form a film of oxide on its surface; forming a via through the interlevel oxide layer to expose a region of the first metal layer; depositing a second metal layer overlying the titanium tungsten cylinder, the interlevel oxide layer, and the exposed region of the first metal layer; patterning the second metal layer; and etching the second metal layer to form a first interconnect coupled to the first metal layer through the titanium tungsten cylinder, and a second interconnect contacting the exposed region of the first metal layer.
Claim 15
Independent Claim
185 words
A method of forming an antifuse, comprising the steps of: forming a first metal layer; depositing a layer of titanium tungsten overlying the first metal layer; patterning the titanium tungsten layer; etching the titanium tungsten layer to remove all except a cylinder of titanium tungsten overlying the first metal layer; forming an interlevel oxide layer overlying the titanium tungsten cylinder and the first metal layer; patterning the interlevel oxide layer; etching the interlevel oxide layer to expose the upper surface of the titanium tungsten cylinder; oxidizing the titanium tungsten cylinder in a plasma of ionized oxygen to form a film of oxide on its surface; forming a via through the interlevel oxide layer to expose a region of the first metal layer; depositing a second metal layer overlying the titanium tungsten cylinder, the interlevel oxide layer, and the exposed region of the first metal layer; patterning the second metal layer; and etching the second metal layer to form a first interconnect coupled to the first metal layer through the titanium tungsten cylinder, and a second interconnect contacting the exposed region of the first metal layer.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1996-09-27 | 1997-03-29 | 1997-09-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-09-27 | 2001-03-29 | 2001-09-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-09-27 | 2005-03-29 | 2005-09-28 | $7700.00 | Window Closed / Lapsed |