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US6184089B1
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Method of fabricating one-time programmable read only memory
Assignee: United Microelectronics Corp
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Filing: 1999-01-27
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Granted: 2001-02-06
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Expires: 2019-01-27
Abstract
Abstract A method of fabricating a one-time programmable read only memory (OTP-ROM) with reduced size is disclosed. In accordance with the method of the present invention, a stacked structure is formed on a substrate. The stacked structure comprises a first oxide layer, a first polysilicon layer, and a second oxide layer formed in sequence on the substrate. The substrate beside the stacked structure is exposed by the stacked structure. An implanted region is formed in the exposed substrate beside the stacked structure. A spacer is formed on a sidewall of the stacked structure. A silicide layer is formed on the implanted region. A silicon nitride layer is formed to cover the second oxide layer, the spacer, and the silicide layer. A second polysilicon layer is formed to cover the silicon nitride layer. The second polysilicon layer is patterned to form a control gate. The first polysilicon layer is further patterned to form a floating gate.
Inventors
- 👤 Kuang-Yeh Chang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 09:29
CPC Classifications
H; H10; H10B; H10B41/00; H10B41/30; H10B69/00
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
140 words
A method of fabricating a one-time programmable read only memory, comprising the steps of: forming a stacked structure on a substrate, wherein the stacked structure comprises a first oxide layer, a first polysilicon layer, and a second oxide layer formed in sequence on the substrate, and the substrate beside the stacked structure is exposed by the stacked structure; forming an implanted region in the exposed substrate beside the stacked structure; forming a spacer on a sidewall of the stacked structure; forming a silicide layer on the implanted region; forming a silicon nitride layer to directly cover the second oxide layer, the spacer, and the silicide layer, forming a second polysilicon layer to cover the silicon nitride layer; and patterning the second polysilicon layer to form a control gate and further patterning the first polysilicon layer to form a floating gate.
Claim 2
Independent Claim
140 words
A method of fabricating a one-time programmable read only memory, comprising the steps of: forming a stacked structure on a substrate, wherein the stacked structure comprises a first oxide layer, a first polysilicon layer, and a second oxide layer formed in sequence on the substrate, and the substrate beside the stacked structure is exposed by the stacked structure; forming an implanted region in the exposed substrate beside the stacked structure; forming a spacer on a sidewall of the stacked structure; forming a silicide layer on the implanted region; forming a silicon nitride layer to directly cover the second oxide layer, the spacer, and the silicide layer, forming a second polysilicon layer to cover the silicon nitride layer; and patterning the second polysilicon layer to form a control gate and further patterning the first polysilicon layer to form a floating gate.
Claim 3
Dependent Claim
15 words
The method of claim 1 , wherein the material of the spacer comprises silicon nitride.
Claim 4
Dependent Claim
15 words
The method of claim 1 , wherein the silicide layer comprises a titanium silicide layer.
Claim 5
Dependent Claim
18 words
The method of claim 1 , wherein the first polysilicon layer is formed by low-pressure chemical vapor deposition.
Claim 6
Dependent Claim
18 words
The method of claim 1 , wherein the second polysilicon layer is formed by low-pressure chemical vapor deposition.
Claim 7
Dependent Claim
60 words
The method of claim 1 , wherein the step of forming the silicide layer comprises: forming a metallic layer on the substrate exposed by the second oxide layer, the spacer, and the stacked structure; performing a thermal treatment to covert the metallic layer, which is in contact with the substrate, into the silicide layer; and removing the remaining metallic layer.
Claim 8
Dependent Claim
28 words
The method of claim 1 , wherein the step of patterning the second polysilicon layer and further patterning the first polysilicon layer comprises a photolithographic and etching process.
Claim 9
Dependent Claim
29 words
The method of claim 1 , wherein the further patterning of the first polysilicon layer comprises a self-aligned etching step with the second polysilicon layer serving as a mask.
Claim 10
Independent Claim
118 words
A method of fabricating a one-time programmable read only memory, comprising the steps of: forming a stacked structure on a substrate, wherein the stacked structure comprises a first oxide layer, a first polysilicon layer, and a second oxide layer formed in sequence on the substrate, and the substrate beside the stacked structure is exposed by the stacked structure; forming an implanted region in the exposed substrate beside the stacked structure; forming a spacer on a sidewall of the stacked structure; forming a silicide layer on the implanted region in the substrate; forming a silicon nitride layer to directly cover the second oxide layer, the spacer, and the silicide layer; forming a control gate on the silicon nitride layer.
Claim 11
Independent Claim
118 words
A method of fabricating a one-time programmable read only memory, comprising the steps of: forming a stacked structure on a substrate, wherein the stacked structure comprises a first oxide layer, a first polysilicon layer, and a second oxide layer formed in sequence on the substrate, and the substrate beside the stacked structure is exposed by the stacked structure; forming an implanted region in the exposed substrate beside the stacked structure; forming a spacer on a sidewall of the stacked structure; forming a silicide layer on the implanted region in the substrate; forming a silicon nitride layer to directly cover the second oxide layer, the spacer, and the silicide layer; forming a control gate on the silicon nitride layer.
Claim 12
Dependent Claim
41 words
The method of claim 9 , wherein the step of forming the silicide layer comprises: forming a metallic layer on the substrate; performing a thermal treatment to convert the metallic layer into the silicide layer; and removing the remaining metallic layer.
Claim 13
Dependent Claim
15 words
The method of claim 9 , wherein the material of the spacer comprises silicon nitride.
Claim 14
Dependent Claim
36 words
The method of claim 9 , wherein the step of forming the control gate comprises: forming a second polysilicon layer on the silicon nitride layer; and patterning the second polysilicon layer to form a control gate.
Claim 15
Dependent Claim
25 words
The method of claim 9 , further comprising patterning the first polysilicon layer to form a floating gate after the formation of the control gate.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-02-06 | 2004-08-07 | 2005-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-02-06 | 2008-08-07 | 2009-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-02-06 | 2012-08-07 | 2013-02-06 | $7700.00 | Window Closed / Lapsed |