US5108941A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making metal-to-polysilicon capacitor
Assignee: Texas Instruments Inc
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Filing: 1990-03-19
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Granted: 1992-04-28
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Expires: 2010-03-19
Abstract
Abstract A metal-to-polysilicon capacitor, a floating-gate transistor containing such a capacitor, and a method for making the same is disclosed. The bottom plate of the capacitor is formed over a field oxide structure, and the multilevel dielectric is deposited thereover. The multilevel dielectric is removed from the capacitor area, and an oxide/nitride dielectric is deposited over the exposed bottom plate and over the multilevel by way of LPCVD. A first layer of titanium/tungsten is preferably deposited prior to contact etch, and the contacts to moat and unrelated polysilicon are formed. Metallization is sputtered overall, and the metal and titanium/tungsten are cleared to leave the metallization filling the contact holes, and a capacitor having a titanium/tungsten and metal top plate.
Inventors
- 👤 James L. Paterson
- 👤 Howard L. Tigelaar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 05:07
CPC Classifications
H; H10; H10D; H10D1/00; H10D1/60; H10D1/68; H10B; H10B41/00; H10D30/00; H10D30/60; H10D30/68; H10D30/681; H10W; H10W10/00; H10W10/01; H10W10/051; H10W10/50
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
150 words
A method for fabricating a capacitor at a surface of a semiconductor body, comprising the steps of: forming a field dielectric structure at a selected portion of said surface; forming a refractory metal layer thereover in contact with said field dielectric structure and with a silicon surface of said semiconductor body; reacting the refractory metal layer to form a silicide where in contact with said silicon surface; removing selected portions of the refractory metal layer which was not reacted to form a silicide, to define a bottom plate overlying said field dielectric structure; forming an interlevel dielectric layer overall; removing a portion of said interlevel dielectric layer over said bottom plate to expose a portion of said bottom plate; forming a capacitor dielectric over said exposed portion of said bottom plate; and forming a top plate comprising a metal layer in contact with said capacitor dielectric over said bottom plate.
Claim 2
Independent Claim
150 words
A method for fabricating a capacitor at a surface of a semiconductor body, comprising the steps of: forming a field dielectric structure at a selected portion of said surface; forming a refractory metal layer thereover in contact with said field dielectric structure and with a silicon surface of said semiconductor body; reacting the refractory metal layer to form a silicide where in contact with said silicon surface; removing selected portions of the refractory metal layer which was not reacted to form a silicide, to define a bottom plate overlying said field dielectric structure; forming an interlevel dielectric layer overall; removing a portion of said interlevel dielectric layer over said bottom plate to expose a portion of said bottom plate; forming a capacitor dielectric over said exposed portion of said bottom plate; and forming a top plate comprising a metal layer in contact with said capacitor dielectric over said bottom plate.
Claim 3
Dependent Claim
12 words
The method of claim 1, wherein said refractory metal layer comprises titanium.
Claim 4
Dependent Claim
24 words
The method of claim 2, wherein a portion of said refractory metal layer overlying said field dielectric structure comprises a conductive compound of titanium.
Claim 5
Dependent Claim
14 words
The method of claim 3, wherein said conductive compound of titanium is titanium nitride.
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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) | 1995-04-28 | 1995-10-28 | 1996-04-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-04-28 | 1999-10-28 | 2000-04-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-04-28 | 2003-10-28 | 2004-04-28 | $7700.00 | Window Closed / Lapsed |