US6236094B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low resistance gate electrodes
Assignee: Altera Corp
•
Filing: 1999-06-22
•
Granted: 2001-05-22
•
Expires: 2019-06-22
Abstract
Abstract Provided is a transistor device, and a process for fabricating such a device, in which a top portion of a polysilicon gate electrode is removed and replaced by a low resistance metal material using a damascene process. Gate electrodes in accordance with the present invention provide improved conductivity over conventional polysilicon and silicide-capped polysilicon gate electrodes, due to the low resistivity of the metal, but do not have the drawbacks associated with the complete removal and replacement of polysilicon with a metal.
Inventors
- 👤 Peter J. Wright
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 11:30
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/01; H10D64/017; H10D64/013; H10D64/01302; H10D64/01304; H10D64/01306; H10D64/01308; H10D64/01312; H10D30/00; H10D30/01; H10D30/021; H10D30/0223; H10D64/60; H10D64/66; H10D64/661; H10D64/662; H10D64/663
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
40 words
A gate electrode for a transistor device, said gate electrode having a thickness, comprising: an upper portion comprising Al, said upper portion comprising at least about ⅓ of the thickness of said gate electrode; and a bottom portion comprising polysilicon.
Claim 2
Dependent Claim
40 words
A gate electrode for a transistor device, said gate electrode having a thickness, comprising: an upper portion comprising Al, said upper portion comprising at least about ⅓ of the thickness of said gate electrode; and a bottom portion comprising polysilicon.
Claim 3
Dependent Claim
25 words
The gate electrode of claim 1 , wherein said upper portion of said gate electrode comprises about ½ of the thickness of said gate electrode.
Claim 4
Dependent Claim
40 words
The gate electrode of claim 1 , wherein said bottom portion of said gate electrode has a thickness sufficient to provide a work function substantially the same as if said bottom portion comprised the entire thickness of the gate electrode.
Claim 5
Dependent Claim
20 words
The gate electrode of claim 3 , wherein said thickness of said bottom portion is about 100 to 1000 Å.
Claim 6
Dependent Claim
17 words
The gate electrode of claim 1 , further comprising vertical spacer dielectric regions bordering said gate electrode.
Claim 7
Dependent Claim
18 words
The gate electrode of claim 1 further comprising a middle portion comprising one or more layers of material.
Claim 8
Dependent Claim
71 words
A semiconductor device, comprising: a semiconductor wafer having a substrate, source and drain regions in said substrate, a gate electrode having a thickness, and a gate dielectric separating said gate electrode from the source and drain regions in said substrate; wherein said gate electrode comprises, an upper portion comprising Al, said upper portion comprising at least about ⅓ of the thickness of said gate electrode; and a bottom portion comprising polysilicon.
Claim 9
Dependent Claim
71 words
A semiconductor device, comprising: a semiconductor wafer having a substrate, source and drain regions in said substrate, a gate electrode having a thickness, and a gate dielectric separating said gate electrode from the source and drain regions in said substrate; wherein said gate electrode comprises, an upper portion comprising Al, said upper portion comprising at least about ⅓ of the thickness of said gate electrode; and a bottom portion comprising polysilicon.
Claim 10
Dependent Claim
24 words
The device of claim 7 , wherein said upper portion of said gate electrode comprises about ½ of the thickness of said gate electrode.
Claim 11
Dependent Claim
39 words
The device of claim 7 , wherein said bottom portion of said gate electrode has a thickness sufficient to provide a work function substantially the same as if said bottom portion comprised the entire thickness of the gate electrode.
Claim 12
Dependent Claim
19 words
The device of claim 9 , wherein said thickness of said bottom portion is about 100 to 1000 Å.
Claim 13
Dependent Claim
16 words
The device of claim 7 , further comprising vertical spacer dielectric regions bordering said gate electrode.
Claim 14
Dependent Claim
12 words
The gate electrode of claim 1 , wherein said metal is aluminum.
Claim 15
Dependent Claim
12 words
The semiconductor device of claim 7 , wherein said metal is aluminum.
Claim 16
Dependent Claim
20 words
The gate electrode of claim 6 wherein one of one or more middle layers of material comprises a metal silicide.
Claim 17
Dependent Claim
19 words
The gate electrode of claim 6 wherein one of one or more middle layers of materialcomprises a silicon nitride.
References Cited (Backward Citations)
US4944836A
Cited
US5227320A
Cited
US5306951A
Cited
US5268330A
Cited
US5447874A
Cited
US5595937A
Cited
US5532178A
Cited
US5688706A
Cited
US5856225A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-05-21 | 2004-11-20 | 2005-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-05-21 | 2008-11-20 | 2009-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-05-21 | 2012-11-20 | 2013-05-22 | $7700.00 | Window Closed / Lapsed |