US5828130A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of forming a landing pad structure in an integrated circuit
Assignee: STMicroelectronics lnc USA
•
Filing: 1996-12-03
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Granted: 1998-10-27
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Expires: 2016-12-03
Abstract
Abstract A method is provided for forming a landing pad of a semiconductor integrated circuit, and an integrated circuit formed according to the same. A plurality of conductive regions are formed over a substrate. A polysilicon landing pad is formed over at least one of the plurality of conductive regions. After the polysilicon is patterned and etched to form the landing pad, tungsten is then selectively deposited over the polysilicon to form a composite polysilicon/tungsten landing pad which is a good etch stop, a good barrier to aluminum/silicon interdiffusion and a good conductor.
Inventors
- 👤 Robert Otis Miller
- 👤 Gregory Clifford Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 13:26
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/40; H10W20/41; H10W20/44; H10W20/4451; H10D; H10D64/00; H10D64/01; H10D64/011; H10D64/0111; H10D64/0113
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
80 words
The structure of a portion of a semiconductor integrated circuit formed at a surface of a body, comprising: an active region in a substrate; a doped polysilicon landing pad overlying a portion of the active region and electrically contacting the active region, a portion of the doped polysilicon landing pad separated from an adjacent conductive element by a distance of between approximately 1000 and 5000 Å; and selectively deposited tungsten overlying the polysilicon to form a composite polysilicon/tungsten landing pad.
Claim 2
Dependent Claim
80 words
The structure of a portion of a semiconductor integrated circuit formed at a surface of a body, comprising: an active region in a substrate; a doped polysilicon landing pad overlying a portion of the active region and electrically contacting the active region, a portion of the doped polysilicon landing pad separated from an adjacent conductive element by a distance of between approximately 1000 and 5000 Å; and selectively deposited tungsten overlying the polysilicon to form a composite polysilicon/tungsten landing pad.
Claim 3
Dependent Claim
17 words
The structure of claim 1, further comprising: sidewall spacers on the ends of the polysilicon landing pad.
Claim 4
Dependent Claim
11 words
The structure of claim 2, wherein the sidewall spacers comprise oxide.
Claim 5
Dependent Claim
13 words
The structure of claim 1, wherein the active area comprises a source/drain region.
Claim 6
Dependent Claim
24 words
The structure of claim 1, further comprising: an oxide layer underlying a portion of the landing pad over the active area in the substrate.
Claim 7
Dependent Claim
22 words
The structure of claim 5, wherein the oxide layer has a thickness on the order of between approximately 500 to 3000 angstroms.
Claim 8
Dependent Claim
23 words
The structure of claim 1, wherein the polysilicon landing pad has a thickness on the order of between approximately 300 to 2000 angstroms.
Claim 9
Dependent Claim
22 words
The structure of claim 1, wherein the selective tungsten has a thickness on the order of between approximately 400 to 1000 angstroms.
Claim 10
Dependent Claim
28 words
The structure of claim 1, further comprising: an interlevel dielectric layer overlying the composite landing pad having an opening therethrough exposing a portion of the composite landing pad.
Claim 11
Dependent Claim
12 words
The structure of claim 9, wherein the interlevel dielectric layer comprises BPSG.
Claim 12
Dependent Claim
17 words
The structure of claim 9, wherein the interlevel dielectric layer comprises BPSG overlying an undoped oxide layer.
Claim 13
Dependent Claim
13 words
The structure of claim 9, further comprising: a conductive contact in the opening.
Claim 14
Dependent Claim
11 words
The structure of claim 12, wherein the conductive contact comprises aluminum.
Claim 15
Dependent Claim
15 words
The structure of claim 12, wherein the conductive contact comprises aluminum overlying a barrier layer.
Claim 16
Dependent Claim
17 words
The structure of claim 9, wherein the opening is substantially over the active area in the substrate.
Claim 17
Dependent Claim
99 words
The structure of a portion of a semiconductor integrated circuit formed at a surface of a body, comprising: a plurality of conductive regions on a substrate; an active region in the substrate adjacent at least one of the conductive regions; a doped polysilicon landing pad overlying a portion of the active region and electrically contacting the active region, a portion of the doped polysilicon landing pad separated from the at least one adjacent conductive region by a distance less than a predetermined metal contact-to-gate space; and selectively deposited tungsten overlying the polysilicon to form a composite polysilicon/tungsten landing pad.
Claim 18
Dependent Claim
99 words
The structure of a portion of a semiconductor integrated circuit formed at a surface of a body, comprising: a plurality of conductive regions on a substrate; an active region in the substrate adjacent at least one of the conductive regions; a doped polysilicon landing pad overlying a portion of the active region and electrically contacting the active region, a portion of the doped polysilicon landing pad separated from the at least one adjacent conductive region by a distance less than a predetermined metal contact-to-gate space; and selectively deposited tungsten overlying the polysilicon to form a composite polysilicon/tungsten landing pad.
Claim 19
Dependent Claim
30 words
The structure of claim 15, wherein at least one of the conductive regions is a transistor gate and wherein the composite landing pad overlies a portion of the transistor gate.
Claim 20
Dependent Claim
23 words
The structure of claim 17, further comprising: oxide sidewalls along the sides of the gate; and an oxide capping layer overlying the gate.
Claim 21
Dependent Claim
14 words
The structure of claim 17, wherein the predetermined metal contact-to-gate space is 5000 Å.
Claim 22
Dependent Claim
17 words
The structure of claim 15, further comprising: sidewall spacers on the ends of the polysilicon landing pad.
Claim 23
Dependent Claim
90 words
The structure of a portion of a semiconductor integrated circuit formed at a surface of a body, comprising: a gate structure overlying a substrate; a source/drain region within the substrate adjacent a region underlying the gate structure; an insulating material adjacent the gate structure and over the source/drain region, wherein the insulating material has a width less than a predetermined metal contact-to-gate space; a doped polysilicon layer overlying a portion of the gate structure and the insulating material and contacting the source/drain region; and tungsten overlying the polysilicon layer pad.
Claim 24
Dependent Claim
90 words
The structure of a portion of a semiconductor integrated circuit formed at a surface of a body, comprising: a gate structure overlying a substrate; a source/drain region within the substrate adjacent a region underlying the gate structure; an insulating material adjacent the gate structure and over the source/drain region, wherein the insulating material has a width less than a predetermined metal contact-to-gate space; a doped polysilicon layer overlying a portion of the gate structure and the insulating material and contacting the source/drain region; and tungsten overlying the polysilicon layer pad.
Claim 25
Dependent Claim
27 words
The structure of claim 21, wherein the predetermined contact-to-gate space is a contact-to-gate space required for a metal contact design rule and is at least 5000 Å.
Claim 26
Dependent Claim
13 words
The structure of claim 21, wherein the insulating material comprises a sidewall spacer.
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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) | 2001-10-26 | 2002-04-27 | 2002-10-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-10-26 | 2006-04-27 | 2006-10-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-10-26 | 2010-04-27 | 2010-10-27 | $7700.00 | Window Closed / Lapsed |