EP0488546A1
Expired / Lapsed
EP
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Contact for integrated circuits
Assignee: STMicroelectronics lnc USA
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Filing: 1991-11-11
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Granted: —
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Expires: 2011-11-11
Abstract
Abstract A method for forming a contact in a semiconductor integrated circuit includes the formation of a conformal oxide layer over the device followed by formation of a doped glass layer. The integrated circuit is heated to cause the glass layer to reflow, improving planarity of the circuit. A second conformal oxide layer is then formed, and contact vias are cut through the three part interlevel dielectric layer. Side walls are then formed in the via by depositing a third conformal layer, and anisotropically etching such layer. This isolates the doped reflowable glass layer from the via. Metal interconnect can then be deposited and defined, forming a contact in the via.
Inventors
- 👤 David Michael Stark
- 👤 Wayne David Clark
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 09:50
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/071; H10W20/081; H10W20/074; H10W20/076; H10W20/40; H10W20/45; H10W20/48
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
113 words
A contact structure for an integrated circuit, comprising: a first conductor on a semiconductor substrate; a first dielectric layer overlying said conductor and the substrate; a second dielectric layer overlying said first dielectric layer; a third dielectric layer overlying said second dielectric layer; an opening through said first, second, and third dielectric layers to expose a portion of said first conductor; sidewall dielectric spacers along sides of said opening; and a second conductor overlying portions of said third dielectric layer and extending into said opening; wherein said second conductor makes electrical contact with said first conductor and is separated from said second insulating layer by said sidewall spacers and said third dielectric layer.
Claim 2
Dependent Claim
15 words
The contact structure of Claim 1, wherein said second dielectric layer comprises a reflowable glass.
Claim 3
Dependent Claim
14 words
The contact structure of claim 1, wherein said first conductor comprises a conductive metal.
Claim 4
Dependent Claim
13 words
The contact structure of claim 1 wherein said first conductor comprises polycrystalline silicon.
Claim 5
Dependent Claim
16 words
The contact structure of claim 4, wherein said polycrystalline silicon is silicided with a refractory metal.
Claim 6
Dependent Claim
14 words
The contact structure of claim 1, wherein said second conductor comprises a conductive metal.
Claim 7
Dependent Claim
20 words
The contact structure of claim 1, wherein said first and third dielectric layers are conformal with their respective underlying structures.
Claim 8
Dependent Claim
79 words
An interlevel dielectric structure for an integrated circuit, comprising: a first dielectric layer of oxide; a second dielectric layer of oxide containing a doping impurity overlying said first oxide layer; a third dielectric layer of oxide overlying said second oxide layer; a plurality of openings through said first, second, and third dielectric layers; and sidewall oxide spacers in said openings, wherein said second dielectric layer is completely surrounded by said first and third dielectric layers and said sidewall spacers.
Claim 9
Dependent Claim
17 words
The structure of claim 2 or claim 8 wherein the second dielectric layer doping impurity comprises boron.
Claim 10
Dependent Claim
17 words
The structure of claim 2 or claim 8, wherein the second dielectric layer doping impurity comprises phosphorous.
Claim 11
Dependent Claim
16 words
The structure or claim 1 or claim 8, wherein said second dielectric layer comprises spin-on glass.
Claim 12
Dependent Claim
18 words
The structure of claim 1 or claim 8, wherein said first and third dielectric layers, are substantially undoped.
Claim 13
Dependent Claim
12 words
The structure of claim 12 wherein said sidewall spacers are substantially undoped.
Claim 14
Dependent Claim
27 words
The structure of claim 2 or claim 8, wherein said second dielectric layer has an upper surface which is more nearly planar than said first dielectric layer.
Claim 15
Independent Claim
144 words
A method for forming an integrated circuit contact structure, comprising the steps of: forming a first dielectric layer over a semiconductor substrate; forming a second dielectric layer over the first dielectric layer; heating the integrated circuit to soften the second dielectric layer, wherein the second dielectric layer partially flows into lower topographic regions of the integrated circuit, whereby an upper surface of the second dielectric layer is more nearly planar than the first dielectric layer; forming a third dielectric layer over the second dielectric layer; forming an opening through the first, second, and third dielectric layers to a conductive region in the substrate; forming sidewall dielectric regions in the opening, wherein the second dielectric layer is separated from the opening thereby; and forming a conductor over portions of the third dielectric layer and extending into the opening of make contact with the conductive region.
Claim 16
Dependent Claim
19 words
The method of claim 15, wherein the second dielectric layer is formed from a glass containing boron or phosphorous.
Claim 17
Dependent Claim
13 words
The method of claim 15, wherein the second dielectric layer comprises spin-on glass.
References Cited (Backward Citations)
US4489481A
Cited
EP0398834A2
Cited
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