US5374591A
Expired / Lapsed
US
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Method of making a metal plug
Assignee: Sony Corp
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Filing: 1992-03-23
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Granted: 1994-12-20
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Expires: 2012-03-23
Abstract
Abstract A metal plug is formed in a connection hole such as a via hole or a contact hole to provide an interconnection between multilayer wires in a semiconductor integrated circuit. First, an adhesion layer is deposited on an insulating film, and an area of the adhesion layer is etched away isotropic etching through an opening in a resist mask, the area being larger than the opening in the resist mask. Thereafter, the insulating film is etched through the opening in the resist mask by anisotropic etching, forming a connection hole in the insulating film. Then, a metal layer such as a blanket tungsten layer is deposited on the adhesion layer and in the connection hole. The metal layer is etched back and the adhesion layer is etched away, leaving the metal layer as a metal plug in the connection hole.
Inventors
- 👤 Toshiaki Hasegawa
- 👤 Junichi Sato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 21:43
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/069; H10W20/071; H10W20/081; H10W20/032; H10W20/056
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
132 words
A method of making a metal plug in a connection hole in an insulating film, comprising the steps of: depositing an adhesion layer on a surface of an insulating film; etching away an area of said adhesion layer by isotropic etching through an opening in a resist mask, said area being larger than said opening in the resist mask; thereafter etching said insulating film through the opening in the resist mask by anisotropic etching, forming a connection hole in said insulating film; which has a substantially constant width; depositing a metal layer on said adhesion layer and in said connection hole; and etching back said metal layer, leaving the metal layer as a metal plug in said connection hole which substantially fills the hole and wherein the plug has a flat top.
Claim 2
Independent Claim
132 words
A method of making a metal plug in a connection hole in an insulating film, comprising the steps of: depositing an adhesion layer on a surface of an insulating film; etching away an area of said adhesion layer by isotropic etching through an opening in a resist mask, said area being larger than said opening in the resist mask; thereafter etching said insulating film through the opening in the resist mask by anisotropic etching, forming a connection hole in said insulating film; which has a substantially constant width; depositing a metal layer on said adhesion layer and in said connection hole; and etching back said metal layer, leaving the metal layer as a metal plug in said connection hole which substantially fills the hole and wherein the plug has a flat top.
Claim 3
Independent Claim
122 words
A method Of making a metal plug in a connection hole in an insulating film, comprising the steps of: depositing an adhesion layer on a surface of an insulating film; etching away an area of said adhesion layer by isotropic etching through an opening in a resist mask, said area being larger than said opening in the resist mask; thereafter etching said insulating film through the opening in the resist mask by anisotropic etching, forming a connection hole in said insulating film; depositing a metal layer on said adhesion layer and in said connection hole; and etching back said metal layer, leaving the metal layer as a metal plug in said connection hole, and wherein said adhesion layer is made of Ti.
Claim 4
Independent Claim
122 words
A method Of making a metal plug in a connection hole in an insulating film, comprising the steps of: depositing an adhesion layer on a surface of an insulating film; etching away an area of said adhesion layer by isotropic etching through an opening in a resist mask, said area being larger than said opening in the resist mask; thereafter etching said insulating film through the opening in the resist mask by anisotropic etching, forming a connection hole in said insulating film; depositing a metal layer on said adhesion layer and in said connection hole; and etching back said metal layer, leaving the metal layer as a metal plug in said connection hole, and wherein said adhesion layer is made of Ti.
Claim 5
Dependent Claim
23 words
A method according to claim 2, further including the step of: nitriding said adhesion layer of Ti into an adhesion layer of TiN.
Claim 6
Independent Claim
153 words
A method of making a metal plug in a connection hole in an insulating film, comprising the steps of: depositing an adhesion layer on a surface of an insulating film; etching away an area of said adhesion layer by isotropic etching through an opening in a resist mask, said area being larger than said opening in the resist mask; thereafter etching said insulating film through the opening in the resist mask by anisotropic etching, forming a connection hole in said insulating film; depositing a metal layer on said adhesion layer and in said connection hole; and etching back said metal layer, leaving the metal layer as a metal plug in said connection hole, and wherein said adhesion layer is deposited as a Ti film and etched with 50 SCCM of a Cl 2 gas under a pressure of 0.05 Torr with a power of 0.08 W/cm 2 at a temperature of 100° C.
Claim 7
Independent Claim
153 words
A method of making a metal plug in a connection hole in an insulating film, comprising the steps of: depositing an adhesion layer on a surface of an insulating film; etching away an area of said adhesion layer by isotropic etching through an opening in a resist mask, said area being larger than said opening in the resist mask; thereafter etching said insulating film through the opening in the resist mask by anisotropic etching, forming a connection hole in said insulating film; depositing a metal layer on said adhesion layer and in said connection hole; and etching back said metal layer, leaving the metal layer as a metal plug in said connection hole, and wherein said adhesion layer is deposited as a Ti film and etched with 50 SCCM of a Cl 2 gas under a pressure of 0.05 Torr with a power of 0.08 W/cm 2 at a temperature of 100° C.
Claim 8
Independent Claim
146 words
A method of making a metal plug in a connection hole in an insulating film, comprising the steps of: depositing an adhesion layer on a surface of an insulating film; etching away an area of said adhesion layer by isotropic etching through an opening in a resist mask, said area being larger than said opening in the resist mask; thereafter etching said insulating film through the opening in the resist mask by anisotropic etching, forming a connection hole in said insulating film; depositing a metal layer on said adhesion layer and in said connection hole; and etching back said metal layer, leaving the metal layer as a metal plug in said connection hole, and wherein said adhesion layer is deposited as a TiN film and etched with 30 SCCM of a Cl 2 gas under a pressure of 0.06 Torr with a power of 0.2 W/cm2.
Claim 9
Independent Claim
146 words
A method of making a metal plug in a connection hole in an insulating film, comprising the steps of: depositing an adhesion layer on a surface of an insulating film; etching away an area of said adhesion layer by isotropic etching through an opening in a resist mask, said area being larger than said opening in the resist mask; thereafter etching said insulating film through the opening in the resist mask by anisotropic etching, forming a connection hole in said insulating film; depositing a metal layer on said adhesion layer and in said connection hole; and etching back said metal layer, leaving the metal layer as a metal plug in said connection hole, and wherein said adhesion layer is deposited as a TiN film and etched with 30 SCCM of a Cl 2 gas under a pressure of 0.06 Torr with a power of 0.2 W/cm2.
Claim 10
Dependent Claim
38 words
A method according to claim 2, wherein said insulating film is etched by reactive ion etching with 80 SCCM of a CHF 3 gas under a pressure of 0.05 Torr with a power of 0.25 W/cm 2 .
Claim 11
Dependent Claim
47 words
A method according to claim 2, wherein the metal layer comprises a blanket tungsten layer and is deposited by CVD with a gas of 30 SCCM of WF 6 and 360 SCCM of SiH 4 under a pressure of 80 Torr at a temperature of 475° C.
Claim 12
Dependent Claim
77 words
A method according to claim 2, wherein the metal layer comprises a blanket tungsten layer and is deposited by CVD first with a gas of 25 SCCM of WF 6 and 15 SCCM of SiH 4 under a pressure of 80 Torr at a temperature of 475° C., and then with a gas of 60 SCCM of WF 6 and 360 SCCM of H 2 under a pressure of 80 Torr at a temperature of 475° C.
Claim 13
Independent Claim
200 words
A method of making a metal plug in a connection hole in an insulating film, comprising the steps of: depositing an adhesion layer on a surface of an insulating film; etching away an area of said adhesion layer by isotropic etching through an opening in a resist mask, said area being larger than said opening in the resist mask; thereafter etching said insulating film through the opening in the resist mask by anisotropic etching, forming a connection hole in said insulating film; depositing a metal layer on said adhesion layer and in said connection hole; and etching back said metal layer, leaving the metal layer as a metal plug in said connection hole, and further including the steps of: forming a first wire as a diffused layer in a semiconductor layer; depositing said insulating film on said semiconductor layer over said first wire before said adhesion layer is deposited on said insulating film; forming said connection hole all the way through said insulating film to said first wire; etching away said adhesion layer; and after said metal plug is left in said connection hole, forming a second wire on said insulating layer in electrically connected relationship to said metal plug.
Claim 14
Independent Claim
200 words
A method of making a metal plug in a connection hole in an insulating film, comprising the steps of: depositing an adhesion layer on a surface of an insulating film; etching away an area of said adhesion layer by isotropic etching through an opening in a resist mask, said area being larger than said opening in the resist mask; thereafter etching said insulating film through the opening in the resist mask by anisotropic etching, forming a connection hole in said insulating film; depositing a metal layer on said adhesion layer and in said connection hole; and etching back said metal layer, leaving the metal layer as a metal plug in said connection hole, and further including the steps of: forming a first wire as a diffused layer in a semiconductor layer; depositing said insulating film on said semiconductor layer over said first wire before said adhesion layer is deposited on said insulating film; forming said connection hole all the way through said insulating film to said first wire; etching away said adhesion layer; and after said metal plug is left in said connection hole, forming a second wire on said insulating layer in electrically connected relationship to said metal plug.
Claim 15
Dependent Claim
57 words
A method according to claim 9, further including the steps of: depositing a second insulating film on said semiconductor layer over said first wire before said insulating film is deposited on said semiconductor layer; thereafter removing a region of said second insulating film which corresponds to said lower wire; and depositing a film in the removed region.
References Cited (Backward Citations)
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| 3.5 Years (Year 4) | 1997-12-19 | 1998-06-20 | 1998-12-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-12-19 | 2002-06-20 | 2002-12-20 | $3760.00 | Window Closed / Lapsed |
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