Patent US5320979A successfully refreshed from Google Patents.
US5320979A
Expired / Lapsed
US
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Method of connecting wirings through connection hole
Assignee: NTT Inc
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Filing: 1993-08-03
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Granted: 1994-06-14
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Expires: 2013-08-03
Abstract
Abstract A method includes the steps of forming an insulating layer on a first conductive layer, forming a connection hole in the insulating layer, performing etching using an ion having a very low etching rate with respect to the first conductive layer and a high etching rate with respect to the insulating layer, thereby forming a taper on a side wall of the connection hole, and forming a second conductive layer on the first layer and the insulating layer. A typical example of an etching ion is an oxygen ion.
Inventors
- 👤 Chisato Hashimoto
- 👤 Katsuyuki Machida
- 👤 Hideo Oikawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 20:11
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/071; H10W20/081; H10W20/082; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P50/283; Y; Y10; Y10S; Y10S438/00; Y10S438/978
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
162 words
A method of connecting wirings through a connecting hole, comprising the steps of: forming a first conductive layer for a first wiring; forming an insulating layer on said first conductive layer; forming a connection hole having a bottom and a side wall on said first conductive layer; forming a metal column on the bottom of said connection hole; forming a taper on the side wall of said connection hole at least near a top of said insulating layer by physical etching with an oxygen ion only, a material of said ion having a characteristic which reacts with said metal column to form an oxide layer for protecting said metal column from etching so that an etching rate with respect to said metal column is lower than that with respect to said insulating layer; and forming a second conductive layer for a second wiring on said insulating layer, said metal column in said connection hole, and the side wall of said connection hole.
Claim 2
Independent Claim
162 words
A method of connecting wirings through a connecting hole, comprising the steps of: forming a first conductive layer for a first wiring; forming an insulating layer on said first conductive layer; forming a connection hole having a bottom and a side wall on said first conductive layer; forming a metal column on the bottom of said connection hole; forming a taper on the side wall of said connection hole at least near a top of said insulating layer by physical etching with an oxygen ion only, a material of said ion having a characteristic which reacts with said metal column to form an oxide layer for protecting said metal column from etching so that an etching rate with respect to said metal column is lower than that with respect to said insulating layer; and forming a second conductive layer for a second wiring on said insulating layer, said metal column in said connection hole, and the side wall of said connection hole.
Claim 3
Dependent Claim
15 words
A method according to claim 1, wherein said metal column comprises tungsten aluminum or molybdenum.
Claim 4
Independent Claim
154 words
A method of connecting wirings through a connecting hole, comprising the steps of: forming a first conductive layer for a first wiring; forming an insulating layer on said first conductive layer; forming a connection hole having a bottom and a side wall on said first conductive layer; forming a taper on the side wall of said connection hole at least near a top of said insulating layer by physical etching with an oxygen ion only, a material of said ion having a characteristic which reacts with said first conductive layer to form an oxide layer for protecting said conductive layer from etching so that an etching rate with respect to said first conductive layer is lower than that with respect to said insulating layer; and forming a second conductive layer for a second wiring on said insulating layer, said first conductive layer in said connection hole, and the side wall of said connection hole.
Claim 5
Independent Claim
154 words
A method of connecting wirings through a connecting hole, comprising the steps of: forming a first conductive layer for a first wiring; forming an insulating layer on said first conductive layer; forming a connection hole having a bottom and a side wall on said first conductive layer; forming a taper on the side wall of said connection hole at least near a top of said insulating layer by physical etching with an oxygen ion only, a material of said ion having a characteristic which reacts with said first conductive layer to form an oxide layer for protecting said conductive layer from etching so that an etching rate with respect to said first conductive layer is lower than that with respect to said insulating layer; and forming a second conductive layer for a second wiring on said insulating layer, said first conductive layer in said connection hole, and the side wall of said connection hole.
Claim 6
Dependent Claim
16 words
A method according to claim 3, wherein said first conductive layer comprises tungsten, aluminum or molybdenum.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-06-13 | 1997-12-13 | 1998-06-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-06-13 | 2001-12-13 | 2002-06-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-06-13 | 2005-12-13 | 2006-06-14 | $7700.00 | Window Closed / Lapsed |