US5432128A
Expired / Lapsed
US
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Reliability enhancement of aluminum interconnects by reacting aluminum leads with a strengthening gas
Assignee: Texas Instruments Inc
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Filing: 1994-05-27
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Granted: 1995-07-11
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Expires: 2014-05-27
Abstract
Abstract This invention encompasses using a strengthened shell to enhance reliability of aluminum leads of a semiconductor device. The invention includes depositing an aluminum layer on a substrate 12, etching the aluminum layer in a predetermined pattern to form aluminum leads 16, exposing the aluminum leads 16 to a strengthening gas to react and form a strengthened shell 18 on the aluminum leads 16, and depositing a dielectric layer 20 over the strengthened shell 18 and the substrate 12. The strengthening gas may contain nitrogen, oxygen, or both. The exposing step may also comprise a rapid thermal anneal, and the dielectric layer 20 is preferably comprised of a material having a dielectric constant of less than 3. An advantage of the invention is to mechanically strengthen the aluminum leads of a semiconductor wafer. In addition, it is an intrinsic operation, rather than extrinsic; the basic material required is already present on the wafer, it is merely altered.
Inventors
- 👤 Robert Tsu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 00:16
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/031
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
109 words
A method for enhancing reliability of aluminum leads of a semiconductor device having a substrate, comprising the steps of: depositing an aluminum layer on said substrate; etching said aluminum layer in predetermined pattern to form aluminum leads; exposing said aluminum leads to a strengthening gas to react with said aluminum leads and form a strengthened shell on said aluminum leads; and depositing a dielectric layer over said strengthened shell and said substrate, said dielectric layer providing a dielectric constant of less than 3 in a region between at least two of said aluminum leads, whereby the lack of strength of the dielectric material is compensated by stronger aluminum leads.
Claim 2
Independent Claim
109 words
A method for enhancing reliability of aluminum leads of a semiconductor device having a substrate, comprising the steps of: depositing an aluminum layer on said substrate; etching said aluminum layer in predetermined pattern to form aluminum leads; exposing said aluminum leads to a strengthening gas to react with said aluminum leads and form a strengthened shell on said aluminum leads; and depositing a dielectric layer over said strengthened shell and said substrate, said dielectric layer providing a dielectric constant of less than 3 in a region between at least two of said aluminum leads, whereby the lack of strength of the dielectric material is compensated by stronger aluminum leads.
Claim 3
Dependent Claim
10 words
The method of claim 1 wherein said gas contains nitrogen.
Claim 4
Dependent Claim
10 words
The method of claim 1 wherein said gas contains oxygen.
Claim 5
Dependent Claim
18 words
The method of claim 1 wherein said exposing said aluminum layer step also comprises a rapid thermal anneal.
Claim 6
Dependent Claim
16 words
The method of claim 1 wherein said strengthened shell comprises nitrogen and is 10-100 Å thick.
Claim 7
Dependent Claim
16 words
The method of claim 1 Wherein said strengthened shell comprises oxygen and is 40-100 Å thick.
Claim 8
Dependent Claim
16 words
The method of claim 1 wherein said aluminum leads have an aspect ratio greater than 1.
Claim 9
Independent Claim
147 words
A method for enhancing reliability of aluminum leads of a semiconductor device having a substrate, comprising the steps of: depositing an insulating layer on said substrate; depositing an aluminum layer on said insulating layer; etching said aluminum layer in a predetermined pattern to form aluminum leads, wherein portions of said insulating layer are exposed; exposing said aluminum leads and said exposed portions of said insulating layer to a strengthening gas in order to react and form a strengthened shell on said aluminum leads and a strengthened insulating layer on said exposed portions of said insulating layer; and depositing a dielectric layer over said strengthened shell and said strengthened insulating layer, said dielectric layer providing a dielectric constant of less than 3 in a region between at least two of said aluminum leads, whereby the lack of strength of the dielectric material is compensated by stronger aluminum leads.
Claim 10
Independent Claim
147 words
A method for enhancing reliability of aluminum leads of a semiconductor device having a substrate, comprising the steps of: depositing an insulating layer on said substrate; depositing an aluminum layer on said insulating layer; etching said aluminum layer in a predetermined pattern to form aluminum leads, wherein portions of said insulating layer are exposed; exposing said aluminum leads and said exposed portions of said insulating layer to a strengthening gas in order to react and form a strengthened shell on said aluminum leads and a strengthened insulating layer on said exposed portions of said insulating layer; and depositing a dielectric layer over said strengthened shell and said strengthened insulating layer, said dielectric layer providing a dielectric constant of less than 3 in a region between at least two of said aluminum leads, whereby the lack of strength of the dielectric material is compensated by stronger aluminum leads.
Claim 11
Dependent Claim
10 words
The method of claim 8 wherein said gas contains nitrogen.
Claim 12
Dependent Claim
10 words
The method of claim 8 wherein said gas contains oxygen.
Claim 13
Dependent Claim
15 words
The method of claim 8 wherein said exposing step also comprises a rapid thermal anneal.
Claim 14
Dependent Claim
21 words
The method of claim 8 wherein said strengthened shell and said strengthened insulating layer comprise nitrogen and are 10-100 Å thick.
Claim 15
Dependent Claim
21 words
The method of claim 8 wherein said strengthened shell and said strengthened insulating layer comprise oxygen and are 40-100 Å thick.
Claim 16
Dependent Claim
16 words
The method of claim 8 wherein said aluminum leads have an aspect ratio greater than 1.
References Cited (Backward Citations)
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