Patent US5582679A successfully refreshed from Google Patents.
US5582679A
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Enhanced metal etch process
Assignee: GlobalFoundries Singapore Pte Ltd
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Filing: 1994-09-12
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Granted: 1996-12-10
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Expires: 2014-09-12
Abstract
Abstract A method for dry etching metal films, specifically aluminum, is described. This process uses photoresist as a mask with a gas mixture of BCl3, Cl2 and N2 used for the RIE. The addition of specific amounts of N2 to the etching chemistry results in non-tapered or non-undercut aluminum shapes. These desired shapes are attributed to the creation of polymer on the sidewall of the aluminum during the etching procedure, thus protecting against the isotropic components of RIE process, which cause the tapering. This RIE process can also be conducted at high enough temperatures, needed to avoid deleterious microloading effects.
Inventors
- 👤 Liu Lianjun
- 👤 Ron-Fu Chu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 22:50
CPC Classifications
C; C23; C23F; C23F4/00; H; H10; H10P; H10P50/00; H10P50/20; H10P50/26; H10P50/264; H10P50/266
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
123 words
A method for forming aluminum patterns on a semiconductor substrate comprising the steps of: depositing a aluminum based layer on said substrate; forming an organic photoresist image on part of said aluminum based layer; anisotropically etching the exposed part of said aluminum based layer in a ambient comprised of between 15 to 30 sccm of BCl3, between 50 to 70 sccm of Cl 2 , and between 10 to 30 sccm of N 2 , at a pressure between 4 to 7 mTorr, and at a temperature between 50° to 70° C., to form a straight wall, aluminum based shape, from said aluminum based layer; and removal of said photoresist image, at a temperature between 60° to 70° C., in an organic solvent.
Claim 2
Independent Claim
123 words
A method for forming aluminum patterns on a semiconductor substrate comprising the steps of: depositing a aluminum based layer on said substrate; forming an organic photoresist image on part of said aluminum based layer; anisotropically etching the exposed part of said aluminum based layer in a ambient comprised of between 15 to 30 sccm of BCl3, between 50 to 70 sccm of Cl 2 , and between 10 to 30 sccm of N 2 , at a pressure between 4 to 7 mTorr, and at a temperature between 50° to 70° C., to form a straight wall, aluminum based shape, from said aluminum based layer; and removal of said photoresist image, at a temperature between 60° to 70° C., in an organic solvent.
Claim 3
Dependent Claim
35 words
The method of claim 1, wherein said aluminum based layer is comprised of pure aluminum deposited via sputtering procedures, at a pressure between 1 to 4 mTorr, to a thickness between 5000 to 10000 Angstroms.
Claim 4
Dependent Claim
40 words
The method of claim 1, wherein said aluminum based layer is comprised of aluminum, containing between 0.8 to 1.5% copper, deposited via sputtering procedures, at a pressure between 1 to 4 mTorr, to a thickness between 5000 to 10000 Angstroms.
Claim 5
Dependent Claim
40 words
The method of claim 1, wherein said aluminum based layer is comprised of aluminum, containing between 0.5 to 1.0% silicon, deposited via sputtering procedures, at a pressure between 1 to 4 mTorr, to a thickness between 5000 to 10000 Angstroms.
Claim 6
Dependent Claim
46 words
The method of claim 1, wherein said aluminum based layer is comprised of aluminum, containing between 0.8 to 1.5% copper, and between 0.5 to 1.0% silicon, deposited via sputtering procedures, at a pressure between 1 to 4 mTorr, to a thickness between 5000 to 10000 Angstroms.
Claim 7
Independent Claim
165 words
A method for forming aluminum patterns on a semiconductor substrate comprising the steps of: depositing a aluminum based layer on said substrate; forming an organic photoresist image on part of said aluminum based layer; anisotropically etching the exposed part of said aluminum based layer, in an ambient comprised of between 15 to 30 sccm of BCl3, between 50 to 70 sccm of Cl 2 , and between 10 to 30 sccm of N 2 , at a pressure between 4 to 7 mTorr, and at a temperature between 50° to 70° C., to form straight wall, aluminum shape, from said aluminum based layer; forming a N 2 containing polymer on the sides of said aluminum shape, during the anisotropic etching of said aluminum based layer, via the addition of between 10 to 30 sccm of N 2 , to the etching ambient; and removal of said photoresist, and said N 2 containing polymer, at a temperature between 60° to 70° C., in an organic solvent.
Claim 8
Independent Claim
165 words
A method for forming aluminum patterns on a semiconductor substrate comprising the steps of: depositing a aluminum based layer on said substrate; forming an organic photoresist image on part of said aluminum based layer; anisotropically etching the exposed part of said aluminum based layer, in an ambient comprised of between 15 to 30 sccm of BCl3, between 50 to 70 sccm of Cl 2 , and between 10 to 30 sccm of N 2 , at a pressure between 4 to 7 mTorr, and at a temperature between 50° to 70° C., to form straight wall, aluminum shape, from said aluminum based layer; forming a N 2 containing polymer on the sides of said aluminum shape, during the anisotropic etching of said aluminum based layer, via the addition of between 10 to 30 sccm of N 2 , to the etching ambient; and removal of said photoresist, and said N 2 containing polymer, at a temperature between 60° to 70° C., in an organic solvent.
Claim 9
Dependent Claim
49 words
The method of claim 1, wherein said anisotropic etching is performed using photoresist as a mask, with said photoresist mask, and any organic compounds, formed during said anisotropic etching, removed in organic solvents, at a temperature between 60° to 70° C., at the conclusion of said anisotropic etching procedure.
Claim 10
Dependent Claim
35 words
The method of claim 1, wherein said anisotropic etching, of said aluminum based layer, is performed at a temperature between 50° to 70° C., with a minimum of 50° C. needed to prevent microloading effects.
Claim 11
Dependent Claim
39 words
The method of claim 1, wherein said anisotropic etching is performed at a pressure between 4 to 7 mTorr, with a maximum pressure of 7 mTorr, to avoid isotropic etching of said aluminum based layer, undercutting said photoresist shape.
Claim 12
Dependent Claim
44 words
The method of claim 6, wherein said anisotropic etching, of said aluminum based layer, is performed at a pressure between 4 to 7 mTorr, with a maximum pressure of 7 mTorr, to avoid isotropic etching of said aluminum based layer, undercutting said photoresist mask.
Claim 13
Dependent Claim
35 words
The method of claim 6, wherein said aluminum based layer is comprised of pure aluminum, deposited via sputtering procedures, at a pressure between 1 to 4 mTorr, to a thickness between 5000 to 10000 Angstroms.
Claim 14
Dependent Claim
40 words
The method of claim 6, wherein said aluminum based layer is comprised of aluminum, containing between 0.8 to 1.5% copper, deposited via sputtering procedures, at a pressure between 1 to 4 mTorr, to a thickness between 5000 to 10000 Angstroms.
Claim 15
Dependent Claim
38 words
The method of claim 6, wherein said aluminum based layer is aluminum, containing between 0.5 to 1.0% silicon, deposited via sputtering procedures, at a pressure between 1 to 4 mTorr, to a thickness between 5000 to 10000 Angstroms.
Claim 16
Dependent Claim
46 words
The method of claim 6, wherein said aluminum based layer is comprised of aluminum, containing between 0.8 to 1.5% copper, and between 0.5 to 1.0% silicon, deposited via sputtering procedures, at a pressure between 1 to 4 mTorr, to a thickness between 5000 to 10000 Angstroms.
Claim 17
Dependent Claim
50 words
The method of claim 6 wherein the said etching mixture is between 15 to 30 sccm of BC13, between 50 to 70 sccm of C12, and between 10 to 30 sccm N2, where the amount of N2 is in excess of 10%, but less then 35%, of the etching mixture.
Claim 18
Dependent Claim
35 words
The method of claim 6, wherein said anisotropic etching of said aluminum based layer, is performed at a temperature between 50° to 70° C., with a minimum of 50° C. needed to prevent microloading effects.
Claim 19
Dependent Claim
52 words
The method of claim 6, wherein said anisotropic etching is performed using photoresist as a mask, with said photoresist mask, and said N 2 containing polymer, formed during said anisotropic etching, removed in an organic solvent, at a temperature between 60° to 70° C., at the conclusion of said anisotropic etching procedure.
Claim 20
Dependent Claim
20 words
The method of claim 6, wherein said aluminum profile is straight walled, without isotropic undercutting of overlying said photoresist shape.
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