US5176790A
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Process for forming a via in an integrated circuit structure by etching through an insulation layer while inhibiting sputtering of underlying metal
Assignee: Applied Materials Inc
•
Filing: 1991-09-25
•
Granted: 1993-01-05
•
Expires: 2011-09-25
Abstract
Abstract An improved process is described for forming one or more vias through an insulation layer by plasma etching to an underlying metal layer without depositing etch residues, including metal sputtered from the underlying metal layer, onto the sidewalls of the vias, which comprises, in one embodiment, using in the gaseous etchant one or more 3-6 carbon fluorinated hydrocarbons having the formula C x H y F z , wherein x is 3 to 6, y is 0 to 3, and z is 2x-y when the fluorinated hydrocarbon is cyclic and z is 2x-y+2 when the fluorinated hydrocarbon is noncyclic. One or more other fluorine-containing gases may also be used as long as the 3-6 carbon fluorinated hydrocarbons comprise at least 10 volume % of the fluorine-containing gas mixture. The fluorinated hydrocarbon gas or fluorine-containing gas mixture also may be mixed with up to 90 volume % total of one or more inert gases to control the taper of the via walls. At least about 5 sccm of the total gas flow must comprise a 3-6 carbon fluorinated hydrocarbon gas, regardless of the volume % of 3-6 carbon fluorinated hydrocarbon gas in the total gas stream flow. In another embodiment, a controlled amount of one or more nitrogen-containing gases are used with one or more fluorine-containing etchant gas wherein the amount of nitrogen-containing gas ranges from about 1 volume part nitrogen-containing gas per 15 volume parts fluorine-containing gas to about 1 volume part nitrogen-containing gas per 2 volume parts fluorine-containing gas.
Inventors
- 👤 Paul Arleo
- 👤 Jon Henri
- 👤 Graham Hills
- 👤 Jerry Wong
- 👤 Robert Wu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 04:17
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/071; H10W20/081; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P50/283
Claims Analysis
Total Claims: 56
Claim 1
Independent Claim
129 words
A process for forming one or more vias by etching through an insulation layer over a metal layer on a semiconductor wafer in an etch chamber without depositing sputtered metal or other etch residues on the sidewall of the via which comprises plasma etching said insulation layer with a fluorine-containing gaseous etchant mixture which includes one or more etch residue inhibitors selected from the group consisting of: a) one or more nitrogen-containing gases, in an amount ranging from about 1 part by volume nitrogen-containing gas to 2 parts by volume of other gases in said mixture to 1 part by volume nitrogen-containing gas to about 15 parts by volume of other gases in said mixture; b) one or more 3-6 carbon fluorinated hydrocarbon gases; and c) mixtures of same.
Claim 2
Dependent Claim
129 words
A process for forming one or more vias by etching through an insulation layer over a metal layer on a semiconductor wafer in an etch chamber without depositing sputtered metal or other etch residues on the sidewall of the via which comprises plasma etching said insulation layer with a fluorine-containing gaseous etchant mixture which includes one or more etch residue inhibitors selected from the group consisting of: a) one or more nitrogen-containing gases, in an amount ranging from about 1 part by volume nitrogen-containing gas to 2 parts by volume of other gases in said mixture to 1 part by volume nitrogen-containing gas to about 15 parts by volume of other gases in said mixture; b) one or more 3-6 carbon fluorinated hydrocarbon gases; and c) mixtures of same.
Claim 3
Dependent Claim
25 words
The process of claim 1 wherein said one or more nitrogen-containing gases are selected from the group consisting of N 2 and N 2 O.
Claim 4
Dependent Claim
21 words
The process of claim 1 wherein said one or more 3-6 carbon fluorinated hydrocarbon gases include C 4 F 8 .
Claim 5
Dependent Claim
59 words
A process for forming one or more vias by etching through an insulation layer over a metal layer on a semiconductor wafer in an etch chamber without depositing sputtered metal or other etch residues on the sidewall of the via which comprises etching said insulation layer with a gaseous mixture which includes one or more 3-6 carbon fluorinated hydrocarbons.
Claim 6
Dependent Claim
59 words
A process for forming one or more vias by etching through an insulation layer over a metal layer on a semiconductor wafer in an etch chamber without depositing sputtered metal or other etch residues on the sidewall of the via which comprises etching said insulation layer with a gaseous mixture which includes one or more 3-6 carbon fluorinated hydrocarbons.
Claim 7
Dependent Claim
81 words
The process of claim 4 wherein said step of forming said via with a gaseous mixture which includes one or more 3-6 carbon fluorinated hydrocarbons further comprises etching said insulation layer with a gaseous mixture which includes one or more fluorinated hydrocarbons having the formula C x H y F z , wherein x is 3 to 6, y is 0 to 3, and z is 2x-y when said fluorinated hydrocarbon is cyclic and 2x-y+2 when said fluorinated hydrocarbon is non-cyclic.
Claim 8
Dependent Claim
46 words
The process of claim 5 wherein said step of forming said via with an etch gas mixture which include one or more of said 3-6 carbon fluorinated hydrocarbons further comprises etching said insulation layer with a fluorinated hydrocarbon having the formula C 4 F 8 .
Claim 9
Dependent Claim
50 words
The process of claim 5 wherein said step of forming said via with an etch gas mixture which include one or more of said 3-6 carbon fluorinated hydrocarbons further includes maintaining a plasma associated with said etch chamber within a power range of from about 300 to about 2500 watts.
Claim 10
Dependent Claim
75 words
The process of claim 7 wherein said step of forming said via with a gaseous mixture which includes one or more 3-6 carbon fluorinated hydrocarbons further comprises etching said insulation layer with a gaseous mixture which includes a mixture of said one or more 3-6 fluorinated gases and one or more other fluorine-containing gases wherein at least 10 volume % of said mixture of fluorine-containing gases comprises said one or more 3-6 carbon fluorinated hydrocarbons.
Claim 11
Dependent Claim
73 words
The process of claim 7 wherein said step of forming said via with a gaseous mixture which includes one or more 3-6 carbon fluorinated hydrocarbons further comprises etching said insulation layer with a gaseous mixture which includes a mixture of said one or more 3-6 fluorinated hydrocarbons and optionally one or more inert gases wherein the amount of said inert gases comprise from 0 to about 90 volume % of said gaseous mixture.
Claim 12
Dependent Claim
144 words
The process of claim 7 wherein said step of forming said via with a gaseous mixture which includes one or more 3-6 carbon fluorinated hydrocarbons further comprises etching said insulation layer with a etchant gas mixture which includes: a) a fluorinated hydrocarbon mixture of said one or more 3-6 carbon fluorinated hydrocarbons and one or more other fluorine-containing gases wherein at least 10 volume % of said fluorine-containing gases in said mixture comprises said one or more 3-6 carbon fluorinated hydrocarbons; and b) optionally one or more inert gases wherein the amount of said inert gases comprises from 0 to about 90 volume % of the total volume of said gaseous mixture of fluorine-containing gases and inert gases; provided, however, that said etchant gas mixture flowing into said etching chamber includes at least 5 sccm of said one or more 3-6 carbon fluorinated hydrocarbons.
Claim 13
Dependent Claim
28 words
The process of claim 10 wherein the amount of said inert gas in said etch gas mixture ranges from about 30 volume % to about 50 volume %.
Claim 14
Dependent Claim
21 words
The process of claim 7 wherein the pressure in said etch chamber ranges from about 5 milliTorr to about 200 milliTorr.
Claim 15
Dependent Claim
31 words
The process of claim 7 wherein the temperature of a wafer support in said etch chamber on which said wafer is mounted ranges from about -120° C. to about 50° C.
Claim 16
Dependent Claim
25 words
The process of claim 13 wherein the temperature of said wafer support in said etch chamber ranges from about 5° C. to about 40° C.
Claim 17
Dependent Claim
35 words
The process of claim 7 wherein the total flow of etch gas into said etch chamber is equivalent to a gas flow into a 13 liter chamber of from about 20 to about 300 sccm.
Claim 18
Dependent Claim
39 words
The process of claim 7 wherein said etch is carried out while subjecting said wafer to a magnetic field having a magnetic strength component parallel to the plane of said wafer ranging from about 1 to about 150 gauss.
Claim 19
Dependent Claim
145 words
A process for forming a via by etching through an insulation layer over a metal layer on a semiconductor wafer in an etch chamber without depositing sputtered metal residues on the sidewall of the via which comprises: a) flowing into said etch chamber an etch gas mixture which includes: i) from about 10 to about 100 volume % of one or more 3-6 carbon fluorinated hydrocarbons having the formula C x H y F z , wherein x is 3 to 6, y is 0 to 3, and z is 2x-y when said fluorinated hydrocarbon is cyclic and 2x-y+2 when said fluorinated hydrocarbon is non-cyclic; and ii) optionally from 0 to about 90 volume % of one or more inert gases; and b) maintaining a plasma within said etch chamber during said etch within a power range of from about 300 to about 2500 watts.
Claim 20
Dependent Claim
145 words
A process for forming a via by etching through an insulation layer over a metal layer on a semiconductor wafer in an etch chamber without depositing sputtered metal residues on the sidewall of the via which comprises: a) flowing into said etch chamber an etch gas mixture which includes: i) from about 10 to about 100 volume % of one or more 3-6 carbon fluorinated hydrocarbons having the formula C x H y F z , wherein x is 3 to 6, y is 0 to 3, and z is 2x-y when said fluorinated hydrocarbon is cyclic and 2x-y+2 when said fluorinated hydrocarbon is non-cyclic; and ii) optionally from 0 to about 90 volume % of one or more inert gases; and b) maintaining a plasma within said etch chamber during said etch within a power range of from about 300 to about 2500 watts.
Claim 21
Dependent Claim
61 words
The process of claim 17 wherein said step of flowing into said etch chamber a gaseous mixture which includes said one or more fluorine-containing gases comprising from about 10 to about 100 volume % of said one or more 3-6 carbon fluorinated hydrocarbons further comprises flowing into said etch chamber a fluorinated hydrocarbon having the formula C 4 F 8 .
Claim 22
Dependent Claim
68 words
The process of claim 17 wherein said gaseous mixture further includes one or more other fluorine-containing gases wherein at least 10 volume % of the total of said fluorine-containing gases in said mixture comprise said one or more 3-6 carbon fluorinated hydrocarbons, provided, however, that said etch gas mixture flowing into said etching chamber includes at least 5 sccm of said one or more 3-6 carbon fluorinated hydrocarbons.
Claim 23
Dependent Claim
33 words
The process of claim 17 wherein the amount of inert gas in said gaseous mixture ranges from about 30 volume % to about 50 volume % of the total volume of said mixture.
Claim 24
Dependent Claim
36 words
The process of claim 17 wherein the total flow of said gaseous mixture into said etch chamber is equivalent to a gas flow into a 13 liter chamber of from about 20 to about 300 sccm.
Claim 25
Dependent Claim
29 words
The process of claim 17 wherein said etch gas mixture flowing into said etching chamber includes at least 5 sccm of said one or more 3-6 carbon fluorinated hydrocarbons.
Claim 26
Dependent Claim
38 words
The process of claim 17 wherein said etch is carried out while immersing said wafer in a magnetic field having a magnetic strength parallel to the plane of said wafer ranging from about 1 to about 150 gauss.
Claim 27
Dependent Claim
46 words
The process of claim 17 wherein the pressure in said etch chamber ranges from about 5 milliTorr to about 200 milliTorr and the temperature of a wafer support in said etch chamber on which said wafer rests ranges from about -120° C. to about 50° C.
Claim 28
Dependent Claim
25 words
The process of claim 24 wherein the temperature of said wafer support in said etch chamber ranges from about 5° C. to about 40° C.
Claim 29
Dependent Claim
214 words
A process for forming a via by etching through an insulation layer over a metal layer on a semiconductor wafer in an etch chamber without depositing sputtered metal or other etch residues on the sidewall of the via which comprises: a) flowing into said etch chamber a gaseous mixture which includes: i) one or more fluorine-containing gases comprising from about 10 to about 100 volume % of one or more 3-6 carbon fluorinated hydrocarbons having the formula C x H y F z , wherein x is 3 to 6, y is 0 to 3, and z is 2x-y when said fluorinated hydrocarbon is cyclic and 2x-y+2 when said fluorinated hydrocarbon is non-cyclic; ii) from 0 to about 90 volume % of one or more other fluorine-containing gases; and iii) one or more inert gases wherein the amount of said inert gases comprise from 0 to about 90 volume % of the total volume of said gaseous mixture of fluorine-containing gases and inert gases; b) maintaining a plasma within said etch chamber during said etch within a power range of from about 300 to about 2500 watts; and c) immersing said wafer in a magnetic field having a magnetic strength parallel to the plane of said wafer ranging from 1 to about 150 gauss.
Claim 30
Dependent Claim
214 words
A process for forming a via by etching through an insulation layer over a metal layer on a semiconductor wafer in an etch chamber without depositing sputtered metal or other etch residues on the sidewall of the via which comprises: a) flowing into said etch chamber a gaseous mixture which includes: i) one or more fluorine-containing gases comprising from about 10 to about 100 volume % of one or more 3-6 carbon fluorinated hydrocarbons having the formula C x H y F z , wherein x is 3 to 6, y is 0 to 3, and z is 2x-y when said fluorinated hydrocarbon is cyclic and 2x-y+2 when said fluorinated hydrocarbon is non-cyclic; ii) from 0 to about 90 volume % of one or more other fluorine-containing gases; and iii) one or more inert gases wherein the amount of said inert gases comprise from 0 to about 90 volume % of the total volume of said gaseous mixture of fluorine-containing gases and inert gases; b) maintaining a plasma within said etch chamber during said etch within a power range of from about 300 to about 2500 watts; and c) immersing said wafer in a magnetic field having a magnetic strength parallel to the plane of said wafer ranging from 1 to about 150 gauss.
Claim 31
Dependent Claim
59 words
The process of claim 25 wherein said step of flowing into said etch chamber a gaseous mixture which includes one or more fluorine-containing gases comprising from about 10 to about 100 volume % of one or more 3-6 carbon fluorinated hydrocarbons further comprises flowing into said etch chamber a fluorinated hydrocarbon having the formula C 4 F 8 .
Claim 32
Independent Claim
116 words
A method for forming one or more vias by etching through an insulation layer over a metal layer on a semiconductor wafer in an etch chamber without depositing sputtered metal or other etch residues on the sidewall of said vias which comprises etching said insulation layer with an etchant gas mixture which includes one or more fluorine-containing etchant gases and one or more nitrogen-containing gases present in an amount ranging from about 1 volume part of said one or more nitrogen-containing gases per 15 volume parts of said one or more fluorine-containing gases to about 1 volume part of said one or more nitrogen-containing gases per 2 volume parts of said one or more fluorine-containing gases.
Claim 33
Independent Claim
116 words
A method for forming one or more vias by etching through an insulation layer over a metal layer on a semiconductor wafer in an etch chamber without depositing sputtered metal or other etch residues on the sidewall of said vias which comprises etching said insulation layer with an etchant gas mixture which includes one or more fluorine-containing etchant gases and one or more nitrogen-containing gases present in an amount ranging from about 1 volume part of said one or more nitrogen-containing gases per 15 volume parts of said one or more fluorine-containing gases to about 1 volume part of said one or more nitrogen-containing gases per 2 volume parts of said one or more fluorine-containing gases.
Claim 34
Dependent Claim
39 words
The process of claim 28 wherein said step of forming said via with said etchant gas mixture further includes maintaining a plasma associated with said etch chamber within a power range of from about 300 to about 2500 watts.
Claim 35
Dependent Claim
25 words
The process of claim 29 wherein said one or more nitrogen-containing gases are selected from the group consisting of N 2 and N 2 O.
Claim 36
Dependent Claim
18 words
The process of claim 29 wherein said one or more nitrogen-containing gases consist essentially of N 2 .
Claim 37
Dependent Claim
75 words
The process of claim 29 wherein said step of forming said vias with an etchant gas mixture of said one or more nitrogen-containing gases and said one or more fluorinated hydrocarbons further comprises etching said insulation layer with a gaseous mixture which further includes one or more inert gases wherein the amount of said one or more inert gases comprise from 1 to about 94 volume % of the total volume of said gaseous mixture.
Claim 38
Dependent Claim
30 words
The process of claim 32 wherein the amount of said one or more inert gases in said gas mixture ranges from about 30 volume % to about 50 volume %.
Claim 39
Dependent Claim
59 words
The process of claim 29 wherein the flow of said gases into said etch chamber is equivalent to a gas flow into a 13 liter chamber of from about 2 to about 3 sccm of said one or more nitrogen-containing gases, and from about 20 to about 30 sccm of each of said one or more fluorinated hydrocarbon gases.
Claim 40
Dependent Claim
37 words
The process of claim 29 wherein said one or more fluorine-containing gases are selected from the group consisting of CHF 3 , CF 4 , C 2 F 6 , mixtures of same, and SF 6 .
Claim 41
Dependent Claim
20 words
The process of claim 29 wherein said one or more fluorine-containing gases comprise one or more 1-6 carbon fluorinated hydrocarbons.
Claim 42
Dependent Claim
40 words
The process of claim 36 wherein said one or more fluorine-containing gases are selected from the group consisting of CHF 3 , CF 4 , C 2 F 6 , NF 3 , SF 6 , and mixtures of same.
Claim 43
Dependent Claim
59 words
The process of claim 36 wherein said one or more fluorine-containing gases comprise one or more 3-6 carbon fluorinated hydrocarbons having the formula C x H y F z , wherein x is 3 to 6, y is 0 to 3, and z is 2x-y when said fluorinated hydrocarbon is cyclic and 2x-y+2 when said fluorinated hydrocarbon is non-cyclic.
Claim 44
Dependent Claim
52 words
The process of claim 36 wherein said one or more fluorine-containing gases comprise a mixture of one or more 3-6 carbon fluorinated hydrocarbons and one or more other fluorinated gases wherein at least 10 volume % of said fluorinated gases in said mixture comprises said one or more 3-6 carbon fluorinated hydrocarbons.
Claim 45
Dependent Claim
21 words
The process of claim 29 wherein the pressure in said etch chamber ranges from about 5 milliTorr to about 200 milliTorr.
Claim 46
Dependent Claim
31 words
The process of claim 29 wherein the temperature of a wafer support in said etch chamber on which said wafer is mounted ranges from about -120° C. to about 50° C.
Claim 47
Dependent Claim
25 words
The process of claim 41 wherein the temperature of said wafer support in said etch chamber ranges from about 5° C. to about 40° C.
Claim 48
Dependent Claim
37 words
The process of claim 29 wherein said etch is carried out while subjecting said wafer to a magnetic field having a magnetic strength parallel to the plane of said wafer ranging from 1 to about 150 gauss.
Claim 49
Independent Claim
152 words
A method for forming one or more vias by etching through an insulation layer over a metal layer on a semiconductor wafer in an etch chamber without depositing sputtered metal residues on the sidewall of the via which comprises: a) flowing into said etch chamber containing said semiconductor wafer an etch gas mixture which includes: i) one or more fluorine-containing etchant gases; and ii) one or more nitrogen-containing gases selected from the group consisting of N 2 and N 2 O; in a ratio ranging from about 1 volume part of said one or more nitrogen-containing gases per 15 volume parts of said one or more fluorine-containing gases to about 1 volume part of said one or more nitrogen-containing gases per 2 volume parts of said fluorine-containing gases; and b) maintaining a plasma within said etch chamber during said etch within a power range of from about 300 to about 2500 watts.
Claim 50
Independent Claim
152 words
A method for forming one or more vias by etching through an insulation layer over a metal layer on a semiconductor wafer in an etch chamber without depositing sputtered metal residues on the sidewall of the via which comprises: a) flowing into said etch chamber containing said semiconductor wafer an etch gas mixture which includes: i) one or more fluorine-containing etchant gases; and ii) one or more nitrogen-containing gases selected from the group consisting of N 2 and N 2 O; in a ratio ranging from about 1 volume part of said one or more nitrogen-containing gases per 15 volume parts of said one or more fluorine-containing gases to about 1 volume part of said one or more nitrogen-containing gases per 2 volume parts of said fluorine-containing gases; and b) maintaining a plasma within said etch chamber during said etch within a power range of from about 300 to about 2500 watts.
Claim 51
Dependent Claim
18 words
The process of claim 44 wherein said one or more nitrogen-containing gases consist essentially of N 2 .
Claim 52
Dependent Claim
40 words
The process of claim 44 wherein said one or more fluorine-containing gases are selected from the group consisting of CHF 3 , CF 4 , C 2 F 6 , NF 3 , SF 6 , and mixtures of same.
Claim 53
Dependent Claim
20 words
The process of claim 44 wherein said one or more fluorine-containing gases comprise one or more 1-6 carbon fluorinated hydrocarbons.
Claim 54
Dependent Claim
39 words
The process of claim 44 wherein said gas mixture further includes one or more inert gases wherein the amount of said inert gases comprise from 1 to about 94 volume % of the total volume of said gas mixture.
Claim 55
Independent Claim
250 words
A method for forming one or more vias by etching through an insulation layer over a metal layer on a semiconductor wafer in an etch chamber without depositing sputtered metal residues on the sidewall of the via which comprises: a) flowing into said etch chamber containing said semiconductor wafer an etch gas mixture which includes: i) one or more fluorine-containing etchant gases selected from the group consisting of CHF 3 , CF 4 , C 2 F 6 , NF 3 , SF 6 , and mixtures of same; ii) N 2 gas; and iii) optionally from 0 to about 94 volume % of an inert gas; in an N 2 to fluorine-containing gas ratio ranging from about 1 volume part N 2 gas per 15 volume parts fluorine-containing gas to about 1 volume part N 2 gas per 2 volume parts fluorine-containing gas; b) maintaining said etch chamber at a pressure ranging from about 5 milliTorr to about 200 milliTorr during said etch; c) maintaining the temperature of a wafer support in said etch chamber on which said wafer is mounted within a range of from about -120° C. to about 50° C. during said etch; d) immersing said wafer in a magnetic field having a magnetic strength parallel to the plane of said wafer ranging from 0 to about 150 gauss during said etch; and e) maintaining a plasma within said etch chamber during said etch within a power range of from about 300 to about 2500 watts.
Claim 56
Independent Claim
250 words
A method for forming one or more vias by etching through an insulation layer over a metal layer on a semiconductor wafer in an etch chamber without depositing sputtered metal residues on the sidewall of the via which comprises: a) flowing into said etch chamber containing said semiconductor wafer an etch gas mixture which includes: i) one or more fluorine-containing etchant gases selected from the group consisting of CHF 3 , CF 4 , C 2 F 6 , NF 3 , SF 6 , and mixtures of same; ii) N 2 gas; and iii) optionally from 0 to about 94 volume % of an inert gas; in an N 2 to fluorine-containing gas ratio ranging from about 1 volume part N 2 gas per 15 volume parts fluorine-containing gas to about 1 volume part N 2 gas per 2 volume parts fluorine-containing gas; b) maintaining said etch chamber at a pressure ranging from about 5 milliTorr to about 200 milliTorr during said etch; c) maintaining the temperature of a wafer support in said etch chamber on which said wafer is mounted within a range of from about -120° C. to about 50° C. during said etch; d) immersing said wafer in a magnetic field having a magnetic strength parallel to the plane of said wafer ranging from 0 to about 150 gauss during said etch; and e) maintaining a plasma within said etch chamber during said etch within a power range of from about 300 to about 2500 watts.
References Cited (Backward Citations)
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| 3.5 Years (Year 4) | 1996-01-05 | 1996-07-06 | 1997-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-01-05 | 2000-07-06 | 2001-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-01-05 | 2004-07-06 | 2005-01-05 | $7700.00 | Window Closed / Lapsed |