Patent EP0788147A2 successfully refreshed from Google Patents.
EP0788147A2
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EP
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Plasma process for etching multicomponent alloys
Assignee: Applied Materials Inc
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Filing: 1997-01-29
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Granted: —
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Expires: 2017-01-29
Abstract
Abstract A method of etching a multicomponent alloy on a substrate, without forming etchant residue on the substrate, is described. In the method, the substrate is placed in a process chamber comprising a plasma generator and plasma electrodes. A process gas comprising a volumetric flow ratio V r of (i) a chlorine-containing gas capable of ionizing to form dissociated Cl + plasma ions and non-dissociated Cl 2 + plasma ions, and (ii) an inert gas capable of enhancing dissociation of the chlorine-containing gas, in introduced into the process chamber. The process gas is ionized to form plasma ions that energetically impinge on the substrate by (i) applying RF current at a first power level to the plasma generator, and (ii) applying RF current at a second power level to the plasma electrodes. The combination of (i) the volumetric flow ratio V r of the process gas and (ii) the power ratio P r of the first power level to the second power level, is selected so that the chlorine-containing etchant gas ionizes to form dissociated Cl + plasma ions and non-dissociated Cl 2 + plasma ions in a number ratio of at least about 0.6:1. The increased amount of dissociated Cl + ions relative to non-dissociated Cl 2 + ions etches the multicomponent alloy on the substrate at an etch rate of at least about 500 nm/min, without forming etchant residue on the substrate.
Inventors
- 👤 Diana Xiaobing Ma
- 👤 Daisuke Tajima
- 👤 Allen Zhao
- 👤 Peter K. Loewenhardt
- 👤 Timothy R. Webb
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 09:18
CPC Classifications
C; C25; C25F; C25F3/00; H; H01; H01J; H01J37/00; H01J37/32; H01J37/32009; H01J37/32082; H01J37/321; C23; C23F; C23F4/00; H10; H10P; H10P50/00; H10P50/20; H10P50/26; H10P50/264; H10P50/266; H10P50/267
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
216 words
A method of etching a multicomponent alloy on a substrate, substantially without forming etchant residue on the substrate, the method comprising the steps of: (a) placing the substrate in a process chamber comprising a plasma generator and plasma electrodes; (b) introducing into the process chamber, process gas comprising a volumetric flow ratio V r of (i) a chlorine-containing gas capable of ionizing to form dissociated Cl + plasma ions and non-dissociated Cl 2 + plasma ions, and (ii) an inert gas capable of enhancing dissociation of the chlorine-containing gas; and (c) ionizing the process gas to form plasma ions that energetically impinge on the substrate by (i) applying RF current at a first power level to the plasma generator, and (ii) applying RF current at a second power level to the plasma electrodes, wherein (i) a power ratio P r of the first power level to the second power level, and (ii) the volumetric flow ratio V r are selected so that the chlorine-containing etchant gas ionizes to form dissociated Cl + plasma ions and non-dissociated Cl 2 + plasma ions in a number ratio of at least about 0.6:1, thereby etching the multicomponent alloy on the substrate at an etch rate of at least about 500 nm/min, substantially without forming etchant residue on the substrate.
Claim 2
Dependent Claim
74 words
A method as claimed in claim 1, wherein the multicomponent alloy on the substrate comprises first and second components, the first components being substantially more reactive to the plasma ions than the second components, and wherein the volumetric flow ratio V r and the power ratio P r are selected so that the first components are etched at an etch rate that is substantially equivalent to a rate of etching of the second components.
Claim 3
Dependent Claim
55 words
A method as claimed in claim 1 or claim 2, wherein the multicomponent alloy is etched to form features that have sidewalls, and wherein the volumetric flow ratio V r and the power ratio P r are selected so that the sidewalls of the features form angles of at least about 85° with the substrate.
Claim 4
Independent Claim
61 words
A method as claimed in any one of the preceding claims, wherein the multicomponent alloy comprises a resist thereon, and wherein the volumetric flow ratio V r and the power ratio P r are selected so that the ratio of the rate of etching of the multicomponent alloy to the rate of etching of the resist is at least about 2.5.
Claim 5
Independent Claim
37 words
A method as claimed in any one of the preceding claims, wherein the chlorine-containing gas ionizes to form dissociated Cl + ions and non-dissociated Cl 2 + ions in a number ratio of at least about 1:1.
Claim 6
Independent Claim
51 words
A method as claimed in any one of the preceding claims, wherein the substrate comprises a barrier layer below the multicomponent alloy, and the volumetric flow ratio V r and the power ratio P r are selected so that the etch rate of the barrier layer is less than about 100nm/minute.
Claim 7
Independent Claim
30 words
A method as claimed in any one of the preceding claims, wherein the volumetric flow ratio V r of chlorine-containing gas to inert gas is from about 4:1 to 1:4.
Claim 8
Independent Claim
22 words
A method as claimed in any one of the preceding claims, wherein the first power level is at least about 750 Watts.
Claim 9
Independent Claim
22 words
A method as claimed in any one of the preceding claims, wherein the second power level is less than about 500 Watts.
Claim 10
Independent Claim
25 words
A method as claimed in any one of the preceding claims, wherein the process gas consists essentially of Cl 2 , BCl 3 and argon.
Claim 11
Independent Claim
196 words
A method of plasma etching a multicomponent alloy on a substrate substantially without forming etchant residue, the method comprising the steps of: (a) placing a substrate in a quasi-remote plasma zone of a process chamber comprising (i) a ceiling with an apex at a height H above the substrate, the height H being from about 100 mm to about 175 mm, for a substrate having a diameter D of from about 150 mm to about 304 mm, and (ii) a plasma generator capable of forming a plasma below the ceiling and above the substrate; (b) introducing into the process chamber, process gas comprising a volumetric flow ratio V r of (i) chlorine-containing gas capable of ionizing to form dissociated Cl + ions and non-dissociated Cl 2 + ions, and (ii) inert gas capable of enhancing dissociation of the chlorine-containing gas; and (c) ionizing the process gas in the quasi-remote plasma zone so that the chlorine-containing gas ionizes substantially directly above the substrate to form dissociated Cl + ions and non-dissociated Cl 2 + ions in a number ratio of at least about 0.6:1, thereby etching the multicomponent alloy on the substrate substantially without forming etchant residue.
Claim 12
Dependent Claim
39 words
A method as claimed in claim 11, wherein in step (a), the quasi-remote plasma zone of the process chamber is surrounded by sidewalls adjacent to the substrate, and comprises a volume of at least about 10,000 cm 3 .
Claim 13
Dependent Claim
39 words
A method as claimed in claim 11 or claim 12, wherein in step (a), the quasi-remote plasma zone of the process chamber has a center located at a distance of about 50 to about 150 mm from the substrate.
Claim 14
Independent Claim
45 words
A method as claimed in any one of claims 11 to 13, wherein in step (a), the ceiling of the quasi-remote plasma zone of the process chamber has at least one of the following shapes: (a) flat; (b) conical; (c) arcuate; and (d) multi-radius dome.
Claim 15
Independent Claim
43 words
A method as claimed in any one of claims 11 to 14, wherein the chlorine-containing gas ionizes in the quasi-remote plasma zone to form dissociated Cl + ions and non-dissociated Cl 2 + ions in a number ratio of at least about 1:1.
Claim 16
Independent Claim
32 words
A method as claimed in any one of claims 11 to 15, wherein the volumetric flow ratio V r of chlorine-containing gas to inert gas is from about 1:1 to about 10:1.
Claim 17
Independent Claim
53 words
A method as claimed in any one of claims 11 to 16, wherein the process gas is ionized in the quasi-remote plasma zone by applying an RF current having a first power level of at least about 750 Watts to a plasma generator comprising an inductor coil adjacent to the quasi-remote plasma zone.
Claim 18
Independent Claim
58 words
A method as claimed in any one of claims 11 to 17, wherein the dissociated Cl + ions and non-dissociated Cl 2 + ions in the quasi-remote plasma zone are attracted to the substrate by applying an RF current having a second power level of less than about 500 Watts to plasma electrodes in the quasi-remote plasma zone.
Claim 19
Independent Claim
37 words
A method as claimed in any one of the preceding claims, wherein the power ratio P r of the first power level to the second power level is at least about 4:1, preferably at least about 7:1.
Claim 20
Independent Claim
29 words
A method as claimed in any one of the preceding claims, wherein the frequency of the RF current applied to the inductor coil is less than about 6 MHZ.
Claim 21
Independent Claim
29 words
A method as claimed in any one of the preceding claims, wherein the frequency of the RF current applied to the plasma electrode is greater than about 6 MHZ.
Claim 22
Independent Claim
39 words
A method as claimed in any one of the preceding claims, wherein the chlorine-containing gas is selected from the group consisting of Cl 2 , HCl, BCl 3 , HBr, CCl 4 , SiCl 4 , and mixtures thereof.
Claim 23
Independent Claim
29 words
A method as claimed in any one of the preceding claims, wherein the inert gas is selected from the group consisting of argon, xenon, krypton, neon, and mixtures thereof.
Claim 24
Independent Claim
151 words
A method of etching a substrate comprising a multicomponent alloy substantially without forming etchant residue, the method comprising the steps of: (a) placing the substrate in a process chamber; (b) introducing into the process chamber, a process gas comprising (i) etchant gas capable of dissociating in an electric field to form dissociated ions and non-dissociated ions, and (ii) inert gas capable of enhancing dissociation of the etchant gas; and (c) applying an electric field to the process gas to form a plasma by maintaining an RF current in an inductor coil surrounding the process chamber, the RF current having a power level of at least about 750 Watts and an RF frequency of less than about 6 MHZ, to obtain a sufficiently elevated ratio of dissociated ions to non-dissociated ions to etch the multicomponent alloy on the substrate at an elevated etch rate substantially without forming etchant residue on the substrate.
Claim 25
Dependent Claim
27 words
A method as claimed in claim 24, wherein the volumetric flow ratio V r of etchant gas to inert gas is from about 1:1 to about 10:1.
Claim 26
Dependent Claim
34 words
A method as claimed in claim 24 or claim 25, wherein the electric field is generated by applying an RF current at a frequency from about 1 to 3 MHZ to the inductor coil.
Claim 27
Independent Claim
30 words
A method as claimed in any one of claims 24 to 26, wherein the power of the RF current applied to the inductor coil is at least about 1000 Watts.
Claim 28
Independent Claim
51 words
A method as claimed in any one of claims 24 to 27, wherein the process chamber comprises plasma electrodes for attracting the plasma to the substrate, and wherein the process further comprises the step of applying an RF voltage at a frequency of greater than 6 MHZ to the plasma electrodes.
References Cited (Backward Citations)
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