Patent US4983253A successfully refreshed from Google Patents.
US4983253A
Expired / Lapsed
US
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Magnetically enhanced RIE process and apparatus
Assignee: HOUSTON - UNIVERSITY PARK HOUSTON TEXAS A STATE AGENCY OF TEXAS, University of
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Filing: 1988-05-27
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Granted: 1991-01-08
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Expires: 2008-05-27
Abstract
Abstract An etching process and apparatus employ a novel magnetic enhancement means and a substantially pure molecular bromine plasma in order to perform in a desired manner for a number of important applications requiring etching of single-crystal and polycrystalline silicon.
Inventors
- 👤 John C. Wolfe
- 👤 Ahmed M. El-Masry
- 👤 Fu-On Fong
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:29
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/24; H10P50/242; H01; H01J; H01J37/00; H01J37/32; H01J37/34; H01J37/3402; H10P50/26; H10P50/264; H10P50/266; H10P50/267; H10P50/268
Claims Analysis
Total Claims: 53
Claim 1
Independent Claim
59 words
An etching process comprising the steps of: supplying power between an anode and a cathode; generating a molecular bromine plasma within a reaction chamber; placing silicon to be etched in the vicinity of said cathode; producing a discharge ring of a planar magnetron around the silicon; and etching said silicon by ions attracted from said plasma toward said cathode.
Claim 2
Dependent Claim
59 words
An etching process comprising the steps of: supplying power between an anode and a cathode; generating a molecular bromine plasma within a reaction chamber; placing silicon to be etched in the vicinity of said cathode; producing a discharge ring of a planar magnetron around the silicon; and etching said silicon by ions attracted from said plasma toward said cathode.
Claim 3
Dependent Claim
20 words
The process of claim 1 in which said bromine plasma is maintained at about 2 m Torr pressure during etching.
Claim 4
Dependent Claim
28 words
The process of claim 2 in which power is supplied between said anode and said cathode so that said cathode bias is from about -85-V to about -105-V.
Claim 5
Dependent Claim
23 words
The process of claim 3 in which power is supplied between said anode and cathode so that said cathode bias is about -90-V.
Claim 6
Independent Claim
66 words
An apparatus for etching a substrate, comprising: a reaction chamber for enclosing the substrate; means for generating a plasma in said reaction chamber; means for supporting said substrate in said reaction chamber at a supporting area; a cathode; and means for magnetically enhancing said plasma to generate a ring-shaped planar magnetron discharge at said cathode, wherein said discharge is larger in diameter than said supporting area.
Claim 7
Independent Claim
66 words
An apparatus for etching a substrate, comprising: a reaction chamber for enclosing the substrate; means for generating a plasma in said reaction chamber; means for supporting said substrate in said reaction chamber at a supporting area; a cathode; and means for magnetically enhancing said plasma to generate a ring-shaped planar magnetron discharge at said cathode, wherein said discharge is larger in diameter than said supporting area.
Claim 8
Dependent Claim
16 words
The apparatus of claim 5 additionally comprising said substrate, wherein said substrate is a silicon wafer.
Claim 9
Dependent Claim
15 words
The apparatus of claim 5 additionally comprising an anode which is disposed opposite said cathode.
Claim 10
Dependent Claim
22 words
The apparatus of claim 5 wherein said means for magnetically enhancing said reaction chamber comprises a first magnet disposed at said cathode.
Claim 11
Dependent Claim
14 words
The apparatus of claim 8 additionally comprising a second magnet disposed at said anode.
Claim 12
Dependent Claim
26 words
The apparatus of claim 5 wherein said means for magnetically enhancing said reaction chamber comprises at least two magnets disposed on opposite sides of said substrate.
Claim 13
Independent Claim
28 words
A method for processing a substrate, comprising placing the substrate in the interior of the discharge ring of a planar magnetron so that the ring surrounds said substrate.
Claim 14
Independent Claim
28 words
A method for processing a substrate, comprising placing the substrate in the interior of the discharge ring of a planar magnetron so that the ring surrounds said substrate.
Claim 15
Dependent Claim
58 words
An etching method comprising the steps of: supplying power between an anode and a cathode; generating a plasma within a reaction chamber; placing a substrate to be etched in the vicinity of said cathode; producing a discharge ring of a planar magnetron around the substrate; and etching said silicon by ions attracted from said plasma toward said cathode.
Claim 16
Dependent Claim
58 words
An etching method comprising the steps of: supplying power between an anode and a cathode; generating a plasma within a reaction chamber; placing a substrate to be etched in the vicinity of said cathode; producing a discharge ring of a planar magnetron around the substrate; and etching said silicon by ions attracted from said plasma toward said cathode.
Claim 17
Dependent Claim
27 words
An etching method comprising the steps of generating a plasma comprising molecular bromine; generating a ring-shaped magnetron discharge; and etching a substrate with ions in said plasma.
Claim 18
Dependent Claim
27 words
An etching method comprising the steps of generating a plasma comprising molecular bromine; generating a ring-shaped magnetron discharge; and etching a substrate with ions in said plasma.
Claim 19
Dependent Claim
47 words
A magnetically enhanced apparatus for etching a substrate, said apparatus comprising: a chamber for enclosing said substrate; means for supporting said substrate; means for etching said substrate which comprises a reactive etchant gas consisting essentially of molecular bromine; and means for generating a ring-shaped planer magnetron discharge.
Claim 20
Dependent Claim
47 words
A magnetically enhanced apparatus for etching a substrate, said apparatus comprising: a chamber for enclosing said substrate; means for supporting said substrate; means for etching said substrate which comprises a reactive etchant gas consisting essentially of molecular bromine; and means for generating a ring-shaped planer magnetron discharge.
Claim 21
Independent Claim
49 words
An apparatus for etching a substrate, said apparatus comprising: a chamber for enclosing said substrate; means for supporting said substrate; means for etching said substrate which comprises a reactive etchant gas comprising at least 90 percent molecular bromine; and means for generating a magnetron discharge that surrounds said substrate.
Claim 22
Independent Claim
49 words
An apparatus for etching a substrate, said apparatus comprising: a chamber for enclosing said substrate; means for supporting said substrate; means for etching said substrate which comprises a reactive etchant gas comprising at least 90 percent molecular bromine; and means for generating a magnetron discharge that surrounds said substrate.
Claim 23
Dependent Claim
14 words
The apparatus of claim 14 wherein said apparatus is a magnetically enhanced RIE apparatus.
Claim 24
Dependent Claim
11 words
The apparatus of claim 15 wherein said magnetron discharge is ring-shaped.
Claim 25
Dependent Claim
17 words
The apparatus of claim 14 additionally comprising said substrate and a ring-shaped magnetron discharge surrounding said substrate.
Claim 26
Dependent Claim
12 words
The apparatus of claim 18 wherein said substrate is a silicon wafer.
Claim 27
Dependent Claim
18 words
The apparatus of claim 19 additionally comprising a magnetron discharge, wherein said magnetron discharge surrounds said silicon wafer.
Claim 28
Dependent Claim
16 words
The apparatus of claim 14 additionally comprising means for introducing said etchant gas to said apparatus.
Claim 29
Dependent Claim
11 words
The apparatus of claim 14 additionally comprising a magnetically enhanced cathode.
Claim 30
Dependent Claim
23 words
The apparatus of claim 14 wherein said magnetic enhancement is provided by a magnet disposed at said cathode to provide a ring-shaped discharge.
Claim 31
Independent Claim
43 words
An apparatus for etching a substrate, said apparatus comprising a chamber for enclosing said substrate; means for supporting said substrate; and means for etching said substrate, said etching means having a silicon selectively measured with respect to silicon dioxide of at least 25.
Claim 32
Independent Claim
43 words
An apparatus for etching a substrate, said apparatus comprising a chamber for enclosing said substrate; means for supporting said substrate; and means for etching said substrate, said etching means having a silicon selectively measured with respect to silicon dioxide of at least 25.
Claim 33
Dependent Claim
22 words
The apparatus of claim 24, wherein said etching means has a silicon selectivity with respect to silicon dioxide of at least 50.
Claim 34
Dependent Claim
22 words
The apparatus of claim 24, wherein said etching means has a silicon selectivity with respect to silicon dioxide of at least 100.
Claim 35
Independent Claim
62 words
An apparatus for etching a substrate, said apparatus comprising a chamber for enclosing said substrate, means for supporting said substrate, and means for etching said substrate, said etching means having an etch rate on a single-crystal silicon wafer of at least 50 nanometers per minute when said apparatus is operated at a voltage of from about -85 V to about -105 V.
Claim 36
Independent Claim
62 words
An apparatus for etching a substrate, said apparatus comprising a chamber for enclosing said substrate, means for supporting said substrate, and means for etching said substrate, said etching means having an etch rate on a single-crystal silicon wafer of at least 50 nanometers per minute when said apparatus is operated at a voltage of from about -85 V to about -105 V.
Claim 37
Dependent Claim
38 words
The apparatus of claim 27, wherein said etching means has an etch rate on said wafer of at least about 50 nanometers per minute when said apparatus is operated at a voltage of less than about -100 V.
Claim 38
Dependent Claim
24 words
The apparatus of claim 27, wherein said etching means has an etch rate on said wafer of at least about 100 nanometers per minute.
Claim 39
Dependent Claim
17 words
The apparatus of claim 27 wherein said etch means comprises a reactive etchant gas comprising molecular bromine.
Claim 40
Dependent Claim
11 words
The apparatus of claim 27 wherein the apparatus is magnetically enhanced.
Claim 41
Independent Claim
52 words
A method of etching a substrate comprising the steps of: enclosing and supporting said substrate within a chamber; and etching said substrate at an etch rate sufficient to provide a selectivity for a silicon substrate of at least 25 when measured with respect to the etch rate on a silicon dioxide substrate.
Claim 42
Independent Claim
52 words
A method of etching a substrate comprising the steps of: enclosing and supporting said substrate within a chamber; and etching said substrate at an etch rate sufficient to provide a selectivity for a silicon substrate of at least 25 when measured with respect to the etch rate on a silicon dioxide substrate.
Claim 43
Dependent Claim
40 words
The method of claim 32 wherein said substrate is etched at an etch rate sufficient to provide a selectivity for a silicon substrate of at least 50 when measured with respect to the etch rate on a silicon dioxide substrate.
Claim 44
Dependent Claim
40 words
The method of claim 33 wherein said substrate is etched at an etch rate sufficient to provide a selectivity for a silicon substrate of at least 100 when measured with respect to the etch rate on a silicon dioxide substrate.
Claim 45
Independent Claim
54 words
A method of etching a substrate, said method comprising the steps of: enclosing a substrate, placing said substrate between an anode and a cathode, providing a voltage from about -85 V to about -105 V across said anode and cathode, and etching said substrate at a rate of at least 50 nanometers per minute.
Claim 46
Independent Claim
54 words
A method of etching a substrate, said method comprising the steps of: enclosing a substrate, placing said substrate between an anode and a cathode, providing a voltage from about -85 V to about -105 V across said anode and cathode, and etching said substrate at a rate of at least 50 nanometers per minute.
Claim 47
Dependent Claim
10 words
The method of claim 35 wherein the substrate comprises silicon.
Claim 48
Dependent Claim
20 words
The method of claim 35 wherein the substrate is etched at a rate of at least 100 nanometers per minute.
Claim 49
Dependent Claim
13 words
The method of claim 35 wherein said voltage is less than -100 V.
Claim 50
Dependent Claim
17 words
The method of claim 35 additionally comprising generating a plasma within said chamber that comprises molecular bromine.
Claim 51
Dependent Claim
15 words
The method of claim 35 additionally comprising generating a planar magnetron discharge to said substrate.
Claim 52
Dependent Claim
12 words
The method of claim 40 wherein said planar magnetron discharge is ring-shaped.
Claim 53
Dependent Claim
13 words
The method of claim 40 wherein said planar magnetron discharge surrounds said substrate.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-01-07 | 1994-07-09 | 1995-01-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-01-07 | 1998-07-09 | 1999-01-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-01-07 | 2002-07-09 | 2003-01-08 | $7700.00 | Window Closed / Lapsed |