Patent US6284093B1 successfully refreshed from Google Patents.
US6284093B1
Expired / Lapsed
US
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Shield or ring surrounding semiconductor workpiece in plasma chamber
Assignee: Applied Materials Inc
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Filing: 2000-09-20
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Granted: 2001-09-04
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Expires: 2020-09-20
Abstract
Abstract A ring or collar surrounding a semiconductor workpiece in a plasma chamber. According to one aspect, the ring has an elevated collar portion having an inner surface oriented at an obtuse angle to the plane of the workpiece, this angle preferably being 135°. This angular orientation causes ions bombarding the inner surface of the elevated collar to scatter in a direction more parallel to the plane of the workpiece, thereby reducing erosion of any dielectric shield at the perimeter of the workpiece, and ameliorating spatial non-uniformity in the plasma process due to any excess ion density near such perimeter. In a second aspect, the workpiece is surrounded by a dielectric shield, and the shield is covered by a non-dielectric ring which protects the dielectric shield from reaction with, or erosion by, the process gases. In a third aspect, the dielectric shield is thin enough to couple substantial power from the cathode to the plasma, thereby improving spatial uniformity of the plasma process near the perimeter of the workpiece. In a fourth aspect, azimuthal non-uniformities in process performance can be ameliorated by corresponding azimuthal variations in the dimensions of the elevated collar and/or the dielectric shield surrounding the workpiece.
Inventors
- 👤 Kuang-Han Ke
- 👤 Bryan Y. Pu
- 👤 Hongching Shan
- 👤 James Wang
- 👤 Henry Fong
- 👤 Zongyu Li
- 👤 Michael D. Welch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 04:15
CPC Classifications
H; H10; H10P; H10P72/00; H10P72/04; H10P72/0441; H01; H01J; H01J37/00; H01J37/32; H01J37/32431; H01J37/32623; H01J37/32633; H01J37/3266; H02; H02N; H02N13/00; H10P72/70; H10P72/72; H10P72/722; H10P72/76; H10P72/7604; H10P72/7606; H10P72/7611; Y; Y10; Y10S; Y10S156/00; Y10S156/915
Claims Analysis
Total Claims: 61
Claim 1
Independent Claim
82 words
A plasma chamber for performing a semiconductor fabrication process on a workpiece, comprising: a cathode electrode having an upper surface facing an interior region of the chamber; a chuck for holding the workpiece so that the workpiece occupies a workpiece area parallel to and immediately above the upper surface of the cathode electrode; a shield, composed of dielectric material, encircling the perimeter of the workpiece area; and a ring, composed of non-dielectric material, overlying at least a portion of the dielectric shield.
Claim 2
Dependent Claim
82 words
A plasma chamber for performing a semiconductor fabrication process on a workpiece, comprising: a cathode electrode having an upper surface facing an interior region of the chamber; a chuck for holding the workpiece so that the workpiece occupies a workpiece area parallel to and immediately above the upper surface of the cathode electrode; a shield, composed of dielectric material, encircling the perimeter of the workpiece area; and a ring, composed of non-dielectric material, overlying at least a portion of the dielectric shield.
Claim 3
Dependent Claim
20 words
A chamber according to claim 1 , wherein the non-dielectric ring overlies a radially inner portion of the dielectric shield.
Claim 4
Dependent Claim
21 words
A chamber according to claim 1 , further comprising a layer of dielectric between the non-dielectric ring and the cathode electrode.
Claim 5
Dependent Claim
31 words
A chamber according to claim 3 , wherein: the layer of dielectric between the non-dielectric ring and the cathode electrode comprises an oxide coating on the surface of the cathode electrode.
Claim 6
Dependent Claim
51 words
A chamber according to claim 3 , wherein: the non-dielectric ring is mounted so as to be spaced away from the cathode electrode, so that a gap exists between the ring and the cathode electrode; and the layer of dielectric between the non-dielectric ring and the cathode electrode comprises said gap.
Claim 7
Dependent Claim
14 words
A chamber according to claim 1 , wherein the non-dielectric material is a metal.
Claim 8
Dependent Claim
14 words
A chamber according to claim 1 , wherein the non-dielectric material is a semiconductor.
Claim 9
Dependent Claim
18 words
A chamber according to claim 7 , wherein the non-dielectric material is silicon and the workpiece includes silicon.
Claim 10
Dependent Claim
48 words
A chamber according to claim 1 , wherein: the upper surface of the cathode electrode has an outer portion extending radially beyond the perimeter of the workpiece area; and the shield includes a layer of dielectric material on the outer portion of the upper surface of the cathode.
Claim 11
Dependent Claim
49 words
A chamber according to claim 1 , wherein: the upper surface of the cathode electrode has an outer portion extending radially beyond the perimeter of the workpiece area; and the shield has an annular shape and is positioned over the outer portion of the upper surface of the cathode.
Claim 12
Dependent Claim
25 words
A chamber according to claim 1 , wherein the non-dielectric material is more resistant than the dielectric material to erosion by said semiconductor fabrication process.
Claim 13
Dependent Claim
138 words
A plasma chamber for performing a semiconductor fabrication process on a workpiece by producing a plasma in an interior region of the chamber, comprising: an RF power supply; a cathode electrode connected to the RF power supply and having an upper surface facing said interior region of the chamber; a chuck for holding the workpiece so that the workpiece occupies a workpiece area parallel to and immediately above the upper surface of the cathode electrode, wherein the upper surface of the cathode electrode has a perimeter which encircles the perimeter of the workpiece area; and a shield composed of dielectric material overlying a portion of the upper surface of the cathode which is outside the perimeter of the workpiece area; wherein the dielectric shield is thin enough to couple RF power from the cathode electrode to the plasma.
Claim 14
Dependent Claim
138 words
A plasma chamber for performing a semiconductor fabrication process on a workpiece by producing a plasma in an interior region of the chamber, comprising: an RF power supply; a cathode electrode connected to the RF power supply and having an upper surface facing said interior region of the chamber; a chuck for holding the workpiece so that the workpiece occupies a workpiece area parallel to and immediately above the upper surface of the cathode electrode, wherein the upper surface of the cathode electrode has a perimeter which encircles the perimeter of the workpiece area; and a shield composed of dielectric material overlying a portion of the upper surface of the cathode which is outside the perimeter of the workpiece area; wherein the dielectric shield is thin enough to couple RF power from the cathode electrode to the plasma.
Claim 15
Dependent Claim
51 words
A plasma chamber according to claim 12 , wherein the dielectric shield is thin enough so that said RF power coupled from the cathode electrode to the plasma is sufficient to cause the plasma to have a sheath above the cathode upper surface which extends radially outward over the dielectric shield.
Claim 16
Dependent Claim
136 words
A magnetically enhanced plasma chamber for performing a semiconductor fabrication process on a workpiece, comprising: a cathode electrode having an upper surface facing an interior region of the chamber; a chuck for holding the workpiece so that the workpiece occupies a workpiece area parallel to and immediately above the upper surface of the cathode electrode, wherein the workpiece area is bounded by a perimeter; a plurality of magnets collectively having a plurality of magnetic axes positioned at respective azimuths spaced around the perimeter of the workpiece area; and a collar encircling the perimeter of the workpiece area; wherein the collar has a physical dimension which ranges between a first value and a second value as a function of azimuth, and said dimension equals the first value near each of said respective azimuths of the magnetic axes.
Claim 17
Dependent Claim
136 words
A magnetically enhanced plasma chamber for performing a semiconductor fabrication process on a workpiece, comprising: a cathode electrode having an upper surface facing an interior region of the chamber; a chuck for holding the workpiece so that the workpiece occupies a workpiece area parallel to and immediately above the upper surface of the cathode electrode, wherein the workpiece area is bounded by a perimeter; a plurality of magnets collectively having a plurality of magnetic axes positioned at respective azimuths spaced around the perimeter of the workpiece area; and a collar encircling the perimeter of the workpiece area; wherein the collar has a physical dimension which ranges between a first value and a second value as a function of azimuth, and said dimension equals the first value near each of said respective azimuths of the magnetic axes.
Claim 18
Dependent Claim
93 words
A chamber according to claim 14 , wherein: the upper surface of the cathode electrode has a perimeter which surrounds and is larger than the perimeter of the workpiece area; the collar includes a dielectric shield overlying a portion of the upper surface of the cathode which is outside the perimeter of the workpiece area; and the dielectric shield has a thickness which differs at different azimuths so that said thickness is said physical dimension of the collar which ranges between said first limit and said second limit as a function of azimuth.
Claim 19
Dependent Claim
31 words
A chamber according to claim 14 , wherein said dimension of the collar equals the second limit at a second plurality of azimuths between said respective azimuths of the magnetic axes.
Claim 20
Dependent Claim
87 words
A plasma chamber for performing a semiconductor fabrication process on a workpiece, comprising: a cathode electrode having an upper surface facing an interior region of the chamber; a chuck for holding the workpiece so that the workpiece occupies a workpiece area parallel to and immediately above the upper surface of the cathode electrode; and a collar encircling the perimeter of the workpiece area, wherein the collar includes an uppermost elevated portion having a height above the upper surface of the cathode electrode which differs at different azimuths.
Claim 21
Dependent Claim
87 words
A plasma chamber for performing a semiconductor fabrication process on a workpiece, comprising: a cathode electrode having an upper surface facing an interior region of the chamber; a chuck for holding the workpiece so that the workpiece occupies a workpiece area parallel to and immediately above the upper surface of the cathode electrode; and a collar encircling the perimeter of the workpiece area, wherein the collar includes an uppermost elevated portion having a height above the upper surface of the cathode electrode which differs at different azimuths.
Claim 22
Dependent Claim
31 words
A plasma chamber according to claim 17 , wherein said differences in said height at different azimuths are established so as to improve the azimuthal uniformity of said semiconductor fabrication process.
Claim 23
Dependent Claim
75 words
A plasma chamber for performing a semiconductor fabrication process on a workpiece, comprising: a cathode electrode having an upper surface facing an interior region of the chamber; a chuck for holding the workpiece so that the workpiece occupies a workpiece area parallel to and immediately above the upper surface of the cathode electrode; and a collar encircling the perimeter of the workpiece area, wherein the collar has an inner diameter which differs at different azimuths.
Claim 24
Dependent Claim
75 words
A plasma chamber for performing a semiconductor fabrication process on a workpiece, comprising: a cathode electrode having an upper surface facing an interior region of the chamber; a chuck for holding the workpiece so that the workpiece occupies a workpiece area parallel to and immediately above the upper surface of the cathode electrode; and a collar encircling the perimeter of the workpiece area, wherein the collar has an inner diameter which differs at different azimuths.
Claim 25
Dependent Claim
32 words
A plasma chamber according to claim 19 , wherein said differences in said inner diameter at different azimuths are established so as to improve the azimuthal uniformity of said semiconductor fabrication process.
Claim 26
Dependent Claim
21 words
A plasma chamber according to claim 19 , wherein the collar includes an elevated portion that extends above the workpiece area.
Claim 27
Dependent Claim
15 words
A plasma chamber according to claim 19 , wherein the collar is a dielectric material.
Claim 28
Dependent Claim
130 words
A magnetically enhanced plasma chamber for performing a semiconductor fabrication process on a workpiece, comprising: a cathode electrode having an upper surface facing an interior region of the chamber; a chuck for holding the workpiece so that the workpiece occupies a workpiece area parallel to and immediately above the upper surface of the cathode electrode, wherein the workpiece area is bounded by a perimeter; a plurality of magnetic poles positioned at respective azimuths spaced around the perimeter of the workpiece area; and a collar encircling the perimeter of the workpiece area, wherein the collar has a physical dimension which ranges between a first limit and a second limit as a function of azimuth, and said dimension equals the first limit near each of said respective azimuths of the magnetic poles.
Claim 29
Dependent Claim
130 words
A magnetically enhanced plasma chamber for performing a semiconductor fabrication process on a workpiece, comprising: a cathode electrode having an upper surface facing an interior region of the chamber; a chuck for holding the workpiece so that the workpiece occupies a workpiece area parallel to and immediately above the upper surface of the cathode electrode, wherein the workpiece area is bounded by a perimeter; a plurality of magnetic poles positioned at respective azimuths spaced around the perimeter of the workpiece area; and a collar encircling the perimeter of the workpiece area, wherein the collar has a physical dimension which ranges between a first limit and a second limit as a function of azimuth, and said dimension equals the first limit near each of said respective azimuths of the magnetic poles.
Claim 30
Dependent Claim
31 words
A chamber according to claim 23 , wherein said dimension of the collar equals the second limit at a second plurality of azimuths between said respective azimuths of the magnetic poles.
Claim 31
Dependent Claim
93 words
A chamber according to claim 23 , wherein: the upper surface of the cathode electrode has a perimeter which surrounds and is larger than the perimeter of the workpiece area; the collar includes a dielectric shield overlying a portion of the upper surface of the cathode which is outside the perimeter of the workpiece area; and the dielectric shield has a thickness which differs at different azimuths so that said thickness is said physical dimension of the collar which ranges between said first limit and said second limit as a function of azimuth.
Claim 32
Dependent Claim
31 words
A chamber according to claim 23 , wherein: the collar extends to a height above the workpiece area; and said physical dimension of the collar is the height of the collar.
Claim 33
Dependent Claim
19 words
A chamber according to claim 26 , wherein the first limit is a lower height than the second limit.
Claim 34
Dependent Claim
37 words
A chamber according to claim 26 , wherein the collar has an elevated portion having a radially inner surface oriented at an angle relative to the workpiece area in the range of 110 degrees to 145 degrees.
Claim 35
Dependent Claim
37 words
A chamber according to claim 26 , wherein the collar has an elevated portion having a radially inner surface oriented at an angle relative to the workpiece area in the range of 120 degrees to 135 degrees.
Claim 36
Dependent Claim
95 words
A plasma-enhanced semiconductor fabrication process, comprising the steps of: providing a process gas mixture into the interior of a plasma chamber; forming a plasma from at least a portion of the process gas mixture within the chamber; providing within the chamber a cathode electrode having an upper surface facing the plasma; holding a workpiece adjacent the upper surface of the cathode electrode; positioning a shield, composed of dielectric material, so as to encircle the perimeter of the workpiece; and positioning a ring, composed of non-dielectric material, overlying at least a portion of the dielectric shield.
Claim 37
Dependent Claim
95 words
A plasma-enhanced semiconductor fabrication process, comprising the steps of: providing a process gas mixture into the interior of a plasma chamber; forming a plasma from at least a portion of the process gas mixture within the chamber; providing within the chamber a cathode electrode having an upper surface facing the plasma; holding a workpiece adjacent the upper surface of the cathode electrode; positioning a shield, composed of dielectric material, so as to encircle the perimeter of the workpiece; and positioning a ring, composed of non-dielectric material, overlying at least a portion of the dielectric shield.
Claim 38
Dependent Claim
27 words
A method according to claim 30 , wherein the non-dielectric material is more resistant than the dielectric material to erosion by chemical species contained in the plasma.
Claim 39
Dependent Claim
128 words
A plasma-enhanced process for etching a hydrocarbon layer on a workpiece, comprising the steps of: providing into the interior of a plasma chamber a process gas mixture for etching said hydrocarbon layer; forming a plasma from at least a portion of the process gas mixture within the chamber; providing within the chamber a cathode electrode having an upper surface facing the plasma; holding said workpiece adjacent the upper surface of the cathode electrode; positioning a shield, composed of dielectric material, so as to encircle the perimeter of the workpiece; and positioning a ring overlying at least a portion of the dielectric shield, wherein the ring is composed of a non-dielectric material which is more resistant than the dielectric material to erosion by chemical species contained in the plasma.
Claim 40
Dependent Claim
128 words
A plasma-enhanced process for etching a hydrocarbon layer on a workpiece, comprising the steps of: providing into the interior of a plasma chamber a process gas mixture for etching said hydrocarbon layer; forming a plasma from at least a portion of the process gas mixture within the chamber; providing within the chamber a cathode electrode having an upper surface facing the plasma; holding said workpiece adjacent the upper surface of the cathode electrode; positioning a shield, composed of dielectric material, so as to encircle the perimeter of the workpiece; and positioning a ring overlying at least a portion of the dielectric shield, wherein the ring is composed of a non-dielectric material which is more resistant than the dielectric material to erosion by chemical species contained in the plasma.
Claim 41
Dependent Claim
22 words
A process according to claim 32 , wherein the shield is composed of silicon dioxide and the ring is composed of silicon.
Claim 42
Dependent Claim
16 words
A process according to claim 32 , wherein the hydrocarbon layer is a lithographic resist material.
Claim 43
Dependent Claim
130 words
A plasma-enhanced process for etching a spin-on glass layer on a workpiece, comprising the steps of: providing into the interior of a plasma chamber a process gas mixture for etching said spin-on glass layer; forming a plasma from at least a portion of the process gas mixture within the chamber; providing within the chamber a cathode electrode having an upper surface facing the plasma; holding said workpiece adjacent the upper surface of the cathode electrode; positioning a shield, composed of dielectric material, so as to encircle the perimeter of the workpiece; and positioning a ring overlying at least a portion of the dielectric shield, wherein the ring is composed of a non-dielectric material which is more resistant than the dielectric material to erosion by chemical species contained in the plasma.
Claim 44
Dependent Claim
130 words
A plasma-enhanced process for etching a spin-on glass layer on a workpiece, comprising the steps of: providing into the interior of a plasma chamber a process gas mixture for etching said spin-on glass layer; forming a plasma from at least a portion of the process gas mixture within the chamber; providing within the chamber a cathode electrode having an upper surface facing the plasma; holding said workpiece adjacent the upper surface of the cathode electrode; positioning a shield, composed of dielectric material, so as to encircle the perimeter of the workpiece; and positioning a ring overlying at least a portion of the dielectric shield, wherein the ring is composed of a non-dielectric material which is more resistant than the dielectric material to erosion by chemical species contained in the plasma.
Claim 45
Dependent Claim
22 words
A process according to claim 35 , wherein the shield is composed of silicon dioxide and the ring is composed of silicon.
Claim 46
Dependent Claim
189 words
A magnetically enhanced plasma chamber for performing a semiconductor fabrication process on a workpiece, comprising: a cathode electrode having an upper surface facing an interior region of the chamber; a chuck for holding the workpiece so that the workpiece occupies a workpiece area parallel to and immediately above the upper surface of the cathode electrode, wherein the workpiece area is bounded by a perimeter; one or more magnets positioned so as to collectively produce a magnetic field at the workpiece area, wherein the magnetic field at the perimeter of the workpiece area has a time-averaged field strength that varies as a function of azimuth around the perimeter of the workpiece area, so that the time-averaged magnetic field strength has a maximum strength at a first set of one or more azimuths and a minimum strength at a second set of one or more azimuths; a collar encircling the perimeter of the workpiece area, wherein the collar has a physical dimension which ranges between a first limit and a second limit as a function of azimuth, and said dimension equals the first limit near each azimuth in the first set.
Claim 47
Dependent Claim
189 words
A magnetically enhanced plasma chamber for performing a semiconductor fabrication process on a workpiece, comprising: a cathode electrode having an upper surface facing an interior region of the chamber; a chuck for holding the workpiece so that the workpiece occupies a workpiece area parallel to and immediately above the upper surface of the cathode electrode, wherein the workpiece area is bounded by a perimeter; one or more magnets positioned so as to collectively produce a magnetic field at the workpiece area, wherein the magnetic field at the perimeter of the workpiece area has a time-averaged field strength that varies as a function of azimuth around the perimeter of the workpiece area, so that the time-averaged magnetic field strength has a maximum strength at a first set of one or more azimuths and a minimum strength at a second set of one or more azimuths; a collar encircling the perimeter of the workpiece area, wherein the collar has a physical dimension which ranges between a first limit and a second limit as a function of azimuth, and said dimension equals the first limit near each azimuth in the first set.
Claim 48
Dependent Claim
24 words
A chamber according to claim 37 , wherein said dimension of the collar equals the second limit near each azimuth in the second set.
Claim 49
Dependent Claim
93 words
A chamber according to claim 37 , wherein: the upper surface of the cathode electrode has a perimeter which surrounds and is larger than the perimeter of the workpiece area; the collar includes a dielectric shield overlying a portion of the upper surface of the cathode which is outside the perimeter of the workpiece area; and the dielectric shield has a thickness which differs at different azimuths so that said thickness is said physical dimension of the collar which ranges between said first limit and said second limit as a function of azimuth.
Claim 50
Dependent Claim
137 words
A plasma chamber for performing a semiconductor fabrication process on a workpiece, comprising: a cathode electrode having an upper surface facing an interior region of the chamber, wherein the upper surface is bounded by a perimeter; a chuck for holding the workpiece so that the workpiece occupies a workpiece area parallel to and immediately above the upper surface of the cathode electrode, wherein the workpiece area has a perimeter that is smaller than, and surrounded by, the perimeter of the workpiece area, so that a portion of the upper surface of the cathode is outside the perimeter of the workpiece area; and a dielectric shield overlying a portion of the upper surface of the cathode which is outside the perimeter of the workpiece area, wherein the dielectric shield has an inner diameter which differs at different azimuths.
Claim 51
Dependent Claim
137 words
A plasma chamber for performing a semiconductor fabrication process on a workpiece, comprising: a cathode electrode having an upper surface facing an interior region of the chamber, wherein the upper surface is bounded by a perimeter; a chuck for holding the workpiece so that the workpiece occupies a workpiece area parallel to and immediately above the upper surface of the cathode electrode, wherein the workpiece area has a perimeter that is smaller than, and surrounded by, the perimeter of the workpiece area, so that a portion of the upper surface of the cathode is outside the perimeter of the workpiece area; and a dielectric shield overlying a portion of the upper surface of the cathode which is outside the perimeter of the workpiece area, wherein the dielectric shield has an inner diameter which differs at different azimuths.
Claim 52
Dependent Claim
146 words
A plasma-enhanced semiconductor fabrication process, comprising the steps of: providing a process gas into an interior region of a plasma chamber; mounting within the chamber a cathode electrode having an upper surface facing said interior region; supplying RF power to the cathode electrode so as to excite at least a portion of the process gas to a plasma state; holding a workpiece so that the workpiece occupies a workpiece area parallel to and immediately above the upper surface of the cathode electrode, wherein the upper surface of the cathode electrode has a perimeter which encircles the perimeter of the workpiece area; and positioning a shield, composed of dielectric material, overlying a portion of the upper surface of the cathode which is outside the perimeter of the workpiece area, wherein the dielectric shield is thin enough to couple RF power from the cathode electrode to the plasma.
Claim 53
Dependent Claim
146 words
A plasma-enhanced semiconductor fabrication process, comprising the steps of: providing a process gas into an interior region of a plasma chamber; mounting within the chamber a cathode electrode having an upper surface facing said interior region; supplying RF power to the cathode electrode so as to excite at least a portion of the process gas to a plasma state; holding a workpiece so that the workpiece occupies a workpiece area parallel to and immediately above the upper surface of the cathode electrode, wherein the upper surface of the cathode electrode has a perimeter which encircles the perimeter of the workpiece area; and positioning a shield, composed of dielectric material, overlying a portion of the upper surface of the cathode which is outside the perimeter of the workpiece area, wherein the dielectric shield is thin enough to couple RF power from the cathode electrode to the plasma.
Claim 54
Dependent Claim
100 words
A plasma-enhanced semiconductor fabrication process, comprising the steps of: providing a plasma in an interior region of a plasma chamber; mounting within the chamber a cathode electrode having an upper surface facing said interior region; holding a workpiece so that the workpiece occupies a workpiece area parallel to and immediately above the upper surface of the cathode electrode; and positioning a collar within the chamber so that the collar encircles the perimeter of the workpiece area, wherein the collar includes an uppermost elevated portion having a height above the upper surface of the cathode electrode which differs at different azimuths.
Claim 55
Dependent Claim
100 words
A plasma-enhanced semiconductor fabrication process, comprising the steps of: providing a plasma in an interior region of a plasma chamber; mounting within the chamber a cathode electrode having an upper surface facing said interior region; holding a workpiece so that the workpiece occupies a workpiece area parallel to and immediately above the upper surface of the cathode electrode; and positioning a collar within the chamber so that the collar encircles the perimeter of the workpiece area, wherein the collar includes an uppermost elevated portion having a height above the upper surface of the cathode electrode which differs at different azimuths.
Claim 56
Dependent Claim
88 words
A plasma-enhanced semiconductor fabrication process, comprising the steps of: providing a plasma in an interior region of a plasma chamber; mounting within the chamber a cathode electrode having an upper surface facing said interior region; holding a workpiece so that the workpiece occupies a workpiece area parallel to and immediately above the upper surface of the cathode electrode; and positioning a collar within the chamber so that the collar encircles the perimeter of the workpiece area, wherein the collar has an inner diameter which differs at different azimuths.
Claim 57
Dependent Claim
88 words
A plasma-enhanced semiconductor fabrication process, comprising the steps of: providing a plasma in an interior region of a plasma chamber; mounting within the chamber a cathode electrode having an upper surface facing said interior region; holding a workpiece so that the workpiece occupies a workpiece area parallel to and immediately above the upper surface of the cathode electrode; and positioning a collar within the chamber so that the collar encircles the perimeter of the workpiece area, wherein the collar has an inner diameter which differs at different azimuths.
Claim 58
Dependent Claim
14 words
A process according to claim 43 , wherein the collar is a dielectric material.
Claim 59
Dependent Claim
193 words
A magnetically-enhanced plasma process for semiconductor fabrication, comprising the steps of: providing a plasma in an interior region of a plasma chamber; mounting within the chamber a cathode electrode having an upper surface facing said interior region; holding a workpiece so that the workpiece occupies a workpiece area parallel to and immediately above the upper surface of the cathode electrode, wherein the workpiece area is bounded by a perimeter; producing a magnetic field at the workpiece area, wherein the magnetic field at the perimeter of the workpiece area has a time-averaged field strength that varies as a function of azimuth around the perimeter of the workpiece area, so that the time-averaged magnetic field strength has a maximum strength at a first set of one or more azimuths and a minimum strength at a second set of one or more azimuths; positioning a collar within the chamber so that the collar encircles the perimeter of the workpiece area, wherein the collar has a physical dimension which ranges between a first limit and a second limit as a function of azimuth, and said dimension equals the first limit near each azimuth in the first set.
Claim 60
Dependent Claim
193 words
A magnetically-enhanced plasma process for semiconductor fabrication, comprising the steps of: providing a plasma in an interior region of a plasma chamber; mounting within the chamber a cathode electrode having an upper surface facing said interior region; holding a workpiece so that the workpiece occupies a workpiece area parallel to and immediately above the upper surface of the cathode electrode, wherein the workpiece area is bounded by a perimeter; producing a magnetic field at the workpiece area, wherein the magnetic field at the perimeter of the workpiece area has a time-averaged field strength that varies as a function of azimuth around the perimeter of the workpiece area, so that the time-averaged magnetic field strength has a maximum strength at a first set of one or more azimuths and a minimum strength at a second set of one or more azimuths; positioning a collar within the chamber so that the collar encircles the perimeter of the workpiece area, wherein the collar has a physical dimension which ranges between a first limit and a second limit as a function of azimuth, and said dimension equals the first limit near each azimuth in the first set.
Claim 61
Dependent Claim
93 words
A process according to claim 45 , wherein: the upper surface of the cathode electrode has a perimeter which surrounds and is larger than the perimeter of the workpiece area; the collar includes a dielectric shield overlying a portion of the upper surface of the cathode which is outside the perimeter of the workpiece area; and the dielectric shield has a thickness which differs at different azimuths so that said thickness is said physical dimension of the collar which ranges between said first limit and said second limit as a function of azimuth.
References Cited (Backward Citations)
US4767641A
Cited
US5225024A
Cited
US5556501A
Cited
US5292399A
Cited
US5298465A
Cited
US5074456A
Cited
US5330607A
Cited
US5213658A
Cited
US5304248A
Cited
US5888414A
Cited
US6074512A
Cited
US6036877A
Cited
US5990017A
Cited
US5271788A
Cited
US5423918A
Cited
US5573596A
Cited
EP0665575A1
Cited
US5474649A
Cited
US5685914A
Cited
US5484486A
Cited
US5552124A
Cited
US5673922A
Cited
US5891348A
Cited
US6024826A
Cited
US5740009A
Cited
US5942042A
Cited
US5922133A
Cited
US6074488A
Cited
US6039836A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2004-09-03 | 2005-03-05 | 2005-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-09-03 | 2009-03-05 | 2009-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-09-03 | 2013-03-05 | 2013-09-04 | $7700.00 | Window Closed / Lapsed |