US5656123A
Expired / Lapsed
US
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Dual-frequency capacitively-coupled plasma reactor for materials processing
Assignee: Novellus Systems Inc
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Filing: 1995-06-07
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Granted: 1997-08-12
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Expires: 2015-06-07
Abstract
Abstract The present invention is directed to a dual frequency capacitively-coupled plasma apparatus for materials processing. According to a first aspect of the present invention, a dual frequency triode reactor includes a VHF (30-300 MHz) RF power supply capacitively coupled to an upper reactor electrode and an HF (0.1-30 MHz) RF power supply capacitively coupled to a lower reactor electrode to which the wafer is attached. The VHF power supply is used to generate and control formation of a low sheath potential, high density plasma for minimum device damage and rapid etching/deposition while the HF power supply is used to provide a DC bias to the wafer substrate. According to a second aspect of the present invention, a tailored, powered upper electrode, at least a portion of which is generally conical in shape, is employed to provide a uniform etch across the diameter of the wafer.
Inventors
- 👤 Siamak Salimian
- 👤 Carol M. Heller
- 👤 Lumin Li
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 21:03
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/32; H01J37/32009; H01J37/32082; H01J37/32091; C; C23; C23C; C23C16/00; C23C16/44; C23C16/50; C23C16/505; C23C16/509; H01J37/32137; H01J37/32155; H01J37/32165; H01J37/32431; H01J37/32532; H01J37/32541; H10; H10P; H10P50/00; H10P50/20; H10P50/24; H10P50/242
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
170 words
A dual frequency, capacitively coupled, plasma reactor for materials processing, said reactor comprising: a vacuum chamber; a first and a second powered electrode disposed within said vacuum chamber; and means for coupling a semiconductor wafer within said vacuum chamber to said second powered electrode, said first powered electrode coupled to a source of VHF RF energy having a frequency in the range of about 30 MHz to about 300 MHz and having a shape including a first generally conically-shaped portion lacking an apex disposed at an outer periphery of said first powered electrode, said first generally conically-shaped portion directed toward said second powered electrode, and a second generally conically-shaped portion having an apex directed away from said second powered electrode, said second generally conically-shaped portion disposed substantially at a center of said second powered electrode and connected to said first generally conically-shaped portion, and said second powered electrode coupled to a source of HF RF energy having a frequency in the range of about 0.1 MHz to about 30 MHz.
Claim 2
Dependent Claim
170 words
A dual frequency, capacitively coupled, plasma reactor for materials processing, said reactor comprising: a vacuum chamber; a first and a second powered electrode disposed within said vacuum chamber; and means for coupling a semiconductor wafer within said vacuum chamber to said second powered electrode, said first powered electrode coupled to a source of VHF RF energy having a frequency in the range of about 30 MHz to about 300 MHz and having a shape including a first generally conically-shaped portion lacking an apex disposed at an outer periphery of said first powered electrode, said first generally conically-shaped portion directed toward said second powered electrode, and a second generally conically-shaped portion having an apex directed away from said second powered electrode, said second generally conically-shaped portion disposed substantially at a center of said second powered electrode and connected to said first generally conically-shaped portion, and said second powered electrode coupled to a source of HF RF energy having a frequency in the range of about 0.1 MHz to about 30 MHz.
Claim 3
Dependent Claim
163 words
A dual frequency, capacitively coupled, plasma reactor for materials processing, said reactor comprising: a vacuum chamber; a first powered electrode disposed within said vacuum chamber; a second powered electrode disposed within said vacuum chamber; and means for coupling a semiconductor wafer within said vacuum chamber to said second powered electrode, said first powered electrode having a shape including a first generally conically-shaped portion lacking an apex disposed at an outer periphery of said first powered electrode, said first generally conically-shaped portion directed toward said second powered electrode, and a second generally conically-shaped portion having an apex directed away from said second powered electrode, said second generally conically-shaped portion disposed substantially at a center of said second powered electrode and connected to said first generally conically-shaped portion and being coupled to a source of VHF RF energy having a frequency of approximately 60 MHz, and said second powered electrode coupled to a source of HF RF energy having a frequency of approximately 13.56 MHz.
Claim 4
Dependent Claim
163 words
A dual frequency, capacitively coupled, plasma reactor for materials processing, said reactor comprising: a vacuum chamber; a first powered electrode disposed within said vacuum chamber; a second powered electrode disposed within said vacuum chamber; and means for coupling a semiconductor wafer within said vacuum chamber to said second powered electrode, said first powered electrode having a shape including a first generally conically-shaped portion lacking an apex disposed at an outer periphery of said first powered electrode, said first generally conically-shaped portion directed toward said second powered electrode, and a second generally conically-shaped portion having an apex directed away from said second powered electrode, said second generally conically-shaped portion disposed substantially at a center of said second powered electrode and connected to said first generally conically-shaped portion and being coupled to a source of VHF RF energy having a frequency of approximately 60 MHz, and said second powered electrode coupled to a source of HF RF energy having a frequency of approximately 13.56 MHz.
Claim 5
Dependent Claim
180 words
A dual frequency, capacitively coupled, plasma reactor for materials processing, said reactor comprising: a vacuum chamber; a first and a second powered electrode disposed within said vacuum chamber, said first powered electrode coupled to a source of VHF RF energy having a frequency in the range of about 30 MHz to about 300 MHz and having a shape including a first generally conically-shaped portion lacking an apex disposed at an outer periphery of said first powered electrode, said first generally conically-shaped portion directed toward said second powered electrode, and a second generally conically-shaped portion having an apex directed away from said second powered electrode, said second generally conically-shaped portion disposed substantially at a center of said second powered electrode and connected to said first generally conically-shaped portion; and said second powered electrode disposed within said vacuum chamber, said second powered electrode coupled to a source of HF RF energy having a frequency in the range of about 0.1 MHz to about 30 MHz and having a generally flat shape for supporting and contacting material to be processed within the reactor.
Claim 6
Dependent Claim
180 words
A dual frequency, capacitively coupled, plasma reactor for materials processing, said reactor comprising: a vacuum chamber; a first and a second powered electrode disposed within said vacuum chamber, said first powered electrode coupled to a source of VHF RF energy having a frequency in the range of about 30 MHz to about 300 MHz and having a shape including a first generally conically-shaped portion lacking an apex disposed at an outer periphery of said first powered electrode, said first generally conically-shaped portion directed toward said second powered electrode, and a second generally conically-shaped portion having an apex directed away from said second powered electrode, said second generally conically-shaped portion disposed substantially at a center of said second powered electrode and connected to said first generally conically-shaped portion; and said second powered electrode disposed within said vacuum chamber, said second powered electrode coupled to a source of HF RF energy having a frequency in the range of about 0.1 MHz to about 30 MHz and having a generally flat shape for supporting and contacting material to be processed within the reactor.
Claim 7
Dependent Claim
178 words
A dual-frequency, capacitively coupled, plasma reactor for materials processing, said reactor comprising: a vacuum chamber; a first and a second powered electrode disposed within said vacuum chamber; said first powered electrode coupled to a source of VHF RF energy having a frequency in the range of about 30 MHz to about 300 MHz and having a shape including a first generally conically-shaped portion lacking an apex disposed at an outer periphery of said first powered electrode, said first generally conically-shaped portion directed toward said second powered electrode, and a second generally conically-shaped portion having an apex directed away from said second powered electrode, said second generally conically-shaped portion disposed substantially at a center of said second powered electrode and connected to said first generally conically-shaped portion; said second powered electrode disposed within said vacuum chamber, said second powered electrode coupled to a source of HF RF energy having a frequency in the range of about 0.1 MHz to about 30 MHz and having a generally flat shape for supporting and contacting material to be processed within the reactor.
Claim 8
Dependent Claim
178 words
A dual-frequency, capacitively coupled, plasma reactor for materials processing, said reactor comprising: a vacuum chamber; a first and a second powered electrode disposed within said vacuum chamber; said first powered electrode coupled to a source of VHF RF energy having a frequency in the range of about 30 MHz to about 300 MHz and having a shape including a first generally conically-shaped portion lacking an apex disposed at an outer periphery of said first powered electrode, said first generally conically-shaped portion directed toward said second powered electrode, and a second generally conically-shaped portion having an apex directed away from said second powered electrode, said second generally conically-shaped portion disposed substantially at a center of said second powered electrode and connected to said first generally conically-shaped portion; said second powered electrode disposed within said vacuum chamber, said second powered electrode coupled to a source of HF RF energy having a frequency in the range of about 0.1 MHz to about 30 MHz and having a generally flat shape for supporting and contacting material to be processed within the reactor.
Claim 9
Independent Claim
200 words
A method of etching a silicon wafer, said method comprising the steps of: placing the silicon wafer into a vacuum chamber having a first powered electrode and a second powered electrode, said first powered electrode having a shape including a first generally conically-shaped portion lacking an apex disposed at an outer periphery of said first powered electrode, said first generally conically-shaped portion directed toward said second powered electrode, and a second generally conically-shaped portion having an apex directed away from said second powered electrode, said second generally conically-shaped portion disposed substantially at a center of said second powered electrode and connected to said first generally conically-shaped portion; placing the wafer into electrical contact with said second powered electrode; applying a source of VHF RF energy in the range of about 30 MHz to about 300 MHz to said first powered electrode in order to form a plasma within said vacuum chamber; and applying a source of HF RF energy in the range of about 0.1 MHz to about 30 MHz to said second powered electrode in order to provide a self-induced DC bias to said wafer in order to control the energy of ions from said plasma striking the wafer.
Claim 10
Independent Claim
200 words
A method of etching a silicon wafer, said method comprising the steps of: placing the silicon wafer into a vacuum chamber having a first powered electrode and a second powered electrode, said first powered electrode having a shape including a first generally conically-shaped portion lacking an apex disposed at an outer periphery of said first powered electrode, said first generally conically-shaped portion directed toward said second powered electrode, and a second generally conically-shaped portion having an apex directed away from said second powered electrode, said second generally conically-shaped portion disposed substantially at a center of said second powered electrode and connected to said first generally conically-shaped portion; placing the wafer into electrical contact with said second powered electrode; applying a source of VHF RF energy in the range of about 30 MHz to about 300 MHz to said first powered electrode in order to form a plasma within said vacuum chamber; and applying a source of HF RF energy in the range of about 0.1 MHz to about 30 MHz to said second powered electrode in order to provide a self-induced DC bias to said wafer in order to control the energy of ions from said plasma striking the wafer.
Claim 11
Independent Claim
199 words
A method of etching a silicon wafer, said method comprising the steps of: placing the silicon wafer into a vacuum chamber having a first powered electrode and a second powered electrode, the first powered electrode having a shape including a first generally conically-shaped portion lacking an apex disposed at an outer periphery of said first powered electrode, said first generally conically-shaped portion directed toward said second powered electrode, and a second generally conically-shaped portion having an apex directed away from said second powered electrode, said second generally conically-shaped portion disposed substantially at a center of said second powered electrode and connected to said first generally conically-shaped portion; placing the wafer into electrical contact with said second powered electrode; applying a source of VHF RF energy in the range of about 30 MHz to about 300 MHz to said first powered electrode in order to form a plasma within said vacuum chamber; applying a source of HF RF energy in the range of about 0.1 MHz to about 30 MHz to said second powered electrode in order to provide a self-induced DC bias to said wafer in order to control the energy of ions from said plasma striking the wafer.
Claim 12
Independent Claim
199 words
A method of etching a silicon wafer, said method comprising the steps of: placing the silicon wafer into a vacuum chamber having a first powered electrode and a second powered electrode, the first powered electrode having a shape including a first generally conically-shaped portion lacking an apex disposed at an outer periphery of said first powered electrode, said first generally conically-shaped portion directed toward said second powered electrode, and a second generally conically-shaped portion having an apex directed away from said second powered electrode, said second generally conically-shaped portion disposed substantially at a center of said second powered electrode and connected to said first generally conically-shaped portion; placing the wafer into electrical contact with said second powered electrode; applying a source of VHF RF energy in the range of about 30 MHz to about 300 MHz to said first powered electrode in order to form a plasma within said vacuum chamber; applying a source of HF RF energy in the range of about 0.1 MHz to about 30 MHz to said second powered electrode in order to provide a self-induced DC bias to said wafer in order to control the energy of ions from said plasma striking the wafer.
Claim 13
Independent Claim
199 words
A method of etching a silicon wafer, said method comprising the steps of: placing the silicon wafer into a vacuum chamber having a first powered electrode and a second powered electrode, the first powered electrode having a shape including a first generally conically-shaped portion lacking an apex disposed at an outer periphery of said first powered electrode, said first generally conically-shaped portion directed toward the second powered electrode, and a second generally conically-shaped portion having an apex directed away from said second powered electrode, said second generally conically-shaped portion disposed substantially at a center of said second powered electrode and connected to said first generally conically-shaped portion; placing the wafer into electrical contact with said second powered electrode; applying a source of VHF RF energy in the range of about 30 MHz to about 300 MHz to said first powered electrode in order to form a plasma within said vacuum chamber; applying a source of HF RF energy in the range of about 0.1 MHz to about 30 MHz to said second powered electrode in order to provide a self-induced DC bias to said wafer in order to control the energy of ions from said plasma striking the wafer.
Claim 14
Independent Claim
199 words
A method of etching a silicon wafer, said method comprising the steps of: placing the silicon wafer into a vacuum chamber having a first powered electrode and a second powered electrode, the first powered electrode having a shape including a first generally conically-shaped portion lacking an apex disposed at an outer periphery of said first powered electrode, said first generally conically-shaped portion directed toward the second powered electrode, and a second generally conically-shaped portion having an apex directed away from said second powered electrode, said second generally conically-shaped portion disposed substantially at a center of said second powered electrode and connected to said first generally conically-shaped portion; placing the wafer into electrical contact with said second powered electrode; applying a source of VHF RF energy in the range of about 30 MHz to about 300 MHz to said first powered electrode in order to form a plasma within said vacuum chamber; applying a source of HF RF energy in the range of about 0.1 MHz to about 30 MHz to said second powered electrode in order to provide a self-induced DC bias to said wafer in order to control the energy of ions from said plasma striking the wafer.
Claim 15
Dependent Claim
15 words
A method according to claim 7 wherein said second powered electrode is a flat electrode.
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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) | 2000-08-11 | 2001-02-10 | 2001-08-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-08-11 | 2005-02-10 | 2005-08-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-08-11 | 2009-02-10 | 2009-08-12 | $7700.00 | Window Closed / Lapsed |