US3901784A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cylindrical rf sputtering apparatus
Assignee: RTX Corp
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Filing: 1974-06-19
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Granted: 1975-08-26
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Expires: 1994-06-19
Abstract
Abstract A cylindrical cathode is used as a vacuum chamber to permit sputtering by means of rf potential on all sides of a workpiece located coaxially within the chamber. Both insulators and conductors may be used as target materials and as workpieces. Even deposition of the sputtered material on long or continuously fed workpieces is achieved by properly terminating the ends of the coaxial sputtering chamber with grounded chambers of larger diameter than the sputtering chamber and of sufficient length to thereby gradually reduce the plasma density along the axial direction to a relatively small value before reaching the end walls.
Inventors
- 👤 Daniel J Quinn
- 👤 Edouard L Paradis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:13
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/32; H01J37/32431; H01J37/32733; H01J37/32752; H01J37/32761; H01J37/3277; C; C23; C23C; C23C14/00; C23C14/22; C23C14/34; C23C14/35; H01J37/34; H01J37/3411; H01J37/3414; H01J37/342
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
154 words
A METHOD FOR UNIFORMLY COATING A WORKPIECE CONTAINED ALONG THE AXIS OF A CYLINDRICAL WORKPIECE CHAMBER BY SPUTTERING ONTO SAID WORKPIECE A COATING FROM A TARGET MATERIAL, SAID WORKPIECE CHAMBER BEING DEFINED BY A CYLINDRICAL METAL ELECTRODE ADAPTED TO SUPPORT SAID TARGET MATERIAL ON THE INNER CIRCUMFERENCE THEREOF, COMPRISING THE STEPS OF FILLING SAID WORKPIECE CHAMBER WITH A GAS AT A LOW PRESSURE, APPLYING A SOURCE OF RF POTENTIAL TO SAID ELECTRODE TO GENERATE A PLASMA IN SAID WORKPIECE CHAMBER, AND REDUCING THE PLASMA DENSITY GRADIENT AT THE ENDS OF SAID WORKPIECE CHAMBER BY TERMINATING EACH END OF SAID WORKPIECE CHAMBER WITH AN ELECTRICALLY GROUNDED METAL CYLINDRICAL TERMINATION CHAMBER WHICH IS ELECTRICALLY INSULATED FROM SAID WORKPIECE CHAMBER AND IS OF GREATER CROSS-SECTIONAL AREA THAN THE CROSS-SECTIONAL AREA OF SAID WORKPIECE CHAMBER, EACH SAID TERMINATION CHAMBER HAVING AN APERTURE THEREIN ALIGNED WITH SAID WORKPIECE CHAMBER TO PERMIT EXPANSION OF SAID PLASMA INTO SAID TERMINATION CHAMBER.
Claim 2
Independent Claim
154 words
A METHOD FOR UNIFORMLY COATING A WORKPIECE CONTAINED ALONG THE AXIS OF A CYLINDRICAL WORKPIECE CHAMBER BY SPUTTERING ONTO SAID WORKPIECE A COATING FROM A TARGET MATERIAL, SAID WORKPIECE CHAMBER BEING DEFINED BY A CYLINDRICAL METAL ELECTRODE ADAPTED TO SUPPORT SAID TARGET MATERIAL ON THE INNER CIRCUMFERENCE THEREOF, COMPRISING THE STEPS OF FILLING SAID WORKPIECE CHAMBER WITH A GAS AT A LOW PRESSURE, APPLYING A SOURCE OF RF POTENTIAL TO SAID ELECTRODE TO GENERATE A PLASMA IN SAID WORKPIECE CHAMBER, AND REDUCING THE PLASMA DENSITY GRADIENT AT THE ENDS OF SAID WORKPIECE CHAMBER BY TERMINATING EACH END OF SAID WORKPIECE CHAMBER WITH AN ELECTRICALLY GROUNDED METAL CYLINDRICAL TERMINATION CHAMBER WHICH IS ELECTRICALLY INSULATED FROM SAID WORKPIECE CHAMBER AND IS OF GREATER CROSS-SECTIONAL AREA THAN THE CROSS-SECTIONAL AREA OF SAID WORKPIECE CHAMBER, EACH SAID TERMINATION CHAMBER HAVING AN APERTURE THEREIN ALIGNED WITH SAID WORKPIECE CHAMBER TO PERMIT EXPANSION OF SAID PLASMA INTO SAID TERMINATION CHAMBER.
Claim 3
Dependent Claim
14 words
The method of claim 1 in which said target material is an electrical conductor.
Claim 4
Dependent Claim
14 words
The method of claim 1 in which said target material is an electrical insulator.
Claim 5
Dependent Claim
38 words
The method of claim 1 including the step of adjusting the frequency of said source of rf potential so that the axial length of said workpiece chamber is short relative to a quarter wavelength of said rf potential.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-08-25 | 1979-02-24 | 1979-08-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-25 | 1983-02-24 | 1983-08-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-25 | 1987-02-24 | 1987-08-26 | $7700.00 | Window Closed / Lapsed |