US4995958A
Expired / Lapsed
US
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Sputtering apparatus with a rotating magnet array having a geometry for specified target erosion profile
Assignee: Varian Semiconductor Equipment Associates Inc
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Filing: 1989-05-22
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Granted: 1991-02-26
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Expires: 2009-05-22
Abstract
Abstract A magnetron sputtering apparatus includes a rotatable magnet. At least a portion of the centerline of the magnet lies on a curve defined by ##EQU1## where ξ(u) is a preselected erosion profile. When stationary, the magnet generates a localized magnetic field of approximately constant width. In operation, when the magnet is rotated, it generates the preselected erosion profile in the target. The preselected erosion profile may be constant.
Inventors
- 👤 Robert L. Anderson
- 👤 John C. Helmer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 16:14
CPC Classifications
H; H01; H01J; H01J25/00; H01J25/50; H01J37/00; H01J37/32; H01J37/34; H01J37/3411; H01J37/345; H01J37/3455; H01J37/3402; H01J37/3405; H01J37/3408
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
98 words
A magnetron sputter apparatus comprising: a vacuum chamber; means for holding a target having a front surface in said vacuum chamber; and rotatable magnetic means for generating a moveable magnetic field over said front surface of said target, said magnetic means being configured so that at least a first portion of the normalized centerline of said magnetic means is describable by an equation of the form ##EQU17## where ξ(u) is a preselected normalized erosion profile to be generated in said target during rotation of said magnetic means, C is a selected constant, and θ has a selected range.
Claim 2
Dependent Claim
98 words
A magnetron sputter apparatus comprising: a vacuum chamber; means for holding a target having a front surface in said vacuum chamber; and rotatable magnetic means for generating a moveable magnetic field over said front surface of said target, said magnetic means being configured so that at least a first portion of the normalized centerline of said magnetic means is describable by an equation of the form ##EQU17## where ξ(u) is a preselected normalized erosion profile to be generated in said target during rotation of said magnetic means, C is a selected constant, and θ has a selected range.
Claim 3
Dependent Claim
34 words
A sputtering apparatus as in claim 1 wherein said preselected erosion profile ξ(u) is constant and said first portion is describable by an equation of the form ##EQU18## ,where C is a selected constant.
Claim 4
Dependent Claim
40 words
A sputtering apparatus as in claim 1 wherein said centerline forms a closed curve and each portion of said curve is described by an equation of said form for a selected choice of C and a selected range of θ.
Claim 5
Dependent Claim
26 words
A sputtering apparatus as in claim 1 wherein a second portion of said centerline is obtained by reflection of said first portion about a selected axis.
Claim 6
Dependent Claim
42 words
A sputtering apparatus as in claim 1 wherein said magnetic means comprises a first plurality of magnets having uniform length, the center of the centerline separating the poles of each of said magnets in said first plurality lying on said first portion.
Claim 7
Dependent Claim
63 words
A sputtering apparatus as in claim 4 wherein said magnetic means comprises a first plurality of magnets and a second plurality of magnets, the center of the centerline separating the poles of each magnet of said first plurality lying on said first portion, the center of the centerline separating the poles of each magnet of said second plurality lying on said second portion.
Claim 8
Dependent Claim
47 words
A sputtering apparatus as in claim 1 including a first and a second retaining means of magnetic material each uniformly spaced from said first portion over most of said portion in order to distribute the magnetic field generated by said magnetic means uniformly along said first portion.
Claim 9
Dependent Claim
13 words
A sputtering apparatus as in claim 7 wherein said retaining means are flexible.
Claim 10
Dependent Claim
9 words
A sputtering apparatus as in claim 1 wherein 0≦θ≦π/2.
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) | 1994-02-25 | 1994-08-27 | 1995-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-02-25 | 1998-08-27 | 1999-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-02-25 | 2002-08-27 | 2003-02-26 | $7700.00 | Window Closed / Lapsed |