Patent US3554281A successfully refreshed from Google Patents.
Patent US3903841A successfully refreshed from Google Patents.
US3903841A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vacuum holder in epitaxial growth apparatus
Assignee: Verizon Laboratories Inc
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Filing: 1974-08-22
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Granted: 1975-09-09
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Expires: 1994-08-22
Abstract
Abstract An assembly for holding a wafer substrate, while it is dipped in an appropriate nutrient solution, rotates the wafer in a horizontal plane and facilitates the coating of a thin film magnetic material on only one side of the wafer. The assembly includes a holder which may have either a flat or a slightly concave, circular face whose diameter is substantially identical to that of the wafer. The holder face has openings in the central region formed through its thickness dimension. When the face is in contact with the wafer, these openings are covered permitting the pressure in the tubular central portion of the holder to be reduced by withdrawing air from it by a vertical connecting tube. The reduced pressure creates forces on the wafer which secure the wafer to the holder. The central region of the holder face may be slightly concave but the peripheral region of the holder face must be substantially flat. The holder is connected to a vertical tube whose upper end in turn is fastened to a chuck. A vacuum pump and an appropriate motor are connected to the chuck which translates the output rotation of the motor and the reduced pressure from the pump to the substrate holder.
Inventors
- 👤 Thomas E Peters
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 13:38
CPC Classifications
C; C30; C30B; C30B19/00; C30B19/06; C30B19/068; H; H01; H01F; H01F41/00; H01F41/14; H01F41/24; H01F41/28
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
242 words
An apparatus for epitaxial growth of magnetic thin film on the substrate when the substrate is dipped into a suitable nutrient solution, including: a. a rotary platinum substrate holder having a face adapted to contact one side of the substrate, the face having a surface area adequate to enclose the entire surface of one side of the substrate so that the side of the substrate in contact with the holder face does not contact the nutrient solution and a circular surface peripheral region of approximately 3mm which is substantially flat and bounds a central surface portion having a concavity corresponding to approximately three interference fringes when viewed under sodium light, b. the holder further being formed with at least one opening adapted to be covered by the substrate and extending froM a central region of the face through a thickness dimension of the holder, c. tubular means connected to the holder about said opening opposed from said face, d. means operative through said tube for reducing the pressure in the opening after the substrate is in contact with the face to secure the substrate to the holder and for rotating the holder about an axis perpendicular to the face of the holder to reduce thickness variations of the magnetic thin film which is grown on the other side of the substrate; and e. nutrient solution containing means operatively associated with said holder to effect said growth when the substrate is dipped therein.
Claim 2
Independent Claim
242 words
An apparatus for epitaxial growth of magnetic thin film on the substrate when the substrate is dipped into a suitable nutrient solution, including: a. a rotary platinum substrate holder having a face adapted to contact one side of the substrate, the face having a surface area adequate to enclose the entire surface of one side of the substrate so that the side of the substrate in contact with the holder face does not contact the nutrient solution and a circular surface peripheral region of approximately 3mm which is substantially flat and bounds a central surface portion having a concavity corresponding to approximately three interference fringes when viewed under sodium light, b. the holder further being formed with at least one opening adapted to be covered by the substrate and extending froM a central region of the face through a thickness dimension of the holder, c. tubular means connected to the holder about said opening opposed from said face, d. means operative through said tube for reducing the pressure in the opening after the substrate is in contact with the face to secure the substrate to the holder and for rotating the holder about an axis perpendicular to the face of the holder to reduce thickness variations of the magnetic thin film which is grown on the other side of the substrate; and e. nutrient solution containing means operatively associated with said holder to effect said growth when the substrate is dipped therein.
Claim 3
Dependent Claim
40 words
The apparatus according to claim 1 wherein the axis of rotation is vertical so that the substrate is in a horizontal plane to minimize the effects on the film thickness of vertical and horizontal temperature gradients in the nutrient solution.
Claim 4
Dependent Claim
86 words
The apparatus according to claim 1 wherein the pressure reducing and rotating means includes a vacuum pump, said tubular means being a rigid tube of extended length affixed to the holder, a motor and a chuck which is connected to the outputs of the motor and the pump and to the tube, the chuck translating the rotating output of the motor to the tube and the reduced pressure from the pump to the hollow portion of the tube and thus to the opening in the holder.
Claim 5
Dependent Claim
13 words
The apparatus according to claim 3 wherein the tube is made of alumina.
Claim 6
Dependent Claim
13 words
The apparatus according to claim 3 wherein the tube is made of nickel.
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) | 1978-09-08 | 1979-03-10 | 1979-09-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-08 | 1983-03-10 | 1983-09-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-08 | 1987-03-10 | 1987-09-09 | $7700.00 | Window Closed / Lapsed |