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US4579083A
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Automatic variable rate evaporation source for thin film deposition
Assignee: Canadian Patents and Development Ltd
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Filing: 1985-04-19
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Granted: 1986-04-01
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Expires: 2005-04-19
Abstract
Abstract An apparatus for automatically controlling the rate of vacuum deposition of thin films on a substrate, consisting of an optical diaphragm or shutter in the form of two overlapping plates which together define a shutter opening between an evaporation crucible and a substrate. The overlapping plates are attached to a pair of rack gears to be moved in opposite directions by a pinion gear to vary the size of the shutter opening through which the evaporated material must pass to be deposited on the substrate. The rate of evaporation is sensed by a quartz crystal monitor and a signal therefrom is compared to a reference signal. The difference between the two signals is used to control the movement of the apertured plates thereby correcting the rate of deposition of the thin film.
Inventors
- 👤 Germain Boivin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 06:59
CPC Classifications
C; C23; C23C; C23C14/00; C23C14/22; C23C14/54; C23C14/542; C23C14/545; C23C14/546
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
229 words
An apparatus for automatically controlling the rate of deposition of thin films on a substrate placed above an evaporation crucible, said apparatus comprising: a pair of superimposed, slidable shutter plates which between them define a rectangular aperture, said rectangular aperture being dimensioned and arranged to form a rectangular shutter opening between said crucible and said thin film so that with said shutter plates in one position said shutter opening is fully open; a pair of rack gears with facing teeth, the rack gears being slidable along parallel paths and having the shutter plates secured thereto with the longitudinal axis of the rectangular aperture defined therebetween, said longitudinal axis is tilted at an angle to the said parallel paths so that the rectangular shutter opening will open and close symmetrically about said longitudinal axis and an axis normal thereto; a pinion between, and meshing with, the facing teeth; drive means connected to said pinion to move both of said plates to open or close said shutter opening; and control means for activating said driving means, said control means comprising: means for sensing and generating a signal in relation to the rate of evaporation; means for generating a reference signal; and means for comparing differences between the signals from said sensing means and said reference signal and for actuating said drive means in response to changes in the rate of deposition.
Claim 2
Independent Claim
229 words
An apparatus for automatically controlling the rate of deposition of thin films on a substrate placed above an evaporation crucible, said apparatus comprising: a pair of superimposed, slidable shutter plates which between them define a rectangular aperture, said rectangular aperture being dimensioned and arranged to form a rectangular shutter opening between said crucible and said thin film so that with said shutter plates in one position said shutter opening is fully open; a pair of rack gears with facing teeth, the rack gears being slidable along parallel paths and having the shutter plates secured thereto with the longitudinal axis of the rectangular aperture defined therebetween, said longitudinal axis is tilted at an angle to the said parallel paths so that the rectangular shutter opening will open and close symmetrically about said longitudinal axis and an axis normal thereto; a pinion between, and meshing with, the facing teeth; drive means connected to said pinion to move both of said plates to open or close said shutter opening; and control means for activating said driving means, said control means comprising: means for sensing and generating a signal in relation to the rate of evaporation; means for generating a reference signal; and means for comparing differences between the signals from said sensing means and said reference signal and for actuating said drive means in response to changes in the rate of deposition.
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) | 1989-03-31 | 1989-09-30 | 1990-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-03-31 | 1993-09-30 | 1994-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-03-31 | 1997-09-30 | 1998-04-01 | $7700.00 | Window Closed / Lapsed |