US3699334A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus using a beam of positive ions for controlled erosion of surfaces
Assignee: Kollsman Instrument Corp
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Filing: 1969-06-16
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Granted: 1972-10-17
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Expires: 1989-06-16
Abstract
Abstract A process and apparatus for controllably eroding the surface of hard materials such as fused quartz, glass, metals and ceramics by the bombardment of the positive ions. Focused argon ions accelerated by potentials of up to 120,000 volts and with a constant beam current are controlled in direction to cause surface erosion of a workpiece to accuracies of up to one-one hundredth of a wavelength of green light. The workpiece is moved at a controlled rate in combination with the control of the beam direction to obtain a controlled erosion pattern over the surface of the workpiece. In another embodiment, an intensity modulated beam current is used. An electron beam is directed at the workpiece in a pattern which surrounds the ion beam to prevent the building up of a positive charge on the work surface. The progress of the erosion is observed and measured by an interferometer system. The movement of the ion beam and workpiece can follow a programmed automatic sequence.
Inventors
- 👤 Murray F Cohen
- 👤 Michael Tarasevich
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 12:46
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/30; H01J37/3002; H01J37/3005; H01J37/02; H01J37/026; H01J37/304; G; G05; G05B; G05B2219/00; G05B2219/30; G05B2219/42; G05B2219/42251; G05B2219/43; G05B2219/43147
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
241 words
Apparatus for controllably eroding a surface of a workpiece to provide a predetermined contour thereon comprising means for mounting the workpiece in an evacuated chamber; means for producing a beam of positive ions traveling through said chamber towards said workpiece including means for variably determining the working characteristics of the ion beam; means for producing relative scanning movement between said beam and said workpiece including electrostatic deflection means, magnetic deflection means, and means for rotating the workpiece on an axis generally perpendicular to said surface, all selectively or concurrently operable for deflecting the path of the ion beam to continuously vary the point of impingement of the beam upon said surface; monitoring means for representing the pattern of erosion of the surface of the workpiece; reference grid means associated with the monitoring means and defining a series of zones thereon; sensing means for producing a first signal containing information from said monitoring means and said reference grid means representing instantaneous depth contour at each point and zone on said surface; and programmed computer control means including means for producing a second signal representing the desired depth contour at each point and zone on said surface, means for comparing each of said signals and for computing average depth errors for each of said reference grid zones and for each of said reference grid points, and means for generating a resultant signal to regulate the ion beam to produce the predetermined surface contour.
Claim 2
Dependent Claim
241 words
Apparatus for controllably eroding a surface of a workpiece to provide a predetermined contour thereon comprising means for mounting the workpiece in an evacuated chamber; means for producing a beam of positive ions traveling through said chamber towards said workpiece including means for variably determining the working characteristics of the ion beam; means for producing relative scanning movement between said beam and said workpiece including electrostatic deflection means, magnetic deflection means, and means for rotating the workpiece on an axis generally perpendicular to said surface, all selectively or concurrently operable for deflecting the path of the ion beam to continuously vary the point of impingement of the beam upon said surface; monitoring means for representing the pattern of erosion of the surface of the workpiece; reference grid means associated with the monitoring means and defining a series of zones thereon; sensing means for producing a first signal containing information from said monitoring means and said reference grid means representing instantaneous depth contour at each point and zone on said surface; and programmed computer control means including means for producing a second signal representing the desired depth contour at each point and zone on said surface, means for comparing each of said signals and for computing average depth errors for each of said reference grid zones and for each of said reference grid points, and means for generating a resultant signal to regulate the ion beam to produce the predetermined surface contour.
Claim 3
Dependent Claim
40 words
Apparatus in accordance with claim 1 wherein said monitoring means is an interferometer having a view field registered on said surface and said reference grid means is a calibrated rectilinear coordinate scale superimposed on the view field of the interferometer.
Claim 4
Dependent Claim
47 words
Apparatus in accordance with claim 1 wherein said resultant signal includes a portion representing the average zonal error for regulating said ion beam to produce the desired contour and a second portion representing the coordinate point error for regulating said ion beam to correct isolated height errors.
Claim 5
Dependent Claim
43 words
Apparatus in accordance with claim 1 wherein said resultant signal is converted from digital pulses to analog voltages in a converting means and said analog voltages are used to control the working characteristics of the ion beam to produce the predetermined surface contour.
Claim 6
Dependent Claim
36 words
Apparatus in accordance with claim 1 wherein said means for determining the working characteristics of the ion beam includes an ion beam focusing and shaping control, a beam current regulating control and an ion acceleration control.
Claim 7
Dependent Claim
200 words
Apparatus for controllably eroding a surface of a workpiece to provide a predetermined contour thereon comprising means for mounting the workpiece in an evacuated chamber; means for producing a beam of positive ions traveling through said chamber towards said workpiece including means for variably determining the working characteristics of the ion beam; means for producing relative scanning movement between said beam and said workpiece for deflecting the path of the ion beam to continuously vary the point of impingement of the beam upon said surface; monitoring means for representing the pattern of erosion at defined discrete points and zones on the surfacE of the workpiece; sensing means for producing a first signal representing instantaneous depth contour at each point and zone on said surface; and programmed computer control means including means for producing a second signal representing the desired depth contour at each point and zone on said surface, means for comparing each of said signals and for computing average depth errors for each of said reference grid zones and for each of said reference grid points, and means responsive to said control signals for generating a resultant signal to regulate the ion beam to produce the predetermined surface contour.
Claim 8
Dependent Claim
200 words
Apparatus for controllably eroding a surface of a workpiece to provide a predetermined contour thereon comprising means for mounting the workpiece in an evacuated chamber; means for producing a beam of positive ions traveling through said chamber towards said workpiece including means for variably determining the working characteristics of the ion beam; means for producing relative scanning movement between said beam and said workpiece for deflecting the path of the ion beam to continuously vary the point of impingement of the beam upon said surface; monitoring means for representing the pattern of erosion at defined discrete points and zones on the surfacE of the workpiece; sensing means for producing a first signal representing instantaneous depth contour at each point and zone on said surface; and programmed computer control means including means for producing a second signal representing the desired depth contour at each point and zone on said surface, means for comparing each of said signals and for computing average depth errors for each of said reference grid zones and for each of said reference grid points, and means responsive to said control signals for generating a resultant signal to regulate the ion beam to produce the predetermined surface contour.
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) | 1975-10-17 | 1976-04-17 | 1976-10-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-17 | 1980-04-17 | 1980-10-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-17 | 1984-04-17 | 1984-10-17 | $7700.00 | Window Closed / Lapsed |