US4338508A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Inscribing apparatus and methods
Assignee: Individual
•
Filing: 1980-12-02
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Granted: 1982-07-06
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Expires: 2000-12-02
Abstract
Abstract Apparatus and methods for inscribing workpieces for the fabrication of masks and direct fabrication of microcircuits are described. The invention is primarily concerned with correcting for positional errors and to this end two coaxial beams (20,32) are directed towards a worktable from opposite sides thereof, the beam (20) serving as the scribing beam and the beam (32), operating in a reading mode, serving to read positional information and generate positional information and appropriate error signals for correcting the point of impact of the beam (20) with the surface of the substrate to be inscribed (28,46). In one embodiment the table (10) is solid and two layers of substrate are used on opposite surfaces of the table (10). The lower substrate (30) constitutes a master substrate which can be left in position while a large number of virgin substrates are exposed on the upper surface of the table (10). In another embodiment the table (44) is in the form of a frame for peripherally supporting a wafer on substrate workpiece (46) so that both upper and lower surfaces of the wafer are exposed to the two electron beams, the underside surface constituting the registration surface. Marks are formed therein by scribing the surface using the beam (32).
Inventors
- 👤 Geraint A. C. Jones
- 👤 Haroon Ahmed
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 20:34
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/30; H01J37/304; H01J37/3045
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
211 words
Apparatus for scribing a workpiece surface comprising: a worktable for supporting a workpiece means, which has opposed parallel workpiece faces exposed to opposite directions; means for generating a first beam; means for directing the first beam towards the worktable for the controlled inscribing of a first of said workpiece faces; means for generating a second beam; means for directing the second beam on an axis effectively co-axial with the axis of the first beam but in the opposite direction towards the opposed worktable face; position indicating means carried on the worktable; means for deriving electrical position signals from impingement of the two beams with the indicator means; comparator means for determining any offset between the axes of the two beams; memory means for storing information relating to said offset; means for moving a workpiece into position so that the two beams impinge on opposite faces thereof, and so that the second beam can detect position control marks on the opposed face of the workpiece; and means for controlling the relative positions of the first beam and the first of the workpiece faces to produce inscribing of said first face positionally controlled dependent on the position control marks on the opposed face and dependent on the stored information relating to the offset.
Claim 2
Dependent Claim
211 words
Apparatus for scribing a workpiece surface comprising: a worktable for supporting a workpiece means, which has opposed parallel workpiece faces exposed to opposite directions; means for generating a first beam; means for directing the first beam towards the worktable for the controlled inscribing of a first of said workpiece faces; means for generating a second beam; means for directing the second beam on an axis effectively co-axial with the axis of the first beam but in the opposite direction towards the opposed worktable face; position indicating means carried on the worktable; means for deriving electrical position signals from impingement of the two beams with the indicator means; comparator means for determining any offset between the axes of the two beams; memory means for storing information relating to said offset; means for moving a workpiece into position so that the two beams impinge on opposite faces thereof, and so that the second beam can detect position control marks on the opposed face of the workpiece; and means for controlling the relative positions of the first beam and the first of the workpiece faces to produce inscribing of said first face positionally controlled dependent on the position control marks on the opposed face and dependent on the stored information relating to the offset.
Claim 3
Dependent Claim
20 words
Apparatus according to claim 1, wherein the said controlling means includes means for controlling the position of the first beam.
Claim 4
Dependent Claim
19 words
Apparatus according to claim 2, wherein the said controlling means includes means for controlling the position of the worktable.
Claim 5
Dependent Claim
56 words
Apparatus according to claim 3, wherein said position control signals deriving means comprises comparator means for producing positional error information signals, means for detecting the magnitude of said error signals, and means for supplying coarse adjustment error signals to the worktable position controlling means and fine adjustment error signals to the first beam position controlling means.
Claim 6
Dependent Claim
32 words
Apparatus according to claim 1, wherein said workpiece means comprises a first workpiece carrying the first workpiece face and a second workpiece carrying the opposed workpiece face bearing the position control marks.
Claim 7
Dependent Claim
61 words
Apparatus according to claim 1, wherein said worktable is in the form of a frame and a single workpiece is supported within the frame and the first beam is directed towards one face of the workpiece and the second beam is directed towards the opposite face of the workpiece for reading marks formed thereon to provide the said position control signals.
Claim 8
Dependent Claim
22 words
Apparatus according to claim 1, wherein the means for generating the first beam is an ion source for producing an ion beam.
Claim 9
Dependent Claim
15 words
Apparatus according to claim 7, wherein the means for directing the ion beam is electrostatic.
Claim 10
Dependent Claim
17 words
Apparatus according to claim 1, wherein the means for generating the second beam is an electron column.
Claim 11
Dependent Claim
17 words
Apparatus according to claim 1, wherein the means for generating the second beam is an ion source.
Claim 12
Dependent Claim
19 words
Apparatus according to claim 1, wherein the axes of the first and second beams are precisely coaxial in space.
Claim 13
Dependent Claim
77 words
Apparatus according to claim 11, wherein, in order to render the first and second beams precisely coaxial in space, reference marks are provided on the worktable/workpiece means assembly, means are provided for deriving pre-alignment correction signals responsive to detection of the reference marks by the two beams, and means are provided for adjusting the relative starting position of the worktable/workpiece means assembly and at least one of the two beams in accordance with said pre-alignment correction signals.
Claim 14
Dependent Claim
84 words
Apparatus according to claim 1, wherein, in order to render the first and second beams effectively coaxial, reference marks are provided on the worktable/workpiece means assembly, means are provided for deriving and storing offset correction signals responsive to detection of the reference marks by the two beams, and means are provided to read the stored offset correction signals to modify the action of the controlling means when the relative positions of the first beam and the first workpiece face are being controlled during inscribing.
Claim 15
Dependent Claim
20 words
Apparatus according to claim 13, wherein the stored offset correction signals are applied to modify the electrical position control signals.
Claim 16
Independent Claim
211 words
A method of scribing a workpiece surface comprising the steps of: supporting a workpiece means on a worktable with two parallel workpiece faces exposed to opposite directions; generating a first beam; directing the first beam towards the first of said workpiece faces to allow for controlled inscribing thereof; generating a second beam; directing the second beam on an axis effectively coaxial with that of the first beam but in the opposite direction onto the opposed workpiece face; providing position control marks on the worktable; deriving electrical position signals from impingement of the two beams with the indicator means; determining any offset between the axes of the two beams by comparing the electrical position signals relating to the two beams; storing information relating to any said offset in memory means; moving a workpiece into position so that the two beams impinge on opposite faces thereof and detecting position control marks on the opposed face of the workpiece by the second beam; and controlling the relative positions of the first beam and the first of the workpiece faces to produce positionally controlled inscribing of said first face dependent on the position control marks on the opposed face and dependent on the stored information relating to any offset in the axes of the beams.
Claim 17
Independent Claim
211 words
A method of scribing a workpiece surface comprising the steps of: supporting a workpiece means on a worktable with two parallel workpiece faces exposed to opposite directions; generating a first beam; directing the first beam towards the first of said workpiece faces to allow for controlled inscribing thereof; generating a second beam; directing the second beam on an axis effectively coaxial with that of the first beam but in the opposite direction onto the opposed workpiece face; providing position control marks on the worktable; deriving electrical position signals from impingement of the two beams with the indicator means; determining any offset between the axes of the two beams by comparing the electrical position signals relating to the two beams; storing information relating to any said offset in memory means; moving a workpiece into position so that the two beams impinge on opposite faces thereof and detecting position control marks on the opposed face of the workpiece by the second beam; and controlling the relative positions of the first beam and the first of the workpiece faces to produce positionally controlled inscribing of said first face dependent on the position control marks on the opposed face and dependent on the stored information relating to any offset in the axes of the beams.
Claim 18
Dependent Claim
25 words
A method according to claim 15, including the additional step of physically pre-aligning the first and second beams in precise coaxial relationship prior to inscribing.
Claim 19
Dependent Claim
43 words
A method according to claim 15, including the additional steps of providing pre-alignment reference marks on the worktable/workpiece means assembly, reading said reference marks to provide offset correction signals, and utilising said offset correction signals to modify the position control signals during inscribing.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-07-05 | 1986-01-04 | 1986-07-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-07-05 | 1990-01-04 | 1990-07-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-07-05 | 1994-01-04 | 1994-07-06 | $7700.00 | Window Closed / Lapsed |