US3699304A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electron beam deflection control method and apparatus
Assignee: International Business Machines Corp
•
Filing: 1969-12-15
•
Granted: 1972-10-17
•
Expires: 1989-12-15
Abstract
Abstract Method and apparatus for controlling the deflection of an energy beam to impinge a workpiece with improved accuracy. A computer and interface unit direct the movement of the beam over a master target to learn and record addresses of impingement areas corresponding to those on a workpiece. Differential current flow in two conductive elements is used to determine accurate location of the address. Upon the substitution of a workpiece for the master target, impingement addresses can be selected without additional corrective deflection circuits.
Inventors
- 👤 Edwin C Baldwin Jr
- 👤 Warren R Wrenner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 14:57
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/30; H01J37/304; H01J37/3045
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
179 words
A method oF establishing precise values for deflection signals to accurately position a beam of charged particles on an impingement area comprising the steps of: forming a master target having predetermined areas thereon for impingement by said beam; obtaining approximate deflection values for said areas by initially deflecting said beam to impinge a portion of selected ones of said areas and storing said approximate values; deflecting said beam from one location to another on said areas in accordance with said stored approximate values of deflection signals for each said area; varying said approximate values of deflection signals in a predetermined manner to move said beam through a position of optimum impingement at each said location; detecting the optimum incidence of said beam on each said area at each said location; obtaining correction values for deflection signals by determining the difference between said approximate values and those values required for deflection to said position of optimum incidence; and altering said stored approximate values of deflection signals for each said location with said correction values found to produce said optimum impingement.
Claim 2
Independent Claim
179 words
A method oF establishing precise values for deflection signals to accurately position a beam of charged particles on an impingement area comprising the steps of: forming a master target having predetermined areas thereon for impingement by said beam; obtaining approximate deflection values for said areas by initially deflecting said beam to impinge a portion of selected ones of said areas and storing said approximate values; deflecting said beam from one location to another on said areas in accordance with said stored approximate values of deflection signals for each said area; varying said approximate values of deflection signals in a predetermined manner to move said beam through a position of optimum impingement at each said location; detecting the optimum incidence of said beam on each said area at each said location; obtaining correction values for deflection signals by determining the difference between said approximate values and those values required for deflection to said position of optimum incidence; and altering said stored approximate values of deflection signals for each said location with said correction values found to produce said optimum impingement.
Claim 3
Dependent Claim
25 words
The method as described in claim 1 wherein said stored values are altered by annexing to said stored values correction values corresponding to said locations.
Claim 4
Dependent Claim
32 words
The method as described in claim 1 wherein the magnitude and sign of said correction values for an location are established relative to the corrected deflection signal values for a preceding location.
Claim 5
Dependent Claim
66 words
The method described in claim 1 wherein said stored deflection signals for an impingement area are defined by coordinate values along each of two orthogonal axes and said values are varied by incrementing one axis value by uniform amounts while changing the other axis value negatively and positively by differing amounts to find optimum impingement by said beam on a said location along said other axis.
Claim 6
Dependent Claim
39 words
The method according to claim 1 further comprising the step of using said stored values and respective correction values to thereafter control the deflection of said beam to corresponding impingement areas on a target other than said master target.
Claim 7
Independent Claim
206 words
A method of accurately controlling the position of impingement of a beam of charged particles on a workpiece which comprises the steps of: forming a master target with impingement areas at predetermined locations corresponding to prospective locations of impingement areas of a workpiece; obtaining approximate deflection values for said areas by initially deflecting said beam to impinge a portion of selected ones of said areas and storing said approximate values; deflecting said beam from one to another of said impingement areas of said master target in accordance with said stored approximate values of deflection signals for each said area; varying said stored approximate deflection signal values to change impingement of said beam on said master target areas after deflection thereto according to said approximate values; detecting the optimum incidence of said beam on each said area during said change; obtaining correction values for deflection signals by determining the difference between said approximate values and those values required for deflection to said position of optimum incidence; and altering said stored approximate values with said correction values producing said optimum incidence; substituting said workpiece for said master target; and deflecting said beam over said work-piece for impingement thereon in accordance with said altered values for said deflection signals.
Claim 8
Independent Claim
206 words
A method of accurately controlling the position of impingement of a beam of charged particles on a workpiece which comprises the steps of: forming a master target with impingement areas at predetermined locations corresponding to prospective locations of impingement areas of a workpiece; obtaining approximate deflection values for said areas by initially deflecting said beam to impinge a portion of selected ones of said areas and storing said approximate values; deflecting said beam from one to another of said impingement areas of said master target in accordance with said stored approximate values of deflection signals for each said area; varying said stored approximate deflection signal values to change impingement of said beam on said master target areas after deflection thereto according to said approximate values; detecting the optimum incidence of said beam on each said area during said change; obtaining correction values for deflection signals by determining the difference between said approximate values and those values required for deflection to said position of optimum incidence; and altering said stored approximate values with said correction values producing said optimum incidence; substituting said workpiece for said master target; and deflecting said beam over said work-piece for impingement thereon in accordance with said altered values for said deflection signals.
Claim 9
Dependent Claim
32 words
The method as described in claim 6 further including the step of selectively unblanking said beam to produce impingement on fewer areas on said workpiece than were impinged upon said master target.
References Cited (Backward Citations)
US3140379A
Cited
US3267250A
Cited
US3373267A
Cited
US3426174A
Cited
US3448240A
Cited
US3479574A
Cited
US3519788A
Cited
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 |