# US 5,345,085 A · Method and structure for electronically measuring beam parameters > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,345,085 A - Document ID: US5345085A - Status: Granted - Kind: A - Application number: 08/037,964 - Filed: 1993-03-26 - Granted: 1994-09-06 - Earliest claimed: 1993-03-26 - Assignees: Etec Systems, Inc. - Inventors: Richard W. Prior - Web page: https://patentgrep.com/patent/US5345085A ## CPC - G01T 1/29: Measurement performed on radiation beams, e.g. position or section of the beam; Measurement of spatial distribution of radiation - H01J 37/304: Controlling tubes by information coming from the objects {or from the beam}, e.g. correction signals - H01J 2237/24507: Intensity, dose or other characteristics of particle beams or electromagnetic radiation - H01J 2237/3045: Deflection calibration - G01T: MEASUREMENT OF NUCLEAR OR X-RADIATION (radiation analysis of materials, mass spectrometry G01N23/00; tubes for determining the presence, intensity, density or energy of radiation or particles H01J47/00) - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) ## Abstract A method of electronically measuring parameters of an beam in a raster scan system includes the steps of: choosing a predetermined pixel to be calibrated, moving a grid adjacent this pixel, strobing the beam, incrementally moving the beam toward an axis of the grid, and integrating the signal resulting from the beam as the beam moves toward the axis. The steps of strobing the beam, incrementally moving the beam, and integrating the signal are repeated until the beam crosses the axis. The value of the accumulated signals, provided for example by a charge amplifier, is used to determine the relative position of the axis of the grid. The value of the accumulated signals associated with another axis is also determined. The relative positions of the two axes determine the relative location of the grid. If the grid location is known, the location of an associated substrate which is typically adjacent the grid is also known. ## Claims ### Claim 1 A method of electronically measuring parameters of a beam in a raster scan system comprising the steps of: (a) choosing a predetermined pixel of the raster scan to be calibrated; (b) moving a grid adjacent said pixel; (c) strobing said beam; (d) incrementally moving said beam toward a first axis of said grid; (e) integrating the signal resulting from said beam as said beam moves toward said first axis; and (f) repeating steps (c) through (e) until a predetermined value of said signal is reached, thereby indicating said beam has crossed said first axis. ### Claim 2 (depends on 1) The method of claim 1 further including the steps of: (g) strobing said beam; (h) incrementally moving said beam toward a second axis of said grid; (i) integrating the signal resulting from said beam as said beam moves toward said second axis; and (j) repeating steps (g) through (i) until said beam crosses said second axis. ### Claim 3 (depends on 1) The method of claim 1 wherein an amplifier integrates said signal resulting from said beam. ### Claim 4 (depends on 3) The method of claim 3 further including the steps of: (b1) resetting said amplifier and (b2) setting said amplifier to an integrate mode. ### Claim 5 (depends on 1) The method of claim 1 wherein step (c) includes unblanking said predetermined pixel for N scans, where N is a predetermined integer. ### Claim 6 (depends on 1) The method of claim 1 further including the steps of (e1) converting a voltage output from said amplifier to a digital signal and (e2) storing said digital signal. ### Claim 7 (depends on 1) The method of claim 1 wherein step (a) includes choosing a plurality of pixels. ### Claim 8 (depends on 7) The method of claim 7 wherein said plurality of pixels are contiguous. ### Claim 9 (depends on 1) The method of claim 1 wherein said grid includes reflective segments on a substrate. ### Claim 10 (depends on 1) The method of claim 1 wherein said grid includes at least one scattering mark on a transmissive surface. ### Claim 11 (depends on 1) The method of claim 1 wherein said raster scan system is a lithographic system. ### Claim 12 (depends on 1) The method of claim 1 wherein said raster scan system is a metrologic system. ### Claim 13 A method of electronically measuring parameters of a beam in a raster scan system comprising the steps of: (a) choosing a predetermined plurality of pixels of said raster scan to be calibrated; (b) moving at least one reflective mark adjacent said plurality of pixels; (c) strobing said beam; (d) incrementally moving said beam toward said at least one reflective mark; (e) integrating the signal resulting from said beam as said beam moves toward said at least one reflective mark; and (f) repeating steps (c) through (e) until said beam crosses said at least one reflective mark. ### Claim 14 (depends on 13) The method of claim 13 wherein said plurality of pixels are contiguous. ### Claim 15 (depends on 13) The method of claim 13 wherein said beam includes a plurality of beam fingers linearly positioned. ### Claim 16 (depends on 13) The method of claim 13 wherein said at least one reflective mark includes a plurality of reflective segments. ### Claim 17 (depends on 13) The method of claim 13 wherein said raster scan system is a lithographic system. ### Claim 18 (depends on 13) The method of claim 13 wherein said raster scan system is a metrologic system. ### Claim 19 A method of electronically measuring parameters of a beam in a raster scan system comprising the steps of: (a) choosing a predetermined plurality of pixels of said raster scan to be calibrated; (b) moving at least one scattering mark on a transmissive surface adjacent said plurality of pixels; (c) strobing said beam; (d) incrementally moving said beam toward said at least one scattering mark; (e) integrating the signal resulting from said beam as said beam moves toward said at least one scattering mark; and (f) repeating steps (c) through (e) until said beam crosses said at least one scattering mark. ### Claim 20 (depends on 19) The method of claim 19 wherein said plurality of pixels are contiguous. ### Claim 21 (depends on 19) The method of claim 19 wherein said beam includes a plurality of beam fingers linearly positioned. ### Claim 22 (depends on 19) The method of claim 19 wherein said at least one scattering mark includes a plurality of scattering segments. ### Claim 23 (depends on 19) The method of claim 19 wherein said raster scan system is a lithographic system. ### Claim 24 A method of electronically measuring parameters of a beam in a vector scan system comprising the steps of: (a) choosing an origin position and a destination position on said vector scan; (b) moving said beam between said origin position and said destination position; (c) unblanking said beam at a predetermined time delay during step (b); (d) repeating steps (b) and (c) for N times, where N is a predetermined integer; (e) incrementally increasing the value of said predetermined time delay; and (f) repeating steps (b) through (e) until said beam has settled at said destination position. ### Claim 25 (depends on 24) The method of claim 24 wherein said vector scan system is a lithographic system. ### Claim 26 A system for electronically measuring beam parameters for substrate patterning comprising: means for positioning said substrate; a detector secured to said means for positioning; a grid positioned over said detector; a charge amplifier coupled to said detector; and means for transferring a signal from said charge amplifier to said means for positioning. ### Claim 27 (depends on 26) The system of claim 26 wherein said charge amplifier comprises: an operational amplifier; a capacitive element coupled in parallel with said operational amplifier; means for switching coupled in parallel with said operational amplifier; an offset adjust coupled in series with said means for switching; and a slope fine adjust coupled between said offset adjust and said means for switching. ### Claim 28 (depends on 27) The system of claim 27 wherein said detector is coupled to the inverting input terminal of said operational amplifier. ### Claim 29 (depends on 28) The system of claim 28 wherein a first voltage source is coupled to the non-inverting input terminal of said operational amplifier. ### Claim 30 (depends on 29) The system of claim 29 wherein said offset adjust and said slope fine adjust are coupled to said inverting input terminal of said operational amplifier. ### Claim 31 (depends on 26) The system of claim 26 wherein said system is a lithographic system. ### Claim 32 (depends on 26) The system of claim 26 wherein said system is a metrologic system. ### Claim 33 A system for electronically measuring parameters of a beam comprising: a substrate having a reflective mark thereon; a detector positioned over said substrate; a charge amplifier coupled to said detector; means for positioning said substrate; and means for transferring a signal from said charge amplifier to said means for positioning. ### Claim 34 (depends on 33) The system of claim 33 wherein said system is a lithographic system. ### Claim 35 (depends on 33) The system of claim 33 wherein said system is a metrologic system. ### Claim 36 A system for electronically measuring parameters of a beam comprising: a transmissive surface having a scattering mark thereon; a detector positioned under said surface; a charge amplifier coupled to said detector; means for positioning said surface; and means for transferring a signal from said charge amplifier to said means for positioning. ### Claim 37 (depends on 36) The system of claim 36 wherein said system is a lithographic system. ### Claim 38 (depends on 36) The system of claim 36 wherein said system is a metrologic system.