# US 9,715,995 B1 · Apparatus and methods for electron beam lithography using array cathode > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,715,995 B1 - Document ID: US9715995B1 - Status: Granted - Kind: B1 - Application number: 14/542,105 - Filed: 2014-11-14 - Granted: 2017-07-25 - Earliest claimed: 2010-07-30 - Assignees: KLA-Tencor Corporation - Applicants: KLA-Tencor Corporation - Inventors: Keith Standiford; Alan D. Brodie; Paul F. Petric - Web page: https://patentgrep.com/patent/US9715995B1 ## CPC - H01J 37/3177: {Multi-beam, e.g. fly's eye, comb probe} - H01J 37/073: Electron guns using field emission, photo emission, or secondary emission electron sources - H01J 2237/31766: Continuous moving of wafer - H01J 2237/31774: Multi-beam - H01J 2237/31781: from patterned cold cathode - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) ## Abstract One embodiment relates to an apparatus for electron beam lithography. The apparatus includes an array of cold cathode electron sources for generating an array of electron beams, and driver circuitry underlying the array of electron sources. The driver circuitry is configured to selectively blank individual electron beams so as to create a patterned array of electron beams. The apparatus further includes an imaging system configured to focus and demagnify the patterned array of electron beams and a movable stage for holding a target substrate. The movable stage is configured to translate the target substrate under the patterned array of electron beams. A computer may be configured to send drive signals to the driver circuitry to cause a pattern to be written onto the target substrate to roll across the array in synchronization with the translation of the target substrate. Other embodiments, aspects and feature are also disclosed. ## Claims ### Claim 1 An apparatus for electron beam lithography comprising: an electron beam column including an array of cold cathode electron sources for generating an array of electron beams; driver circuitry underlying the array of cold cathode electron sources, the driver circuitry being configured to selectively blank individual electron beams in the array of electron beams so as to create a patterned array of electron beams; an imaging system configured to focus and demagnify the patterned array of electron beams; and a target substrate held on a movable stage, wherein the movable stage is configured to translate the target substrate under the patterned array of electron beams, wherein a pattern is written onto an area of the target substrate in first and second passes of the target substrate under the electron beam column, wherein a grid of pixels for the first pass is a rectangular grid that has a horizontal spacing between adjacent pixel positions in the horizontal direction and a vertical spacing between adjacent pixel positions in the vertical direction, and wherein a grid of pixels of the second pass is offset from the grid of pixels of the first pass by half the horizontal spacing in the horizontal direction and by half the vertical spacing in the vertical direction. ### Claim 2 (depends on 1) The apparatus of claim 1, further comprising: a computer coupled to the driver circuitry, wherein drive signals sent by the computer to the driver circuitry causes pixels to be written onto the target substrate to roll across the array in synchronization with the translation of the target substrate. ### Claim 3 (depends on 1) The apparatus of claim 1, further comprising: a sidewall surrounding each cold cathode electron source in the array. ### Claim 4 (depends on 3) The apparatus of claim 3, further comprising: a plurality of conductive layers in each sidewall; and a plurality of insulative layers in each sidewall, wherein the conductive and insulative layers alternate. ### Claim 5 (depends on 3) The apparatus of claim 3, wherein voltages are applied to the conductive layers in a sidewall of an electron source so as to create a crossover in an electron beam generated by the electron source. ### Claim 6 (depends on 5) The apparatus of claim 5, wherein the imaging system is configured to image the crossover onto a surface of the target substrate. ### Claim 7 (depends on 1) The apparatus of claim 1, wherein the cold cathode electron sources comprise ballistic electron emitters. ### Claim 8 (depends on 7) The apparatus of claim 7, wherein the ballistic electron emitters include a diamond coating. ### Claim 9 A method of electron beam lithography, the method comprising: generating an array of electron beams using an electron beam column with an array of cold cathode electron sources; selectively blank individual electron beams in the array of electron beams using driver circuitry underlying the array of cold cathode sources so as to create a patterned array of electron beams; focusing and demagnifying the patterned array of electron beams using an imaging system; and performing multiple passes of translating a target substrate under the patterned array of electron beams using a movable stage holding the target substrate, wherein a pattern is written onto an area the target substrate in first and second passes of the target substrate under the electron beam column, wherein a grid of pixels for the first pass is a rectangular grid that has a horizontal spacing between adjacent pixel positions in the horizontal direction and a vertical spacing between adjacent pixel positions in the vertical direction, and wherein a grid of pixels of the second pass is offset from the grid of pixels of the first pass by half the horizontal spacing in the horizontal direction and by half the vertical spacing in the vertical direction. ### Claim 10 (depends on 9) The method of claim 9, further comprising: sending drive signals by a computer to the driver circuitry to cause pixels to be written onto the target substrate to roll across the array in synchronization with the translation of the target substrate. ### Claim 11 (depends on 9) The method of claim 9, wherein each cold cathode electron source in the array is surrounded by a sidewall. ### Claim 12 (depends on 11) The method of claim 11, wherein the sidewall includes a plurality of conductive layers and a plurality of insulative layers in each sidewall, wherein the conductive and insulative layers alternate. ### Claim 13 (depends on 12) The method of claim 12, further comprising: applying voltages to the conductive layers in a sidewall of an electron source so as to create a crossover in an electron beam generated by the electron source. ### Claim 14 (depends on 13) The method of claim 13, further comprising: using the imaging system to image the crossover onto a surface of the target substrate. ### Claim 15 (depends on 9) The method of claim 9, wherein the cold cathode electron sources comprise ballistic electron emitters. ### Claim 16 (depends on 15) The method of claim 15, wherein the ballistic electron emitters include a diamond coating. ### Claim 17 A system for electron beam lithography comprising: an array of cold cathode electron sources for generating an array of electron beams; driver circuitry underlying the array of cold cathode electron sources, the driver circuitry being configured to selectively blank individual electron beams in the array of electron beams so as to create a patterned array of electron beams; an imaging system configured to focus and demagnify the patterned array of electron beams; a target substrate held on a movable stage, wherein the movable stage is configured to translate the target substrate under the patterned array of electron beams; and a computer coupled to the driver circuitry, wherein drive signals sent by the computer to the driver circuitry causes a pattern to be written onto the target substrate to roll across the array in synchronization with the translation of the target substrate, wherein the pattern is written onto an area of the target substrate in first and second passes of the target substrate under the electron beam column, wherein a grid of pixels for the first pass is a rectangular grid that has a horizontal spacing between adjacent pixel positions in the horizontal direction and a vertical spacing between adjacent pixel positions in the vertical direction, and wherein a grid of pixels of the second pass is offset from the grid of pixels of the first pass by half the horizontal spacing in the horizontal direction and by half the vertical spacing in the vertical direction. ### Claim 18 (depends on 17) The system of claim 17, wherein voltages are applied to the conductive layers in a sidewall of an electron source so as to create a crossover in an electron beam generated by the electron source, and wherein the imaging system is used to image the crossover onto a surface of the target substrate.