# US 11,127,564 B2 · Scanning electron microscope with objective lens below sample stage > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,127,564 B2 - Document ID: US11127564B2 - Status: Granted - Kind: B2 - Application number: 16/743,250 - Filed: 2020-01-15 - Published: 2020-07-16 - Granted: 2021-09-21 - Earliest claimed: 2019-01-15 - Assignees: Kkt Holdings Syndicate - Applicants: KKT Holdings Syndicate - Inventors: Tzu-Yi Kuo; Yu-Kuang Tseng - Web page: https://patentgrep.com/patent/US11127564B2 ## CPC - H01J 37/28: with scanning beams {(H01J37/268, H01J37/292, H01J37/2955 take precedence)} - H01J 37/145: Combinations of electrostatic and magnetic lenses - H01J 37/1475: {magnetic} - H01J 37/20: Means for supporting or positioning the object or the material; Means for adjusting diaphragms or lenses associated with the support - H01J 37/244: Detectors; Associated components or circuits therefor - H10P 72/7624: {characterised by the mechanical construction of the susceptor, stage or support} - H01J 2237/047: Changing particle velocity - H01J 2237/04926: combined - H01J 2237/1035: Immersion lens - H01J 2237/1415: Bores or yokes, i.e. magnetic circuit in general - H01J 2237/20257: Magnetic coupling - H01J 2237/24475: Scattered electron detectors - H01J 2237/2511: Auger spectrometers - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 ## Abstract An immersion objective lens is configured below a stage such that multiple detectors can be configured above sample for large beam current application, particularly for defect inspection. Central pole piece of the immersion objective lens thus can be provided that a magnetic monopole-like field can be provided for electron beam. Auger electron detector thus can be configured to analyze materials of sample in the defect inspection. ## Claims ### Claim 1 A charged particle beam apparatus, comprising: a charged particle source for providing a charged particle beam; a condenser lens for condensing the charged particle beam; a scanning unit for scanning the charged particle beam on a sample; a stage including an electrostatic chuck for supporting the sample, a first mesa movable in a first direction, and a second mesa movable in a second direction, wherein the first direction is different from the second direction; a detector system for receiving signal particles from the sample after the charged particle beam impinges on the sample; and an objective lens, below said electrostatic chuck stage, including a central polepiece aligned to the charged particle beam for focusing the charged particle beam on the sample, wherein the central polepiece protrudes through the first mesa and the second mesa and is located below and adjacent to the electrostatic chuck. ### Claim 2 (depends on 1) The charged particle beam apparatus according to claim 1, wherein the charged particle source provides an electron beam. ### Claim 3 (depends on 2) The charged particle beam apparatus according to claim 2, wherein said stage is a maglev stage. ### Claim 4 (depends on 3) The charged particle beam apparatus according to claim 3, wherein said maglev stage includes a first mesa movable along a first direction horizontally, a second mesa movable along a second direction horizontally perpendicular to the first direction, and an electrostatic chuck on the second mesa. ### Claim 5 (depends on 4) The charged particle beam apparatus according to claim 4, wherein said first mesa and second mesa are vertically movable. ### Claim 6 (depends on 5) The charged particle beam apparatus according to claim 5, wherein the central polepiece protrudes to the sample. ### Claim 7 (depends on 6) The charged particle beam apparatus according to claim 6, wherein the signal particles includes secondary electrons (SE), backscattered electrons (BSE), and Auger electrons (AE). ### Claim 8 (depends on 7) The charged particle beam apparatus according to claim 7, wherein said detector system includes a SE detector, a BSE detector, and an AE detector for receiving secondary electrons, backscattered electrons, and Auger electrons respectively. ### Claim 9 (depends on 8) The charged particle beam apparatus according to claim 8, further comprising a booster inside the condenser lens to accelerate the electron beam. ### Claim 10 (depends on 9) The charged particle beam apparatus according to claim 9, further comprising a retard electrode above the sample to retard the electron beam. ### Claim 11 (depends on 10) The charged particle beam apparatus according to claim 10, further comprising a ferrite layer below said retard electrode to couple with a magnetic field generated by the objective lens. ### Claim 12 (depends on 11) The charged particle beam apparatus according to claim 11, further comprising a first Wien filter for filtering the secondary electrons into said SE detector, and a second Wien filter for filtering the backscattered electrons into said BSE detector. ### Claim 13 (depends on 12) The charged particle beam apparatus according to claim 12, further comprising a variable deflector around the central pole piece of the objective such that said objective lens is a variable axis lens. ### Claim 14 (depends on 13) The charged particle beam apparatus according to claim 13, wherein the variable axis lens is a moving objective lens. ### Claim 15 (depends on 14) The charged particle beam apparatus according to claim 14, further comprising a first deflector and a second deflector to move the electron beam along an axis of the moving objective lens. ### Claim 16 (depends on 13) The charged particle beam apparatus according to claim 13, wherein the variable axis lens is a swing objective lens. ### Claim 17 (depends on 16) The charged particle beam apparatus according to claim 16, further comprising a deflector to moving the electron beam along an axis of the swing objective lens. ### Claim 18 An electron beam apparatus, comprising: an electron source for providing an electron beam; a condenser lens for condensing the electron beam; a scanning unit for scanning the charged particle beam on a sample; a first objective lens below said condenser lens for focusing the electron beam; a maglev stage, below said first objective lens, including an electrostatic chuck for supporting the sample, a first mesa movable in a first direction, and a second mesa movable in a second direction, wherein the first direction is orthogonal to the second direction; a detector system for receiving signal electrons from the sample after the electron beam impinges on the sample; and a second objective lens, below said electrostatic chuck, including a central polepiece, aligned to the charged particle beam and protruding towards the sample, for focusing the electron beam on the sample, wherein the central polepiece protrudes through the first mesa and the second mesa and is located below and adjacent to the electrostatic chuck. ### Claim 19 (depends on 18) The electron beam apparatus according to claim 18, further comprising a retard electrode above the sample to retard the electron beam. ### Claim 20 (depends on 19) The electron beam apparatus according to claim 19, further comprising a ferrite layer below said retard electrode to couple with a magnetic field generated by the second objective lens.