# US 12,224,155 B2 · Ion milling device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,224,155 B2 - Document ID: US12224155B2 - Status: Granted - Kind: B2 - Application number: 17/788,610 - Filed: 2019-12-24 - Published: 2022-11-17 - Granted: 2025-02-11 - Earliest claimed: 2019-12-24 - Assignees: Hitachi High-Tech Corporation - Applicants: Hitachi High-Tech Corporation - Inventors: Shota Aida; Hisayuki Takasu; Atsushi Kamino; Hitoshi Kamoshida - Web page: https://patentgrep.com/patent/US12224155B2 ## CPC - H01J 37/243: {Beam current control or regulation circuits (H01J37/241 takes precedence)} - H01J 37/3056: {for microworking, e. g. etching of gratings or trimming of electrical components} - H01J 37/20: Means for supporting or positioning the object or the material; Means for adjusting diaphragms or lenses associated with the support - H01J 2237/0213: Avoiding deleterious effects due to interactions between particles and tube elements - H01J 2237/20214: Rotation - H01J 2237/31745: for preparing specimen to be viewed in microscopes or analyzed in microanalysers - H01J 2237/31749: Focused ion beam - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) ## Abstract Provided is an ion milling apparatus capable of enhancing reproducibility of an ion distribution. The ion milling apparatus includes: an ion source 101; a sample stage 102 on which a sample to be processed by being irradiated with an unfocused ion beam from the ion source 101 is placed; and a measurement member holding unit 106 that holds an ion beam current measurement member 105. A covering material 120 is provided so as to cover at least a surface of the measurement member holding unit 106 and the sample stage 102 facing the ion source 101. A material of the covering material 120 contains, as a main component, an element having an atomic number smaller than that of an element of a material of a structure on which the covering material is provided. The ion beam current measurement member 105 is moved in an irradiation range of the ion beam on a trajectory, which is located between the ion source and the sample stage, in a state where the ion beam is output from the ion source 101 under a first irradiation condition, and an ion beam current flowing when the ion beam current measurement member 105 is irradiated with the ion beam is measured. ## Claims ### Claim 1 An ion milling apparatus comprising: an ion source; a sample stage on which a sample to be processed by being irradiated with an unfocused ion beam from the ion source is placed; a measurement member holding unit that holds a linear ion beam current measurement member extending in a first direction; and a control unit, wherein a covering material is provided so as to cover at least a surface of the measurement member holding unit and the sample stage facing the ion source, a material of the covering material contains, as a main component, an element having an atomic number smaller than that of an element of a material of a structure on which the covering material is provided, and the control unit is configured to move the ion beam current measurement member in an irradiation range of the ion beam on a trajectory, which is located between the ion source and the sample stage and extends in a second direction orthogonal to the first direction, in a state where the ion beam is output from the ion source under a first irradiation condition, and measure an ion beam current flowing through the ion beam current measurement member when the ion beam current measurement member is irradiated with the ion beam. ### Claim 2 (depends on 1) The ion milling apparatus according to claim 1, further comprising: a sample chamber, wherein the covering material is provided on an inner wall of the sample chamber facing the ion source. ### Claim 3 (depends on 1) The ion milling apparatus according to claim 1, wherein the covering material contains carbon as a main component. ### Claim 4 (depends on 1) The ion milling apparatus according to claim 1, further comprising: an electrode disposed in a vicinity of the trajectory, wherein the control unit is configured to measure the ion beam current in a state where a predetermined positive voltage is applied to the electrode. ### Claim 5 (depends on 4) The ion milling apparatus according to claim 4, wherein the control unit is configured to measure an ion beam profile indicating a relationship between the ion beam current and a position of the ion beam current measurement member when the ion beam current is measured. ### Claim 6 (depends on 5) The ion milling apparatus according to claim 5, wherein the control unit is configured to calculate a peak value and a half width of the ion beam profile. ### Claim 7 (depends on 5) The ion milling apparatus according to claim 5, further comprising: a sample chamber; and an ion source position adjustment mechanism disposed in the sample chamber, wherein the ion source is attached to the sample chamber via the ion source position adjustment mechanism, the ion source is a penning type ion source, and one or more of a discharge voltage of the ion source, and a gas flow rate or a working distance of the ion source are adjustable based on the ion beam profile. ### Claim 8 (depends on 4) The ion milling apparatus according to claim 4, wherein the electrode is disposed closer to the side of the sample stage than the trajectory and at a position where the ion beam current measurement member and the electrode overlap each other as viewed from the ion source when an ion beam center of the ion beam from the ion source and the ion beam current measurement member intersect each other. ### Claim 9 (depends on 4) The ion milling apparatus according to claim 4, wherein the electrode is graphite carbon. ### Claim 10 (depends on 4) The ion milling apparatus according to claim 4, wherein the electrode is disposed at a position closer to the side of ion source than the trajectory and not irradiated with the ion beam from the ion source. ### Claim 11 (depends on 10) The ion milling apparatus according to claim 10, wherein the electrode is copper or phosphor bronze, and the covering material is provided on the electrode. ### Claim 12 (depends on 4) The ion milling apparatus according to claim 4, wherein the sample stage is used as the electrode. ### Claim 13 (depends on 1) The ion milling apparatus according to claim 1, wherein the ion beam current measurement member is a linear material of graphite carbon whose cross section has a cylindrical shape and whose diameter is equal to or less than a half width of the ion beam.