# US 2014/0190934 A1 · Method for preparing samples for imaging > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0190934 A1 - Document ID: US20140190934A1 - Status: Published application - Kind: A1 - Application number: 14/144,902 - Filed: 2013-12-31 - Published: 2014-07-10 - Earliest claimed: 2011-06-03 - Assignees: FEI Company - Applicants: FEI Company - Inventors: Michael Schmidt; Jeffrey Blackwood; Stacey Stone; Sang Hoon Lee; Ronald Kelley - Web page: https://patentgrep.com/patent/US20140190934A1 ## CPC - G01N 1/32: Polishing; Etching - G01N 1/286: {involving mechanical work, e.g. chopping, disintegrating, compacting, homogenising (microtomes G01N1/06; pulverising in general B02C; mixing in general B01F)} - H01J 37/3056: {for microworking, e. g. etching of gratings or trimming of electrical components} - G01N 2001/2886: {Laser cutting, e.g. tissue catapult} - H01J 2237/31745: for preparing specimen to be viewed in microscopes or analyzed in microanalysers - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) ## Abstract A method and apparatus is provided for preparing samples for observation in a charged particle beam system in a manner that reduces or prevents artifacts. Material is deposited onto the sample using charged particle beam deposition just before or during the final milling, which results in an artifact-free surface. Embodiments are useful for preparing cross sections for SEM observation of samples having layers of materials of different hardnesses. Embodiments are useful for preparation of thin TEM samples. ## Claims ### Claim 1 A method of preparing a sample for analysis, the method comprising: directing an ion beam toward a work piece to remove material and expose a surface, the exposed surface having irregularities; depositing material on the exposed surface, the deposited material smoothing the irregularities; and directing an ion beam toward the work piece to remove at least some deposited materials and some material from the exposed surface to produce a smooth surface. ### Claim 2 (depends on 1) The method of claim 1 in which the sample material is a porous material. ### Claim 3 (depends on 1) The method of claim 1 in which the deposited material is formed by the dissociation of a precursor material, and the precursor material is activated by exposing the exposed surface to electrons, ions, X-rays, light, heat, or microwave radiation, as a result of which the precursor material dissociates in a non-volatile part that forms the deposit and a volatile part. ### Claim 4 (depends on 1) The method of claim 1 further comprising depositing a protective layer onto the surface of the work piece using charged particle beam deposition. ### Claim 5 (depends on 1) The method of claim 1 in which directing an ion beam toward a work piece to remove material includes directing an ion beam perpendicular to the work piece surface. ### Claim 6 (depends on 1) The method of claim 1 in which depositing material on the exposed surface includes tilting the work piece and depositing the material using charged particle beam deposition. ### Claim 7 (depends on 1) The method of claim 1 in which directing an ion beam toward a work piece to remove material and expose a surface includes directing the ion beam using a first beam current and in which directing an ion beam toward the work piece to remove the deposited materials includes directing the ion beam using a second beam current, less than the first beam current. ### Claim 8 (depends on 1) The method of claim 1 in which directing an ion beam toward a work piece to remove material and expose a surface includes directing an ion beam from a plasma ion source, the ion beam having a beam current greater than 50 nA. ### Claim 9 (depends on 1) The method of claim 1 in which directing an ion beam toward a work piece to remove material includes cutting a trench to expose a cross section for observation by a scanning electron microscope. ### Claim 10 (depends on 1) The method of claim 1 in which directing an ion beam toward a work piece to remove material includes forming a lamella for observation on a transmission electron microscope. ### Claim 11 (depends on 1) The method of claim 1 in which directing an ion beam toward a work piece includes directing an ion beam toward a work piece composed of layers of materials of different hardnesses, the ion beam creating the irregularities in a softer layer after passing through harder layer. ### Claim 12 (depends on 1) The method of claim 1 in which directing an ion beam toward a work piece includes directing an ion beam toward a work piece composed of at least a layer of a metal and a layer of an oxide or nitride of the metal. ### Claim 13 (depends on 1) The method of claim 1 further comprising directing an ion beam toward a work piece to expose a second face depositing a layer of a material onto the exposed second sample face. ### Claim 14 An charged particle beam apparatus comprising: an ion source; a focusing column for focusing the ions onto a work piece in a sample vacuum chamber; a gas injection system for providing a precursor gas at the work piece surface; a controller for controlling the operation of the charged particle beam system in accordance with stored computer-readable instructions; and a computer readable memory storing computer instruction for controlling the charged particle beam system to: directing an ion beam toward a work piece to remove material and expose a surface, the exposed surface having irregularities; depositing material on the exposed surface, the deposited material smoothing the irregularities; directing an ion beam toward the work piece to remove the deposited materials and some material from the exposed surface to produce a smooth cross sectional face. ### Claim 15 (depends on 1) A non-transitory computer-readable storage medium configured with a computer program, where the storage medium so configured causes a computer to control a charged particle beam system to carry out the steps of the method of claim 1.