Method for separating specimen and method for analyzing the specimen separated by the specimen separating method

{
  "publication_number": "US5270552A",
  "country": "US",
  "kind": "A",
  "title": "Method for separating specimen and method for analyzing the specimen separated by the specimen separating method",
  "abstract": "When a desired portion is separated from an integrated circuit chip or a semiconductor wafer, the portion is separated without dividing the chip or the wafer, so that the separated specimen can be moved to a desired position, and the separated specimen can be set to a desired attitude. Therefore, various analyses on the specimen through TEM, SEM, SIMS and so on can be carried out. A minute piece of specimen is cut and separated from the substrate of a specimen by use of a three-dimensional minute processing technique and a micro-manipulation technique. A surface of the specimen is subjected to an FIB processing from at least two kinds of angles, the separated specimen being mechanically connected to an external probe in a step for separating a part of the specimen including a portion to be analyzed. The separated specimen is supported by the probe, being moved. The separated specimen is subjected to analysis through TEM, SEM, SIMS, etc.",
  "claims": [
    "1. A method for separating a minute portion from a specimen, comprising the steps of: irradiating a surface of the specimen with focused ion beams from at least two different directions so that the specimen is subjected to focused ion beam processing; connecting a probe with a portion of said specimen to be separated before said portion is separated from said specimen; and separating said portion from said specimen, while said separated portion of said specimen is supported by said probe.",
    "2. A method for separating a specimen according to claim 1, wherein said portion of said specimen and said probe are connected through a redeposition film of sputtering particles produced through the focused ion beam processing.",
    "3. A method for separating a specimen according to claim 1, wherein said portion of said specimen and said probe are connected through a beam induced deposition film formed by focused ion beam irradiation in a gas atmosphere.",
    "4. A method for separating a specimen according to any one of claims 1 through 3, wherein said focused ion beam processing is etching supported by a reactive gas atmosphere.",
    "5. A method for separating a specimen according to claim 1, wherein said specimen s a semiconductor wafer.",
    "6. A method for separating a specimen according to claim 1, wherein said probe includes a holder section having a thickness not thinner than 50 μm, and a probe head provided on one surface of said holder section, said probe head being projected from the top end of said holder section, said probe head having a thickness not thicker than 10 μm.",
    "7. A method for separating a specimen according to claim 6, wherein said probe is manufactured by use of a semiconductor manufacturing process.",
    "8. A method for separating a specimen according to any one of claims 1 through 3, wherein the contact between said portion of said specimen and said probe is judged by a change in luminance of an image of secondary particles in the vicinity of said portion to be separated from said specimen.",
    "9. A specimen analysis method for separating a minute portion from the specimen and for analyzing the minute portion, comprising the steps of: irradiating a surface of the specimen with focused ion beams from at least two different directions so that the specimen is subjected to focused ion beam processing; connecting a probe with a portion of said specimen to be separated before said portion is separated from said specimen; separating said portion from said specimen, while said separated portion of said specimen is supported by said probe; and observing a sectional image of said separated portion of said specimen, by use of an observation means, in a state where said separated portion of said specimen is being supported by said probe.",
    "10. A specimen analysis method for separating a minute portion from the specimen and for analyzing the minute portion, comprising the steps of: irradiating a surface of the specimen with focused ion beams from at least two different directions so that the specimen is subjected to focused ion beam processing; connecting a probe with a portion of said specimen to be separated before said portion is separated from said specimen; separating said portion from said specimen, while said separated portion of said specimen is supported by said probe; partially thinning said portion of said specimen during or after separation of said portion from said specimen; and observing said thinned portion by use of a transmission electron microscope.",
    "11. A specimen analysis method for separating a minute portion from the specimen and for analyzing the minute portion, comprising the steps of: irradiating a surface of the specimen with focused ion beams from at least two different directions so that the specimen is subjected to focused ion beam processing; connecting a probe with a portion of said specimen to be separated before said portion is separated from said specimen; separating said portion from said specimen, while said separated portion of said specimen is supported by said probe; and obtaining component information of said separated portion of said specimen through secondary ion analysis, in a state where said separated portion of said specimen is being supported by said probe.",
    "12. A method for separating a minute portion from a specimen, comprising the steps of: irradiating a surface of the specimen with a focused ion beam substantially perpendicularly to said surface, said focused ion beam being rectangularly scanned in the vicinity of a portion to be separated from said specimen to form a hole having a predetermined depth; tilting said surface of the specimen relative to an irradiation axis of said focused ion beam with an angle less the 90 degrees, and irradiation a side portion of said specimen forming said hole with the focused ion beam in order to form a bottom hole substantially parallel to the surface of said portion to be separated; irradiation said surface of the specimen with said focused ion beam substantially perpendicularly to said surface, and scanning said focused ion beam along a circumferential portion to be separated so as to form trenches along said circumferential portion; contacting a top portion of a probe of a manipulator with the surface of said portion to be separated; connecting said top portion of said probe to the surface of said portion to be separated; irradiating said surface of said specimen with said focused ion beam substantially perpendicularly to said surface, and scanning said focused ion beam along said circumferential portion to be separated so as to form a notched groove along said circumferential portion to separate said portion from said specimen; and moving said separated portion connected to said top portion of said probe to a predetermined position by said manipulator.",
    "13. A method for separating a specimen according to claim 12, wherein said portion of said specimen and said top portion of said probe are connected through a beam induced deposition film formed by the focused ion beam irradiation in a gas atmosphere.",
    "14. A method for separating a specimen according to claim 12, wherein said probe is made of an electrically conductive material, being connected to a power supply through a high resistance, and wherein it is determined from a change of electric potential of said specimen whether said top portion of said probe is contacted with said portion to be separated or not."
  ],
  "description_excerpt": "The present invention relates to a method for separating a specimen and a method for analyzing the separated specimen, and particularly relates to a method for separating a minute region from the substrate of a specimen such as a semiconductor wafer, and an analysis method using the separating method.\n\nAs a conventional technique of such a separating method, there has been a technique disclosed in \"Microscopy of Semiconducting Materials Conference, Oxford, (1989), pp. 501-506\". In this document, there is a description about an example in which a thin film specimen analyzed through a transmission electron microscope (hereinafter abbreviated to \"TEM\") is cut out by use of a focused ion beam (hereinafter abbreviated to \"FIB\").\n\nAccording to the contents of disclosure in the above document, a chip 71 having a length of several mm and a width of 100-500 μm is cut out from a semiconductor integrated circuit by use of a diamond wafering saw, being fixedly mounted on a copper grid 72 (standard grid of the TEM for observing the chip), as shown in FIG. 7. Then the chip 71 is processed by the FIB to be formed into a thin film specimen 73. Then the thin film specimen 73 is irradiated with an electron beam 74, being observed by use of the TEM. In FIG. 7, the reference numeral 75 represents a rectangular opening.\n\nAs another conventional technique, there has been a technique disclosed in \"Proceedings of International Reliability Physics Symposium, (1989), pp. 43-52\".",
  "cpc": [
    "H01J 37/3056",
    "G01N 23/2202",
    "H01J 2237/2007",
    "H01J 2237/20264",
    "H01J 37/20",
    "H01J 37/31"
  ],
  "ipc": [
    "G01N 1/28",
    "G01N 23/22",
    "H01J 37/20",
    "H01J 37/305",
    "H01J 37/31"
  ],
  "assignees": [
    "Hitachi Ltd"
  ],
  "inventors": [
    "Tsuyoshi Ohnishi",
    "Tohru Ishitani"
  ],
  "filing_date": "1992-08-21",
  "publication_date": "1993-12-14",
  "grant_date": "1993-12-14",
  "priority_date": "1991-08-22",
  "application_number": "US-93323292-A",
  "family_id": "16595397",
  "cited_by_count": 247,
  "citations": [
    "US5086230A",
    "US4939364A",
    "US5093572A",
    "US5149973A"
  ]
}