# US 10,319,559 B2 · Method and device for testing samples by means of an electron or ion beam microscope > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,319,559 B2 - Document ID: US10319559B2 - Status: Granted - Kind: B2 - Application number: 15/257,667 - Filed: 2016-09-06 - Published: 2017-06-01 - Granted: 2019-06-11 - Earliest claimed: 2015-09-04 - Applicants: Tim Dahmen; Niels de Jonge - Inventors: Tim Dahmen; Niels de Jonge - Web page: https://patentgrep.com/patent/US10319559B2 ## CPC - H01J 37/222: {Image processing arrangements associated with the tube} - H01J 37/10: Lenses - H01J 37/20: Means for supporting or positioning the object or the material; Means for adjusting diaphragms or lenses associated with the support - H01J 37/265: {Controlling the tube; circuit arrangements adapted to a particular application not otherwise provided, e.g. bright-field-dark-field illumination} - H01J 37/28: with scanning beams {(H01J37/268, H01J37/292, H01J37/2955 take precedence)} - H01J 2237/2611: Stereoscopic measurements and/or imaging - H01J 2237/2802: Transmission microscopes - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) ## Abstract The disclosed subject matter relates to testing a sample by means of a particle beam microscope in which the sample is scanned in a point-wise manner by a focused beam of charged particles thereby generating imaging signals. The particle beam dose applied per scanning point is changed during scanning. ## Claims ### Claim 1 A method for testing a sample, comprising: identifying a set of first sample points; impinging a focused beam of charged particles on the first sample points at a first dose level; detecting a set of first signal intensities induced by the impact of the focused beam of charged particles on the first sample points; from the set of first sample points, selecting a set of second sample points based on the first signal intensities; impinging the focused beam of charged particles on the second sample points at a second dose level; and detecting a set of second signal intensities induced by the impact of the focused beam of charged particles on the second sample points; wherein the second sample points correspond to first sample points having signal intensities that exhibit a gradient having a magnitude greater than a predetermined minimum gradient. ### Claim 2 (depends on 1) The method of claim 1, wherein the first dose level is higher than the second dose level. ### Claim 3 (depends on 1) The method of claim 1, further comprising generating an image based on the set of second signal intensities. ### Claim 4 (depends on 3) The method of claim 3, wherein the generated image is based on a combination of the first signal intensities and the second signal intensities. ### Claim 5 (depends on 1) The method of claim 1, wherein the first sample points and the second sample points are situated on a two-dimensional grid on the surface of the sample. ### Claim 6 (depends on 1) The method of claim 1, wherein the focused beam of charged particles comprises a focused beam of electrons. ### Claim 7 (depends on 1) The method of claim 1, wherein an inclination angle of the sample relative to the beam of charged particles is different at the first sample points than an inclination angle of the sample relative to the focused beam of charged particles at the second sample points. ### Claim 8 (depends on 1) The method of claim 1, further comprising: from the set of first sample points, selecting a set of third sample points based on the first signal intensities; impinging the focused beam of charged particles on the third sample points at a third dose level; and detecting a set of third signal intensities induced by the impact of the focused beam of charged particles on the third sample points. ### Claim 9 (depends on 8) The method of claim 8, further comprising generating an image based on a combination of the first signal intensities, the second signal intensities, and the third signal intensities. ### Claim 10 (depends on 8) The method of claim 8, wherein selecting the set of third sample points comprises selecting sample points of the first set of sample points having a gradient of first signal intensities below a predetermined gradient. ### Claim 11 (depends on 1) The method of claim 1, wherein selecting the set of second sample points comprises selecting first sample points based on gradients of the first signal intensities. ### Claim 12 A charged particle beam microscope, comprising: a lens system configured to focus a charged particle beam onto a sample; and one or more control units programmed to: identify a first set of sample points, each of the first set of sample points corresponding to first points on a surface of a sample; impinge the focused charged particle beam on the sample points of the first set of sample points at a first dose level; detect first signal intensities induced by the impact of the focused charged particle beam on the sample points of the first set of sample points; from the first set of sample points, select a second set of sample points based on the first signal intensities; impinge the focused charged particle beam on the sample points of the second set of sample points at a second dose level, wherein the first and second dose levels are different; and detect second signal intensities induced by the impact of the focused charged particle beam on the sample points of the second set of sample points, wherein the second set of sample points corresponds to sample points whose detected signal intensities exhibit at least a minimum gradient. ### Claim 13 (depends on 12) The charged particle beam microscope of claim 12, wherein the second dose level is higher than the first dose level. ### Claim 14 The charged particle beam microscope of claim-12, wherein the one or more control units are further programmed to generate an image based on the second signal intensities induced by the impact of the focused charged particle beam on the sample points of the second set of sample points. ### Claim 15 (depends on 12) The charged particle beam microscope of claim 12, wherein the one or more control units are further programmed to generate an image based on a combination of the first signal intensities and the second signal intensities. ### Claim 16 (depends on 12) The charged particle beam microscope of claim 12, wherein the source of charged particles is an electron source. ### Claim 17 (depends on 12) The charged particle beam microscope of claim 12, wherein the one or more control units are further programmed to: from the set of first set of sample points, select a set of third set of sample points having a gradient of first signal intensities below a predetermined gradient; impinge the focused charged particle beam on the sample points of the third set of sample points at a third dose level; and detect third signal intensities induced by the impact of the focused charged particle beam on the sample points of the third set of sample points. ### Claim 18 (depends on 17) The charged particle beam microscope of claim 17, wherein the one or more control units are further programmed to generate an image based on a combination of the first signal intensities, the second signal intensities, and the third signal intensities. ### Claim 19 (depends on 12) The charged particle beam microscope of claim 12, wherein selecting the set of second sample points comprises selecting first sample points having a gradient of first signal intensities at least at a predetermined gradient. ### Claim 20 A method for testing a sample comprising: identifying a set of first sample points; impinging a focused beam of charged particles on the first sample points at a first dose level; detecting a set of first signal intensities induced by the impact of the focused beam of charged particles on the first sample points; from the set of first sample points, selecting a set of second sample points based on the first signal intensities; impinging the focused beam of charged particles on the second sample points at a second dose level; and detecting a set of second signal intensities induced by the impact of the focused beam of charged particles on the second sample points; wherein an inclination angle of the sample relative to the beam of charged particles is different at the first sample points than an inclination angle of the sample relative to the focused beam of charged particles at the second sample points. ### Claim 21 A method for testing a sample, comprising: identifying a set of first sample points; impinging a focused beam of charged particles on the first sample points at a first dose level; detecting a set of first signal intensities induced by the impact of the focused beam of charged particles on the first sample points; from the set of first sample points, selecting a set of second sample points based on the first signal intensities; impinging the focused beam of charged particles on the second sample points at a second dose level; detecting a set of second signal intensities induced by the impact of the focused beam of charged particles on the second sample points; and generating an image based on the set of second signal intensities, wherein the generated image is based on a combination of the first signal intensities and the second signal intensities. ### Claim 22 A method for testing a sample, comprising: identifying a set of first sample points; impinging a focused beam of charged particles on the first sample points at a first dose level; detecting a set of first signal intensities induced by the impact of the focused beam of charged particles on the first sample points; from the set of first sample points, selecting a set of second sample points based on the first signal intensities; impinging the focused beam of charged particles on the second sample points at a second dose level; detecting a set of second signal intensities induced by the impact of the focused beam of charged particles on the second sample points, wherein the first sample points and the second sample points are situated on a two-dimensional grid on the surface of the sample. ### Claim 23 A method for testing a sample, comprising: identifying a set of first sample points; impinging a focused beam of charged particles on the first sample points at a first dose level; detecting a set of first signal intensities induced by the impact of the focused beam of charged particles on the first sample points; from the set of first sample points, selecting a set of second sample points based on the first signal intensities; impinging the focused beam of charged particles on the second sample points at a second dose level; detecting a set of second signal intensities induced by the impact of the focused beam of charged particles on the second sample points, wherein an inclination angle-of the sample relative to the beam of charged particles is different at the first sample points than an inclination angle of the sample relative to the focused beam of charged particles at the second sample points. ### Claim 24 A charged particle beam microscope, comprising: a lens system configured to focus a charged particle beam onto a sample; and one or more control units programmed to: identify a first set of sample points, each of the first set of sample points corresponding to first points on a surface of a sample; impinge the focused charged particle beam on the sample points of the first set of sample points at a first dose level; detect first signal intensities induced by the impact of the focused charged particle beam on the sample points of the first set of sample points; from the first set of sample points, select a second set of sample points based on the first signal intensities; impinge the focused charged particle beam on the sample points of the second set of sample points at a second dose level, wherein the first and second dose levels are different; detect second signal intensities induced by the impact of the focused charged particle beam on the sample points of the second set of sample points, and generate an image based on a combination of the first signal intensities and the second signal intensities. ### Claim 25 A charged particle beam microscope, comprising: a lens system configured to focus a charged particle beam onto a sample; and one or more control units programmed to: identify a first set of sample points, each of the first set of sample points corresponding to first points on a surface of a sample; impinge the focused charged particle beam on the sample points of the first set of sample points at a first dose level; detect first signal intensities induced by the impact of the focused charged particle beam on the sample points of the first set of sample points; from the first set of sample points, select a second set of sample points based on the first signal intensities; impinge the focused charged particle beam on the sample points of the second set of sample points at a second dose level, wherein the first and second dose levels are different; detect second signal intensities induced by the impact of the focused charged particle beam on the sample points of the second set of sample points from the set of first set of sample points; select a set of third set of sample points having a gradient of first signal intensities below a predetermined gradient; impinge the focused charged particle beam on the sample points of the third set of sample points at a third dose level; and detect third signal intensities induced by the impact of the focused charged particle beam on the sample points of the third set of sample points.