# US 12,469,676 B2 · In-situ etch rate or deposition rate measurement system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,469,676 B2 - Document ID: US12469676B2 - Status: Granted - Kind: B2 - Application number: 17/800,565 - Filed: 2021-02-03 - Published: 2023-05-04 - Granted: 2025-11-11 - Earliest claimed: 2020-02-20 - Assignees: BüHler Alzenau GmbH - Applicants: BüHler Alzenau GmbH - Inventors: Steffen Guertler; Mario Berlinger; Ralf Sperling - Web page: https://patentgrep.com/patent/US12469676B2 ## CPC - H01J 37/304: Controlling tubes by information coming from the objects {or from the beam}, e.g. correction signals - G01B 11/0675: {using interferometry} - G01B 11/0683: {measurement during deposition or removal of the layer} - H01J 37/226: {Optical arrangements for illuminating the object; optical arrangements for collecting light from the object} - H01J 37/3053: {for evaporating or etching} - H01J 2237/30466: Detecting endpoint of process - H01J 2237/3151: Etching - H01J 2237/31749: Focused ion beam - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) - G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS ## Abstract A system is provided for in-situ ion beam etch rate or deposition rate measurement, including: a vacuum chamber; an ion beam source configured to direct an ion beam onto a first surface of a sample located within the vacuum chamber and to etch the first surface of the sample with an etch rate; or a material source configured to deposit material onto a first surface of a sample located within the vacuum chamber with a deposition rate; and an interferometric measurement device located at least partially within the vacuum chamber and configured to direct light onto a second surface of the sample and to determine the etch rate of the ion beam or the deposition rate of the deposited material in-situ based on light reflected from the sample. ## Claims ### Claim 1 System for in-situ ion beam etch rate or a deposition rate measurement, comprising: a vacuum chamber; an ion beam source configured to direct an ion beam onto a first surface of a sample located within the vacuum chamber and to etch the first surface of the sample with an etch rate; or a material source (111a) configured to deposit material onto a first surface of a sample located within the vacuum chamber with a deposition rate; and an interferometric measurement device located at least partially within the vacuum chamber and configured to direct light onto a second surface of the sample and to determine the etch rate of the ion beam or the deposition rate of the deposited material in-situ based on light reflected from the sample. ### Claim 2 (depends on 1) The system of claim 1, wherein the interferometric measurement device is configured to determine the etch rate while etching the first surface of the sample or to determine the deposition rate while depositing the material onto the first surface of the sample. ### Claim 3 (depends on 1) The system of claim 1, wherein the etch rate is the amount of material removed from the sample's first surface over time and the deposition rate is the amount of material deposited onto the sample's first surface over time. ### Claim 4 (depends on 1) The system of claim 1, wherein the interferometric measurement device is a high precision optical low-coherence interferometer, HP-OLCI. ### Claim 5 (depends on 1) The system of claim 1, wherein the second surface of the sample is opposite the first surface of the sample. ### Claim 6 (depends on 1) The system of claim 1, wherein the interferometric measurement device is configured to determine the thickness of the sample over time and to determine the etch rate or the deposition rate based on the thickness variation of the sample over time. ### Claim 7 (depends on 1) The system of claim 1, wherein the interferometric measurement device comprises a sensor configured to direct the light onto the second surface of the sample and to collect light reflected back from the sample. ### Claim 8 (depends on 7) The system of claim 7, wherein the sensor comprises optical components to direct the light onto the second surface of the sample and to collect light reflected back from the sample and preferably wherein the sensor is located within the vacuum chamber and preferably wherein the sensor comprises the sample. ### Claim 9 (depends on 8) The system of claim 8, wherein the sensor comprises a housing and wherein the sample is located inside the housing and preferably wherein the housing comprises an opening and the sample is located at the opening such that the ion beam can reach the sample's first surface through the opening. ### Claim 10 (depends on 9) The system of claim 9, wherein the housing comprises a graphite outer surface. ### Claim 11 (depends on 1) The system of claim 1, wherein the interferometric measurement device comprises a cooling device in contact with the sample and configured to cool the sample. ### Claim 12 (depends on 1) The system of claim 1, wherein the interferometric measurement device comprises a positioning device configured to position the light at at least one predetermined location onto the second surface of the sample and preferably wherein the system further comprises a controller configured to control the positioning device to position the light at the second surface of the sample at a location corresponding to the center of the ion beam to determine a peak etch rate of the ion beam. ### Claim 13 (depends on 12) The system of claim 12, further comprising a controller configured to control the positioning device to position the light at the second surface of the sample at a plurality of locations corresponding to locations within the ion beam profile to determine an etch rate of the ion beam profile. ### Claim 14 (depends on 1) The system of claim 1, further comprising an alignment device configured to align the ion beam with respect to the first surface of the sample, wherein the alignment device preferably comprises a Faraday cup and a position camera or a characterization device configured to characterize the ion beam by a point-scan and calculate the offset to an initial start point. ### Claim 15 Method for in-situ ion beam etch rate or deposition rate measurement, wherein the method comprises: directing an ion beam onto a first surface of a sample located within a vacuum chamber to etch the first surface of the sample with an etch rate; or depositing material onto a first surface of a sample located within the vacuum chamber with a deposition rate; directing light of an interferometric measurement device located at least partially within the vacuum chamber onto a second surface of the sample; and determining the etch rate of the ion beam or the deposition rate of the deposited material in-situ based on light reflected from the sample.