# US 10,371,579 B1 · Black silicon blackbody calibration target > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,371,579 B1 - Document ID: US10371579B1 - Status: Granted - Kind: B1 - Application number: 15/386,821 - Filed: 2016-12-21 - Granted: 2019-08-06 - Earliest claimed: 2016-12-21 - Assignees: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration - Applicants: The United States of America as Represented by the Administrator of NASA - Inventors: William R. Johnson; Karl Y. Yee; Simon J. Hook - Web page: https://patentgrep.com/patent/US10371579B1 ## CPC - G01J 5/53: Reference sources, e.g. standard lamps; Black bodies - G01J: MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY (light sources F21, H01J, H01K, H05B; investigating properties of materials by optical means G01N) ## Abstract The disclosure is directed to a blackbody calibration target having a textured silicon substrate comprising a base comprising a plurality of needle like structures extending away from the base and having a total emissivity of greater than 99.5% from an electromagnetic radiation source having a wavelength greater than or equal to about 400 nanometers and less than or equal to about 1 mm. The disclosure is further directed to a blackbody calibration target system, and instrument which includes the blackbody calibration target, and a method of calibrating an instrument. ## Claims ### Claim 1 A blackbody calibration target comprising: a textured silicon substrate comprising a base comprising a plurality of needle like structures extending away from the base, wherein the textured silicon substrate has a total emissivity of greater than 99.5% from an electromagnetic radiation source having a wavelength greater than or equal to 400 nanometers and less than or equal to 1 millimeter. ### Claim 2 (depends on 1) The blackbody calibration target of claim 1, having a total emissivity of greater than 99.5% from an electromagnetic radiation source having a wavelength of greater than or equal to 700 nanometers and less than or equal to 20 micrometers. ### Claim 3 (depends on 1) The blackbody calibration target of claim 1, wherein the needle like structures are present on at least a portion of the base at a density of greater than or equal to 40,000 needle like structures per square millimeter. ### Claim 4 (depends on 1) The blackbody calibration target of claim 1, wherein the silicon substrate comprises monocrystalline silicon, polycrystalline silicon, amorphous silicon, or a combination thereof. ### Claim 5 (depends on 1) The blackbody calibration target of claim 1, wherein the silicon substrate further comprises at least one additional element selected from Groups 13 to 16 of the periodic table, present in an amount sufficient to produce a resistivity in the silicon substrate of less than or equal to 1 ohm-cm. ### Claim 6 (depends on 1) The blackbody calibration target of claim 1, wherein the plurality of needle like structures extend away from the base to an average height from the base of greater than or equal to 1 micrometer determined perpendicular to the base, and have an average width of less than or equal to 1 micrometer determined at an average midpoint height of the structures parallel to the base. ### Claim 7 (depends on 6) The blackbody calibration target of claim 6, wherein the needle like structures have an average height from the base of less than or equal to 50 micrometers. ### Claim 8 (depends on 1) The calibration target of claim 1, wherein the plurality of needle like structures extending away from the base are produced by contacting a surface of the silicon substrate with an inductively coupled plasma comprising SF6 and O2 gas, without a mask, at a forward power, a temperature, a pressure and for a period of time sufficient to etch the surface to produce the plurality of needle like structures extending away from the base. ### Claim 9 (depends on 8) The blackbody calibration target of claim 8, wherein the temperature is less than or equal to −120° C. ### Claim 10 (depends on 1) The calibration target of claim 1, comprising a plurality of the textured substrates fitted together. ### Claim 11 (depends on 10) The calibration target of claim 10, wherein a first textured substrate has different emissivity properties than a second textured substrate. ### Claim 12 A blackbody calibration system comprising a blackbody calibration target in thermal communication with a controlled temperature source, the blackbody calibration target comprising a textured silicon substrate comprising a base comprising a plurality of needle like structures extending away from the base, wherein the textured silicon substrate has a total emissivity of greater than 99.5% from an electromagnetic radiation source having a wavelength greater than or equal to 400 nanometers and less than or equal to 1 millimeter. ### Claim 13 (depends on 12) The blackbody calibration system of claim 12, wherein the plurality of needle like structures extend away from the base to an average height from the base of greater than or equal to 1 micrometer and less than or equal to 50 micrometers, determined perpendicular to the base, and have an average width of less than or equal to 1 micrometer determined at an average midpoint height of the structures parallel to the base. ### Claim 14 (depends on 12) The blackbody calibration system of claim 12, wherein the needle like structures are present on at least a portion of the base at a density of greater than or equal to 40,000 needle like structures per square millimeter. ### Claim 15 (depends on 12) The blackbody calibration system of claim 12, wherein the silicon substrate further comprises at least one additional element selected from Groups 13 to 16 of the periodic table present in an amount sufficient to produce a resistivity in the silicon substrate of less than or equal to 1 ohm-cm. ### Claim 16 (depends on 12) The blackbody calibration system of claim 12, wherein the plurality of needle like structures extending away from the base are produced by contacting a surface of the silicon substrate with an inductively coupled plasma comprising SF6 and O2 gas, without a mask, at a forward power, a temperature, a pressure and for a period of time sufficient to etch the surface to produce the plurality of needle like structures extending away from the base, wherein the temperature is less than or equal to −120° C. ### Claim 17 An instrument comprising: an electromagnetic radiation source in optical communication with a detector along an optical path; and a blackbody calibration system arrangable within the optical path, wherein the blackbody calibration system comprises a blackbody calibration target in thermal communication with a controlled temperature source, the blackbody calibration target comprising a textured silicon substrate comprising a base comprising a plurality of needle like structures extending away from the base to an average height of greater than or equal to about 1 micrometer and less than or equal to 50 micrometers, determined perpendicular to the base, and having an average width of less than or equal to about 1 micrometer determined at an average midpoint height of the structures parallel to the base, the blackbody calibration target having a total emissivity of greater than 99.5% at a wavelength greater than or equal to 400 nanometers an less than or equal to about 1 millimeter.