# US 2010/0165340 A1 · Spectroscopic scatterometer system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2010/0165340 A1 - Document ID: US20100165340A1 - Status: Published application - Kind: A1 - Application number: 12/642,670 - Filed: 2009-12-18 - Published: 2010-07-01 - Earliest claimed: 1998-03-06 - Assignees: KLA-Tencor Technologies Corporation - Inventors: Yiping Xu; Ibrahim Abdulhalm - Web page: https://patentgrep.com/patent/US20100165340A1 ## CPC - G03F 7/70625: {Dimensions, e.g. line width, critical dimension [CD], profile, sidewall angle or edge roughness} - G01B 11/0641: {with measurement of polarization} - G01N 21/211: {Ellipsometry (optical thickness measurement G01B11/06)} - G01N 21/4788: {Diffraction (for sizing particles G01N15/0205)} - G01N 21/55: Specular reflectivity - G01N 21/9501: {Semiconductor wafers (manufacturing processes per se of semiconductor devices implementing a measuring step H10P74/20)} - G01N 21/956: Inspecting patterns on the surface of objects {(contactless testing of electronic circuits G01R31/308; testing currency G07D; manufacturing processes per se of semiconductor devices implementing a measuring step H10P74/20)} - G01N 21/95607: {using a comparative method} - G03F 7/70491: {Information management, e.g. software; Active and passive control, e.g. details of controlling exposure processes or exposure tool monitoring processes} - G03F 7/70616: {Monitoring the printed patterns} - G01N 2021/213: {Spectrometric ellipsometry} - G01N 2021/556: {Measuring separately scattering and specular} - G01N 2021/95615: {with stored comparision signal} - H10P 74/203: {Structural properties, e.g. testing or measuring thicknesses, line widths, warpage, bond strengths or physical defects} - G03F: PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR; (phototypographic composing devices B41B; photosensitive materials or processes for photographic purposes G03C; electrophotography, sensitive layers or processes therefor G03G) - G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS - 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) - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 ## Abstract Before the diffraction from a diffracting structure on a semiconductor wafer is measured, where necessary, the film thickness and index of refraction of the films underneath the structure are first measured using spectroscopic reflectometry or spectroscopic ellipsometry. A rigorous model is then used to calculate intensity or ellipsometric signatures of the diffracting structure. The diffracting structure is then measured using a spectroscopic scatterometer using polarized and broadband radiation to obtain an intensity or ellipsometric signature of the diffracting structure. Such signature is then matched with the signatures in the database to determine the grating shape parameters of the structure. ## Claims ### Claim 1 A scatterometer for measuring one or more parameters of a periodic diffracting structure of a sample, said one or more parameters comprising shape of lines, linewidth, pitch, height and/or side wall angle of the periodic diffracting structure, said scatterometer comprising: a reference database that includes a plurality of ellipsometric functions, each ellipsometric function corresponding to a set of values of said one or more parameters, said values including at least values of line width, height and side wall angle of periodic diffracting structures; a source which emits broadband radiation; a polarizer that polarizes the broadband radiation to produce a sampling beam sampling the periodic diffracting structure; a detector detecting ellipsometric parameters of a diffraction from the periodic diffracting structure of said broadband radiation over a range of wavelengths; a processor comparing said detected ellipsometric parameters to said plurality of ellipsometric functions in said database to determine said shape of lines, linewidth, pitch, height and/or side wall angle of the periodic diffracting structure, wherein said processor determines at least the line width, height and side wall angle of the periodic diffracting structure; and a device measuring data related to at least an index of refraction of a structure adjacent to the periodic diffracting structure. said periodic diffracting structure located on a surface of a sample, wherein said adjacent structure is away from said periodic diffracting structure so that said data related to at least said index of refraction of the adjacent structure is measured without measuring said periodic diffracting structure, and the processor uses said data related to at least the index of refraction of the adjacent structure to reduce number of parameters of the database and processing time for determining said parameters of the periodic diffracting structure. ### Claim 2 An instrument for measuring one or more parameters of a periodic diffracting structure located adjacent to a structure of a sample, said one or more parameters comprising shape of lines, linewidth, pitch, height and/or side wall angle of the periodic diffracting structure, said instrument comprising: a reference database that includes a plurality of ellipsometric functions, each ellipsometric function corresponding to a set of values of said one or more parameters, said values including at least values of line width, height and side wall angle of periodic diffracting structures; a source of broadband radiation; a polarizer polarizing said radiation to provide a sampling beam towards the sample; an analyzer for receiving radiation from the sampling beam diffracted by the periodic diffracting structure to provide an output beam; a spectrometer for detecting intensity data from the output beam simultaneously at a plurality of wavelengths; a device measuring data related to at least an index of refraction of the adjacent structure; a processor for controlling said polarizer and analyzer so that ellipsometric functions are measured, and determining at least the line width, height and side wall angle of the periodic diffracting structure by comparison of said measured ellipsometric functions to said ellipsometric functions in the reference database, said periodic diffracting structure located on a surface of a sample, wherein said adjacent structure is away from said periodic diffracting structure so that said data related to at least the index of refraction of the adjacent structure is measured without measuring said periodic diffracting structure, and the processor uses said data related to at least the index of refraction of the adjacent structure to reduce number of parameters of the database and processing time for determining said parameters of the periodic diffracting structure. ### Claim 3 (depends on 2) The instrument of claim 2, wherein said device comprises a spectroscopic ellipsometer, spectrophotometer or spectroreflectometer. ### Claim 4 (depends on 2) The instrument of claim 2, wherein said device also measures thickness of the adjacent structure. ### Claim 5 An instrument for measuring one or more parameters of a periodic diffracting structure of a sample, said one or more parameters comprising shape of lines, linewidth, pitch, height and/or side wall angle of the diffracting structure, comprising: a spectroscopic device measuring data related to film thickness and index of refraction of the sample over a spectrum; a scatterometer measuring intensity or ellipsometric data from the periodic diffracting structure of said sample, and a processor determining said one or more parameters of the periodic diffracting structure using said data related to the index of refraction of the sample over the spectrum. ### Claim 6 (depends on 5) The instrument of claim 5, wherein the processor uses said data related to the film thickness of the sample over the spectrum to reduce number of parameters of the database and processing time for determining said one or more parameters of the periodic diffracting structure. ### Claim 7 A scatterometer for measuring one or more parameters of a periodic diffracting structure of a sample, said one or more parameters comprising shape of lines, linewidth, pitch, height and/or side wall angle of the periodic diffracting structure, said scatterometer comprising: a reference database that includes a plurality of ellipsometric functions, each ellipsometric function corresponding to a set of values of said one or more parameters, said values including at least values of line width, height and side wall angle of periodic diffracting structures; a source which emits broadband radiation; a polarizer that polarizes the broadband radiation to produce a sampling beam sampling the periodic diffracting structure; means for detecting ellipsometric parameters of a diffraction from the periodic diffracting structure of said broadband radiation over a range of wavelengths; means for comparing said detected ellipsometric parameters to said plurality of ellipsometric functions in the database to determine said shape of lines, linewidth, pitch, height and/or side wall angle of the periodic diffracting structure, wherein said comparing means determines at least the line width, height and side wall angle of the periodic diffracting structure; and a device measuring data related to at least an index of refraction of a structure adjacent to the periodic diffracting structure. ### Claim 8 (depends on 7) The scatterometer of claim 7, wherein said adjacent structure is away from said periodic diffracting structure so that said data related to at least the index of refraction of the adjacent structure is measured without measuring said periodic diffracting structure, and the comparing means uses said data related to at least the index of refraction of the adjacent structure to reduce number of parameters of the database and processing time for determining said parameters of the periodic diffracting structure. ### Claim 9 (depends on 7) The scatterometer of claim 7, wherein said device comprises a spectroscopic ellipsometer, spectrophotometer or spectroreflectometer. ### Claim 10 (depends on 7) The scatterometer of claim 7, wherein said device also measures a thickness of the adjacent structure. ### Claim 11 (depends on 10) The scatterometer of claim 10, wherein the thickness of the adjacent structure is not a parameter in the reference database. ### Claim 12 (depends on 7) The scatterometer of claim 7, wherein the index of refraction of the adjacent structure is not a parameter in the reference database. ### Claim 13 A scatterometer for measuring one or more parameters of a periodic diffracting structure of a sample, said one or more parameters comprising shape of lines, linewidth, pitch, height and/or side wall angle of the structure, said scatterometer comprising: a reference database that includes a plurality of signature curves, each signature curve corresponding to a set of values of said one or more parameters, said values including at least values of line width, height and side wall angle of periodic diffracting structures; a source which emits broadband radiation; a polarizer that polarizes the broadband radiation to produce a sampling beam at an oblique angle to the sample sampling the periodic diffracting structure; a detector detecting intensity data of a diffraction from the periodic diffracting structure of said broadband radiation over a range of wavelengths; and a processor comparing said detected intensity data to said plurality of signature curves in the reference database to determine said shape of lines, linewidth, pitch, height and/or side wall angle of the periodic diffracting structure, wherein said processor determines at least the line width, height and side wall angle of the periodic diffracting structure; said reference database constructed using information related to film thickness of an adjacent structure that is obtained without measuring said periodic diffracting structure. ### Claim 14 A scatterometer for measuring one or more parameters of a periodic diffracting structure of a sample, said one or more parameters comprising shape of lines, linewidth, pitch, height and/or side wall angle of the structure, said scatterometer comprising: a reference database that includes a plurality of signature curves, each signature curve corresponding to a set of values of said one or more parameters, said values including at least values of line width, height and side wall angle of periodic diffracting structures; a source which emits broadband radiation; a polarizer that polarizes the broadband radiation to produce a sampling beam at an oblique angle to the sample sampling the periodic diffracting structure; a detector detecting intensity data of a diffraction from the periodic diffracting structure of said broadband radiation over a range of wavelengths; and a processor comparing said detected intensity data to said plurality of signature curves in the reference database to determine said shape of lines, linewidth, pitch, height and/or side wall angle of the periodic diffracting structure, wherein said processor determines at least the line width, height and side wall angle of the periodic diffracting structure; said reference database constructed using an index of refraction of an adjacent structure that is obtained without measuring said periodic diffracting structure to reduce the number of signature curves in the reference database. ### Claim 15 A scatterometer for measuring one or more parameters of a periodic diffracting structure of a sample, said one or more parameters comprising shape of lines, linewidth, pitch, height and/or side wall angle of the structure, said scatterometer comprising: a reference database that includes a plurality of signature curves, each signature curve corresponding to a set of values of said one or more parameters, said values including at least values of line width, height and side wall angle of periodic diffracting structures; a source which emits broadband radiation; a polarizer that polarizes the broadband radiation to produce a sampling beam at an oblique angle to the sample sampling the periodic diffracting structure; a detector detecting intensity data of a diffraction from the periodic diffracting structure of said broadband radiation over a range of wavelengths; and a processor comparing said detected intensity data to said plurality of signature curves in the reference database to determine said shape of lines, linewidth, pitch, height and/or side wall angle of the periodic diffracting structure, wherein said processor determines at least the line width, height and side wall angle of the periodic diffracting structure; said sample comprising an adjacent structure having at least an index of refraction, said scatterometer further comprising a device measuring data related to said at least the index of refraction of the adjacent structure without measuring said periodic diffracting structure. ### Claim 16 (depends on 15) The scatterometer of claim 15, wherein the processor uses said data related to at least the index of refraction of the adjacent structure to reduce number of parameters of the database and processing time for determining said one or more parameters of the periodic diffracting structure.