# US 2024/0201077 A1 · Phase-Resolved Optical Metrology for Substrates > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2024/0201077 A1 - Document ID: US20240201077A1 - Status: Published application - Kind: A1 - Application number: 18/389,316 - Filed: 2023-11-14 - Published: 2024-06-20 - Earliest claimed: 2022-12-14 - Assignees: Applied Materials, Inc. - Applicants: Applied Materials, Inc. - Inventors: Nedal SALEH; Zhiming JIANG; Xiaodong ZHANG; Arun Ramaswamy SRIVATSA - Web page: https://patentgrep.com/patent/US20240201077A1 ## CPC - G01N 21/3103: {Atomic absorption analysis} - G01N 21/3563: for analysing solids; Preparation of samples therefor - G01N 21/8422: {Investigating thin films, e.g. matrix isolation method} - G01N 2021/3568: {applied to semiconductors, e.g. Silicon} - G01N 2021/3595: {using FTIR} - G01N 2201/126: Microprocessor processing - 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) ## Abstract The methods and apparatus provide phase-resolved optical metrology for determining qualities of a substrate and films thereon. Transmitted and reflected signals are coupled using both amplitude and phase information to improve the metrology information obtained from film layers on the substrate. ## Claims ### Claim 1 A method for determining an absorption profile for a film on a substrate, comprising: illuminating the substrate with a broadband spectrum; obtaining amplitude and phase for reflection beams from a first surface of the substrate; obtaining amplitude and phase for transmission beams propagating through the substrate and beyond a second surface of the substrate; forming a model of the substrate by coupling the amplitude and phase of the reflection beams and the amplitude and phase of the transmission beams to form a phase-resolved signal with a first sub-signal at a first end of a Standing-Wave-Ratio (SWR) envelope that resolves top layer information and a second sub-signal at a second end of the SWR envelope that resolves substrate bulk information; determining the absorption profile of the film on the substrate and the substrate based on the model of the substrate; and using the absorption profile to perform a corrective action during processing of the film or substrate. ### Claim 2 (depends on 1) The method of claim 1, wherein the film is an epitaxial layer. ### Claim 3 (depends on 1) The method of claim 1, wherein processing of the film or substrate includes physical vapor deposition, chemical vapor deposition, or resist layer deposition. ### Claim 4 (depends on 1) The method of claim 1, wherein the film has a thickness of one atomic layer. ### Claim 5 (depends on 1) The method of claim 1, wherein the film is a stack of two or more film layers. ### Claim 6 (depends on 1) The method of claim 1, wherein the substrate is silicon, silicon carbide, quartz, or sapphire. ### Claim 7 (depends on 1) The method of claim 1, wherein the broadband spectrum includes wavelengths of approximately 2 microns to approximately 20 microns. ### Claim 8 (depends on 1) The method of claim 1, wherein a single source is used to illuminate the substrate. ### Claim 9 (depends on 1) The method of claim 1, wherein obtaining the amplitude and phase of the transmission beams and the amplitude and phase of the reflection beams includes scanning at a speed that resolves fringes of amplitudes and phases. ### Claim 10 (depends on 1) The method of claim 1 is performed without prior substrate pre-measurements. ### Claim 11 (depends on 1) The method of claim 1, wherein the film is composed of an unknown material. ### Claim 12 A non-transitory, computer readable medium having instructions stored thereon that, when executed, cause a method for determining an absorption profile for a film on a substrate to be performed, the method comprising: illuminating the substrate with a broadband spectrum; obtaining amplitude and phase for reflection beams from a first surface of the substrate; obtaining amplitude and phase for transmission beams propagating through the substrate and beyond a second surface of the substrate; forming a model of the substrate by coupling the amplitude and phase of the reflection beams and the amplitude and phase of the transmission beams to form a phase-resolved signal with a first sub-signal at a first end of a Standing-Wave-Ratio (SWR) envelope that resolves top layer information and a second sub-signal at a second end of the SWR envelope that resolves substrate bulk information; and determining the absorption profile of the film on the substrate and the substrate based on the model of the substrate. ### Claim 13 (depends on 12) The non-transitory, computer readable medium of claim 12, wherein the broadband spectrum includes wavelengths of approximately 2 microns to approximately 20 microns. ### Claim 14 (depends on 12) The non-transitory, computer readable medium of claim 12, wherein the film is a stack of two or more film layers. ### Claim 15 (depends on 12) The non-transitory, computer readable medium of claim 12, wherein obtaining the amplitude and phase of the transmission beams and the amplitude and phase of the reflection beams includes scanning at a speed that resolves fringes of amplitudes and phases. ### Claim 16 (depends on 12) The non-transitory, computer readable medium of claim 12, wherein the method is performed without prior substrate pre-measurements. ### Claim 17 A metrology apparatus for determining an absorption profile for a film on a substrate, comprising: a broadband illumination source configured to produce an infrared (IR) illumination band beam; a beam splitter configured to split the IR illumination band beam; a fixed mirror configured to receive the IR illumination band beam; a movable mirror configured to receive the IR illumination band beam and move to alter resolution of the metrology apparatus; a reflection detector configured to obtain amplitude and phase of a reflection of the IR illumination band beam; a transmission detector configured to obtain amplitude and phase of a transmission of the IR illumination band beam through the film and the substrate; and a controller configured to alter a step distance of the movable mirror to less than a shortest wavelength in the IR illumination band beam or to alter a velocity of the movable mirror to a lowest possible continuous velocity wherein the reflection detector and the transmission detector are configured to detect at a sampling rate greater than the velocity divided by a shortest wavelength of the illumination band beam. ### Claim 18 (depends on 17) The metrology apparatus of claim 17, wherein the IR illumination band beam includes wavelengths of approximately 2 microns to approximately 25 microns. ### Claim 19 (depends on 17) The metrology apparatus of claim 17, wherein the step distance is less than approximately 2 microns. ### Claim 20 (depends on 17) The metrology apparatus of claim 17, wherein the sampling rate is approximately 100 Hz.