Hyperspectral multispot optical reflectometer

Abstract

The optical reflectance measurement system includes a processing chamber, a substrate support configured to receive a substrate, a light source configured to transmit an incident light beam, an optical fiber bundle coupled to the light source and optically coupled to a lens assembly, the lens assembly optically coupled to at least a first optical fiber and configured to transmit to and receive from at least one region of the substrate through a transparent window, an optical splitter positioned within the optical fiber bundle, and a return fiber bundle coupled to the optical splitter and coupled to a detection system, the detection system configured to reference a reference light beam against a reflected light beam to improve the signal-to-noise ratio, analyze the full spectrum of the reflected light beam, and determine at least one characteristic of at least one region of the substrate.

Description

TECHNICAL FIELD

[0001] <0001>Embodiments of the present disclosure generally relate to improvements in optical reflectometry for substrate processing systems. BACKGROUND ART

[0002] <0002>The geometric dimensions of semiconductor devices have been significantly reduced in size since such devices were first introduced decades ago. The increase in circuit density has placed further demands on the processes used to fabricate semiconductor devices. For example, as circuit density increases, pitch size rapidly decreases to dimensions below 50 nm, while vertical dimensions such as trench depth remain relatively constant, resulting in a high aspect ratio of features, i.e., their height divided by width. The opening area ratio of device features (proportion relative to the entire wafer) is becoming increasingly smaller, which results in a smaller proportion of light containing information about the features. At the same time, features with smaller openings tend to have increased depth, reducing the light exiting from the bottom of the features and further reducing the signal-to-noise ratio (SNR).

[0003]

[0003] Precisely controlling the dimensions of such high-density, submicron-sized features is crucial for the reliable formation of semiconductor devices. Conventionally, features such as transistors and capacitors are formed within semiconductor devices by patterning the surface of the substrate to define the lateral dimensions of the features, followed by etching the substrate to remove material and define the features. In order to form features with desired electrical performance, the dimensions of the features must be formed within the range of control specifications. Therefore, it may be necessary to partially remove one or more layers using a dry etching or plasma etching process. For example, for endpoint detection, interference fringe patterns can be simulated for various layers and then compared with signals measured during etching. This method is very effective and can be used to monitor etching and endpoint detection of substrates having multiple layers on top.

[0004]

[0004] Typically, an in-situ optical reflectometer transmits light from a reflectometer to a substrate processing chamber using an optical fiber cable and receives reflected light from the substrate. Conventional optical fiber cables can measure parameters on the substrate such as film quality, film thickness, or structural width. However, due to the large distance between the lens and the substrate being processed, the effective beam size on the substrate ranges from a few millimeters to over 10 millimeters. A large beam size makes it difficult to focus the beam onto the wafer, and the reflected beam contains information from many features on the substrate that is not of interest. This makes it difficult to identify and filter out the target features of interest. Therefore, there is a need for improvement in in-situ optical reflectometers in the art. [Overview of the Initiative]

[0005]

[0005] Embodiments of the present disclosure generally relate to improvements in optical reflectance measurement methods for substrate processing systems.

[0006]

[0006] One general embodiment includes an optical reflectance measurement system. The optical reflectance measurement system also includes a processing chamber having a ceiling, side walls, and a bottom that define an internal space, the ceiling including a transparent window. The system also includes a substrate support disposed within the internal space, the substrate support being configured to receive a substrate. The system also includes a light source disposed outside the internal space and configured to transmit an incident light beam. The system also includes an optical fiber bundle disposed outside the internal space, the optical fiber bundle may include at least a first optical fiber coupled to the light source and optically coupled to a lens assembly, the lens assembly being disposed above a transparent window and optically coupled to at least the first optical fiber, configured to transmit to and receive from at least one area of ​​the substrate through the transparent window, and an optical splitter disposed within the optical fiber bundle. The system also includes a return fiber bundle, which may include at least a first return fiber coupled to an optical splitter and coupled to a detection system, the detection system being configured to reference a reference light beam and the reflected light beam to improve the signal-to-noise ratio (SNR) for analysis of the reflected light beam, to analyze the full spectrum of the reflected light beam, and to determine at least one characteristic of at least one region of the substrate based on the analysis of the full spectrum of the reflected light beam. Other embodiments of this model include corresponding computer systems, apparatus, and computer programs recorded on one or more computer storage devices, each configured to perform the actions of the method.

[0007]

[0007] One general embodiment includes an optical reflectance measurement method. The method also includes transmitting an incident light beam from a light source to an optical splitter via an optical fiber bundle which may include at least a first optical fiber. The method also includes transmitting a first portion of the incident light beam from the optical splitter to a lens assembly via an optical fiber bundle which may include a plurality of return fibers. The method also includes transmitting a second portion of the incident light beam as a reference light beam from the optical splitter to a detection system via a return fiber bundle which may include a plurality of return fibers. The method also includes focusing the first portion of the incident light beam as an incident ray from the lens assembly onto at least one area of ​​a substrate placed in a processing chamber. The method also includes receiving a reflected ray from at least one area of ​​the substrate at the lens assembly. The method also includes transmitting the reflected ray as a reflected light beam from the lens assembly to an optical splitter via an optical fiber bundle. The method also includes transmitting the reflected light beam from the optical splitter to a detection system via a return fiber bundle. The method also includes determining at least one characteristic of at least one region of the substrate. Other embodiments of this aspect include corresponding computer systems, apparatus, and computer programs recorded on one or more computer storage devices, each configured to perform the actions of the method.

[0008]

[0008] To enable a detailed understanding of the above-described features of the Disclosure, a more specific description of the Disclosure, which has been briefly summarized above, can be obtained by referring to embodiments. Some of these embodiments are illustrated in the accompanying drawings. However, it should be noted that the accompanying drawings are only illustrative embodiments and should not be considered to limit the scope of the Disclosure, and other equally valid embodiments are also permitted. [Brief explanation of the drawing]

[0009] [Figure 1]

[0009] This is a schematic cross-sectional view of an exemplary plasma processing chamber having a detection system according to one embodiment of the present disclosure. [Figure 2]

[0010] This is an illustrative schematic cross-sectional view of a collimated optical path, which is commonly used in the prior art and includes a bundle of optical fibers configured to transmit and receive light within a processing chamber. [Figure 3]

[0011] This is an exemplary schematic cross-sectional view of an optical path of a single optical fiber configured to transmit and receive light within a processing chamber, according to one embodiment of the present disclosure. [Figure 4]

[0012] This is a schematic cross-sectional view of the design and optical path of a fiber optic bundle, comprising a fiber optic bundle configured to transmit and receive light within a processing chamber, according to one embodiment of the present disclosure. [Figure 4A]

[0013] This is a cross-sectional view of the exit of an optical fiber bundle configured to transmit and receive light within a processing chamber, according to one embodiment of the present disclosure. [Figure 4B]

[0014] This is an exemplary cross-sectional view of a light beam transmitted from multiple optical fibers, as it is received and reflected from the surface of a substrate, according to one embodiment of the present disclosure. [Figure 5A]

[0015] A graph of single-wavelength referencing (reference) according to one embodiment of the present disclosure is shown. [Figure 5B]

[0016] A graph of multi-wavelength referencing (reference) according to one embodiment of the present disclosure is shown. [Figure 6]

[0017] This is a flowchart of a method for emitting and collecting reflected light in a processing chamber according to one embodiment of the present disclosure. [Modes for carrying out the invention]

[0010]

[0018] For ease of understanding, the same reference numerals have been used to indicate identical elements common to the figures where possible. It is intended that elements and features of one embodiment can be advantageously incorporated into other embodiments without further description.

[0011]

[0019] The embodiments of this disclosure generally relate to improvements in optical reflectance measurement methods for substrate processing systems.

[0012]

[0020] Figure 1 is a schematic cross-sectional view of an exemplary processing chamber 100 from a substrate processing system having a detection system 164, according to one embodiment of the present disclosure. Preferred processing chambers include inductively coupled and capacitively coupled plasma etching chambers (e.g., TETRA® photomask etching systems and SYM3® etching systems), both of which are available, among other things, from Applied Materials, Inc. in Santa Clara, California. Other types of processing chambers, including capacitively coupled parallel plate chambers, magnetically enhanced ion etching chambers, and inductively coupled plasma etching chambers, may be adapted to benefit from the present invention.

[0013]

[0021] The processing chamber 100 includes a chamber body 102 and an energy-permeable ceiling 103, that is, a ceiling that transmits energy and light. The chamber body 102 has side walls, a ceiling 103, and a chamber bottom 107. The chamber body 102, side walls, ceiling 103, and chamber bottom 107 define the internal space of the processing chamber 100. The chamber body 102 is manufactured from a metal such as anodized aluminum or stainless steel. The ceiling 103 is mounted on the chamber body 102. The ceiling 103 may be flat, rectangular, arched, conical, dome-shaped, or multi-radial. The ceiling 103 is manufactured from an energy-permeable material such as ceramic or other dielectric material. A dielectric coil 126 is positioned above the ceiling 103 of the processing chamber 100 and is used to supply energy to the gas inside the processing chamber 100 during processing.

[0014]

[0022] The substrate support 116 is placed in a processing chamber 100 having a substrate support surface 188 that supports the substrate 120 during processing. The substrate support 116 may include an electrostatic chuck comprising at least a portion of the substrate support 116 that is conductive and can function as a processing bias cathode.

[0015]

[0023] The processing gas is introduced into the processing chamber 100 from the processing gas source 148 via the gas distributor 122. The gas distributor 122 may be located above the substrate support 116, either in the ceiling 103 or within the chamber body 102. For each processing gas, or alternatively a mixture of processing gases, a mass flow controller (not shown) is positioned between the gas distributor 122 and the processing gas source 148 to adjust the respective flow rates of the processing gas into the chamber body 102.

[0016]

[0024] The internal space 114 is defined within the chamber body 102 between the substrate support 116 and the ceiling 103. Plasma is formed from the processing gas within the internal space 114 using a coil power supply 127 that powers a dielectric coil 126, generating an electromagnetic field within the internal space 114 through the RF matching network 135. The substrate support 116 may include electrodes placed therein, which are powered by an electrode power supply 125 and generate a capacitive electric field within the processing chamber 100 through the RF matching network 128. RF power is applied to the electrodes in the substrate support 116 while the chamber body 102 is electrically grounded. The capacitive electric field is orthogonal to the plane of the substrate support 116 and influences a kind of orientation that is more perpendicular to the substrate 120, resulting in more perpendicularly oriented anisotropic etching of the substrate 120.

[0017]

[0025] The process gas and etchant by-products are exhausted from the processing chamber 100 through the exhaust system 130. The exhaust system 130 may be located at the bottom 107 of the processing chamber 100 or at another part of the chamber body 102 of the processing chamber 100 to remove the process gas. A throttle valve 132 is provided in the exhaust port 134 to control the pressure inside the processing chamber 100.

[0018]

[0026] Figure 1 further shows an optical fiber bundle 104 configured to detect features in or on a substrate 120 disposed within the processing chamber 100. The optical fiber bundle 104 has a diameter of about 0.05 mm to about 2 mm. For example, the optical fiber bundle 104 has a diameter of about 1 mm. In one embodiment, the optical fiber bundle 104 is included within a detection system 164. The detection system 164 may be an optical reflectometry measurement system. For example, it is a spectroscopic reflectometry measurement system configured to process input channels and determine one or more properties of a substrate disposed within the processing chamber. For example, the detection system 164 may be an interferometer endpoint detection system configured to process input channels and determine one or more properties of a substrate disposed within the processing chamber 100. In one embodiment that can be combined with other embodiments, the detection system 164 is capable of processing multiple input channels simultaneously. For example, the detection system 164 can process from about 1 to about 20 input channels simultaneously. For example, the detection system 164 can process from about 10 to about 50 input channels simultaneously. For example, the detection system 164 can process about 10 input channels simultaneously.

[0019]

[0027] In one embodiment that can be combined with other embodiments, the detection system 164 can switch between banks (not shown) of input channels to measure additional regions of the substrate 120. For example, the detection system 164 may include multiple banks, each of which may include multiple input channels. For example, the detection system 164 may include from about 1 to about 20 banks. For example, the detection system 164 may include at least 1 to about 20 banks. For example, the detection system 164 may include 10 banks. Each bank includes a number of input channels. For example, each bank includes from about 1 to about 20 input channels. For example, each bank includes from about 10 to about 50 input channels. For example, each bank includes about 10 input channels.

[0020]

[0028] In one embodiment that can be combined with other embodiments, the detection system 164 determines one or more properties of the substrate (e.g., feature dimensions, feature height, plasma radiation emission, changes in plasma properties, or the like) to determine the endpoint of one or more stages of the etching process. The endpoint of the etching stage may arrive, for example, when the layer of the substrate 120 is sufficiently removed, or when the lower layer is exposed by etching. In another embodiment, the endpoint of the etching state may arrive when a desired dimension, such as a desired height of a feature, is obtained. By determining the endpoint of the etching stage, it is possible to stop etching the substrate 120 when the stage is completed, thus reducing the occurrence of over-etching or under-etching of the substrate 120. The endpoint of one or more stages can be determined by monitoring the radiation emission from the plasma within the processing chamber 100, and the plasma emits radiation whose intensity and wavelength change in response to changes in the composition of the excited gas. For example, a change in the composition of the excited gas may occur by etching the upper layer of the substrate 120 to expose the lower layer. In this manner, the detection system 164 monitors one or more properties of the radiation emission to determine the extent of etching or other conditions of the substrate within the processing chamber 100.

[0021]

[0029] The characteristics of one or more substrate processing stages in the processing chamber 100 can be determined by the detection system 164. In one embodiment, the endpoint of a substrate processing stage may be reached, for example, when a layer of the substrate 120 has been sufficiently removed or etched to expose the underlying layer. In another embodiment, the endpoint of a substrate processing stage may occur when a desired dimension, such as a desired height or film thickness of a feature, has been obtained. Once the stage is complete, it is possible to stop processing the substrate 120, thus reducing defects in the substrate, such as over-etching or under-etching of the substrate 120. The endpoint of one or more substrate processing stages can be determined by monitoring the radiative emissions from the plasma in the processing chamber 100, which emits radiation whose intensity and wavelength change depending on changes in the composition of the excited gas. For example, a change in the composition of the excited gas may result from etching the upper layer to expose the underlying layer on the substrate 120. Thus, the detection system 164 analyzes the radiative emissions to determine the degree of substrate processing or other conditions in the processing chamber 100.

[0022]

[0030] The detection system 164 further includes a light source 166, a lens assembly 168, a photodetector 170, an optical splitter 172, and a controller 150. The light source 166 is configured to emit a light beam through the optical splitter 172 and an optical fiber bundle 104. The light beam strikes the substrate 120 and is reflected back through the optical fiber bundle 104. After passing through the optical fiber bundle 104 and the optical splitter 172, the light beam returns to the photodetector 170. For example, the lens assembly 168 is configured to focus the light beam into the incident light beam 176. The incident light beam 176 passes through the ceiling 103 towards the substrate support surface 188, illuminating a region on the surface 121 of the substrate 120 or a beam spot 180. In one embodiment, which can be combined with other embodiments, the detection system 164 can manipulate the lens assembly 168 so that the beam spot 180 strikes different regions of the substrate 120 for measurement.

[0023]

[0031] The incident light beam 176 is reflected by the surface 121 of the substrate 120 to form a reflected light beam 178. At least a portion of the reflected light beam 178 is directed perpendicular to the substrate support surface 188, passes back to the ceiling 103, and is directed to the photodetector 170 through the optical fiber bundle 104 and the optical splitter 172. The photodetector 170 is configured to measure the intensity of the reflected light beam 178. An exemplary photodetector 170 is a spectrophotometer.

[0024]

[0032] Alternatively, the optical fiber bundle 104 can be used without the lens assembly 168, such that the optical fiber bundle 104 is directly connected to the ceiling 103 and a single collimator is placed between the optical fiber bundle 104 and the ceiling 103. For example, a focusing lens 174b (i.e., as a collimator) can be placed directly between the optical fiber bundle 104 and the ceiling 103. In embodiments described herein, a collimator may not be present.

[0025]

[0033] The light source 166 has a monochromatic or polychromatic light source that generates an incident light beam 176 used to illuminate a beam spot 180 on the substrate 120. The intensity of the incident light beam 176 is selected to be sufficiently high to allow the reflected light beam 178 to have a measurable intensity. In one embodiment, the light source 166, such as a xenon (Xe) lamp, provides polychromatic light and generates an emission spectrum of light with wavelengths from about 200 nm to about 800 nm. The light source 166 may include a polychromatic light source. The polychromatic light can be filtered to select the frequency containing the incident light beam 176. A color filter can be placed in front of the photodetector 170 to filter out all wavelengths except for the desired wavelength of light before measuring the intensity of the reflected light beam 178 entering the photodetector 170. The light source 166 may also include a monochromatic light source that provides light of the selected wavelength, such as a helium-neon (He-Ne) laser, or a neodymium-doped yttrium-aluminum-garnet (Nd-YAG) laser, LED, or other monochromatic light source.

[0026]

[0034] One or more mirrors 186 and one or more focusing lenses (e.g., focusing lenses 174a and 174b) can be used to focus the incident light beam 176 from the light source 166 to form a beam spot 180 on the surface 121 of the substrate 120. One or more mirrors 186 and one or more focusing lenses (e.g., focusing lenses 174a and 174b) can be used to return and focus the reflected light beam 178 onto the active surface of the photodetector 170. In one embodiment, which can be combined with other embodiments, one or more mirrors may be fixed mirrors, adjustable mirrors, or digital mirror devices (DMDs). The size or area of ​​the beam spot 180 must be sufficiently large to compensate for variations in the surface topography and device design features of the substrate 120. The size of the beam spot 180 makes it possible to detect features and characteristics of the substrate 120, such as feature pitch and depth, film thickness, and other physical properties. The area of ​​the reflected light beam is large enough to activate most of the active light detection surface of the photodetector 170.

[0027]

[0035] The incident light beam 176 and the reflected light beam 178 are directed through a transparent window 182 of the processing chamber 100. The transparent window 182 allows the incident light beam 176 and the reflected light beam 178 to enter and exit the processing environment of the processing chamber 100. The substrate support surface 188 of the substrate support 116 on which the substrate 120 is placed is positioned parallel to the ceiling 103. In one embodiment, the transparent window 182 is located within the ceiling 103 of the processing chamber 100 and is directed toward the substrate 120 and the substrate support 116. The transparent window 182 is configured to receive the incident light beam from the detection system 164. The transparent window 182 enables the transmission of the incident light beam 176 to the substrate. The transparent window 182 also allows the reflected light beam 178 to pass through the substrate 120 as it reflects off it. The transparent window 182 is further configured to transmit the reflected light beam 178 to the detection system 164.

[0028]

[0036] The controller 150 is electrically connected via wire 158 to a detection system 164, which includes a photodetector 170, the controller 150, and a light source 166. The controller 150 processes the spectrum by using advanced spectral analysis techniques, which include calculating a portion of the real-time measured waveform spectrum of the reflected light beam 178 reflected from the beam spot 180 on the substrate 120 and comparing the spectrum with a stored characteristic waveform pattern. In one embodiment, which can be combined with other embodiments, the controller 150 calculates and adjusts the position and orientation of the lens assembly 168.

[0029]

[0037] The controller 150 includes a programmable central processing unit (CPU) 152 that operates together with memory 154 (e.g., non-volatile memory) and support circuitry 156. The support circuitry 156 is conventionally connected to the CPU 152 and includes caches, clock circuits, input / output subsystems, power supplies, etc., and combinations thereof, which are connected to its various components to facilitate control of the processing chamber 100.

[0030]

[0038] The CPU 152 is one of any form of general-purpose computer processor used in industrial environments, such as a programmable logic controller (PLC), for controlling various components and subprocessors of a processing system. The memory 154 connected to the CPU 152 is non-temporary and is typically one or more readily available memories, such as random access memory (RAM), read-only memory (ROM), a floppy disk drive, a hard disk, or any other form of local or remote digital storage.

[0031]

[0039] Typically, memory 154 takes the form of a non-temporary computer-readable storage medium (e.g., non-volatile memory) containing instructions, which, when executed by the CPU 152, facilitate the operation of the processing chamber 100. The instructions in memory 154 take the form of a program product, such as a program that implements the method of the present disclosure. The program code may conform to any one of several different programming languages. In one embodiment, the present disclosure may be implemented as a program product stored in a computer-readable storage medium for use in a computer system. One or more programs in the program product define the function of the embodiment (including the method described herein).

[0032]

[0040] Exemplary non-temporary computer-readable storage media include, but are not limited to, (i) non-writable storage media on which information is permanently stored (e.g., read-only memory devices in a computer, such as CD-ROM disks readable by a CD-ROM drive, flash memory, ROM chips, or any type of solid-state non-volatile semiconductor memory element (e.g., SSDs (solid-state drives))) and (ii) writable storage media on which modifiable information is stored (e.g., floppy disks in a diskette drive or hard disk drive, or any type of solid-state random-access semiconductor memory). Such computer-readable storage media constitute embodiments of the disclosure if they carry computer-readable instructions that direct the functions of the methods described herein. In some embodiments, the methods described herein or parts thereof are performed by one or more application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other types of hardware implementations. In some other embodiments, the substrate processing and / or substrate handling methods described herein are performed by a combination of software routines, ASICs, and / or other types of hardware implementations. One or more controllers 150 may be used with one or any combination of the various systems described herein.

[0033]

[0041] Figure 2 is an illustrative schematic cross-sectional view of a collimated optical path, commonly used in the prior art, which includes an optical fiber configured to transmit and receive light within a processing chamber.

[0034]

[0042] An incident light beam 176 originating from a light source 166 is focused by an optical fiber bundle 104. The incident light beam is received by an optical splitter 172. In some embodiments, the optical splitter 172 is positioned along the length of the optical fiber bundle 104. In other embodiments, the optical splitter 172 may be positioned at the light source 166. The incident light beam 176 originating from the light source 166 passes through the optical splitter 172 and exits the optical fiber bundle 104 at an exit 264 of the fiber bundle. The exit 264 of the fiber bundle is positioned above a lens assembly 168 that includes a lens acting as a collimator. The incident light beam 176 has an initial spot size approximately equal to the diameter of the optical fiber. For example, the initial spot size 260 may have a diameter of about 100 micrometers (μm). The incident light beam 176 exits the exit 264 of the fiber bundle in a spread pattern, and each incident ray 236 interacts with a different part of the lens assembly 168. The incident light ray 236 then passes through the lens assembly 168, where it is collimated and transmitted toward the substrate 120. After impacting the substrate 120, the incident light ray 236 is reflected toward the optical fiber bundle 104 as reflected light ray 240.

[0035]

[0043] Due to spatial constraints, the distance from the fiber bundle exit point 264 to the lens assembly 168 is typically smaller than the distance between the lens assembly 168 and the surface of the substrate 120. As a result, the substrate image size 242 on the surface of the substrate 120 is amplified compared to the initial spot size 260. For example, the substrate image size 242 may have a diameter of 10 millimeters (mm). For example, the substrate image size 242 may have a diameter of 100 mm. The area of ​​the substrate image size 242 is the area measured by the detection system 164.

[0036]

[0044] After passing through the lens assembly, the reflected light rays 240 are returned to the optical fiber bundle 104. Collectively, the reflected light rays 240 constitute the reflected light beam 178. The reflected light rays 240 are then returned to the optical splitter 172. A first portion (e.g., about 50%) of the reflected light beam 178 received by the optical splitter 172 is subsequently transmitted to the detection system 164 via the return fiber bundle 208.

[0037]

[0045] Figure 3 is an exemplary schematic cross-sectional view of the optical path of a single optical fiber configured to transmit and receive light within the processing chamber 100, demonstrating improved spatial resolution on the substrate.

[0038]

[0046] The incident light beam 176 emitted by the light source 166 is received by the optical fiber bundle 104. The optical fiber bundle 104 contains multiple fibers. Each fiber in the optical fiber bundle 104 has a diameter between approximately 0.01 mm and 1 mm. For example, the diameter of each fiber in the optical fiber bundle 104 is approximately 0.5 mm. The optical fiber bundle 104 transmits the incident light beam 176, which is received by the optical splitter 172. In some embodiments, the optical splitter 172 is positioned along the length of the optical fiber bundle 104. In other embodiments, the optical splitter 172 may be positioned at the light source 166. In other embodiments, the optical splitter 172 may be positioned at the end of the optical fiber bundle 104.

[0039]

[0047] A first portion (e.g., about 50%) of the received incident light beam 176 is transmitted by the optical splitter 172 as a reference light beam 206 and sent to the detection system 164 through the return fiber bundle 208. The reference light beam 206 is received by the detection system 164 and used as a reference to reduce noise and improve the signal-to-noise ratio (SNR). A second portion (e.g., about 50%) of the received incident light beam 176 is transmitted by the optical splitter 172 and exits the optical fiber bundle 104 through the fiber bundle exit 264.

[0040]

[0048] The fiber bundle exit 264 is located above the lens assembly 168, as shown along with the fiber-to-lens distance 252. The incident light beam 176 has an initial spot size approximately equal to the diameter of one of the multiple fibers in the optical fiber bundle 104. For example, the initial spot size 260 has a diameter of about 0.01 mm to 1 mm. For example, the diameter of the initial spot size 260 is about 0.5 mm. The fiber-to-lens distance 252 is about 40 mm to about 80 mm. For example, the fiber-to-lens distance 252 is about 50 mm.

[0041]

[0049] The focusing lens assembly 168 has a lens-to-substrate distance 254 from the substrate 120. The lens-to-substrate distance 254 is based on the ratio of the fiber-to-lens distance 252. For example, the ratio of the lens-to-substrate distance 254 is about 1:1 to about 10:1. For example, the ratio of the lens-to-substrate distance 254 is about 4:1. In another embodiment, the ratio of the lens-to-substrate distance 254 is about 5:1.

[0042]

[0050] As each incident ray 236 interacts with a different part of the lens assembly 168, the incident light beam 176 exits the fiber bundle outlet 264 in a spreading pattern. The incident ray 236 then passes through the lens assembly 168, where it is focused (rather than collimated) and transmitted toward the substrate 120.

[0043]

[0051] After impacting the substrate 120, the incident light ray 236 is reflected back towards the optical fiber bundle 104 as a reflected light ray 240. Due to spatial constraints, the distance from the exit 264 of the fiber bundle to the lens assembly 168 is typically smaller than the distance between the lens assembly 168 and the surface of the substrate 120. As a result, the substrate image size 242 on the surface of the substrate 120 is amplified. For example, the substrate image size 242 can be larger than the initial spot size 260 by the ratio of the lens-substrate distance 254 to the fiber-lens distance 252. For example, the substrate image size 242 has a diameter of about 0.01 mm to 10 mm. For example, the substrate image size 242 has a diameter of about 0.4 mm. For example, the substrate image size 242 has a diameter of about 0.1 mm. For example, the substrate image size 242 has a diameter of about 4 mm. Compared with Figure 2, the optical path described herein provides a reduction in the substrate image size 242. Reducing the substrate image size from 242 reduces the amount of information about non-target areas of the substrate that are included in the reflected signal / spectrum, thereby improving the system's sensitivity and detail resolution.

[0044]

[0052] The reflected light rays 240 are returned to the lens assembly 168. After passing through the lens assembly 168, the reflected light rays 240 are transmitted to the optical fiber bundle 104. Collectively, the reflected light rays 240 constitute the reflected light beam 178. In one embodiment, the optical fiber bundle 104 may be concentric with the lens assembly 168. The received reflected light rays 240 are subsequently transmitted to the optical splitter 172. A first portion (e.g., about 50%) of the reflected light beam 178 received by the optical splitter 172 is subsequently transmitted to the detection system 164 via the return fiber bundle 208. A second portion (e.g., about 50%) of the reflected light beam 178 received by the optical splitter 172 is transmitted to the light source 166 via the optical fiber bundle 104.

[0045]

[0053] Figure 4 is a schematic cross-sectional view of the design and optical path of a fiber optic bundle, which includes a fiber optic bundle 310 configured to transmit and receive light within a processing chamber 100, illustrating a multispot hyperspectral system.

[0046]

[0054] The incident light beam 176 generated from the light source 166 is focused by the optical fiber bundle 310. The optical fiber bundle 310 has a diameter of approximately 0.05 mm to approximately 2 mm. For example, the optical fiber bundle has a diameter of approximately 1 mm. The optical fiber bundle includes a plurality of optical fibers 302. For example, optical fibers 302a, 302b, 302c, and 302d. Each fiber of the plurality of optical fibers 302 has a diameter of approximately 0.01 mm to 1 mm. For example, the optical fiber 302 has a diameter of approximately 0.5 mm. Each of the plurality of optical fibers 302 includes an outlet 264 for the fiber bundle.

[0047]

[0055] The incident light beam 176 is transmitted to an optical splitter 172 by multiple optical fibers 302. In some embodiments, the optical splitter 172 is positioned along the length of the optical fiber bundle 104. In other embodiments, the optical splitter 172 may be positioned at the light source 166. In one embodiment, about 50% of the received incident light beam 176 exits through the optical splitter 172 and is sent to the detection system 164 as a reference light beam 206 through a return fiber bundle 312 containing multiple return fibers 302. In other embodiments, a lower or higher percentage of the received incident light beam 176 exits through the optical splitter 172 and is sent to the detection system 164 as a reference light beam 206 through the return fiber bundle 312.

[0048]

[0056] In one embodiment, which can be combined with other embodiments, the optical splitter 172 optically splits the reference light beam 206 from the incident light beam 176. In another embodiment, which can be combined with other embodiments, the optical splitter 172 splits the reference light beam 206 from the incident light beam 176 by redirecting a portion of the multiple fibers 302 from the optical fiber bundle 310 to the return fiber bundle 312. In one embodiment, which can be combined with other embodiments, the reference light beam 206 may be attenuated before being received by the detection system 164. In one embodiment, which can be combined with other embodiments, the reference light beam 206 may be attenuated by the detection system 164. As illustrated in Figure 5A and described below, the reference light beam 206 is utilized by the detection system 164 to reduce noise and improve the signal-to-noise ratio (SNR).

[0049]

[0057] In another embodiment, which can be combined with other embodiments, the optical splitter 172 allows each first portion of the multiple return fibers to receive a sub-portion of the reference light beam corresponding to a region of the light source 166, and each second portion of the multiple return fibers to receive a sub-portion of the reflected light beam that originally corresponds to the same region of the light source. As illustrated in Figure 5B and described below, this allows the detection system 164 to further improve the SNR, i.e., improve the SNR for measuring each region of the substrate.

[0050]

[0058] The remainder of the received incident light beam 176 (approximately 50% of the light originating from the light source 166) passes through the optical splitter 172 and exits the optical fiber bundle 310 from the multiple optical fibers 302 as incident rays 236. For example, the incident rays 236 from optical fiber 302a, optical fiber 302b, optical fiber 302c, and optical fiber 302d are all directed towards the focusing lens 174b. In other embodiments, a smaller or larger proportion of the light originating from the light source 166 passes through the optical splitter 172 and exits the optical fiber bundle 310 from the multiple optical fibers 302 as incident rays 236.

[0051]

[0059] The fiber outlet 264 of the optical fiber bundle 310 is positioned further away from the focal point of the focusing lens 174b, indicated by the distance 252 between the fiber lenses. The fiber-lens distance 252 is approximately 40 millimeters (mm) to approximately 80 mm. For example, the fiber-lens distance 252 is approximately 50 mm. The focusing lens 174b also has a lens-substrate distance 254 from the substrate 120. The incident light ray 236 passes through the focusing lens 174b. The incident light ray 236 exits the focusing lens 174b and contacts the substrate 120 within or around the substrate image size 242. The area of ​​the substrate image size 242 formed by the incident light ray 236 is larger than the outlet of the optical fiber bundle 310. The larger area of ​​the substrate image size 242 is generally due to space constraints. For example, the distance 252 between the fiber and the lens is usually smaller than the distance 254 between the lens and the substrate, resulting in a larger area of ​​the substrate image size 242 on the substrate.

[0052]

[0060] After impacting the substrate 120, the reflected light beam 178 is reflected back towards the optical fiber bundle 310 as reflected light rays 240. The reflected light rays 240 reflected by the substrate 120 are returned to the focusing lens 174b. After passing through the focusing lens 174b, the reflected light rays 240 are returned to the same fiber of the multiple optical fibers 302 that are the source of the incident light rays 236. For example, they are returned to optical fiber 302a, optical fiber 302b, optical fiber 302c, and optical fiber 302d. In another embodiment, which can be combined with other embodiments, the reflected light rays 240 are returned to different fibers of the multiple optical fibers 302, compared to the fiber of the multiple optical fibers that are the source of the incident light rays 236.

[0053]

[0061] The reflected light beam 240 is then returned to the optical splitter 172. Approximately 50% of the reflected light beam 178 received by the optical splitter 172 is then transmitted via the return fiber bundle 312 to the photodetector 170 of the detection system 164. Approximately 50% of the reflected light beam 178 received by the optical splitter 172 is then transmitted via the optical fiber bundle 310 to the light source 166.

[0054]

[0062] In one embodiment, which can be combined with other embodiments, the detection system 164 can measure multi-wavelength (broadband spectrum) reflected light beams 178 collected by each of the multiple fibers 302.

[0055]

[0063] In another embodiment, which can be combined with other embodiments, the reflected light beam 178 may be filtered or unfiltered, attenuated or unattenuated, and a photodiode or charge-coupled device (CCD) used in the detection system 164 is used to measure the total power of each fiber of the multiple fibers 302.

[0056]

[0064] In another embodiment, which can be combined with other embodiments, the detection system 164 can simultaneously measure multiple wavelengths (broadband spectra) of reflected light beams 178 collected by each of the multiple fibers 302. Each of the multiple fibers 302 transmits reflected light rays 240 collected from different locations on the substrate to different parts of the detection system 164, enabling the detection system 164 to perform multispectral measurements at multiple locations simultaneously.

[0057]

[0065] Figure 4A is a cross-sectional view of the exit of an optical fiber bundle configured to transmit and receive light within a processing chamber according to one embodiment of the present disclosure. More specifically, Figure 4A illustrates an incident light beam 176 transmitted by a plurality of optical fibers 302 as an incident light ray 236. The incident light ray 236 emitted from the exit 264 of each fiber bundle has an initial spot size 260 that is approximately equal to the diameter of the optical fiber bundle 104. The initial spot sizes 260 of the plurality of fibers 302 are a reduction from the initial spot size 260 shown in Figure 2.

[0058]

[0066] Figure 4B is an exemplary cross-sectional view of an embodiment of the present disclosure in which a light beam transmitted from multiple optical fibers 302 is received and reflected on the surface of a substrate 120. More specifically, Figure 4B is a cross-sectional view of an incident light ray 236 received from multiple optical fibers 302, optical fiber 302a, optical fiber 302b, optical fiber 302c, and optical fiber 302d, and reflected as a reflected light ray 240 from multiple reflection regions 302' (reflection region 302a', reflection region 302b', reflection region 302c', and reflection region 302d'). These fall within or approximately the area of ​​the substrate image size 242 on the substrate 120 shown in Figure 4. The reflected light ray 240 emanating from the reflection region 302' has a substrate image size 242. The substrate image size 242 is larger than the initial spot size 260. For example, the substrate image size 242 has a diameter of approximately 0.1 mm to 10 mm. The substrate image size 242 is approximately 0.05 mm to 4 mm. For example, the substrate image size 242 is approximately 1 mm. The substrate image size 242 shown in Figure 4B is a reduction from the substrate image size 242 shown in Figure 2B. Each of the multiple reflection regions 302' simultaneously returns the multicolor reflection spectra of different regions of the substrate for analysis and measurement by the detection system 164.

[0059]

[0067] The optical fiber bundle 310 disclosed herein allows for an increase in the number of reflective regions 302' by having a plurality of optical fibers 302. Each of the reflective regions 302' includes a reduced substrate image size 242, which is a reduction from the substrate image size 242 in the embodiment of Figure 2. In one embodiment, which can be combined with other embodiments, the reduced substrate image size 242 can be obtained by reducing the diameter of the input fiber, which makes it possible to improve the spatial resolution by about 10 times or more compared to current reflectivity measurement devices and methods.

[0060]

[0068] In another embodiment, which can be combined with other embodiments, the optical fiber bundle 310 described herein has multiple optical fibers 302, thereby improving the sensitivity of the reflectometer by allowing the entire spectrum of each fiber to measure smaller, individual regions of the substrate. In another embodiment, which can be combined with other embodiments, increasing the number of reflect regions 302' (each having a reduced substrate image size 242) allows more regions of the substrate to be analyzed simultaneously and separately with higher sensitivity compared to current reflectance measurement devices and methods. In another embodiment, which can be combined with other embodiments, increasing the number of reflect regions 302' having a reduced substrate image size 242 enables differential measurement and improves detection sensitivity. For example, reflect region 302a' may correspond to a portion of the substrate with no features, fewer features, or more features compared to reflect region 302d', which may enable differential measurement of two regions of the substrate. In another embodiment, which can be combined with other embodiments, an increase in the number of reflective regions 302' having a reduced substrate image size 242 may allow each portion of the reflected light beam 178 collected by multiple optical fibers 302 to enter a different portion of the detection system 164 for analysis.

[0061]

[0069] Figure 5A shows graph 500, titled "Single Wavelength Reference." This illustrates the time-dependent intensity drift of an exemplary light source (e.g., light source 166), and how a detection system (e.g., detection system 164) compensates for this intensity drift by using a reference, thereby improving signal stability and SNR.

[0062]

[0070] Graph 500 includes two axes. The horizontal axis 510, labeled "Time," represents the increase in time from t0 on the left side of the graph to t+n on the right side. The vertical axis 520, labeled "Intensity," represents intensity values ​​indicating an increase in intensity above approximately point 522 and a decrease in intensity below approximately point 522.

[0063]

[0071] Graph 500 includes two plotted trend lines (a first trend line 502 and a second trend line 504). The first trend line 502 shows the time-dependent drift of the intensity of an exemplary light source, e.g., light source 166. Looking at the first trend line 502, we see that the intensity of the light source initially begins with a sharp increase in intensity 502a, followed by a sharp decrease in intensity 502b. Immediately thereafter, the decrease in intensity begins to slow down (502c), reaching a semi-continuous intensity 502d.

[0064]

[0072] This change in intensity over time poses a problem for the detection system. Without a reference point, such as the one shown by the first trend line 502, it would be impossible to reliably compare a measurement obtained at one point in time with one obtained at a later point in time, because the change in intensity essentially alters the measurement.

[0065]

[0073] The second trend line 504 shows the time-dependent drift of the intensity of an exemplary light source (e.g., light source 166) using a reference by the detection system 164. Using the reference, the sharp increases and decreases of the first trend line 502 are instead represented as a decayed increase 504a followed by a constant intensity value 504b. Using the reference, the intensity of the light source is normalized and the SNR is improved.

[0066]

[0074] Figure 5B shows graph 550, titled “Multiple Wavelength Reference,” which illustrates the SNR improvement obtained by the reference in the detection system 164 across multiple wavelengths of light. Graph 550 includes two axes. The horizontal axis 510, labeled “Intensity,” shows the various light source intensities at different wavelengths from the left to the right of graph 550. The vertical axis 520, labeled “SNR,” plots the signal-to-noise improvement.

[0067]

[0075] Graph 550 includes two plotted regions (a first region 552 without reference, and a second region 554 with reference). The first region 552, without reference, shows that the SNR improves slightly across multiple wavelengths of light as the lamp intensity increases. The second region 554, with reference, shows that the detection system 164 described herein can improve the SNR across multiple wavelengths of light.

[0068]

[0076] Figure 6 is a flowchart of a method 600 for emitting and collecting reflected light in a processing chamber, according to one embodiment of the present disclosure. Method 600 can be understood by referring to Figures 4, 4A, and 4B. Figure 6 has a simplified version of the subject matter of the invention as defined in the claims and is not intended to limit the present disclosure.

[0069]

[0077] Step 610 of Method 600 includes transmitting a first portion of the incident light beam to at least one region of the substrate 120 placed in the processing chamber 100.

[0070]

[0078] Step 610 of Method 600 may include transmitting an incident light beam 176 from a light source 166 to an optical splitter 172 via an optical fiber bundle 310 including at least a first optical fiber. Step 610 of Method 600 may include transmitting at least a sub-portion of the incident light beam 176 from at least a first sub-region of the light source 166 to at least a first optical fiber, and receiving at least a sub-portion of the incident light beam 176 from at least a first optical fiber at the optical splitter 172.

[0071]

[0079] Step 610 of Method 600 may include transmitting a first portion of the incident light beam 176 from the optical splitter 172 to the lens assembly 168 via the optical fiber bundle 310. Step 610 of Method 600 may include splitting at least a sub-portion of the incident light beam 176 into at least a first sub-portion of the incident light, the at least first sub-portion of the incident light corresponding to at least a first sub-region of the light source 166, returning the at least first sub-portion of the incident light from the optical splitter 172 to at least a first optical fiber, and transmitting the at least first sub-portion of the incident light from at least a first optical fiber to the lens assembly 168.

[0072]

[0080] Step 610 of Method 600 may include focusing a first portion of the incident light beam 176 as an incident ray from the lens assembly 168 onto at least one area of ​​the substrate 120 placed in the processing chamber 100. Step 610 of Method 600 may include receiving at least a first sub-portion of the incident light beam 176 from the optical splitter 172 via the optical fiber bundle 310, and focusing at least a first sub-portion of the incident light beam 176 as an incident ray 236 from the lens assembly 168 onto at least one area of ​​the substrate 120.

[0073]

[0081] Step 620 of Method 600 includes transmitting a second portion of the incident light beam 176 as a reference light beam 206 to the detection system 164.

[0074]

[0082] Step 620 of Method 600 may include transmitting a second portion of the incident light beam 176 as a reference light beam 206 from the optical splitter 172 to the detection system 164 via a return fiber bundle 312 including at least one return fiber.

[0075]

[0083] Step 620 of Method 600 may include splitting at least a sub-part of the incident light beam 176 into at least a second sub-part of the incident light, wherein the at least second sub-part of the incident light corresponds to at least a first sub-region of the light source 166; transmitting at least a second sub-part of the incident light from the optical splitter 172 to at least a first return fiber as at least a first sub-part of the reference light beam 206 to the detection system 164; and the detection system 164 receiving at least a first sub-part of the reference light beam 206 from at least a first return fiber, wherein the at least first sub-part of the reference light beam 206 corresponds to at least a first sub-region of the light source 166.

[0076]

[0084] Step 630 of Method 600 includes receiving a first portion of the incident light beam 176 as a reflected light beam 178 from at least one region of the substrate 120 in the detection system 164.

[0077]

[0085] Step 630 of Method 600 may include receiving reflected light rays 240 from at least one region of the substrate 120 with the lens assembly 168; transmitting the reflected light rays 240 from the lens assembly 168 to at least the first optical fiber of the optical fiber bundle 310 as at least the first sub-part of the reflected light beam 178; transmitting the reflected light rays 240 from the lens assembly 168 to the optical splitter 172 via the optical fiber bundle 310 as the reflected light beam 178; and transmitting the reflected light beam 178 from the optical splitter 172 to the detection system 164 via the return fiber bundle 312.

[0078]

[0086] Step 630 of Method 600 may include receiving reflected light rays 240 from at least one region of the substrate 120 with the lens assembly 168, and transmitting the reflected light rays 240 as at least a first sub-part of the reflected light beam 178 from the lens assembly 168 to at least a first optical fiber.

[0079]

[0087] Step 640 of Method 600 includes determining at least one characteristic of at least one region of the substrate 120.

[0080]

[0088] Step 640 of Method 600 may include receiving at least a first sub-part of a reference light beam 206, wherein at least a first sub-part of the reference light beam 206 corresponds to at least a first sub-region of a light source 166; receiving at least a first sub-part of a reflected light beam 178, wherein at least a first sub-part of the reflected light beam 178 corresponds to at least a first sub-part of incident light, wherein at least a first sub-part of incident light corresponds to at least a first sub-region of a light source 166; and referencing the first sub-part of the reference light beam 206 with respect to the first sub-part of the reflected light beam 178 in order to improve a first signal-to-noise ratio (SNR).

[0081]

[0089] Step 640 of Method 600 may include analyzing the full spectrum of the reflected light beam 178 based in part on the first SNR, where the full spectrum is between approximately 200 nanometers (nm) and approximately 800 nm.

[0082]

[0090] Step 640 of Method 600 may include determining, based on a first SNR, at least one height of a feature located on the substrate 120 in at least one region, at least one dimension of a feature located on the substrate 120 in at least one region, at least one wavelength of plasma emission from at least one region of the substrate 120, at least one intensity of plasma emission from at least one region of the substrate 120, or a combination thereof, and analyzing the full spectrum of the reflected light beam 178.

[0083]

[0091] Step 640 of Method 600 is to receive at least a first sub-part of a reference light beam 206, wherein at least a first sub-part of the reference light beam 206 corresponds to at least a first sub-region of a light source 166; to receive at least a second sub-part of a reference light beam 206, wherein at least a second sub-part of the reference light beam 206 corresponds to at least a second sub-region of a light source 166; and to receive at least a first sub-part of a reflected light beam 178 from at least a first region of the substrate 120, wherein at least a first sub-part of the reflected light beam 178 corresponds to at least a first sub-part of the incident light, and at least a first sub-part of the incident light is a light source This may include receiving at least a first sub-portion of the reflected light beam 178 corresponding to at least a first sub-region of 166, and receiving at least a second sub-portion of the reflected light beam 178 from at least a second region of the substrate 120, wherein at least a second sub-portion of the reflected light beam 178 corresponds to at least a second sub-portion of incident light, and at least a second sub-portion of incident light corresponds to at least a second sub-region of the light source 166, and referencing a first sub-portion of the reference light beam 206 to the first sub-portion of the reflected light beam 178 to improve a first SNR, and referencing a second sub-portion of the reference light beam 206 to the second sub-portion of the reflected light beam 178 to improve a second SNR.

[0084]

[0092] Step 640 of Method 600 may include analyzing the full spectrum (about 200 nanometers (nm) to about 800 nm) of at least a first sub-part of the reflected light beam 178, based in part on a first SNR, and analyzing the full spectrum (about 200 nanometers (nm) to about 800 nm) of at least a second sub-part of the reflected light beam 178, based in part on a second SNR.

[0085]

[0093] Step 640 of Method 600 is to determine at least one characteristic of at least a first region of the substrate 120 based on an improved first SNR, and to analyze the full spectrum of at least a first sub-part of the reflected light beam 178, wherein determining at least one characteristic further includes determining at least one height of a feature placed on at least a first region of the substrate 120, at least one dimension of a feature placed on at least a first region of the substrate 120, at least one wavelength of plasma emission from at least a first region of the substrate 120, at least one intensity of plasma emission from at least a first region of the substrate 120, or a combination thereof; and to determine at least one characteristic of at least a second region of the substrate 120 based on an improved first SNR. Determining at least one characteristic of at least a second region of the substrate 120 based on an improved first SNR, which includes determining at least one height of a feature located on at least a second region of the substrate 120, at least one dimension of a feature located on at least a second region of the substrate 120, at least one wavelength of plasma emission from at least a second region of the substrate 120, at least one intensity of plasma emission from at least a second region of the substrate 120, or a combination thereof; and analyzing the full spectrum of at least a second sub-portion of the reflected light beam 178, and comparing at least one characteristic of at least a first region of the substrate 120 with at least one characteristic of at least a second region of the substrate 120 in order to improve the detection density of at least one characteristic of at least a second region of the substrate 120.

[0086]

[0094] Step 560 of Method 600 includes repeating the preceding steps, steps 610, 620, 630, and / or 640 as necessary until the measurement and analysis of the substrate 120 is completed. Further considerations

[0087]

[0095] This specification includes details of several specific embodiments, which should be interpreted not as a limitation on the scope of what is claimed, but as a description of features that may be specific to a particular embodiment. Certain features described herein in relation to a separate embodiment may also be implemented in combination in a single embodiment. Conversely, various features described in relation to a single embodiment may be implemented separately in multiple embodiments or as part of any suitable subcombination. Furthermore, the features described above are described as functioning in a particular combination and may initially be claimed as such, but one or more features from the claimed combination may, in some cases, be removed from that combination, and the claimed combination may cover a subcombination or a variation of a subcombination.

[0088]

[0096] We have described specific embodiments of the subject matter. Other embodiments, modifications, and permutations of the described embodiments are within the scope of the following claims, as will be obvious to those skilled in the art. Although the operations are shown in a specific order in the drawings or claims, it should not be understood that it is necessary to perform the operations in the specific order shown, or in a sequential order, or to perform all of the described operations (some operations may be considered optional) in order to obtain the desired results. Multitasking or parallel processing (or a combination of multitasking and parallel processing) is performed when it is deemed advantageous and appropriate under certain circumstances.

[0089]

[0097] Furthermore, the separation or integration of various system modules and components in the embodiments described above should not be understood as necessary in all embodiments. It should be understood that the program components and systems described can generally be integrated into a single software product or packaged into multiple software products.

[0090]

[0098] Therefore, the exemplary embodiments described above do not define or limit this disclosure. Other modifications, substitutions, and alterations are possible without departing from the spirit and scope of this disclosure.

[0091]

[0099] Although various steps in the method or process of the embodiment are shown and described sequentially, those skilled in the art will understand that some or all of the steps may be performed in a different order, combined, omitted, or performed in parallel. These steps may be performed actively or passively. This method or process may be repeated or extended to support multiple components or multiple users within a field environment. Therefore, it should not be considered that the scope is limited to the specific arrangement of steps shown in the flowchart or diagram.

[0092]

[0100] Unless otherwise defined, all technical and scientific terms used have the same meaning as those commonly understood by those skilled in the art in the field to which these systems, apparatus, methods, processes, and compositions belong.

[0093]

[0101] In this disclosure, terms such as “top,” “bottom,” “side,” “up,” “down,” “up,” “down,” “above,” “below,” “horizontal,” and “vertical” do not refer to absolute directions. Instead, these terms refer to directions relative to an unspecified reference plane, which may be vertical, horizontal, or any other angular direction.

[0094]

[0102] The singular forms “a,” “an,” and “the” include multiple references unless otherwise specified by the context. In the claims, references to singular elements are intended to mean “one or more,” not “one and only one,” unless otherwise specified. Unless otherwise specified, the term “some” refers to one or more.

[0095]

[0103] Embodiments of this disclosure may preferably "comprise," "consist," or "consist essentially of" the disclosed limiting features, and may also be implemented even when there are no undisclosed limiting features. As used herein and in the appended claims, the words "comprise," "has," and "include," and all their grammatical variations, are intended to have an open and non-restrictive meaning that does not exclude additional elements or steps.

[0096]

[0104] "Optional" and "optionally" mean that the material, event, or situation described afterward may or may not be present. The description includes cases where the material, event, or situation occurs and cases where it does not.

[0097]

[0105] The expression "determining" encompasses a wide variety of actions. For example, "determining" may include calculating, arithmetic, processing, deriving, investigating, looking up (e.g., looking up a table, database, or other data structure), and verifying. Furthermore, "determining" may include receiving (e.g., receiving information) and accessing (e.g., accessing data in memory). In addition, "determining" may include resolving, selecting, choosing, and establishing.

[0098]

[0106] When the words "approximately" or "about" are used, they may mean that there may be a variation of up to ±10%, up to 5%, up to 2%, up to 1%, up to 0.5%, up to 0.1%, or up to 0.1% in the value.

[0099]

[0107] A range can be expressed as a range from one specific value to another specific value (including both ends). When such a range is expressed, it should be understood that another embodiment is a range from one specific value to another specific value, including all specific values ​​and their combinations within that range.

[0100]

[0108] The terms "first" and "second," when used, are arbitrarily assigned and are solely for the purpose of distinguishing two or more components of a system, apparatus, or composition. It should be understood that the terms "first" and "second" serve no other purpose, are not part of the names or descriptions of the components, and do not necessarily define the relative locations or positions of the components. Furthermore, the mere use of the terms "first" and "second" does not necessitate the existence of a "third" component, although its possibility is contemplated within the scope of the various embodiments described.

[0101]

[0109] As used in this book, “CPU,” “a processor,” “at least one processor,” or “one or more processors” generally refers to a single processor configured to perform one or more processes, or to multiple processors configured to collectively perform one or more processes. When using multiple processors, the execution of one or more processes can be divided among different processors, but it is also possible for one processor to perform multiple processes, and for multiple processors to collectively perform a single process. Similarly, “a memory,” “at least one memory,” or “one or more memories” generally refers to a single memory configured to store data and / or instructions, or to multiple memories configured to collectively store data and / or instructions.

[0102]

[0110] Although only a few exemplary embodiments have been described in detail, those skilled in the art will readily understand that many modifications are possible in the exemplary embodiments without substantially departing from the disclosed scope described. Therefore, all such modifications are intended to fall within the scope of this disclosure as defined in the following claims.

Claims

1. An optical reflectance measurement system, A processing chamber having a ceiling, side walls, and bottom that define the internal space, wherein the ceiling is equipped with a transparent window, A substrate support disposed within the internal space, wherein the substrate support is configured to receive a substrate, A light source is positioned outside the aforementioned internal space and configured to transmit an incident light beam, A bundle of optical fibers disposed outside the internal space, comprising at least a first optical fiber coupled to the light source and optically coupled to the lens assembly, wherein the lens assembly is positioned on the transparent window and optically coupled to the at least first optical fiber, and The incident light beam is transmitted as an incident ray to at least one region of the substrate through the transparent window. Receiving reflected light rays from at least one region of the substrate through the transparent window, and The reflected light beam is transmitted to the optical fiber bundle as a reflected light beam. It is configured to do the following: Optical fiber bundle and An optical splitter is placed within the optical fiber bundle, A return fiber bundle comprising at least a first return fiber coupled to the optical splitter and coupled to a detection system, wherein the detection system To improve the signal-to-noise ratio (SNR), a reference light beam and the reflected light beam are referenced. Analyzing the full spectrum of the reflected light beam based on the SNR in part, and Based on the above analysis, determine at least one characteristic of the at least one region of the substrate. A return fiber bundle configured to perform the following: An optical reflectance measurement system, including...

2. The optical reflectance measurement system according to claim 1, wherein the full spectrum is between approximately 200 nanometers (nm) and approximately 800 nm.

3. The at least one characteristic of the at least one region of the substrate is The height of at least one feature disposed on the at least one region of the substrate, At least one dimension of a feature disposed on the at least one region of the substrate, At least one wavelength of plasma radiation emission from the at least one region of the substrate, At least one intensity of the radiative emission of the plasma from the at least one region of the substrate, or These combinations The optical reflectance measurement system according to claim 1, including the above.

4. The optical reflectance measurement system according to claim 1, wherein the light source is a monochromatic light source.

5. The optical reflectance measurement system according to claim 1, wherein the light source is a multicolor light source.

6. The aforementioned at least first optical fiber is Receiving at least a sub-portion of the incident light beam from at least a first sub-region of the light source, To transmit at least the sub-portion of the incident light beam, To receive at least a sub-portion of the reflected light beam, and To transmit at least the sub-part of the reflected light beam, The optical reflectance measurement system according to claim 1, configured to perform the following:

7. The optical reflectance measurement system according to claim 1, wherein at least the first optical fiber has a diameter between about 0.1 millimeters (mm) and about 0.5 mm.

8. The optical reflectance measurement system according to claim 1, wherein one of the at least one regions of the substrate has a substrate image size having a diameter between approximately 0.1 millimeters (mm) and approximately 10 mm.

9. The at least first return fiber is Receiving at least a sub-portion of the aforementioned reference light beam, To transmit at least the sub-part of the reference light beam, To receive at least a first sub-portion of the reflected light beam, and To transmit at least the sub-part of the reflected light beam, The optical reflectance measurement system according to claim 1, configured to perform the following:

10. The aforementioned optical splitter is, Receiving at least a sub-portion of the incident light beam from at least the first optical fiber, Dividing the incident light beam into at least a sub-part into at least a first sub-part of the incident light and at least a second sub-part of the incident light, To transmit at least the first sub-portion of the incident light to at least the first optical fiber, To transmit at least the second sub-portion of the incident light to at least the first return fiber as at least the sub-portion of the reference light beam, To receive at least a sub-portion of the reflected light beam, and To transmit at least a sub-portion of the reflected light beam to at least a second return fiber, The optical reflectance measurement system according to claim 1, configured to perform the following:

11. The lens assembly includes at least one focusing lens, and the lens assembly is To receive at least a first sub-portion of incident light from the aforementioned at least first optical fiber, Focusing at least the first sub-portion of the incident light onto at least one region of the substrate, Receiving reflected light rays from at least one region of the substrate, and The reflected light is transmitted to the at least first optical fiber as at least a first sub-part of the reflected light beam. The optical reflectance measurement system according to claim 1, configured to perform the following:

12. The optical reflection measurement system according to claim 11, wherein at least a first region of the substrate has a substrate image size having a diameter between approximately 0.1 mm and 10 mm.

13. The detection system comprises a spectroscopic reflectance measurement system, and the spectroscopic reflectance measurement system is Receiving at least a sub-portion of the reference light beam, wherein the at least sub-portion of the reference light beam corresponds to at least a first sub-region of the light source, and Receiving at least a sub-portion of the reflected light beam, wherein the at least sub-portion of the reflected light beam receives at least a sub-portion of the reflected light beam corresponding to at least a first sub-region of the light source. The optical reflectance measurement system according to claim 1, further configured to perform the following:

14. An optical reflectance measurement method, Transmitting an incident light beam from a light source to an optical splitter via an optical fiber bundle including at least a first optical fiber, Transmitting the first portion of the incident light beam from the optical splitter to the lens assembly via the optical fiber bundle, A second portion of the incident light beam is transmitted from the optical splitter to the detection system as a reference light beam via a return fiber bundle including at least one return fiber. The first portion of the incident light beam is focused as an incident ray from the lens assembly onto at least one region of a substrate placed in the processing chamber. The lens assembly receives reflected light rays from at least one region of the substrate. The reflected light beam is transmitted from the lens assembly to the optical splitter via the optical fiber bundle, as a reflected light beam. The reflected light beam is transmitted from the optical splitter to the detection system via the return fiber bundle. To improve the signal-to-noise ratio (SNR), the reference light beam is referenced relative to the reflected light beam. Based on the improved SNR, the full spectrum of the reflected light beam is analyzed, and Based on the above analysis, at least one characteristic of the at least one region of the substrate is determined. Optical reflectance measurement method, including

15. The transmission of the incident light beam from the light source to the optical splitter is further, Transmitting at least a sub-portion of the incident light beam from at least a first sub-region of the light source to at least a first optical fiber, and The optical splitter receives at least a sub-portion of the incident light beam from at least the first optical fiber. The method according to claim 14, including the method described in claim 14.

16. The transmission of the first portion of the incident light beam from the optical splitter to the lens assembly is further: Dividing at least a sub-portion of the incident light beam into at least a first sub-portion of the incident light, wherein the at least first sub-portion of the incident light corresponds to the at least first sub-region of the light source, Returning at least the first sub-portion of the incident light from the optical splitter to the at least first optical fiber, To transmit the at least first sub-portion of the incident light from the at least first optical fiber to the lens assembly, The method according to claim 14, including the method described in claim 14.

17. The transmission of the second portion of the incident light beam as the reference light beam from the optical splitter to the detection system is further: Dividing at least a sub-portion of the incident light beam into at least a second sub-portion of the incident light, wherein the at least second sub-portion of the incident light corresponds to at least a first sub-region of the light source, Transmitting at least a second sub-part of the incident light from the optical splitter to the at least first return fiber as at least a first sub-part of the reference light beam, and The detection system receives the at least first sub-portion of the reference light beam from the at least first return fiber, wherein the at least first sub-portion of the reference light beam receives the at least first sub-portion of the reference light beam corresponding to the at least first sub-region of the light source. The method according to claim 14, including the method described in claim 14.

18. Further, focusing the first portion of the incident light beam onto at least one region of the substrate placed in the processing chamber, as an incident ray from the lens assembly, Receiving at least a first sub-portion of the incident light beam from the optical splitter via the optical fiber bundle, and The incident light beam is to be focused from the lens assembly onto at least one region of the substrate, by focusing at least the first sub-portion of the incident light beam onto that region. The method according to claim 14, including the method described in claim 14.

19. The reflected light beam is further transmitted from the lens assembly to the optical splitter via the optical fiber bundle, as the reflected light beam. The reflected light rays are received by the lens assembly from at least one region of the substrate, and The reflected light rays are transmitted from the lens assembly to the at least first optical fiber as at least a first sub-part of the reflected light beam. The method according to claim 14, including the method described in claim 14.

20. To improve the signal-to-noise ratio (SNR), referencing the reference light beam relative to the reflected light beam is further... Receiving at least a first sub-portion of the reference light beam, wherein the at least first sub-portion of the reference light beam corresponds to the at least first sub-region of the light source, Receiving at least a first sub-portion of the reflected light beam, wherein the at least first sub-portion of the reflected light beam corresponds to at least a first sub-portion of the incident light, and the at least first sub-portion of the incident light corresponds to at least a first sub-region of the light source, and To improve the first signal-to-noise ratio (SNR), the first sub-part of the reference light beam is referenced to the first sub-part of the reflected light beam. The method according to claim 14, including the method described in claim 14.

21. Analyzing the full spectrum of the reflected light beam based on the partially improved SNR further, Analyzing the full spectrum of at least a first sub-part of the reflected light beam, partially based on a first signal-to-noise ratio (SNR), wherein the full spectrum is between approximately 200 nanometers (nm) and approximately 800 nm. The method according to claim 14, including the method described in claim 14.

22. Determining at least one characteristic of the at least one region of the substrate further involves: The process includes determining and analyzing the full spectrum of the reflected light beam based on a first signal-to-noise ratio (SNR), wherein the full spectrum is defined as: The height of at least one feature disposed on the at least one region of the substrate, At least one dimension of a feature disposed on the at least one region of the substrate, At least one wavelength of plasma radiation emission from the at least one region of the substrate, At least one intensity of the radiative emission of the plasma from the at least one region of the substrate, or The method according to claim 14, which is a combination of these.

23. To improve the signal-to-noise ratio (SNR), referencing the reference light beam relative to the reflected light beam is further... Receiving at least a first sub-portion of the reference light beam, wherein the at least first sub-portion of the reference light beam corresponds to at least a first sub-region of the light source, Receiving at least a second sub-portion of the reference light beam, wherein the at least second sub-portion of the reference light beam corresponds to at least a second sub-region of the light source, Receiving at least a first sub-portion of the reflected light beam from at least a first region of the substrate, wherein the at least first sub-portion of the reflected light beam corresponds to at least a first sub-portion of the incident light, and the at least first sub-portion of the incident light corresponds to at least a first sub-region of the light source, Receiving at least a second sub-portion of the reflected light beam from at least a second region of the substrate, wherein the at least second sub-portion of the reflected light beam corresponds to the at least second sub-portion of the incident light, and the at least second sub-portion of the incident light corresponds to the at least second sub-region of the light source, To improve the first SNR, the first sub-part of the reference light beam is referenced to the first sub-part of the reflected light beam, and To improve the second SNR, the second sub-part of the reference light beam is referenced to the second sub-part of the reflected light beam. The method according to claim 14, including the method described in claim 14.

24. Analyzing the full spectrum of the reflected light beam based on the partially improved SNR further, Analyzing the full spectrum of at least a first sub-part of the reflected light beam, partially based on a first signal-to-noise ratio (SNR), wherein the full spectrum is approximately 200 nanometers (nm) to approximately 800 nm, and Analyzing the full spectrum of at least a second sub-part of the reflected light beam, based in part on a second SNR, wherein the full spectrum is between approximately 200 nanometers (nm) and approximately 800 nm. The method according to claim 14, including the method described in claim 14.

25. Based on the above analysis, determining at least one characteristic of the at least one region of the substrate is further: Based on the improved first SNR, determining at least one characteristic of at least a first region of the substrate, and analyzing the full spectrum of at least a first sub-portion of the reflected light beam, wherein determining the at least one characteristic further, At least one height of a feature disposed on the at least first region of the substrate, At least one dimension of a feature disposed on the at least first region of the substrate, At least one wavelength of plasma radiation emission from at least the first region of the substrate, At least one intensity of the radiative emission of the plasma from at least the first region of the substrate, or These combinations This includes determining the improved first SNR, determining at least one characteristic of at least a first region of the substrate, and analyzing the full spectrum of at least a first sub-part of the reflected light beam. Based on the improved second SNR, determining at least one characteristic of at least a second region of the substrate, and analyzing the full spectrum of at least a second sub-portion of the reflected light beam, wherein determining the at least one characteristic further, At least one height of a feature disposed on the at least second region of the substrate, At least one dimension of a feature disposed on the at least second region of the substrate, At least one wavelength of plasma radiation emission from at least the second region of the substrate, At least one intensity of the plasma radiation emission from at least the second region of the substrate, or These combinations This includes determining the improved second SNR, determining at least one characteristic of at least a second region of the substrate, and analyzing the full spectrum of at least a second sub-part of the reflected light beam, and To improve the detection density of at least one characteristic in at least a second region of the substrate, the at least one characteristic in at least a first region of the substrate is compared with the at least one characteristic in at least a second region of the substrate. The method according to claim 14, including the method described in claim 14.

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