Hyperspectral multipoint optical reflectometer

Abstract

An optical reflectance measurement system, the optical reflectance measurement system comprising: a processing chamber; a substrate support, wherein the substrate support is 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 wherein the lens assembly is 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 the transparent window; the optical splitter is arranged in the optical fiber bundle; and a return fiber bundle coupled to the optical splitter, and coupled to a detection system, where the detection system is configured to refer a reflected beam to a reference beam to improve a signal-to-noise ratio, analyze a full spectrum of the reflected beam, and determine at least one characteristic of the at least one region of the substrate.

Description

Technical Field

[0001] Embodiments of this disclosure generally relate to improvements in optical reflection measurement for substrate processing systems. Background Technology

[0002] Since the introduction of semiconductor devices decades ago, the size of their geometry has shrunk dramatically. Increased circuit density places additional demands on the processes used to manufacture these devices. For example, as circuit density increases, pitch size rapidly decreases to below 50 nm, while vertical dimensions (such as trench depth) remain relatively constant. This results in an increase in the feature aspect ratio (i.e., its height divided by its width). The aperture area of ​​the device feature becomes a smaller percentage of the entire wafer, producing a smaller percentage of light carrying information about the feature. Simultaneously, features with smaller apertures tend to be deeper, reducing light emanating from the bottom of the feature and further decreasing the signal-to-noise ratio (SNR).

[0003] Precise control of the dimensions of such high-density, submicron features is crucial for the reliable formation of semiconductor devices. Features, such as transistors and capacitors, are conventionally formed in semiconductor devices by patterning the surface of a substrate to define the lateral dimensions of the feature and then etching the substrate to remove material and define the feature. For features to have the desired electrical properties, their dimensions must be formed within controlled specifications. This may necessitate the use of dry etching or plasma etching processes to partially remove one or more layers. For example, for endpoint detection, interference fringe patterns can be simulated for each layer and then compared with measured signals during etching. This method is highly effective and can be used for monitoring the etching and endpoint detection of substrates with multiple layers on top.

[0004] Typically, in-situ optical reflectometers use fiber optic cables to transmit light from the reflectometer and receive reflected light from the substrate in a substrate processing chamber. Conventional fiber optic cables can measure parameters such as film quality, film thickness, or the width of structures on the substrate. However, due to the large distance between the lens and the substrate being processed, the effective beam size at the substrate varies from a few millimeters to over 10 millimeters. This 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 are not of interest. This makes it difficult to identify and filter the target features of interest. Therefore, there is a need in the art for improvements to in-situ optical reflectometers. Summary of the Invention

[0005] Embodiments of this disclosure generally relate to improvements in optical reflectometers for substrate processing systems.

[0006] One general aspect includes an optical reflectance measurement system. The optical reflectance measurement system also includes a processing chamber having a top plate, sidewalls, and a bottom defining an internal volume, wherein the top plate contains a transparent window. The system also includes a substrate support located within the internal volume, wherein the substrate support is configured to receive a substrate. The system also includes a light source located outside the internal volume, the light source being configured to transmit an emitted light beam. The system also includes an optical fiber bundle located outside the internal volume, the optical fiber bundle including at least a first optical fiber coupled to the light source and optically coupled to a lens assembly, wherein the lens assembly is disposed above the transparent window and optically coupled to the at least first optical fiber, and is configured to: transmit through the transparent window to at least one region of the substrate, and receive through the transparent window from at least one region of the substrate; a beam 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 a beam splitter and coupled to a detection system, wherein the detection system is configured to: reference a reference beam and a reflected beam to improve the signal-to-noise ratio (SNR), analyze the reflected beam, analyze the full spectrum of the reflected beam, and determine at least one characteristic of at least one region of the substrate based on the analysis of the full spectrum of the reflected beam. Other embodiments of this aspect include corresponding computer systems, devices, and computer programs recorded on one or more computer storage devices, each configured to perform the actions of the method.

[0007] A general aspect includes an optical reflectance measurement method. The method also includes transmitting an incident light beam from a light source to a beam splitter via a bundle of optical fibers, including at least a first optical fiber. The method also includes transmitting a first portion of the incident light beam from the beam splitter to a lens assembly via the optical fiber bundle. The method also includes transmitting a second portion of the incident light beam as a reference beam from the beam splitter to a detection system via a return optical fiber bundle, including multiple return optical fibers. The method also includes focusing the first portion of the incident light beam as incident light from the lens assembly onto at least one region of a substrate disposed within a processing chamber. The method also includes receiving reflected light from at least one region of the substrate at the lens assembly. The method also includes transmitting the reflected light as a reflected beam from the lens assembly to the beam splitter via the optical fiber bundle. The method also includes transmitting the reflected beam from the beam splitter to the detection system via the return optical 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, devices, and computer programs recorded on one or more computer storage devices, each configured to perform the actions of the method. Attached Figure Description

[0008] To gain a more detailed understanding of the features described above in this disclosure, a more specific description of the disclosure, which has been briefly summarized above, can be obtained with reference to the embodiments, some of which are illustrated in the accompanying drawings. However, it will be noted that the drawings illustrate only exemplary embodiments and are not intended to limit the scope of the disclosure, and may allow for other equivalent and effective embodiments.

[0009] Figure 1 This is a schematic cross-sectional view of an example plasma processing chamber with a detection system according to an example of this disclosure.

[0010] Figure 2 This is an example schematic cross-sectional view of a collimated optical path having an optical fiber bundle configured to transmit and receive light in a processing chamber, as commonly used in the prior art.

[0011] Figure 3 This is an example schematic cross-sectional view of an optical path of a single optical fiber configured to transmit and receive light in a processing chamber, according to an example of this disclosure.

[0012] Figure 4 This is a schematic cross-sectional view of an optical fiber bundle design according to an example of the present disclosure, and an optical path having an optical fiber bundle configured to transmit and receive light in a processing chamber.

[0013] Figure 4A This is a cross-sectional view of the exit of an optical fiber bundle configured to transmit and receive light in a processing chamber, according to an example of this disclosure.

[0014] Figure 4B This is an example cross-sectional view of a light beam transmitted from multiple optical fibers in a receiving state and reflected at the surface of a substrate, according to an example of this disclosure.

[0015] Figure 5A A diagram of a single-wavelength reference according to an example of this disclosure is shown.

[0016] Figure 5B A diagram of a multi-wavelength reference according to an example of this disclosure is shown.

[0017] Figure 6 This is a flowchart of a method for emitting and collecting reflected light in a processing chamber, according to an example of this disclosure.

[0018] For ease of understanding, the same reference numerals have been used to identify common elements in the figures where possible. It is anticipated that elements and features of one embodiment may be advantageously incorporated into other embodiments without further description. Detailed Implementation

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

[0020] Figure 1 This is a schematic cross-sectional view of an example processing chamber 100 from a substrate processing system having a detection system 164, according to an example of this disclosure. Suitable processing chambers include inductively coupled and capacitively coupled plasma etching chambers, such as TETRA... ® Photomask Etching System and SYM3 ® Etching systems (both available from Applied Materials, Santa Clara, California) and other systems. Other types of processing chambers may be adapted to benefit from this invention, including, for example, capacitively coupled parallel-plate chambers and magnetically enhanced ion etching chambers, as well as inductively coupled plasma etching chambers.

[0021] The processing chamber 100 includes a chamber body 102 and a top plate 103 that is energy-transparent, i.e., allows energy and light to pass through it. The chamber body 102 has sidewalls, the top plate 103, and a chamber bottom 107. The chamber body 102, sidewalls, top plate 103, and chamber bottom 107 define the internal volume of the processing chamber 100. The chamber body 102 is made of metal (such as anodized aluminum or stainless steel). The top plate 103 is mounted on the chamber body 102. The top plate 103 may be flat, rectangular, arcuate, conical, dome-shaped, or multi-radius. The top plate 103 is made of an energy-transparent material (such as ceramic or other dielectric materials). An induction coil 126 is disposed above the top plate 103 of the processing chamber 100 and is used to excite the gas within the processing chamber 100 during processing.

[0022] A substrate support 116 is disposed in a processing chamber 100. The substrate support 116 has a substrate support surface 188 to support a substrate 120 during processing. The substrate support 116 may include an electrostatic chuck, wherein at least a portion of the substrate support 116 is conductive and can be used as a process bias cathode.

[0023] Processing gases are introduced into the processing chamber 100 from the processing gas source 148 via a gas distributor 122. The gas distributor 122 may be disposed in the top plate 103 or the chamber body 102, above the base plate support 116. A mass flow controller (not shown) for each processing gas or, alternatively, for a mixture of processing gases is disposed between the gas distributor 122 and the processing gas source 148 to regulate the corresponding flow rate of the processing gas into the chamber body 102.

[0024] Internal volume 114 is defined within chamber body 102 between substrate support 116 and top plate 103. Plasma is formed within internal volume 114 by process gas using coil power supply 127, which supplies power to induction coil 126 to generate an electromagnetic field within internal volume 114 via RF matching network 135. Substrate support 116 may include electrodes disposed therein, which are powered by electrode power supply 125 and generate a capacitive electric field within processing chamber 100 via RF matching network 128. RF power is applied to the electrodes in substrate support 116 when chamber body 102 is electrically grounded. The capacitive electric field is transverse to the plane of substrate support 116 and influences the orientation of charged material more orthogonal to substrate 120 to provide more vertically oriented anisotropic etching of substrate 120.

[0025] Processing gases and etchant byproducts are discharged from the processing chamber 100 through a discharge system 130. The discharge system 130, which may be located in the chamber bottom 107 of the processing chamber 100 or in another part of the chamber body 102 of the processing chamber 100, is used to remove processing gases. A throttle valve 132 is located in the discharge port 134 to control the pressure in the processing chamber 100.

[0026] Figure 1 Further illustrated is an optical fiber bundle 104 configured to detect features within or on a substrate 120 disposed in the processing chamber 100. The optical fiber bundle 104 has a diameter of approximately 0.05 mm to approximately 2 mm. For example, the optical fiber bundle 104 has a diameter of approximately 1 mm. In one example, the optical fiber bundle 104 is included in a detection system 164. The detection system 164 may be an optical reflectance measurement system. For example, a spectral reflectance measurement system configured to process input channels and determine one or more characteristics of a substrate disposed in 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 characteristics of a substrate disposed in the processing chamber 100. In one example that can be combined with other examples, the detection system 164 is capable of processing several input channels simultaneously. For example, the detection system 164 is capable of processing between approximately 1 input channel and approximately 20 input channels simultaneously. For example, the detection system 164 is capable of processing between approximately 10 input channels and approximately 50 input channels simultaneously. For example, the detection system 164 can process data simultaneously across approximately 10 input channels.

[0027] In one embodiment that can be combined with other examples, the detection system 164 is capable of switching between input channel groups (not shown) to measure additional areas of the substrate 120. For example, the detection system 164 may include several groups, each group having several input channels. For example, the detection system 164 may include between about 1 group and about 20 groups. For example, the detection system 164 may include between at least 1 group and about 20 groups. For example, the detection system 164 may include 10 groups. Each group includes several input channels. For example, each group includes between about 1 input channel and about 20 input channels. For example, each group includes between about 10 input channels and about 50 input channels. For example, each group includes between about 10 input channels.

[0028] In one example, which can be combined with other examples, the detection system 164 determines one or more characteristics of the substrate (such as feature size, feature height, plasma radiation emission, changes in plasma characteristics, or the like) to determine the endpoint of one or more stages of the etching process. For example, the endpoint of an etching stage may occur when a layer of substrate 120 has been sufficiently removed or etched through to expose the underlying layer. In another example, the endpoint of an etching state may occur when the desired dimensions (such as the desired height of the feature) have been achieved. Determining the endpoint of an etching stage allows etching of substrate 120 to be stopped once the stage is complete, thus reducing the occurrence of over-etching or under-etching of substrate 120. The endpoint of one or more stages can be determined by monitoring the radiation emission from plasma in the processing chamber 100, the intensity and wavelength of which change depending on the composition of the excitation gas. For example, a change in the composition of the excitation gas can be caused by etching through a capping layer to expose the underlying layer on substrate 120. Therefore, the detection system 164 monitors one or more characteristics of radiation emission to determine the degree of etching of the substrate or other conditions in the processing chamber 100.

[0029] The characteristics of one or more stages of substrate processing in processing chamber 100 can be determined by detection system 164. In one example, for instance, the end of a substrate processing stage may occur when a layer of substrate 120 has been sufficiently removed or etched through to expose the underlying layer. In another example, the end of a substrate processing stage may occur when the desired dimensions (such as the desired height of a feature or film thickness) have been achieved. Determining the end of a substrate processing stage allows processing of substrate 120 to be stopped once the stage is complete, thus reducing substrate defects, such as over-etching or under-etching of substrate 120. The end of one or more substrate processing stages can be determined by monitoring the radiation emission from plasma in processing chamber 100, the intensity and wavelength of which vary depending on the composition of the excitation gas. For example, a change in the composition of the excitation gas can be caused by etching through a capping layer to expose the underlying layer on substrate 120. Therefore, detection system 164 analyzes the radiation emission to determine the degree of substrate processing or other conditions in processing chamber 100.

[0030] The detection system 164 further includes a light source 166, a lens assembly 168, a photodetector 170, a beam splitter 172, and a controller 150. The light source 166 is configured to emit a light beam through the beam splitter 172 and through the fiber bundle 104. The light beam strikes the substrate 120 and is reflected back through the fiber bundle 104. After passing through the fiber bundle 104 and the beam splitter 172, the light beam returns to the photodetector 170. For example, the lens assembly 168 is configured to focus the light beam onto the incident beam 176. The incident beam 176 passes through the top plate 103 toward the substrate support surface 188 and illuminates an area or beam spot 180 on the surface 121 of the substrate 120. In one embodiment, which can be combined with other examples, the detection system 164 can manipulate the lens assembly 168 such that the beam spot 180 falls on different areas of the substrate 120 for measurement.

[0031] An incident beam 176 is reflected by surface 121 of substrate 120 to form a reflected beam 178. At least a portion of the reflected beam 178 passes through top plate 103, fiber bundle 104, and beam splitter 172 in a direction perpendicular to substrate support surface 188 and is guided back to photodetector 170. Photodetector 170 is configured to measure the intensity of the reflected beam 178. An exemplary photodetector 170 is a spectrometer.

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

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

[0034] One or more mirrors 186 and one or more focusing lenses (such as focusing lenses 174a and 174b) may be used to focus the incident 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 (such as focusing lenses 174a and 174b) may be used to focus the reflected beam 178 back onto the active surface of the photodetector 170. In one embodiment that may be combined with other examples, the mirrors may be fixed mirrors, adjustable mirrors, or digital-mirror devices (DMDs). The size or area of ​​the beam spot 180 should be large enough to compensate for variations in the surface topography and component design features of the substrate 120. The size of the beam spot 180 enables the detection of features and characteristics of the substrate 120, such as characteristic pitch and depth, film thickness, and other physical properties. The area of ​​the reflected beam is large enough to activate most of the active photodetector surface of the photodetector 170.

[0035] An incident beam 176 and a reflected beam 178 are guided through a transparent window 182 of the processing chamber 100. The transparent window 182 allows the incident beam 176 and the reflected beam 178 to pass into and out of the processing environment of the processing chamber 100. A substrate support surface 188 on which a substrate 120 is placed is disposed parallel to a top plate 103 of a substrate support 116. In one embodiment, the transparent window 182 is located in the top plate 103 of the processing chamber 100 and oriented relative to the substrate 120 and the substrate support 116. The transparent window 182 is configured to receive an incident beam from a detection system 164. The transparent window 182 allows the incident beam 176 to be transmitted to the substrate. The transparent window 182 also allows the reflected beam 178 to pass through it after being reflected from the substrate 120. The transparent window 182 is further configured to transmit the reflected beam 178 to the detection system 164.

[0036] Controller 150 is electrically coupled to detection system 164 via wiring 158. Detection system 164 includes photodetector 170, controller 150, and light source 166. Controller 150 calculates a portion of the waveform spectrum of a reflected beam 178 reflected from beam spot 180 on substrate 120 in real time and processes the spectrum using advanced spectral analysis techniques, including comparing the spectrum with stored characteristic waveform patterns. In one embodiment, which can be combined with other examples, controller 150 calculates and adjusts the position and orientation of lens assembly 168.

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

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

[0039] Typically, memory 154 is in the form of a non-transitory computer-readable storage medium containing instructions (e.g., non-volatile memory) that, when executed by CPU 152, facilitate the operation of processing chamber 100. The instructions in memory 154 are in the form of a program product, such as a program implementing the methods of this disclosure. The program code may conform to any of several different programming languages. In one instance, this disclosure may be implemented as a program product stored on a computer-readable storage medium for use with a computer system. The program product defines the functionality of the implementation (including the methods described herein).

[0040] Illustrative non-transitory computer-readable storage media include, but are not limited to: (i) non-writable storage media on which information can be permanently stored (e.g., read-only memory devices within a computer, such as CD-ROM discs readable by a CD-ROM drive, flash memory, ROM chips, or any type of solid-state non-volatile semiconductor memory device, such as a solid-state drive (SSD)); and (ii) writable storage media on which variable information is stored (e.g., floppy disks or hard disks within a disk drive, or any type of solid-state random access semiconductor memory). Such computer-readable storage media are embodiments of this disclosure when carrying computer-readable instructions that guide the functions of the methods described herein. In some embodiments, the methods described herein, or portions 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 disposal methods described herein are performed by a combination of software routines, ASICs, FPGAs, and other types of hardware implementations. One or more controllers 150 may be used with one or any combination of the various systems described herein.

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

[0042] An incident beam 176 originating from light source 166 is collected by fiber bundle 104. The incident beam is received by beam splitter 172. In some instances, beam splitter 172 is positioned along the length of fiber bundle 104. In other instances, beam splitter 172 may be positioned at light source 166. The incident beam 176 originating from light source 166 is transmitted through beam splitter 172 and exits fiber bundle 104 at fiber bundle exit 264. Fiber bundle exit 264 is positioned above lens assembly 168, which includes lenses that act as collimators. The incident beam 176 has an initial spot size approximately equal to the diameter of the fiber. For example, the diameter of the initial spot size 260 may be approximately 100 micrometers (μm). As the incident rays 236 interact with different portions of lens assembly 168, the incident beam 176 exits fiber bundle exit 264 in an unfolded pattern. The incident rays 236 then pass through lens assembly 168, where they are collimated and propagate toward substrate 120. After impacting the substrate 120, the incident light 236 is reflected back to the fiber bundle 104 as a reflected light 240.

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

[0044] After passing through the lens assembly, the reflected light 240 returns to the fiber bundle 104. The reflected light 240 together form the reflected beam 178. The reflected light 240 then returns to the beam splitter 172. A first portion (e.g., about 50%) of the reflected beam 178 received at the beam splitter 172 is then transmitted to the detection system 164 via the return fiber bundle 208.

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

[0046] An incident light beam 176 emitted by light source 166 is received by fiber bundle 104. Fiber bundle 104 includes a plurality of optical fibers. Each of the plurality of optical fibers in fiber bundle 104 has a diameter between approximately 0.01 mm and 1 mm. For example, the diameter of each of the plurality of optical fibers in fiber bundle 104 is approximately 0.5 mm. Fiber bundle 104 transmits the incident light beam 176 and receives it through beam splitter 172. In some embodiments, beam splitter 172 is disposed along the length of fiber bundle 104. In other embodiments, beam splitter 172 may be disposed at light source 166. In other embodiments, beam splitter 172 may be disposed at an end of fiber bundle 104.

[0047] A first portion (e.g., about 50%) of the received incident beam 176 is transmitted as a reference beam 206 through the beam splitter 172, through the return fiber bundle 208, and the detection system 164. The reference 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 beam 176 is transmitted through the beam splitter 172 and exits the fiber bundle 104 at the fiber bundle exit 264.

[0048] The fiber bundle outlet 264 is positioned above the lens assembly 168, illustrated by the fiber-to-lens distance 252. The incident beam 176 has an initial spot size approximately equal to the diameter of the fiber in the plurality of fibers of the fiber bundle 104. For example, the initial spot size 260 has a diameter between about 0.01 mm and 1 mm. For example, the diameter of the initial spot size 260 is about 0.5 mm. The fiber-to-lens distance 252 is from about 40 mm to about 80 mm. For example, the fiber-to-lens distance 252 is about 50 mm.

[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 between about 1:1 and about 10:1. For example, the ratio of the lens-to-substrate distance 254 is about 4:1. In another example, the ratio of the lens-to-substrate distance 254 is about 5:1.

[0050] As the incident light rays 236 interact with different portions of the lens assembly 168, the incident beam 176 exits the fiber bundle exit 264 in an unfolded pattern. The incident light rays 236 then pass through the lens assembly 168, where they are focused but not collimated, and propagate toward the substrate 120.

[0051] After impacting the substrate 120, the incident light 236 is reflected back to the fiber bundle 104 as reflected light 240. Due to space constraints, the distance from the fiber bundle exit 264 to the lens assembly 168 is typically smaller than the distance between the lens assembly 168 and the surface of the substrate 120. This results in a magnification of the substrate image size 242 on the surface of the substrate 120. For example, the substrate image size 242 can be larger than the initial spot size 260 by approximately the ratio of the distance 254 from the lens to the substrate to the distance 252 from the fiber to the lens. For example, the substrate image size 242 has a diameter between approximately 0.01 mm and 10 mm. For example, the diameter of the substrate image size 242 is approximately 0.4 mm. For example, the diameter of the substrate image size 242 is approximately 0.1 mm. For example, the diameter of the substrate image size 242 is approximately 4 mm. Figure 2 In contrast, the optical path described herein provides a reduction in the substrate image size 242. Reducing the substrate image size 242 results in the reflected signal / spectrum containing less information about non-targeted areas of the substrate, thereby increasing system sensitivity and detail resolution.

[0052] The reflected light ray 240 returns to the lens assembly 168. After passing through the lens assembly 168, the reflected light ray 240 is transmitted to the fiber bundle 104. The reflected light rays 240 together form the reflected beam 178. In one example, the fiber bundle 104 may be concentric with the lens assembly 168. The received reflected light ray 240 is then transmitted to the beam splitter 172. A first portion (e.g., about 50%) of the reflected beam 178 received at the beam splitter 172 is then transmitted to the detection system 164 via the return fiber bundle 208. A second portion (e.g., about 50%) of the reflected beam 178 received at the beam splitter 172 is transmitted to the light source 166 via the fiber bundle 104.

[0053] Figure 4 This is a schematic cross-sectional view showing the fiber bundle design of a multi-point hyperspectral system and the optical path of the fiber bundle 310 configured to transmit and receive light in the processing chamber 100.

[0054] An incident beam 176 originating from light source 166 is collected by an 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, such as optical fibers 302a, 302b, 302c, and 302d. Each of the plurality of optical fibers 302 has a diameter between approximately 0.01 mm and 1 mm. For example, optical fiber 302 has a diameter of approximately 0.5 mm. Each of the plurality of optical fibers 302 includes an optical fiber bundle outlet 264.

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

[0056] In one embodiment that can be combined with other examples, beam splitter 172 optically separates reference beam 206 from incident beam 176. In another embodiment that can be combined with other examples, beam splitter 172 separates reference beam 206 from incident beam 176 by redirecting a portion of a plurality of optical fibers 302 from fiber bundle 310 to return fiber bundle 312. In one embodiment that can be combined with other examples, reference beam 206 may be attenuated before being received by detection system 164. In one embodiment that can be combined with other examples, reference beam 206 may be attenuated by detection system 164. As shown and below. Figure 5A The explanation is that the detection system 164 uses a reference beam 206 to reduce noise and improve the signal-to-noise ratio (SNR).

[0057] In another embodiment, which can be combined with other examples, beam splitter 172 allows first portions of multiple return fibers to each receive a sub-portion of a reference beam corresponding to a region of light source 166, and allows second portions of multiple return fibers to each receive a sub-portion of a reflected beam initially corresponding to the same region of the light source. This is illustrated and described below. Figure 5B The explanation is that this allows for additional SNR improvement, or allows for SNR improvement through the measurement of each region of the substrate by the detection system 164.

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

[0059] The fiber bundle exit 264 of the fiber bundle 310 is positioned further than the focal point of the focusing lens 174b, shown as the fiber-to-lens distance 252. The fiber-to-lens distance 252 is approximately 40 mm to approximately 80 mm. For example, the fiber-to-lens distance 252 is approximately 50 mm. The focusing lens 174b additionally has a lens-to-substrate distance 254 from the substrate 120. An 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 near the substrate image size 242. The area of ​​the substrate image size 242 formed by the incident light ray 236 is larger than the exit of the fiber bundle 310. The larger area of ​​the substrate image size 242 is generally attributed to space constraints. For example, the fiber-to-lens distance 252 is generally smaller than the lens-to-substrate distance 254, resulting in an increased area of ​​the substrate image size 242 on the substrate.

[0060] After impacting the substrate 120, the reflected light 178, as the reflected ray 240, is reflected back to the fiber bundle 310. The reflected ray 240, reflected by the substrate 120, returns to the focusing lens 174b. After passing through the focusing lens 174b, the reflected ray 240 returns to the same fiber among the plurality of fibers 302 from which the incident ray 236 originated. For example, to fibers 302a, 302b, 302c, and 302d. In other embodiments that can be combined with other examples, the reflected ray 240 returns to a fiber among the plurality of fibers 302 that is different from the fiber among the plurality of fibers from which the incident ray 236 originated.

[0061] The reflected light 240 then returns to the beam splitter 172. Approximately 50% of the reflected beam 178 received at the beam 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 beam 178 received at the beam splitter 172 is then transmitted via the fiber bundle 310 to the light source 166.

[0062] In one instance that can be combined with other examples, the detection system 164 is capable of measuring multiple wavelengths (broadband spectrum) of the reflected beam 178 collected by each of the multiple optical fibers 302.

[0063] In other instances that can be combined with other examples, the reflected beam 178 may be filtered or unfiltered, attenuated or unattenuated, and the total power of each of the multiple optical fibers 302 may be measured using a photodiode or charge-coupled device (CCD) employed in the detection system 164.

[0064] In other embodiments that can be combined with other examples, the detection system 164 is capable of simultaneously measuring multiple wavelengths (broadband spectrum) of reflected light beams 178 collected by each of the multiple optical fibers 302. Each of the multiple optical fibers 302 transmits reflected light 240 collected from different locations on the substrate to different parts of the detection system 164, enabling the detection system 164 to perform multi-location multispectral measurements simultaneously.

[0065] Figure 4A This is a cross-sectional view of the exit of an optical fiber bundle 310 configured to transmit and receive light in a processing chamber 100, according to an embodiment of this disclosure. More specifically, Figure 4A The diagram shows an incident beam 176, acting as incident light 236, transmitted 236 through multiple optical fibers 302. The incident light 236 emitted from each fiber bundle exit 264 has an initial spot size 260 approximately equal to the diameter of the fiber bundle 104. The initial spot size 260 of the multiple optical fibers 302 is relative to... Figure 2 The initial spot size of 260 is shown as a reduction.

[0066] Figure 4B This is an example cross-sectional view of a light beam transmitted from a plurality of optical fibers 302 in a receiving state and reflected at the surface of substrate 120, according to an embodiment of the present disclosure. More specifically, Figure 4B This is a cross-sectional view of the incident light 236 received from multiple optical fibers 302, namely optical fibers 302a, 302b, 302c, and 302d, and reflected as reflected light 240 from multiple reflecting regions 302', namely reflecting regions 302a', 302a', 302a', and 302a', which fall within... Figure 4 The substrate image size 242 is located in or near the area on the substrate 120 shown. The reflected light ray 240 emitted from the reflective 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 between about 0.1 mm and 10 mm. The substrate image size 242 is about 0.05 mm to 4 mm. For example, the substrate image size 242 is about 1 mm. Figure 4B The substrate image size 242 shown is relative to Figure 2 The size of the substrate image 242 shown in B is reduced. Each of the multiple reflective regions 302' simultaneously returns the multicolor reflectance spectrum of different regions of the substrate, which is used for analysis and measurement by the detection system 164.

[0067] The fiber bundle 310 disclosed herein increases 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 relative to... Figure 2 The substrate image size 242 is reduced in this example. In one example that can be combined with other examples, reducing the input fiber diameter allows for a reduced substrate image size 242, which, when compared to current reflectance measurement devices and methods, allows for an improvement in spatial resolution of approximately ten times or more.

[0068] In another example that can be combined with other examples, the fiber bundle 310 disclosed herein improves reflectometer sensitivity by having multiple fibers 302, allowing the entire spectrum of each fiber to measure a smaller and separate region of the substrate. In another example that can be combined with other examples, increasing the number of reflective regions 302' (each with a reduced substrate image size 242) allows for the simultaneous and separate analysis of more regions of the substrate, and provides increased sensitivity compared to current reflectometer apparatuses and methods. In another example that can be combined with other examples, increasing the number of reflective regions 302' with reduced substrate image size 242 allows for differential measurements with improved detection sensitivity. For example, reflective region 302a' may fall on a portion of the substrate that is featureless, has fewer or more features than reflective region 302d', thereby allowing differential measurements between two regions of the substrate. In another example that can be combined with other examples, increasing the number of reflective regions 302' with reduced substrate image size 242 allows each portion of the reflected beam 178 collected by the multiple fibers 302 to enter a different portion of the detection system 164 for analysis.

[0069] Figure 5A The figure 500, titled “Single Wavelength Reference,” illustrates the intensity drift of an example light source (e.g., light source 166) over time and how a detection system (e.g., detection system 164) compensates for the intensity drift by improving signal stability and SNR through the reference.

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

[0071] Chart 500 includes two plotted trend lines, a first trend line 502 and a second trend line 504. The first trend line 502 shows the intensity drift of an example light source (e.g., light source 166) over time. Observing the first trend line 502, it shows that initially, the intensity of the light source first begins with a sharp increase in intensity 502a, followed by a sharp decrease in intensity 502b. Shortly thereafter, the intensity decrease begins to gradually slope, 502c, and reaches a semi-continuous intensity 502d.

[0072] This change in intensity over time introduces problems for the detection system. Without a reference, as shown by the first trend line 502, a measurement taken at one point in time cannot be reliably compared with a measurement taken at a later point in time because the change in intensity inherently alters the measured value.

[0073] The second trend line 504 shows the intensity drift of the example light source (e.g., light source 166) over time and is referenced by the detection system 164. With the reference in place, the sharp increases and decreases of the first trend line 502 are replaced by a damped rise 504a, followed by a constant intensity value 504b. With the reference in place, the intensity of the light source is normalized, and the SNR is improved.

[0074] Figure 5B The diagram 550, titled "Multi-wavelength Reference," illustrates the SNR improvement over multiple wavelengths of light obtained by referencing the detection system 164. 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 improvement in signal-to-noise ratio.

[0075] Figure 550 includes two plotted areas: a first area 552 without a reference and a second area 554 with a reference. The first area 552 shows a small improvement in the SNR across multiple wavelengths of light as lamp intensity increases without a reference. The second area 554 shows that, with a reference, the detection system 164 described herein can improve the SNR across multiple wavelengths of light.

[0076] Figure 6 This is a flowchart of a method 600 for emitting and collecting reflected light in a processing chamber according to an example of this disclosure. Method 600 may be referenced. Figure 4 ,and Figures 4A to 4B To understand. Figure 6 This includes a simplified version of the claimed object and is not intended to limit this disclosure.

[0077] Operation 610 of method 600 includes transmitting a first portion of the incident beam to at least one region of a substrate 120 disposed within the processing chamber 100.

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

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

[0080] Operation 610 of method 600 may include focusing a first portion of the incident beam 176 as incident light from the lens assembly 168 onto at least one region of the substrate 120 disposed within the processing chamber 100. Operation 610 of method 600 may include receiving at least a first sub-portion of the incident beam 176 from the beam splitter 172 via the fiber bundle 310, and focusing at least a first sub-portion of the incident beam 176 as incident light 236 from the lens assembly 168 onto at least one region of the substrate 120.

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

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

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

[0084] Operation 630 of method 600 includes receiving a first portion of an incident beam 176 from at least one region of substrate 120 as a reflected beam 178 at detection system 164.

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

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

[0087] Operation 640 of method 600 includes determining at least one characteristic of a region of substrate 120.

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

[0089] Operation 640 of method 600 may include analyzing the full spectrum of the reflected beam 178 in part based on the first SNR, wherein the full spectrum is between about 200 nanometers (nm) and about 800 nm.

[0090] Operation 640 of method 600 may include determining, based on a first SNR and by analyzing the full spectrum of the reflected beam 178, at least one height of a feature disposed on at least one region substrate 120, at least one size of a feature disposed on at least one region substrate 120, at least one wavelength of radiative emission of plasma from at least one region of substrate 120, at least one intensity of radiative emission of plasma from at least one region of substrate 120, or a combination thereof.

[0091] Operation 640 of method 600 may include receiving at least a first sub-portion of reference beam 206, wherein the at least first sub-portion of reference beam 206 corresponds to at least a first sub-region of light source 166; receiving at least a second sub-portion of reference beam 206, wherein the at least second sub-portion of reference beam 206 corresponds to at least a second sub-region of light source 166; and receiving at least a first sub-portion of reflected beam 178 from at least a first region of substrate 120, wherein the at least first sub-portion of reflected beam 178 corresponds to at least a first sub-portion of incident light. The sub-part corresponds to at least a first sub-region of the light source 166 and receives at least a second sub-part of the reflected beam 178 from at least a second region of the substrate 120, wherein the at least second sub-part of the reflected beam 178 corresponds to 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 second sub-region of the light source 166, the first sub-part of the reflected beam 178 is referenced to the first sub-part of the reference beam 206 to improve the first SNR, and the second sub-part of the reflected beam 178 is referenced to the second sub-part of the reference beam 206 to improve the second SNR.

[0092] Operation 640 of method 600 may include analyzing the full spectrum of at least a first sub-portion of the reflected beam 178 in part based on a first SNR, wherein the full spectrum is between about 200 nanometers (nm) and about 800 nm, and analyzing the full spectrum of at least a second sub-portion of the reflected beam 178 in part based on a second SNR, wherein the full spectrum is between about 200 nanometers (nm) and about 800 nm.

[0093] Operation 640 of method 600 may include determining at least one characteristic of at least a first region of substrate 120 based on an improved first SNR and analysis of the full spectrum of at least a first sub-portion of reflected beam 178, wherein determining at least one characteristic further includes determining: at least one height of a feature disposed on at least a first region of substrate 120, at least one size of a feature disposed on at least a first region of substrate 120, at least one wavelength of radiative emission of plasma from at least a first region of substrate 120, at least one intensity of radiative emission of plasma from at least a first region of substrate 120, or a combination thereof, and analyzing the full spectrum of at least a second sub-portion of reflected beam 178 based on an improved first SNR. The spectroscopy is used to determine at least one characteristic of at least a second region of the substrate 120, wherein determining at least one characteristic further includes determining: at least one height of a feature disposed on at least a second region of the substrate 120, at least one size of a feature disposed on at least a second region of the substrate 120, at least one wavelength of radiative emission of plasma from at least a second region of the substrate 120, at least one intensity of radiative emission of plasma from at least a second region of the substrate 120, or a combination thereof, 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 to improve the detection density of at least one characteristic of at least a second region of the substrate 120.

[0094] Operation 560 of method 600 includes repeating the previous operations as needed, namely operations 610, 620, 630 and / or 640, until the measurement and analysis of substrate 120 is completed.

[0095] Additional considerations

[0096] Although this specification contains numerous details of specific embodiments, these should not be construed as limiting the scope of claims, but rather as descriptions of features specific to particular embodiments. Certain features described herein may also be implemented in combination in a single embodiment within the context of separate embodiments. Conversely, individual features described in the context of a single embodiment may also be implemented separately in multiple embodiments or in any suitable sub-combination. Furthermore, although previously described features may be described as functioning in certain combinations and even initially claimed in this way, in some cases, one or more features from the claimed combination may be removed from that combination, and the claimed combination may be for sub-combinations or variations thereof.

[0097] Specific implementations of the objective have been described. Other implementations, modifications, and arrangements of the described implementations are within the scope of the appended claims, as will be apparent to those skilled in the art. Although operations are depicted in a specific order in the drawings or claims, this should not be construed as requiring that such operations be performed in the specific or sequential order shown, or that all shown operations (some operations may be considered optional) to achieve the desired result. In some cases, multitasking or parallel processing (or a combination of multitasking and parallel processing) may be advantageous and performed as deemed appropriate.

[0098] Furthermore, the separation or integration of the various system modules and components in the previously described embodiments should not be construed as requiring such separation or integration in all embodiments. It should be understood that the described program components and systems can typically be integrated together in a single software product or packaged into multiple software products.

[0099] Therefore, the exemplary embodiments described above do not define or limit this disclosure. Other changes, substitutions, and modifications are possible without departing from the spirit and scope of this disclosure.

[0100] Although the steps in the implementation method or process are presented and described sequentially, those skilled in the art will understand that some or all of the steps may be performed in a different order, may be combined or omitted, and some or all of the steps may be performed in parallel. Steps may be performed actively or passively. The method or process may be repeated or extended to support multiple components or multiple users within a field environment. Therefore, the scope should not be considered limited to the specific arrangement of the steps shown in the flowchart or diagram.

[0101] Unless otherwise defined, all technical and scientific terms used have the same meaning as commonly understood by one of ordinary skill in the art to which such systems, equipment, methods, processes and components pertain.

[0102] In this disclosure, the terms “top,” “bottom,” “side,” “above,” “below,” “up,” “down,” “upward,” “downward,” “horizontal,” “vertical,” and the like do not refer to absolute directions. Rather, these terms refer to directions relative to a non-specific reference plane. This non-specific reference plane may be vertical, horizontal, or other angularly oriented.

[0103] Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” include plural references. Within the claims, references to elements in the singular form are not intended to mean “one and only one,” but rather “one or more” unless specifically stated otherwise. Unless specifically stated otherwise, the term “some” refers to one or more.

[0104] Embodiments of this disclosure may suitably “comprise the disclosed limiting features,” “belong to the disclosed limiting features,” or “consistently consist of the disclosed limiting features,” and may be practiced without any undisclosed limiting features. As used herein and in the appended claims, the words “comprising,” “having,” and “including,” and all their grammatical variations, are intended to have an open, non-limiting meaning that does not exclude additional elements or steps.

[0105] "Optional" and "depending on the circumstances" mean that the material, event, or situation described below may or may not exist or occur. The description includes instances where the material, event, or situation has occurred and instances where it has not occurred.

[0106] As used, the term "determine" encompasses a wide variety of actions. For example, "determine" can include calculation, operation, processing, derivation, investigation, lookup (e.g., searching in a table, database, or other data structure), and confirmation. Furthermore, "determine" can include receiving (e.g., receiving information) and accessing (e.g., accessing data in memory). Additionally, "determine" can include solving, selecting, choosing, and building.

[0107] When the terms “approximately” or “about” are used, this term may mean that the difference in values ​​can be as high as ±10%, up to 5%, up to 2%, up to 1%, up to 0.5%, up to 0.1%, or up to 0.1%.

[0108] A range can be expressed as from about one specific value to about another specific value, including end values. When expressing such a range, it will be understood that another implementation is from one specific value to another specific value, together with all specific values ​​within that range and their combinations.

[0109] As used, terms such as “first” and “second” are arbitrarily designated and intended only to distinguish between two or more components of a system, device, or assembly. It will be understood that the terms “first” and “second” serve no other purpose and are not names or descriptive parts of the components, nor do they necessarily define the relative location or position of the components. Furthermore, it will be understood that the mere use of the terms “first” and “second” does not require the existence of any “third” component, although such possibilities are contemplated within the scope of the various embodiments described.

[0110] As used, “CPU,” “processor,” “at least one processor,” or “one or more processors” generally refers to a single processor configured to perform one or more operations, or multiple processors configured to collectively perform one or more operations. In the case of multiple processors, the performance of one or more operations may be distributed among the different processors, although one processor may perform multiple operations, and multiple processors may collectively perform a single operation. Similarly, “memory,” “at least one memory,” or “one or more memory” generally refers to a single memory configured to store data and / or instructions, or multiple memory modules configured to collectively store data and / or instructions.

[0111] Although only a few exemplary embodiments have been described in detail, those skilled in the art will readily understand that numerous modifications to the exemplary embodiments are possible without substantially departing from the scope of the described disclosure. Therefore, all such modifications are intended to be included within the scope of this disclosure, as defined in the following claims.

Claims

1. An optical reflectance measurement system, the optical reflectance measurement system comprising: A processing chamber having a top plate, side walls, and a bottom defining an internal volume, wherein the top plate includes a transparent window; A substrate support located within the internal volume, wherein the substrate support is configured to receive a substrate; A light source, located outside the internal volume, is configured to transmit an incoming light beam; An optical fiber bundle, located outside the internal volume, comprising at least one first optical fiber coupled to the light source and optically coupled to a lens assembly, wherein the lens assembly is disposed above the transparent window and optically coupled to at least the first optical fiber, and configured as follows: The incident light beam is transmitted as an incident ray through the transparent window to at least one area of ​​the substrate. Reflected light from at least one region of the substrate is received through the transparent window, and The reflected light is transmitted as a reflected beam to the fiber bundle; A beam splitter, wherein the beam splitter is disposed within the fiber bundle; as well as Return fiber bundle, the return fiber bundle including at least one first return fiber coupled to the beam splitter and coupled to the detection system, wherein the detection system is configured to: The reference beam and the reflected beam are used to improve the signal-to-noise ratio (SNR). The full spectrum of the reflected beam is analyzed in part based on the SNR, and Based on the analysis, at least one characteristic of at least one region of the substrate is determined.

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

3. The optical reflection measurement system of claim 1, wherein the at least one characteristic of the at least one region of the substrate comprises: At least one height of the feature provided in at least one region of the substrate; At least one dimension of a feature disposed on at least one region of the substrate; At least one wavelength of radiation emitted by plasma from at least one region of the substrate; At least one intensity of the radiation emission of the plasma from at least one region of the substrate; or Its combination.

4. The optical reflection measurement system as claimed in claim 1, wherein the light source is a monochromatic light source.

5. The optical reflection measurement system as claimed in claim 1, wherein the light source is a multicolor light source.

6. The optical reflection measurement system of claim 1, wherein at least the first optical fiber is configured as follows: Receive at least one sub-portion of the incident beam from at least one first sub-region of the light source; Transmitting at least the sub-part of the incident beam; Receive at least the sub-part of the reflected beam; as well as Transmit at least the sub-part of the reflected beam.

7. The optical reflection measurement system of claim 1, wherein at least the first optical fiber has a diameter between about 0.1 mm and about 0.5 mm.

8. The optical reflection measurement system of claim 1, wherein the region of the at least one area of ​​the substrate has a substrate image size with a diameter between about 0.1 mm and about 10 mm.

9. The optical reflection measurement system of claim 1, wherein at least the first return fiber is configured as follows: Receive at least one sub-portion of the reference beam; Transmitting at least the sub-part of the reference beam; Receives at least a first sub-part of the reflected beam; and Transmit at least the sub-part of the reflected beam.

10. The optical reflection measurement system of claim 1, wherein the beam splitter is configured as follows: Receive at least one sub-portion of the incident beam from at least the first optical fiber; The incident beam is divided into at least one first sub-part and at least one second sub-part of incident light. Transmit the at least first sub-portion of the incident light to at least the first optical fiber; Transmit at least the second sub-portion of the incident light to at least one sub-portion of the reference beam, which is at least the first return fiber. Receive at least the sub-part of the reflected beam; as well as At least a portion of the reflected beam is transmitted to at least one second return fiber.

11. The optical reflectance measurement system of claim 1, wherein the lens assembly comprises at least one focusing lens, and the lens assembly is configured to: Receive at least a first sub-portion of incident light from at least the first optical fiber; The at least one first sub-portion of the incident light is focused onto at least one region of the substrate; Receives reflected light from at least one region of the substrate; as well as The reflected light is transmitted as at least a first sub-part of the reflected beam to the at least first optical fiber.

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

13. The optical reflectance measurement system of claim 1, wherein the detection system comprises a spectral reflectance measurement system, further configured as follows: Receiving at least one sub-portion of the reference beam, wherein at least said sub-portion of the reference beam corresponds to at least one first sub-region of the light source; and Receive at least one sub-portion of the reflected beam, wherein the at least said sub-portion of the reflected beam corresponds to at least the first sub-region of the light source.

14. A method for measuring optical reflectance, the method comprising: The incident beam is transmitted from the light source to the beam splitter through an optical fiber bundle containing at least one first optical fiber. The first portion of the incident beam is transmitted from the beam splitter to the lens assembly via the fiber optic bundle; The second portion of the incident beam is transmitted from the beam splitter to the detection system as a reference beam via a return fiber bundle containing at least one return fiber. The first portion of the incident beam is focused as incident light from the lens assembly onto at least one region of a substrate disposed within the processing chamber. The lens assembly receives reflected light from at least one region of the substrate; The reflected light is transmitted to the beam splitter as a reflected beam from the lens assembly via the fiber bundle; The reflected beam from the beam splitter is transmitted to the detection system via the return fiber bundle; The reflected beam is referenced to the reference beam to improve the signal-to-noise ratio (SNR); The full spectrum of the reflected beam is analyzed in part based on the improved SNR; as well as Based on the analysis, at least one characteristic of at least one region of the substrate is determined.

15. The method of claim 14, wherein transmitting the incident beam from the light source to the beam splitter further comprises: Transmit at least a sub-portion of the incident beam from at least a first sub-region of the light source to the at least first optical fiber; and The at least one sub-portion of the incident beam from the at least first optical fiber is received at the beam splitter.

16. The method of claim 14, wherein transmitting the first portion of the incident beam from the beam splitter to the lens assembly further comprises: dividing the at least one sub-portion of the incident light beam into at least one first sub-portion of incident light, wherein the at least one first sub-portion of incident light corresponds to the at least one first sub-region of the light source; as well as The incident light is returned from the beam splitter to the at least first optical fiber; as well as The at least one first sub-portion of the incident light is transmitted from the at least first optical fiber to the lens assembly.

17. The method of claim 14, wherein transmitting the second portion of the incident beam as the reference beam from the beam splitter to the detection system further comprises: The incident beam is divided into at least one sub-part of the incident light and at least one second sub-part of the incident light, wherein the at least one second sub-part of the incident light corresponds to the at least one first sub-region of the light source; The at least one second sub-portion of the incident light is transmitted from the beam splitter to the at least one first return fiber as at least one first sub-portion of the reference beam; as well as The detection system receives at least one first sub-portion of the reference beam from at least the first return fiber, wherein the at least one first sub-portion of the reference beam corresponds to the at least one first sub-region of the light source.

18. The method of claim 14, wherein focusing the first portion of the incident light beam as incident light from the lens assembly onto at least one region of a substrate disposed within the processing chamber further comprises: At least a first sub-portion of the incident beam from the beam splitter is received through the fiber optic bundle; and The at least one first sub-portion of the incident beam is focused as an incident ray from the lens assembly onto at least one region of the substrate.

19. The method of claim 14, wherein transmitting the reflected light as the reflected beam from the lens assembly to the beam splitter via the fiber bundle further comprises: The reflected light is received at least one region of the substrate at the lens assembly; and The reflected light is transmitted from the lens assembly as at least a first sub-part of the reflected beam to at least the first optical fiber.

20. The method of claim 14, wherein referencing the reflected beam to the reference beam to improve the signal-to-noise ratio further comprises: Receive at least one first sub-part of the reference beam, wherein the at least one first sub-part of the reference beam corresponds to the at least one 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, wherein the at least first sub-portion of the incident light corresponds to the at least first sub-region of the light source; and The first sub-part of the reflected beam is referenced to the first sub-part of the reference beam to improve the first signal-to-noise ratio (SNR).

21. The method of claim 14, wherein analyzing the full spectrum of the reflected beam in part based on the improved SNR further comprises: The full spectrum of at least a first sub-part of the reflected beam is analyzed in part based on a first signal-to-noise ratio (SNR), wherein the full spectrum is between about 200 nanometers (nm) and about 800 nm.

22. The method of claim 14, wherein determining at least one characteristic of the at least one region of the substrate further comprises: The determination is based on the first signal-to-noise ratio (SNR) and analysis of the full spectrum of the reflected beam: At least one height of a feature disposed on at least one region of the substrate; At least one dimension of the feature provided in at least one region of the substrate; At least one wavelength of radiation emitted by plasma from at least one region of the substrate; At least one intensity of the radiation emission of the plasma from at least one region of the substrate; or Its combination.

23. The method of claim 14, wherein referencing the reflected beam to the reference beam to improve the signal-to-noise ratio (SNR) further comprises: Receive at least one first sub-portion of the reference beam, wherein the at least one first sub-portion of the reference beam corresponds to at least one first sub-region of the light source; Receive at least one second sub-portion of the reference beam, wherein the at least one second sub-portion of the reference beam corresponds to at least one second sub-region of the light source; Receive at least a first sub-part of the reflected light beam from at least a first region of the substrate, wherein the at least first sub-part of the reflected light beam corresponds to at least a first sub-part of the incident light, wherein the at least first sub-part of the incident light corresponds to the at least first sub-region of the light source; Receive at least a second sub-part of the reflected light beam from at least a second region of the substrate, wherein the at least second sub-part of the reflected light beam corresponds to at least a second sub-part of the incident light, wherein the at least second sub-part of the incident light corresponds to the at least second sub-region of the light source; The first sub-part of the reflected beam is referenced to the first sub-part of the reference beam to improve the first SNR; and The second sub-part of the reflected beam is referenced to the second sub-part of the reference beam to improve the second SNR.

24. The method of claim 14, wherein analyzing the full spectrum of the reflected beam in part based on the improved SNR further comprises: The full spectrum of at least a first sub-portion of the reflected beam is analyzed, in part, based on a first signal-to-noise ratio (SNR), wherein the full spectrum is between about 200 nanometers (nm) and about 800 nm; and The full spectrum of at least a second sub-part of the reflected beam is analyzed in part based on the second SNR, wherein the full spectrum is between about 200 nanometers (nm) and about 800 nm.

25. The method of claim 14, wherein determining at least one characteristic of the at least one region of the substrate based on the analysis further comprises: Based on the improved first SNR and analysis of the full spectrum of at least a first sub-part of the reflected beam, at least one characteristic of at least a first region of the substrate is determined, wherein determining the at least one characteristic further comprises determining: At least one height of a feature disposed on at least the first region of the substrate; At least one dimension of a feature disposed on at least the first region of the substrate; At least one wavelength of radiation emitted by plasma from at least the first region of the substrate; At least one intensity of the radiation emission of the plasma from at least the first region of the substrate; or Its combination; Based on the improved second SNR and by analyzing the full spectrum of at least a second sub-part of the reflected beam, at least one characteristic of at least a second region of the substrate is determined, wherein determining the at least one characteristic further comprises determining: At least one height of a feature disposed on at least the second region of the substrate; At least one dimension of a feature disposed on at least the second region of the substrate; At least one wavelength of radiation emitted by plasma from at least the second region of the substrate; At least one intensity of the radiation emission of the plasma from at least the second region of the substrate; or Its combination; as well as The at least one characteristic of at least the first region of the substrate is compared with the at least one characteristic of at least the second region of the substrate to improve the detection density of the at least one characteristic of at least the second region of the substrate.

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