Optical sensing platform

Abstract

Embodiments of multi-channel optical sensor system are disclosed. In one embodiment, the multi-channel optical sensor system includes a sensor platform, a first sensor-side optical pathway, a second sensor-side optical pathway, and a separable optical interface having a sensor-side optical interface and a system-side optical interface that are configured to optically couple the first sensor-side optical pathway to the first system-side optical pathway and optically couple the second sensor-side optical pathway to the second system-side optical pathway. The first sensor-side optical pathway and the second sensor-side optical pathway are configured to optically collect first and second optical response signals that are representative of a characteristic to be measured. The multi-channel optical sensor system further includes an analyzer is configured to determine a first characteristic based on the first optical response signal and determine a second characteristic based on the second optical response signal.

Description

OPTICAL SENSING PLATFORMCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims priority to U.S. Provisional Application Serial No. 63 / 709,654 filed on October 21, 2024, entitled “Optical Sensing Platform”, the contents of which are incorporated herein by reference.TECHNICAL FLIED

[0002] The following generally relates to optical sensing, and particularly to an optical sensing platform for semiconductor applications including a separable optical interface.BACKGROUND

[0003] Optical sensors are used for a variety of applications, including but not limited to the measurement of temperature, strain, pressure, position, distance, plasma intensity, ion energy, gas concentration, gas temperature, gas flow, chemical concentrations, gas species and the like, as well as the distribution and / or uniformity of such characteristics. Optical sensors have the advantage that they are immune to radio-frequency energy and high magnetic fields which is particularly advantageous in applications related to semiconductor manufacturing (for example to measure temperature and position of wafers, electrostatic chucks, shower heads and other components in the radio-frequency environments inside and around wafer processing chambers), high voltage environments, heating and curing, and test and measurement.

[0004] Optical sensor systems typically include an optical probe having a fiber optic or other optical pathway configured to direct light (a.k.a. an “optical response signal” from an environment or object to be sensed or measured or from sensing material(s) to a converter or analyzer to determine one or more characteristics of the object, environment, or sensing material(s).

[0005] In some cases, the sensing material(s) may be part of the optical probe while, in other cases, the optical probe and the sensing material(s) may be separate. In some cases, the optical probe assembly may include an optical connector and in some cases a separate fiber optic or other optical pathway may be used to optically connect the optical probe or optical probe assembly to the converter.

[0006] In some optical sensor systems, the optical fiber or other optical pathway may also direct light (a.k.a. an “optical excitation signal”) to the environment, object, and / or sensing material(s), for example to excite the sensing material(s) in the environment resulting in emission of light (a.k.a. an “optical response signal” or “optical excitation response signal”) from the environment or the sensing material(s) that is representative of one or more characteristics of the environment or the sensing material(s). For example, an optical sensor system may include an optical pump source (e.g., a laser or LED), whose emission is directed through the optical pathway to an optical probe containing a sensing material such as a phosphor or thermographic phosphor, thereby exciting the phosphor to phosphoresce.Characteristics of the phosphorescence, for example intensity, spectral power distribution, decay time constant and the like may be used to determine one or more characteristics, for example temperature, pressure or the like. In some optical sensor systems the optical excitation response signal may consist of all or a portion of a modified version of the optical excitation signal, for example reflected from a surface, sensing material or environment, ora spectrally modified version of the optical excitation signal, for example one or more portions of the spectrum of the optical excitation signal reduced or eliminated, for example by absorption or transmission.

[0007] In other applications, materials already in the environment, such as gases, liquids or solids, for example those used in the process itself (for example one or more semiconductor wafers or other part or parts to be processed, the gas or gases, or liquid or liquids used in the process, in any associated processes (for example chamber preparation or thermal or process parameter setup, heat-up, cool-down steps or cleaning steps or the like) or in the construction of the environment (for example one or more components of the processing chamber) may provide an optical excitation response signal, for example with or without an optical excitation signal.

[0008] In addition to measuring, sensing, or determining a characteristic at one point, it is desirable to measure the distribution or uniformity of such characteristics. For example, advances in semiconductor fabrication require increasingly tighter control of all parameters, and uniformity of those parameters, within a semiconductor chamber.

[0009] Most sensors are single point, which can provide information, for example temperature, in a specific location. Multiple single point sensors may be used to gain uniformity information, for example within one component of a process chamber or within or between multiple components, for example a chuck holding the wafer, and edge ring ora showerhead. The disadvantage of this approach utilizing single point sensors is that it requires multiple penetrations or interfaces to the sensed environment (one for each single point sensor), takes up space and becomes increasingly expensive as the number of sensors increases.

[0010] Another approach to providing larger numbers of sensing points is to use an instrumented platform that contains multiple sensors, for example a wafer-based sensor. In some examples these may have the form of a semiconductor wafer with several to tens of sensors (for example thermocouples) placed across the wafer with wired communication to a readout or analyzer unit. There are two challenges with this approach. The first is that it may not be possible to use a wired approach, for example in wafer fabrication equipment having multiple chambers and automated wafer handling. Second, because they are wired, they do not work well in high RF, voltage or magnetic field environments.

[0011] Another approach is to include a battery and electronics on the wafer that allow data to be recorded for subsequent viewing and analysis. However, these are very expensive, have extremely short lifetimes (on the order of about 4 hours) and are limited to a relatively low and narrow temperature range because of the inability of the electronics and battery to survive and operate under typical process temperatures. They cannot provide real-time data in plasma or RF systems (for example plasma etch or deposition systems) because the high-intensity RF fields preclude stable radio transmission from inside the RF environment to an external receiver. In addition, these typically cannot be used under the actual process conditions because the process gases are often corrosive and will damage the system, for example damage the battery and / or electronics.

[0012] An alternate approach to providing larger numbers of sensing points is to use a Fiber Bragg Grating (FBG) optical sensor. FBG sensors contain multiple sensing points along a single fiber, allowing relatively large number of sensing points with a single optical interface into the system. However, FBG sensors suffer from several disadvantages. One disadvantage is that they are sensitive to severaldifferent characteristics, for example temperature, pressure and strain; thus producing a system to measure, sense, or determine only one characteristic requires specialized accommodation, for example mounting, isolation, etc. These can lead to additional costs or restrictions on use in various environmental conditions such as high and low temperatures or reactive gas environments. As an example, a compliant material may be required to minimize or eliminate strain in a FBG designed for temperature sensing, but compliant materials typically have a relatively narrow operating temperature range (too low and they become less compliant and too high and they start to degrade and outgas).

[0013] What is needed is an easy-to-use, real-time system for multi-point sensing one or more characteristics simultaneously, over wide environmental conditions, that minimizes the number of penetrations or interfaces at a reasonable cost.SUMMARY

[0014] In one embodiment, the multi-channel optical sensor system comprises a sensor platform, a first sensor-side optical pathway having an optical axis and a second sensor-side optical pathway having an optical axis, each having a proximal end and a distal end. The sensor platform comprises a portion of the first sensorside optical pathway and a portion of the second sensor-side optical pathway, and the first sensor-side optical pathway and the second sensor-side optical pathway are configured to optically collect a first optical response signal and a second optical response signal, respectively, representative of a characteristic to be sensed.

[0015] The multi-channel optical sensor system further comprises a separable optical interface including a sensor-side optical interface, a system-side optical interface comprising a first system-side optical pathway having a first optical axis and a second system-side optical pathway having a second optical axis, each having a proximal end and a distal end. The sensor-side optical interface and the system-side optical interface are separable and are configured to optically couple the first sensorside optical pathway to the first system-side optical pathway and optically couple the second sensor-side optical pathway to the second system-side optical pathway. The system further comprises at least one analyzer, wherein the first system-side optical pathway and the second system-side optical pathway are optically coupled to the at least one analyzer and the at least one analyzer is configured to determine at least afirst characteristic based at least in part on the first optical response signal and determine at least a second characteristic based at least in part on the second optical response signal.

[0016] The first characteristic and the second characteristic may consist of temperature, heat flux, charge, strain, wobble, levelness, vibration, position, concentricity, one or more dimensions or distances, etch rate, deposition rate, particle concentration, electric field, voltage, temperature gradients, pressure, deposition on at least a portion of a system component, erosion of at least a portion of a system component, plasma intensity, plasma density, gas constituents, activated species or ions within a plasma, particle concentration, humidity, spectral power density, electric field, erosion of at least a portion of the shower head, deposition on at least a portion of the shower head, erosion of at least a portion of the edge ring, deposition on at least a portion of the edge ring, the spacing between a shower head and a sensor wafer platform, the planarity between a shower head and a sensor wafer platform, or the position of the sensor wafer platform relative to a wafer support.

[0017] The sensor-side optical interface or the sensor platform may include a sensor-side optical alignment feature and the system-side optical interface may include a system-side optical alignment feature wherein the sensor-side optical alignment feature and the system-side optical alignment feature are configured to align the optical axis of the first system-side optical pathway with the optical axis of the first sensor-side optical pathway and align the optical axis of the second systemside optical pathway with the optical axis of the second sensor-side optical pathway.

[0018] In some embodiments, the first system-side optical pathway and second system-side optical pathways comprise a single imaging optical fiber having a proximal end and a distal end, wherein at least a first portion of the proximal end of the single imaging optical fiber is optically coupled to the first sensor-side optical pathway, and at least a second portion of the proximal end of the second portion of the imaging optical fiber is optically coupled to the second sensor-side optical pathway, wherein the first portion of the single imaging optical fiber is different from the second portion of the single imaging optical fiber. The analyzer may further include at least one an imaging system, wherein the at least one imaging system is optically coupled to the distal end of the single imaging optical fiber and is configuredto receive at least a portion of the first and second optical response signals, and provide at least one first signal representative of the first optical response signal to the analyzer, and to provide at least one second signal representative of the second optical response signal to the analyzer, and wherein the analyzer is configured to determine at least a first characteristic to be sensed based at least in part on the first signal representative of the first optical response signal and determine at least a second characteristic to be sensed based at least in part on the second signal representative of the second optical response signal.BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Embodiments will now be described with reference to the appended drawings wherein:

[0020] FIGS. 1 and 2A are cross-section schematic views of an example embodiment of an optical sensor system.

[0021] FIGS. 2B and 2C are top schematic views of portions of an example embodiment of an optical sensor system.

[0022] FIG. 3A is a cross-section schematic view of an example embodiment of an optical sensor system.

[0023] FIG. 3B is a top schematic view of the example embodiment of an optical sensor system shown in FIG. 3A.

[0024] FIG. 4A is an isometric schematic view of a portion of an example embodiment of an optical sensor system.

[0025] FIGS. 4B and 4C are cross-section schematic views of a portion of the optical sensor system shown in FIG. 4A.

[0026] FIGS. 5A and 5B are cross-section schematic views of a portion of an example embodiment of an optical sensor system.

[0027] FIGS. 6A-6D are top views of a portion of an example embodiments of a component of an optical sensor system.

[0028] FIGS 7A-7C are isometric schematic views of a portion of an example embodiment of an optical sensor system.

[0029] FIG. 7D is a top schematic view of a portion of an example embodiment of an optical sensor system.

[0030] FIG. 7E is a cross-section schematic view of a portion of the optical sensor system shown in FIG 7D.

[0031] FIG. 8A is a cross-section schematic of an example embodiment of an optical sensor system.

[0032] FIG. 8B is a schematic of optical signals moving through the optical sensor system shown in FIG. 8A portion of an example optical sensor system.

[0033] FIGS. 9A-9F are schematic views of a portion of an example embodiment of an optical sensor system.

[0034] FIG. 10A is a schematic view of a portion of an example optical sensor system and associated optical spectra.

[0035] FIG. 10B is a graph of optical spectra.

[0036] FIG. 10C is a schematic view of a portion of an example embodiment of an optical sensor system.

[0037] FIG. 10D is a schematic view of a portion of an example embodiment of an optical sensor system.

[0038] FIG. 10E is a graph of optical spectra.

[0039] FIG. 11 is a cross-section schematic view of a portion of an example embodiment of an optical sensor system.

[0040] FIG. 12A is a cross-section schematic view of a portion of an example embodiment of an optical sensor system.

[0041] FIGS. 12B and 12C are top schematic views of a portion of the example embodiment of the optical sensor system shown in FIG. 12A.

[0042] FIG. 13A is a cross-section schematic view of a portion of an example embodiment of an optical sensor system.

[0043] FIGS. 13C-13E are schematic views of a portion of the example embodiment of the optical sensor system shown in FIG. 13A.

[0044] FIGS. 14A and 14B are schematic views of portions of an example embodiment of an optical sensor system.

[0045] FIG. 15 is a schematic view of a portion of an example embodiment of an optical sensor system.

[0046] FIGS. 16A-16J are schematic views of portions of an example embodiment of an optical sensor system.

[0047] FIGS. 17A-17E are schematic views of portions of an example embodiment of an optical sensor system.

[0048] FIGS. 18A-18F are schematic views of portions of an example embodiment of an optical sensor system.

[0049] FIGS. 19A-C are schematic views of portions of an example embodiment of an optical sensor system.

[0050] FIGS. 20A is a cross-section view of a portion of an example embodiment of an optical sensor system.

[0051] FIG. 20B is a schematic view of a portion of an example embodiment of an optical sensor system.stopperDETAILED DESCRIPTION

[0052] Example embodiments are described herein with reference to the accompanying drawings. Unless otherwise expressly stated, in the drawings the sizes, positions, etc., of components, features, elements, etc., as well as any distances therebetween, are not necessarily to scale, and may be exaggerated for clarity. Likewise, values and durations shown in graphical figures, (such as graphs of signal intensity over time), are not necessarily to scale. In the drawings, like numbers refer to like elements throughout. Thus, the same or similar numbers may be described with reference to other drawings even if they are neither mentioned nor described in the corresponding drawing. Also, even elements that are not denoted by reference numbers may be described with reference to other drawings.

[0053] The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. Unless otherwisedefined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art.

[0054] For the purposes of the present disclosure, the term “a” or “an” entity refers to one or more of that entity. As such, the terms “a” or “an”, “one or more” and “at least one” can be used interchangeably herein. As such, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0055] It should be recognized that the terms “comprises” and / or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. Unless indicated otherwise, terms such as “first,” “second,” etc., are only used to distinguish one element from another. For example, one coupler could be termed a “first coupler” and similarly, another coupler could be termed a “second coupler”, or vice versa.

[0056] Unless indicated otherwise, spatially relative terms, such as “below,” “beneath,” “lower,” “above,” and “upper,” “opposing,” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element or feature, as illustrated in the figures. It should be recognized that the spatially relative terms are intended to encompass different orientations in addition to the orientation depicted in the figures. For example, if an object in the figures, is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the term “below” can encompass both an orientation of above and below. An object may be otherwise oriented (e.g., rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may be interpreted accordingly. A set of reference axes (e.g., X, Y, Z), directions, or coordinates, and the rotation around them (e.g., 0X, 0Y, 0Z) may be included in the figures for the purpose of orienting the reader to facilitate understanding of the figures and the specification, and do not necessarily indicate that any particular feature or element is aligned with, or is orthogonal to, any other feature or element.

[0057] The paragraph numbers used herein are for organizational purposes only, and, unless explicitly stated otherwise, are not to be construed as limiting the subject matter described. It will be appreciated that many different forms, embodiments and combinations are possible without deviating from the teachings of this disclosure and so this disclosure should not be construed as limited to the example embodiments set forth herein. Rather, these examples and embodiments are provided so that this disclosure will be thorough and complete, and will convey the scope of the disclosure to those skilled in the art.

[0058] The embodiments described herein relate to the equipment, system configurations, and methods for optical sensing platforms containing a separable or separated multi-channel optical interface requiring only one interface or penetration to the environment to be sensed (also referred to herein as the “sensed environment”). The optical sensing platform provides multiple optical channels, providing capability to measure, sense, or determine one or more types of characteristics at multiple sensing points. In various embodiments, in use, a portion of the separable optical interface may be stationary and a mating portion of the optical interface may be movable, however in other embodiments both portions may be movable or both portions may be stationary. In various embodiments one or more components of the optical interface may be removed from the sensing environment. In various embodiments the optical sensing platform may include at least two portions, a sensor-side optical interface and a system-side optical interface and the two may be optically coupled to each other and configured to send optical signals between the two across a separable interface between the two. In various embodiments the sensor-side optical interface and system-side optical interface may be located adjacent to or in contact with each other (for example with less than about 1000 microns, or less than about 500 microns, or less than about 100 microns between the two during the conveyance of an optical signal) for example to improve coupling and reduce optical losses, however in other embodiments the sensor-side optical interface and the system-side optical interface may be configured to provide coupling when the two are separated, for example separated by about 10 millimeters, or about 100 millimeters, or about 500 millimeters.

[0059] In various embodiments the optical sensor system may be configured to operate within or over a range of wavelengths, for example from about 200nanometers to about 5,000 nanometers, or in the range of about 300 nanometers to about 2,000 nanometers, or in the range of about 390 nanometers to about 1 ,000 nanometers. The wavelength range over which the optical sensor system operates is not a limitation of the present invention.

[0060] In various embodiments the optical sensor system may be used in semiconductor processing applications, for example, the optical sensing system may be configured to sense one or more characteristics of one or more components of the process chamber, for example a wafer holder, susceptor, electrostatic chuck, edge ring, focus ring, showerhead, gas distribution system or the like. In various embodiments one or more chamber components, for example the process chamber itself, wafer holder, susceptor, electrostatic chuck, edge ring, focus ring, showerhead, gas distribution system or the like may be configured as the sensing platform or part of the sensing platform; for example having optical sensing points on or in such components. In various embodiments, a portion of the optical sensing system may be moveable within the process chamber or removable from the process chamber. In various embodiments the optical sensor system may include a sensing platform in the form of a semiconductor wafer which may be optically coupled to a chamber optical interface, for example when positioned on the wafer holder or when the wafer is being transferred into or out of the process chamber. In various embodiments the system or chamber optical interface may remain in place during conventional operation and the sensor wafer may be transported into the chamber when required, using standard wafer transport mechanisms, where the sensor wafer optical interface optically couples to the chamber optical interface, providing a pathway for multiple optical signals between the sensor wafer in the chamber and an analysis and optional control system outside of the chamber. In various embodiments the sensor wafer and chamber interface may be configured so that the sensor wafer may capture information in real time under actual process conditions, for example, including process temperatures, pressures, plasma exposure, process gas exposure, concentricity of the wafer to the underlying chuck, spacing and / or uniformity between the wafer and showerhead and the like.

[0061] In some embodiments, a chamber or system-side optical interface may be configured on a wafer transport mechanism, where the sensor wafer optical interface optically couples to the chamber optical interface, providing a pathway formultiple optical signals between the sensor wafer on the wafer transfer mechanism and an analysis and optional control system outside of the chamber. In such embodiments, the sensor wafer and system-side optical interface may be configured so that the sensor wafer may capture information in real time, for example, while the wafer is being transferred into and out of the chamber, under actual process conditions, for example including temperature, heat flux, charge, strain, wobble, levelness, vibration, position, concentricity, one or more dimensions or distances, etch rate, deposition rate, particle concentration, electric field, voltage, temperature gradients, pressure, deposition on system components, erosion of system components, plasma intensity, plasma density, gas constituents, activated species or ions within a plasma, particle concentration, humidity, spectral power density, electric field, erosion of at least a portion of the shower head, deposition on at least a portion of the shower head, erosion of at least a portion of the edge ring, deposition on at least a portion of the edge ring, the spacing between a shower head and a sensor wafer platform, the planarity between a shower head and a sensor wafer platform, or the position of the sensor wafer platform relative to a wafer support.

[0062] In various embodiments, sensing is performed through optical means and one or more optical signals are conveyed optically, through a penetration or interface into the environment to be sensed. This eliminates the need for electronics, wires or batteries within the sensing environment and minimizes the space required for a multi-point sensing system, allowing for the aforementioned advantages.

[0063] FIG. 1 shows an example embodiment of an optical sensor system 100, including a support 104, a system-side optical interface 114, a sensor platform 110 and a sensor-side optical interface 112 where sensor platform 110 includes two sensor optical pathways 124 and 124’ and optional sensing elements 122 and 122’, respectively, and a platform optical pathway 130 optically coupled to an analyzer or converter 140, where the support 104 is separable from the sensor platform 110, and the system-side optical interface 114 optically couples to sensor-side optical interface 112, through a separable interface delineated by dashed line A-A’. In various embodiments, the combination of optically coupled sensor-side optical interface 112 and system-side optical interface 114 form an optical interface to the sensed environment having multiple separate or individual optical channels in a single interface or penetration to the sensed environment.

[0064] The platform optical pathway 130 may be part of or incorporated within one or more components configured to position or hold up the support 104, however in other embodiments the platform optical pathway 130 may be separate from components configured to position or hold up support 104. One or more alignment features may be configured on the system-side optical interface 114 and / or the sensor-side optical interface 112 and / or support 104 and / or the sensor platform 110 to aid in alignment of one or more optical pathways between system-side optical interface 114 and sensor-side optical interface 112. In other embodiments, the support 104 or other elements may be configured to support and provide mechanical and optical alignment between optical pathways of sensing platform 110 and the corresponding optical pathways in system-side optical interface 114. The sensing elements 122 and 122’ as well as other sensing elements described herein may include or comprise any of a wide variety of optical components, including one or more lenses (e.g., half ball lens, a ball lens, cylindrical lenses), prisms, mirrors, dichroic filters, dichroic mirrors, refractive optics, reflective optics, optical filters, one or more optical fibers (e.g., side-firing optical fibers, optical fiber bundles, imaging optical fibers, unterminated (bare) optical fibers), solid light guides, phosphors, thermographic phosphors, optical gratings, fiber Bragg gratings or non-linear optical crystals. Those skilled in the art will appreciate that any of a wide variety of optical elements or optical components may be included in the sensing elements.

[0065] In various embodiments, the sensor optical pathway 124 (also referred to herein as the “sensing optical pathway”) has a distal end located in the environment to be sensed or that is coupled in some way (e.g., optically or thermally) to an object to be sensed. In various embodiments, an optional sensing element 122 may be optically coupled to the distal end of the sensor optical pathway 124. In various embodiments, the sensing element 122 may include a material that emits one or more wavelengths of light in response to a characteristic to be measured, sensed, or determined in the sensing environment, (e.g., temperature, pressure, strain or the like). In other embodiments, the sensing element 122 may include one or more phosphors or thermographic phosphors. In other embodiments, the sensing element 122 may include one or more optical elements configured to transmit light from the sensor optical pathway 124 to one or more other sensing elements 122 or to the sensed environment or to one or more objects in the sensed environment. In variousembodiments, the sensing element 122 may include one or more optical elements configured to collect light from one or more other sensing elements or from the sensed environment or from an object in the sensed environment and convey it back into the sensor optical pathway 124.

[0066] In various embodiments, the system-side optical interface 114 may be configured to support and provide optical and mechanical alignment between corresponding optical channels in the system-side optical interface 114 and the sensor-side optical interface 112. In various embodiments, the number of sensor optical pathways in the sensor-side optical interface 112 is equal to the number of sensor optical pathways in the sensing platform 110, however in other embodiments the number of optical channels in the sensor-side optical interface 112 and the number of sensor optical pathways in the sensing platform 110 may be different. In various embodiments, the number of optical channels in the system-side optical interface 114 is equal to the number of sensor optical pathways 124 in the sensing platform 110, however in other embodiments the number of optical pathways in the system-side optical interface 114 and the number of sensor optical pathways 124 in sensing platform 110 may be different.

[0067] While FIG. 1 shows two sensor optical pathways 124 and 124’, in other embodiments sensor platform 110 may include one or more than two sensor optical pathways. Sensing elements 122 and 122’ may be the same, for example to measure or sense the same characteristic, for example at different locations or they may be different, for example to measure a different characteristic or to measure or sense the same characteristic with different capabilities, for example range, resolution, uncertainty or the like. While FIG. 1 shows sensor platform 110 being supported by support 104, in other embodiments sensor platform 110 may be supported by other means and may or may not be in contact with the support 104. The position of the sensor platform 110 relative to the support 104 is not a limitation of the present invention. In various embodiments, the sensor platform 110 may be supported by the support 104, or the sensor platform 110 may be positioned on the support 104, but the system-side optical interface 112 may not be part of the support 104, but rather located elsewhere. As discussed herein, the sensor platform 110 may be a sensor wafer, as discussed with reference to FIG. 1, however, in other embodiments, the sensor platform 110 may be a chamber component (e.g., an edgering, a showerhead, or the like). In other words, the sensor optical pathways 124, the sensing elements 122, and the sensor-side optical interface 112 may be located in various positions, platforms or components.

[0068] In various embodiments, the sensor-side optical interface 112 and the system-side optical interface 114 are separable along an interface denoted by line A-A’. In various embodiments, the sensor platform 110 may be removable or separable from support 104, and the sensor support 104 may be configured to mate with the sensor platform 110 such that the system-side optical interface 114 is optically coupled with the sensor-side optical interface 112, allowing the sensor platform 110 to be repeatably placed on and removed from support 104, while maintaining alignment and optical coupling over the course of repeated placements and removals. In some embodiments, when the sensor platform is optically coupled to the system-side optical interface, the position of the sensor platform is adjustable to maximize the first optical response signal and the second optical response signal.

[0069] Referring to FIG. 1 , in various embodiments, the sensor-side optical interface 112 and the system-side optical interface 114 may be separated by a gap 106. In various embodiments, the gap 106 may be zero or substantially zero, in which case at least portions of the sensor-side optical interface 112 and portions of the system-side optical interface 114 are in contact or are essentially in contact. However, in other embodiments, the gap 106 may be in the range of 0 microns to about 1 ,000 microns, or in the range of about 5 microns to about 500 microns, or in the range of about 5 microns to about 250 microns. In various embodiments, the optical sensor system may be configured with much larger gaps 106, for example about 100 millimeters or about 500 millimeters or about 1 ,000 millimeters. The size of the gap 106 is not a limitation of the present invention. In various embodiments, the gap 106 may be filled or partially filled by the atmosphere in the sensing chamber or process environment, and in other embodiments the gap 106 may be filled or partially filled with another medium. In various embodiments, the gap 106 may be filled or partially filled with a solid (e.g., alumina, aluminum oxynitride, silicon carbide, diamond or the like). The gap 106 may be filled or partially filled with a solid that is transparent or translucent to some or all wavelengths of optical radiation used in the optical sensor system. In various embodiments, a purge medium, for example a purge gas, not shown in FIG. 1 , may be introduced into the gap 106 or in the regionof the gap 106 to help protect the optical interface and / or to maintain a low-optical attenuation interface, for example, to reduce deposits forming on or degradation of the optical interfaces of the system-side optical interface 114 and the sensor-side optical interface 112. In various embodiments, all ora portion of gap 106 may be configured or filled with a liquid or solid, (e.g., a lens, mirror, index matching liquid or the like).

[0070] In various embodiments, the sensing elements 122 and 122’ may be placed in different positions within the sensing platform 110 to provide uniformity data (e.g., uniform temperature information) by sensing at different locations across the sensing platform 110. For example, FIG. 1 shows the sensing element 122 positioned a distance 129 from the center of the sensing platform 110 while the sensing element 122’ is positioned a distance 128 from the center of sensing platform 110. In various embodiments, the distances 128 and 129 may be the same, while in other embodiments they may be different. The location of sensing elements 122 is not a limitation of the present invention.

[0071] In various embodiments, the sensing element 122 may be configured as one or more sensing materials. In various embodiments, such sensing materials may reflect or modify an optical excitation signal or emit optical radiation (i.e., an optical response signal), for example, as a result of stimulation by an optical excitation signal or in response to a characteristic of a process chamber or its components. In various embodiments, the sensing material may be a phosphor or a thermographic phosphor, optically coupled to the end of the sensor optical pathway 124. In various embodiments, the sensing element 122 may be configured as an optical emission point or an optical collection point, for example including one or more optical elements (e.g., a lens, ball lens, filter), for example, to sample optical emission from one or more components (e.g., a wafer holder, susceptor, electrostatic chuck, showerhead or the like) or materials (e.g., a gas, liquid, plasma or the like) in the sensed environment (e.g., an optical spectrum or an optical spectrum vs. time).

[0072] In various embodiments, one or more sensing elements 122 may be configured as an optical emission point and one or more sensing elements 122’ may be configured as an optical collection point, such that all or a portion of the optical radiation emitted from a sensing element 122 may be collected by a different sensing element 122’. In various embodiments, all or portions of the optical radiation emittedfrom a sensing element 122 may be absorbed and / or reflected by a process environment (e.g., inside a semiconductor processing chamber) and / or components within the process environment before being collected by a different sensing element 122’. All or portions of the optical radiation emitted from or by a sensing element 122 may be configured to excite optical radiation from one or more gases and / or materials and or components within the process environment, which may be partially or completely collected by a different sensing element 122’.

[0073] While FIG. 1 shows the sensor-side optical interface 112 and the systemside optical interface 114 as positioned in the center or substantially in the center of the sensing platform 110 and the support 104, in other embodiments the sensor-side optical interface 112 and the system-side optical interface 114 may be positioned off center or in any other location.

[0074] In various embodiments, the sensor-side optical interface 112 may be part of the sensing platform 110 and the system-side optical interface 114 may be a part of support 104. In various embodiments, the sensor-side optical interface 112 and / or the system-side optical interface 114 may be configured to provide mechanical support and / or optical alignment for the sensor optical pathways 124 and 124’ to the platform optical pathway 130, in other embodiments the sensor-side optical interface 112 and / or the system-side optical interface 114 may include other components or be configured to provide other features. For example, in various embodiments, the sensor-side optical interface 112 and / or the system-side optical interface 114 may include one or more optical elements (e.g., a refractive optic, a reflective optic, a prism, a half ball lens, a ball lens, a filter, a dichroic mirror or the like). One or more optical elements may be provide and configured to optimize the optical coupling efficiency between the sensor optical pathways 124 and 124’ and the platform optical pathway 130.

[0075] While FIG. 1 shows two sensor optical pathways 124 and 124’, in other embodiments sensing platform 110 may include one sensor optical pathway or more than two sensor optical pathways. In various embodiments multiple sensor optical pathways positioned across the area of sensing platform 110 permits measurement and evaluation of the uniformity of the measured characteristics. While the sensorside optical interface 112 and the system-side optical interface 114 are shown as configured to support two sensor optical pathways 124 and 124’, in otherembodiments the sensor-side optical interface 112 and the system-side optical interface 114 may be configured to support one sensor optical pathway or more than two sensor optical pathways.

[0076] The sensing elements 122 and 122’ may be configured to sense at least one characteristic of the sensing platform 110 or at least one characteristic of the environment within the enclosure or chamber 202 (see FIG. 2A). In various embodiments, a sensed characteristic may include, but is not limited to, temperature, temperature gradients, heat flux, pressure, charge, strain, wobble, levelness, vibration, position, concentricity, one or more dimensions or distances, for example between a sensor wafer platform and a chamber component or between various chamber components, etch rate, deposition rate, particle concentration, electric field, voltage, deposition on system components, erosion or etching of system components, plasma intensity and density, gas constituents within the chamber, activated species or ions within a plasma or within the chamber, particle concentration, humidity, spectral power density and or wavelength intensity(s) within the chamber or the like.

[0077] In various embodiments, the sensor optical pathway 124 may be configured to convey light to a sensing element 122 and / or to convey light emitted by or collected by a sensing element 122 to the sensor-side optical interface 112 and eventually to the analyzer 140..

[0078] In various embodiments, a sensor optical pathway 124 may be configured to convey light, for example from a source outside of the sensed area to a sensing element 122, and the light may be at least partially absorbed by sensing element 122, were the sensing element 122 is configured to emit a different light, which may be conveyed along an optical path (for example sensor optical pathway 124) to the sensor-side optical interface 112 and eventually to the analyzer 140.

[0079] In various embodiments, a sensor optical pathway 124, with or without a sensing element 122, may be configured to convey light, for example, from a source outside of the sensed area, along an optical pathway 124 to, and optionally out of the end of a sensor optical pathway 124 or sensing element 122, such that all or a portion of the light may or may not be reflected off of an element in the optical pathway, and be configured to convey at least a portion of the reflected lightcollected at or by the end of a sensor optical pathway 124’, with or without a sensing element 122’ to the sensor-side optical interface 112 and eventually to the analyzer 140.

[0080] While FIG. 1 shows a sensing element 122 at the end of a sensor optical pathway 124, in other embodiments a sensing element 122 may be positioned anywhere along the sensor optical pathway 124. While FIG. 1 shows a single sensing element 122 at the end of a sensor optical pathway 124, in other embodiments more than one sensing element 122 may be positioned at the end or anywhere along the sensor optical pathway 124.

[0081] In various embodiments a sensing platform may include multiple sensing units or sensor optical pathways, each having the same type of sensing element, however in other embodiments sensing units or sensor optical pathways having different types of sensing elements may be positioned within one sensing platform, to allow simultaneous measurement of multiple characteristics. In various embodiments a sensing platform may include multiple sensors having different types of sensing elements, providing uniformity information for multiple characteristics simultaneously.

[0082] In various embodiments, the optical analyzer or converter 140 is configured to convert the optical signals from the sensor optical pathways 124 and 124’ and / or the sensing elements 122 and 122’ into a sensed characteristic, for example temperature, strain or the like. In various embodiments, the analyzer 140 may be used alone or may be coupled to additional equipment 150 through a coupling 145. While the optical analyzer 140 is shown as one unit in FIG. 1, in various embodiments more than one optical analyzer may be utilized, for example, to support larger numbers of sensing units. In various embodiments, more than one analyzer of different types may be utilized, for example, to support determination of more than one sensed characteristic. The coupling 145 may have various configurations or combinations of configurations, for example electrical, optical or wireless. The additional equipment 150 may include one or more display units, a computer, a microcontroller, a microprocessor, a part of additional analysis and / or control equipment or the like.

[0083] In various embodiments, the thickness of the sensor platform 110 may be uniform or substantially uniform over the entire sensor platform, however in other embodiments the thickness may vary over extent of the sensor platform 110. The thickness or portions of the thickness of the sensor platform 110 may be in a range of about 100 microns to about 10,000 microns, or in a range of about 500 microns to about 2,000 microns.

[0084] In various embodiments, the sensor optical pathway 124 and / or the platform optical pathway 130 may comprise an optical train configured to allow the optical signals listed above to propagate through free space or a combination of free-space, optical fibers, fiber bundles, waveguides, and various optical elements, such as refractive or reflective optical elements. In various embodiments, the individual fibers in the bundle may be fused together at one or both ends of the fiber bundle. In still other embodiments, the optical path may also include any of a wide variety of optical elements operative to allow optical signals to propagate between the sensing element 122 and the analyzer 140. In various embodiments, an optical pathway may include a single-mode or multi-mode optical fiber or a fiber bundle. The optical fibers or fiber bundles may be made using plastic, quartz, silica, glass, sapphire or the like. The waveguides may be made using silicon nitride, silicon dioxide, sapphire, silicon carbide or the like.

[0085] FIG. 2A shows an example embodiment of the optical sensor system 100 of FIG. 1 including a wafer-based sensor platform 110 in a semiconductor process chamber or enclosure 202 having an interior volume or region 210 in which sensing is to occur, the semiconductor process chamber including a support 104 (e.g., a susceptor, wafer holder, chuck, vacuum chuck, electrostatic chuck or the like), an optional edge or focus ring 204, an optional gas distribution system 206, (e.g., a showerhead), and a single optical interface or penetration to the sensed environment (in this example a sensor platform or wafer 110) consisting at least of a sensor-side optical interface 112 and a system-side optical interface 114 configured to support multiple optical channels. In various embodiments the optical sensing system may be configured with one or more additional interfaces, for example, between the system-side optical interface 114 and the converter 140. While FIG. 2A shows a support 104, an edge ring 204, and a showerhead 206, in other embodiments some or all of these may be absent, or other elements may be present. The specificconfiguration of the semiconductor process chamber is not a limitation of the invention. In various embodiments semiconductor applications may not include a chamber, for example in track or conveyor systems.

[0086] The optical sensing system 100 may be configured with one or more additional interfaces (not shown in FIG. 2A for clarity) between the system-side optical interface 114 and the analyzer or converter 140. The additional interfaces may include a vacuum seal, a gas-tight seal, one or more optical interfaces or the like. While FIG. 2A shows a single chamber penetration, in other embodiments more than one chamber penetration may be utilized. In some embodiments, the interface between the sensor-side optical interface 112 and the system-side optical interface 114 may be configured as a vacuum seal or a gas-tight seal.

[0087] FIGS. 2B and 2C show a top view of example embodiments of a wafer -based sensor 110 having multiple sensing points 122 as might be configured for use in semiconductor applications, such as in the system of FIG. 2A. The multiple sensing points 122 of the wafer-based sensor in FIG. 2C include sensing points at the periphery of the wafer-based sensor, while FIG. 2B includes sensing points at or near the periphery as well as at various points within the wafer-based sensor. The specific number, position and layout of the sensing points 122 is not a limitation of the present invention. In various embodiments the wafer-based sensor 110 may have one or more characteristics, for example, materials of construction, diameter, thickness, weight, and the like, the same or similar as used in standard semiconductor processes, to facilitate handling and prevent contamination. The wafer-based sensor may be constructed in part from standard semiconductor wafer materials, for example silicon, gallium arsenide, sapphire or the like. The material of construction of a wafer-based sensor is not a limitation of the present invention. In various embodiments a wafer-based sensor may have a diameter similar to or the same as standard semiconductor wafers, for example 100 millimeters, 150 millimeters, 200 millimeters, 300 millimeters, ,450 millimeters or the like. In various embodiments a wafer-based sensor may have a thickness similar to or the same as standard semiconductor wafers, for example in the range of about 100 microns to about 10,000 microns, or in the range of about 200 microns to about 5,000 or in the range of about 500 microns to about 2,000 microns.

[0088] Referring to FIG. 2A, in the illustrated embodiment, the sensor-side optical interface 112 and the system-side optical interface 114 are separable along the interface denoted by B-B’. In various embodiments the wafer-based sensor 110 may be removable or separable from the support 104 and the sensor support 104 may be configured to mate with the wafer-based sensor 110 such that the systemside optical interface 114 is optical coupled to the sensor-side optical interface 112, allowing the wafer-based sensor 110 to be repeatably placed on and removed from the support 104. The additional equipment 150 may include a readout or one or more monitors or control equipment used to monitor conditions or processes taking place within the enclosure 202. In various embodiments, the pressure within the enclosure 202 may be less than atmospheric pressure, at or substantially at atmospheric pressure, or above atmospheric pressure. In various embodiments the pressure within the enclosure 102 may vary with time.

[0089] FIG. 3A shows an example embodiment of an optical sensor system 300 exemplifying a different optical interface geometry than that of optical sensor system 100 of FIG. 1. In the optical sensor system 300, the sensor-side optical interface 112 is positioned at the side or edge of the sensor platform 110 and the system-side optical interface 114 is positioned adjacent to the sensor-side optical interface 112 (to aid in optical coupling between the two) and is not part of the support 104. In various embodiments, the system-side optical interface 114 may be part of or installed in a chamber component, for example an edge ring. Referring to FIG. 3A, in the illustrated embodiment, the sensor-side optical interface 112 and the systemside optical interface 114 are separable along an interface denoted by C-C’. FIG. 3A shows a first sensor optical pathway 124 positioned above a second sensor optical pathway 124’ by a distance denoted by 310. In various embodiments, sensing elements and / or sensing points (for example sensing points 122) and / or sensor optical pathways 124 may be on the same or similar level or plane, that is co-planar, while in other embodiments the sensing elements and / or the sensing points (for example the sensing points 122) and / or the sensor optical pathways 124 may not be co-planar. While FIG. 3A does not show a chamber, in other embodiments, the system 300 of FIG. 3A may include a chamber and optional chamber components, as discussed with reference to FIG. 2A and elsewhere herein. While FIG. 3A shows the platform optical pathway 130 as parallel to the surface of the sensor platform110, in other embodiments, the platform optical pathway 130 may have a portion that extends in a different direction, for example after exiting the system-side optical interface 114, the platform optical pathway 130 may turn about 90 degrees and extend through a portion of support 104.

[0090] FIG. 3B shows a top view of an example embodiment of a wafer-based sensor 110 having multiple sensing points 122 as might be configured for use in semiconductor applications, such as the system of FIG. 3A. The sensor-side optical interface 112 is located at the periphery of the wafer-based sensor or sensor platform 110 and the system-side optical interface 114 is located adjacent to the sensor-side optical interface 112 and is not part of the support 104. Referring to FIG. 3B, in the illustrated embodiment, the sensor-side optical interface 112 and the system-side optical interface 114 are separable along the interface denoted by C-C’.

[0091] Sensing points 122 of the wafer-based sensor 110 in FIG. 3B include sensing points at the periphery of the wafer-based sensor 110 as well as at various points within the wafer-based sensor 110. The specific number, position and layout of sensing points is not a limitation of the present invention. In various embodiments the wafer-based sensor 110 may have one or more characteristics, for example, materials of construction, diameter, thickness, weight and the like, the same or similar as used in standard semiconductor processes, to facilitate handling and prevent contamination.

[0092] In various embodiments the single separable optical interface may have different configurations to support multiple optical channels. In various embodiments the single separable interface supporting multiple optical channels may be configured to support multiple independent optical channels in parallel, or it may be configured to support multiple independent optical channels in series.

[0093] FIGS. 4B and 4C show cross-section views of the partial view of an example optical sensing system 400 of FIG. 4A, taken along the line D-D’ with a single separable optical interface (denoted by E-E’) including the sensor-side optical interface 112 and the system-side optical interface 114 configured to support multiple independent optical channels in parallel. The portions of the optical sensing systems shown in FIGS. 4A and 4B are shown in a separated configuration (separated along the line E-E’) while that of FIG. 4C is shown in a non-separatedconfiguration. The separable optical interface shown in FIGS. 4A-4C has nine independent optical channels and is made up of nine optical channels, each channel having its own sensor optical pathway 124 and an optional sensing element 122. Each of the nine sensor optical pathways 124 is optically coupled to nine separate optical pathways within the sensor-side optical interface, which are in turn optically coupled to nine separate optical pathways in the support-(or system) side optical interface 114, which are in turn are optically coupled to the support optical channels 480 and eventually optically coupled to the analyzer 140 (not shown in FIGS. 4A-4C).

[0094] For clarity, FIGS. 4B and 4C only show three optical channels. Each channel includes an optional sensing element 122, 122’, 122” optically coupled to a sensor optical pathway 124, 124’, 124”, which in turn is optically coupled to a sensor side optical interface 112 having three separate optical channels, each of which are optically coupled to their respective three separate optical channels in the systemside optical interface 114, which are in turn optically coupled to their respective support optical channels 480 and eventually optically coupled to the analyzer 140 (not shown in FIGS. 4A-4C). While FIGS. 4A-4B show nine independent optical channels, in other embodiments the number of independent channels may be more or less than nine, for example 16, 25, 50, 100, or more.

[0095] In various embodiments, the optical axes of the sensor optical pathways are parallel to or substantially parallel to the surface of the sensor platform 110 and / or the support 104, while the optical axes of the optical pathways in the sensorside optical interface 112 ultimately need to be perpendicular or substantially perpendicular to the surface of the sensor platform 110 and / or the support 104, to support optical coupling between the sensor-side optical interface 112 and the system-side optical interface 114. FIGS. 5A and 5B show example embodiments of configurations that are used to change the orientation of the optical axes.

[0096] FIG. 5A and 5B shows two example embodiments of details of a sensorside optical interface 112. On the left side of FIG. 5A, an optional sensing element 122 is optically coupled to a sensor optical pathway 520, which is in turn optically coupled to an optical element (shown as a half ball lens 540) which is configured to change the orientation of the optical axis by about 90°, thus optically coupling the signal to a system optical pathway 530 in the system-side optical interface 114.

[0097] While the optical element 540 is shown as a ball lens 540 in FIG. 5A, in other embodiments the optical element 540 may be a mirror, refractive lens, ball lens, dichroic mirror, prism or the like. While the sensor optical pathway 520, the optional sensing element 122, the optical element 540 and the sensor-side optical interface 112 are all shown as being located within the body of the sensor platform 110, in other embodiments all or portions of the sensor optical pathway 520, the optional sensing element 122, the optical element 540 and the sensor-side optical interface 112, may be located outside the body of the sensor platform 110. In various embodiments, the sensor optical pathways 520 and 520’ and the system optical pathways 530, 530’, and 530” may be provided as optical fibers (singular or plural). So, throughout this disclosure, the sensor optical pathway 520, and the sensor optical pathway 520’ may also be referred to herein as “optical fiber 520” and “optical fiber 520’”, respectively. Likewise, the system optical pathway 530, the system optical pathway 530’, and the system optical pathway 530” may also be referred to herein as “optical fiber 530” and “optical fiber 530’”, and “optical fiber 530””, respectively.

[0098] On the right side of FIG. 5A, an optional sensing element 122’ is optically coupled to a sensor optical pathway 520’, where the sensor optical pathway 520’ is physically configured within sensor-side optical interface 112 so that it is optically coupled to an optical fiber 530’ in the system-side optical interface 114. In various embodiments, the end of sensor optical pathway 520’ located within the sensor-side optical interface 112 may be terminated with a ferrule (not shown in FIG. 5A for clarity).

[0099] In various embodiments, a portion of the sensor optical pathway 520’ located within the sensor-side optical interface 112 may be located in a passage, channel, or groove 525 in the sensor-side optical interface 112, where the groove 525 and a passage, channel, or groove 535 are configured to align the optical axis of the optical fiber 520’ with the optical axis of the optical fiber 530’. The sensing elements 122, 122’, the optical fibers 520, 520’ and the sensor-side optical interface 112 are all located within the body of the sensor platform 110. Those skilled in the art will appreciate that in other embodiments, all or portions of the sensing elements 122, 122’, the optical fibers 520, 520’ and the sensor-side optical interface 112 may be located outside of the body of sensor platform 110. In various embodiments, thesensor-side optical interface 112 includes a portion of the optical fiber 520 configured to convey light between the proximal end of optical fiber 520 and a proximal end of optical fiber 530 located in system-side optical interface 114, where the separable interface is identified by the dashed line A-A’.

[0100] The left side of FIG. 5B shows an example embodiment similar to that of the right side of FIG. 5A, but with a least a portion of the sensor optical pathway 520 located outside of the sensor platform 110. In various embodiments, a portion of sensor optical pathway 520 may be located outside of the sensor-side optical interface 112 and may be covered with an optional cap 550. In various embodiments sensor-side optical interface may extend above the surface of sensor platform 110 and be configured to enclose at least a portion of the sensor optical pathway 520. In various embodiments, the sensor optical pathway 520 may be inserted into sensor-side optical interface 112 without a ferrule (as shown in FIG. 5B or with a ferrule as described in reference to FIG. 5A. In various embodiments, the end of the sensor optical pathway 520 that is inserted into sensor-side optical interface 11 may be configured to optically couple to the system optical pathway 530.

[0101] In various embodiments, the sensor optical pathway 520 may extend outside the body of the sensor platform 110 to allow for a larger bend radius of the sensor optical pathway 520, for example, if sensor optical pathway 520 is an optical fiber or fiber bundle, when transitioning from a vertical to horizontal geometry. As shown in FIG. 5B, the portion of the optical fiber 520 extending outside the body of the sensor platform 110 may be covered by the optional cap 550. In various embodiments, the optional cap 550 may be configured to protect at least one of a portion of the sensor-side optical interface 112, the optical fiber 520, or the interior of the sensor platform 110.

[0102] In various embodiments, the may consist of one optical fiber, however in other embodiments, optical fibers such as the optical fibers 520 and 530 may consist of a bundle of multiple small diameter optical fibers. In various embodiments a fiber bundle may provide a smaller radius of curvature than a single larger fiber. In various embodiments, a fiber bundle may include about 10 to about 1,000 individual fibers, where each individual fiber may have a diameter in the range of about 5 microns to about 150 microns.

[0103] In various embodiments, the sensor-side optical interface 112 and / or system-side optical interface 114 and / or the cap 550 may be constructed of metal, for example aluminum, steel, titanium or the like, graphite, ceramic, for example aluminum nitride, alumina, silicon carbide, zirconia or the like, a semiconductor, for example silicon, gallium arsenide, indium phosphide or the like, or any other material. Those skilled in the art will appreciate that the sensor-side optical interface 112 and / or system-side optical interface 114 may be constructed of any of a variety of materials.

[0104] Referring to FIGS. 5A and 5B, in various embodiments, the optical pathway or fiber 530 is located in the groove or passage 535, which is itself located in the system-side optical interface 114. In various embodiments, the system-side optical interface 114 may contain multiple grooves or passages 535, each of which may be configured to align the optical axis of the optical fiber 530 to the optical axis of the ball lens or optical element 540. In various embodiments, the optical fiber 530 may be held in place or affixed to the system-side optical interface 114 by various means, for example adhesive, press-fit, clamping or the like.

[0105] In various embodiments, the sensor-side optical interface 112 is optically aligned or substantially optically aligned to the system-side optical interface 114. In various embodiments each of the optical channels in the sensor-side optical interface are optically aligned or substantially optically aligned to the respective optical channels in the system-side optical interface. In various embodiments optically aligned may mean optically coupled. When referred to in the context of a separable optically aligned interface or component, optically aligned may means optically coupled but not mechanically attached to each other.

[0106] In various embodiments, when the sensor optical pathways 520 and 530 are provided as optical fibers, these optical fibers may be the same or they may be different. In various embodiments, the optical fiber 520 may have the same or substantially the same diameter as the optical fiber 530, however in other embodiments the optical fiber 520 may have a smaller or larger diameter than the optical fiber 530. In various embodiments, a difference in diameter between the optical fiber 520 and the optical fiber 530 may provide some misalignment tolerance. In an example embodiment, the optical fiber 520 may be smaller than the optical fiber 530 (as shown in FIGS. 5A and 5B), for example, to allow some misalignmenttolerance between the two without substantially reducing the intensity or power of the signal conveyed to optical fiber 530. The optical fibers 520 and 530 may have a diameter in the range of about 10 microns to about 2,000 microns or in the range of about 25 microns to about 1 ,500 microns or in the range of about 100 to about 500 microns, however the diameter of optical fibers 520 and 530 may be any size. In various embodiments, the optical fiber 530 may have a diameter in the range of about 1.2 to about 3 times that of the diameter of the optical fiber 520 or in the range of about 1.4 to about 2 times that of the diameter of the optical fiber 520. In various embodiments, the ratio of the diameter of the optical fibers 520 to the diameter of the optical fibers 530 may be in a range of about 0.1 to about 10 or in a range of about 0.2 to about 5. The optical fibers 520 and 530 may be provided as multi-mode optical fibers, single-mode optical fibers, solid light guides, light guide rods or the like. In various embodiments, the ends of the optical fibers located in the system-side optical interface 114 and the sensor-side optical interface 112 may be cleaved, lapped and / or polished. In various embodiments the optical fibers may be made from glass, plastic, silica, quartz, sapphire or the like. One or both of the system-side optical interface 114 and the sensor-side optical interface 112 may be configured with one or more optical elements such as one or more lenses, mirrors or the like.

[0107] In various embodiments, the optical centers and / or physical centers of the optical fibers in the sensor-side optical interface 112 and the corresponding optical centers and / or physical centers of the optical fibers in the system-side optical interface 114 may be aligned or co-linear. In various embodiments, any misalignment between these optical fiber centers may be less than about ±2.5%, less than about ±5%, less than about ±10%, or less than about ±25% of the diameter of the optical fibers.

[0108] FIGS. 6A-6D show example embodiments of multi-channel configurations of various optical interfaces, for example, where used in the sensor-side optical interface 112 and / or the system-side optical interface 114. FIGS. 6A-6C show example embodiments of circular optical interface configurations having 9, 36 and 100 independent optical channels as represented by 9, 26 and 100 separate optical fibers 530, respectively, arranged in a square grid. FIG. 6D shows an example embodiment of a circular optical interface 620 having 112 independent optical channels where the layout of the channels is modified to maximize the number ofchannels in the circular optical interface area. While FIGS. 5A, 5B and 6A-6D show circular optical interfaces (the sensor-side optical interface 112 and the system-side optical interface 114), in other embodiments the shape of the optical interface may be different, for example a square, a rectangle, a triangle, a trapezoid or any shape.

[0109] As discussed herein, in various embodiments it is desirable to keep the number of penetrations into a sensing environment to a minimum, ideally to one penetration, but in addition, in various embodiments it may be desirable to minimize the physical size of the penetration. Referring to FIGS. 6A to 6D, for a given size of optical fiber within the optical interface, in various embodiments increasing the number of independent channels will result in an increase in the diameter of the optical interface. As an example, for optical fibers 530 having a diameter of about 300 microns, the table below shows the diameter of the optical interface for different numbers of independent channels (the independent optical fibers 530).# of independent Optical interfaceoptical channels diameter (mm)9 316 425 4.536 5.2549 664 6.7581 7.5100 8.25

[0110] Referring to FIGS. 6A-6D and 7A-7D, in an example embodiment the system-side optical interface 114 may include one or more alignment features, for example a key 610 or a chamfer 610 which may be configured to align or mate witha corresponding key 710 ora chamfer 720, respectively, on the sensor-side optical interface 112. In various embodiments such alignment features may be configured to align or substantially align the optical axis of each optical channel portion in the sensor-side optical interface with its corresponding optical channel portion in the system-side optical interface.

[0111] FIGS. 7 A and 7B show an example embodiment of a nine-channel sensor-side optical interface 112 incorporating a key alignment feature 710 and a chamfer alignment feature 720 that are configured to mate with a key alignment feature 610 and a chamfer alignment feature 620, respectively of a nine channel system-side optical interface 114. In various embodiments, one or more alignment features may be utilized to achieve alignment in different directions or angles. In various embodiments, one or more alignment features may be incorporated to center the sensor-side optical interface 112 over the system-side optical interface 114, for example chamfer alignment features 720 and 620 respectively. In various embodiments, one or more alignment features may be incorporated to provide or ensure rotational alignment of the sensor-side optical interface 112 with the systemside optical interface 114, for example key alignment features 710 and 610 respectively. In various embodiments, such alignment features may be configured to align or substantially align the optical axis of each optical channel portion in the sensor-side optical interface with its corresponding optical channel portion in the system-side optical interface.

[0112] FIGS. 7C-7E show an example embodiment of a 9 channel sensor-side optical interface 112 incorporating alignment features 735 and 735’ and a 9-channel system-side optical interface 114 incorporating alignment feature 730 and 730’ that are configured to mate with alignment features 735 and 735’ respectively on systemside optical interface 114. In various embodiments such alignment features may be configured to align or substantially align the optical axis of each optical channel portion in the sensor-side optical interface with its corresponding optical channel portion in the system-side optical interface.

[0113] In various embodiments, the alignment features as discussed herein may be incorporated in one or more components, for example sensor-side optical interface 112, system-side optical interface 114, support 104, sensor platform 110, or other components or elements in the optical sensing system.

[0114] In various embodiments, the optical center and / or physical center of the optical channels in sensor-side optical interface 112 and the optical center and / or physical center of the optical channels in system-side optical interface 114 may aligned or co-linear. In various embodiments the alignment between the optical centers may be less than about ±2.5%, or less than about ±5%, or less than about ±10% or less than about ±25% of the diameter of the optical pathway, optical fiber, or fiber bundle.

[0115] FIG. 8A shows a schematic view of an example embodiment of an optical sensor system 800 including a chamber or enclosure 202 surrounding or partially surrounding a sensing environment 210 as described herein (particularly with respect to FIGS. 4B and 4C), optional optical connectors 823, a converter 140 having three channels 810, 811 and 812, optical pathways 530, 530’ and 530” configured to optically couple to optical pathways 830, 831, and 832 respectively, which in turn are optically coupled to channels 810, 811 and 812 respectively, of the converter 140 through optional connectors 820.

[0116] The converter 140 includes at least one light source 840 configured to emit or otherwise provide at least one optical excitation signal 841 to the optical sensor system (for example to the sensing point 122), at least one detector 850 configured to receive an optical response signal 851 from sensing point 122 in response to the optical excitation signal 841 , where the converter is configured to measure one or more properties or characteristics of an optical response signal 851 received from the sensing point 122, and determine at least one characteristic associated with the sensing point 122 (for example temperature, pressure, strain or the like).

[0117] In various embodiments the optical excitation signal 841 may have a wavelength in the range of about 200 nanometers to about 700 nanometers, or in the range of about 390 nanometers to about 500 nanometers, however the wavelength of the optical excitation signal is not a limitation of the present invention. The optical response signal 851 may have a wavelength in the range of about 100 nanometers to about 10,000 nanometers, or in the range of about 200 nanometers to about 2,000 nanometers, or in the range of about 400 nanometers to about 1 ,500 nanometers, however the wavelength of the optical excitation signal is not a limitation of the present invention. In various embodiments, for example for temperaturemeasurement utilizing a phosphor sensing element 122, the optical excitation signal 841 may have a wavelength in the range of about 390 to about 600 nanometers, or in the range of about 390 to about 450 nanometers and the optical response signal 851 may have a wavelength in the range of about 450 to about 1 ,000 nanometers, or in the range of about 500 to about 850 nanometers.

[0118] In various embodiments, and as shown in FIG. 8B, the optical response signal 851 may include a portion identified as the “optical excitation response signal” 852 and / or a portion identified as the “optical excitation independent signal” 853 (852 and 853 are not shown in FIG. 8A for clarity). The optical excitation response signal 852 is an optical signal that is in response to the optical excitation signal 841. The optical excitation independent signal 853 may be present with or without the presence of or in response to the optical excitation signal 841.

[0119] In various embodiments, the sensing point 122, ora portion of sensing point 122 may be excited or partially excited by the optical excitation signal 841 and may emit an optical response signal 851 in response to the optical excitation signal 841, wherein the optical response signal 851 includes at least one optical excitation response signal 852 representative of one or more characteristics at the sensing point 122.

[0120] In various embodiments, the converter 140 is in optical communication with sensing point 122 via one or more optical pathways configured to allow the optical response signal 851 to propagate to the converter 140. In the illustrated embodiment, the optical path is provided as one or more optical fibers and / or one or more optical fiber bundles all going through the single optical interface between the sensor-side optical interface 112 and the system-side optical interface 114. In other embodiments, the optical path may comprise an optical train configured to allow the optical signals listed above to propagate through free space or a combination of free-space, optical fibers, waveguides, and various optical elements, such as refractive or reflective optical elements. In still other embodiments, the optical path may also include any of a wide variety of optical elements operative to allow the optional optical excitation signal 841 to propagate to sensing point 122.

[0121] In various embodiments, the converter 140 provides the optical excitation signal 841 to sensing point 122 and receives and measures the returning opticalresponse signal 851. In these embodiments, the optical response signal 851 may include one or more undesirable or un-used components, for example, the optical excitation independent signal 853, which may be filtered out by the optical element 845 or other optical elements, which may be provided as a dichroic filter, bandpass filter, high-pass filter, or low-pass filter, such as an optional filter 847.

[0122] In the illustrated embodiment, the converter 140 includes at least one light source 840, at least one detector 850, at least one first optical element 845, at least one optional optical element 842, and at least one optional optical element 849 (shown as a lens), wherein the first optical element 845, the optional optical element 842, and the optional optical element 849 are positioned in optical communication with the optical path 830 (while FIG. 8A shows the optical path 830 as outside of the converter 140, the optical path or portions of the optical path continue within the converter 140 and are also identified as 830 for simplicity. Though only one light source 840, one detector 850, one optical element 845, one optional optical element 842, and one optional optical element 849 are illustrated in FIG. 8A, those skilled in the art will appreciate that the converter 140 may include any number of these devices or components. While FIG. 8A shows the converter 140 having three channels, in other embodiments the converter 140 may have fewer or more channels than three.

[0123] In the illustrated embodiment, at least one power supply 860, at least one controller 862 and at least one optional display 864 are in electrical communication with the light source 840 and the detector 841 by at least one communications link 866, though in some embodiments the power supply 860, the controller 862, and the display 864 may be mounted in or on a housing for the converter 140 (the housing not shown for clarity in FIG. 8A). In other embodiments, the controller 862 and the optional display 864 may be in wireless communication with the detector 850 and the light source 840. Optionally, though not shown in FIG. 8A, the controller 862 may be configured to provide a wired or wireless signal to additional equipment. In some embodiments, the detector 850 and the light source 840 may be optionally mounted to at least one substrate 870 or to the optional housing. In various embodiments, the controller 862 may include both control functions and processing functions as required for operation. For example, the controller 862 may be configured to drive the light source 840 to emit the optical excitation signal 841 to the sensing point 122at wavelengths, intensities, and durations required fora particular function of the optical sensor system 800. In various embodiments the detector 850 is configured to receive at least a portion of the optical response signal 851 , and to provide at least one signal or measurement data representative of the optical response signal 851. The controller 862 may be configured to gather the measurement data by sampling the detector 850 and any other detectors or devices (e.g., temperature measurement devices within the converter 140, controller 862 or the like). Also, the controller 862 may be configured to separate the signal or measurement data representative of the optical response signal 851 into two or more components (e.g., the optical excitation response signal 852 and the optical excitation independent response signal 853).

[0124] In various embodiments, the controller 862 is configured to calculate at least one sensed characteristic based on the optical response signal 851. The sensed characteristic may comprise an intensity or amplitude, a change in intensity or amplitude over a time period, an intensity decay rate, an optical power spectrum, or one or more portions of an optical power spectrum of the optical response signal 851 or the like. The controller 862 is configured to calculate a sensed characteristic based on at least one of the characteristics of the signal representative of the optical response signal 851.

[0125] In various embodiments, the converter 140 and or the controller 862 may be configured to determine the spectral power density of the optical response signal 851 , (e.g., the power or intensity of the optical response signal 851 as a function of wavelength). In various embodiments, all or portions of the optical spectrum captured at a sensing point may be used to determine one or more characteristics of the process environment. In various embodiments, the process environment consists of one or more gases that are introduced into the process chamber, which then may undergo various gas-phase or surface reactions (for example reactions on chamber surfaces or the wafer surface). In various embodiments, spectroscopic methods known to those skilled in the art, such as infrared spectroscopy, Raman spectroscopy, and analysis of the wavelength and intensity of various spectral components, may be utilized to determine the composition, abundance, density, mole fraction and other characteristics of the gas phase and surface phase environments throughout the duration of the process.

[0126] The multi-channel sensor system of the present invention, coupled with the ability to position sensing points in the position of the wafer as well as surrounding chamber components provides heretofore unavailable capability to provide both spatial and temporal information about the process, in real time, as the process proceeds. In various embodiments, the sensing points located in various chamber components, (e.g., the edge ring, the chamber wall or the shower head), can provide spatial and real time information throughout the entire production process of actual product wafers. In various embodiments, a sensor wafer platform can provide spatial and real time information, (e.g., about the environment, temperature, chemistry, deposition or etch rates and other characteristics) at the surface of the wafer. This capability may be used to tune or optimize the process while the process is running, rather than using a test wafer that can only be analyzed after the entire process is complete. This capability can reduce the setup time required to ensure multiple chambers are performing the same, for example, as used in the Copy Exact approach. In various embodiments the controller 862 may also be configured to perform any required calibration or compensation of various devices (e.g., the detector 850, the light source 840, and the like). In various embodiments, the controller 862 may be configured to process the measurement data received from the detector 850 and other measurement devices or sensors, compute any compensations or corrections or other processing functions to calculate final object characteristics. In other embodiments, the controller 862 may be configured to transmit any measurement data or results to other devices (e.g., displays, process equipment, and the like.)

[0127] While FIG. 8A shows the controller 862, the power supply 860, the optional display 864 and the communications link 866 as being part of an individual channel, in other embodiments a controller 862, and / or a power supply 860, and / or an optional display 864 and / or communications link 866 may be shared by one or more or all channels of the converter 140.

[0128] In the illustrated embodiment, the optical element 845 may be a dichroic filter or dichroic mirror. In the illustrated embodiment, the light source 840 may be configured to emit the optical excitation signal 841 that is directed to the optical path 830 by the dichroic mirror 845 and the optical element 849. In various embodiments, the light source 840 may be a light-emitting diode, a laser, a vertical cavity surfaceemitting laser or the like. In various embodiments, the optical element 845 may be configured to reflect the optical excitation signal 841 and allow the optical response signal 851 to propagate therethrough. For example, in the illustrated embodiment, the optical element 845 may be a dichroic filter configured to reflect greater than about 95% of the optical excitation signal 841 from the light source 840 to the optical path 830 and allow greater than about 95% of the optical response signal 851 to propagate therethrough toward the second mirror or optical element 842 configured to reflect the optical response signal 851 toward the detector 850. In various embodiments, the optional optical element 847 and the detector 850 may be configured to be optically coupled to optical response signal 851 without mirror or optical element 842.

[0129] In various embodiments, though not shown in FIG. 8A, the optical element 845 may be provided as an optical splitter (e.g., a bulk optical beamsplitter, fiber optic splitter, bifurcated optical fiber bundle, or optical circulator) instead of a dichroic filter or dichroic mirror. Those skilled in the art will appreciate that any of a wide variety of optical arrangements may be used to direct the optical excitation signal 841 to the system optical pathway 530 and to allow the optical response signal 851 to propagate to the detector 850. Though only a single detector 850 is shown in FIG. 8A, any number or variety of detectors or detector arrays may be used, depending on the wavelengths of the optical response signal 851 to be measured, for example a single detector, a multi-channel detector, a charge coupled device (CCD), a CCD array, a spectrometer or the like. In various embodiments the optical response signal 851 may be spectrally separated into two or more components, with each component directed to a separate detector 850. In various embodiments, this spectral separation may be effected using a dichroic filter, a dichroic mirror or the like.

[0130] In various embodiments, (though not shown in FIG. 8A), at least one temperature sensor (e.g., thermocouple, thermistor, second photodiode, etc.) may be positioned in thermal communication with the detector 850 and configured to provide information regarding the temperature of the detector 850 (also referred to herein as a “system temperature”) that may be used to identify and correct for temperature-based effects of the detector. In various embodiments at least one temperature sensor (thermocouple, thermistor, second photodiode, etc.) may bepositioned in thermal communication with one or more portions of the amplification and / or processing circuitry or other portions of converter 140. In other embodiments, this temperature sensor may be attached to or integrated with the detector 850. In addition, in other embodiments, at least one temperature sensor (thermocouple, thermistor, second detector, etc.) may be positioned in thermal communication with the controller 862 and / or within the optional housing (not shown in FIG. A for clarity) and configured to provide information regarding the temperature of the controller 862 and / or the temperature within the optional housing that may be used to identify and correct for temperature-based effects of the controller 862 or its amplification and / or processing circuits.

[0131] In the illustrated embodiment, at least one optional filter 847 may be positioned in optical communication with the detector 850, for example, between the detector 850 and the sensing element 122 in order to prevent stray light (or light having wavelengths not intended for detection) from reaching the detector 850. In various embodiments, the optional filter 847 may be a longpass filter configured to transmit about at least 95% of light intended for detection to the detector 850. The optional filter 847 may be provided as any combination of shortpass, bandpass, notch, or neutral density filters. Those skilled in the art will appreciate that any of a wide variety of filters having a wide variety of performance specifications can be used. Optionally, no filters may be used.

[0132] In various embodiments, an optical sensor system may be configured to measure temperature using a thermographic phosphor as the temperature sensing element 122. Referring again to FIG. 8A, FIG. 8A shows a schematic view of a temperature sensor system 190 including a converter 140 and phosphor sensing element 122, wherein the converter 140 is configured to provide an optical excitation signal 841 and to measure one or more properties or characteristics of the optical response signal 851 (including one or more portions of the optical excitation response signal 852 and the optical-excitation-independent signal 853 (described herein and shown in FIG. 8B) received from the sensing element 122. In various embodiments, the thermographic phosphor, when excited by a suitable pump source, may phosphoresce and one or more properties of the phosphorescence, for example amplitude, spectral power density, phosphorescence decay time or the like,may be dependent on temperature, and with a suitable calibration, be used to determine temperature.

[0133] FIG. 9A shows an example diagram of an embodiment of portions of a semiconductor processing chamber 900 configured with one or more “multi-channel sensing interfaces+sensing elements” identified as 93x (e.g., 931-939 shown in FIGS. 9A-9E). Each of the “multi-channel sensing interfaces+sensing elements” includes a system optical pathway 994 optically coupled at its proximal end to a system-side optical interface 114 and optically coupled to at least one converter 140 at its distal end (not shown in FIGS. 9A-9E for clarity). The system-side optical interface 114 is optically coupled to a sensor-side optical interface 112, with at least one sensor optical pathway 992 optically coupled at its distal end to at least one sensing element 122 and optically coupled at its proximal end to the sensor-side optical interface 112. The “multi-channel sensing interfaces+sensing elements” 931-939 may also be referred to herein as an “interface-element pair” singular or “interface-element pairs” plural. The interface-element pairs 93x are located in multiple places (in different portions or in different locations) in the semiconductor processing chamber 900 or on the associated components of the semiconductor processing chamber 900 as shown in FIGS. 9A-9E. Interface-element pairs 93x are shown in FIGS. 9A-9E with one sensing element 122 and one sensor optical pathway 992, for clarity, however, as discussed herein, in various embodiments the optical interface including the system-side optical interface 114 and sensor-side optical interface 112 are multi-channel optical interfaces and are configured to support multiple sensor optical pathways 992 and / or multiple sensing elements 122.

[0134] Referring to FIG. 9A, an embodiment of a semiconductor processing chamber 900 includes a chamber 910 and a chamber lid 914 enclosing an environment to be sensed 210, a gas inlet 916 and an exhaust outlet 912, a wafer support (also known as a wafer chuck, susceptor or electrostatic chuck) 920 with a passage 921 providing access to the interior of the wafer support 920, an edge or focus ring 923, a showerhead 918 configured to distribute the gases from the gas inlet 916 through a gas distribution panel 917 to chamber interior 210, and an optional chamber optical feedthrough 919 which may be configured to optically convey system optical pathway 994 out of the interior 210 of the semiconductor processing chamber 900.

[0135] Referring to FIGS. 9A and 9F, in one embodiment, a sensing platform may be configured as a sensor wafer 925 which includes a sensor-side optical interface 112, at least one sensor optical pathway 992 and at least one sensing element 122. In various embodiments, the semiconductor processing chamber 900 may include an interface-element pair 931 configured with a separable optical interface between the system-side optical interface 114 included in and positioned in the center or substantially in the center of wafer holder 920 and the sensor-side optical interface 112 also included in and located in the center or substantially in the center of the sensor wafer 925, such that when the system-side optical interface 114 is mated with or positioned on or adjacent to sensor-side optical interface 112, the two are optically coupled.

[0136] Referring to FIGS. 9A and 9F, in various embodiments a sensing platform may be configured as a sensor wafer 925 which includes a sensor-side optical interface 112, at least one sensor optical pathway 992 and at least one sensing element 122. In various embodiments, the semiconductor processing chamber 900 may include an interface-element pair 932 configured with a separable optical interface between the system-side optical interface 114 included in but outside of the center region of wafer holder 920 and the sensor-side optical interface 112 included in but outside the center region of sensor wafer 925, such that when the system-side optical interface 114 is mated with or positioned on or adjacent to sensor-side optical interface 112, the two are optically coupled.

[0137] In various embodiments, the sensing platform may be configured as a sensor wafer 925 which includes a sensor-side optical interface 112, at least one sensor optical pathway 992 and at least one sensing element 122. In various embodiments, the semiconductor processing chamber 900 may include an interfaceelement pair 934 configured with a separable optical interface between the systemside optical interface 114 included in edge ring 923 and the sensor-side optical interface 112 included in the sensor wafer 925, such that when the system-side optical interface 114 is mated with, positioned on, or adjacent to the sensor-side optical interface 112, the two are optically coupled.

[0138] Referring to FIGS. 9A and 9F, in various embodiments, a sensing platform may be configured as all or a portion of edge ring 923 which includes a sensor-side optical interface 112, at least one sensor optical pathway 992 and atleast one sensing element 122. In various embodiments, the semiconductor processing chamber 900 may include an interface-element pair 933 configured with a separable optical interface between the system-side optical interface 114 included in the wafer holder 920 and the sensor-side optical interface 112 included in the edge ring 923, such that when the system-side optical interface 114 is mated with or positioned on or adjacent to the sensor-side optical interface 112, the two are optically coupled.

[0139] The sensing platform may be configured as all or a portion of a showerhead 918 which includes a sensor-side optical interface 112, the sensor optical pathway 992 and the sensing element 122. In various embodiments, the semiconductor processing chamber 900 may include an interface-element pair 935 configured with a separable optical interface between the system-side optical interface 114 included in the chamber wall 910 and the sensor-side optical interface 112 included in the showerhead 918, such that when the system-side optical interface 114 is mated with or positioned on or adjacent to the sensor-side optical interface 112, the two are optically coupled. In various embodiments, all or a portion of the sensor-side optical interface 112 and / or all or a portion of the optical pathway 992 and / or all or a portion of the sensor element 122 may be placed in or on the gas distribution panel 917, however, the position of sensor-side optical interface 122, optical pathway 992 and sensor element 122 is not a limitation of the invention.

[0140] Referring to FIGS. 9B and 9F, in various embodiments, a sensing platform may be configured as all or a portion of an edge ring 923 which includes a sensor-side optical interface 112, at least one sensor optical pathway 992 and at least one sensing element 122. In various embodiments, a semiconductor processing chamber 900 may include an interface-element pair 936 configured with a gap between the system-side optical interface 114 included in a chamber wall 210 and the sensor-side optical interface 112 included in the edge ring 923, such the system-side optical interface 114 is optically coupled to the sensor-side optical interface 112 across a gap 950. In various embodiments, the gap 950 may be at least about 0.5 millimeters, at least about 1 millimeter, at least about 10 millimeters, at least about 25 millimeters, at least about 100 millimeters, or at least about 500 millimeters. Those skilled in the art will appreciate that the gap 950 may be any size. While FIG. 9B shows interface-element pairs 936 configured between the edge ring923 and the chamber wall 210, in other embodiments other interface-element pairs, for example 93x, may be configured with a gap between system-side optical interface 114 and sensor-side optical interface 112.

[0141] Referring to FIGS. 9B and 9F, in various embodiments the sensing platform may be configured as a sensor wafer 925 which includes a sensor-side optical interface 112, at least one sensor optical pathway 992 and at least one sensing element 122. In various embodiments, the semiconductor processing chamber 900 may include a first interface-element pair 937 configured with a first separable optical interface between the sensor-side optical interface 112 included in sensor wafer 925 and a first system-side optical interface 114 included in edge ring 923 and a second interface-element pair 937’ configured with a second system-side optical interface 114’ (not identified in FIG 9B for clarity) included in the edge ring 923 and a third system-side optical interface 114” (not identified in FIG 9B for clarity) included in the wafer holder 920 such that when the sensor-side optical interface 112 is mated with or positioned on or adjacent to the first system-side optical interface 114, the two are optically coupled, and that when the second system-side optical interface 114’ is mated with or positioned on or adjacent to the third system-side optical interface 114”, the two are optically coupled.

[0142] Referring to FIGS. 9B and 9F, in various embodiments, a sensing platform may be configured as a sensor wafer 925 which includes a sensor-side optical interface 112, at least one sensor optical pathway 992 and at least one sensing element 122. In various embodiments, a semiconductor processing chamber 900 may include an interface-element pair 938 configured with a separable optical interface between a system-side optical interface 114 included in an optical lift pin 953 that is included in the wafer holder 920 and the sensor-side optical interface 112 included in sensor wafer 925, such that when the system-side optical interface 114 is mated with or positioned on or adjacent to sensor-side optical interface 112, the two are optically coupled.

[0143] FIGS. 9C and 9D show an example embodiment of an optical lift pin, as discussed in reference to FIG. 9B, including a portion of wafer holder 920, a portion of a sensor wafer 925, and an optical lift pin 953, which may be configured to move up and down in a lift pin passage 955 and may be configured to be or include an optical pathway, for example, an optical pathway 994, and / or a system-side opticalinterface 114 (not shown), which may be configured to optically couple to the sensorside optical interface 112 (not shown) included in the sensor wafer 925. FIG. 9F shows a more detailed view of the interface-element pair 938.

[0144] In various embodiments one or more lift pins, for example three, may be incorporated into the wafer holder, wafer support, or the electrostatic chuck 920, and may be configured to raise and lower such that the top surface of the lift pin is above the top surface of the wafer holder 920 in the raised position, allowing space for a transfer tool to be positioned between the top surface of the wafer holder 920 and the bottom surface of the sensor wafer 925 to move the sensor wafer 925 (and semiconductor wafers for processing) in and out of the semiconductor processing chamber. While FIGS. 9C and 9D show the system-side optical pathway 994 through the length of optical lift pin 953, in other embodiments all or a portion of optical lift pin 952 may be or include an optical pathway optically coupled to the system-side optical pathway 994 at one end and optically coupled to the sensor-side optical interface 112 on the other side of the optical lift pin 952. In various embodiments, the optical lift pin 953 may be transparent or substantially transparent to wavelengths of light used in the sensor wafer 925. In various embodiments, the optical lift pin 953 may have an optical transmission of at least about 50% or at least about 75% or at least about 85% to wavelengths of light used in the sensor wafer 925. In various embodiments, the optical lift pin 953 may have a transmission of at least about 50% or at least about 75% or at least about 85% to wavelengths of light in the range of about 390 nanometers to about 800 nanometers, however in other embodiments the sensing system and optical lift pin 953 may be configured to operate at wavelengths in a shorter or longer wavelength range. In various embodiments, the system-side optical pathways may also include all or portions of any of a wide variety of optical components, including one or more lenses (e.g., half ball lens, a ball lens, cylindrical lenses), prisms, mirrors, dichroic filters, dichroic mirrors, refractive optics, reflective optics, optical filters, one or more optical fibers (e.g., side-firing optical fibers, optical fiber bundles, imaging optical fibers, unterminated (bare) optical fibers), solid lightguides, phosphors, thermographic phosphors, optical gratings, fiber Bragg gratings or non-linear optical crystals. Those skilled in the art will appreciate that any of a wide variety of optical elements or optical components may be included in the system-side optical pathways.

[0145] Referring to FIGS. 9B and 9F, in various embodiments, a sensing platform may be configured as all or a portion of a showerhead 918 which includes a sensor-side optical interface 112, at least one sensor optical pathway 992 and at least one sensing element 122. In various embodiments, the semiconductor processing chamber 900 may include a separable interface-element pair 939 configured with a translation system 959 configured to translate or move the systemside optical interface 114 within the semiconductor processing chamber to a position where it may be optically coupled to the sensor-side optical interface 112 included in showerhead 918 (interface-element pairs 93x are shown in the optically uncoupled position in FIG. 9B).

[0146] Referring to FIG. 9E, in various embodiments, a sensing platform may be configured as one or more sensing elements 122 located within the semiconductor process chamber 900 that may be in optical communication with a converter 140 outside of the semiconductor process chamber 900, through an optical pathway including at least one window 981 through which a probe optical beam 982 may be transmitted to optically couple to one or more sensing elements 122. In various embodiments, the window 981 has a transmittance of at least 75%, at least 85%, or at least 95% for wavelengths in probe optical beam 982. In various embodiments, the probe optical beam 982 may be scanned by a scanning system 980 to position it such that it can probe more than one sensing element 122. In various embodiments, the scanning system or mirror 980 may include a galvo mirror, a single face scanning mirror, a polygonal scanning mirror, a MEMS mirror, a digital light guide, or the like. Those skilled in the art will appreciate that many different methods of scanning may be used. In various embodiments, the scanning mirror or system 1450 may scan in one or more dimensions.

[0147] In various embodiments, separating the sensing element 122 from the rest of the sensing system may provide certain advantages, for example, in not requiring contact to the area or item to be sensed, providing more flexibility in configuration of components within the semiconductor process chamber and reducing the impact of the sensing system on the area or item to be sensed. For example, in embodiments where the sensing element 122 is configured to sense temperature, the elimination of contact of the rest of the sensor system may result in less perturbation of the actual temperature at the measurement point.

[0148] In various embodiments, the probe optical beam 982 may be conveyed or optically coupled to the converter 140 through an optional optical pathway 984. In various embodiments, the optical pathway 984 may include an optical fiber, an optical fiber bundle and / or one or more optical elements (e.g., a refractive optic, a reflective optic, a mirror, or the like).

[0149] In various embodiments, the scanning system 980 may be configured to optically couple an optical excitation signal from the light source 840 of the converter 140 (described in reference to FIG. 8A) to a specific sensing element 122, thus providing multiplexing of the optical excitation signals and the optical response signals. In various embodiments, different sensors may be activated and / or read at different times, resulting in time-multiplexing of the sensor array.

[0150] While FIGS. 9A-9E show specific configurations of the optical interfaceelement pairs 93x, in other embodiments, the optical interface-element pairs 93x may be part of or located in other areas of the chamber 900 and / or the chamber walls 910, the lid 914, the showerhead 918, the edge ring 923, the wafer holder, the electrostatic chuck 920, or any other of the components in the semiconductor processing system.

[0151] In various embodiments, the edge ring 923 may be removable from the semiconductor processing chamber 900, for example, manually or using automated or semi-automated wafer handling equipment. In various embodiments, the showerhead 918 may be removable from the semiconductor processing chamber 900, either manually or using automated or semi-automated wafer handling equipment. In various embodiments, the sensor wafer 925 may be removable from semiconductor processing chamber 900 manually or using automated or semiautomated wafer handling equipment. In various embodiments, the separable optical interface permits removal and return of various chamber components or sensor wafer platforms without the need for additional mechanical disassembly. The separable optical interface permits removal and replacement of various chamber components or sensor wafer platforms (e.g., when a component has reached its lifetime) without the need for additional mechanical disassembly.

[0152] In various embodiments, all or portions of the sensing platform may be consumable (e.g., a consumable sensor wafer 925, a consumable edge ring 923, aconsumable showerhead 918, or the like). The optical sensor system may be configured to detect and / or monitor the state of consumption of all or portions of the sensing platform or detect and / or monitor the state of consumption of other components within the semiconductor processing chamber. In various embodiments consumption may include degradation of the functionality of the component, a removal of material from the component (e.g., etching of the component, deposition of material on the component, change in shape of critical dimensions of a component, such as distances, diameters of passages in the showerhead, or the like). In various embodiments, the optical sensing system may be utilized to provide information that may in part be used to determine the timing and necessity of maintenance or replacement of components.

[0153] The sensing elements 122 may be a location on or in one or more chamber components (e.g., the sensor wafer 925, the showerhead 918, the edge ring 923, the wafer support 920, or any other chamber component), or it may be a distinct sensing element attached or integrated into a chamber component, for example a phosphor sensing element, or, as shown as sensing element 122’ of FIG.9E, it may be a volume of the region within the semiconductor processing chamber.

[0154] The optical data may be multiplexed over one or more optical channels to increase the number of sensed points without increasing the number of optical channels and / or to reduce the size of the interface or penetration into the sensed environment or chamber. Example multiplexing approaches include wavelength multiplexing, spatial multiplexing, (e.g., within a fiber bundle or coherent optical fiber, temporal or time-multiplexing or the like). Those skilled in the art will appreciate that any specific multiplexing approach may be used. The optical sensing system may be configured for one multiplexing approach or multiple multiplexing approaches. In other embodiments, the optical sensing system may be configured for two or more different multiplexing approaches.

[0155] In various embodiments, the optical information may be wavelength-multiplexed, for example, one optical channel may convey different optical information using different wavelengths. In various embodiments, a multiplexed sensor optical channel may be configured to sense the same characteristic at more than one location and / or may be configured to sense multiple different characteristics at a single location.

[0156] FIG. 10A shows an example embodiment of a portion of a sensing system configured for wavelength-multiplexing including two of the same sensing elements or points 122 and 122’ optically coupled to a single sensor optical pathway 124 along the sensor optical pathway 124 to an analyzer 140, along with two example spectra 1010 and 1015 of light from the sensing elements or points 122 and 122’. In various embodiments, the sensing elements or points 122 and 122’ may be configured to emit light, each having the same or essentially the same spectral power density across a range of wavelengths, as shown by the curve 1010. In various embodiments, the optical sensing system may be configured to separate and analyze different wavelength ranges, for example, a wavelength range 1021 centered approximately at a wavelength L1 and a wavelength range 1022 centered approximately at a wavelength L2, corresponding to sensing elements or points 122 and 122’ respectively, thus providing an optical signal from two different locations or sensing elements multiplexed over one optical channel. While FIG. 10A shows two sensing elements or points 122 and 122’, in other embodiments more than two sensing elements or points may be optically coupled to a single sensor optical pathway.

[0157] In various embodiments, the spectral characteristics in each wavelength range may change in a similar way or in different ways in response to a change in the characteristic to be measured. The integrated or peak intensity of the spectrum may change, the spectral power density may change, the time decay constant of the emission may change, or the like. The spectra vs. intensity plot in FIG. 10A shows an example embodiment of a change in emission intensity, from spectrum 1010 to spectrum 1015, under different measurement conditions, such as different temperatures. While the example in FIG. 10A shows a change in the intensity of the spectrum with different measurement conditions, in other embodiments, such changes may include changes in the spectral power density (the intensity at each wavelength) or temporal characteristics of the spectrum or portions of the spectrum, such as a change in intensity of the detected emission intensity at one or more wavelengths as a function of time.

[0158] In various embodiments, the converter 140 may be configured to wavelength-demultiplex a wavelength-multiplexed signal. In various embodiments, the converter 140 may include one or more filters and detectors (for example asdescribed in reference to FIG. 8A) or one or more spectrometers, CCDs or CCD arrays, or the like to perform such wavelength demultiplexing. In various embodiments, additional optical elements may be located between the sensing elements or points 122 and 122’ to aid in or to perform the wavelength multiplexing or demultiplexing (e.g., one or more filters, mirrors, gratings or the like).

[0159] In various embodiments, the wavelength demultiplexing may occur outside of the converter 140, for example, along the optical pathway between the sensing element 122 and the converter 140. FIG. 10B shows an example plot of wavelength vs. intensity 1045 for emission from sensing elements 122, 122’ and 122”. In various embodiments, the dashed boxes 1041, 1041’ and 1041” represent the spectral filter characteristics of filters 1040, 1040’ and 1041” shown in FIG. 10C, respectively. In various embodiments, the filter 1040 may be a high pass filter or a notch or bandpass filter, the filter 1040’ may be a notch or bandpass filter, and the filter 1040” may be a low pass or notch or bandpass filter. In other embodiments, the filters 1040, 1040’ and 1040” may be any kind of filters and have any spectral characteristics.

[0160] FIG. 10C shows a schematic of an example system having three sensing elements 1050, 1050’ and 1050”, and three filters 1040, 1040’ and 1040” having spectral characteristics representative of the dashed boxes 1041, 1041’ and 1041” shown in FIG. 10C, respectively. In various embodiments, the sensing elements 1050, 1050’, 1050” may be the same or different. Optical branches 1060, 1060’ and 1060” are optically coupled to an optical fiber 1065 which in turn is optically coupled to a photodetector system 1070 and / or a spectrometer 1072. In various embodiments, the photodetector system 1070 may be configured with filters or other optical elements to separate the signal from optical fiber 1065 into the three optical ranges associated with the spectral ranges 1041, 1041’ and 1041”. In various embodiments, the photodetector system 1070 may have more than one photodetector. In various embodiments, the signal from the optical fiber 1065 may be analyzed by the spectrometer 1072 to determine its spectral content as a function of wavelength. With this system, optical signals from three different wavelength ranges and / or three different locations may be transmitted through one optical fiber 1065. FIG. 10C shows three optical channels comprising respective sensing elements 1050, 1050’ and 1050”, filters 1040, 1040’ and 1040”, and branches 1060,1060’ and 1060”. In other embodiments, there may be more or less than three optical channels.

[0161] In various embodiments, the sensing elements 1050, 1050’ and 1050” may be sensing points configured to collect light in the environment of each sensing point. For example, a light collecting point may include a lens or filter, and the system may be configured to collect light emitted within the semiconductor process or process chamber. The photodetector 1070, the spectrometer 1072 and the analyzer 140 may be configured to analyze the light from each of the light collection points to determine one or more characteristics of the process environment within or around the process chamber.

[0162] Similar to the light collecting system 110 described in reference to FIGS.10A- 10C utilizing one or more wavelength filters 1040, FIG. 10D shows an example embodiment of a system including two different phosphors or thermographic phosphors 1080 and 1081, each optically coupled to a transmission pathway 1065 by respective branches 1060, 1060’ which are in turn optically coupled to a photodetector 1070 and / or spectrometer 1073. The phosphors 1080 and 1081 may be used to convert absorbed radiation in one wavelength range (e.g., from an optical excitation signal) to a higher or lower wavelength range. FIG. 10E shows an exemplary schematic of spectral signals 1083 and 1084 of emission from the phosphor sensing elements 1080 and 1081, respectively. In various embodiments, light emission from the phosphor sensing elements 1080 and 1081 may be in response to absorption of an optical response signal, as described herein.

[0163] In various embodiments, the sensing elements 1080 and 1081 may be a phosphors or thermographic phosphors embedded in glass ora ceramic phosphor. In various embodiments, the photodetector system 1070 may be configured with filters or other optical elements to separate the signal from optical pathway 1065 into the two optical ranges associated with spectra 1083, 1084. In various embodiments, the photodetector system 1070 may have more than one photodetector. The signal from optical pathway 1065 may be analyzed by the spectrometer 1073 to determine its spectral content as a function of wavelength. In various embodiments, the analyzer 140 may be configured to determine a characteristic of the environment near the sensing elements 1080 and 1081, for example, to determine a temperature. While FIG. 10D shows two optical channels, in other embodiments such systemsmay have fewer or more optical channels. In various embodiments, optional optical elements 1090 may be located between optical pathways 1060 and 1060’ and sensing elements 1080 and 1081 respectively. In various embodiments, the optional optical elements 1090 may be located between the sensing elements 1080 and 1081 and the environment to be sensed (not shown in FIG. 10D for clarity). In various embodiments, the optical elements 1090 may include reflective optics, refractive optics, mirrors, dichroic filters, dichroic mirrors, or the like

[0164] In various embodiments, the optical information may be spatially multiplexed, for example, one optical channel may convey different optical information in different portions of the optical pathway. FIG. 11 shows an example embodiment of a portion of a sensing system 1100 configured for spatial multiplexing, including three sensing elements 122, 122’ and 122” optically coupled to an optical pathway 1110 through sensor-side optical pathways 124 and a systemside optical interface 114, where the optical pathway 1110 may be optically coupled to a converter 140 (not shown in FIG. 11 for clarity). In addition to sensing elements, the sensor-side optical pathways may also include all or portions of any of a wide variety of optical components, including one or more lenses (e.g., half ball lens, a ball lens, cylindrical lenses), prisms, mirrors, dichroic filters, dichroic mirrors, refractive optics, reflective optics, optical filters, one or more optical fibers (e.g., sidefiring optical fibers, optical fiber bundles, imaging optical fibers, unterminated (bare) optical fibers), solid light guides, phosphors, thermographic phosphors, optical gratings, fiber Bragg gratings or non-linear optical crystals. Those skilled in the art will appreciate that any of a wide variety of optical elements or optical components may be included in the sensor-side optical pathways.

[0165] FIGS. 12A-C show example embodiments of portions of a spatially multiplexed optical sensor system. FIG. 12A shows a coherent or imaging optical pathway 1210 (corresponding to the optical pathway 1110 of FIG. 11) optically coupled through a system-side optical interface 114 to optical channels 120, 120’ and 120” on one end and optically coupled to a converter 1140 on the other end. In various embodiments, the coherent or imaging optical pathway 1210 may include a fiber bundle in which the fibers are aligned to be in the same position at each end, thus being able to transmit an image from one end to the other. The sensing optical channels 120, 120’ and 120” are optically coupled to and transmitted through thecoherent imaging pathway 1210 along the imaging pathway channels 1250, 1250’ and 1250” respectively.

[0166] FIG. 12B shows an example schematic of an end view 1245 at separable interface A-A’ (FIG. 12A) of the coherent imaging pathway 1210 with multiple optical channels 1250 within coherent imaging pathway 1200. FIG. 12C shows an example schematic of an end view 1247 at interface C-C’ of the coherent imaging pathway 1210 with multiple optical channels 1250 within the coherent imaging pathway 1210. As shown in FIGS. 12B and 12C, the position of optical channels 1250 is the same at each end of the coherent imaging pathway 1210. In various embodiments, the converter 1140 may be configured with multiple channels, each of which is optically coupled to a different optical channel 1250, however in other embodiments, the converter 1140 may be configured differently, for example as a scanning system to sequentially access each optical channel 1250 in the coherent imaging pathway 1210. The scanning system or mirror system may include a galvo mirror, a single face scanning mirror, a polygonal scanning mirror, a MEMS mirror, a digital light guide or the like.

[0167] In various embodiments, all or a portion of the individual fibers at one or both ends of a fiber bundle may be fused together, for example, to simplify handling and manufacturing. In various embodiments, a mask, for example delineating portions of the end face of the imaging fiber 1210, may be employed at one or both ends of a fiber bundle to help separate the optical signals from each individual channel and reduce crosstalk between the individual channels.

[0168] FIGS. 13A-E show example embodiments of portions of a spatially multiplexed optical sensor system including a fiber bundle optical pathway 1310 (corresponding to the optical pathway 1210 of FIG. 12A) optically coupled through a system-side optical interface 114 to optical channels 120, 120’ and 120” on one end and optically coupled to individual channels of the converter 140 (e.g., the converter channels 140, 140b, 140c and the like) on the other end through multiple fiber bundle portions 1314, 1314’ and 1314”. In various embodiments, the fiber bundle optical pathway 1310 may include a fiber bundle in which the fibers are not necessarily aligned from end to end (as is the case with the coherent imaging optical pathway 1210 of FIGS. 12A-12C). Referring to FIG. 13A, fiber bundle 1310 isseparated into multiple optical channels, identified as 1314, 1314’ and 1314” corresponding to sensor optical channels 120, 120’ and 120” respectively.

[0169] FIG. 13B shows an example schematic of an end view 1345 at separable interface A-A’ (see FIG. 13A) of the fiber bundle 1310 showing the optical coupling of the sensor optical channels 120 to the fiber bundle 1310 in which each sensor optical channel is optically coupled to a portion of the fibers in the fiber bundle 1310.

[0170] FIG. 13C shows an example schematic of an end view 1347 at interface C-C’ (see FIG. 13A) of fiber bundle portions 1314, 1314’, and 1314” in which signals from the optical channels 120 are conveyed along a portion of fibers in the fiber bundle 1310. As shown in FIGS. 13B and 13C, the signal from the sensor optical channels 120 may be conveyed along portions of fiber bundle 1310, which is then split into separate fiber bundle portions 1314, each of which conveys the signal from at least one sensor optical channel 120 which is then optically coupled from the fiber bundle portions 1314 into a separate channel of a converter 140.

[0171] While the separable optical interface has been shown as having a round or circular shape, for example, in FIGS. 4A, 6A-6D, 7A-7E, 12B, 12C, 13B and 13C, in other embodiments the optical interface, including the sensor-side optical interface 112 and the system-side optical interface 114, may have a different shape, for example a square, a rectangle, a triangle, a hexagon or any other shape. FIG. 13D shows an example rectangular optical interface 1350 and example locations of a single row of sensor optical channels 120 within the optical interface 1350. FIG. 14E shows an example rectangular optical interface 1351 and example locations of a double row of sensor optical channels 120 within the optical interface 1351. In various embodiments, the optical interfaces and / or optical pathways may have different shapes (e.g., independent optical fiber optical pathways, coherent optical fiberoptical pathways, fiber bundle optical pathways, or the like).

[0172] FIGS. 14A shows an example embodiment of a system configured to separate individual sensor optical channels 120 from a combined optical pathway, for example an optical pathway 1110, as described in reference to FIG. 11. FIG. 14B shows an example embodiment of a portion of this system. In various embodiments, the system separates and optically interfaces individual optical channels to separate channels of a converter 140. In various embodiments, thesystem includes a converter 140 (also described herein with reference to FIG. 8A), a combined optical pathway 1110 and a scanning assembly 1450 which may be configured to optically couple an input 1440 of the detector 140 to a portion of the combined optical pathway 1110 through an optical pathway 1453 and the scanning assembly 1450. In various embodiments, the portion of combined optical pathway 1110 that is coupled to the converter 140 may correspond to a sensor optical channel 120. Referring to FIG. 14A, the scanning system 1450 is shown optically coupling a portion of the face of combined optical pathway 1110 corresponding to a sensor optical channel 120 to a detector 850, while in FIG. 14B the scanning system 1450 is shown optically coupling a portion of the face of the combined optical pathway 1110 corresponding to the sensor optical channel 120’ to the detector 850. In various embodiments, different sensing elements, corresponding to different optical sensor pathways 120 may be activated and / or read at different times, for example sequentially, resulting in a time-multiplexed system.

[0173] In various embodiments, the scanning system 1450 may be configured to optically couple an excitation signal, for example, from the light source 840 of the converter 140 to a specific optical channel of the combined optical pathway 1110, thus providing multiplexing of both optical excitation and optical response signals.

[0174] In various embodiments, the combined optical pathway 1110 may include a coherent or imaging optical pathway, as described in reference to FIGS. 12A-12C, a fiber bundle as described in reference to FIGS. 14A-14E, individual optical fibers, or any other configuration. In various embodiments, the scanning system or mirror 1450 may include a galvo mirror, a single face scanning mirror, a polygonal scanning mirror, a MEMS mirror, a digital lightguide or the like. In various embodiments, the scanning mirror or system 1450 may scan in one dimension or more than one dimension.

[0175] While FIGS. 14A and 14B show an example of multiplexing using a scanning system, in other embodiments other multiplexing and time-multiplexing configurations may be utilized. In various embodiments, a time-multiplexed system may be configured with a multi-channel optical switch or optical multiplexer between the converter 140 and the optical pathways leading to the sensing elements or sensing points. FIG. 14C shows an example embodiment of a portion of a multiplexed system including a converter 140 having one optical channel which isoptically coupled to an optical switch 1475 through an optical pathway 1470. In various embodiments, the optical switch 1475 is configured to couple the optical pathway 1470 to any one of output optical pathways 1472. In various embodiments, each of the output optical pathways is optically coupled eventually to a different sensing point or sensing element (not shown in FIG. 14C for clarity). In various embodiments, the optical switch 1475 may sequentially optically couple the optical pathway 1470 to each of the output optical pathways 1472, for example first to the output optical pathway 1472, then to the output optical pathway 1472’ and so on. In various embodiments, the frequency of addressing each output optical pathway may be the same or may be different. While FIG. 14C shows 6 (six) output optical channels, in other embodiments the number of optical channels may be less than 6 (six) or greater than 6 (six). In various embodiments the optical switch or multiplexer may be configured to optically couple one or both of the optical response signal and the optical excitation signal.

[0176] FIG. 15 shows an example embodiment of a system configured to separate individual sensor optical channels 120 (not shown) from a combined optical pathway, for example, a combined optical pathway 1110, as described in reference to FIG. 11 , into individual optical channels for analysis. In various embodiments, the combined optical pathway 1110 may be optically coupled to a converter 1560 through a fixture 1545. In various embodiments, the fixture 1545 may be a connector or the like and may be, at least in part, configured to align the combined optical pathway 1110 in front of an optical lens 1520. In various embodiments, the optical signal from the combined optical pathway 1110 is optically coupled through the optical lens 1520 and an optical lens 1524, creating an image of the end face of combined optical pathway 1110 on an imaging sensor array 1540, and the signals from the imaging sensor array 1540 representative of different portions of the combined optical pathway 1100 are then analyzed by a processing system 1549 to determine one or more desired measured characteristics. In various embodiments, the imaging sensor array 1540 may include a one-dimensional or two-dimensional imaging array (e.g., a CCD imaging sensor, an array of individual sensors, a camera, or the like) the specifics of the imaging sensor array 1540 are not a limitation of the present invention.

[0177] In various embodiments, the converter 1560 may be configured to provide an excitation signal to the sensing element 122 (not shown in FIG. 15) through the combined optical pathway 1100. In various embodiments, the excitation signal is light emitted by a light source 1550 (e.g., an LED or laser) that is reflected by a dichroic mirror 1522 towards the lens 1520 which focuses and optically couples the excitation signal into the end face of the combined optical pathway 1100. In various embodiments, the optical response signal from the sensing element 122 is transmitted through the combined optical pathway 1100, through the optical element 1520 and the dichroic mirror 1522 and focused by the optical element 1524 on the imaging sensor array 1540, as described herein. In various embodiments, the imaging sensor array 1540 may provide an image of the end face of the combined optical pathway 1100, which then may be analyzed by the analysis system 1549. In various embodiments, the analysis system 1549 may be configured to analyze all optical channels of the combined optical pathway 1100 simultaneously, however in other embodiments, this analysis may be done in serially or in some other sequence. In various embodiments, the imaging system 1540 may provide an image of the end face of the combined optical pathway 1100 at periodic intervals, (e.g., about every 1 millisecond, about every 5 milliseconds, or about every 25 milliseconds), however the period at which images are captured is not a limitation of the present invention.

[0178] In various embodiments, a multiple channel optical interface may be used to provide position information, for example, the relative position of a chamber component incorporating the sensor-side optical interface 112 and a chamber component incorporating the system-side optical interface 114. Referring to FIGS.9A-9E, in various embodiments, relative positions may be determined for a sensor wafer 925 relative to a wafer holder 920, for example to determine if the sensor wafer 925 is centered on the wafer holder 920. In various embodiments, the position, for example spacing orcentering, of a showerhead 918 may be determined relative to the sensor wafer 925. In various embodiments, the position of the edge ring 923, for example spacing or centering, may be determined relative to the wafer holder 920, the sensor wafer 925, or the showerhead 918.

[0179] In various embodiments, the entire optical pathway from the sensing point to the analyzer may be configured with coherent or imaging optical pathways, and the sensing point may be configured to capture an image of the interior of thesemiconductor process chamber. In various embodiments regions of interest for image capture may include the wafer support, the electro-static chuck, the edge ring, the shower head or the like.

[0180] FIGS. 16A-16F show views of an example embodiment of a multiplechannel separable optical interface configured to provide position information, incorporating eleven optical channels, nine of which are in a cross configuration, one above an end-cross position and one below an end-cross position. FIGS. 16A-16F show the relative positions of the individual optical channels in the sensor-side optical interface 112 relative to individual optical channels in the system-side optical interface 114, at the separable interface A-A’ (as shown for example in FIG. 5B). Referring to FIGS. 16A-16F, FIG. 16A shows an example embodiment where the sensor-side optical interface 112 is aligned with the system-side optical interface 114, meaning that each individual sensor optical pathway 520 or the optical axis of each individual sensor optical pathway 520, in the sensor-side optical interface 112 is aligned with a respective system optical pathway 530 or the optical axis of the system optical pathway 530, in the system-side optical interface 114. FIG. 16A also shows an XY coordinate plan showing the relative shift in position of the sensor-side optical interface 112 with respect to the system-side optical interface 114. FIG. 16B shows an example embodiment where the sensor-side optical interface 112 is rotated clockwise with respect to the system-side optical interface 114. FIG. 16C shows an example embodiment where the sensor-side optical interface 112 (shown in dashed lines) is offset in the +Y direction with respect to the system-side optical interface 114. FIG. 16D shows an example embodiment where the sensor-side optical interface 112 (shown in dashed lines) is offset in the -X direction with respect to the system-side optical interface 114. FIG. 16E shows an example embodiment where the sensor-side optical interface 112 (shown in dashed lines) is offset in the -X direction and offset in the +Y direction with respect to the system-side optical interface 114. FIG. 16F shows an example embodiment where the sensor-side optical interface 112 (shown in dashed lines) is offset in the -X direction, offset in the +Y direction and is rotated clockwise with respect to the system-side optical interface 114.

[0181] In various embodiments, the relative intensity or signal strength of the sensor optical channels 530 may be used to determine the relative position of thesensor-side optical interface 112 and the system-side optical interface 114 and thus the relative positions of the chamber components in which each interface is incorporated. For example, referring to FIG. 16B, the clockwise rotation results in the center channel intensity remaining substantially the same, while the other channels in the cross have a reduced intensity and a signal still present at the endcross positions. If the rotation was counterclockwise, the intensity of the end-cross positions would monotonically decrease, while the intensity of the two additional channels on the periphery of the sensor-side optical interface 114 increase in strength. In various embodiments, rotation can be distinguished from a vertical or lateral translation by evaluation of the relative signal strengths of the intensity of the cross positions. In translation, the change in intensity of the cross positions is the same or about the same for all the positions, while for rotation, the change in intensity is larger for positions closer to the periphery.

[0182] In various embodiments, the sensor optical channels 520 may be replaced by an optical element configured to reflect light back into the corresponding system optical channels 530. FIG. 16G shows an example embodiment of a sensorside optical interface 112 including a plurality of optical elements 1610 corresponding to a plurality of system optical channels 530 included in a system-side optical interface 114. In various embodiments, the optical elements 1610 may be a reflective surface or film, for example aluminum, silver or gold or the like, or may be an optical element configured to reflect light back in the direction from which it came, for example a prism, a retroreflector, a cat’s eye retroreflector or the like. In various embodiments, a converter, though not shown, may be configured to provide an optical excitation signal to each of the system optical channels 530 and to determine a reflected intensity of the reflected optical response signal from each of the system optical channels 530, and use the reflected intensity ora change in intensity (for example, the ratio or difference between the optical excitation signal and the optical response signal) to determine the relative positions of the sensor-side optical interface 112 and the system-side optical interface 114, as described herein, and thus the relative position of chamber components incorporating the sensor-side optical interface 112 and the system-side optical interface 114.

[0183] In various embodiments, the relative position to be determined may include a spacing 1611 between the sensor-side optical interface 112 and thesystem-side optical interface 114 as shown in FIG. 16H, a planarity or angular alignment 1612 between the sensor-side optical interface 112 and the system-side optical interface 114 as shown in FIG. 161, and / or the lateral, rotational, and / or angular alignment 1613 between the sensor-side optical interface 112 and the system-side optical interface 114 as shown in FIG. 16J and as described in reference to FIGS. 16A-16F. In various embodiments, the chamber components may include a susceptor, a wafer holder, an electrostatic chuck, an edge ring, a showerhead or the like.

[0184] In various embodiments, the sensor-side optical interface 112 may be replaced by a chamber component that has been configured to have a sufficiently reflective surface to reflect light back into the corresponding system optical channels 530. In various embodiments, the relative position to be determined may include the spacing between the chamber component and the system-side optical interface 114, the planarity between the chamber component and the system-side optical interface 114, and / or the lateral, angular, or rotational alignment between the chamber component and the system-side optical interface 114. In various embodiments, the system-side optical interface 114 may be part of a sensor wafer, permitting geometrical measurements between various chamber components and the position of the wafer, while in other embodiments the system-side optical interface 114 may be part of a chamber component, permitting geometrical measurements between different chamber components.

[0185] In various embodiments, relative position sensing optical channels may be distinct from other sensing optical channels configured to sense or determine a different characteristic, as shown in FIG. 16H, which shows an example embodiment including both relative position sensing elements 1610 and sensor optical channels 520 optically coupled to sensing elements 122 in one sensor-side optical interface 112, and multiple system-side optical channels, with different system-side optical channels configure for either relative position sensing or sensing of other characteristics by the sensing elements 122, however in other embodiments, sensing optical channels may be used for both relative position sensing and sensing at least one other characteristic.

[0186] While FIGS. 16A-16F show a configuration with eleven channels, in other embodiments a different number of channels and a different arrangement ofchannels within the sensor-side optical interface 112 and the system-side optical interface may be utilized.

[0187] In various embodiments, a sensing element 122 may have a variety of different configurations, for example, reflecting whatever characteristic is to be sensed. FIG. 17A shows an example embodiment of a sensing element 122 which includes a sensing material 1715 optically coupled to a sensor optical channel 1710. In various embodiments, the sensing material 1715 may include one or more phosphor materials that may be configured to absorb at least a portion of an optical excitation signal and emit an optical response signal that is used by the optical sensor system to determine a characteristic to be sensed or measured (e.g., temperature). In various embodiments, the phosphor may be incorporated in a binder (e.g., a polymeric material, a glass, a ceramic or the like). In various embodiments, the sensing material may be in a rectangular solid chip form, for example, having a dimension in the range of about 100 microns to about 5,000 microns, or in the range of about 200 microns to about 1 ,000 microns. While FIG.17A shows the sensing material 1715 in physical contact with the sensor optical channel 1710, in other embodiments, a gap may be introduced between sensing material 1715 and the sensor optical channel 1710. In various embodiments, the sensing material 1715 may be configured to emit light in response to one or more conditions within the sensed environment, without stimulation from an external source such as the light source in the converter.

[0188] FIG. 17B shows an example embodiment of a sensing element 122 including an optical fiber 1720 and one or more Fiber Bragg Grating (FBG) sensors 1725 (two FBG sensors 1725 and 1725’ (also referred to herein as “sensing points”) are shown in FIG. 17B). An FBG sensor incorporates a grating reflector within an optical fiber, where the grating reflector is configured to reflect a portion of an input broadband light signal at a specific frequency. Configuring FBG sensors with different reflection frequencies in a single fiber allows for sensing multiple points along the single optical fiber. The reflection frequency is dependent on changes in the characteristics of the optical fiber, such as the index of refraction, and conditions that cause a change in the optical fiber characteristics result in a shift in reflected frequency, which can be detected and related to the change in condition, for example temperature or strain. In various embodiments, a multiple channelseparable optical sensor system may include one or more FBG sensors or FBG sensing points. In various embodiments, an optically multiplexed sensor system may include a FBG sensor system.

[0189] FIG. 17C shows an example embodiment of a sensing element 122 configured to sample light collected by the end of sensor optical channel 1710. In various embodiments, the sensor optical channel 1710 may include an optical fiber or a fiber bundle or the like. In other embodiments, one or more optical elements may be configured at the end of the sensor optical channel 1710 to modify the region or direction that is optically sampled. For example, a sensor optical channel 1710 may collect light according to its numerical aperture in a direction parallel to the axis of the sensor optical channel 1710. FIG. 17D shows an example embodiment of a portion of a sensor wafer 110 including sensor optical channel 1710, which will optically sample the environment parallel to and just above the surface of the sensor wafer 110. FIG. 17E shows an example embodiment of a portion of a sensor wafer 110 including the sensor optical channel 1710 and an optical element 1727 configured to collect light perpendicular to the surface of sensor wafer 110 and optionally to direct an optical excitation signal to the region above the optical element 1727 perpendicular to the surface of the sensor wafer 110, providing a means to optically sample a region farther above the surface of the sensor wafer 110 than that sampled by the configuration discussed in reference to FIG. 17D. In various embodiments, the optical element 1727 may include one or more of a mirror, prism, refractive lens, total internal reflection optical element, a grating or the like.

[0190] In various embodiments a sensor wafer may constructed from one or more semiconductor wafers, for example silicon, gallium arsenide or other semiconductor materials. In various embodiments, a sensor wafer may be constructed of wafers formed of other materials, for example ceramics such as, but not limited to, aluminum nitride, silicon carbide, alumina, sapphire, zirconia, metals such as but not limited to aluminum, titanium, steel or the like, or fiberglass or polymers such as PEEK or Torlon. The materials of construction of the wafers are not a limitation of the present invention. In various embodiments, the sensor wafer may have a form factor identical or similar to that of standard size semiconductor wafers, for example having a diameter of about 100 millimeters, or about 150 millimeters, or about 200 millimeters, or about 300 millimeters, and having athickness in a range of about 50 microns to about 10,000 microns, or in a range of about 300 microns to about 2,000 microns.

[0191] FIGS. 18A-18C show example embodiments of a portion of a sensor wafer 1800 constructed from two silicon wafers, including a bottom wafer 1811 and a top wafer 1810, including at least one passage or groove 1820 formed in the bottom wafer 1811 and configured to contain at least a portion of a sensor optical pathway 1822, wherein the sensor-side optical interface 112 includes passages 1841 which may be configured to position the sensor optical pathway 1822 in optical communication with a system optical pathway 1824 which is positioned within a passage 1842 in the system-side optical interface 114, in which the top wafer 1810 has a portion 1815 removed to allow for bending of the sensor optical pathway 1822 from a position substantially parallel to the surface of the bottom wafer 1811 to a position substantially perpendicular to the surface of the bottom wafer 1811, allowing the sensor optical pathway 1820 to be positioned within one of the passages 1841 , and a cap 1825 enclosing all portions of the sensor wafer 1800 not enclosed by the wafers 1810 and 1811.

[0192] In various embodiments, the top wafer 1810 and the bottom wafer 1811 may have standard thickness, however in other embodiments, one or both may be thinned so that their combined thickness is less than the thickness of two standard wafers, or that the total thickness is the same as or about the same as one standard wafer.

[0193] In various embodiments, the sensor optical pathway 1822 is optically coupled to a sensing element, for example, a sensing element 1830 as shown in FIG. 18B (where the sensor optical pathway 1822 in FIG. 18A is optically coupled to the sensor optical pathway 1822 in FIG. 18B at point F), or to the sensing element 1835 as shown in FIG. 18C (where the sensor optical pathway 1822 in FIG. 18A is optically coupled to the sensor optical pathway 1822 in FIG. 18B at point F and the sensing element 1835 is a prism). In various embodiments, the cap 1825 may be sealed to the top surface of wafer 1810, forming a gas-tight or hermetic seal and preventing exposure of the internal components of the sensor wafer 1800 to the environment external to the sensor wafer 1800. In various embodiments, the cap 1825 may be made of a ceramic, for example ceramics such as, but not limited to, aluminum nitride, silicon carbide, alumina, sapphire, zirconia, metals such as but notlimited to aluminum, titanium, steel or the like, or fiberglass or polymers such as PEEKorTorlon. The materials of construction of the cap are not a limitation of the present invention.

[0194] FIG. 18D shows an example embodiment of a portion of a sensor wafer 1801 including a top wafer 1810 and a bottom wafer 1811, a passage or groove 1820 formed in the bottom wafer 1811 and configured to contain at least a portion of the sensor optical pathway 1822, the sensor-side optical interface 112, and including an optical element 1837 configured to convey light from the sensor optical pathway 1822 to the system-side optical interface 114 including the system optical pathway 1824. In contrast to the sensor wafer 1800 discussed in reference to FIG. 18A, the sensor wafer 1801 in FIG. 18D does not have a cap, and thus has the same or substantially the same thickness overall, and in various embodiments does not have any exposed material other than that of the wafers 1810 and 1811.

[0195] FIGS. 18E and 18F show example embodiments of a portion of a sensor wafer 1801 configured to optically sense the environment above the sensor wafer, including a top wafer 1810, a bottom wafer 1811, a sensor optical pathway 1822, an optical element 1835 (e.g., a prism or mirror configured to direct light to and / or receive light from the region above the optical element 1835), and a window 1850 configured to seal the internal portion of the sensor wafer 1801. In various embodiments, a portion of the top wafer 1810 may be removed and the window 1850 may be formed such that the top of the window 1850 is co-planar or substantially coplanar with the top surface of the top wafer 1810, as shown in FIG. 18E, while in other embodiments the window 1850 may be formed over the top of top wafer 1810, leaving an empty volume 1852 as shown in FIG. 18F.

[0196] While FIGS. 18A-18F show grooves 1820 formed in the bottom wafer 1811, in various embodiments, the grooves may be in the top wafer 1810 or in both the top wafer 1810 and the bottom wafer 1811.

[0197] In various embodiments, the sensor optical pathway, for example the sensor optical pathway 1822 discussed in reference to FIG. 18A may be an optical fiber or a fiber bundle, however in other embodiments, the sensor optical pathway may be a free-space optical pathway or an optical waveguide.

[0198] In various embodiments, the top wafer 1810 and the bottom wafer 1811 may be attached to or sealed to each other by a variety of means, for example including an adhesive, wafer bonding, electrostatic bonding or the like.

[0199] In various embodiments, a sensor wafer may be manufactured using integrated circuit and / or micro-electromechanical system (MEMS) and / or photonic integrated circuit components and devices, design, validation and testing approaches, software, equipment, and process techniques.

[0200] In other embodiments, a sensor wafer may include sensor optical pathways in the form of optical waveguides formed from materials used in integrated circuit, MEMS and / or photonic integrated circuit manufacturing processes. For example, a waveguide may be formed in silicon, silicon oxide, or silicon nitride. In other embodiments, other materials may be used to form optical waveguides.

[0201] In other embodiments, optical gratings may be formed in the sensor wafer using integrated circuit, MEMS and / or photonic integrated circuit manufacturing processes and may be configured to change the direction of light transmission, for example from a sensor optical waveguide conveying light parallel to the sensor wafer surface to a direction perpendicular to the surface of the sensor wafer within the sensor-side optical interface 112.

[0202] In other embodiments, optical gratings may be formed in the sensor wafer using integrated circuit, MEMS and / or photonic integrated circuit manufacturing processes and may be configured to change the direction of light transmission, for example from a sensor optical waveguide conveying light parallel to the sensor wafer surface to a direction perpendicular to the surface of the sensor wafer at a sensing element site or sensing point, for example, replacing the optical element 1835 as discussed in reference to FIG. 18C with a grating formed within the sensor wafer.

[0203] In various embodiments, device components used in the integrated circuit, MEMS and / or photonic integrated circuits may be incorporated into a sensor wafer. For example, a ring resonator may be used as a sensing point with an optical waveguide as the sensor optical pathway, resulting in all sensing elements being fabricated using standard integrated circuit, MEMS and / or photonic integrated circuit manufacturing techniques.

[0204] FIG. 19A shows a top view schematic of an example embodiment of an edge ring 1900 including an edge ring body 1910 with a semiconductor wafer 1930 positioned thereon, one sensor-side optical interface 112 and 6 (six) sensing elements or sensing points 122 optically coupled to a sensor-side optical interface 112 by respective sensor optical pathways 124.

[0205] FIG. 19B shows a cross-section schematic of the edge ring 1900 shown in FIG. 19A installed on an ESC or chuck 1920 with a semiconductor wafer 1930 positioned on the chuck 1920 through a cut line A-A’ of FIG. 19A. The edge ring 1900 includes an edge ring body 1910 and the sensor-side optical interface 112 which is optically coupled to the system-side optical interface 114. In various embodiments, the system-side optical interface 114 may be located or partially located in the electrostatic chuck or wafer support 1920.

[0206] FIG. 19C shows a cross-section schematic of the edge ring 1900 installed on the ESC or chuck 1920 through the cut line B-B’ of FIG. 19A. The edge ring 1900 includes the edge ring body 1910 and the sensor-side optical interface 112 incorporating a portion of the sensor optical pathway 124 and a prism 1955, and one sensing element or sensing point 122. In various embodiments, optical signals are transmitted from the prism 1955 or the sensor point 122 through the optical pathway 1965 to the system side optical interface 114 and then to the platform optical pathways 130, which may then be optically coupled to an analyzer (not shown in FIG. 19C for clarity). In various embodiments, the optical pathway 1965 may be free-air or free-space optical pathways or partially free-air or free-space optical pathways, while in other embodiments the optical pathway 1965 may not include any portions of free-air or free-space optical pathways.

[0207] In various embodiments, the optical sensor system may be configured to evaluate or determine the condition of various chamber components, for example related to the shower head, edge ring, wafer support or the like. In various embodiments, an optical excitation signal may be directed to all or part of a chamber component and the optical sensing points may be configured to collect light reflected from the all or part of a chamber component. A change in the reflectance over time may be used to determine the condition of the all of or part of a chamber component and / or may be used to determine whether it is time for cleaning or replacement of part(s) or to perform other preventative or corrective maintenance.

[0208] FIGS. 20A and 20B show views of an example embodiment of using the optical sensor system to evaluate the condition of a gas outlet ports 2010 or 2011 in the gas distribution panel 917 of a shower head.

[0209] FIG. 20A shows a cross-section schematic of a portion of the shower head including a portion of the gas distribution panel 917, gas outlets 2010 and 2011, and a light collecting system 2020, wherein the gas distribution panel 917 has a surface 2087. FIG. 20A shows deposits 2030 and 2031 formed on or accreted on at least a portion of the gas outlets 2010 and 2011. In various embodiments the deposits 2030 and 2031 may change the gas flow characteristics, resulting in changes or non-uniformities in the properties of the processed wafers. While FIG.20A shows deposits 2030, 2031 , in other embodiments the gas outlets 2010 and 2011 may be subject to erosion or etching, resulting in an increase in the size of at least a portion of the gas outlets 2010 and 2011.

[0210] FIG. 20B shows a schematic of an example embodiment of an analysis system 2040 that may be used to evaluate the intensity of reflected light from the light collecting system 2020 as a result of changes to the configuration of the gas outlets 2010 and 2011 shown in FIG. 20A. In various embodiments, the analysis system 2040 includes an optical source 2050 optically coupled to an optical coupler 2060, which transmits light 2070 to the light collecting system 2020. Light reflected back into the light collecting system 2020 (for example from the gas outlets 2010 and 2011 and / or the deposits 2030, 2031 ) which is optically coupled into the optical coupler 2060 which is configured to separate transmitted light 2070 from reflected light 2071 , the latter then optically coupled to an optical power meter 2055. In various embodiments, the amount or percentage of reflected light may be baselined when a new showerhead is installed and then monitored continuously or periodically during operation or at other times. In other embodiments, this system may be used to monitor the effectiveness of in-situ cleaning for removal of the deposits.

[0211] In some embodiments, the sensor system is configured to allow imaging of at least a portion of the interior of the semiconductor process chamber. In various embodiments, an imaging system may be configured to visualize the gas outlets 2010 and 2011 , to allow visual inspection of the gas outlets. In various embodiments, an imaging system may be configured to view all or portions of thewafer being processed, the edge ring, the showerhead, the wafer support, the electrostatic chuck, or other chamber components.

[0212] Referring back to FIG. 20A, the light collecting system 2020 is positioned above the gas outlet 2011 , leaving space to allow gas to flow past the light collecting system 2020, and into and through the gas outlet 2011 as identified by a dashed line 2086. The size of the light collecting system 2020 may be selected to reduce the impact of its presence on the flow of gas through the gas outlet 2011. In various embodiments, the flow of gas between the gas outlets 2010 and 2011 may be different, which may be undesirable, for example, resulting in non-uniformity in the process and subsequently the wafer to be processed. So, in some embodiments, the size and / or shape of gas outlet 2011 may be configured to achieve equal gas flow properties between the gas outlets 2010 and 2011. In various embodiments, the gas outlet 2011 may have a larger opening 2082 in the surface 2087 than the opening 2081 in the surface 2088. The openings 2080 and / or 2081 may be the same or different from each other. Likewise, the openings 2082 and / or 2081 may be the same or different from the opening 2080 in the gas outlet 2010. In various embodiments the shape and / or configuration of gas outlet 2011 may be determined using simulation, computational flow dynamics, empirical studies or the like.

[0213] For simplicity and clarity of illustration, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the examples described herein. However, it will be understood by those of ordinary skill in the art that the examples described herein may be practiced without these specific details. In other instances, well-known methods, procedures and components have not been described in detail so as not to obscure the examples described herein. Also, the description is not to be considered as limiting the scope of the examples described herein.

[0214] It will be appreciated that the examples and corresponding diagrams used herein are for illustrative purposes only. Different configurations and terminology can be used without departing from the principles expressed herein. For instance, components and modules can be added, deleted, modified, or arranged with differing connections without departing from these principles.

[0215] The steps or operations in the flow charts and diagrams described herein are just for example. There may be many variations to these steps or operations without departing from the principles discussed above. For instance, the steps may be performed in a differing order, or steps may be added, deleted, or modified.

[0216] Although the above principles have been described with reference to certain specific examples, various modifications thereof will be apparent to those skilled in the art as outlined in the appended claims.

Claims

Claims:What is claimed is:

1. A multi-channel optical sensor system, the system comprising:a sensor platform;at least a first sensor-side optical pathway having an optical axis and at least a second sensor-side optical pathway having an optical axis, each having a proximal end and a distal end, wherein:(i) the sensor platform comprises at least a portion of the first sensor-side optical pathway and at least a portion of the second sensor-side optical pathway, and(ii) the first sensor-side optical pathway and the second sensor-side optical pathway are configured to optically collect a first optical response signal and a second optical response signal, respectively, representative of a characteristic to be sensed;a separable optical interface comprising:a sensor-side optical interface;a system-side optical interface comprising a first system-side optical pathway having a first optical axis and a second system-side optical pathway having a second optical axis, each having a proximal end and a distal end, wherein the sensor-side optical interface and the system-side optical interface are separable and are configured to:(i) optically couple the first sensor-side optical pathway to the first systemside optical pathway, and(ii) optically couple the second sensor-side optical pathway to the second system-side optical pathway; andat least one analyzer, wherein the first system-side optical pathway and the second system-side optical pathway are optically coupled to the at least one analyzer and the at least one analyzer is configured to:(i) determine at least a first characteristic based at least in part on the first optical response signal and(ii) determine at least a second characteristic based at least in part on the second optical response signal.

2. The multi-channel optical sensor system of claim 1, wherein:(i) the sensor-side optical interface further includes the first sensor-side optical pathway and the second sensor-side optical pathway and(ii) the sensor-side optical interface is configured to optically couple the proximal end of the first sensor-side optical pathway to the first system-side optical pathway and the proximal end of the second sensor-side optical pathway to the second system-side optical pathway.

3. The multi-channel optical sensor system of claim 1 , wherein the at least a first characteristic and the at least a second characteristic are selected from the group consisting of temperature, heat flux, charge, strain, wobble, levelness, vibration, position, concentricity, one or more dimensions or distances, etch rate, deposition rate, particle concentration, electric field, voltage, temperature gradients, pressure, deposition on at least a portion of a system component, erosion of at least a portion of a system component, plasma intensity, plasma density, gas constituents, activated species or ions within a plasma, particle concentration, humidity, spectral power density, electric field, erosion of at least a portion of the shower head, deposition on at least a portion of the shower head, erosion of at least a portion of the edge ring, deposition on at least a portion of the edge ring, the spacing between a shower head and a sensor wafer platform, the planarity between a shower head and a sensor wafer platform, or the position of the sensor wafer platform relative to a wafer support.

4. The multi-channel optical sensor system of claim 1 , further comprising at least a first sensing element, wherein the first sensing element is disposed over at least a portion of the distal end of the first sensor-side optical pathway.

5. The multi-channel optical sensor system of claim 4, wherein the at least a first sensing element comprises at least one selected from the group consisting of a half ball lens, a ball lens, a prism, a mirror, a dichroic filter, a refractive optic, a reflective optic, an optical filter, a side-firing optical fiber, an optical fiber, an optical fiber bundle, a solid light guide, an imaging optical fiber, an unterminated (bare) optical fiber, a phosphor, a thermographic phosphor, an optical grating, a fiber Bragg grating ora non-linear crystal.

6. The multi-channel optical sensor system of claim 4, wherein the at least a first sensing element is configured to emit at least one first optical response signal representative of the at least a first characteristic.

7. The multi-channel optical sensor system of claim 6, further comprising a first optical excitation signal, wherein the at least a first sensing element is configured to emit at least one first optical response signal representative of at least one first characteristic to be measured by the first sensing element, in response to the first optical excitation signal.

8. The multi-channel optical sensor system of claim 1 , wherein at least a portion of the first system-side optical pathway or the second system-side optical pathway comprises at least one selected from the group consisting of a half ball lens, a ball lens, a prism, a mirror, a dichroic filter, a dichroic mirror, a refractive optic, a reflective optic, an optical filter, a side-firing optical fiber, an optical fiber, an optical fiber bundle, a solid light guide, an imaging optical fiber, an unterminated (bare) optical fiber, a phosphor, a thermographic phosphor, an optical grating, a fiber Bragg grating ora non-linear crystal.

9. The multi-channel optical sensor system of claim 1 , wherein at least a portion of the first sensor-side optical pathway or the second sensor optical pathway comprises at least one selected from the group consisting of a half ball lens, a ball lens, a prism, a mirror, a dichroic filter, a dichroic mirror, a refractive optic, a reflective optic, an optical filter, a side-firing optical fiber, an optical fiber, an optical fiber bundle, a solid light guide, an imaging optical fiber, an unterminated (bare) optical fiber, a phosphor, a thermographic phosphor, an optical grating, a fiber Bragg grating ora non-linear crystal.

10. The multi-channel optical sensor system of claim 1 , wherein at least a portion of the first sensor-side optical pathway or the second sensor-side optical pathway comprises at least one selected from the group consisting of a half ball lens, a ball lens, a prism, a mirror, a dichroic filter, a dichroic mirror, a refractive optic, a reflective optic, an optical filter, a side-firing optical fiber, an optical fiber, an opticalfiber bundle, a solid light guide, an imaging optical fiber, an unterminated (bare) optical fiber, a phosphor, a thermographic phosphor, an optical grating, a fiber Bragg grating ora non-linear crystal.

11. The multi-channel optical sensor system of claim 1 or 2, wherein at least one of the sensor-side optical interface or the sensor platform comprise:a sensor-side optical alignment feature, wherein the system-side optical interface comprises a system-side optical alignment feature, and wherein the sensorside optical alignment feature and the system-side optical alignment feature are configured to:(i) align the optical axis of the first system-side optical pathway with the optical axis of the first sensor-side optical pathway; and(ii) align the optical axis of the second system-side optical pathway with the optical axis of the second sensor-side optical pathway.

12. The multi-channel optical sensor system of claim 2, wherein the sensor platform further comprises a front face and the optical axis of the first system-side optical pathway and the optical axis of the second system-side optical pathway are perpendicular to the front face.

13. The multi-channel optical sensor system of claim 12, wherein:the first sensor-side optical pathway, the second sensor-side optical pathway, and the sensor-side optical interface are configured to optically couple the first sensor optical pathway to the first system-side optical pathway and optically couple the second sensor-side optical pathway to the second system-side optical pathway.

14. The multi-channel optical sensor system of claim 13, wherein at least a portion of at least one of the first sensor-side optical pathway and the second sensor-side optical pathway comprises at least one selected from a group of a half ball lens, a ball lens, a prism, a mirror, a dichroic filter, a dichroic mirror, a refractive optic, a reflective optic, an optical filter, a side-firing optical fiber, an optical fiber, an optical fiber bundle, a solid light guide, an imaging optical fiber, an unterminated (bare) optical fiber, a phosphor, a thermographic phosphor, an optical grating, and a fiber Bragg grating or a non-linear crystal.

15. The multi-channel optical sensor system of claim 2, wherein at least a portion of the first sensor-side optical pathway and the second sensor-side optical pathway have a first diameter, and at least a portion of the first system-side optical pathway and the second system-side optical pathway have a second diameter, and a ratio of the first diameter to the second diameter is in a range of 0.2 to 5.

16. The multi-channel optical sensor system of claim 1, wherein the sensor platform comprises a sensor wafer.

17. The multi-channel optical sensor system of claim 16, wherein the sensor wafer comprises a base and a cover and at least a portion of the sensor-side optical pathway is disposed in the sensor wafer.18 The multi-channel optical sensor system of claim 16, wherein the system-side optical interface is at least partially disposed on, over or in at least one selected from the group of a susceptor, an electrostatic chuck or an edge ring.19 The multi-channel optical sensor system of claim 16, wherein the sensor wafer at least partially comprises at least one material selected from the group consisting of silicon, silicon dioxide, glass, silicon carbide, silicon nitride, quartz, silica, alumina, sapphire, or diamond.

20. The multi-channel optical sensor system of claim 16, wherein the sensor wafer has a diameter in a range of about 10 millimeters to about 450 millimeters and a thickness in a range of 25 microns to 20,000 microns.

21. The multi-channel optical sensor system of claim 1 , wherein at least a portion of the sensor platform comprises a semiconductor process chamber component.

22. The multi-channel optical sensor system of claim 21 , wherein the semiconductor process chamber component comprises at least one selected from the group of a susceptor, an electrostatic chuck, an edge ring or a shower head, or a portion of a semiconductor process chamber wall.

23. The multi-channel optical sensor system of claim 1, wherein when the sensor platform is optically coupled to the system-side optical interface and a position of the sensor platform is adjustable to maximize the first optical response signal and the second optical response signal.

24. The multi-channel optical sensor system of claim 1, wherein the multi-channel optical sensor system is at least in part configured to measure temperature, further comprising at least one sensing element optically coupled to the first sensorside optical pathway; wherein:(i) the at least one sensing element is configured to emit at least a first optical response signal representative of the temperature of the sensing element,(ii) the at least one analyzer comprises at least one light source configured to emit at least one optical excitation signal and at least one first detector configured to receive at least a portion of the first optical response signal,(iii) the sensor-side optical pathway and the system-side optical interface are configured to allow the at least one optical excitation signal to propagate from the at least one light source to the at least one sensing element and to allow at least a portion of the first optical response signal to propagate from the at least one sensing element to the at least one first detector;(iv) the at least one first detector is configured to provide at least one signal representative of the first optical response signal to the at least one analyzer, (v) the at least one analyzer is configured to calculate a temperature based at least in part on at least one characteristic of the at least one signal representative of the first optical response signal.

25. The multi-channel optical sensor system of claim 24, wherein the at least one characteristic of the one signal representative of the first optical response signal comprises at least one selected from a group of an intensity or amplitude, a change in intensity or amplitude over a time period, an intensity decay rate, an optical power spectrum, or one or more portions of an optical power spectrum.

26. The multi-channel optical sensor system of claim 1 , wherein the first and second system-side optical pathways comprise a single optical fiber bundle that isdivided into a first and second portion, wherein at least a portion of the first portion of the single fiber bundle is optically coupled to the first sensor optical pathway and at least a portion of the second portion of the single fiber bundle is optically coupled to the second sensor optical pathway.

27. The multi-channel optical sensor system of claim 1, wherein:(i) the first system-side optical pathway and second system-side optical pathways comprise a single imaging optical fiber having a proximal end and a distal end,(ii) at least a first portion of the proximal end of the single imaging optical fiber is optically coupled to the first sensor-side optical pathway,(iii) at least a second portion of the proximal end of the second portion of the imaging optical fiber is optically coupled to the second sensor-side optical pathway, (iv) the first portion of the single imaging optical fiber is different from the second portion of the single imaging optical fiber, and(v) the at least one analyzer further comprises at least one an imaging system, wherein:the at least one imaging system is optically coupled to the distal end of the single imaging optical fiber and configured to:(i) receive at least a portion of the first and second optical response signals, and(ii) provide at least one first signal representative of the first optical response signal to the at least one analyzer, and to provide at least one second signal representative of the second optical response signal to the at least one analyzer, and wherein the at least one analyzer is configured to:a. determine at least a first characteristic to be sensed based at least in part on the at least one first signal representative of the first optical response signal andb. determine at least a second characteristic to be sensed based at least in part on at least one second signal representative of the second optical response signal.

28. The multi-channel optical sensor system of claim 27, wherein the at least a first characteristic to be sensed and the at least a second characteristic to be sensed are selected from the group consisting of temperature, heat flux, charge, strain, wobble, levelness, vibration, position, concentricity, one or more dimensions or distances, etch rate, deposition rate, particle concentration, electric field, voltage, temperature gradients, pressure, deposition on system components, erosion of system components, plasma intensity, plasma density, gas constituents, activated species or ions within a plasma, particle concentration, humidity, spectral power density, electric field, erosion of at least a portion of the shower head, deposition on at least a portion of the shower head, erosion of at least a portion of the edge ring, deposition on at least a portion of the edge ring, the spacing between a shower head and a sensor wafer platform, the planarity between a shower head and a sensor wafer platform, or the position of the sensor wafer platform relative to a wafer support.

29. The multi-channel optical sensor system of claim 27, wherein the at least one imaging system comprises at least one selected from a group of a CCD array, an imaging camera, an array of detectors or a scanning system configured to scan across the distal end of the system-side optical pathway.

30. The multi-channel optical sensor system of claim 1, wherein the optical path between the at least one analyzer and the distal end of at least one of the first sensor-side optical pathway and the second sensor-side optical pathway are configured to transmit an image and the at least one analyzer is configured to provide an image of representative of that captured by the distal end of at least one of the first sensor-side optical pathway and the second sensor optical pathway.

31. The multi-channel optical sensor system of claim 1 , wherein the at least one analyzer is configured to measure the intensity of at least one of the first optical response signal and the second optical response signal at a first time and at a second time, wherein the second time is later than the first time, and the difference in the intensity of the at least one first and second optical response signals at the first time and at the second time is representative of a change in a system component.

32. The multi-channel optical sensor system of claim 31 , wherein the change in a system component is selected from the group consisting of erosion of at least a portion of the shower head, deposition on at least a portion of the shower head, a change in spacing between a shower head and a wafer support, erosion of at least a portion of the edge ring, or deposition on at least a portion of the edge ring.

33. The multi-channel optical sensor system of claim 31 , wherein the multichannel optical sensor system is configured to operate and provide information during processing of product wafers.

34. The multi-channel optical sensor system of claim 1 , wherein the at least one analyzer is configured to determine a spectral power density, including an amplitude of radiation at each wavelength of the optical response signal.

35. The multi-channel optical sensor system of claim 34, wherein the at least one analyzer is configured to at least in part determine a composition and an abundance of one or more constituents based at least in part on an analysis of the optical response signal.

36. The multi-channel optical sensor system of claim 1, wherein:the first sensor-side optical pathway is configured to optically collect a first optical response signal comprising a first optical response signal from a first sensing point along the first sensor-side optical pathway and a second optical response signal from a second sensing point along the first sensor-side optical pathway, representative of a characteristic to be sensed, wherein the first sensing point is located at a different position than the second sensing point along the first sensorside optical pathway, andwherein the at least one analyzer is configured to spectrally separate the first optical response signal into a signal representative of the first optical response signal and a signal representative of the second optical response signal anddetermine at least a first characteristic to be sensed based at least in part on the signal representative of the first optical response signal and at least a first characteristic to be sensed based at least in part on the signal representative of the second optical response signal.

37. The multi-channel optical sensor system of claim 36, wherein the first sensing point comprises a first phosphor and the second sensing element comprises a second phosphor.

38. The multi-channel optical sensor system of claim 37, wherein the first phosphor is the same as the second phosphor.

39. The multi-channel optical sensor system of claim 1 , wherein at least a portion of the sensor platform comprises an edge ring, wherein the sensor-side optical interface is optically coupled to the system-side optical interface at least partially disposed in a wafer support.

40. The multi-channel optical sensor system of claim 1 , wherein at least a portion of the sensor platform comprises a sensor wafer, wherein the sensor-side optical interface is optically coupled to a system-side optical interface at least partially disposed in an edge ring.

41. The multi-channel optical sensor system of claim 40, further comprising a second system-side optical interface, wherein at least a portion of the second system-side optical interface is at least partially disposed in a wafer support, wherein the second system-side optical interface is optically coupled to the analyzer.

42. The multi-channel optical sensor system of claim 1, wherein the sensor platform comprises a sensor wafer.

43. The multi-channel optical sensor system of claim 1 , further comprising:a semiconductor process chamber and at least one process gas, wherein at least a portion of the sensor platform, at least a portion of the sensor-side optical interface and at least a portion of the system-side optical interface are disposed in the semiconductor process chamber;wherein the at least one process gas is introduced into the semiconductor process chamber, and the at least first characteristic to be sensed and the at least second characteristic to be sensed are selected from the group consisting oftemperature, heat flux, charge, strain, wobble, levelness, vibration, position, concentricity, one or more dimensions or distances, etch rate, deposition rate, particle concentration, electric field, voltage, temperature gradients, pressure, deposition on system components, erosion of system components, plasma intensity, plasma density, gas constituents, activated species or ions within a plasma, particle concentration, humidity, spectral power density, electric field, erosion of at least a portion of the shower head, deposition on at least a portion of the shower head, erosion of at least a portion of the edge ring, deposition on at least a portion of the edge ring, the spacing between a shower head and a sensor wafer platform, the planarity between a shower head and a sensor wafer platform, or the position of the sensor wafer platform relative to a wafer support.

Images