Improved optical access for spectroscopic monitoring of semiconductor processes.

Abstract

The present disclosure recognizes the advantages of improved optical access, for example, for spectroscopic monitoring of semiconductor processing. In one aspect, the present disclosure provides a gas distributor usable in a processing chamber. Unlike conventional gas distributors, the disclosed gas distributor includes one or more optically transmissive sections for improved optical access in the chamber. In one example, the gas distributor includes (1) an opaque section including a first set of gas distribution holes, and (2) at least one optically transmissive section coupled to the opaque section and positioned to receive light through a window of the chamber.

Description

[Technical field]

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 420,953, entitled "Improved Optical Access for Spectroscopic Monitoring of Semiconductor Processes," filed by Mark Meloni on October 31, 2022, which is commonly assigned with this application and is incorporated by reference in its entirety herein.

[0002] The present disclosure relates generally to optical spectroscopy systems and methods of use, and more particularly to improved optical access for monitoring optical signals during semiconductor processing from within semiconductor processing equipment. [Background technology]

[0003] Optical monitoring of semiconductor processes is an established method for controlling processes such as etching, deposition, chemical mechanical polishing, and implantation. Optical emission spectroscopy (OES) and interferometric endpoint (IEP) are two basic types of operating modes for data collection. During OES, light emitted from a process, usually a plasma, is collected and analyzed to identify and track changes in atomic and molecular species that indicate the state or progress of the process being monitored. During IEP, light is typically provided by an external light source, such as a flash lamp, and directed towards the workpiece. Upon reflection from the workpiece, the light from the light source carries information indicative of the workpiece condition in the form of the workpiece reflectance. Extraction and modeling of the workpiece reflectance can provide information such as film thickness and feature size / depth / width, among other properties. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Patent No. 7,049,156

[0005] Reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which: [Brief description of the drawings]

[0006] [Figure 1] FIG. 1 is a block diagram of a system employing an OES and / or IEP to monitor and / or control conditions of a plasma or non-plasma process in a semiconductor process tool having a gas distributor, also referred to as a showerhead, constructed in accordance with the principles of the present disclosure. [Diagram 2] 1 is a cross-sectional detailed view of a portion of a gas distributor of a semiconductor processing tool including provisions from improved optical access according to the present disclosure. [Diagram 3] 1 is a schematic cross-sectional view of various elements of a semiconductor processing system interacting with optical signal transmission in accordance with the present disclosure; [Figure 4] 4 is a plot of relative signal levels associated with optical transmission and reflection from various sub-elements of the schematic cross-section of FIG. 3 in accordance with the present disclosure. [Diagram 5] FIG. 2 is a flow diagram of an exemplary method for manufacturing a gas distributor performed in accordance with the principles of the present disclosure. [Figure 6] FIG. 1 is a flow diagram of an exemplary method for processing a workpiece using a gas distributor constructed in accordance with the principles of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] In the following description, reference is made to the accompanying drawings, which form a part of this specification and which show by way of example specific embodiments in which the present disclosure may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosure, and it is to be understood that other embodiments may be utilized. It is also to be understood that structural, procedural, and system changes may be made without departing from the spirit and scope of the present disclosure. Therefore, the following description should not be interpreted in a limiting sense. For clarity of explanation, like features shown in the accompanying drawings are indicated with like reference numerals, and similar features as shown in alternative embodiments in the drawings are indicated with like reference numerals. Other features of the present disclosure will be apparent from the accompanying drawings and the following detailed description. It should be noted that for clarity of explanation, certain elements in the drawings may not be drawn to scale.

[0008] The constant advancement of semiconductor processes towards faster process speeds, smaller feature sizes, more complex structures, larger wafers, and more complex process chemicals places great demands on process monitoring technologies. For example, higher data rates are required to accurately monitor faster etch rates of very thin layers where changes of a few angstroms (atomic layers) are significant, such as in fin field-effect transistors (FINFETs) and three dimensional NAND (3D NAND) structures. In many cases, both OES and IEP methods require wider optical bandwidths and larger signal-to-noise ratios to aid in detecting small changes in reflectance and / or optical emission.

[0009] Large wafer sizes with small feature sizes across components and stringent requirements for within-wafer and across-wafer uniformity impose many constraints on the design of semiconductor processing equipment. These constraints can limit the implementation of features that support optical monitoring access. For example, shining light on and receiving reflected light from a workpiece in a processing chamber is an important aspect of optical monitoring. Gas distributors are one example of a component in a processing chamber that can impact optical monitoring.

[0010] A typical gas distributor is a metal or ceramic structure containing an enclosed volume with many small holes inside to support uniform distribution of process gases within the processing chamber. A gas plenum connected to a gas supply line can supply gas for distribution. The gas distributor can be coupled to the side of the processing chamber, suspended from the lid, or positioned in another manner common in the industry. The gas distributor holes can range from about 0.1 mm to 2 mm in diameter and can penetrate an outlet plate several millimeters thick, with the resulting holes having a relatively high aspect ratio. The spacing between holes can be as little as 1 mm to 10 mm center-to-center, with the resulting "open area" density being a few percent. The combination of small open area and high aspect ratio limits angular tolerance and is problematic for optical monitoring, since the open area directly scales the signal level and high aspect ratios require tight control of beam aiming and positioning. The effective spot size for the resulting measurement can therefore be a single 1 mm diameter area for a 300 mm diameter wafer. This is relevant to characterizing the wafer using less than 1% of the significant area of ​​the wafer surface, e.g., about 0.001%. The working distance between the optical interface of the process chamber and the wafer being processed can range from less than 10 cm to more than 1 m. Therefore, the angular orientation and angular stability of components often need to be fractions of a single degree to allow the transmission and reflection of the monitoring optical signal. As the temperature and pressure of the process chamber change, the position and angular orientation of several components can shift, disrupting the passage of the optical signal and rendering the optical monitoring system inoperable.

[0011] Thus, disclosed herein is an application to one or more components of a semiconductor processing chamber that supports improved optical access for spectroscopic monitoring. In one aspect, the present disclosure provides a gas distributor that can be used in a processing chamber. Unlike conventional gas distributors, the disclosed gas distributor includes one or more optically transmissive sections for improved optical access in the processing chamber. In addition to the optically transmissive sections, the gas distributor includes an opaque section having holes for gas distribution, referred to herein as gas distribution holes.

[0012] The dimensions of the optically transmissive section may not be constant. For example, as illustrated in FIG. 2, the optically transmissive section (optically transmissive section 210) may fill the area of ​​the gas distribution holes of the opaque section or may replace a single gas distribution hole (optically transmissive sections 211 and 250). As represented by optically transmissive sections 210 and 250, one or more optically transmissive sections may also include at least one gas distribution hole, which may be a set of gas distribution holes. The one or more optically transmissive sections and the set of gas distribution holes of the opaque section may have the same gas distribution rate. The optically transmissive section may not include a gas distribution hole, as represented by optically transmissive section 211. The gas distributor may include multiple optically transmissive sections of the same size or different sizes, as illustrated in FIG. 2. FIG. 1 shows a process system including a processing chamber having a gas distributor disclosed herein.

[0013] With particular regard to monitoring and evaluating the state of a semiconductor process within a process tool, FIG. 1 illustrates a block diagram of a process system 100 that utilizes OES and / or IEP to monitor and / or control the state of a plasma or non-plasma process within a semiconductor process tool 110. The semiconductor process tool 110, or simply process tool 110, generally encapsulates a workpiece, represented by a wafer 120 in FIG. 1, and possibly a process plasma 130, in a typically partially evacuated volume of a process chamber 135 that may contain various process gases. The process tool 110 may include one or more optical interfaces, or simply interfaces 140 and 142, to enable viewing into the process chamber 135 at various positions and orientations. The interfaces 140 and 142 may include multiple types of optical elements, such as, but not limited to, optical filters, lenses, windows, apertures, optical fibers, etc.

[0014] For IEP applications, the light source 150 may be connected to the interface 140 directly or through a fiber optic cable assembly 153. As shown in this configuration, the interface 140 is oriented perpendicular to the surface of the wafer 120 and is often centered relative to the surface. Light from the light source 150 may enter the interior volume of the process chamber 135 in the form of a collimated beam 155. The beam 155 may be received by the interface 140 again upon reflection from the wafer 120. In a typical application, the interface 140 may be an optical collimator. After being received by the interface 140, the light may be transferred to the spectrometer 160 via a fiber optic cable assembly 157 for detection and conversion to a digital signal. The light may include provided light and detected light and may include, for example, a wavelength range from deep ultraviolet (DUV) to near-infrared (NIR). The wavelengths of interest may be selected from any subrange of the wavelength range. For larger substrates or when understanding wafer non-uniformity is a concern, an additional optical interface (not shown in FIG. 1 ) may be used, such as optical interface 140, oriented perpendicular to wafer 120. The additional optical interface may be optically coupled to light source 150 or associated with an additional light source. Processing tool 110 may also include additional optical interfaces, such as optical interface 142, positioned at different locations for other monitoring options.

[0015] Of particular concern for IEP applications are chamber components that impede the transmission and reflection of the collimated beam 155. In particular, the chamber lid 112 may strongly interact with the collimated beam 155, compromising the application of optical monitoring of the wafer 120 in the process chamber 135. The chamber lid 112 is primarily a mechanical component that maintains the hermetic seal of the process chamber 135, allowing containment of the process chemicals and any process plasma. To support optical monitoring, the chamber lid 112 may include a portion that is optically transparent or translucent. Typically, this portion is a separate component, i.e., a window or viewport, but in certain applications where the chamber lid 112 is made of quartz, a viewport may be made from a polished portion of the integral lid.

[0016] The gas distributor may also cause interference with the transmission and reflection of the collimated beam 155. However, the process system 100 includes a gas distributor 115 that provides the primary function of uniformly distributing process gas across the surface of the wafer 120 while at least reducing optical interference. Thus, instead of a conventional gas distributor, the gas distributor 115 includes at least one optically transmissive section in addition to the opaque sections of a typical gas distributor. As with the opaque sections, the one or more optically transmissive sections may include a set of gas distribution holes, such as represented by the gas distributor 200 of FIG. 2. The gas distributor 115 may include a combination of optically transmissive sections with gas distribution holes and optically transmissive sections without gas distribution holes. As discussed above with respect to conventional gas distributors, the gas distribution holes are small holes ranging from 0.1 mm to 2 mm in diameter, have a relatively high aspect ratio, and may be spaced as far apart as 1 mm to 10 mm from center to center.

[0017] For OES applications, interface 142 may be oriented to collect optical emissions from plasma 130. Interface 142 may simply be a viewport or may additionally include other optical components such as lenses, mirrors, and optical wavelength filters. Fiber optic cable assembly 159 may direct any collected light to spectrometer 160 for detection and conversion to a digital signal. Spectrometer 160 may include a CCD sensor and converter for detection and conversion. Multiple interfaces may be used separately or in parallel to collect optical signals related to OES.

[0018] In many semiconductor processing applications, it is common to collect both OES and IEP optical signals, which poses several problems for using the spectrometer 160. Typically, OES signals are continuous in time, while IEP signals can be either continuous or discrete in time, or both. Mixing these signals poses many challenges, as process control often requires detecting small changes in both OES and IEP signals, and variations inherent in one signal can mask the observation of changes in the other signal. Supporting multiple spectrometers for each type of signal is not advantageous for reasons of, for example, cost, complexity, inconvenience of synchronizing signal timing, calibration, and packaging.

[0019] After detection and conversion of the received optical signal by the spectrometer 160 to an analog electrical signal, the analog electrical signal is typically amplified and digitized within a subsystem of the spectrometer 160 and passed to a signal processor 170. The signal processor 170 may be, for example, an industrial PC, a PLC, or other system, and employs one or more algorithms to generate an output 180, such as an analog or digital control value representing, for example, the intensity of a particular wavelength or the ratio of two wavelength bands. Alternatively, instead of a separate device, the signal processor 170 may be integrated with the spectrometer 160. The signal processor 170 may employ OES algorithms to analyze the emission intensity signal at one or more predetermined wavelengths and determine trend parameters, such as endpoint detection, etch depth, etc., that relate to and can be used to access the state of the process. For IEP applications, the signal processor 170 may employ algorithms to analyze a broadband portion of the spectrum to determine film thickness. See, for example, U.S. Patent No. 7,049,156, entitled "System and Method for In-situ Monitor and Control of Film Thickness and Trench Depth," which is incorporated herein by reference. Output 180 can be transferred via communication link 185 to process tool 110 to monitor and / or modify the production process occurring in chamber 135 of process tool 110.

[0020] The components of FIG. 1 as shown and described are simplified for convenience and are commonly known. As mentioned above, a gas distributor 115 including at least one optically transmissive section, such as gas distributor 200 or gas distributor 350, is used in place of a conventional gas distributor. In addition to the general functionality, spectrometer 160 or signal processor 170 may also be configured to identify stationary and transient optical and non-optical signals and process these signals according to the methods and / or features disclosed herein. Thereby, spectrometer 160 or signal processor 170 may include algorithms, processing capabilities, and / or logic for identifying and processing optical signals and time trends extracted therefrom. The algorithms, processing capabilities, and / or logic may be in the form of hardware, software, firmware, or any combination thereof. The algorithms, processing capabilities, and / or logic may be present in one computing device or distributed across multiple devices, such as spectrometer 160 and signal processor 170.

[0021] FIG. 2 shows in cross section a detail of a portion of a gas distributor 200 of a semiconductor processing tool including provisions for improved optical access according to the principles of the present disclosure. Unlike conventional gas distributors, the gas distributor 200 includes modified regions designed and manufactured to support the inclusion of an optically transmissive section, also referred to as a transparent component. The optically transmissive section 210 may be, for example, a sapphire or fused silica disk with a diameter ranging from about 0.25 inches to 1 inch and a thickness ranging from about 0.04 inches to 0.25 inches. The optically transmissive section 210 mates with a feature of the gas distributor 200 that holds it, such as a non-transparent component, also referred to as an opaque section 215 of the gas distributor 200. As illustrated in FIG. 2, the mating feature may be a hole of appropriate size created within the opaque section 215 of the gas distributor 200, or material removed from the opaque section 215. Thus, gas distributor 200 can be manufactured by modifying an already made and approved gas distributor to add optically transmissive section 210 (and optically transmissive sections 211 and 250), or can be manufactured from the beginning with one or more openings for one or more optically transmissive sections.

[0022] The optically transmissive section 210 may be retained by a retainer, such as a retaining ring 220, which may be a threaded or snap ring mechanism. The optically transmissive section 210 may also be sealed to other portions of the gas distributor 200 via a seal, such as an O-ring 230. The optically transmissive section 210 may include a plurality of holes of appropriate size, pitch, and cross-section to maintain gas flow characteristics close to those in the opaque section 215 of the gas distributor 200. For example, the opaque section 215 may include a first set of gas distribution holes as described above with respect to the gas distributor 115, and the optically transmissive section 210 coupled to the opaque section 215 may include a second set of gas distribution holes, which provide the same gas distribution and flow rate as the first set of gas distribution holes. Although FIG. 2 shows essentially all of the original material above and below the optically transmissive section 210 removed, certain portions of the gas distributor 200 may be retained to support necessary mechanical mounting or other requirements. Specifically, in embodiments where the gas distributor 200 is metallic or conductive, the portion of the gas distributor 200 closest to the process plasma (the exit nozzle or "bottom" side in FIG. 2) may be retained to ensure plasma uniformity.

[0023] The optically transmissive section 210 may generally be considered a "window" if a plane parallel to this component is used. The optically transmissive section 210 may otherwise be a non-planar optical element that provides additional modifications or benefits to the optical signal. Compared to the optical access provided by one or more holes in the generally opaque section 215, the inclusion of the optically transmissive section 210 provides essentially unrestricted optical access throughout its diameter. As described above, the gas distributor 200 may include multiple optically transmissive sections 210. The number, size, and positioning of the multiple optically transmissive sections may follow any requirements regarding optical access for monitoring. The optically transmissive sections 211 and 250 represent additional optically transmissive sections for additional optical access.

[0024] As represented by optically transmissive sections 211 and 250, gas distributor 200 may include one or more additional optically transmissive sections having smaller diameters compared to the diameter of optically transmissive section 210, thereby minimizing perturbation of process conditions in modified or open areas of opaque section 215 relative to unmodified areas of opaque section 215. Optically transmissive sections 211 and 250 replace individual gas distribution holes in section 215, but gas distributor 200 may also include other optically transmissive sections having different diameters and positioned at different locations. Portions of the exit nozzles of the optically transmissive sections may be retained subject to limitations imposed on optical access due to their non-optically transmissive portions. Gas distributor 200 may include optically transmissive sections positioned between gas distribution holes of opaque section 215, and these positioned optically transmissive sections may not include gas distribution holes.

[0025] The optically transmissive section may or may not include one or more gas distribution holes. For example, optically transmissive section 211 does not include gas distribution holes, and optically transmissive section 250 includes distribution holes. Like optically transmissive section 210, optically transmissive section 250 also includes O-ring 252 and retainer 254. The optically transmissive section may also be bonded to opaque section 215 using a bonding agent, such as represented by bond 213 used to secure optically transmissive section 211. A bonding agent may also be used to seal the coupling. The bonding agent may be a conventional epoxy, adhesive, material, etc. used in the industry. The bonding agent may vary depending on the material of opaque section 215 and the optically transmissive section. As represented by the different optically transmissive sections in FIG. 2, any combination of size, location, presence or absence of gas distribution holes, number of gas distribution holes, and bonding means may vary.

[0026] FIG. 3 is a schematic cross-section of various elements of a semiconductor processing system 300 that interact with optical signal transmission. The various components may be located in or proximate to a processing chamber, such as processing chamber 135 of FIG. 1. For example, components 140, 112, and 115 of FIG. 1 may be components 310, 342, and 350 of FIG. 3. An optical interface 310, such as an optical collimator, provides an optical signal 320 that is used to characterize a portion of a wafer 330. The optical signal 320 may first interact with a window or viewport 340 in a chamber lid 342 and be partially reflected therefrom, thereby forming a scattered beam 345. The window 340 may be tilted with respect to the optical axis of the optical interface 310 so that the scattered beam 345 is not recollected by the optical interface 310, since the scattered beam 345 does not contain information about the wafer 330. Optical signal 320 may also interact with and scatter from optically transmissive section 351 that is part of gas distributor 350, thereby forming scattered beam 360. Optically transmissive section 351 may also be tilted with respect to the optical axis of optical interface 310 to avoid recollection of scattered beam 360. A tilt of 3 to 5 degrees or more may be used.

[0027] The holes for gas flow through the optically transmissive section 351 are represented by gas distribution holes 352. The hole spacing, size, etc. can be as described in accordance with the optically transmissive section 210 of FIG. 2. Furthermore, if the optically transmissive section 351 is tilted, the gas distribution holes 352 may be non-perpendicular to the surface of the optically transmissive section 351 such that the trajectory of the gas flow exiting the optically transmissive section 351 coincides with the trajectory through the gas distribution holes 357 of the opaque section 355 of the gas distributor 350. Thus, the centerline through the vertical axis of the gas distribution holes 352 of the optically transmissive section 351 and the centerline through the vertical axis of the gas distribution holes 357 of the opaque section 355 are parallel. Also, the retainer and seal for the optically transmissive section 351 are not shown in FIG. 3 but can be used as described in FIG. 2 with the modification of the tilt of the optically transmissive section 351 relative to the opaque section 355 of the gas distributor 350.

[0028] FIG. 4 is a plot 400 of signal levels associated with optical transmission and reflection from various sub-elements of the schematic cross-section of FIG. 3. Plot 400 has an x-axis in wavelengths and a y-axis in signal counts. Spectrum 410 represents the useful optical signal that is recollected when an unmodified or conventional gas distributor is utilized and the optical signal is severely limited by the gas distributor holes. Spectrum 420 represents the optical signal that may result from recollection of unwanted reflections from surfaces other than the surface of the wafer. Spectrum 430 represents the original source signal level. Spectrum 440 represents the useful recollected signal level including losses due to spectrum 420 when a gas distributor including a transparent component as disclosed herein is used.

[0029] 5 shows a flow diagram of an exemplary method 500 of manufacturing a gas distributor implemented according to the principles of the present disclosure. The gas distributor manufactured can be, for example, any of the gas distributors disclosed herein that include at least one optically transmissive section. Method 500 can be repeated for multiple optically transmissive sections. Method 500 can be used for one or more optically transmissive sections. Method 500 begins at step 505.

[0030] In step 510, voids are created in the gas distributor. The voids can be created by drilling holes in the gas distributor, more specifically, in the opaque section of the gas distributor. The opaque section can be designed with gas distribution holes that provide the desired distribution and flow rate. Thus, the opaque section can be approved for operation. The opaque section can be made of, for example, aluminum or another metal, depending on the application (e.g., gases present in the process chamber) for which the gas distributor will be used.

[0031] Voids can also be created during the creation of the opaque sections. For example, the opaque sections can be made of ceramics and voids can be created during the formation of the ceramic for the opaque sections. Regardless of the material, multiple voids can be created when multiple optically transmissive sections are used.

[0032] At step 520, the optically transparent section is placed in the void. The optically transparent section may be placed in the void at an angle or tilt as noted in FIG. 3. Retainers and seals may be used to place the optically transparent section in the void. If a seal is present, it may be thicker or wider on one side to compensate for the tilt. One or more retainers may be used to secure the optically transparent section in the void of the opaque section. A lip may also be formed on the void to hold the optically transparent section in place and help maintain the proper tilt if a tilt is present. A bonding agent may also be used to seal and secure the optically transparent section in the void. Method 500 ends at step 530.

[0033] 6 shows a flow diagram of an exemplary method 600 for processing a workpiece using a gas distributor made in accordance with the principles of the present disclosure. Method 600 can be performed in a processing chamber, such as processing chamber 135 of FIG. 1. Method 600 is an IEP monitoring method. Additional steps may be included in method 600, such as providing light to the workpiece from an external light source, such as external light source 150. Method 600 begins with step 605.

[0034] In step 610, gas is distributed into the processing chamber using a gas distributor that includes at least one optically transmissive section. Any one of a number of gas distributors disclosed herein can be used.

[0035] In step 620, light reflected from a workpiece in the process chamber is obtained. The reflected light is obtained through at least one optically transmissive section and transmitted through an optical interface, such as optical interface 140, to a spectrometer. The reflected light can be transmitted through a fiber optic cable assembly, such as fiber optic cable assembly 157 of FIG. 1.

[0036] In step 630, the processing of the workpiece is monitored using the reflected light. A spectrometer may be used for monitoring. Method 600 proceeds to step 640, where it ends. Method 600 may be repeated multiple times during processing of the workpiece in the processing chamber. The workpiece may be, for example, a wafer, such as wafer 120.

[0037] The above and other modifications may be made in the optical measurement systems and subsystems described herein without departing from the scope of the present disclosure. For example, while certain examples are described in connection with semiconductor wafer processing equipment, it may be understood that the optical measurement systems described herein may be adapted to other types of processing equipment, such as roll-to-roll thin film processing, solar cell manufacturing, or any application where high precision optical measurements may be required. Additionally, while certain examples discussed herein describe the use of a general optical analysis device, such as an imaging spectrometer, it is understood that multiple optical analysis devices with known relative sensitivities may be utilized. Additionally, while the term "wafer" has been used herein in describing aspects of the present disclosure, it is understood that other types of workpieces may be used, including quartz plates, phase shift masks, LED substrates, and other non-semiconductor processing related substrates, as well as solid, gaseous, and liquid workpieces.

[0038] The embodiments described herein have been selected and described to best explain the principles and practical applications of the present disclosure and to enable others skilled in the art to understand the disclosure of various embodiments with various modifications as appropriate for the particular use contemplated. The specific embodiments described herein may be implemented in various modifications and environments without departing from the scope and intent of the present disclosure, and are in no way intended to limit the scope of the present disclosure. Thus, the present disclosure is not intended to be limited to the embodiments shown, but should be accorded the widest scope consistent with the principles and features described herein.

[0039] The flowcharts and block diagrams in the drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present disclosure. In this regard, each block in the flowcharts or block diagrams may represent a module, segment, or portion of code, which includes one or more executable instructions for implementing one or more specified logical functions. It should also be noted that in some alternative implementations, the functions noted in the blocks may occur out of the order noted in the drawings. For example, two blocks shown in succession may in fact be executed substantially simultaneously, or the blocks may sometimes be executed in the reverse order, depending on the functionality involved. It should also be noted that each block in the block diagrams and / or flowchart diagrams, and combinations of blocks in the block diagrams and / or flowchart diagrams, may be implemented by a special purpose hardware-based system that performs the specified functions or acts, or a combination of special purpose hardware and computer instructions.

[0040] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly indicates otherwise. Furthermore, it will be understood that the terms "comprises" and / or "comprising," when used herein, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0041] As will be appreciated by those skilled in the art, portions disclosed herein may be embodied as methods, systems, or computer program products. Thus, the disclosed portions may take the form of entirely hardware embodiments, entirely software embodiments (including firmware, resident software, microcode, etc.), or embodiments combining software and hardware aspects, generally referred to herein as "circuits" or "modules." Configured or configured means, for example, designed, fabricated, or programmed with the logic, algorithms, processing instructions, and / or features necessary to perform one or more tasks.

[0042] Various aspects of the present disclosure, including the apparatus, systems, and methods disclosed herein, may be claimed. Aspects disclosed herein include the following:

[0043] A. A gas distributor for semiconductor processing in a chamber, comprising: (1) an opaque section including a first set of gas distribution holes; and (2) at least one optically transmissive section coupled to the opaque section and positioned to receive light through a window of the chamber.

[0044] B. A processing chamber comprising: (1) a lid having a window; and (2) a gas distributor, the gas distributor comprising an opaque section including a first set of gas distribution holes and at least one optically transmissive section coupled to the opaque section and aligned with the window to receive light.

[0045] C. A method of manufacturing a gas distributor for a processing chamber, the method comprising: (1) creating a void in the gas distributor; and (2) placing an optically transmissive section in the void.

[0046] D. A method for processing a workpiece using a processing chamber, the method including: (1) distributing a gas within the processing chamber using a gas distributor having at least one optically transmissive section; (2) obtaining light reflected from a workpiece located within the processing chamber through the at least one optically transmissive section; and (3) using the reflected light to monitor an interaction between the gas and the workpiece.

[0047] Each of the embodiments A, B, C, and D may have one or more of the following additional elements in combination: Element 1: The gas distributor has a plurality of optically transmissive sections coupled to an opaque section, the plurality of optically transmissive sections positioned within the opaque section to receive light. Element 2: At least one optically transmissive section includes a second set of gas distribution holes, the second set of gas distribution holes providing the same gas distribution and flow rate as the first set of gas distribution holes. Element 3: The longitudinal axis of at least one optically transmissive section is non-parallel to the longitudinal axis of the opaque section. Element 4: The longitudinal axis of at least one optically transmissive section is tilted in a range of 3 to 5 degrees compared to the longitudinal axis of the opaque section. Element 5: The second set of gas distribution holes are parallel to the first set of gas distribution holes. Element 6: Further comprising a seal located between a portion of the at least one optically transmissive section and the opaque section. Element 7: Further comprising a retainer that secures the at least one optically transmissive section to the opaque section. Element 8: At least one optically transmissive section is made of sapphire. Element 9: At least one optically transmissive section is made of fused silica. Element 10: At least one optically transmissive section is a prism having a diameter ranging from about 0.25 inches to 1 inch and a thickness ranging from about 0.04 inches to 0.25 inches. Element 11: A diameter of at least one gas distribution hole in the second set of gas distribution holes is different from a diameter of at least one gas distribution hole in the first set of gas distribution holes. Element 12: Comprising a plurality of optically transmissive sections each having a set of gas distribution holes that provide the same gas distribution and flow rate as the first set of gas distribution holes. Element 13: The gas distributor has a plurality of optically transmissive sections coupled to an opaque section, the plurality of optically transmissive sections positioned within the opaque section to receive light through the window. Element 14: At least one optically transmissive section includes a second set of gas distribution holes, the second set of gas distribution holes providing the same gas distribution and flow rate as the first set of gas distribution holes. Element 15: The second set of gas distribution holes are parallel to the first set of gas distribution holes.Element 16: A longitudinal axis of the at least one optically transmissive section is non-parallel to a longitudinal axis of the opaque section. Element 17: The at least one optically transmissive section is bonded to the opaque section by a bonding agent. Element 18: The placing includes fixing and sealing the optically transmissive section within the void. Element 19: The placing includes disposing the optically transmissive section at an angle to the longitudinal axis of the gas distributor.

Claims

1. 1. A gas distributor for semiconductor processing in a chamber, comprising: an opaque section including a first set of gas distribution holes; at least one optically transmissive section coupled to the opaque section and positioned to receive light through a window of the chamber.

2. 2. The gas distributor of claim 1, wherein the gas distributor comprises a plurality of optically transmissive sections coupled to the opaque section, the plurality of optically transmissive sections positioned within the opaque section to receive the light.

3. 2. The gas distributor of claim 1, wherein the at least one optically transmissive section includes a second set of gas distribution holes, the second set of gas distribution holes providing the same gas distribution and flow rate as the first set of gas distribution holes.

4. The gas distributor of claim 3 , wherein a longitudinal axis of the at least one optically transmissive section is non-parallel to a longitudinal axis of the opaque section.

5. 5. The gas distributor of claim 4, wherein the longitudinal axis of the at least one optically transmissive section is tilted in a range of 3 to 5 degrees compared to the longitudinal axis of the opaque section.

6. 6. The gas distributor of claim 3, wherein the second set of gas distribution holes are parallel to the first set of gas distribution holes.

7. The gas distributor of claim 3 , further comprising a seal located between a portion of the at least one optically transmissive section and the opaque section.

8. The gas distributor of claim 3 , further comprising a retainer securing the at least one optically transmissive section to the opaque section.

9. The gas distributor according to claim 1 , wherein the at least one optically transmissive section is made of sapphire.

10. The gas distributor of claim 1 , wherein the at least one optically transmissive section is made of fused silica.

11. 6. The gas distributor of claim 3, wherein the at least one optically transmissive section is a prism having a diameter ranging from about 0.25 inches to 1 inch and a thickness ranging from about 0.04 inches to 0.25 inches.

12. 6. The gas distributor of claim 3, wherein a diameter of at least one gas distribution hole in the second set of gas distribution holes is different from a diameter of at least one gas distribution hole in the first set of gas distribution holes.

13. 6. The gas distributor of claim 3, comprising a plurality of optically transmissive sections each having a set of gas distribution holes that provide the same gas distribution and flow rate as the first set of gas distribution holes.

14. a lid having a window; a gas distributor, the gas distributor comprising: an opaque section including a first set of gas distribution holes; and at least one optically transmissive section coupled to the opaque section and aligned with the window to receive light.

15. 15. The processing chamber of claim 14, wherein the gas distributor comprises a plurality of optically transmissive sections coupled to the opaque section, the plurality of optically transmissive sections positioned within the opaque section to receive the light through the window.

16. 15. The processing chamber of claim 14, wherein the at least one optically transmissive section comprises a second set of gas distribution holes, the second set of gas distribution holes providing the same gas distribution and flow rate as the first set of gas distribution holes.

17. 17. The processing chamber of claim 16, wherein the second set of gas distribution holes are parallel to the first set of gas distribution holes.

18. The processing chamber of claim 14 , wherein a longitudinal axis of the at least one optically transmissive section is non-parallel to a longitudinal axis of the opaque section.

19. The processing chamber of claim 14 , wherein the at least one optically transmissive section is bonded to the opaque section by a bonding agent.

20. 1. A method of manufacturing a gas distributor for a processing chamber, comprising the steps of: creating a void in the gas distributor; and placing an optically transmissive section within said void.

21. 21. The method of claim 20, wherein said placing comprises fixing and sealing said optically transmissive section within said void.

22. The method of claim 20 , wherein said positioning comprises disposing said optically transmissive section at an angle relative to a longitudinal axis of said gas distributor.

23. 1. A method for processing a workpiece using a processing chamber, comprising: Distributing gas into a processing chamber using a gas distributor having at least one optically transmissive section; obtaining light reflected from a workpiece located within the processing chamber through the at least one optically transmissive section; and using the reflected light to monitor an interaction of the gas with the workpiece.

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