WO2026024656A1

WO2026024656A1 - Showerhead metrology and processing station

Info

Publication number: WO2026024656A1
Application number: PCT/US2025/038544
Authority: WO
Inventors: Yogesh Babbar; Jorge Reyes; Amaris Angela DE LA ROSA-MORENO; Cristian Cavallero RHEINISCH; Joshua Nathaniel Eric MAK
Original assignee: Lam Research Corp
Current assignee: Lam Research Corp
Priority date: 2024-07-24
Filing date: 2025-07-21
Publication date: 2026-01-29
Anticipated expiration: 2027-01-24

Abstract

Disclosed herein is a method and apparatus to detect blockage of holes in a showerhead faceplate. The apparatus comprises at minimum a gantry system, a sensor array mechanically coupled to the gantry system, and a showerhead mounting fixture. The gantry system is operable to scan the sensor array over the faceplate of the showerhead, where the faceplate comprises a plurality of holes. The gantry system is operable to position the sensory array over individual holes of the plurality of holes to measure a flow velocity of a test gas passing through one or more holes, obtain enlarged images of holes having apparent blockage, and measure static internal pressure of the showerhead.

Description

SHOWERHEAD METROLOGY AND PROCESSING STATION

CLAIM OF PRIORITY

[0001] This application claims priority of U.S. provisional patent application No. 63,675, 126 titled “Showerhead Metrology and Processing Station” filed July 24, 2024, which is incorporated by reference in its entirety.

BACKGROUND

[0002] Substrate processing for etch and deposition form a backbone of the semiconductor industry. While a variety of processing techniques may be utilized, virtually all processes utilize a showerhead to deliver process gases to a substrate awaiting process. A showerhead can be used to distribute gas over an entire substrate. Distribution of holes in showerheads may be designed to provide process uniformity during etch or deposition. While formation of holes may be carried out by machining and subsequent chemical polishing, examining integrity of holes formed is important during fabrication as well as during the lifetime of the showerhead. As such, methods are being investigated to accomplish effective examination of holes and other design features or showerheads and other similar gas distribution apparatuses.

BRIEF DESCRIPTION OF DRAWINGS

[0003] Material described herein is illustrated by way of example and not by way of limitation in accompanying figures. For simplicity and clarity of illustration, elements illustrated in figures are not necessarily drawn to scale. For example, dimensions of some elements may be exaggerated relative to other elements for clarity. Also, various physical features may be represented in their simplified “ideal” forms and geometries for clarity of discussion, but it is nevertheless to be understood that practical implementations may approximate illustrated ideals. For example, smooth surfaces and square intersections may be drawn in disregard of finite roughness, comer-rounding, and imperfect angular intersections characteristic of structures formed by nanofabrication techniques. Further, where considered appropriate, reference labels have been repeated among figures to indicate corresponding or analogous elements.

[0004] Fig. 1 illustrates a cutaway isometric view of a showerhead having blockage of some holes in the faceplate of the showerhead, according to at least one implementation. [0005] Fig. 2A illustrates a perspective view of a showerhead inspection apparatus, in accordance with at least one implementation.

[0006] Fig. 2B illustrates a profile view of a flow sensor engaged over a showerhead faceplate during a flow" measurement of a test gas through a plurality of holes in the faceplate, according to at least one implementation.

[0007] Fig. 2C illustrates an exemplary one-dimensional flow sensor array comprising a one-dimensional array of flow sensing elements, in accordance with at least one implementation.

[0008] Fig. 2D illustrates an exemplary tw o-dimensional How sensor array comprising a two-dimensional array of flow measuring elements, in accordance with at least one implementation.

[0009] Fig. 2E illustrates a heat map showing a false-color plan view' image of flow velocity from a plurality of holes in a showerhead faceplate, in accordance w ith at least one implementation.

[0010] Fig. 3 illustrates a cross-sectional view of showerhead inspection apparatus comprising an optical recording system to detect blockage of exit holes in a showerhead, in accordance with at least one implementation.

[0011] Fig. 4 illustrates a plan view⁷ of a showerhead inspection image recorded by an image capture device, in accordance with at least one implementation.

[0012] Fig. 5 illustrates a perspective view of a showerhead inspection apparatus, in accordance with at least one implementation.

[0013] Fig. 6A illustrates a schematic representation of a multi-measurement sensor array mounted on a sensor platform, in accordance with at least one implementation.

[0014] Fig. 6B illustrates a schematic representation of an embodiment of a pressure sensor in the multi -measurement sensor array shown in Fig. 6A, in accordance with at least one implementation.

[0015] Fig. 6C illustrates a schematic representation of another embodiment of the pressure sensor shown in Fig. 6B, in accordance with at least one implementation.

[0016] Fig. 6D illustrates a schematic representation of the multi-measurement sensor array of Fig. 6A, showing a camera module deployed to examine a faceplate hole having apparent blockage, in accordance with at least one implementation.

[0017] Fig. 6E illustrates a schematic representation of the multi-measurement sensor array of Fig. 6A. showing an optical fiber port deployed over a selected region of the showerhead faceplate for spectroscopic analysis by a spectrometry system coupled to the optical fiber port, in accordance with at least one implementation.

[0018] Fig. 7 illustrates a flow chart summarizing a first method for operating a blockage detection apparatus, in accordance with at least one implementation.

[0019] Fig. 8 illustrates a flowchart summarizing a second method for operating a blockage detection apparatus, in accordance with at least one implementation.

[0020] Fig. 9 illustrates a processor system with a machine-readable storage medium having machine-readable instructions that when executed cause a microcontroller in a circuit board of a control unit for the computing system shown in Fig. 2A to execute machine- readable instructions according to the method described in Figs. 7 and 8, in accordance with at least one implementation.

DETAILED DESCRIPTION

[0021] One or more apparatus and methods are described to assess hole blockage in a process tool showerhead. In at least one implementation, a gas flow sensor is incorporated in a scanning apparatus comprising a gantry system to raster-scan a sensor array across a show erhead to measure gas flow- issuing from individual holes on the faceplate of the showerhead in a test fixture (e.g., ex-situ of a process tool) of a show erhead inspection apparatus. In at least one implementation, the sensor array comprises a flow sensor, a pressure sensor, a distance sensor, a camera module for magnified images, and an optical port for attachment of optical fibers for enabling spectroscopy.

[0022] Measurements of gas flow from individual holes yield data on the blockage status of the individual holes. In at least one implementation, measurement data may be displayed as a two-dimensional heat or other type of map of test gas flow rates at each hole position on the showerhead faceplate. In some implementations, air may be used as a test gas that is pumped into an inlet of the show erhead. The flow- rate of air issuing from faceplate holes may be measured by a sensor array that is scanned across the faceplate and mapped. In at least one implementation, the sensor array may be placed in proximity with a faceplate of a showerhead.

[0023] The sensor array may comprise a large format plate or printed circuit board carrying an array of sensors indicated above. In at least one implementation, the carrier may be as large as the showerhead faceplate. In at least one implementation, an array of flow sensors may be integrated on the carrier at positions corresponding to pattern and pitch of the holes in the showerhead. In this manner, the sensor array may be moved vertically by a gantry system into proximity of the faceplate without moving the sensor array laterally. In at least one implementation, flow measurements at each hole may be obtained simultaneously when the sensor array is aligned to the hole pattern.

[0024] In at least one implementation, the pressure sensor on the sensor array may be employed to obtain a static internal pressure of the showerhead. The static pressure measurement may be used to determine the gas conductance of the internal passages of the showerhead as well as that of the holes. Low gas conductance can indicate internal blockages. [0025] In at least one implementation, a camera module may be used to capture magnified images of the bore of the holes found to have apparent blockages from flow measurements. The magnified images may show any partial blockage or full blockages that may be due to material accumulated in the hole. Other hole obstructions, such as drilling burs and bottlecaps, may be present in the holes of newly manufactured showerheads. Thus, the showerhead inspection apparatus may be employed for manufacturing quality control or for maintenance of in-service showerheads.

[0026] In at least one implementation, flow measurements may be supplemented by optical imaging of the entirety of the faceplate or portions of the faceplate. Imaging light exiting from holes in the faceplate can readily assess hole blockage by showing individual holes that have some degree of blockage with a high degree of certainty . By machine analysis of such images, a flow head may be positioned over a region of the faceplate to confirm presence of blocked holes, in accordance with at least one implementation.

[0027] In at least one implementation, light may be introduced into the body of the showerhead, and reflected laterally to diffuse the light as uniformly as possible within the plenum of the showerhead. Light may exit through holes in the faceplate, forming a two- dimensional diffraction pattern corresponding to the hole array. Light intensity from individual holes may be correlated to a degree of blockage, where the highest intensity of light exiting individual holes may indicate lack of blockage whereas lower to zero intensity may indicate some degree of blockage. Blockage may be due to manufacturing variability⁷, trapped particles or accumulation of solid material within the holes resulting from a mechanical and/or chemical polishing etch process. In some implementations, optical imaging results can be supplemented by flow measurements directed to specific portions of the showerhead, where the optical method indicates the presence of blocked holes, affirming or nullifying the optical result.

[0028] Fig. 1 illustrates a cutaway isometric view of a showerhead 100 having blockage of some holes 114. In at least one implementation, showerhead 100 comprises a faceplate 102 integrally attached to a stem portion 104. A cavity having a z-height h and width w extending between sidewalls 105 may be present within showerhead 100 and extending in the z- direction between a surface 106 at the top of stem portion 104 and surface 108 at bottom side of faceplate 102. Such a cavity is a plenum 110, designed to distribute process gases that enter plenum 110 via an inlet 112 within stem portion 104 and is distributed into a process chamber via holes 114 that extend between surface 108 on bottom side of faceplate 102 and a surface 116 on top side of faceplate 102. In at least one implementation, holes 114 extend a distance t between surface 116 and surface 108.

[0029] In at least one implementation, the ensemble of holes 114 form a regular array, where any suitable pattern symmetry may be employed. In some implementations, holes 114 are arranged in a square array pattern. In some implementations, hexagonal pattern symmetries may be employed. Other non-regular patterns may also be employed in at least one implementation, including non-square rectangular patterns and interpenetrating arrays of different hole diameters may be employed. A particular pattern type may be suitable for a desired uniform or non-uniform distribution of process gases over a semiconductor wafer for material deposition or etching processes.

[0030] In some implementations, showerhead 100 comprises a baffle structure (not shown) within plenum 110. In at least one implementation, a baffle may be positioned over inlet 112 to deflect a process gas stream laterally as it enters plenum 110, enhancing gas distribution uniformity within plenum 110. In at least one implementation, showerhead 100 may comprise additional baffle structures (not shown) that are situated further from inlet 1 12 to enhance mixing within plenum 110.

[0031] The cutaw ay view⁷ of Fig. 1 reveals blockages 118, 120, and 122 within some of holes 114. Blockage 118 is an example of a solid plug of solid material that extends the length t between surfaces 108 and 116. Blockage 120 is an example of a solid plug that extends a portion of length t. Blockage 122 is an example of a partial plug, w here the material forms a quasi-cylindrical ring around the periphery⁷ of the exit hole, leaving a reduced diameter hole through which process gases may pass through the partially blocked exit hole, but with a restricted flow rate compared to unblocked holes 114. Other types of full or partial blockage may be present within holes 114, which in each case reduces or fully blocks flow- of process gases through multiple holes 114. The occurrence of hole blockage can significantly disturb intended flow- patterns from showerhead 100, causing degradation of deposition or etch quality. [0032] Hole blockage may result during manufacture of showerhead 100, whereby holes 114 are generally drilled into faceplate 102. For example, faceplate 102 may comprise aluminum. A chemical polishing process may be applied to faceplate 102, which may debur drilled holes 114 by dissolution of aluminum particles around newly drilled holes 114, as well as dissolve asperities and machining marks to form smooth surfaces. During polishing, solid material consisting of aluminum (or other material) particles may accumulate withing holes 114, or precipitate within holes 114 during the polishing process. As holes 114 may have diameters of less than 1 mm, visual inspection of showerhead 100 or faceplate 102 may not detect blocked holes. Enhanced methods may be called upon to accurately detect blockage of holes 114.

[0033] Fig. 2A illustrates a perspective view of a showerhead inspection apparatus 200. In at least one implementation, showerhead inspection apparatus 200 comprises a sensor array 202 mounted on a gantry' system 204. Gantry system 204 is operable to scan sensor array 202 in a rectangular pattern over faceplate 102 of showerhead 100, which may be mounted on a showerhead mounting fixture 205. Gantry’ system 204 may be motorized by a linear motor or rotary stepper motor, for example, that enables precision positioning of sensor array 202 over individual holes 114. In some implementations, gantry' system 204 comprises at least a first rail extending, for example in the x-direction in the figure. Gantry' system 204 may further comprise a second rail orthogonal to the first rail, extending in the y-direction. In some implementations, gantry system 204 may further comprise a third rail orthogonal to the first and second rails, extending in the z-direction. Gantry' system 204 may comprise one or more drive motors (not shown) to translate sensor array 202 to desired positions over showerhead 100.

[0034] In at least one implementation, sensor array 202 comprises a temperature sensing element (not shown) that detects a change in temperature when a gas flows over it, causing convective cooling (or warming) of the temperature sensing element. The temperature sensing element may be calibrated to correlate the change in temperature to a flow velocity' or rate of a specific gas or range of gases. For example, a particular test gas may be dry air. In some implementations, the temperature sensing element may be a resistive bridge circuit, where one resistor of the resistive bridge may be exposed to a gas flow. The resistance of the exposed resistor may have a temperature coefficient of resistance that enables a large change in resistance with change in temperature of the resistor. The changes in resistance may either balance or unbalance the resistive bridge. For example, a voltage difference between two nodes in the resistive bridge circuit due to the balance or imbalance may be read and correlated to a change in resistance of the exposed resistor. The resistance change of the exposed resistor may be correlated in turn to a change in temperature of the element, which may be correlated to a flow velocity of a particular gas such as dry air.

[0035] In some implementations, sensor array 202 may be operated under high vacuum and/or at high temperatures (e.g., above 100°C). For example, flow sensor array 202 may be carried by a suitable gantry system to be installed in a process chamber. A showerhead may be inspected in-situ by such an apparatus.

[0036] In some implementations, sensor array 202 comprises a sensor array comprising a plurality of miniaturized Wheatstone bridge sensors. For example, sensor array 202 may comprise a sensor array comprising multiple Wheatstone bridge sensors arranged in a pattern and pitch that substantially matches an array of holes 114 machined in showerhead 100. In such a configuration, multiple holes 114 can be simultaneously analyzed by sensor array 202. For example, flow velocities of a test gas such as dry air issuing from individual holes 114 may be simultaneously measured. Proximity of sensor array 202 may be adjusted to obtain accurate flow velocity readings. In at least one implementation, the sensor array may be formed on a continuous sheet that has sufficient dimensions to cover the entirety of faceplate 102, enabling all holes 114 on showerhead 100 to be simultaneously analyzed.

[0037] In some implementations, sensor array 202 can comprise a plurality of dots of temperature-sensitive dye. A temperature-sensitive dye can change color based on temperature. For example, cholesterol ester liquid crystal mixtures can undergo reproducible color changes over a wide range of visible wavelengths as a function of temperature. By optically scanning an array of temperature sensitive dye array using a charge coupled device (CCD) camera, for example, temperature readings can be performed in a rapid manner. For example, a CCD image of the sensor array on sensor array 202 may be analyzed for color changes using machine vision. Temperature readings may be correlated to flow velocities of test gases issuing from individual holes 114.

[0038] In other implementations, sensor array 202 can comprise a sensor array comprising one or more strain gauges. In at least one implementation, individual strain gauges comprise stretchable resistive elements that are incorporated into resistive bridges or other configurations.

[0039] In some implementations, sensor array 202 is coupled to a computing system 208 by a data cable. In at least one implementation, computing system 208 comprises a processor and a memory coupled to the processor (not shown). Computing system 208 is operable to execute software instructions for moving sensor array 202 by gantry system 204, whereby computing system 208 is interfaced to a motor driver circuit 210. In at least one implementation, gantry system 204 comprises x, y, and z drive motors 212 that are controlled by motor driver circuit 210.

[0040] In an example, gantry system 204 is operable to convey sensor array 202 to positions over surface 116 of showerhead 100 (e.g., faceplate 102) by execution of software by computing system 208. whereby drive motors 212 move sensor array 202 to specified locations, coordinates of all holes 114 may be stored in memory and translated to movement commands that are sent to motor driver circuit 210.

[0041] In some implementations, showerhead inspection apparatus 200 includes test gas conduit 206 coupled to inlet 112 of showerhead 100. Additionally, test gas conduit 206 may be connected to a test gas source (not shown). The test gas may be dry air (e.g., having relative humidity >5%). Other test gases may include dry nitrogen, argon, or helium, for example, such as may be used as a make-up gas or carrier gas in a deposition or etch process. [0042] In at least one implementation, showerhead inspection apparatus 200 includes a global camera 213. Global camera 213 may employ a wide-angle lens to capture an image of the entire surface 116 of faceplate 102. Here, global camera 213 may use visible or ultraviolet light to image surface 116 to find defects, such as physical marring, discoloration due to deposits or chemical transformations such as oxidation.

[0043] Fig. 2B illustrates a profile view of sensor array 202 engaged over faceplate 102 of showerhead 100 during flow measurement of a test gas through holes 114. In at least one implementation, sensor array 202 is within a distance d from surface 116 of faceplate 102 to sample gas jets 214 issuing from holes 114. Gas jets 214 are shown as parabolic flow- velocity profiles as they issue from holes 114. Gas jets 214 flowing from unblocked holes 114 are unshaded while gas jets 216 flowing from partially blocked holes are shaded grey. Fully blocked exit holes 218 exhibit no gas jet flow and are depicted as black dots, sensor array 202 comprises one or more integrated flow' sensors that are aligned over one or more holes 114, measuring the flow velocity of individual gas jets 214. As noted above, gas jets 214 may comprise dry air. nitrogen, or argon. In at least one implementation, a liquid may be employed as a test fluid.

[0044] Fig. 2C illustrates an example of a one-dimensional flow sensor array 220. In at least one implementation, one-dimensional flow sensory' array 220 comprises a plurality of flow sensors 222, herein represented by the resistor symbol within a circle. The resistor may represent a resistive bridge network (e.g., a Wheatstone bridge), for example, which may be calibrated to measure a gas flow from gas jets 214 by measuring resistance changes due to thermal effects of an exposed resistor in contact with a flow within the resistive bridge network within flow sensors 222. In at least one implementation, flow sensors 222 may be arranged in a one-dimensional array (here extending in the x-direction in the figure), where flow sensors 222 are spaced by a pitch p that may substantially match a pitch of holes 114 on faceplate 102. During operation, sensor array 202 may be positioned over a row of holes 114 on faceplate 102 of showerhead 100 by gantry system 204 simultaneously measure multiple flow rates from a linear row of holes 114. Sensor array 202 nay be advanced one row at a time by gantry system 204 under command by computing system 208 to measure the entirety of the exit hole array. In some implementations, sensor array 202 may comprise a thermal mass flow sensor. Such sensors may have a temperature sensor and heat source, where changes in temperature of a thermal mass on the sensor are calibrated to indicate flow velocities of air or other gases.

[0045] Fig. 2D illustrates an example of a two-dimensional flow sensor array 230. In at least one implementation, flow sensors 222 are arranged in a two-dimensional array extending in both x and y directions in the figure. Flow sensors 222 may be substantially as described above regarding Fig. 2C. In at least one implementation, flow sensors 222 are spaced by a pitch pi and p2 that may substantially match a pitch of holes 114 on faceplate 102. In at least one implementation, a two-dimensional flow sensor array 230 may be incorporated on sensor array 202. In at least one implementation, two-dimensional flow sensor array 230 may comprise several flow' sensors 222 that is a portion of the total number of holes 114 in faceplate 102. During operation, gantry system 204 may position sensor array 202 over patches of faceplate 102, aligning flow' sensors 222 over subarrays of holes 114. [0046] Fig. 2E illustrates a heat map 250, showing a false-color plan view image of flowvelocity from a plurality of exit holes, for example as measured by a one-dimensional flow' sensor array 220 or a two-dimensional flow sensor array 230. In at least one implementation, a false color scale corresponding to a range of flow velocities may range betw een white and black, where white indicates maximum flow velocity, and shades of dark to light grey indicate low to medium flow velocities. Maximum flow velocity or flow rate is indicative of gas jets 214 issuing from unblocked exit holes, where shades of gray indicate degrees of blockage. In at least one implementation, heat map 250 enables manual or machine vision inspection of a plurality of holes 114, with the ability to visualize partially blocked exit holes (measurement of gas jets 216) and fully blocked exit holes 218. as shown. [0047] In at least one implementation, sensor array 202 comprising a single flow sensor may be raster-scanned over faceplate 102 by gantry system 204 (Fig. 2A) to position an individual flow sensor over individual holes 114. In at least one implementation, sensor array 202 comprises one-dimensional flow sensor array 220 or two-dimensional flow sensor array 230, whereby individual flow sensors, as described above. One- or two-dimensional arrays of flow sensors on sensor array 202 enables sensor array 202 to simultaneously measure multiple holes 114. reducing analysis time. Greater time savings may be achieved with larger sensor arrays.

[0048] Fig. 3 illustrates a cross-sectional view of a blockage detection apparatus 300, comprising an optical recording system to detect blockage of holes 114 in showerhead 100. In at least one implementation, blockage detection apparatus 300 comprises an illumination device 302 within a light source fixture 304. In at least one implementation, illumination device 302 is a light emitting diode (LED) configured to emit monochromatic visible or near infrared light, or polychromatic light (e.g.. white light). In some implementations, illumination device 302 is a fiber optic coupler comprising a collimating lens. In at least one implementation, an optical fiber such as a fiber 306 may be optically coupled at an end 306A to an external light source. In some implementations, an external light source may be a LED or an incandescent lamp.

[0049] In at least one implementation, illumination device 302 is optically coupled to a light pipe 308. In at least one implementation, light pipe 308 comprises a transparent optical material, such as glass, fused silica, Lucite, polymethyl methacrylate, or another suitable polymer. In at least one implementation, light pipe 308 has a circular cross section. In at least one implementation, light pipe 308 has an elliptical or rectangular cross section.

[0050] In at least one implementation, light pipe 308 extends into plenum 110 of showerhead 100 through inlet 112. In at least one implementation, end 308A of light pipe 308 may be adjusted to a distance di over a baffle structure 310 within plenum 110. Baffle structure 310 may serve to divert flow of process gases entering plenum 110 through inlet 112. In at least one implementation, baffle structure 310 may scatter light emanating from end 308A of light pipe 308 within plenum 110. For example, scattered light may be reflections of light from light pipe 308 caused by a reflective surface on baffle structure 310. Light from light pipe 308 may scatter by reflections, as indicated by arrows in the figure, from upper surface 106 and sidewall 105 of plenum 110. In at least one implementation, surface 106 and sidewall 105 may be highly polished or coated with a reflective coating to enhance light scattering within plenum 110. Scattered light may illuminate plenum 110 uniformly or non-uniformly. Scattered light may find its way to holes 114, whereby light mayshine out of holes 114 to impinge on an image capture device 312.

[0051] Blockages within some holes 1 14 (e.g., plugs 314, 316, and 318) wholly or partially block light from shining through the affected exit holes. The thickness of downw ard pointing arrows indicates partial transmission of light by partial plugs 316 and 318. Light impinging on image capture device 312 may be spatially resolved. For example, image capture device 312 comprises a sheet of photographic film. In other examples, image capture device 312 comprises an array of CCD chips operable to capture patterns of light shining through holes 114.

[0052] Fig. 4 illustrates a plan view of a blockage detection image 400 recorded by image capture device 312. In at least one implementation, blockage detection image 400 comprises multiple illumination zones 402, 404, 406, and 408. In at least one implementation, blockage detection image 400 is an image of a collective pattern of light emanating from holes 114. In at least one implementation, illumination zone 402 is the innermost illumination zone at the center of blockage detection image 400, followed by illumination zones 404, 406, and 408. The dark and light patterns within illumination zones 402-408 are due at least in part to Fresnel diffraction. Illumination zone 402 may be directly under baffle structure 310 (Fig. 3), which deflects most of the light entering from light pipe 308 light laterally, leaving no path for direct illumination of the center portion of surface 116 of faceplate 102. Little light passes through exit holes within the center portion of faceplate 102, causing a dark disk in illumination zone 402. Illumination zone 404 adjacent to illumination zone 402 is brightest as Fresnel diffraction generally produces such alternating zones of dark and bright near the center of the illuminated area. Illumination zone 406 adjacent to illumination zone 404 is less bright and may gradually blend into darker illumination zone 408. In some implementations, illumination zone 404 may be characterized by rays 410 extending into illumination zone 408.

[0053] In an example, blockages 412, 414, 416, and 418 appear in blockage detection image 400 as darkened holes 114 and are thus detected by inspection or machine vision analysis of blockage detection image 400. Blockages 412-418 may occur randomly within some holes 1 14. While four blocked exit holes are shown in the illustration, any number of blockages may appear in blockage detection image 400. Blockages 412-418 may be any of the type shown in Fig. 1 (e.g., blockages 118, 120, and 122).

[0054] Fig. 5 illustrates a perspective view of a showerhead inspection apparatus 500. In at least one implementation, showerhead inspection apparatus 500 includes a mirror 502, a mirror 504 and an image capture device 506. Image capture device 506 may be a camera, such as a digital camera. In at least one implementation, image capture device 506 is configured to capture an image of blockage detection image 400 that is reflected from mirrors 502 and 504. In an example, mirror 502 is positioned a distance d over faceplate 102 of showerhead 100. In at least one implementation, distance d2 is adjustable so that the entirety of blockage detection image is reflected from mirror 502 to mirror 504. In at least one implementation, both mirrors 502 and 504 are titled relative to a reference plane. Both mirrors 502 and 504 may be adjusted or adjustable to have an angle theta with respect to a reference plane (e.g., with respect to the x-y plane in the figure) to allow light ray 508 to reach mirror 504 and avoid interference by showerhead 100. Both distance and angle theta may also be adjustable to relay the entirety of blockage detection image 400 to image capture device 506. For example, distance d:> may be 1 to 2 meters and theta may range between 15 and 45 degrees.

[0055] In at least one implementation, showerhead inspection apparatus 500 is operable to autonomously analyze blockage detection image 400. Image capture device 506 is electrically coupled to a computing system 510. Computing system 510 may compnse a local dedicated processor (not shown) or a remote computer running machine vision software. In some implementations, computing system 510 is operable to detect and locate any apparently blocked holes 114, for example, at blockage 414. Based on image analysis data and software instructions executed by computing system 510, computing system 510 is operable to direct sensor array 202 to be repositioned over any apparently blocked holes 1 14, such as at blockage 414. In at least one implementation, computing system 510 is interfaced to motors 514 in a gantry system, such as gantry system 204 shown in Fig. 1, via a motor driver circuit 512. Coordinates of apparently block holes 114 may be computed and signals sent to motor driver circuit 512 to translate sensor array 202 over an individual hole 114 that to confirm a suspected blockage by measuring the flow velocity of a test gas.

[0056] In some implementations, light source fixture 304 may be interchangeable with conduit 206. Light source fixture 304 comprises light pipe 308 (shown in Fig. 3) that extends into the plenum of showerhead 100 through an inlet (e.g.. inlet 112. Fig. 1). In some implementations, light source fixture 304 includes an attachment for conduit 206 so that a manual step whereby light source fixture 304 is removed and conduit 206 is attached, may be eliminated. To this end, a test gas may be flowed into showerhead 100 through conduit 206 while light source fixture 304 remained mounted so that imaging and flow measurement phases of blockage detection are fully automated. [0057] Fig. 6A illustrates a schematic representation of a multi-measurement sensor array 600, whereby sensor array 600 is mounted on a sensor platform 602. In at least one implementation, multi-measurement sensor array 600 comprises a pressure sensor 604, a camera module 606, a distance/displacement sensor 608, and a flow sensor 610. In some implementations, multi-measurement sensor array 600 may further comprise an X-ray fluorescence head and/or an optical fiber port 612 for enabling other spectroscopic techniques. Spectroscopic measurements can aid in determining surface contamination and aging of the showerhead, for example. In at least one implementation, camera module 606 can be employed for visual examination of holes. Pressure sensor 604 is described below regarding Figs. 6B and 6C. Flow⁷ sensor 610 has been substantially described above.

[0058] In at least one implementation distance/displacement sensor 608 is a laser-based device. For example, distance/displacement sensor 608 may be a mechanical micrometerbased device. In the illustrative example shown in Fig. 6A, multi-measurement sensor array 600 is positioned over showerhead faceplate 614. Sensor platform 602 is attached to gantry member 616. which is attached to a gantry system, such as gantry system 204 shown in Fig. 2A. The double-headed arrow indicates that the gantry system enables vertical (z-direction) movement of sensor platform 602. Movement of multi-measurement sensor array 600 is also enabled in the x and y directions by the gantry' system.

[0059] In at least one implementation, distance/displacement sensor 608 may be employed for measuring flatness of showerhead faceplate 614 by sensor platform 602 over showerhead faceplate 614. In at least one implementation, distance/displacement sensor 608 may be useful for measuring non-planarities of show erhead faceplate 614, such as sag due to w ear, important for refurbishing considerations of used showerheads. Also detectable by distance/displacement sensor 608 are non-planarities in showerhead faceplate 614 due to machining defects. In other implementations distance/displacement sensor 608 may be employed for measuring the vertical displacement, or height, of multi-measurement sensor array 600 over showerhead faceplate 614. In some implementations, the displacement of sensor platform 602 from showerhead faceplate 614 may be part of a closed feedback loop configured control the z-motion of the gantry system. The gantry system may be controlled in this manner to maintain a constant gap betw een sensor platform 602 and faceplate 614. This displacement gap may be adjusted for maximum sensor performance, for example.

[0060] In at least one implementation, distance/displacement sensor 608 is an optical sensor comprising a laser to send light pulses for a time-of-flight measurement to obtain a distance measurement. Precision of the distance measurement may be in the micron range. In at least one implementation, a scan over the surface of showerhead faceplate 614 may be performed by causing the sensor platform 602 to raster over showerhead faceplate 614, or by following geometric patterns while displaced above showerhead faceplate 614. The gantry system may maintain a constant z-height displacement (relative to a reference z-height) over showerhead faceplate 614 while scanning. Distance measurements may be taken at subsecond intervals, and mapped to location on the faceplate. Deviations in displacement as small as 10 microns may be detected, indicating non-planarities of the faceplate that may be spatially resolved by the mapping process.

[0061] In at least one implementation, once non-planarity mapping of showerhead faceplate 614 is complete, the gantry system may move multi-sensor array 600 over portions of showerhead faceplate 614 to position flow sensor 610 sensor platform 602 over each hole to verily flow rates. . The flow rate of a test gas may be recorded for each hole. Individual holes having anomalous flow rates may be revisited after a complete assessment of all holes of the faceplate.

[0062] To measure flow accurately, flow sensor 610 is positioned above each hole at a specified distance that is precisely controlled. If a local non-planarity has been mapped in the hole location during the preliminary mapping of faceplate flatness, any height deviations local to the hole location are factored into a displacement correction to compensate for the local non-planarity. This may be done to maintain a high-precision flow measurement that depends on displacement of flow sensor 610 from the hole. As noted, the functional aspects of flow sensor 610 have been substantially described above (e.g., Fig. 2C or Fig. 2D). In at least one implementation, coordinates of all holes in showerhead faceplate 614 are stored and accessible to a control processor. As described above, flow rates for each hole are recorded and may be stored in a database. When the flow data are analyzed by system software and anomalies in flow rate are found for one or more holes, any or all sensors 604-610 may be positioned over any or all of the holes exhibiting anomalous flow behavior for further probing. In other implementations, static pressure within the showerhead itself may be measured to determine if there are internal blockages within the plenum or manifold passages that are holding up flow to the holes. Such pressure measurements may be performed by pressure sensor 604, as described below.

[0063] Fig. 6B illustrates a schematic representation of pressure sensor 604A in multimeasurement sensor array 600. As shown, pressure sensor 604A is contacted to show erhead faceplate 614 and is configured to seal about a hole of interest. In at least one implementation, pressure sensor 604A comprises an integrated pressure sensor (e.g., an electronic manometer). Pressure sensor 604A optionally comprises a stem 618 extending outwardly from the main portion of pressure sensor 604 A. Stem 618 may enable connection of flexible tube to couple an external pressure sensor to the chamber 620 within pressure sensor 604. As gas flows into pressure sensor 604A, gas pressure within chamber 620 equilibrates with gas pressure within the internal passages, such as the plenum of the showerhead. A pressure sensor coupled to chamber 620 may register a pressure reading, indicating internal static gas pressure(s) within the showerhead. Such measurements may be made while a test gas flows from all functioning holes in showerhead faceplate 614. Static pressure anomalies may indicate presence of blockages within internal passages of the showerhead.

[0064] In at least one implementation, static pressure measurements may be employed to obtain gas conductance of the showerhead, which would be a global measurement of conductance of the plurality of holes and internal passages (including plenum and manifold(s)) combined. For example, if a mass flow controller is employed to set a precise flow rate of a test gas, measurement of the static pressure would yield gas conductance as flow rate and pressure are known quantities. For example, gas conductance may be determined by the relation Q/P, where Q is a flow rate and P is a pressure. The gas conductance may be compared to a design conductance value. A low conductance by this criterion may indicate internal as well as hole blockages, for example.

[0065] Fig. 6C illustrates a schematic representation of pressure sensor 604B in multimeasurement sensor array 600. In a manner like pressure sensor 604A, pressure sensor 604B pressure sensor 604may be contacted to showerhead faceplate 614 and sealed over a hole of interest. In pressure sensor 604B, chamber 620 is open to the environment via through-hole 622. Gas flowing into pressure sensor 604B flow through chamber 620 and out into the environment via through-hole 622, enabling measurement of ambient pressure. For example, local external pressures in the vicinity of a hole of interest may be measured. Local external pressures across showerhead faceplate 614 may be mapped by scanning multi-measurement sensor array 600 over showerhead faceplate 614. These measurements may be made within the vacuum of a process chamber, or in a normal air atmosphere. Measurements may also be made at elevated temperatures.

[0066] Fig. 6D illustrates a schematic representation of multi-measurement sensor array 600, where camera module 606 is deployed to examine the hole of interest 626. Camera module 606 may comprise a CCD device and employ a microscope objective 628 or a macro lens for image magnification. For example, microscope objective 628 may have a 5x to lOx magnification capability. Here, hole of interest 626 has an obstruction 630 within its bore, For example, obstruction 630 may be a buildup of debris or prematurely reacted film precursor. Hole of interest 626 may also have a bun or bottlecap obstruction resulting from drilling operations during showerhead manufacture. Micrographs of holes in question that are obtained by camera module 606 may be recorded as part of the quality⁷ control or diagnostic inspection documentation for the showerhead to document blocked holes.

[0067] Fig. 6E illustrates a schematic representation of multi-measurement sensor array 600, where optical fiber port 612 is deployed to examine the composition of a deposit 624 on the surface of a selected region of showerhead faceplate 614. In at least one implementation, optical fiber port 612 is coupled optically (by an optical fiber) to a spectroscopy system for spectroscopic measurements on deposit 624 or on a discolored area of the faceplate. Hie spectroscopy system may comprise a spectrometer and a light source. In at least one implementation, deposit 624 may be detected by image analysis of a global image obtained by global camera 213 shown in Fig. 2A.

[0068] The thickness of deposit 624 is exaggerated for visibility⁷, but it may be a buildup of material from multiple deposition operations involving the showerhead. While deposit 624 is used for exemplary purposes, deposit 624 may also represent an area of oxidation, embrittlement, or other localized chemical transformation of the material of the faceplate. The buildup of deposit 624 is undesirable and may be a result of process recipes that may encourage growth of deposits on showerhead faceplate 614. For diagnostic purposes, a spectroscopic analysis may be desired or necessary to identify the composition of deposit 624 or chemical transformation of the area in question. Here, multi-measurement sensor array 600 may be moved to position optical fiber port 612 over deposit 624. In at least one implementation, an optical fiber 632 may be attached to optical fiber port 612 from a spectroscopy system configured for infrared, visible or ultraviolet spectroscopy.

[0069] Optical fiber 632 may transport broadband or narrow band excitation light from a spectrometer or light source, and transport reflected light back to a spectrometer to scan an absorption spectrum of deposit 624. As noted above, deposit 624 may represent a discoloration of a region of faceplate 614. which can indicate a chemical transformation of the material of construction of the faceplate. In some implementations, a laser may be employed as a light source. In at least one implementation, optical fiber port 612 may be replaced by a miniature self-contained spectroscopy system, comprising a spectrometer and light source in a compact package. [0070] In at least one implementation, optical fiber port 612 may be replaced by an X-ray fluorescence head to obtain fluorescence spectra using X-ray excitation.

[0071] Fig. 7 illustrates a flowchart 700 summarizing a method for operating a blockage detection apparatus, such as showerhead inspection apparatus 200, in accordance with at least one implementation. Flowchart 700 may be performed by hardware, software, or a combination of them.

[0072] At operation 702. a partial or full image of the faceplate is captured by a global imaging system positioned above a showerhead mounted in a showerhead inspection apparatus such as showerhead inspection apparatus 200. Such a global imaging system may be represented by camera 213 as shown in Fig. 2A. Camera 213 may be a component of showerhead inspection apparatus 200. as shown in Fig. 2A. In at least one implementation, camera 213 may be equipped with a wide-angle lens to capture the entire faceplate in one image. In at least one implementation, camera 213 is on a gantry system and may be translated in the x, y and z directions (or by cylindrical coordinates r, 0, z) to enable capture of enlarged images of portions of the showerhead faceplate.

[0073] Images captured by camera 213 or by a more extensive imaging system involving more than one camera may be analyzed by image analysis software for detection of visible defects or marring on the faceplate surface. For example, any scratches, gouges, discolorations of the faceplate may be found in this way. Defects such as discolorations may indicate buildup of organic deposits on in-service showerhead faceplates from repeated film deposition processing or may indicate chemical transformations of the material of construction of the showerhead or faceplate, such as oxidation. These forms of defects may be further inspected more closely by the disclosed mobile sensors, such as camera module 606 and/or by spectroscopic analysis on a mobile multi-sensor platform (e.g.. sensor platform 602). In some implementations, such imaging may be part of post-manufacture quality control of showerheads by a manufacturer of such equipment. In some implementations, such imaging can also be performed for periodic maintenance of in-service showerheads.

[0074] At operation 704. a distance measurement sensor (e.g., distance/displacement sensor 608) is scanned over the faceplate to measure a two-dimensional flatness profile of the showerhead faceplate. In at least one implementation, the distance measurement sensor is an optical sensor comprising a laser to send light pulses for a time-of-flight measurement to obtain a distance measurement. [0075] The time-of-flight of a laser pulse is proportional to a distance between the distance sensor and the faceplate (e.g.. one half the speed of light divided by the time of flight), where the distance may be determined at each point of a two-dimensional coordinate system on the faceplate. Precision of the distance measurement may be in the micron range. In at least one implementation, a scan over the surface of the showerhead faceplate may be performed by causing the sensor platform to raster over the faceplate, or by following geometric patterns while displaced above the faceplate.

[0076] The gantry system may maintain a constant z-height displacement (relative to a reference z-height) across the faceplate while scanning. Distance measurements may be taken at distance intervals following a two-dimensional coordinate system of the faceplate and mapped to those coordinates on the faceplate. Deviations in vertical displacement as small as 10 microns may be detected, indicating non-planarities of the faceplate that are spatially resolved by the mapping process.

[0077] The two-dimensional flatness profile may be employed to maintain a precise vertical displacement of the sensor array from the faceplate when measuring flow rates of a test gas through individual holes, as accuracy of such flow rate measurements may depend on maintaining a specified vertical displacement between the holes and the flow sensor (e g., flow sensor 604A or 604B). In at least one implementation, the vertical displacement is a sum of a predetermined distance and the two-dimensional flatness profile.

[0078] At operation 706. a flow sensor, such as flow sensor 604 (Fig. 6A), is affixed to a two-axis or three-axis gantry system, such as gantry system. In at least one implementation, the sensor array is positioned over a show erhead faceplate, such as faceplate 102 of showerhead 100. The sensor array may comprise a data cable that is coupled to a processor (e.g., within computing system 208, Fig. 2A). In at least one implementation, the processor is operable to execute software instructions that command movement of the sensor array over individual exit holes (e.g., holes 114). For example, coordinates of each exit hole may be stored within memory coupled to the processor (e.g., computing system 208). The sensor array may be translated by the gantry system through commands to a motor driver, such as motor driver circuit 210 (Fig. 2A). which drives gantry motors, such as motors 212 (Fig. 2A) coupled to the gantry system.

[0079] At operation 708, the sensor array measures the How velocity of a test gas flowing through an individual exit hole, as shown in Fig. 2B. As noted above, the flow sensor may operate as a Wheatstone bridge, for example, where one resistor element of the bridge is exposed to the flow, which may tend to cool the resistor element. In at least one implementation, the resistor may be heated by the flow if the test gas is preheated. The resistance of the element will decrease (or increase if heated), and this change in resistance can be calibrated to convert to flow velocity so that the latter may be measured. The processor may execute a software algorithm to perform the measurement by gathering incoming data from the flow sensor and store the data in a memory.

[0080] A heat map such as heat map 250 show n in Fig. 2C may be generated by the processor, showing a false color plot of test gas flow through the plurality of exit holes on the show erhead faceplate. A heat map such as heat map 250 may be read by a human operator to detect blockages. A showerhead having one or more blockages may be flagged for servicing or rejected, for example.

[0081] Fig. 8 illustrates a flowchart 800 summarizing a method for operating a blockage detection apparatus, such as showerhead inspection apparatus 500, in accordance with at least one implementation. Flow chart 800 may be performed by hardware, software, or a combination of them.

[0082] At operation 802. a showerhead inspection apparatus, such as showerhead inspection apparatus 200 (Fig. 2A) is fitted with a showerhead, such as showerhead 100 to a test fixture. The test fixture may be part of the show erhead inspection station, that provides a three-dimensional gantry', such as gantry system 204 (Fig. 2A).

[0083] In at least one implementation, flow data that had been collected by a mobile flow sensor (e.g., flow sensor 610) is analyzed (for example, by software) to identify holes in the showerhead faceplate having flow rate below a threshold value. As the coordinates of all faceplate holes are stored in a database, coordinates of any holes identified as having low flow rates are collected, holes 114.

[0084] At operations 804 and 806. a sensor array is positioned over a vicinity of a first identified hole by means of the gantry system. The gantry system may first bring a microscope camera (e.g., camera module 606, Fig. 6A) over the first identified hole. In atr least one implementation, a processor of the computing system (e.g., computing system 208) may direct a gantry system (e.g.. gantry system 204) to translate a flow sensor, over the hole exhibiting apparent blockage. For example, the computing system may include or be coupled to a motor driver circuit, such as motor driver circuit 210 (Fig. 2A). The motor driver circuit is coupled to x, y, and/or z motors of the gantry system. The processor of the computing system may issue commands to the motor driver circuit to position the sensor array over the exit hole. [0085] In some implementations, the microscope camera may employ a microscope objective (e.g., microscope objective 628) having a 5x to I Ox magnification. In some implementations, the microscope camera may employ a macro lens to obtain enlargements of hole bores to determine if the hole bore is occluded. An occlusion may comprise an obstruction, such as obstruction 630 (Fig. 6D) due to material buildup or manufacturing artefacts such as burrs and bottlecaps due to hole formation by drilling, for example.

[0086] In at least one implementation, the camera module may be coupled to a processor within a computing system, such as computing system 208 (Fig. 2A), where a raw blockage detection image is stored. For example, the camera module may be a digital microscope (e.g., having a magnification of lOx or greater) or a digital camera having a macro lens having a magnification of less and lx to 5x, for example, where the camera module outputs the captured image to a computer through an interface cable, such as a Universal Serial Bus (USB) cable.

[0087] At operation 808, in at least one implementation, the computing system may execute software to analyze the image using machine vision algorithms to detect and/or visualize the presence of apparent blockage (e.g., obstruction 630) with one or more exit holes. If a blockage is identified by such an analysis, the computing device may identify or calculate coordinates of identified holes that have blockage. The coordinates of holes identified as having blockage may be recorded in a database for further reference.

[0088] At operation 810. the internal pressure of the showerhead may be optionally measured to supplement assessment of blockage with any indication that internal passages of the showerhead may also be blocked. For such measurements, a pressure sensor, such as pressure sensor 604A or 604B (Fig. 6B or Fig. 6C) may be positioned over any open hole. As noted above, the pressure sensor may seal over a hole (or multiple holes) to measure static pressure within the plenum and/or other internal passages. Static pressure may be measured with a test gas flowing through all open holes. Static pressures within a normal range (determined by design) may indicate that internal passages are mostly unblocked. Pressures above the normal range may indicate a large degree of hole blockage, but internal passages may not be blocked. Pressures low er than normal may indicate internal blockage preventing adequate gas flow within the plenum (or distribution manifold(s)).

[0089] At operation 812, data, such as images recorded by the camera module, static pressure data, as well as flow' data, may be stored in a database for retrieval at a later time or for immediate use. For example, the computing system may generate a report that is sent to a client for post-manufacture qualify control or maintenance records. [0090] In at least one implementation, the combination of the blockage detection image and flow sensor may advantageously increase efficiency of blockage detection and significantly reduce detection time by first obtaining a global image of the faceplate to locate apparent blockage and then moving a flow sensor as a probe over the suspected blockage to confirm the presence of blockage within one or more exit holes.

[0091] At operation 810. flow of a test gas such as dry air, nitrogen or argon may be initiated by the computing system into the showerhead through the light source fixture without human intervention, or by manual changeout of the light source fixture to a conduit (e.g. conduit 206; see Fig. 5). In at least one implementation, the flow sensor is operational to measure the flow velocity of the test gas and send measurement data to the computing system. In at least one implementation, the computing system may then determine if the exit hole has blockage by comparing the measured flow velocity to known values of flow velocities through unblocked exit holes, or by comparing the measured flow velocities from several neighboring exit holes to that of the exit hole in question.

[0092] Fig. 9 illustrates a processor system 900 with a machine-readable storage medium having machine-readable instructions that when executed cause a circuit board of a control unit of computing system 208 shown in Fig. 2A to execute machine-readable instructions according to the method summarized by flowcharts 700 and 800, shown in Figs. 7and 8, respectively, for example. In at least one implementation, a microcontroller may be configured to measure and report intra-bandgap density of states, in accordance with at least one implementation. In at least one implementation, processes described herein may be stored in a machine-readable medium (e.g., 903) as computer-executable instructions. In at least one implementation, a machine-readable storage medium may be random access memory' (RAM). In at least one implementation, processor system 900 comprises memory 901, processor 902, machine-readable storage medium 903 (also referred to as tangible machine-readable medium), communication interface 904 (e.g., wireless or wired interface), and network bus 905 coupled together as shown. In at least one implementation, processor system 900 may be part of computing system 208 or 510, shown respectively in Figs. 2A and 5.

[0093] In at least one implementation, processor 902 is a digital signal processor (DSP), an application specific integrated circuit (ASIC), a general-purpose central processing unit (CPU), or a low power logic implementing a simple finite state machine to perform various processes described herein.

[0094] In at least one implementation, various logic blocks of processor system 900 are coupled together via network bus 905. Any suitable protocol may be used to implement network bus 905. In at least one implementation, machine-readable storage medium 903 includes instructions (also referred to as program software code/instructions) for raster scanning a flow sensor head (e.g., sensor array 202) to deposit nanoparticles in a patterned coded into software stored in machine-readable storage medium 903.

[0095] In at least one implementation, machine-readable storage media 903 is a machine- readable storage media with instructions for positioning sensor array 202 in showerhead inspection apparatuses 200 or 500. In at least one implementation, machine-readable medium 903 has machine-readable instructions, that when executed, cause processor 902 to perform the method discussed herein (e.g., see flowcharts 700 and 800 in Fig. 7 or Fig. 8).

[0096] In at least one implementation, program software code/instructions associated with various implementations may be implemented as part of an operating system or a specific application, component, program, object, module, routine, or other sequence of instructions or organization of sequences of instructions referred to as "program software code/instructions," "operating system program software code/instructions," "application program software code/instructions," or simply "software" or firmware embedded in processor. In some implementations, program software code/instructions associated with processes of various implementations are executed by processor system 900.

[0097] In at least one implementation, machine-readable storage media 903 is a computer executable storage medium. In at least one implementation, program software code/instructions associated with various implementations are stored in computer executable storage medium 903 and executed by processor 902. Here, computer executable storage medium 903 is a tangible machine-readable medium 903 that can be used to store program software code/instructions and data that, when executed by a computing device, causes one or more processors (e.g., processor 902) to perform a process.

[0098] In at least one implementation, tangible machine-readable medium 903 may include storage of executable software program code/instructions and data in various tangible locations, including for example, ROM, volatile RAM, non-volatile memory, and/or cache, and/or other tangible memory as referenced in present application. Portions of this program software code/instructions and/or data may be stored in any one of these storage and memory devices. In some implementations, program software code/instructions can be obtained from other storage, including, e.g., through centralized servers or peer to peer networks and the like, including Internet. Different portions of software program code/instructions and data can be obtained at different times and in different communication sessions or in the same communication session. [0099] In at least one implementation, software program code/instructions associated with various implementations can be obtained in their entirety prior to execution of a respective software program or application. Alternatively, portions of software program code/instructions and data can be obtained dynamically, e.g., just in time, when needed for execution. Alternatively, some combination of these ways of obtaining software program code/instructions and data may occur, e.g., for different applications, components, programs, objects, modules, routines, or other sequences of instructions or organization of sequences of instructions, by way of example. Thus, it is not required that data and instructions be on a tangible machine-readable medium 903 in entirety at a particular instance of time.

[00100] In at least one implementation, tangible machine-readable medium 903 include but are not limited to recordable and non-recordable type media such as volatile and nonvolatile memory devices, read only memory (ROM), random access memory (RAM), flash memory devices, floppy and other removable disks, magnetic storage media, optical storage media (e.g., Compact Disk Read-Only Memory (CD ROMs), Digital Versatile Disks (DVDs), etc.), among others. In at least one implementation, software program code/instructions may be temporarily stored in digital tangible communication links while implementing electrical, optical, acoustical, or other forms of propagating signals, such as carrier waves, infrared signals, digital signals, etc. through such tangible communication links.

[00101] In some instances, well-known methods and devices are shown in block diagram form, rather than in detail, to avoid obscuring at least one implementation. Reference throughout this specification to “an implementation,” “one implementation,” “in at least one implementation,” or “some implementations” means that a particular feature, structure, function, or characteristic described in connection with implementation is included in at least one implementation. Thus, appearances of phrase “in an implementation,” “in at least one implementation,” or “in one implementation” or “some implementations” in various places throughout this specification are not necessarily referring to same implementation of disclosure. Furthermore, particular features, structures, functions, or characteristics may be combined in any suitable manner in one or more implementations. For example, a first implementation may be combined with a second implementation anywhere particular features, structures, functions, or characteristics associated with two implementations are not mutually exclusive. [00102] The various definitions here are provided as examples to describe the written description and claims. The plain meaning of the terms is applicable in addition to the examples.

[00103] As used in herein, singular forms “a,” “an,” and “the” are intended to include plural forms as well, unless context clearly indicates otherwise. It will also be understood that term “and/or” as used herein refers to and encompasses all possible combinations of one or more of associated listed items.

[00104] Here, “coupled” and “connected,” along with their derivatives, may be used herein to describe functional or structural relationships between components. These terms are not intended as synonyms for each other. Rather, in particular implementations, “connected” may be used to indicate that two or more elements are in direct physical, optical, or electrical contact with each other. “Coupled” may be used to indicated that two or more elements are in either direct or indirect (with other intervening elements between them) physical, electrical or in magnetic contact with each other, and/or that tw o or more elements co-operate or interact with each other (e.g., as in a cause an effect relationship).

[00105] Here, “over,” “under.” "betw een,” and “on” as used herein refer to a relative position of one component or material with respect to other components or materials w here such physical relationships are notew orthy. For example, in context of materials, one material or material disposed over or under another may be directly in contact or may have one or more intervening materials. Moreover, one material disposed between two materials may be directly in contact with two layers or may have one or more intervening layers. Tn contrast, a first material “on” a second material is in direct contact with that second material/material. Similar distinctions are to be made in context of component assemblies. As used throughout this description, and in claims, a list of items joined by term “at least one of’ or “one or more of’ can mean any combination of listed terms.

[00106] Here, “adjacent” generally refers to a position of a thing being next to (e.g., immediately next to or close to with one or more things between them) or adjoining another thing (e.g., abutting it).

[00107] Here, “signal” may refer to current signal, voltage signal, magnetic signal, or data/clock signal.

[00108] Here, “device” may generally refer to an apparatus according to context of usage of that term. For example, a device may refer to a stack of layers or structures, a single structure or layer, a connection of various structures having active and/or passive elements, etc. Generally, a device is a three-dimensional structure with a plane along x-y direction and a height along z direction of an x-y-z Cartesian coordinate system. In at least one implementation, plane of device may also be plane of an apparatus which comprises device. [00109] Unless otherwise specified in explicit context of their use, terms “substantially equal,” “about equal,” and “approximately equal” mean that there is no more than incidental variation between two things so described. Such variation is typically no more than +/-10% of a predetermined target value.

[00110] Here, “left.” “right.” “front,” “back,” “top.” “bottom,” “over,” “under,” and similar terms are used for descriptive purposes and not necessarily for describing permanent relative positions. For example, terms “over,” “under,” “front side,” “back side,” “top,” “bottom,” “over,” “under,” and “on” as used herein refer to a relative position of one component, structure, or material with respect to other referenced components, structures, or materials within a device, where such physical relationships are noteworthy. These terms are employed herein for descriptive purposes only and predominantly within context of a device z-axis and therefore may be relative to an orientation of a device. Hence, a first material “over” a second material in context of a figure provided herein may also be “under” second material if device is oriented upside-down relative to context of figure provided. Similar distinctions are to be made in context of component assemblies.

[00111] Here, a device that is “configured to” perform a task or function may be configured (e.g., programmed and/or hardwired) at a time of manufacturing by a manufacturer to perform the function. In at least one example, the device may be configurable (or reconfigurable) by a user after manufacturing to perform the function and/or other additional or alternative functions. In at least one example, the configuring may be through firmware and/or software programming of the device, through a construction and/or layout of hardware components and interconnections of the device, or a combination thereof. [00112] Here, “between” may be employed in context of z-axis, x-axis or y-axis of a device. A material that is between two other materials may be in contact with one or both of those materials. In another example, a material that is between two or other material may be separated from both of other two materials by one or more intervening materials. A material “between” two other materials may therefore be in contact with either of other two materials. In another example, a material “between” two other materials may be coupled to other two materials through an intervening material. A device that is between two other devices may be directly connected to one or both of those devices. In another example, a device that is between two other devices may be separated from both of other two devices by one or more intervening devices. [00113] Here, “showerhead mounting fixture” may generally refer to a portion of a blockage detection apparatus that holds a showerhead for blockage inspection in a blockage detection apparatus.

[00114] Here, “gantry system” may generally refer to a rail system designed to carry an object and translate it along a first rail generally by motorized control. In at least one implementation, a gantry system may include at least a first rail. In at least one implementation, a gantry system may include a second rail perpendicular to the first rail, and a third rail mutually perpendicular to the first and second rails. First, second and third rails may extend in a three-dimensional x, y, z coordinate system.

[00115] Here, “geometric pattern” may generally refer to a scanning pattern employed by the gantry system that may follow a polar or rectangular coordinate system over the faceplate. [00116] Here, “vertical displacement” may generally refer to a vertical distance between a sensor array and a showerhead faceplate that is held constant by the gantry system.

[00117] Here, “hole” or “exit hole” may generally refer to a plurality of openings in a showerhead faceplate. Exit holes enable distribution of process gases in an even manner over a substrate in a process chamber.

[00118] Here, “showerhead” may generally refer to a process gas distribution device that has a resemblance in appearance and function to a showerhead in a bathroom shower. A showerhead comprises a plurality of exit holes for distribution of a process gas in an even manner, generally over a semiconductor substrate within a process chamber.

[00119] Here, “faceplate” may generally refer to a top plate or portion of a showerhead that is perforated with a plurality’ of exit holes. A faceplate may interface with a plenum or cavity' within the body of a showerhead, within which process gases mix and/or diffuse to spread within the plenum and pass through the plurality of exit holes into a process chamber. [00120] Here, “image capture device” may generally refer to a camera or a charge capture device (CCD) that is operable to capture an image and store it electronically.

[00121] Here, “global camera” may generally refer to a camera having a normal angle lens or wide angle lens for obtaining unmagnified images, usually from some distance from the subject.

[00122] Here, “global image” may generally to an image captured by a global camera. For example, a global camera as an image capture device may capture an image of a showerhead faceplate to be analyzed for the physical condition of the faceplate. [00123] Here, “marring” or “discoloration” may generally refer to the physical condition of a showerhead faceplate. Marring may refer to scratches or gouges, and discoloration may refer to regions of oxidation or changes in color due to chemical modification or stains.

[00124] Here, “machine vision software” may generally refer to software specializing in operating an image capture device and analyzing the image in real time to determine and/or analyze features of the image.

[00125] Here, “position coordinates” may generally refer to x and y coordinates of centers of exit holes on a showerhead faceplate. In at least one implementation, position coordinates are absolute coordinates referred to a reference coordinate on the showerhead faceplate or other structure.

[00126] Here, “two-dimensional flatness profile” may generally refer to a vertical profile map of the faceplate disc, where the degree of flatness is measured. The flatness profile provides a measure of non-planarily of the faceplate surface, where non-planarities of the faceplate is mapped.

[00127] Here, “motor drive circuit” may generally refer to an electronic circuit designed to drive stepper motors and the like. A motor drive circuit is coupled to a processor of a computer system and is controlled by the processor.

[00128] Here, “computing system” may generally refer to a processor or collection of processors in a general computer or in a dedicated circuit.

[00129] Here “test gas” may generally refer to a standard gas used for measuring flowvelocity by a llow sensor. A test gas may be dry air, nitrogen, or argon, for example.

[00130] Here, “blockage” may generally refer to debris or material that accumulates in an exit hole and partially or completely blocks the exit hole.

[00131] Here, “flow rate” may generally refer to a volumetric flow rate of flowing gases. Flow rates may be measured as a volume per time, such as standard cubic centimeters per minute (SCCM). In some implementations, flow velocity is measured and converted to a volumetric flow rate.

[00132] Here, “showerhead inspection apparatus” may generally refer to a system for finding exit holes in a showerhead that exhibit blockage. In at least one implementation, a showerhead inspection apparatus comprises a showerhead mounting feature, a gantry system and a sensor array mounted on the gantry system.

[00133] Here, “flow sensor” may generally refer to a sensor configured to measure volumetric flow rates or flow velocities. A sensor array may comprise an array of flow sensors. For example, an array of flow sensors may comprise a one-dimensional sensor array or a two-dimensional sensor array.

[00134] Here, '‘flow sensing elements” may generally refer to elements configured to sense gas flow or provide signals to measure a gas flow. Flow sensing elements may be arranged in one- or two-dimensional arrays.

[00135] Here, “sensor array” may generally refer to a group of sensors of different types. The sensor array may have a group of various sensors mounted on a platform.

[00136] Here, “distance sensor” may generally refer to a sensor configured to measure distances. An example is a laser-based sensor, where a time-of-flight measurement of laser light pulses may be employed to measure distances with high precision.

[00137] Here, “time-of-flight” may generally refer to the time required for a laser pulse to be detected after emission from a distance sensor using laser pulse time-of-flight technique to measure distances. The distance traversed by the pulse is one half the speed of light divided by the time of flight of the pulse.

[00138] Here, “heat map” may generally refer to a two-dimensional projection of a three- dimensional mapping where a third dimension, such as a z-axis, is represented by colors, such as colors of the rainbow, or by shades of a single color. The coloration or shading of a heat map is generally referred to as a false color image or map. The heat map may be easier to plot or interpret than a true three-dimensional plot. The term “heat map” was derived from false colors or shades assigned to infrared images of objects obtained by infrared photography, where a shading scale of a particular color typically has a progression of shades from darkest to lightest to represent a temperature scale of the objects in the image.

[00139] Here, “false color image” or “false color map” may generally refer to the coloration of a heat map. showing changes in colors as the z-axis value changes from low to high values. The colors or shades are generally shown as a progression from red to violet, or from darkest to lightest shades of a single color in a legend. These colors or shades chosen to represent numerical values of a z-axis for a 3D plot have no relation to the actual colors of the object in the map, thus the term “false color”. The term “false color” may be used to describe colored 2D or 3D plots showing surfaces, velocity distributions, stress distributions, temperature distributions, pressure distributions and the like obtained by numerical, microscopic or macroscopic analysis, where, for example, the topography of the surface is represented by colors or shades of a color to indicate a numerical z-height value. Sometimes the colors or shades may be superimposed on the true three-dimensional topography of an object. The colors were termed "false" to avoid mistaking the real color of a surface (if any) with the color scale used in the heat map.

[00140] Here, '‘pressure sensor’’ may generally refer to a sensor configured to measure pressures.

[00141] Here, “optical fiber port’’ may generally refer to a structure configured to couple to an optical fiber, providing appropriate optical elements to couple light from the optical fiber to output devices. The optical fiber may be coupled to a spectroscopy system, for example.

[00142] Here, “camera module” may generally refer to a digital image capture device employing a coupled charge device (CCD) to produce digital images. The camera module may comprise a lens such as a macro lens or a microscope objective.

[00143] Here, “macro lens” may generally refer to a lens designed for macrophotography, to obtain close-up images to show small details. A macro lens may have sub-unity magnification to up to 5x magnification.

[00144] Here, “microscope objective” may refer to an optical system comprising one or more lenses for microscopic imaging. A microscope objective can have lx to several hundred times magnification power.

[00145] Here, “enlarged image” may generally refer to magnified images obtained by a camera module having a macro lens or a microscope objective for image magnification. [00146] Here, “spectroscopy system” may generally refer to a spectrometer and light source.

[00147] Here, “spectroscopic data” may be data contained in a spectrum obtained by a spectroscopy system.

[00148] Here, “spectrum” may generally refer to a plot of a light signal intensity vs. its wavelength or frequency over a specific range. A spectrum may be collected by a spectroscopy system comprising a light source and a spectrometer to resolve the light into narrow bands of frequencies or wavelengths. Light, which may be infrared, visible, ultraviolet or x-ray, can be transmitted through or reflected from a subject medium. Some wavelengths of the light may be absorbed by the medium. Transmitted or reflected light maybe recorded by a detector as a function of wavelength. The wavelengths of the light are resolved by a spectrometer. A spectrum may be of light transmitted through a medium of interest or light reflected from a medium of interest.

[00149] Structures of various examples described herein can also be described as method(s) of forming those structures or apparatuses, and method(s) of operation of these structures or apparatuses. The following examples are provided that illustrate the various examples of the disclosure. The examples can be combined with other examples. As such, various examples can be combined with other examples without changing the scope of the invention.

[00150] Example 1 is an apparatus, comprising: a showerhead mounting fixture (205) operable to mount a showerhead (100); a gantry system (204); and a sensor array (202. 600) comprising one or more sensors carried on a platform (602) attached to the gantry system, wherein the gantry system is operable to scan the sensor array over a faceplate (102, 614) of the show erhead (100), wherein the faceplate (102, 614) comprises a plurality of holes (114), and wherein the gantry system is operable to position any sensor (604 - 612) of the sensor array (600) over individual holes the plurality of holes to determine if any individual hole of the plurality of holes is at least partially blocked, and also to determine is any internal passages of the show-erhead is partially or fully blocked.

[00151] Example 2 is an apparatus as in any of the examples, particularly example 1, further comprising an image capture device (213) positioned over the showerhead mounting fixture (205). where the image capture device is configured to capture at least one image of the faceplate (e.g., 102) of the showerhead.

[00152] Example 3 is an apparatus as in any of the examples, particularly example 1, wherein the sensor array includes a flow sensor (610).

[00153] Example 4 is an apparatus as in any of the examples, particularly example 1, wherein the sensor array includes a distance sensor (608).

[00154] Example 5 is an apparatus as in any of the examples, particularly example 1, wherein the sensor array includes a pressure sensor (604).

[00155] Example 6 is an apparatus as in any of the examples, particularly example 1, wherein the sensor array includes an optical fiber port (612).

[00156] Example 7 is an apparatus as in any of the examples, particularly example 6, wherein the optical fiber port is configured to enable attachment of an optical fiber (632) to the sensor array.

[00157] Example 8 is an apparatus as in any of the examples, particularly example 1, wherein the sensor array includes a camera module (606), wherein the camera module comprises a microscope objective or a macro lens (628).

[00158] Example 9 is an apparatus as in any of the examples, particularly example 3, wherein the flow sensor includes an array of flow sensing elements (222. Figs 2C and 2D), and wherein a pitch of the array of flow sensing elements substantially matches a pitch of the plurality of holes (114).

[00159] Example 10 is an apparatus as in any of the examples, particularly example 1, wherein the gantry system includes one or more drive motors (212), wherein a computing system is coupled to a motor drive circuit (210) which is coupled to the one or more drive motors, wherein the computing system (208) is operable to store coordinates of the individual holes of the plurality of holes (114) and command the one or more drive motors to position the sensor array (202) over at least a portion of the plurality of holes.

[00160] Example 11 is a method, comprising mounting a showerhead in a showerhead inspection apparatus (200), wherein the showerhead comprises a faceplate (202, 614) having a plurality of holes (114) extending through the faceplate, wherein the plurality of holes is coupled to a plenum or distribution manifold within the showerhead (see Figs. 6A-6E), and wherein the showerhead inspection apparatus comprises: a gantry' system (204); and a sensor array comprising a flow sensor (610), a pressure sensor (604), a distance sensor (608), and a camera module (606), wherein the sensor array is carried on a platform (602 or 202) attached to the gantry system; obtaining a two-dimensional flatness profile of the faceplate; scanning the sensor array over the faceplate; and measuring a flow rate of a test gas passing through individual holes of the plurality' of holes.

[00161] Example 12 is a method as in any of the examples, particularly example 11, wherein scanning the sensor array over the faceplate includes translating the sensor array by the gantry system over the faceplate, wherein a vertical displacement (see Fig. 5) between the sensor array and the faceplate is maintained across the faceplate, and wherein the vertical displacement is a sum of a predetermined distance and the two-dimensional flatness profile. [00162] Example 13 is a method as in any of the examples, particularly example 11, wherein obtaining the two-dimensional flatness profile of the faceplate includes scanning the sensor array over the faceplate in a geometric pattern at a constant displacement, and determining a time-of-flight of a laser light pulse emanating from the distance sensor at regular distance intervals, wherein the time-of-flight is proportional to a distance between the distance sensor and the faceplate determined for a two-dimensional coordinate system on the faceplate, and wherein the two-dimensional flatness profile is determined by a difference between the constant displacement and the distance determined by the distance sensor.

[00163] Example 14 is a method as in any of the examples, particularly example 11, wherein measuring the flow rate of the test gas passing through the individual holes includes positioning the flow sensor over an individual hole and reading one or more data signals from the flow sensor by a computing system (208).

[00164] Example 15 is a method as in any of the examples, particularly example 14, further includes creating a heat map (250) of the faceplate, wherein the heat map comprises a false color image of one or more flow rates from the individual holes, wherein a false color scale corresponds to a range of flow velocities.

[00165] Example 16 is a method as in any of the examples, particularly example 11, further comprising: identifying holes having a blockage (obstruction 630); positioning the sensor array over the holes having the blockage, wherein the camera module (606) is positioned over an individual hole of the holes having the blockage; and obtaining one or more enlarged images (by 606) of the holes having the blockage.

[00166] Example 17 is a method as in any of the examples, particularly example 16, wherein obtaining the one or more enlarged images of the holes having the blockage comprises analyzing by machine vision software (e.g., within computing system 208) the one or more enlarged images to determine an extent of occlusion and to identify a physical cause of the blockage.

[00167] Example 18 is a method as in any of the examples, particularly example 11 , further comprising determining an internal static pressure of the showerhead (e.g., by pressure sensor 604A or 604B).

[00168] Example 19 is a method as in any of the examples, particularly example 18, wherein determining the internal static pressure of the showerhead comprises positioning the pressure sensor (604A or 604B) of the sensor array (600) to seal an entrance of the pressure sensor around an individual hole of the plurality of holes in the faceplate and obtaining a pressure measurement while the test gas is flowing in the showerhead (see Figs. 6B and 6C). [00169] Example 20 is a method as in any of the examples, particularly example 11, further comprising obtaining a spectrum of a selected region of the faceplate to obtain chemical information of the selected region, wherein an optical fiber port (612) on the sensor array is positioned over the selected region (e.g., 624) by the gantry system, and wherein the optical fiber port is optically coupled to a light source and a spectrometer.

[00170] Example 21 is a method as in any of the examples, particularly example 11 , further comprising obtaining a global image of the faceplate by an image capture device (213) positioned over the faceplate (102), wherein the global image (by 213) is analyzed to determine a presence of a marring or a discoloration of the faceplate. [00171] Example 22 is a method as in any of the examples, particularly example 11, further comprising recording a blockage detection image of the faceplate of the showerhead. [00172] Example 23 is a method as in any of the examples, particularly example 22, wherein capturing the blockage detection image of the faceplate of the showerhead includes shining a light through the plurality⁷ of holes by coupling a light source into a plenum of the showerhead, and wherein a mirror system reflects a light pattern emerging from the faceplate of the showerhead to an image capture device (see Figs. 3 and 4).

[00173] Example 24 is a method as in any of the examples, particularly example 23, wherein analyzing the blockage detection image to locate the blockage includes determining a position coordinate of the blockage (see Figs. 4 and 5).

[00174] Example 25 is a method as in any of the examples, particularly example 24, wherein positioning the flow sensor over a target hole comprises driving the gantry system to move the flow sensor to the position coordinate of the target hole, and wherein the flow sensor measures the flow rate of the test gas at the position coordinate of the target hole (see Fig. 5).

[00175] Example la is an apparatus, comprising: a showerhead mounting fixture operable to mount a showerhead (100); a gantry⁷ system (204); and a sensor array (202) coupled to the gantry⁷ system, wherein the gantry⁷ system is operable to raster scan the sensor array over a faceplate of the showerhead, wherein the faceplate comprises a plurality of exit holes (114), and wherein the gantry system is operable to position the sensor array⁷ over one or more individual exit holes of the plurality of exit holes to measure a flow velocity of a test gas through the one or more individual exit holes of the plurality⁷ of exit holes.

[00176] Example 2a is an apparatus as in any of the examples, particularly example la, wherein the gantry system includes a computing system (208) operable to store one or more coordinates of the one or more individual exit holes.

[00177] Example 3a is an apparatus as in any of the examples, particularly example la, wherein the sensor array includes a single flow sensor (610).

[00178] Example 4a is an apparatus as in any of the examples, particularly example la, wherein the sensor array includes a plurality of flow sensors (220 or 230).

[00179] Example 5a is an apparatus as in any of the examples, particularly example 4a, wherein the plurality⁷ of flow sensors includes an array of one or more flow sensors (222), and wherein a pitch of the array of the one or more flow sensors substantially matches a pitch of the plurality of exit holes (114). [00180] Example 6a is an apparatus as in any of the examples, particularly example la, wherein the gantry system includes one or more drive motors (212), wherein a computing system is coupled to a motor drive circuit (210) which is coupled to the one or more drive motors of the gantry system, wherein the computing system is operable to store coordinates of the one or more individual exit holes of the plurality⁷ of exit holes and command the one or more drive motors to position the sensor array over at least a portion of the plurality of exit holes, and wherein one or more individual flow sensors are positioned over the one or more individual exit holes.

[00181] Example 7a is an apparatus, comprising a showerhead mounting fixture (205) operable to mount a showerhead; a light source fixture (304) operable to mount on a stem (104) of the showerhead; a mirror system (502 and 504) operable to relay an image of a faceplate of the showerhead to an image capture device (506); a gantry system; and a sensor array (202) coupled to the gantry⁷ system, wherein the gantry system is operable to scan the sensor array over the faceplate of the showerhead, wherein the faceplate comprises a plurality⁷ of exit holes, and wherein the gantry system is operable to position the sensor array over one or more individual exit holes of the plurality of exit holes to measure a flow velocity of a test gas through the one or more individual exit holes.

[00182] Example 8a is an apparatus as in any of the examples, particularly example 7a, wherein the light source fixture (304) includes a light pipe (308) to extend within an inlet (112) of the showerhead, and wherein the light pipe is optically coupled to a light source (302).

[00183] Example 9a is an apparatus as in any of the examples, particularly example 8a, wherein the light source is any one of a polychromatic light source or a monochromatic light source.

[00184] Example 10a is an apparatus as in any of the examples, particularly example 7a, wherein the mirror system includes two or more mirrors (502 and 504) including a first mirror (502) and a second mirror (504), wherein the first mirror is positioned at a distance over the faceplate of the showerhead when mounted in the showerhead mounting fixture, wherein the first mirror is tilted at an angle such that the first minor is operable to reflect the image of the faceplate (102) of the showerhead (100) to the second mirror, wherein the second mirror is tilted at the angle, and wherein the second mirror is operable to reflect the image of the faceplate to the image capture device (see Fig. 5). [00185] Example 1 la is an apparatus as in any of the examples, particularly example 7a, wherein the image capture device (506) is coupled to a computing system (510), and wherein the computing system is operable to execute a set of machine vision software instructions. [00186] Example 12a is an apparatus as in any of the examples, particularly example 1 la, wherein the set of machine vision software instructions are operable to locate one or more apparent blockages (e.g.. 314, 316, 318, 414, 416. 418) within the one or more individual exit holes (114) of the plurality of exit holes.

[00187] Example 13a is an apparatus as in any of the examples, particularly example 12a, wherein the computing system is operable to determine one or more position coordinates of the one or more apparent blockages within the one or more individual exit holes of the plurality of exit holes.

[00188] Example 14a is an apparatus as in any of the examples, particularly example 13a, wherein the computing system is operable to command a motor drive circuit (512) coupled to one or more drive motors (514) on the gantry system, wherein the computing system is operable to send the one or more position coordinates to the motor drive circuit to move the sensor array to the one or more position coordinates of the one or more apparent blockages. [00189] Example 15a is an apparatus as in any of the examples, particularly example 14a, wherein the computing system is operable to read data from the sensor array (202) to measure the flow rate of the test gas that flows from the one or more apparent blockages.

[00190] Example 16a is a method, comprising mounting a showerhead in a test fixture of a blockage detection apparatus, the showerhead having a showerhead faceplate; supplying a test gas to the showerhead; scanning a sensor array over the showerhead faceplate, wherein the showerhead faceplate comprises a plurality of exit holes; and measuring a flow velocity of the test gas passing through one or more individual exit holes of the plurality of exit holes. [00191] Example 17a is a method as in any of the examples, particularly example 16a, wherein scanning the sensor array over the showerhead faceplate includes translating the sensor array by a gantry system over the showerhead faceplate, and wherein one or more flowsensors on the sensor array are positioned over one or more exit holes of the plurality of exit holes.

[00192] Example 18a is a method as in any of the examples, particularly example 17a, wherein a computing system is coupled to a motor drive circuit coupled to one or more drive motors on the gantry system, and wherein a plurality- of position coordinates of the plurality of exit holes is stored in a memory within the computing system, and wherein the method includes commanding, by the computing system, the one or more drive motors to position the one or more flow sensors over individual exit holes of the plurality of exit holes.

[00193] Example 19a is a method as in any of the examples, particularly example 17a, wherein measuring the flow velocity of the test gas passing through the one or more individual exit holes includes reading one or more data signals from the one or more flow sensors on the sensor array by a computing system.

[00194] Example 20a is a method as in any of the examples, particularly example 19a, further includes creating a heat map (250) of the showerhead faceplate, wherein the heat map comprises a false color image (see Fig. 2E; e.g., 218, 216) of one or more flow velocities from the one or more individual exit holes, wherein a false color scale corresponds to a range of flow rates.

[00195] Example 21a is a method, comprising mounting a showerhead in a test fixture of a blockage detection apparatus; recording a blockage detection image of a faceplate of the showerhead, wherein the faceplate comprises a plurality of exit holes; analyzing the blockage detection image to locate an apparent blockage within one or more individual exit holes of the plurality of exit holes; positioning a sensor array over a target exit hole having the apparent blockage (e.g., 414); and measuring a flow velocity of a test gas flowing through the target exit hole.

Claims

CLAIMS What is claimed is:

1. An apparatus, comprising: a showerhead mounting fixture operable to mount a showerhead; a gantry system; and a sensor array comprising one or more sensors carried on a platform attached to the gantry system; wherein the gantry system is operable to scan the sensor array over a faceplate of the showerhead, wherein the faceplate comprises a plurality of holes, and wherein the gantry system is operable to position any sensor of the sensor array over individual holes the plurality of holes to determine if any individual hole of the plurality of holes is at least partially blocked, and also to determine is any internal passages of the showerhead is partially or fully blocked.

2. The apparatus of claim 1, further comprising an image capture device positioned over the showerhead mounting fixture, where the image capture device is configured to capture at least one image of the faceplate of the showerhead.

3. The apparatus of claim 1, wherein the sensor array includes a flow sensor.

4. The apparatus of claim 1, wherein the sensor array includes a distance sensor.

5. The apparatus of claim 1, wherein the sensor array includes a pressure sensor.

6. The apparatus of claim 1, wherein the sensor array includes an optical fiber port.

7. The apparatus of claim 6, wherein the optical fiber port is configured to enable attachment of an optical fiber to the sensor array.

8. The apparatus of claim 1, wherein the sensor array includes a camera module, wherein the camera module comprises a microscope objective or a macro lens.

9. The apparatus of claim 3, wherein the flow sensor includes an array of flow sensing elements, and wherein a pitch of the array of flow sensing elements substantially matches a pitch of the plurality of holes.

10. The apparatus of claim 1, wherein the gantry system includes one or more drive motors, wherein a computing system is coupled to a motor drive circuit which is coupled to the one or more drive motors, wherein the computing system is operable to store coordinates of the individual holes of the plurality of holes and command the one or more drive motors to position the sensor array over at least a portion of the plurality' of holes.

11. A method, comprising: mounting a showerhead in a showerhead inspection apparatus, wherein the showerhead comprises a faceplate having a plurality of holes extending through the faceplate, wherein the plurality of holes is coupled to a plenum or distribution manifold within the showerhead, and wherein the showerhead inspection apparatus comprises: a gantry system; and a sensor array comprising a floyv sensor, a pressure sensor, a distance sensor, and a camera module, wherein the sensor array is carried on a platform attached to the gantry system; obtaining a two-dimensional flatness profile of the faceplate; scanning the sensor array over the faceplate; and measuring a flow rate of a test gas passing through individual holes of the plurality of holes.

12. The method of claim 11, w herein scanning the sensor array over the faceplate includes translating the sensor array by the gantry system over the faceplate, wherein a vertical displacement between the sensor array and the faceplate is maintained across the faceplate, and wherein the vertical displacement is a sum of a predetermined distance and the two-dimensional flatness profile.

13. The method of claim 11, wherein obtaining the two-dimensional flatness profile of the faceplate includes scanning the sensor array over the faceplate in a geometric pattern at a constant displacement, and determining a time-of-flight of a laser light pulse emanating from the distance sensor at regular distance intervals, wherein the time-of-flight is proportional to a distance between the distance sensor and the faceplate determined for a two-dimensional coordinate system on the faceplate, and wherein the two-dimensional flatness profile is determined by a difference between the constant displacement and the distance determined by the distance sensor.

14. The method of claim 11. wherein measuring the flow rate of the test gas passing through the individual holes includes positioning the flow sensor over an individual hole and reading one or more data signals from the flow sensor by a computing system.

15. The method of claim 14, further includes creating a heat map of the faceplate, wherein the heat map comprises a false color image of one or more flow rates from the individual holes, wherein a false color scale corresponds to a range of flow velocities.

16. The method of claim 11, further comprising: identifying holes having a blockage; positioning the sensor array over the holes having the blockage, wherein the camera module is positioned over an individual hole of the holes having the blockage; and obtaining one or more enlarged images of the holes having the blockage.

17. The method of claim 16, wherein obtaining the one or more enlarged images of the holes having the blockage comprises analyzing by machine vision software the one or more enlarged images to determine an extent of occlusion and to identify a physical cause of the blockage.

18. The method of claim 11, further comprising determining an internal static pressure of the showerhead.

19. The method of claim 18, wherein determining the internal static pressure of the showerhead comprises positioning the pressure sensor of the sensor array to seal an entrance of the pressure sensor around an individual hole of the plurality of holes in the faceplate and obtaining a pressure measurement while the test gas is flowing in the showerhead.

20. The method of claim 11, further comprising obtaining a spectrum of a selected region of the faceplate to obtain chemical information of the selected region, wherein an optical fiber port on the sensor array is positioned over the selected region by the gantry system, and wherein the optical fiber port is optically coupled to a light source and a spectrometer.

21. The method of claim 11, further comprising obtaining a global image of the faceplate by an image capture device positioned over the faceplate, wherein the global image is analyzed to determine a presence of a marring or a discoloration of the faceplate.

22. The method of claim 11, further comprising recording a blockage detection image of the faceplate of the showerhead.

23. The method of claim 22, wherein capturing the blockage detection image of the faceplate of the showerhead includes shining a light through the plurality of holes by coupling a light source into a plenum of the showerhead, and wherein a mirror system reflects a light pattern emerging from the faceplate of the showerhead to an image capture device.

24. The method of claim 23, wherein analyzing the blockage detection image to locate the blockage includes determining a position coordinate of the blockage.

25. The method of claim 24, wherein positioning the flow sensor over a target hole comprises driving the gantry system to move the flow sensor to the position coordinate of the target hole, and wherein the flow sensor measures the flow rate of the test gas at the position coordinate of the target hole.