Pedestal setup with camera wafer
The fixture with an annular platform and conical pins ensures precise alignment between the pedestal and showerhead, addressing reproducibility and uniformity issues in substrate processing systems, enhancing wafer uniformity and preventing damage.
Patent Information
- Application Number
- JP2025076019
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2019-07-29
- Filing Date
- 2025-05-01
- Publication Date
- 2025-07-30
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
Existing substrate processing systems face challenges in achieving reproducible and accurate alignment between the pedestal and the showerhead, leading to non-uniform gas flow and increased non-uniformity on the wafer, often causing scratches and misalignment due to loose or tight fixtures.
A fixture with an annular platform and conical pins is used, aligning the camera wafer at the center of the pedestal, ensuring reproducible alignment by using non-abrasive materials and tight tolerances, allowing for various pedestal sizes and types, and incorporating a camera for precise alignment with the showerhead.
The fixture provides accurate, reproducible, and specific alignment of the pedestal with the showerhead, preventing scratches and improving uniformity on the wafer, compatible with different pedestal sizes and materials, and accommodating system-level tolerances.
Smart Images
Figure 2025111755000001_ABST
Abstract
Description
Technical Field
[0001] Cross - Reference to Related Applications This disclosure is a PCT international application of U.S. Provisional Patent Application No. 62 / 879,654, filed on Jul. 29, 2019. The entire disclosure of the application referenced above is incorporated herein by reference.
[0002] This disclosure generally relates to substrate processing systems, and more particularly to fixtures for setting up a pedestal using a camera wafer.
Background Art
[0003] The background description provided here is for the purpose of generally presenting the content of the present disclosure. Within the scope described in this background art section, research by the inventors named at the present time, as well as aspects of the description that cannot be separately regarded as prior art at the time of filing, are not admitted as prior art against the present disclosure, whether explicitly or implicitly.
[0004] Substrate processing systems typically include a plurality of processing chambers (also called process modules) that perform deposition, etching, and other processes on substrates such as semiconductor wafers. Examples of processes that can be performed on a substrate include, but are not limited to, plasma enhanced chemical vapor deposition (PECVD) processes, chemically enhanced plasma vapor deposition (CEPVD) processes, and sputtering physical vapor deposition (PVD) processes. Additional examples of processes that can be performed on a substrate include, but are not limited to, etching (e.g., chemical etching, plasma etching, reactive ion etching, etc.) and cleaning processes.
[0005] During processing, the substrate is placed on a substrate support such as a pedestal or an electrostatic chuck (ESC) in the processing chamber of the substrate processing system. During deposition, a gas mixture containing one or more precursors is introduced into the processing chamber, and plasma is applied to activate a chemical reaction. During etching, a gas mixture containing an etching gas is introduced into the processing chamber, and plasma is applied to activate a chemical reaction. A computer-controlled robot typically transfers the substrate from one processing chamber to another in the order in which the substrates are processed. SUMMARY OF THE INVENTION
[0006] The apparatus comprises an annular member disposed along a first plane, and N first members extending perpendicularly to the first plane from the outer diameter of the annular member, where N is an integer greater than 2. The first portion of each of the N first members extends above the first plane, and the second portion of each of the N first members extends below the first plane. The apparatus further comprises N second members extending radially outward from the second portions of the N first members along a second plane parallel to the first plane. Each of the N second members is between different pairs of the N first members.
[0007] In another feature, the annular member, the N first members, and the N second members constitute a single structure.
[0008] In another feature, the annular member, the N first members, and the N second members are made of metal.
[0009] In another feature, the apparatus further comprises N third members made of a non-abrasive material, having equal lengths and extending downward from the N second members respectively perpendicular to the second plane.
[0010] In another feature, the device further comprises N pins made of a non-abrasive material, having equal lengths and conical ends, and extending downward from each of the N second members perpendicular to the second plane. The N pins are equidistant from the center of the annular member and include threads engageable with the threaded slots in the N second members.
[0011] In another feature, the device further comprises N third members made of a non-abrasive material, having equal lengths and disposed in respective slots in the N second members. Each of the N third members is arcuate and includes a first element, a second element, and a third element. The first element is fastened to each of the N second members parallel to the second plane. The second element extends perpendicularly downward from the first element below the second plane and below each of the N second members. The third element extends perpendicularly downward from the first element below the second plane and below each of the N second members, and extends less than the second element.
[0012] In another feature, the first, second, and third elements constitute a single structure.
[0013] In another feature, the first element has an arc length longer than that of the second and third elements.
[0014] In another feature, the distal ends of the third elements of the N third members are in a plane parallel to the second plane.
[0015] In another feature, the device further comprises N pins made of a non-abrasive material, having equal lengths and extending perpendicularly downward with respect to the second plane through respective threaded slots in the N second members that are at the same radial distance from the center of the annular member. Each of the N pins includes an upper portion, a conical bottom, and a threaded portion between the upper and bottom portions engageable with respective ones of the threaded slots.
[0016] In yet another aspect, the method comprises placing an apparatus on an upper surface of a pedestal within a processing chamber. The apparatus comprises an annular member, N support members, and N pins, where N is an integer greater than 2. The N support members support the annular member in a plane parallel and above the upper surface of the pedestal. The N pins are disposed perpendicular to the plane along the circumference of the annular member. Each of the N pins includes a thread engageable with a respective threaded slot within the apparatus. Each of the N pins faces towards the upper surface of the pedestal and includes a conical end engageable with the periphery of the upper surface of the pedestal. The method further includes aligning the center of the annular member with the center of the pedestal by adjusting one or more of the N pins.
[0017] In yet another aspect, the method further includes placing N level indicating devices in respective slots within the apparatus in contact with each of the N pins. The method further includes aligning the center of the annular member with the center of the pedestal by adjusting one or more of the N pins until the N level indicating devices indicate the same level.
[0018] In yet another aspect, the method further includes placing a wafer concentrically on the annular member. The wafer includes a camera at the center of the wafer. The camera is oriented towards a showerhead disposed on the pedestal within the processing chamber. The method further includes using the camera to capture one or more images of the showerhead. The method further includes aligning the center of the pedestal with the center of the showerhead based on the one or more images.
[0019] In other features, the method further includes arranging wafers concentrically on an annular member. The wafer includes a camera at the center of the wafer. The camera is oriented toward a showerhead disposed on a pedestal within the processing chamber. The wafer further includes a wireless transmitter that communicates with the camera and a computing device external to the processing chamber. The method further includes transmitting one or more images to the computing device using the wireless transmitter, processing the one or more images at the computing device, and aligning the center of the pedestal with the center of the showerhead based on the processing.
[0020] In other features, the method further includes arranging wafers concentrically on an annular member. The wafer includes a camera at the center of the wafer. The camera is oriented toward a showerhead disposed on a pedestal within the processing chamber. The wafer further includes a wireless transmitter that communicates with the camera and a computing device external to the processing chamber. The method further includes closing the processing chamber and generating a vacuum within the processing chamber. The method further includes capturing one or more images of the showerhead using the camera and transmitting the one or more images to the computing device using the wireless transmitter. The method further includes processing the one or more images at the computing device and moving the pedestal based on the processing until the center of the pedestal is aligned with the center of the showerhead.
[0021] Other fields to which the present disclosure is applicable will become apparent from the detailed description, the claims, and the drawings. The detailed description and the specific examples are for illustrative purposes only and are not intended to limit the scope of the present disclosure.
Brief Description of the Drawings
[0022] The present disclosure will be more fully understood from the detailed description and the accompanying drawings.
[0023]
Figure 1
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Figure 2
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Figure 3
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Figure 4
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Figure 5
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Figure 6
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Figure 7
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Figure 10
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Figure 11
[0033]
Figure 12
[0034]
Figure 13
[0035] In these drawings, reference numbers may be reused to refer to similar and / or identical elements. DETAILED DESCRIPTION OF THE INVENTION
[0036] The uniformity on the wafer (e.g., in a deposition process) depends on the alignment of the pedestal and the showerhead. The gap between the pedestal and the showerhead bore affects the flow of the process gas. A non-uniform gap causes a non-uniform flow, which in turn increases the non-uniformity. The pedestal is typically set up with reference to the center of the processing chamber, which results in a non-uniform gap.
[0037] For aligning the pedestal and the showerhead, a wafer with a camera integrated at the center of the wafer (hereinafter referred to as a camera wafer) is used. However, it is difficult to achieve reproducible results when using the camera wafer for alignment between the camera wafer and the pedestal. The current fixtures used with the camera wafer either fit loosely on the pedestal, adversely affecting the reproducibility of the setup, or are too tight, causing scratches on the pedestal. To achieve a close alignment between the pedestal and the showerhead, the camera wafer needs to be firmly placed at the center of the pedestal. The fixture used with the camera wafer needs to provide reproducibility to the alignment process. The fixture also needs to accommodate various pedestal sizes and variations (tolerances).
[0038] Fixtures designed in accordance with the present disclosure place a camera wafer on a pedestal without causing scratches to the pedestal and provide a reproducibility of up to 0.005 inches (0.127 millimeters). The fixtures improve the reproducibility of the alignment process between the pedestal and the showerhead. The fixtures are compatible with pedestals of various sizes regardless of whether the pedestal is bare, coated, or conditioned, and regardless of the material (e.g., metal, ceramic, etc.) used in the construction of the pedestal.
[0039] In the current method of setting up the pedestal, the pedestal is aligned with the spindle. The fixtures used for this purpose have large tolerances and do not necessarily align the pedestal with the showerhead. The misalignment leads to azimuthal non-uniformity. The increasing demand for uniformity on the wafer may cause a low-reliability pedestal alignment process to create multiple openings in the processing chamber to recover the processing chamber after pedestal installation or replacement.
[0040] By using the systems and methods of the present disclosure, a camera wafer is used to set up each pedestal in alignment with its showerhead while accurately compensating for large system-level tolerances. Fixtures designed in accordance with the present disclosure are dimensioned to be close to the outer diameter (OD) of the camera wafer. That is, the fixture uses the OD of the camera wafer, which is manufactured with tight tolerances, to place the camera wafer at the center of the fixture.
[0041] The fixture with the camera wafer is placed on the upper surface of the pedestal. The camera wafer is placed on the raised annular platform of the fixture parallel to the upper surface of the pedestal. Due to the design features of the fixture described in detail below, the raised annular platform of the fixture provides a ventilation path for the confined air, good connectivity between the camera wafer used for alignment and the data acquisition device, and easy access to the camera wafer for placement and removal of the camera wafer. The fixture has three legs (referred to as contact pads in the following description) made of a non-abrasive surface to prevent damage to the pedestal surface. The tolerances of the height and parallelism of the legs are strictly controlled.
[0042] The fixture is centered on the pedestal using three conical pins with reference to the OD of the pedestal. The conical pins are made of a non-abrasive material to protect the pedestal surface. The conical pins are screwed into the fixture and can be adjusted to accommodate pedestals of various ODs. The length of the conical pins is strictly controlled. When the conical pins are adjusted so that the fixture and the pedestal are centered, the conical ends of the conical pins slide vertically (up and down) along the OD of the pedestal. This allows the fixture to move horizontally parallel to the upper surface of the pedestal, facilitating the alignment of the fixture and the center of the pedestal.
[0043] To align the center of the fixture and the pedestal, the height of the upper surface of the conical pins with respect to the reference plane of the fixture is measured using a dial gauge (level indicator). When all three conical pins are set to the same height, the endpoints of the conical pins define a circle concentric with the fixture and the camera wafer. At this point, the centers of the fixture and the camera wafer are aligned with the center of the pedestal. Next, by moving the pedestal as described in detail below, the center of the pedestal is aligned with the center of the shower head (i.e., the centers of the camera wafer and the fixture are aligned with the hole in the center of the shower head).
[0044] It is also possible to deliberately create a calculated offset between the center of the fixture and the center of the pedestal by changing the height of the pin using the fixture. Using this feature, an intentional offset can be created between the pedestal and the shower head to compensate for non-uniformities in other azimuth angles. The fixture has markings for aligning notches on the camera wafer for the reproducibility of the alignment procedure.
[0045] Thus, the fixture according to the present disclosure provides an alignment that is accurate, reproducible, and specific to the pedestal. The fixture is compatible with various pedestal sizes. The fixture has non-abrasive contacts. The fixture performs pedestal alignment at the height in the process because the raised annular platform of the fixture is used in the alignment process.
[0046] The present disclosure is configured as follows. First, an example of a processing chamber is shown and described with reference to FIG. 1. Subsequently, the structure of the fixture according to the present disclosure is described with reference to FIGS. 2 to 11. Thereafter, the use of the fixture for aligning the pedestal with the shower head is described with reference to FIGS. 12 and 13. Specifically, the details of the structure of the fixture are shown and described with reference to FIGS. 2 to 7. The technical drawings of the fixture are shown in FIGS. 8 to 11. Next, the alignment process using the fixture is described with reference to FIGS. 12 and 13. Specifically, a system comprising the fixture and a computing device used for aligning the pedestal with the shower head is shown and described with reference to FIG. 12. A method of aligning the pedestal with the shower head using the fixture is shown and described with reference to FIG. 13.
[0047] FIG. 1 shows an example of a substrate processing system 100 including a processing chamber 102. Although this example is described in the context of plasma enhanced chemical vapor deposition (PECVD), the teachings of the present disclosure can be applied to other types of substrate processing such as atomic layer deposition (ALD), plasma enhanced ALD (PEALD), CVD, or other processes including etching processes. System 100 includes a processing chamber 102 that surrounds other components of system 100 and includes an RF plasma (when used). The processing chamber 102 includes an upper electrode 104 and an electrostatic chuck (ESC) 106 or other substrate support. During operation, a substrate 108 is placed on the ESC 106.
[0048] For example, the upper electrode 104 can include a gas distribution device 110 such as a showerhead for introducing and distributing process gases. The gas distribution device 110 can include a stem portion including one end connected to the upper surface of the processing chamber 102. The base portion of the showerhead is generally cylindrical and extends radially outward from the opposite end of the stem portion at a location spaced from the upper surface of the processing chamber 102. The surface or faceplate of the base portion of the showerhead facing the substrate includes a plurality of holes through which vaporized precursors, process gases, or purge gases flow. Alternatively, the upper electrode 104 can include a conductive plate and the process gases can be introduced in another manner.
[0049] The ESC 106 includes a base plate 112 that acts as a lower electrode. The base plate 112 supports a heating plate 114 that can correspond to a ceramic multi-zone heating plate. A thermal resistance layer 116 can be disposed between the heating plate 114 and the base plate 112. The base plate 112 can include one or more channels 118 for flowing a coolant through the base plate 112.
[0050] When plasma is used, the RF generation system 120 generates an RF voltage and outputs it to one of the upper electrode 104 and the lower electrode (e.g., the base plate 112 of the ESC 106). The other of the upper electrode 104 and the base plate 112 can be DC grounded, AC grounded, or floating. As just one example, the RF generation system 120 can include an RF generator 122 that generates RF power supplied to the upper electrode 104 or the base plate 112 by the matching and distribution network 124. In other examples, the plasma may be generated inductively or remotely.
[0051] The gas delivery system 130 includes one or more gas sources 132-1, 132-2, …, and 132-N (collectively gas sources 132), where N is an integer greater than zero. The gas sources 132 are connected to the manifold 140 by valves 134-1, 134-2, …, and 134-N (collectively valves 134) and mass flow controllers 136-1, 136-2, …, and 136-N (collectively mass flow controllers 136). The vapor delivery system 142 supplies the vaporized precursor to the manifold 140 or another manifold (not shown) that is connected to the processing chamber 102. The output of the manifold 140 is supplied to the processing chamber 102.
[0052] The temperature controller 150 can be connected to a plurality of thermal control elements (TCEs) 152 disposed on the heating plate 114. The temperature controller 150 can be used to control the plurality of TCEs 152 and control the temperature of the ESC 106 and the substrate 108. The temperature controller 150 can communicate with the coolant assembly 154 and control the flow of coolant through the channel 118. For example, the coolant assembly 154 can include a coolant pump, a reservoir, and one or more temperature sensors (not shown). The temperature controller 150 operates the coolant assembly 154 and selectively flows coolant through the channel 118 to cool the ESC 106. The valve 156 and the pump 158 can be used to discharge reactants from the processing chamber 102. The system controller 160 controls the components of the system 100.
[0053] Figure 2 shows a fixture 200 for aligning a pedestal according to the present disclosure with a showerhead. The fixture 200 includes an annular platform 202 on which a camera wafer (shown in FIG. 3) is placed. The annular platform 202 can also be referred to as an annular element, portion, or member of the fixture 200. The annular platform 202 is parallel to the plane of the camera wafer. The outer diameter (OD) of the annular platform 202 closely matches the OD of the camera wafer. The fixture 200 is manufactured such that the OD of the annular platform 202 conforms to the OD of the camera wafer. Thus, when the camera wafer is placed on the annular platform 202, the centers of the camera wafer and the annular platform 202 are automatically aligned.
[0054] The OD of the annular platform 202 (and thus the OD of the camera wafer) is constrained by a plurality of arcuate vertical elements of the fixture 200. For example, three vertical elements are shown as 204-1, 204-2, and 204-3 (collectively the vertical elements 204). The vertical elements 204 may also be referred to as the vertical portions or members of the fixture 200. Each vertical element 204 extends circumferentially around the OD of the annular platform 202. The vertical elements 204 are perpendicular to the plane of the annular platform 202 (and thus to the plane of the camera wafer). The vertical elements 204 are integrated with and extend from the annular platform 202. That is, the vertical elements 204 and the annular platform 202 are manufactured as a single piece and cannot be separated from each other.
[0055] The first (upper) portion of each vertical element 204 extends vertically above the annular platform 202 and constrains the camera wafer. The second (bottom) portion of each vertical element 204 extends vertically below the annular platform 202 and does not contact the upper surface of the pedestal. Rather, when the fixture 200 is placed on the upper surface of the pedestal, the bottom of the vertical element 204 and the annular platform 202 are lifted above the upper surface of the pedestal by a set of contact pads (described below).
[0056] The vertical elements 204 are not connected to each other to form a cylindrical shape surrounding the annular platform 202. Rather, in the example shown with three vertical elements 204, the arc length of each vertical element 204 is less than one-third of the OD of the annular platform 202. That is, the sum of the arc lengths of the vertical elements 204 is less than the OD of the annular platform 202. The centers of the arc lengths of the vertical elements 204 are at the vertices of an equilateral triangle. The centers of the arc lengths of the vertical elements 204, and the vertices of the equilateral triangle, are on a circle that is concentric with the center of the annular platform 202 (i.e., with the center of the fixture 200). Although three vertical elements are shown, N vertical elements may be used instead, where N is an integer greater than 2.
[0057] The fixture 200 further includes a plurality of arcuate horizontal elements 206-1, 206-2, and 206-3 (collectively referred to as horizontal elements 206, all three of which are seen in FIGS. 5 and 8) that extend radially outward from the OD of the annular platform 202. The horizontal elements 206 may also be referred to as the horizontal part or member of the fixture 200. The horizontal elements 206 are perpendicular to the vertical elements 204. The horizontal elements 206 are in a plane parallel to the plane of the annular platform 202 (and thus parallel to the plane of the camera wafer).
[0058] The plane in which the horizontal elements 206 are located is below the plane in which the annular platform 202 is located (and thus below the plane of the camera wafer). The plane in which the horizontal elements 206 are located is closer to the upper surface of the pedestal than the plane in which the annular platform 202 is located. The plane in which the horizontal elements 206 are located is also referred to as the reference plane in the following description. The bottom of the horizontal elements 206 and the bottom of the vertical elements 204 are on the same plane.
[0059] Similar to the vertical elements 204, the horizontal elements 206 are not connected to each other to form an annular shape surrounding the annular platform 202. Rather, the ends of each horizontal element 206 are connected to two vertical elements 204. Specifically, each horizontal element 206 is connected to different pairs of vertical elements 204. For example, the first and second ends of the horizontal element 206-1 are connected to the first ends of the vertical elements 204-1 and 204-2, respectively, the first and second ends of the horizontal element 206-2 are connected to the second end of the vertical element 204-2 and the first end of the vertical element 204-3, respectively, and the first and second ends of the horizontal element 206-3 are connected to the second ends of the vertical elements 204-3 and 204-1, respectively.
[0060] The center of the arc length of the horizontal element 206 is also at the vertex of the equilateral triangle. The center of the arc length of the horizontal element 206 and the vertex of the equilateral triangle are on a circle concentric with the center of the annular platform 202 (i.e., the center of the fixture 200). The number of horizontal elements 206 is the same as the number of vertical elements 204. The horizontal element 206 is also integrated with the vertical element 204 and extends from the vertical element 204. That is, the horizontal element 206, the vertical element 204, and the annular platform 202 are manufactured as a single part, the fixture 200, and cannot be separated from each other.
[0061] Each of the horizontal elements 206 includes contact pads (shown as 208-1, 208-2, and 208-3 and collectively referred to as contact pads 208) placed on a pedestal. The contact pads 208 are also arc-shaped like the horizontal elements 206 and are inserted into slots within the horizontal elements 206. The contact pads 208 are shown and described in more detail with reference to FIG. 10. The contact pads 208 can also be referred to as a support structure, member, or element of the fixture 200. As just one example, the contact pads 208 can be located at or near the first end of the horizontal element 206. Thus, the contact pads 208 are at the vertices of the equilateral triangle and are on a circle concentric with the center of the annular platform 202 (i.e., the center of the fixture 200).
[0062] Each of the horizontal elements 206 includes pins 210 used for alignment. The pins 210 are inserted into threaded slots within the horizontal elements 206. Each pin 210 includes an upper measurement surface (or head portion) 212, a thread 214, and a conical (or bottom) portion 216 for adjustment, as described in detail below. The pins 210 are shown in more detail in FIG. 11. The thread 214 engages with the threaded slots within the horizontal elements 206 and is small enough (e.g., 100 threads per inch) for fine adjustment during alignment.
[0063] The conical portion 216 is designed to engage with the OD (i.e., the perimeter, circumference, or circle) of the upper surface of the pedestal when the pin 210 is rotated and slide vertically along it. That is, the conical portion 216 is designed to slide vertically with respect to the plane of the annular platform 202 and the plane of the camera wafer. The conical portion 216 is designed to accommodate and adjust to pedestals with various ODs, as described below with reference to FIG. 12.
[0064] For example, the pin 210 can be located adjacent to the contact pad 208 on the horizontal element 206. The pin 210 is at the vertex of an equilateral triangle. Further, the location of the pin 210 is tightly controlled with respect to the center of the fixture 200, which is also the center of the camera wafer, due to the tight tolerances during the manufacture of the fixture 200. Specifically, the location of the pin 210 is on a circle concentric with the center of the fixture 200 (i.e., the center of the annular platform 202), which aids in the alignment procedure as described in detail below.
[0065] Each of the horizontal elements 206 includes a receptacle for mounting a level measurement device (or level indicator) 220. Each level indicator 220 measures or indicates the level of the corresponding horizontal element 206 with respect to the plane of the annular platform 202 (and thus with respect to the plane of the camera wafer). As just one example, the level indicator 220 can be located at or near the second end of the horizontal element 206. The level indicator 220 displays a base level (zero) on a reference plane that is the plane in which the horizontal element 206 lies. The level indicator 220 measures the height of the pin 210. When the heights of all three pins 210 are equal, the conical endpoints of the pins 210 define a concentric circle (i.e., above) with respect to the center of the fixture 200, which is also the center of the camera wafer and the center of the annular platform 202.
[0066] The locations of the shown contact pads 208, pins 210, and level indicators 220 are merely examples. These locations can be at locations other than those shown as long as the symmetry of the locations is maintained as described above. For example, the positions of the contact pads 208 and level indicators 220 on each horizontal element 206 can be switched (i.e., exchanged). Alternatively, the level indicators 220 can be positioned between the contact pads 208 and pins 210 on each horizontal element 206. Alternatively, the contact pads 208 can be positioned between the level indicators 220 and pins 210 on each horizontal element 206.
[0067] Note that the number of contact pads 208, pins 210, and level indicators 220 is the same as the number of horizontal elements 206. Throughout this disclosure, the quantities of three for the vertical and horizontal elements 204 and 206, and the contact pads 208, pins 210, and level indicators 220 are used merely as examples. The number of each of these items can be any number greater than or equal to three. For example, if four of each of these items are used, the symmetric arrangement of these items can be represented by a square instead of an equilateral triangle, and the vertices of the square are on a circle concentric with the center of the fixture 200.
[0068] Furthermore, although the arc length of the vertical element 204 is shown to be longer than the arc length of the horizontal element 206, the arc length of the vertical element 204 can be shorter than the arc length of the horizontal element 206. Alternatively, the arc length of the vertical element 204 can be equal to the arc length of the horizontal element 206.
[0069] The annular platform 202 is lifted by the second (bottom) portion of the vertical element 204, and since the plane in which the horizontal element 206 lies is below the plane of the annular platform 202, a notch (i.e., a gap, opening, passage, or window) exists between the annular platform 202 and the horizontal element 206. The notches are denoted as 222-1, 222-2, and 222-3 (collectively notches 222, all three notches 222 are seen in FIG. 5). The number of notches 222 is the same as the number of the horizontal element 206 and the vertical element 204. The notches 222 provide a ventilation path for the trapped air, good connectivity between the camera wafer used for alignment and the data acquisition device, and easy access to the camera wafer for placement and removal of the camera wafer.
[0070] The fixture 200 is made of metal as a single part comprising the annular platform 202 and the vertical and horizontal elements 204 and 206. The fixture 200 can also be made of a non-metallic material. The contact pads 208 of the fixture 200 are made of a non-metallic material and a non-abrasive material such as polyoxymethylene or polyether ketone (PEEK). The contact pads 208 are fastened (e.g., fixed with bolts) to the fixture 200 and sealed to avoid dimensional deviation. The pins 210 are made of a non-metallic material and a non-abrasive material such as polyoxymethylene or polyetherimide. The pins 210 are locked using set screws. These non-metallic materials and non-abrasive materials prevent scratches on the pedestal when the contact pads 208 and / or the pins 210 contact the upper surface of the pedestal.
[0071] The fixture 200 includes markings 230 with which the notches on the camera wafer are aligned. However, the camera wafer can be aligned with any other reference point on the fixture 200. The fixture 200 includes markings 232 for aligning the fixture 200 with the pedestal hole. The fixture 200 includes markings 234 for aligning the fixture 200 with the spindle orientation.
[0072] Figure 3 shows the camera wafer 300. On the first (upper) side facing the showerhead, the camera wafer 300 includes a camera 302 at the center of the camera wafer 300. On the second (bottom) side facing the pedestal, the camera wafer 300 includes a wireless transmitter (e.g., a Bluetooth device) as shown in FIG. 12 and electrical contacts 304 for charging the wireless transmitter and the camera 302. The fixture 200 is manufactured such that the OD of the annular platform 202 of the fixture 200 closely matches the OD 306 of the camera wafer 300.
[0073] Figure 4 shows the fixture 200 together with the camera wafer 300. As can be seen, the OD 306 of the camera wafer 300 closely matches the OD of the annular platform 202 of the fixture 200.
[0074] Figure 5 shows a view from the bottom of the fixture 200. This figure shows all three horizontal elements 206 and all three pins 210. For the sake of brevity, only one level indicator 220 is shown.
[0075] Figure 6 shows a part of the fixture 200 that exemplifies elements manufactured with tight tolerances. These elements include an annular platform 202 that defines the wafer plane and is perfectly horizontal. The OD 203 of the annular platform 202 closely matches the OD 306 of the camera wafer 300 (in order to place the camera wafer 300 at the center of the fixture 200). The upper surface 205 of the horizontal element 206 defines a reference plane and is perfectly horizontal and in a plane parallel to the plane of the annular platform 202 (i.e., the wafer plane). The upper surfaces 205 of all the horizontal elements 206 are perfectly horizontal and in the same plane (i.e., the reference plane) parallel to the plane of the annular platform 202 (i.e., the wafer plane). The set screw 250 is shown as just an example and is not essential. The fixture 200 operates as described regardless of the presence or absence of the set screw 250.
[0076] The upper surfaces of all the pins 210 are completely horizontal and lie in the same plane parallel to the plane of the annular platform 202. The threads 214 of the pins 210 are small enough for fine adjustment during the alignment procedure. The conical portion 216 is designed to correspond to and adjust to pedestals with various ODs. The pins 210 are substantially identical. Specifically, the lengths of the pins 210, the pitches of the threads 214, and the dimensions of the conical portions 216 are strictly controlled.
[0077] The dimensions of all elements of the fixture 200 are strictly controlled to provide accurate alignment between the fixture 200 and the camera wafer, between the fixture 200 and the pedestal, and between the fixture 200, the pedestal, and the shower head. The tightly controlled dimensions also ensure the reproducibility of the alignment procedure within the same chamber and between different chambers.
[0078] Figure 7 shows an additional view of the fixture 200. Figures 8 - 11 show the technical drawings of the fixture 200 that show the features of the fixture 200 in more detail. Figures 8 and 9 show additional views and details of the fixture 200. Figure 10 shows additional views and details of the contact pad 208. Figure 11 shows additional views and details of the pins 210.
[0079] In Figure 10, the contact pad 208 is shown in more detail. The contact pad 208 includes a first portion 1000, a second portion 1002, and a third portion 1004. The first, second, and third portions 1000, 1002, and 1004 may also be referred to as the first, second, and third elements or members of the contact pad 208. The first, second, and third portions 1000, 1002, and 1004 are manufactured as a single piece and cannot be separated from each other.
[0080] The contact pad 208 is arcuate, but the contact pad 208 has the general shape of the letter "T". The first portion 1000 forms the upper horizontal portion of the letter "T". The second and third portions 1002 and 1004 form the vertical portion of the letter "T". The arc length or arc width of the first portion 1000 is greater than the arc length or arc width of the second and third portions 1002 and 1004, thereby giving the T-shape to the contact pad 208. The third portion 1004 is shorter than the second portion 1002 which forms a stepped structure as described below.
[0081] The first portion 1000 is parallel to the plane in which the annular platform 202 and the horizontal element 206 are located (i.e., the wafer plane and the reference plane). The first portion 1000 includes one or more receptacles that receive fasteners that fasten the contact pads 208 to the respective horizontal elements 206. The second and third portions 1002 and 1004 extend vertically downward from the first portion 1000 in a direction away from the horizontal element 206 towards the pedestal. The second portion 1002 is longer than the third portion 1004. Thus, a stepped structure is formed between the distal ends of the second and third portions 1002 and 1004. Specifically, the stepped structure is formed by extending the distal end of the third portion 1004 towards the approximate center of the second portion 1002 and from there the remaining portion of the second portion 1002 descends from the distal end (and the stepped portion) of the third portion 1004 towards the pedestal.
[0082] The remaining portion of the second portion 1002 (i.e., from the stepped portion to the distal end of the second portion 1002) surrounds the OD of the pedestal, and the distal end of the third portion 1004 (i.e., the stepped portion) is placed on the pedestal. The length (or height) of the third portion 1004 is slightly greater than the length (or height) of the horizontal element 206. That is, the third portion 1004 extends slightly beyond the bottom of the horizontal element 206 (also, since the bottoms of the horizontal and vertical elements 206 and 204 are in the same plane, the bottom of the vertical element 204). In other words, the distal end of the third portion 1004 (i.e., the stepped portion) extends slightly beyond the bottom of the horizontal element 206. Thus, the contact pad 208 lifts the vertical and horizontal elements 204 and 206 above the upper surface of the pedestal.
[0083] Thus, the contact pad 208 prevents contact between the upper surface of the pedestal and the bottoms of the horizontal and vertical elements 206 and 204, and prevents scratches on the upper surface of the pedestal. The only elements of the fixture 200 that contact the upper surface of the pedestal are the distal end of the third portion 1004 of the contact pad 208 (i.e., the stepped portion) and the conical portion 216 of the pin 210.
[0084] Furthermore, the distance between the distal end of the second portion 1002 and the point where the distal end of the third portion 1004 merges with the second portion 1002 (i.e., where the step is formed) is greater than the portion of the pin 210 that protrudes below the horizontal element 206 (e.g., the conical portion 216). Thus, the pointed end of the conical portion 216 of the pin 210 is protected (damage is prevented) when the fixture 200 is placed on the contact pad 208 on any surface (i.e., when the distal end of the second portion 1002 of the contact pad 208 is placed), especially when the fixture 200 is not in use and is being stored.
[0085] FIG. 12 schematically shows a system 1200 comprising a fixture 200 and a computing device 1202 for aligning a pedestal 1204 with a showerhead 1206 within a processing chamber 1208. The fixture 200 uses a camera wafer 300 including a camera 302 to align the pedestal 1204 with the showerhead 1206 as described below. The camera wafer 300 includes a wireless transmitter (e.g., a Bluetooth device) 1210 that communicates with the camera 302 and the computing device 1202.
[0086] The computing device 1202 is external to the processing chamber 1208 and includes a wireless transmitter (e.g., a Bluetooth device). For example, the computing device 1202 can include a laptop computer, a tablet, or a smartphone. The computing device 1202 includes a database of images of various showerheads, such as the showerhead 1206, captured from the center of pedestals such as the pedestal 1204. These images serve as reference images during the alignment process.
[0087] The computing device 1202 runs an application that receives an image of the showerhead 1206 captured by the camera 302. The computing device 1202 compares the image with the reference images of the showerheads in the database and guides the alignment process as described below. The system 1200 includes a pedestal movement mechanism 1212 (e.g., one or more actuators) that can be used to move the pedestal 1204 during the alignment process as described below.
[0088] In use, the camera wafer 300 is placed on an annular platform 202 of the fixture 200. Due to the tight tolerances observed during the manufacture of the fixture 200, the OD of the camera wafer 300 and the annular platform 202 approximately match exactly. Thus, the center of the camera wafer 300 and the center of the annular platform 202, which is also the center of the fixture 200, are automatically aligned.
[0089] Next, the fixture 200 with the camera wafer 300 is placed on the pedestal 1204. The bottom of the contact pad 208 (specifically, the bottom or the stepped portion of the element 1004) is placed on the upper surface of the pedestal 1204. When the fixture 200 is manufactured, the contact pads 208 are fastened to their respective horizontal elements 206, and then the bottom of the contact pad 208 (specifically, the bottom or the stepped portion of the element 1004) is machined so that the bottom or the stepped portion of the element 1004 is on the same plane. The machining ensures that the horizontal elements 206 are in the same horizontal plane (reference plane) parallel to the plane passing through the bottom of the contact pad 208 (specifically, passing through the bottom of the element 1004 or through the stepped portion).
[0090] Therefore, the upper surface of the pedestal 1204, which is presumed to be horizontal (achieved using some other mechanism), is parallel to the plane in which the horizontal elements 206 are located (i.e., the reference plane) and the plane in which the camera wafer 300 is located (i.e., the wafer plane). In other words, the contact pads 208 ensure that when the fixture 200 including the camera wafer 300 is placed on the upper surface of the pedestal 1204, the upper surfaces of the fixture 200, the camera wafer 300, and the pedestal 1204 are parallel to each other.
[0091] The next task is to align the center of the fixture 200 (i.e., the center of the camera wafer 300) with the center of the pedestal 1204. To align the center of the fixture 200 with the center of the pedestal 1204, the pin 210 is adjusted as follows. The pin 210 is adjusted so that the upper surfaces of the fixture 200, the camera wafer 300, and the pedestal 1204 are concentric as follows. As described above with reference to FIG. 2, the location of the pin 210 on the horizontal element 206 of the fixture 200 is on a circle concentric with the center of the fixture 200 (and the center of the camera wafer 300). The conical portion 216 of the pin 210 is used to align the fixture 200 with pedestals having various ODs as follows. The amount of OD variation that the pin 210 can adjust is a function of the dimensions of the conical portion 216.
[0092] First, the level indicator 220 is installed on each horizontal element 206 of the fixture 200 and set to zero. Next, the level indicator 220 is moved and brought into contact with the upper surface 212 of each pin 210. The height of the pin 210 is adjusted by rotating the upper surface 212 of the pin 210 clockwise or counterclockwise until all the level indicators 220 display the same value (i.e., show the same display value). At this point, the tip of the conical portion 216 of the pin defines a circle that is concentric with the center of the fixture 200. That is, the center of the fixture 200 and the center of the camera wafer 300 are aligned with the center of the pedestal 1204. If an offset is desired between the center of the wafer and the center of the pedestal, the pin 210 is adjusted until the desired offset is achieved.
[0093] Next, the center of the pedestal 1204 is aligned with the center of the showerhead 1206 as follows. The process chamber 1208 is closed. The pedestal 1204 is optionally moved to the process position using the pedestal movement mechanism 1212. A vacuum is created inside the process chamber 1208. The camera 302 on the camera wafer 300 captures an image of the showerhead 1206. The wireless transmitter 1210 transmits the captured image of the showerhead 1206 to the computing device 1202.
[0094] Computing device 1202 compares the captured image with a reference image of the showerhead 1206 stored in the database. Based on the comparison, computing device 1202 determines whether the center of the showerhead 1206 in the captured image is aligned with the camera 302 and thus with the center of the pedestal 1204. If not so aligned, the pedestal movement mechanism 1212 is used to move the pedestal 1204, and another image of the showerhead 1206 is captured and sent to the computing device 1202. This process is repeated until alignment is achieved (i.e., until the captured image matches the reference image). At this point, the center of the pedestal 1204 is aligned with the center of the showerhead 1206 (e.g., with the hole at the center of the showerhead 1206). Thus, the center of the pedestal 1204, the center of the camera wafer 300, and the center of the showerhead 1206 are aligned.
[0095] Thus, the fixture 200 and the camera wafer 300 are used to first align the center of the fixture / wafer with the center of the pedestal and subsequently align the center of the pedestal with the center of the showerhead. The fixture 200 provides reproducibility within 0.005 inches. For example, when the fixture 200 is used and reused to align the pedestal with the showerhead within the same processing chamber, and when the fixture 200 is rotated, e.g., 180 degrees, for a subsequent use instance with respect to a previous use instance, the alignment results in the two instances differ by no more than 0.005 inches. Similar reproducibility is achieved between processing chambers (i.e., when the fixture 200 is used in different processing chambers).
[0096] FIG. 13 shows a method 1300 for aligning a pedestal with a shower head in a processing chamber using a fixture 200. At 1302, a camera wafer is placed within the fixture. At 1304, the fixture with the camera wafer is placed on the pedestal. At 1306, a level indicator is placed on the fixture. At 1308, the level indicator is reset to zero. At 1310, the level indicator is moved to contact the top of a pin on the fixture.
[0097] At 1312, method 1300 determines whether all level indicators show the same display value (i.e., whether the top surfaces of the pins are at the same level or in the same plane). At 1314, one or more pins are adjusted by rotating the head portion clockwise or counterclockwise until all level indicators display the same value. At 1316, after all level indicators display the same value (i.e., after all pins are at the same level), the center of the fixture and the center of the camera wafer are aligned with the center of the pedestal, and the processing chamber is closed. At 1318, the pedestal is optionally moved to a process position. At 1320, a vacuum is created within the processing chamber.
[0098] At 1322, a camera at the center of the camera wafer within the fixture captures an image of the shower head. At 1324, a wireless transmitter within the camera wafer transmits the captured image to a computing device external to the processing chamber. At 1326, the computing device compares the captured image with a reference image. At 1328, method 1300 determines whether the camera (i.e., the center of the pedestal) is aligned with the center of the shower head. Method 1300 ends when the camera (i.e., the center of the pedestal) is aligned with the center of the shower head. At 1330, if the camera (i.e., the center of the pedestal) is not aligned with the center of the shower head, the pedestal is moved and method 1300 returns to 1322.
[0099] The foregoing description is merely exemplary in nature and is not intended to limit in any way the disclosure, its application, or its use. The broad teachings of the disclosure can be implemented in a variety of forms. Thus, while the disclosure includes specific examples, other variations will be apparent upon consideration of the drawings, the specification, and the following claims, and the true scope of the disclosure should not be limited to such examples. It should be understood that one or more steps in a method may be performed in a different order (or simultaneously) without changing the principles of the disclosure.
[0100] Furthermore, while each embodiment has been described above as having certain features, any one or more of these features described with respect to any embodiment of the disclosure may be implemented in, and / or combined with, any other embodiment (even if such a combination is not explicitly described). In other words, the described embodiments are not mutually exclusive, and the interchange of one or more embodiments with each other is within the scope of the disclosure.
[0101] Spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers, etc.) are described using various terms such as "connected," "engaged," "coupled," "adjacent," "next to," "on," "above," "below," and "disposed." Also, when a relationship between a first element and a second element is described in the above disclosure, unless explicitly described as "direct," the relationship may be a direct relationship with no other intervening elements between the first and second elements, but there may also be an indirect relationship with one or more intervening elements (spatially or functionally) between the first and second elements.
[0102] As used herein, the expression "at least one of A, B, and C" should be construed in the sense of a logical (A or B or C) using non-exclusive logical OR, and should not be construed in the sense of "at least one of A, at least one of B, and at least one of C".
[0103] In some embodiments, the controller is part of a system, and such a system may be part of the examples described above. Such a system can comprise a semiconductor processing apparatus including one or more processing tools, one or more chambers, one or more processing platforms, and / or specific processing components (such as a wafer pedestal, a gas flow system, etc.). These systems may be integrated with electronics for controlling the operation of the system before, during, and after processing of a semiconductor wafer or substrate.
[0104] Such electronics may be referred to as a "controller" and may control various components or sub-components of one or more systems. The controller may be programmed to control any of the processes disclosed herein, depending on the processing requirements and / or the type of system. Such processes include feeding of processing gases, temperature setting (e.g., heating and / or cooling), pressure setting, vacuum setting, power setting, radio frequency (RF) generator setting, RF matching circuit setting, frequency setting, flow rate setting, fluid feeding setting, position and motion setting, loading and unloading of wafers to and from tools, and loading and unloading of wafers to and from other transfer tools and / or load locks connected or interfaced to a particular system.
[0105] In a broad sense, a controller may be defined as an electronic device having various integrated circuits, logic, memory, and / or software that receives commands, issues commands, controls operations, enables cleaning operations, enables endpoint measurements, etc. The integrated circuits may include a chip in the form of firmware that stores program instructions, a digital signal processor (DSP), a chip defined as an application-specific integrated circuit (ASIC), and / or one or more microprocessors, i.e., a microcontroller that executes program instructions (e.g., software).
[0106] Program instructions are instructions communicated to the controller in the form of various individual settings (or program files) that may define operating parameters for performing a specific process on or for a semiconductor wafer or for a system. The operating parameters may, in some embodiments, be part of a recipe defined by a process engineer to implement one or more processing steps in the fabrication of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or wafer dies.
[0107] In some embodiments, the controller may be part of a computer that is integrated or coupled with the system or otherwise network-connected to the system, or may be coupled to such a computer, or a combination thereof. For example, the controller may be within the "cloud" or may be all or part of a fab host computer system. This enables remote access to wafer processing. The computer may enable remote access to the system, monitor the current progress of fabrication operations, consider the history of past fabrication operations, consider trends or performance criteria from multiple fabrication operations, change the parameters of the current process, set the processing steps following the current process, or initiate a new process.
[0108] In some examples, a remote computer (e.g., a server) can provide a process recipe to the system through a network. Such a network may include a local network or the Internet. The remote computer may include a user interface that enables entry or programming of parameters and / or settings, and such parameters and / or settings are then communicated from the remote computer to the system. In some examples, the controller receives instructions in the form of data. Such data specifies parameters for each processing step to be performed during one or more operations. It should be understood that the parameters may be specific to the type of process being performed and the type of tool that the controller is configured to interact with or control.
[0109] Thus, as described above, the controller may be distributed, for example, by comprising one or more individual controllers that are network-connected to each other and cooperate towards a common purpose (such as the processes and controls described herein). Examples of distributed controllers for such purposes would include one or more integrated circuits on a chamber that are remotely located (e.g., at the platform level or as part of a remote computer) and communicate with one or more integrated circuits that are combined to control a process in the chamber.
[0110] Exemplary systems can include, but are not limited to, a plasma etching chamber or module, a deposition chamber or module, a spin rinse chamber or module, a metal plating chamber or module, a cleaning chamber or module, a bevel edge etching chamber or module, a physical vapor deposition (PVD) chamber or module, a chemical vapor deposition (CVD) chamber or module, an atomic layer deposition (ALD) chamber or module, an atomic layer etching (ALE) chamber or module, an ion implantation chamber or module, a tracking chamber or module, and any other semiconductor processing system that may be associated with or used in the fabrication and / or manufacture of semiconductor wafers.
[0111] As described above, depending on one or more process steps performed by a tool, the controller may communicate with one or more other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, proximate tools, tools located throughout the factory, a main computer, another controller, or a tool used for material transport to load and unload a wafer container to and from a tool location and / or load port within a semiconductor manufacturing facility.
Claims
1. An annular member disposed along a first plane, N first members extending perpendicularly from the outer diameter of the annular member with respect to the first plane, where N is an integer greater than 2, a first portion of each of the N first members extending above the first plane, and a second portion of each of the N first members extending below the first plane, N second members extending radially outward from the second portions of the N first members along a second plane parallel to the first plane, each of the N second members being between different pairs of the N first members, The apparatus comprising the above.
2. The apparatus according to claim 1, wherein the annular member, the N first members, and the N second members constitute a single structure.
3. The apparatus according to claim 1, wherein the annular member, the N first members, and the N second members are made of metal.
4. The apparatus according to claim 1 further comprises N third members made of a non-abrasive material, having equal lengths and extending downward from the N second members perpendicularly to the second plane.
5. The apparatus according to claim 4 further comprises N pins made of a non-abrasive material, having equal lengths and conical ends, extending downward from the N second members perpendicularly to the second plane, wherein the N pins are equidistant from the center of the annular member and include threads engageable with threaded slots in the N second members. The apparatus.
6. The apparatus according to claim 1 further comprises N third members made of a non-abrasive material, having equal lengths and disposed in respective slots in the N second members, each of the N third members being arcuate, a first element fastened to each of the N second members parallel to the second plane, a second element extending vertically downward from the first element below the second plane and below each of the N second members, and a third element extending vertically downward from the first element below the second plane and below each of the N second members, extending less than the second element. Including The apparatus.
7. The apparatus according to claim 6, wherein the first, second, and third elements constitute a single structure.
8. The apparatus according to claim 6, wherein the first element has an arc length longer than that of the second and third elements.
9. The apparatus according to claim 6, wherein the distal ends of the third elements of the N third members are in a plane parallel to the second plane.
10. The apparatus according to claim 6 further comprises N pins made of a non-abrasive material extending perpendicularly downward with respect to the second plane through respective threaded slots in the N second members having equal lengths and being at the same radial distance from the center of the annular member, each of the N pins has an upper part, a conical bottom, and a threaded part between the upper part and the bottom engageable with each of the threaded slots.
11. Placing the apparatus on the upper surface of a pedestal in a processing chamber, the apparatus comprising an annular member, N support members supporting the annular member in a plane parallel and above the upper surface of the pedestal, where N is an integer greater than 2, N pins arranged perpendicular to the plane along the circumference of the annular member, each of the N pins including a thread engageable with a respective threaded slot in the apparatus and facing the upper surface of the pedestal and including a conical end engageable with the periphery of the upper surface of the pedestal, aligning the center of the annular member with the center of the pedestal by adjusting one or more of the N pins .
12. The method according to claim 11 further comprises placing N level indicating devices in respective slots in the apparatus in contact with each of the N pins, aligning the center of the annular member with the center of the pedestal by adjusting one or more of the N pins until the N level indicating devices indicate the same level.
13. The method according to claim 11 further comprises placing a wafer concentrically on the annular member, the wafer including a camera centered on the wafer and oriented towards a showerhead disposed on the pedestal in the processing chamber, capturing one or more images of the showerhead using the camera, aligning the center of the pedestal with the center of the showerhead based on the one or more images.
14. The method according to claim 11 further comprises Place a wafer concentrically on the annular member, the wafer including a camera centered on the wafer and oriented towards a showerhead disposed on the pedestal within the processing chamber, the camera including a wireless transmitter that communicates with a computing device external to the processing chamber, Transmit the one or more images to the computing device using the wireless transmitter, Process the one or more images in the computing device, A method comprising aligning the center of the pedestal with the center of the showerhead based on the processing.
15. The method according to claim 11, Place a wafer concentrically on the annular member, the wafer including a camera centered on the wafer and oriented towards a showerhead disposed on the pedestal within the processing chamber, the camera including a wireless transmitter that communicates with a computing device external to the processing chamber, Close the processing chamber, Generate a vacuum within the processing chamber, Capture one or more images of the showerhead using the camera, Transmit the one or more images to the computing device using the wireless transmitter, Process the one or more images in the computing device, A method comprising moving the pedestal based on the processing until the center of the pedestal is aligned with the center of the showerhead.