Gap measurement from showerhead to base using a capacitive sensor board.

Abstract

A sensor disk configured to measure a gap between a first structure and a second structure in a process chamber of a substrate processing system comprises an upper surface, at least one first capacitive sensor arranged on the upper surface of the sensor disk and configured to generate a first measurement signal indicative of a first distance between the upper surface of the sensor disk and the first structure, a lower surface, and at least one second capacitive sensor arranged on the lower surface of the sensor disk and configured to generate a second measurement signal indicative of a second distance between the lower surface of the sensor disk and the second structure.

Description

Technical Field

[0001] Cross Reference to Related Application This application claims the benefit of U.S. Provisional Application No. 63 / 233,516, filed on August 16, 2021. The entire disclosure of the above application is incorporated herein by reference.

[0002] The present disclosure relates to a test substrate for a substrate processing system, and in particular to a test substrate including a capacitive sensor. Background Art

[0003] The background art described herein is for the purpose of generally presenting the content of the present disclosure. The invention of the presently named inventor, to the extent it is described in this background section and in aspects of the description that do not qualify as prior art at the time of filing, is not expressly or implicitly admitted as prior art to the present disclosure.

[0004] Substrate processing systems are used to perform processing such as deposition and etching of films on a substrate (e.g., a semiconductor wafer). For example, deposition may be performed to deposit conductive films, dielectric films, or other types of films using chemical vapor deposition (CVD), plasma enhanced CVD (PECVD), atomic layer deposition (ALD), plasma enhanced ALD (PEALD), and / or other deposition processes. During deposition, the substrate may be placed on a substrate support (e.g., a pedestal), and during one or more process steps, one or more precursor gases may be supplied to a processing chamber using a gas distribution device (e.g., a showerhead). In PECVD or PEALD processes, plasma is used to activate chemical reactions within the processing chamber during deposition. Summary of Invention

[0005] A sensor disk configured to measure the gap between a first structure and a second structure in the processing chamber of a substrate processing system comprises an upper surface and at least one first capacitive sensor disposed on the upper surface of the sensor disk and configured to generate a first measurement signal indicating a first distance between the upper surface of the sensor disk and the first structure, and a lower surface and at least one second capacitive sensor disposed on the lower surface of the sensor disk and configured to generate a second measurement signal indicating a second distance between the lower surface of the sensor disk and the second structure.

[0006] Other features include: at least one first capacitive sensor includes three capacitive sensors located on the upper surface of the sensor disk; at least one second capacitive sensor includes three capacitive sensors located on the lower surface of the sensor disk; at least one first capacitive sensor is configured to form a first capacitor together with a first structure and to generate a first measurement signal based on a first capacitance of the first capacitor; at least one second capacitive sensor is configured to form a second capacitor together with a second structure and to generate a second measurement signal based on a second capacitance of the second capacitor. The sensor disk further includes a concave region defined on its lower surface. The concave region extends from the outer edge of the sensor disk to the central region.

[0007] Other features include a sensor disk and a controller configured to receive a first measurement signal and a second measurement signal and calculate the gap width between a first structure and a second structure based on them. The controller is configured to calculate the gap width based on a first distance, a second distance, and the thickness of the sensor disk. The controller is further configured to calculate the gap width based on stored data that associates a first capacitance formed between at least one first capacitive sensor and the first structure with the first distance, and a second capacitance formed between at least one second capacitive sensor and the second structure with the second distance. The first structure is a shower head, and the second structure is a pedestal.

[0008] A system configured to measure the gap between a first structure and a second structure in the processing chamber of a substrate processing system comprises: at least one first capacitive sensor located on the upper surface of a sensor disk; at least one second capacitive sensor located on the lower surface of a sensor disk; and a controller configured to receive a first measurement signal from at least one first capacitive sensor indicating a first distance between the upper surface of the sensor disk and the first structure, and a second measurement signal from at least one second capacitive sensor indicating a second distance between the lower surface of the sensor disk and the second structure, and to calculate the width of the gap between the first structure and the second structure based on the first and second measurement signals.

[0009] In other features, the controller is configured to calculate the gap width based on a first distance, a second distance, and the thickness of the sensor disk. The controller is further configured to calculate the gap width based on stored data relating a first capacitance formed between at least one first capacitive sensor and a first structure to the first distance, and a second capacitance formed between at least one second capacitive sensor and a second structure to the second distance. The concave region is defined on the underside of the sensor disk and extends from the outer edge of the sensor disk to the central region. The system further includes a mechanical indexer including an end effector, and the concave region is configured to accept the end effector.

[0010] A method for measuring the gap between a first structure and a second structure in the processing chamber of a substrate processing system includes the steps of: placing a sensor disk in an end effector; installing the sensor disk in the gap between the first structure and the second structure; determining a first distance between the upper surface of the sensor disk and the first structure and a second distance between the lower surface of the sensor disk and the second structure using the sensor disk; and calculating the width of the gap between the first structure and the second structure based on the first and second distances.

[0011] In other features, the sensor disk includes at least one first capacitive sensor located on its upper surface and at least one second capacitive sensor located on its lower surface. The method further includes the steps of: generating a first measurement signal indicating a first distance between the upper surface of the sensor disk and a first structure using at least one first capacitive sensor; generating a second measurement signal indicating a second distance between the lower surface of the sensor disk and a second structure using at least one second capacitive sensor; and calculating the width of the gap between the first structure and the second structure based on the first measurement signal, the second measurement signal, and the thickness of the sensor disk.

[0012] In other features, the method further includes the steps of generating a first measurement signal based on a first capacitance formed between at least one first capacitive sensor and a first structure, and generating a second measurement signal based on a second capacitance formed between at least one second capacitive sensor and a second structure. The sensor disk includes a concave region defined on its underside, the concave region extending from the outer edge of the sensor disk to a central region, and the step of placing the sensor disk on an end effector includes placing the concave region of the sensor disk on the end effector. The step of installing the sensor disk includes placing the sensor disk at an intermediate point between the first structure and the second structure. The first structure is a shower head, and the second structure is a pedestal.

[0013] Further application areas of this disclosure will become apparent from the modes for carrying out the invention, the claims, and the drawings. The modes for carrying out the invention and specific examples are for illustrative purposes only and are not intended to limit the scope of this disclosure. [Brief explanation of the drawing]

[0014] This disclosure will be better understood from the embodiments for carrying out the invention and the accompanying drawings.

[0015] [Figure 1] A functional block diagram of an embodiment of the substrate processing system according to this disclosure.

[0016] [Figure 2A] An embodiment of a sensor disk according to the present disclosure.

[0017] [Figure 2B] An isometric view of the top surface of the sensor disk of FIG. 2A.

[0018] [Figure 2C] An isometric view of the bottom surface of the sensor disk of FIG. 2A.

[0019] [Figure 2D] Another embodiment of a sensor disk according to the present disclosure.

[0020] [Figure 3] An embodiment of a method for determining a distance between a showerhead and a pedestal using the sensor disk according to the present disclosure.

[0021] In the drawings, reference numerals may be repeated to identify similar and / or identical elements. DESCRIPTION OF EMBODIMENTS FOR CARRYING OUT THE INVENTION

[0022] A gap is defined between a lower surface of a gas distribution device (e.g., a showerhead) and an upper surface of a substrate support (e.g., a pedestal). Substrate processing parameters (e.g., deposition rate, plasma profile, etc.) may vary depending on the characteristics of the gap. Gap characteristics that may affect processing parameters include the gap width (i.e., the vertical distance between the showerhead and the substrate support) and horizontal variations in width (e.g., variations caused by a tilted showerhead or tilted substrate support surface).

[0023] Various methods may be used to measure the gap. The showerhead and the substrate may be adjusted based on the measurement values to achieve the desired gap width and orientation. For example, the tilt (i.e., level) and height of the showerhead, as well as the height of the substrate support, may be adjustable. In some embodiments, a sensor disk or a wafer may be placed on the substrate support. One or more capacitive sensors are arranged on the upper surface of the sensor disk (i.e., the surface of the sensor disk facing the showerhead).

[0024] The capacitive sensor is configured to measure the distance between the upper surface of the sensor disk and the showerhead. For example, as the distance changes, the capacitance detected by the capacitive sensor also changes. The capacitive sensor generates a measurement signal indicative of the capacitance and the corresponding distance, which can later be used to determine the gap width. The capacitive sensor may be calibrated according to a known distance (e.g., a known distance of a predetermined material). As the distance between the capacitive sensor and the showerhead increases, the accuracy of the measurement signal decreases. For example, the accuracy of the measurement signal may decrease as an exponential function of distance.

[0025] A sensor disk or substrate according to some embodiments of the present disclosure includes sensors such as capacitive sensors on both the upper surface (i.e., the surface facing the showerhead) and the lower surface (i.e., the surface facing the substrate support). The sensor disk is installed between an upper surface of a processing chamber or another structure (e.g., a gas distribution device such as a showerhead) and a substrate support (e.g., an end effector such as a spindle or a robot arm) without contacting either the showerhead or the substrate support. For example, the sensor disk may be positioned and suspended at a midpoint between the showerhead and the substrate support.

[0026] Accordingly, a sensor positioned on the upper surface of the sensor disk is configured to measure a first distance between the sensor disk and the shower head, and a capacitive sensor positioned on the lower surface of the sensor disk is configured to measure a second distance between the sensor disk and the substrate support. The sum of the first distance, the second distance, and the thickness of the sensor disk corresponds to the measured gap width between the shower head and the substrate support. At least one of the inclination (i.e., level) of the shower head, the height of the shower head, and the height of the substrate support can be adjusted based on the measured gap width.

[0027] Referring here to Figure 1, an example of a substrate processing system 100 according to the principles of the present disclosure is shown. The above example relates to a PECVD system, but other plasma substrate processing chambers may be used. The substrate processing system 100 comprises a processing chamber 104 surrounding the other components of the substrate processing system 100. The substrate processing system 100 comprises an upper electrode 108 and a substrate support such as a base 112 including a lower electrode 116. A substrate (not shown) is placed on the base 112 between the upper electrode 108 and the lower electrode 116 during processing. The following description relates to a single processing chamber 104 and base 112, but the principles of the present disclosure may be used in systems comprising multiple processing chambers, and processing chambers comprising multiple processing stations and bases (e.g., a quad-station module (QSM)).

[0028] For example, the upper electrode 108 may include a showerhead 124 for introducing and distributing process gas. Alternatively, the upper electrode 108 may include a conductive plate, and the process gas may be introduced by another means. In some examples, the lower electrode 116 may correspond to a conductive electrode embedded in a non-conductive base. Alternatively, the base 112 may include an electrostatic chuck containing a conductive plate that functions as the lower electrode 116.

[0029] The radio frequency (RF) generation system 126 generates an RF voltage and outputs it to the upper electrode 108 and / or the lower electrode 116 when plasma is used. In some examples, either the upper electrode 108 or the lower electrode 116 may be DC-grounded, AC-grounded, or at a floating potential. For illustrative purposes only, the RF generation system 126 may comprise one or more RF voltage generators 128, such as RF generator 128 (e.g., a capacitively coupled plasma RF power generator, a bias RF power generator, and / or other RF power generators), which generate the RF voltage. The RF voltage is supplied to the lower electrode 116 and / or the upper electrode 108 by one or more matched distribution networks 130. For example, as shown in the figure, the RF generator 128 provides the RF voltage and / or bias voltage to the lower electrode 116. The lower electrode 116 may receive power alternately or additionally from other power sources, such as power supply 132. In other examples, the RF voltage may be supplied to the upper electrode 108, or the upper electrode 108 may be connected to an earth reference.

[0030] An exemplary gas supply system 140 comprises one or more gas sources 144-1, 144-2, ..., and 144-N (collectively, gas source 144) (where N is an integer greater than zero). The gas sources 144 supply one or more gases (e.g., precursors, inert gases, etc.) and mixtures thereof. Vaporized precursors may be used. At least one of the gas sources 144 may contain a gas used in the pretreatment process of the present disclosure (e.g., NH3, N2, etc.). The gas sources 144 are connected to a manifold 154 by valves 148-1, 148-2, ..., and 148-N (collectively, valve 148), and mass flow controllers 152-1, 152-2, ..., and 152-N (collectively, mass flow controller 152). The output of the manifold 154 is supplied to the processing chamber 104. For example, the output of manifold 154 is supplied to showerhead 124. In some examples, an ozone generator 156 may be provided between the mass flow controller 152 and manifold 154 as needed. In some examples, the substrate processing system 100 may include a liquid precursor supply system 158. The liquid precursor supply system 158 may be integrated into the gas supply system 140 as shown in the figure, or it may be outside the gas supply system 140. The liquid precursor supply system 158 is configured to provide liquid and / or solid precursors at room temperature by means of a bubbler, direct liquid injection, vapor draw, etc.

[0031] The heater 160 may be connected to a heater coil 162 located on the base 112 to heat the base 112. The heater 160 may be used to control the temperature of the base 112 and the substrate.

[0032] Valves 164 and pumps 168 may be used to discharge reactants from the processing chamber 104. A controller 172 may be used to control various components of the substrate processing system 100. For example, the controller 172 may be used to control the flow of process gas, carrier gas, and precursor gas, plasma firing and extinction, reactant removal, and monitoring of chamber parameters. The controller 172 may receive measurement signals indicating process parameters, the state of the processing chamber 104, etc., via one or more sensors 174 located throughout the substrate processing system 100.

[0033] The controller 172 according to this disclosure is further configured to receive a measurement signal from a sensor disk 178 positioned between the shower head 124 and the base 112. For example, the sensor disk 178 is positioned in an end effector 182, which places the sensor disk 178 in the gap between the shower head 124 and the base 112. Capacitive sensors 186 are positioned on the opposing upper and lower surfaces of the sensor disk 178. The capacitive sensors generate a measurement signal based on the capacitive sensing distance between the sensor disk 178 and the shower head 124, and between the sensor disk 178 and the base 112, as will be described in more detail below. Although the distance between the shower head 124 and the base 112 has been described, the principle of this disclosure can also be applied to measuring the distance between the base 112 and the upper electrode, upper surface, etc., of the processing chamber 104.

[0034] Referring next to Figures 2A, 2B, and 2C, embodiments of a sensor disk 200 located between a shower head 204 and a base 208 according to the present disclosure are shown. For example, the sensor disk 200 is placed on an end effector 212 configured to install the sensor disk 200 on one or more processing stations 216. For example, the end effector 212 may be coupled to a spindle 220 of a mechanical indexer 224 configured to move the end effector 212 up and down and rotate the end effector 212 between two or more processing stations 216. The mechanical indexer 224 may correspond to a mechanical indexer configured to transport substrates between different processing stations within a processing chamber or process module (e.g., a multi-station module).

[0035] Sensors 228-1 and 228-2 (collectively referred to as sensors 228) are positioned on the upper surface 232 and lower surface 236 of the sensor disk 200, respectively. Each sensor 228 comprises a sensor electrode. For example, the sensor electrodes are made of a highly conductive material such as copper. In some embodiments, the sensor electrodes may include a non-conductive coating to prevent corrosion, oxidation, etc. Although each sensor 228 is shown to include three sensor electrodes, in other embodiments, a sensor 228 may include fewer or more sensor electrodes. The spacing of each sensor electrode and their respective sizes may also differ. For example, increasing the total area occupied by the sensor 228 (e.g., increasing the diameter of the sensor electrodes) may result in better sensitivity to detecting gaps and inclines.

[0036] Figure 2B shows an isometric view of the top surface 232, and Figure 2C shows an isometric view of the bottom surface 236. The sensor 228 is referred to herein as a capacitive sensor, but may be used in conjunction with other suitable types of proximity sensors (such as laser sensors and infrared sensors). The sensor 228 generates measurement signals 240 (e.g., one or more first measurement signals from sensor 228-1 and one or more second measurement signals from sensor 228-2) based on the capacitive sensing distance between the sensor disk 200 and the shower head 204 and between the sensor disk 200 and the base 208.

[0037] Although the three sensors 228 are shown arranged on both sides of the sensor disk 200, in other embodiments, fewer (e.g., one or two) or more (e.g., four or more) sensors 228 may be provided on both sides. For example, as the number of sensors 228 increases, the distance between the shower head 204 and the base 208, the tilt of the shower head 204, etc., can be determined with greater accuracy.

[0038] For example, the sensor disk 200 is installed in the gap G between the shower head 204 and the base 208. Sensor 228-1 is positioned to generate a measurement signal 240 based on the distance between the upper surface 232 of the sensor disk 200 and the shower head 204 (e.g., the width of the gap g1). In other words, sensor 228-1 is facing upwards. Conversely, sensor 228-2 is positioned to generate a measurement signal 240 based on the distance between the lower surface 236 and the base 208 (e.g., the width of the gap g2). In other words, sensor 228-2 is facing downwards.

[0039] Therefore, the width of the gap G corresponds to the sum of the widths of gaps g1 and g2 and the thickness t of the sensor disk 200 (including the thickness of sensors 228-1 and 228-2) (i.e., G = g1 + g2 + t). As shown in Figure 2A, sensors 228-1 and 228 protrude upward and downward from the sensor disk 200, respectively, but in some embodiments, sensors 228 may be embedded in the sensor disk 200 such that their surfaces are coplanar (i.e., flat) with the surface of the sensor disk 200. Therefore, in different embodiments, the thickness t may correspond to the distance between the upper surface 232 and the lower surface 236 of the sensor disk 200 (i.e., the thickness of the substrate of the sensor disk 200), the thickness of the sensor disk 200 including sensors 228-1 and 228-2, and so on.

[0040] Sensor 228 generates a measurement signal 240 based on capacitance that varies depending on the width of gaps g1 and g2. For example, each of the sensors 228 may be configured to generate a reference signal of known amplitude and frequency (e.g., an excitation signal having a sinusoidal waveform, a square wave waveform, etc.) to excite the sensor 228 (e.g., the lower plate or lower electrode of the sensor 228). As a result, a capacitor is formed between the sensor 228 and the respective surfaces of the shower head 204 and the base 208. The capacitance of the resulting capacitor is measured by each sensor 228 and indicates the distance between the capacitive sensor and the corresponding surface of the shower head 204 or base 208. That is, the capacitance of capacitive sensor 228-1 indicates the respective distance between capacitive sensor 228-1 and the corresponding part of the shower head 204. Conversely, the capacitance of capacitive sensor 228-2 indicates the respective distance between capacitive sensor 228-2 and the corresponding part of the base 208.

[0041] Therefore, the measurement signal 240 indicates the capacitance of the sensor 228, and then the distance between each sensor and the respective part of the shower head 204 or base 208. For example, the measurement signal 240 may include a digital or analog value of each capacitance. In one embodiment, the sensor 228 is configured to measure a variable resistance or variable reactance that indicates capacitance, determine the capacitance based on the measured resistance or reactance, and output a digital value indicating capacitance (as each of the measurement signals 240).

[0042] In some embodiments, the measurement signal 240 is provided to a communication interface, such as a wireless interface 244. The wireless interface 244 transmits the measurement signal 240 (i.e., the wireless signal 248 including a digital value indicating capacitance) to an external device outside the processing station 216, such as a controller 252. For example, the controller 252 corresponds to the controller 172 in Figure 1. In some embodiments, the wireless interface 244 may transmit the measurement signal 240 to the controller 252 in real time or near real time. In other embodiments, the sensor disk 200 may include a memory configured to store measurement data corresponding to the measurement signal 240, which may be read when the sensor disk 200 is removed from the processing station 216. In some embodiments, the wireless interface 244 may interact with the memory to transmit the measurement data in batches (for example, in a four-station room, the wireless interface 244 may wait until all four stations have been measured before transmitting the measurement data to the controller 252) or periodically (i.e., after a set time has elapsed). As shown in Figure 2B, the sensor disk 200 may include one or more batteries 256. The batteries 256 provide power to the sensor 228 and the wireless interface 244. Batch transmission or periodic transmission may reduce the power consumption of the wireless interface 244.

[0043] Therefore, the sensor disk 200 is configured to determine the width of the gap G without being handed over (i.e., installed) on the base 208. Furthermore, the sensor disk 200 can remain on the end effector 212, reducing the time required to measure the gap and reducing the generation of particles associated with the handover between the end effector 212 and the base 208, while being passed through multiple processing stations to measure each gap.

[0044] Furthermore, since the sensor disc 200 remains on the end effector 212, the required clearance between the sensor disc 200, the shower head 204, and the base 208 may be reduced. In other words, since the end effector 212 does not place the sensor disc 200 on the base 208, the end effector 212 does not need to be lowered and removed from the processing station 216 during measurement. Accordingly, the thickness of the sensor disc 200, including the sensor 228, can be increased (e.g., to 10 mm or more) to reduce the distance between the sensor 228 and the surfaces of the shower head 204 and the base 208.

[0045] For example, for a gap G of approximately 17.0 mm (e.g., within 10%) and a sensor disk 200 thickness t of approximately 11.0 mm (e.g., within 10%), each of the gaps g1 and g2 may be reduced to approximately 3.0 mm (e.g., within 10%). Therefore, the thickness t of the sensor disk 200 may be at least 60% (e.g., 60% to 70%) of the width of the gap G for gaps G less than 20.0 mm. As the width of the gap G increases, the thickness t of the sensor disk 200 may be increased to maintain relatively small gaps g1 and g2 (e.g., less than 5.0 mm, 3 mm or less). The accuracy of the sensor 228 (i.e., the accuracy of the relationship between capacitance and distance) is inversely proportional to the distance and increases exponentially as the distance decreases. Therefore, increasing the thickness t improves the accuracy of the measurement signal 240.

[0046] In some embodiments, the bottom surface 236 is flat (e.g., planar) and is supported by the end effector 212. In other embodiments, as shown in Figure 2C, the bottom surface 236 includes a recessed region or socket 260 configured to receive the end effector 212. That is, the shape of the recessed region 260 is configured to accommodate the end effector 212 so that the end effector 212 is embedded inside the bottom surface 236 of the sensor disk 200. For example, the recessed region 260 extends from the outer edge of the sensor disk 200 to the central region. When the sensor disk 200 is supported by the end effector 212, the bottom surface 264 of the end effector 212 may be flat (i.e., coplanar) with the bottom surface 236 of the sensor disk 200 (as shown in the figure), or may be slightly (e.g., 0 to 1.5 mm) above or below the bottom surface 236. In this way, the end effector 212 makes it easier to install the sensor disk 200 at the midpoint between the shower head 204 and the base 208 so that the gaps g1 and g2 are approximately the same (for example, within 5% of each other), regardless of the thickness t of the sensor disk 200.

[0047] In some embodiments, the base 208 (or the top surface of the base 208) may be made of a nonmetal, such as ceramic. Thus, the top surface of the base 208 does not have to be configured to form a capacitor with the sensor 228-2. In these embodiments, a metal plate, ring, or other structure (e.g., a metal disk 268 shown in Figure 2A) may be placed on the base 208 as necessary to provide a metal surface that the sensor 228-2 can detect. For example, the metal disk 268 contains the same material as the showerhead 204 such that equal distances correspond to substantially equal capacitance. Calculating the gap g2 may involve obtaining (e.g., adding) a known thickness of the metal disk 268. In other embodiments, the metal disk 268 may be placed on the base 208 to reduce the gap g2 and improve the accuracy of capacitance sensing.

[0048] In another embodiment shown in Figure 2D, the sensor disk 200 includes an upper disk 200-1 and a lower disk 200-2 (collectively referred to as the sensor disk 200). Sensor 228-1 is positioned on or inside the upper surface of the upper disk 200-1. Conversely, sensor 228-2 is positioned on or inside the lower surface of the lower disk 200-2. The upper disk 200-1 and the lower disk 200-2 are coupled to each other (for example, using a number of support columns 272) to define a gap 276. An end effector 212 is inserted into the gap 276 to remove, support, and transport the sensor disk 200. In this way, the sensor disk 200 can be configured to minimize gaps g1 and g2. For example, the thicknesses of the upper disk 200-1 and the lower disk 200-2 may be increased to reduce gaps g1 and g2.

[0049] Although it has been stated above that the sensor disk 200 includes sensors 228 on both its top and bottom surfaces, in another embodiment the sensor disk 200 may include sensors on only one side (e.g., either the top or bottom surface). In this embodiment the sensor disk 200 may first be placed on the end effector 212 in a first orientation (i.e., with the sensors 228 facing a first direction, such as upward toward the shower head 204) to measure a first gap g1. The sensor disk 200 may then be placed in a second orientation (i.e., inverted) with the sensors 228 facing the opposite second direction (i.e., downward toward the base 208) to measure a second gap g2.

[0050] Figure 3 shows an embodiment of method 300 according to the present disclosure, which uses a sensor disk (e.g., sensor disk 200) to determine the distance between a first structure (e.g., a shower head such as shower head 204, the upper surface of a processing chamber, etc.) and a second structure (e.g., a base such as base 208, the lower surface of a processing chamber, etc.). Method 300 (e.g., controller 252) performs a calibration process in 302 to generate and store calibration data relating the measured capacitance to the distance between the sensor 228 and each surface. For example, the calibration process may be performed in a processing station including a shower head and base, which are made of the same material as the shower head 204 and base 208, etc., and are arranged at a known distance. In this way, method 300 stores data relating the measured capacitance determined by the sensor 228 to the actual distance between the sensor 228 and each surface of the shower head and base.

[0051] In 304, the sensor disk 200 is transported to a mechanical indexer 224 (for example, on the end effector 212). For example, the sensor disk 200 is handed over from a transport robot to the end effector 212 at the loading station of a multi-station process module. In 308, the end effector 212 places the sensor disk 200 between a showerhead and a base in the first processing station. In some embodiments, the first processing station is the loading station. In other embodiments, the mechanical indexer 224 rotates to place the sensor disk 200 in a processing station different from the loading station.

[0052] In 312, Method 300 (e.g., a mechanical indexer 224 for the controller 252) places the sensor disk 200 at a predetermined position between the showerhead and the loading station. For example, the predetermined position is the midpoint (i.e., the intermediate position) between the showerhead and the loading station. For example, the mechanical indexer 224 is configured to adjust the vertical position of the sensor disk 200 by moving the end effector 212 up and down. Method 300 (e.g., the controller 252) determines the intermediate point based on the relative capacitance of sensors 228-1 and 228-2 at different vertical positions.

[0053] In one embodiment, a mechanical indexer 224 adjusts the sensor disk 200 through different positions (e.g., from the lowest position to the highest position, or vice versa) to measure the capacitances of sensors 228-1 and 228-2 at the different positions. At the lowest position, the capacitance of sensor 228-2 will be large (indicating a relatively small distance to the base), and the capacitance of sensor 228-1 will be small (indicating a relatively large distance to the showerhead). Conversely, at the highest position, the capacitance of sensor 228-2 will be small (indicating a relatively large distance to the base), and the capacitance of sensor 228-1 will be large (indicating a relatively small distance to the showerhead).

[0054] At each position, Method 300 determines the difference between the capacitance of sensor 228-1 (e.g., the average capacitance of two or more sensors 228-1) and the capacitance of sensor 228-2 (e.g., the average capacitance of two or more sensors 228-2). The position corresponding to the minimum difference between the capacitance of sensor 228-1 and the capacitance of sensor 228-2 corresponds to the midpoint between the showerhead and the base (e.g., assuming the surface materials of the showerhead and the base are the same). That is, when sensor disk 200 is located at the midpoint, the distance between both sides of sensor disk 200 and the respective surfaces of the showerhead and the base is the same, so Method 300 may assume that the capacitances measured by sensors 228-1 and 228-2 will also be substantially the same.

[0055] In 316, method 300 measures the capacitance of each of sensors 228-1 and 228-2 (for example, with the sensor disk 200 in a predetermined position such as an intermediate position). For example, as described above, sensor 228 generates a measurement signal 240 indicating the measured capacitance, and the measurement signal 240 is transmitted to controller 252 as a digital value. In 320, method 300 (for example, controller 252) calculates the distance between each part of the shower head and base (for example, the width of the gap G) based on the capacitance. For example, controller 252 calculates the distance based on the measured capacitance and stored calibration data that associates capacitance with distance for each sensor 228. Controller 252 may store the calculated distance for reading, display, etc.

[0056] As described above, even if method 300 determines the distance with the sensor disk 200 in an intermediate position, in other embodiments, the capacitance and distance may be determined without determining an intermediate position, with the sensor disk 200 in a position other than the intermediate position. For example, a mechanical indexer 224 may maintain the same nominal or calibration position during the process and rotate the sensor disk 200 through multiple processing stations to measure the distance between each showerhead and base without adjusting the vertical position of the sensor disk 200.

[0057] In 322, the showerheads and / or bases of one or more processing stations may be adjusted as necessary based on a measured gap G. The measured gap G may indicate that the showerhead is tilted, or that the distance between the showerhead and the base is greater than or less than a desired distance. In some embodiments, the adjustment is performed manually (e.g., by accessing the inside of the process module during supply). In other embodiments, the adjustment may be performed automatically by raising or lowering either or both of the showerheads and / or bases using their respective actuators relative to the controller 252. The adjustment may be repeated until the measured gap corresponds to a desired gap. For example, in method 300, steps 316, 320, and 322 may be repeated until a desired gap is achieved.

[0058] In 324, method 300 determines whether to measure the gap G of another processing station. If true, method 300 proceeds to 328. If false, method 300 proceeds to 332. In 328, method 300 (e.g., mechanical indexer 224) rotates the end effector 212 to place the sensor disk 200 at another processing station, and proceeds to 312.

[0059] In step 332, the sensor disk 200 is removed from the mechanical indexer 224. For example, the sensor disk 200 is returned to the loading station and removed using a transport robot. The sensor disk 200 may be stored in a substrate processing system (e.g., a buffer station in a vacuum transport module or front-end module), removed from the substrate processing system, and transported to another multi-station module. One or more steps of method 300 may be omitted or rearranged while still achieving the objective of determining the distance between the shower head (e.g., shower head 204) and the base (e.g., base 208). For example, the calibration step (302) may be omitted.

[0060] The foregoing description is essentially illustrative and is not intended to limit the Disclosure, its application, or its use. The broad teachings of this Disclosure can be implemented in various forms. Thus, although this Disclosure includes certain examples, the true scope of this Disclosure should not be so limited, as other variations become apparent when considering the drawings, specification, and the claims below. It should be understood that one or more steps within a Method may be performed in a different order (or simultaneously) without altering the principles of this Disclosure. Furthermore, although each embodiment is described above as having certain features, any one or more of those features described in relation to the embodiments of this Disclosure can be implemented in other embodiments and / or in combination with features of other embodiments (even if such combination is not specified). In other words, the embodiments described are not mutually exclusive, and rearrangements of one or more embodiments remain within the scope of this Disclosure.

[0061] The spatial and functional relationships between elements (e.g., between modules, between circuit elements, between semiconductor layers, etc.) are described using a variety of terms, including “connected,” “mating,” “joined,” “adjacent,” “proximity,” “above,” “upward,” “downward,” and “positioned.” When a relationship between a first element and a second element is described in the above disclosure, unless it is explicitly stated to be “direct,” the relationship may be a direct relationship in which no other intervening elements exist between the first and second elements, but at the same time, it may be an indirect relationship in which one or more intervening elements (spatially or functionally) exist between the first and second elements. The expression “at least one of A, B, and C” as used herein should be interpreted as meaning the logic using the non-exclusive logic OR (A OR B OR C), and not as “at least one of A, at least one of B, and at least one of C.”

[0062] In some embodiments, the controller is part of a system which may be part of the examples described above. Such a system may include a semiconductor processing apparatus comprising a processing tool, a chamber, a processing platform, and / or specific processing components (such as a wafer pedestal, a gas flow system, etc.). These systems may be integrated with electronic equipment for controlling pre-processing, processing, and post-processing operations of semiconductor wafers or substrates. These electronic equipment may be referred to as “controllers” and may control various components or sub-components of the system. Depending on the processing requirements and / or the type of system, the controller may be programmed to control any of the processes disclosed herein, including the supply of processing gases, temperature settings (e.g., heating and / or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow rate settings, fluid supply settings, position operation settings, wafer loading and unloading to and from tools and other transport tools, and / or wafer loading and unloading to and from load locks connected to or coupled to a particular system.

[0063] Generally, a controller may be defined as an electronic device having various integrated circuits, logic, memory, and / or software that receive and issue instructions, control operations, enable cleaning operations, enable endpoint measurements, etc. An integrated circuit may include a firmware-type chip that stores program instructions, a chip defined as a digital signal processor (DSP), an application-specific integrated circuit (ASIC), and / or one or more microprocessors or microcontrollers that execute program instructions (e.g., software). Program instructions may be instructions that are communicated to the controller in the form of various individual settings (or program files) that define operating parameters for performing a particular process on or for a semiconductor wafer, or for a system. In some embodiments, the operating parameters may be part of a recipe defined by a process engineer to realize one or more processing steps in the manufacturing of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or wafer molds.

[0064] In some embodiments, the controller may be part of a computer integrated with or connected to the system, or otherwise networked to the system, or a combination thereof, or connected to such a computer. For example, the controller may reside in a “cloud” enabling remote access to wafer processing, or may be all or part of a fab host computer system. The computer may enable remote access to the system to monitor the progress of manufacturing operations, investigate the history of past manufacturing operations, investigate trends or performance criteria from multiple manufacturing operations, modify parameters of the current operation, set up subsequent processing steps for the current operation, or start a new process. In some examples, a remote computer (e.g., a server) may provide process recipes to the system via a network that may include a local network or the internet. The remote computer may include a user interface that enables the entry or programming of parameters and / or settings that are then transmitted from the remote computer to the system. In some examples, the controller receives instructions in a data format that specify the parameters of each processing step 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 configured to be connected to or controlled by the controller. Therefore, as described above, the controllers may be distributed by, for example, including one or more separate controllers that are networked together and by cooperating toward a common purpose such as the processes and controls described herein. An example of controllers distributed toward such a purpose would be one or more integrated circuits in a chamber that are located remotely (for example, at the platform level or as part of a remote computer) and communicate with one or more integrated circuits that cooperate to control the processes in the chamber.

[0065] Exemplary systems, though not limited to them, may include plasma etching chambers or modules, deposition chambers or modules, spin rinse chambers or modules, metal plating chambers or modules, cleaning chambers or modules, bevel edge etching chambers or modules, physical vapor deposition (PVD) chambers or modules, chemical vapor deposition (CVD) chambers or modules, atomic layer deposition (ALD) chambers or modules, atomic layer etching (ALE) chambers or modules, ion implantation chambers or modules, track chambers or modules, and any other semiconductor processing systems that may be used in connection with or in use in the fabrication and / or manufacture of semiconductor wafers.

[0066] As described above, depending on the processing steps performed by the tool, the controller may communicate with one or more of the following: other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, nearby tools, tools installed throughout the factory, a main computer, another controller, or tools used for material handling to load and unload wafer containers to and from tool locations and / or load ports in a semiconductor manufacturing plant.

Claims

1. A sensor disk configured to measure the gap between a first structure and a second structure in the processing chamber of a substrate processing system, Top surface and, At least one first capacitive sensor disposed on the upper surface of the sensor disk, configured to generate a first measurement signal indicating a first distance between the upper surface of the sensor disk and the first structure, The bottom and, At least one second capacitive sensor disposed on the lower surface of the sensor disk, configured to generate a second measurement signal indicating a second distance between the lower surface of the sensor disk and the second structure, A sensor disk equipped with this feature.

2. A sensor disk according to claim 1, The at least one first capacitive sensor is a sensor disk comprising three capacitive sensors disposed on the upper surface of the sensor disk.

3. A sensor disk according to claim 1, The sensor disk comprises three capacitive sensors disposed on the lower surface of the sensor disk, wherein the at least one second capacitive sensor is a sensor disk.

4. A sensor disk according to claim 1, The at least one first capacitive sensor is a sensor disk configured to (i) form a first capacitor having the first structure and (ii) generate a first measurement signal based on the first capacitance of the first capacitor.

5. A sensor disk according to claim 4, The at least one second capacitive sensor is a sensor disk configured to (i) form a second capacitor having the second structure, and (ii) generate the second measurement signal based on the second capacitance of the second capacitor.

6. A sensor disk according to claim 1, further, The lower surface of the sensor disk is provided with a defined concave region, The aforementioned concave region is a sensor disk that extends from the outer edge of the sensor disk to the central region.

7. A system comprising the sensor disk according to claim 1, further, It is a controller, (i) Receiving the first measurement signal and the second measurement signal, (ii) Based on the first measurement signal and the second measurement signal, calculate the width of the gap between the first structure and the second structure. A system equipped with a controller configured in such a way.

8. The system according to claim 7, The controller is configured to calculate the width of the gap based on the first distance, the second distance, and the thickness of the sensor disk.

9. The system according to claim 8, The controller is configured to calculate the width of the gap based on stored data, further relating (i) a first capacitance formed between the at least one first capacitive sensor and the first structure to the first distance, and (ii) a second capacitance formed between the at least one second capacitive sensor and the second structure to the second distance.

10. A sensor disk according to claim 1, A sensor disk in which the first structure is a shower head and the second structure is a base.

11. A system configured to measure the gap between a first structure and a second structure in the processing chamber of a substrate processing system, It is a sensor disk, At least one first capacitive sensor disposed on the upper surface of the sensor disk, A sensor disk including at least one second capacitive sensor disposed on the lower surface of the sensor disk, It is a controller, A first measurement signal indicating a first distance between the upper surface of the sensor disk and the first structure is received from at least one first capacitive sensor. A second measurement signal indicating a second distance between the lower surface of the sensor disk and the second structure is received from at least one of the second capacitive sensors. A controller configured to calculate the width of the gap between the first structure and the second structure based on the first measurement signal and the second measurement signal, A system that includes these features.

12. The system according to claim 11, The controller is configured to calculate the width of the gap based on the first distance, the second distance, and the thickness of the sensor disk.

13. The system according to claim 12, The controller is configured to calculate the width of the gap based on stored data, further relating (i) a first capacitance formed between the at least one first capacitive sensor and the first structure to the first distance, and (ii) a second capacitance formed between the at least one second capacitive sensor and the second structure to the second distance.

14. The system according to claim 11, A system in which a concave region is defined on the lower surface of the sensor disk and extends from the outer edge of the sensor disk to the central region.

15. The system according to claim 14, further, A system comprising a mechanical indexer including an end effector, wherein the concave region is configured to receive the end effector.

16. A method for measuring the gap between a first structure and a second structure in the processing chamber of a substrate processing system, The process of placing the sensor disk on the end effector, A step of installing the sensor disk in the gap between the first structure and the second structure, A step of determining (i) a first distance between the upper surface of the sensor disk and the first structure, and (ii) a second distance between the lower surface of the sensor disk and the second structure, using the sensor disk. A step of calculating the width of the gap between the first structure and the second structure based on the first distance and the second distance, Methods that include...

17. The method according to claim 16, The method wherein the sensor disk includes at least one first capacitive sensor disposed on the upper surface of the sensor disk and at least one second capacitive sensor disposed on the lower surface of the sensor disk.

18. The method according to claim 17, further, A step of generating a first measurement signal indicating the first distance between the upper surface of the sensor disk and the first structure using at least one first capacitive sensor, A step of generating a second measurement signal indicating the second distance between the lower surface of the sensor disk and the second structure using at least one second capacitive sensor, A step of calculating the width of the gap between the first structure and the second structure based on the first measurement signal, the second measurement signal, and the thickness of the sensor disk, Methods that include...

19. The method according to claim 18, further, A step of generating the first measurement signal based on the first capacitance formed between the at least one first capacitive sensor and the first structure, A step of generating the second measurement signal based on the second capacitance formed between the at least one second capacitive sensor and the second structure, Methods that include...

20. The method according to claim 16, A method comprising the steps of positioning the sensor disk on an end effector, wherein the sensor disk includes a concave region defined on the lower surface of the sensor disk, the concave region extending from the outer end of the sensor disk to a central region, and the steps of positioning the sensor disk on an end effector include positioning the concave region of the sensor disk on the end effector.

21. The method according to claim 16, The step of installing the sensor disk includes installing the sensor disk at an intermediate point between the first structure and the second structure.

22. The method according to claim 16, A method wherein the first structure is a shower head and the second structure is a base.

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