A system and method for non-contact temperature measurement

Abstract

The application provides a system for non-contact temperature measurement, comprising a transfer robot; at least one measurement wafer, the measurement wafer comprising: a wafer-shaped substrate, a first temperature sensor arranged on the substrate, at least one optical temperature sensor, a battery and a processor coupled to a wireless communication unit; and a system control unit configured to perform a non-contact temperature measurement operation; in the working state, the transfer robot positions the measurement wafer at a predetermined distance from a heated surface to perform non-contact temperature measurement on the heated surface. The corresponding measurement method is also provided. The application can quickly, repeatedly and accurately measure the high-temperature surface in the semiconductor process cavity, which can realize the adaptation to the high-temperature environment of the cavity under the condition of accurate temperature measurement, the service life of the measurement wafer can be significantly improved, and the adapted cavity temperature range is also significantly improved.

Description

Technical Field

[0001] This invention belongs to the field of instrumentation, specifically to the field of measuring instruments, especially temperature measurement in high-precision manufacturing processes, and more specifically to non-contact temperature measurement, particularly a measurement system and method for non-contact in-situ high-temperature monitoring in semiconductor processing equipment. Background Technology

[0002] Semiconductor manufacturing involves numerous high-temperature processes, such as material deposition, plasma etching, and thermal annealing. Precise temperature control is crucial for achieving high-quality manufacturing results in terms of repeatability, yield, and wafer-to-wafer uniformity. Therefore, temperature monitoring is essential for achieving temperature control. In semiconductor manufacturing, the process temperature in environments such as cavities directly affects factors such as film thickness, material composition, internal stress, critical pattern dimensions, and etching rates. Even minute temperature changes of just a few degrees Celsius, or even less than 1 degree Celsius, can lead to significant drifts in device performance and yield. Furthermore, these high-temperature processes are typically performed in vacuum or low-pressure environments, and in controlled process gases, making direct temperature measurement challenging. From an optimized perspective, temperature measurements in environments such as cavities must be performed without disrupting the vacuum environment or interfering with process conditions; that is, in-situ temperature measurement.

[0003] Traditionally, substrate temperature is estimated using thermocouples embedded within wafer support structures, such as pedestals or electrostatic chucks. The temperature of these wafer support structures is typically calibrated during process equipment installation or periodic maintenance. However, this method does not accurately represent the true temperature of the wafer being processed because the measured temperature depends on the cavity's thermal history and the thermal coupling between the wafer and the chuck. Furthermore, this temperature correlation can drift over time due to factors such as cavity contamination, hardware aging, or process variations. Additionally, it is difficult to deploy dense arrays of embedded sensors to measure the temperature distribution on the wafer without compromising plasma characteristics and process uniformity.

[0004] Some traditional in-situ wafer temperature monitoring techniques rely on optical tube systems integrated within the wafer support structure. For example, US Patent 7,560,007 describes a system in which a temperature-sensitive fluorescent material is disposed on the back side of a sensing substrate, an optical fiber embedded in an electrostatic chuck transmits excitation light to the fluorescent material, and the emitted fluorescence is collected by the optical tube to determine the substrate temperature. While such methods enable in-situ thermal characterization, they require precise optical alignment within the electrostatic chuck and permanent integration of the optical fiber. These technical requirements make it difficult to map the temperature distribution of the wafer supported on the substrate, and their deployment is limited to equipment specifically configured with such optical fibers.

[0005] Some existing technologies employ calibration wafers with thermocouples to directly measure wafer temperature. For example, US Patent 5,746,513 describes a wafer-shaped temperature calibration device in which a thermocouple is placed in a cavity formed within the wafer, and the cavity is filled with a thermally conductive medium to improve thermal coupling between the wafer and the thermocouple. While such thermocouple-based wafers can provide direct temperature readings, they typically require the integration of electronic circuitry, processors, memory, and batteries. These electronic components have inherent temperature limitations that prevent reliable operation and shorten their lifespan. The typical maximum operating temperature of this type of temperature sensing element is approximately 150°C, thus limiting the applicability of these devices in relatively low-temperature processes.

[0006] To extend the operating temperature range of wafer-like temperature calibration equipment, existing technologies have proposed several solutions, with the general idea being to enable electronic components to operate for a limited time during high-temperature measurements. However, due to the relatively fixed wafer area and size, coupled with limitations imposed by electronic circuitry requirements, heat transfer from the wafer to the electronic components enclosed within it remains relatively rapid. This results in a limited maximum sustainable operating temperature for these wafer-like temperature calibration devices in existing technologies, typically below approximately 400°C.

[0007] Given the aforementioned limitations, further improvements are still needed in the field to enable precise in-situ wafer-level temperature monitoring within semiconductor process cavities, with an operating environment temperature range exceeding 400°C, while maintaining compatibility with existing equipment configurations and without adversely affecting process uniformity. Summary of the Invention

[0008] To address the technical deficiencies of existing technologies, the purpose of this invention is to provide a non-contact temperature measurement system capable of rapidly and accurately measuring the in-situ temperature of high-temperature heated surfaces within a semiconductor manufacturing cavity without requiring hardware modifications to the cavity or interrupting vacuum integrity during the manufacturing process. This system integrates a transfer robot, a measurement wafer, and a system control unit, which is configured to coordinate positioning, measurement, and data acquisition operations.

[0009] According to one aspect of the invention, the measurement wafer provided by the invention includes a wafer-shaped substrate, the wafer-shaped substrate including a first temperature sensor, and at least an optical temperature sensor (e.g., a thermopile array, a thin infrared sensor, or a pyrometer), a battery, a processor, and a wireless communication unit. The system control unit commands a transfer robot to position the measurement wafer at a predetermined distance from a heated surface (e.g., a wafer handling device, a wafer chuck (electrostatic chuck), or a spray head), and maintain the measurement wafer at that position for a non-contact temperature measurement interval. During this interval, the processor on the measurement wafer uses the optical sensor to acquire temperature data and stores the data locally or wirelessly transmits it to the system control unit. The robot then removes the measurement wafer from the cavity within a predetermined time period to avoid excessive heat exposure.

[0010] Preferably, the wireless communication unit can be disposed on the wafer substrate or outside the wafer substrate, such as on the charging unit or FOUP described below. Such variations are within the protection scope of this invention.

[0011] In some embodiments, the predetermined distance and time interval are derived from a calibration relationship between the transient temperature response obtained through measurements previously performed using the measurement wafer and the distance between the measurement wafer and the heated surface. The system control unit may use a lookup table to dynamically adjust the distance based on real-time temperature readings, or use calibrated robot coordinates to determine robot positioning. In some embodiments, the measurement wafer also includes a distance sensor to provide a direct, real-time measurement of the distance between the wafer and the heated surface.

[0012] The measurement wafer can contain multiple optical temperature sensors distributed on its surface, enabling spatially resolved temperature mapping of the heated target. Preferably, the overall height of the measurement wafer is less than 6 mm, allowing insertion into narrow process gaps while maintaining compatibility with standard wafer handling mechanisms.

[0013] To withstand high-temperature environments, the measurement wafer may further include a heat-reflective coating disposed on one or both sides of the wafer-shaped substrate and applied to almost all exposed components (except the optical sensor surface) to reduce thermal load. Suitable coating materials include Al, Au, Ag, Al2O3, SiO2, Si3N4, and TiO2.

[0014] The system may also include controllable wafer support pins on the wafer chuck, whose height is adjusted by the system control unit to ensure consistent positioning of the measurement wafer before temperature measurement operations, thereby improving the accurate positioning of the measurement wafer within the cavity.

[0015] According to one aspect of the present invention, a system for non-contact temperature measurement is provided, comprising:

[0016] A robotic arm for transport;

[0017] The feature is that it further includes at least one measurement wafer, the measurement wafer comprising: a wafer-shaped substrate, on which a first temperature sensor is disposed, and at least one optical temperature sensor, a battery, and a processor coupled to a wireless communication unit; and

[0018] A system control unit is configured to perform non-contact temperature measurement operations;

[0019] In operation, the transfer robot positions the measurement wafer at a predetermined distance from a heated surface in order to perform non-contact temperature measurement on the heated surface.

[0020] According to another aspect of the present invention, a measurement method for the above-described non-contact temperature measurement system is provided, characterized by comprising the following steps:

[0021] (i) Control the transfer robot to position the measurement wafer at a predetermined distance from a heated surface;

[0022] (ii) Instructing the processor on the measurement wafer to perform non-contact temperature measurement of the heated surface via the optical temperature sensor, and storing the corresponding temperature data in the memory or wirelessly transmitting the corresponding temperature data to the system control unit; and

[0023] (iii) Control the transfer robot to remove the measurement wafer from the processing chamber within a predetermined time interval.

[0024] According to another aspect of the present invention, a system for non-contact temperature measurement is provided, comprising:

[0025] A robotic arm for transport;

[0026] A measurement wafer, the measurement wafer comprising: a wafer-shaped substrate, on which a first temperature sensor is disposed, and at least one optical temperature sensor, a battery, and a processor coupled to a wireless communication unit; and

[0027] A system control unit is configured to perform a non-contact temperature measurement operation, the system control unit being further configured to:

[0028] (i) Control the transfer robot to position the measurement wafer at a predetermined distance from a heated surface;

[0029] (ii) Instructing the processor on the measurement wafer to perform non-contact temperature measurement of the heated surface via the optical temperature sensor, and storing the corresponding temperature data in the memory or wirelessly transmitting the corresponding temperature data to the system control unit; and

[0030] (iii) Control the transfer robot to remove the measurement wafer from the processing chamber within a predetermined time interval.

[0031] Preferably, a memory is further disposed on the wafer-shaped substrate, and the memory is connected to and communicates with the processor.

[0032] Preferably, a wireless communication unit coupled to the processor is further disposed on the wafer-shaped substrate.

[0033] Preferably, the measurement wafer is a thin measurement wafer.

[0034] Preferably, the optical sensor is a thin optical sensor.

[0035] Preferably, the system control unit is further configured to: control the transfer robot to load a processing wafer onto a wafer chuck before positioning the measurement wafer, and wherein the heating surface includes the processing wafer.

[0036] Preferably, the heating surface is the surface of a wafer chuck or a spray head.

[0037] Preferably, the predetermined distance and the predetermined time interval are derived from a calibration relationship between transient wafer temperature and wafer-to-surface distance, which is obtained by multiple temperature measurements on the wafer recorded at different distances from the heated surface.

[0038] Preferably, the system control unit is configured to use a lookup table stored in the system memory to determine the predetermined distance.

[0039] Preferably, the system control unit is further configured to dynamically adjust the predetermined distance based on real-time wafer temperature readings.

[0040] Preferably, the distance between the measuring wafer and the heated surface is determined based on the calibration position of the transfer robot.

[0041] Preferably, the measurement wafer further includes an optical distance sensor configured to perform real-time measurement of the distance between the measurement wafer and the heating surface.

[0042] Preferably, the at least one optical temperature sensor includes an infrared sensor, a thermopile array, or a pyrometer.

[0043] Preferably, the at least one optical temperature sensor comprises a thermopile array, wherein each thermopile element of the array is optically coupled to a corresponding optical system configured to define a measurement area on the target surface.

[0044] Preferably, the measuring wafer includes a plurality of optical temperature sensors distributed in a predetermined pattern on the wafer-shaped substrate to measure the temperature of different regions of the heated surface.

[0045] Preferably, the height of the measuring wafer is less than 6 millimeters.

[0046] Preferably, the system further includes a plurality of wafer support pins disposed on the wafer chuck, wherein the height of the wafer support pins can be controlled by the system control unit.

[0047] Preferably, it further includes a charging unit integrated with the FOUP, the charging unit being configured to electrically couple with the measurement wafer and charge a battery disposed thereon when the measurement wafer is received into the slot of the FOUP.

[0048] Preferably, the device further includes a charging unit implemented as a separate module, the charging unit being configured to receive the measurement wafer, charge a battery disposed on the measurement wafer, and retrieve data stored in the measurement wafer memory.

[0049] In summary, this invention provides a multifunctional, robotic, wafer-like platform capable of rapidly, repeatably, and accurately measuring high-temperature surfaces in semiconductor process cavities. It can adapt to high-temperature environments within cavities while maintaining accurate temperature measurement, significantly extending the lifespan of the measured wafers and significantly expanding the applicable cavity temperature range. This improves process control, equipment diagnostics, and cavity temperature uniformity assessment, offering a wider range of applications and suitable for harsh high-temperature and other challenging environments. Attached Figure Description

[0050] A more complete understanding of the invention and its many incidental advantages will be readily obtained and understood by referring to the following detailed description and accompanying drawings, in which the same reference numerals denote the same elements in different figures. The drawings described briefly below are not drawn to scale.

[0051] Figure 1 This is a schematic diagram illustrating an exemplary semiconductor processing system, which includes a loading cavity, a transfer cavity, and a processing cavity;

[0052] Figure 2 An embodiment of a measurement wafer configured for non-contact temperature measurement is shown;

[0053] Figure 3 This is a block diagram illustrating one embodiment of a non-contact temperature measurement system, which includes a measuring wafer, a transfer robot, and a system control unit;

[0054] Figure 4 This is a flowchart illustrating one embodiment of a non-contact temperature measurement operation performed using a measurement wafer;

[0055] Figure 5 It is a simulation diagram showing the functional relationship between the temperature of a wafer and time in a vacuum environment, for two different distances from the heated surface being measured;

[0056] Figure 6 This is a flowchart illustrating one embodiment of a calibration process for determining the relationship between the temperature-measuring wafer-heating surface spacing and the allowable exposure time of the measurement wafer;

[0057] Figure 7A , Figure 7B , Figure 7C , Figure 7D Schematic diagrams illustrating various embodiments of measuring wafers and their applications in measuring different heated surface temperatures within semiconductor process cavities;

[0058] Figure 8A , Figure 8B , Figure 8C , Figure 8D It is a schematic top view of various predetermined patterns of multiple optical temperature sensors distributed on a wafer-shaped substrate according to certain embodiments of measuring wafers;

[0059] Figure 9 This is a flowchart illustrating one embodiment of dynamic distance adjustment operation, wherein real-time wafer temperature readings are used to modify the distance between the measuring wafer and the heated surface being measured; and

[0060] Figure 10A , Figure 10B , Figure 10C Schematic diagrams are shown of various embodiments of the arrangement of heat-reflective coatings on a wafer, including coatings applied to the lower surface, upper surface and exposed components, or both sides of a wafer-shaped substrate. Detailed Implementation

[0061] In the following detailed description of embodiments of the present invention, numerous specific details are set forth in order to provide a thorough understanding of the embodiments. However, it will be apparent to those skilled in the art that embodiments of the invention can be practiced without these specific details. In other instances, well-known methods, procedures, components, and circuits have not been described in detail to avoid unnecessarily obscuring aspects of the embodiments of the invention.

[0062] Furthermore, it should be understood that the present invention is not limited to these embodiments. Modifications, variations, alterations, substitutions, and equivalents of the present invention and its embodiments without departing from the spirit and scope of the invention are all within the protection scope of the present invention.

[0063] One object of the present invention is to provide a non-contact in-situ temperature measurement system and method for heated surfaces within a semiconductor manufacturing cavity. For example... Figure 1 As shown, the semiconductor processing system 100 may include a loading cavity 110, a transfer cavity 115, and a processing cavity 120 configured to accommodate a wafer cassette 112 (also referred to as a FOUP, front-opening universal cassette). A wafer transfer robot 117 is configured to transfer wafers between the wafer cassette 112 and the processing cavity 120. In one embodiment, Figure 1 The processing chamber 120 shown may be a plasma processing chamber and may include a spray head 124, a bottom electrode including a wafer chuck 126 (e.g., an electrostatic chuck), and a plurality of wafer receiving pins 128. During operation, plasma is generated by introducing one or more process gases into the processing chamber at a predetermined pressure and flow rate and applying an RF electric field generated by an RF power matching network (not shown).

[0064] According to one embodiment of the present invention, and with reference to Figure 3 as well as Figure 1 and Figure 2 The present invention provides a non-contact in-situ temperature measurement system 300, comprising a transfer robot 117 and a measurement wafer 200. For example... Figure 2 As shown, the measurement wafer 200 includes a wafer-shaped substrate 210, a first temperature sensor 230 mounted on the substrate for measuring the substrate's own temperature, one or more optical temperature sensors 220a-220d for remote non-contact temperature measurement of a target surface, a battery 240, a processor 250 coupled to a wireless communication unit 260, and a memory 270. Preferably, the optical temperature sensors 220a-220d are optical temperature sensors. The battery 240 is preferably a rechargeable battery, and more preferably a rechargeable thin battery. In other variations, the battery 240 may also be other power sources, all of which are within the scope of this invention. To adapt the measurement wafer 200 to existing wafer manufacturing environments, in a preferred embodiment, the overall height of the measurement wafer is configured to be thin. For example, in a preferred embodiment, the overall height dimension is less than 6 mm.

[0065] Preferably, the first temperature sensor can be a thermocouple. Preferably, the first temperature sensor is used to measure the temperature of the temperature-sensing wafer itself, or in a preferred embodiment, to measure the temperature of the wafer-shaped substrate. More preferably, the first temperature sensor is used to measure the temperature of each workpiece on the substrate, for example, in an embodiment including multiple first temperature sensors, the first temperature sensors can be used to measure the temperature of the optical temperature sensor, or the temperature of the processor, or the temperature of the wireless communication unit, or the temperature of the memory, etc. Such variations are within the scope of protection of this invention.

[0066] like Figure 3 As shown, the non-contact in-situ temperature measurement system 300 further includes a system control unit 160, which is coupled to the transmission robot 117 and the measurement wafer 200 via a wireless communication unit 260. The system control unit 160 is configured to perform non-contact temperature measurement operation control.

[0067] A non-contact temperature measurement method according to an embodiment of the present invention is combined with Figure 3 And in Figure 4 As shown in the image. For ease of description, as... Figure 4 The measurement method 400 shown first executes step 410, placing the measurement wafer into the wafer cassette of the loading cavity. Then, in step 420, the system control unit determines a predetermined distance relative to the heated surface to be measured, based on previous simulations, empirical calibrations, or both. In a variation, the system control unit also determines a predetermined time interval for which the measurement wafer should be held in that position. Next, in step 430, the system control unit controls a transfer robot to transfer the measurement wafer into the processing cavity and position it at a predetermined distance from the heated surface.

[0068] Then, step 440 is executed. Once the measurement wafer reaches the set position, the system control unit instructs the processor on the measurement wafer to perform rapid temperature measurement on the heated surface using one or more optical temperature sensors (220 or 220a-220d), and stores the corresponding temperature data in memory or wirelessly transmits it to the system control unit. Those skilled in the art will understand that, preferably, the optical temperature sensors 220a-220d are optical temperature sensors. Then, step 450 is executed. At or after a predetermined time interval, the system control unit controls a transfer robot to remove the measurement wafer from the processing cavity.

[0069] According to some embodiments, the non-contact in-situ temperature measurement system 300 further includes a charging unit 170 configured to charge a battery 240 disposed on the measurement wafer. In one embodiment, the charging function is integrated with the FOUP 112, i.e., the charging unit 170 is integrated into a conventional FOUP. A conventional FOUP may be equipped with a charging interface and one or more electrical contact elements. After the charging unit 170 is integrated into the FOUP, when the measurement wafer is received into a designated slot in the wafer cassette within the loading cavity 110, the measurement wafer is electrically connected to the contact element, thereby initiating battery charging. Those skilled in the art will understand that in the above process, the charging interface of the rechargeable battery of the measurement wafer is connected to the charging unit 170 to charge the rechargeable battery of the measurement wafer. In a variation, the charging unit 170 may be configured as a wireless charging unit to charge the rechargeable battery of the measurement wafer wirelessly. In some embodiments, the charging unit 170 is further configured to retrieve measurement data stored in the memory 270 and transmit the data to the system control unit 160, for example, via a wireless communication link. In such embodiments, no wireless communication unit is provided on the measurement wafer. When the measurement wafer is connected to the charging unit 170, the data interface of the charging unit 170 reads the measurement data from the memory 270 and transmits the data to a host computer or backend server via the wireless communication link of the charging unit 170. Such variations are all within the scope of protection of this invention.

[0070] In another embodiment, the charging unit 170 is implemented as a separate module located outside the semiconductor processing system 100. In this configuration, the measurement wafer is unloaded from the loading cavity 110 and manually placed into the separate charging unit. This separate charging unit is configured to charge the onboard battery and extract stored data from the measurement wafer for subsequent analysis or transmission to the system control unit.

[0071] The following description explains how the non-contact in-situ temperature measurement system 300 achieves in-situ high-temperature measurement without damaging the measurement wafer, and how to determine a predetermined distance and a predetermined time interval, wherein the predetermined time interval is the time the measurement wafer stays at the predetermined distance.

[0072] One method to prevent overheating of the measurement wafer is to position it at a controlled distance from the heat source. In a vacuum or low-pressure environment, heat transfer to the fluid is negligible due to the lack of direct contact with the heat source, and conductive heat transfer through the surrounding gas is also minimal. Therefore, heat transfer to the measurement wafer primarily occurs through thermal radiation; that is, thermal radiation from the heated surface will have a temperature effect on the measurement wafer. As the distance between the measurement wafer and the heated surface increases, the radiative coupling between the two surfaces decreases, thereby reducing the heating rate of the measurement wafer and effectively isolating the temperature of the measurement wafer itself from the temperature of the heated surface, thus achieving better technical results.

[0073] Figure 5 This simulation illustrates the time-varying temperature response of a wafer to two different spacings in a vacuum environment. In this simulation, the heat source (e.g., a wafer chuck, a spray head for handling wafers, or a plasma processing chamber) is maintained at a temperature of 600°C (T0). heat =600). Initially, the measurement wafer is located in the loading cavity at an ambient temperature of approximately 25°C. At time t=0, the transfer robot moves the measurement wafer into the processing cavity and positions it at a selected distance from the heat source.

[0074] Using a first-order lumped thermal approach-to-equilibrium model, the temperature of a wafer can be approximated as follows:

[0075]

[0076] Where T(0) = 25℃, and T represents the effective thermal time constant, which depends on the distance between the measuring wafer and the heat source, the emissivity of their respective surfaces, the wafer thickness, and the thermal capacity of the measuring wafer.

[0077] In the simulated scenario shown, the measurement wafer is positioned relative to the heat source at both "near" and "far" distances, with the far distance being approximately four times the near distance. Due to reduced radiative coupling at the larger spacing, the thermal time constant T2 associated with the far location is significantly larger than the time constant T1 associated with the near location. Therefore, as Figure 5 As shown, the measurement wafers located further from the heat source exhibit a significantly slower temperature rise.

[0078] Several electronic components, such as batteries, processors, and memory, mounted on the measurement wafer typically have a rated operating temperature only below about 150°C. To prevent thermal damage to these components, the system control unit preferably limits the maximum exposure time Δt during which the measurement wafer remains near the heated surface. During this controlled exposure interval, optical temperature sensors 220a-220d, etc., perform temperature measurements. Those skilled in the art will understand that the aforementioned maximum exposure time Δt can be interpreted as the predetermined time interval described above, and the same interpretation applies hereinafter.

[0079] As described above, the temperature rise of the measured wafer can be approximated using a first-order thermal model characterized by a time constant that depends on the spacing, the (thermal) emissivity of the relative surfaces, and the thermal mass of the measured wafer. Therefore, in a preferred embodiment, the system control unit selects an exposure time Δt that is less than a predetermined fraction of the corresponding time constant T, such that the temperature of the measured wafer remains below the safe threshold of the electronic component. By jointly controlling the spacing and exposure time Δt, the system can achieve accurate in-situ temperature measurement of the heated surface while maintaining the measured wafer within safe operating temperature limits. In extreme cases, if the exposure time Δt must be greater than the time constant T due to operating conditions, the lifespan of the measured wafer may be appropriately reduced. However, since it still controls the exposure time of the measured wafer near the heat source compared to conventional technologies, the lifespan of the measured wafer is still far greater than that of conventional wafer-type temperature sensing systems. These variations are all within the scope of protection of this invention.

[0080] Typically, the lifespan of electronic components decreases as their operating temperature increases. By jointly controlling the spacing and exposure time as described above, the temperature rise of the metrology wafer is limited, significantly reducing the thermal stress on the electronic components mounted on the metrology wafer. Therefore, compared to conventional temperature measurement equipment that relies on long exposure times or direct thermal coupling, the electronic components of this low-profile metrology wafer exhibit higher reliability and longer lifespan, even if the metrology wafer remains in the measurement position for a short period after the nominal exposure time has ended.

[0081] In one embodiment, the non-contact in-situ temperature measurement system 300 determines the distance d between the measuring wafer and the measured heated surface, as well as the allowable time interval Δt, based on the calibration relationship between the transient wafer temperature and the wafer-heated surface distance obtained from multiple calibration measurements. Figure 6 As shown. For ease of explanation, Figure 6The measurement method shown is labeled 600. First, step 610 is executed, setting the transfer robot to position the measurement wafer at an initial maximum distance from the heating surface, and then step 620 is executed to place the measurement wafer into the loading cavity. Then, step 630 is executed, after the loading cavity is evacuated, the transfer robot moves the measurement wafer into the processing cavity and positions it at a selected distance d from the heating surface.

[0082] During step 640, the transient temperature profile (temperature over time) of the measurement wafer is measured. Next, step 650 is performed, comparing each temperature reading with a predetermined critical temperature corresponding to the maximum permissible operating temperature of the electronic components on the measurement wafer. Then, step 660 is performed; if the measured temperature exceeds the critical temperature, the measurement wafer is returned to the loading cavity. Then, step 670 is performed to begin subsequent calibration cycles, setting the next distance d by a decreasing amount. By repeating this calibration process at different distances, a set of transient temperature profiles corresponding to multiple wafer-surface pitches is generated. Based on these results, a lookup table or function relating the predetermined pitch d to the corresponding permissible exposure time Δt is established according to the critical temperature threshold of the measurement wafer components.

[0083] refer to Figure 7A , Figure 7B , Figure 7C , Figure 7D Several exemplary embodiments of measuring wafer 200 are shown to enable the non-contact in-situ temperature measurement system 300 to measure the temperature of different target surfaces within the processing cavity.

[0084] like Figure 7A As shown, the measurement wafer 720 includes one or more optical temperature sensors 722 mounted on the underside of a wafer-shaped substrate 724. For clarity, reference numeral 710 collectively refers to components integrated with the measurement wafer, including a first temperature sensor 230, a battery 240, a processor 250, a wireless communication unit 260, and a memory 270. In this embodiment, the wafer chuck 126 is heated, and the measurement wafer 720 is positioned above the wafer chuck 126 at a distance of d1. This configuration can be determined according to reference... Figure 4 The described measurement method 400 is used to measure the surface temperature of the wafer chuck 126.

[0085] refer to Figure 7BIn an alternative embodiment, the system control unit 160 is configured to control the transfer robot to first load the processing wafer 730 onto the wafer chuck 126, and then position the measurement wafer 720 above the processing wafer 730 at a distance of d2. Since the temperature of the processing wafer 730 is typically lower than the temperature of the wafer chuck 126 during operation, this configuration allows the measurement wafer 720 to directly measure the surface temperature of the processing wafer 730. Those skilled in the art will understand that the processing wafer 730 is preferably a wafer used in the actual processing, and the surface temperature of the wafer being processed during the actual processing can be measured in situ through the above measurement process.

[0086] refer to Figure 7C In another embodiment, the measuring wafer 740 includes one or more optical temperature sensors 742 mounted on the upper side of the wafer-shaped substrate 744. In this embodiment, the spray head 124 is heated, and the measuring wafer 740 is positioned below the spray head 124 at a distance of d3. This configuration is used according to a reference. Figure 4 The described measurement method 400 is used to measure the surface temperature of the spray head 124.

[0087] refer to Figure 7D In another embodiment, the measuring wafer 750 includes one or more optical temperature sensors 754 and 756 respectively mounted on the lower and upper sides of the wafer-shaped substrate 752. The system control unit 160 is configured to control a transfer robot to first load the processing wafer 730 onto the wafer chuck 126, and then position the measuring wafer 750 between the spray head 124 and the processing wafer 730, thereby enabling simultaneous measurement of the surface temperatures of the processing wafer 730 and the spray head 124.

[0088] Optical sensors for non-contact temperature measurement may include infrared sensors, thermopile sensors or thermopile arrays, pyrometers, or other radiation thermometry devices capable of detecting thermal radiation emitted from a heated surface without physical contact. Such sensors enable rapid, non-invasive temperature measurement of surfaces located within a processing chamber. Preferably, the aforementioned infrared sensors and other sensors are thin-film sensors, and these variations are within the scope of this invention.

[0089] For example, a thermopile sensor is a temperature sensing device formed by connecting multiple thermocouples in series and / or parallel. Each thermocouple generates a small voltage when a temperature difference exists between its hot and cold junctions. The thermopile sensor includes an infrared absorber to absorb incident thermal radiation from a target surface, thereby heating the hot junction relative to the cold junction. The voltages generated by the individual thermocouples are combined to produce a larger, measurable output signal that correlates with the temperature of the target surface. Thermopile devices can exhibit fast response times, such as on the order of milliseconds, enabling transient temperature measurements.

[0090] In one embodiment, the optical temperature sensor 220 includes a thin thermopile sensor integrated with an optical system configured to collect thermal radiation flux from a target surface. The optical system may include a focusing lens, a set of lenses, an aperture, or other optical elements for defining the measurement area and controlling the sensor's field of view, thereby improving spatial selectivity and measurement accuracy.

[0091] In various embodiments, measuring the wafer includes multiple optical temperature sensors distributed on a wafer-shaped substrate according to a predetermined spatial pattern. The predetermined pattern can be selected to provide representative temperature sampling of different regions of the heated surface, such as the central region, mid-radius region, and peripheral region of a wafer chuck or spray head.

[0092] refer to Figure 8A , Figure 8B , Figure 8C , Figure 8D Multiple optical temperature sensors can be placed at predetermined radial, angular, or both locations to provide uniform, symmetrical, or otherwise optimized spatial coverage on the wafer substrate. In some embodiments, the sensors are arranged in a concentric ring pattern, such as... Figure 8A The sensors are arranged in a concentric ring pattern, such as 810. Figure 8B The radial spoke pattern is arranged in 820, such as Figure 8C The 830 is arranged in a triangular grid, or as shown in the example. Figure 8D The grid is arranged in a hexagonal pattern of 840. In other variations, other predetermined patterns can be used to correspond to the expected or known heat distribution within the processing cavity. The selected layout allows temperature measurements obtained from the distributed optical sensors to be used to accurately reconstruct the spatial temperature distribution map of the heated surface.

[0093] Each optical temperature sensor is oriented to receive thermal radiation emitted from the heated surface and generate a corresponding temperature signal. When the measurement wafer is positioned at a predetermined measurement distance, the sensor array simultaneously or sequentially captures multiple local temperature readings from the heated surface. These readings can be stored in onboard memory or wirelessly transmitted to the system control unit for analysis.

[0094] By distributing optical temperature sensors across a wafer-shaped substrate, the wafer can be measured to detect temperature field inhomogeneities, such as localized hotspots, radial gradients, or asymmetric heating patterns. The system control unit can further process the received data to calculate a spatial temperature map of the heated surface, evaluate system performance, or adjust cavity parameters to improve temperature uniformity in subsequent wafer processing operations.

[0095] This distributed sensor configuration enables comprehensive, multi-point temperature characterization without contact with the heated surface and provides higher fidelity compared to single-point or centrally located sensors.

[0096] In some embodiments, the system control unit is further configured to dynamically adjust the spacing between the measuring wafer and the heating surface based on real-time wafer temperature data obtained from the first temperature sensor 230 on the wafer. (See reference...) Figure 9 For ease of expression, Figure 9 The measurement method shown is labeled 900. In step 910, the measurement wafer is first loaded into the loading cavity and then transferred to the processing cavity. After being exposed to thermal radiation from the heated surface, the temperature of the measurement wafer begins to rise. Then, in step 920, after the measurement wafer is positioned within the processing cavity, the first temperature sensor 230 on the wafer immediately measures the wafer temperature. Next, in step 930, the system control unit monitors the measured wafer temperature or its rate of change and compares the measured value with a predetermined safety threshold corresponding to the maximum permissible operating temperature of the electronic components mounted on the measurement wafer.

[0097] In step 940, if the measured wafer temperature rises faster than expected or approaches a safety threshold within a predetermined margin, the system control unit automatically instructs the transfer robot to increase the distance between the measuring wafer and the heated surface, thereby reducing the radiative heat flux incident on the measuring wafer. Conversely, if the real-time wafer temperature remains within a safe operating range, the system control unit can decrease the distance to improve measurement accuracy. In step 950, once the measuring wafer is positioned at the updated distance, the optical temperature sensor performs a non-contact temperature measurement of the heated surface. Steps 920, 930, 940, and 950 can be repeated to obtain multiple remote temperature measurements. By continuously evaluating real-time wafer temperature data and dynamically adjusting the distance during measurement intervals, the system enhances measurement reliability while preventing thermal damage to the measuring wafer. In step 960, after the predetermined measurement conditions are met, the system control unit commands the transfer robot to return the measuring wafer to the loading cavity.

[0098] In some embodiments, the system control unit determines the distance between the measurement wafer and the heated surface based on the calibrated positional relationship of the transfer robot. The transfer robot may undergo a calibration procedure during equipment setup, preventative maintenance, or before performing non-contact temperature measurement operations. During this calibration procedure, reference positions within the processing cavity are measured, such as a known reference plane on the wafer chuck, the upper surface of the heated base, or mechanical stops associated with the robot arm, and stored in the system control unit.

[0099] The calibration data establishes a mapping between the commanded robot coordinates and the actual physical position of the measurement wafer relative to the heating surface. Once calibrated, the robot's positioning accuracy allows the system control unit to calculate or retrieve the precise distance between the measurement wafer and the heating surface at any specified robot position. When the system control unit instructs the transfer robot to move the measurement wafer to the predetermined measurement position, it uses the stored calibration information to confirm that the wafer is placed at the required measurement distance. Therefore, the system can reliably reproduce the distance required for optical temperature measurement without direct mechanical contact or the need for additional distance sensors.

[0100] In some embodiments, the measuring wafer further includes a distance sensor configured to perform real-time measurement of the distance between the measuring wafer and the heated surface. Preferably, the distance sensor is an optical distance sensor, which can operate using triangulation, time-of-flight, structured light projection, laser ranging, or other non-contact optical ranging techniques suitable for semiconductor processing environments. In a variation, a capacitive distance sensor may also be used for real-time measurement of the distance; such variations are within the scope of this invention.

[0101] By obtaining continuous or periodic distance measurements using the aforementioned measurement method, the optical distance sensor provides the system control unit with accurate, real-time feedback on the actual position of the measured wafer relative to the heated surface. This allows the system control unit to verify whether the measured wafer is positioned at a predetermined distance, detect deviations caused by mechanical tolerances or thermal drift, and dynamically adjust the position of the measured wafer as necessary to maintain measurement accuracy and prevent excessive thermal load. In this way, the integration of the optical distance sensor enhances the reliability of the non-contact temperature measurement process.

[0102] In some embodiments, such as Figure 1 As shown, the system further includes a plurality of wafer support pins 128 disposed on a wafer chuck within the processing cavity. These wafer support pins are configured to vertically support a wafer (e.g., the processing wafer described above) or the measurement wafer provided by the present invention at a defined height above the chuck surface. The support pins may be arranged in a conventional three-pin or multi-pin pattern, and each pin may move between at least one raised position and one lowered position.

[0103] The height of the wafer support pins can be controlled by the system control unit. During operation, the system control unit can command a braking mechanism (such as a pneumatic actuator, electromechanical lifter, or cam-based mechanism) to adjust the vertical position of one or more pins. By selectively raising or lowering the support pins, the system can adjust the spacing between the measurement wafer and the chuck heating surface. This height adjustment allows the system to achieve appropriate spacing for temperature measurement, wafer handover, cavity adjustment, or other operational sequences.

[0104] refer to Figure 10A , Figure 10B , Figure 10C In some embodiments, the measurement wafer includes a heat-reflective coating disposed on one or both sides of the wafer-shaped substrate to reduce heat load during exposure to heated surfaces. As shown in Figure 10-A, a heat-reflective coating 1010 may be applied to the underside of the wafer-shaped substrate to reflect radiant heat from the heated wafer chuck. In another embodiment shown in Figure 10-B, a heat-reflective coating 1020 is applied to the top side of the wafer-shaped substrate, and an additional coating 1030 is applied to virtually all exposed components mounted on the wafer-shaped substrate, thereby reducing radiant heating from the overhead spray nozzles. Figure 10-C illustrates an embodiment in which heat-reflective coatings are provided on both the top and bottom sides of the wafer-shaped substrate for environments with radiant heat from both directions. Applying heat-reflective coatings to these areas and components minimizes unwanted heat absorption and enhances the thermal stability of onboard electronics during high-temperature cavity operation.

[0105] The thermally reflective coating selectively avoids the optical temperature sensing surface, allowing the optical temperature sensor to maintain an unobstructed view of the heated surface and accurately detect thermal radiation. Various masking, deposition, or patterning techniques can be used to prevent the coating from covering the active optical aperture while still providing substantially complete thermal shielding elsewhere on the measurement wafer.

[0106] Heat-reflective coatings can be formed from materials with high reflectivity in relevant infrared or thermal radiation bands. Exemplary coating materials include aluminum (Al), gold (Au), silver (Ag), alumina (Al₂O₃), silicon dioxide (SiO₂), silicon nitride (Si₃N₄), and titanium dioxide (TiO₂). These materials can be applied using sputtering, evaporation, chemical vapor deposition, sol-gel coating, or other thin-film deposition processes compatible with wafer-level fabrication. By reflecting most of the incident radiation energy, the coating helps maintain the measurement wafer near its desired operating temperature, thereby improving measurement accuracy, extending component life, and maintaining system reliability.

[0107] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A system for non-contact temperature measurement, comprising: A robotic arm for transport; The feature is that it further includes at least one measurement wafer, the measurement wafer comprising: a wafer-shaped substrate, on which a first temperature sensor is disposed, and at least one optical temperature sensor, a battery, and a processor coupled to a wireless communication unit; and A system control unit is configured to perform non-contact temperature measurement operations; In operation, the transfer robot positions the measurement wafer at a predetermined distance from a heated surface in order to perform non-contact temperature measurement on the heated surface.

2. A measurement method for the system according to claim 1, characterized in that, Includes the following steps: (i) Control the transfer robot to position the measurement wafer at a predetermined distance from a heated surface; (ii) Instruct the processor on the measurement wafer to perform non-contact temperature measurement on the heated surface via the optical temperature sensor, and store the corresponding temperature data in a memory or wirelessly transmit the corresponding temperature data to the system control unit; as well as (iii) Control the transfer robot to remove the measurement wafer from the processing chamber within a predetermined time interval.

3. The system of claim 1 or the measurement method of claim 2, wherein the system control unit is further configured to: control the transfer robot to load a processing wafer onto a wafer chuck before positioning the measurement wafer, and wherein the heating surface includes the processing wafer.

4. The system according to claim 1 or the measurement method according to claim 2, wherein the heating surface is the surface of a wafer chuck or a spray head.

5. The measurement method according to claim 2, wherein the predetermined distance and the predetermined time interval are derived from a calibration relationship between transient wafer temperature and wafer-to-surface distance, the calibration relationship being obtained by multiple wafer temperature measurements recorded at different distances from the heated surface.

6. The system of claim 1 or the measurement method of claim 2, wherein the system control unit is configured to use a lookup table stored in the system memory to determine the predetermined distance.

7. The measurement method according to claim 2, wherein the system control unit is further configured to dynamically adjust the predetermined distance based on real-time wafer temperature readings.

8. The system of claim 1 or the measurement method of claim 2, wherein the distance between the measurement wafer and the heating surface is determined based on the calibration position of the transfer manipulator.

9. The system of claim 1, wherein the measuring wafer further includes a distance sensor configured to perform real-time measurement of the distance between the measuring wafer and the heated surface.

10. The system according to claim 1 or the measurement method according to claim 2, wherein the at least one optical temperature sensor comprises an infrared sensor, a thermopile array, or a pyrometer.

11. The system of claim 1 or the measurement method of claim 2, wherein the at least one optical temperature sensor comprises a thermopile array, and wherein each thermopile element of the array is optically coupled to a corresponding optical system configured to define a measurement area on a target surface.

12. The system of claim 1, wherein the measuring wafer includes a plurality of optical temperature sensors distributed in a predetermined pattern on the wafer-shaped substrate to measure the temperature of different regions of the heated surface.

13. The system of claim 1, wherein the height of the measuring wafer is less than 6 mm.

14. The system according to claim 1, further comprising a plurality of wafer support pins disposed on the wafer chuck, wherein the height of the wafer support pins can be controlled by the system control unit.

15. The system of claim 1, further comprising a charging unit integrated with the FOUP, the charging unit being configured to: electrically couple with the measurement wafer and charge a battery disposed thereon when the measurement wafer is received into the slot of the FOUP.

16. The system of claim 1, further comprising a charging unit implemented as a separate module, the charging unit being configured to receive the measurement wafer, charge a battery disposed on the measurement wafer, and retrieve data stored in a memory of the measurement wafer.

17. The system of claim 1, wherein the measurement wafer includes a heat-reflective coating disposed on at least one of a first side, a second side, or both sides of the wafer-shaped substrate, and further disposed on at least a portion of exposed components on the wafer-shaped substrate excluding the temperature-sensing surface, wherein, The heat-reflective coating comprises materials selected from any one or more of the following groups: aluminum (Al), gold (Au), silver (Ag), aluminum oxide (Al2O3), silicon dioxide (SiO2), silicon nitride (Si3N4), and titanium dioxide (TiO2).

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