Measuring device

Abstract

The present invention provides a measuring device. The measuring device comprises a mass measuring station for measuring the mass and / or change in mass of a wafer, and a spectral imaging system for performing spectral imaging of at least a portion of the wafer.

Description

Technical Field

[0001] The present invention relates to a measuring device for performing mass measurement and spectral imaging, and more particularly, but not limited to, a measuring device for semiconductor wafer measurement.

Background Art

[0002] Electronic devices are manufactured on substrates such as semiconductor wafers using various processing techniques such as deposition, etching, cleaning, and / or other treatments. Examples of deposition techniques include chemical vapor deposition (CVD), physical vapor deposition (PVD), atomic layer deposition (ALD), etc. Examples of removal or etching techniques include stripping, wet etching, dry etching, chemical mechanical polishing (CMP), etc.

[0003] These substrate treatments generally cause changes in the side or surface of the substrate and / or changes in the mass of the substrate. For example, deposition generally increases the mass of the substrate, while etching generally decreases the mass of the substrate. During production, it is desirable to evaluate the substrate in order to determine whether the process is being correctly performed and / or to adjust the process prior to subsequent substrate production.

[0004] Such evaluation of the substrate can be performed by measuring the mass of the substrate during processing and / or the change in mass. For example, the mass of the substrate can be measured before and after a particular processing step, and the change in mass of the substrate caused by the processing step can be used to determine whether the processing step is being correctly performed and / or to adjust the processing step prior to subsequent substrate production.

[0005] Mass measurement devices are available that can provide high-precision measurement of the mass and / or change in mass of a substrate during processing. Therefore, such mass measurement devices can be used to provide high-precision monitoring of substrate processing.

[0006] However, simply measuring the mass and / or change in mass of a substrate may not be sufficient to perform a complete evaluation of the substrate. For example, measuring the mass and / or change in mass of a substrate during processing only provides a single measurement result for the entire substrate and therefore does not provide spatial or uniformity information about the processing. For instance, for a given mass of material deposited on the side or surface of the substrate, the measured mass and / or change in mass will be the same regardless of the distribution of the deposited material on the side or surface of the substrate.

[0007] It is also known to evaluate the uniformity of the sides or surface of a substrate using optical measurement techniques. For example, multiple optical sensors and a spectrometer may be used to acquire spectra from the sides or surface of the substrate at multiple individual measurement locations on the sides or surface of the substrate. Multiple spectra may be used to evaluate the uniformity of the sides or surface of the substrate and to acquire substrate uniformity information, such as a uniformity map of the sides or surface of the substrate.

[0008] Generally, the side or surface of a substrate is the front, top, upper, or main side or main surface of the substrate. It may also be referred to as the front, top, upper, or main surface of the substrate.

[0009] Furthermore, generally speaking, the side or surface of a substrate is the side or surface on which the device is provided or manufactured.

[0010] U.S. Patent No. 10,989,652 (B2) discloses a measurement system for substrate processing, including a mass measurement station for measuring the mass and / or mass change of a substrate. The measurement system further includes a standalone optical measurement station, which includes a plurality of optical sensors and a spectrometer for measuring spectra from a plurality of measurement locations on the substrate. The measurement system further includes a controller, which includes a modeling module for generating thickness values ​​at the plurality of measurement stations based on the spectra from the plurality of measurement locations and a learned model. The controller further includes a spatial modeling module for generating a spatial thickness distribution model for the substrate based on the thickness values ​​at the plurality of measurement locations from the modeling module and the mass and / or mass change from the mass measurement station.

[0011] Therefore, under U.S. Patent No. 10,989,652 (B2), both measurement data acquired for a substrate at a mass measurement station and measurement data acquired for a substrate at a standalone optical measurement station are used to evaluate the substrate. For example, measurement data acquired from a standalone optical measurement station may provide spatial or uniformity information regarding the processing that is not present in measurement data acquired from a mass measurement station. Thus, this combination of different types of measurement data allows for better monitoring of the substrate processing than using either mass measurement or optical measurement alone.

[0012] This invention was conceived in light of the above considerations. [Overview of the project]

[0013] According to a first aspect of the present invention, a measuring device is provided comprising a mass measuring station for measuring the mass and / or change in mass of a wafer, and a spectral imaging system for performing spectral imaging of at least a portion of the wafer.

[0014] Accordingly, in a first aspect of the present invention, the measuring apparatus includes both a mass measuring station for measuring the mass and / or change in mass of a wafer and a spectral imaging system for performing spectral imaging of at least a portion of the wafer. Thus, the apparatus can be used to both determine the mass and / or change in mass of a wafer and to acquire spectral imaging data of the wafer.

[0015] Integrating a mass measurement station and a spectral imaging system into a single device can offer several advantages. For example, the footprint of this device may be smaller than that of a standalone mass measurement station and a standalone spectral imaging system. Furthermore, the cost of producing this device may be lower than that of providing separate standalone mass measurement stations and spectral imaging systems.

[0016] The spectral imaging data of the wafer and the mass and / or mass changes of the wafer can be synergistically combined to provide more detailed information about one or more parameters of the wafer than could be determined from spectral imaging data alone or from mass and / or mass changes alone.

[0017] For example, mass and / or mass change can be used as constraints when determining uniformity data for a wafer from spectral imaging data in order to obtain more accurate uniformity data for the wafer.

[0018] Alternatively, or as an addition, spectral imaging data may be used to provide uniformity data in addition to measured mass and / or mass change. For example, spectral imaging data may be used to determine the uniformity of a pattern of interest, such as thickness or limiting dimensions (e.g., size of a particular feature). The uniformity of a pattern of interest may indirectly indicate, for example, the mass distribution.

[0019] Measurements of wafer mass and / or changes in mass by a mass measurement station can be extremely sensitive to one or more of vibration, electromagnetic noise, and temperature fluctuations. A spectral imaging system, for example, compared to other types of optical measurement systems, may be able to perform spectral imaging of at least a portion of the wafer with minimal movement of the spectral imaging system and / or any component of the spectral imaging system. Therefore, a spectral imaging system may not have a significant adverse effect on measurements by a mass measurement station.

[0020] A mass measuring device according to a first aspect of the present invention may have any one of the following optional features, or any combination thereof, if applicable.

[0021] The mass measurement station and spectral imaging system will be integrated into a single instrument.

[0022] The mass measurement station and the spectral imaging system may be integrated together, and / or connected together, and / or attached together, and / or fixed together, either directly or indirectly through one or more other parts or components or stations of the apparatus.

[0023] The mass measurement station and spectral imaging system may be contained within or on top of a single housing, enclosure, or casing.

[0024] A spectral imaging system can be for performing spectral imaging of at least a part of a side surface or a front surface of a wafer.

[0025] The side surface or the front surface of the wafer can be the front surface, the upper surface, the upper side, or the main side surface or the main front surface of the wafer. It may alternatively be referred to as the front surface, the upper surface, the upper side, or the main surface of the wafer.

[0026] The side surface or the front surface of the wafer can be the side surface or the front surface of the wafer on which a device is provided or a device is manufactured.

[0027] A spectral imaging system can be for performing spectral imaging of a side surface or a front surface (e.g., the front surface, the upper surface, the upper side, or the main side surface or the main front surface) of a wafer.

[0028] Performing spectral imaging of at least a part of the wafer can include obtaining spectral imaging data for at least a part of the wafer.

[0029] [[ID=二十一]]Performing spectral imaging of at least a part of the wafer can include obtaining optical spectral imaging data for at least a part of the wafer. [[ID=二十二]] [[ID=二十三]]

[0030] [[ID=二十四]] [[ID=二十五]]Performing spectral imaging of at least a part of the wafer can include obtaining a spectral image of at least a part of the wafer. [[ID=二十六]] [[ID=二十七]]

[0031] [[ID=二十八]] [[ID=二十九]]Performing spectral imaging of at least a part of the wafer can include obtaining an optical spectral image of at least a part of the wafer. [[ID=三十]] [[ID=三十一]]

[0032] [[ID=三十二]] Spectral imaging can involve acquiring optical spectral information across every point on an image, such as every pixel in an image. Spectral imaging can be a general term referring to the combination of spectroscopy and imaging. Optical spectral information may be acquired for only a portion of the optical spectrum, or for the entire optical spectrum.

[0033] Therefore, a spectral image may include the optical spectrum, or a partial optical spectrum, at each pixel of the image.

[0034] Spectral imaging may involve acquiring intensity data for each point or pixel in an image across a specific wavelength range, for example, a wavelength range of 400 to 1000 nm.

[0035] As will be explained below, multispectral imaging and hyperspectral imaging are two subsets of spectral imaging.

[0036] Spectral imaging can refer to imaging that uses multiple wavelengths or wavelength bands across the electromagnetic spectrum, for example, multiple wavelengths or wavelength bands across the visible spectrum or optical spectrum.

[0037] For example, a spectral imaging system may use wavelengths in the visible to near-infrared range, such as wavelengths in the range of 400 nm to 1000 nm. Of course, wavelengths above or below this range may also be used.

[0038] Spectral imaging systems can use wavelengths in the visible to mid-infrared range, for example, within the range of 400 nm to 8000 nm. Of course, wavelengths above or below this range can also be used.

[0039] Spectral imaging systems can utilize wavelengths in optical spectra.

[0040] Spectral imaging can mean acquiring imaging data in which a spectrum (e.g., optical spectrum) is obtained for each (every) pixel in the image.

[0041] A spectral image can be an image in which the spectrum (e.g., optical spectrum) is contained for each (every) pixel in the image.

[0042] Spectral imaging data can be imaging data that contains a spectrum (e.g., optical spectrum) for each (every) pixel in the image.

[0043] A spectrum generally covers a predetermined spectral range.

[0044] Spectral imaging can mean acquiring image or imaging data in which intensity versus wavelength (or frequency) data is obtained for each pixel of the image.

[0045] A spectral image can be an image that contains intensity versus wavelength (or frequency) data for each (every) pixel in the image.

[0046] Spectral imaging data can be imaging data that contains intensity versus wavelength (or frequency) data for each (every) pixel in an image.

[0047] Spectral imaging data can refer to spectral reflectance data, such as optical spectral reflectance data.

[0048] The acquired spectrum is a continuous spectrum over a predetermined spectral range, and may, for example, comprise multiple continuous wavelengths or wavelength bands. Alternatively, the acquired spectrum is a discontinuous spectrum over a predetermined spectral range, and may, for example, comprise multiple wavelengths or wavelength bands, at least some of which are discontinuous.

[0049] For example, such a spectrum may comprise five or more, or ten or more, or fifteen or more, or twenty or more, or thirty or more, or forty or more, or fifty or more, or one hundred or more wavelengths or wavelength bands, and these may be continuous and / or discontinuous. The number of wavelengths or wavelength bands may be, for example, 1000 or less, or 500 or less, or 300 or less, or 200 or less.

[0050] The spectral image may correspond to, show, or measure the spectral reflectance of a side or surface of a wafer, for example, all areas of the side or surface of the wafer, or all areas of a portion of the side or surface of the wafer.

[0051] Performing spectral imaging of a wafer corresponds to, or may include, measuring the spectral reflectance of the entire side or surface of the wafer, or a portion of the side or surface of the wafer.

[0052] Performing spectral imaging may involve acquiring multiple different images for or using multiple different wavelengths, wavelength ranges, or wavelength bands of illumination (i.e., each of the multiple different images is acquired for or using different wavelengths, wavelength ranges, or wavelength bands of illumination).

[0053] Performing spectral imaging may involve acquiring a single image for multiple different wavelengths or wavelength ranges or wavelength bands of illumination (i.e., a single image acquired simultaneously for multiple different wavelengths or wavelength ranges or wavelength bands of illumination).

[0054] A spectral imaging system can be an optical spectral imaging system.

[0055] A spectral imaging system may be a multispectral imaging system or a hyperspectral imaging system.

[0056] Both multispectral imaging and hyperspectral imaging are examples of spectral imaging.

[0057] Multispectral imaging (sometimes referred to as multiband imaging) may involve acquiring intensity at multiple wavelengths or wavelength bands across a given spectral range. These multiple wavelengths or wavelength bands may or may not be continuous. Generally, the number of wavelengths or wavelength bands is between 5 and 15 across a given spectral range, but more or fewer may be used. For example, in a particular example, a multispectral imaging system may acquire data at 100nm intervals across six wavelength bands with a 50nm bandwidth over the spectral range of 400–1000nm. For example, bands centered at 450nm, 550nm, 650nm, 750nm, 850nm, and 950nm.

[0058] Similar to multispectral imaging, hyperspectral imaging may involve acquiring intensity at multiple wavelengths or wavelength bands across a given spectral range. These multiple wavelengths or wavelength bands are generally continuous wavelengths or wavelength bands, and therefore the acquired spectrum is continuous. Generally, the number of wavelengths or wavelength bands used is in the range of 50 to 250 across a given spectral range, but more or fewer may be used. For example, in a particular case, a hyperspectral imaging system may acquire data at 120 wavelengths or continuous wavelength bands with a bandwidth of 5 nm across a spectral range of 400 to 1000 nm.

[0059] Therefore, the main difference between hyperspectral imaging and multispectral imaging may be that hyperspectral imaging uses a greater number of narrower wavelengths or wavelength bands than multispectral imaging, thereby providing more detail and / or higher spectral resolution for each pixel of the image than multispectral imaging.

[0060] As mentioned above, the term spectral imaging includes both multispectral imaging and hyperspectral imaging.

[0061] Hyperspectral imaging may include acquiring hyperspectral cube data, or hyperspectral data cubes, for at least a portion of the side or surface of a wafer.

[0062] Hyperspectral imaging data may include hyperspectral data cubes.

[0063] This measuring device can be configured to generate wafer uniformity data based on the output of a spectral imaging system for at least the wafer.

[0064] Uniformity data may indicate the uniformity of one or more parameters of a wafer across its sides or surface.

[0065] Uniformity data may indicate the uniformity of one or more dimensions of a wafer across its sides or surface. These one or more dimensions may be one or more dimensions of layers or patterns of interest on the wafer.

[0066] For example, uniformity data may relate to one or more of the following types of uniformity: the thickness of a layer on the side or surface of a wafer, the limit dimensions of a pattern on the side or surface of a wafer, or the uniformity of a pattern of interest across the side or surface of a wafer.

[0067] Uniformity data may include one or more of the following: thickness data, limit dimension data, depth data, and material density data.

[0068] This measuring device can be configured to generate wafer uniformity data based on both the output of a spectral imaging system for the wafer and measurements of the wafer's mass and / or change in mass.

[0069] This measurement device may be configured to use a trained model or a machine learning model to generate wafer uniformity data.

[0070] For example, a trained model, or machine learning model, can relate homogeneity data to spectral imaging data.

[0071] A trained model, or machine learning model, can be generated using machine learning, for example. Machine learning may include supervised learning models selected from a group consisting of, for example, linear models, support vector machine models, decision tree models, random forest models, and Gaussian models.

[0072] A trained model, or machine learning model, may be generated, for example, by correlating spectral imaging data and / or mass and / or mass change for one or more wafers with uniformity data for one or more wafers, the uniformity data including at least one of thickness data, critical dimension data, depth data, and material density data, which can be accurately measured, for example, using one or more known measurement methods. Alternatively, the uniformity data may be determined by unsupervised learning, for example, based on clustering operations on optical spectral data from different locations on the wafer.

[0073] A spectral imaging system may be configured to perform spectral imaging of at least a portion of a wafer while the wafer is in a mass measurement station.

[0074] Therefore, the spectral imaging system can be integrated with or integrated into the mass measurement station.

[0075] For example, part or all of the spectral imaging system may be located inside or within the mass measurement station.

[0076] In this way, integrating the mass measurement station with the spectral imaging system can reduce the amount of time required to acquire spectral imaging data and mass and / or changes in mass compared to measuring them at separate locations.

[0077] A mass measurement station may include a device for measuring the weight or mass of a wafer and / or changes in weight or mass, and a spectral imaging system may be configured to perform spectral imaging of at least a portion of the wafer while the wafer is loaded onto the device.

[0078] For example, the above device may comprise a load cell and a pan or support for supporting the wafer during measurement, and the spectral imaging system may be configured to perform spectral imaging of at least a portion of the wafer while the wafer is loaded onto the pan or support.

[0079] This measuring device may be equipped with a thermalization station for changing the wafer temperature.

[0080] For example, when a wafer is loaded into a mass measurement station, it is advantageous for the wafer to be at the same temperature as the mass measurement station. Otherwise, the temperature difference between the wafer and the mass measurement station can cause problems such as convection inside the mass measurement station, or changes in the temperature of the air inside the mass measurement station, and therefore changes in the buoyancy experienced by the wafer. These problems can negatively affect the accuracy of measuring the wafer's mass and / or change in mass.

[0081] Therefore, a thermal equilibrium station is used to change the temperature of a wafer to a predetermined temperature, and / or to cause a predetermined change in the temperature of a wafer.

[0082] A thermal equilibrium station may be used to equalize the temperature of a wafer to a predetermined temperature.

[0083] Generally, when a wafer is placed on a thermal equilibrium station, its temperature is higher than the wafer's predetermined or desired temperature. Therefore, in such cases, the thermal equilibrium station will cool the wafer to the desired or predetermined temperature. Of course, alternatively, when a wafer is placed on a thermal equilibrium station, its temperature may be lower than the wafer's predetermined or desired temperature. Therefore, in such cases, the thermal equilibrium station will heat the wafer to the desired or predetermined temperature.

[0084] The spectral imaging system may be configured to perform spectral imaging of at least a portion of the wafer while the wafer is in a thermal equilibrium station.

[0085] In this way, integrating the thermal equilibrium station with the spectral imaging system can reduce the amount of time required to acquire spectral imaging data and to change the wafer temperature compared to performing these steps separately.

[0086] A thermal equilibrium station may include a temperature-changing device or portion for changing the temperature of a wafer, and a spectral imaging system may be configured to perform spectral imaging of at least a portion of the wafer while the wafer is loaded onto the temperature-changing device or portion.

[0087] For example, the temperature change device or component may comprise a heat transfer plate, which may be a plate or block of material, and the spectral imaging system may be configured to perform spectral imaging of at least a portion of the wafer while the wafer is on the heat transfer plate.

[0088] A temperature-changing device or component may include a passive temperature-changing device or component, or an active temperature-changing device or component.

[0089] A passive temperature change device or part may mean a device or part that does not have a powered heating or cooling device.

[0090] An active temperature change device or part may mean a device or part having one or more power heating or cooling devices, such as a Peltier device.

[0091] The apparatus may include a wafer handling system for loading wafers into a mass measurement station and for loading wafers into a thermal equilibrium station. The wafer handling system may also unload wafers from the mass measurement station and the thermal equilibrium station.

[0092] A single wafer handling system is possible.

[0093] The wafer handling system may include one or more robotic arms. The robotic arms, or each robotic arm, may include one or more end effectors for supporting or holding wafers.

[0094] The mass measurement station and the first thermal equilibration station may be arranged in a stack, i.e., a vertical stack.

[0095] This measuring device may be equipped with two or more thermal equilibrium stations. For example, this measuring device may be equipped with a first thermal equilibrium station and a second thermal equilibrium station.

[0096] The wafer handling system may be for loading wafers into a mass measurement station, for loading wafers into a first thermal equilibrium station, or for loading wafers into a second thermal equilibrium station.

[0097] The spectral imaging system may be configured to perform spectral imaging of at least a portion of the wafer while the wafer is in a first thermal equilibrium station, or the spectral imaging system may be configured to perform spectral imaging of at least a portion of the wafer while the wafer is in a second thermal equilibrium station.

[0098] The first thermal equilibrium station may be an active thermal equilibrium station, and the second thermal equilibrium station may be a passive thermal equilibrium station.

[0099] This apparatus may be configured to transport a wafer to a first thermal equilibrium station, then from the first thermal equilibrium station to a second thermal equilibrium station, and then from the second thermal equilibrium station to a mass measurement station.

[0100] A second thermal equilibrium station may be configured to change the wafer temperature to be equal to, substantially equal to, or within a predetermined temperature range of, the temperature of the mass measurement station.

[0101] This measuring device may include a spectral imaging station equipped with a spectral imaging system.

[0102] A spectral imaging station may include a housing or chamber for accommodating at least a portion of a spectral imaging system.

[0103] A spectral imaging station may include a support for holding the wafer during spectral imaging of at least a portion of it. For example, the support may be a chuck, plate, or block of material.

[0104] The spectral imaging station and mass measurement station will be integrated into a single instrument.

[0105] The mass measurement station and the spectral imaging station may be integrated together, and / or connected together, and / or attached together, and / or fixed together, either directly or indirectly through one or more other parts, components, or stations of the apparatus.

[0106] Mass measurement stations and spectral imaging stations can be arranged in a stack, i.e., a vertical stack.

[0107] The mass measurement station and spectral imaging station may be contained within or on top of a single housing, enclosure, or casing.

[0108] The measuring apparatus may include a wafer handling system for loading wafers into a mass measurement station and for loading wafers into a spectral imaging station. The wafer handling system may also be for loading wafers into any thermal equilibrium stations included in the apparatus, for example, a first thermal equilibrium station, or first and second thermal equilibrium stations.

[0109] A single wafer handling system is possible.

[0110] The wafer handling system may include one or more robotic arms. The robotic arms, or each robotic arm, may include one or more end effectors for supporting or holding wafers.

[0111] A spectral imaging system may be equipped with a detector for acquiring spectral imaging data.

[0112] The detector may include a camera, such as a spectral imaging camera, such as a multispectral imaging camera or a hyperspectral imaging camera.

[0113] A spectral imaging system may include an illumination source and a detector for acquiring spectral imaging data.

[0114] The spectral imaging system may further include optical elements configured to direct illumination from an illumination source onto a wafer and to direct the illumination reflected from the wafer onto a detector.

[0115] The illumination source can emit light with wavelengths in the visible to near-infrared range, for example, within the range of 400 nm to 1000 nm. Of course, wavelengths above or below this range can also be used.

[0116] The illumination source can emit light with wavelengths in the visible to mid-infrared range, for example, within the range of 400 nm to 8000 nm. Of course, wavelengths above or below this range can also be used.

[0117] Lighting may include or be light.

[0118] A light source may include or be a light source.

[0119] The detector can acquire spectral imaging data from the illumination reflected from the wafer.

[0120] The detector can acquire spectral reflectance data from at least a portion of the wafer, for example, at least a portion of the side or surface of the wafer.

[0121] Lighting generally includes light, specifically visible light.

[0122] The illumination source may consist of a single broadband light source, or multiple narrower broadband light sources, which may be halogen, xenon arc, or LED, but are not limited to these.

[0123] The optical elements may include one or more of a beam splitter, one or more lenses, one or more polarizers, a focusing optical element, and / or one or more mirrors. The specific configuration of the optical elements is not essential to the present invention, and various different arrangements and configurations are possible. The arrangements disclosed herein are merely illustrative examples.

[0124] The detector may be equipped with a spectral imaging camera or a hyperspectral imaging camera. Therefore, references to hyperspectral imaging cameras below may be replaced with references to spectral imaging cameras, unless inconsistent.

[0125] A spectral imaging camera refers to a camera configured to perform spectral imaging and / or acquire spectral images and / or spectral imaging data.

[0126] A hyperspectral imaging camera refers to a camera configured to perform hyperspectral imaging and / or acquire hyperspectral images and / or acquire hyperspectral imaging data.

[0127] A hyperspectral imaging camera may be configured to perform hyperspectral imaging of at least a portion of a wafer in a single shot or exposure, and / or to acquire a hyperspectral image and / or hyperspectral imaging data of at least a portion of the wafer.

[0128] A hyperspectral imaging camera may be positioned to acquire images of the entire side or surface of a wafer, or of a portion of the side or surface of a wafer. In the latter case, the hyperspectral imaging camera may be movable to image another portion of the side or surface of the wafer, or one or more additional hyperspectral imaging cameras may be provided to image one or more other portions of the side or surface of the wafer.

[0129] The illumination source may include a broadband light source. For example, a broadband light source may include a broadband continuous light bulb, a broadband pulsed light bulb, or a supercontinuum laser.

[0130] A hyperspectral imaging camera can perform hyperspectral imaging and / or acquire hyperspectral images and / or hyperspectral imaging data by imaging broadband light reflected from the sides or surface of a wafer.

[0131] A spectral imaging system may include a mechanism, arrangement, or means for controllably selecting a specific wavelength, wavelength range, or wavelength band to be detected by a detector.

[0132] A spectral imaging system may include a mechanism, arrangement, or means for selectively changing a specific wavelength, wavelength range, or wavelength band of illumination to be detected by the detector.

[0133] A spectral imaging system may include an imaging camera, such as a CCD camera, for acquiring an image of at least a portion of the wafer. As described above with respect to hyperspectral cameras, the imaging camera may be movable or there may be multiple imaging cameras.

[0134] A spectral imaging system may be configured to acquire multiple different images of at least a portion of a wafer using an imaging camera for specific wavelengths or wavelength ranges or wavelength bands with different illumination.

[0135] A spectral imaging system, or the processor or controller of a device, may be configured to combine data from multiple different images to acquire a spectral image or spectral imaging data.

[0136] The illuminator may be operable to select a specific wavelength, a specific wavelength range, or a specific wavelength band of light emitted by the illuminator.

[0137] The illuminator may be operable to selectively change a specific wavelength, a specific wavelength range, or a specific wavelength band of light emitted by the illuminator.

[0138] The illumination source may include multiple illumination sources, each having a different wavelength or wavelength range or wavelength band, configured to operate independently, or illumination sources having adjustable or selectable wavelengths or wavelength ranges.

[0139] For example, multiple illuminators can be independently selected and operated so that each illuminator emits a specific wavelength, wavelength range, or wavelength band.

[0140] Multiple illumination sources may include one or more of a multicolor light source, multiple LEDs, or multiple lasers having different emission wavelengths, wavelength ranges, or wavelength bands.

[0141] Alternatively, a light source, such as a broadband light source, may be used with one or more filters to selectively transmit a specific wavelength, wavelength range, or wavelength band of illumination.

[0142] For example, the filter may comprise multiple bandpass filters, each configured to transmit different specific wavelengths or wavelength ranges of illumination. The multiple bandpass filters may be independently positioned along the illumination path. For example, the multiple bandpass filters may be mounted on a wheel so that each can be rotated along the illumination path.

[0143] Alternatively, the filter may comprise an adjustable or tunable filter that is tunable or tunable to selectively transmit a specific wavelength or wavelength range of illumination. For example, the adjustable filter may be an acousto-optic adjustable filter.

[0144] Alternatively, the filter may include a diffraction grating. The diffraction grating may be movable and / or rotatable in the path of illumination to change a specific wavelength or wavelength range or wavelength band on the detector.

[0145] Alternatively, the filter may include an optical dispersion device such as a prism. The optical dispersion device may be movable and / or rotatable in the path of illumination to change a specific wavelength or wavelength range or wavelength band on the detector.

[0146] The spectral imaging system may further include a reflector configured to reflect light from an illumination source onto a wafer, and a detector may be positioned to receive the light reflected from the wafer. The reflector may be used in place of the optical elements described above. The use of a reflector may help to provide effective illumination of the sides or surface of the wafer to enable effective spectral imaging of the wafer.

[0147] The reflector may comprise any suitable reflective element for reflecting light from an illumination source onto the side or surface of the wafer. The spectral imaging system may comprise a support for supporting the wafer during spectral imaging of the wafer, and the reflector is configured (e.g., shaping, positioning, and positioning) to reflect light from an illumination source onto the wafer when the wafer is on the support.

[0148] The detector may be positioned (e.g., by positioning) to directly receive light reflected from the side or surface of the wafer. For example, there may be no intervening optical components between the wafer and the detector.

[0149] A reflector may comprise a concave reflective surface positioned to reflect light from an illumination source onto the wafer. The use of a concave reflective surface facilitates uniform illumination across the sides or surface of the wafer, enabling effective spectral imaging across the entire side or surface of the wafer. As an example, the concave reflective surface may take the form of a reflective dome positioned on the wafer, i.e., on a support for the wafer.

[0150] A concave reflective surface may be positioned such that its central (e.g., principal) axis is substantially aligned with the center of the wafer. For example, the central axis of the concave reflective surface may be substantially aligned with the center of the support of a spectral imaging system for supporting the wafer during spectral imaging of the wafer. Thus, the concave reflective surface may be positioned substantially symmetrically with respect to the wafer and / or support. This facilitates uniform illumination across the entire side or surface of the wafer.

[0151] An aperture may be formed in the reflector, and the detector may be positioned to receive light reflected from the wafer through the aperture in the reflector. In this way, the detector may be positioned on the opposite side of the reflector from the wafer (e.g., outward). This can facilitate effective illumination of the wafer by avoiding interference with the reflection of light by the reflector, as well as making it easier to mount the detector and make the necessary connections to it. This can also contribute to making the spectral imaging system more compact.

[0152] The aperture may be positioned and sized to allow the detector to receive reflected light from all or part of the wafer. The aperture may correspond to a hole (through hole) or opening in the reflector.

[0153] If the reflector has the concave reflective surface described above, the opening may be formed within the concave reflective surface. For example, the opening may be located at the vertex of the concave reflective surface. Alternatively, the opening may be offset from the vertex of the concave reflective surface. Here, the vertex of the concave reflective surface may refer to the position of the concave reflective surface on its central axis.

[0154] A reflector may be configured to reflect light from an illumination source as diffused light. In other words, a reflector may be configured to diffuse incident light from an illumination source. Diffusing light from an illumination source can contribute to providing a more uniform (smoother) distribution of illumination across the wafer. For example, this can avoid or reduce peaks in illumination intensity in different regions of the wafer, and thus improve the reproducibility of spectral measurements across the wafer.

[0155] For example, a reflector may have a coating configured to diffuse the light incident on the reflector. For instance, the concave reflective surface described above may have a light-diffusing coating.

[0156] As described above, the spectral imaging system may include a support for receiving (e.g., holding, supporting) the wafer during spectral imaging of the wafer. The illumination source may then include one or more light sources arranged around the support, and a reflector is positioned to face the support and one or more light sources. For example, one or more light sources may be mounted adjacent to the support. In this way, the reflector can reflect light from one or more light sources toward the support (and therefore the wafer). Arranging one or more light sources around the support may contribute to making the spectral imaging system more compact, as the light sources can be directly integrated into the spectral imaging system without the need to provide optical elements for coupling light from external light sources. Furthermore, such an arrangement may contribute to providing uniform illumination across the wafer.

[0157] In some cases, the illumination source may comprise multiple light sources arranged around the support (for example, in a ring). In this way, light from the multiple light sources is reflected onto the wafer, enabling effective illumination of the wafer's sides or surface. The multiple light sources may be evenly spaced around the support.

[0158] If the reflector has a concave reflective surface, one or more light sources may be angled (e.g., tilted, oriented) toward the central axis of the concave reflective surface. In other words, light from one or more light sources may be directed inward toward the central axis or vertex of the concave reflective surface. As a result, the angle of incidence of light on the side or surface of the wafer may be relatively low, which may facilitate spectral imaging of the wafer.

[0159] This measuring device may be configured to determine wafer dimensions at multiple locations on the wafer based on the output of a spectral imaging system and a trained model. For example, the device may include a processor or controller for determining dimensions. The dimensions may be, for example, dimensions of interest, such as the thickness of a film or material layer on the side or surface of the wafer, or limit dimensions, or sidewall angles, or etching hole diameters. Generally, the dimensions may be the dimensions of a layer or pattern of interest on the wafer.

[0160] The measuring device, for example, the processor or controller of the measuring device, may be further configured to generate a spatial distribution model of dimensions for the side or surface of a wafer, based on determined dimensions at multiple locations.

[0161] This measuring device may be configured to generate a spatial distribution model of dimensions for a wafer's side or surface based on determined dimensions at multiple locations and the mass and / or change in mass of the wafer measured by a mass measurement station.

[0162] The measuring device, for example, the processor or controller of the measuring device, may be configured to determine information regarding the warp or curvature of the wafer from the output of the spectral imaging system.

[0163] The measuring device, for example, the processor or controller of the measuring device, may be configured to use a spectral imaging system to acquire multiple images at different wavelengths or wavelength ranges, analyze the out-of-focus pattern in each of the multiple images, and determine information regarding the warp or curvature of the wafer from the results of the above analysis.

[0164] According to a second aspect of the present invention, a measuring device is provided which includes an imaging system for performing imaging of at least a portion of a wafer, the measuring device being configured to determine information regarding the warpage or curvature of the wafer from the output of the imaging system.

[0165] The imaging system may be a spectral imaging system, such as an optical spectral imaging system.

[0166] The measuring device, for example, the processor or controller of the measuring device, may be configured to acquire an image using an imaging system, analyze out-of-focus patterns in the image, and determine information regarding the warp or curvature of the wafer from the results of the above analysis.

[0167] The measuring device, for example, the processor or controller of the measuring device, may be configured to use an imaging system to acquire multiple images at different wavelengths or wavelength ranges, analyze the out-of-focus pattern in each of the multiple images, and determine information regarding the warp or curvature of the wafer from the results of the above analysis.

[0168] If the imaging system is a spectral imaging system, the processor may be configured to use spectral imaging data for one or a subset of different wavelengths or wavelength ranges to determine information about wafer warp or curvature. In particular, it is not required that the processor use all of the spectral imaging data to determine information about wafer warp or curvature; instead, this information may be determined using only a portion or subset of the spectral imaging data. Specifically, the processor may use one or a subset of channels (i.e., wavelengths or wavelength ranges) of the spectral imaging data to determine information about wafer warp or curvature.

[0169] A measuring device according to a second embodiment of the present invention may have any of the features of the first embodiment of the present invention, unless otherwise specified.

[0170] A measuring device of any of these embodiments may be configured to perform optical interferometry between a wafer and a reference wafer.

[0171] A measuring apparatus in any embodiment may include a reference unit comprising a reference wafer, and the spectral imaging system may be configured to perform optical interferometry between the wafer and the reference wafer.

[0172] According to a third aspect of the present invention, a measuring device is provided which includes a spectral imaging system for performing spectral imaging of at least a portion of a wafer, the measuring device being configured to perform optical interferometry between the wafer and a reference wafer.

[0173] This measuring device may include a reference unit equipped with a reference wafer, and the spectral imaging system may be configured to perform optical interferometry between the wafer and the reference wafer.

[0174] When performing optical interferometry, it is not necessary to use all of the spectral imaging data. Instead, the measurement device can be configured to use one or a subset of the channels of the spectral imaging data.

[0175] The present invention includes combinations of the embodiments and preferred features described, unless such combinations are obviously unacceptable or clearly avoidable. Next, embodiments and experiments illustrating the principle of the present invention will be described with reference to the attached figures. [Brief explanation of the drawing]

[0176] [Figure 1] This is a schematic diagram of a mass measuring device.

[0177] [Figure 2] This is a schematic diagram of a measuring device according to the first embodiment of the present invention.

[0178] [Figure 3] This is a schematic diagram of a measuring device according to a second embodiment of the present invention.

[0179] [Figure 4] This is a schematic diagram of a measuring device according to a third embodiment of the present invention.

[0180] [Figure 5] This is a schematic diagram of a measuring device according to a fourth embodiment of the present invention.

[0181] [Figure 6] This is a schematic diagram of a measuring device according to one embodiment of the present invention.

[0182] [Figure 7] This is a schematic diagram of a measuring device according to one embodiment of the present invention.

[0183] [Figure 8] This is a schematic diagram of a part of a measuring device according to one embodiment of the present invention.

[0184] [Figure 9] This figure shows an exemplary analysis of hyperspectral imaging data in one embodiment of the present invention.

[0185] [Figure 10] This is a schematic diagram of a measuring device according to one embodiment of the present invention.

[0186] [Figure 11] This figure shows an example of measurement data acquired using the measuring device shown in Figure 10.

[0187] [Figure 12] This is a schematic diagram of a part of a measuring device according to one embodiment of the present invention. [Modes for carrying out the invention]

[0188] Next, aspects and embodiments of the present invention will be described with reference to the attached figures. Further aspects and embodiments will be apparent to those skilled in the art. All references mentioned herein are incorporated herein by reference.

[0189] Figure 1 is a schematic diagram of a mass measuring device 1 for measuring the mass and / or change in mass of a wafer such as a semiconductor wafer. The mass measuring device 1 comprises a first thermal equilibrium station 3, a second thermal equilibrium station 5, and a mass measuring station 7.

[0190] The mass measurement station 7 is configured to measure the mass and / or change in mass of a wafer. The mass measurement station 7 comprises a measurement chamber 9 and a device 11 housed in the measurement chamber 9. The device 11 is configured to measure the weight or mass of a wafer loaded on the device 11 and / or change in weight or mass.

[0191] The device 11 comprises a load cell 13 and a pan or support 15 coupled to the load cell 13 and configured to support a wafer during measurement by the device 11.

[0192] The measurement chamber 9 may form an enclosed environment around the device 11. For example, the measurement chamber 9 may maintain substantially uniform air density, air pressure, and air temperature of the air around the device 11. The measurement chamber 9 may have openings (not shown), such as appropriately sized slots, in its side walls to allow wafers to be transported into the measurement chamber 9 by, for example, an end effector of a robotic arm and positioned on the pan 15 of the device 11. When not in use, the openings may be covered by doors or covers (not shown) that can be opened to allow the measurement chamber 9 to be substantially closed or sealed when performing measurements using the device 11.

[0193] Of course, the configuration of the mass measurement station 7, and / or the measurement chamber 9, and / or the device 11 may differ from that shown in Figure 1.

[0194] The first thermal equilibrium station 3 and the second thermal equilibrium station 5 are for changing the temperature of the wafer before it is loaded into the mass measurement station 7. Specifically, during operation, the wafer is sequentially loaded into the first thermal equilibrium station 3 and then into the second thermal equilibrium station 5 before being loaded into the mass measurement station 7. Therefore, the temperature of the wafer is changed by both the first thermal equilibrium station 3 and the second thermal equilibrium station 5 before the wafer is loaded into the mass measurement station 7.

[0195] Of course, in other embodiments, only a single thermal equilibrium station, for example, only the first thermal equilibrium station 3 or only the second thermal equilibrium station 5, may be included in the mass measuring device 1.

[0196] If the wafer's temperature differs from that of the mass measurement station 7 when the wafer is placed in / moved, this can adversely affect the accuracy of the mass measurement. For example, if the wafer's temperature differs from that of the measurement chamber 9, when the wafer is inserted into the measurement chamber 9, the wafer's temperature may cause convection in the air inside the measurement chamber 9, which can adversely affect the accuracy of the mass measurement. Alternatively, or additionally, if the wafer's temperature differs from that of the measurement chamber 9, when the wafer is placed in / moved into the measurement chamber 9, this can cause a change in the temperature of the air inside the measurement chamber 9, which can change the buoyancy relative to the wafer. This can adversely affect the accuracy of the mass measurement.

[0197] Therefore, the first thermal equilibrium station 3 and the second thermal equilibrium station 5 may be configured to change the wafer temperature to be equal to or within a predetermined temperature of the mass measurement station 7, for example, to be equal to or within a predetermined temperature of the measurement chamber 9. For example, the first thermal equilibrium station 3 and the second thermal equilibrium station 5 may be configured to change the wafer temperature to be within ±0.1°C of the temperature of the mass measurement station 7 or the measurement chamber 9.

[0198] The first thermal equilibrium station 3 is configured to cause the majority of the total temperature change of the wafer caused by the first thermal equilibrium station 3 and the second thermal equilibrium station 5, while the second thermal equilibrium station 5 is configured to cause a smaller temperature change of the wafer than the first thermal equilibrium station 3.

[0199] In this embodiment, the first thermal equilibrium station 3 and the second thermal equilibrium station 5 may be for cooling the wafer, since the temperature of the wafer when it reaches the mass measuring device 1 after processing is generally higher than the temperature of the mass measuring station 7 or the measuring chamber 9. Of course, if the temperature of the wafer is lower than the temperature of the mass measuring station 7 or the measuring chamber 9, the first thermal equilibrium station 3 and / or the second thermal equilibrium station 5 may be for heating the wafer instead.

[0200] The first thermal equilibrium station 3 is configured to actively change the temperature of the wafer, for example, by actively cooling the wafer. In particular, the first thermal equilibrium station 3 may use one or more power heating or cooling devices, such as one or more thermoelectric devices, to increase or decrease the temperature of the wafer. When cooling the wafer, the first thermal equilibrium station 3 may actively dissipate heat from the wafer, for example, into an airflow passing through or adjacent to the first thermal equilibrium station 3.

[0201] The first thermal equilibration station 3 includes a first temperature-changing section 17 on which a wafer can be positioned and which is configured to change the temperature of the wafer (e.g., to cool or heat the wafer). For example, the first temperature-changing section 17 may comprise a plate or a block. The plate or block may be made of or comprise one or more materials having good thermal conductivity (e.g., Al).

[0202] The first temperature-changing section 17 may further comprise a plurality of Peltier elements attached to and / or in contact with the bottom surface (or another part of the plate or block) of the plate or block. The Peltier elements may be operable to actively dissipate heat from the plate or block, for example, into an airflow, when cooling the wafer. For example, the Peltier elements may be operable to control the temperature of the plate or block to a predetermined temperature.

[0203] The first thermal equilibrium station 3 may include a chamber that surrounds or partially surrounds the first temperature change portion 17, the chamber having an opening through which a wafer can be inserted, for example by an end effector of a robotic arm, and positioned on the first temperature change portion 17.

[0204] The second thermal equilibrium station 5 is configured to passively change the temperature of the wafer, for example, by passively cooling the wafer. In particular, the second thermal equilibrium station 5 includes a second temperature change section 19 located above the measurement chamber 9. The second temperature change section 19 may include a plate or a block. The plate or block may be made of or include one or more materials having good thermal conductivity, such as Al.

[0205] The second temperature-varying portion 19 preferably has a high thermal mass such that its temperature changes slowly and slightly when heat is supplied to it, and / or has good lateral thermal conductivity such that it maintains a substantially uniform temperature across its upper surface.

[0206] The second thermal equilibrium station 7 may include a chamber that surrounds or partially surrounds the second temperature change portion 19, the chamber having an opening through which a wafer can be inserted, for example by an end effector of a robotic arm, and positioned on the second temperature change portion 19.

[0207] The second temperature-changing portion 19 is positioned directly above the measuring chamber 9, and therefore there is good thermal contact between the second temperature-changing portion 19 and the measuring chamber 9. The second temperature-changing portion 19 is in direct physical contact with the measuring chamber 9. For example, the second temperature-changing portion 19 may be attached to or fixed to the measuring chamber 9 using, for example, one or more bolts (not shown) and / or a thermally conductive adhesive layer (not shown).

[0208] As a result of good thermal contact between the second temperature-changing section 19 and the measurement chamber 9, the second temperature-changing section 19 can be in substantially thermal equilibrium with the measurement chamber 9 and therefore can have substantially the same temperature as the measurement chamber 9 (when the thermal load on the second temperature-changing section 19 is low). Therefore, when a wafer is loaded onto the second temperature-changing section 19, the wafer can be brought into thermal equilibrium with the measurement chamber 9 and therefore has substantially the same temperature as the measurement chamber 9.

[0209] As shown in Figure 1, the mass measuring apparatus 1 further comprises a wafer handling system 2 for loading wafers into each of the first thermal equilibrium station 3, the second thermal equilibrium station 5, and the mass measuring station 7, and for removing wafers from each of these stations. For example, the wafer handling system 2 may comprise one or more robotic arms 4, each having one or more end effectors 6 for supporting and / or transporting wafers. Of course, the configuration of the wafer handling system may differ from that shown in Figure 1. Although shown separately in Figure 1, the wafer handling system is generally integrated with the apparatus 1.

[0210] As shown in Figure 1, the first thermal equilibrium station 3, the second thermal equilibrium station 5, and the mass measurement station 7 are integrated into a single device. In other words, the first thermal equilibrium station 3, the second thermal equilibrium station 5, and the mass measurement station 7 are all connected together and / or fixed together and / or mounted to each other in a stack.

[0211] Of course, in other embodiments, the relative positions of the first thermal equilibrium station 3, the second thermal equilibrium station 5, and the mass measurement station 7 may differ from those shown in Figure 1. For example, the order of each station in the stack may differ, and / or one or more of those stations may be positioned to the side of one of the other stations, rather than above or below one of the other stations.

[0212] Figure 2 is a schematic diagram of a measuring device 21 according to a first embodiment of the present invention.

[0213] The measuring device 21 may be a modified version of the mass measuring device 1 shown in Figure 1. Therefore, the measuring device 21 may have any of the features of the mass measuring device 1 shown in Figure 1 or described above, provided that these features are not incompatible with those described below.

[0214] Some features of the measuring device 21, which are the same as those of the mass measuring device 1 shown in Figure 1, are shown in Figure 2 using the same reference numerals, and their descriptions are not repeated for the sake of brevity.

[0215] The measuring device 21 according to the first embodiment of the present invention differs from the mass measuring device 1 in Figure 1 in that the measuring device 21 further includes a hyperspectral imaging system 23.

[0216] As shown in Figure 2, in this embodiment, the hyperspectral imaging system 23 is integrated with (or therein) the first thermal equilibrium station 3, and is therefore configured to perform hyperspectral imaging of the wafer 25 while the wafer 25 is loaded onto the first temperature change portion 17 of the first thermal equilibrium station 3.

[0217] In Figure 2, all components of the hyperspectral imaging system 23 are shown to be located inside the first thermal equilibrium station 3. However, one, some, or all of these components may be located outside the first thermal equilibrium station 3.

[0218] In this embodiment, the hyperspectral imaging system 23 includes a hyperspectral imaging camera 26 configured to perform hyperspectral imaging of the side or surface of a wafer, acquire a hyperspectral image of the side or surface of a wafer, or acquire hyperspectral imaging data of the side or surface of a wafer. Furthermore, the hyperspectral imaging system 23 further includes an illumination source 27, such as a broadband light source, configured to generate illumination such as light for performing hyperspectral imaging of the side or surface of a wafer, acquiring a hyperspectral image of the side or surface of a wafer, or acquiring hyperspectral imaging data of the side or surface of a wafer.

[0219] The hyperspectral imaging camera 26 may include, for example, a snapshot camera or a pushbloom camera.

[0220] Furthermore, the hyperspectral imaging system 23 further includes an optical element 29 configured to direct or guide illumination generated by an illumination source 27 onto a wafer loaded on the first temperature-varying portion 17, and to direct the illumination reflected from the wafer (e.g., reflected light) to a hyperspectral imaging camera 26, for the purpose of performing hyperspectral imaging and / or acquiring hyperspectral images or hyperspectral imaging data. For example, as described below, the optical element 29 may include one or more of a beam splitter and one or more lenses, such as a convex lens.

[0221] Of course, the arrangement of the illumination source 27, optical element 29, and camera 26 may differ from that schematically shown in Figure 2.

[0222] Therefore, in this embodiment, hyperspectral imaging of the wafer may be performed while the wafer is positioned on a first temperature change portion 17 in the first thermal equilibrium station 3 and its temperature is being changed by the first temperature change portion 17. Thus, a hyperspectral image and / or hyperspectral imaging data of the wafer 25 may be acquired while the wafer is positioned on the first temperature change portion 17.

[0223] Hyperspectral imaging data may correspond to, indicate, or measure the spectral reflectance (e.g., optical spectral reflectance) of the side or surface of a wafer, for example, all areas of the side or surface of the wafer, or all areas of a portion of the side or surface of the wafer.

[0224] Hyperspectral imaging data may include spectral data, such as optical spectral data, for all areas of the side or surface of the wafer, or for all areas of a portion of the side or surface of the wafer.

[0225] Hyperspectral imaging data may include or comprise optical spectral data.

[0226] Hyperspectral imaging data may include hyperspectral data cubes for part or all of the side or surface of the wafer.

[0227] A hyperspectral image or hyperspectral imaging data may be an image that contains spectral data (e.g., optical spectral data) for each pixel of the image.

[0228] A hyperspectral image or hyperspectral imaging data may be an image that contains the optical spectrum for each pixel of the image.

[0229] A hyperspectral image or hyperspectral imaging data can be a single image containing intensity versus wavelength data for each pixel of the image.

[0230] Alternatively, a hyperspectral image or hyperspectral imaging data may include multiple images, each corresponding to a different wavelength, wavelength range, or wavelength band of illumination, and each containing intensity data for each pixel of the image.

[0231] As described above, combining wafer hyperspectral imaging with wafer thermal equilibrium in this way can offer several advantages over performing both steps separately. For example, the total footprint and cost of the measurement equipment may be reduced, and the total measurement time for the wafer in the measurement equipment may be reduced.

[0232] Furthermore, as described above, the hyperspectral imaging system 23 has minimal moving parts (compared to some other types of optical measurement systems) and therefore causes minimal vibration, so the hyperspectral imaging system 23 may not adversely affect the measurements being performed on the first wafer by the mass measurement station 7 at the same time that hyperspectral imaging is being performed on the second wafer by the hyperspectral imaging system 23.

[0233] Furthermore, since the hyperspectral imaging system 23 has minimal moving parts (compared to some other types of optical measurement systems), the hyperspectral imaging system 23 can generate reduced electromagnetic noise and therefore may not adversely affect measurements being performed on the first wafer by the mass measurement station 7 while hyperspectral imaging is being performed on the second wafer by the hyperspectral imaging system 23.

[0234] The measuring device 21 further comprises a processor 31 or controller configured to receive hyperspectral imaging data from the hyperspectral imaging system 23 and mass measurement data (mass and / or change in mass) from the mass measurement station 7.

[0235] The processor 31 may be configured to evaluate one or more parameters of the wafer based on either or both of the hyperspectral imaging data and / or mass measurement data (mass and / or change in mass). For example, the processor may be configured to determine uniformity data relating to the side or surface of the wafer based on the hyperspectral imaging data, or based on both the hyperspectral imaging data and mass measurement data (mass and / or change in mass). The uniformity data may relate to one or more of the uniformity of, for example, the thickness of a layer on the side or surface of the wafer, or the limit dimensions of a pattern on the side or surface of the wafer. The uniformity data may relate to the uniformity of a pattern of interest across the wafer. The uniformity data may relate to a specific dimension of the wafer.

[0236] Combining mass measurement data (mass and / or change in mass) with hyperspectral imaging data can improve the reliability and sensitivity of uniformity data determination compared to using hyperspectral imaging data alone. Alternatively, or as an addition, combining hyperspectral imaging data with mass measurement data (mass and / or change in mass) can provide uniformity information not provided by mass measurement data alone. Therefore, hyperspectral imaging data and mass measurement data can be combined synergistically to improve the evaluation of one or more parameters of a wafer.

[0237] The hyperspectral imaging system 23 may be configured to perform hyperspectral imaging of an entire side or surface of a wafer 25 and / or to acquire a hyperspectral image or hyperspectral imaging data. Alternatively, the hyperspectral imaging system 23 may be configured to perform hyperspectral imaging of a portion of a side or surface of a wafer and / or to acquire a hyperspectral image or hyperspectral imaging data. In this case, a hyperspectral imaging system 23 having multiple different hyperspectral imaging systems 23, or multiple different hyperspectral imaging cameras 26, may be used to acquire different hyperspectral images or hyperspectral imaging data of different parts of a wafer. Alternatively, a part of the hyperspectral imaging system 23, e.g., an optical element 29 and / or a hyperspectral imaging camera 26, may be movable (e.g., translatable parallel to the side or surface of the wafer) to acquire a hyperspectral image or hyperspectral imaging data of different parts of a side or surface of a wafer. Alternatively, the wafer, or a support supporting the wafer, may be movable (e.g., translatable parallel to the side or surface of the wafer) to acquire a hyperspectral image or hyperspectral imaging data of different parts of a side or surface of a wafer.

[0238] Hyperspectral imaging data can be used to determine or measure the uniformity of the wafer's sides or surface, for example, the uniformity of a pattern of interest across the wafer's sides or surface.

[0239] The processor 31 may be configured to use hyperspectral imaging data to perform the following steps: (i) identify one or more locations of interest on the side or surface of the wafer; (ii) extract optical spectral information (or spectra) from each location of interest; and (iii) analyze the extracted optical spectral information (or spectra) to obtain wafer uniformity information.

[0240] The extracted spectral information (or spectrum) can be combined with mass measurement data (mass and / or change in mass) for the wafer to provide a more reliable and accurate analysis of the wafer, potentially enabling, for example, more accurate and reliable comparisons of inter-wafer uniformity or intra-wafer uniformity.

[0241] Figure 3 is a schematic diagram of a measuring device 33 according to a second embodiment of the present invention. In the second embodiment, the hyperspectral imaging system 23 is integrated with (or in) the second thermal equilibrium station 5 instead of the first thermal equilibrium station 3, and is therefore configured to perform hyperspectral imaging of the wafer 25 while the wafer 25 is loaded onto the second temperature change portion 19 of the second thermal equilibrium station 5.

[0242] In Figure 3, all components of the hyperspectral imaging system 23 are shown to be located inside the second thermal equilibrium station 5. However, one, some, or all of these components may be located outside the second thermal equilibrium station 5.

[0243] In some cases, the features and operation of the measuring device 33 according to the second embodiment may be the same as those of the measuring device 21 according to the first embodiment, provided that there are no incompatibilities.

[0244] Features in Figure 3 that are the same as, or correspond to, those in Figures 1 and 2 are indicated by the same reference numerals in Figure 3, and their descriptions are not repeated here for the sake of brevity.

[0245] Figure 4 is a schematic diagram of a measuring device 35 according to a third embodiment of the present invention. In the third embodiment, the hyperspectral imaging system 23 is integrated with (or therein) the mass measurement station 7 instead of the first thermal equilibrium station 3 or the second thermal equilibrium station 5, and the hyperspectral imaging system 23 is configured to perform hyperspectral imaging of the wafer 25 while the wafer 25 is loaded onto the pan 15 of the device 11 in the mass measurement station 7.

[0246] In Figure 4, all components of the hyperspectral imaging system 23 are shown to be located inside the mass measurement station 7. However, one, some, or all of these components may be located outside the mass measurement station 7.

[0247] In some cases, the features and operation of the measuring device 35 according to the third embodiment may be the same as those of the measuring device 21 according to the first embodiment, provided that there are no incompatibilities.

[0248] Features of Figure 4 that are the same as, or correspond to, those of Figures 1, 2, and 3 are indicated by the same reference numerals in Figure 4, and their descriptions are not repeated here for the sake of brevity.

[0249] In the embodiment shown in Figure 4, device 11 may be controlled not to perform measurements while the hyperspectral imaging system 23 is performing hyperspectral imaging, in order to avoid the operation of the hyperspectral imaging system 23 affecting the accuracy of measurements by device 11.

[0250] Figure 5 is a schematic diagram of a measuring device 37 according to a fourth embodiment of the present invention. In the fourth embodiment, the hyperspectral imaging system 23 is contained within a hyperspectral imaging station 39, instead of being integrated into one of the other stations 3, 5, or 7. The hyperspectral imaging station 39 is separate from the first thermal equilibrium station 3, the second thermal equilibrium station 5, and the mass measurement station 7.

[0251] The first thermal equilibrium station 3, the second thermal equilibrium station 5, the mass measurement station 7, and the hyperspectral imaging station 39 are all integrated into a single device. For example, the first thermal equilibrium station 3, the second thermal equilibrium station 5, the mass measurement station 7, and the hyperspectral imaging station 39 are all connected together and / or fixed together and / or mounted to each other in a stack.

[0252] In a fourth embodiment, the wafer handling system 2 is further configured to load wafers into the hyperspectral imaging station 39 and to remove wafers from the hyperspectral imaging station 39. Thus, a single wafer handling system 2 is used to load and unload wafers into and from each of the first thermal equilibrium station 3, the second thermal equilibrium station 5, the mass measurement station 7, and the hyperspectral imaging station 39.

[0253] In the fourth embodiment, the hyperspectral imaging station 39 is positioned above the first thermal equilibrium station 3. Of course, in other embodiments, the hyperspectral imaging station 39 may be positioned differently.

[0254] In this embodiment, the hyperspectral imaging station 39 is separate from the first thermal equilibrium station 3, the second thermal equilibrium station 5, and the mass measurement station 7, but is connected to at least one of the first thermal equilibrium station 3, the second thermal equilibrium station 5, and the mass measurement station 7.

[0255] The hyperspectral imaging station 39 includes a support, such as a chuck, for supporting a wafer during hyperspectral imaging.

[0256] Furthermore, the hyperspectral imaging station 39 may include a housing or chamber for surrounding a wafer during hyperspectral imaging. The housing or chamber may have an opening for inserting and removing the wafer from the hyperspectral imaging station 39.

[0257] During the operation of the measuring device 33, the wafer is sequentially moved between the hyperspectral imaging station 39, the first thermal equilibrium station 3, the second thermal equilibrium station 5, and the mass measurement station 7. Therefore, a hyperspectral image or hyperspectral imaging data of the wafer is generated before thermal equilibrium and mass measurement of the wafer. Alternatively, the wafer may be moved to the hyperspectral imaging station 39 after mass measurement station 5.

[0258] Figure 6 is a schematic diagram of a measuring device 41 according to one embodiment of the present invention.

[0259] Figure 6 may be a partial view of the system 33 of the second embodiment shown in Figure 3, in which the hyperspectral imaging system 23 is integrated with (or into) the second thermal equilibrium station 5. Thus, the embodiment in Figure 6 may include any of the features of the second embodiment, unless incompatible, and the second embodiment may include any of the features of Figure 6, unless incompatible. Alternatively, the embodiment in Figure 6 may be a separate embodiment without the additional features of the second embodiment.

[0260] Features of Figure 6 that are the same as, or correspond to, the features of the previous embodiments described above are indicated by the same reference numerals in Figure 6, and their descriptions are not repeated here for the sake of brevity.

[0261] As in the second embodiment shown in Figure 3, the hyperspectral imaging system 23 is configured to perform hyperspectral imaging of the wafer 25 while the wafer 25 is loaded onto the temperature change portion 19 of the thermal equilibrium station.

[0262] The optical element 29 of the hyperspectral imaging system 23 is configured to direct illumination generated by the illumination source 27 onto the wafer 25 loaded on the temperature change portion 19, and to direct the illumination reflected from the wafer 25 onto the hyperspectral imaging camera 26, in order to perform hyperspectral imaging and / or acquire hyperspectral images or hyperspectral imaging data.

[0263] In this embodiment, the optical element 29 includes a beam splitter 43 that directs light from the illumination source 27 towards the wafer 25 and transmits light from the wafer 25 towards the hyperspectral imaging camera 26.

[0264] Furthermore, the optical element 29, in combination with the beam splitter 43, further comprises a plurality of lenses 45a, 45b, and 45c for illuminating the wafer 25 with light generated by the illumination source 27 and for directing the light from the wafer to the hyperspectral imaging camera 26 in order to perform hyperspectral imaging and / or acquire hyperspectral images or hyperspectral imaging data.

[0265] For example, these multiple lenses may include a first lens 45a positioned on the optical path from the illumination source 27 to the beam splitter 43, a second lens 45b positioned on the optical path between the beam splitter 43 and the wafer 25, and a third lens 45c positioned on the optical path between the beam splitter 43 and the hyperspectral imaging camera 26.

[0266] Furthermore, in this embodiment, the optical element 29 further includes an optional polarizer 47 on the optical path between the beam splitter 43 and the hyperspectral imaging camera 26, for example, a third lens 45c and the hyperspectral imaging camera 26. Of course, if a polarizer 47 is included, it may be located at a different position relative to the other components of the optical element 29.

[0267] Of course, this is merely one example of a suitable optical element 29, and other configurations of the optical element 29 are possible to achieve the same or similar effects and may be used instead of the optical element 29 described above. A specific configuration or arrangement of the optical element 29 is not essential to the present invention.

[0268] In this embodiment, the illumination source 27 is a broadband light source. For example, the illumination source 27 may be configured to simultaneously emit light having a wide range of wavelengths. The illumination source 27 may include a polarizer. The broadband light source may be, for example, a broadband continuous light bulb, a broadband pulsed light bulb, or a supercontinuum laser.

[0269] In Figure 6, the hyperspectral imaging system 23 is shown to acquire a hyperspectral image or hyperspectral imaging data of the entire upper side or surface of the wafer 25. In an alternative configuration, the hyperspectral imaging system 23 may instead be configured to acquire an image of only a portion of the upper side or surface of the wafer. One or more parts of the hyperspectral imaging system 23 may be movable or adjustable to change the area of ​​the upper side or surface of the wafer being imaged. Alternatively, the hyperspectral imaging system 23 may comprise a plurality of hyperspectral imaging cameras 26 arranged to acquire images of different portions of the side or surface of the wafer 25.

[0270] Figure 7 is a schematic diagram of a measuring device 49 according to one embodiment of the present invention. The measuring device 49 is a modified version of the measuring device 41 in Figure 6.

[0271] Features of the previous embodiments described above, or features corresponding to those in Figure 7, are indicated by the same reference numerals in Figure 7, and their descriptions are not repeated here for the sake of brevity.

[0272] In the embodiment shown in Figure 7, an imaging camera such as a charge-coupled device (CCD) camera 51 is used instead of the hyperspectral imaging camera 26. In this embodiment, a hyperspectral image or hyperspectral imaging data of the wafer is acquired using the CCD camera 51 by selecting different wavelengths to be imaged by the CCD camera 51, by selecting different wavelengths to be emitted by the illumination source 53, or by selecting different wavelengths to be input to the CCD camera 51.

[0273] For example, the illumination source 53 may be controllable to selectively emit light having a specific wavelength, wavelength range, or wavelength band. For example, the illumination source 53 may include a plurality of different illumination sources, each configured to emit light having a different specific wavelength, wavelength range, or wavelength band, and each of the plurality of different illumination sources may be selectively activated to selectively emit light having its respective wavelength, wavelength range, or wavelength band. For example, the plurality of illumination sources may include a plurality of LEDs having different wavelengths, or a plurality of lasers having different wavelengths.

[0274] Alternatively, the illuminator 53 may be a single illuminator that is tunable or adjustable to adjust or select the wavelength, wavelength range, or wavelength band of light emitted by the illuminator. In other words, the illuminator 53 may be tunable to a specific wavelength, wavelength range, or wavelength band. For example, the illuminator may be a tunable laser.

[0275] In this way, a hyperspectral image or hyperspectral imaging data of the wafer can be obtained by taking a series of images using the CCD camera 51 at different wavelengths of light emitted by the illumination source 53.

[0276] Alternatively, the illumination source 53 may be a broadband light source as described above, and the hyperspectral imaging system 23 may include a wavelength selection device for selecting a specific wavelength or wavelength range or wavelength band from the light emitted by the broadband light source to be used to perform spectral imaging.

[0277] For example, the hyperspectral imaging system 23 may include a bandpass filter. For example, the hyperspectral imaging system 23 may include an adjustable or tunable bandpass filter. The bandpass filter may be positioned on the optical path from the illumination source, for example, adjacent to the illumination source. Alternatively, the bandpass filter may be positioned at another location on the optical path from the illumination source to the CCD camera 51.

[0278] Therefore, a wavelength-selective device, such as a bandpass filter, can be tuned or adjusted to select a specific wavelength, wavelength range, or wavelength band to be imaged using the CCD camera 51.

[0279] A suitable example of a wavelength-selective device may be a bandpass filter wheel comprising several different bandpass filters that selectively transmit light having different specific wavelengths, wavelength ranges, or wavelength bands, and the bandpass filter wheel may be rotated to position different of those bandpass filters in the optical path.

[0280] Another example of a suitable wavelength-selective device could be an adjustable filter, such as an acousto-optic adjustable filter.

[0281] Another example of a suitable wavelength-selective device is a diffraction grating, which may be movable and / or rotatable to vary a selected wavelength or wavelength range or wavelength band, as imaged by a CCD camera 51.

[0282] Another example of a suitable wavelength-selective device is an optical dispersion device, such as a prism, which may be movable and / or rotatable to vary a selected wavelength or wavelength range or wavelength band, as imaged by a CCD camera 51.

[0283] One embodiment may use a supercontinuum laser as the light source in combination with an acousto-optically adjustable filter on the illumination side, and a high-resolution CCD camera as the detector. Such a configuration may enable the measurement of high-resolution images with a high-resolution broadband spectrum at a high signal-to-noise ratio and at high speed.

[0284] Figure 8 is a schematic diagram of a part of a measuring device according to one embodiment of the present invention.

[0285] In particular, the arrangement shown in FIG. 8 can be used as or included in the hyperspectral imaging station 39 in FIG. 5. Thus, the embodiment of FIG. 8 can include any of the features of the fourth embodiment, provided it is not incompatible, and the fourth embodiment can include any of the features of FIG. 8, provided it is not incompatible.

[0286] Specifically, FIG. 8 shows the configuration of the hyperspectral imaging system 23 in the hyperspectral imaging station 39 in FIG. 5. The hyperspectral imaging system 23 can have any of the features of any of the hyperspectral imaging systems 23 described above, provided it is not incompatible.

[0287] Furthermore, the hyperspectral imaging system 23 further includes a support 55 for supporting the wafer during hyperspectral imaging of the wafer 25. For example, the support 55 can comprise a chuck or a plate or a block.

[0288] In this embodiment, the support 55 is only for supporting the wafer 25 during hyperspectral imaging and is not configured to cause a predetermined change in the temperature of the wafer 25.

[0289] Thus, the hyperspectral imaging system 23 is not integrated with (or into) a thermal equilibration station or a mass measurement station.

[0290] Of course, the different embodiments described above can be combined together in various ways. For example, any of the hyperspectral imaging systems 23 of FIG. 6 or FIG. 7 can be used in any of the first to fourth embodiments described above.

[0291] Furthermore, as shown in the figure, it is not mandatory to include two different thermal equilibration stations. Instead, only a single thermal equilibration station may be included, which could be, for example, an active or passive thermal equilibration station, and could correspond to either the first thermal equilibration station 3 or the second thermal equilibration station 5 in Figure 1. In some embodiments, the apparatus may not include a thermal equilibration station, and instead, the hyperspectral imaging system may be integrated with (or into) the mass measurement station 7, or provided as a separate hyperspectral imaging station 39 attached to, fixed to, or mounted on the mass measurement station 7.

[0292] Furthermore, it is not essential that these stations are mounted in a stack, one after the other, as shown in the figure. Instead, in other embodiments, one or more of these stations may be positioned side by side, for example.

[0293] As described above, the hyperspectral imaging data acquired by the hyperspectral imaging system 23 in any embodiment of the present invention may be processed or used to evaluate one or more parameters of a wafer, such as the uniformity of the wafer's side or surface, for example, the uniformity of a dimension or pattern of interest across the wafer's side or surface.

[0294] For example, using the system in Figure 6, the hyperspectral imaging data may include optical spectral data for every pixel of the entire field image of the wafer or a partial image of the wafer.

[0295] One or more image processing algorithms may be used to select optical spectral data from hyperspectral imaging data from a point or area of ​​interest on a wafer.

[0296] The selected optical spectral data can then be analyzed to obtain wafer uniformity information, for example, to generate a wafer uniformity map for the sides or surfaces of the wafer.

[0297] Alternatively, using the system shown in Figure 7, for example, the hyperspectral imaging data may include multiple images of the wafer acquired for different selected wavelengths or wavelength ranges or wavelength bands of illumination.

[0298] Processing hyperspectral imaging data may include using one or more image processing algorithms to extract intensity data from a point or area of ​​interest on a wafer from each of several images (corresponding to different wavelengths of illumination), and combining the intensity data for each point or area of ​​interest to generate optical spectral data for that point or area of ​​interest.

[0299] As described above, the acquired optical spectral data can then be analyzed to obtain wafer uniformity information, such as a wafer uniformity map for the sides or surface of the wafer.

[0300] In either case, the mass measurement data (mass and / or change in mass) obtained for the wafer can be combined with optical spectral data to obtain wafer uniformity information.

[0301] This processing can be carried out by processor 31.

[0302] The measuring device (e.g., processor 31) may include a modeling module that generates dimensions of interest at multiple points or areas of interest based on acquired optical spectral data and a trained model.

[0303] A trained model can relate uniformity data to optical spectral data.

[0304] A trained model can be generated, for example, using machine learning. Machine learning may include supervised learning models selected from a group consisting of, for example, linear models, support vector machine models, decision tree models, random forest models, and Gaussian models.

[0305] A trained model may be generated, for example, by correlating optical spectral data from multiple measurement locations on a wafer with uniformity data for the wafer, the uniformity data including at least one of thickness data, critical dimension data, depth data, and material density data, which can be accurately measured, for example, using one or more known measurement methods.

[0306] The measuring device (e.g., processor 31) may further include a spatial modeling module that generates a spatial distribution model of dimensions of interest about the side or surface of a wafer, based on the dimensions at a plurality of points or areas of interest.

[0307] Furthermore, the spatial modeling module may also use the mass or change in mass of the wafer measured by the mass measurement station 7 when generating a spatial distribution model. For example, the mass or change in mass may be used by the spatial modeling module as a constraint on the spatial distribution model.

[0308] Alternatively, the measuring device (e.g., processor 31) may include a modeling module that generates wafer uniformity data based on acquired optical spectral data and a trained model, and the mass and / or change in mass of the wafer from the mass measurement station may optionally also be used to generate wafer uniformity data. The trained model may relate the uniformity data to the optical spectral data and optionally to the mass and / or change in mass of the wafer. In one embodiment, the following specific steps may be performed to process hyperspectral imaging data and data on mass and / or changes in mass.

[0309] · Establish a coordinate system for the wafer using intensity data from one or more wavelength bands from hyperspectral imaging data.

[0310] · Optionally, create a die map of the wafer.

[0311] · Discard hyperspectral imaging data from outside the zone / area of interest on the wafer based on the coordinate system established above.

[0312] · Process optical information from the zone / area of interest across the wafer to determine wafer uniformity.

[0313] · One or more of the above steps may involve the use of data on the mass and / or change in mass of the wafer obtained from one or more of the mass measurement measurements on the wafer before processing of the wafer and the mass measurement measurements on the wafer after processing of the wafer.

[0314] · Data on mass and / or change in mass and / or hyperspectral imaging data may be combined to create a machine learning model. The machine learning model may be used to predict the within-wafer uniformity of the wafer.

[0315] · One or more of the above steps may involve using (separately measured) mass center information about the wafer when determining the within-wafer uniformity.

[0316] Suitable data processing methods are described, for example, in U.S. Patent No. 10,989,652 (B2), the entire content of which is incorporated herein by reference.

[0317] Hyperspectral imaging may be performed on the same wafer both before and after processing, and the hyperspectral imaging data from both before and after processing may be used to determine uniformity information.

[0318] In addition to, or instead of, uniformity data, other types of wafer evaluations may be performed. For example, hyperspectral imaging data may be used to determine wafer warpage or curvature using achromatic defocus imaging.

[0319] For example, as shown in Figure 9, hyperspectral imaging data may include, or be used to generate, multiple images of the side or surface of a wafer for different wavelengths or wavelength ranges or wavelength bands of illumination. For example, Figure 9 shows a first image 57 of the wafer acquired at a first wavelength or wavelength range or wavelength band, and a second image 59 of the wafer acquired at a second wavelength or wavelength range or wavelength band of the wafer.

[0320] When a wafer is warped, that is, when the wafer is not flat, each of the multiple images will contain both an in-focus area and an out-of-focus area. For example, in the two images in Figure 9, an in-focus area 61 and an out-of-focus area 63 are shown.

[0321] Using one or more image processing algorithms, the patterns of in-focus and out-of-focus areas in each of multiple images may be analyzed, and based on this analysis, the shape of the wafer (e.g., the amount and shape of the wafer's curvature or warp) may be determined.

[0322] Information regarding the wafer's shape can be combined with other data determined based on hyperspectral imaging data and / or mass measurement data (mass and / or change in mass) to determine other information about the wafer. For example, the wafer shape determined as described above can be combined with information about the wafer's thickness and / or a film on the wafer's sides or surface, determined based on mass measurement data and / or hyperspectral imaging data, to determine the stress in that film. For example, the stress in that film can be calculated at a global or local level based on the wafer's curvature information.

[0323] Of course, it is not necessary to use all of the hyperspectral imaging data to perform this analysis. For example, this analysis can be performed using one or more channels of the imaging data.

[0324] Figure 10 is a schematic diagram of a measuring device according to one embodiment of the present invention. This measuring device is a modified version of the measuring device 41 shown in Figure 6 and described above (or, alternatively, a modified version of the measuring device 49 shown in Figure 7 and described above).

[0325] In particular, the measuring apparatus in Figure 10 is modified to include an interferometer reference unit 65 to enable interference measurements on the wafer. The interferometer reference unit 65 comprises a reference wafer 67 supported on a support 69. The interferometer reference unit 65 further comprises a lens (or other optical element) for directing light that has passed through the beam splitter 43 onto the reference wafer 67.

[0326] Light reflected from the reference wafer 67 and subsequently incident on the hyperspectral imaging camera 26 interferes with light reflected from the wafer 25 and subsequently incident on the hyperspectral imaging camera 26.

[0327] By analyzing the interference pattern resulting from this interference and imaged by the hyperspectral imaging camera 26, it may be possible to identify differences between wafer 25 and reference wafer 67, such as differences in wafer warpage or curvature, differences in wafer edge profiles, or differences between macro features on the side or surface of wafer and macro features on the side or surface of reference wafer.

[0328] Of course, when performing such an analysis, it is not necessary to use all of the hyperspectral imaging data acquired by the hyperspectral imaging camera 26. Instead, one or a subset of the channels (i.e., individual frequencies or frequency bands) may be used for the analysis.

[0329] Figure 11 shows an example of measurement data acquired using the measuring device shown in Figure 10.

[0330] Figure 11 shows the edge profile 71 of wafer 25 and the interference pattern 73 resulting from interference light from the edges of wafer 25 and the edges of the reference wafer 67. The interference pattern 73 may be analyzed to determine similarities between the edges of wafer 25 and the edges of the reference wafer 67, and / or to determine or measure the wafer edge profile of wafer 25.

[0331] Edge profile information, combined with measurements of the wafer's mass and / or change in mass, can be used to determine mass loss during an edge cleaning process performed on the wafer.

[0332] Figure 12 is a schematic diagram of a part of a measuring device according to one embodiment of the present invention. In particular, Figure 12 shows a hyperspectral imaging system 75 that can be used as part of a measuring device according to the present invention. For example, the hyperspectral imaging system 75 can be used instead of the hyperspectral imaging system 23 in the embodiments of Figures 2, 3, 4, and / or Figure 5. Thus, the embodiment of Figure 12 may include features of any of the embodiments of Figures 2 to 5, and vice versa, unless incompatible.

[0333] The hyperspectral imaging system 75 includes a support 76 for supporting the wafer 25 during hyperspectral imaging of the wafer. Depending on the particular embodiment, the support 76 may be configured as a single support comprising, for example, a chuck or a plate, or as a temperature-varying portion. For example, when the hyperspectral imaging system 75 is used as part of the measuring device 21 in Figure 2, the support 76 may correspond to a first temperature-varying portion 17. When the hyperspectral system 75 is used as part of the measuring device 33 in Figure 2, the support 76 may correspond to a second temperature-varying portion 19. When the hyperspectral system 75 is used as part of the measuring device 35 in Figure 4, the support 76 may correspond to the pan 15 of the device 11. When the hyperspectral system 75 is used as part of the measuring device 37 in Figure 5, the support 76 may correspond to a support (e.g., a chuck) of the hyperspectral imaging station 39.

[0334] The hyperspectral imaging system 75 further includes illumination sources implemented as multiple light sources 77 mounted around the support 76 adjacent to (e.g., adjacent to) it. Although two light sources 77 are shown in Figure 12, in practice there can be a different (e.g., more) number of light sources mounted around the support 76. For example, the light sources 77 may be arranged in a ring around the support 76. The light sources 77 may be arranged so that they are evenly spaced around the support 76.

[0335] The light source 77 may include any suitable type of light source. For example, the light source 77 may be a broadband light source, such as a broadband LED.

[0336] The hyperspectral imaging system 75 further includes a reflector in the form of a concave reflective surface 78. The concave reflective surface 78 faces the support 76 and a light source 77 positioned around the support 76, and is positioned to reflect light emitted by the light source 77 onto the wafer 25 on the support 76. The concave reflective surface 78 may have any preferred curved or dome-shaped form for reflecting light toward the support 76. The central axis 79 (i.e., principal axis) of the concave reflective surface 78 may be substantially aligned with the center of the support 76. In this way, when the wafer 25 is on the support, the concave reflective surface 78 may be substantially centered with the wafer 25.

[0337] The concave reflective surface 78 may be configured to reflect light from the light source 77 as diffuse light, that is, the concave reflective surface 78 may reflect diffuse light toward the wafer 25. In this way, the wafer 25 can be illuminated by the diffuse light from the concave reflective surface 78. This can result in relatively uniform (smooth) illumination across the sides or surface of the wafer 25.

[0338] In some cases, the concave reflective surface 78 may include a coating configured to diffuse light incident on the concave reflective surface 78. For example, the coating may include a white matte coating or finish on the concave reflective surface 78, and / or a PTFE coating. As another example, Spectraflect® or Permaflect®, provided by Labsphere, may provide a suitable diffuse reflective coating.

[0339] In some cases, the material of the concave reflective surface 78 may be selected to diffuse the reflected light, for example, so that a coating may not be required. For example, the concave reflective surface 78 may be made from an acrylic material that has suitable light diffusion properties.

[0340] The hyperspectral imaging system 75 further includes a hyperspectral imaging camera 80 configured to perform hyperspectral imaging of the side or surface of a wafer, acquire a hyperspectral image of the side or surface of a wafer, or acquire hyperspectral imaging data of the side or surface of a wafer. The hyperspectral imaging camera 80 may be, for example, one of those described with respect to the hyperspectral imaging camera 26.

[0341] The hyperspectral imaging camera 80 is positioned to receive light reflected from the wafer 25. The hyperspectral imaging camera 80 is positioned on the opposite side of the concave reflective surface 78 compared to the support 76 and the wafer 25. Therefore, an opening (aperture, through hole) is formed in the concave reflective surface 78 so that light reflected from the wafer 25 can reach the hyperspectral imaging camera 80. In the illustrated example, a portion of the hyperspectral imaging camera 80 (e.g., a lens) protrudes through the opening in the concave reflective surface 78 to receive light reflected from the wafer 25.

[0342] Arrow 81 in Figure 12 indicates the optical path in the hyperspectral imaging system 75 during hyperspectral imaging of the wafer 25. As can be seen, light emitted from the light source 77 is emitted toward the concave reflective surface 78. The light from the light source 77 is reflected toward the wafer 25 by the concave reflective surface 78. As described above, the reflected light can be diffused by the concave reflective surface 78. The wafer 25 reflects the received light, and a portion of it is received by the hyperspectral imaging camera 80.

[0343] As shown in the figure, the hyperspectral imaging camera 80 may be mounted so that it is centered with respect to the central axis 79 of the wafer 25 and / or the concave reflective surface 78. For example, the hyperspectral imaging camera 80 may be mounted at the apex of the hyperspectral imaging camera 80. This may facilitate hyperspectral imaging of the wafer 25. Alternatively, the hyperspectral imaging camera 80 may be positioned offset from the central axis 79 of the concave reflective surface 78.

[0344] The light sources 77 can be positioned such that the light emitted by them is angled (tilted) toward the central axis 79 of the concave reflective surface 78. This can result in a relatively small incident angle of the reflected light on the wafer 25, which can facilitate hyperspectral imaging of the wafer 25.

[0345] The concave reflective surface 78 may form part of the housing 82 or chamber for surrounding the wafer 25 during spectral imaging. In particular, the concave reflective surface 78 may be provided as a curved (domed) inner surface of the housing 82 facing the support 76. The light sources 77 may be mounted on the surface of the housing adjacent to the support 76 (e.g., adjacent to or near it) so that they face the concave reflective surface 78. In the illustrated example, the light sources 77 are mounted on the side wall of the housing 82 surrounding the support 76.

[0346] The above description refers to a hyperspectral imaging system. However, other embodiments of the present invention may use, for example, a spectral imaging system or a multispectral imaging system instead of a hyperspectral imaging system. Accordingly, references to a hyperspectral imaging system and / or a hyperspectral imaging camera above may be replaced with references to a spectral imaging system and / or a spectral imaging camera, or a multispectral imaging system and / or a multispectral imaging camera, unless such references are incompatible.

[0347] In the above description, or in the following claims, or in the accompanying drawings, the disclosed features, as appropriately expressed in their specific forms, or with respect to means for carrying out the disclosed functions, or methods or processes for obtaining the disclosed results, may be used individually or in any combination of such features to realize the present invention in its various forms.

[0348] While the present invention has been described in relation to the exemplary embodiments described above, many equivalent modifications and variations will be apparent to those skilled in the art when this disclosure is given. Therefore, the exemplary embodiments of the present invention described above are illustrative and not limiting. Various modifications of the described embodiments can be made without departing from the spirit and scope of the invention.

[0349] To avoid misunderstanding, the theoretical explanations provided herein are provided for the purpose of improving the reader's understanding. The inventors do not wish to be bound by any of these theoretical explanations.

[0350] Any headings used herein are for organizational purposes only and should not be interpreted as limiting the subject matter described.

[0351] Throughout this Spec., including the following claims, unless the context requires otherwise, the words “comprise” and “include,” as well as variations such as “comprises,” “comprising,” and “including,” will be understood to imply that they include the described complete or step or group of complete or step, but not to imply that they exclude other complete or step or group of complete or step.

[0352] It should be noted that the singular forms “a,” “an,” and “the” used herein and in the appended claims include plural referents unless the context explicitly specifies otherwise. Herein, ranges may be expressed as “about” a particular value and / or “about” another particular value. When such ranges are expressed, another embodiment includes a range from a particular value and / or another particular value. Similarly, when a value is expressed as an approximation by the use of the preceding word “about,” it will be understood that a particular value forms another embodiment. The term “about” with respect to numbers is optional and means, for example, + / - 10%.

Claims

1. A measuring device, A mass measuring station for measuring the mass and / or change in mass of a wafer, A spectral imaging system for performing spectral imaging of at least a portion of a wafer, A measuring device equipped with the following features.

2. A measuring device according to claim 1, A measuring device wherein the spectral imaging system is a multispectral imaging system or a hyperspectral imaging system.

3. A measuring device according to claim 1 or 2, The measuring device is configured to generate wafer uniformity data based at least on the output of the spectral imaging system.

4. A measuring device according to claim 3, A measuring device configured to generate wafer uniformity data based on the output of the spectral imaging system and the mass and / or change in mass measured by the mass measurement station.

5. A measuring device according to claim 3 or 4, A measuring device configured to generate wafer uniformity data using a machine learning model and / or a trained model.

6. A measuring device according to any one of claims 1 to 5, The spectral imaging system is a measuring device configured to perform spectral imaging of at least a portion of the wafer while the wafer is in the mass measurement station.

7. A measuring device according to any one of claims 1 to 6, The mass measurement station comprises a device for measuring the weight or mass of a wafer and / or changes in weight or mass, The spectral imaging system is configured to perform spectral imaging of at least a portion of the wafer while the wafer is loaded onto the device. Measuring device.

8. A measuring device according to any one of claims 1 to 7, The measuring device comprises a thermal equilibrium station for changing the temperature of a wafer.

9. A measuring device according to claim 8, The spectral imaging system is a measuring device configured to perform spectral imaging of at least a portion of the wafer while the wafer is in the thermal equilibrium station.

10. A measuring device according to claim 8 or 9, The thermal equilibrium station includes a temperature change device for changing the temperature of the wafer, The spectral imaging system is configured to perform spectral imaging of at least a portion of the wafer while the wafer is loaded onto the temperature-changing device. Measuring device.

11. A measuring device according to claim 10, wherein the temperature change device is Passive temperature change device, or Active temperature change device Measuring devices, including those mentioned above.

12. A measuring device according to any one of claims 8 to 11, The measuring device comprises a wafer handling system for loading a wafer into the mass measuring station and for loading a wafer into the thermal equilibrium station.

13. A measuring device according to any one of claims 8 to 12, The measuring device comprises a first thermal equilibrium station and a second thermal equilibrium station. The spectral imaging system is configured to perform spectral imaging of at least a portion of the wafer while the wafer is in the first thermal equilibrium station, or The spectral imaging system is configured to perform spectral imaging of at least a portion of the wafer while the wafer is in the second thermal equilibrium station. Measuring device.

14. A measuring device according to any one of claims 1 to 5, The measurement device comprises a spectral imaging station equipped with the spectral imaging system.

15. A measuring device according to claim 14, The measuring apparatus comprises a wafer handling system for loading the wafer into the mass measurement station and for loading the wafer into the spectral imaging station.

16. A measuring device according to claim 14 or 15, A measuring apparatus wherein the spectral imaging station comprises a support for supporting the wafer during spectral imaging of at least a portion of the wafer.

17. A measuring device according to any one of claims 1 to 16, The spectral imaging system, Light source and A detector for acquiring spectral imaging data, A measuring device equipped with the following features.

18. A measuring device according to claim 17, The detector includes a hyperspectral imaging camera. Measuring device.

19. A measuring device according to claim 17 or 18, A measuring device in which the illumination source includes a broadband light source.

20. A measuring device according to claim 17, The illumination source is operable to select a specific wavelength or a specific wavelength range of illumination. Measuring device

21. The measuring device according to claim 20, wherein the illumination source is Multiple illuminators, each having a different wavelength or wavelength range, wherein the multiple illuminators are configured to operate independently, or Illumination source with adjustable or selectable wavelength or wavelength range. Measuring devices, including those mentioned above.

22. A measuring device according to claim 17, A measuring device comprising a spectral imaging system that includes a filter for selectively transmitting a specific wavelength or wavelength range of illumination.

23. The measuring device according to claim 22, wherein the filter is A plurality of bandpass filters, each of which is configured to transmit different specific wavelengths or wavelength ranges of illumination, An adjustable filter that can be adjusted to selectively transmit a specific wavelength or wavelength range of light. Diffraction grating, or Optical dispersion devices A measuring device comprising one or more of the following.

24. A measuring device according to any one of claims 17 to 23, A measuring device comprising, the spectral imaging system, an optical element configured to direct illumination from the illumination source onto a wafer and illumination from the wafer onto a detector.

25. A measuring device according to any one of claims 17 to 23, A measuring device comprising a reflector configured to reflect light from the illumination source onto the wafer, wherein the spectral imaging system further comprises a reflector, and the detector is positioned to receive the light reflected from the wafer.

26. A measuring device according to claim 25, A measuring device wherein the reflector comprises a concave reflective surface arranged to reflect the light from the illumination source onto the wafer.

27. A measuring device according to claim 25 or 26, A measuring device in which an opening is formed in the reflector, and the detector is positioned to receive light reflected from the wafer through the opening in the reflector.

28. A measuring device according to any one of claims 25 to 27, A measuring device in which the reflector is configured to reflect the light from the illumination source as diffused light.

29. A measuring device according to any one of claims 1 to 28, The measuring device is configured to determine the dimensions of the wafer at multiple locations on the wafer based on the output of the spectral imaging system and a machine learning model and / or a trained model.

30. A measuring device according to claim 29, The measuring device is further configured to generate a spatial distribution model of the dimensions based on the determined dimensions at least at the plurality of locations.

31. A measuring device according to claim 30, A measuring device configured to generate the spatial distribution model of the dimensions based on the determined dimensions at the plurality of locations and the mass and / or change in mass of the wafer measured by the mass measuring station.

32. A measuring device according to any one of claims 1 to 31, A measuring device configured to determine information regarding the warp or curvature of the wafer from the output of the spectral imaging system.

33. A measuring device according to claim 32, wherein the measuring device is Using the spectral imaging system, multiple images at different wavelengths or wavelength ranges are acquired. Analyze the out-of-focus patterns in each of the aforementioned multiple images, From the results of the above analysis, information regarding the warpage or curvature of the wafer is determined, A measuring device configured to perform the following actions.

34. A measuring device according to any one of claims 1 to 33, A measuring device configured to perform optical interferometry between the wafer and a reference wafer.

35. A measuring device according to claim 34, The measurement device comprises a reference unit having a reference wafer, and the spectral imaging system is configured to perform interference measurements between the wafer and the reference wafer.

Images