Spectroscopic or microscope device and method for operating same

Abstract

A spectral device or a microscope device is operated by measuring an intensity distribution of a laser beam directed along a trajectory through the device, the intensity distribution being measured at a reference position in the trajectory. The shape of the laser beam is configured based on the measured intensity distribution.

Description

Technical Field

[0001] This invention relates to microscope apparatus or spectroscopic apparatus and methods of operating such apparatus. Background Technology

[0002] Accurate and reliable spectral or microscopic analysis of solid bulk, surface, and any subsurface interface is essential for understanding the manufacturing quality and properties of technically important materials and devices, developing new multifunctional materials, and understanding material failure.

[0003] Widely used and highly developed methods for surface chemical analysis include spectroscopic and microscopic techniques. Spectroscopic techniques may involve probing surfaces using electromagnetic radiation, electron beams, ions, or laser beams. Microscopic techniques may involve probing surfaces using electron beams. Well-known spectroscopic techniques include, for example, X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), secondary ion mass spectrometry (SIMS), and laser-induced breakdown spectroscopy (LIBS). Well-known microscopy techniques may include X-ray techniques or electron microscopy. Well-known electron microscopy techniques include, for example, scanning electron microscopy (SEM) and transmission electron microscopy (TEM).

[0004] The two most widely used and well-developed methods for surface chemical analysis are electron spectroscopy techniques: X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES). XPS is a photoelectron spectroscopy method in which the electron core level and valence band spectra of atoms in a solid are obtained by irradiating the material with an X-ray beam. Chemical state information is extracted from the spectrum in the form of electron binding energy shifts caused by changes in the local chemical environment. AES is similar to XPS, but it is based on analyzing Auger electrons emitted as part of the relaxation process following core level excitation. For AES, excitation occurs due to incident radiation being either X-rays or an electron beam.

[0005] Often, it is important to determine the chemical composition at depths greater than the XPS / AES analysis depth. To achieve this, the material must be removed from the surface and the XPS / AES analysis repeated on the new surface exposed by the material removal. This cycle of material removal and XPS / AES analysis continues until the chemical composition has been recorded at the target depth. The elemental composition of each layer is calculated and plotted as a function of the number of cycles (called the depth distribution). If the depth is measured, and the material removal rate is assumed to be constant, a depth distribution can be plotted for the chemical composition as a function of the etched depth.

[0006] In XPS / AES depth profile analysis, material removal is typically achieved by bombarding the sample with an ion gun mounted in the spectrometer. The ion gun can produce single-atom ion beams or (multi-atom) clustered ion beams. The ion beam is aligned with an X-ray spot (for XPS) or an electron beam (for AES) on the sample surface, allowing for cyclic depth profile analysis. The ion gun accelerates ions to high energies, which, once they strike the surface, have sufficient energy to remove surface atoms in a process called sputtering. However, many materials are ion beam sensitive. This means that the sputtering process disrupts the underlying surface, causing changes in chemical composition to be recorded throughout the XPS / AES depth profile. In compounds, this may take the form of sputtering one element more than others, called preferred sputtering, and is particularly common for inorganic materials. For polymers, in addition to preferentially sputtering elements such as oxygen from the polymer, the ion beam also disrupts the molecular structure. Therefore, for ion-beam sensitive materials, the ability of XPS / AES to provide accurate quantitative compositional information may be compromised, potentially leading to incorrect chemical compositions recorded throughout XPS / AES sputtering depth profiles. Furthermore, the degree of preferred sputtering varies depending on ion beam conditions and material composition. The degree of preferred sputtering cannot be reliably predicted for any new material or ion beam condition. Therefore, when performing depth profile analysis on potential ion-beam sensitive materials, analysts cannot know whether preferred sputtering is altering the apparent composition of the collected depth profile. For a technique considered capable of providing accurate chemical composition, incorrect compositions recorded during depth profile measurements and the inability to know whether this occurs in the material under study are significant problems. Cluster ion beams enable significantly reduced damage to most thermal polymers during depth profile analysis. Additionally, cluster ion beams have been shown to reduce, but not eliminate, preferred sputtering in metal oxides. However, the use of cluster ion beams also introduces new problems stemming from thermal spikes associated with cluster ion beam impacts.

[0007] WO2024 / 052232 (incorporated herein by reference) seeks to address some of these problems by using laser pulses for material ablation combined with electron spectroscopy techniques such as XPS and AES. It describes a method comprising ablating material from a region of a sample surface by irradiating it with one or more laser pulses; irradiating at least a portion of the region with an excitation beam of electron or electromagnetic radiation; measuring the intensity and energy of electrons emitted from the at least a portion of the region of the sample due to the excitation beam; and repeating the steps of ablating the material, irradiating with the excitation beam, and measuring the intensity and energy to determine a quantitative surface depth distribution, thereby obtaining the chemical composition of at least a portion of the sample.

[0008] However, depth distribution analysis using laser beams requires precise and controlled removal of material from the sample. Therefore, accurate control of the laser beam used to perform sample ablation is crucial for optimizing ablation conditions and achieving optimal pit formation, and thus enabling depth distribution analysis. The goal is to achieve this precise control while minimizing surface morphology variations in the sample being analyzed. Summary of the Invention

[0009] According to a first embodiment, the present invention provides a method for operating a spectroscopic device or a microscope device, the method comprising: measuring (particularly in a vacuum) the intensity distribution of a laser beam guided along a trajectory passing through the device, the intensity distribution being measured at a reference position in the trajectory; and configuring the shape of the laser beam based on the measured intensity distribution. Specifically, the intensity distribution is measured by irradiating a profile measuring element with the laser beam, wherein the profile measuring element intersects the laser beam at the reference position.

[0010] By measuring the intensity distribution of the laser beam at a reference location and then configuring the shape of the laser beam based on the measured intensity distribution, the laser beam profile can be accurately controlled and optimized in situ. This facilitates ensuring accurate material removal from the sample during subsequent ablation and accurate depth distribution analysis.

[0011] Intensity distribution refers to the spatial intensity distribution of a laser beam. It can be the intensity distribution across the beamwidth of the laser beam at a reference location. In this paper, beamwidth refers to the diameter of the beam spot size.

[0012] As used in this article in the context of configuring the laser beam shape based on the measured intensity distribution, configuration means that if necessary, the shape of the laser beam is adjusted based on the measured intensity distribution, and if no adjustment based on the measured intensity distribution is required, the current shape of the laser beam is maintained.

[0013] The reference position can be located at a fixed distance (referred to herein as reference distance RD) from the focal point of the laser beam. The reference distance can be zero. Preferably, the reference distance is non-zero, thus the reference position is spaced apart from the focal point of the laser beam. The reference position can be upstream of the focal point of the laser beam. The reference distance can be, for example, 0.01-100 mm from the focal point of the laser beam, preferably 0.1-10 mm, and more preferably 1-5 mm. The focal point of the laser beam can be defined as being one focal length away from the focusing lens of the objective lens that focuses the laser beam when guided along the trajectory of the laser beam through the device. The reference distance can be, for example, in the range of 0.01% to 5% of the focal length, preferably in the range of 0.1% to 5%, and more preferably in the range of 0.5% to 2.5% of the focal length. The reference distance can be predetermined. The reference distance can be selected by the user.

[0014] The step of measuring the intensity distribution of a laser beam at a reference location may include irradiating a profile measuring element with the laser beam, wherein, during the step of measuring the intensity distribution of the laser beam, the profile measuring element intersects with the laser beam at the reference location. Specifically, during the step of measuring the intensity distribution of the laser beam, the surface of the profile measuring element may intersect with the laser beam at the reference location. Intersection of the profile measuring element with the laser beam means that at least a portion of the profile measuring element intersects with the laser beam in space to a certain extent, such that there is at least some overlap between them. Intersection of the profile measuring element with the laser beam does not require the laser beam to have the same spatial extent as the profile measuring element at the intersection point. During the step of measuring the intensity distribution of the laser beam, at least a portion of the surface of the profile measuring element may overlap with the laser beam. The plane of the surface of the profile measuring element intersecting with the laser beam may be referred to as the profile measuring plane. The laser beam may intersect the profile measuring plane at a non-zero angle. The laser beam may intersect the profile measuring plane at an angle, for example, between 5 degrees and 175 degrees. The area of ​​the surface of the profile measuring element in the profile measuring plane may be greater than the beam width of the laser beam at the reference location. Alternatively, the area of ​​the contour measuring element in the contour measuring plane can be smaller than the beam width of the laser beam at the reference position, and the contour measuring element can be translated across the region of the laser beam spot at the reference position, such that the contour measuring element is scanned across the laser beam spot at the reference position. The step of measuring the intensity distribution of the laser beam can be referred to herein as the contour measuring step.

[0015] The profile measurement element may include a laser-sensitive material. The profile measurement element may be composed of a laser-sensitive material. The profile measurement element may include a laser-sensitive material coated on a sensor device. The laser-sensitive material may be directly coated on the sensor device (i.e., without intervening features). The profile measurement element may consist of a laser sensor material coated on the sensor device. According to an embodiment where the laser-sensitive material is coated on the sensor device, the profile measurement element may include both: the laser-sensitive material and the sensor device. Alternatively, the sensor device may not constitute part of the profile measurement element and may be located remotely from the laser-sensitive material. The sensor device may include one or more cameras. The laser-sensitive material and / or the sensor device may be compatible with ultra-high vacuum (UHV) conditions. Typically, sample ablation is performed under vacuum conditions. By employing a profile measurement element compatible with ultra-high vacuum conditions, it becomes possible to measure the intensity distribution of a laser beam under vacuum conditions and therefore in situ using the profile measurement element.

[0016] Laser-sensitive materials can be configured to change upon irradiation with a laser beam and / or to emit light upon irradiation with a laser beam. Sensor devices can be configured to detect changes in the laser-sensitive material and / or emissions from the laser-sensitive material.

[0017] Laser-sensitive materials may include luminescent materials configured to emit photons when irradiated with a laser beam. The luminescent material may be a phosphorescent or fluorescent material. Optionally, the luminescent material may be an upconversion anti-Stokes phosphor, optionally used to convert infrared laser light into visible light.

[0018] If the contour measuring element includes or is composed of a laser-sensitive material, the step of measuring the intensity distribution of a laser beam at a reference location may include detecting changes in the laser-sensitive material or emissions from it when irradiated with a laser beam. These changes or emissions can be detected using a sensor device, which may have the laser-sensitive material coated thereon or be located away from the laser-sensitive material. The changes in the laser-sensitive material or emissions from it when irradiated with a laser beam may be related to the intensity of the laser beam irradiating it. This makes it possible to determine the intensity distribution of the laser beam irradiating the laser-sensitive material based on detected changes in the laser-sensitive material or emissions from it. The intensity of the emissions from the laser-sensitive material may be proportional to the intensity of the laser beam irradiating it.

[0019] A profile measurement element may include a laser sensor. The profile measurement element may consist of or be composed of a laser sensor. If the profile measurement element includes or is composed of a laser sensor, the laser sensor can be configured to measure the intensity of the laser beam illuminating it. The laser sensor may include one or more cameras. The laser sensor may be compatible with ultra-high vacuum (UHV) conditions. Typically, sample ablation is performed under vacuum conditions and can be performed under ultra-high vacuum conditions. By employing a laser sensor compatible with ultra-high vacuum conditions, it becomes possible to use the laser sensor to measure the intensity distribution of the laser beam under vacuum conditions and therefore in situ.

[0020] The apparatus may include a sample stage. During the step of measuring the intensity distribution, a profile measuring element may be arranged on the sample stage. The sample stage may be configured to absorb or dissipate heat generated by the profile measuring element when it is arranged on the sample stage. The sample stage may include a heat sink configured to receive heat generated by the profile measuring element when it is arranged on the sample stage. This is particularly advantageous in embodiments employing a profile measuring element comprising a sensor device having a laser-sensitive material coated thereon or a profile measuring element comprising a laser sensor, since the laser sensor or sensor device may generate heat during use. This heat generation may cause the laser sensor or sensor device to overheat or degrade its performance, especially when the sensor device or laser sensor is arranged inside a vacuum chamber during the measurement of the intensity distribution of the laser beam.

[0021] The method may include coupling a profile measuring element to a sample stage before the step of measuring the intensity distribution and decoupling the profile measuring element from the sample stage after the step of measuring the intensity distribution, such that the profile measuring element is coupled to the sample stage during the step of measuring the intensity distribution. This coupling may include mechanical coupling and / or electrical coupling and / or thermal coupling of the profile measuring element to the sample stage.

[0022] If the profile measuring element includes a laser sensor, optionally, during the intensity distribution measurement step, the laser sensor can be detachably electrically coupled to the sample stage, such that the sample stage transmits power to the laser sensor. The method may further include transmitting data from the laser sensor to a processing device while the laser sensor is electrically coupled to the sample stage. The step of transmitting data from the laser sensor to the processing device can be performed using a wired connection that optionally includes one or more pairs of twisted pairs. Using twisted pairs for data transmission helps maintain signal integrity and reduce noise interference. Optionally, a wired connection (which may employ one or more pairs of twisted pairs) can be used to transmit power to and / or data from the laser sensor.

[0023] If the profile measuring element includes a laser-sensitive material coated on the sensor device, the sensor device can be detachably electrically coupled to the sample stage during the intensity distribution measurement step, allowing the sample stage to transfer power to the sensor device. The method may further include transmitting data from the sensor device to a processing device while the sensor device is electrically coupled to the sample stage. Optionally, the step of transmitting data from the sensor device to the processing device can be performed using a wired connection that optionally includes one or more pairs of twisted pairs. Using twisted pairs for data transmission helps maintain signal integrity and reduce noise interference. Optionally, a wired connection (which may employ one or more pairs of twisted pairs) can be used to transmit power to and / or data from the sensor device.

[0024] The profile measuring element can be supported on a bracket. The profile measuring element can be directly supported on the bracket, eliminating any intervening features between them. Mechanical and / or electrical and / or thermal coupling with the sample stage can be achieved via the bracket. The bracket and / or sample stage may include wired connections.

[0025] The method may further include: after configuring the shape of the laser beam based on the measured intensity distribution, ablating material from a portion of the sample surface by irradiating that portion with the laser beam. This step of ablating material from a portion of the sample surface by irradiating it with the laser beam can be referred to as the sample ablation step. Optionally, during the step of ablating material from a portion of the sample surface, that portion of the sample surface intersects with the laser beam at a reference position. Therefore, the laser beam intersects with the sample surface during the sample ablation step and with the contour measuring element at the same position (reference position) within the laser beam trajectory during the contour measuring step. Thus, the laser beam intensity distribution can be measured and adjusted at the same position where sample ablation occurs. This helps ensure accurate removal of material from the sample during ablation. Ensuring accurate removal of material from the sample during ablation is important for subsequent accurate depth distribution analysis.

[0026] A portion of the sample surface ablated by the laser beam may lie within a plane referred to herein as the sampling plane. During the ablation of the sample surface, the laser beam may intersect the sampling plane at a non-zero angle. This non-zero angle may be between 5 degrees and 175 degrees. The non-zero angle between the laser beam and the sampling plane during the sample ablation step may be substantially the same as the non-zero angle between the laser beam and the profile measurement plane during the profile measurement step. The non-zero angle between the laser beam and the sampling plane during the sample ablation step may differ from the non-zero angle between the laser beam and the profile measurement plane during the profile measurement step by within 5 degrees, preferably within 2 degrees, and more preferably within 1 degree. The sampling plane may be parallel to the profile measurement plane.

[0027] The method may further include, after the step of ablating material from a portion of the sample surface, performing spectroscopic or microscopic analysis on at least a portion of the ablated portion, optionally wherein the spectroscopic analysis includes X-ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy, Auger electron spectroscopy, secondary ion mass spectrometry, and / or laser-induced breakdown spectroscopy, optionally wherein the microscopic analysis includes electron microscopy (TEM or SEM). The step of performing spectroscopic or microscopic analysis on at least a portion of the ablated portion may be referred to herein as the analysis step. The step of performing spectroscopic or microscopic analysis on at least a portion of the ablated portion may include guiding an imaging beam along a trajectory within the apparatus to the ablated portion. During the step of performing the spectroscopic or microscopic analysis, the imaging beam may intersect the ablated portion at an imaging position in the trajectory of the imaging beam. Optionally, the imaging beam may include an ultraviolet beam, an X-ray beam, an electron beam, an ion beam, and / or a laser beam. The plane of the surface of the ablated sample and the plane of the surface of the ablated portion therefrom are referred to herein as the sampling plane. The angle between the imaging beam and the sampling plane during the analysis step may be a non-zero angle. Non-zero angles can be between 5 degrees and 175 degrees. The angle between the imaging beam and the sampling plane during the analysis step can be the same as the angle between the laser beam and the sampling plane during the sample ablation step.

[0028] The method may further include: after performing a spectral analysis or microscopic analysis step, performing one or more further cycles of ablation and analysis, each cycle including a step of further ablation of material from a portion of the sample surface, followed by a step of performing spectral analysis or microscopic analysis on at least a portion of the further ablated portion, and after performing one or more further cycles, determining the depth distribution of the composition of at least a portion of the ablated portion of the sample surface, optionally wherein the depth distribution is quantitative.

[0029] After the step of measuring the intensity distribution, the method may further include: (i) positioning the sample and / or the profile measuring element and / or (ii) redirecting the laser beam; thus, during the step of ablating material from a portion of the sample surface, that portion of the sample surface intersects with the laser beam at a reference position.

[0030] According to one embodiment, during the step of measuring the intensity distribution, both the sample and the profile measuring element can be arranged on the sample stage. According to such an embodiment, after the step of measuring the intensity distribution, the method may further include: (i) moving the sample and the profile measuring element relative to a reference position by moving the sample stage, and / or (ii) redirecting the laser beam to move the reference position relative to the sample and the profile measuring element; such that during the step of ablating at least a portion of the sample surface, that portion of the sample surface intersects with the laser beam at the reference position.

[0031] The step of configuring the laser beam shape may include: configuring the laser beam to achieve a substantially flat-topped or flat-topped intensity distribution at a reference location. A flat-topped intensity distribution has an intensity distribution that is substantially uniform across the beam width. Achieving such a flat-topped intensity distribution facilitates accurate and efficient depth distribution analysis while also ensuring that the laser beam has sufficient throughput to ablate the sample.

[0032] The steps of configuring a laser beam may include controlling one or more optical elements configured to shape the laser beam. The one or more optical elements may include diffractive optical elements and / or refractive optical elements. Specifically, a beam shaper comprising one or more optical elements, which may be diffractive optical elements and / or refractive optical elements, may be configured to shape the laser beam. The steps of configuring a laser beam may include controlling the beam shaper. The steps of configuring a laser beam may include controlling the positioning and / or tilting of the beam shaper.

[0033] Optionally, the method may include co-aligning the imaging beam and the laser beam such that the imaging position coincides with a reference position. "Coincident" as used herein refers to spatial coincidence, meaning there is at least some overlap between them. The alignment of the imaging beam and the laser beam does not require the laser beam to have the same spatial extent as the imaging beam at the point of coincidence. The beamwidth of the imaging beam at the imaging position may be smaller than the beamwidth of the laser beam at the reference position. The ratio of the beamwidth of the imaging beam at the imaging position to the beamwidth of the laser beam at the reference position may be, for example, at least 3:1, preferably at least 4:1, and more preferably at least 5:1. Such ratios are beneficial for improving the quality of the depth distribution produced by the ablation and analysis steps.

[0034] The step of co-aligning the imaging beam and the laser beam may include: detecting the illumination of the contour measuring element by the imaging beam and / or detecting the illumination of the contour measuring element by the laser beam. Optionally, during the step of co-aligning the imaging beam and the laser beam, the contour measuring element intersects with the laser beam at a reference position and with the imaging beam at an imaging position. The step of co-aligning the imaging beam and the laser beam may include: detecting the area of ​​the contour measuring element illuminated by the imaging beam and / or detecting the area of ​​the contour measuring element illuminated by the laser beam. Based on the detected area of ​​the contour measuring element illuminated by the laser beam and the detected area of ​​the contour measuring element illuminated by the imaging beam, the orientation of the imaging beam and / or the laser beam may be adjusted. The orientation of the imaging beam and / or the laser beam may be adjusted such that the area of ​​the contour measuring element illuminated by the laser beam at least overlaps, preferably completely overlaps, the area of ​​the contour measuring element illuminated by the imaging beam, preferably centered thereon.

[0035] According to this embodiment where the imaging beam and the laser beam are co-aligned, the contour measuring element may include a laser-sensitive material or a laser sensor. If the contour measuring element includes a laser-sensitive material, the laser-sensitive material may be configured to change or emit light when irradiated by the imaging beam, and to change or emit light when irradiated by the laser beam. As discussed above, the laser-sensitive material may optionally be coated on the sensor device. If the contour measuring element alternatively includes a laser sensor, the laser sensor may be configured to detect both the irradiation by the laser beam and the irradiation by the imaging beam.

[0036] Optionally, the spectroscopic or microscopic apparatus may include a vacuum chamber. The trajectory of the laser beam may be such that, during the following steps, a reference position is positioned at a location within the vacuum chamber: the intensity distribution of the laser beam at the reference position within the spectroscopic or microscopic apparatus is measured, and the shape of the laser beam is configured based on the measured intensity distribution.

[0037] As discussed above, the method may further include the steps of ablating material from a portion of a sample surface by irradiating it with a laser beam and performing spectral analysis on at least a portion of the ablated portion. The trajectory of the laser beam may be such that, during the steps of ablating material from a portion of the sample surface by irradiating it with a laser beam and performing spectral analysis on at least a portion of the ablated portion, a reference position is arranged at a location within the vacuum chamber.

[0038] The method may further include: moving the profile measuring element into a vacuum chamber (optionally via a sample exchange chamber) before the step of measuring the intensity distribution, and removing the profile measuring element from the vacuum chamber after the step of measuring the intensity distribution. Therefore, in some embodiments, the profile measuring element may optionally be located within the vacuum chamber only during the step of measuring the intensity distribution of the laser beam. In embodiments where the profile measuring element includes a laser sensor or sensor device, this may be advantageous in reducing overheating of the profile measuring element.

[0039] The laser beam used can be a pulsed laser beam. The laser beam may include one or more pulses having a duration of 1 nanosecond (ns), 1 picosecond (ps), 1 femtosecond (fs), or optionally in the range of 1 ps to 1 fs.

[0040] The laser beam can be an infrared laser beam, a visible laser beam, or an ultraviolet laser beam.

[0041] According to a second embodiment of the invention, a spectroscopic or microscopic apparatus is provided, comprising: a laser beam assembly configured to generate and guide a laser beam along a trajectory through the apparatus; and a laser beam analyzer configured to measure the intensity distribution of the laser beam at a reference location within the trajectory. The laser beam assembly includes a beam shaper configured to shape the laser beam based on the measured intensity distribution.

[0042] Any features or advantages described with respect to the method herein are equally applicable to the apparatus.

[0043] The reference position can be located at a fixed distance (referred to herein as reference distance RD) from the focal point of the laser beam. The reference distance can be zero. Preferably, the reference distance is non-zero, such that the reference position is spaced apart from the focal point of the laser beam. The reference position can be upstream of the focal point of the laser beam. The reference distance can be, for example, 0.01-100 mm from the focal point of the laser beam, preferably 0.1-10 mm, and more preferably 1-5 mm. The device can include an objective focusing lens configured to focus the laser beam. The focal point of the laser beam can be defined as being one focal length away from the objective focusing lens. The reference distance can be in the range of, for example, 0.01% to 5% of the focal length, preferably 0.1% to 5%, and more preferably 0.5% to 2.5% of the focal length. The reference distance can be predetermined. The reference distance can be selected by the user.

[0044] The laser beam can be configured to operate in ablation mode to ablate a portion of the material from the sample surface. The laser beam can also be configured to operate in profilometry mode during the measurement of its intensity distribution. In profilometry mode, the energy of the laser beam can be lower than that in ablation mode.

[0045] A laser beam analyzer may include a profile measuring element. As discussed above, the profile measuring element may include or be composed of a laser-sensitive material. The laser-sensitive material may be configured to change upon irradiation with a laser beam and / or configured to emit light upon irradiation with a laser beam.

[0046] When a laser-sensitive material is irradiated with a laser beam, the changes in the laser-sensitive material, or the emissions from it, may be related to the intensity of the laser beam irradiating it. This makes it possible to determine the intensity distribution of the laser beam irradiating the laser-sensitive material based on these changes or emissions. The intensity of the emissions from the laser-sensitive material may be proportional to the intensity of the laser beam irradiating it.

[0047] A laser beam analyzer may include a laser-sensitive material and a sensor device. The sensor device may or may not be part of the profile measurement element of the laser beam analyzer. The sensor device may be configured to detect changes in the laser-sensitive material or emissions from it. The sensor device may include one or more cameras. The laser-sensitive material may be coated on the sensor device, and in such an arrangement, the profile measurement element may include, optionally consist of, the laser-sensitive material coated on the sensor device. Alternatively, the sensor device may be located within the apparatus but away from the laser-sensitive material, and in such an arrangement, the sensor device may be part of the laser beam analyzer but not part of the profile measurement element. The sensor device may be positioned such that it can receive emissions generated by the laser-sensitive material and / or can image the laser-sensitive material to detect changes in it. The laser-sensitive material and / or the sensor device may be compatible with ultra-high vacuum (UHV) conditions. Typically, sample ablation is performed under vacuum conditions and can be performed under ultra-high vacuum conditions. By employing a profile measurement element compatible with ultra-high vacuum conditions, it becomes possible to measure the intensity distribution of a laser beam under vacuum conditions and therefore in situ using the profile measurement element.

[0048] If the profile measuring element includes a laser-sensitive material, the laser beam analyzer may include a reflector configured to reflect an image of the laser-sensitive material or emissions from the laser-sensitive material. If the laser beam analyzer includes a sensor device located away from the laser-sensitive material, the reflector may be configured to reflect an image of the laser-sensitive material or emissions from the laser-sensitive material toward the sensor device.

[0049] Laser-sensitive materials may include luminescent materials configured to emit photons when irradiated with a laser beam. The luminescent material may be a phosphorescent or fluorescent material. Optionally, the luminescent material may be an upconversion anti-Stokes phosphor, optionally used to convert infrared laser light into visible light.

[0050] A profile measurement element may include a laser sensor. The profile measurement element may consist of or be composed of a laser sensor. If the profile measurement element includes or is composed of a laser sensor, the laser sensor can be configured to measure the intensity of the laser beam illuminating it. The laser sensor may include one or more cameras. The laser sensor may be compatible with ultra-high vacuum (UHV) conditions. By employing a laser sensor compatible with UHV conditions, it becomes possible to use the laser sensor to measure the intensity distribution of the laser beam under vacuum conditions and therefore in situ.

[0051] The device may further include a sample stage configured to support a sample. The sample stage may also optionally be configured to support the profile measuring element simultaneously or independently.

[0052] The apparatus can be configured to (i) optionally move the profile measuring element and / or the sample by moving the sample stage, and / or (ii) redirect the laser beam to reconfigure the apparatus from a first configuration in which the profile measuring element intersects the laser beam at a reference position to a second configuration in which the sample intersects the laser beam at a reference position. The first configuration may be referred to herein as the profile measuring configuration, and the second configuration may be referred to herein as the sample ablation configuration. The profile measuring configuration may be used when the laser beam is configured to operate in profile measuring mode, and the sample ablation configuration may be used when the laser beam is configured to operate in ablation mode.

[0053] The sample stage can be configured to absorb or dissipate the heat generated by the profile measuring element when it is supported by the sample stage. The sample stage may include a heat sink configured to receive the heat generated by the profile measuring element when it is supported by the sample stage. This is particularly advantageous for embodiments employing profile measuring elements comprising a sensor device coated with a laser-sensitive material or including a laser sensor, as the laser sensor or sensor device may generate heat during use. This heat generation can lead to overheating or performance degradation of the laser sensor or sensor device, especially when the sensor device or laser sensor is arranged inside a vacuum chamber during the measurement of the intensity distribution of the laser beam.

[0054] In embodiments where the contour measurement element includes a laser sensor, the sample stage can be configured to be detachably electrically coupled to the laser sensor when the laser sensor is supported on the sample stage. The sample stage may include an electrical coupling element configured to be detachably electrically coupled to the laser sensor when it is supported on the sample stage. The electrical coupling element can be configured to transmit power to and / or data from the laser sensor. A laser sensor that is only powered and / or available for data transmission operations when supported on the sample stage can advantageously reduce heat generation by the laser sensor. Heat generation can cause overheating and performance degradation of the laser sensor, especially when the laser sensor is arranged within a vacuum chamber during use.

[0055] The electrical coupling element may include a wired connection configured to transmit power to and / or data from the laser sensor, optionally wherein the wired connection includes one or more pairs of twisted pairs.

[0056] In one embodiment, the electrocoupling element can be configured to transmit power to a laser sensor, and the device may further include a data connection configured to transmit data from the laser sensor. The data connection may be a wireless data connection. In another embodiment, the electrocoupling element can be configured to transmit power to and from the laser sensor. For example, a wired connection (which may include one or more pairs of twisted pairs) can be configured to both transmit power to and from the laser sensor.

[0057] In embodiments where the contour measuring element includes a laser-sensitive material coated on the sensor device, the sample stage can be configured to be detachably electrically coupled to the sensor device when the sensor device is supported on the sample stage. The sample stage may include an electrical coupling element configured to be detachably electrically coupled to the sensor device when it is supported on the sample stage. The electrical coupling element can be configured to transmit power to and / or data from the sensor device. A sensor device that is only powered and / or available for data transmission operations when supported on the sample stage can advantageously reduce heat generation by the sensor device. Heat generation can lead to overheating and performance degradation of the sensor device, especially when the sensor device is arranged within a vacuum chamber during use.

[0058] The electrical coupling element may include a wired connection configured to transmit power to and / or data from the sensor device, optionally wherein the wired connection includes one or more pairs of twisted pairs.

[0059] In one embodiment, the electrocoupling element can be configured to transmit power to a sensor device, and the device may further include a data connection configured to transmit data from the sensor device. The data connection may be a wireless data connection. In another embodiment, the electrocoupling element can be configured to transmit power to and from the sensor device. For example, a wired connection (which may include one or more pairs of twisted pairs) can be configured to both transmit power to and from the sensor device.

[0060] The device may further include a support configured to support the profile measuring element. The support may be configured to be detachably mechanically coupled to the sample stage.

[0061] In embodiments where the contour measuring element includes a laser sensor, the sample stage can be configured to be detachably electrically coupled to the laser sensor via the support when the support is mechanically coupled to the sample stage. In embodiments where the contour measuring element includes a laser-sensitive material coated on a sensor device, the sample stage can be configured to be detachably electrically coupled to the sensor device via the support when the support is mechanically coupled to the sample stage.

[0062] In embodiments where the contour measurement element includes a laser sensor, the electrical coupling element may be a stage electrical coupling element, and the support may include a support electrical coupling element electrically connected to the laser sensor. The support electrical coupling element may be configured to be detachably electrically coupled to the stage electrical coupling element when the support is mechanically coupled to the sample stage.

[0063] The support electrical coupling element and the stage electrical coupling element can be configured to transmit power to and / or data from a laser sensor when the support is mechanically coupled to the sample stage. The stage electrical coupling element may include one or more stage electrical contacts, and the support electrical coupling element may include one or more support electrical contacts. When the support is mechanically coupled to the sample stage, the stage electrical contacts may be configured to directly contact the support electrical contacts.

[0064] The bracket electrical coupling element may include a wired connection configured to transmit power and / or data to the laser sensor. The wired connection may include one or more pairs of twisted pairs.

[0065] In embodiments where the contour measurement element includes a sensor device, the electrical coupling element may be a stage electrical coupling element, and the support may include a support electrical coupling element electrically connected to the sensor device. The support electrical coupling element may be configured to be detachably electrically coupled to the stage electrical coupling element when the support is mechanically coupled to the sample stage. The support electrical coupling element and the stage electrical coupling element may be configured to transmit power to and / or data from the sensor device when the support is mechanically coupled to the sample stage.

[0066] The stage electrical coupling element may include one or more stage electrical contacts, and the support electrical coupling element may include one or more support electrical contacts. When the support is mechanically coupled to the sample stage, the stage electrical contacts may be configured to directly contact the support electrical contacts.

[0067] The bracket electrical coupling element may include a wired connection configured to transmit power and / or data to a sensor device. The wired connection may include one or more pairs of twisted-pair cables.

[0068] The device may further include a processing device configured to receive data from a laser sensor or sensor device via an electrical coupling element and / or a data connection.

[0069] The device may further include a vacuum chamber. The laser beam assembly may be configured to guide the laser beam such that a reference position is positioned within the vacuum chamber.

[0070] The sample stage can be installed inside a vacuum chamber.

[0071] The laser beam assembly can be located outside a vacuum chamber, which includes a window configured to allow the laser beam to pass through it.

[0072] The apparatus may include a transfer assembly for moving a profile measuring element into and out of a vacuum chamber, optionally via a sample exchange chamber. Thus, the profile measuring element can be located within the vacuum chamber during intensity distribution measurement and then removed from the vacuum chamber after the intensity distribution is measured. In embodiments where the profile measuring element includes a laser sensor or sensor device coated thereon with a laser-sensitive material, minimizing the time the profile measuring element spends within the vacuum chamber may help reduce heat generation by the profile measuring element.

[0073] In embodiments employing a stent, the transfer assembly can be configured to move the stent into and out of a vacuum chamber, optionally via a sample exchange chamber.

[0074] The device may further include an imaging beam assembly configured to generate and guide an imaging beam along a trajectory within the device, optionally wherein the imaging beam is one or more of an ultraviolet beam, an electron beam, an ion beam, an X-ray beam, and / or a laser beam.

[0075] In embodiments employing a contour measuring element including a laser-sensitive material, the laser-sensitive material can be configured to change or emit light upon illumination by an imaging beam, and also to change or emit light upon illumination by a laser beam. This laser-sensitive material can be used to detect both laser beam illumination and imaging beam illumination to achieve co-alignment of the imaging and laser beams. As discussed above, the laser-sensitive material can optionally be coated onto the sensor device. If the contour measuring element alternatively includes a laser sensor, the laser sensor can be configured to detect both laser beam illumination and imaging beam illumination to achieve co-alignment of the imaging and laser beams. Attached Figure Description

[0076] Referring to the following non-limiting drawings, embodiments of the present disclosure will now be described by way of example only, wherein:

[0077] Schematic cross-sectional view

[0078] Figure 1 is a schematic diagram of an exemplary embodiment of the device according to the present invention.

[0079] Figure 2 is a schematic diagram showing the optical setup that can be used in the apparatus and method of the present invention to generate, shape and guide a laser beam.

[0080] Figure 3 is a schematic diagram showing an optical setup that can be used in the apparatus and method of the present invention to generate, shape and guide a laser beam, the laser beam having a flat-topped or flat-topped beam intensity distribution.

[0081] Figure 4 is a schematic cross-sectional view of a portion of the apparatus of Figure 1, illustrating the use of a beam analyzer that can be used in an exemplary embodiment of the present invention, the beam analyzer including a profile measurement element as a laser-sensitive material.

[0082] Figure 5A is a schematic cross-sectional view of a profile measuring element that can be used in the beam analyzer of Figure 4, wherein both the profile measuring element and the sample are arranged on the sample stage of the device.

[0083] Figure 5B is a schematic perspective view of a profile measuring element that can be used in the beam analyzer of Figure 4, arranged on a sample holder.

[0084] Figure 6 is a schematic cross-sectional view of a portion of the apparatus of Figure 1, illustrating the use of a beam analyzer that can be used in an exemplary embodiment of the present invention, the beam analyzer including a profile measuring element as a laser sensor.

[0085] Figure 7 is a schematic cross-sectional view of a portion of the apparatus of Figure 1, illustrating the use of a beam analyzer that can be used in an exemplary embodiment of the present invention, the beam analyzer comprising a profile measuring element as a laser-sensitive material coated on a sensor device.

[0086] Figure 8A is a schematic perspective view of the laser sensor of Figure 6 arranged on the sensor bracket of the device.

[0087] Figure 8B is a schematic perspective view of the sensor device of Figure 7 coated with laser-sensitive material, wherein the sensor device is arranged on the sensor support of the device.

[0088] Figure 8C is a schematic cross-sectional view of the sensor bracket of Figure 8A or Figure 8B, which is mechanically coupled to the sample stage of the device via the sample stage and electrically coupled to the power supply and processing equipment of the device.

[0089] Figure 9 is an exemplary embodiment of the method of the present invention.

[0090] Figure 10 is an exemplary implementation of the method in Figure 9.

[0091] Figure 11 is an exemplary implementation of the method in Figure 9.

[0092] Figure 12 is a schematic diagram of steps 201 to 206 of implementing the method of Figure 10 using the apparatus of Figure 1.

[0093] Figure 13 is a schematic diagram of steps 301 to 306 of implementing the method of Figure 11 using the apparatus of Figure 1.

[0094] Figure 14A is a graphical representation showing the evolution of pits formed by repeated sample ablation using a laser beam, where the laser beam has a Gaussian intensity distribution at a reference location, and the sample surface intersects with the laser beam at the reference location during ablation.

[0095] Figures 14B and 14C are graphical representations of the depth distribution, which can be generated after repeated cycles of sample ablation and spectral or microscopic analysis of the ablated portion using a laser beam and an imaging beam. The laser beam has a Gaussian intensity distribution at the reference position, intersecting the sample surface with the laser beam at the reference position during ablation and with the imaging beam at the imaging position during analysis. The ratio of the beamwidth of the laser beam at the reference position to the beamwidth of the imaging beam at the imaging position is 5:1 for Figure 14B, while the ratio is 2:1 for Figure 14C.

[0096] Figure 14D is a graphical representation showing the evolution of pits formed by repeated sample ablation using a laser beam, where the laser beam has a perfectly flat-topped intensity distribution at the reference location, and the sample surface intersects with the laser beam at the reference location during ablation.

[0097] Figure 14E is a graphical representation of the depth distribution, which can be generated after repeated cycles of sample ablation and spectral or microscopic analysis of the ablated portion using a laser beam and an imaging beam. The laser beam has a flat-topped cap-shaped intensity distribution at the reference position.

[0098] Figures 15A to 15C illustrate the generation of intensity distributions using a beam analyzer that includes a beam profile measurement element, which is a laser-sensitive material. The laser-sensitive material intersects with the laser beam at a reference location while the intensity distribution is measured. The laser-sensitive material is a phosphorescent material that fluoresces under laser beam irradiation. The arrangement shown in Figure 4 is used to obtain the intensity distribution. Figure 15A is the original image of the laser-sensitive material fluorescing under laser beam irradiation. Figures 15B and... Figure 15C This is a digitally magnified heatmap of the laser beam intensity distribution, generated by processing the original image of Figure 15A. The camera exposure in Figure 15C has been adjusted compared to Figure 15B.

[0099] Figure 15D shows the intensity distribution of the same laser beam used in Figures 15B and 15C. The intensity distribution is represented as a thermal image. The intensity distribution is generated using a profilometry camera that intersects the laser beam at a reference position. The profilometry camera is not under vacuum conditions.

[0100] Figures 16A and 16D show the intensity distribution of a laser beam generated using a beam analyzer that includes a beam profile measurement element, which is a laser-sensitive material. The laser-sensitive material intersects the laser beam at a reference position while the intensity distribution is measured. The laser-sensitive material is a phosphorescent material that fluoresces when irradiated by the laser beam. The arrangement shown in Figure 4 is used to obtain the intensity distribution under vacuum conditions. Figures 16A and 16C are initial raw images of the laser-sensitive material fluorescing under laser beam irradiation. Figures 16B and 16D are the intensity distribution of the laser beam as thermal maps. Figure 16B was generated by processing the raw image of Figure 16A, and Figure 16D was generated by processing the raw image of Figure 16C. Compared to Figure 16A, the optics used to shape the laser beam in Figure 16C were adjusted to achieve a more accurate flat-top intensity distribution at the reference position. The angle of incidence between the laser beam and the laser-sensitive material was 45 degrees when the images shown in Figures 16A and 16C were captured.

[0101] Figure 16E shows the intensity distribution of the same laser beam used in Figures 16A to 16D, where the incident angle between the laser beam and the laser-sensitive material is 90 degrees. The intensity distribution is represented as a thermal image. The intensity distribution was obtained using a profile measuring camera that intersects the laser beam at a reference position. The profile measuring camera was not under vacuum conditions.

[0102] Figures 17A and 17B show the intensity distribution of a laser beam generated by a beam analyzer, including a beam profile measuring element, which is a laser-sensitive material arranged on a sensor support. The laser sensor intersects the laser beam at a reference position while simultaneously measuring the intensity distribution. The angle of incidence between the laser beam and the laser sensor was 43 degrees when the image shown in Figure 17A was captured. The arrangement shown in Figure 8C is used to obtain the intensity distribution under vacuum conditions. Figure 17A is the initial raw image taken with the laser sensor while irradiated with the laser beam. Figure 17B is the intensity distribution of the laser beam as a thermal image. Figure 17B was generated by processing the raw image of Figure 17A. Detailed Implementation

[0103] Figure 1 is a schematic diagram of a spectroscopic apparatus or microscope apparatus 10, referred to herein as apparatus 10, according to the present invention. Apparatus 10 may include a controller 100 configured to operate components of the control apparatus 10. The apparatus may include a processing device 120 electrically coupled to the controller 100. The processing device 120 may form part of the controller 100. Apparatus 10 may include a vacuum chamber 20 configured to receive a sample 110 (not shown in Figure 1) therein. Apparatus 10 may include a sample stage 70 configured to support the sample 110 thereon. The sample stage 70 may be disposed within the vacuum chamber 20.

[0104] The device 10 includes a laser beam assembly 40 configured to generate a laser beam and guide it along a trajectory within the device 10. Figures 2 and 3 illustrate exemplary optical arrangements of the laser beam assembly 40. Figure 2 also shows an exemplary trajectory of the laser beam, including a reference position 300 and a focal point 320. The controller 100 can be configured to control the positioning of components of the laser beam assembly 40.

[0105] As best shown in Figure 3, the reference position 300 can be located at a reference distance (RD) from the laser beam focus 320. Based on the arrangement of the optical components within the laser beam assembly, the focus 320 is located at a known position within the laser beam trajectory. The reference distance can be zero, such that the reference position 300 is at the laser beam focus 320. Preferably, the reference distance is non-zero, such that the reference position is spaced apart from the laser beam focus 320. As shown in Figure 2, the reference position 300 can be upstream of the laser beam focus 320. The term "upstream" is used in the context of the laser beam during normal use (i.e., the laser beam propagating in an upstream-to-downstream direction). The reference distance can be, for example, 0.01-100 mm from the focus, preferably 0.1-10 mm, and more preferably 105 mm from the focus. The laser beam focus can be defined as being one focal length away from the focusing lens of the objective lens that focuses the laser beam when guided along the trajectory of the laser beam through the device. The reference distance can be in the range of, for example, 0.01% to 5% of the focal length, preferably 0.1% to 5% of the focal length, and more preferably 0.5% to 2.5% of the focal length. The reference distance can be predetermined. The reference distance can be selected by the user. The laser beam assembly 40 can be configured to control the direction of the laser beam, and thereby control the position of the reference position 300 within the device 10. The laser beam assembly 40 can be configured to guide the laser beam such that the reference position is located within the vacuum chamber 20 of the device 10. The vacuum chamber 20 can be an ultra-high vacuum chamber. The ultra-high vacuum chamber has a vacuum level equal to or less than 1.0 × 10⁻⁶. -8 The pressure is mbar.

[0106] The laser beam can be a femtosecond, picosecond, or nanosecond laser beam. If the laser beam is a femtosecond laser beam, the laser source 410 can be a diode-pumped Yb medium capable of providing a range of pulse lengths, pulse wavelengths, and pulse energies. In an exemplary embodiment, the laser beam can be a femtosecond laser with a wavelength of 1030 nm and a pulse length of 160 fs. Alternatively, the laser wavelength can be 515 nm or 343 nm. Shorter or longer pulses can also be used, such as in the range of 10 fs to 10 ps, ​​or even less than 1 fs to 1 ns. The beamwidth of the laser beam at reference position 300 can be in the range of about 50-500 μm, preferably 100-300 μm. The pulse repetition rate may vary. In some embodiments, pulse repetition rates on the order of about 10 kHz can be used.

[0107] Apparatus 10 includes a laser beam analyzer 500 configured to measure the intensity distribution of a laser beam at a reference position 300 within the laser beam trajectory. The beam analyzer 500 is discussed in further detail below.

[0108] The laser beam assembly 40 may include a laser beam source 410 configured to generate a laser beam. The laser beam may be generated as a continuous beam, a pulse, or a pulse train. The laser beam assembly 40 may include one or more optical components configured to shape and guide the laser beam, as shown in FIG2. Specifically, the laser beam assembly 40 may include a beam shaper 420 configured to shape the laser beam. A reference position 300 may be downstream of the beam shaper 420 and upstream of the focal point 320, as shown in FIG2. Therefore, the reference position may be defined as being at a fixed distance from the beam shaper 420, which may be predetermined. Specifically, the reference position may be located at a position on the image plane of the beam shaper 420.

[0109] Controller 100 and / or processing device 120 may be configured to receive an intensity distribution generated by beam analyzer 500 and, based on the measured intensity distribution, determine and control adjustments to the positioning of beam shaper 420 to achieve the desired intensity distribution at a reference location. Beam shaper 420 may include one or more optical elements configured to shape the laser beam based on the intensity distribution measured by beam analyzer 500. Controller 100 and / or processing device 120 may be configured to receive an intensity distribution generated by beam analyzer 500 and, based on the measured intensity distribution, determine and control adjustments to the positioning of one or more optical components of beam shaper 420 to achieve the desired intensity distribution at a reference location. In the exemplary embodiments shown in Figures 2 and 3, beam shaper 420 includes diffractive optical elements (DOEs) configured to shape the laser beam. The desired intensity distribution is optionally a cap-shaped intensity distribution (a uniform intensity spot of rectangular, square, circular, or other shape), as shown in Figure 2. The diffractive optical element, referred to herein as a flat-topped cap or flat-topped beam shaper, can be configured to convert a generally Gaussian-distributed incident laser beam into a flat-topped cap-shaped intensity distribution, as shown in Figure 2. The beam shaper 420 can be configured to shape the laser beam based on a measured intensity distribution to achieve a flat-topped cap-shaped intensity distribution at reference position 300. For example, the controller 100 and / or processing device 120 can be configured to determine and control one or more optical elements of the beam shaper 420 based on the measured intensity distribution to achieve the flat-topped cap-shaped intensity distribution at reference position 300. Specifically, the controller 100 can be configured to control the beam shaper to translate in a direction orthogonal to the laser beam propagation direction and / or rotate and / or tilt the beam shaper 420 angularly based on the measured intensity distribution.

[0110] The laser beam assembly 40 may include a beam shaper positioning mechanism (not shown) configured to adjust the position of the beam shaper 420, more specifically, the position of the optical elements of the beam shaper 420, in a direction orthogonal to the laser beam propagation direction. The laser beam assembly 40 may also include a beam shaper tilting mechanism (not shown) configured to tilt the beam shaper 420, more specifically, tilt the optical elements of the beam shaper 420. The controller 100 and / or processing device 120 may be configured to determine and control the beam shaper positioning mechanism and / or the beam shaper tilting mechanism based on measured intensity distribution to achieve a flat-topped intensity distribution at reference position 300.

[0111] The laser beam assembly 40 may include an objective focusing lens 450 downstream of the beam shaper 420. The controller 100 may be configured to control the positioning of the objective focusing lens 450. The position of the objective focusing lens can be adjusted to adjust the direction of the laser beam and thereby adjust the position of the reference position 300 within the device 10. The positioning of the objective focusing lens 450 can also be manually controlled by the user.

[0112] In the exemplary embodiments shown in Figures 2 and 3, the laser beam may first pass through a variable beam expander 415 to increase the beam's cross-sectional area. The incident laser beam may have a Gaussian shape (TEM). 00 And the variable beam expander 415 can be used for the nominal 1 / e required by the beam shaper 420. 2 The diameter is adjusted and aligned. Then, the beam shaper 420 converts the Gaussian intensity distribution into a flat-topped intensity distribution (a uniform intensity spot in the shape of a circle, square, or rectangle).

[0113] As shown in Figure 2, the laser beam assembly 40 may optionally include other optical components configured to guide and focus the laser beam. The laser beam assembly 40 may include a mirror 425 downstream of the beam shaper 420, which guides the laser beam toward the variable attenuator 430 and polarization adjustment optics 435. The variable attenuator 430 may be used to reduce beam power / energy if desired. The polarization adjustment optics 435 may consist of a zero-order half-wave plate or a zero-order quarter-wave plate and may be rotatable. A second beam expander 440 may be positioned before the mirror 445 to adjust the spot size of the beam at the focal point 320. The mirror 445 guides the laser beam through a focusing lens 450, which focuses the laser beam to the desired spot size. The laser beam may pass through a window 25, such as a glass window, configured to transmit the laser beam passing through it into the vacuum chamber 20.

[0114] The controller 100 can be configured to control the laser beam assembly 40 to operate in either a profile measurement mode or an ablation mode. The profile measurement mode can be used when measuring the intensity distribution of the laser beam. The ablation mode can be used when the sample is ablated by the laser. The beam width of the laser beam at the reference position can be the same in both the profile measurement and ablation modes. The energy of the laser beam at the reference position in the profile measurement mode can be different from, and preferably lower than, the energy of the laser beam in the ablation mode. The laser beam generated by the laser beam assembly 40 can be configured to ablate the sample 110 when operating in ablation mode. During sample ablation, a portion of the sample surface may intersect the laser beam at the reference position. This portion of the sample surface can be a target area of ​​the sample. The plane of the sample surface that intersects the laser beam at the reference position during ablation can be referred to herein as the sampling plane. The laser beam can intersect the sampling plane at a non-zero angle during sample ablation. During sample ablation, the incident angle between the laser beam and the sampling plane may be the same as the incident angle between the laser beam and the profile measurement surface when the intensity distribution of the laser beam is being measured. The sampling plane can be parallel to the profile measurement plane.

[0115] The energy of the laser beam in profile measurement mode at reference position 300 may be lower than the energy required to ablate the profile measurement element 510 and / or the sample 110; for example, the energy of the laser beam in profile measurement mode may be less than 100 µJ. The energy of the laser beam in ablation mode may be sufficient to ablate the sample 110 and may be higher than the energy of the laser beam in profile measurement mode. The energy of the laser beam in ablation mode can vary depending on the required material and ablation amount, such as between 10 nJ and 2000 µJ, or more preferably between 50 µJ and 1000 µJ.

[0116] Controller 100 can be configured to receive input from a user to set parameters of the laser beam operating in ablation mode, such that the energy provided at reference position 300 is sufficient to ablate the sample. For example, controller 100 can be configured to control the pulse energy and / or pulse duration such that the energy provided at reference position 300 is above the ablation threshold of the sample material but below the energy or duration sufficient to damage the remaining surface chemistry. Controller 100 can receive input from a user interface or another computer. Input may include settings designed to adjust one or more of pulse energy, pulse duration, pulse repetition frequency, and wavelength. Alternatively, input may provide an indication of the expected material or material type. The controller may include algorithms, lookup tables, libraries, or databases, such as those used when a computer program is executed on the controller's processing device, to provide laser parameters optimized for ablation of the surface while avoiding or minimizing damage to the underlying chemical composition for the expected material or material type of the sample. These parameters can be further optimized to provide rapid ablation while minimizing damage to the underlying chemical composition.

[0117] The controller 100 can be configured to set parameters for the laser beam operating in ablation mode such that the energy provided at reference position 300 is sufficient to ablate the sample based on an investigation scan of the sample surface to be ablated. The investigation scan may include performing electron spectroscopy, such as XPS or AES. Other sample investigation scan techniques may also be used. In one example, for a monolayer sample, the investigation scan can determine the elemental composition in the surface layer. A library of similar materials can then be used to optimize settings such as flux, frequency, pulse duration, and wavelength to achieve the desired ablation rate (i.e., nanometer / layer or / pulse) that preserves the chemical information in the surface layer. The number of pulses can then be set for the desired distribution depth or layer. Pits such as size, shape, and / or surface roughness or variations can also be considered. For multilayer samples, the method used for a monolayer can be repeated for each layer. Alternatively, for multilayer samples, prior knowledge of the layer-by-layer composition or a preliminary depth distribution can be used to determine the laser parameters to be used. For example, the preliminary depth distribution may include an approximate assessment of the composition, followed by optimization of settings using a library of similar materials as for a monolayer. If the library is insufficient or inaccurate for the sample, the ablation rate can be determined by ex-situ analysis (e.g., mechanical profilometry, microscopy, or white light interferometry) using the pits formed by different energy densities and pulse / level numbers.

[0118] The apparatus 10 may include an imaging beam assembly 50 configured to generate and guide an imaging beam along a trajectory within the apparatus 10. The imaging beam may be referred to as an excitation beam. The imaging beam may be one or more of an ultraviolet beam, an electron beam, an ion beam, an X-ray beam, and / or a laser beam. The apparatus 10 may further include an analyzer 80 and / or a detector 90 configured to detect electrons, ions, and / or photons generated by the imaging beam incident on a sample surface. The imaging beam assembly 50 may include an imaging beam source. The generation and direction of the imaging beam may be controlled by a controller 100.

[0119] The laser beam assembly 40 and the imaging beam assembly 50 can be configured such that they respectively guide the laser beam and the imaging beam to the same target region. By alternately operating the laser beam assembly 40 to ablate portions of the sample surface and operating the imaging beam to irradiate at least a portion of the ablated portion of the sample, a compositional depth distribution of the sample can be established. With this arrangement, the imaging beam can optionally be centered at the center of the ablation-formed pit. Specifically, the imaging beam assembly 50 can be guided such that the ablated portion of the sample intersects with the imaging position of the imaging beam within its trajectory. The imaging beam can intersect with the sampling plane of the sample. The angle between the imaging beam and the sampling plane can be a non-zero angle. The angle between the imaging beam and the sampling plane during analysis can be the same as the angle between the laser beam and the sampling beam during sample ablation. The imaging position can be a fixed distance from the focal point, which is predetermined and / or selected by the user. The imaging position can be the focal point of the imaging beam. The focal point of the imaging beam is a known parameter of the imaging beam assembly, which is defined based on the arrangement and configuration of the optical and / or electro-optical components within the imaging beam assembly 50.

[0120] Depending on the type of imaging beam, analyzer 80, and detector 90 used in apparatus 10, apparatus 10 can be defined as a spectroscopic apparatus or a microscopic apparatus. For example, the imaging beam assembly 50, analyzer 80, and detector 90 can be configured for X-ray photoelectron spectroscopy. In such an embodiment, the imaging beam used will be an X-ray beam, and the analyzer 80 and detector 90 will be configured to measure the intensity and energy of the emitted photoelectrons. Alternatively, the imaging beam assembly 50, analyzer 80, and detector 90 can be configured for Auger electron spectroscopy. In such an embodiment, the imaging beam used will be an electron beam, and the analyzer 80 and detector 90 will be configured to measure the intensity and energy of the emitted Auger electrons. Alternatively, the imaging beam assembly 50, analyzer 80, and detector 90 can be configured for ultraviolet photoelectron spectroscopy. In such an embodiment, the imaging beam used will be an ultraviolet beam, and the analyzer 80 and detector 90 will be configured to measure the intensity and energy of the emitted photoelectrons. Alternatively, the imaging beam assembly 50, analyzer 80, and detector 90 can be configured for secondary ion mass spectrometry (SIMS). In such an embodiment, the imaging beam used will be an ion beam, and the analyzer 80 and detector 90 will be configured to measure the intensity and energy of the secondary ions. Alternatively, the imaging beam assembly 50, analyzer 80, and detector 90 can be configured for laser-induced breakdown spectroscopy. In such an embodiment, the imaging beam used will be a laser beam, and the analyzer 80 and detector 90 will be configured to measure the intensity and wavelength of emitted photons. Alternatively, the imaging beam assembly 50, analyzer 80, and detector 90 can be configured for electron microscopy, such as scanning electron microscopy, transmission electron microscopy, or scanning transmission electron microscopy. In such an embodiment, the imaging beam used will be an electron beam, and the detector 90 will be configured to measure electrons.

[0121] The imaging beam assembly 50 can be configured to perform any combination of the imaging techniques discussed above. For example, the imaging beam assembly 50 can be configured to perform X-ray photoelectron spectroscopy and Auger electron microscopy by employing an X-ray beam and an electron beam.

[0122] The imaging beam assembly 50 may include an imaging beam source configured to generate an imaging beam. The imaging beam may pass through a window (not shown) in the vacuum chamber 20, which allows the imaging beam to travel through it (such as a glass window) to reach the sample surface within the vacuum chamber 20.

[0123] In an embodiment where the imaging beam is an X-ray beam, the imaging beam source can be an X-ray source configured to produce X-rays. The X-rays can be monochromatic X-rays and can be generated from a high-energy electron gun arranged to accelerate electrons toward a target anode. The target anode can be aluminum, such that the resulting X-rays are generated at appropriate energies. The X-rays can be guided to the vacuum chamber 20 via a monochromator crystal.

[0124] During analysis, the emission of electrons from the sample surface can cause positive charge to accumulate on the sample. Therefore, device 10 may further include a diffuse electron gun configured to provide charge neutralization at the sample surface during analysis. This is most pronounced when the sample surface is insulating, as the charge accumulation remains on the surface and is not dissipated by the transport of charge across the sample. Positive charge can affect XPS spectra, for example, by causing peaks to shift towards higher binding energies and become distorted. The diffuse electron gun can be of any suitable type, such as that disclosed in GB 2411763 A. The diffuse electron gun neutralizes the charge on the sample surface by replenishing the emitted electrons. This neutralization stabilizes and controls the charging of the sample surface.

[0125] As discussed above, apparatus 10 includes a beam analyzer 500 configured to measure the intensity distribution of a laser beam at a reference position 300. The beam analyzer 500 can be configured to measure the intensity distribution of a 2D laser beam at the reference position 300. More specifically, the beam analyzer 500 can be configured to measure the intensity distribution of a laser beam at the reference position 300 within a contour measurement plane.

[0126] The beam analyzer 500 may include a profile measuring element 510. When measuring the intensity distribution, the profile measuring element 510 may intersect with the laser beam at a reference position 300. In other words, when measuring the intensity distribution of the laser beam, the profile measuring element 510 may intersect with the laser beam at the reference position 300. In the step of measuring the intensity distribution of the laser beam, the laser beam may be incident on the surface of the profile measuring element 510 at a non-zero angle. During the step of measuring the intensity distribution of the laser beam, at least a portion of the surface of the profile measuring element 510 may overlap with the laser beam. The area of ​​the surface of the profile measuring element 510 in the profile measuring plane may be larger than the area of ​​the laser beam spot size at the reference position 300. Alternatively, the area of ​​the profile measuring element in the profile measuring plane may be smaller than the beam width of the laser beam at the reference position, and the profile measuring element may be translated across the region of the laser beam spot at the reference position, such that the profile measuring element is scanned across the laser beam spot at the reference position.

[0127] Therefore, the apparatus 10 can be configured in either a first configuration or a second configuration, with the first configuration used when measuring the intensity of the laser beam and the second configuration used when sample ablation is in progress. The first configuration can be referred to as the profilometry configuration, and the second configuration can be referred to as the sample ablation configuration. In the profilometry configuration, the profilometry element 510 intersects with the laser beam at a reference position 300. In the sample ablation configuration, the surface of the sample 110 intersects with the laser beam at a reference position 300. During spectral or microscopic analysis of the ablated portion of the sample, the apparatus can be configured in a third configuration, which can be referred to as the analysis configuration, wherein the ablated portion of the sample 110 intersects with the imaging beam at an imaging position. For both the sample ablation configuration and the analysis configuration, the sample 110 can be located in the same position within the apparatus 10. In such an arrangement, the imaging beam and the laser beam can be co-aligned. In such an arrangement, the imaging beam and the laser beam can coincide. Alternatively, for the analysis configuration, the sample 110 can be located in a different position within the apparatus 10 compared to the sample ablation configuration. In this arrangement, the imaging beam and the laser beam will not be co-aligned.

[0128] The profile measuring element 510 may include a laser-sensitive material 520 or a laser sensor 530. The profile measuring element 510 may be composed of the laser-sensitive material 520, as shown in FIG. 4, or it may be composed of the laser sensor 530, as shown in FIG. 6. When measuring the intensity distribution of a laser beam, the profile measuring element 510 may be arranged within a vacuum chamber 20. When measuring the intensity distribution of a laser beam, the profile measuring element 510 may be supported on a sample stage 70. The laser-sensitive material 520 may be configured to undergo a detectable change upon irradiation with a laser beam and / or to generate emission upon irradiation with a laser beam. If the profile measuring element 510 includes a laser-sensitive material 520 configured to undergo a detectable change and / or to generate emission upon irradiation with a laser beam, the beam analyzer 500 may further include a sensor device 521 configured to detect changes in the laser-sensitive material 520 or emission from the laser-sensitive material. Sensor device 521 can be configured to process detected changes in the laser-sensitive material 520 or emissions from the laser-sensitive material to generate an intensity distribution of the laser beam. Laser sensor 530 can be configured to process the detected intensity of the laser beam to generate an intensity distribution of the laser beam. Processing device 120 can be configured to receive the intensity distribution of the laser beam from laser sensor 530 or sensor device 521. Alternatively, processing device 120 can be configured to receive raw data from laser sensor 530 and / or sensor device 521 and process the raw data to generate an intensity distribution.

[0129] As discussed above, the laser-sensitive material 520 can be configured to undergo a detectable change upon irradiation with a laser beam and / or to generate emission upon irradiation with a laser beam. The detectable change and / or the generated emission may be related to the intensity of the laser beam irradiating the laser-sensitive material 520. Specifically, the generated emission can be at an intensity proportional to the intensity of the laser beam irradiating the laser-sensitive material 520. When the device 10 is in a contour measurement configuration (i.e., when measuring the intensity distribution of the laser beam), the laser-sensitive material 520 can intersect the laser beam at a reference position 300. As discussed above, the laser beam can be guided such that the reference position 300 can be arranged within the vacuum chamber 20, and therefore, when the device is in a contour measurement configuration, the laser-sensitive material 520 can also be arranged within the vacuum chamber 20, as shown in Figures 4 and 7. Therefore, the laser-sensitive material 520 can be used to measure the intensity distribution of a laser beam in situ. The vacuum chamber can be an ultra-high vacuum chamber and the laser-sensitive material 520 can be compatible with ultra-high vacuum (UHV) conditions. Compatibility means that the laser-sensitive material 520 may not significantly degrade or release gas when in a vacuum chamber under UHV conditions.

[0130] As discussed above and illustrated in the embodiments shown in Figures 4 and 7, in addition to the laser-sensitive material 520, the beam analyzer 500 may also include a sensor device 521. The sensor device 521 may be configured to detect changes in the laser-sensitive material 520 or emissions from it. The sensor device 521 may be a camera, such as a CCD camera or a CMOS camera. The laser-sensitive material 520 may be coated onto the sensor device 521. In such an embodiment, the sensor device 521 and the laser-sensitive material 520 coated thereon together constitute the contour measuring element 510. Alternatively, the sensor device 521 may be located away from the laser-sensitive material 520 and may not be considered part of the contour measuring element 510. In such an embodiment, the contour measuring element may be composed of the laser-sensitive material 520.

[0131] The laser-sensitive material 520 may include a luminescent material configured to emit photons when irradiated with a laser beam. Specifically, the laser-sensitive material 520 may include phosphorescent and / or fluorescent materials. The laser-sensitive material 520 may include a phosphor as an upconversion phosphor. An upconversion phosphor converts absorbed photons from the laser beam into photons with shorter wavelengths. Alternatively, the laser-sensitive material 520 may include a downconversion phosphor. A downconversion phosphor converts absorbed photons from the laser beam into photons with longer wavelengths. The laser-sensitive material may include a phosphor configured to convert laser beam irradiation into visible light. By way of example, the laser-sensitive material may include an upconversion anti-Stokes phosphor, and optionally, the laser beam may be an infrared (IR) laser beam. The upconversion phosphor may absorb infrared photons and emit photons in the visible range. As a further example, the laser beam may be an ultraviolet (UV) laser beam, and the laser-sensitive material 520 may include a downconversion phosphor that can be configured to absorb ultraviolet photons from the ultraviolet laser beam and emit photons in the visible range.

[0132] In one embodiment, the laser-sensitive material 520 can be configured to emit photons at an intensity proportional to the intensity of the laser beam irradiating it. The sensor device 521 can be configured to detect the intensity of photons emitted from the beam profile measuring element in a profile measuring plane. The sensor device 521 and / or processing device 120, which can be connected to the sensor device 521, can be configured to generate an image of the laser beam intensity distribution based on the proportional relationship between the intensity of photons emitted from the laser-sensitive material 520 and the intensity of the laser beam irradiating the laser-sensitive material 520. In such an embodiment, the sensor device 521 can be one or more cameras, such as a CCD camera or a CMOS camera.

[0133] In embodiments employing a laser-sensitive material that emits emission upon irradiation with a laser beam, when the device 10 is in a contour measurement configuration (i.e., when measuring the intensity distribution of the laser beam), the sensor device 521 can be arranged inside or outside a vacuum chamber. The sensor device 521 may include a sensing surface 521a, and the sensor device 521 may be positioned such that the sensing surface 521a receives emission from the laser-sensitive material 520.

[0134] In a particularly advantageous embodiment, such as the one shown in FIG. 4, when the device 10 is in the contour measurement configuration, the laser-sensitive material 520 is arranged inside the vacuum chamber 20 and the sensor device 521 is arranged outside the vacuum chamber 20 (when measuring the intensity distribution of the laser beam). In such an embodiment, the sensor device 521 will be under ambient pressure when measuring the intensity distribution of the laser beam. Advantageously, this avoids overheating of the sensor device 521.

[0135] When the device 10 is in the profile measurement configuration (i.e., when measuring the intensity distribution of the laser beam), the laser-sensitive material 520 can be arranged on a support 60, as shown in FIG. 5B, which is arranged on a sample stage 70. The support 60 used in such an embodiment can be any known sample support. Alternatively, when the device 10 is in the profile measurement configuration, the laser-sensitive material 520 can be arranged directly on the sample stage 70, as shown in FIG. 5A. In such an arrangement, the sensor device 521 is optionally arranged outside the vacuum chamber 20 and therefore does not need to be compatible with vacuum conditions, which can be UHV conditions. By placing the sensor device 521 outside the vacuum chamber, but placing the laser-sensitive material 520 inside the vacuum chamber when measuring the intensity distribution, the intensity distribution of the laser beam can be measured in situ without requiring an arrangement that makes the sensor device 521 compatible with vacuum conditions. This embodiment avoids overheating of the sensor device 521 and its subsequent degradation and gas release. Furthermore, since the sensor device 521 is arranged outside the vacuum chamber 20, data can be transmitted from the sensor device 521 using a wired connection without opening the vacuum chamber 20 and subsequently ventilating it, or without using a feedthrough connection. During the measurement of intensity distribution, the sensor device 521 can be positioned outside the vacuum chamber 20 such that it receives the emission from the laser-sensitive material 520 within the vacuum chamber 20 via a window 26 within the vacuum chamber 20. In such an arrangement, the window 26 will be configured to transmit the emission from the laser-sensitive material. For example, the window 26 can be made of glass.

[0136] Alternatively, when the device 10 is in the profile measurement configuration (i.e., during the measurement of intensity distribution), the sensor device 521 can be arranged within the vacuum chamber 20, as shown in FIG. 7. As shown in FIG. 8B, when the device 10 is in the profile measurement configuration, the sensor device 521 can be supported on a bracket 60' (referred to herein as sensor bracket 60'), which can be configured to reduce overheating of the sensor device 521 during operation under vacuum conditions. This helps to reduce escaping or degradation from the sensor device 521. The sensor bracket 60' is discussed in further detail below. In the exemplary embodiment shown in FIG. 7, the laser-sensitive material 520 is configured to emit light when irradiated with a laser beam and is directly coated on the sensing surface 521a of the sensor device 521. "Directly on" means that there is no intermediary material between the laser-sensitive material 520 and the sensing surface 521a of the sensor device 521. When the device 10 is in the contour measurement configuration (i.e., during the measurement of the intensity distribution of the laser beam), the sensor device 521 can be positioned and / or the laser beam can be guided such that the laser-sensitive material 520 intersects with the laser beam at a reference position 300.

[0137] In one embodiment, the laser-sensitive material 520 can be configured to undergo a visible change when irradiated with a laser beam, wherein the visible change may be correlated with the intensity of the laser beam irradiating the material. The visible change may, for example, be a color change of the laser-sensitive material 520, wherein there is a correlation between the color change of the laser-sensitive material 520 and the intensity of the laser beam irradiating the material. The visible change may, for example, be a visible change in the texture of the laser-sensitive material 520, wherein there is a correlation between the texture change of the laser-sensitive material 520 and the intensity of the laser beam irradiating the material.

[0138] By way of example, laser-sensitive material 520 can be configured to be ablated by a laser beam irradiating the material when the laser is operating in profile measurement mode. Laser-sensitive material 520 can be configured to exhibit different color and / or texture changes due to the ablation depth, which may be related to the intensity of the laser beam irradiating the laser-sensitive material 520. For example, laser-sensitive material 520 may consist of multiple layers with different colors and / or textures. The depth to which the laser beam ablates the laser-sensitive material 520 may vary due to variations in the intensity of the laser beam on the laser-sensitive material 520. Different ablation depths may result in the exposure of different layers of the laser-sensitive material 520. If the layers of the laser-sensitive material 520 have different textures and / or colors, then imaging of the laser-sensitive material 520 by sensor device 521 after laser beam irradiation can be used to determine different ablation depths across the laser-sensitive material 520. The different intensities of the laser beam at reference position 300 can then be determined from the different ablation depths across the laser-sensitive material 520. The sensor device 521 and / or processing device 120, which can be connected to the sensor device 521, can be configured to generate an intensity distribution of the laser beam at a reference position 300 based on an image of the laser-sensitive material 520 after the laser beam irradiates it. The generated intensity distribution will be a two-dimensional (2D) intensity distribution of the laser beam at the reference position 300 (in the profile measurement plane).

[0139] In embodiments employing a laser-sensitive material 520 configured to undergo visible changes upon irradiation with a laser beam, the sensor device 521 may be a camera configured to image the laser-sensitive material 520. When the device 10 is in a contour measurement configuration (i.e., during the measurement of the intensity distribution of the laser beam), the sensor device 521 may be positioned inside or outside the vacuum chamber. The sensor device 521 may be positioned such that it can image the laser-sensitive material 520 during the measurement of the intensity distribution. In a particularly advantageous embodiment, as shown in FIG. 4, when the device 10 is in a contour measurement configuration, the laser-sensitive material 520 is arranged inside the vacuum chamber 20 and the sensor device 521 is arranged outside the vacuum chamber. In such an embodiment, the sensor device 521 will be under ambient pressure during the measurement of the intensity distribution. The sensor device 521 may be positioned outside the vacuum chamber in a location that allows the sensor device 521 to image the laser-sensitive material 520 inside the vacuum chamber 20 through a window 26 within the vacuum chamber 20. In this arrangement, window 26 can be transparent. For example, window 26 can be made of glass. In this arrangement, sensor device 521 does not need to be compatible with vacuum conditions, which can be UHV conditions. When the device 10 is in the profile measurement configuration, by arranging sensor device 521 outside the vacuum chamber but arranging laser-sensitive material 520 inside the vacuum chamber 20, the intensity distribution of the laser beam can be measured in situ without adjusting sensor device 521 to be compatible with vacuum conditions. This arrangement will prevent overheating and degradation of sensor device 521. This arrangement will prevent contamination of vacuum chamber 20 due to gas release from sensor device 521.

[0140] Optionally, the beam analyzer 500 includes a reflector 522 configured to reflect an image or photons from the laser-sensitive material 520 toward a sensor device 521, which is optionally a camera. An exemplary embodiment of this arrangement is shown in Figure 4. This arrangement can be used, for example, when the laser-sensitive material 521 is configured to emit visible light or undergo a visible change when irradiated with a laser beam.

[0141] In a particularly advantageous embodiment, the laser-sensitive material 520 can be sensitive to both the imaging beam and the laser beam. Therefore, the laser-sensitive material 520 can be used to co-align the laser beam and the imaging beam, as discussed further in detail in the context of this method. The laser beam and the imaging beam can be co-aligned such that the imaging beam coincides with the laser beam at a reference position 300. The laser beam and the imaging beam can be co-aligned such that the imaging position coincides with the reference position. "Coincident" as used herein refers to spatial coincidence, such that there is at least some overlap between them. The overlap between the imaging beam and the laser beam does not require the laser beam to have the same spatial extent as the imaging beam at the point of coincidence. The laser beam and the imaging beam can be co-aligned such that the area of ​​the imaging beam irradiating the laser-sensitive material 520 at least partially overlaps, preferably completely overlaps, the area of ​​the laser beam irradiating the laser-sensitive material 520. As discussed above, the shape of the laser beam can be configured to achieve a substantially flat-topped or flat-topped intensity distribution at the reference position 300. Preferably, the laser beam and the imaging beam can be co-aligned, such that the area of ​​the laser-sensitive material 520 irradiated by the imaging beam overlaps only with a portion of the laser beam having a flat-top or flat-top cap-shaped intensity distribution.

[0142] The laser-sensitive material 520 can be configured to undergo detectable changes and / or emit radiation when irradiated with a laser beam and when irradiated with an imaging beam. The detectable changes and / or emitted radiation resulting from irradiation of the laser-sensitive material with an imaging beam can be distinguished from the detectable changes and / or emitted radiation resulting from irradiation of the laser-sensitive material with a laser beam. For example, if the laser-sensitive material is a luminescent material, the photons emitted when irradiated with a laser beam can have a different wavelength than the photons emitted when irradiated with an imaging beam.

[0143] As discussed above, sensor device 521 can be used to detect changes in the laser-sensitive material 520 caused by laser beam irradiation and / or emission from the laser-sensitive material. The same sensor device 521 or additional sensor devices (not shown) can be used to detect changes in the laser-sensitive material 520 caused by imaging beam irradiation and / or emission from the laser-sensitive material. If additional sensor devices are used, they can be arranged away from the laser-sensitive material 520. Sensor device 521 and other sensor devices (if used) and / or processing device 120 can be configured to determine the area of ​​the laser-sensitive material 520 irradiated by the imaging beam and the area of ​​the laser-sensitive material 520 irradiated by the laser beam. Processing device 120 can be configured to determine whether the area of ​​the laser-sensitive material 520 irradiated by the laser beam at least partially overlaps, optionally completely overlaps, the area of ​​the laser-sensitive material 520 irradiated by the imaging beam. Processing device 120 can be configured to determine adjustments to the laser beam assembly 40 and / or the image beam assembly 50 such that the area irradiated by the imaging beam at least partially overlaps with the area irradiated by the laser beam. The determined adjustments may, for example, be adjustments to the positioning of the optical components of the laser beam assembly 40 and / or the image beam assembly 50.

[0144] In one embodiment, the laser-sensitive material 520 may include a luminescent material, such as a phosphorescent material and / or a fluorescent material, configured to emit photons when irradiated by a laser beam and when irradiated by an imaging beam. The laser-sensitive material 520 may include a single luminescent material configured to emit photons when irradiated by a laser beam and when irradiated by an imaging beam. By way of example, the laser-sensitive material 520 may include a phosphor configured to convert both photons from the laser beam and photons from the imaging beam into visible light. For example, the imaging beam may be an X-ray beam, the laser beam may be a UV laser beam, and the laser-sensitive material 520 may include a phosphorescent material configured to convert both UV and X-ray photons into visible light.

[0145] The laser-sensitive material 520 may include a mixture of luminescent materials comprising a first luminescent material configured to emit photons when irradiated by a laser beam and a second luminescent material configured to convert photons when irradiated by an imaging beam, wherein the first and second luminescent materials are respectively phosphorescent or fluorescent. The laser-sensitive material 520 may also include a mixture of phosphors comprising a first phosphor configured to convert photons from the laser beam into visible light and a second phosphor configured to convert photons from the imaging beam into visible light. For example, the imaging beam may be an X-ray beam, the laser beam may be a UV laser beam, and the laser-sensitive material 520 may include a first phosphor configured to convert UV photons into visible light and a second phosphor configured to convert X-ray photons into visible light.

[0146] In one embodiment, the laser-sensitive material 520 can be configured to undergo visible changes, such as color changes and / or texture changes, when irradiated with an imaging beam and when irradiated with a laser beam. As discussed above, sensor device 521 can be used to image the visible changes in the laser-sensitive material 520 caused by irradiation with the laser beam. The same sensor device 521 or another sensor device (not shown) can be configured to image the visible changes in the laser-sensitive material 520 caused by irradiation with the imaging beam. In such an embodiment, sensor device 521 can be a camera. Processing device 120 connected to sensor device 521 can then determine whether the imaging beam is co-aligned with the laser-sensitive material based on the image of the laser-sensitive material received from sensor device 521 (and, if used, other sensor devices). The processing device 120 can determine adjustments to the laser beam assembly 40 and the image beam assembly 50, such as positioning the optical components of the laser beam assembly 40 and / or the image beam assembly 50, to achieve co-alignment of the imaging beam and the laser beam based on the image.

[0147] As discussed above, the laser-sensitive material 520 can be configured to emit and / or change, wherein the emission or change is related to the intensity of the laser beam irradiating the material, thereby generating an intensity distribution of the laser beam based on the detected emission / change and correlation. It is not necessary to generate an intensity distribution of the imaging beam for co-alignment of the imaging beam and the laser beam. Therefore, the laser-sensitive material 520 can be configured to emit and / or change, wherein the emission or change does not need to be related to the intensity of the imaging beam. In fact, instead, co-alignment of the imaging beam and the laser beam can be based on detecting whether the area of ​​the laser beam irradiating the laser-sensitive material 520 at least partially overlaps, preferably completely overlaps, the area of ​​the imaging beam irradiating the laser-sensitive material 520. However, in some embodiments, the laser-sensitive material 520 can be configured to emit and / or change when irradiated with the imaging beam, wherein these emission and / or changes are related to the intensity of the imaging beam. In such embodiments, the intensity distribution of the image can be generated by the sensor device 521 and / or the processing device 120 coupled to the sensor device 521. Such an intensity distribution will be two-dimensional (in the profile measurement plane).

[0148] As discussed above, the beam analyzer may include a laser sensor 530, instead of the laser-sensitive material 520, configured to measure the intensity distribution of a laser beam, as shown in FIG6. When the device 10 is in the profile measurement configuration (i.e., when measuring the intensity of the laser beam), the laser sensor 530 may intersect the laser beam at a reference position 300. Specifically, when the device 10 is in the profile measurement configuration, the sensing surface 530a of the laser sensor 530 may intersect the laser beam at the reference position 300. As discussed above, the laser beam may be guided such that the reference position 300 may be arranged within the vacuum chamber 20. Therefore, as shown in FIG6, when the device 10 is in the profile measurement configuration (i.e., when measuring the intensity distribution of the laser beam), the laser sensor 530 may be arranged within the vacuum chamber 20. Thus, the laser sensor 530 can be used to measure the intensity distribution of the laser beam in situ. The vacuum chamber can be an ultra-high vacuum chamber, and the laser sensor 530 can be compatible with ultra-high vacuum (UHV) conditions. Compatibility means that the laser sensor 530 may not significantly degrade or release gas when placed in the vacuum chamber 20 under UHV conditions. The laser sensor 530 may include or consist of one or more cameras (such as CCD cameras or CMOS cameras). The camera may have a coating that acts as a neutral density filter to reduce damage to the camera from the laser beam. The camera can be configured to detect the intensity of the laser beam received at its sensing surface 530a and generate an image of the laser beam intensity distribution. Measuring the laser beam intensity distribution and generating an image of the laser beam intensity distribution using such cameras is known in the art, but such cameras are prone to degradation and overheating when placed under vacuum conditions. According to the device of the invention, the laser sensor 530 can be supported on a bracket 60' (referred to herein as sensor bracket 60'), as shown in FIG8A, which can be configured to reduce overheating of the laser sensor 530 when operating under vacuum conditions. This helps reduce gas release or degradation of the laser sensor 530. The sensor holder 60' is discussed in further detail below.

[0149] Laser sensor 530 can be configured to sense both a laser beam and an imaging beam, and thus can be used to co-align the laser beam and the imaging beam. Laser sensor 530 can be configured to distinguish between illumination received by the laser beam and illumination received by the imaging beam. As discussed above, laser sensor 530 can be configured to detect the intensity of the laser beam irradiating it. Laser sensor 530 can be configured to detect at least the area irradiated by the imaging beam, optionally detecting the intensity of the irradiation. Processing device 120 connected to the laser sensor can determine whether the imaging beam is co-aligned with the laser-sensitive material based on a comparison of the imaging beam irradiated area detected by laser sensor 530 with the laser beam irradiated area detected by laser sensor 530. Processing device 120 can determine adjustments to the laser beam assembly 40 and the image beam assembly 50, for example, positioning the optical components of the laser beam assembly 40 and / or the image beam assembly 50 to achieve co-alignment of the imaging beam and the laser beam based on the detected area. For example, the imaging beam could be an X-ray beam, while the laser beam could be an ultraviolet laser beam. The laser sensor 530 could be a sensor capable of detecting both X-rays and ultraviolet light, such as a camera, for example, a CCD camera.

[0150] The imaging beam assembly 50 and the laser beam assembly 40 can be controlled such that the beam width of the imaging beam at the imaging position is similar to, and preferably smaller than, the beam width of the laser beam at the reference position 300.

[0151] The device 10 may further include a sample exchange chamber 30 coupled to the vacuum chamber 20. The sample 110 and / or the profile measuring element 510 may be inserted into or removed from the vacuum chamber 20 via the sample exchange chamber 30.

[0152] As discussed above, the contour measuring element 510 may be (i) a laser-sensitive material 520 (according to the embodiment of FIG4), (ii) a laser-sensitive material 520 coated on the sensor device 521 (according to the embodiment of FIG6); or (iii) a laser sensor 530 (according to the embodiment of FIG7).

[0153] As discussed above, the sample stage 70 can be configured to support a sample 110 (not shown in FIG. 1) and / or a contour measuring element 510 thereon. Referring to the x, y, and z directions shown in FIG. 1, the sample stage 70 can be translated in the xy plane and tilted relative to the xy plane. The sample stage 70 can also be moved in the z direction. If the sample stage 70 is not tilted relative to the xy plane and receives the sample 110 and / or the contour measuring element 510 thereon, the sampling plane and / or the contour measuring plane can be arranged parallel to the xy plane. Alternatively, the sample stage 70 can be tilted relative to the xy plane at a non-zero angle and can receive the sample 110 and / or the contour measuring element 510 thereon, such that the sampling plane and / or the contour measuring plane can be arranged at a non-zero angle relative to the xy plane. In the arrangement of contour measuring elements, the area of ​​the contour measuring element within the contour measuring plane can be smaller than the beam width of the laser beam at the reference position, and the contour measuring element can be translated across the area of ​​the laser beam spot at the reference position. This translation can be performed by translating the sample stage 70 on which the contour measuring element 510 is arranged.

[0154] The sample stage 70 can be configured to receive the sample 110 and the profile measuring element 510 at spaced-apart positions on the sample stage 70, as shown in FIG. 5A. These positions are spaced apart along the surface of the sample stage 70. These positions can be spaced apart in the xy plane. As shown in FIG. 5A, the position for receiving the sample 110 can also be spaced apart in the z-direction from the position for receiving the profile measuring element 510. In fact, in the exemplary embodiment shown in FIG. 5A, the profile measuring element is optionally received on a raised portion 70a of the sample stage 70, which is spaced apart from the position of the sample 110 in the xy plane.

[0155] Alternatively, the sample stage 70 can be configured to receive the sample 110 and the profile measuring element 510 one by one. For example, the sample stage 70 can be configured to receive the sample 110 or the profile measuring element at the same position on the sample stage 70.

[0156] The sample stage 70 may include a heat sink 71 configured to receive heat generated by the profile measuring element 510 when it is supported on the sample stage 70. The heat sink 71 may be a thermally conductive block within the sample stage 70, such as a metal block made of aluminum or stainless steel. The sample stage 70 may be at least partially composed of the thermally conductive material forming the heat sink 71. When the profile measuring element 510 is positioned on the sample stage 70, the heat sink 71 may be thermally coupled to the profile measuring element 510. Thermal coupling between the sample stage 70 and the profile measuring element 510 can be maintained during movement of the sample stage 70.

[0157] Sample 110 and / or contour measuring element 510 can be directly arranged on sample stage 70. Alternatively, sample 110 and / or contour measuring element 510 can be supported by bracket 60, which is arranged on sample stage 70, as shown in FIG1. ​​Bracket 60 can be configured to support one of sample 110 or contour measuring element 510. Different brackets 60 can be used for each of sample 110 and contour measuring element 510. Alternatively, bracket 60 can be configured to support both sample 110 and contour measuring element 510 simultaneously.

[0158] A transfer assembly (e.g., a transfer rod (not shown)) can be configured to be detachably mechanically coupled to the holder 60 and configured to move the holder 60 (e.g., by translation) into and out of the vacuum chamber 20 (optionally via the sample exchange chamber 30). Once the holder 60 is in place within the vacuum chamber 20, the transfer assembly can be mechanically decoupled from the holder 60. The transfer assembly can be a transfer rod that can be detachably engaged with the holder 60, for example, by screwing the transfer rod into and screwing it into a corresponding recess in the holder 60.

[0159] The apparatus 10 may include a stage positioning mechanism (not shown) configured to adjust the position of the sample stage 70. The stage positioning mechanism may be configured to adjust the position of the sample stage 70 in the xy plane and / or in the z direction. The stage positioning mechanism may be configured to adjust the position of the sample stage 70 by in-plane rotational movements (such as rotation in the xy plane). For example, the stage positioning mechanism may be configured to rotate the sample stage 70 about an axis in the z direction. The apparatus 10 may also include a tilting mechanism that tilts the sample stage 70 at a non-zero angle relative to the xy plane. The positioning mechanism and / or tilting mechanism used to position the sample stage 70 may be controlled by the controller 100.

[0160] In an arrangement in which the contour measuring element 510 and the sample 110 are simultaneously arranged on the sample stage 70, the controller 100 can be configured to control the sample stage positioning mechanism to translate or rotate the sample stage 70, so as to reconfigure the device between a contour measuring configuration in which the contour measuring element 510 intersects the laser beam at a reference position 300 and an analytical configuration in which the sample 110 intersects the laser beam at a reference position 300.

[0161] Alternatively, the sample stage 70 can be configured to receive both the sample 110 and the profile measuring element 510. For example, the sample stage can first receive a support 60 on which the profile measuring element 510 is supported, the support 60 being subsequently removed from the vacuum chamber 20, optionally via a sample exchange chamber 30. The profile measuring element 510 can be replaced by the sample 110, after which the support 60 is reinserted into the vacuum chamber via the sample exchange chamber 30. Alternatively, the support 60 having the profile measuring element 510 can be replaced by a different support 60 having the sample 110.

[0162] If the contour measuring element 510 is a laser-sensitive material 520, then the support 60 used to support the laser-sensitive material 520 can be a standard sample holder known in the art, as shown in FIG5A. In such an embodiment, the sensor device 521 can be arranged away from the laser-sensitive material 520 and the laser-sensitive material 520 can be directly disposed on the surface of the support 60, as shown in FIG5A. The upper surface of the support 60 can be configured to receive the laser-sensitive material 520, while the lower surface of the support 60 can be configured to mate with the sample stage 70. The terms “upper” and “lower” refer to the orientation of the support 60 during normal use when measuring the intensity distribution of the laser beam.

[0163] If the contour measuring element 510 is a laser-sensitive material 520 coated on the sensor device 521, or if the contour measuring element 510 is a laser sensor 530, supporting the laser sensor 530 or sensor device 521 with a standard sample holder known in the art may cause the sensor device 521 or laser sensor 530 to overheat and degrade. However, the inventors have created a holder 60', referred to herein as sensor holder 60', which can be used to detachably mechanically and / or thermally and / or electrically couple the sensor device 521 or laser sensor 530 to the sample stage 70, and to mitigate overheating and damage to the sensor device 521 or laser sensor 530 when used under vacuum conditions. Sensor holder 60' is shown in Figures 8A, 8B, and 8C. During movement of the sample stage 70, thermal and / or electrical and / or mechanical coupling between the contour measuring element 510 and the sample stage 70 via sensor holder 60' can be maintained.

[0164] Sensor holder 60' can be configured to hold and / or support sensor device 521 or laser sensor 530. Sensor holder 60' can be configured to be mechanically coupled to sample stage 70. Preferably, sensor holder 60' can be configured to be detachably mechanically coupled to sample stage 70. The upper surface of sensor holder 60' can be configured to receive sensor device 521 (coated with laser-sensitive material 520) or laser sensor 530 thereon, and the lower surface of sensor holder 60' can be configured to mate with sample stage 70. The terms "upper" and "lower" refer to the orientation of sensor holder 60' during normal use when measuring the intensity distribution of the laser beam. Sensor holder 60' and sample stage 70 can include detachable complementary mating devices, such as corresponding pins and recesses / grooves. Detachable complementary mating devices can be configured to generate electrical signals that can be received by, for example, processor 120 or controller 100 when mated. Such electrical signals can be used to confirm the mechanical mating of sensor holder 60' and sample stage 70. In the exemplary embodiment shown in FIG8C, the detachable complementary fit optionally includes a pin 61 protruding from the lower surface of the sensor holder 60' and a corresponding recess 72 optionally formed in the upper surface of the sample stage 70.

[0165] When the sensor holder 60' is mechanically coupled to the sample stage 70, the sensor holder 60' can be configured to thermally couple the sample stage 70 to the sensor device 521 or laser sensor 530 disposed on the sensor holder 60'. If the sample stage 70 includes a heat sink 71 as discussed above, then when the sensor holder 60' is mechanically coupled to the sample stage 70, the sensor holder 60' can be configured to thermally couple the heat sink 71 of the sample stage 70 to the laser sensor 530 or sensor device 521 disposed on the sensor holder 60'. For example, the sensor holder 60' may include one or more holder thermal coupling elements 62, which are thermally coupled to the sensor device 521 or laser sensor 530 when the sensor device 521 or laser sensor 530 is disposed on the sensor holder 60'. The support thermal coupling element 62 can be configured to be detachably thermally coupled to the heat sink 71 of the sample stage 70 when the sensor support 60' is mechanically coupled to the sample stage 70. Therefore, when the support 60' is mechanically decoupled from the sample stage 70, the support thermal coupling element 62 and the heat sink 71 will also be thermally decoupled. The support thermal coupling element 62 can be made of a thermally conductive material and can extend between the upper and lower surfaces of the sensor support 60'. When the laser sensor 530 or sensor device 521 is arranged on the sensor support 60', the support thermal coupling element 62 can be configured to directly contact the laser sensor 530 or sensor device 521.

[0166] In the exemplary embodiment shown in FIG8C, the thermal coupling element 62 is optionally a thermally conductive via extending through the thickness of the sensor holder 60' between the upper and lower surfaces of the sensor holder 60'. The conductive via is a through-hole filled with a thermally conductive material that extends through the thickness of the sensor holder 60' (from the upper to the lower surface of the sensor holder 60'). In the exemplary embodiment shown in FIG8C, the heat sink 71 forms part of the upper surface of the sample stage 70. Therefore, when the sample stage 70 and the sensor holder 60' are mechanically coupled together, the heat sink 71 can be aligned with and in direct contact with the thermal coupling element 62.

[0167] In an alternative embodiment not shown, the heat sink 71 may not form part of the upper surface of the sample stage 70. In such an arrangement, the sample stage 70 may include a stage thermal coupling element, such as one or more thermally conductive vias, extending between the heat sink 71 and the upper surface of the sample stage 70.

[0168] The sample stage 70 can be configured to be electrically coupled to, and optionally to, transmit power to and / or transmit data from, the sensor device 521 or the laser sensor 530 (indirectly or directly) when arranged on it. When the sensor holder 60' and the sample stage 70 are mechanically coupled together, the sample stage 70 can be configured to be electrically coupled to the sensor device 521 or the laser sensor 530 via the sensor holder 60'. The sample stage 70 and the holder 60' can be detachably electrically coupled together such that when the sensor holder 60' and the sample stage 70 are mechanically decoupled, the sample stage 70 is also electrically decoupled from the sensor holder 60'. Therefore, the sensor device or laser sensor is only energized and / or available for data transmission when mechanically coupled to the stage via the sensor holder 60' and thus arranged for measuring the intensity distribution of the laser beam. Limiting the amount of time that the laser sensor or sensor device is powered on and / or available for data transmission advantageously reduces overheating of the laser sensor or sensor device within the vacuum chamber 20.

[0169] In embodiments where the sample stage 70 is configured to receive a sensor device 521 or a laser sensor 530, and power is supplied to the sensor device or laser sensor 530, the sample stage 70 may be electrically connected to a power supply 800 that may be disposed outside the vacuum chamber 20. The sample stage 70 may be electrically coupled to the power supply 800 via a fixed (i.e., permanent) electrical connection (e.g., via a wired connection), as shown in Figures 6, 7, and 8C. The sample stage 70 may be configured to be detachably electrically coupled to the laser sensor or sensor device via a sensor holder 60' when receiving the laser sensor or sensor device.

[0170] In embodiments where the sample stage 70 is configured to receive data from sensor device 521 or laser sensor 530, the sample stage 70 can be electrically coupled to processing device 120, which can be disposed outside the vacuum chamber 20. The sample stage 70 can be electrically connected to processing device 120 via a fixed (i.e., permanent) electrical connection (such as a wired connection), as shown in Figures 6, 7, and 8C. Wired connections are particularly advantageous for achieving high-speed, low-noise data transmission. The sample stage 70 can be configured to be detachably electrically coupled to laser sensor 530 or sensor device 521 via sensor bracket 60' when receiving data from laser sensor 530 or sensor device 521.

[0171] Therefore, the sensor holder 60' enables the transmission of data and / or the supply of power to the sensor device 521 or laser sensor 530 disposed inside the vacuum chamber 20 via a wired connection, without requiring the vacuum chamber 20 to be opened for connection. Thus, the sensor device 521 or laser sensor 530 can measure the intensity distribution of the laser beam in situ under vacuum conditions without the risk of contaminating the vacuum chamber 20 or without the need to ventilate the vacuum chamber 20 after measuring the intensity distribution.

[0172] The sample stage 70 may include an electrical coupling element 700, referred to herein as the stage electrical coupling element 700. The sensor bracket 60' may include an electrical coupling element 600, referred herein as the bracket electrical coupling element 600. The bracket electrical coupling element 600 may be electrically coupled to the sensor device 521 or the laser sensor 530 via a fixed (i.e., permanent) electrical connection (such as a wired connection).

[0173] The support electrical coupling element 600 can be configured to be detachably electrically coupled to the stage electrical coupling element 700 when the sensor support 60' is mechanically coupled to the sample stage 70. Specifically, the support electrical coupling element 600 and the stage electrical coupling element 700 can be configured to be detachably electrically coupled together, such that when the support 60' is mechanically decoupled from the sample stage, the support electrical coupling element 600 will be electrically decoupled from the stage electrical coupling element 700. The support electrical coupling element 600 and the stage electrical coupling element 700 can be configured to transmit power to and / or transmit data from the sensor device 521 or laser sensor 530 disposed on the sensor support 60' when the support electrical coupling element 600 and the stage electrical coupling element 700 are electrically coupled together.

[0174] If the sample stage 70 includes a heat sink 71 and a stage electrical coupling element 700, as shown in FIG8C, then the stage electrical coupling element 700 may be electrically insulated from the heat sink 71. For example, the sample stage 70 may include an electrically insulating (and optionally thermally insulating) material that separates the electrical coupling element 700 from the heat sink 71. Apart from the heat sink 71, the stage electrical coupling element 700, and the stage thermal coupling element (if present), the sample stage 70 may be made of an electrically insulating (and optionally thermally insulating) material.

[0175] If the sensor bracket 60' includes a bracket thermal coupling element 62 and a bracket electrical coupling element 600, such as Figure 8AAs shown in Figures 8B and 8C, the bracket electrical coupling element 600 can be electrically insulated from the bracket thermal coupling element 62. For example, the sensor bracket 60' can include an electrically insulating (and optionally, thermally insulating) material that separates the bracket electrical coupling element 600 from the bracket thermal coupling element 62. Apart from the bracket electrical coupling element 600 and the bracket thermal coupling element 62, the sensor bracket 60' can be made of an electrically insulating (and optionally thermally insulating) material.

[0176] As shown in Figure 8C, the stage electrical coupling element 700 may include one or more stage electrical contacts 710. As shown in Figures 8A to 8C, the bracket electrical coupling element 600 may include one or more bracket electrical contacts 610. When the sensor bracket 60' and the sample stage 70 are mechanically coupled together, the bracket electrical contacts 610 may be configured to align with and directly contact the stage electrical contacts 710. The bracket electrical contacts 610 may be disposed on the lower surface of the sensor bracket 60'. The stage electrical contacts 710 may be disposed on the upper surface of the sample stage 70. The stage electrical contacts 710 and the bracket electrical contacts 610 may be made of conductive material.

[0177] As shown in Figures 8A to 8C, the bracket electrical coupling element 600 may include an electrical connector, referred to herein as bracket electrical connector 620, which provides an electrical connection between bracket electrical contacts 620 and a sensor device 521 or laser sensor 530 on sensor bracket 60'. Bracket electrical connector 620 may be configured to transmit power and / or data between bracket electrical contacts 610 and the laser sensor 530 or sensor device 521 on sensor bracket 60'. Bracket electrical connector 620 may be permanently electrically connected to bracket electrical contacts 610. For example, bracket electrical connector 620 may be soldered to bracket electrical contacts 610. Bracket electrical connector may be configured to be detachably electrically connected to sensor device 521 or laser sensor 530 when sensor device 521 or laser sensor 530 is received on sensor bracket 60'. For example, the bracket electrical connector 620 can be configured to detachably connect to a port (such as a USB port) of the sensor device 521 or the laser sensor 530. This arrangement allows for removal from the bracket 60' and, optionally, replacement of the sensor device 521 or the laser sensor 530. The bracket electrical connector 620 may include a wired connection comprising one or more wires and / or conductive vias extending from the bracket electrical contacts to the upper surface of the sensor bracket 60' for connection to the laser sensor 530 or the sensor device 521 thereon. Optionally, the wired connection may include one or more pairs of twisted-pair cables.

[0178] In the exemplary embodiments shown in Figures 8A to 8C, the bracket electrical coupling element 600 includes bracket electrical contacts 610 disposed on the lower surface of the bracket 60', and the bracket electrical connection 620 is a wired connection permanently electrically connected to the bracket electrical contacts and configured to be detachably electrically connected to the laser sensor 530 or sensor device 521 when disposed on the upper surface of the bracket 60'. The wires of the wired connection optionally extend between the lower and upper surfaces of the sensor bracket 60' through through-holes formed in the thickness of the sensor bracket 60'. Alternatively, the wires of the wired connection may extend between the lower and upper surfaces of the sensor bracket 60' around the exterior of the sensor bracket 60'. The wired connection optionally includes one or more pairs of twisted pairs.

[0179] As shown in Figure 8C, the platform electrical coupling element 700 may further include an electrical connector, referred to herein as platform electrical connector 720, between platform electrical contacts 710 and power supply 800. Power supply 800 and / or processing device 120 may be disposed outside vacuum chamber 20. Platform electrical connector 720 may include a wired connection between platform electrical contacts 710 and power supply 800 and / or processing device 120, as shown in Figure 8C. The wired connection may extend through vacuum feedthrough 900 between the interior and exterior of vacuum chamber. The wired connection may include a first wired connection between platform electrical contacts 710 and vacuum feedthrough and a second wired connection between vacuum feedthrough 900 and power supply 800 and / or processing device 120. The first and / or second wired connections may include one or more pairs of twisted pairs.

[0180] In a particularly advantageous embodiment, the bracket electrical connector 620 includes one or more pairs of twisted pairs, and the first wired connection of the platform electrical connector 720 includes one or more pairs of twisted pairs. The use of twisted pairs for data and power transmission within the vacuum chamber 20 helps maintain signal integrity and reduce noise interference.

[0181] In a particularly advantageous embodiment, the detachable electrical coupling between the sample stage 70 and the sensor device 521 or laser sensor 530 via the sensor holder 60' can be configured to both transmit power to and from the sensor device 521 or laser sensor 530 when the sensor holder 60' is mechanically coupled to the sample stage 70. However, it is also contemplated that embodiments in which data transmission from the sensor device and / or laser sensor is performed via a separate data connection are also envisioned. The data connection can be a wireless data connection, such as Bluetooth. The data connection can be between the sensor device 521 or laser sensor 530 and the processing device 120.

[0182] In some implementations, the sensor bracket 60' may optionally be integrally formed with the sensor device 521 or the laser sensor 530.

[0183] Exemplary implementation of the method

[0184] Figures 9 through 11 illustrate exemplary embodiments of the method according to the invention. A controller 100 can be used to control and cause the execution of the method. The controller 100 may be equipped with logic (e.g., in the form of software instructions) for controlling and causing the execution of steps of the method described herein. The controller may include non-transitory memory for storing computer-readable instructions and a processor for executing the computer-readable instructions. The methods disclosed herein can be implemented by executing computer-readable instructions in a processor. The processor of the controller may be the processing device 120 discussed above. These methods may optionally be implemented using the apparatus 10 discussed above, as schematically shown in Figures 12 and 13. The controller 100 can be used to control features of the apparatus 10 to implement the method. For example, controller 100 can control the stage positioning mechanism and / or stage tilting mechanism used to position the sample stage 70; if the transfer element is used to move the sample 110 and / or the contour measuring element 510, controller 100 can control the movement of the transfer element; controller 100 can control the movement of the optical elements (such as beam shapers) of the laser beam assembly 40, such that the shape of the laser beam at reference position 300 is adjusted based on the measured intensity distribution; controller can control the features of the imaging beam assembly 50 used to generate and guide the imaging beam.

[0185] The order of the method steps shown in Figures 9 to 11 and Figures 12 and 13 can be varied, provided that the context allows and some method steps can be performed simultaneously. Furthermore, describing a step as performed after another does not preclude the execution of an intermediate step.

[0186] Step 101

[0187] The method shown in Figure 9 is a method of operating a spectroscopic apparatus or microscope apparatus according to the claimed invention. The spectroscopic apparatus or microscope apparatus may be the apparatus 10 discussed above.

[0188] According to the method in Figure 9, a laser beam is guided along a trajectory through the device, and the intensity distribution of the laser beam is measured at a reference position 300 within the trajectory (step 101). This step may be referred to herein as the contour measurement step. The resulting intensity distribution can be a two-dimensional intensity of the laser beam at reference position 300 in the contour measurement plane. The intensity distribution can be represented as a heatmap. The heatmap can be a two-dimensional graph using color gradations to indicate the intensity of the laser beam in the contour measurement plane. Alternatively, for example, the intensity distribution can be represented on a 3D graph. The x, y coordinates of the graph represent the shape laser contour in the contour measurement plane, and the z coordinate represents the intensity of the laser beam in the contour measurement plane. As yet another alternative, the intensity distribution can be provided on a graph, displaying the intensity through a line cross-section of an area plot.

[0189] If the device 10 is used to perform the method of FIG9, it can be arranged in a contour measurement configuration during step 101.

[0190] As discussed above, the reference position 300 can be located at a fixed distance (referred to herein as the reference distance RD) from the laser beam focus 320. This is depicted in Figure 2. As discussed above, the reference distance can be zero. Preferably, the reference distance is non-zero, such that the reference position 300 is spaced apart from the laser beam focus 320. The reference position 300 can be upstream of the laser beam focus. The reference distance can be, for example, 0.01-100 mm from the laser beam focus, preferably 0.1-10 mm from the laser beam focus, and more preferably 1-5 mm from the laser beam focus. The laser beam focus can be defined as being one focal length away from the focusing lens of the focusing laser beam when guided along the trajectory of the laser beam through the device. The reference distance can be in the range of, for example, 0.01% to 5% of the focal length, preferably in the range of 0.1% to 5% of the focal length, and more preferably in the range of 0.5% to 2.5% of the focal length. The reference distance can be predetermined. The reference distance can be selected by the user.

[0191] Optionally, the intensity distribution of a laser beam at a reference position 300 can be measured by irradiating a contour measuring element (such as contour measuring element 510 discussed above) that intersects the laser beam at the reference position 300 during step 101. In other words, contour measuring element 510 may intersect the laser beam at the reference position 300. Specifically, the surface of contour measuring element 510 may intersect the laser beam at the reference position 300. During the contour measurement step, a plane of the surface of contour measuring element 510 (the contour measurement plane) intersects the laser beam at a non-zero angle. This non-zero angle may be substantially the same as the expected non-zero angle between the sampling plane and the laser beam during sample ablation. During the step of measuring the intensity distribution of the laser beam, at least a portion of the surface of contour measuring element 510 in the contour measurement plane may overlap with the laser beam. The area of ​​contour measuring element 510 in the contour measurement plane may be larger than the area of ​​the laser beam spot size at the reference position 300. Alternatively, the area of ​​the contour measuring element 510 in the contour measuring plane may be smaller than the beam width of the laser beam at the reference position 300, and the contour measuring element may be translated across the area of ​​the laser beam spot at the reference position 300 during the contour measuring step, such that the contour measuring element is scanned across the laser beam spot at the reference position 300 during the contour measuring step. The contour measuring element 510 may be part of a beam analyzer (such as the beam analyzer 500 discussed above).

[0192] Step 101 may include guiding the laser beam and / or arranging the profile measuring element 510 such that the profile measuring element 510 intersects the laser beam at a reference position 300. As discussed above, during step 101, the laser beam may be guided such that the reference position 300 may be arranged within the vacuum chamber of the device (such as vacuum chamber 20 discussed above). Therefore, at least while the intensity distribution of the laser beam is being measured, i.e., at least during step 201, the profile measuring element 510 may be arranged within vacuum chamber 20.

[0193] Before measuring the intensity distribution, the method may include: transporting the profile measuring element 510 to a location within the apparatus, optionally to a location within the vacuum chamber 20 of the apparatus 10. The profile measuring element 510 may be guided to the vacuum chamber 20 via the sample exchange chamber 30 to avoid disrupting the vacuum of the vacuum chamber 20.

[0194] Before measuring the intensity distribution, the method may include arranging the profile measuring element 510 on a sample stage (such as the sample stage 70 discussed above) within the apparatus. The method may include arranging the profile measuring element 510 on the sample stage 70 within the vacuum chamber 20 before the step of measuring the intensity distribution. The profile measuring element 510 may be arranged directly (i.e., without an intervening structure) or indirectly (i.e., with an intervening structure) on the sample stage 70 within the vacuum chamber 20.

[0195] Arranging the profile measuring element 510 on the sample stage 70 may include adjusting the position of the sample stage 70 in the x,y plane and / or in the z direction and / or tilting the sample stage 70. The positioning and / or tilting mechanisms discussed above may be used to adjust the position and / or tilt the sample stage 70.

[0196] If the profile measuring element 510 is arranged on the sample stage 70, the profile measuring element 510 can be tilted, for example, by tilting the sample stage 70, so that the angle between the laser beam and the profile measuring plane during the profile measuring step is the same as the expected angle between the laser beam and the sampling plane during the profile measuring step.

[0197] Arranging the profile measuring element 510 on the sample stage 70 may include mechanically and / or thermally and / or electrically coupling the profile measuring element 510 to the sample stage 70. As discussed above, mechanical coupling of the profile measuring element 510 to the sample stage 70 may enable thermal and / or electrical coupling between the profile measuring element 510 and the sample stage 70. As discussed above, the sample stage 70 may include a heat sink 71. Thermal coupling of the profile measuring element 510 to the sample stage 70 may result in heat transfer from the profile measuring element 510 to the heat sink 71 of the sample stage 70. This may be advantageous in reducing overheating of the profile measuring element 510, particularly advantageous in embodiments where the profile measuring element includes a sensor device 521 or a laser sensor 530 disposed within the vacuum chamber 20.

[0198] During the arrangement of the profile measuring element 510 on the sample stage 70, the profile measuring element 510 may be supported on a bracket (such as brackets 60, 60' discussed above). Brackets 60, 60' may be standard brackets, such as sample brackets known in the art, or may be a bracket referred to above as sensor bracket 60'. As discussed above, mechanical and / or thermal and / or electrical coupling between the profile measuring element 510 and the sample stage 70 may be achieved via sensor bracket 60'. For example, sensor bracket 60' may be optionally used if the profile measuring element 510 is a laser sensor 530 or if the profile measuring element 510 is a sensor device 521 coated thereon with laser-sensitive material 520. If the sensor device 521 is arranged away from the laser-sensitive material 520 and the profile measuring element 510 is composed of laser-sensitive material 520, a standard sample bracket may be used as bracket 60.

[0199] The profile measuring element 510 can be supported on supports 60, 60' before being transported into the vacuum chamber 20. The profile measuring element 510 can then be transported into the vacuum chamber 20 while still on supports 60, 60'. A transfer assembly (such as the transfer rod discussed above) can be used to transport the profile measuring element 510 into the vacuum chamber 20. If the profile measuring element 510 is supported on supports 60, 60' during the measurement of the intensity distribution (during step 101), the transfer assembly can be mechanically coupled to supports 60, 60', then inserted into the vacuum chamber 20 or sample exchange chamber 30, and subsequently mechanically decoupled from supports 60, 60' once they are positioned on the sample stage 70. Alternatively, the supports 60 and 60' may already be arranged inside the vacuum chamber 20, and the profile measuring element 510 may be arranged on the supports 60 and 60' after the profile measuring element 510 has been inserted into the vacuum chamber 20.

[0200] When measuring the intensity distribution of the laser beam, i.e. during step 101, the laser beam can be operated in the contour measurement mode discussed above. As discussed above, in contour measurement mode, the laser beam can irradiate the contour measurement element 510 with a lower energy than that suitable for sample ablation.

[0201] In an exemplary embodiment, the laser beam can be generated by a laser source and shaped using a beam shaper (such as beam shaper 420 discussed above). A reference position can be downstream of beam shaper 420 and upstream of the laser beam focal point. Reference position 300 can be located at the image plane of beam shaper 420. In an exemplary embodiment, the laser beam can be shaped from a generally Gaussian incident laser beam into a cap-shaped intensity distribution. The laser beam can be expanded prior to shaping by beam shaper 420. After shaping by beam shaper 420, the laser beam can be focused using an objective focusing lens (such as objective focusing lens 450 discussed above). The laser beam can be generated, shaped, and guided using the laser beam assembly 40 discussed above. Other optical components can be used to guide and shape the laser beam. For example, as shown in Figure 3, the laser beam can also selectively pass through a variable attenuator 430, a polarization adjustment optics 435, and a second beam expander 440, which can be positioned between the beam shaper 420 and the objective focusing lens 450. The variable attenuator 430 can be used to reduce beam power / energy. A mirror can be used to guide the laser beam, as shown in Figure 3.

[0202] The laser beam may optionally be generated outside the vacuum chamber 20 and then transmitted into the vacuum chamber 20 via a window (such as window 25 discussed above), as shown in Figures 2 and 3.

[0203] The contour measuring element 510 may include the laser-sensitive material 520 or the laser sensor 530 discussed above. If the laser-sensitive material 520 is used as the contour measuring element 510, the laser-sensitive material will intersect the laser beam at a reference position 300 during the measurement of the intensity distribution of the laser beam. If the contour measuring element 510 includes the laser sensor 530, the sensing surface 530a of the laser sensor 530 will intersect the laser beam at a reference position 300 during the measurement of the intensity distribution of the laser beam.

[0204] If a laser-sensitive material 520 is used as the profile measuring element 510, measuring the intensity distribution of the laser beam can include detecting changes in the laser-sensitive material 520 or emissions from it when irradiated by the laser beam. The description of the laser-sensitive material 520 above also applies to the laser-sensitive material 520 used in this method. Measuring the intensity distribution of the laser beam can include detecting changes in the laser-sensitive material 520 caused by irradiation by the laser beam or emissions from it, and correlating the detected changes or emissions with the intensity of the laser beam irradiating the laser-sensitive material 520.

[0205] If the laser-sensitive material 520 emits light when irradiated by a laser beam, measuring the intensity of the laser beam can include detecting the intensity of the emission from the laser-sensitive material 520. As discussed above, the laser-sensitive material 520 can be configured to emit light when irradiated by a laser beam, the emission having an intensity proportional to the intensity of the laser beam irradiating the material. Therefore, by detecting the intensity of the emission from the laser-sensitive material 520, the intensity of the laser beam on the laser-sensitive material 520 can be determined based on a proportional relationship, thereby determining the intensity of the laser beam at reference position 300. As discussed above, the emitted light can be, for example, visible light.

[0206] If the laser-sensitive material 520 undergoes a detectable change when irradiated by a laser beam, measuring the intensity of the laser beam can include detecting the change in the laser-sensitive material 520 when irradiated by the laser beam. The detectable change can be correlated with the intensity of the laser beam irradiating the laser-sensitive material 520. Optionally, the detectable change can be a visible change in the laser-sensitive material 520. A visible change can be a change in texture and / or color. Examples of laser-sensitive materials 520 that exhibit visible changes (which can be changes in texture and / or color) have been discussed above and are equally applicable to this method. Detecting changes in the laser-sensitive material 520 can include capturing images of the laser-sensitive material 520 before and after irradiation and subsequently determining the change in the laser-sensitive material 520 by comparing the captured images.

[0207] A sensor device (such as sensor device 521 discussed above) can be used to detect changes in or emission from the laser-sensitive material 520 when it is irradiated with a laser beam. As discussed above, sensor device 521 can be a camera, such as a CCD or CMOS camera. As discussed above, the laser-sensitive material 520 can be directly coated onto the sensing surface 521a of sensor device 521. In this arrangement, sensor device 521 and the laser-sensitive material 520 coated thereon constitute a contour measuring element 510. Such an arrangement is shown in FIG. 7 and can be used in this method. Alternatively, sensor device 521 can be located away from the laser-sensitive material 520, i.e., spaced apart from it. In such an arrangement, contour measuring element 510 is the laser-sensitive material 520. If the sensor device 521 is located away from the laser-sensitive material 520, it can be positioned outside the vacuum chamber 20 and, during the measurement of the intensity distribution of the laser beam, can receive or image the emission from the laser-sensitive material 520 through window 26. This may help reduce overheating of the sensor device 521 that might otherwise occur under vacuum conditions. Optionally, measuring the intensity distribution of the laser beam may include reflecting an image of the laser-sensitive material 520 or the emission from it onto the sensing surface 521a of the sensor device 521, such as by means of a reflector (such as reflector 522 discussed above). Such an arrangement is shown in Figure 4 and can be used in this method.

[0208] If a laser sensor 530 (such as the laser sensor 530 discussed above) is used as the contour measuring element 510, measuring the intensity of the laser beam can include detecting the intensity of the laser beam illumination using the laser sensor 530. As discussed above, the laser sensor 530 can be a camera, such as a CCD or CMOS camera. Such an arrangement is shown in Figure 6 middle.

[0209] In embodiments employing a laser sensor 530 or sensor device 521 coated with a laser-sensitive material 520, the laser sensor 530 or sensor device 521 may be positioned on a sample stage 70 during the intensity distribution measurement as described above. This method may include transmitting power to the laser sensor 530 or sensor device 521 via the sample stage 70 during the intensity distribution measurement. The sample stage 70 may be electrically coupled to a power source (such as the power source 800 discussed above). The sample stage 70 may be positioned within the vacuum chamber 20, and the power source 800 may be positioned outside the vacuum chamber 20, as discussed above. The electrical connection between the sample stage 70 and the power source 800 may be a fixed (i.e., permanent) electrical connection, such as a wired connection, which may extend through the vacuum feedthrough 900 to avoid disrupting the vacuum of the vacuum chamber 20. When the laser sensor 530 or sensor device 521 is positioned on the sample stage 70, the laser sensor 530 or sensor device 521 can be detachably electrically coupled to the sample stage 70 and therefore detachably electrically coupled to the power supply 800. When the laser sensor 530 or sensor device 521 is turned on during the contour measurement step, heat may be transferred from the laser sensor 530 or sensor device 521 to the heat sink 71 within the sample stage 70 due to the thermal coupling between the sample stage 70 and the laser sensor 530 or sensor device 521 on it.

[0210] The method may include transmitting data from laser sensor 530 or sensor device 521 during or after the step of measuring the intensity distribution of a laser beam. Data transmission may be wireless, such as via Bluetooth or a wired connection. The step of transmitting data from laser sensor 530 or sensor device 521 may include transmitting data from laser sensor 530 or sensor device 521 to the processing device 120 and / or controller 100 discussed above. The intensity distribution may be generated by laser sensor 530 or sensor device 521, and the data transmitted to processing device 120 and / or controller 100 may include the generated intensity distribution. Alternatively, the data transmitted from laser sensor 530 or sensor device 521 to processing device and / or controller 100 may include raw data obtained by laser sensor 530 or sensor device 521. Processing device 120 and / or controller 100 may generate the intensity distribution based on the raw data received from laser sensor 530 or sensor device 521.

[0211] In embodiments where the laser sensor 530 or sensor device 521 is arranged on the sample stage 70 during intensity distribution measurement, data can be transmitted from or from the sensor device 521 or laser sensor 530 via the sample stage 70. The sample stage 70 can be electrically connected to the processing device 120 and / or the controller 100, for example, via a wired connection. When the laser sensor 530 or sensor device 521 is arranged on the sample stage 70, the laser sensor 530 or sensor device 521 can be detachably electrically coupled to the sample stage 70 and therefore detachably electrically coupled to the processing device. This detachable electrical coupler can be configured for data transmission.

[0212] During step 101, data and power can be transmitted to the sensor device 521 or the laser sensor 530 via the sample stage 70. Power transmission can be performed via electrical coupling between the sample stage 70 and the power supply 800, and via detachable electrical coupling between the sample stage 70 and the laser sensor 530 or sensor device 521. Data transmission can be performed via electrical coupling between the sample stage 70 and the processing device 120, and via detachable electrical coupling between the sample stage 70 and the laser sensor 530 or sensor device 521. Electrical coupling between the sample stage 70 and the processing device 120 and / or the controller 100 can be achieved using a wired connection, which may optionally include one or more pairs of twisted-pair cables, as discussed above.

[0213] Laser sensor 530 or sensor device 521 can be arranged on sensor holder 60', as discussed above. In such an arrangement, laser sensor 530 or sensor device 521 can be detachably electrically and / or thermally coupled to sample stage 70 via sensor holder 60', while sensor holder 60' is mechanically coupled to sample stage 70.

[0214] The detachable electrical coupling and / or thermal coupling via sensor holder 60' discussed above in the context of device 10 can be equally applied to this method. For example, detachable electrical coupling can be achieved by using electrical contacts that achieve electrical coupling when in direct contact with each other. As discussed above, detachable electrical coupling will be achieved when there is direct contact between the electrical contacts of sensor holder 60' (described above as holder electrical contact 610) and the electrical contacts of sample stage 70 (described above as stage electrical contact 710). The direct contact between holder electrical contact 610 and stage electrical contact 710 is achieved when sensor holder 60' and sample stage 70 are mechanically coupled (and thus aligned). Stage electrical contact 710 is electrically connected to power supply 800 and / or processing device 120 via, for example, a wired connection. Holder electrical contact 610 is electrically connected to laser sensor 530 or sensor device 521 on it via, for example, a wired connection.

[0215] As discussed above, detachable thermal coupling can be achieved, for example, through direct contact between the heat sink 71 and the thermal coupling element 62 of the support. Direct contact is achieved when the sensor support 60' and the sample stage 70 are mechanically coupled and thus aligned.

[0216] As discussed above, in the advantageous embodiment employing sensor holder 60', power supply to and data transmission from the sensor device 521 or laser sensor 530 can only occur when the sensor holder 60', on which it supports the sensor device 521 or laser sensor 530, is mechanically coupled to the sample stage 70. This reduces unnecessary power consumption of the laser sensor 530 or sensor device 521 within the vacuum chamber 20 during periods when the sensor device 521 or laser sensor 530 is not positioned for use, and thus reduces its overheating.

[0217] In an embodiment employing a sensor device 521 located away from the laser-sensitive material 520, the sensor device 521 can be arranged outside the vacuum chamber 20 and thus can be directly electrically connected to the processing device 120 to transmit data, for example, via a wired connection therebetween. Arranging the sensor device 521 outside the vacuum chamber 20 may help reduce overheating of the sensor device 521. However, since the laser-sensitive material 520 will be arranged inside the vacuum chamber 20, the intensity distribution will still be advantageously measured in situ.

[0218] During the step of measuring the intensity distribution at reference position 300, the laser beam intersects with the profile measuring element 510 at reference position 300. The surface of the profile measuring element 510 that intersects with the laser beam is located in the profile measuring plane, and the angle between the profile measuring plane and the laser beam is a non-zero angle.

[0219] If the intensity distribution generated during step 101 is initially poor due to misalignment of the beam profile measuring element 510 and the laser beam, or for example, due to the beam profile measuring element 510 itself, the relative positioning of the beam profile measuring element 510 and the laser beam can be adjusted before repeating the intensity distribution measurement of the laser beam. Therefore, by measuring the intensity distribution of the laser beam in situ using the beam profile measuring element 510, this allows for immediate, real-time adjustment of the beam profile measuring element 510 and the optical components of the laser beam assembly 40 to achieve an accurate laser beam intensity distribution.

[0220] Step 102

[0221] Once the intensity distribution of the laser beam has been measured, the method includes the step of configuring the shape of the laser beam based on the measured intensity distribution (step 102). The step of configuring the shape of the laser beam based on the measured intensity distribution may include: (i) if the measured intensity distribution is the desired shape, then not adjusting the shape of the laser beam; or (ii) if the measured intensity distribution is not the desired shape, then adjusting the shape of the laser beam.

[0222] The shape of the laser beam can be configured during step 102 to achieve a substantially flat-topped or flat-topped intensity distribution at reference position 300. The step of configuring the laser beam shape based on the measured intensity distribution can therefore include: (i) if the measured intensity distribution is substantially flat-topped or flat-topped, then not adjusting the shape of the laser beam; or (ii) if the measured intensity distribution is not substantially flat-topped or flat-topped, then adjusting the shape of the laser beam.

[0223] The step of configuring the laser beam shape may include adjusting one or more optical elements configured to shape the laser beam. The adjusted optical element may be a beam shaper, which may be a diffractive optical element. This may be the beam shaper 420 discussed above, which is configured to convert an incident laser beam that is substantially Gaussian distributed into a uniform intensity spot of rectangular, square, circular, or other shapes (flat-topped beam profile).

[0224] Adjusting an optical element (e.g., beam shaper 420) to configure the shape of a laser beam may include adjusting the position of the optical element in one or more directions orthogonal to the laser beam propagation direction. Adjusting an optical element to configure the shape of a laser beam may include adjusting the position of the optical element or adjusting the tilt of the optical element. The beam shaper positioning mechanism and / or beam shaper tilting mechanism discussed above may be used for such adjustments.

[0225] Processing device 120 can determine whether and how to adjust optical elements (e.g., beam shaper 420) to achieve a substantially desired intensity distribution at reference position 300 based on measured intensity distribution. For example, a non-uniform measured intensity distribution (non-flat-topped intensity distribution) or a flat-topped intensity distribution with asymmetrical tilt can be corrected by adjusting the positioning and / or tilting of the optical elements. Processing device 120 can send instructions or input parameters, such as to controller 100, to control the positioning and / or tilting of the optical elements, thereby adjusting the optical elements to change the shape of the laser beam at reference position 300. These instructions or input parameters are generated based on the measured intensity distribution.

[0226] Once the shape of the laser beam has been configured based on the measured intensity distribution, the intensity distribution of the laser beam can optionally be measured again to check whether the intensity distribution at reference position 300 now corresponds to the desired intensity distribution. In other words, step 101 can be repeated after performing step 102. If the measured intensity distribution does not yet sufficiently correspond to the desired intensity distribution, the optics of the laser beam can be further adjusted based on the further measured intensity distribution. In fact, by measuring the intensity distribution of the laser beam in situ, the configuration of the laser beam can be adjusted immediately (in real time) to ensure that the desired laser beam intensity distribution is achieved at reference position 300.

[0227] Step 103

[0228] After measuring the intensity distribution of the laser beam at reference position 300 and configuring the shape of the laser beam based on the measured intensity distribution, the method may include: ablating material from a portion of the sample surface (step 103). This step may be referred to as the sample ablation step. During the sample ablation step, a portion of the sample surface intersects with the laser beam at reference position 300. In other words, the sample surface may intersect with the laser beam at reference position 300. The portion of the sample surface 110 that intersects with the laser beam at reference position 300 may be the target region of the sample, i.e., the region of interest. As discussed above, the plane of the sample surface that intersects with the laser beam is called the sampling plane. The angle of intersection between the laser beam and the sampling plane during the sample ablation step may be the same as the angle of intersection between the laser beam and the profile measurement plane during the profile measurement step. The laser beam is used to perform sample ablation. As discussed above, the laser beam assembly 40 may be used to generate and guide the laser beam. The laser beam assembly 40 may be operated during the sample ablation step according to the ablation mode discussed above. Therefore, the energy of the laser beam at the reference position 300 during the sample ablation step may be higher than the energy of the laser beam at the reference position during the contour measurement step.

[0229] As discussed above, during the profilometry step, the profilometry element 510 intersects the laser beam at reference position 300. After the profilometry step and before the sample ablation step, the method may include: moving the sample 110 and / or the profilometry element 510 and / or redirecting the laser beam such that during the sample ablation step, a portion of the sample surface (but not the profilometry element 510) intersects the laser beam at reference position 300. In other words, the device 10 may be reconfigured such that the laser beam no longer intersects the profilometry element 510 at reference position 300, but instead intersects the sample 110 at reference position 300. As discussed above, the configuration of the device 10 during the profilometry step may be referred to as the profilometry configuration, and the configuration of the device 10 during the sample ablation step may be referred to as the sample ablation configuration.

[0230] The laser beam can be redirected so that the position of the reference position 300 within the device 10 during the contour measurement step differs from the position of the reference position 300 within the device 10 during the sample ablation step. For example, if the laser beam assembly 40 is used, the positioning of the objective lens 450 can be adjusted to adjust the direction of the laser beam and the positioning of the reference position 300.

[0231] Preferably, the direction of the laser beam is maintained such that the reference position 300 is located at the same position inside the device 10, and optionally at the same position inside the vacuum chamber 20, for both the contour measurement step and the sample ablation step. In this arrangement, the sample 110 and the contour measurement element 510 will be moved relative to the reference position 300 between the contour measurement step and the sample ablation step.

[0232] During the contour measurement step and the sample ablation step, the sample 110 and the contour measurement element 510 may coexist within the device 10, optionally within the vacuum chamber 20, but are moved relative to the reference position 300 between the contour measurement step and the sample ablation step, such that the sample 110 is irradiated by the laser beam during the sample ablation step but not during the contour measurement step, and the contour measurement element is irradiated by the laser beam during the contour measurement step but not during the sample ablation step.

[0233] Alternatively, during the profilometry step and / or the sample ablation step, the profilometry element 510 and the sample 110 may not be present simultaneously within the vacuum chamber 20. For example, after performing the profilometry step, the profilometry element 510 can be removed from the vacuum chamber 20. The sample 110 can be inserted into the vacuum chamber 20 after the profilometry step and before the sample ablation step. In such an arrangement, the reference position 300 can be in the same position within the vacuum chamber 20 during both the profilometry step and the sample ablation step. In this arrangement, the position of the profilometry element 510 within the vacuum chamber 20 during the profilometry step will be the same as the position of the sample 110 within the vacuum chamber 20 during the sample ablation step.

[0234] If the sample 110 is not already in the apparatus 10 or in the vacuum chamber 20 of the apparatus 10, the method may include: transporting the sample 110 into the apparatus 10, optionally into the vacuum chamber 20 of the apparatus 10 prior to the sample ablation step. The sample 110 may be introduced into the vacuum chamber 20 via the sample exchange chamber 30 to avoid disrupting the vacuum of the vacuum chamber 20.

[0235] If, as discussed above, supports 60, 60' are used for the profile measuring element 510, the profile measuring element 510, together with its supports 60, 60', can be removed from the vacuum chamber 20, and the profile measuring element 510 can be replaced with a sample 110, which may be on the same or different supports 60, 60'. The transfer element discussed above can be used to move the sample 110 and / or the profile measuring element 510. For example, the transfer element can be inserted into the vacuum chamber 20 via the sample exchange chamber 30, mechanically coupled to the supports 60, 60' on which the profile measuring element 510 is located, to remove the supports 60, 60' from the vacuum chamber 20 via the sample exchange chamber 30, and subsequently mechanically decoupled from the supports 60, 60' on which the profile measuring element 510 is located. Optionally, the transfer element can then be mechanically coupled to the supports 60, 60' on which the sample 110 is mounted, optionally moving the supports 60, 60' onto which the sample is mounted into the vacuum chamber 20 via the sample exchange chamber 30, and then mechanically decoupled from the supports 60, 60' once the supports are inside the vacuum chamber 20. The transfer element can then be removed from the vacuum chamber 20.

[0236] Sample 110 may be supported on a sample stage (such as sample stage 70 discussed above) during sample ablation. The method may include: arranging sample 110 on sample stage 70 within vacuum chamber 20, followed by sample ablation. Sample 110 may be supported directly (i.e., without an intervening structure) or indirectly (i.e., with an intervening structure, such as supports 60, 60') on sample stage 70 within vacuum chamber 20.

[0237] Arranging the sample 110 on the sample stage 70 may include adjusting the position of the sample stage 70 in the x, y plane and / or the z direction, and / or rotating the sample stage 70 about an axis in the z direction and / or tilting the sample stage 70.

[0238] During the sample ablation step, the position of sample 110 on the sample stage 70 can be the same as the position of profile measuring element 510 on the sample stage 70 during the profile measurement step. With this arrangement, the profile measuring element 510 can be removed from the sample stage 70 after the profile measurement step, and sample 110 can be placed on the sample stage before the sample ablation step. With this arrangement, the reference position 300 will be in the same position within the vacuum chamber 20 during both the sample ablation step and the profile measurement step.

[0239] Sample 110 can be positioned on sample stage 70 at a location spaced apart from the position of profile measuring element 510 on sample stage 70, for example, spaced apart in the xy plane. In this arrangement, sample 110 and profile measuring element 510 can be simultaneously located on sample stage 70. An example of this arrangement is shown in Figure 5A. The distance between profile measuring element 510 and sample 110 allows sample 110 to be irradiated by the laser beam while profile measuring element 510 is not irradiated, and vice versa. More specifically, the distance between profile measuring element 510 and sample 110 can be greater than the beam width of the laser beam at reference position 300. With this arrangement, both sample 110 and profile measuring element 510 can be located on sample stage 70 during the profile measurement step and the sample ablation step.

[0240] According to one embodiment, during both the contour measurement step and the sample ablation step, the contour measurement element 510 and the sample 110 are located on the sample stage 70. For both the contour measurement step and the sample ablation step, the sample stage 70, the contour measurement element 510, and the sample 110 can be maintained in the same position within the device 10. The laser beam can be redirected such that the contour measurement element 510 intersects the laser beam at a reference position 300 during the contour measurement step, and the sample intersects the laser beam at the reference position 300 during the sample ablation step.

[0241] According to an alternative embodiment, where both the contour measuring element 510 and the sample 110 are located on the sample stage 70 during the contour measurement step and the sample ablation step, the reference position 300 can be maintained in the same position within the apparatus 10 during the sample ablation step. With this arrangement, the sample 110 and the contour measuring element 510 can be moved relative to the reference position 300 such that the contour measuring element 510 intersects the laser beam at the reference position 300 during the contour measurement step, and the sample surface 110 intersects the laser beam at the reference position 300 during the sample ablation step. Optionally, the sample 110 and the contour measuring element 510 can be moved relative to the reference position 300 by moving the sample stage 70, which supports the sample 110 and the contour measuring element 510, relative to the reference position 300. For example, the sample stage 70 can be rotated about an axis in the z-direction or translated in the xy-plane. In this arrangement, there will be no relative movement between the sample 110, the profile measuring element 510, and the sample stage 70. The sample stage 70 can be moved using the stage positioning mechanism discussed above. Therefore, this can be done without interrupting the vacuum condition 20. Alternatively, the sample 110 and the profile measuring element 510 can be moved relative to the reference position 300 and relative to the sample stage 70. For example, a manipulator can be used to move the sample 110 and the profile measuring element 510. If the supports 60, 60' are used to support the sample 110 and / or the profile measuring element 510 thereon, as discussed above, the movement of the sample 110 and the profile measuring element 510 relative to the reference position 300 can be achieved by moving the supports 60, 60' relative to the reference position 300 and relative to the sample stage 70.

[0242] The laser beam can be turned off after the intensity distribution of the laser beam is measured or after the shape of the laser beam is configured, until a portion of the sample 110 is arranged such that the region intersects the laser beam at the reference position 300.

[0243] Once the sample 110 is positioned such that a portion of the sample surface will intersect with the laser beam at reference position 300, the laser beam can be switched on to perform sample ablation (step 103). As discussed above, the laser can be operated in its ablation mode during step 103 such that the energy of the laser beam at reference position 300 is suitable for ablation of the sample.

[0244] Advantageously, according to this method, the intensity distribution of the laser beam is measured, and the shape of the laser beam is configured based on the intensity distribution measured at a position (reference position 300) within the trajectory of the laser beam intersecting the sample surface during sample ablation. Thus, the shape of the laser beam at the spot where the sample will be ablated is accurately controlled, and the resulting pit due to ablation is thus accurately generated according to the desired shape, which, as discussed above, can be a flat-topped shape. Precise control of sample ablation and precise control of the shape of the pit formed by ablation facilitate accurate depth distribution analysis, as discussed in further detail below.

[0245] Optionally, the method may include adjusting the parameters of the laser beam according to the material of the sample before performing sample ablation. For example, the laser beam may be adjusted to rapidly ablate more material or reduce damage to the surface composition. Different sample materials may require lower laser beam energy for ablation and / or may be more susceptible to damage with longer pulses and / or multiple pulses of different frequencies.

[0246] Step 104

[0247] Once sample ablation has been performed (step 103), the method may include: performing spectral or microscopic analysis on at least a portion of the ablated portion by guiding an imaging beam onto the ablated portion (step 104). This step may be referred to as the analysis step. This step may include: guiding the imaging beam along a trajectory within the device to the ablated portion. Thus, during the analysis step, the imaging beam is guided to a new sample surface created by sample ablation. During the analysis step, the ablated portion may intersect with an imaging position of the imaging beam in the trajectory of the imaging beam. The imaging position may, for example, be the focal point of the imaging beam. Thus, during the analysis step, the imaging beam may be focused on the ablated portion. Alternatively, the imaging position may, for example, be a non-zero fixed distance from the focal point, which is set by the user and / or predetermined.

[0248] An imaging beam can be generated using the imaging beam source of the imaging beam assembly 50. As discussed above, the type of analysis performed will depend on the type of imaging beam, analyzer 80, and detector 90 used. In spectroscopic analysis, electrons and / or ions generated by the interaction of the imaging beam with the ablated surface can be received by the analyzer 80 and detector 90, and their energy and / or intensity can be measured to determine the chemical composition of the ablated surface. In microscopic analysis, instead of measuring the energy of electrons and / or ions, their position and / or intensity may be measured to determine a microscopic image of the ablated surface, such as in TEM or SEM analysis.

[0249] Preferably, the spot size of the imaging beam on the ablated portion is smaller than the size of the ablated portion. The beam width of the imaging beam at the imaging location can be smaller than the diameter of the ablated portion. The imaging beam can illuminate a portion of the ablated portion (the area of ​​the illuminated region is smaller than the total area of ​​the ablated portion). Otherwise, if the area illuminated by the imaging beam is larger than the area of ​​the ablated portion, the imaging beam may incident on the edges or sidewalls of the ablated portion. This may result in the emission and analysis of electrons / ions originating from the edges or sidewalls in addition to those emitted from the surface to be studied. These electrons / ions from the edges or sidewalls may originate from a different chemical composition than the surface of the pit to be studied, potentially leading to inaccurate measurements. The imaging beam can be guided such that it is centered on the ablated portion (pit) formed by the ablation step. Ideally, the ratio of the pit width to the diameter of the spot size at the imaging location can be at least 3:1, at least 4:1, or at least 5:1.

[0250] In an exemplary embodiment, the imaging beam may be an X-ray beam, and the analyzer 80 and detector 90 may be configured to measure photoelectrons emitted from the ablated surface, such that the spectral analysis performed during step 106 is XPS. In an alternative exemplary embodiment, the imaging beam may be an electron beam, and the analyzer 80 and detector 90 may be configured to measure Auger electrons emitted from the ablated surface, such that the spectral analysis performed during step 106 is AES. In an alternative exemplary embodiment, the imaging beam may be an ultraviolet beam, and the analyzer 80 and detector 90 may be configured to measure photoelectrons emitted from the ablated surface, such that the spectral analysis performed during step 106 is UPS. In an alternative exemplary embodiment, the imaging beam may be an electron beam, and the analyzer 80 and detector 90 may be configured to measure electrons, such that the microscopic analysis performed during step 106 is electron microscopy.

[0251] The imaging beam intersects with the ablated portion of the sample at the imaging position during the analysis step without moving the sample 110. In this arrangement, the laser beam and the imaging beam are co-aligned. This co-alignment of the imaging beam and the laser beam can be performed before the sample ablation step. The imaging beam and the laser beam can be co-aligned so that the imaging position coincides with the reference position. This arrangement is illustrated in Figure 10 and depicted in Figure 12. This arrangement will be discussed in further detail below.

[0252] Alternatively, if the imaging beam and the laser beam are not co-aligned and therefore the imaging position does not coincide with the reference position, the method may include moving the sample 110 between the sample ablation step and the analysis step, such that the moved sample 110 intersects with the laser beam at the reference position 300 and with the imaging beam at the imaging position. In other words, the method may include moving the sample 110 relative to the reference position 300 and relative to the imaging position after the sample ablation step and before the analysis step. Such an arrangement is illustrated in FIG11 and depicted in FIG13. This arrangement will be discussed in further detail below.

[0253] The sample ablation and analysis steps (steps 103 and 104) can be repeated to establish compositional information for each layer of sample 110, as described in step 105. The execution of sample ablation and subsequent analysis can be termed an ablation-analysis cycle. Each cycle includes a step of further ablation of material from a region of the sample surface (i.e., ablation of more material from the ablated portion), followed by a step of performing spectral or microscopic analysis on at least a portion of the further ablated portion. Therefore, each cycle results in the formation and analysis of deeper pits. In step 106, a compositional depth distribution can be generated or calculated based on the compositional information of each layer. The depth distribution can be quantitative.

[0254] During sample ablation, laser-induced periodic surface structures (LIPSS) may form on the sample surface. However, altering the linear polarization direction of the laser beam using polarization-adjusting optics during or between sample ablation steps can minimize the potential waviness. Therefore, the method may include incrementally or continuously rotating the angle of the linearly polarized laser beam during or between sample ablation steps. Alternatively, the method may include converting the linearly polarized beam into a beam with circular or elliptical polarization. Sample rotation, polarization rotation, and / or polarization conversion can reduce LIPSS and thus reduce roughness at the bottom of pits formed during ablation and / or enable a deeper depth distribution. For example, between each step of sample ablation, or if pulsed laser is used for sample ablation, the polarization plane of the sample surface 110 and / or the laser beam may be rotated, for example, by 55 degrees between each laser pulse. The rotation between each laser pulse can be selected to effectively suppress LIPSS formation; this rotation can be between 10 and 80 degrees (such as between 40 and 70 degrees, e.g., 55 degrees). The rotation can be performed about an axis parallel to the z-direction. Alternatively, the laser beam can be converted to elliptical or circular polarization to suppress LIPSS formation.

[0255] Exemplary implementations of the method are illustrated in Figures 10 and 11 and depicted in Figures 12 and 13, respectively.

[0256] The method illustrated in Figure 10 is an exemplary implementation of the method in Figure 9. Steps 201, 202, 203, 204, 205, and 206 in Figure 10 correspond to steps 101, 102, 103, 104, 105, and 106 in Figure 9, respectively. These steps have been discussed above and will not be described again to avoid repetition. The method in Figure 10 optionally requires an additional step (step 201a) to co-align the imaging beam and the laser beam. The laser beam and the imaging beam can be co-aligned such that the imaging beam coincides with the laser beam at a reference position 300. In other words, the imaging beam can be co-aligned with the laser beam such that the imaging beam and the laser beam intersect at a reference position 300. Specifically, the imaging beam can be co-aligned with the laser beam such that the imaging position coincides with the reference position of the laser beam and the imaging position of the imaging beam when the laser beam and the imaging beam are co-aligned within the device. This point where the reference position of the laser beam and the imaging position of the imaging beam coincide can be called the coincidence point.

[0257] The beam width of the imaging beam at the imaging position may be different from the beam width of the laser beam at the reference position 300. Optionally, the beam width of the imaging beam at the imaging position may be smaller than the beam width of the laser beam at the reference position 300. The step of co-aligning the imaging beam and the laser beam may include controlling the spot size of the imaging beam at the imaging position to be similar to or smaller than the spot size of the laser beam at the reference position 300.

[0258] According to the method of Figure 10, the step of co-aligning the imaging beam and the laser beam is optionally performed before the sample ablation step and the analysis step (steps 203, 204), and also optionally before the profilometry step (step 201). In a particularly advantageous embodiment of the method of Figure 10, the co-alignment of the imaging beam and the laser beam can be performed using a profilometry element 510. The laser beam can be guided such that the profilometry element 510 intersects with the laser beam at a reference position 300. The imaging beam can be guided such that the profilometry element 510 intersects with the imaging beam at an imaging position. The co-alignment step may include detecting the illumination of the profilometry element 510 by the imaging beam and / or detecting the illumination of the profilometry element 510 by the laser beam. Specifically, the co-alignment step may include detecting the area of ​​the profilometry element 510 illuminated by the imaging beam and detecting the area of ​​the profilometry element 510 illuminated by the laser beam. Based on the detected area of ​​the profilometry element 510 illuminated by the laser beam and the detected area of ​​the profilometry element 510 illuminated by the imaging beam, the orientation of the imaging beam and / or the laser beam can be adjusted. The direction of the imaging beam and / or the laser beam can be adjusted so that the area of ​​the laser beam illuminating the contour measuring element 510 at least overlaps, preferably completely overlaps, the area of ​​the imaging beam illuminating the contour measuring element 510, preferably with that area as the center.

[0259] During step 201a (which may be referred to as the co-alignment step), the imaging beam can be generated and guided using the imaging beam assembly 50 discussed above. The laser beam assembly 40 discussed above can be used to generate and guide the laser beam. The energy of the laser beam during co-alignment may be lower than the energy of the laser beam during the sample ablation step. For example, the energy of the laser beam during co-alignment may be less than 100 µJ. The energy of the laser beam in ablation mode can vary depending on the desired material and ablation amount, such as between 10 nJ and 2000 µJ, or more preferably between 50 µJ and 1000 µJ.

[0260] During step 201a, the contour measuring element 510 may be simultaneously or sequentially illuminated by the imaging beam and the laser beam. For example, if the imaging beam illuminating the contour measuring element 510 can be detected independently of the laser beam illuminating the contour measuring element 510, then the laser beam and the imaging beam can be simultaneously directed onto the contour measuring element 510 during step 201a. If the imaging beam illuminating the contour measuring element 510 cannot be detected independently of the laser beam illuminating the contour measuring element 510, then the laser beam and the imaging beam can be sequentially (and in any order) directed onto the contour measuring element 510 during step 201a.

[0261] In the exemplary embodiment of FIG10, the step of co-aligning the imaging beam and the laser beam (step 201a) is optionally performed before the contour measurement step (before step 201). However, the step of co-aligning the imaging beam and the laser beam can also be performed after the contour measurement step (after step 201) and optionally after the step of configuring the laser beam shape based on the measured intensity distribution (after step 202). In such an arrangement, during the step of co-aligning the imaging beam and the laser beam, the imaging beam can be aligned with the reference position 300 by detecting the illumination of the contour measurement element 510 by the imaging beam, and in particular, detecting the area of ​​the contour measurement element 510 illuminated by the imaging beam. In such an arrangement, it is not necessary to detect the illumination of the contour measurement element by the laser beam during the step of co-aligning the imaging beam and the laser beam. This is because the area of ​​the contour measurement element 510 illuminated by the laser beam can be determined based on the intensity distribution generated in step 201. In this arrangement, after the contour measurement step is performed, the laser beam can maintain its trajectory and the position of the reference position 300 within the device 10, and the direction of the imaging beam can be adjusted during the co-alignment step to align the imaging position with the reference position 300.

[0262] The contour measuring element 510 used in the method of FIG10 can be sensitive to both the laser beam and the imaging beam. Examples of such contour measuring elements 510 have been discussed above in the context of apparatus 10, and these examples are applicable to this method.

[0263] As discussed above, if the contour measuring element 510 includes a laser-sensitive material 520, the laser-sensitive material 520 can be configured to undergo detectable changes and / or generate emission upon illumination with an imaging beam, and is configured to undergo detectable changes and / or generate emission upon illumination with a laser beam. Optionally, detectable changes and / or emission caused by imaging beam illumination can be distinguished from detectable changes and / or emission caused by laser beam illumination.

[0264] The same sensor device, such as sensor device 521, can be used to detect changes in the laser-sensitive material 520 and / or emission from the laser-sensitive material caused by laser beam irradiation used in the contour measurement and co-alignment steps, and to detect changes in the laser-sensitive material 520 and / or emission from the laser-sensitive material caused by imaging beam irradiation used in the co-alignment step. As discussed above, sensor device 521 may have the laser-sensitive material 520 coated thereon, or may be located away from the laser-sensitive material 520, as discussed above. Alternatively, sensor device 521 can be used to detect changes in the laser-sensitive material 520 and / or emission from the laser-sensitive material caused by laser beam irradiation used in the contour measurement and co-alignment steps, and additional sensor devices can be used to detect changes in the laser-sensitive material 520 and / or emission from the laser-sensitive material caused by imaging beam irradiation. Other sensor devices, if used, may be located away from the laser-sensitive material 520.

[0265] If the contour measurement element 510 includes a laser sensor, such as the laser sensor 530 discussed above, then during the co-alignment step, the laser sensor 530 can be used to detect the illumination of the laser beam on its sensing surface 530a and to detect the illumination of the imaging beam on its sensing surface 530a.

[0266] If the imaging beam and the laser beam do not simultaneously illuminate the contour measurement element 510 during the co-alignment step, the laser beam can be turned off when the imaging beam illuminates the contour measurement element 510, or the imaging beam can be turned off when the laser beam illuminates the contour measurement element 510.

[0267] According to the method in Figure 9, it is described that the laser beam can be redirected between the contour measurement step (step 101) and the sample ablation step (step 102) to change the position of the reference position 300 within the device 10. The method in Figure 10 differs from that in Figure 9 in that, according to the method in Figure 10, the reference position 300 must be at the same position within the device 10 for both the contour measurement step (step 101) and the sample ablation step (step 103). Therefore, according to the method in Figure 10, between the contour measurement step and the sample ablation step, the sample 110 and the contour measurement element 510 are moved relative to the reference position 300 so that the sample 110 (not the contour measurement element 510) intersects with the laser beam at the reference position 300. Figure 10 In this method, for both the sample ablation step (step 103) and the analysis step (step 104), the sample 110 is located in the same position inside the device 10.

[0268] Figure 11 is an exemplary implementation of the method of Figure 9, which is an alternative implementation of the method of Figure 10. Figure 11Steps 301, 302, 303, 304, 305, and 306 correspond to steps 101, 102, 103, 104, 105, and 106 in Figure 9, respectively, and will not be described again to avoid repetition. Figure 11 differs from the embodiment in Figure 10 because the imaging beam and the laser beam are not co-aligned. The imaging beam and the laser beam are guided such that the imaging position does not coincide with the reference position 300. The imaging position can be spaced from the reference position at a fixed distance, which can be predetermined and / or selected by the user. The imaging position can be spaced from the reference position, for example, in the xy plane and / or in the z direction. This fixed distance can be greater than the beam width of the imaging beam at the imaging position and the beam width of the laser beam at the reference position 300, such that there is no overlap between the spot formed by the imaging beam at the imaging position and the spot formed by the laser beam at the reference position 300. Figure 11 differs from the embodiment of Figure 9 because it requires an additional step (304a) after the sample ablation step (after step 303) and before the analysis step (before step 304). Step 304a of Figure 11 requires moving the sample within the apparatus 10 between the sample ablation step (step 303) and the analysis step (step 104). During the sample ablation step (step 304), the sample 110 intersects with the laser beam at a reference position 300. The sample 110 is then moved relative to the reference position 300 during step 304a such that its ablated portion subsequently intersects with the imaging beam at an imaging position spaced apart from the reference position 300. Spectroscopic or microscopic analysis is then performed using the intersection of the ablated portion of the sample 110 and the imaging beam at the imaging position.

[0269] During step 304a, the movement of sample 110 relative to reference position 300 (and relative to imaging position) can be achieved in a manner similar to the movement of sample 110 discussed above. For example, sample 110 can be moved by using a manipulator, by using a transfer element, by moving the supports 60, 60' (if supports 60 / 60' are used) that support sample 110, and / or by moving the sample stage 70, as discussed above.

[0270] Step 305 is similar to step 105, except that it includes a repeated sample ablation step and a spectral or microscopic analysis step. However, step 305 differs from step 105 in that it additionally requires (i) moving the sample such that the ablated portion of the sample intersects with the laser beam at reference position 300 before the repeated ablation process, and (ii) moving the sample after further ablation has been performed such that the further ablated portion intersects with the imaging beam at the imaging position before the spectral or microscopic analysis of the repeated ablation portion.

[0271] Figure 12 schematically depicts an exemplary implementation of steps 201 to 204 of the method of Figure 10 performed on device 10. Figure 13 schematically depicts an exemplary implementation of steps 301 to 304 of the method of Figure 11 performed on device 10. The steps of the method are separated by dashed lines. The steps are performed sequentially from the top to the bottom of the figure. Dashed arrows are used to depict the movement of components. Solid arrows extending from the laser beam assembly 40 and the imaging beam assembly 50 depict exemplary paths of the laser beam and the imaging beam, respectively. The absence of an arrow extending from the laser beam assembly 40 indicates that the laser beam assembly 40 is turned off, such that the laser beam is not used during this step. Similarly, the absence of an arrow extending from the imaging beam assembly 50 indicates that the imaging assembly 50 is turned off, such that the imaging beam is not used during this step.

[0272] An exemplary path of electrons and / or ions emitted by the sample during step 204 is shown using solid arrows from sample 110 to detector 90 and analyzer 80.

[0273] In the exemplary schematic diagrams of Figures 12 and 13, the profile measuring element 510 is arranged on supports 60, 60', which may be the sensor support 60' discussed above, and the sample 110 is optionally arranged on the corresponding support 60. The method shown optionally includes: inserting the profile measuring element 510 arranged on the supports 60, 60' into the vacuum chamber 20 via the sample exchange chamber 30 and arranging the profile measuring element 510 together with the supports 60, 60' on the sample stage 70, and then performing a profile measuring step (step 201).

[0274] In the exemplary schematic diagrams depicted in Figures 12 and 13, the reference position 300 optionally remains in the same position within the apparatus 10 during method execution. The depicted method optionally includes: transferring the profile measuring element 510 from the vacuum chamber 20 via the sample exchange chamber 30 after the step of configuring the laser beam shape (after step 102) and before the sample ablation step (before step 103), and subsequently inserting the sample 110 into the vacuum chamber 20 via the sample exchange chamber 30. During transport from the vacuum chamber 20, the profile measuring element 510 is arranged on its supports 60, 60', and during transport into the vacuum chamber 20, the sample 110 is arranged on its support 60. During the movement of the sample 110 and the profile measuring element 510, the laser beam assembly 40 and the imaging beam assembly 50 are shut down.

[0275] As discussed above, the method of Figure 10, schematically illustrated in Figure 12, differs from the method of Figure 11 shown in Figure 13 in that it further includes a step of co-aligning the imaging beam and the laser beam (step 201a). In the schematic depiction of Figure 12, the step of co-aligning the imaging beam and the laser beam is optionally performed before the contour measurement step (before step 201). In the exemplary schematic shown in Figure 12, the step of co-aligning the imaging beam and the laser beam optionally includes detecting the illumination of the contour measurement element 510 by the imaging beam and subsequently detecting the illumination of the contour measurement element 510 by the laser beam. However, the detection of the illumination of the contour measurement element 510 by the imaging beam and the contour measurement element during step 201a can be performed in any order.

[0276] As discussed above, during steps 201-206 of the method in Figure 10, as shown in Figure 12, the reference position 300 remains in the same position within the device 10. Optionally, as shown in Figure 12, the sample stage 70 also remains in the same position within the device 10 during steps 201-206. Therefore, after step 202 and before step 203, the sample 110 is inserted into the vacuum chamber 20 and positioned on the sample stage 70 at the same location as the profilometry element 510 was on the sample stage 70 during step 201. For the sample ablation step (step 203) and the analysis step (step 204), the sample 110 remains in the same position on the sample stage 70. During the analysis step, the imaging beam is switched on to generate an imaging beam. The imaging beam has already been aligned with the laser beam during the co-alignment step (step 201a) such that the imaging position necessarily coincides with the reference position 300. Therefore, the imaging position necessarily coincides with the ablated portion of sample 110, where the ablated portion is still in the same position inside device 10 for the sample ablation and analysis steps (steps 203, 204).

[0277] The method of Figure 11 shown in Figure 13 differs from the method of Figure 10 shown in Figure 12 in that it does not include the step of co-aligning the imaging beam and the laser beam. Instead, the imaging beam is guided to a different position inside the device 10 relative to the laser beam. The method includes: after sample ablation using a laser beam that intersects the sample at a reference position 300 (step 303), moving the sample 110 such that the ablated portion of the sample 110 intersects the imaging beam at the imaging position. The reference position 300 is spaced apart from the imaging position, for example, in the xy plane and / or in the z direction. After the sample ablation step and before the analysis step, the sample 110 can be moved in the xy plane and / or in the z direction, as follows: Figure 13 As shown in FIG13, in the exemplary embodiment shown in FIG13, the sample 110 is moved by moving the sample stage 70, specifically, the sample stage 70 is translated in the xy plane.

[0278] As shown in Figure 13, once the sample 110 has been moved so that its ablated portion intersects with the imaging beam at the imaging position, the imaging beam can be switched on, and microscopic and / or spectral analysis can be performed by irradiating the ablated portion with the imaging beam (step 304).

[0279] Depth distribution generation

[0280] The following provides an example of how to generate the depth distribution in steps 106, 206, and 306, wherein the spectroscopic technique used is optionally AES or XPS and is described in more detail in WO2024 / 052232A1, the reference of which is incorporated herein by reference. Detector 90 and analyzer 80 can receive and count the number (intensity) and energy of photoelectrons or Auger electrons emitted from the surface of the ablated portion of sample 110 after excitation by an X-ray or electron imaging beam, respectively. The total electron intensity is plotted as a function of electron energy (binding energy or kinetic energy). Quantification in the electron spectrum is based on the direct relationship between the intensity of the photoelectron and / or Auger electron peaks and the mole fraction concentration of the element within the analytical depth range. This relationship is described by equation (1), where I is the peak intensity, J is the photon flux, ρ is the concentration of atoms or ions, σ is the electron emission cross section, K is the spectrometer factor, and L is the electron decay length:

[0281] (1)

[0282] The emission cross section σ is the probability that photoelectrons or Auger electrons will be emitted due to exposure to a high-energy source. This cross section varies with element, electron orbital, and total angular momentum. The spectrometer factor K takes into account the differences in detector performance between instruments and combines the transmission function (i.e., the proportion of electrons transmitted through the detector as a function of kinetic energy) and the detector efficiency (i.e., the proportion of transmitted electrons that contribute to the detected signal). The inelastic mean free path describes the distance an emitted electron travels before inelastic scattering. However, in equation (1), the more accurate term attenuation length L is used, which corrects for the inelastic mean free path of elastic scattering and allows determination of the intensity emitted from a given depth in a given direction. Inelastic scattering results in electrons not contributing to the intensity of the photoelectron peak and / or Auger electron peak.

[0283] The contribution of each of the above factors (σ, K, L) to the photoelectron / Auger electron intensity of any particular peak in the spectrum is combined into a single term called the sensitivity factor F, which allows for the determination of the relative proportion of this element in the analytical depth (see Equation (2) below). The sensitivity factor can be taken from a library of theoretically determined, experimentally determined, or user-determined values. If the library value has already been determined on / for an electron spectrometer with a different transmission function, then correction for this different transmission function will be required.

[0284] Peak intensity is typically measured graphically as the integrated area of ​​the photoelectron and / or Auger electron peaks, and then the background signal is subtracted using an appropriate method. Different methods are used to calculate the background C, including linear methods, the Shirley method, or the Tougaard method. Other methods exist for determining peak intensity, such as using peak height instead of peak area and measuring peak-to-peak differential spectra, which is encountered in electronically excited Auger spectroscopy.

[0285] Using equation (1) and assuming a constant photon flux, and based on the assumption of a homogeneous mixture of elements within the analytical depth range, the atomic percentage concentration of an element can be calculated using normalized peak intensities. Based on this assumption, the concentration of element A within the multi-element material is given by equation (2):

[0286] (2)

[0287] I and F represent the peak intensity and sensitivity factor of the element detected in the spectrum (I0 and F1). A It is the peak intensity of element A, F A (This is the sensitivity factor for element A). However, when using an electron source to generate Auger electrons, corrections due to matrix effects will be required. It is assumed that the sample contains a homogeneous mixture of elements within the analytical depth range to quantify the photoelectron and Auger electron spectra, but if such elemental distributions are known or expected to occur within the analytical depth range, other methods that more accurately describe the elemental distribution within the analytical depth can be used.

[0288] Peak convolution can occur due to the presence of overlapping energy peaks or multiple chemical states. To quantify the different chemical states in such cases, peak fitting is required to separate the peak intensity contribution from the various components present, and then these contributions are quantified separately. The binding energy / kinetic energy of different chemical states of an element is determined from standard spectra recordings of materials known in their composition or from available spectral libraries.

[0289] To construct the depth distribution, electronic spectra were recorded from the surface of the ablated portion of sample 110 after each laser ablation cycle. The spectra were quantified and the chemical composition was determined based on equation (2). For the surface and at each cycle / depth where the electronic spectra had been recorded, the fractional composition of each element or elemental chemical state was plotted as a function of the number of laser ablation cycles or the depth. The number of cycles can be converted to depth by measuring the depth or by using prior knowledge of the layer thickness.

[0290] Experimental data

[0291] As discussed above, it is particularly advantageous to obtain a flat-topped beam profile at a reference position of 300° and thus use a laser beam with a flat-topped beam distribution at its incident point on the sample surface to ablate the sample surface. This is evident when viewing Figures 14A to 14E obtained through simulation. The simulations used to obtain Figures 14A to 14E employed samples with the same multilayer structure, consisting of alternating chromium and nickel layers on a silicon substrate. This structure was repeatedly ablated to obtain the pits shown in Figures 14A and 14D. The structure underwent repeated cycles of ablation and analysis of the ablated portions using both laser and imaging beams to obtain the depth distribution shown in Figures 14B, 14C, and 14E. Figure 14A The simulation up to Figure 14E is based on the following assumptions: during ablation, the sample surface is at a 90-degree angle relative to the laser beam, and during analysis, the sample surface is at a 90-degree angle relative to the imaging beam. The laser beam is incident (i.e. intersecting) the sample surface at a position referred to above as reference position 300, and the imaging beam is incident (i.e. intersecting) the sample surface at a position referred to above as imaging position.

[0292] Figure 14A illustrates layer-by-layer ablation, which occurs by performing repeated sample ablation using a laser beam with a Gaussian intensity distribution at a reference position 300, thereby forming pits. Figures 14B and 14C show depth profiles obtained through repeated cycles of ablation and analysis of the ablated portions, where sample ablation is performed using a laser beam with a Gaussian beam distribution at a reference position 300 (the type shown in Figure 14A). Figure 14B shows a near-optimal depth profile obtained when ablation is performed using a laser beam with a Gaussian intensity distribution at the reference position, and Figure 14C shows a suboptimal depth profile obtained when ablation is performed using a laser beam with a Gaussian intensity distribution at the reference position. The decrease in depth profile quality in Figure 14C compared to Figure 14B is due to the ratio of the laser beam spot size at the reference position to the imaging beam spot size at the imaging position. Figure 14B uses a larger ratio of the laser beam spot size at the reference position to the imaging beam spot size at the imaging position compared to Figure 14C. For Figure 14B, the ratio of the laser beam spot size at the reference position to the imaging beam spot size at the imaging position is 5:1; and for Figure 14C, the ratio of the laser beam spot size at the reference position to the imaging beam spot size at the imaging position is 2:1.

[0293] When selecting the spot size or beamwidth of the laser beam incident on the sample for ablation, there is a trade-off between achieving sufficient ablation flux and achieving an ideal size ratio of the laser beam spot size to the imaging beam spot size incident on the sample. A smaller spot size results in increased flux for ablation. However, ideally, the spot size of the imaging beam at the imaging location is smaller than the spot size of the laser beam at the reference location 300 (i.e., the area irradiated by the imaging beam is smaller than the area of ​​the ablated portion). Specifically, the spot size of the imaging beam at the imaging location would ideally be at most 1 / 5 of the spot size of the laser beam at the reference location 300. A smaller spot size of the imaging beam is desired compared to the laser beam spot size on the sample to avoid the imaging beam incident on the edges or sidewalls of the pits formed by ablation. Imaging beams incident on edges or sidewalls may cause electrons / ions originating from the edges or sidewalls to be emitted and analyzed in addition to those from the surface to be studied. These electrons / ions from the edges or sidewalls may originate from a different chemical composition than the surface of the pit being studied, potentially leading to inaccurate measurements. Indeed, comparing Figures 14B and 14C reveals the effect of the ratio of the laser beam spot size at the reference position to the imaging beam spot size at the imaging position on the quality of the generated depth distribution. It can be understood that the smaller the laser beam spot size, and thus the smaller the pit formed during ablation, the more sensitive the quality of the depth distribution is to the alignment of the imaging beam with the pit center. Finally, it should be noted that while reducing the imaging beam spot size at the imaging position improves the quality of the generated depth distribution, it also increases the time required to image the ablation portion.

[0294] With this in mind, the inventors discovered that by shaping the laser beam to form a flat-topped or flat-topped intensity distribution at reference position 300, the spot size of the laser beam can be reduced to increase throughput without compromising the quality of the depth distribution that may be generated or the time required to perform analysis of the ablation portion. In fact, by employing a laser beam with a flat-topped intensity distribution at reference position 300, it becomes possible to use an imaging beam with a reasonable spot size at the imaging position and allows for some alignment deviation of the imaging beam towards the center of the ablation-formed pit.

[0295] Figure 14D illustrates layer-by-layer removal, which occurs by performing repeated sample ablation using a laser beam with a flat-topped intensity distribution at reference position 300, thereby forming pits. Figure 14E shows a depth distribution map obtained by repeated cycles of ablation and analysis of the ablated portions, wherein sample ablation is performed using a laser beam with a flat-topped intensity distribution at reference position 300 (the type of laser beam shown in Figure 14D).

[0296] As shown in Figure 14D, uniform removal of sample material using a flat-topped beam distribution at reference position 300 resulted in an accurate depth distribution after at least 50 iterations (cycles). Indeed, the depth distribution correctly determined that each chromium layer had a 100% chromium atom concentration, each nickel layer had a 100% nickel atom concentration, and the silicon substrate layer had a 100% silicon atom concentration. Figures 14B and 14C show that using a Gaussian beam distribution at reference position 300 resulted in a less accurate depth distribution. Accuracy decreased with further iterations (cycles). Indeed, with further ablation and analysis cycles, the atomic concentrations of the relevant elements detected in this layer decreased. For example, in Figure 14C, at 45 iterations (cycles), the detected chromium atom concentration was approximately 80% but should have been 100%, while the detected nickel atom concentration was approximately 20% but should have been 0%. Although Figure 14E shows the perfect depth distribution that should have been expected based on the performed simulation, the actual achievable depth distribution may not be entirely perfect. Nevertheless, it is understandable that by employing a laser beam with a flat-topped intensity distribution at reference position 300 instead of a Gaussian distribution at reference position 300, higher quality depth distribution can be achieved without compromising the efficiency of depth distribution analysis.

[0297] The flat-topped intensity distribution shown in Figure 14D and used to obtain the depth distribution in Figure 14E is achieved by optical elements (such as beam shapers), but these optical elements are sensitive and require adjustment. Therefore, Figure 14 demonstrates the importance of determining and controlling the intensity distribution of the laser beam at reference position 300 for generating an accurate depth distribution. By measuring the intensity distribution of the laser beam at reference position 300 (i.e., in situ) inside device 10 and configuring the shape of the laser beam, any subsequent sample ablation and spectral analysis can be optimized, resulting in a more accurate depth distribution. Typically, sample ablation and analysis can be performed under vacuum conditions. It is particularly advantageous to use the beam profile measuring element 510 discussed above to measure the intensity distribution of the laser beam, where the beam profile measuring element 510 can withstand vacuum conditions. This is because the beam profile measuring element 510 can be arranged within the vacuum chamber 20 to measure the intensity distribution of the laser beam without significantly contaminating the vacuum chamber 20, thus making it possible to measure the intensity distribution in situ without disrupting the vacuum.

[0298] Figures 15A to 15C illustrate the intensity distribution of a laser beam generated using a beam profile measuring element 510, which is a laser-sensitive material 520, specifically a phosphorescent material that fluoresces upon illumination. The laser-sensitive material 520 intersects the laser beam at a reference position 300. The final intensity distribution is represented as a thermogram and is shown in Figure 15C. In Figures 15B and 15C, the intensity is higher at the center of the distribution and decreases towards the outer edges of the profile. Figure 4 The arrangement shown generates an intensity distribution, but the vacuum chamber 20 is ventilated and opened. Figure 15A is a raw image of the laser-sensitive material 520 fluorescing due to laser beam irradiation. This image was taken by a sensor device 521 arranged outside the vacuum chamber 20, as shown in Figure 4. The sensor device 521 used is a CMOS camera. This raw image is processed by the sensor device 521 and / or the processing device 120 connected thereto to generate the intensity distribution represented as a thermal image shown in Figure 15B, and after adjusting the exposure of the sensor device 521, the intensity distribution shown in Figure 15C is obtained. Figure 15D is a laser beam intensity distribution represented as a thermal image generated using a profile measurement camera arranged at reference position 300 instead of the laser-sensitive material 520. In Figure 15D, the intensity is higher at the center of the distribution and decreases towards the outer edge of the profile. As can be seen by comparing Figures 15C and 15D, the intensity distribution generated using the laser-sensitive material 520 and sensor device 521 is similar to the intensity distribution generated using a contour measuring camera. Therefore, this indicates that the laser-sensitive material 520 and sensor device 521 can be advantageously used to measure the intensity distribution of a laser beam.

[0299] Figures 16A to 16D illustrate the intensity distribution of a laser beam generated using a beam profile measuring element, which is a laser-sensitive material 520, particularly a phosphorescent material that fluoresces upon irradiation. Figures 16A to 16D demonstrate the benefits of configuring optical elements for shaping the laser beam in situ and in vacuum to achieve a flat-topped intensity distribution at reference position 300, as described in steps 102, 202, and 302. The intensity distribution generated in Figures 16A to 16D is achieved by intersecting the laser beam at a 43-degree angle of incidence with the laser-sensitive material 520 at reference position 300.

[0300] In Figures 16A and 16B, the intensity is higher towards the left side of the distribution and decreases towards the upper right edge of the profile. The arrangement shown in Figure 4 is used to generate the intensity distribution. The vacuum chamber 20 is under ultra-high vacuum conditions and is therefore not ventilated. Figures 16A and 16C are initial raw images of the fluorescence emitted by the laser-sensitive material due to laser beam irradiation. The images were taken by a sensor device 521 arranged outside the vacuum chamber 20, as shown in Figure 4. The sensor device 521 used is a CMOS camera. The intensity distribution obtained by processing this raw image (using sensor device 521 and / or processing device 120 connected thereto) is shown in Figures 16B and 16D, respectively.

[0301] Figure 16E shows the intensity distribution as a thermal image, taken using a profile measuring camera positioned at reference position 300 instead of the laser-sensitive material 520, but without the camera being in a vacuum. The sensing surface of the profile measuring camera is orthogonal to the laser beam arrangement. Figure 16E shows the accurate intensity distribution of the laser beam at reference position 300.

[0302] As can be seen by comparing Figures 16D and 16E, using a profile measuring element 510, which is arranged inside the vacuum chamber 20 as a laser-sensitive material, in conjunction with a sensor device 521 arranged outside the vacuum chamber 20, produces an intensity distribution similar to that of a profile measuring camera under non-vacuum conditions. Therefore, this demonstrates that the arrangement shown in Figure 4 can be advantageously used to measure the intensity of a laser beam in situ under vacuum conditions without disrupting the vacuum.

[0303] When capturing the original images of Figures 16A and 16C, the laser beam was incident on the laser-sensitive material 520 at an angle of approximately 43 degrees. The intensity distribution generated based on the original image of Figure 16A, as shown in Figure 16B, is compared to... Figure 16D The intensity distribution generated based on the original image in Figure 16C is not very accurate. In fact, the intensity distribution in Figure 16E is more closely related to the intensity distribution in Figure 16D than the intensity distribution in Figure 16B. By measuring the intensity distribution of the laser beam in situ, the positioning of the beam profile measuring element 510 (in this case, the laser-sensitive material 520) and / or the optical elements of the laser beam assembly 40 can be adjusted to improve the accuracy of the generated intensity distribution. For example, in this case, the positioning and tilt of the beam shaper are adjusted based on the initial measured intensity distribution in Figure 16B, resulting in a more accurate intensity distribution as shown in Figure 16D.

[0304] It should be noted that the original image captured in Figure 15A exhibits a "halo effect" around its center that may affect the generated intensity distribution. This halo effect can be mitigated by using a threshold to eliminate noise and / or lower intensity emission. It can also be mitigated by properly attenuating the incident laser beam using a neutral density filter to reduce low-level illumination of the phosphorescent material. For example, the halo effect was eliminated for Figures 16A and 16C.

[0305] Figure 17A is a raw image taken by a laser sensor 530, which is a CMOS camera, positioned at reference location 300. During the measurement of the intensity distribution of the laser beam, the laser sensor 530 is positioned on a sensor holder 60' inside the vacuum chamber 20 as shown in Figure 8C, under vacuum conditions. The laser beam is incident on the laser sensor 530 at an angle of approximately 43 degrees. This raw image is processed by the sensor device 521 and / or the processing device 120 connected thereto to generate the intensity distribution as represented by the thermal map shown in Figure 17B. As discussed above, the sensor holder 60' enables the laser sensor 530 to function properly without overheating or gas release. The intensity distribution map shows higher intensity towards the lower left side of the distribution, and the intensity decreases towards the upper right edge of the profile. Figure 17 demonstrates that it is possible to accurately measure the intensity distribution of a laser beam using a laser sensor in situ and under vacuum conditions.

[0306] Although embodiments of this disclosure have been described above and illustrated in the accompanying drawings, these are merely examples and are not limiting. Those skilled in the art will understand that alternatives are possible within the scope of this disclosure.

[0307] All aspects and / or features disclosed in this specification can be combined in any combination, except where at least some of these features and / or steps are mutually exclusive combinations. Specifically, preferred features of this disclosure apply to all aspects and embodiments of this disclosure and can be used in any combination. Similarly, features described in non-essential combinations can be used alone (rather than in combination).

[0308] The aspects and / or features described in the context of apparatus 10 may be applicable to the methods described herein. The aspects and / or features described in the context of the method may be used as features of apparatus 10.

[0309] As used herein (including in the claims), unless the context otherwise requires, the singular form of a term shall be construed to include the plural form, and vice versa, where the context permits. For example, unless the context otherwise requires, the singular designation such as “a / an” (such as a separator or analyzer) herein (including in the claims) means “one or more” (e.g., one or more separators, or one or more analyzers). Throughout the specification and claims of this disclosure, the words “comprising,” “including,” “having,” and “containing,” and variations thereof, such as “comprising” and “including” or similar, mean that the stated feature includes any subsequent additional features and is not intended (and does not) exclude the presence of other components.

[0310] The use of any and all examples or exemplary language provided herein (“e.g.,” “such as,” “e.g.,” and similar language) is intended only to better illustrate the contents of this disclosure and, unless otherwise stated, does not imply any limitation on the scope of this disclosure. The language in the specification should not be construed as indicating that any unclaimed element is essential to the implementation of this disclosure.

Claims

1. A method for operating a spectroscopic apparatus or a microscope apparatus, the method comprising: The intensity distribution of a laser beam guided along a trajectory through the device in a vacuum is measured, the intensity distribution at a reference position in the trajectory being measured by irradiating a profile measuring element with the laser beam, wherein the profile measuring element intersects the laser beam at the reference position; and The shape of the laser beam is configured based on the measured intensity distribution.

2. The method according to claim 1, wherein the reference position is located at a reference distance from the focal point of the laser beam.

3. The method according to any of the preceding claims, wherein the method further comprises: After configuring the shape of the laser beam based on the measured intensity distribution, the material is ablated from a portion of the sample surface by irradiating it with the laser beam.

4. The method of claim 3, wherein during the step of ablating material from a portion of the sample surface, the portion of the sample surface intersects with the laser beam at the reference location.

5. The method according to claim 3 or claim 4, further comprising: After the step of ablation of material from a portion of the sample surface, at least a portion of the ablated portion is subjected to spectral or microscopic analysis, wherein the spectral analysis optionally includes X-ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy, Auger electron spectroscopy, secondary ion mass spectrometry and / or laser-induced breakdown spectroscopy, and wherein the microscopic analysis optionally includes electron microscopy (TEM or SEM).

6. The method of claim 5, further comprising: After the step of performing spectral analysis or microscopic analysis, one or more further cycles of ablation and analysis are performed, each cycle including the step of further ablation of material from the region of the sample surface, followed by the step of performing spectral analysis or microscopic analysis on at least a portion of the further ablated portion, and after the one or more further cycles, the depth distribution of the composition of at least a portion of the ablated portion of the sample surface is determined, optionally wherein the depth distribution is quantitative.

7. The method according to claim 5 or claim 6, wherein the step of performing spectral or microscopic analysis on at least a portion of the ablated portion comprises: The imaging beam is guided along the trajectory within the device to the ablation portion, wherein during the spectral or microscopic analysis step, the imaging beam intersects the ablation portion at an imaging location in the trajectory of the imaging beam, optionally wherein the imaging beam includes an ultraviolet beam, an X-ray beam, an electron beam, an ion beam, and / or a laser beam.

8. The method of claim 7, wherein the method further comprises: The imaging beam and the laser beam are aligned so that the imaging position coincides with the reference position.

9. The method according to any of the preceding claims, wherein the step of configuring the shape of the laser beam comprises: The laser beam is configured to achieve a substantially flat-topped or flat-topped intensity distribution at the reference location.

10. The method according to any of the preceding claims, wherein the step of configuring the laser beam comprises: The control is configured to shape one or more optical elements of the laser beam.

11. The method of claim 10, wherein the one or more optical elements comprise diffractive optical elements and / or refractive optical elements.

12. The method according to any of the preceding claims, wherein the contour measuring element comprises a laser-sensitive material or a laser sensor, optionally wherein the contour measuring element comprises the laser-sensitive material coated on a sensor device, optionally wherein the laser sensor or sensor device comprises one or more cameras, optionally wherein the laser-sensitive material, sensor device and / or laser sensor is compatible with ultra-high vacuum (UHV) conditions.

13. The method of claim 12, wherein the contour measuring element comprises a laser-sensitive material, wherein the step of measuring the intensity distribution of the laser beam at the reference location comprises: The detection method involves detecting changes in the laser-sensitive material or emissions from the laser-sensitive material when irradiated with the laser beam, optionally wherein the intensity of the emissions from the laser-sensitive material is proportional to the intensity of the laser beam irradiating it.

14. The method of claim 12 or claim 13, wherein the laser-sensitive material comprises a luminescent material configured to emit photons when irradiated with the laser beam, optionally wherein the luminescent material is a phosphorescent or fluorescent material, optionally wherein the luminescent material is an upconversion anti-Stokes phosphor, optionally used to convert infrared laser light into visible light.

15. The method according to any one of claims 8 to 14, wherein the step of co-aligning the imaging beam and the laser beam comprises: Detecting the illumination of the contour measuring element by the imaging beam and / or detecting the illumination of the contour measuring element by the laser beam, optionally wherein, during the step of co-aligning the imaging beam and the laser beam, the contour measuring element intersects the laser beam at the reference position and the imaging beam at the imaging position.

16. The method of claim 15 when it is dependent on any one of claims 13 to 15, wherein (i) the contour measuring element comprises a laser-sensitive material, wherein the laser-sensitive material is configured to change or emit light when irradiated by the imaging beam, and / or wherein (ii) the contour measuring element comprises the laser sensor, wherein the laser sensor is configured to detect irradiation by the imaging beam.

17. The method according to any one of claims 3 to 8, wherein after the step of measuring the intensity distribution, the method comprises: (i) Positioning the sample and / or the contour measuring element and / or (ii) Redirecting the laser beam; Therefore, during the step of ablating material from a portion of the sample surface, the region of the sample surface intersects with the laser beam at the reference position.

18. The method according to any of the preceding claims, wherein the profile measuring element is arranged on the sample stage during the step of measuring the intensity distribution.

19. The method of claim 18, wherein the sample stage is configured to absorb or dissipate heat generated by the contour measuring element when the contour measuring element is arranged on the sample stage, optionally wherein the sample stage includes a heat sink configured to receive heat generated by the contour measuring element when the contour measuring element is arranged on the sample stage.

20. The method according to claim 18 or claim 19 when dependent on claim 17, wherein the sample is arranged on the sample stage during the step of measuring the intensity distribution. After the step of measuring the intensity distribution, the method further includes: (i) moving the sample and the contour measuring element relative to the reference position by moving the sample stage, and / or (ii) redirecting the laser beam to move the reference position relative to the sample and the contour measuring element; This ensures that during the step of ablating at least a portion of the sample surface, the portion of the sample surface intersects with the laser beam at the reference position.

21. The method according to any one of claims 18 to 20, wherein the method comprises: Before performing the step of measuring the intensity distribution, the profile measuring element is coupled to the sample stage, and after performing the step of measuring the intensity distribution, the profile measuring element is decoupled from the sample stage, such that during the step of measuring the intensity distribution, the profile measuring element is coupled to the sample stage.

22. The method of claim 21, wherein the coupling comprises mechanically and / or electrically and / or thermally coupling the contour measuring element to the sample stage.

23. The method of claim 22, wherein (i) the contour measuring element includes the laser sensor, and during the step of measuring the intensity distribution, the laser sensor is detachably electrically coupled to the sample stage such that the sample stage transmits power to the laser sensor; or wherein (ii) the contour measuring element includes the laser-sensitive material coated on the sensor device, and during the step of measuring the intensity distribution, the sensor device is detachably electrically coupled to the sample stage such that the sample stage transmits power to the sensor device.

24. The method according to any of the preceding claims, wherein (i) the contour measuring element includes the laser sensor, and wherein the method further comprises: When the laser sensor is electrically coupled to the sample stage, data is transmitted from the laser sensor to the processing device, optionally wherein a wired connection is used to perform the step of transmitting data from the laser sensor to the processing device, the wired connection optionally comprising one or more pairs of twisted pairs; or wherein (ii) the contour measuring element comprises the laser-sensitive material coated on the sensor device, wherein the method further comprises: when the sensor device is electrically coupled to the sample stage, transmitting data from the sensor device to the processing device, optionally wherein a wired connection is used to perform the step of transmitting data from the sensor device to the processing device, the wired connection optionally comprising one or more pairs of twisted pairs.

25. The method according to any one of claims 22 to 24, wherein the contour measuring element is supported on a bracket, and wherein mechanical coupling and / or electrical coupling and / or thermal coupling with the sample stage are achieved via the bracket.

26. The method of claim 25 when dependent on claim 24, wherein the support and / or the sample stage includes the wired connection.

27. The method according to any of the preceding claims, wherein the spectroscopic device or microscope device includes a vacuum chamber, wherein the trajectory of the laser beam is such that the reference position is arranged at a location within the vacuum chamber during the following steps: measuring the intensity distribution of the laser beam at the reference position within the spectroscopic device or microscope device and configuring the shape of the laser beam based on the measured intensity distribution.

28. The method of claim 27 when it is dependent on any one of claims 3 to 8, wherein the trajectory of the laser beam is such that, during the steps of ablating material from a portion of a sample surface by irradiating it with the laser beam and performing spectral analysis on at least a portion of the ablated portion, the reference position is arranged at a location within the vacuum chamber. During the steps of ablating material from a portion of the sample surface and performing spectral or microscopic analysis on at least a portion of the ablated portion, the sample is placed inside the vacuum chamber.

29. The method of claim 27 or claim 28, wherein the method comprises: Optionally, the profile measuring element is moved into the vacuum chamber via a sample exchange chamber before the step of measuring the intensity distribution is performed, and the profile measuring element is removed from the vacuum chamber after the step of measuring the intensity distribution is performed.

30. The method according to any of the preceding claims, wherein the laser beam is a pulsed laser beam, optionally wherein the laser beam comprises one or more pulses having a duration equal to or less than 1 ns, or equal to or less than 1 ps, or equal to or less than 1 fs, optionally in the range of 1 ps to 1 fs.

31. The method according to any of the preceding claims, wherein the laser beam is an infrared laser beam, a visible laser beam, or an ultraviolet laser beam.

32. A spectroscopic apparatus or microscope apparatus, comprising: Vacuum chamber; A laser beam assembly configured to generate and guide a laser beam along a trajectory through the vacuum chamber; and A laser beam analyzer is configured to measure the intensity distribution of the laser beam at a reference position within a trajectory arranged at a location in the vacuum chamber, wherein the laser beam analyzer includes a profile measuring element that intersects the laser beam at the reference position; The laser beam assembly includes a beam shaper configured to shape the laser beam based on a measured intensity distribution.

33. The spectroscopic or microscopic apparatus of claim 32, wherein the laser beam is configured to operate in an ablation mode for ablating material from a portion of the sample surface.

34. The spectroscopic apparatus or microscope apparatus of claim 32 or 33, wherein the spectroscopic apparatus or microscope apparatus further comprises an imaging beam assembly configured to generate and guide an imaging beam along a trajectory within the apparatus, optionally wherein the imaging beam is one or more of an ultraviolet beam, an electron beam, an ion beam, an X-ray beam, and / or a laser beam.

35. The spectroscopic apparatus or microscope apparatus according to any one of claims 32 to 34, wherein the laser beam analyzer includes a profile measuring element comprising a laser-sensitive material or a laser sensor, optionally wherein the laser-sensitive material is configured to change and / or emit emission when irradiated with the laser beam, optionally wherein the laser beam analyzer includes the laser-sensitive material and a sensor device configured to detect changes in the laser-sensitive material or emission from the laser-sensitive material, further optionally wherein the profile measuring element includes the laser-sensitive material coated on the sensor device.

36. The spectroscopic apparatus or microscope apparatus of claim 35, wherein the laser sensor or the sensor device comprises one or more cameras, and optionally wherein the laser-sensitive material and / or the laser sensor and / or the sensor device are compatible with ultra-high vacuum (UHV) conditions.

37. The spectroscopic or microscopic apparatus of claim 35 or claim 36, wherein (i) the profile measuring element is a laser-sensitive material, wherein the laser-sensitive material is configured to change or emit light when irradiated by the imaging beam, and / or wherein (ii) the profile measuring element is a laser sensor, wherein the laser sensor is configured to detect irradiation by the imaging beam.

38. The spectroscopic or microscopic apparatus according to any one of claims 35 to 37, wherein the laser-sensitive material is configured to emit light at an intensity proportional to the intensity of the laser beam irradiating it.

39. The spectroscopic or microscopic apparatus of claim 38, wherein the laser-sensitive material comprises a luminescent material configured to emit photons when irradiated by the laser beam, optionally wherein the luminescent material is a phosphorescent or fluorescent material, further optionally wherein the luminescent material is an upconversion anti-Stokes phosphor, optionally used to convert infrared laser light into visible light.

40. The spectroscopic apparatus or microscope apparatus according to any one of claims 35 to 39, wherein the profile measuring element comprises a laser-sensitive material, and wherein the laser beam analyzer comprises a reflector configured to reflect an image of the laser-sensitive material or an emission from the laser-sensitive material.

41. The spectroscopic apparatus or microscope apparatus according to any one of claims 32 to 40, further comprising a sample stage configured to support a sample.

42. The spectroscopic or microscopic apparatus of claim 41 when it is dependent on any one of claims 35 to 40, wherein the sample stage is configured to support the profile measuring element.

43. The spectroscopic or microscopic apparatus of claim 42, wherein the apparatus is configured to: (i) optionally move the profile measuring element and / or the sample by moving the sample stage, and / or (ii) redirect the laser beam to reconfigure the apparatus from a first configuration in which the profile measuring element intersects the laser beam at the reference position to a second configuration in which the sample intersects the laser beam at the reference position.

44. The spectroscopic or microscopic apparatus of claim 42 or 43, wherein the sample stage is configured to absorb or dissipate heat generated by the profile measuring element when the profile measuring element is supported by the sample stage, optionally wherein the sample stage includes a heat sink configured to receive heat generated by the profile measuring element when the profile measuring element is supported by the sample stage.

45. A spectroscopic apparatus or microscope apparatus according to claim 41 when dependent on any one of claims 36 to 40, or according to any one of claims 42 to 44, wherein (i) the profile measuring element includes the laser sensor, and the sample stage is configured to be detachably electrically coupled to the laser sensor when the laser sensor is supported on the sample stage, optionally wherein the sample stage includes an electrical coupling element configured to be detachably electrically coupled to the laser sensor when the laser sensor is supported on the sample stage, further optionally wherein the electrical coupling element is configured to transmit power to the laser sensor and / or transmit data from the laser sensor, or (ii) The contour measuring element includes the laser-sensitive material coated on the sensor device, and the sample stage is configured to be detachably electrically coupled to the sensor device when the sensor device is supported on the sample stage. Optionally, the sample stage includes an electrical coupling element configured to be detachably electrically coupled to the sensor device when the sensor device is supported on the sample stage. Optionally, the electrical coupling element is configured to transmit power to the sensor device and / or transmit data from the sensor device.

46. ​​The spectroscopic apparatus or microscope apparatus of claim 45, wherein the electrocoupling element is configured to transmit power to the laser sensor or the sensor device, wherein the apparatus further includes a data connection configured to transmit data from the laser sensor or the sensor device, optionally wherein the data connection is a wireless data connection.

47. The spectroscopic apparatus or microscope apparatus of claim 45 or 46, wherein the electrical coupling element comprises a wired connection configured to transmit power to and / or from the laser sensor or the sensor device, optionally wherein the wired connection comprises one or more pairs of twisted pairs.

48. The spectroscopic apparatus or microscope apparatus according to claim 41 when dependent on any one of claims 37 to 40, or the spectroscopic apparatus or microscope apparatus according to any one of claims 42 to 47, further comprising a support configured to support the profile measuring element, wherein the support is configured to be detachably mechanically coupled to the sample stage.

49. The spectroscopic apparatus or microscope apparatus of claim 48 when it is dependent on any one of claims 45 to 47, wherein the profile measuring element comprises the laser sensor or the laser-sensitive material coated on the sensor device, and the sample stage is configured to be detachably electrically coupled to the laser sensor or the sensor device via the support when the support is mechanically coupled to the sample stage.

50. The spectroscopic apparatus or microscope apparatus of claim 49, wherein the electrical coupling element is a stage electrical coupling element, wherein the support includes a support electrical coupling element electrically connected to the laser sensor or the sensor device, wherein the support electrical coupling element is configured to be detachably electrically coupled to the stage electrical coupling element when the support is mechanically coupled to the sample stage, optionally wherein the support electrical coupling element and the stage electrical coupling element are configured to transmit power to the laser sensor or the sensor device and / or transmit data from the laser sensor or the sensor device when the support is mechanically coupled to the sample stage.

51. The spectroscopic apparatus or microscope apparatus of claim 50, wherein the stage electrical coupling element includes one or more stage electrical contacts and the support electrical coupling element includes one or more support electrical contacts, wherein the stage electrical contacts are configured to directly contact the support electrical contacts when the support is mechanically coupled to the sample stage.

52. The spectroscopic apparatus or microscope apparatus of claim 50 or 51, wherein the support electrical coupling element includes a wired connection configured to transmit power and / or data to the laser sensor or the sensor device, optionally wherein the wired connection includes one or more pairs of twisted pairs.

53. The spectroscopic apparatus or microscope apparatus according to any one of claims 45 to 52, further comprising a processing device configured to receive data from the laser sensor or the sensor device via the electrical coupling element and / or the data connection.

54. The spectroscopic apparatus or microscope apparatus according to any one of claims 32 to 53, further comprising a vacuum chamber, wherein the laser beam assembly is configured to guide the laser beam such that the reference position is arranged at a location within the vacuum chamber.

55. The spectroscopic apparatus or microscope apparatus of claim 54 when it is dependent on any one of claims 41 to 53, wherein the sample stage is mounted in the vacuum chamber.

56. The spectroscopic or microscopic apparatus of claim 54 or 55, wherein the laser beam assembly is positioned outside the vacuum chamber, wherein the vacuum chamber includes a window configured to allow the laser beam to pass through it.

57. A spectroscopic or microscopic apparatus according to any one of claims 54 to 56 when dependent on any one of claims 36 to 54, wherein the apparatus includes a transfer assembly for moving the profile measuring element into and out of the vacuum chamber, optionally via a sample exchange chamber.

58. The spectroscopic or microscopic apparatus of claim 57 when it is dependent on any one of claims 48 to 52, wherein the transfer assembly is configured to optionally transfer the support into and out of the vacuum chamber via a sample exchange chamber.

59. The spectroscopic or microscopic apparatus according to any one of claims 32 to 58, wherein the beam shaper comprises one or more optical elements configured to shape the laser beam, optionally wherein the one or more optical elements comprise diffractive optical elements and / or refractive optical elements, optionally wherein the beam shaper is configured to shape the laser beam based on a measured intensity distribution to achieve a substantially flat-topped or flat-topped intensity distribution at the reference location.

60. The spectroscopic apparatus or microscope apparatus according to any one of claims 32 to 59, wherein the reference position is located at a reference distance from the focal point of the laser beam.

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