Apparatus and method for analyzing and / or processing a sample using a particle beam

Abstract

What is proposed is an apparatus (100, 400) for analyzing and / or processing a sample (10) using a particle beam (114), comprising a providing unit (110) for providing the particle beam (114) and a test structure (200) attached to the providing unit (110), wherein the apparatus (100, 400) is configured to perform an etching process and / or a deposition process on the test structure (200) using the particle beam (114).

Description

Technical Field

[0001] The present invention relates to an apparatus and a corresponding method for analyzing and / or processing a sample using a particle beam.

[0002] The entire content of the priority application DE102021120913 filed on August 11, 2021 is incorporated herein by reference.

Background Art

[0003] Microlithography is used, for example, to produce microstructured components such as integrated circuits. A microlithography process is carried out using a lithography apparatus having an illumination system and a projection system. In this case, the image of a mask (reticle) illuminated by the illumination system is projected by the projection system onto a substrate, for example a silicon wafer, which is coated with a photosensitive layer (photoresist) and arranged in the image plane of the projection system in order to transfer the mask structure to the photosensitive coating of the substrate.

[0004] In this case, since the mask or lithography mask is used for many exposures, it is very important that there are no defects in the mask. Therefore, considerable effort is made to inspect the defects of the lithography mask and to repair the identified defects. The defects of the lithography mask can be orders of magnitude larger in the range of a few nanometers. To repair such defects, an apparatus that provides a very high spatial resolution is required for the repair process.

[0005] An apparatus suitable for this purpose activates a local etching or deposition process based on particle beam-induced processes.

[0006] EP1587128 discloses such a device that uses a charged particle beam, in particular the electron beam of an electron microscope, to initiate a chemical process. When using charged particles, there is a possibility of charging of the sample if the sample is non-conductive or has low conductivity. This can cause the beam deflection to become uncontrollable and limit the achievable process resolution. Therefore, it has been proposed to place a shielding element very close to the processing position, thereby minimizing the charging of the sample and improving the resolution and control of the process.

[0007] DE10208043 discloses a material processing system that can be used in a material processing method by material deposition from a gas, such as chemical vapor deposition (CVD), or material removal by a supplied reaction gas. In this case, in particular, the gas reaction that brings about material deposition or material removal is initiated by an energy beam directed at the region of the workpiece to be processed.

[0008] DE102019200696 discloses a device for determining the position of elements on a photomask. Markers 550, 850 and 950 are used.

[0009] In order to accurately implement this type of process, it is necessary to highly control a variety of different operating parameters of the device. Heretofore, in methods of beam analysis, material contrast analysis, or methods of analyzing particle beam induced processes such as, for example, an etching process or deposition processes at the start of a process, it has been necessary to load various samples into the device. In this case, it is necessary to interrupt the operation of the device each time, for example, because the process atmosphere is destroyed, so even if the nominal operating parameters of the device are the same, differences in operation may occur in subsequent processes. This is related to, for example, the collimation of the particle beam, the operating parameters of the detector, the valve settings of the process gas, etc. In addition, heretofore, it has only been possible to confirm the actual composition of the process atmosphere in a complex manner with a time delay, which makes it difficult to monitor the process.

[0010] Therefore, for this purpose, it is desirable to determine and / or control important operating parameters and / or process parameters for performing analysis and / or process operations in situ without interrupting the operation of the device, particularly while maintaining the process atmosphere. SUMMARY OF THE INVENTION

[0011] In view of this background, an object of the present invention is to provide an improved device and a corresponding method for analyzing and / or processing a sample using a particle beam.

[0012] According to a first aspect, a device for analyzing and / or processing a sample using a particle beam is proposed. The device comprises a providing unit for providing a particle beam, and a shielding element for electrical and / or magnetic shielding. The shielding element has a through opening for the particle beam to pass through to the sample, and the shielding element and / or the holding element for holding the shielding element has at least one test structure. The apparatus further comprises an aligning unit for aligning the particle beam, the shielding element, and / or the holding element so that the particle beam can be incident on the test structure. and a determining unit for determining at least one current operating parameter and / or process parameter of the apparatus that depends on the interaction of the particle beam with the test structure when the particle beam is incident on the test structure.

[0013] The apparatus has the advantage that at least one current operating parameter and / or process parameter can be determined in-situ. This means that the current operating parameters and / or process parameters of a planned analysis and / or process operation on a sample already introduced into the apparatus can first be verified using the test structure, and then the analysis and / or process operation can be carried out based on the determined current operating parameters and / or process parameters. This is different from existing apparatuses especially in that the sample is already introduced, and thus the process atmosphere is continuously maintained during the determination and subsequent analysis or processing. Thus, the possibility of in-situ process control arises. In particular, in this way, it is possible to optimally set or adjust each operating parameter and / or process parameter before starting the analysis and / or processing.

[0014] The sample is, for example, a lithography mask having a feature size in the range of 10 nm to 10 μm. This can be, for example, a transmissive lithography mask for DUV lithography (DUV: "deep ultraviolet", operating light wavelength in the range of 30 to 250 nm), or a reflective lithography mask for EUV lithography (EUV: "extreme ultraviolet", operating light wavelength in the range of 1 to 30 nm). The processing processes executed in this case include, for example, an etching process in which material is locally removed from the surface of the sample, a deposition process in which material is locally added to the surface of the sample, and / or similar processes that are locally activated, such as the formation of a passivation layer or the compression of a layer.

[0015] The particle beam is, in particular, a charged particle such as, for example, an ion, an electron, or a positron. Thus, the providing unit has, for example, a beam generation unit including an ion source or an electron source. A particle beam composed of charged particles can be affected by an electric field and a magnetic field, that is, for example, it can be accelerated, directed, shaped, and / or focused. For this purpose, the providing unit can have a number of elements configured to generate corresponding electric and / or magnetic fields. The elements are particularly arranged between the beam generation unit and the shield element. The particle beam is preferably focused onto a test structure to determine current operating parameters and / or process parameters. This is understood to mean, for example, that the particle beam has a predetermined diameter, in particular a minimum diameter, when it hits the test structure. The providing unit preferably includes a dedicated housing in which the aforementioned elements are arranged, and the housing is, for example, maintained at a residual gas pressure of 10 -6 ~10 -8 mbar and is embodied as a vacuum housing.

[0016] The shielding element can be held by a holding element. The shielding element is arranged, for example by the holding element, at or on the opening of the supply unit through which the particle beam is directed onto the sample at the processing position, and in particular forms the component of the device closest to the supply unit on the sample stage of the device in the beam direction. The connection between the holding element and the shielding element can be achieved, for example, by welding, clamping, and / or adhesion. The holding element and the shielding element can be of one-part or one-piece design. "One-part" means that the holding element and the shielding element are combined to form one unit. This can be achieved in a force-locking, form-fitting, and / or cohesive manner. A force-locking connection presupposes that a vertical force is applied to the surfaces connected to each other. A form-fitting connection is obtained by frictional engagement. The mutual displacement of the surfaces is prevented as long as the reaction force caused by static friction is not exceeded. A force-locking connection can also exist as a magnetic force-locking engagement. An interlock connection is obtained when at least two connection partners engage, with one inside the other or one behind the other. In a cohesive connection, the connection partners are held together by atomic or molecular forces. A cohesive connection is an irreversible connection that can only be separated by destroying the connection means. Cohesion enables connections by adhesion, soldering, or welding, etc. What "one-piece" means in this context is that the holding element and the shielding element are produced from the same material in a primary forming process such as casting or extrusion.

[0017] The holding element can take the form of fixing means for fixing the shielding element on the supply unit or on its vacuum housing.

[0018] The holding element is produced, for example, partly or wholly from cupronickel. The shielding element is produced, for example, partly or wholly from nickel.

[0019] In an embodiment, the holding element and the shielding element take the form of a single component, in particular a monolithic form. This is possible by means of a special production method, in particular the LIGA process (LIGA: abbreviation for the German Lithographie, Galvanik und Abformung [lithography, electroplating, and molding]).

[0020] This device is, for example, a scanning electron microscope. In order to achieve high resolution, the electron beam needs to be very precisely controlled with respect to, in particular, the electron energy, the beam diameter (hereinafter referred to as the focus) when it impinges on the sample, and the temporal stability of the impingement point. In particular, in the case of a sample having a cross-section composed of a non-conductive or slightly conductive material, charges accumulate on the sample due to the incidence of charged particles, and this forms an electric field. Not only the particles of the particle beam but also, for example, secondary electrons and backscattered electrons detected to generate an image are affected by the electric field, which can, for example, cause a decrease in resolution.

[0021] The electrical shielding element can be a shielding element for shielding the electric field generated by the charges accumulated on the sample. For example, the shielding element shields the electric field of the charges, that is, it serves to spatially delimit the electric field, in particular up to the smallest possible gap between the shielding element and the sample. For this purpose, the shielding element comprises a conductive material. As an example, the shielding element is grounded so that the charges impinging on the shielding element are dissipated. In other embodiments, the shielding element shields a magnetic field. In addition, it is possible that the electric field and / or magnetic field is not (or is not exclusively) generated by the sample (in particular by the charges accumulated on the sample). The electric field and / or magnetic field may be generated within the device, in particular within the supply unit (for example within the electron beam column), or may be located elsewhere.

[0022] The shielding element itself is preferably two-dimensional in shape. The surface can form a three-dimensional shape having a convex cross-section in the direction of the sample stage. The convex cross-section preferably forms the cross-section closest to the sample stage, i.e., the distance between the sample stage or the sample and the shielding element is minimized in the region of the convex cross-section. In the convex cross-section, the shielding element has a through-opening, and the particle beam passes through the through-opening and is incident on the sample. In the spatial region on the shielding element where the particle beam arrives, the electric field of the charge on the sample is effectively shielded by the shielding element. It should also be noted that the shielding element can further have a through-opening, and one or more through-openings can be arranged outside the convex cross-section of the shielding element. Note that the term "convex" should be understood from the perspective of the beam source. From the perspective of the sample or the sample stage, the convex cross-section can also be considered a concave cross-section. The shielding element can have a concave cross-section in addition to the convex cross-section. The convex cross-section can also be referred to as the swelling or bulge of the shielding element in the direction towards the sample stage.

[0023] As an example, during the analysis or processing of a sample using a particle beam, the distance from the sample in the convex cross-section of the shielding element is at most 100 μm, preferably at most 50 μm, preferably at most 25 μm, more preferably at most 10 μm. The smaller this distance, the less the influence of the electrical interference field on the particle beam.

[0024] As a result, the particle beam can be very accurately controlled during the analysis and / or processing of the sample, and is less likely to be affected by random and / or uncontrollable interference. Therefore, very high resolution is possible both during image acquisition in a scanning electron microscope, etc., and during processing methods performed using a particle beam, such as particle beam-induced etching or deposition processes, ion implantation, and / or further structural change processes.

[0025] The providing unit is, for example, an electron column that can supply an electron beam having an energy in the range of 10 eV to 10 keV and a current in the range of 1 μA to 1 pA. The providing unit can alternatively be an ion source that provides an ion beam. During the analysis and / or processing of the sample, the particle beam preferably achieves an irradiation area having a diameter in the range of, for example, 1 nm to 100 nm and is focused onto the surface of the sample.

[0026] The holding element for holding the shield element is preferably conductive and has the same potential as the shield element. Accordingly, the holding element is also set to shield the electric field. The holding element can take the form of a mechanical fixation of the shield element. In a preferred embodiment, the holding element, together with the shield element, is designed to be movable relative to the sample and / or relative to the providing unit (in particular, by the alignment unit), for example, by fixing the holding element to the housing of the providing unit with a suitable bearing. In this case, an actuator can be provided to establish the position of the holding element. Alternatively or additionally, the shield element can be held in a movable manner by the holding element. Accordingly, some examples will first be described in terms of the alignment unit being set to align the particle beam, the shield element, and / or the holding element so that the particle beam can be incident on the test structure.

[0027] The holding element and / or the shielding element have a test structure that can determine operating parameters and / or process parameters. The test structure is formed, in particular, in accordance with the operating parameters or process parameters to be determined. This means that the test structure is appropriately adapted and formed for each respective operating parameter or process parameter to be determined. In particular, the test structure can have regions formed differently for different operating parameters and / or process parameters to be determined. Alternatively or additionally, it is possible to provide a plurality of different test structures arranged on both the shielding element and the holding element. For example, the test structure can comprise a structure having a specific spatial resolution for checking the resolution of an electron microscope.

[0028] In this case, the test structure is arranged, in particular, on one side of the holding element and / or the shielding element facing the providing unit.

[0029] The alignment unit can comprise both a mechanically active unit and an electrically and / or magnetically active unit. The mechanically active unit is set, for example, to move the holding element and / or the shielding element such that the particle beam collides with and interacts with the test structure rather than passing through the opening of the shielding element. The electrically and / or magnetically effective unit is set, for example, to deflect the particle beam in that the operating parameters of the deflection unit of the providing unit are appropriately adjusted such that the particle beam collides with the test structure rather than passing through the opening of the shielding element.

[0030] The operating parameters in this context are particularly understood to mean the settings of the device effective at a specific junction point, and the process parameters are understood to mean, in particular, the parameters that can be determined by the implementation of the process.

[0031] The operating parameters determinable with the proposed device include the settings of the supply unit, in particular the current, the acceleration voltage, and / or in the case of an electron column, the respective voltages of the beam guide and the beam-forming elements, the settings of detectors such as secondary electron detectors and / or backscattered electron detectors, and in particular the composition of the process atmosphere such as the partial pressure of one or more process gases supplied.

[0032] The process parameters determinable with the proposed device include the current etch rate of the etching process and / or the current deposition rate of the deposition process, the spatial resolution of the etching process and / or the deposition process, etc.

[0033] In an embodiment, the device comprises a vacuum housing for providing a vacuum inside, and at least a holding element and a shield element are arranged inside the vacuum housing.

[0034] In one embodiment of the device, the test structure has a structure with a spatial resolution of 1 / μm to 1000 / μm in spatial frequency.

[0035] This structure can be provided, for example, by two different materials in an alternating arrangement. When the particle beam takes the form of an electron beam, materials suitable for this purpose are in particular those with the largest difference in atomic number.

[0036] This structure can also comprise, for example, a topographic structure with lines having very narrow transition regions and trenches arranged in height.

[0037] This structure can also comprise an arrangement of materials with mutually discrete edges, which results in a sharp change in the contrast of the secondary electron image, based on which the beam parameters can be determined.

[0038] This structure preferably has a plurality of regions each having a different spatial resolution.

[0039] Using this test structure, for example, it is possible to calibrate the providing unit and / or the particle beam so as to achieve a specific minimum resolution, thereby ensuring that features in a sample having a minimum size corresponding to the minimum resolution can be reliably determined in the analysis and / or process operation.

[0040] The test structure can be generated in-situ, in particular, for example, by a particle beam induced deposition and / or an etching process.

[0041] In a further embodiment of the device, the test structure includes at least one specific first material and a specific second material other than the first material to provide a specific material contrast.

[0042] Based on the specific material contrast provided in this way, it is particularly possible to calibrate the secondary electron detector and / or the backscattered electron detector. This enables reliable determination of features on the sample with an optimally set contrast in the analysis and / or process operation.

[0043] More specifically, the specific material contrast relates to a specific difference in the atomic numbers of the first material and the second material. In this case, a specific first element has a specific first atomic number, and a specific second element is correspondingly selected and has a specific second atomic number different from each other.

[0044] In a further embodiment of the device, the device includes a detector for detecting backscattered electrons and / or secondary electrons, and the specific first material and the specific second material are selected such that the detector can be calibrated to detect backscattered electrons and / or secondary electrons by a specific material contrast.

[0045] The test structure preferably comprises the same materials as those present on the sample. This includes both the materials that make up the sample itself and materials that are known to potentially exist on the sample in the form of impurities. Thus, it is possible to provide the same material contrast that is likewise present during the analysis and / or processing of the sample, which improves the detection of the sample structure and / or defect sites on the sample, and / or the process control of the processes carried out on the sample.

[0046] In a further embodiment of the device, the test structure has a predetermined area for carrying out an etching process and / or a deposition process.

[0047] The predetermined area consists in particular of a specific material suitable for testing and / or adjusting the process parameters of the etching process and / or the deposition process.

[0048] For example, in the case of a transmissive photomask, chromium, molybdenum silicon, and / or silicon nitride are used for structuring the absorbing layer, and in the case of a reflective photomask, tantalum and / or tantalum nitride are used. To repair defects in such photomasks in a controlled manner, for example, excess material that can be achieved by a particle beam induced etching process is removed. Thus, the materials suitable for the predetermined area are chromium, and / or molybdenum silicon, and / or silicon nitride, and / or tantalum, and / or tantalum nitride. It should be noted that the predetermined area can be composed of a plurality of cross-sections each comprising a different material.

[0049] A test structure having a defined region can also be set up to determine the beam profile and / or beam quality of a particle beam such that local changes occur in the test structure depending on the local intensity of the particle beam, for example where the particle beam is irradiated onto the test structure at a plurality of sites on the test structure. Information regarding the beam profile of the particle beam can be determined by measuring or analyzing the size of the changed region. In this way, it is possible to check, for example, whether the particle beam has a preferred beam profile and / or a preferred focus. The changed region is preferably analyzed by microscopy of the test structure or the changed region, in particular by electron micrographs. For example, the diameter and appearance of a crater (in the case of an etching process) or a bulge (in the case of a deposition process) can be used to determine the beam diameter, and / or the beam shape, and / or the intensity distribution within the particle beam. For example, this can be achieved at a plurality of positions within the test structure by setting different focus positions of the particle beam at each of the different positions. Thus, it is possible to determine the beam profile of a plurality of cross-sectional planes, from which additional conclusions can be drawn, particularly regarding possible causes where the beam profile does not have the intended appearance.

[0050] In a further embodiment of the apparatus, the defined region for the implementation of the etching process and / or the deposition process has the same material composition as the sample.

[0051] In this embodiment, the operating parameters leading to the predetermined process parameters for which the sample is analyzed and / or processed can advantageously be determined in advance, i.e., before the start of the analysis and / or processing of the sample, from the test structure. Subsequently, the analysis and / or processing of the sample can be carried out under exactly the same conditions, in particular in the same process atmosphere, so that the analysis and / or processing can be carried out in a particularly accurate and reliable manner. This enables both a reduction in the processing period and a reduction in the level of defective samples. In addition, it is possible to accurately adjust the operating parameters for each case across a plurality of processes and / or samples such that the predetermined process parameters are achieved. This means that it is already possible to determine the operating parameters in advance so that the process parameters can be kept constant across a plurality of processes and / or samples, rather than assuming that the same operating parameters always lead to the same process parameters.

[0052] In a further embodiment of the device, the test structure is arranged on the side facing the providing unit of the holding element and / or the shielding element.

[0053] In a further embodiment of the device, the alignment unit comprises a movement unit for moving the holding element, and / or the shielding element, and / or the particle beam deflection unit in place, and the particle beam deflection unit is set to direct the particle beam towards either the through-opening or the test structure.

[0054] In a second aspect, a device for analyzing and / or processing a sample using a particle beam is proposed. The device comprises a providing unit for providing a particle beam, and a shielding element for electrical and / or magnetic shielding, the shielding element having a through-opening for the particle beam to pass through to the sample, the device further comprising It comprises an exciter unit for inducing a holding element for holding a shield element, and the shield element and / or the vibrating element are arranged on the holding element or the shield element so as to vibrate mechanically. This device further comprises a detection unit for detecting the vibration characteristics of the holding element, the shield element, and / or the vibration element induced to vibrate, and a determination unit for determining at least one current operating parameter and / or process parameter of the device according to the detected vibration characteristics.

[0055] This device has the same advantages as those described for the device of the first aspect. The embodiments, features, as well as the descriptions and definitions described for the device of the first aspect are equally applicable to the device of the second aspect, and vice versa. In particular, the device in one aspect may similarly have additional features of the devices in other aspects.

[0056] This device can particularly determine the operating parameters and / or process parameters that affect the vibration of the holding element, the shield element, and / or the vibration element. These are, in particular, the vibrating mass, and / or the reset force, and / or the parameters that affect the damping of the vibration of each vibration element.

[0057] For ease of understanding, the holding element, the shield element, or the vibration element can be imagined as a spring-mass system. Such a system has, briefly speaking, three parameters that determine the vibration characteristics. These parameters are the spring constant (unit: N / m), the mass (unit: g), and the damping (unit, for example: N·s / m). Based on these three parameters, it is possible to predict the vibration characteristics in response to excitation, or conversely, to confirm at least one parameter by detecting (measuring) the vibration characteristics after excitation.

[0058] In this case, the holding element, the shielding element, and / or the vibrating element may have different vibration modes that can be induced by the oscillator unit, depending on their design and the locations where they are fixed. In this case, the induced vibration modes may particularly include two-dimensional modes or three-dimensional modes. The holding element and / or the shielding element may each be particularly optimized for this application, which means that the holding element and / or the shielding element have a mechanical structure such that a specific vibration mode is induced. The vibrating element is an element particularly envisioned for this application and is, for example, a cantilever fixed at one end or a vibrating bar fixed at both ends.

[0059] The holding element, the shielding element, and / or the vibrating element may particularly be suitable for the implementation of a test structure as described for the first aspect, particularly for particle beam induced deposition and / or etching processes, and may have a predetermined intended area.

[0060] The oscillator unit includes, for example, an electrostrictive element, such as a piezo actuator. The oscillator unit is particularly set such that a specific element vibrates mechanically at a specific frequency from a specific frequency band. It can be said that the oscillator unit provides a variable excitation frequency.

[0061] Similarly, the detection unit may also include an electrostrictive element. In particular, the oscillator unit may first function as an oscillator and then as a detection unit.

[0062] Alternatively or additionally, the detection unit may be set to detect vibration characteristics in an optical manner.

[0063] The vibration characteristics can include any characteristic parameter of the mechanical vibration of an object. Examples are amplitude, attenuation, frequency, in particular the resonance frequency and / or multiples of the resonance frequency. In this case, it is preferable that the amplitude and attenuation are detected as a function of the exciter frequency. Each vibration characteristic is in particular time-dependent. In an embodiment, it is also possible to detect the evolution of the vibration characteristics over time, and the evolution of the vibration characteristics over time can be used to verify the evolution over time of the operating parameters and / or the process parameters.

[0064] Based on the detected vibration characteristics, it is possible to use the corresponding physical model and / or mathematical model to identify the mechanical parameters of each vibration element, such as, for example, the modulus of elasticity, mass, mass distribution, cross-sectional shape, etc.

[0065] The determination unit can be implemented in the form of hardware and / or software. In the case of a hardware implementation, the determination unit can take the form of, for example, a computer or a microprocessor. In the case of a software implementation, the determination unit can take the form of a computer program product, a function, a routine, an algorithm, a part of the program code, or an executable object.

[0066] In one embodiment of the device, the exciter unit and / or the detection unit are arranged on and held by a holding element.

[0067] In a further embodiment of the device, the vibration element comprises at least one cantilever.

[0068] The vibration element or the cantilever is arranged on the holding element and / or the shielding element in such a way that, in particular, the particle beam can be radiated onto the side of the vibration element facing the providing unit. This means that the vibration element is not hidden from the perspective of the particle beam. For example, the vibration element is arranged in another opening of the shielding element.

[0069] There may be cases where a plurality of cantilevers are arranged parallel to each other, and in such cases, the vibration characteristics can be determined individually for each cantilever.

[0070] In a further embodiment of the device, the detection unit is configured to detect the vibration characteristics by means of a laser.

[0071] This means that the detection unit includes, for example, a laser by which a laser beam is irradiated onto a holding element, a shielding element, and / or a vibrating element, and a photodiode for detecting the reflection of the laser beam, and it is possible to determine the deflection of the vibrating element based on the shift of the incidence point of the reflected laser beam.

[0072] In a further embodiment of the device, the device comprises a process gas provision unit for supplying a process gas into the sample, and the determination unit is configured to determine at least one partial pressure and / or at least one gas concentration of a species present in the process gas according to the detected vibration characteristics.

[0073] In this context, supplying a process gas into the sample more specifically means that the process gas is guided into the sample and released in the immediate vicinity of the sample. For example, the device comprises a gas supply unit configured to guide the process gas to the sample through a passage opening of the shielding element. In this case, the process gas flows through the through-opening in the direction of the particle beam. Thus, the process gas is also present, in particular, in the region of the holding element, the shielding element, and / or the vibrating element, surrounding or flowing around it, and the composition of the process gas is essentially the same as that of the sample.

[0074] The partial pressure and / or gas concentration can be determined according to the vibration characteristics based on a physical model and / or a mathematical model for explaining the adsorption of gas molecules on the surface and / or based on a reference measurement value and / or a calibration curve. An overview of this technique is given, for example, by the paper "Recent advances in gas phase microcantilever-based sensing" by the authors Z. Long, L. Kou, M. Sepaniak and X. Hou, published in 2013 in Volume 32 / Edition 2 of the journal "Reviews in Analytical Chemistry" by De Gruyter Verlag (DOI: https: / / doi.org / 10.1515 / revac-2012-0034).

[0075] In a third aspect, a method for analyzing and / or processing a sample using a particle beam by means of analysis and / or process operations within a device is proposed. This method comprises providing a test structure in a vacuum chamber of the device, evacuating the vacuum chamber to provide a process atmosphere for carrying out the analysis and / or process operations, irradiating the test structure with a particle beam, detecting the interaction of the particle beam with the test structure, and determining at least one current operating parameter and / or process parameter for the analysis and / or process operations according to the detected interaction.

[0076] This method is preferably carried out using a device according to the first aspect. The advantages mentioned for the device according to the first aspect are equally applicable to the proposed method. The embodiments and features specified for the device according to the first aspect are correspondingly applicable to the proposed method.

[0077] In an embodiment of this method, the method comprises performing a test analysis and / or a test process on a test structure in a process atmosphere to check current operating parameters and / or process parameters. This means that the analysis and / or process operations on which the sample is analyzed and / or processed are carried out by tests on or using the test structure.

[0078] Preferably, prior to evacuation of the vacuum chamber, the introduction of the sample into the vacuum chamber has already been carried out. For example, the sample is already placed at a subsequent processing position. After the operating parameters and / or process parameters have been determined, it is possible to directly carry out the analysis and / or process operations without interrupting or interrupting the process atmosphere (the atmosphere inside the vacuum chamber).

[0079] In an embodiment of this method, this further comprises adjusting at least one operating parameter of the device according to the current operating parameters and / or the determined process parameters, and performing an analysis and / or a process operation in the process atmosphere using the adjusted operating parameters.

[0080] In this embodiment, the analysis and / or process operations are optimized and can thus be carried out with higher reliability and accuracy. This improves the quality of the analysis and / or processing of the sample.

[0081] In a fourth aspect, a method for analyzing and / or processing a sample using a particle beam by means of an analysis and / or a process operation within a device is proposed. The device has a shielding element for electrical and / or magnetic shielding, the shielding element having a through-opening for the particle beam to pass through to the sample. The method comprises evacuating the vacuum chamber of the device to provide a process atmosphere for carrying out the analysis and / or process operation; Inducing mechanically the holding element for holding the shielding element, the shielding element, and / or the vibrating element disposed on the holding element or the shielding element to vibrate; Detecting the vibration characteristics of the holding element, the shielding element, and / or the vibrating element induced to vibrate; Determining at least one current operating parameter and / or process parameter of the device according to the detected vibration characteristics.

[0082] This method is preferably implemented using the device according to the second aspect. The advantages mentioned for the device according to the second aspect are equally applicable to the proposed method. The embodiments and features specified for the device according to the second aspect are correspondingly applicable to the proposed method.

[0083] In one embodiment of this method, the holding element, the shielding element, and / or the vibrating element has a predetermined region made of a specific material, and this method further includes Detecting the vibration characteristics at at least two different joints; Determining the current etching rate of the specific material according to the change in the vibration characteristics.

[0084] A material for forming a specific material, depending on the composition of the process atmosphere, in particular the process gas currently being supplied and / or the process gas that was supplied in the previous process, the material can be spontaneously etched by the residual process gas present in the process atmosphere. The expression "spontaneous etching" is understood in this case to mean that the removal of the material occurs unintentionally and / or without being caused in a controlled manner, such as by the supply of energy at the current bonding point. Due to the etching action, the vibrating mass and / or thickness of the vibrating element decreases, and thus, for example, the resonant frequency of the vibrating element changes. This can be used to confirm the average removal of the material during the observation period and also to determine the current etching rate. The etching rate can be used, for example, to determine the partial pressure of the etching gas and / or the residual gas concentration of the etching gas in the process atmosphere. Therefore, this method is particularly suitable for determining the contamination of the vacuum chamber by unwanted gases, especially when the unwanted gas is the process gas from the previous process.

[0085] In an embodiment of this method, a particle beam for performing a particle beam induced etching process is irradiated onto a test structure (especially a predetermined region thereof), and is irradiated intensively in particular. This makes it particularly possible to determine whether an activatable precursor gas of the etching gas is present in the process atmosphere and its concentration. Alternatively or additionally, the current etching rate can be determined for a planned etching process on the sample, in which case, for example, the operating parameters of the device can be adjusted to affect the etching rate in a controlled manner.

[0086] In a further embodiment of this method, the method further comprises the step of supplying a process gas to a holding element, a shielding element, and / or a vibrating element, and the step of irradiating a predetermined region with a particle beam for performing a particle beam induced deposition process and / or an etching process on a predetermined region on the holding element, the shielding element, and / or the vibrating element. Detecting vibration characteristics at at least two different junction points irradiated with a particle beam; Determining a deposition rate of a particle beam induced etching process or an etching rate of a particle beam induced deposition process in response to a change in the vibration characteristics.

[0087] Instead of, and / or in addition to, the deposition rate, it is possible to determine further characteristics of the deposition, such as density. For this purpose, for example, the mass of the deposit is confirmed based on the vibration characteristics, and the volume of the deposit is confirmed based on a microscopic image of the deposit, in particular an electron micrograph.

[0088] Suitable process gases for the deposition of materials or the growth of raised structures are, in particular, alkyl compounds of main group elements, metals or transition elements. Examples thereof are (cyclopentadienyl)trimethylplatinum CpPtMe3 (Me = CH4), (methylcyclopentadienyl)trimethylplatinum MeCpPtMe3, tetramethyltin SnMe4, trimethylgallium GaMe3, ferrocene Cp2Fe, bisarylchromium Ar2Cr, and / or, for example, chromium hexacarbonyl Cr(CO)6, molybdenum hexacarbonyl Mo(CO)6, tungsten hexacarbonyl W(CO)6, dicobalt octacarbonyl Co2(CO)8, triruthenium dodecacarbonyl Ru3(CO) 12, carbonyl compounds of main group elements, metals, or transition elements such as iron pentacarbonyl Fe(CO)5, and / or, for example, alkoxide compounds of main group elements, metals, or transition elements such as tetraethyl orthosilicate Si(OC2H5)4, tetraisopropoxytitanium Ti(OC3H7)4, and / or, for example, halogen compounds of main group elements, metals, or transition elements such as tungsten hexafluoride WF6, tungsten hexachloride WCl6, titanium tetrachloride TiCl4, boron trifluoride BF3, silicon tetrachloride SiCl4, and / or, for example, complexes comprising main group elements, metals, or transition elements such as copper bis(hexafluoroacetylacetonate) Cu(C5F6HO2)2, dimethylgold trifluoroacetylacetonate Me2Au(C5F3H4O2), and / or, organic compounds such as carbon monoxide CO, carbon dioxide CO2, aliphatic and / or aromatic hydrocarbons.

[0089] Suitable process gases suitable for etching the material are, for example, xenon difluoride XeF2, xenon dichloride XeCl2, xenon tetrachloride XeCl4, water vapor H2O, heavy water D2O, oxygen O2, ozone O3, ammonia NH3, nitrosyl chloride NOCl, and / or any of the halogen compounds of XNO, XONO2, X2O, XO2, X2O2, X2O4, X2O6, where X is a halide. Further process gases for etching the material are specified in the applicant's U.S. Patent Application No. 13 / 0103281.

[0090] The additional gas can be added in proportion to the process gas, for example, to better control the processing process. Examples of the additional gas include oxidizing gases such as hydrogen peroxide H2O2, nitrous oxide N2O, nitric oxide NO, nitrogen dioxide NO2, nitric acid HNO3, and other oxygen-containing gases, and / or halogen compounds such as chlorine Cl2, hydrogen chloride HCl, hydrogen fluoride HF, iodine I2, hydrogen iodide HI, bromine Br2, hydrogen bromide HBr, phosphorus trichloride PCl3, phosphorus pentachloride PCl5, phosphorus trifluoride PF3, and other halogen-containing gases, and / or reducing gases such as hydrogen H2, ammonia NH3, methane CH4, and other hydrogen-containing gases. These additional gases can be used, for example, as buffer gases for the etching process or as passivation media and the like.

[0091] According to another aspect, an apparatus for analyzing and / or processing a sample using a particle beam is provided. The apparatus includes a providing unit for providing a particle beam, and a test structure attached to the providing unit, and the apparatus is configured to perform an etching process and / or a deposition process on the test structure using the particle beam.

[0092] According to an embodiment, the apparatus further includes a determining unit for determining at least one current operation parameter and / or process parameter of the apparatus according to the interaction between the particle beam and the test structure on which the etching process and / or the deposition process is performed.

[0093] According to an embodiment, the test structure is disposed inside the internal volume defined by the providing unit.

[0094] According to an embodiment, the apparatus further includes an electron microscope, and the test structure is disposed within the depth of field of the electron microscope.

[0095] According to an embodiment, the apparatus comprises a test structure on which an etching process and / or a deposition process has been performed.

[0096] According to an embodiment, the apparatus comprises a process gas providing unit for supplying a process gas to the test structure in order to perform an etching process and / or a deposition process on the test structure using a particle beam.

[0097] According to an embodiment, the providing unit has an opening for the particle beam to pass through to the sample, and the test structure is disposed inside or adjacent to the opening.

[0098] According to an embodiment, the apparatus further comprises a shield element for electrical and / or magnetic shielding, the shield element has a through-opening for the particle beam to pass through to the sample, and the shield element and / or a holding element for holding the shield element comprises the test structure.

[0099] According to an embodiment, the apparatus comprises an alignment unit for aligning the particle beam and the test structure with respect to each other so that the particle beam is incident on the test structure.

[0100] According to an embodiment, at least one determined operating parameter comprises telecentricity of the providing unit.

[0101] According to an embodiment, the apparatus comprises a vibrator unit for inducing the test structure to vibrate mechanically, a detection unit for detecting at least vibration characteristics of the test structure, and a determination unit for determining at least one current operating parameter and / or process parameter of the apparatus according to the detected vibration characteristics.

[0102] According to an embodiment, the test structure is formed on a cantilever.

[0103] According to an embodiment, the detection unit is configured to detect vibration characteristics by a laser.

[0104] According to an embodiment, the apparatus further includes a process gas supply unit for supplying a process gas to the sample, and the determination unit is configured to determine at least one partial pressure and / or at least one gas concentration of a species present in the process gas according to the detected vibration characteristics.

[0105] According to a further aspect, a system including the apparatus and the sample described above is provided.

[0106] According to an embodiment, the apparatus is configured to perform an etching process and / or a deposition process on the sample using a particle beam.

[0107] According to an embodiment, at least a part of the test structure and at least a part of the sample have the same material composition.

[0108] According to a further aspect, a method for providing a test structure for analyzing and / or processing a sample using a particle beam within the apparatus is provided, the apparatus including a providing unit configured to provide a particle beam, and a test structure attached to the providing unit, and the method includes performing an etching process and / or a deposition process on the test structure using the particle beam.

[0109] According to a further aspect, a method for analyzing and / or processing a sample using a particle beam using the apparatus is provided, the method including performing the method as described above, and detecting an interaction between the particle beam and the test structure. including determining at least one current operating parameter and / or process parameter of the device in response to the detected interaction.

[0110] Subsequently, the sample can be analyzed and / or processed in response to the determined at least one current operating parameter and / or process parameter of the device.

[0111] All aspects and embodiments as described above can be combined as would be considered appropriate by those skilled in the art.

[0112] In this case, "a(n)" should not be understood as being precisely limited to one element. Rather, a plurality of elements, for example two, three, or more, can also be provided. Other numbers used in this specification should not be understood in the sense that there are strict limitations on the number of the described elements. Rather, unless otherwise indicated, the numbers can vary up and down.

[0113] Further possible implementations of the present invention also include any combination of features or embodiments not explicitly mentioned above or below with respect to the exemplary embodiments. In this case, those skilled in the art can also add individual aspects as improvements or supplements to the respective basic forms of the present invention.

[0114] Further advantageous configurations and aspects of the present invention are the subject matter of the dependent claims and also the subject matter of the operation examples of the present invention described below. The present invention will be described in detail below by way of preferred embodiments with reference to the accompanying drawings.

Brief Description of the Drawings

[0115]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

[0116] Unless otherwise specified, the same or functionally equivalent elements are given the same reference numerals in the figures. Also, note that the figures in the drawings are not necessarily to scale.

[0117] Figure 1 illustrates a schematic diagram of a first operating example of an apparatus 100 for analyzing and / or processing a sample 10 using a particle beam 114. The apparatus 100 is preferably disposed within a vacuum housing (not shown). The apparatus 100 includes a providing unit 110 for providing the particle beam 114 and a sample stage 102 for holding the sample 10, and the sample stage is disposed below the providing unit 110. Note that the sample 10 is not part of the apparatus 100. The apparatus 100 and the sample 10 together form a system 1.

[0118] The sample 10 is, for example, a lithography mask having a feature size in the range of 10 nm to 10 μm. This can be, for example, a transmissive lithography mask for DUV lithography (DUV: "deep ultraviolet", operating light wavelength in the range of 30 to 250 nm), or a reflective lithography mask for EUV lithography (EUV: "extreme ultraviolet", operating light wavelength in the range of 1 to 30 nm). The process operations performed on the sample 10 using the apparatus 100 include, for example, an etching process in which material is locally removed from the surface of the sample 10, a deposition process in which material is locally applied to the surface of the sample 10, and / or a similar local activation process such as the formation of a passivation layer or the compression of a layer.

[0119] The providing unit 110 particularly includes a particle beam generating unit 112 for generating the particle beam 114. The particle beam 114 consists of charged particles such as, for example, ions or electrons. The example of FIG. 1 includes an electron beam. Thus, the providing unit 110 is also called an electron column (or an electron beam column), and the apparatus 100 forms, for example, a scanning electron microscope. The electron beam 114 is guided by a beam guiding element (not shown in FIG. 1). This is also referred to as an electron optical unit. Further, the electron column 110 may include a detector (not shown in FIG. 1) for detecting an electron signal generated from, for example, backscattered electrons and / or secondary electrons.

[0120] The electron column 110 has a dedicated vacuum housing 113 and, for example, 10-6 mbar to 10 -8 Exhaustion is carried out until the residual gas pressure of mbar. The opening 116 for the electron beam 114 is arranged on the lower side. The opening 116 is covered by a shield element 130 fixed above the opening 116 by a holding element 120 that can be attached to the housing 113. The holding element 120 comprises, for example, a plurality of screws for screwing the shield element into the electron column 110. The shield element 130 and / or the holding element 120 can form part of the providing unit 110 and define its internal volume 111 (this can be, for example, 10 -6 mbar to 10 -8 mbar of residual gas pressure can be exhausted, and / or can be partially or completely arranged inside the vacuum housing 113).

[0121] The shield element 130 has a two-dimensional shape and comprises a conductive material. The shield element is preferably formed from a material that is inert with respect to the process gas atmosphere and has a very small influence on the assumed process even if there is any. As an example, the shield element 130 is formed from gold or nickel. The shield element 130 has a convex cross-section 117 with respect to the sample stage 102 and the sample 10. The convex cross-section 117 curves in the direction of the sample stage 102. The convex cross-section 117 has a through-opening 132 for the particle beam 114 to pass through. The through-opening 132 particularly comprises the point of the convex cross-section 117 closest to the sample stage 102. Thus, the distance between the shield element 130 and the sample stage 102 or the sample 10 is minimized in the region of the through-opening 132. During the operation of the device 100, the distance between the through-opening 132 and the sample 10 is preferably 5 μm to 30 μm, and preferably 10 μm. Preferably, the sample stage 102 has a positioning unit (not shown), whereby the distance between the sample stage 102 and the electron column 110 can be set.

[0122] The shielding unit 116 may have a planar region from which the convex cross-section 117 protrudes. The planar region preferably extends radially from the upper end of the convex cross-section 117. The transition portion where the planar region joins the convex cross-section 117 may have a concave curvature. The shielding element 116 is fixed to the opening 114 of the electron column 110, for example, at the outer edge of the planar region.

[0123] In this example, a ground potential is applied to the shielding element 130. This means that the shielding element 130 is set to shield the electric field E (in other embodiments, the magnetic field). To illustrate this, FIG. 1 shows, as an example, the charge Q that exists on the sample 10 and generates the electric field E. In particular, in the case of the sample 10 that is non-conductive or (at least in cross-section) slightly conductive, when the electron beam 114 is incident on the sample 10, as illustrated in FIG. 1, the sample 10 becomes charged, and thus, the electric field E is formed. FIG. 1 shows, as an example, the negative charge Q resulting from the incidence of the electron beam 114. In other embodiments, the electric field and / or the magnetic field may originate from the electron column 110 itself, or may be formed or generated within the electron column 110.

[0124] The test structure 200 is arranged, for example, on the shielding element 130. The test structure 200 may be arranged on the inner surface of the shielding element 130 so as to be arranged inside the internal volume 111 of the providing unit 110. The test structure 200 may be attached to the shielding element 130. In one embodiment, the attachment is formed as an agglomeration bond. In another embodiment, the attachment is provided by a test structure 200 formed integrally with the shielding element 130. For example, the test structure 200 may be defined by the inner surface of the shielding element 130.

[0125] The test structure 200 can be formed and can provide one or more functions as described in detail below with reference to FIG. 3. Examples of such functions are dissolution tests with dissolution test patterns, contrast tests with contrast patterns (in particular, material contrast and / or secondary electron contrast at at least one edge), or process tests by regions of a particular material on which each process is tested. Alternative terms for "test" include "adjustment", "calibration", or "running-in operation".

[0126] Additionally, what is disposed between the beam generation unit 112 and the shield element 130 can, in this example, be an alignment unit 140 designed as a jet deflection unit. The alignment unit 140 is set to deflect the electron beam 114 onto the through-opening 132 or onto the test structure 200. For this purpose, the alignment unit 140 is connected to a voltage source that provides a voltage for generating an electric field suitable for deflecting the particle beam 114. In FIG. 1, A shows the beam path when the alignment unit 140 directs the electron beam 114 onto the through-opening 132, and B shows the beam path when the alignment unit 140 directs the electron beam 114 onto the test structure 200.

[0127] The switching from beam path A to beam path B, or vice versa, can be achieved, for example, within a short time from 1 μs to 1 s. This means that even during the analysis of the sample 10 or the process operation, the electron beam 114 can be periodically directed onto the test structure 200, for example, to monitor certain beam characteristics or process characteristics.

[0128] When the electron beam 114 is directed towards the test structure 200, an interaction occurs between the electron beam 114 and the test structure 200. As already stated at the beginning, this interaction can be detected by a detector. The alignment unit 140 can be used in the same way, for example, in a dual function as a detector for detecting backscattered electrons or secondary electrons. Preferably, additional detectors are provided, for example, arranged at a further spatial angle with respect to the test structure 200 and / or sensitive to electrons of different energies. For the sake of clarity, FIG. 1 does not show additional detectors.

[0129] The apparatus 100 additionally comprises a determination unit 150 which is set to determine the operating parameters and / or process parameters of the apparatus 100 in response to the detected interaction. The determination unit 150 is set to receive corresponding measurement data regarding the interaction (for the sake of clarity, FIG. 1 does not show data wires, etc.). The measurement data can include, for example, a scanning electron microscope image of the test structure, which can be used to check the current resolution of the electron microscope, which is an example of the current operating parameters of the apparatus 100.

[0130] Since the test structure 200 is not destroyed during the operation of the apparatus 100 for analyzing and / or processing the sample 10, it can remain within the vacuum housing of the apparatus 100 while the sample 10 is being analyzed or processed. Thus, it is possible to determine the current operating parameters and / or process parameters in-situ, i.e., under essentially the same conditions under which subsequent analysis and / or processing will be carried out. Thus, it is possible to ensure that the operating parameters and / or process parameters have the desired values or are adjusted such that successful analysis and / or processing of the sample 10 is possible.

[0131] FIG. 2 illustrates a schematic diagram of a second embodiment of an apparatus 100 for analyzing and / or processing a sample 10 using a particle beam 114. The apparatus 100 of FIG. 2 is identical to the apparatus of FIG. 1, except for the differences described below. In FIG. 2, the holding element 120 has a two-dimensional shape and is placed on the providing unit 110 by an alignment unit 140 in the form of a moving unit. The moving unit 140 is configured to move the holding element 120 and a shield element 130 fixed to the holding element 120 therewith, particularly in a direction parallel to the sample surface of the sample 10 and in a direction essentially perpendicular to the particle beam 114.

[0132] The shield element 130 is fixed (e.g., in a one-piece or monolithic manner) on the holding element 120 and in this example has a flat shape rather than a convex shape, although it is also possible to use the convex-shaped shield element 130 of FIG. 1. For clarity, the grounding of the shield element 130 is not shown in FIG. 2. In this example of operation, the holding element is made of, for example, nickel silver.

[0133] In this example, two test structures 200 are placed on the holding element 120 and the shield element 130 respectively, which preferably provide different functions, i.e., consist of different structures, as will be described in detail below with reference to FIG. 3 for example.

[0134] The alignment unit 140 enables the holding element 120, together with the shield element 130 and the test structures 200, to move relative to the particle beam 114 such that the particle beam 114 does not exit through the passage opening 132, but optionally irradiates any one of the test structures 200. In other words, each test structure 200 is pushed under the particle beam 114. Therefore, it is also possible to use the apparatus 100 of FIG. 2 to check the current operating parameters and / or process parameters using the test structures 200.

[0135] It should also be noted that the apparatuses 100 of FIGS. 1 and 2 can be combined with each other. In addition, each of them can have a process gas supply unit 170, for example, as described with reference to FIG. 8.

[0136] FIG. 3 shows a schematic top view of a shield element 130 having a plurality of test structures 202, 204, 206, 208, M1, M2. In this case, the shield element 130 has a mesh structure with a plurality of through openings 132, and only the central through opening is given a reference number. The shield element 130 has a convex shape, for example, as shown in FIG. 1, and the central through opening 132 is the lowest (closest to the sample 10). Additional through openings 132 can be utilized for the passage of the particle beam 114 (see FIGS. 1 or 2). However, in this example, particularly when the process gas PG is supplied from above as described with reference to FIG. 8 (see FIG. 8), it functions as a through opening for the process gas PG (see FIGS. 8 or 9).

[0137] The test structures 202, 204, 206, 208, M1, M2 are arranged in or in part of the through openings 132 near the edge to provide different functions for determining the current operating parameters and / or process parameters.

[0138] The structure 202 has, for example, a spatial resolution at a frequency of 1 / μm to 1000 / μm. The structure 202 can, for example, comprise a topographical structure and / or a structured arrangement of different materials. In one example, the structure comprises gold clusters or gold nanoparticles on a surface, for example, on a carbon substrate (see also FIG. 12), and the gold clusters have a size of, for example, 2.5 nm to 500 nm.

[0139] The test structure 203 consists of at least two different materials M1, M2, and thus provides a material contrast. The materials are in particular specific materials M1, M2 selected so as to provide a specific material contrast, and by using this, one or more detectors of the device 100 can be calibrated. Preferably, the test structure 203 consists of three or more materials in order to provide correspondingly different material contrasts. Examples of possible materials M1, M2 are C, Cr, Mo, Si, Ta, Ru, W, Rh, Pt, Re, and Au, and there are possibilities of two or more different combinations of these materials M1, M2. The materials described above are conductive materials. It is also possible to use non-conductive materials such as quartz and sapphire. In a preferred embodiment, two or more materials M1, M2 with the largest difference in atomic number are combined.

[0140] In addition, there are two predetermined regions 204, 206 intended for and suitable for the implementation of a particle beam induced deposition process and / or a particle beam induced etching process. The predetermined regions 204, 206 are preferably composed of the same material as the material of the sample 10 to be etched (see FIG. 1 or FIG. 2), or the material of the sample 10 at the site where the deposition process is performed. Examples of these are Cr, MoSi, SiN, SiON, Ta, TaN, TaBN, Ru, or quartz.

[0141] When the materials M1, M2 in which the test structure 203 and / or the predetermined regions 204, 206 are formed are electrically insulating, it is further possible to provide a shielding unit for the test structure 203 and the predetermined regions 204, 206 (not shown). This shielding unit can shield the electric field generated by the charging of the test structure 203 and / or the predetermined regions 204, 206 by the incident particle beam in the direction opposite to the beam direction, and can avoid or reduce the electrostatic effects caused by the charging. This enhances the reliability of the results determined using the test structure 203 and / or the predetermined regions 204, 206.

[0142] In addition, the shield element 130 has an arrangement comprising the oscillator unit 160 and the vibration element 208 in one of the through openings 132. In this case, the vibration element 208 comprises two individual cantilevers that can execute vibrations independently. The cantilevers can be composed of different materials and / or can have different shapes. The oscillator unit 160 is set to mechanically vibrate the vibration element 208. The oscillator unit 160 comprises, for example, a piezoelectric actuator. The oscillator unit 160 can simultaneously function as a detection unit set to detect the vibration characteristics of the vibrations executed by the vibration element 208. Based on the detected vibration characteristics, further operating parameters and / or process parameters can be determined. The functions provided in this way are described in detail with reference to FIGS. 4 to 9.

[0143] When the shield element 130 described above is used in one of the devices 100 of FIGS. 1 or 2, the particle beam 114 can be selectively directed to any of the structures 202, 203, 204, 206, 208 using the alignment unit 140 in order to determine the corresponding operating parameters and / or process parameters of the device 100 according to the detected interaction of the particle beam 114 with the specific structures 202, 203, 204, 206, 208.

[0144] It should be noted that in an embodiment, the shield element 130 can have only the individual structures 202, 203, 204, 206, 208, M1, M2 described and / or can have further structures of this kind. When the shield element 130 includes the vibration element 208 and the oscillator unit 160 and the devices 100, 400 further have a detection unit 162 (see FIGS. 4 or 8) for detecting the vibration characteristics of the vibrating vibration element 208, the devices 100, 400 combine the features and functions of the device 100 of FIGS. 1 or 2 with the features and functions of the device 400 of FIGS. 4 or 8.

[0145] FIG. 4 illustrates a schematic diagram of an embodiment of an apparatus 400 for analyzing and / or processing a sample 10 using a particle beam 114. The basic configuration of apparatus 400 corresponds to the basic configuration of the apparatuses of FIGS. 1 and 2. As described with reference to FIGS. 1 or 2, the test structure 200 is not owned by apparatus 400 in this example, and apparatus 400 additionally has an exciter unit 160 configured to mechanically vibrate a vibration element 208 disposed on the exciter unit 160. In addition, above the vibration element 208, an optical detection unit 162 is disposed that detects vibration characteristics A(f), φ(f) (see FIG. 6) of the vibration element 208 based on optical measurement and outputs it to, for example, a determination unit 150. The more precise functional modes of the exciter unit 160 of the vibration element 208 and of the detection unit 162 are described in detail below with reference to FIGS. 5 and 6.

[0146] Based on the detected vibration characteristics A(f), φ(f), it is possible to determine the operating parameters and / or process parameters of apparatus 400, such as the partial pressure of the process gas, the composition of the process atmosphere, the etching rate, and / or the deposition rate. This is also described in detail below.

[0147] Note that the features described above with reference to apparatus 400 can be integrated with the features of apparatus 100 of FIGS. 1 and / or 2. For example, the alignment unit 140 can be designed as described with reference to FIG. 1, or an additional alignment unit 140 can be provided. In addition, in an embodiment, the alignment unit 140 can be completely omitted.

[0148] FIG. 5 illustrates a schematic view of the vibration element 208 that can be used to determine the deposition rate or the etching rate. This is, for example, the vibration element 208 that exists within the apparatus 400 of FIG. 4 and / or is disposed on the shield element 130 of FIG. 3. The oscillator unit 160 is configured to cause mechanical vibrations W to be executed on the vibration element 208. The vibration element 208 takes the form of a cantilever, for example. The cantilever 208 has a predetermined region 204 made of, for example, chromium at the front end and is intended to perform a particle beam induced etching process.

[0149] The detection unit 162 for detecting the vibration characteristics A(f), φ(f) (see FIG. 6) includes a laser 163 and a photodetector 164. This measurement principle is known from scanning electron microscopes.

[0150] By irradiating the particle beam 114 onto the predetermined region 204 (for example, another embodiment of the test structure 200), it is possible to cause an etching process, particularly when a precursor gas is present around the cantilever 208 in the process atmosphere. This is converted directly or indirectly into active species by the incidence of the particle beam 114 and then chemically reacts with the atoms of the predetermined region 204 to form volatile reactants. Such an etching process particularly reduces the mass of the cantilever 208, which can be detected by the detected changes in the vibration characteristics A(f), φ(f). In other words, the detected changes in the vibration characteristics A(f), φ(f) can be used to conclude the decrease in the mass of the cantilever 208 and thus the current decrease in the etching rate in the etching process. In the case of a deposition process where a material is deposited on the cantilever 208, this can be correspondingly utilized to determine the current deposition rate.

[0151] FIG. 6 illustrates an explanatory diagram having two measurement curves as examples of the detected vibration characteristics A(f) and φ(f). This example relates to the amplitude A(f) of the vibration executed by the excitation elements 120, 130, 208 (see FIGS. 1 to 5) as a function of the excitation frequency f, the vibration of the vibrator, and the phase shift φ(f) between the excited vibration. The horizontal axis illustrates the excitation frequency f, and the vertical axis illustrates the deflection based on the curve A(f) and the phase shift based on the curve φ(f). At the resonance frequency f R , the element induced to vibrate has the maximum amplitude. The illustrated example illustrates a schematic view of the situation of a cantilever with a free end. Other vibration systems may have different operations. In particular, a more highly degree-of-freedom vibration system that executes two-dimensional or three-dimensional vibrations may illustrate different behaviors, particularly more complex behaviors, in this case.

[0152] As described above with reference to FIG. 5, if there is a change in the mass of the cantilever 208, this has, for example, the effect of shifting the resonance frequency f R . The change in mass can be concluded from the change in the resonance frequency f R .

[0153] FIG. 7 illustrates a schematic view of an operation example of the holding element 120 having the shield element 130 and the vibrator unit 160. In this example, the vibrator unit 160 is set to induce mechanical vibration of the shield element 130, and the shield element 130 is particularly adapted for this function. This means that the shield element 130 further has the function of the vibration element 208 in addition to the shielding effect. For example, the central bar of the shield element 130 having the through opening 132 functions as a vibration element 208 having two fixed ends. The vibrator unit 160 is fixed on the holding element 120. The holding element 120 in this example has further openings for passing the process gas PG supplied from above (see FIGS. 8 and 9). These openings are optional. The vibration characteristics A(f), φ(f) of the vibration element 208 (see FIG. 6) can be optically detected, for example, as described with reference to FIG. 5.

[0154] Figure 8 illustrates a schematic view of a second embodiment of a further apparatus 400 for analyzing and / or processing a sample 10 using a particle beam 114. Apparatus 400 has the same features as apparatus 400 described with reference to FIG. 4. In addition thereto, apparatus 400 has a process gas supply unit 170. This comprises a process gas reservoir 171 containing a process gas PG which is, for example, in a solid or liquid state at low temperature or in a highly compressed gaseous state under high pressure. The process gas PG can be supplied from the reservoir 171 via a conduit 173 to the particle beam providing unit 110, in particular to a region directly above a shield element 130 which preferably has a plurality of openings so that the process gas PG can flow towards the sample 10, as illustrated, for example, in FIG. 3. This supply of the process gas PG can be referred to as a "top-down" supply. Alternatively, it is also possible to supply the process gas PG to the sample 10 from the side (not shown). A valve 172 can be used for regulating the process gas flow rate.

[0155] The process gas PG may comprise a mixture of different gas species, where the gas species are understood to mean both pure elements such as H2, He, O2, N2 and compound gases such as CH4, NH3, H2O, SiH4. It is preferred that the partial pressure of each gas species can be adjusted by the supply and / or removal of each gas species, in particular via the valve 172 and a vacuum pump (not shown).

[0156] Note that the process gas supply unit 170 illustrated in FIG. 8 can also be used in the apparatus 100 of FIG. 1 or FIG. 2.

[0157] FIG. 9 illustrates, in two schematic views, determining the residence time of process gas PG on the surface of a vibration element 208 that takes the form of a cantilever and can be mechanically induced to vibrate by an exciter unit 160 (not shown) (see FIGS. 3, 4, 5, 7, 8). A detection unit 162 (not shown) (see FIGS. 3, 4, 5, 7) is set to detect vibration characteristics A(f), φ(f) (see FIG. 6). In the first state I, the process atmosphere PA has the process gas PG present relatively densely. Accordingly, the individual molecules of the process gas PG are adsorbed in a high-density layer (single layer). Thus, the mass of the cantilever 208 is increased by the mass of this single layer, and a specific resonance frequency f R (see FIG. 6) is established. In the second state II, for example, the gas supply of the process gas PG is stopped and the process atmosphere PA becomes thinner. Accordingly, the molecules adsorbed on the cantilever 208 are also volatilized in the same way, and the adsorbed mass decreases. As a result, the resonance frequency f R changes compared to state I. By observing the change over time of the resonance frequency f R , it is possible to confirm, for example, the residence time of the process gas PG in the cantilever 208. Note that it is also possible to detect and evaluate other vibration characteristics in order to determine this process parameter and / or other operating parameters or process parameters instead of the resonance frequency f R .

[0158] FIG. 10 illustrates a schematic block diagram of an example of the operation of a first method of analyzing and / or processing a sample 10 (see FIGS. 1, 2, 4, or 8) by an analysis and / or process operation in apparatuses 100, 400. In step S10, a test structure 200 (see FIGS. 1-3) is provided within the vacuum enclosure of apparatuses 100, 400. In a second step S11, the vacuum enclosure is evacuated to provide a process atmosphere PA (see FIG. 9) for performing the analysis and / or process operation. Optionally, this step comprises the supply of one or more process gases PG (see FIGS. 8 or 9). In a third step S12, a particle beam 114 (see FIGS. 1, 2, 4, 5, 8) is irradiated onto the test structure 200. This step particularly comprises aligning the particle beam 114 onto the test structure 200, for example by an alignment unit 140. In a fourth step S13, the interaction of the particle beam 114 with the test structure 200 is detected. The interaction is detected particularly by a detector such as a backscattered electron detector and / or a secondary electron detector. Alternatively, it is also possible to use other detectors, such as an optical detector. If apparatuses 100, 400 have an excitation unit 160 (see FIGS. 3, 4, 5, 7) configured to induce a mechanical vibration W (see FIG. 5) of a holding element 120 (see FIGS. 1, 2, 4, 8), a shield element 130 (see FIGS. 1, 2, 4, 8) and / or a vibration element 208 (see FIGS. 3, 4, 5, 7, 8), and a detection unit 162 (see FIGS. 4, 5, 8) are configured to detect vibration characteristics A(f), φ(f) (see FIG. 6), and this arrangement forms a combination of the test structure and the detector. In a fifth step S14, at least one current operation parameter of apparatuses 100, 400 and / or a process parameter for the analysis and / or process operation is determined in response to the detected interaction. In this case, particularly, measurement data detected by each detector and explaining the interaction between the particle beam 114 and the test structure 200 is evaluated by one or more physical and / or mathematical models.

[0159] This method can be implemented using either apparatus 100 or 400 of FIGS. 1, 2, 4, or 8. Sample 10 is, in particular, a lithography mask. Test structure 200 has, in particular, the same or a similar material and / or structure as the lithography mask.

[0160] FIG. 11 illustrates a schematic block diagram of an example of the operation of a second method for analyzing and / or processing a sample 10 (see FIGS. 1, 2, 4, 8) using a particle beam 114 (see FIGS. 1, 2, 4, 8) by analysis and / or process operations in apparatuses 100, 400. The apparatuses 100, 400 have a shield element 130 (see FIGS. 1, 2, 4, 7, 8) held by a holding element 120 (see FIGS. 1, 2, 4, 7, 8) to shield a magnetic field E (see FIG. 1) generated by a charge Q accumulated on the sample 10 (see FIG. 1). Further, the shield element 130 has a passage opening 132 (see FIGS. 1 to 4, 7, 8) for passing the particle beam 114 over the sample 10. In a first step S20 of this method, the vacuum housing of the apparatuses 100, 400 is evacuated to provide a process atmosphere PA (see FIG. 9) for performing the analysis and / or process operations. Optionally, this step comprises the supply of one or more process gases PG (see FIG. 8 or FIG. 9). In a second step 21, the holding element 120, the shield element 130, and / or a vibration element 208 (see FIGS. 4, 5, 7, 8, 9) disposed on the holding element 120 or the shield element 130 is induced to perform a mechanical vibration W (see FIG. 5). In a third step S22, vibration characteristics A(f), φ(f) (see FIG. 6) of the induced vibrating holding element 120, shield element 130, and / or vibration element 208 are detected. The vibration characteristics A(f), φ(f) are detected in particular by an optical detector and / or by a piezoresistive sensor element such as a piezoelectric crystal. In a fourth step S23, at least one current operating parameter and / or process parameter of the apparatuses 100, 400 is determined according to the detected vibration characteristics A(f), φ(f). In this case, in particular, measurement data detected by each detector and explaining the interaction between the particle beam 114 and the test structure 200 is evaluated by one or more physical models and / or mathematical models.

[0161] This method can be implemented using either apparatus 100 or 400 of FIGS. 1, 2, 4, or 8. Sample 10 is in particular a lithography mask. Holding element 120, shielding element 130, and / or vibrating element 208 preferably have a test structure 200 (see FIGS. 1-3).

[0162] The methods described with reference to FIGS. 10 and 11 can in particular be combined. Both methods are suitable for monitoring and / or optimizing the analysis of sample 10 and / or the process operation by apparatus 100, 400 in that an optimal adjustment of the operating parameters and / or process parameters is performed respectively.

[0163] FIG. 12 illustrates an example of an electron micrograph IMG of a test structure 200 (see FIGS. 1-3) for verifying the resolution of an electron microscope or for calibrating an electron microscope.

[0164] The test structure 200 used is gold nanoparticles on carbon. The gold nanoparticles in image IMG stand out in bright color against the carbon substrate.

[0165] Based on image IMG, it is possible to determine, for example, the resolution achieved with an electron microscope. Advantageously, for this purpose, for example, from the generation process for the generation of the test structure and / or by sampling the test structure with a scanning electron microscope or the like, the size distribution of the gold nanoparticles can be known. In addition, based on image IMG, the beam profile of the electron beam can be confirmed, for example, by analyzing the intensity transition along the edge resulting from the gold nanoparticles.

[0166] In the apparatus 100 of FIG. 13, an arm 1300 attached to the housing 113 of the providing unit 110 may be provided. The arm 1300 may hold a horizontal platform 1302. The arm 1300 and / or the platform 1302 may be integrally formed with the housing 113. In other embodiments, the platform 1302 may be directly attached to (and / or integrally formed with) the housing 113 or any other part of the providing unit 110. The arm 1300 may extend (at least partially) in the vertical direction as shown in FIG. 13.

[0167] (For example, as described in any of the above embodiments) The test structure 200 may be disposed on the platform 1302 so as to face the beam generating unit 112. The test structure 200 may be attached to the platform 1302, which includes the case where the test structure 200 is integrally formed with the platform 1302 (for example, the test structure 200 is the surface of the platform 1302). Thus, generally speaking, the test structure 200 may be directly or indirectly attached to the providing unit 110 (i.e., via other components), which may include the case where the test structure is integrally formed with the providing unit 110 or its components. The attachment may be achieved by force lock, form fit, and / or agglomeration methods (as defined above).

[0168] The apparatus 100 is configured to perform an etching process and / or a deposition process on the test structure 200 using the particle beam 114. A process gas supply unit 170 as shown in FIG. 8 may be provided to supply a process gas PG (see FIG. 8) to the test structure 200 for etching the test structure 200 and depositing materials thereon. For this purpose, the particle beam 114 may interact with the process gas PG. The gas supply unit 170 may also supply a process gas to the sample 10 for etching the sample 10 and / or depositing materials on the sample 10 under the action of the particle beam 114.

[0169] All of the embodiments described above are applicable to the embodiment of FIG. 13, and vice versa. For example, the platform 1302 may form the vibration element 208 together with the test structure 200.

[0170] The test structure 200 disposed on the platform 1302 (right side of FIG. 13) is disposed inside the internal volume 111 surrounded by the housing 113. For example, the arm 1300 is connected inside the housing 113. The platform 1302' may extend horizontally above the opening 116.

[0171] On the other hand, in a further embodiment illustrated on the left side of FIG. 13, the test structure 200' is disposed outside the internal volume 111. For example, the arm 1300' is attached to the outer portion of the housing 113. The platform 1302' may extend horizontally under the opening 116.

[0172] More generally, as shown in FIG. 13, the test structure 200 may be disposed inside (when viewed along the beam A) or adjacent to the opening 16 for the particle beam to exit from the providing unit 110.

[0173] The reference sign DOF indicates the depth of field (DOF) of the providing unit 110 (in particular, the DOF of the electron microscope provided by the providing unit 110). The DOF is the distance between the nearest object and the farthest object that are acceptably sharply focused. As can be seen, the DOF can be designed to include the test structure 200. The DOF can be designed to include the sample 10 as well. Thus, both (the sample 10 and the test structure 200) can be imaged in sharp focus. The DOF can be, for example, up to 100 micrometers, up to 10 micrometers, or up to 1 micrometer, and / or at least 1 micrometer, 10 micrometers, or 100 micrometers.

[0174] When the test structure 200 is etched or a material is deposited thereon, an image (or any other interaction) of the etched or deposited structure (not shown in FIG. 13) can be acquired using the particle beam 114. Based on the said image or other interaction, the determination unit 150 determines the current operating parameters or process parameters. For example, the determination unit 150 determines, for example, the telecentricity of the providing unit 110, particularly of an electron microscope.

[0175] As described above, the present invention has been explained with reference to the operation examples, but the present invention can be variously modified.

Explanation of reference numerals

[0176] 1 System 10 Sample 100 Apparatus 102 Sample stage 110 Providing unit 111 Internal volume 112 Beam generation unit 113 Housing 114 Particle beam 116 Opening 117 Convex cross-section 120 Holding element 130 Shielding element 132 Through-opening 140 Alignment unit 150 Determination unit 160 Exciter unit 162 Acquisition unit 163 Laser 164 Photodetector 170 Process gas supply unit 171 Process gas reservoir 172 Valve 173 Line 200 Test structure 202 Structure 203 Structure 204 Predetermined region 206 Predetermined region 208 Vibration element 400 device 1300 arm 1302 platform φ(f) Phase (vibration characteristic) A beam path A(f) Amplitude (vibration characteristic) B beam path DOF Depth of field E magnetic field line f Frequency f R Resonance frequency IMG Electron micrograph M1 material M2 material PA Process atmosphere PG Process gas Q Charge S10 Method step S11 Method step S12 Method step S13 Method step S14 Method step S20 Method step S21 Method step S22 Method step S23 Method step W Vibration

Claims

1. An apparatus (100, 400) for analyzing and / or processing a sample (10) using a particle beam (114), comprising: A providing unit (110) for providing the particle beam (114), the providing unit (110) having an aperture (116) for the particle beam (114) to pass through to the sample (10); A test structure (200) attached to the providing unit (110), the test structure (200) being disposed inside or adjacent to the aperture (116); The apparatus (100, 400) is configured to perform an etching process and / or a deposition process on the test structure (200) using the particle beam (114). Apparatus (100, 400).

2. The apparatus according to claim 1, further comprising a determining unit (150) for determining at least one current operating parameter and / or process parameter of the apparatus (100) according to the interaction between the particle beam (114) and the test structure (200) on which the etching process and / or deposition process is performed.

3. The apparatus according to claim 1 or 2, wherein the test structure (200) is disposed inside an internal volume (111) defined by the providing unit (110).

4. The apparatus according to claim 1 or 2, further comprising an electron microscope, wherein the test structure (200) is disposed within the depth of field of the electron microscope.

5. The apparatus according to claim 1 or 2, comprising the test structure (200) on which the etching process and / or deposition process has been performed.

6. The apparatus according to claim 1 or 2, further comprising a process gas supply unit (170) for supplying a process gas to the test structure (200) for performing the etching process and / or the deposition process on the test structure (200) using the particle beam (114).

7. Further comprising a shield element (130) for electrical and / or magnetic shielding, said shield element (130) having a through-opening (132) for the particle beam (114) to pass through to the sample (10), and said shield element (132), and / or a holding element (120) for holding said shield element (132), comprising said test structure (200), the apparatus according to claim 1 or 2.

8. The apparatus according to claim 1 or 2, further comprising an alignment unit (140) for aligning the particle beam (114) and the test structure (200) with each other such that the particle beam (114) is incident on the test structure (200).

9. The apparatus according to claim 2, wherein the at least one determined operating parameter includes telecentricity of the providing unit (110).

10. An exciter unit (160) for inducing the test structure (200) to vibrate mechanically (W); A detection unit (162) for detecting at least the vibration characteristics (A(f), φ(f)) of the test structure (200); The apparatus according to claim 1 or 2, further comprising a determination unit (150) for determining at least one current operating parameter and / or process parameter of the apparatus (100) according to the detected vibration characteristics (A(f), φ(f)).

11. The apparatus according to claim 10, wherein the test structure (200) is formed on a cantilever (208).

12. The apparatus according to claim 10, wherein the detection unit (162) is set to detect the vibration characteristics (A(f), φ(f)) using a laser (163).

13. The apparatus according to claim 10, further comprising a process gas supply unit (170) for supplying a process gas (PG) to the sample (10), and the determination unit (150) is set to determine at least one partial pressure and / or at least one gas concentration of the species present in the process gas (PG) according to the detected vibration characteristics (A(f), φ(f)).

14. A system (1) comprising the apparatus (100, 400) according to claim 1 or 2 and a sample (10).

15. The system according to claim 14, wherein the apparatus (100) is configured to perform an etching process and / or a deposition process on the sample (10) using the particle beam (114).

16. The system according to claim 14, wherein at least a part of the test structure (200) and at least a part of the sample (10) have the same material composition.

17. A method for providing a test structure (200) for analyzing and / or processing a sample (10) using a particle beam (114) within an apparatus (100, 400), the apparatus (100, 400) comprising: A providing unit (110) configured to provide the particle beam (114), the providing unit (110) having an opening (116) for the particle beam (114) to pass through to the sample (10); The test structure (200) attached to the providing unit (110), the test structure (200) being disposed inside or adjacent to the opening (116), the method comprising: Performing an etching process and / or a deposition process on the test structure (200) using the particle beam (114). Method.

18. A method for analyzing and / or processing a sample (10) using a particle beam (114) using the apparatus (100, 400), the method comprising: Executing the method according to claim 17; Detecting the interaction of the particle beam (114) with the test structure (200) (S13); Determining at least one current operating parameter and / or process parameter of the apparatus (100, 400) according to the detected interaction (S14). Method.

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