Method for operating a particle beam device, computer program product, and particle beam device for carrying out the method
Patent Information
- Application Number
- DE102024116866
- Authority / Receiving Office
- DE · DE
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2024-06-14
- Publication Date
- 2026-10-01
- Estimated Expiration
- 2044-06-14
AI Technical Summary
Existing particle beam devices struggle to maintain a large image field consistently across different operating modes and conditions, such as varying working distances and landing energies, leading to imaging errors and reduced spatial resolution.
A method and device that utilize a deflection system with multiple deflection units to adjust the particle beam's position along the optical axis based on defined working distances or landing energies, ensuring a consistent large image field by optimizing the beam's path and focal parameters.
Enables a consistently large image field across varying operating conditions, reducing imaging errors and enhancing spatial resolution by dynamically adjusting the beam's position and energy settings.
Smart Images

Figure 00000000_0000_ABST
Abstract
Description
[0001] The invention relates to a method for operating a particle beam device for imaging, analyzing, and / or processing an object. Furthermore, the invention relates to a computer program and a particle beam device for carrying out the method. For example, the particle beam device is configured as an electron beam device and / or as an ion beam device.
[0002] Electron beam instruments, in particular a scanning electron microscope (hereinafter also referred to as SEM) and / or a transmission electron microscope (hereinafter also referred to as TEM), are used to examine objects (hereinafter also referred to as samples) in order to obtain knowledge about their properties and behavior under certain conditions.
[0003] In a SEM, an electron beam (hereinafter also called a primary electron beam) is generated by a beam generator and focused onto the object under investigation by a beam guidance system. A deflection device, in the form of a scan unit, guides the primary electron beam across the surface of the object. The electrons of the primary electron beam interact with the object. As a result of this interaction, electrons are emitted from the object (so-called secondary electrons), and electrons from the primary electron beam are backscattered (so-called backscattered electrons). The secondary electrons and the backscattered electrons are detected and used to generate an image. This produces a picture of the object under investigation.Furthermore, the interaction generates interaction radiation, such as X-rays or cathodoluminescence light, which is detected by a detector to analyze the object and subsequently evaluated.
[0004] In a TEM, a primary electron beam is also generated by a beam generator and directed onto the object under investigation by a beam guidance system. The primary electron beam passes through the object. As the primary electron beam passes through the object, the electrons interact with the material. The electrons passing through the object are imaged onto a fluorescent screen or a detector (e.g., a camera) by a system consisting of a lens and a projector. This imaging can also be performed in the scan mode of the TEM. Such a TEM is generally referred to as a STEM.Additionally, it may be possible to detect electrons backscattered from the object under investigation and / or secondary electrons emitted by the object under investigation using a further detector in order to image the object under investigation.
[0005] It is known to combine the functions of a STEM and a SEM in a single particle beam instrument. This particle beam instrument thus enables the investigation of objects with a SEM function and / or a STEM function.
[0006] Furthermore, a particle beam device with an ion beam column is known. Ions are generated by means of an ion beam generator arranged in the ion beam column and used to process an object. For example, material is removed from the object or material is applied to the object, for example by introducing a gas. Additionally or alternatively, the ions are used for imaging.
[0007] Furthermore, it is known from the prior art to use combination devices for examining objects, in which both electrons and ions can be directed onto the object under investigation. For example, it is known to equip a SEM with an additional ion beam column. Ions are generated by means of an ion beam generator arranged in the ion beam column, which are used for the preparation of an object (for example, removing material from the object or applying material to the object) or for imaging. For this purpose, the ions are scanned across the object using a deflection device in the form of a scanning unit. The SEM serves here in particular to observe the preparation, but also for further examination of the prepared or unprepared object.
[0008] When generating an image of an object, a particle beam instrument can produce an image of the object with high spatial resolution. This is achieved primarily by using a very small diameter primary electron beam in the plane of the object. Furthermore, the spatial resolution can be improved the more the electrons of the primary electron beam are initially accelerated in the particle beam instrument and then decelerated to a desired energy (called landing energy) at the objective lens or in the area between the objective lens and the object. For example, the electrons of the primary electron beam are accelerated with an accelerating voltage of 2 kV to 30 kV and guided through an electron column of a particle beam instrument. Only in the area between the objective lens and the object are the electrons of the primary electron beam decelerated to the desired landing energy at which they strike the object.The landing energy of the electrons in the primary electron beam, for example, is in the range of 10 eV to 30 keV.
[0009] To scan a particle beam across an object, it is known to arrange a scanning device on a particle beam instrument. For example, the scanning device is designed as a deflection device. The deflection device has a first deflection unit and a second deflection unit, wherein the first deflection unit and the second deflection unit are arranged one behind the other along the optical axis of the particle beam instrument. By combining the deflections of the particle beam achievable by the first deflection unit and the second deflection unit, the position of a virtual tipping point of the particle beam can be shifted along the optical axis of the particle beam instrument, whereby the deflection appears virtually as if it were generated by a tilting about this tipping point.
[0010] It is known to operate a particle beam instrument in a so-called "fisheye mode" to generate a large image of an object (for example, a large semiconductor wafer). To achieve the "fisheye mode," the first and second deflection units produce deflections in the same direction. This results in a relatively large overview image of the object. In other words, the fisheye mode provides a very large field of view from the particle beam instrument.
[0011] Regarding the state of the art, reference is made to DE 10 2010 053 194 A1 and DE 10 2011 076 893 A1.
[0012] The invention is based on the objective of providing a method and a particle beam device for carrying out the method, with which a large image field of the particle beam device can always be achieved in different operating modes of the particle beam device.
[0013] According to the invention, this problem is solved by a method having the features of claim 1 or 12. A computer program product with program code that controls a particle beam device for carrying out the method is defined by the features of claim 18. Furthermore, a particle beam device for imaging, analyzing, and / or processing an object is defined by the features of claim 19. Further features of the invention will become apparent from the following description, the appended claims, and / or the accompanying drawings.
[0014] The method according to the invention serves to operate a particle beam device for imaging, analyzing, and / or processing an object. The particle beam device has at least one beam generator for generating a particle beam with charged particles. For example, the charged particles are electrons or ions. Furthermore, the particle beam device has an objective lens for focusing the particle beam onto the object.
[0015] In the method according to the invention, a distance is set using a control unit of the particle beam device. The distance is defined either (a) by an object distance between an outer boundary of the objective lens of the particle beam device and the object, or (b) by a focal plane distance between the outer boundary of the objective lens of the particle beam device and a focal plane of the objective lens. The aforementioned distance according to case (a) or case (b) is also referred to as the working distance. Possibilities for setting the distance are explained in more detail below.
[0016] The particle beam device has a deflection unit comprising at least one first deflection unit and at least one second deflection unit. Looking from the beam generator towards the objective lens, the first deflection unit and then the second deflection unit are arranged along the optical axis. For example, the first deflection unit and / or the second deflection unit are located within the objective lens of the particle beam device. In particular, it is provided that the first deflection unit and / or the second deflection unit are located within the objective lens along the optical axis of the particle beam device. The first deflection unit is, for example, designed as an electrostatic and / or magnetic deflection unit. Furthermore, it is provided, for example, that the second deflection unit is designed as an electrostatic and / or magnetic deflection unit.
[0017] In the method according to the invention, the particle beam generated by the beam generator of the particle beam device is deflected to a position along the optical axis of the particle beam device, depending on the defined distance (i.e., the defined working distance), using the deflection device. The position is thus related to the defined distance. In other words, the particle beam is guided to this position along the optical axis of the particle beam device by the deflection device, depending on the defined working distance. The aforementioned position of the particle beam along the optical axis of the particle beam device is, for example, the tipping point of the particle beam already explained above.At this position along the optical axis of the particle beam instrument, a central path of the particle beam has an axial distance perpendicular to the optical axis of the particle beam instrument. The central path is essentially the mean path of the particle beam. All paths of the particle beam revolve around this mean path. The sum of all the paths of the particle beam determines the diameter of the particle beam.At the specified distance (i.e., the specified working distance), the axial distance of the central path of the particle beam at this position along the optical axis is smaller than all other axial distances of the central path of the particle beam perpendicular to the optical axis, wherein, for the specified distance according to case (a), the other axial distances are arranged between a center of the second deflection unit of the deflection device and the object, and wherein, for the specified distance according to case (b), the other axial distances are arranged between the center of the second deflection unit of the deflection device and the focal plane.
[0018] The invention ensures that a sufficiently large image field of the particle beam device can always be achieved at different fixed distances (i.e., different fixed working distances). In other words, the aforementioned position of the particle beam along the optical axis (i.e., the tipping point of the particle beam) is selected as a function of the fixed distance (i.e., the fixed working distance) such that a desired image field of the particle beam device can be achieved. The method according to the invention can be carried out manually and / or automatically.
[0019] In one embodiment of the method according to the invention, it is additionally or alternatively provided that the distance (i.e., the working distance) is determined according to case (a) by a relative movement of the object with respect to the objective lens and / or by determining the object distance. Determining the object distance includes, for example, measuring the object distance and / or reading the object distance from a measuring device. In a further embodiment of the method according to the invention, it is additionally or alternatively provided that the distance is determined according to case (b) by controlling the objective lens to position a focal plane of the objective lens and / or by determining the focal plane distance. Determining the focal plane distance includes, for example, measuring the focal plane distance and / or reading the focal plane distance from the measuring device.
[0020] In a further embodiment of the method according to the invention, it is additionally or alternatively provided that the distance (i.e., the working distance) is determined by at least one of the following method steps: (i) moving an object holder on which the object is arranged along the optical axis of the particle beam device; (ii) moving the object holder on which the object is arranged relative to the optical axis of the particle beam device, wherein the movement is not perpendicular to the optical axis; (iii) moving the objective lens of the particle beam device along the optical axis of the particle beam device using a movement device; and (iv) moving the objective lens of the particle beam device relative to the optical axis using the movement device, wherein the movement is not perpendicular to the optical axis.
[0021] In a further embodiment of the method according to the invention, it is additionally or alternatively provided that the position of the particle beam along the optical axis corresponding to the defined distance (i.e., the defined working distance) is loaded into the control unit from a database and / or a storage unit. The deflection of the particle beam is then carried out using the deflection device such that the particle beam is guided to the loaded position. In other words, in this embodiment of the method according to the invention, the position of the tipping point is stored in a database and / or a storage unit as a function of the working distance. Once the working distance is defined, the corresponding position can be loaded from the database and / or the storage unit and set.
[0022] In a further embodiment of the method according to the invention, it is additionally or alternatively provided that the position of the particle beam along the optical axis corresponding to the defined distance (i.e., the defined working distance) is calculated using the control device. For example, the corresponding position can be calculated by means of a simulation of the particle beam's path under predefined and adjustable conditions. These conditions include, for example, values of control parameters for components of the particle beam device, with which the path of the particle beam within the device and / or the shape of the particle beam can be influenced. In the simulation, calculations using a linear approximation or a method also known as "ray tracing" can be used.For example, after calculating the position corresponding to the specified distance, the particle beam is deflected to this position along the optical axis of the particle beam device using the deflection device.
[0023] Additionally or alternatively, the object is imaged and an image of it is generated. The objective lens is excited with an objective lens current such that the image of the object fulfills a desired imaging criterion. Subsequently, the distance is determined using the objective lens current.
[0024] In a further embodiment of the method according to the invention, it is additionally or alternatively provided that when the defined distance (i.e., the defined working distance) is changed, the corresponding position of the particle beam along the optical axis also changes. Thus, in this embodiment of the method according to the invention, the defined distance is a first distance, the corresponding position of the particle beam along the optical axis is a first corresponding position, the object distance is a first object distance, the focal plane distance is a first focal plane distance, and the axial distance of the central path of the particle beam at the first corresponding position is a first axial distance. This embodiment of the method according to the invention comprises the following process steps: - Determining a second distance using the control device of the particle beam device, wherein the second distance is greater than the first distance, and wherein the second distance is either (c) a second object distance between the outer boundary of the objective lens of the particle beam device and the object or (d) a second focal plane distance between the outer boundary of the objective lens of the particle beam device and the focal plane of the objective lens; - Deflection of the particle beam to a second position along the optical axis of the particle beam device, corresponding to the second distance, as a function of the specified second distance, using the deflection device. At the second position along the optical axis, the central path of the particle beam has a second axial distance perpendicular to the optical axis of the particle beam device, wherein, for the specified second distance, the second axial distance of the central path of the particle beam at the second position along the optical axis is smaller than all other axial distances of the central path of the particle beam perpendicular to the optical axis of the particle beam device. For the specified second distance according to case (c), the other axial distances are arranged between the center of the second deflection unit of the deflection device and the object.For the specified second distance according to case (d), the further axial distances between the center of the second deflection unit of the deflection device and the focal plane are arranged. A distance of the second position to the outer edge of the objective lens is smaller than a distance of the first position to the outer edge of the objective lens.
[0025] In a further embodiment of the method according to the invention, it is additionally or alternatively provided that a landing energy, with which particles of the particle beam strike the object, is set and / or determined using the control device. For example, determining the landing energy includes measuring the landing energy and / or reading the landing energy from a landing energy measuring device. The deflection of the particle beam to the corresponding position along the optical axis of the particle beam device is additionally carried out as a function of the landing energy using the deflection device. For example, in the embodiment of the method according to the invention described here, the control device used is a control device that includes an acceleration device and / or a deceleration device for the particles of the particle beam.
[0026] In one embodiment of the method according to the invention, it is additionally or alternatively provided that the position corresponding to the defined distance is also dependent on the landing energy. In other words, the position corresponding to the defined distance depends on the landing energy. For example, it is provided that the position corresponding to the defined distance and dependent on the landing energy is loaded from the database and / or the storage unit into the control unit.
[0027] In a further embodiment of the method according to the invention, it is additionally or alternatively provided that, if a threshold landing energy is not reached, a position is used as the position of the particle beam along the optical axis corresponding to the specified distance, which is located closer to the outer boundary of the objective lens (i.e., has a smaller distance to the outer boundary of the objective lens) than the position of the particle beam along the optical axis (i) if the threshold landing energy is exceeded or (ii) if the landing energy corresponds to the threshold landing energy.
[0028] In a further embodiment of the method according to the invention, it is additionally or alternatively provided to reduce imaging errors in a generated image. For this purpose, in this embodiment of the method according to the invention, a raster device of the particle beam instrument is controlled to scan the particle beam across the object depending on the landing energy and / or the defined distance, such that errors in the representation of the object are reduced and / or eliminated. For example, the deflection device is configured as the raster device. In particular, it is provided that the first deflection unit and / or the second deflection unit form / form the raster device. The lower the landing energy at the same defined distance, the more nonlinearly the raster device is excited.The excitation of the first deflection unit and the second deflection unit can be described by a set of functions that run over an index i and depend on the desired position x and y of the particle beam on the object:. fi(x,y)=ai⋅x+bi⋅y+ci⋅x3+di⋅x2⋅y+ei⋅x⋅y2+fi⋅y3
[0029] In the functions shown above, f i Only linear and cubic terms are considered. However, constant terms (to shift the rasterized image field) and / or quadratic terms (to compensate for deviations from the symmetry of the components) can also be added.
[0030] The functions run over the indices 1x, 1y, 2x and 2y, which correspond to the x and y excitation of the first and second deflection units.
[0031] Ideally, the linear components are designed as follows, without component tolerances and with perfect adjustment: a1x=U⋅cosφ b1x=−U⋅sinφ a1y=U⋅sinφ b1y=U⋅cosφ a2x=V⋅cos(φ+τ) b2x=−V⋅sin(φ+τ) a2y=V⋅sin(φ+τ) b2y=V⋅cos(φ+τ)
[0032] The ratio of U to V determines the position along the optical axis. Scaling U and V changes the size of the image field. The orientation of the image field can be rotated using φ. Several parameters are taken into account with τ: (i) the installation position of the second deflection unit relative to the first deflection unit, (ii) the influence of the Larmor rotation of the axial magnetic field of the objective lens in the region between the two deflection units, and (iii) the axial distance of the central path of the particle beam at the position along the optical axis.
[0033] Between the 16 cubic coefficients c i up to f iWith i being equal to 1x, 1y, 2x, and 2y, there are relationships that depend on whether the origin of the nonlinear deflection (distortion) of the particle beam, which one wishes to compensate for, lies in the objective lens or in multipoles of the scanning array. With ideal alignment and ideal components of the particle beam instrument, the following applies to the first deflection unit d without raster rotation (φ = 0). 1x = f 1x = c 1y = e 1y = 0. However, this does not apply to the second deflection unit due to the necessary τ. For a purely electrostatic objective lens and aligned deflection units, τ is 0, and d also applies here. 2x = f 2x = c 2y = e 2y = 0.
[0034] The greater the defined distance at the same landing energy, the greater the non-linear component in the excitation of the grid system becomes, if a linear component in the excitation of the grid system remains constant.
[0035] The invention also relates to a further method. This further method according to the invention serves to operate a particle beam device for imaging, analyzing, and / or processing an object. The particle beam device has at least one beam generator for generating a particle beam with charged particles. For example, the charged particles are electrons or ions. Furthermore, the particle beam device has an objective lens for focusing the particle beam onto the object.
[0036] In a further method according to the invention, a landing energy is set, at which particles of a particle beam generated by the beam generator of a particle beam device strike the object, using a control device and / or the landing energy is determined by the control device. Determining the landing energy includes, for example, measuring the landing energy and / or reading the landing energy from a measuring device.
[0037] The particle beam device for carrying out the further method according to the invention comprises a deflection unit provided with at least one first deflection unit and at least one second deflection unit. Viewed from the beam generator towards the objective lens, the first deflection unit and then the second deflection unit are arranged along the optical axis. For example, the first deflection unit and / or the second deflection unit are arranged within the objective lens of the particle beam device. In particular, it is provided that the first deflection unit and / or the second deflection unit are arranged within the objective lens along the optical axis of the particle beam device. The first deflection unit is, for example, designed as an electrostatic and / or magnetic deflection unit. Furthermore, it is, for example, provided that the second deflection unit is designed as an electrostatic and / or magnetic deflection unit.
[0038] In the further method according to the invention, the particle beam generated by the beam generator of the particle beam device is deflected to a position along the optical axis of the particle beam device corresponding to the set and / or determined landing energy (i.e., depending on the set and / or determined landing energy) using the deflection device. In other words, the particle beam is guided to this position along the optical axis of the particle beam device by the deflection device, depending on the set and / or determined landing energy. The aforementioned corresponding position of the particle beam along the optical axis of the particle beam device is, for example, the tipping point of the particle beam already explained above.At this position along the optical axis of the particle beam instrument, a central path of the particle beam has an axial distance perpendicular to the optical axis of the particle beam instrument. Regarding the definition of the central path, reference is made to the explanations above, which also apply here. At the set and / or determined landing energy, the axial distance of the central path of the particle beam at this position along the optical axis is smaller than all other axial distances of the central path of the particle beam perpendicular to the optical axis. Furthermore, at the set and / or determined landing energy, the other axial distances are, in case (a), either located between the center of the second deflection unit of the deflection device and the object, or, in case (b), located between the center of the second deflection unit of the deflection device and the focal plane.
[0039] The further method according to the invention ensures that a sufficiently large image field of the particle beam device can always be achieved at different landing energies. In other words, the aforementioned position of the particle beam along the optical axis (i.e., the tipping point of the particle beam) is selected as a function of the set and / or determined landing energy such that a desired image field of the particle beam device can be achieved. The further method according to the invention can be carried out manually and / or automatically.
[0040] In one embodiment of the further method according to the invention, it is additionally or alternatively provided that the control device used is a control device that includes an acceleration device and / or a deceleration device for the particles of the particle beam. The landing energy of the particles of the particle beam device can be adjusted by means of the acceleration device and / or the deceleration device.
[0041] In a further embodiment of the method according to the invention, it is additionally or alternatively provided that the position of the particle beam along the optical axis corresponding to the set and / or determined landing energy is loaded into the control unit from a database and / or a storage unit. The deflection of the particle beam is carried out using the deflection device such that the particle beam is guided to the loaded position. In other words, the position of the tipping point, depending on the set and / or determined landing energy, is stored in a database and / or on a storage unit. Once the landing energy has been set and / or the landing energy of the particles in the particle beam has been determined, the corresponding position can be loaded from the database and / or the storage unit.The particle beam is deflected using the deflection device in such a way that the particle beam is guided to the charged position.
[0042] In a further embodiment of the further method according to the invention, it is additionally or alternatively provided that, if a threshold landing energy is undershot, a position is used as the position of the particle beam along the optical axis corresponding to the set and / or determined landing energy, which is located closer to the outer boundary of the objective lens (i.e., has a smaller distance to the outer boundary of the objective lens) than the position of the particle beam along the optical axis (i) if the threshold landing energy is exceeded or (ii) if the landing energy corresponds to the threshold landing energy.
[0043] In one embodiment of the further method according to the invention, it is additionally or alternatively provided to reduce imaging errors in a generated image. For this purpose, in this embodiment of the further method according to the invention, a raster device of the particle beam instrument is controlled to scan the particle beam across the object depending on the landing energy, such that errors in the representation of the object are reduced and / or eliminated. For example, the deflection device is configured as the raster device. In particular, it is provided that the first deflection unit and / or the second deflection unit form the raster device. The lower the landing energy at a constant working distance, the more nonlinearly the particle beam is deflected by the raster device.The greater the working distance with the same set and / or determined landing energy, the greater the non-linear component in the excitation of the grid device becomes, if a linear component in the excitation of the grid device remains constant.
[0044] As explained above, in a further embodiment of the methods according to the invention, it is additionally or alternatively provided that an electrostatic and / or magnetic deflection device is used as the deflection device.
[0045] All the preceding and following embodiments of the methods according to the invention are not limited to the explained sequence of process steps. The invention also includes different sequences of process steps that are suitable for solving the problem in accordance with the invention. Alternatively or additionally, the parallel execution of at least two process steps is also provided for in the methods according to the invention. Furthermore, the preceding and following embodiments of the methods according to the invention are not limited to the complete scope of all process steps mentioned above or below. In particular, it is provided that in further embodiments, one or more of the preceding or following process steps are omitted.
[0046] The invention also relates to a computer program product comprising program code that is loadable or loaded into a processor of a particle beam device, wherein, when executed in the processor, the program code controls the particle beam device such that a method with at least one of the preceding or following features, or with a combination of at least two of the preceding or following features, is carried out. In other words, the invention also relates to a non-volatile, computer-readable medium comprising software that is loadable or loaded into a processor of a particle beam device, wherein, when executed in the processor, the software controls the particle beam device such that a method with at least one of the preceding or following features, or with a combination of at least two of the preceding or following features, is carried out.The software includes executable code for performing at least one process step.
[0047] In this respect, the invention also relates to a processor that is arranged on a particle beam device and is designed to carry out a method with at least one of the preceding or following features or with a combination of at least two of the preceding or following features.
[0048] The invention further relates to a particle beam device for imaging, analyzing, and / or processing an object, the particle beam device having already been explained above and further specified below. This is summarized briefly below. The particle beam device according to the invention comprises at least one beam generator for producing a particle beam with charged particles. The charged particles are, for example, electrons or ions. Furthermore, the particle beam device according to the invention comprises at least one objective lens for focusing the particle beam onto the object. The object is designed to be movable relative to the objective lens. The particle beam device according to the invention also comprises at least one deflection device, which is provided with at least one first deflection unit and at least one second deflection unit.Viewed from the beam generator towards the objective lens, the first deflection unit and then the second deflection unit are arranged along the optical axis. For example, the first deflection unit and / or the second deflection unit are arranged within the objective lens of the particle beam device. In particular, it is provided that the first deflection unit and / or the second deflection unit are arranged within the objective lens along the optical axis of the particle beam device. The first deflection unit is, for example, designed as an electrostatic and / or magnetic deflection unit. Furthermore, it is provided, for example, that the second deflection unit is designed as an electrostatic and / or magnetic deflection unit.Furthermore, the particle beam device according to the invention comprises at least one detector for detecting interaction particles and / or interaction radiation that result from an interaction of the particle beam with the object upon impact of the particle beam. In addition, the method according to the invention comprises at least one control unit equipped with at least one processor. A computer program product with the features already mentioned above is loaded into the processor.
[0049] In one embodiment of the particle beam device according to the invention, it is additionally or alternatively provided that the particle beam device has at least one acceleration device for accelerating the particles and / or a deceleration device for decelerating the particles in the particle beam device.
[0050] In a further embodiment of the particle beam device according to the invention, it is additionally or alternatively provided that the particle beam device has a movable object holder on which the object can be arranged. For example, the object holder is a movable object table (a so-called stage). Additionally or alternatively, it is provided that the particle beam device according to the invention has a movement device for moving the objective lens.
[0051] In a further embodiment of the particle beam device according to the invention, the first deflection unit is additionally or alternatively arranged in the objective lens. The second deflection unit is also additionally or alternatively arranged in the objective lens.
[0052] In a further embodiment of the particle beam device according to the invention, it is additionally or alternatively provided that the beam generator is configured as a first beam generator and the particle beam as a first particle beam with first charged particles. The objective lens is configured as a first objective lens for focusing the first particle beam onto the object. Furthermore, the particle beam device according to the invention has at least one second beam generator for generating a second particle beam with second charged particles. In addition, the particle beam device according to the invention has at least one second objective lens for focusing the second particle beam onto the object.
[0053] In particular, it is intended that the particle beam device according to the invention be designed as an electron beam device and / or as an ion beam device.
[0054] Further practical embodiments and advantages of the invention are described below in connection with the drawings. They show: Fig. 1 a schematic representation of a first embodiment of a particle beam device according to the invention; Fig. 2 a schematic representation of a second embodiment of a particle beam device according to the invention; Fig. 3 a schematic representation of a third embodiment of a particle beam device according to the invention; Fig. 4 a schematic representation of an embodiment of a movable object table; Fig. 5 a further schematic representation of the embodiment of the movable object table according to Fig. 4; Fig. 6 a schematic representation of a process of a first embodiment of the method according to the invention; Fig. 7 a schematic representation of a process of a second embodiment of the method according to the invention; Fig. 8 a schematic representation of a process of a third embodiment of the method according to the invention; Fig. 9 a schematic representation of a process of a fourth embodiment of the method according to the invention; Fig. 10 a schematic representation of a process of a fifth embodiment of the method according to the invention; Fig. 11 a schematic representation of a sequence of a sixth embodiment of the method according to the invention; and Fig. 12 a schematic representation of a process of a seventh embodiment of the method according to the invention.
[0055] The invention will now be explained in more detail using particle beam devices in the form of a SEM and in the form of a combination device comprising an electron beam column and an ion beam column. It is expressly pointed out that the invention can be used with any particle beam device, in particular with any electron beam device and / or any ion beam device.
[0056] Fig. Figure 1 shows a schematic representation of an embodiment of a particle beam device according to the invention in the form of a SEM 100. The SEM 100 comprises a beam generator 1 with an electron source, an extraction electrode 2, a control electrode 3, and an anode 4. The anode 4 forms a source-side end of a beam guide tube 21 of the SEM 100. The beam generator 1 is, for example, configured as a thermal field emitter. Alternatively, the beam generator 1 is, for example, configured as a thermal tungsten emitter or as a LAB6 emitter.
[0057] Electrons emitted from the source 1 form a primary electron beam. Due to a potential difference between the source 1 and the anode 4, the electrons are accelerated to anode potential. The potential of the anode 4 is, for example, 1 kV to 30 kV positive relative to the potential of the source 1, so that the electrons have a kinetic energy in the range between 1 keV and 30 keV.
[0058] The SEM 100, starting from the anode 4 and looking towards an objective lens 10 along an optical axis 20, first has a first condenser lens 5 and then a second condenser lens 6. An aperture unit 7 is arranged in the beam guide tube 21 between the first condenser lens 5 and the second condenser lens 6. The objective lens 10 is located in the Fig. The SEM 100 shown in Figure 1 is designed as a magnetic lens and has a pole shoe 22 with a pole shoe gap 23. A ring coil 11 for generating the magnetic field of the objective lens 10 is arranged in the pole shoe 22.
[0059] Starting from the second condenser lens 6 and extending towards the objective lens 10, a deflection device comprising a first deflection unit 9 and a second deflection unit 12 is arranged along the optical axis 20 of the SEM 100. The first deflection unit 9 is located on the source side at the objective lens 10. The second deflection unit 12, on the object side, is located inside the objective lens 10 at the beam guide tube 21. The first deflection unit 9 and the second deflection unit 12 are crossed beam deflection units. In other words, both the first deflection unit 9 and the second deflection unit 12 are configured to deflect the primary electron beam in two non-parallel directions perpendicular to the direction of the optical axis 20. For example, the first deflection unit 9 and / or the second deflection unit 12 may be designed as magnetic deflection units.In particular, the first deflection unit 9 and / or the second deflection unit 12 each have, for example, four air coils arranged around the optical axis 20 of the SEM 100. However, the invention is not limited to the aforementioned number of air coils. Rather, any number of air coils suitable for the invention can be used. Additionally or alternatively, it is provided that the first deflection unit 9 and / or the second deflection unit 12 are designed as electrostatic deflection units. In particular, the first deflection unit 9 and / or the second deflection unit 12 each have, for example, four electrodes arranged around the optical axis 20 of the SEM 100, which can be subjected to different electrostatic potentials. However, the invention is not limited to the aforementioned number of electrodes. Rather, any number of electrodes suitable for the invention can be used.
[0060] The objective lens 10 is arranged on a sample chamber 13. In particular, the objective lens 10 projects through an opening in the sample chamber 13 into an interior space of the sample chamber 13. A movable stage 19 is arranged in the interior space of the sample chamber 13. An object 15 can be arranged on the stage 19.
[0061] The primary electron beam, generated by the beam generator 1 and shaped by the first condenser lens 5 and / or the second condenser lens 6, is focused into an object plane 16 by means of the objective lens 10. Suitable excitations of the first deflection unit 9 and the second deflection unit 12 ensure that the primary electron beam can be deflected in the object plane 16 perpendicular to the optical axis 20 of the SEM 100 such that the surface of the object 15, located in the object plane 16, can be scanned by different deflections of the primary electron beam. The electrons of the primary electron beam interact with the object 15. As a result of this interaction, electrons are emitted by the object 15 (so-called secondary electrons), and electrons from the primary electron beam are backscattered (so-called backscattered electrons).The secondary electrons and backscattered electrons are detected and used to generate images. This produces an image of the object under investigation 15. Furthermore, interaction radiation, such as X-rays or cathodoluminescence, is generated during the interaction and is detected and subsequently evaluated for the analysis of the object 15.
[0062] For the detection of the aforementioned interaction particles and / or interaction radiation, a first detector unit 14 is arranged, for example, in the sample chamber 13. Additionally or alternatively, a second detector unit 8 is arranged, for example, in the beam guide tube 21 for the detection of the aforementioned interaction particles in the area between the first deflection unit 9 and the second condenser lens 6.
[0063] At the in Fig. In the embodiment of the SEM 100 shown in Figure 1, a pressure-stage aperture holder 17 is provided, which can be arranged on the pole piece 22 of the objective lens 10 projecting into the sample chamber 13. The pressure-stage aperture holder 17 has a pressure-stage aperture with an aperture opening 18. Further pressure-stage apertures can, for example, be arranged inside the beam guide tube 21 of the SEM 100. These are shown in the Fig. 1 not shown. Also in the Fig. 1 Vacuum pumps, which are required to generate and maintain the vacuum required for the operation of the SEM 100 within the beam guide tube 21 and the sample chamber 13, are not shown.
[0064] If the SEM 100 is to be operated under high vacuum in the sample chamber 13, the pressure-stage diaphragm holder 17 is not strictly necessary and can therefore be removed from the polarizing shoe 22 of the objective lens 10. However, if the SEM 100 is to be operated at a relatively high pressure in the sample chamber 13 (pressures in the range of approximately 1 to 3000 Pa), the pressure-stage diaphragm holder 17 should be mounted on the polarizing shoe 22 of the objective lens 10 so that a sufficiently good vacuum can be maintained within the beamline 21 by differential pumping despite the higher pressure in the sample chamber 13. With the pressure-stage diaphragm holder 17 mounted, the edge of the aperture 18 within the pressure-stage diaphragm holder 17 results in a cropping of the image field that can be scanned in the object plane 16.
[0065] In particular, the first detector unit 14, the second detector unit 8, the first deflection unit 9, and the second deflection unit 12 are connected to a control unit 123, which has a monitor 124. The control unit 123 processes detection signals generated by the first detector unit 14 and the second detector unit 8 and displays them as images on the monitor 124. The control unit 123 also has a database 126 in which data is stored and from which data is read. Furthermore, the control unit 123 is connected to other units of the SEM 100. This is described in Fig. 1 not shown further.
[0066] The control unit 123 of the SEM 100 has a processor 127. A computer program product containing program code is loaded into the processor 127, which, when executed, performs a procedure for operating the SEM 100. This is explained in more detail below.
[0067] With the SEM 100, it is possible to set a distance A using the control unit 123 of the SEM 100. The distance A is defined either (a) by an object distance between an outer boundary of the objective lens 10 of the SEM 100 and the object 15, or (b) by a focal plane distance between the outer boundary of the objective lens 10 of the SEM 100 and a focal plane of the objective lens 10. The focal plane lies, for example, in the object plane 16. The aforementioned distance A according to case (a) or case (b) is also referred to as the working distance. For example, in case (a), the distance A is set by moving the stage 19 and / or moving the objective lens 10 with a movement device 25. In particular, in case (b), the distance A is set by varying the excitation of the objective lens 10 along the optical axis 20 of the SEM 100.
[0068] Fig. Figure 2 shows a schematic representation of another SEM 100. This additional SEM 100 has a first radiation source in the form of an electron source 101, which is configured as a cathode. Furthermore, this additional SEM 100 is provided with an extraction electrode 102 and an anode 103, which is mounted on one end of a beam guide tube 104 of the additional SEM 100. For example, the electron source 101 is configured as a thermal field emitter. However, the invention is not limited to such an electron source 101. Rather, any electron source suitable for the invention can be used.
[0069] Electrons emitted from electron source 101 form a primary electron beam. Due to a potential difference between electron source 101 and anode 103, the electrons are accelerated to anode potential. In the embodiment shown here, the anode potential is 100 V to 35 kV relative to the ground potential of a sample chamber housing 120, for example 5 kV to 15 kV, particularly 8 kV. Alternatively, it could also be at ground potential.
[0070] Two condenser lenses are arranged on the beam guide tube 104: a first condenser lens 105 and a second condenser lens 106. Looking from the electron source 101 towards a first objective lens 107, the first condenser lens 105 and then the second condenser lens 106 are arranged. It is explicitly noted that further embodiments of the SEM 100 may have only a single condenser lens. A first aperture unit 108 is arranged between the anode 103 and the first condenser lens 105. The first aperture unit 108, together with the anode 103 and the beam guide tube 104, is at a high-voltage potential, namely the potential of the anode 103 or at ground. The first aperture unit 108 has numerous first aperture openings 108A, one of which is located in Fig. Figure 2 shows, for example, two first aperture openings 108A are present. Each of the numerous first aperture openings 108A has a different opening diameter. By means of an adjustment mechanism (not shown), it is possible to set a desired first aperture opening 108A on an optical axis OA of the further SEM 100. It is explicitly noted that in further embodiments, the first aperture unit 108 may only be provided with a single first aperture opening 108A. In this embodiment, an adjustment mechanism cannot be provided. The first aperture unit 108 is then designed to be stationary. A stationary second aperture unit 109 is arranged between the first condenser lens 105 and the second condenser lens 106. Alternatively, it is provided that the second aperture unit 109 is designed to be movable.
[0071] The first objective lens 107 has pole shoes 110 in which a bore is formed. The beam guide tube 104 is guided through this bore. A coil 111 is arranged in the pole shoes 110.
[0072] An electrostatic delay device is arranged in a lower section of the beam guide tube 104. This device comprises a single electrode 112 and a tubular electrode 113. The tubular electrode 113 is located at one end of the beam guide tube 104, which faces an object 125 mounted on a movable object holder 114.
[0073] The tubular electrode 113, together with the beam guide tube 104, is at the potential of the anode 103, while the individual electrode 112 and the object 125 are at a lower potential than that of the anode 103. In this case, this is the ground potential of the housing of the sample chamber 120. In this way, the electrons of the primary electron beam can be slowed down to a desired energy, which is required for the examination of the object 125.
[0074] Object 125 and the single electrode 112 can also be at different potentials, including potentials different from ground. This makes it possible to adjust the location of the delay of the primary electron beam relative to object 125. For example, if the delay is performed quite close to object 125, imaging errors are reduced.
[0075] The SEM 100 further comprises a deflection device with a first deflection unit 130 and a second deflection unit 115. The first deflection unit 130 is arranged on the source side within the first objective lens 107. The second deflection unit 115, on the object side, is arranged within the first objective lens 107 on the beam guide tube 104. The first deflection unit 130 and the second deflection unit 115 are crossed beam deflection units. In other words, both the first deflection unit 130 and the second deflection unit 115 are configured to deflect the primary electron beam in two non-parallel directions, which are oriented perpendicular to the direction of the optical axis OA of the SEM 100. For example, the first deflection unit 130 and / or the second deflection unit 115 are designed as magnetic deflection units.In particular, the first deflection unit 130 and / or the second deflection unit 115 each have, for example, four air coils arranged around the optical axis OA of the further SEM 100. However, the invention is not limited to the aforementioned number of air coils. Rather, any number of air coils suitable for the invention can be used. Additionally or alternatively, it is provided that the first deflection unit 130 and / or the second deflection unit 115 are designed as electrostatic deflection units. In this case, the first deflection unit 130 and the second deflection unit 115 are arranged within the beam guide tube 104. In particular, the first deflection unit 130 and / or the second deflection unit 115 each have, for example, four electrodes arranged around the optical axis OA of the SEM 100, which can be subjected to different electrostatic potentials.The invention is not limited to the aforementioned number of electrodes. Rather, any number of electrodes suitable for the invention can be used. The primary electron beam is deflected by means of the first deflection unit 130 and the second deflection unit 115 and can be scanned (or rasterized) across the object 125. The electrons of the primary electron beam interact with the object 125. As a result of this interaction, interaction particles are generated, which are then detected. In particular, electrons are emitted from the surface of the object 125 – so-called secondary electrons – or electrons from the primary electron beam are backscattered – so-called backscattered electrons.
[0076] For the detection of secondary electrons and / or backscattered electrons, a detector array comprising a first detector 116 and a second detector 117 is arranged in the beamline 104. The first detector 116 is arranged along the optical axis OA on the source side, while the second detector 117 is arranged along the optical axis OA on the object side within the beamline 104. The first detector 116 and the second detector 117 are offset from each other in the direction of the optical axis OA of the SEM 100. Both the first detector 116 and the second detector 117 each have a through-hole through which the primary electron beam can pass. The first detector 116 and the second detector 117 are approximately at the potential of the anode 103 and the beamline 104, respectively. The optical axis OA of the SEM 100 passes through the respective through-holes.
[0077] The second detector 117 is primarily used for the detection of secondary electrons. Upon exiting the object 125, the secondary electrons initially possess low kinetic energy and move in any direction. The strong suction field emanating from the tubular electrode 113 accelerates the secondary electrons towards the first objective lens 107. The secondary electrons enter the first objective lens 107 in an approximately parallel direction. The beam diameter of the secondary electrons remains small even within the first objective lens 107. The first objective lens 107 exerts a strong effect on the secondary electrons, creating a comparatively short focus with sufficiently steep angles to the optical axis OA, such that the secondary electrons diverge considerably after passing through the focus and strike the second detector 117 on its active surface.Electrons backscattered from object 125—that is, backscattered electrons which, compared to the secondary electrons, have a relatively high kinetic energy upon exiting object 125—are detected by the second detector 117 only to a small extent. The high kinetic energy and the angles of the backscattered electrons to the optical axis OA upon exiting object 125 result in a beam waist, i.e., a beam region with a minimum diameter, of backscattered electrons located near the second detector 117. A large proportion of the backscattered electrons pass through the aperture of the second detector 117. The first detector 116 therefore serves primarily to detect the backscattered electrons.
[0078] In a further embodiment of the SEM 100, the first detector 116 can additionally be equipped with a retarding grid 116A. The retarding grid 116A is arranged on the side of the first detector 116 facing the object 125. The retarding grid 116A has a negative potential with respect to the potential of the beam guide tube 104, such that only backscattered electrons with high kinetic energy pass through the retarding grid 116A to the first detector 116. Additionally or alternatively, the second detector 117 has another retarding grid, which is configured analogously to the aforementioned retarding grid 116A of the first detector 116 and has an analogous function.
[0079] Furthermore, the additional SEM 100 in the sample chamber 120 has a chamber detector 119, for example an Everhart-Thornley detector or an ion detector, which has a metal-coated detection surface that shields light.
[0080] The detection signals generated by the first detector 116, the second detector 117 and the chamber detector 119 are used to generate an image or images of the surface of the object 125.
[0081] It is explicitly noted that the apertures of the first aperture unit 108 and the second aperture unit 109, as well as the through-holes of the first detector 116 and the second detector 117, are exaggerated. The through-holes of the first detector 116 and the second detector 117 have a perpendicular dimension OA ranging from 0.5 mm to 5 mm. For example, they are circular and have a diameter ranging from 1 mm to 3 mm perpendicular to the optical axis OA.
[0082] In the embodiment shown here, the second aperture unit 109 is designed as a pinhole aperture and is provided with a second aperture opening 118 for the passage of the primary electron beam, which has a diameter in the range of 5 µm to 500 µm, for example 35 µm. Alternatively, in a further embodiment, the second aperture unit 109 is provided with several aperture openings that can be mechanically moved relative to the primary electron beam or that can be reached by the primary electron beam using electrical and / or magnetic deflection elements. The second aperture unit 109 is designed as a pressure-stage aperture. This separates a first region in which the electron source 101 is arranged and in which an ultra-high vacuum prevails (10 -7 hPa up to 10 -12 hPa), from a second area which has a high vacuum (10 -3 hPa up to 10 -1hPa). The second area is the intermediate pressure area of the jet guide tube 104, which leads to the sample chamber 120.
[0083] Sample chamber 120 is under vacuum. A pump (not shown) is arranged on sample chamber 120 to generate the vacuum. During the Fig. In the embodiment shown in Figure 2, the sample chamber 120 is operated in a first pressure range or in a second pressure range. The first pressure range includes only pressures less than or equal to 10 -3 hPa, and the second pressure range only includes pressures greater than 10 -3 hPa. To ensure these pressure ranges, the sample chamber 120 is vacuum-sealed.
[0084] The object holder 114 is arranged on an object table 122. The object table 122 is designed to be movable in three mutually perpendicular directions, namely in an x-direction (first table axis), in a y-direction (second table axis), and in a z-direction (third table axis). Furthermore, the object table 122 can be rotated about two mutually perpendicular rotation axes (table rotation axes). The invention is not limited to the object table 122 described above. Rather, the object table 122 can have further translational and rotational axes along which or about which the object table 122 can move.
[0085] The SEM 100 further comprises a third detector 121, which is arranged in the sample chamber 120. More precisely, the third detector 121 is located behind the stage 122 along the optical axis OA, as seen from the electron source 101. The stage 122, and thus the specimen holder 114, can be rotated so that the object 125, which is mounted on the specimen holder 114, can be irradiated by the primary electron beam. As the primary electron beam passes through the object 125 under investigation, the electrons of the primary electron beam interact with the material of the object 125. The electrons passing through the object 125 are detected by the third detector 121.
[0086] A radiation detector 500 is arranged at the sample chamber 120. This detector detects interaction radiation, such as X-rays and / or cathodoluminescence, generated when the primary electron beam strikes the object 125. The radiation detector 500, the first detector 116, the second detector 117, and the chamber detector 119 are connected to a control unit 123, which includes a monitor 124. The third detector 121 is also connected to the control unit 123, but this is not shown for clarity. The control unit 123 processes detection signals generated by the first detector 116, the second detector 117, the chamber detector 119, the third detector 121, and / or the radiation detector 500 and displays them as images on the monitor 124.
[0087] The control unit 123 also includes a database 126 in which data is stored and from which data is read. Furthermore, the control unit 123 is connected to the deflection unit in the form of the first deflection unit 130 and the second deflection unit 115. In addition, the control unit 123 is connected to other units of the further SEM 100. This is not shown in detail for the sake of clarity.
[0088] The control unit 123 of the SEM 100 also includes a processor 127. A computer program product containing program code is loaded into the processor 127, which, when executed, performs a procedure for operating the SEM 100. This is explained in more detail below.
[0089] With the SEM 100, it is possible to set a distance A using the control unit 123 of the SEM 100. The distance A is defined either (a) by an object distance between an outer boundary of the first objective lens 107 of the SEM 100 and the object 125, or (b) by a focal plane distance between the outer boundary of the first objective lens 107 of the SEM 100 and a focal plane of the first objective lens 107. The aforementioned distance A according to case (a) or case (b) is also referred to as the working distance. For example, in case (a), the distance A is set by moving the stage 122 and / or moving the first objective lens 107 with a movement device 25. For example, in case (b), the distance A is set by varying the excitation of the first objective lens 107 along the optical axis OA of the SEM 100.
[0090] Fig. Figure 3 shows a particle beam device in the form of a combination device 200. The combination device 200 has two particle beam columns. One of the combination devices 200 is equipped with the additional SEM 100, as shown in the Fig. Figure 2 already shows the system, but without sample chamber 120. Instead, the additional SEM 100 is arranged on a sample chamber 201. Sample chamber 201 is under vacuum. A pump (not shown) is arranged on sample chamber 201 to generate the vacuum. In the Fig. In the embodiment shown in section 3, the sample chamber 201 is operated in a first pressure range or in a second pressure range. The first pressure range includes only pressures less than or equal to 10 -3 hPa, and the second pressure range only includes pressures greater than 10 -3 hPa. To ensure these pressure ranges, sample chamber 201 is vacuum-sealed.
[0091] The chamber detector 119 is arranged in the sample chamber 201. It is designed, for example, as an Everhart-Thornley detector or as an ion detector and has a metal-coated detection surface that shields light. Furthermore, the third detector 121 is arranged in the sample chamber 201.
[0092] The second SEM 100 serves to generate a first particle beam, namely the primary electron beam described above, and features the optical axis already mentioned above, which is located in the Fig. 3 is designated with the reference numeral 709 and is hereinafter also referred to as the first beam axis. Secondly, the combination device 200 is equipped with an ion beam device 300, which is also arranged on the sample chamber 201. The ion beam device 300 also has an optical axis, which is located in the Fig. 3 is designated with the reference numeral 710 and is subsequently also referred to as the second beam axis.
[0093] The other SEM 100 is arranged vertically with respect to sample chamber 201. In contrast, the ion beam device 300 is arranged at an angle of approximately 0° to 90° to the SEM 100. In the Fig. Figure 3 shows, for example, an arrangement of approximately 50°. The ion beam device 300 has a second beam generator in the form of an ion beam generator 301. Ions are generated by the ion beam generator 301, forming a second particle beam in the form of an ion beam. The ions are accelerated by means of an extraction electrode 302, which is at a predetermined potential. The second particle beam then passes through an ion optic of the ion beam device 300, the ion optic comprising a condenser lens 303 and a second objective lens 304. The second objective lens 304 ultimately generates an ion probe, which is focused onto the object 125 arranged on a specimen holder 114. The specimen holder 114 is arranged on a specimen stage 122.
[0094] Above the second objective lens 304 (i.e., in the direction of the ion beam generator 301), an adjustable or selectable aperture 306 and a deflection device are arranged. The deflection device comprises a first deflection unit 307 and a second deflection unit 308. The first deflection unit 307 is located on the source side within the second objective lens 304. The second deflection unit 308, on the object side, is located within the second objective lens 304. The first deflection unit 307 and the second deflection unit 308 are crossed beam deflection units. In other words, both the first deflection unit 307 and the second deflection unit 308 are designed to deflect the ion beam in two non-parallel directions, which are oriented perpendicular to the direction of the optical axis in the form of the second beam axis 710 of the ion beam device 300.For example, the first deflection unit 307 and / or the second deflection unit 308 are designed as magnetic deflection units. In particular, the first deflection unit 307 and / or the second deflection unit 308 each have, for example, four air coils arranged around the optical axis in the form of the second beam axis 710 of the ion beam device 300. However, the invention is not limited to the aforementioned number of air coils. Rather, any number of air coils suitable for the invention can be used. Additionally or alternatively, it is provided that the first deflection unit 307 and / or the second deflection unit 308 are designed as electrostatic deflection units.In particular, the first deflection unit 307 and / or the second deflection unit 308 each have, for example, four electrodes arranged around the optical axis in the form of the second beam axis 710 of the ion beam device 300, which can be subjected to different electrostatic potentials. However, the invention is not limited to the aforementioned number of electrodes. Rather, any number of electrodes suitable for the invention can be used. By means of the first deflection unit 307 and the second deflection unit 308, the ion beam is deflected and can be scanned (or rasterized) over the object 125.
[0095] As explained above, the object holder 114 is arranged on the object table 122. Also in the Fig. In the embodiment shown in Figure 3, the object stage 122 is designed to be movable in three mutually perpendicular directions, namely in an x-direction (first table axis), in a y-direction (second table axis), and in a z-direction (third table axis). Furthermore, the object stage 122 can be rotated about two mutually perpendicular axes of rotation (table rotation axes).
[0096] The one in Fig. The distances shown between the individual units of the combination device 200 are exaggerated in order to better illustrate the individual units of the combination device 200.
[0097] A radiation detector 500 is arranged at the sample chamber 201, with which interaction radiation, for example X-rays and / or cathodoluminescence light, is detected. The radiation detector 500 is connected to a control unit 123, which has a monitor 124.
[0098] The control unit 123 processes detection signals received from the first detector 116 (in Fig. 3 not shown), the second detector 117 (in Fig. 3 not shown), the chamber detector 119, the third detector 121 and / or the radiation detector 500 are generated and displays these in the form of images on the monitor 124.
[0099] The control unit 123 also has a database 126 in which data is stored and from which data is read. Furthermore, the control unit 123 is connected to the deflection device in the form of the first deflection unit 130 (in Fig. 3 not shown) and the second deflection unit 115 (in Fig. 3 not shown) for the primary electron beam of the further SEM 100 as well as with the deflection device in the form of the first deflection unit 307 and the second deflection unit 308 for the ion beam of the ion beam device 300.
[0100] The control unit 123 of the combination device 200 has a processor 127. A computer program product containing program code is loaded into the processor 127, which, when executed, performs a procedure for operating the combination device 200. This is explained in more detail below.
[0101] The combination device 200 also allows for the setting of working distances. For example, with the additional SEM 100, a distance A1 can be set using the control unit 123. The distance A1 is defined either (a) by an object distance between an outer boundary of the first objective lens 107 of the additional SEM 100 and the object 125, or (b) by a focal plane distance between the outer boundary of the first objective lens 107 of the additional SEM 100 and a focal plane of the first objective lens 107. The aforementioned distance A1 according to case (a) or case (b) is also referred to as the working distance. For example, in case (a), the distance A1 is set by moving the stage 122 and / or moving the first objective lens 107 with the movement device 25. For example, in case (b), the distance A1 is set by varying the excitation of the first objective lens 107 along the first beam axis 709 of the additional SEM 100.Furthermore, it is possible to set a distance A2 using the control device 123. The distance A2 is defined either (a) by an object distance between an outer boundary of the second objective lens 304 of the ion beam device 300 and the object 125, or (b) by a focal plane distance between the outer boundary of the second objective lens 304 of the ion beam device 300 and a focal plane of the second objective lens 304. The aforementioned distance A2 according to case (a) or case (b) is also referred to as the working distance. For example, in case (a), the distance A2 is set by moving the stage 122 and / or moving the second objective lens 304 with a movement device 25. For example, in case (b), the distance A2 is set by varying the excitation of the second objective lens 304 along the second beam axis 710 of the ion beam device 300.
[0102] The following section will now refer to object table 122 of the further SEM 100 according to the Fig. 2 and the combination device 200 according to the Fig. 3 discussed in more detail. The object stage 122 is designed as a movable object stage, which is located in the Fig. 4 and Fig. 5 is shown schematically. Regarding the object table 19 of the SEM 100 according to the Fig. The same applies to 1.
[0103] It should be noted that the invention is not limited to the object stage 122 described herein. Rather, the invention can include any movable object stage suitable for the invention.
[0104] The object holder 114 is arranged on the object stage 122. The object stage 122 has movement elements which ensure that the object stage 122 moves in such a way that an area of interest on the object 125 can be examined, for example, using a particle beam. The movement elements are located in the Fig. 4 and Fig. 5 are shown schematically and are explained below.
[0105] The specimen stage 122 has a first movement element 600, which is arranged, for example, on a housing 601 of the sample chamber 120 or 201, in which the specimen stage 122 is in turn arranged. The first movement element 600 enables movement of the specimen stage 122 along the z-axis (third table axis). Furthermore, a second movement element 602 is provided. The second movement element 602 enables rotation of the specimen stage 122 about a first table rotation axis 603, which is also referred to as the tilt axis. This second movement element 602 serves to tilt the object 125 about the first table rotation axis 603, with the object 125 being arranged on the specimen holder 114.
[0106] A third movement element 604 is arranged on the second movement element 602. This third movement element serves as a guide for a slide and ensures that the object stage 122 is movable in the x-direction (first table axis). The aforementioned slide is itself a further movement element, namely a fourth movement element 605. The fourth movement element 605 is designed such that the object stage 122 is movable in the y-direction (second table axis). For this purpose, the fourth movement element 605 has a guide in which another slide is guided, on which the object holder 114 is arranged. The object holder 114 is in turn equipped with a fifth movement element 606, which enables the object holder 114 to be rotated about a second table rotation axis 607. The second table rotation axis 607 is oriented perpendicular to the first table rotation axis 603.
[0107] Due to the arrangement described above, the object table 122 of the embodiment discussed here has the following kinematic chain: first movement element 600 (movement along the z-axis) - second movement element 602 (rotation about the first table rotation axis 603) - third movement element 604 (movement along the x-axis) - fourth movement element 605 (movement along the y-axis) - fifth movement element 606 (rotation about the second table rotation axis 607).
[0108] In a further embodiment (not shown), it is provided that further movement elements are arranged on the object table 122, so that movements along further translational axes and / or around further rotational axes are made possible.
[0109] As from the Fig. As can be seen in Figure 5, each of the aforementioned motion elements is connected to a drive unit in the form of a motor M1 to M5. The first motion element 600 is connected to a first drive unit M1 and is driven by a drive force provided by the first drive unit M1. The second motion element 602 is connected to a second drive unit M2, which drives the second motion element 602. The third motion element 604 is in turn connected to a third drive unit M3. The third drive unit M3 provides a drive force to drive the third motion element 604. The fourth motion element 605 is connected to a fourth drive unit M4, with the fourth drive unit M4 driving the fourth motion element 605. Furthermore, the fifth motion element 606 is connected to a fifth drive unit M5.The fifth drive unit M5 provides a drive force which drives the fifth motion element 606.
[0110] The aforementioned drive units M1 to M5 can, for example, be designed as stepper motors and are controlled by a drive control unit 608 and are each supplied with a supply current by the drive control unit 608 (see Fig. 5) It is explicitly pointed out that the invention is not limited to movement by stepper motors. Rather, any drive units suitable for the invention can be used as drive units, for example, brushless motors or piezo actuators.
[0111] The following describes embodiments of the method according to the invention with regard to the SEM 100 in accordance with the Fig. 1 explained in more detail. Regarding the further SEM 100 according to the Fig. 2 and the combination device 200 according to the Fig. The same applies to section 3.
[0112] Fig. Figure 6 shows an embodiment of the method according to the invention, which is used with the SEM 100 according to the Fig. 1 is carried out. In the embodiment of the method according to the invention, as described in the Fig. In process step S1, a distance A is set using the control unit 123 of the SEM 100. The distance A is defined either (a) by an object distance between the outer edge of the objective lens 10 of the SEM 100 and the object 15, or (b) by a focal plane distance between the outer edge of the objective lens 10 of the SEM 100 and a focal plane of the objective lens 10. The aforementioned distance according to case (a) or case (b) is also referred to as the working distance. For example, it is provided that the setting of the distance A (i.e., the setting of the working distance) according to case (a) is carried out by a relative movement of the object 15 with respect to the objective lens 10 (for example, by a movement of the object 15 and / or by a movement of the objective lens 10) and / or by determining the object distance.Determining the object distance includes, for example, measuring the object distance and / or reading the object distance from a measuring device. In a further embodiment of the method according to the invention, it is additionally or alternatively provided that the determination of the distance A according to case (b) is carried out by controlling the objective lens 10 to position a focal plane of the objective lens 10 and / or by determining the focal plane distance. Determining the focal plane distance includes, for example, measuring the focal plane distance and / or reading the focal plane distance from the measuring device.In a further embodiment of the method according to the invention, it is additionally or alternatively provided that the distance A (i.e., the working distance) is determined by at least one of the following method steps: (i) moving the object stage 19, on which the object 15 is arranged, along the optical axis 20 of the SEM 100; (ii) moving the object stage 19, on which the object 15 is arranged, relative to the optical axis 20 of the SEM 100, wherein the movement is not perpendicular to the optical axis 20; (iii) moving the objective lens 10 of the SEM 100 along the optical axis 20 of the SEM 100 using the movement device 25; and (iv) moving the objective lens 10 of the SEM 100 relative to the optical axis 20 using the movement device 25, wherein the movement is not perpendicular to the optical axis 20.
[0113] In process step S2, in the embodiment of the inventive process according to the Fig. Section 6 provides that the particle beam, in the form of the primary electron beam, is deflected by the deflection device, consisting of the first deflection unit 9 and the second deflection unit 12, to a position along the optical axis 20 of the SEM 100, depending on the specified distance A (i.e., the specified working distance). Therefore, the aforementioned position corresponds to the specified distance A. In other words, the primary electron beam is guided to this position along the optical axis 20 of the SEM 100 by the first deflection unit 9 and the second deflection unit 12, depending on the specified working distance A. The aforementioned position of the primary electron beam along the optical axis 20 of the SEM 100 is, for example, the tipping point of the primary electron beam already explained above.At this position along the optical axis 20 of the SEM 100, a central path of the primary electron beam has an axial distance perpendicular to the optical axis 20 of the SEM 100. Regarding the definition of the central path, reference is made to the explanations above, which also apply here. At the specified distance A (i.e., the specified working distance), the axial distance of the central path of the primary electron beam at this position along the optical axis 20 is smaller than all other axial distances of the central path of the primary electron beam perpendicular to the optical axis 20, wherein, for the specified distance A according to case (a), the other axial distances are arranged between a center of the second deflection unit 12 and the object 15, and wherein, for the specified distance A according to case (b), the other axial distances are arranged between the center of the second deflection unit 12 and the focal plane of the objective lens 10.
[0114] Fig. Figure 7 shows a further embodiment of the method according to the invention. The embodiment of the method according to the invention is shown in Figure 7. Fig. 7 is based on the embodiment of the method according to the invention. Fig. 6. Reference is therefore made to the above statements, which also apply here. In contrast to the embodiment of the method according to the invention as described above... Fig. Figure 6 shows the embodiment of the method according to the Fig. 7. A further process step, namely process step S1A, is introduced between process step S1 and process step S2. In process step S1A, the position of the primary electron beam along the optical axis 20 corresponding to the defined distance A (i.e., the defined working distance) is loaded into the control unit 123 from the database 126 of the SEM 100 and / or from another storage unit. In process step S2, the primary electron beam is then deflected using the deflection device in the form of the first deflection unit 9 and the second deflection unit 12 such that the primary electron beam is guided to the loaded position. In other words, in this embodiment of the method according to the invention, the position of the tipping point is stored in the database 126 and / or in the storage unit as a function of the working distance A.Once the working distance A is determined, the corresponding position can be loaded from database 126 and / or the storage unit. The primary electron beam is guided to this position by the deflection device consisting of the first deflection unit 9 and the second deflection unit 12.
[0115] Fig. Figure 8 shows a further embodiment of the method according to the invention. The embodiment of the method according to the invention is shown in Figure 8. Fig. 8 is based on the embodiment of the method according to the invention. Fig. 6. Reference is therefore made to the above statements, which also apply here. In contrast to the embodiment of the method according to the invention as described above... Fig. Figure 6 shows the embodiment of the method according to the Fig. 8 introduces a further process step between process step S1 and process step S2, namely process step S1B. In process step S1B, the position of the primary electron beam corresponding to the defined distance A (i.e., the defined working distance) along the optical axis 20 of the SEM 100 is calculated using the control unit 123. Regarding the calculation, reference is made to the explanations above, which also apply here. In process step S2, the primary electron beam is then deflected using the deflection device in the form of the first deflection unit 9 and the second deflection unit 12 such that the primary electron beam is guided to the calculated position. Additionally or alternatively, the position corresponding to distance A is stored in the database 126 and / or the storage unit.
[0116] Fig. Figure 9 shows a further embodiment of the method according to the invention. The embodiment of the method according to the invention is shown in Figure 9. Fig. 9 is based on the embodiment of the method according to the invention. Fig. 6. Reference is therefore made to the above statements, which also apply here. In contrast to the embodiment of the method according to the invention as described above... Fig. 6. Process steps S1 and S2 are performed multiple times in succession. For example, process step S1 is performed first, then process step S2, then process step S1 again, and then process step S2 again. Thus, the distance A is set multiple times, and the primary electron beam is deflected multiple times to the position corresponding to the set distance A. In this embodiment of the method according to the invention, it is additionally or alternatively provided that when the set distance A (i.e., the set working distance A) is changed, the corresponding position of the primary electron beam along the optical axis 20 of the SEM 100 also changes.In this embodiment of the method according to the invention, the defined distance A is a first distance, the associated position of the primary electron beam along the optical axis 20 is a first associated position, the object distance is a first object distance, the focal plane distance is a first focal plane distance, and the axial distance of the central path of the primary electron beam at the first associated position is a first axial distance. When the process step S1 is repeated, a second distance is defined using the control unit 123 of the SEM 100. However, the second distance A is greater than the first distance A. The second distance A is defined either (c) by a second object distance between the outer boundary of the objective lens 10 of the SEM 100 and the object 15, or (d) by a second focal plane distance between the outer boundary of the objective lens 10 of the SEM 100 and the focal plane of the objective lens 10.For example, it is provided that the determination of the second distance A (i.e., the determination of the second working distance A) according to case (a) is carried out by a relative movement of the object 15 with respect to the objective lens 10 and / or by determining the object distance. Determining the object distance includes, for example, measuring the object distance and / or reading the object distance from a measuring device. In a further embodiment of the method according to the invention, it is additionally or alternatively provided that the determination of the second distance A according to case (b) is carried out by controlling the objective lens 10 to position a focal plane of the objective lens 10 and / or by determining the focal plane distance. Determining the focal plane distance includes, for example, measuring the focal plane distance and / or reading the focal plane distance from the measuring device.In a further embodiment of the method according to the invention, it is additionally or alternatively provided that the second distance A is determined by at least one of the following process steps: (i) moving the object stage 19, on which the object 15 is arranged, along the optical axis 20 of the SEM 100; (ii) moving the object stage 19, on which the object 15 is arranged, relative to the optical axis 20 of the SEM 100, wherein the movement is not perpendicular to the optical axis 20; (iii) moving the objective lens 10 of the SEM 100 along the optical axis 20 of the SEM 100 using the movement device 25; and (iv) moving the objective lens 10 of the SEM 100 relative to the optical axis 20 using the movement device 25, wherein the movement is not perpendicular to the optical axis 20. In the repeated process step S2, in the embodiment of the method according to the invention, it is... Fig. It is provided that the primary electron beam is deflected by the deflection device, consisting of the first deflection unit 9 and the second deflection unit 12, to a second position along the optical axis 20 of the SEM 100, depending on the defined second distance A (i.e., the defined second working distance A). Thus, the aforementioned second position corresponds to the defined second distance A. In other words, the primary electron beam is guided to this second position along the optical axis 20 of the SEM 100 by the first deflection unit 9 and the second deflection unit 12, depending on the defined second working distance A. The aforementioned second position of the primary electron beam along the optical axis 20 of the SEM 100 is, for example, the tipping point of the primary electron beam already explained above.At this second position along the optical axis 20 of the SEM 100, the central path of the primary electron beam has an axial distance perpendicular to the optical axis 20 of the SEM 100. At the defined second distance A (i.e., the defined second working distance), the axial distance of the central path of the primary electron beam at this second position along the optical axis 20 is smaller than all other axial distances of the central path of the primary electron beam perpendicular to the optical axis 20, wherein, for the defined second distance A according to case (a), the other axial distances are arranged between a center of the second deflection unit 12 and the object 15, and wherein, for the defined second distance A according to case (b), the other axial distances are arranged between the center of the second deflection unit 12 and the focal plane.The distance of the second position to the outer edge of the objective lens 10 is smaller than the distance of the first position to the outer edge of the objective lens 10. In other words, as the working distance increases, the distance of the corresponding position of the primary electron beam to the outer edge of the objective lens 10 becomes smaller.
[0117] Fig. Figure 10 shows a further embodiment of the method according to the invention.
[0118] The embodiment of the method according to the invention Fig. 10 is based on the embodiment of the method according to the invention. Fig. 6. Reference is therefore made to the above statements, which also apply here. In contrast to the embodiment of the method according to the invention as described above... Fig. 6 In the embodiment of the method according to the invention Fig. 10 For example, after process step S1, a process step S1C is carried out. In process step S1C, a landing energy with which the electrons of the primary electron beam strike the object 15 is determined using the control device 123. In other words, the landing energy is set and / or determined. For example, determining the landing energy includes measuring the landing energy and / or reading the landing energy from a landing energy measuring device. In contrast to the embodiment of the method according to the invention, Fig. 6 In the embodiment of the method according to the invention Fig. Instead of process step S2, process step S2A is now performed. Process step S2A initially comprises process step S2, so reference is made to all explanations given above, which also apply here. In addition, in process step S2A, the primary electron beam is deflected by the deflection device in the form of the first deflection unit 9 and in the form of the second deflection unit 12, depending on the landing energy. Thus, the primary electron beam is deflected to a position that corresponds to both the specified distance A and the specified landing energy. In other words, the position of the primary electron beam along the optical axis 20 of the SEM 100 depends on both the specified distance A and the specified landing energy.For example, it is intended that the position corresponding to the specified distance A, which is also dependent on the landing energy, is loaded from database 126 and / or from the storage unit into the control unit 123. Reference is made to the explanations given above, which also apply here.
[0119] In a further embodiment of the method according to the invention, it is additionally or alternatively provided that, if a threshold landing energy is not reached, a position is used as the position of the primary electron beam along the optical axis 20 of the SEM 100 corresponding to the specified distance A, which is closer to the outer boundary of the objective lens 10 than a position of the primary electron beam along the optical axis 20 of the SEM 100 (i) if the threshold landing energy is exceeded or (ii) if the landing energy corresponds to the threshold landing energy.
[0120] To adjust the landing energy, the control device 123 may have an acceleration device and / or a deceleration device and / or be connected to the acceleration device and / or deceleration device.
[0121] In a further embodiment of the method according to the invention, it is additionally or alternatively provided to reduce imaging errors in a generated image. For this purpose, in this embodiment of the method according to the invention, the first deflection unit 9 and the second deflection unit 12 of the SEM 100 are controlled for scanning the primary electron beam across the object 15 as a function of the landing energy and / or the defined distance A, such that errors in the representation of the object 15 are reduced and / or eliminated. The lower the landing energy at the same defined distance, the more nonlinear the excitation of the first deflection unit 9 and the second deflection unit 12. The greater the defined distance A at the same landing energy, the greater the nonlinear components in the excitations of the first deflection unit 9 and the second deflection unit 12, provided the linear components in the respective excitations remain constant.Regarding nonlinear excitation, reference is made to the explanations above, which also apply here.
[0122] The embodiments of the method according to the invention described above ensure that a sufficiently large image field of the SEM 100 can always be achieved at different defined distances (i.e., different defined working distances). In other words, the aforementioned position of the primary electron beam along the optical axis 20 (i.e., the tilting point of the primary electron beam) is selected as a function of the defined distance (i.e., the defined working distance A) such that a desired image field of the SEM 100 can be achieved. The method according to the invention can be carried out manually and / or automatically.
[0123] Fig. Figure 11 shows a further embodiment of the method according to the invention, which is used with the SEM 100 according to the Fig. 1 is carried out. This embodiment of the method according to the invention comprises process step S20. In process step S20, a landing energy with which electrons of the primary electron beam strike the object 15 is determined using the control device 123. In other words, the landing energy is set and / or determined. For setting the landing energy, the control device 123 may have an acceleration device and / or a deceleration device and / or be connected to the acceleration device and / or deceleration device. For example, determining the landing energy includes measuring the landing energy and / or reading the landing energy from a landing energy measuring device.
[0124] In process step S21, in the embodiment of the process according to the invention, it is Fig. It is provided that the particle beam, in the form of the primary electron beam, is deflected by the deflection device, consisting of the first deflection unit 9 and the second deflection unit 12, to a position along the optical axis 20 of the SEM 100, depending on the specified landing energy. Accordingly, the aforementioned position corresponds to the specified landing energy. In other words, the primary electron beam is guided to this position along the optical axis 20 of the SEM 100 by the first deflection unit 9 and the second deflection unit 12, depending on the specified landing energy. The aforementioned position of the primary electron beam along the optical axis 20 of the SEM 100 is, for example, the tipping point of the primary electron beam already explained above. At this position along the optical axis 20 of the SEM 100, the central path of the primary electron beam has an axial distance perpendicular to the optical axis 20 of the SEM 100.Regarding the definition of the central orbit, reference is made to the explanations above, which also apply here. At the specified landing energy, the axial distance of the central orbit of the primary electron beam at this position along the optical axis 20 is smaller than all other axial distances of the central orbit of the primary electron beam perpendicular to the optical axis 20, wherein the other axial distances are arranged either between a center of the second deflection unit 12 and the object 15 or between the center of the second deflection unit 12 and the focal plane.
[0125] Fig. Figure 12 shows a further embodiment of the method according to the invention.
[0126] The embodiment of the method according to the invention Fig. 12 is based on the embodiment of the method according to the invention. Fig. 11. Reference is therefore made to the above statements, which also apply here. In contrast to the embodiment of the method according to the invention as described above... Fig. 11 shows the embodiment of the method according to the invention. Fig. 12 introduces a further process step between process step S20 and process step S21, namely process step S20A. In process step S20A, the position of the primary electron beam along the optical axis 20 corresponding to the specified landing energy is loaded into the control unit 123 from the database 126 of the SEM 100 and / or from another storage unit. In process step S21, the primary electron beam is then deflected using the deflection device in the form of the first deflection unit 9 and the second deflection unit 12 such that the primary electron beam is guided to the loaded position. In other words, in this embodiment of the method according to the invention, the position of the tipping point is stored in the database 126 and / or in the storage unit as a function of the landing energy.Once the landing energy is determined, the corresponding position can be loaded from the database 126 and / or the storage unit, and the primary electron beam can be directed to this position using the deflection device in the form of the first deflection unit 9 and the second deflection unit 12.
[0127] In a further embodiment of the method according to the Fig. 11. It is additionally or alternatively provided that, if a threshold landing energy is not reached, a position of the primary electron beam along the optical axis 20 of the SEM 100 is used which is closer to the outer boundary of the objective lens 10 than a position of the primary electron beam along the optical axis 20 of the SEM 100 (i) if the threshold landing energy is exceeded or (ii) if the landing energy is equal to the threshold landing energy.
[0128] In a further embodiment of the method according to the Fig. In this embodiment of the inventive method, it is additionally or alternatively provided to reduce imaging errors in a generated image. For this purpose, the first deflection unit 9 and the second deflection unit 12 of the SEM 100 are controlled for scanning the primary electron beam across the object 15 as a function of the landing energy and / or the defined distance A, such that errors in the representation of the object 15 are reduced and / or eliminated. The lower the landing energy at the same defined distance, the more nonlinear the excitation of the first deflection unit 9 and the second deflection unit 12. The greater the defined distance A at the same landing energy, the greater the nonlinear components in the excitations of the first deflection unit 9 and the second deflection unit 12, provided the linear components in the respective excitations remain constant.Regarding nonlinear excitation, reference is made to the explanations above, which also apply here.
[0129] The on the Fig. The embodiments of the method according to the invention, as described in section 11, ensure that a sufficiently large image field of the SEM 100 can always be achieved at different landing energies. In other words, the aforementioned position of the primary electron beam along the optical axis 20 (i.e., the tilting point of the primary electron beam) is selected depending on the set and / or determined landing energy such that a desired image field of the SEM 100 can be achieved. These embodiments can also be carried out manually and / or automatically.
[0130] All the preceding and following embodiments of the methods according to the invention are not limited to the explained sequence of process steps. The invention also includes different sequences of process steps that are suitable for solving the problem in accordance with the invention. Alternatively or additionally, the parallel execution of at least two process steps is also provided for in the methods according to the invention. Furthermore, the preceding and following embodiments of the methods according to the invention are not limited to the complete scope of all process steps mentioned above or below. In particular, it is provided that in further embodiments, one or more of the preceding or following process steps are omitted.
[0131] The features of the invention disclosed in this description, in the drawings, and in the claims can be essential for realizing the invention in its various embodiments, both individually and in any combination. The invention is not limited to the described embodiments. It can be varied within the scope of the claims and taking into account the knowledge of the person skilled in the art. Reference symbol list 1 radiation source 2 Extraction electrode 3 Control electrode 4 Anode 5 first condenser lens 6 second condenser lens 7 aperture units 8 second detector unit 9 first deflection unit 10 objective lens 11 Ring coil 12 second deflection unit 13 Sample chamber 14 first detector unit 15 objects 16 Object level 17 pressure stage aperture holders 18 aperture 19 movable object table 20 optical axis 21 Beam guide tube 22 pole shoe 23 Pole shoe gap 25 Movement device 100 SEM 101 Electron source 102 Extraction electrode 103 Anode 104 Beam guide tube 105 first condenser lens 106 second condenser lens 107 first objective lens 108 first aperture unit 108A first aperture 109 second aperture unit 110 pole shoes 111 Coil 112 individual electrodes 113 Pipe electrode 114 object holders 115 second deflection unit 116 first detector 116A Counterfield grid 117 second detector 118 second aperture 119 Chamber detector 120 sample chamber 121 third detector 122 Object table 123 Control unit 124 Monitor 125 objects 126 database 127 processor 130 first deflection unit 200 combination device 201 Sample chamber 300 ion beam device 301 Ion Beam Generators 302 Extraction electrode in the ion beam device 303 Condenser lens 304 second lens 306 adjustable or selectable aperture 307 first deflection unit 308 second deflection unit 500 radiation detector 600 first movement element 601 Housing 602 second movement element 603 first table rotation axis 604 third movement element 605 fourth movement element 606 fifth movement element 607 second table rotation axis 608 Drive control unit M1 first drive unit M2 second drive unit M3 third drive unit M4 fourth drive unit M5 fifth drive unit 709 first beam axis 710 second beam axis A fixed distance A1 fixed distance A2 fixed distance OA optical axis S1 Procedure step S1A Procedure step S1B Procedure step S1C process step S2 process step S2A process step S20 Procedure step S20A Process step S21 Procedure step QUOTES INCLUDED IN THE DESCRIPTION
[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature
[0000] DE 10 2010 053 194 A1
[0011] DE 10 2011 076 893 A1
[0011]
Claims
[1] Method for operating a particle beam device (100, 200) for imaging, analyzing and / or processing an object (15, 125), wherein the method comprises the following process steps: - Determining a distance (A, A1, A2) using a control device (123) of the particle beam device (100, 200), wherein the distance (A, A1, A2) is either (a) an object distance between an outer boundary of an objective lens (10, 107, 304) of the particle beam device (100, 200) and the object (15, 125) or (b) a focal plane distance between the outer boundary of the objective lens (10, 107, 304) of the particle beam device and a focal plane (16) of the objective lens (10, 107, 304); - Deflection of a particle beam generated by a beam generator (1, 101, 301) of the particle beam device (100, 200) to a position corresponding to a defined distance (A, A1, A2) along an optical axis (20, 709, 710, OA) of the particle beam device (100, 200) using a deflection device (9, 12, 115, 130, 307, 308) as a function of the defined distance (A, A1, A2), wherein the deflection device (9, 12, 115, 130, 307, 308) comprises at least one first deflection unit (9, 130, 307) and at least one second deflection unit (12, 115, 308), wherein, starting from the beam generator (1, 101, 301) in In the direction of the objective lens (10, 107, 304), the first deflection unit (9, 130, 307) and then the second deflection unit (12, 115, 308) are arranged along the optical axis (20, 709, 710, OA), with a central path of the particle beam at the position along the optical axis (20, 709, 710, OA) at an axial distance perpendicular to the optical axis (20, 709, 710,OA) of the particle beam device (100, 200), wherein at the specified distance (A, A1, A2) the axial distance of the central path of the particle beam at the position along the optical axis (20, 709, 710, OA) is smaller than all other axial distances of the central path of the particle beam perpendicular to the optical axis (20, 709, 710, OA) of the particle beam device (100, 200), wherein for the specified distance (A, A1, A2) according to case (a) the further axial distances between a center of the second deflection unit (12, 115, 308) of the deflection device (9, 12, 115, 130, 307, 308) and the object (15, 125) are arranged, and wherein for the specified distance (A, A1, A2) according to case (b) the further axial distances between the center the second deflection unit (12, 115, 308) of the deflection device (9, 12, 115, 130, 307, 308) and the focal plane (16) are arranged. [2] Method according to claim 1, wherein (i) the determination of the distance (A, A1, A2) according to case (a) is carried out by a relative movement of the object (15, 125) in relation to the objective lens (10, 107, 304) and / or by determining the object distance; (ii) the determination of the distance (A, A1, A2) according to case (b) is carried out by controlling the objective lens (10, 107, 304) to position a focal plane (16) of the objective lens (10, 107, 304) and / or by determining the focal plane distance. [3] Method according to claim 1 or 2, wherein determining the distance (A, A1, A2) according to case (a) comprises at least one of the following method steps: (i) Moving an object holder (19, 114, 122) on which the object (15, 125) is arranged along the optical axis (20, 709, 710, OA); (ii) Moving the object holder (19, 114, 122) on which the object (15, 125) is arranged relative to the optical axis (20, 709, 710, OA), wherein the movement is not perpendicular to the optical axis (20, 709, 710, OA); (iii) Moving the objective lens (10, 107, 304) of the particle beam device (100, 200) along the optical axis (20, 709, 710, OA) using a movement device (25); (iv) Moving the objective lens (10, 107, 304) of the particle beam device (100, 200) relative to the optical axis (20, 709, 710, OA) using the movement device (25), wherein the movement is not perpendicular to the optical axis (20, 709, 710, OA). [4] Method according to one of the preceding claims, wherein the position of the particle beam along the optical axis (20, 709, 710, OA) corresponding to the specified distance (A, A1, A2) is loaded into the control device (123) from a database (126) and / or from a storage unit, and wherein the deflection of the particle beam is carried out using the deflection device (9, 12, 115, 130, 307, 308) such that the particle beam is guided to the loaded position. [5] Method according to one of the preceding claims, wherein the position of the particle beam along the optical axis (20, 709, 710, OA) corresponding to the specified distance (A, A1, A2) is calculated using the control device (123). [6] Method according to one of the preceding claims, wherein an image of the object (15, 125) is produced by imaging the object (15, 125), wherein the objective lens (10, 107, 304) is excited with an objective lens current such that the image of the object (15, 125) fulfills a desired imaging criterion, and wherein the distance (A, A1, A2) is determined using the objective lens current. [7] Method according to any one of the preceding claims, wherein the specified distance (A, A1, A2) is a first distance, wherein the position of the particle beam along the optical axis (20, 709, 710, OA) is a first position, wherein the object distance is a first object distance, wherein the focal plane distance is a first focal plane distance, wherein the axial distance of the central path of the particle beam at the first position is a first axial distance, and wherein the method comprises the following process steps: - Determining a second distance (A, A1, A2) using the control device (123) of the particle beam device (100, 200), wherein the second distance is greater than the first distance, and wherein the second distance is either (c) by a second object distance between the outer boundary of the objective lens (10, 107, 304) of the particle beam device (100, 200) and the object (15, 125) or (d) by a second focal plane distance between the outer boundary of the objective lens (10, 107, 304) of the particle beam device (100, 200) and the focal plane (16) of the objective lens (10, 107, 304); - Deflection of the particle beam to a second position along the optical axis (20, 709, 710, OA) of the particle beam device (100, 200) corresponding to the second distance using the deflection device (9, 12, 115, 130, 307, 308) depending on the specified second distance, wherein the central path of the particle beam at the second position along the optical axis (20, 709, 710, OA) has a second axial distance perpendicular to the optical axis (20, 709, 710, OA) of the particle beam device (100, 200), wherein, at the specified second distance, the second axial distance of the central path of the particle beam at the second position along the optical axis (20, 709, 710, OA) is smaller than all other axial distances of the central path of the particle beam perpendicular to the optical axis (20, 709, 710, OA) of the particle beam device (100, 200), where for the specified second distance (A, A1,A2) according to case (c) the further axis distances between the center of the second deflection unit (12, 115, 308) of the deflection device (9, 12, 115, 130, 307, 308) and the object (15, 125) are arranged and wherein, for the specified distance (A, A1, A2) according to case (d), the further axis distances between the center of the second deflection unit (12, 115, 308) of the deflection device (9, 12, 115, 130, 307, 308) and the focal plane (16) are arranged, wherein a distance of the second position to the outer boundary of the objective lens (10, 107, 304) is less than a distance of the first position to the outer boundary of the objective lens (10, 107, 304). [8] Method according to one of the preceding claims, wherein a landing energy with which particles of the particle beam strike the object (15, 125) is set and / or determined using the control device (123), wherein the deflection of the particle beam to the position corresponding to the specified distance (A, A1, A2) along the optical axis (20, 709, 710, OA) of the particle beam device (100, 200) is additionally carried out depending on the landing energy using the deflection device (9, 12, 115, 130, 307, 308). [9] Method according to claim 8, wherein the control device (123) is a control device comprising an acceleration device (112, 113) and / or deceleration device (112, 113) for the particles of the particle beam. [10] Method according to one of claims 8 or 9, wherein, in the event of a threshold landing energy being undershot, a position is used as the position of the particle beam along the optical axis (20, 709, 710, OA) corresponding to the specified distance (A, A1, A2), which is closer to the outer boundary of the objective lens (10, 107, 304) than the position of the particle beam along the optical axis (20, 709, 710, OA) (i) when the threshold landing energy is exceeded or (ii) when the landing energy is equal to the threshold landing energy. [11] Method according to any one of claims 8 to 10, wherein the method comprises at least one of the following process steps: (i) a scanning device (9, 12, 115, 130, 307, 308) of the particle beam device (100, 200) for scanning the particle beam over the object (15, 125) is controlled depending on the landing energy and / or the specified distance (A, A1, A2) such that errors in a representation of the object (15, 125) are reduced and / or eliminated; (ii) the lower the landing energy at the same fixed distance (A, A1, A2), the more nonlinearly the particle beam is deflected by the scanning device (9, 12, 115, 130, 307, 308); (iii) the greater the specified distance (A, A1, A2) at the same landing energy, the greater the non-linear component in the excitation of the grid device (9, 12, 115, 139, 397, 308) will be, if a linear component in the excitation of the grid device (9, 12, 115, 130, 307, 308) remains constant. [12] Method for operating a particle beam device (100, 200) for imaging, analyzing and / or processing an object (15, 125), wherein the method comprises the following process steps: - Setting a landing energy with which particles of a particle beam generated by a beam generator (1, 101, 301) of a particle beam device (100, 200) strike the object (15, 125) using a control device (123) and / or determining the landing energy by the control device (123); - Deflection of the particle beam to a position corresponding to the set and / or determined landing energy along an optical axis (20, 709, 710, OA) of the particle beam device (100, 200) as a function of the landing energy using a deflection device (9, 12, 115, 130, 307, 308) which has at least one first deflection unit (9, 130, 307) and at least one second deflection unit (12, 115, 308), wherein, starting from the beam generator (1, 101, 301) in the direction of the objective lens (10, 107, 304), first the first deflection unit (9, 130, 307) and then the second deflection unit (12, 115, 308) are deflected along the optical axis (20, 709, 710, OA). are arranged, wherein a central path of the particle beam at the position along the optical axis (20, 709, 710, OA) has an axial distance perpendicular to the optical axis (20, 709, 710, OA) of the particle beam device (100, 200),wherein, at the set and / or determined landing energy, the axial distance of the central path of the particle beam at the position corresponding to the set and / or determined landing energy along the optical axis (20, 709, 710, OA) is smaller than all other axial distances of the central path of the particle beam perpendicular to the optical axis (20, 709, 710, OA) of the particle beam device (100, 200), wherein the other axial distances are either (a) between a center of the second deflection unit (12, 115, 308) of the deflection device (9, 12, 115, 130, 307, 308) and the object (15, 125) or (b) between the center of the second deflection unit (12, 115, 308) of the deflection device (9, 12, 115, 130, 307, 308) and a focal plane (16) of an objective lens (10, 107, 304) of the particle beam device (100, 200) are arranged. [13] Method according to claim 12, wherein the control device (123) is a control device which has an acceleration device (112, 113) and / or deceleration device (112, 113) for the particles of the particle beam. [14] Method according to claim 12 or 13, wherein the position of the particle beam along the optical axis (20, 709, 710, OA) corresponding to the set and / or determined landing energy is loaded into the control device (123) from a database (126) and / or from a storage unit, and wherein the deflection of the particle beam is carried out using the deflection device (9, 12, 115, 130, 307, 308) such that the particle beam is guided to the loaded position. [15] Method according to any one of claims 12 to 14, wherein, in the event of a threshold landing energy being undershot, a position is used that is closer to the outer boundary of the objective lens (10, 107, 304) than the position of the particle beam along the optical axis (20, 709, 710, OA) (i) when the threshold landing energy is exceeded or (ii) when the landing energy is equal to the threshold landing energy. [16] Method according to any one of claims 12 to 15, wherein the method comprises at least one of the following process steps: (i) a scanning device (9, 12, 115, 130, 307, 308) of the particle beam device (100, 200) for scanning the particle beam over the object (15, 125) is controlled depending on the set and / or detected landing energy in such a way that errors in a representation of the object (15, 125) are reduced and / or eliminated; (ii) the lower the set and / or determined landing energy at the same working distance (A, A1, A2), the more nonlinearly the particle beam is deflected by the scanning device (9, 12, 115, 130, 307, 308); (iii) the greater the working distance (A, A1, A2) at the same set and / or determined landing energy, the greater the non-linear component in the excitation of the grid device (9, 12, 115, 130, 307, 308) will be, if a linear component in the excitation of the grid device (9, 12, 115, 130, 307, 308) remains constant. [17] Method according to any of the preceding claims, wherein the deflection device (9, 12, 115, 130, 307, 308) is an electrostatic and / or magnetic deflection device (9, 12, 115, 130, 307, 308). [18] Computer program product comprising a program code that can be loaded into a processor (127) and which, when executed, controls a particle beam device (100, 200) such that a method according to at least one of the preceding claims is carried out. [19] Particle beam device (100, 200) for imaging, analyzing and / or processing an object (15, 125) with - at least one beam generator (1, 101, 301) for generating a particle beam with charged particles; - at least one objective lens (10, 107, 304) for focusing the particle beam onto the object (15, 125), wherein the object (15, 125) is movable relative to the objective lens (10, 107, 304); - at least one deflection device (9, 12, 115, 130, 307, 308) comprising at least one first deflection unit (9, 130, 307) and at least one second deflection unit (12, 115, 308), wherein, viewed from the beam generator (1, 101, 301) in the direction of the objective lens (10, 107, 304), first the first deflection unit (9, 130, 307) and then the second deflection unit (12, 115, 308) are arranged along an optical axis (20, 709, 710, OA) of the particle beam device (100, 200); - at least one detector unit (8, 14, 116, 117, 119, 121, 500) for the detection of interaction particles and / or interaction radiation resulting from an interaction of the particle beam with the object (15, 125), and with - at least one control device (123) comprising at least one processor (127) in which a computer program product according to claim 18 is loaded. [20] Particle beam device (100, 200) according to claim 19, wherein the particle beam device (100, 200) has at least one acceleration device (112, 113) for accelerating the particles and / or a deceleration device (112, 113) for decelerating the particles in the particle beam device (100, 200). [21] Particle beam device (100, 200) according to claim 19 or 20, wherein the particle beam device (100, 200) has at least one of the following features: (i) a movable object holder (19, 114, 122) on which the object (15, 125) is arranged; (ii) a movement device (25) for moving the objective lens (10, 107, 304). [22] Particle beam device (100, 200) according to one of claims 19 to 21, wherein the particle beam device (100, 200) has at least one of the following features: (i) the first deflection unit (9, 130, 307) is arranged in the objective lens (10, 107, 304); (ii) the second deflection unit (12, 115, 308) is arranged in the objective lens (10, 107, 304). [23] Particle beam device (200) according to one of claims 19 to 22, wherein the beam generator (101) is configured as a first beam generator and the particle beam is configured as a first particle beam with first charged particles, wherein the objective lens (107) is configured as a first objective lens for focusing the first particle beam onto the object (125), and wherein the particle beam device (200) further comprises: (i) at least one second beam generator (301) for generating a second particle beam with second charged particles; and (ii) at least one second objective lens (304) for focusing the second particle beam onto the object (125). [24] Particle beam device (100, 200) according to any one of claims 19 to 23, wherein the particle beam device (100, 200) is an electron beam device and / or an ion beam device.
Citation Information
Patent Citations
Particle beam device with deflection system
DE102010053194A1
Method and particle beam device for focusing a particle beam
DE102011076893A1
Charge particle beam device
DE112014007154B4
Scanning transmission electron microscope and scanning transmission electron microscopy
US20060151701A1
Charged particle beam adjustment method, and charged particle beam device
JP2010016007A