DE102020129976A1 - Method for removing material from an object using a particle beam device, computer program product, particle beam device for carrying out the method, and system with a particle beam device and a data memory - Google Patents

Abstract

The invention relates to a method for removing material from an object using a particle beam device. The invention also relates to a computer program product and a particle beam device with which this method can be carried out. The method comprises the following steps: identifying an ablation area on the object at which material of the object is to be ablated with the particle beam; Defining a shape of the ablation area and/or an ablation depth of the ablation area using a control unit of the particle beam device; Establishing a data connection of the control unit of the particle beam device with a data memory that is locally separate from the particle beam device; selecting a control parameter stored in the data memory depending on the defined shape of the excavation area and/or the defined excavation depth; loading the selected control parameter from the data store into the control unit; Controlling a controllable unit of the particle beam device by means of the control unit using the selected control parameter; and ablation of the material of the object in the ablation area with the particle beam using the unit of the particle beam device controlled with the control parameter.

Description

The invention relates to a method for removing material from an object using a particle beam device that has a particle beam with charged particles. The invention also relates to a computer program product and a particle beam device with which this method can be carried out. The particle beam device is designed to remove material from the object. For example, the particle beam device is designed as an electron beam device and/or as an ion beam device.

Electron beam devices, 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 (samples) in order to obtain knowledge of the properties and behavior under certain conditions.

In an SEM, an electron beam (also referred to below as a primary electron beam) is generated by a beam generator and focused on an object to be examined by a beam guidance system. The primary electron beam is guided over a surface of the object to be examined by means of a deflection device. The electrons of the primary electron beam interact with the object to be examined. As a result of the interaction, interaction particles and/or interaction radiation are produced. In particular, electrons are emitted by the object as interaction particles (so-called secondary electrons) and electrons of the primary electron beam are scattered back at the object (so-called backscattered electrons). The secondary electrons and the backscattered electrons are detected with a particle detector and used for image generation. An image of the object to be examined is thus obtained. X-rays and/or cathodoluminescent light, in particular, are produced as interaction radiation. The interaction radiation is detected with a radiation detector and used in particular to analyze the object.

In a TEM, a primary electron beam is also generated by means of a beam generator and directed onto an object to be examined by means of a beam guidance system. The primary electron beam radiates through the object to be examined. When the primary electron beam passes through the object to be examined, the electrons of the primary electron beam interact with the material of the object to be examined. The electrons passing through the object to be examined are imaged by a system consisting of a lens and a projective lens on a fluorescent screen or on a detector (e.g. a camera). The imaging can also take place in the scan mode of a TEM. Such a TEM is usually referred to as a STEM. In addition, it can be provided that electrons scattered back from the object to be examined and/or secondary electrons emitted by the object to be examined can be detected by means of a further detector in order to image an object to be examined.

It is also known from the prior art to use combination devices for examining objects in which both electrons and ions can be guided onto an object to be examined. For example, it is known to additionally equip an SEM with an ion beam column. By means of an ion beam generator arranged in the ion beam column, ions are generated 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. The SEM is used here in particular for observing the preparation, but also for further examination of the prepared or unprepared object.

It is known from the prior art to identify a removal area on the object, material of the object to be removed in the removal area. Furthermore, it is known to define a shape of the area to be removed and a depth of removal of the area to be removed. Using his specialist knowledge and/or his experience, a user then sets values of control parameters for units of the particle beam device on a control unit in order to achieve the desired specified shape of the ablation area and the desired specified ablation depth. As control parameters, the user selects control parameters that influence properties of the particle beam device, for example a tilt angle of the object in relation to the particle beam, the extent of the particle beam on the object and/or a path of the particle beam along which the particle beam is guided over the object. Other properties that can be influenced by control parameters are explained in more detail below.

The disadvantage here is that the control parameters are always selected on the basis of the knowledge of the user. However, if the user is inexperienced and/or the object is made of a material unfamiliar to the user, this selection may not be sufficient to achieve the desired ablation area shape and depth.

The invention is therefore based on the object of specifying a method and a particle beam device with which a desired shape of the ablation area and a desired depth of ablation on the object can be achieved using a particle beam.

According to the invention, this object is achieved by means of a method having the features of claim 1. Claim 7 provides a computer program product with a program code that is or can be loaded into a processor and, when executed, controls a particle beam device in such a way that a method according to the invention is carried out. The invention also relates to a particle beam device with the features of claim 8 and a system with the features of claim 11. Further features of the invention result from the following description, the attached claims and/or the attached figures.

The method according to the invention serves to remove material from an object with a particle beam device that has a particle beam with charged particles. For example, a particle beam is generated with at least one particle beam generator of the particle beam device. The particle beam has charged particles. For example, the particles are electrons or ions. In particular, it is provided that the particle beam is guided or focused onto the object with at least one objective lens. Due to an interaction of the particle beam with the object, interaction radiation and/or interaction particles arise. For example, the interaction radiation is X-rays and/or cathodoluminescent light. The interaction radiation can be detected with at least one radiation detector. The interaction particles are, for example, secondary particles emitted by the object, in particular secondary electrons, and/or backscattered particles, in particular backscattered electrons. These can be detected with at least one particle detector.

• - Identifizieren eines Abtragungsbereichs am Objekt, an dem Material des Objekts mit dem Teilchenstrahl abgetragen werden soll;
• - Festlegen einer Form des Abtragungsbereichs und/oder einer Abtragungstiefe des Abtragungsbereichs unter Verwendung einer Steuereinheit des Teilchenstrahlgeräts;
• - Herstellen einer Datenverbindung der Steuereinheit des Teilchenstrahlgeräts mit einem Datenspeicher, der vom Teilchenstrahlgerät örtlich getrennt ist;
• - Auswählen mindestens eines in dem Datenspeicher gespeicherten Steuerparameters in Abhängigkeit der festgelegten Form des Abtragungsbereichs und/oder der festgelegten Abtragungstiefe;
• - Laden des ausgewählten Steuerparameters von dem Datenspeicher in die Steuereinheit;
• - Ansteuern mindestens einer ansteuerbaren Einheit des Teilchenstrahlgeräts mittels der Steuereinheit unter Verwendung des ausgewählten Steuerparameters; sowie
• - Abtragen des Materials des Objekts am Abtragungsbereich mit dem Teilchenstrahl unter Verwendung der mit dem Steuerparameter angesteuerten Einheit des Teilchenstrahlgeräts.

The method according to the invention comprises the following steps:

• - Identifying a removal area on the object at which material of the object is to be removed with the particle beam;
• - defining a shape of the ablation area and/or an ablation depth of the ablation area using a control unit of the particle beam device;
• - Establishing a data connection of the control unit of the particle beam device with a data memory which is locally separate from the particle beam device;
• - selecting at least one control parameter stored in the data memory as a function of the specified shape of the excavation area and/or the specified excavation depth;
• - loading the selected control parameter from the data memory into the control unit;
• - Controlling at least one controllable unit of the particle beam device by means of the control unit using the selected control parameter; such as
• - Removal of the material of the object in the removal area with the particle beam using the controlled with the control parameter unit of the particle beam device.

For example, a rectangular shape is selected as the shape of the ablation area. However, the invention is not limited to the aforementioned form. Rather, any form of ablation area that is suitable for the invention can be selected in the case of the invention.

The ablation depth of the ablation area is an extension of the ablation area starting from the surface of the object in the direction of the material of the object, ie the interior of the object. Basically, the ablation depth defines the extent of the ablation area from the surface of the object into the material of the object, i.e. the interior of the object.

• - Auswahl eines Teilchenstrahlerzeugers. Beispielsweise ist der Teilchenstrahlerzeuger als lonenstrahlerzeuger ausgebildet. Insbesondere kann der Teilchenstrahlerzeuger als Flüssigmetallionenstrahlerzeuger oder als Plasmaionenstrahlerzeuger ausgebildet sein;
• - ein Strom des Teilchenstrahls des Teilchenstrahlgeräts, wobei der Strom mit einer Strommesseinrichtung im Teilchenstrahlerzeuger oder mit einer Strommesseinrichtung, die dem Teilchenstrahlerzeuger nachgeschaltet ist, gemessen wird;
• - eine Ausdehnung des Teilchenstrahls am Objekt;
• - ein Kippwinkel des Objekts in Bezug auf den Teilchenstrahl, mit dem das Material abgetragen wird;
• - eine Abtragrate, wobei die Abtragrate ein Maß dafür ist, wieviel Material mit dem Teilchenstrahl pro einer wählbaren Zeiteinheit abgetragen wird;
• - eine Dosis des Teilchenstrahls, wobei die Dosis ein Maß dafür ist, wieviel geladene Teilchen auf einer wählbaren Fläche des Objekts während der wählbaren Zeiteinheit auftreffen;
• - ein Druck, welcher in einer Probenkammer des Teilchenstrahlgeräts herrscht, wobei das Objekt in der Probenkammer angeordnet ist;
• - ein Abstand, nämlich der Arbeitsabstand, zwischen der Objektivlinse des Teilchenstrahlgeräts und einer Oberfläche des Objekts;
• - ein Weg des Teilchenstrahls, entlang dessen der Teilchenstrahl über das Objekt gescannt wird;
• - eine Scanrichtung, in welcher der Teilchenstrahl entlang des Wegs geführt wird;
• - eine Verweildauer des Teilchenstrahls an einem ersten Scanpunkt des Objekts, bevor der Teilchenstrahl zu einem zweiten Scanpunkt des Objekts geführt wird;
• - ein Abstand zwischen zwei benachbarten Scanpunkten in einer ersten Richtung. Beispielsweise ist die erste Richtung die horizontale Richtung;
• - ein Abstand zwischen zwei benachbarten Scanpunkten in einer zweiten Richtung, wobei die zweite Richtung senkrecht zur ersten Richtung ausgerichtet ist. Beispielsweise ist die zweite Richtung die vertikale Richtung;
• - eine erste Wartezeit, die abgewartet wird, bevor der Teilchenstrahl von einer ersten Scanzeile zu einer zweiten Scanzeile geführt wird, um insbesondere Relaxationsprozesse zu kompensieren;
• - eine zweite Wartezeit, die abgewartet wird, bevor nach Erstellung einer ersten Abbildung des Objekts eine zweite Abbildung des Objekts erstellt wird, um insbesondere Relaxationsprozesse zu kompensieren; sowie
• - eine Defokussierung des Teilchenstrahls am Objekt, um thermische Effekte und/oder Aufladungseffekte zu kompensieren.

The control parameter is a physical variable with which the setting of the unit of the particle beam device can be changed, so that a property of the particle beam device is set and/or influenced. The control parameter is used, for example, to set and/or influence at least one of the properties of the particle beam device listed below:

• - Selection of a particle beam generator. For example, the particle beam generator is designed as an ion beam generator. In particular, the particle beam generator can be designed as a liquid metal ion beam generator or as a plasma ion beam generator;
• - A current of the particle beam of the particle beam device, the current being measured with a current measuring device in the particle beam generator or with a current measuring device which is connected downstream of the particle beam generator;
• - an expansion of the particle beam at the object;
• - a tilt angle of the object in relation to the particle beam with which the material is removed;
• - A removal rate, the removal rate being a measure of how much material is removed with the particle beam per a selectable time unit;
• - a dose of the particle beam, the dose being a measure of how many charged particles impinge on a selectable area of the object during the selectable unit of time;
• - A pressure which prevails in a sample chamber of the particle beam device, the object being arranged in the sample chamber;
• - a distance, namely the working distance, between the objective lens of the particle beam device and a surface of the object;
• - a path of the particle beam, along which the particle beam is scanned over the object;
• - a scanning direction in which the particle beam is guided along the path;
• - a dwell time of the particle beam at a first scanning point of the object before the particle beam is guided to a second scanning point of the object;
• - a distance between two adjacent scan points in a first direction. For example, the first direction is the horizontal direction;
• - a distance between two adjacent scan points in a second direction, the second direction being oriented perpendicular to the first direction. For example, the second direction is the vertical direction;
• - A first waiting time, which is awaited before the particle beam is guided from a first scan line to a second scan line, in order in particular to compensate for relaxation processes;
• - A second waiting time, which is awaited before a second image of the object is created after the creation of a first image of the object, in order in particular to compensate for relaxation processes; such as
• - a defocusing of the particle beam on the object in order to compensate for thermal effects and/or charging effects.

It is explicitly pointed out that the invention is not limited to the use of control parameters for setting and/or influencing the aforementioned properties of the particle beam device. Rather, any control parameters that are suitable for the invention can be used in the invention for setting and/or influencing any properties of the particle beam device.

The invention has the advantage that, by means of the method according to the invention, control parameters which are stored in the data memory and of which it is already known that they ensure the production of the specified shape of the ablation area and the specified ablation depth on the object, for setting the unit or the Units of the particle beam device are used. Basically, the data memory includes a database which has control parameters, of which it is known that when these control parameters are used to control the unit of the particle beam device, the specified shape of the ablation area and the specified ablation depth on the object are achieved when material of the object is ablated. For example, the control parameters stored in the data memory are based on empirical values from the past, whereby the empirical values cannot only come from a single user, but for example from numerous users who use the empirical values known to them, which are necessary to achieve the specified shape of the removal area and/or the specified ablation depth on the object have been saved.

In one embodiment of the method according to the invention, it is additionally or alternatively provided that the data connection is established via the Internet and/or an intranet. For example, the data connection is wireless and/or via a physical data line, in particular a cable.

In a further embodiment of the method according to the invention, it is additionally or alternatively provided that the control parameter is changed and the changed control parameter is stored in the data memory as a function of the defined shape of the removal area and/or the defined removal depth. This embodiment of the method according to the invention is particularly advantageous when it is foreseeable that the specified shape of the ablation area and/or the specified ablation depth cannot be achieved or can only be achieved insufficiently for any reason. In this case, the control parameter is changed in such a way that the specified shape of the ablation area and/or the specified ablation depth is/are achievable. The changed control parameter is then stored in the data memory so that this changed control parameter can be used later of the method according to the invention can be used.

• - Auswählen mindestens eines in dem Datenspeicher gespeicherten zweiten Steuerparameters in Abhängigkeit der festgelegten Form des Abtragungsbereichs und/oder der festgelegten Abtragungstiefe;
• - Laden des ausgewählten zweiten Steuerparameters von dem Datenspeicher in die Steuereinheit;
• - Ansteuern der ersten Einheit und/oder mindestens einer ansteuerbaren zweiten Einheit des Teilchenstrahlgeräts mittels der Steuereinheit unter Verwendung des zweiten Steuerparameters; sowie
• - Abtragen des Materials des Objekts am Abtragungsbereich mit dem Teilchenstrahl unter Verwendung der mit dem zweiten Steuerparameter angesteuerten ersten Einheit des Teilchenstrahlgeräts und/oder der zweiten Einheit des Teilchenstrahlgeräts.

In yet another embodiment of the method according to the invention, it is additionally or alternatively provided that the control parameter is a first control parameter, the controllable unit of the particle beam device being a controllable first unit of the particle beam device and the method also comprising the following steps:

• - selecting at least one second control parameter stored in the data memory as a function of the specified shape of the excavation area and/or the specified excavation depth;
• - loading the selected second control parameter from the data memory into the control unit;
• - Controlling the first unit and/or at least one controllable second unit of the particle beam device by means of the control unit using the second control parameter; such as
• - Removal of the material of the object in the removal area with the particle beam using the first unit of the particle beam device controlled with the second control parameter and/or the second unit of the particle beam device.

The second control parameter is a physical variable with which the setting of the first unit and/or the second unit of the particle beam device can be changed, so that a property of the particle beam device is set and/or influenced. The second control parameter is used, for example, to set and/or influence at least one of the properties of the particle beam device listed above.

In one embodiment of the method according to the invention, it is additionally or alternatively provided that ions and/or electrons are used as charged particles.

In a further embodiment of the method according to the invention, it is additionally or alternatively provided that the ablation area is examined by means of X-ray spectroscopy and/or mass spectroscopy (for example SIMS). In this case, for example, it is examined whether the material of the object in the ablation area corresponds to a material composition that one would like to examine. In addition, it is planned to select the control parameter depending on the material composition determined during the investigation. Thus, that control parameter is loaded into the control unit with which it is particularly possible to achieve the specified shape of the ablation area and/or the specified ablation depth for the determined material composition.

In yet another embodiment of the method according to the invention, it is additionally or alternatively provided that any control parameter is loaded from the data memory and, depending on the defined shape of the removal area and/or the defined removal depth, the value of the control parameter is loaded using the control parameter loaded from the data memory is calculated (e.g. by scaling the control parameter loaded from the data store) appropriate to achieve the specified shape of the excavation area and/or the specified excavation depth. In yet another embodiment of the method according to the invention, it is additionally or alternatively provided that, in the event that no control parameter is stored in the data memory, of which it is known that when this control parameter is used, the specified form of the ablation area and/or the specified ablation depth is achievable, a control parameter is selected/loaded or a plurality of control parameters are selected/loaded which achieve/achieve a shape of the excavation area and/or the excavation depth which differs only slightly from the defined shape of the excavation area and the defined excavation depth. For example, the deviation is less than 2%. Thereafter, the control parameter and/or the control parameters are/are adjusted in such a way that the defined shape of the removal area and/or the defined removal depth can be achieved.

Even if the method according to the invention is described with regard to the removal of material from an object using a particle beam device, the method according to the invention, which has one of the above or below features or a combination of at least two of the above or below features, can additionally or alternatively be carried out in an analogous manner be used for a deposition of material on or on the object.

Even if the method according to the invention is described with reference to a particle beam, the method according to the invention, which has one of the above or below features or a combination of at least two of the above or below features, can additionally or alternatively be carried out in an analogous manner with a laser beam , where in this case the current is not measured and is set, but an intensity of the laser beam.

The invention also relates to a computer program product with a program code that can be loaded or is loaded into a processor of a particle beam device, the program code controlling the particle beam device when executed in the processor in such a way that a method with at least one of the above or following features or with a combination carried out by at least two of the above or below features.

The invention also relates to a particle beam device for removing material from an object. The object is arranged in a sample chamber of the particle beam device, for example. 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 is provided with at least one objective lens for focusing the particle beam onto the object. In addition, the particle beam device has, for example, at least one scanning device for scanning the particle beam over the object. Furthermore, the particle beam device according to the invention is provided with at least one detector for detecting interaction particles and/or interaction radiation which result/result from an interaction of the particle beam with the object. The particle beam device according to the invention is also provided with at least one display device for displaying an image and/or a result of an analysis of the object. In addition, the particle beam device according to the invention has at least one control unit with a processor into which an aforementioned computer program product is loaded.

In one embodiment of the particle beam device according to the invention, it is additionally or alternatively provided that the beam generator is designed as a first beam generator, the particle beam being designed as a first particle beam with first charged particles and the objective lens being a first objective lens for focusing the first particle beam the object is formed. Furthermore, the particle beam device has at least one second beam generator for generating a second particle beam with second charged particles and at least one second objective lens for focusing the second particle beam onto the object.

In a further embodiment of the particle beam device according to the invention, it is provided that the particle beam device is an electron beam device and/or an ion beam device.

The invention also relates to a system with a particle beam device with at least one of the above or below features or with a combination of at least two of the above or below features. In addition, the system has a data memory that is locally separate from the particle beam device and in which at least one control parameter is stored that can be used to control a unit of the particle beam device. The data memory can be connected to the particle beam device via a data connection. As shown above, the data connection is provided, for example, via the Internet and/or via an intranet.

• 1 eine schematische Darstellung einer Ausführungsform eines Teilchenstrahlgeräts;
• 2 das Teilchenstrahlgerät gemäß der 1 in einer weiteren schematischen Darstellung;
• 3 eine schematische Darstellung einer Ausführungsform eines Systems mit einem Teilchenstrahlgerät und einem mit dem Teilchenstrahlgerät verbindbaren Datenspeicher;
• 4 eine schematische Darstellung eines Ablaufdiagramms einer Ausführungsform des erfindungsgemäßen Verfahrens;
• 5 eine schematische Darstellung von weiteren Verfahrensschritten der Ausführungsform des erfindungsgemäßen Verfahrens gemäß der 4; sowie
• 6 eine schematische Darstellung von zusätzlichen Verfahrensschritten der Ausführungsform des erfindungsgemäßen Verfahrens gemäß den 4 und 5.

The invention is described in more detail below on the basis of embodiments using drawings. Show it:

• 1 a schematic representation of an embodiment of a particle beam device;
• 2 the particle beam device according to the 1 in a further schematic representation;
• 3 a schematic representation of an embodiment of a system with a particle beam device and a data memory that can be connected to the particle beam device;
• 4 a schematic representation of a flow chart of an embodiment of the method according to the invention;
• 5 a schematic representation of further process steps of the embodiment of the method according to the invention 4 ; such as
• 6 a schematic representation of additional process steps of the embodiment of the method according to the invention 4 and 5 .

The invention will now be explained in more detail using a particle beam device in the form of a combination device that has an electron beam column and an ion beam column. It is expressly pointed out that the invention can be used in any particle beam device, in particular in any electron beam device and/or any ion beam device.

1 shows a schematic representation of an embodiment of a particle beam device 1 according to the invention. The particle beam device 1 has a first particle beam column 2 in the form of an ion beam column and a second particle beam column 3 in the form of an electron beam column. The first particle beam column 2 and the second particle beam column 3 are arranged on a sample chamber 100 in which an object 16 to be examined and/or processed is arranged.

It is explicitly pointed out that the invention is not restricted to the fact that the first particle beam column 2 is designed as an ion beam column and the second particle beam column 3 as an electron beam column. Rather, the invention also provides that the first particle beam column 2 can be configured as an electron beam column and the second particle beam column 3 can be configured as an ion beam column. A further embodiment of the invention provides that both the first particle beam column 2 and the second particle beam column 3 are each designed as an ion beam column.

2 shows the particle beam device 1 of FIG 1 in a more detailed representation. For reasons of clarity, the sample chamber 100 is not shown.

The first particle beam column 2 in the form of the ion beam column has a first optical axis 4 . Furthermore, the second particle beam column 3 has a second optical axis 5 in the form of the electron beam column. The first particle beam column 2 is arranged tilted at an angle to the second particle beam column 3 . The angle can be in a range from 50° to 90°, for example. However, the invention is not limited to an angle in the aforementioned range. Rather, any suitable value for the angle can be chosen.

The second particle beam column 3 in the form of the electron beam column will first be discussed below. The second particle beam column 3 has a second beam generator 6 , a first electrode 7 , a second electrode 8 and a third electrode 9 . The first electrode 7 has the function of a suppressor electrode, while the second electrode 8 has the function of an extractor electrode. The third electrode 9 is designed as an anode and at the same time forms one end of a beam guide tube 10. The second beam generator 6 generates a second particle beam in the form of an electron beam. Electrons exiting the second beam generator 6 are accelerated to anode potential due to a potential difference between the second beam generator 6 and the third electrode 9, for example in the range from 1 kV to 30 kV. The second particle beam in the form of the electron beam passes through the beam guide tube 10 and is focused on the object 16 to be examined. This is discussed in more detail below.

The beam guidance tube 10 passes through a collimator unit 11 which has a first annular coil 12 and a yoke 13 . A pinhole diaphragm 14 and a first detector 15 with a central opening 17 in the beam guidance tube 10 along the second optical axis 5 are arranged downstream of the collimator unit 11 , seen from the second beam generator 6 in the direction of the object 16 . The beam guiding tube 10 then runs through a hole in a second objective lens 18. The second objective lens 18 is used to focus the second particle beam onto the object 16. For this purpose, the second objective lens 18 has a magnetic lens 19 and an electrostatic lens 20. The magnetic lens 19 is provided with a second ring coil 21 , an inner pole piece 22 and an outer pole piece 23 . The electrostatic lens 20 has an end 24 of the beam guiding tube 10 and a terminal electrode 25 . The end 24 of the beam guiding tube 10 and the terminal electrode 25 form an electrostatic deceleration device. The end 24 of the beam guiding tube 10 lies together with the beam guiding tube 10 at the anode potential, while the terminal electrode 25 and the object 16 lie at a potential which is lower than the anode potential. In this way, the electrons of the second particle beam can be decelerated to a desired energy that is desired for examining or imaging the object 16 . The second particle beam column 3 also has a scanning device 26, by which the second particle beam can be deflected and scanned over the object 16.

For imaging, the first detector 15 arranged in the beam guidance tube 10 is used to detect secondary electrons and/or backscattered electrons which are produced as a result of the interaction of the second particle beam with the object 16 . The detector signals generated by the first detector 15 are transmitted to a control unit 101 for imaging. The control unit 101 is also connected to the scanning device 26 . The control unit 101 controls the speed and the direction with which the second particle beam is scanned over the object 16 .

The object 16 is arranged on a sample carrier (not shown), with which the object 16 is arranged to be movable in three mutually perpendicular axes (namely an x-axis, a y-axis and a z-axis). In addition, the sample carrier can be rotated about two mutually perpendicular axes of rotation. It is thus possible to bring the object 16 into a desired position.

As already mentioned above, the reference numeral 2 identifies the first particle beam column in the form of the ion beam column. The first particle beam column 2 has a first beam generator 27 in the form of an ion source. The first beam generator 27 serves to generate a first particle beam in the form of an ion beam. Furthermore, the first particle beam column 2 is provided with an extraction electrode 28 and a collimator 29 . Along the first optical axis 4 in the direction of A variable aperture 30 is connected downstream of the collimator 29 at the object 16 . The first particle beam is focused onto the object 16 by means of a first objective lens 31 in the form of focusing lenses. Scanning electrodes 32 are provided to scan the first particle beam across the object 16 .

When the first particle beam impinges on the object 16, the first particle beam interacts with the material of the object 16. For example, material is removed from object 16 .

In addition to the first detector 15, the particle beam device 1 also has a further detector, namely the second detector 103 (cf. 1 ). The second detector 103 is arranged in the sample chamber 100, specifically along the second optical axis 5 in the beam direction from the second beam generator 6 in the direction of the object 16, seen after the object 16. The second detector 103 detects particles transmitted through the object 16 or scattered particles Particles of the second particle beam detected. The second detector 103 generates detection signals which are fed to the control unit 101 for further processing.

In addition, a third detector in the form of a radiation detector 104 is arranged in the sample chamber 100 . The radiation detector 104 detects interaction radiation that is produced when the electron beam and/or the ion beam interacts with the material of the object 16 . For example, the interaction radiation is x-ray radiation, which is used in particular for x-ray spectroscopy. Furthermore, the interaction radiation is, for example, cathodoluminescent light.

The control unit 101 has a processor 102 . A computer program product is loaded in the processor 102, which, when executed in the processor 102, controls the particle beam device 1 in such a way that it carries out method steps of the method according to the invention. This is explained in more detail below.

3 shows a schematic representation of a system 300 with the particle beam device 1. The system 300 also has a data memory 200 in which at least one control parameter is stored or in which a plurality of control parameters are stored, which can be used to control a unit of the particle beam device 1 /are. The data memory 200 is physically separate from the particle beam device 1 and can be connected to the particle beam device 1 via a data connection 201 . The data connection 201 is provided, for example, via the Internet and/or via an intranet.

Each control parameter is a physical variable with which the setting of at least one of the above-mentioned units of the particle beam device 1, which have been explained with regard to the particle beam device 1, can be changed, so that at least one property of the particle beam device 1 is set and/or influenced. The control parameter is used, for example, to set and/or influence at least one of the properties of the particle beam device 1 listed above.

Below is an embodiment of the method based on the 4 and 5 explained, the method being carried out with the system 300, in particular the particle beam device 1.

The current of the ion beam is set in a method step S1. For example, the current of the ion beam is adjusted in such a way that a desired nominal current of the ion beam and an actual current of the ion beam measured with a straw measuring device (not shown) deviate from one another by only approximately 5%. In addition, it can be provided in method step S1 that the focusing of the ion beam and stigmators (not shown) of the first particle beam column 2 in the form of the ion beam column are adjusted. Also, a displacement of an image, which can occur when switching between imaging with the ion beam and imaging with the electron beam, can be smaller than the diameter of the ion beam on the object 16. For example, a Faraday cup is used as the current measuring device, which has an input opening having. A eucentric axis runs through a center of the entrance opening. Ideally, the same image detail is always displayed when switching between imaging with the ion beam and imaging with the electron beam.

In a method step S2, the actual current of the ion beam is measured using the above-mentioned current measuring device, for example the Faraday cup. In addition or as an alternative to this, it is provided to use a current measuring device for this purpose, which is arranged externally on the particle beam device 1 . By measuring this and adjusting the current of the ion beam again, it is possible to adjust the current of the ion beam in such a way that the desired nominal current of the ion beam and the actual current of the ion beam measured with the current measuring device (not shown) are only about 2% or only about 0 .5% differ from each other.

As a current measuring device used in the above process steps, For example, a Faraday cup can be used, the entrance opening of which has a diameter of 50 μm. A screen of the Faraday cup, on which the inlet opening is arranged, is made of copper and/or molybdenum, for example. This material is very conductive. Furthermore, the Faraday cup has a depth approximately ten times greater than the diameter of the entrance aperture. For example, the depth of the Faraday cup is greater than 2mm. A panel carrier, on which the panel is arranged, is made of aluminum, for example. In particular, provision is made for the panel and the panel support to be flush. The Faraday cup can be height-adjustable.

In method step S3, an ablation area is identified on the object 16. Material of the object 16 is to be removed with the ion beam in the ablation area.

In method step S4, the object holder is adjusted in such a way that the object 16 is tilted with respect to the ion beam. For example, the object 16 is tilted in such a way that a grazing incidence (ie a perpendicular incidence) of the ion beam on the object 16 is made possible.

In method step S5, an X-ray spectroscopy examination is carried out in the ablation area of the object 16. For this purpose, the electron beam is guided onto the ablation area of the object 16 . The material composition of the object 16 in the ablation area is examined. As will be explained in more detail below, it is additionally provided to select a control parameter depending on the material composition determined during the examination.

In method step S6, a shape of the ablation area and/or an ablation depth of the ablation area is defined using the control unit 101 of the particle beam device 1. For example, a rectangular shape is selected as the shape of the ablation area. However, the invention is not limited to the aforementioned form. Rather, any form of ablation area that is suitable for the invention can be selected in the case of the invention. As already mentioned above, the ablation depth of the ablation area is an extension of the ablation area starting from the surface of the object 16 in the direction of the material of the object 16, ie into the interior of the object 16. Basically, the depth of ablation defines the extent of the area of ablation from the surface of the object 16 into the material of the object 16 .

In method step S7, the data connection 201 is established between the control unit 101 of the particle beam device 1 and the data memory 200, which is physically separate from the particle beam device 1.

In method step S8, at least one control parameter stored in data memory 200 or a plurality of control parameters stored in data memory 200 is selected depending on the specified form of the excavation area and/or the specified excavation depth. The selection is made, for example, in such a way that control parameters are selected, of which it is already known that they ensure the production of the defined shape of the area to be removed and the defined depth of removal on the object 16 . In addition, it is provided to select the control parameter or parameters depending on the material composition of the ablation area determined during the examination, in which the achievement of the defined shape of the ablation area and/or the defined excavation depth is particularly easy. Basically, the data memory 200 includes a database which has control parameters which are known to result in the specified shape of the ablation area and the specified ablation depth on the object 16 when these control parameters are used to control units of the particle beam device 1 . For example, the control parameters stored in data memory 200 are based on empirical values from the past, with the empirical values not only coming from a single user, but, for example, from numerous users who use the empirical values known to them, which are necessary to achieve the specified shape of the ablation area and/or used at the specified depth of excavation on object 16. Control parameters are also selected with which, given the determined material composition, it is particularly possible to achieve the defined shape of the area to be removed and/or the defined depth of removal.

In the event that no control parameter is stored in the data memory 200 of which it is known that the specified shape of the ablation area and/or the specified ablation depth can be achieved using this control parameter, one or more control parameters are selected that achieve(s) a shape of the area of excavation and/or depth of excavation that deviates only slightly from the specified shape and depth of excavation. For example, the deviation is less than 2%.

In step S9, the selected control parameter(s) is/are removed from the data memory 200 is loaded into the control unit 101 of the particle beam device 1 .

In method step S10, at least one of the above-mentioned units of the particle beam device 1 is controlled by the control unit 101 using the loaded control parameter associated with the corresponding unit or using the loaded control parameters associated with the corresponding unit. As explained above, each control parameter is a physical variable with which the setting of at least one of the above-mentioned units of the particle beam device 1, which have been explained with regard to the particle beam device 1, can be changed, so that at least one property of the particle beam device 1 is set and/or influenced. The control parameter or parameters is/are used, for example, to set and/or influence at least one of the properties of the particle beam device 1 listed above.

In method step S11, the number of scan points to which the ion beam is guided when scanning over the ablation area of the object 16 is determined. Furthermore, the speed at which the ion beam is scanned over the ablation area of the object 16 (ie the scanning speed) is determined.

In method step S12, the material of object 16 is removed in the removal area with the ion beam using the unit(s) of particle beam device 1 controlled with the control parameter(s).

6 shows additional method steps which can be carried out after method step S12. In method step S13, after the material has been removed from the area removed, the area removed is measured. Furthermore, the measured removal area is compared with the defined shape of the removal area and the defined removal depth. In method step S14, a check is made as to whether the measured removal area deviates from the defined shape of the removal area and the defined removal depth. If no discrepancy is found or the discrepancy is less than, for example, one percent, then the method ends. However, if a discrepancy is found, then in method step S15 the control parameter or parameters are readjusted. If necessary, material is again removed from the removal area in order to achieve the defined shape of the removal area and the defined depth of removal. In other words, in method step S15 the control parameter or parameters are changed in such a way that the defined shape of the area to be removed and/or the defined depth of removal is/are achievable. The changed control parameter or the changed control parameters is/are then stored in the method step S16 in the data memory 200 so that this/these changed control parameter(s) can be used in a later implementation of the method according to the invention.

The features of the invention disclosed in the present description, in the drawings and in the claims can be essential both individually and in any combination for the realization of the invention in its various embodiments. The invention is not limited to the embodiments described. It can be varied within the scope of the claims and taking into account the knowledge of the person skilled in the art.

Reference List

1

particle beam device

2

first particle beam column in the form of an ion beam column

3

second particle beam column in the form of an electron beam column

4

first optical axis

5

second optical axis

6

second beam generator

7

first electrode

8th

second electrode

9

third electrode

10

beam guide tube

11

collimator unit

12

first toroidal coil

13

yoke

14

pinhole

15

first detector

16

object

17

central opening

18

second objective lens

19

magnetic lens

20

electrostatic lens

21

second toroidal coil

22

inner pole shoe

23

outer pole shoe

24

end of the beam guiding tube

25

termination electrode

26

scanning device

27

first beam generator

28

extraction electrode

29

collimator

30

variable aperture

31

first objective lens

32

scanning electrodes

100

sample chamber

101

control unit

102

processor

103

second detector

104

radiation detector

200

data storage

201

Data Connection

300

system

S1 to S16

process steps

Claims (11)

Method for removing material from an object (16) using a particle beam device (1) which has a particle beam with charged particles, the method comprising the following steps: - Identifying a removal area on the object (16) on which material of the object (16) is to be removed with the particle beam; - defining a shape of the ablation area and/or an ablation depth of the ablation area using a control unit (101) of the particle beam device (1); - Establishing a data connection (201) of the control unit (101) of the particle beam device (1) with a data memory (200) which is locally separated from the particle beam device (1); - Selecting at least one control parameter stored in the data memory (200) as a function of the specified shape of the excavation area and/or the specified excavation depth; - loading the selected control parameter from the data memory (200) into the control unit (101); - Controlling at least one controllable unit (6 to 9, 11 to 14, 18 to 32) of the particle beam device (1) by means of the control unit (101) using the selected control parameter; such as - Removal of the material of the object (16) in the removal area with the particle beam using the controlled with the control parameter unit (6 to 9, 11 to 14, 18 to 32) of the particle beam device (1). procedure after claim 1 , wherein the data connection (201) is established via the Internet and/or an intranet. Method according to one of the preceding claims, wherein (i) the control parameter is changed; and (ii) the changed control parameter is stored in the data memory (200) as a function of the specified excavation area and/or the specified excavation depth. Method according to one of the preceding claims, in which the control parameter is a first control parameter, the controllable unit (6 to 9, 11 to 14, 18 to 32) of the particle beam device (1) having a controllable first unit (6 to 9, 11 to 14, 18 to 32) of the particle beam device (1), and wherein the method further comprises the following steps: - selecting at least one second control parameter stored in the data memory (200) as a function of the specified shape of the excavation area and/or the specified excavation depth; - loading the selected second control parameter from the data memory (200) into the control unit (101); - Controlling the first unit (6 to 9, 11 to 14, 18 to 32) and/or at least one second unit (6 to 9, 11 to 14, 18 to 32) of the particle beam device (1) by means of the control unit (101). using the second control parameter; such as - Ablation of the material of the object (16) in the ablation area with the particle beam using the first unit (6 to 9, 11 to 14, 18 to 32) of the particle beam device (1) controlled with the second control parameter and/or the second unit (6 to 9, 11 to 14, 18 to 32) of the particle beam device (1). Method according to one of the preceding claims, ions and/or electrons being used as charged particles. Method according to one of the preceding claims, in which the ablation area is examined by means of X-ray spectroscopy and/or mass spectroscopy and in which the control parameter is selected as a function of the material composition of the object (16) determined during the examination. Computer program product with a program code which can be loaded into a processor (102) and which when executed is a particle beam device (1) controls such that a method according to at least one of the preceding claims is carried out. Particle beam device (1) for removing material from an object (16), with - at least one beam generator (6, 27) for generating a particle beam with charged particles; - At least one objective lens (18, 31) for focusing the particle beam onto the object (16); - At least one scanning device (26, 32) for scanning the particle beam over the object (16); - At least one detector (15, 103, 104) for detecting interaction particles and/or interaction radiation resulting from an interaction of the particle beam with the object (16); - at least one display device for displaying the image and/or a result of the analysis of the object (16); and with - at least one control unit (101) with a processor (102) in which a computer program product claim 7 is loaded. Particle beam device (1) after claim 8 , wherein the beam generator (27) is designed as a first beam generator and the particle beam is designed as a first particle beam with first charged particles, the objective lens (31) being designed as a first objective lens for focusing the first particle beam onto the object (16), and wherein the particle beam device (1) further comprises: - at least one second beam generator (6) for generating a second particle beam with second charged particles; and - at least one second objective lens (18) for focusing the second particle beam onto the object (16). Particle beam device (1) after claim 8 or 9 , wherein the particle beam device (1) is an electron beam device and/or an ion beam device. System (300) with - a particle beam device (1) according to one of Claims 8 until 10 ; and with - a data memory (200) that is locally separate from the particle beam device (1) and can be connected to the particle beam device (1) via a data connection (201), wherein in the data memory (200) at least one control parameter for controlling a unit (6 to 9 , 11 to 14, 18 to 32) of the particle beam device (1) is stored.

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