ion source

Abstract

The present invention relates to an ion source 10 for generating ions 16 or an ion beam 16a, comprising an ion generation chamber 11 for generating ions 16. To ensure monitoring, and in particular safety, of the ion source 10, the ion source 10 comprises a pressure measurement device 30 associated with the ion generation chamber 11, the pressure measurement device 30 comprising a first pressure measurement device 31, which is in particular designed in the form of a gas friction manometer or in particular comprises a gas friction manometer. The present invention further relates to a method for handling the ion source 10.

Description

[Technical Field]

[0001] The present invention relates firstly to an ion source, and more particularly to an ion generating device having an ion source, and to a method dealing with an ion source, in particular for generating ions in an ion source. [Background technology]

[0002] Ion sources, also known as ion guns or plasmatrons in some designs, are used to generate ions and, in some designs, ion beams. The ions are often generated in an ion generation chamber. The ions, and possibly some directional movement of the ions, are first generated in the ion generation chamber. This generation often takes place in a vacuum. Ion sources themselves are known in various forms from the state of the art and are familiar to experts, so there is no need to describe them in more detail here.

[0003] An ion source is, inter alia, a component of an ion-generating device or system in which ions are used in the processing of a workpiece. Ion sources may be used in a wide variety of areas, such as nuclear fusion, mass spectrometers, implantation systems, ion microprobes, rocket propulsion systems, etc.

[0004] The applicant's published patent application DE 102021129731 A1 discloses an ion generating device for use in an implantation system, the implantation system comprising an ion generating device which comprises an ion source as a component thereof, the ions being generated by the ion source. The ion beam is generated in an ion beam generating device, which comprises a device for extracting ions by means of an electrostatic field and / or a device for mass separating ions in a mass spectrometer and / or a device for accelerating ions. Furthermore, the ion generating device comprises a device for deflecting the ion beam in an electric field, by means of which the ion beam is directed onto the workpiece to be processed. Finally, the ion generating device comprises means for implanting ions into the workpiece to be processed. The workpiece is located in a processing chamber of the implantation system, and the implantation process also takes place in the processing chamber of the implantation system. The ion beam, generated in an ion source and directed in the ion generating device, impinges on the workpiece to be processed. A pressure measuring device in the form of a gas friction manometer is assigned to the processing chamber of the implantation system. The pressure measuring device is used to measure the pressure, in particular the vacuum, in the processing chamber of the implantation system during the implantation process. The pressure measurement signal generated is used to determine a correction factor that also accounts for ions that are neutralized during the process. Summary of the Invention [Problem to be solved by the invention]

[0005] It is an object of the present invention to further improve the performance of such ion sources. [Means for solving the problem]

[0006] According to the present invention, this object is solved by an ion source having the features of independent claim 1 forming a first aspect of the invention, an ion generating device having the features of independent claim 10 forming a second aspect of the invention, and a method having the features of independent claim 11 forming a third aspect of the invention.

[0007] Further features and details of the invention can be obtained from the dependent claims, the description and the drawings. For the disclosure of one aspect of the invention, reference should always be made in full to the disclosure of the other two aspects of the invention, since the features and details described with respect to one of the aspects of the invention also apply in full to the features and details described with respect to each of the other aspects of the invention, and vice versa.

[0008] The present invention is not limited to any particular application of the ion source, nor is the present invention limited to any particular type of ion source.

[0009] The basic idea of ​​the present invention is that the pressure measurement device is now directly associated with the ion source. Therefore, the pressure of the ion source, in particular at or within the ion source, is preferably determined individually for the ion source. In this way, the performance of the ion source is further improved. This can be achieved in various ways. For example, the ion source can be precisely controlled and / or monitored using the pressure determined by the pressure measurement device. In particular, the pressure measuring device may also be used to determine and / or control and / or monitor important parameters of the ion source, in particular control parameters. Alternatively or additionally, the pressure measuring device may also be used to monitor the safety of the ion source.

[0010] According to the invention, at least one gas friction manometer is used for pressure and process monitoring, especially in the region of the ion source, although the invention is not limited to this embodiment.

[0011] The monitoring is preferably carried out independently of the application area and application process in which and for which the ion source is used. The monitoring is carried out directly at the ion source, i.e., immediately, which makes it possible to influence, if necessary, at a very early stage.

[0012] According to a first aspect of the present invention, an ion source is provided comprising the features of independent claim 1.

[0013] Ion sources are used to generate ions or ion beams, meaning that the ion source is provided in such a way that it generates or can generate at least ions and, depending on the configuration, also ion beams. In particular, an ion source is a device in which ions are generated. Ions are atoms that carry an electric charge. The ion source according to the present invention can be used to generate both positive and negative ions of a wide variety of chemical elements, as well as singly and multiply charged ions. In a simple embodiment, the ion source is used to generate ions. In another embodiment, the ion source is used to generate an ion beam in addition to generating the ions themselves. In this case, the ion source generates more or less directional movement of the ions.

[0014] The ion source comprises at least one ion generation chamber in which ions are generated. A chamber is in particular a preferably small space, mostly or completely closed, in which ions are generated. In one embodiment, the ion generation chamber comprises a chamber wall that defines the chamber interior space. If necessary, one or more connections for further components, inlets and outlets may be provided in the chamber wall, as will be explained in more detail below with reference to illustrative examples. The ion generation chamber may, for example, be designed as a cylindrical chamber, although the invention is of course not limited to this particular embodiment.

[0015] However, in further embodiments, the ion source may also comprise further components, located on or within the ion generation chamber, designed and arranged to generate an ion beam, in particular a directed ion beam, which may be of different types depending on the nature of the ion source.

[0016] Furthermore, according to the present invention, the ion source comprises a pressure measuring device associated with the ion generation chamber, the pressure measuring device comprising at least one first pressure measuring device. Thus, according to the present invention, the pressure measuring device is directly associated with the ion generation chamber. This means that the pressure measuring device is provided to cooperate with the ion generation chamber, in particular to enable determination of the pressure in the ion generation chamber. The pressure measuring device is in particular a device by means of which pressure, in particular a pressure ratio, is detected, e.g., measured or determined. In one embodiment, the pressure measuring device is preferably connected to the ion generation chamber such that the pressure at or in the ion generation chamber is measured or can be measured by the pressure measuring device.

[0017] The pressure measuring device and the first pressure measuring device may be designed in different ways, some embodiments of which are further described herein.

[0018] In one embodiment, the pressure measurement device is designed in the form of a physical entity. An entity is to be understood as a unit. A physical entity is a physical unit. Therefore, all components represent internal components related to the pressure measurement device. In particular, this means that all components are arranged or formed in a housing.

[0019] In a second embodiment, the pressure measuring device is designed partly in the form of a physical entity and partly in the form of a functional entity. A functional entity is characterized in particular in that the components are spatially separated from one another and the entity results from the functional interaction of the individual components. In this case, only a subset of the components are internal components in the sense of the first embodiment. At least one component of the pressure measuring device is designed as an external component to the pressure measuring device.

[0020] In a third embodiment, the pressure measuring device is designed as a purely functional entity, meaning that all components are designed as independent, spatially separated components, but the individual components are functionally connected to each other in an appropriate manner to realize the pressure measuring device.

[0021] According to the invention, the pressure measuring device comprises a first pressure measuring device which is designed in a special manner.

[0022] In principle, the present invention is not limited to a particular type of first pressure measurement device. Several embodiments are described herein. In one embodiment, the first pressure measurement device is designed as a pressure measurement device for high accuracy and / or long-term stable pressure measurement. In a preferred embodiment, the first pressure measurement device is designed in the form of a gas friction pressure gauge, also referred to herein as an SRG, or the first pressure measurement device comprises a gas friction pressure gauge.

[0023] Negative pressures, especially pressures within the ion production chamber, which are often vacuum, can be measured quite accurately through the use of a gas friction manometer. The generated pressure measurement signal can also be used to determine the correction factor.

[0024] The SRG (semi-permeable gas pressure gauge) is non-ionizing, less dependent on the gas species than many other measuring devices, such as ionization gauges or Pirani gauges, less sensitive to coatings, and especially very stable over time. This is because only the reduction in the rotation speed of a contactless rotating sphere in a vacuum is determined. This is a mathematical method without any electrical and / or mechanical components in the measuring range.

[0025] Gas friction manometers are characterized by a high degree of absolute accuracy and / or long-term stability. Furthermore, they do not affect the vacuum, are resistant to the media used, and are as insensitive as possible to contaminants.

[0026] According to one embodiment, a gas friction manometer comprises a rotating ball. Such a gas friction manometer basically works as follows: the ball is frictionlessly mounted in a magnetic field. An external rotating magnetic field acts as a drive for the ball, putting it into a rotational state and causing it to rotate. The drive is then switched off. The ball is decelerated by the molecules in the remaining gas. A scanning coil measures the reduction in rotational speed and is used to determine the particle density of the gas. The deceleration rate can be measured directly as a measure of density or pressure. In this way, only global properties of the ball are included in the measurement and stored together with a coefficient (calibration coefficient). The rest of the setup is not variable or prone to errors. The measured pressure value provided by the gas friction manometer is preferably provided in the form of an electrical signal.

[0027] Gas friction manometers have a high degree of accuracy (1% of the measured value) and work in principle throughout the entire measurement range, but are currently only available in the high vacuum (HV) range (>10 to 1x10 -7 The pressure measuring device has a fairly simple design with a rotating ball as a sensor and operates without contact with components to which vacuum or mechanical stress is applied and without feedthroughs. All information and interactions are transmitted to the vacuum via magnetic and electromagnetic forces. Gas friction manometers therefore have no electrically or mechanically stressed components, achieve correspondingly high long-term stability (deviation <1% / year), are robust, corrosion-resistant, and are, for example, made entirely of metal. Because the measurement signal is based on changes in the sphere's rotation speed rather than changes in distance or gas ionization, the process is less affected by the effects of temperature, aging, or coatings. Due to their accuracy and long-term stability in high vacuum, gas friction manometers are used as transfer standards in many calibration laboratories.

[0028] According to another embodiment, the first pressure measuring device is designed as a so-called ion meter measuring tube, which will be explained in more detail in the present specification. The invention is not limited to the examples mentioned.

[0029] In principle, it is sufficient for the pressure measurement device to comprise a single first pressure measurement device. According to another embodiment, the pressure measurement device comprises two or more pressure measurement devices. In one embodiment, for example, at least one pressure measurement device is designed as a first pressure measurement device in the form of a gas friction manometer or comprises a gas friction manometer. However, the pressure measurement device may also comprise two or more first pressure measurement devices. Alternatively, the pressure measuring device may comprise at least one first pressure measuring device and at least one further pressure measuring device, where the at least one further pressure measuring device is preferably designed in a different manner and is designated as a second pressure measuring device for distinction. The present invention is not limited to a specific type of second pressure measuring device. Further, several example embodiments are described herein. For example, the first pressure measuring device may also be called a measuring tube.

[0030] Several embodiments of various pressure measurement devices are described below.

[0031] For example, if measurements are typically taken in a vacuum rather than in air, at least one second pressure measuring device or second measuring tube may also be provided, for example in the form of a compound transducer. A transducer is in particular a converter or transformer that converts one form of energy into another. In one embodiment, such a compound transducer may comprise, for example, a Pirani component and a piezo component. Pirani components are specific measuring devices that measure pressure in particular in the coarse and fine vacuum ranges and are generally familiar to those skilled in the art. If the pressure measuring device comprises only one pressure measuring device, in one embodiment, this pressure measuring device is designed in the form of a compound transducer. In one embodiment, such a composite transducer may consist of a first pressure measuring device, in particular in the form of a gas friction manometer, for example having a measurement range of 10-8 mbar to 10-3 mbar, and a further pressure measuring device, in particular a combined Pirani component and possibly a piezoelectric component, for example having a measurement range of 10-3 mbar to 1000 mbar.

[0032] To cover the entire pressure range with the pressure measuring device, according to one embodiment, a first pressure measuring device is used, for example, in the form of an ion meter measuring tube, having a measuring range of 10 mbar to 10 mbar. Ion meter measuring tubes, also known as ionization gauges, are well-known pressure measuring devices for determining pressure in the high and ultra-high vacuum range. A second pressure measuring device or second pressure measuring meter, for example, having a measuring range of 10 mbar to 1000 mbar, can be provided in the form of a hybrid transducer. Such a hybrid transducer combines two measuring principles, for example, Pirani and Piezo, and is installed in one measuring tube. In another embodiment, this second pressure measuring device is provided as a simple transducer with only one measuring principle.

[0033] In one embodiment, a gas friction manometer is used instead of an ION meter component, in which case the first and second pressure measuring devices are provided, for example, as separate measuring tubes.

[0034] According to another embodiment, the pressure measurement device is provided in the form of a single pressure measurement device. In this case, the pressure measurement device can be provided as a composite transducer that covers the entire range and combines, for example, several measurement principles. For example, such a composite transducer can have an ion meter component and, for example, a Pirani component and / or a piezo component. In one embodiment, a gas friction manometer is used instead of the ion meter component.

[0035] In one embodiment, a control device is assigned to the ion source, in particular the control device is the sum of all components that affect the ion source. The control device may take the form of a hardware or software component, or a combination thereof. In particular, the control device comprises a processor device in which at least part of the method according to the third aspect of the invention is executed. The control device preferably comprises interfaces to various components of the ion source. For example, some values ​​or parameters of the ion source are recorded by the components, transmitted to the control device, and analyzed in the control device. In this case, individual components of the ion source may be controlled accordingly via the control device. This will be explained in more detail below using illustrative examples, in particular in relation to the method according to the third aspect of the invention. In some embodiments, the control device is at least partly a component of the ion source. Alternatively, the control device is a component external to the ion source, in which case it is at least temporarily connected to and communicates with the ion source via an interface, for example wirelessly or by wire.

[0036] In one embodiment, the first pressure measuring device is connected to the ion production chamber, for example, via a suitable connection. In another embodiment, the first pressure measuring device is located within the ion production chamber.

[0037] In one embodiment, the ion generation chamber is designed as an ion generation chamber with a negative pressure, in particular as a vacuum-tight ion generation chamber. To this end, in one embodiment, the ion generation chamber is connected to an exhaust device, for example, a vacuum pump. In one embodiment, the exhaust device is connected to a control device via a suitable interface.

[0038] In one embodiment, the first pressure measurement device is aligned horizontally, which means that the first pressure measurement device has a vertical orientation with respect to the ion generation chamber. If such a configuration is not directly possible, a corresponding angled connection, such as a corresponding angled tube, may be provided between the first pressure measurement device and the ion generation chamber.

[0039] The present invention is not limited to a particular type of ion source. For example, ionization of molecules can be achieved by impact ionization, chemical ionization, thermal ionization, or field ionization. In an electric field, for example, ions can be generated, focused, deflected by electric or magnetic lenses, and then accelerated. The ion source according to the present invention is not limited to a particular type of ionization, the only requirement being that the ionization of molecules be carried out in an environment, in particular in a chamber in which the pressure can be measured.

[0040] In one type of ion source, the ionization of the molecules to be ionized is carried out in an ion generation chamber under negative pressure or in vacuum, which is preferably connected to an exhaust device through which the ion generation chamber is subjected to negative pressure / vacuum.

[0041] In one embodiment, the ion source is designed as an ion source for electron ionization. This type of ionization is a fairly widely used ionization method. In particular, electrons from a cathode, a so-called filament such as an incandescent filament, are accelerated by an electric field. The electrons are emitted from the surface of the cathode. These electrons are accelerated in an electric field to an anode. These electrons are sent through the molecules to be ionized, e.g., the corresponding gas, as they move through the ion generation chamber. In particular, an acceleration voltage is applied for this purpose. When the electrons collide with the molecules, the molecules are ionized. These ionized molecules are introduced into the ion generation chamber, e.g., in the form of a gas flow. When the molecules and the electrons approach each other and interact, ionization can occur. In particular, the ion generation chamber is a vacuum-tight component. The electron ionization is carried out in particular under negative pressure, e.g., in a vacuum. The pressure prevailing in the ion generation chamber is measured by a first pressure measuring device in the form of a gas friction manometer.

[0042] In one embodiment, a cathode, particularly in the form of a filament, and an anode are arranged in the ion generation chamber. In one embodiment, the cathode and / or the anode are connected to a control device via a suitable interface. The first pressure measurement device is preferably arranged spatially separated from the cathode or at a spatial distance from the cathode. For example, the ion source is designed as a cold cathode source or a hot cathode source.

[0043] However, in principle the first pressure measuring device may be located at any point on or within the ion generation chamber, depending for example on where the vacuum connection is located.

[0044] In one embodiment, the ion generation chamber is connected to a supply of molecules to be ionized, in particular a gas supply, via which the molecules to be ionized are supplied to the ion generation chamber, i.e. the inner space of said chamber, in particular in the form of a gas flow.

[0045] In one embodiment, the supply interacts with a mass flow control device. In one embodiment, the mass flow control device is located in the feed or provides a transition between the supply and the ion generation chamber. In particular, the mass flow control device is a component that can control the mass flow rate of the molecules to be ionized entering the ion generation chamber, in particular to a set value. In one embodiment, the mass flow control device is connected to a control device via an interface for this purpose. In one embodiment, the mass flow control device comprises a controller and a valve that interacts with the controller. The use of such a mass flow control device in conjunction with an ion source is shown below by way of example. The pressure value is measured by a first pressure measuring device in the ion generation chamber and compared with the set value. In particular, the regulation is performed in the control unit. The mass flow control device is actuated accordingly as necessary to ensure that the set value and the actual value coincide, for example by opening the valve of the supply to the ion generation chamber accordingly or by reducing the size of the inlet opening. This will also be explained below with respect to the method according to the invention, so in this respect reference is also made to the corresponding explanation below in full.

[0046] In one embodiment, the ion source further features an extraction device that, among other things, serves to extract ions from, for example, the plasma to form a beam. Such an extraction device is therefore provided in particular for shaping the ion beam and / or aligning the ion beam and / or extracting ions from the supplied ionized molecules. In one embodiment, the extraction device is part of the ion source. In this case, the ion source comprises both the ion generation chamber and the extraction device. In another embodiment, such an extraction device is associated with the ion source, in particular downstream of the ion source. This means that the ion source cooperates with the extraction device, and the extraction device is connected downstream of the ion source. In this case, only ions are generated in the ion source, and then the ions are generated into an ion beam in the extraction device.

[0047] In one embodiment, the ion generation chamber comprises an outlet for the generated ions and / or the generated ion beam.

[0048] In one embodiment, a pre-acceleration device is provided in the ion generation chamber. The pre-acceleration device pre-accelerates ions generated in the ion generation chamber. In one embodiment, the pre-acceleration device is connected to the control device via a suitable interface.

[0049] In one embodiment, a lens device is provided in the ion production chamber. The lens device, for example in the form of a focusing lens device, for example in the form of an electrostatic lens device, focuses the ion beam. If the lens device is designed to be variable, in one embodiment the lens device is connected to the control device via a suitable interface.

[0050] In the above-described embodiments, the pre-acceleration device and / or the focusing device, respectively, are components of the ion source. According to another embodiment, the pre-acceleration device and / or the focusing device are not components of the ion source. In this case, the pre-acceleration device and / or the focusing device are downstream of or associated with the ion source.

[0051] The pressure measuring device, in particular the first pressure measuring device, may perform or fulfill various tasks and functions in conjunction with the ion source. Some examples of these tasks and functions, which may be realized individually or in any combination, are listed below. For example, the pressure measuring device, in particular the first pressure measuring device, may be designed or provided to control and / or monitor the ion source, in particular to determine and / or control and / or monitor important parameters, in particular control parameters, of the ion source, in particular to control and / or monitor a mass flow control device, and / or to measure the pressure inside the ion generation chamber, and / or to determine the cleanliness of components inside the ion generation chamber, and / or to determine the airtightness of the ion source.

[0052] For example, the pressure measuring device, particularly the first pressure measuring device, monitors the mass flow control device, i.e., adjusts the gas inlet to the ion generation chamber and thus regulates the pressure. Alternatively, the pressure measuring device measures the pressure of the ion generation chamber itself, i.e., measures the quality of the vacuum. Alternatively, the pressure measuring device measures the cleanliness of the ion source components in the vacuum. For example, ion sources are changed approximately every two weeks due to reactions with corrosive gases. Despite careful storage, new ion sources become covered with "dirt," which initially diffuses into the ion generation chamber and thus causes higher vacuum pressures. Alternatively, the pressure measuring device measures the airtightness of the ion source. Maintenance and associated evacuation can cause leaks when the system is restarted, for example, if seals are not properly secured or components are damaged. In particular, the pressure measuring device according to the present invention, particularly the first pressure measuring device, generally serves as a safety device.

[0053] According to a second aspect of the present invention, an ion generating device is provided comprising the features of independent claim 11.

[0054] The ion generation device firstly comprises an ion source, the ion source having an ion generation chamber for generating ions and a pressure measurement device associated with the ion generation chamber, the pressure measurement device comprising a first pressure measurement device, in particular designed in the form of a gas friction manometer or in particular comprising a gas friction manometer. In particular, the ion generation device comprises an ion source according to the first aspect of the invention. To avoid repetition, reference is therefore made in full to the description relating to the first aspect of the invention at this point.

[0055] Furthermore, the ion generation device comprises an extraction device, which is in particular arranged to generate and / or guide the ion beam and / or extract ions from the supplied ionized molecules. In an embodiment, the extraction device is at least partially part of or associated with the ion source. In this respect, reference is also made in full to the corresponding description of the ion source according to the invention above.

[0056] The ion generating device further comprises a device for accelerating ions generated in the ion source, which accelerates ions to a final energy and is a separate and independent component from the pre-acceleration device through which ions generated in the ion generating chamber of the ion source are pre-accelerated. However, in some embodiments, only one acceleration device may be provided, which performs both pre-acceleration and final acceleration of ions.

[0057] Furthermore, the ion generation device may also comprise a device for mass separating the ions in a mass separator and / or a device for deflecting the ion beam in an electric field, by means of which the ion beam is directed onto the workpiece to be processed, in particular onto the substrate of the workpiece.

[0058] All of the above-mentioned components of the ion generating device may also be components of the ion source, in which case the ion source assumes the function of the ion generating device. In another embodiment, the ion source is an independent functional and / or structural entity in which only ions are generated. In this case, other features of the ion generating device are not part of the ion source but are associated with the ion source.

[0059] In one embodiment, the ion source according to the invention and / or the ion generating device according to the invention are used in conjunction with an ion implantation system. Ion implantation is a method for introducing foreign atoms in the form of ions into a substrate. In this way, the material properties of the substrate can be modified. Such an implantation method essentially involves the following steps: first, ions are generated in an ion source, for example an ion source according to the first aspect of the invention; then the ions are extracted by an electrostatic field; then the ions are mass separated in a mass separator; then the ions are accelerated and deflected by an electric field. These steps are performed, for example, in the ion generating device according to the invention or, as far as extraction is concerned, possibly in the ion source according to the invention. Finally, the substrate is implanted.

[0060] However, the ion source according to the first aspect of the invention may be used in a wide variety of areas, for example in nuclear fusion, mass spectrometers, implantation systems, ion microprobes, rocket propulsion systems, etc. The invention is not limited to any particular field of application.

[0061] According to a third aspect of the present invention, there is provided a method comprising the features of independent patent claim 12. The method is a method for handling an ion source, i.e. the method is used to determine how to use an ion source in a specific manner. In one embodiment, the use refers to the generation of ions or an ion beam. However, in one embodiment, the use also refers to the monitoring and / or control of an ion source. In one embodiment, the use is a combination of the two types of use.

[0062] In particular, the method is used to treat an ion source according to the first aspect of the invention, and in this respect, to avoid repetition, reference is made in full to the description of the first aspect of the invention.

[0063] The ion source is provided such that, within an ion generation chamber of the ion source, ions are generated from molecules that are ionized in an ionization process.

[0064] The method according to the invention is characterized in that a pressure value in or within the ion generation chamber is detected or determined before and / or during and / or after the ionization process via a pressure measuring device assigned to the ion generation chamber, the pressure measuring device comprising a first pressure measuring device, which is in particular designed in the form of a gas friction manometer or in particular comprises a gas friction manometer, in this way the pressure measuring device can be used to carry out pressure and process monitoring in the region of the ion source.

[0065] In one embodiment, the method further comprises the steps of: a) supplying the ion source with molecules to be ionized, in particular in a gas flow, via a supply to the ion generation chamber, and b) generating ions from the molecules to be ionized in the ion generation chamber in an ionization step, which step thus also generates ions or an ion beam.

[0066] In one embodiment, the method performs pressure and process monitoring in the region of the ion source by a pressure measurement device before and / or during and / or after the ionization process, and serves to set parameters of the ionization process based thereon, such that the generation of ions is performed based on results determined as part of the monitoring.

[0067] In one embodiment, the ion source is released or the ionization process is initiated when the pressure measuring device, in particular the first pressure measuring device, measures that the pressure value, in particular the vacuum pressure, in the ion generation chamber is below a certain predetermined pressure value.

[0068] In this case, the ion source or ionization process is released only when, for example, the gas inlet, i.e., mass flow control device, is activated, the valve to a particular vacuum pump is activated, if necessary, the vacuum shutter to the next process chamber is activated, etc., or only when the pressure measurement device, in particular the first pressure measurement device, measures that the vacuum pressure falls below a particular level, otherwise components may be damaged, the actual process may be jeopardized, or, for example, harmful gases may escape from the chamber.

[0069] According to another embodiment, the ionization process may alternatively or additionally be initiated or carried out when the pressure measurement device is bypassed. In this case, in one embodiment, a suitable switching device connected to the control device via a suitable interface may be used to individually switch whether the pressure measurement device is switched or bypassed, if necessary, at the start and / or during the ionization process. Such a procedure may be useful, for example, if there is a risk of the pressure measurement device failing, especially during the ionization process.

[0070] In one embodiment, the first pressure measurement device, in particular the first pressure measurement device, is used to monitor and / or calibrate a mass flow control device provided for supplying the molecules to be ionized. This is shown by way of example.

[0071] In particular in the case of a first pressure measuring device in the form of a gas friction manometer, it is possible to calibrate the mass flow controller for a 100% linear characteristic. In one embodiment, standard cubic centimeters per minute (sccm) is plotted or mapped against pressure. This is preferably done within the control device described above. The unit "sccm" is used to represent a specified gas flow rate, i.e., particle number or gas mass per time period, independent of pressure and temperature, i.e., particle flow rate or mass flow rate. If the curve is not linear, this means that the mass flow control device is out of sync, i.e., not functioning correctly.

[0072] Typically, various processes involving different gas mixtures and amounts are performed on a processing system. For example, a process or "recipe" may be comprised of various gas amounts. This is illustrated by an example where such a process or "recipe" is comprised of various gas species, e.g., H, BF, and Ar, e.g., A step: H2 (1 sccm), BF3 (2 sccm) and argon (1 sccm), and Another step: PH3 (3 sccm) and argon (1 sccm) is.

[0073] Sometimes there are such process adjustments, i.e., slight changes in "sccm." This change is reflected in the pressure and can be measured by a pressure measurement device, particularly a first pressure measurement device such as a gas friction manometer. This pressure measurement device can be used to verify whether the process and components are adapting to the changes. Of course, many other processes involving other gas mixtures and gas amounts are possible.

[0074] A further advantage of the ion source and the method according to the invention is the reduction of the process window. Because the solution according to the invention, and in particular the values ​​determined by the solution, are reproducible and consistent, the pressure window within which the ionization process can be carried out can be reduced and optimized (e.g., from a process pressure of 2E-5 mbar and the standard measuring tube limit of 5E-6 mbar / 4E-5 mbar to the gas friction manometer limit of 1.6E-5 mbar / 2.4E-5 mbar). Through this optimization, the amount of gas required for optimal results can be accurately determined, ultimately leading to a reduction in the amount of gas and resulting in cost savings.

[0075] In an embodiment, the pressure measuring device, in particular the first pressure measuring device, is realized to control and / or monitor the ion source, in particular to determine and / or control and / or monitor important parameters of the ion source, in particular to control and / or monitor a mass flow control device, and / or to measure the pressure inside the ion generation chamber, and / or to determine the cleanliness of components inside the ion generation chamber, and / or to determine the airtightness of the ion source.

[0076] Depending on the system and type, standard installed measuring tubes associated with ion generation typically fail within 2 to 8 weeks. This failure results in unplanned system downtime, but at the very least requires trained personnel to repair / replace the measuring tube. With the solution according to the invention, these drawbacks can now be avoided.

[0077] The invention will now be described in more detail with reference to the accompanying drawings. [Brief explanation of the drawings]

[0078] [Figure 1] 1 is a schematic diagram of an ion source according to the present invention; [Figure 2] 1 is a schematic diagram of a first pressure measurement device designed as a gas friction manometer interacting with an ion source. DETAILED DESCRIPTION OF THE INVENTION

[0079] FIG. 1 shows an embodiment of an ion source 10 according to the present invention. The ion source 10 comprises an ion generation chamber 11 having a chamber wall 11a, which defines an inner chamber space 11b. The ion generation chamber 11 is connected to a connection flange 34 of a pressure measurement device 30 via a connection 12. For simplicity's sake, this pressure measurement device 30, which will be described in more detail below with reference to FIG. 2, comprises only a first pressure measurement device 31 in the form of a gas friction manometer for illustrating the principles of the present invention. The components of the first pressure measurement device 31 are located in a housing 33. The first pressure measurement device 31 is oriented perpendicular to the ion generation chamber 11, as indicated by an arrow 32.

[0080] The ion generation chamber 11 is also connected to a supply 14 for molecules 15 to be ionized, which are delivered to the ion generation chamber 11 in the form of a gas flow. The molecules 15 to be ionized are shown as small circles in Figure 1. A mass flow control device 17 is located or formed within the supply 14 to control the quality of the ionized molecules 15 supplied.

[0081] A cathode 13a with a filament and an anode 13b are positioned in the ion generation chamber 11 to generate ions 16, shown as small squares in Figure 1. A magnetic field can be applied via a magnet 29 provided.

[0082] A pre-acceleration device 19 and a lens device 20 are also provided in the ion production chamber 11 for producing the ion beam 16a. Depending on the configuration, the pre-acceleration device 19 and the lens device 20 are components of the ion source 10. Alternatively, the pre-acceleration device 19 and the lens device 20 are independent components compared to the ion source 10, in which case they are connected downstream of or associated with the ion source 10. This is indicated diagrammatically in the ion production chamber 11 by dashed-dotted lines.

[0083] The generated ion beam 16 a leaves the ion generation chamber 11 via an outlet 18 .

[0084] In the example embodiment shown in FIG. 1 , the ion source 10 is designed as an ion source for electron ionization. In this process, electrons from a cathode 13a, in particular a so-called filament such as an incandescent filament, are accelerated by an electric field. The electrons are emitted from the surface of the cathode 13a. These electrons are accelerated in the electric field to the anode. These electrons are sent through the molecules 15 to be ionized, e.g., the corresponding gas, as they move through the ion generation chamber 11. When the electrons collide with the molecules 15 to be ionized, the molecules are ionized, i.e., become ions 16.

[0085] The ion generation chamber 11 is in particular a vacuum-tight component. In particular, electron ionization takes place in a vacuum. For this purpose, the ion generation chamber 11 is connected to a vacuum pump 22. The pressure prevailing in the ion generation chamber 11 is measured by a first pressure measuring device 31 in the form of a gas friction manometer.

[0086] Before and / or during and / or after the ionization process, the pressure value in the ion generation chamber 11 is recorded or determined via a pressure measuring device 30 assigned to the ion generation chamber 11, said pressure measuring device 30 comprising at least one first pressure measuring device 31 in the form of a gas friction manometer. In this way, the first pressure measuring device 31 can be used to carry out pressure and process monitoring in the region of the ion source 10.

[0087] To this end, a control device 21 is preferably assigned to the ion source 10, the control device 21 being at least temporarily connected to and communicating with the various components of the ion source 10 via appropriate interfaces. For example, the control device 21 is connected to the mass flow control device 17 via interface 23, to the first pressure measurement device 31 via interface 24, to the pre-acceleration device 19 via interface 25, to the vacuum pump 22 via interface 26, to the cathode 13a via interface 27, and to the anode 13b via interface 28. Naturally, the invention is not limited to the interfaces shown, as these interfaces are exemplary in nature and serve to illustrate the control device 21 and its functions.

[0088] For example, the ion source 10 is enabled to operate or the ionization process is initiated only when the first pressure measuring device 31 measures that the pressure value, in particular the vacuum pressure, in the ion generation chamber 11 is below a certain predetermined pressure value. A switching device (not shown) can also be used to switch the pressure measuring device 31 into a bypass at the start of the ionization process, so that the ionization process can be initiated and / or performed without the pressure measuring device 31 if necessary.

[0089] For example, the first pressure measuring device 31 may be used to monitor and / or calibrate a mass flow control device 17 provided for supplying the amount of molecules 15 to be ionized to the ion generation chamber 11. This is shown by way of example.

[0090] The mass flow control device 17 is connected to the control unit 21 via an interface 23. The pressure value is measured by a first pressure measuring device 31 in the ion generation chamber 11 and compared with a set value. Regulation is made in the control device 21, whereby the pressure value generated by the first pressure measuring device 31 is transmitted to the control device 21 via an interface 24. To ensure that the set value and the actual value match, the mass flow control device 17 is actuated accordingly, if necessary, for example by opening or reducing accordingly the size of the inlet opening of the supply 14 to the ion generation chamber 11.

[0091] In a preferred embodiment, the first pressure measuring device 31 is designed in the form of a gas friction manometer. An example of an embodiment of such a gas friction manometer will now be described with reference to FIG. 2. The individual components of the gas friction manometer are located in a housing 33. One characteristic feature of the gas friction manometer is formed by a vacuum tube 35 or measuring tube, which has a closed end 35b on one side and is connected at the other end to the ion generation chamber. The direction of connection is indicated here by an arrow 35a.

[0092] The gas friction manometer comprises a system of magnets and coils. Figure 2 shows an example of permanent magnets 37a, 37b, as well as a drive coil 38, a levitation / stabilization coil 39, a velocity detection coil 40 and a vibration damping coil 41.

[0093] The ball 36 is frictionlessly assembled within a magnetic field. The magnetic field is generated by permanent magnets 37a and 37b. To maintain the height, the magnetic field of the permanent magnets 37a and 37b is superimposed with a slowly varying DC current (position control) and a high frequency (impedance measurement) to determine the height. The ball 36 is passively stabilized horizontally (stable equilibrium). An external rotating magnetic field (approximately 400 Hz) rotates the ball 36, and the reduction in rotational speed is measured by a speed detection coil 40, which measures the gas particle density from friction. In this way, only the global characteristics of the ball 36 are included in the measurement and stored along with a coefficient (calibration factor). The rest of the configuration is not variable or prone to error. The gas friction manometer has a simple design (one rotating ball 36), operates without contact and without wear, and operates via electromagnetic forces in a vacuum. Gas friction manometers therefore have no electrically or mechanically loaded components and achieve correspondingly high long-term stability (drift < 1% / year), are robust and corrosion-resistant (all-metal). As the measurement signal is based on changes in the number of rotations of the sphere and not on changes in distance or ionization, the process is less affected by temperature, ageing or coating effects. [Explanation of symbols]

[0094] 10. Ion Source 11 Ion generation chamber 11a Chamber wall 11b Chamber inner space 12 Connection for pressure measuring device 13a Cathode 13b Anode 14. Supply for molecules to be ionized 15 Ionized molecules 16 Aeon 17 Mass flow control devices 18. Exit for generated ions 16a Ion beam 19 Pre-acceleration device 20 Lens Device 21 Control Device 22 Vacuum pump 23 Interface 24 Interface 25 Interface 26 Interface 27 Interface 28 Interface 29 Magnet 30 Pressure measuring device 31 First pressure measuring device (gas friction pressure gauge) 32 Vertical Alignment 33 Housing 34 Connection flange 35 Vacuum tube (measurement tube) 35a Connection direction to ion generation chamber 35b Closed end of vacuum tube 36 balls 37a permanent magnet 37b Permanent magnet 38 drive coil 39 Levitation / stabilization coil 40 Speed ​​detection coil 41 Vibration damping coil

Claims

1. An ion source (10) that generates ions (16) or an ion beam (16a), The ion source (10) comprises an ion generation chamber (11) that generates the ions (16), and a pressure measuring device (30) associated with the ion generation chamber (11). The pressure measuring device (30) comprises a first pressure measuring device (31), The first pressure measuring device (31) is an ion source (10) which is designed in particular in the form of a gas friction pressure gauge, or which is equipped in particular with a gas friction pressure gauge.

2. The ion source according to claim 1, characterized in that the first pressure measuring device (31) is connected to the ion generation chamber (11), or the first pressure measuring device (31) is located inside the ion generation chamber (11), and / or the first pressure measuring device (31) is positioned perpendicular to the ion generation chamber (11) (32).

3. The ion source according to claim 1, characterized in that the ion generation chamber (11) is designed as an ion generation chamber having negative pressure, in particular as a vacuum airtight ion generation chamber.

4. The ion source according to claim 1, wherein the cathode (13a), particularly a filamentous cathode (13a), and the anode (13b) are arranged within the ion generation chamber (11), and in particular the first pressure measuring device (31) is provided at a certain spatial distance from the cathode (13a).

5. The ion source according to claim 1, characterized in that the ion generation chamber (11) is connected to a supply unit (14) of molecules to be ionized (15), particularly a gas supply unit, and the supply unit (14) particularly interacts with a mass flow rate control device (17).

6. The ion source (11) comprises an extraction device, the extraction device being configured to generate an ion beam (16a) and / or guide the ion beam (16a) and / or extract ions (16) from the supplied ionizable molecules (15), or the extraction device being associated with the ion source (10), as described in claim 1.

7. The ion source according to claim 1, characterized in that the ion generation chamber (11) comprises an outlet (18) for the generated ions (16) and / or the generated ion beam (16a), and / or a pre-accelerating device (19) is provided within the ion generation chamber (11), and / or a lens device (20) is provided within the ion generation chamber (11).

8. The ion source according to claim 1, characterized in that the pressure measuring device (30), in particular the first pressure measuring device (31), is designed or provided to control and / or monitor the ion source (10), in particular to determine and / or adjust and / or monitor important parameters of the ion source (11), in particular control parameters, in particular to control and / or monitor the mass flow rate control device (17), and / or measure the pressure inside the ion generation chamber (11), and / or determine the cleanliness of the components inside the ion generation chamber (11), and / or determine the airtightness of the ion source (10).

9. The ion source (10) is characterized in that it is designed as an ion source for electron ionization, as described in claim 1.

10. An ion generating device, wherein the ion generating device is - An ion source (10) having an ion generation chamber (11) that generates ions (16), and a pressure measuring device (30) associated with the ion generation chamber (11), wherein the pressure measuring device (30) comprises a first pressure measuring device (31), the first pressure measuring device (31) is particularly designed in the form of a gas friction pressure gauge, or particularly comprises a gas friction pressure gauge, and in particular the ion source (10) is the ion source according to any one of claims 1 to 9, - An extraction device provided for generating and / or inducing and / or supplying an ion beam (16a) to extract ions (16) from ionizable molecules (15), wherein the extraction device is at least partially part of the ion source (10) or connected to the ion source (10), - A device for accelerating the ions generated in the ion source (10) An ion generating device equipped with the following features.

11. A method for handling an ion source (10), particularly an ion source (10), and more particularly a method for generating ions (16) in an ion source (10) according to any one of claims 1 to 9, wherein the ion source (10) is provided such that in the ionization step, ions (16) are generated from molecules (15) to be ionized in an ion generation chamber (11) of the ion source (10), A method characterized in that the pressure value in / within the ion generation chamber (11) is detected or determined before and / or during and / or after the ionization step via a pressure measuring device (30) assigned to the ion generation chamber (11), wherein the pressure measuring device (30) has a first pressure measuring device (31), and the first pressure measuring device (31) is designed in particular in the form of a gas friction pressure gauge, or comprises a gas friction pressure gauge.

12. a) A step of supplying the molecules to be ionized (15) to the ion generation chamber (11) of the ion source (10) via the supply unit (14), particularly in a gaseous flow, b) The ionization step of generating ions (16) from the molecules (15) to be ionized in the ion generation chamber (11) The method according to claim 11, characterized by the above.

13. The method according to claim 11, characterized in that when the pressure measuring device (30), in particular the first pressure measuring device (31), measures that the pressure value in the ion generation chamber (11), in particular the vacuum pressure, falls below a specific predetermined pressure value, the ion source (10) is released or the ionization process is started.

14. The method according to claim 11, characterized in that a mass flow control device (17) provided to supply the ionized molecules (15) is controlled and / or monitored and / or calibrated by the pressure measuring device (30), particularly the first pressure measuring device (31).

15. The method according to claim 11, characterized in that the pressure measuring device (30), in particular the first pressure measuring device (31), controls and / or monitors the ion source (10), in particular determines and / or adjusts and / or monitors important parameters of the ion source (11), and / or measures the pressure inside the ion generation chamber (11), and / or determines the cleanliness of the components inside the ion generation chamber (11), and / or determines the airtightness of the ion source (10).

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