TW201535458A - System and method for measuring properties of a charged particle beam - Google Patents

Abstract

A system is disclosed for measuring properties of a charged particle beam output by a charged particle beam generator. The system comprises: a probe assembly, a beam deflection control module and a detection module. The probe assembly comprises a plurality of probes arrayed across a plane on a mount, each probe comprising at least two elongate, electrically conductive elements arranged such that their respective elongate directions make a non-zero angle with one another in the plane of the array. The beam deflection control module is adapted to control the deflection of the charged particle beam along a measurement path which crosses sequentially at least two of the elongate, electrically conductive elements of at least one of the probes. The detection module is connected to the electrically conductive elements of each of the plurality of probes, and is adapted to detect electric signals output sequentially by the electrically conductive elements of each probe upon intersection of the charged particle beam therewith. The detected electric signals from each probe are indicative of properties of the charged particle beam when directed to the location of the respective probe across the probe assembly by the charged particle beam generator. A corresponding method of measuring properties of a charged particle beam output by a charged particle beam generator is also disclosed.

Description

System and method for measuring the properties of charged particle beams

The present invention relates to systems and methods for measuring the properties of charged particle beams, including electron beams and ion beams, such as their width and/or intensity profile.

Charged particle beams have many industrial applications, including material processing operations such as welding, additive layer manufacturing, 3D printing and drilling, cutting, curing, melting, gasification or other processes whereby the beam is used. Modify or process materials or workpieces. The characteristics of the beam, such as size and strength, affect the processing results, so its usefulness is to be able to measure the properties of the beam in order to check whether the beam meets the desired criteria for processing, and if not, adjust the beam properties accordingly. .

Various probe devices are known for measuring the properties of charged particle beams. In a first category, the probe includes a masking plate having a plurality of non-parallel slits therethrough that deflect the beam passing through them. The portion of the beam that passes through each slit is collected by a Faraday cup and the resulting electrical signal can be used to reconstruct an intensity map of the beam. An example of such a method is disclosed in U.S. Patent No. US-B-7,348,568. US-B-7,875,860, meanwhile, A plurality of Faraday cups that replace the slits each receive a portion of the scattered beam. A similar technique disclosed in "Electron beam diagnostics: a new release of the Diabeam system" issued by Dilthey et al., Volume 2, Nos. 2, 3, pp. 77-85, June 15, 2001, is used on the Faraday Cup. The pinhole of the board, on which the beam is scanned line by line. A variant of this method is described in U.S. Patent No. 6,977,382, in which the beam is scanned line by line on the needle and the reflected signals are collected by a number of backscattered electron detectors.

Another form of probe includes one or more wires configured to intersect the beam during relative movement of the beam to the (etc.) wire. British Patent No. GB-B-1209034 discloses several examples. A partial beam current is collected on the (etc.) wiring and detects the resulting electrical signal output by the (etc.) wiring. The pulse derived from the probe represents the approximate energy density profile of the beam at the intersection (or several).

All of the conventional probe devices including those described above are designed to measure the properties of the beam along or very close to the axis of the beam generator (e.g., the axis of the electron gun). For example, electron beam processors have historically used to weld and melt a material's beam typically at most a few millimeters away from the main axis. For example, typical beam deflections for conventional processing applications are less than 1 degree and widths are less than 10 millimeters.

In accordance with a first aspect of the present invention, a system for measuring the properties of a charged particle beam output by a charged particle beam generator includes: A probe assembly comprising a plurality of probes arranged in an array in a plane on a single piece, each probe comprising at least two elongate conductive elements configured to be their respective The elongate directions form a non-zero angle with each other in the plane of the array; a beam deflection control module is adapted to control the deflection of the charged particle beam along a measurement path, the measurement path sequentially traversing the probe At least two of the elongate conductive elements of at least one of the pins; and a detection module coupled to the conductive elements of each of the plurality of probes The electrical signals output by the conductive elements of the respective probes in sequence when intersecting the charged particle beam, the detected electrical signals from the respective probes indicate that the charged particle beam is used throughout the probe by the charged particle beam generator The nature of the needle assembly when it points to the position of each probe.

By providing an array of multiple probes in this manner, the properties of the beam over a wide range of beam deflection angles (corresponding to the extent of the array) can be measured and not just at or near the axis. Each probe enables measurement of the properties (eg, width and intensity) exhibited by the beam as it is deflected to the position of the probe, thereby enabling the ability to change the properties of the beam as it deflects to the off-axis position to be detected at any time. And, if necessary, correct it so that the beam properties remain substantially uniform over the range of deflection angles. This is obviously important, for example, in the exit process, such as electron beam plus layer fabrication or 3D printing and electron beam surface texturing, which deflects the beam over a wide area and the need to maintain beam quality, even in beam deflection. When leaving the axis of the electron gun hundreds of millimeters. For example, the beam may need to sweep a width of up to 400 at an angle of up to 25 degrees. Millimeter of workpiece.

The probe array preferably extends across the working area and the beam moves over it during operation of the device to which the array is applied. Thus, the array allows for the measurement of beam properties at various locations in the work area (corresponding to discrete locations of the probes), and thus can be used to provide assurance that the beam properties are consistent across the work area, and/or provide Feedback allows adjustment of the beam optical parameters to achieve this guarantee. For example, aerospace manufacturers with strict quality control require this beam guarantee. The probe array allows for the measurement of beam properties over the entire working area without the need for any manual adjustment of the probe components, so in the case of a vacuum chamber, beam characterization and single pumping cycles in the machine can be done quickly if needed. (single pump down cycle). In addition, there are no moving parts, so the system is robust and reliable.

The individual signals output by the respective elements are detected by the individual probes forming the conductive elements, and the individual probes are substantially insensitive to the landing angle of the beam as the beam traverses it. This is important because, as mentioned above, the angle at which the beam hits the individual probes can vary significantly, about zero degrees for probes adjacent to the main axis, for example up to 25 degrees for probes around the array. In contrast, most conventional probe types are only suitable for measuring the nature of the beam hitting the probe substantially along its normal (i.e., about zero degrees). For example, probe devices based on a number of slits or a pinhole require the slits or the holes to be narrow and pass through a thick substrate to achieve good resolution without melting the substrate. Similarly, if the beam strikes the probe at an angle that is significantly away from zero, the wall of the slit or hole can obstruct the beam passage and prevent any signal detection. However, the conductive element will output a signal, independent of its intersection with the beam. Degree effects, even if significantly away from zero. Thus, the probe of the present invention is fully operable at any position of the array, which enables consistent measurement of beam properties at various probe locations. Moreover, all of the probes can be identical to each other and interchangeable or moved from one location to another within the array without damage.

By providing each probe with at least two elongate conductive elements configured such that their respective elongate directions are in the plane of the array (substantially perpendicular to the axis of the beam generator (eg, electron gun)) Forming a non-zero angle with each other, that is, making the elements non-parallel, measuring the properties of the beam in at least two directions at each probe position, thereby enabling, for example, measuring the beam size and shape at each probe (for example, ellipticity). For example, given the knowledge of the beam velocity and the angle at which the measurement path traverses the individual components, the duration of the electrical signal output by the component can be calculated as the width of the beam in a direction perpendicular to the direction of the element's elongate shape. Thus, at least two directions in which the properties of the respective probes are measured will depend on the elongate direction of the elements, while these may vary from probe to probe, preferably all of the components of the array that make up the array are along the same The at least two directions are configured whereby the beam properties in the same at least two directions are measured at the respective probe positions. Other preferred features of the individual probes are described below.

The detected signals may be used without knowing which component or probe is the source of each signal, for example by checking that each signal satisfies one or more predetermined criteria, in which case it may be determined that the signal is being shot. The beam properties of the individual probe positions across the beam have an acceptable degree of uniformity. However, more information is available, if the signals are each attributed to the probe, and the particular component for which it originates within the probe is preferred because of the beam The property can then be associated with its offset position (i.e., probe position) and against the absolute orientation of the elements. Therefore, the detection module is more suitable for identifying the one of the long conductive elements of the probe as the source of each detected electrical signal. This can be achieved, for example, by grouping the detection modules into a plurality of channels, one for each component, thereby automatically distinguishing incoming signals from each other. In this case, the elements themselves need to be electrically isolated from each other to avoid cross-talk.

However, in a more preferred embodiment, the elongate conductive elements of the respective probes are in electrical contact with each other. For example, the elements may be in physical contact with each other, or connected by another conductive member, or even integrated with each other. For example, the at least two elongate members can be a single conductive wire or different portions of other wires that are manipulated to align the various portions in different directions, for example, by winding wires around a suitable clamp. Electrically contacting the components of each probe with each other simplifies the construction of the probe assembly because each probe only needs to make one electrical connection. The detection module can then receive signals from the various probes on different channels. More preferably, however, the elongate conductive elements of each probe are connected in parallel or in series with other probes, and the detection module is adapted to receive the conductive elements from the probe assembly on a single channel. The electrical signals are output. This is particularly beneficial because only a single through hole is required between the detection module and the probe assembly and this greatly simplifies the deployment of the system, especially when used in a vacuum chamber, which is a common situation, where The individual conduits inside and outside the chamber must be carefully machined to maintain vacuum.

When the detection module receives from a single channel from one In the case of the above probe or component signal, the detection module preferably includes a correlation section adapted to identify the one of the probes as a source of each detected electrical signal, based on the The knowledge of the measurement path (preferred is preferred) and the detection time of each electrical signal and/or the order in which the electrical signals are detected. For example, if the path followed by the beams traversing the elements is known, since the order in which the signals are received is the same as the order in which the beams intersect the elements, each signal can be attributed to a component by which it is The order of detection or by the timestamp corresponding to each signal. Knowledge of this measurement path can be obtained in a number of ways. In one embodiment, the system may rely on stored information regarding the path that the beam should follow, and therefore preferably provides memory for storing measurement path data, preferably including: the starting position of the beam The path that will be followed by the beam, and, if desired, at least at the intersection of the conductive elements. However, for more accuracy, it is preferred to be based on the identification of the timely deflection of the beam, so that this knowledge of the measurement path is advantageously provided by a beam position monitoring unit, which is suitable for use from the charged particle beam generator and/or Or the beam deflection control module receives information about the current deflection of the beam. In some cases, a combination of these two methods may be appropriate.

The beam can be deflected along the (predeterminedly preferred) measurement path by a number of methods under the control of the beam deflection control module. Typically, the charged particle beam generator (eg, an electron gun) includes a primary beam deflection unit and a primary controller adapted to generate and output a primary control signal to the primary beam deflection unit for directing the beam to a Move the selected position or along a primary beam path, during normal operation, it will take the move to make The beam moves along the intended material processing path, such as a weld line or the like. In some cases, the beam deflection control module of the system of the present invention can be implemented with a primary controller of the charged particle beam generator that is programmed to move the beam along the desired measurement path as needed. However, this method is not preferred because many beam generators contain distorted autobeam adjustments, such as astigmatism, cloth angle dependencies, so if the primary controller is programmed to cause the beam to follow the measurement The path is deflected and the beam undergoes an automatic adjustment, which means that the properties it measures at the various elements will differ differently and not accurately represent the beam at the point of the probe. Moreover, such controllers typically define a beam path in a digital manner, that is, as a series of discrete locations that form a continuous line if the beam moves sufficiently slowly therebetween. However, when the beam is preferably moved at high speed across the probe elements to prevent the elements from melting, the digital nature of the path may cause the beam to be illuminated at a discontinuous position, which may cause the beam to pass through the The speed of the probe element changes, causing the probe signal to be distorted. Although this can be corrected by post-processing of the signal, this is not desirable because it complicates signal processing and interpretation.

Therefore, in a preferred implementation, the beam deflection control module includes a primary controller that is configured to output a primary control signal and is superimposed on the primary control signal output by the primary controller. The control signal defines a primary beam path such that the primary beam deflection unit directs the beam to move along the measurement path that is combined with one of the primary beam paths and any of the primary beam paths. In this way, the primary controller "unawares" the additional deflection imposed by the secondary control signal on the beam and thus does not proceed Automatic beam adjustment caused by additional deflection such that the beam properties are substantially the same as when the beam is moved across the elements of any of the probes, and the measured properties accurately indicate that the beam is pointing at the The nature of the probe position. In addition, the secondary control signal is preferably analogous and thus does not have the above-mentioned problems associated with digital control.

Alternatively, the beam deflection control module may include a primary beam deflection unit disposed downstream of the primary beam deflection unit and the primary controller is configured to output a primary control signal to the secondary a beam deflecting unit, the secondary control signal defining a primary beam path such that the primary and the secondary beam deflecting unit together direct the beam along the secondary beam path and any primary beam path One of the combined measurement paths moves. Again, additional deflections are imposed on the beam in this manner without affecting any adjustments made by the beam generator. This implementation is particularly suitable when retrofitting the system to an existing charged particle beam generator. An apparatus embodiment is described below that includes a probe assembly and a secondary beam deflecting unit that can be easily installed in such machines without the need to modify the machine.

It should be noted that in some cases, the primary and/or secondary (if any) beam deflection unit may not accurately achieve the deflection indicated by the (etc.) control signal, ie, bias deviation (deflection discrepancy), in this case, the beam may not accurately follow the desired measurement path (at least initially). The following describes the technology that takes this into consideration.

During the measurement process, typically the coarse motion of the beam from one probe position to the next is performed by the beam generator, such as defined by the primary beam path described above. The beam can be continuously moved from one probe to the next (in Invariant or variable speed), or directed to a number of discrete positions, one corresponding to each probe, and the beam is turned off at an intermediate position. The beam deflection control module causes beam fretting to cause the beam to shift away from the primary path to produce the desired measurement path. The deviation may be applied continuously, or may be synchronized with the primary path based on knowledge of beam velocity and timing, but optimally, the beam deflection control module includes a monitoring portion adapted from the The charged particle beam generator receives information about the current deflection of the beam, the primary control signal from the primary controller is preferred, and the secondary control signal is output in response to the received information. This allows the beam to be offset from its primary path at a selected point on the path to form the measurement path.

Preferably, the beam deflection control module is adapted to output the secondary control signal by returning the beam deflection to one or more predefined trigger positions, and each predefined trigger position corresponds to one of the probes. The position of the different person is preferred. For example, the secondary control signal can define a substantially circular or arcuate path that is superimposed on the primary path at the selected trigger locations, causing the beam to traverse a plurality of the probes corresponding to the trigger positions The at least two elongated conductive elements of each of them. As described above, the primary control signal can be configured such that the beam remains stationary at each of the trigger positions, such that upon reaching each position, the beam moves only under the control of the secondary control signal to define the Measuring path.

Preferably, each probe remains close to the center of the probe within the measurement path followed by the beam, for example within 2 to 5 millimeters, such that the deflection away from the center of the probe to follow the measurement path is small. As such, the measured properties of the beam at the measurement path can be used as the beam at the center of the probe. Approximate representation.

However, the beam deflection is implemented such that the measurement path preferably includes at least one line segment traversing at least two of the elongate conductive elements of one of the probes, all of which are preferred, the line segment Be substantially circular or follow a substantial arc. For example, the circle or arc may preferably be centered on the center of the probe and, advantageously, may have a small radius of, for example, 2 to 4 mm such that the deflection of the beam away from the center of the probe is small. Preferably, the circular or arcuate segment is a deflection path defined by the secondary control signal output by the secondary controller and is optimal for output having a constant beam velocity. A circular or arcuate path is preferred because circular or arcuate control signals are more accurately generated due to the nature of the dependent waveform input due to deflection means, compared to other path forms including straight segments or corners. . The constant beam speed is preferably such that the detected electrical signals from the various components can be directly compared to each other. However, if necessary, the variation in beam speed can be corrected during post processing. Circular or arcuate paths are also particularly useful for detecting any deflection deviation of the beam, as described below.

For a landing angle that is quite far from the normal, the actual path traversed by the beam may not correspond to the expected path because the plane of the probe array will effectively pass the beam path at an angle (regardless of any deflection) deviation). For example, the controller is used here to instruct the beam to be machined around a circle, however at high angles (i.e., toward the periphery of the probe array), the angular velocity of the beam will be constant, the beam An ellipse is drawn on the probe assembly instead of a circle. Similarly, the beam changes speed as it travels along the path, which causes the detected signals from the various components to have different durations. Time, even if the beam is completely symmetrical. In order to avoid this, the secondary controller is preferably adapted to modify the secondary control signal by means of the deflection angle of the beam, preferably by applying an elliptical correction deflection to each probe position such that the beam is The path followed on the probe assembly is substantially circular or arcuate at each probe of the array (and thus the beam velocity remains the same).

The measurement path can intersect the elements of a single probe if only the nature of the beam at one location is measured. However, in order to determine the beam properties at various locations, preferably the measurement path comprises a plurality of line segments, each line segment traversing at least two of the elongate conductive elements of one of the probes, all being Preferably, each line segment intersects one of the different ones of the probes. Most preferably, the measurement path is configured to sequentially intersect all of the probes. As mentioned above, the measurement path may be discontinuous between the line segments (i.e., the beam is turned off). Advantageously, the starting point and/or the ending point of the or each line segment does not coincide with any of the elongate conductive elements. This is beneficial because it reduces the risk of the beam staying on one of the components and possibly melting the component, either during low speed movement or at rest.

As described above, based on the knowledge of the measurement path, the identification of each component originating from that component can be accomplished. However, in an advantageous refinement, the probes each further comprise a marking element that is electrically conductive and has a width greater than the width of the elongate electrically conductive element in a direction traversed by the measuring path, the measuring path additionally crossing The marking component, wherein an electrical signal output by each marking component when intersecting the charged particle beam has a peak amplitude greater than that output by the elongated component, and wherein the detecting module is suitable for A small portion of the elongate conductive element within a probe is identified as the source of each detected electrical signal based on the electrical signal output by the marking element. Since the position of the elongate conductive elements of the probe relative to the marking element is known, this helps to identify the signals: for example, the first signal received after the high amplitude mark signal can be attributed to the measurement path. An element adjacent to the tag element, and the like. This is used when the measurement path is formed by imposing a primary control signal on a primary control signal applied by the beam generator (as described above) because, if the secondary control signal is cyclic, it The phase may be different at each probe location, which means that the order of the beams across the components of a probe may be different from the different probes.

Providing the marking signal in this manner enables the detection module to monitor only the current deflection of the beam (eg, from the primary controller) based on the beam generator, which will enable the module to assign individual signals to The probe from which it originates, and then the marker signal, allows each signal to be individually assigned to an individual component within the identification probe. Therefore, in this case, the detection module is suitable for identifying that the probe is the source of each detected electrical signal based on the knowledge of the measurement path and the detection time of each electrical signal and/or detecting the electrical signals. The or a sequence, and based at least in part on the electrical signal output by the marking element, identifies the elongated conductive element of the identified probe as a source of respective detected electrical signals.

Individual probes may have different configurations. In a particularly preferred embodiment, the at least two elongate conductive elements of each of the probes comprise at least first and second elongate conductive elements configured such that their respective elongate directions are in the plane of the array The essences are orthogonal to each other. By collecting Signals from orthogonal elements that measure and/or compare the width of the beam in two orthogonal directions, thereby providing an indication of the shape of the beam spot, such as ellipticity, or detecting the beam The intensity profile of each of these two directions. Most preferably, these two directions align with the x, y axes of the beam generator. A minimum of two directions is required in order to establish a two-dimensional intensity map of the beam; however, better resolution will be achieved by providing individual probes with more elements aligned in different directions. Accordingly, preferably, each probe includes at least three (at least four better) elongate conductive elements configured such that their respective elongate directions form a non-zero angle with each other in the plane of the array, such differences It is preferred that the elongate directions are substantially equiangularly spaced from one another. For example, when there are 3 components, they have an angle of 60 degrees to each other, and when there are 4 components, they have an angle of 45 degrees to each other. Many more components are potentially installed in individual probes with different orientations to further increase resolution.

Advantageously, the at least two elongate conductive elements of the respective probes have at least one intersection between them (eg, where they cross each other or are interconnected), the elements being electrically contacted herein good. For example, all of the elements of any of the probes may cross each other at the center or other location of the probe. This provides additional physical support for each component. In a particularly preferred embodiment, at least two of the elongate conductive elements of any of the probes are configured such that their elongate directions extend radially from their intersections and are preferably centered at the intersection. Corners are separated from each other. In combination with a circular or arcuate path designed to traverse the elements and a measurement path centered at the intersection, this enables detection and correction of any deflection deviation of the beam, as described below.

In a particularly preferred embodiment, the at least two elongate conductive elements of each probe comprise at least two conductive filaments that intersect each other at a non-zero angle, the conductive filaments being a continuous conductive filament as desired. Different parts. This provides a particularly simple construction and is also very robust. For example, the conductive filaments can include wires, straps or strips.

Advantageously, the elongate conductive elements have a width in the plane of the array that is equal to or greater than their thickness in a direction perpendicular to the array. This minimizes the sensitivity of the probes to the angle of incidence of the beam because any particles received by the sides of the elements are minimal compared to the front side (facing the beam source). For example, the elements can have a substantially square or circular cross section or be rectangular if the width is greater than the thickness. (The width of the element is defined as the dimension in the array plane that is perpendicular to the lengthwise direction). A strip element having a substantially flat surface is particularly preferred because it reduces the degree of backscattering compared to, for example, circular wiring.

The width of the elongate conductive elements has an effect on the accuracy of measuring beam properties. If the width of each element is equal to or greater than the width of the beam, it is not possible to deduct any information about the intensity profile of the beam, however the width of the beam is still measurable. Therefore, it is preferred that the width of each elongate conductive element in the plane of the array is less than the diameter of the charged particle beam in the plane of the array, between one third and two thirds of the diameter of the charged particle beam. Preferably. The narrower the component, the higher the resolution of the beam profile can be measured. However, in practice, if the component is too narrow, it is liable to fail due to overheating when irradiated by the beam. The typical beam width of the plane to be machined (and the probe assembly should be placed in it) is about 0.5 mm, so In a preferred embodiment, the elements each have a width in the range of 5 to 200 microns. The widths of all components do not have to be the same, but the same is preferred to avoid this need to be taken into account during signal processing.

In order to discretely receive electrical signals from the various components and to distinguish the electrical signals, the beam should only intersect one element at any one time as it moves along the measurement path. Accordingly, preferably, the at least two elongate conductive elements are spaced apart from one another by at least one of their lengths by a distance at least equal to (greater than preferably) the diameter of the charged particle beam in the plane of the array. The length of this portion should also be at least equal to or greater than the beam diameter whereby the full width of the beam can be accommodated without intersecting any other elements. Accordingly, in preferred embodiments, the at least two elongate conductive elements are spaced apart from each other by at least 0.5 mm, preferably at least 1 mm, at least along one of their lengths.

In a particularly preferred implementation, each of the probes includes a frame that is configured to support the elongate conductive elements at at least two points across an aperture defined by the frame. The frame may or may not completely enclose the aperture. By providing support for such elements in this manner, it is possible to use narrower and less robust elements, as these elements are not required to be self-supporting. In an advantageous embodiment, the frame comprises a tube section, such as a collar, preferably a cylindrical tube portion, the elongate conductive elements being configured to traverse the tube (flat) One or both ends. The (etc.) conductive member can be wrapped around the frame to form a desired configuration consisting of elements having different elongate orientations.

Preferably, the frame body includes a conductive portion that is assembled to connect the at least two elongated conductive elements to the detecting module. a circuit. This provides a simple and reliable means of electrically connecting all of the components in each probe and connecting them to the detection module.

The configuration of the probes can be based on any desired layout throughout the array, but in general, preferably the configuration of the plurality of probes is based on a regular grid throughout the array (eg, orthogonal, hexagonal) And so on, and preferably a probe included on the axis of the charged particle beam generator, whereby the beam properties at a regularly spaced series of locations on the working area can be measured. However, in some cases, when it is said that the machine is dedicated to a particular job, it is preferred to configure the probes according to some other scheme to measure the beam properties at locations that are particularly important for the job.

Preferably, the frame comprises a plate having a plurality of apertures in which the plurality of probes are disposed, the plate preferably being electrically conductive and optionally assembled to provide an electrical connection between the probes and A circuit connected to the detection module. Preferably, the array of probes is located in a plane substantially perpendicular to the axis of the charged particle beam generator.

These detected signals indicate the nature of the beam and are therefore "unprocessed" as compared to voltage, current or time thresholds or the like. Preferably, however, the system further includes a signal processor adapted to calculate beam properties based on the knowledge of the detected electrical signals and beam measurement paths. The calculated properties can be output to the user of the system, for example by being displayed on a monitor or the like, or otherwise using it.

In a particularly preferred embodiment, the signal processor is adapted to calculate a width of the beam in at least two directions at at least one probe position based on the at least two elongated conductive shapes from the respective probes yuan The detected electrical signals of the pieces, and the knowledge of the speed at which the beam traverses the elements. For example, the total duration of each signal will correspond to the time the beam traverses the various elements and the given knowledge of the beam speed, which can be converted into the distance the beam travels at that time. This would correspond to the beam width plus the element width (in the direction of the measurement path), which is known, thereby allowing calculation of the beam width in a direction perpendicular to the elongate direction of the element.

Also preferably, the signal processor is adapted to calculate an intensity profile of the beam in at least two directions at at least one probe position based on the at least two elongate conductive elements from the respective probes These detect the electrical signal, as well as the knowledge of the width of the beam. For example, when the beam traverses an element, the magnitude of the detected signal will depend on the width of the beam in the direction of the element's elongate shape and any beam intensity variations. Since the width of the beam can be measured independently as described above, the intensity profile of the beam in a direction perpendicular to the elongate direction of the element can then be calculated.

In another preferred embodiment, the signal processor is adapted to calculate an intensity map of the beam in two dimensions at at least one probe position from the respective probes by tomographic reconstruction The detected electrical signals of the at least two elongated conductive elements of the pin. This can be accomplished using conventional reconstruction methods, such as using an inverse Radon function to de-convolute the collected signals from all of the components within a probe. The more components that are mounted on each probe, the better the resolution that can be achieved.

Preferably, the signal processor is adapted to calculate a property of the beam in at least two directions at each of the plurality of probe positions, Preferably, the width of the beam, the intensity profile of the beam and/or the intensity map of the beam.

As described above, in practice, the beam may suffer from a deflection deviation, which means that the actual position of the (equal) deflection unit guiding the beam is inaccurately matched to the indication. If this is not known, for example because the beam traverses the individual elements at an angle different from what is expected, even (in extreme cases), the measured properties may be distorted in a different order. Therefore, in a preferred embodiment, the signal processor is more suitable (before calculating the properties of the beam) to detect any deflection deviation of the beam at at least one probe position, And generating and outputting a deflection deviation feedback signal to the charged particle beam generator based on the interval between adjacent detected electrical signals of the at least two elongated conductive elements from the respective probes This deflection deviation. It is preferred to know the expected (time) interval between the signals based on the predetermined measurement path and the probe geometry, at least in the relative interval of the pair of adjacent signals (if the beam speed is not accurately known), or in absolute Interval (if beam speed is known). The signal processor can therefore compare the actual interval from one signal to the next and use this to compare with the expected interval. If it matches, it is known that the beam follows the expected measurement path and can be measured for properties, as described above. If the (absolute or relative) actual interval between the signals does not match the expected, this indicates a bias deviation. The signal processor outputs a signal to the charged particle beam generator to enable correction of the beam deflection to thereby displace the measurement path of the beam such that it aligns the probe. In a particularly preferred embodiment, the signal generator performs the calibration by: (a) detecting at least one probe position, detecting any deflection of the beam. Poor, based on the spacing between adjacent detected electrical signals of the at least two elongated conductive elements from the respective probes; (b) generating and outputting a bias deviation feedback signal to the charged particle beam generation In order to correct any deviation deviation calculated by the beam in step (a), the properties of the beam can be calculated based on the detected electrical signal output after correcting any deviation deviation.

In a particularly preferred aspect, the technique is practiced using a probe configuration having at least two elongate conductive elements configured such that their elongate directions extend radially from their intersection and at the intersection They are separated from each other at equal angles. The measurement path is configured to include at least one line segment traversing at least two (all preferably preferred) elongated conductive elements of the probe, the line segment being substantially circular or following a substantial arc and centered on the At the position of the intersection of the elements, the elongate directions extend from the intersection. As a result, if the beam accurately follows the measurement path, the time intervals between the detected signals from the elements of the probe should be equal. Similarly, any difference in the spacing between adjacent ones of the detected electrical signals from the elements of the probe indicates a bias deviation. For example, the path may be centered incorrectly or not round enough, and if not corrected, this would cause the beam to intersect the elements at an unknown angle. In this case, preferably, the correction of the deflection deviation is performed by adjusting the deflection of the beam until the interval between adjacent ones of the detected electrical signals from the components of the probe is substantially equal to zero. The difference.

The above technique enables correction of any deflection deviation to calibrate the beam generator and is preferably done automatically by the system without operator intervention. For example, a feedback algorithm can be implemented to adjust the deflection control signal based on the feedback signal to correct any deviation detected.

The output of the system can be used to provide diagnostic information or guarantee to the user, but in a preferred embodiment, additionally or alternatively, the system further includes a feedback module for generating and supplying a feedback signal to the charged particle beam. The generator thereby adjusts the properties of the charged particle beam based on the properties measured by the system. For example, feedback based on the measured width (diameter) or shape of the beam can be used to adjust the beam focus achieved by the beam generator. Again, this can be done automatically by the system by providing an appropriate feedback algorithm.

It should be noted that in accordance with a first aspect of the invention, the system need not include the charged particle beam generator. For example, the system can be retrofitted to an existing beam generator, such as an electron gun. According to a second aspect of the present invention, there is provided apparatus comprising a charged particle beam generator and a system according to the first aspect of the present invention, configured to measure a charged particle beam output by the charged particle beam generator The nature. The charged particle beam generator preferably includes a charged particle source, a particle acceleration unit for accelerating charged particles from the particle source along an axis to form a charged particle beam, and a primary deflection unit adapted to cause the charged particle beam The deflection is remote from the axis and a primary controller is adapted to output a primary control signal for controlling the deflection applied by the primary deflection unit.

The diagnostic system disclosed herein is particularly suitable for use in material processing applications where the workpiece or material (including gaseous materials) is modified by applying the charged particle beam. Accordingly, a third aspect of the present invention further provides a material processing tool comprising the apparatus as described above. In a particularly preferred embodiment, the tool is one of the following:

An electron beam welding tool, the charged particle beam is suitable for welding materials; a layered manufacturing tool, the charged particle beam is suitable for processing powder materials, and fusion is preferred; a curing tool, the charged particle beam is suitable for To cure a workpiece; a cutting tool, the charged particle beam is suitable for cutting material; a melting or gasification tool, the charged particle beam is suitable for melting and/or gasifying the material; the tool is a gas processing tool, The charged particle beam is suitable for treating gaseous substances, and combustion fumes are preferred; a disinfecting tool, the charged particle beam is suitable for disinfecting solid or liquid; and a drilling tool, the charged particle beam is suitable for drilling a workpiece; Or a material texturing tool suitable for forming a plurality of protrusions or structures on a workpiece.

A fourth aspect of the invention provides a method of measuring the properties of a charged particle beam output by a charged particle beam generator, the method comprising: providing a probe assembly comprising arranging across a plane on a frame a plurality of probes of the array, each probe comprising at least two elongate conductive elements configured such that their respective elongate directions form a non-zero angle with each other in the plane of the array; Controlling the deflection of the charged particle beam to sequentially traverse at least two of the elongate conductive elements of at least one of the probes in accordance with a measurement path; and detecting the respective probes The electrical signals are sequentially output by the conductive elements as they intersect the charged particle beam, and the detected electrical signals from the respective probes indicate the nature of the charged particle beam when directed at the location of the respective probes.

As described above in describing the first aspect of the invention, this technique enables measurement of the properties of the beam at each probe location, such as its width and intensity profile. The method can be implemented with a system in accordance with a first aspect of the invention and can include preferred features and steps corresponding to any of the features described above.

According to a fifth aspect of the present invention, there is provided a probe for measuring properties of a charged particle beam, the probe comprising a frame defining an aperture and at least two supported by the frame and traversing the aperture The elongate conductive elements are configured such that their respective elongate directions form a non-zero angle with each other in a plane in which the frame is located.

In a particularly preferred embodiment, the system of the first aspect of the invention can be implemented with a plurality of such probes. As previously mentioned, by arranging the elements on a frame that traverses an aperture, the elements are supported (preferred at at least two points), which allows for the use of thinner and less robust elements. This then improves the resolution of the measured values. Preferably, the at least two elongate conductive elements are in electrical contact with each other and are integrated with one another as desired. The elements may traverse the aperture on different sides of the frame, but are preferably located in the same plane.

The probe may have any of the preferred features mentioned above in describing the first aspect of the invention.

According to a sixth aspect of the invention, there is provided apparatus for measuring the properties of a charged particle beam output by a charged particle beam generator, comprising: a probe assembly comprising a plane across a frame Aligning a plurality of probes in an array, each probe comprising at least two elongate conductive elements configured such that their respective elongate directions form a non-zero angle with each other in the plane of the array; a beam deflection a unit adapted to deflect the charged particle beam to move along a measurement path; wherein the beam deflection unit is supported on the probe assembly with a support assembly disposed therebetween, the beam deflection unit being oriented In use, the charged particle beam can be deflected throughout the probe assembly by the beam deflection unit.

In this way, the probe assembly and the secondary deflection unit can be simply loaded into a machine with a charged particle beam generator without the need to modify the machine. The beam deflecting unit is coupled to a controller, such as the beam deflection control module, and a receiving input, such as the secondary beam steering signal, in use to control the beam deflection. The probe assembly is connected to a detection module as described above, which is suitable for detecting electrical signals output by the probes. Preferably, the probe assembly, the beam deflecting unit and the support assembly are supplied as a unit such that the mounting only requires the unit to be placed into the machine in a properly aligned manner and the appropriate signal correction is accomplished. In other cases, the device can be supplied as a kit that includes a probe assembly, a deflection coil, and a support assembly, as well as a local assembly.

The device can be used in the system of the first aspect of the invention The probe assembly is provided and the beam deflection is achieved (at least in part). The probe assembly can have any of the features mentioned above in describing the first aspect of the invention, and the probes can be configured to contain any of the features described above. The beam deflection unit can include a beam deflection coil.

Preferably, the support assembly includes one or more support arms coupled between the probe assembly and the beam deflecting unit. Advantageously, the members are configured such that the axis of the beam deflection unit is substantially perpendicular to the plane of the probe assembly.

1‧‧‧Material Processing Tools

2‧‧‧vacuum studio

3‧‧‧Workbench/workpiece table

4‧‧‧Base

5‧‧‧Flour bed

5a‧‧ layer

10‧‧‧Charged particle beam generator

11‧‧‧ Controller

12‧‧‧Digital to analog converter

15‧‧‧Electronic gun

16‧‧‧Powered particle source

17‧‧‧Accelerator

18‧‧‧ deflected means

20‧‧·beam diagnostic system

21‧‧‧ probe assembly

21‧‧‧Signal catheter

21a‧‧‧Shielded leads

22‧‧‧Detection module

22a‧‧‧Association module

23‧‧‧Ball deflection control module

23a‧‧‧Secondary deflection unit

24‧‧‧ Signal Processor or Computer

25‧‧‧ memory

26, 26a‧‧‧Monitoring module

26b‧‧‧Feedback Module

27‧‧‧Sheet/board/mounting board/array board

28‧‧‧ lines

29a‧‧‧Resistors

29b‧‧‧ instruments

30, 30', 30", 30''', 30IIIV, 30a, 30b, 30c‧ ‧ probes

31, 31a‧‧‧ frame

31b‧‧‧Ceramic holders

32, 33, 33', 33a, 33b, 34, 34', 34a, 34b‧‧‧ components

36, 36a‧‧‧Marking components

38‧‧‧ intersection

39‧‧‧Leader

40a, 40b, 40c‧‧‧ trigger position

50‧‧‧ device

51‧‧‧Support components

A‧‧‧ gun axis

B‧‧·beam

BW‧‧·beam width

B(i), B(ii)‧‧‧ position

C‧‧‧ area

D‧‧‧Distance

F-F’‧‧‧Normal position

G‧‧‧ Grounding

Lx, Ly‧‧‧ interval

Lx, ly‧‧‧ length

MP‧‧‧Measurement path

P1‧‧‧ primary beam path

P2‧‧‧second beam path

S‧‧‧ Space

T, T33a, T34a‧‧‧ duration

T33b, T34b‧‧‧ signal duration

W‧‧‧Component width

x, y, x30a, x30b, y30a, y30b‧‧‧ directions

Θ‧‧‧ angle

(1) to (4) ‧ ‧ signals

Embodiments of the system and method for measuring the properties of a charged particle beam of the present invention are now described with reference to the accompanying drawings.

Figure 1 schematically depicts an exemplary material processing tool comprising an apparatus comprising an exemplary charged particle beam generator and a system in accordance with a first embodiment of the present invention; and Figure 2 shows an exemplary probe assembly suitable for use in the first The system shown in the figure, and the circuit for illustrating the electrical signals suitable for collecting the components; FIG. 3 illustrates an exemplary probe suitable for use in the probe assembly shown in FIG. 2; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An electrical connection of a probe element of one of the probe assemblies shown in FIG. 2 is illustrated; FIG. 5 is a schematic view showing a portion of the probe assembly of FIG. 2, on which a beam is depicted Demonstration measurement path; Figure 6 shows an example suitable for use with the probe assembly shown in Figure 5 a portion of the elongated conductive element, and in one embodiment, the beam traversing the position of the element; Figure 7 depicts an exemplary electrical signal detectable from one of the elongated conductive elements of Figure 5; Figure 8(a) schematically depicts an exemplary series of electrical signals detectable from the probe assembly of Figure 5 in a particular embodiment, and Figures 8(b) and 8(c) illustrate two Corresponding beam shape for different probe positions; Figure 9(a) schematically illustrates the passage of the beam through the exemplary elongated conductive element in another embodiment, and Figure 9(b) depicts the output by the component Exemplary telegram in response to intersection with the beam; Figure 10 schematically depicts an exemplary primary beam path (Fig. 10(a)), secondary beam path (10(b)) in a particular embodiment Figure), and the resulting measurement path (Fig. 10c); Fig. 11 schematically depicts an exemplary primary beam path (Fig. 11(a)), secondary beam path (11th (b)) in another embodiment Figure), and the resulting measurement path (Fig. 11c); Fig. 12 shows selected components of the apparatus in accordance with the second embodiment of the present invention; and Fig. 13 schematically depicts an exemplary material processing tool It comprises an apparatus comprising an exemplary charged particle beam generator and a system according to a third embodiment of the invention; Figure 13 (a) schematically depicts a device according to another embodiment of the invention; Figure 14(a) Forming a probe according to a fourth embodiment of the present invention Two probes in one part of the component, the probe assembly forming part of the system, on which an exemplary measurement path of the beam is drawn, and Figure 14(b) shows the correspondence of the detectable exemplary electrical signal Curve; Figure 15(a) shows selected components of the probe according to yet another embodiment of the present invention, and Figure 15(b) shows additional components of the same probe; Figures 16(a) and 16(b) The figure schematically depicts two other exemplary probes on which an exemplary measurement path of the beam is depicted; FIG. 17 shows another exemplary probe in accordance with an embodiment of the present invention; and 18th The graph of the graph depicts an exemplary sequence of electrical signals that can be detected from the probe shown in Figure 15.

The following description is directed to an embodiment that focuses generally on a charged particle beam that will measure its properties as an electron beam. However, it should be understood that the disclosed systems and methods are equally applicable to cation beams.

The systems and methods of the present invention can be used to diagnose beam properties in a variety of different industrial applications including, for example, electron beam welding of materials, ion beam drilling, surface texturing, and the like. A particular application of particle beams that are deflected at various angles of incidence above a large working envelope is additive manufacturing. As such, the systems and methods of the present invention are particularly well suited for use in additive manufacturing tools, and the following description will use this embodiment. However, it should be understood that such systems and methods can be transferred to any other type of equipment that utilizes charged particle beams.

A type of formal description using additive manufacturing of particle beams In the U.S. Patent No. US-A-2012/0234671 and using a high power beam, an electron beam is preferred to produce complex articles. The material processing tool 1 described in FIG. 1 is an additive manufacturing tool disclosed in US Pat. No. US-A-2012/0234671, which is incorporated in the beam diagnostic system according to the first embodiment of the present invention. 20, and a charged particle beam generator 10, such as an electron gun.

As described in US Pat. No. US-A-2012/0234671, the tool 1 uses a powder bed 5 carried on a table 3 to produce a metal object melted by the deflected electron beam B in the layer 5a. The equipment comprises a vacuum working chamber 2 equipped with an electron gun 15. The electron gun comprises a charged particle source 16, such as a thermal ion emitter (e.g., a heated cathode) or a plasma source, such as those disclosed in U.S. Patent No. WO-A-2013/051296, an accelerator 17, such as an anode, and a deflecting means. 18, for example a magnetic deflection coil for controlling the direction in which the beam B is generated in accordance with an instruction from the controller 11. Within chamber 2, a powder bed 5 can be lowered through base 4 to allow for the production of layers, and there are typically several powder funnels and a dip system (not shown) to spread the powder of each layer.

The electron gun 15 typically has a wide angle deflection system 18 such that a powder bed 5 up to 400 mm in diameter can be addressed at a working distance of about 500 mm. The size of the addressable member is limited by the angle θ at which the beam deflects away from the gun body axis A, which is achievable without excessive beam spot distortion, which affects the quality of the construction portion. In order to accurately calibrate such an electron beam 3D printer, the nature of the beam spot above the powder bed 5 must be described.

System 20 enables measurement throughout the calibration process The beam properties of the zone are used for this purpose. System 20 includes a probe assembly 21 that, when in use, is mounted in the normal position F-F' of the powder bead of the machine. The machine usually has a suitable mounting point for mounting a conventional calibration plate (i.e., a plate with an array of holes is used to provide manual adjustment of the beam deflection to ensure accuracy). The probe assembly 21 carries an array of probes spaced apart on the working area, each probe being configured to enable measurement of the beam properties at that location, as detailed below. The signal from probe assembly 21 is output by signal conduit 21 (e.g., one or more cables) to detection module 22, which is adapted to capture the signal it outputs as beam B traverses each probe. The beam is controlled to move along the measurement path by the beam deflection control module 23, which in this embodiment is implemented by a plurality of deflection coils 18 of the beam generator 15. Alternative techniques are also envisioned, as described below. The detected signal reveals the nature of beam B at each probe location. For example, the beam deflection can be triggered and the scope card collects the signal and transmits the data to the signal processor or computer 24 for post processing and storage. By synchronizing, the collected pulses can be correlated with X, Y measurements at various locations on the powder bed containing the probe elements.

The system 20 can also include, as needed, the associated module 22a for assigning each detected signal to the origin of the probe (and, if desired, the components within the probe, as described below), and the signal processor is configured to The original signal calculates parameters such as beam width or intensity profile. System 20 may also include memory for providing information regarding the measurement path that the beam follows during the calibration process and/or monitoring module 26a for controlling based on controller 11 and/or beam deflection from the beam generator The feedback from module 23 monitors the timely location of the beam. A feedback module 26b can also be provided for generating and supplying based on measured properties The feedback signal is given to the beam generator. Each of these as desired components will be described below.

The principle of operation of the probe assembly 21 will be explained with reference to the exemplary probe assembly shown in FIG. This includes a frame 27, such as a board, which carries a plurality of probes 30 arranged in an array on a frame, preferably arranged in a regular grid. In Fig. 2, for the sake of clarity of illustration, only three of the probes 30a, 30b, 30c are indicated, but it can be seen that in this embodiment a total of 16 probes are arranged in a 4x4 orthogonal grid. Any number (2 or more) of probes may be provided and preferably includes one at the center of the array (not shown in this embodiment) on the lance axis A when in use. For example, a 5x5 array can be particularly advantageous. The probes are typically spaced 1 to 10 cm apart from each other on the plate 27, for example, in this embodiment, the spacing L _x along the x-axis of the machine is about 5 cm and the spacing L _y along the machine y-axis. It is 5 cm. The frame may include, for example, an electrically conductive (e.g., aluminum) plate having an aperture for each probe location. The signals from the probes are both output at line 28 and via resistor 29a (e.g., a 50 ohm resistor) to ground G, and the voltage across it is detected by appropriate meter 29b. The measured signal is then taken using a screened lead 21a to the coaxial vacuum via to allow for extraction outside the vacuum chamber of the detection module 22.

An example of one of the probes 30 is shown in Figure 3. This includes the at least two elongate conductive elements 32 being configured such that they form a non-zero angle (i.e., non-parallel) with each other in the elongate direction of the array plane, i.e., a plane perpendicular to the axis A of the lance, here an xy plane . In this embodiment, preferably one element 33 is aligned with the machine x-axis direction and the other element 34 is aligned with the machine y-axis direction such that the two are substantially orthogonal. Make beam characteristics comparable Direct correlation of the machine direction is desirable, but this is not required. For example, each element 32 may be formed from a conductive wire, such as a wire, ribbon or strip, if desired, supported by a frame 31, such as a hollow tube. For example, in this particular embodiment, the elements are formed from tungsten wires that intersect each other at intersections 38. It should be noted that elements 32 may or may not be in electrical contact with each other depending on how the signals are to be collected and processed. In one embodiment, the elements 32 are isolated from one another and their signals are output to the detection module on individual channels. However, it is preferred to use a single channel output to simplify system deployment so that elements 32 can be electrically connected to each other, such as by contact at intersection 38 and/or by a frame 31 that can conduct or at least include a conductive portion or passage. The signal from component 32 can then be coupled to the detection module by a lead 39 that is coupled to either the frame or component 32.

The signals from the various probes 30 can be collected by the individual dedicated input channels of the detection module 22, but as mentioned above, a single channel is preferred, so preferably all of the probes are connected in series or in parallel, for example, Appropriate tracks or wiring of the mounting board 27 or by forming a board 27 of electrically conductive material. The schematic of Figure 4 depicts a suitable scheme for connecting nine probe arrays, as shown in Figure 3, with each probe having two intersecting elements 33,34. In this case, the probe elements of the array are all connected in parallel to a single via 21 that connects the probe assembly 21 to the detection module 22.

Each element 32 outputs an electrical signal upon receiving charged particles from beam B that has passed it. Thus, beam B is controlled by module 23 to follow a measurement path that traverses at least two of elongate elements 32 provided in probe 30. In some cases, it may be necessary to measure the beam at the probe locations. The only one of the properties, in which case the measurement path can be defined for a single probe, but more typically, one wants to measure several of the beam properties in the probe positions, all probe positions It is better.

An embodiment of a suitable measurement path MP is shown in Fig. 5, which overlaps with the enlarged portion of the probe assembly 21 shown in Fig. 2. Probes 30 are all shown in Figure 3, each having two elongate members 33, 34 aligned with the x and y axes of the machine. The measurement path begins with a beam directed at probe 30a at position B. The beam traverses element 33a first and then traverses element 34a as it traverses a substantially circular arc segment of path MP. The elements are configured such that they are sufficiently spaced apart from each other (at least where they would intersect the beam) such that the beam strikes only one element at any one time. That is, the space S between adjacent elements on the measurement path is at least equal to the beam width BW, which is preferably greater. A typical beam width is about 0.5 mm, so a space S of at least 1 mm is preferred, and at least 2 mm is preferred. The size of the probe is such that the path followed by the beam traverses the elements sequentially, in such a way that there is no need for a large deflection away from the nominal probe position (eg, the center of the probe) such that the beam traverses The properties of the beam will be substantially the same at the location of the various components within a probe. By making the probes small, the detection of the beam is next to a particular location above the work area such that the detection results are representative of the beam's respective central position of the probe at the work area. For example, the lengths l _x , l _y of the two wires forming the elongate elements may in this case be between 5 and 10 mm, such as 8 mm in a particular embodiment, such that the radius is about 2.5. The path of the arc of millimeters will provide the necessary sequence signals. In a preferred embodiment, the measurement path follows a small radius within each probe, for example between 2 and 4 mm, such that the corresponding angular displacement of the beam from the center of the probe is also small.

In the illustrated embodiment, the path segments only traverse the individual elements 32 once, but in other cases, the path segments can be substantially circular, in which case, in this embodiment, the probes are traversed. Each component is twice. This helps to improve the accuracy of the measured properties, since the average of the two signals from each component can be used to calculate the measured value. The beam can also be configured to surround each probe multiple times if desired. It is not necessary to use circular or arcuate measurement path segments for interfacing with the elements of the respective probes, but is preferred for the following reasons.

At the end of the arcuate segment, the beam continues along the measurement path MP to the next probe 30b. It should be noted that for this movement the beam can be cut so as not to damage the plate 27, so that the path MP is actually discontinuous. Upon reaching the next probe 30b, the beam is controlled to follow another arcuate line segment to traverse the elements 33b and 34b of the probe 30b. The beam is controlled to continue along the measurement path in this manner until it has traversed the elements of all of the probes at the location where the beam properties are to be measured.

An embodiment of the nature of the signal measurement that can be obtained in this manner is described with reference to Figures 6 through 9. Figure 6 shows a schematic elongated conductive element, such as element 33a of probe 30a shown in Figure 5, and the path that beam B traverses in the embodiment of Figure 5. Specifically, B(i) is the position at which the beam first strikes the element 33a, and B(ii) is the position at which the beam exits the element. When the beam is at position B(i), the component begins to output an electrical signal and ends when the beam is at position B(ii), that is, when it has moved through a distance D, which is equal to perpendicular to the component. Direction element of the long direction The width w of the piece plus the sum of the beam widths BW, that is, the width in the y-axis direction, in this case. It should be noted that in the more general case where the measurement path MP does not vertically traverse the elongate direction of the element, the effective element width contributing to the signal will be large and this will be taken into account when processing signals based on known crossing angles.

Figure 7 shows an exemplary signal output by element 33a: here it is a voltage-time graph, however the signal current can also be measured. The duration T of the sum signal is obtained to find the corresponding distance D traveled by the beam B based on the known speed of the beam. After the distance D is obtained, the beam width BW can be calculated because the element width w is known. Thus, the signal from element 33a can be processed to give a measure of the beamwidth BW along the x-axis at the position of probe 30a, and preferably a signal processor 24 suitable for accomplishing this calculation. Similarly, the signal that is subsequently output when the beam intersects the element 34a can be processed to obtain a measurement of the beam width along the y-axis direction at the position of the probe 30a. Together with these points to the probe 30a, these together provide a shape or ellipticity indicative of the beam spot.

It can be seen that in order to understand the signal of the translation, it must be able to identify which component is the source of each signal and this can be done in many ways. As mentioned above, the independent channels can output signals from the various components, in which case they are naturally different from each other. However, it is preferable to connect all the components together so that the signals are output on a single channel. Therefore, the detection module 22 is suitable for assigning each signal based on the knowledge of the measurement path MP and the order of detecting the signals or detecting the time of each signal. The source component of it.

Knowledge of the measurement path can be obtained in different ways. in In one embodiment, the detection module can be provided with a memory 25 (Fig. 1) in which details of a predetermined path to be followed by the beam are stored, for example, it strikes the probe assembly 21 at each instant of the selected time period. The xy coordinate of the time, or the corresponding vector data. This information also includes the speed of the beam is preferred. However, the accuracy of the beam can be controlled to be inaccurate, so for better accuracy, it is preferred that the detection module be provided with a monitoring module 26 for monitoring the current based on the deflection applied to the beam at the time (eg , in time) the beam position. This may involve receiving feedback from the controller 11 and/or the beam deflection control module 23 (however, as described below, at the desired beam position output by the controller 11 and/or the beam deflection control module 23 There may still be deviations, and the technology that will be used to handle the matter). Given the knowledge of the beam path, the sequential signals received by a single channel can be correctly assigned to the elements derived from them.

For example, Figure 8 is a schematic representation of the output trace from the probe assembly 21 shown in Figure 5 as the beam moves along the illustrated beam path. At time t ₁ a first detection signal (1) and attributable to the probe member 33a to 30a, by virtue of which it is the first detection signal or the beam will travel a distance from the starting point of the element 33a Given the knowledge, it is multiplied by the known beam velocities corresponding to time t ₁ . Alternatively, the monitoring module 26 may check the reference at time t ₁ in time of the beam position. The duration T _{33a of the} signal corresponds to the width of the beam along the x-direction (x _30a ) at the probe position 30a, as previously described. The next signal (2) can likewise be attributed to the element 34a of the probe 30a, so its duration T _34a provides the width of the beam at the same position along the y-direction (y _30a ). Likewise, the shape or at least the ellipticity of the beam spot as it is directed at the position of the probe 30a can be determined. As shown in FIG. 8(b), in this embodiment, it is found that the duration of the first signal (1) is longer than that of the second signal (2), and thus the beam spot is found to be elongated rather than precise in the x direction. Round shape.

Continuing along the trace of Figure 8(a), the third and fourth signals (3) and (4) can be associated with elements 33b and 34b of the next probe 30b by applying the same principles. The signal durations T _33b and T _34b provide the width of the beam spot in the x, y direction (x _30b , y _30b ) when pointing to the probe 30b, since in this case the durations are similar, such as 8th ( c) As shown, the beam spot is found to be substantially circular. Of course, these calculations assume that the widths of the individual elements 33, 34 are equal. This is not necessarily the case. If not, their different widths need to be taken into account when processing.

The detected signal can also be used to obtain a profile of the beam intensity (i.e., current density) in a direction perpendicular to the elongate direction of each element. This is illustrated in Figure 9, where Figure 9(a) shows beam B beginning to cross element 32 along measurement path MP, and Figure 9(b) depicts curve (i) detection signal and (ii) Increasing the contribution of beam B across the width of the element in the length direction of the element (y-direction) to the signal, and (iii) the derivative variation of the beam intensity in the x-direction. When beam B traverses element 32 at any one time, the strip portion of the beam is incident on the element (shown in the underlined portion of Figure 9(a)) and the signal measured at that time will be horizontal The current density of the collected beam is proportional. As the relative motion progresses, the different strip portions of the beam spot are sampled by element 32 and the detected signal changes accordingly. However, since the beam spot has a substantially circular shape, the length l of the element 32 illuminated by the beam will vary over time according to a function l(t) that can be estimated if the beam shape is known. The detected signal (i) generated by the function l(t) shown in Figure 9(b) is actually received. The sum of the change indicated by the broken line (ii) and the actual intensity change of the beam indicated by (iii). Therefore, since the function l(t) can be estimated (for example, based on the width measurement mentioned in the description of FIGS. 6 to 8), the intensity profile (iii) can be calculated from the detected signal (i).

The intensity profile is measured along a direction perpendicular to the elongate direction of the component, so that the device shown in Figure 5 is available in the x, y directions by means of elements 33a and 34b, respectively. This can also be repeated at each probe location.

If desired, the signals can be further processed to obtain a two-dimensional intensity map of the beam spot. This is achieved by topological reconstruction on the contours taken in multiple directions to unwind the signals. For example, the well-known Lagrangian inverse function can be used for this purpose. This goal requires the smallest of the two profiles obtained by beam spotting in different directions, but a better resolution will be achieved when more than two such profiles are available. Probes with additional components are particularly suitable for this purpose, as will be described below with reference to Figures 15 and 16.

These measured properties can be used to adjust the beam generator to modify the beam properties as needed. For example, in many applications, it is desirable for the work area to have substantially uniform beam properties. Thus, the system can include a feedback module 26b adapted to generate and output a feedback signal to a beam generator (e.g., controller 11) that can be used to adjust an optical system, such as an electron gun, to modify the beam width, shape, or intensity as desired. It may be preferable to automate this method by providing a generator and/or system with a suitable algorithm, which can adjust the beam to achieve the desired output without further operator input.

The beam deflection control module can be implemented in a variety of ways. In some embodiments, the controller 11 of the beam generating device (hereinafter referred to as the "primary" controller) can be used to move the beam along the desired measurement path by programming the primary controller accordingly. However, since in many cases this is not preferred, the primary controller will adjust the beam to correct for distortion, such as astigmatism. Due to these angular dependencies, if the primary controller deflects the beam away from the probe position where the beam properties are to be measured (eg, the center of the probe), the beam is automatically adjusted to account for the offset, Thus the beam traversing the individual probe elements does not have the same properties as when the beam is pointing at the intended location. In addition, primary controller 11 typically outputs digital control that may result in unintentional discontinuity of the beam path when the beam is deflected over the probe elements at high speeds.

Therefore, by avoiding the primary controller 11, it is preferable to impose a beam that causes the desired measurement path to be shifted to the beam. The primary controller is programmed to transport the beam along the primary beam path P _{1 to} move the beam from one probe position to the next. The beam deflector control module followed by the addition of the secondary beam path (or "offset") P ₂ on the primary beam path. The measurement path comprises a secondary beam path P ₂ superimposed on the primary beam path P ₁ (i.e., MP = P ₁ + P ₂ ).

Figure 10 shows an embodiment of the primary and secondary beam paths used to form the measurement path (similar to that mentioned in the description of Figure 5), in which case the beam traverses substantially at each probe position. Outside the circular path segment. Figure 10(a) shows the primary beam path P ₁ output by the primary controller 11. Beam B is moved from one probe 30a to the next 30b, each at the center of the probe. This is the location of the probe that will record the measured properties. Each of the sequential positions is recorded as a trigger position 40a, 40b, 40c. The secondary beam path P _{2 is} shown in Figure 10(b) and includes a short straight movement away from the center of the probe, followed by a substantially circular line segment designed to cause the beam to traverse a number of elements in a probe, As mentioned above.

In operation, the beam is moved by the primary controller 11 to position 40a. The beam deflection control module 23 receives information from the primary controller via the monitoring module 26 regarding the current position of the beam according to the primary beam path. When the position 40a is recorded as the trigger position in response to the beam reaching the position, the beam deflection module 23 outputs a secondary beam path control signal representative of the path P ₂ , which causes the beam B to be deflected away from the probe 30a. The center and the circular path segment following the surrounding probe 30a are as shown in Fig. 10(c). Upon completion (e.g., after a preset delay), the primary controller moves the beam at a probe location 40b and 30b which again trigger the output control signal of the secondary beam of P _2. The resulting measurement path is shown in section 10 (c) of FIG, this discontinuity dashed line indicates the path where the beam is cut off (built into the primary beam path P _1).

Preferably, the start and end points of each circular segment are away from any elongate member, as shown in the embodiment of Fig. 10, so that the beam does not remain on any of the components for a significant period of time as this may cause the component to overheat and melt. . For example, the beam deflection can be stationary at a 270 degree position at the center of the probe until triggered to complete a journey.

Another embodiment of the appropriate measurement path and primary and secondary beam path contributions are shown in FIG. Here, the primary beam path P ₁ (Fig. 11(a)) is a continuous line from one probe to the next, wherein the beam is offset from the center of the probe to avoid the intersection of the elements. The secondary beam path P ₂ is a substantially circular line segment (Fig. 11(b)). In this case, there is no trigger point and the beam deflection control module does not need to receive feedback regarding the current position of the beam on the primary beam path. The secondary beam control signal is continuously output, and thus the measurement path MP follows the spiral as shown in Fig. 11(c). Although the path no longer uses the knowledge of the path (eg, from the monitoring module) to traverse the components of the various probes in the same position or in the same order, the detection module can correctly attribute each pulse to the respective component. . In order to prevent damage to the board 27, the primary controller can cut the beam B for the portion between the probes.

As mentioned above, the circular or arcuate segments of the measurement path are preferred and one of the reasons is that the elements are configured to extend radially from a central intersection as illustrated, the path intersecting the various elements at the same angle, That is, vertically. Furthermore, by applying a constant travel angular velocity as a secondary control signal, the speed of the beam can be kept constant, which simplifies the processing of the detected signal. However, with a landing angle away from the normal (for example, at the periphery of the array), although the angular velocity of the beam will not change, the beam will depict an ellipse instead of a circle because the array plane is at that angle with the beam. cross. Likewise, the speed of the beam will change as it travels. This causes different pulse widths on the X and Y traces, even if the beam is completely symmetrical. This distortion can be corrected if the secondary control signal is dependent on the beam deflection angle (as known by the monitoring portion 26). For example, the beam deflection control module 23 can be configured to produce an elliptical correction deflection for each probe position such that the path of the beam around the probe remains circular such that the beam velocity is constant. Alternatively, the correction can be done after the signal is processed. The following will describe the circular or arcuate measurement path His advantages.

This secondary beam path can be imposed on the beam in a variety of ways. Figure 12 shows the selected components that have been mentioned by the tool in the description of Figure 1. Here, the deflection coil 18 of the electron gun 15 itself is used to apply all necessary deflections to the beam. The beam path of the primary control signal P ₁ output from the primary controller 11 and typically by digital to analog converter 12. The beam path of the secondary control signal P ₂ by the beam deflector control module generates and outputs the signal path and measuring the deflection coil 18 are then superimposed on the received control signal to the primary beam path P ₁ to form 23. For example, the secondary beam path control signal can be generated by two arbitrary function generators that are synchronized to produce a single sine wave output and phase shifted by 90 degrees to produce a perfect circle deflection.

An alternative implementation is shown in Fig. 13, which is a modified version of the layered manufacturing tool 1' which has been mentioned in the description of Fig. 1. The same components as those described above are denoted by the same reference numerals and will not be described again. In this embodiment, the beam deflection control module 23 further includes a secondary deflection unit 23a, such as a second set of deflection coils, disposed downstream of the primary deflection unit 18 along the gun axis A. Therefore, the primary deflection unit 18 is from the (unmodified) primary control signal of the controller 11 to control the beam, while the secondary deflection unit 23a imposes an offset on the beam based on the secondary beam control signal from the module 23. B. This has the advantage that there is no need to change the electronics of the machine, which is useful when retrofitting the probe system to an existing machine.

In a particularly advantageous implementation, the secondary deflection unit 23a and the probe assembly 21 are mounted in an integrated device, and Figure 13a shows an embodiment. Device 50 includes probe assembly 21 as described above, and a beam The deflecting unit 23a is, for example, a deflecting coil. The beam deflecting unit 23a is supported by the support assembly 51 on the probe assembly, where it includes four support arms 51, one at each corner of the probe assembly (although any number can be installed). Preferably, the support assembly 51 securely couples the deflection unit to the probe assembly such that when the properties of the beam are to be measured, the device as a whole can be placed straight into the machine, such as the tool 1'. Alternatively, the device can be provided as a kit and assembled in place.

To mount the measurement system, the device 50 is placed into the vacuum chamber 2 of the machine in alignment with the beam axis A. The probe assembly 23 can be assembled to the workpiece table 3 with accessories that are typically installed in such machines for mounting manual calibration plates. Therefore, the deflection unit is automatically positioned by the support assembly. The deflecting unit 23a is connected to the controller by two coaxial through holes, such as the beam deflection control module 23, in order to implement a secondary beam control signal, such as a circular deflection.

As described above, the probe outputs are connected to the detection module 22 for detecting and processing the electrical signals output by the probe elements.

This approach allows the system and method of the present invention to be easily deployed in existing machines that utilize charged particle beams without having to modify the beam generator control system of the machine. The modular unit can be temporarily loaded into the machine without having to change the system itself. The support assembly can, for example, include a support arm, such as a dowel and pre-machined hole, or any other suitable structure that properly positions the beam deflection unit.

In the presently described specific embodiment, the detected signals are attributed to the individual probe elements based entirely on the knowledge of the beam path. As mentioned above, in order to achieve good accuracy, in practice, this requires the use of receiving The current deflection of the beam is monitored from the primary controller 11 and the monitoring portion 26, preferably also from the positional information of the beam deflection control module 23. In theory, if the secondary beam path is known when the beam reaches the known trigger position and its exact shape and phase are known, the system can rely solely on feedback on the primary beam path, which allows identification as the origin of each signal. The probe then depends on the order of the signals within a probe to determine which of the components in the probe is the source of the signal. However, in practice, the secondary beam path may not be exactly the same, and, in particular, at the instant where it is output, may not start at the same location near the probe. Similarly, as in the specific embodiment of Figure 11, in the case of a continuous secondary deflection signal, it is typically one of the components of the respective probes that are first traversed by the beam.

Figure 14(a) shows a portion of the probe assembly modified to assist in identifying the source of each signal, in accordance with another embodiment. Here, the configurations of the respective probes 30a, 30b are substantially the same as those described above in the description of FIG. 5 and the like. Each of the probes is provided with marking elements 36, 36 containing conducting elements that are wider in the direction of the measuring path than the elongate elements 33, 34. For example, the marking element can comprise a peg or protrusion of the probe frame. In the same manner as each of the elongate members 33, 34, the marker member 36 is electrically coupled to the detection module. Due to its large width, when hit by the beam B, the marking element generates an electrical signal having a large peak amplitude compared to that originating from the elongate members 33, 34, and thus can be used as a marking signal. Other signals are identified based on their order relative to the tag.

The graph of Fig. 14(b) depicts an exemplary sequence of electrical signals detected when beam B follows the measurement path MP of Fig. 14(a). Should pay attention to The illustration is clear and does not show all the signals that will be generated. The first three signals (1), (2), and (3) are attributed to the probe 30a by feedback from the monitoring unit 26. The magnitude of the second signal (2) is substantially greater than the other signals and is known to originate from the marker element 36a. As a result, based on the knowledge of the probe geometry, pulse (1) can be attributed to element 33a, and pulse (3) can be attributed to element 34a. When the beam reaches the probe 30b, as seen in Figure 14(b), the beam begins at different locations near the probe thereby traversing the elements in a different order. This is identified by the presence of the marker pulse (4) as the first pulse attributable to probe 30b, allowing subsequent pulses (5) and (6) to be matched to elements 34b and 33b, respectively.

Figure 15 shows another embodiment of a probe 30' suitable for use in the system of the present invention. As shown in Fig. 15(a), the probe is based on the frame 31a which is a cylindrical tube portion similar to the collar in the previous embodiment, and defines a central opening. The frame 31 is preferably electrically conductive and can be made of, for example, stainless steel. The outer surface of the frame is provided with eight axial grooves equally spaced around the frame and for holding the elongated conductive elements 32. For example, the forming element 32 can be wrapped around the frame by grooves with continuous wiring such that it traverses itself as shown to provide elements of different orientations. In this embodiment, a total of four different directions are placed: elements along the x, y directions, and elements that are equidistant from them in both directions. In this way, by providing an additional measurement direction, the width of the beam spot in more directions can be measured, so that its shape can be determined more accurately. In addition, a higher resolution intensity map can be reconstructed. It should be noted that it is preferred that all of the components fall in the same flat plane such that the properties of the beam are measured at the same height relative to the working surface, although this is not required.

In this embodiment, the member 32 is made of 18 micron tungsten wire held to a frame 31a having an outer diameter of 12 mm and an inner diameter of 8 mm. The frame 31 is housed in a ceramic holder 31b which itself is mounted to a specific position in the machine work area by drilling holes fixed to the array plate 27.

In the embodiments depicted so far, the probe elements are formed with intersections at the center of the probe, such as a crosshair configuration. However, this is not required, and Figure 16 shows some other embodiments of an exemplary probe configuration that can be used. In both cases, the probe is based on a tubular frame 31 having a circular cross section, but this is not required and the frame may take any shape that defines a central aperture. In the 16th (a) embodiment, four elongate elements are provided and configured to form a square or rectangular shape. Elements 33 and 33' are aligned with the x-axis of the machine, and elements 34 and 34' are aligned with the y-axis of the machine. Preferably, the elements are in electrical contact with one another and/or in contact with the frame 31 at corner intersections: for example, the elements may be formed by surrounding four posts that are disposed on the front of the frame 31 to define four corners. Winding the wiring. An arrangement like this has the advantage that there are no components in the center of the probe 30", which means that the beam does not need to be deflected immediately away from the center of the probe to avoid melting of the element: the beam can stay in the center of the probe harmlessly. The beam may intersect any two or more of the elements, for example by following a circular measurement path MP, as illustrated. In this case, the measurement path will traverse the elements at various angles and this will Need to consider signal processing, as mentioned above.

In the embodiment of Fig. 16(b), three elements 33, 34 and 35 are provided and are arranged at any angle so as not to be parallel to each other. There are also no elements in the center of the probe 30''', which is advantageous for the above reasons. The beam can employ any measurement path that traverses at least two of the elements. In this case, a right angle measuring path MP made of two straight portions is shown, from which the same information as described above can be obtained. However, paths like these are more difficult to implement accurately than the substantially circular or arcuate paths as described above, especially with analog control because the control signal needs to be superimposed with many high frequency components to approximate the expected line and / Or sharp corners. In contrast, a circular or arcuate beam deflection can be easily achieved at high speed without distortion.

The probes used in the system of the invention are advantageous and particularly suitable for use in the present application, whereby the properties of the beam can be measured at widely different angles of incidence, since the probes are substantially insensitive to the landing angle of beam B. This is because the conducting element 32 is used for sampling the beam and outputting the detected signal. The conductive elements produce a signal regardless of the angle of the beam incident thereon. As a result, all of the probes in the array can have the same construction and are interchangeable because each can cope with the entire range of landing angles that are experienced at different locations above the work area. Thus, the multi-position probe enables consistent measurement of melting/material processing performance over the dispersed working area where the particle beam deflects to various locations.

To further remove any remaining angular sensitivity, it is preferred that the elongate conductive elements have a width in the array plane (i.e., perpendicular to the shank axis A) that is equal to or greater than their thickness in the vertical direction of the array. For example, this criterion is achieved by a wire having a circular cross section or a flat wire, strip or tape having a thin dimension that is configured perpendicular to the axis of the probe. This minimizes the sensitivity of the probe to the beam incidence angle because any particles received on the side of the element are minimized compared to the front side (facing the beam source). A strip element having a substantially flat surface is particularly preferred because it reduces the degree of backscattering compared to, for example, circular wiring. Fig. 17 shows another embodiment of such a probe 30 ^IIIV in which the elements 33, 34 are integrally formed with each other by a conductive foil which hangs across the frame 31.

As mentioned above, the beam deflection achieved by the deflection unit 18 (and/or 17, if any) may not correspond exactly to the expected deflection indicated by the controller 11 and/or the module 23, ie, There may be deviations in deflection. In this case, the beam does not exactly follow the expected measurement path and this may result in distortion of the measured properties, because for example the beam does not traverse the individual elements at the desired angle. Accordingly, the system preferably includes means for detecting and correcting any such deviations, and advantageously, this is accomplished by a signal processor 24 based on the time interval between detected electrical signals.

A suitable technique for an exemplary scenario is described below in which a circular measurement path and a probe as shown in Fig. 15 are used, that is, four intersecting conductive wires are effectively formed with elongated shapes extending radially from the intersection. 8 components in the direction. The circular measurement path is designed to be centered at the intersection so that it traverses the various elements at the same angle (90 degrees). In one experiment, the beam was driven to follow this measurement path at a constant frequency of 10 kHz (ie, 10,000 path circuits were completed per second). The beam is designed to have a beam current of 0.25 mA at 100 kV with clear focus. Figure 18 is a graph showing (i) the secondary deflection signal supplied to the deflection unit (or several) in the y-axis direction, in volts and time (the period in which the circular deflection is shown), and (ii) Detected the telegraph. Region C corresponds to a circuit of the path during which the components are crossed 8 times, so 8 electrical signals (1) through (8) are detected.

The signal processor measures the time interval ΔT of each pair of adjacent signals. For example, the interval between the signals (1) and (2) is ΔT ₁₂ . If the beam accurately follows the desired measurement path, the interval ΔT of each pair of adjacent signals should be equal, that is, ΔT ₁₂ = ΔT ₂₃ = ΔT ₃₄ , and so on. In the case of Figure 18, as seen by the graph, the equally unequal display beam does not accurately follow the expected measurement path, for example, it may be eccentric, or may not be round enough, i.e., at the expected beam deflection (encoding There is a deviation between the deflection control signal and the actual implementation. As a result, the signal width and peak are also different from each other, and to some extent this may indicate that the nature of the beam changes with direction, which is also because the beam traverses the individual components at an unknown angle other than 90 degrees. .

In order to correct this, the signal processor preferably generates and outputs a feedback signal to the (equal) deflection unit based on the difference in ΔT. Adjusting the deflection control based on the feedback via an appropriate algorithm to reduce any difference between the measured ΔT values is preferred to reduce the point at which the beam is expected to follow the expected path to zero. Then using the above principle, the beam properties can be accurately measured based on the subsequently detected electrical signals.

Although it is particularly preferred to implement this technique using circular measurement paths and radially extending probe elements as described above, this is not required. For example, based on the planned measurement path and the known probe geometry, the (absolute or relative) ΔT expected value for each pair of adjacent signals can be calculated, and the feedback algorithm can be designed to adjust the beam deflection until these expected values are obtained. . However, this calculation is simplified with the above implementation because all expected ΔT values will be equal.

It can also store corrections calculated and applied using this technology and during future processing performed by tools added to the system. The tool is available.

The following are some of the advantages of preferred embodiments of the system and method of the present invention:

‧Enhanced beam properties are quantified measurements at many discrete locations throughout the work area, such as width, shape, and/or strength, including high beam deflection angles.

‧ Each probe is tiny such that it is better to measure the beam at the location close to the probe on the work area.

• The use of elongated conductive elements such as wires allows measurements to be made independently of the beam landing angle, so the probes act accurately, even for high deflection angles.

‧ Probes can all be connected together to simplify vacuum chamber connections: only a single via is required.

‧ The system allows measurement over the entire work area without any manual adjustment of the probe components or operator intervention, so in the case of a vacuum chamber, beam characterization can be done quickly and within a single pumping cycle of the machine.

• Integration of beam deflection and data collection provides fully automated measurements; once the measurement path is initialized, no operator input is required.

‧ Beam measurements can be collected very quickly (for example, dozens of locations below 1 second).

• All measurements can be made in a single machine pumping cycle, which allows for a short total measurement time.

‧The preferred circular beam deflection allows for high speed deflection with accurate beam positioning and velocity, enabling detection of high power beams.

‧ No moving parts, simple operator settings.

‧ The probe system can be easily retrofitted to existing beam generators or integrated into material processing tools.

21‧‧‧ probe assembly

21a‧‧‧Shielded leads

22‧‧‧Detection module

23‧‧‧Ball deflection control module

24‧‧‧ Signal Processor or Computer

30a, 30b, 30c‧‧ ‧ probe

33a, 33b, 34a, 34b‧‧‧ components

Claims (82)

A system for measuring the properties of a charged particle beam output by a charged particle beam generator, comprising: a probe assembly comprising a plurality of probes arranged in an array across a plane on a frame, Each of the probes includes at least two elongate conductive elements configured such that their respective elongate directions form a non-zero angle with each other in the plane of the array; a beam deflection control module adapted to control the charged particle beam edge a deflection of a measurement path that sequentially traverses at least two of the elongate conductive elements of at least one of the probes; and a detection module coupled to the plurality of The conductive elements of each of the probes are adapted to detect the electrical signals output by the conductive elements of the respective probes in sequence when intersecting the charged particle beam, the detections from the respective probes The electrical signal indicates the nature of the charged particle beam as it is directed across the probe assembly to the position of the respective probes. The system of claim 1, wherein the detecting module is more suitable for identifying the long conductive element of the probe as a source of each detected electrical signal. The system of claim 1 or 2, wherein the elongate conductive elements of the respective probes are in electrical contact with each other and integrated with each other as needed. The system of claim 3, wherein the elongated conductive elements of each probe are connected in parallel or in series with other probes, and The detection module is adapted to receive the electrical signals output by the conductive elements of the probe assembly on a single channel. The system of claim 3, wherein the detection module includes an association portion adapted to identify the one of the probes as a source of each detected electrical signal. It is based on the knowledge of the measurement path and the detection time of each electrical signal and/or the order in which the electrical signals are detected. The system of claim 5, wherein the knowledge of the measurement path is provided by a memory that has been stored in the measurement path data, the stored measurement path data preferably including: a starting position of the beam, The path that will be followed by the beam, and, if desired, at least at the intersection of the conductive elements. The system of claim 5, wherein the knowledge of the measurement path is provided by a beam position monitoring unit adapted to receive from the charged particle beam generator and/or the beam deflection control module Information about the current deflection of the beam. The system of claim 5, wherein the knowledge of the measurement path is provided by a memory that has been stored in the measurement path data and a beam position monitoring unit, and the beam position monitoring unit is adapted to The charged particle beam generator and/or the beam deflection control module receives information regarding the current deflection of the beam. The system of any one of clauses 1 to 8, wherein the charged particle beam generator comprises a primary beam deflecting unit and a primary controller adapted to generate and output a primary control Signal to The primary beam deflecting unit is configured to guide the beam to a selected position or to move along a primary beam path, and the beam deflection control module includes a primary controller that is assembled to output a primary stage The control signal is superimposed on the primary control signal output by the primary controller, the secondary control signal defining a primary beam path such that the primary beam deflection unit directs the beam along the secondary beam path The measurement path moves in combination with one of any primary beam paths. The system of any one of clauses 1 to 8, wherein the charged particle beam generator comprises a primary beam deflecting unit and a primary controller adapted to generate and output a primary control Signaling to the primary beam deflecting unit for directing the beam to a selected position or along a primary beam path, and the beam deflection control module includes a primary beam deflection unit a downstream primary beam deflecting unit and a primary controller are configured to output a primary control signal to the secondary beam deflecting unit, the secondary control signal defining a primary beam path, such that the primary The secondary beam deflecting unit together directs the beam to move along the measurement path that is combined with one of the primary beam paths and any of the primary beam paths. The system of claim 9 or 10, wherein the beam deflection control module comprises a monitoring unit adapted to receive information about the current deflection of the beam from the charged particle beam generator. The primary control signal from the primary controller is preferred, and the secondary control signal is output in response to the received information. The system of claim 11, wherein the beam is biased The folding control module is adapted to output the secondary control signal by returning the beam deflection to one or more predefined trigger positions, and each of the predefined trigger positions is preferably corresponding to a position of one of the probes. The system of claim 12, wherein the primary control signal is configured to sequentially direct the beam to a plurality of discrete locations each corresponding to a different probe and each being a predefined trigger location Thereby, upon reaching each discrete position, the beam is deflected by the beam deflection control module to move along the measurement path corresponding to the secondary beam path. The system of any one of clauses 9 to 13, wherein the secondary control signal output by the secondary controller defines a substantially circular or arcuate deflection path having a constant The beam speed is preferred. The system of claim 14, wherein the secondary controller is adapted to modify the secondary control signal by the deflection angle of the beam, preferably by applying an ellipse correction to each probe position. The path followed by the deflection such that the beam follows the probe assembly is substantially circular or arcuate at each probe of the array. The system of any one of clauses 1 to 15, wherein the measuring path comprises at least one line segment traversing at least one of the elongate conductive elements of one of the probes Two, all preferred, the line segments are substantially circular or follow a substantial arc. The system of any one of clauses 1 to 16, wherein the measurement path comprises a plurality of line segments, each line segment traversing the line At least two of the elongate conductive elements of one of the probes are all preferred, and each line segment intersects a different one of the probes. The system of claim 17, wherein the measurement path is discontinuous between the line segments. The system of claim 16, wherein the starting point and/or the ending point of the or each line segment does not coincide with any of the elongate conductive elements. The system of any one of clauses 1 to 19, wherein each of the probes further comprises a marking element that is electrically conductive and has a width greater than the isometric conductive element being measured a width of the direction in which the path traverses, the measurement path additionally traversing the marking element, whereby an electrical signal output by each marking element when intersecting the charged particle beam is greater than a peak amplitude output by the elongate element, And wherein the detecting module is adapted to identify the elongated conductive element in a probe as a source of each detected electrical signal based at least in part on the electrical signal output by the marking component. The system of claim 20, wherein the detection module is adapted to identify the probe as a source of each detected electrical signal based on the measurement path. And the detection time of each of the electrical signals and/or the sequence of detecting the electrical signals, and identifying the length of the identified probe based at least in part on the electrical signal output by the marking component The shaped conductive elements are the source of each detected electrical signal. The system of any one of claims 1 to 21 The at least two elongate conductive elements of each of the probes include at least first and second elongate conductive elements configured such that their respective elongate directions are substantially orthogonal to one another in the plane of the array . The system of any one of claims 1 to 22, wherein each probe comprises at least 3, or at least 4, more preferably elongated conductive elements configured for their The respective elongate directions form a non-zero angle with each other in the plane of the array, and the respective different elongate directions are preferably substantially equiangularly spaced from one another. The system of any one of clauses 1 to 23, wherein the at least two elongate conductive elements of each probe have at least one intersection between them, such Electrical contact of the components is preferred here. The system of claim 24, wherein the at least two elongate conductive elements are configured such that their elongate directions extend radially from an intersection between them and at the intersection It is preferred to be equiangularly spaced apart from each other. The system of claim 25, wherein the measuring path comprises at least one of the at least one of the elongate conductive elements traversing one of the probes, all of which are Preferably, the line segment is substantially circular or follows a substantially circular arc and is centered at the intersection of the elements from which the elongate direction extends. The system of any one of clauses 1 to 26, wherein the at least two elongate conductive elements of each probe comprise at least two conductions that intersect each other at a non-zero angle Silk, the conduction The wire is required to be a different part of a continuous conductive filament. The system of claim 27, wherein the conductive filaments comprise wires, ribbons or strips. The system of any one of clauses 1 to 28, wherein the width of the elongate conductive elements in the plane of the array is equal to or greater than the thickness of the elongate conductive elements in a direction perpendicular to the array. . The system of any one of clauses 1 to 29 wherein the width of each elongate conductive element in the plane of the array is less than the diameter of the charged particle beam in the plane of the array, It is preferred that between one third and two thirds of the diameter of the charged particle beam. The system of any one of clauses 1 to 30, wherein each elongate conductive element has a width in the plane of the array of between 5 and 200 microns. The system of any one of clauses 1 to 31, wherein the at least two elongate conductive elements are spaced apart from each other by at least a distance along at least one of their lengths. Greater than, preferably, the diameter of the charged particle beam in the plane of the array. The system of any one of clauses 1 to 32, wherein the at least two elongate conductive elements are at least 0.5 mm apart from each other along at least one of their lengths. , at least 1 mm is better. The system of any one of claims 1 to 33, wherein each of the probes comprises a frame that is assembled to traverse at least two of the apertures defined by the frame Supporting these elongated conductive points at points element. The system of claim 34, wherein the frame comprises a tube portion, preferably a cylindrical tube portion, the elongate conductive members being configured to traverse one or both ends of the tube portion. The system of claim 34, wherein the frame comprises a conductive portion that is configured to connect the at least two elongated conductive elements to the detection module. a circuit. The system of any one of clauses 1 to 36, wherein the plurality of probes are configured according to a regular grid throughout the array and including a probe in the charged particle beam This axis of the generator is preferred. The system of any one of claims 1 to 37, wherein the frame comprises a plate having a plurality of apertures in which the plurality of probes are disposed, the plate preferably Conductive and, if desired, assembled to provide a circuit electrically coupled between the probes and to the detection module. The system of any one of clauses 1 to 38, wherein the probe array is located in a plane substantially perpendicular to the axis of the charged particle beam generator. The system of any one of claims 1 to 39, further comprising a signal processor adapted to calculate the beam based on the knowledge of the detected electrical signals and the beam measurement path The nature. The system of claim 40, wherein the signal processor is adapted to calculate that the beam is at least two at at least one probe position The width of the direction is based on the detected electrical signals from the at least two elongate conductive elements of the respective probes, and the speed knowledge of the beam across the elements. The system of claim 40, wherein the signal processor is adapted to calculate an intensity profile of the beam in at least two directions at at least one probe position based on the respective probes The detected electrical signals of the at least two elongated conductive elements of the pin, and the knowledge of the width of the beam. The system of any one of claims 40 to 42, wherein the signal processor is adapted to calculate an intensity map of the beam in two dimensions at at least one probe position, The detected electrical signals from the at least two elongate conductive elements of the respective probes are reconstructed by chromatography. The system of any one of claims 40 to 43 wherein the signal processor is adapted to calculate that the beam is at least two at each of the plurality of probe positions The nature of the direction preferably includes the width of the beam, the intensity profile of the beam, the intensity map of the beam, and/or the beamer. The system of any one of claims 40 to 44, wherein the signal processor is adapted to detect the shot at at least one probe position before calculating the properties of the beam Any deviation deviation of the beam based on the spacing between adjacent detected electrical signals from the at least two elongated conductive elements of the respective probes, and generating and outputting a bias deviation feedback signal to the charged Particle beam generator to correct This deflection deviation. The system of any one of claims 1 to 45, further comprising a feedback module for generating and supplying a feedback signal to the charged particle beam generator, whereby the system is based thereon The properties are measured to adjust the properties of the charged particle beam. The system of any one of claims 1 to 46, wherein the charged particle beam is an electron beam or an ion beam. An apparatus comprising a charged particle beam generator and a system according to any one of claims 1 to 47, wherein the charged particle beam is measured by the charged particle beam generator Several properties of the output. The apparatus of claim 48, wherein the charged particle beam generator comprises a charged particle source, and a particle acceleration unit is configured to accelerate charged particles from the particle source along an axis to form a charged particle beam. A primary deflection unit is adapted to deflect the charged particle beam away from the axis and a primary controller is adapted to output a primary control signal for controlling the deflection applied by the primary deflection unit. A material processing tool comprising: an apparatus according to claim 48 or claim 49, wherein the tool is one of: an electron beam welding tool, the charged particle beam is suitable for welding Material; a layered manufacturing tool, the charged particle beam is suitable for processing powder materials, and it is preferred to fuse them; a curing tool, the charged particle beam is suitable for curing a workpiece; a cutting tool, the charged particle beam is suitable for cutting a material; a melting or gasification tool, the charged particle beam is suitable for melting and/or gasifying the material The tool is a gas processing tool, the charged particle beam is suitable for treating gaseous substances, burning smoke is preferred; a disinfecting tool, the charged particle beam is suitable for disinfecting solid or liquid; a drilling tool, the charged particle The bundle is suitable for use in drilling a workpiece; or a material texturing tool suitable for forming a plurality of protrusions or structures on a workpiece. A method of measuring the properties of a charged particle beam output by a charged particle beam generator, the method comprising the steps of: providing a probe assembly comprising a plurality of probes arranged in an array across a plane on a frame Each probe includes at least two elongate conductive elements configured such that their respective elongate directions form a non-zero angle with each other in the plane of the array; controlling the deflection of the charged particle beam to follow a measurement path And traversing at least two of the elongate conductive elements of at least one of the probes; and detecting telecommunications output by the conductive elements of the respective probes in sequence when intersecting the charged particle beam Number, the detected electrical signals from the respective probes indicate that the charged particle beam is at the location pointing to the respective probe The nature of the time. The method of claim 51, further comprising identifying the one of the probes as the source of each of the detected electrical signals. The method of claim 51, wherein the at least all of the electrical signals output by the at least two elongate conductive elements of a probe are detected on a single channel. The method of claim 53, wherein all of the electrical signals output by the plurality of probes are detected on a single channel. The method of claim 53 or 54 further includes associating each detected electrical signal with a conductive component derived therefrom based on the knowledge of the measurement path and the detection time of each electrical signal and / or the order in which the signals are detected. The method of claim 55, comprising: extracting stored measurement path data to provide the knowledge of the measurement path, the stored measurement path data preferably including: a starting position of the beam, The path that will follow the beam and, if desired, at least at the intersection of the conductive elements. The method of claim 55, comprising: monitoring a current deflection of the beam to provide the knowledge of the measurement path. The method of claim 55, comprising extracting the stored measurement path data and monitoring the current deflection of the beam to provide the knowledge of the measurement path together. The party described in any one of claims 51 to 58 The method, wherein the charged particle beam generator comprises a primary beam deflecting unit and a primary controller adapted to generate and output a primary control signal to the primary beam deflecting unit for directing the beam to a selected position Or moving along a primary beam path, and controlling the deflection of the charged particle beam to follow the measurement path includes: outputting a primary control signal superimposed on the primary control signal output by the primary controller, The secondary control signal defines a primary beam path such that the primary beam deflection unit directs the beam to move along the measurement path that is combined with one of the primary beam paths and any of the primary beam paths. The method of any one of clauses 51 to 59, wherein the charged particle beam generator comprises a primary beam deflecting unit and a primary controller adapted to generate and output a primary control Signaling to the primary beam deflecting unit for directing the beam to a selected position or along a primary beam path, and the step of controlling the deflection of the charged particle beam to follow the measurement path includes: outputting a secondary control signal to a primary beam deflecting unit disposed downstream of the primary beam deflecting unit, the secondary control signal defining a primary beam path such that the primary and secondary beam deflecting units are together The beam is directed to move along the measurement path that is combined with one of the primary beam paths and any of the primary beam paths. The method of claim 59, wherein the method further comprises monitoring a current deflection of the beam, and wherein the output of the secondary control signal is in response to the monitored deflection. The method of claim 61, wherein the secondary control The output of the signal is back to the beam deflection to one or more predefined trigger positions, and each predefined trigger position is preferably corresponding to a different one of the probes. The method of claim 62, wherein the primary control signal sequentially directs the beam to a plurality of discrete positions each corresponding to a different probe and each being a predefined trigger position, thereby arriving at At each discrete position, the beam is deflected to move along the measurement path corresponding to the secondary beam path. The method of any one of clauses 51 to 63, wherein the measuring path comprises at least one line segment traversing at least one of the elongate conductive elements of one of the probes Two, all preferred, the line segments are substantially circular or follow a substantial arc. The method of claim 64, wherein the at least two elongate conductive elements are configured such that their elongate directions extend radially from an intersection between them and at the intersection Preferably, the measurement is substantially equiangularly spaced apart from each other, and wherein the measurement path includes at least one of the plurality of elongated conductive elements traversing one of the probes, all of which are preferred, the line segment being Substantially circular or following a substantial arc and centered at the intersection of the elements, the elongate directions extend from the intersection. The method of any one of clauses 51 to 65, wherein the measuring path comprises a plurality of line segments, each line segment traversing the elongate conductive element of one of the probes At least two of them are all preferred, and each line segment intersects one of the probes. The method of claim 66, wherein the measurement path is discontinuous between the line segments. The method of any one of claims 64 to 67, wherein the starting point and/or the ending point of the or each line segment does not coincide with any of the elongate conductive elements. The method of any one of clauses 51 to 68, further comprising calculating the properties of the beam based on knowledge of the detected electrical signals and the beam measurement path. The method of claim 69, wherein the calculating the properties of the beam comprises calculating a width of the beam in at least two directions at at least one probe position based on the respective probes The detected electrical signals of the at least two elongated conductive elements of the needle, and the knowledge of the speed at which the beam traverses the elements. The method of claim 69, wherein the calculating the properties of the beam comprises: calculating an intensity profile of the beam in at least two directions at at least one probe position, The detected electrical signals based on the at least two elongate conductive elements from the respective probes, and the knowledge of the width of the beam. The method of any one of clauses 69 to 71, wherein the calculating the properties of the beam comprises: calculating one of the two dimensions in the at least one probe position An intensity map that reconstructs the detected electrical signals from the at least two elongate conductive elements of the respective probes by chromatography. The party as claimed in any one of claims 69 to 72 a method, wherein, at each of the plurality of probe positions, calculating a property of the beam in at least two directions, the properties preferably including the width of the beam, the intensity of the beam The contour and/or the intensity map of the beam. The method of any one of clauses 51 to 73, further comprising: generating and supplying a feedback signal to the charged particle beam generator, whereby the measurement based on the charged particle beam Properties are obtained to adjust the properties of the charged particle beam. The method of any one of claims 69 to 74, comprising: (a) detecting at least one probe position, detecting any deviation deviation of the beam, based on Interval between adjacent detected electrical signals from the at least two elongated conductive elements of the respective probes; (b) generating and outputting a bias deviation feedback signal to the charged particle beam generator for correction Any deviation of the deflection calculated by the beam in step (a); and (c) calculating the properties of the beam based on the detected electrical signals output after correcting any deflection deviation. The method of claim 75, wherein the at least two elongate conductive elements of the respective probes are configured such that their elongate directions extend radially from an intersection between them And spaced apart from each other at equal angles around the intersection, and the measuring path includes at least one of the at least two of the elongate conductive elements traversing the probe, preferably all of which are substantially circular Or follow a substantial arc and set Centered at the intersection of the elements, the elongate directions extending from the intersection, whereby in step (a) the adjacent two of the detected electrical signals from the components of the probe Any difference in the interval indicates a bias deviation. The method of claim 76, wherein the correction of the deflection deviation in step (b) is performed by adjusting a deflection of the beam until a detected electrical signal of the components from the probe The spacing between adjacent two has a difference substantially equal to zero. The method of any one of clauses 51 to 77, wherein the charged particle beam is an electron beam or an ion beam. A probe assembly for measuring the properties of a charged particle beam, comprising: a plurality of probes arranged in an array across a plane on a frame, each probe comprising: a frame defining an aperture; And at least two elongate conductive elements supported by the frame and traversing the aperture are configured such that their respective elongate directions form a non-zero angle with each other in a plane in which the frame is located. A device for measuring the properties of a charged particle beam output by a charged particle beam generator, comprising: a probe assembly comprising a plurality of probes arranged in an array across a plane on a frame, Each of the probes includes at least two elongate conductive elements configured such that their respective elongate directions form a non-zero angle with each other in the plane of the array; a beam deflecting unit adapted to deflect the charged particle beam into Along a measurement path movement; wherein the beam deflection unit is supported on the probe assembly with a support assembly disposed therebetween, the beam deflection unit being oriented such that, in use, the beam is deflected The unit, the charged particle beam can be deflected throughout the probe assembly. The device of claim 80, wherein the support assembly includes one or more support arms coupled between the probe assembly and the beam deflection unit. The device of claim 80, wherein the axis of the beam deflection unit is substantially perpendicular to the plane of the probe assembly.