Method of handling defects of microlithographic photomasks

Abstract

The invention relates to a method for treating defects (D) in a microlithographic photomask (100), in which a process gas is activated by means of a particle beam (802), in which a control unit (828) is provided for controlling a deflection unit (816) having a control bandwidth (GF), in which the deflection unit (816) for deflecting the particle beam (802) is configured to direct the particle beam (802) over the photomask (100), and in which the deflection unit (816) is configured to deflect the particle beam (802) over the photomask (100). Comprising the steps of a) providing (S1) an image (200 ') of at least a portion of the photomask (100), b) determining a repair shape (108, 500, 502, 1102, 1104, 1300-1304, 1400-1410, 1500-1508) in the image (200') based on a control bandwidth (GF), where the repair shape (108, 500, 502, 1102, 1104, 1300-1304, 1400-1410, 1500-1508) comprises a defect (D), and c) providing a particle beam (802) at m pixels (410) of the repair shape (108, 500, 502, 1102, 1104, 1300-1304, 1400-1410, 1500-1508) by means of a deflection unit (816) and activating a process gas to treat the defect (D).

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] The content of the priority application DE 10 2023 129 605.1 is incorporated by reference in its entirety. Technical Field

[0003] The present invention relates to a method, a computer program product and an apparatus for processing defects of a microlithography photomask. Background Art

[0004] Microlithography is used to produce microstructured component parts, such as integrated circuits. Microlithography processes are performed using a lithography apparatus comprising an illumination system and a projection system. In this case, the image of a photomask (reticle) illuminated by the illumination system is projected by the projection system onto a substrate (e.g. a silicon wafer) which is coated with a photosensitive layer (photoresist) and arranged in the image plane of the projection system, so that the mask structure is transferred to the photosensitive coating of the substrate.

[0005] In order to achieve smaller structure sizes and thus increase the integration density of microstructured components, light with very short wavelengths, such as deep ultraviolet (DUV) or extreme ultraviolet (EUV), is increasingly used. The wavelength of DUV is, for example, 193 nm, and the wavelength of EUV is, for example, 13.5 nm.

[0006] In this case, microlithography photomasks even have structure sizes ranging from a few nanometers to several hundred nanometers. The production of such photomasks is very complex and therefore very costly. This is the case in particular because the photomasks must be defect-free, otherwise it is not possible to ensure that the structures produced by means of the photomask on the silicon wafer exhibit the desired functionality. In particular, the quality of the structures on the photomask is decisive for the quality of the integrated circuits produced by means of the photomask on the wafer.

[0007] It is for this reason that microlithography photomasks are checked for defects and any defects found are repaired in a targeted manner. Typical defects include the absence of envisaged structures, for example because the etching process was not successfully carried out, or the presence of unenvisaged structures, for example because the etching process was carried out too quickly or produced its effects in the wrong place. These defects can be remedied by targeted etching of excess material or targeted deposition of additional material at the appropriate locations; this can be achieved, for example, in a very targeted manner by means of an electron beam induced process (FEBIP, "focused electron beam induced process").

[0008] DE 10 2017 208 114 A1 describes a method for particle beam induced etching of a photolithography mask. In this case, a particle beam (in particular an electron beam) and an etching gas are provided at the location to be etched on the photolithography mask. The particle beam activates a local chemical reaction between the photolithography mask material and the etching gas, as a result of which the material is locally ablated from the photolithography mask.

[0009] Against this background, the problem to be solved by the present invention is to provide an improved method and an improved device for treating defects of microlithography photomasks. Summary of the invention

[0010] According to a first aspect, a method for treating defects of a microlithography photomask is provided, wherein a process gas is activated by means of a particle beam, wherein a control unit is arranged for controlling a deflection unit having a control bandwidth, wherein the deflection unit for deflecting the particle beam is configured to direct the particle beam over the photomask, the method comprising the following steps:

[0011] a) providing an image of at least a portion of a photomask;

[0012] b) determining a repair shape in the image based on the controlled bandwidth, wherein the repair shape includes the defect; and

[0013] c) Providing a particle beam at m pixels of the repair shape by means of a deflection unit and activating a process gas to cure the defect.

[0014] Taking the control bandwidth into account when determining the repair shape allows taking into account the settling behaviour of the particle beam on the target pixel. Thus, especially when repairing defects, an improved edge shape, in particular an improved edge steepness or an improved edge profile, can be obtained.

[0015] The processing of defects comprises in particular the etching of defects, within the scope of which material is locally ablated from the photomask or material is deposited on the photomask in the region of the defect. For example, the proposed method allows better etching away of superfluous structures in the region of the defect or better addition of missing structures in the region of the defect.

[0016] The repaired shape includes the defect, that is, the repaired shape contains the defect.

[0017] For example, an image of at least a portion of the photomask is recorded by a scanning electron microscope (SEM). For example, the image of at least a portion of the photomask has a spatial resolution of the order of a few nanometers. The image can also be recorded using a scanning probe microscope (SPM), such as an atomic force microscope (AFM) or a scanning tunneling microscope (STM).

[0018] The method may in particular comprise the step of capturing an image of at least a portion of the photomask by means of a scanning electron microscope and / or a scanning probe microscope.

[0019] For example, a microlithography photomask is a photomask for an EUV lithography apparatus. In this case, EUV stands for "extreme ultraviolet" and indicates that the wavelength of the working light is between 0.1 nm and 30 nm, in particular 13.5 nm. In an EUV lithography apparatus, a beam shaping and illumination system is used to direct the EUV radiation onto a photomask (also called a "reticle"), which is in particular in the form of a reflective optical element (reflective photomask). The photomask has a structure that is imaged in a reduced manner onto a wafer or the like by a projection system of the EUV lithography apparatus.

[0020] For example, a microlithography photomask can also be a photomask for a DUV lithography apparatus. In this case, DUV stands for "deep ultraviolet" and indicates that the wavelength of the working light is between 30 nm and 250 nm, in particular 193 nm or 248 nm. In a DUV lithography apparatus, a beam shaping and illumination system is used to direct the DUV radiation onto a photomask, which is in particular in the form of a transmissive optical element (transmissive photomask). The photomask has a structure that is imaged onto a wafer or the like in a reduced manner by a projection system of the DUV lithography apparatus.

[0021] For example, a microlithography photomask comprises a substrate and a structure formed on the substrate by a coating. For example, the photomask is a transmission photomask, in which case the pattern to be imaged is realized in the form of an absorbing (i.e., opaque or partially opaque) coating on a transparent substrate. Alternatively, the photomask can also be a reflective photomask, for example, particularly for EUV lithography. Binary or phase-shifting photomasks are contemplated in the embodiments.

[0022] For example, the substrate comprises silicon dioxide (SiO2), such as fused quartz. For example, the structured coating comprises chromium, chromium compounds, tantalum compounds and / or compounds made of silicon, nitrogen, oxygen and / or molybdenum. The substrate and / or coating may also comprise other materials.

[0023] In the case of a photomask for EUV lithography equipment, the substrate may include an alternating sequence of molybdenum layers and silicon layers.

[0024] Using the proposed method, defects of a photomask, in particular defects of a structured coating of a photomask, can be identified, located and repaired. Specifically, the defect is a (e.g., absorbing or reflecting) coating of the photomask that is incorrectly applied to the substrate. The method can be used to add coating to locations on the photomask where the coating is missing. In addition, the method can be used to remove coating from locations on the photomask where the coating was incorrectly applied.

[0025] For this purpose, the geometry of the defect is determined in the recorded image of at least a portion of the photomask. For example, the two-dimensional geometry of the defect is determined. The determined geometry of the defect is referred to below as the so-called repair shape.

[0026] m pixels are defined in a repair shape for particle beam induced treatment of the repair shape. During the method, a particle beam is directed to each of the m pixels of the repair shape. In particular, the intensity maximum of the electron beam is directed to each center of each of the m pixels. In other words, the m pixels of the repair shape represent a grating, in particular a two-dimensional grating, of the repair shape for particle beam induced treatment. For example, the m pixels of the repair shape correspond to the incident area of ​​the particle beam during the particle beam induced treatment of the defect. For example, the pixel size is selected in such a way that due to the Gaussian intensity distribution of the electron beam, the intensity distribution of the electron beam directed to the center of the pixel drops to a predetermined intensity at the edge of the pixel. The predetermined intensity may correspond to a drop to half of the intensity maximum, or to any other fraction of the intensity maximum of the electron beam. For example, the pixel size and / or the electron beam full width at half maximum are in the sub-nanometer range or on the order of a few nanometers.

[0027] For example, the process gas is a precursor gas and / or an etching gas. For example, the process gas can be a mixture of multiple gas components, i.e., a process gas mixture. For example, the process gas can be a mixture of multiple gas components, wherein each gas component has only a specific molecular type.

[0028] In particular, alkyl compounds of main group elements, metals or transition elements may be considered as precursor gases suitable for depositing or growing lift structures. Examples thereof are (cyclopentadienyl) trimethyl platinum (CpPtMe3Me=CH4), (methylcyclopentadienyl) trimethyl platinum (MeCpPtMe3), tetramethyltin (SnMe4), trimethylgallium (GaMe3), ferrocene (Cp2Fe), diaryl chromium (Ar2Cr), and / or carbonyl compounds of main group elements, metals or transition elements, such as, for example, hexacarbonyl chromium (Cr(CO)6), hexacarbonyl molybdenum (Mo(CO)6), hexacarbonyl tungsten (W(CO)6), dicobalt octacarbonyl (Co2(CO)8), triruthenium dodecacarbonyl (Ru3(CO)8), and triruthenium dodecacarbonyl (Ru3(CO)6). 12), iron pentacarbonyl (Fe(CO)5), and / or alkoxide compounds of main group elements, metals or transition elements, such as, for example, tetraethyl silicate (Si(OC2H5)4), tetraisopropoxytitanium (Ti(OC3H7)4), and / or halides of main group elements, metals or transition elements, such as, for example, tungsten hexafluoride (WF6), tungsten hexachloride (WCl6), titanium tetrachloride (TiCl4), boron trifluoride (BF3), silicon tetrachloride (SiCl4), and / or complexes containing main group elements, metals or transition elements, such as, for example, bis(hexafluoroacetylacetonate)copper (Cu(C5F6HO2)2), trifluoroacetylacetonatedimethylgold (Me2Au(C5F3H4O2)), and / or organic compounds, such as carbon monoxide (CO), carbon dioxide (CO2), aliphatic hydrocarbons and / or aromatic hydrocarbons, etc.

[0029] For example, the etching gas may include: xenon difluoride (XeF2), xenon dichloride (XeCl2), xenon tetrachloride (XeCl4), steam (H2O), heavy water (D2O), oxygen (O2), ozone (O3), ammonia (NH3), nitrosyl chloride (NOCl) and / or one of the following halides: XNO, XONO2, X2O, XO2, X2O2, X2O4, X2O6, where X is a halide. Other etching gases for etching one or more deposited test structures are described in detail in the applicant's U.S. patent application No. 13 / 0103281.

[0030] The process gas may contain other additional gases, for example, oxidizing gases, such as hydrogen peroxide (H2O2), nitrous oxide (N2O), nitrogen oxide (NO), nitrogen dioxide (NO2), nitric acid (HNO3) and other oxygen-containing gases and / or halides, such as chlorine (Cl2), hydrogen chloride (HCl), hydrogen fluoride (HF), iodine (I2), hydrogen iodide (HI), bromine (Br2), hydrogen bromide (HBr), phosphorus trichloride (PCl3), phosphorus pentachloride (PCl5), phosphorus trifluoride (PF3) and other halogen-containing gases and / or reducing gases, such as hydrogen (H2), ammonia (NH3), methane (CH4) and other hydrogen-containing gases. These additional gases can be used, for example, in etching processes, as buffer gases, as passivation media, etc.

[0031] For example, an activation particle beam is provided with the aid of an apparatus, which may include: a particle beam source for creating a particle beam; a particle beam guiding device (e.g., a scanning unit) configured to direct the particle beam to each pixel of a repair shape, multiple repair shapes, or each repair sub-shape of a photomask; a particle beam shaping device (e.g., an electronic or beam optical component) configured to shape the particle beam, and in particular to focus the particle beam; at least one storage container configured to store a process gas or at least a gas component of a process gas; and at least one gas supply device configured to provide a process gas or at least one gas component of a process gas having a predetermined gas amount flow rate to each pixel of a repair shape, multiple repair shapes, or each repair sub-shape.

[0032] For example, the active particle beam includes an electron beam, an ion beam and / or a laser beam.

[0033] For example, the electron beam is provided by means of a modified scanning electron microscope.For example, an image of at least a portion of the photomask is recorded using the same modified scanning electron microscope that provides the activation electron beam.

[0034] The activating particle beam activates, in particular, a local chemical reaction between the photomask material and the process gas, which leads to a local deposition of material on the photomask from the gas phase or a local conversion of material of the photomask into the gas phase.

[0035] The activation particle beam is continuously provided at each pixel of the repair shape, multiple repair shapes or each repair sub-shape, for example through a particle beam guiding device (particularly a deflection unit). In step c) of the method, the activation particle beam retains a predetermined dwell time at each pixel. For example, the dwell time is 100ns.

[0036] The repair shape may include the defect in whole or in part. The repair shape may have: a kidney shape, a U shape or a ring shape. In the present case, a "repair shape" may also refer to a repair sub-shape, provided there is nothing to the contrary.

[0037] For example, the number "m" and / or "n" (see below) is in each case greater than 100, 1000, 10,000, 100,000 or 1,000,000.

[0038] According to one embodiment, before step a), in particular before or when the particle beam column is put into operation to perform steps a) to c), a control bandwidth is determined or provided, wherein the determined or provided control bandwidth or a value derived therefrom is preferably stored in a data memory before step b) and used in step b).

[0039] The control bandwidth or a value derived therefrom can in particular be stored in a computer program which is executed within the scope of the above-described method.

[0040] According to a further embodiment, step b) comprises:

[0041] b1) subdividing (S2-1) a repair shape (108) containing a defect (D) into k repair sub-shapes (1102, 1104) based on a control bandwidth (GF), and selecting one of the k repair sub-shapes (1102, 1104); and / or

[0042] b2) subdividing (S2-2) the repair shape (108) containing the defect (D) into k repair sub-shapes (1300-1304, 1400-1410) and selecting one of the k repair sub-shapes (1300-1304, 1400-1410), wherein the selection is performed based on a control bandwidth (GF),

[0043] Wherein, step c) comprises:

[0044] A particle beam (802) is provided at m pixels (410) of the selected k repair sub-shapes (1300-1304, 1400-1410) by means of a deflection unit (816), and a process gas is activated to treat the defect (D).

[0045] Therefore, the control bandwidth can be taken into account already during the subdivision of the repair shape or only during the selection of the individual repair sub-shapes, in particular when determining the order of the repair sub-shapes that the particle beam sweeps through successively in time. According to a variant, both the subdivision and the selection can be implemented based on the control bandwidth. "k" can be greater than or equal to 2, 10 or 100.

[0046] According to a further embodiment, the determination according to step b) or the subdivision according to step b1) and / or the selection according to step b2) is performed based on a spacing or a jump width between two restoration shapes or between two of the k restoration subshapes.

[0047] The larger the spacing or jump width, the longer it usually takes for the particle beam to reach a settled state again. It is therefore particularly advantageous to link this information to the control bandwidth.

[0048] According to a further embodiment, step c) comprises:

[0049] Providing a particle beam at m pixels of a first repair shape or at m pixels of a first of k repair sub-shapes by means of a deflection unit and activating a process gas to treat the defect;

[0050] A particle beam is provided at n pixels of the second repair shape or at n pixels of a second one of the k repair sub-shapes by means of a deflection unit, and a process gas is activated to treat the defect.

[0051] Specifically, before switching to the next repair shape, each of the k repair sub-shapes may be scanned or raster scanned by the particle beam more than 100 or more than 1000 times, and then the particle beam may be scanned over the repair shape more than 100 or more than 1000 times in turn. The particle beam may be deactivated or raster scanned between repetitions to allow process gas to flow into each repair sub-shape.

[0052] According to a further embodiment, the first pixel and / or the last pixel of the n or m pixels are selected in a random manner.

[0053] This avoids unwanted patterns on the photomask.

[0054] According to a further embodiment, each of the k repair sub-shapes is formed uninterruptedly in the scanning direction of the particle beam.

[0055] These can therefore be scanned quickly and without jump effects (sedimentation of the particle beam).

[0056] According to a further embodiment, a scan line method is used in step b1) or b2).

[0057] This mathematical approach allows for a simple and efficient division of the repair shape into multiple repair sub-shapes, each of which is convex and / or has no interruptions (i.e., no cuts) at least in the scanning direction. Therefore, the particle beam does not need to overcome gaps, cuts, etc. This avoids jumping or settling effects.

[0058] According to a further embodiment, the repair shape comprises a cutout, the size of the cutout being between 5 nm and less than 10 μm.

[0059] According to further embodiments, a spacing between two pixels within a corresponding one of the k repair sub-shapes or a repair shape is smaller than 40, 20 or 5 nm.

[0060] According to a further embodiment, the deflection unit comprises a multipole, in particular an octupole, for beam deflection purposes.

[0061] Other beam deflection devices, such as capacitor plates or magnetic coils, may be used instead of a multipole or octopole.

[0062] According to a further embodiment, in step c), the particle beam is moved along a straight line and / or along a line parallel to or perpendicular to the line.

[0063] According to a further embodiment, in step c), the particle beam is parallel to one and / or the longest edge of the k repair sub-shapes.

[0064] Undesired jumps of the particle beam can thus be avoided, or an efficient scanning of the repair shape or repair sub-shape by the particle beam can be achieved.

[0065] According to a further embodiment, in step b), a first repair shape and a second repair shape comprising the defect are determined, wherein the second repair shape is at least partially located within the first repair shape.

[0066] Advantageously, a so-called bias effect can be achieved thereby; this also makes it possible to take into account the sedimentation behavior of the particle beam at the target location (target pixel).

[0067] According to a further embodiment, the contour of the second restoration shape is partially concave relative to the contour of the first restoration shape.

[0068] According to a further embodiment, the second repair shape partially has the same contour as the first repair shape.

[0069] Depending on the jumping pixels or the target pixels of the particle beam, it may or may not be necessary to shift the contour relative to the first repair shape, as the case may be.

[0070] According to a further embodiment, when the first and second repair shapes overlap between two adjacent contours of the first and second repair shapes, one or more pixels are located along a straight line intersecting the two adjacent contours.

[0071] According to a second aspect, a computer program product is provided, wherein the computer program product comprises a plurality of instructions, which, when executed by an apparatus for processing defects of a microlithography mask, cause the apparatus to perform the above method steps.

[0072] The computer program product may be provided or supplied, such as, for example, a computer program medium, for example, as a storage medium, such as a memory card, USB stick, CD-ROM, DVD, or in the form of another file downloadable from a server in the network. For example, in a wireless communication network, this may be achieved by transmitting appropriate files using the computer program product or computer program component.

[0073] According to a third aspect, there is provided an apparatus for treating defects of a microlithography mask. The apparatus comprises:

[0074] a process gas supply device for providing process gas,

[0075] a particle source for providing a particle beam,

[0076] a deflection unit for deflecting the particle beam so as to provide the particle beam at m pixels of the repair shape and activate the process gas,

[0077] a control unit for controlling the deflection unit with a control bandwidth,

[0078] a detector unit for providing an image of at least a portion of the photomask;

[0079] A determining unit is configured to determine a repair shape in the image based on the control bandwidth, wherein the repair shape contains the defect.

[0080] Each of the units mentioned above and below (e.g., computing device, control unit, determination unit) may be implemented using hardware and / or software. In the case of hardware implementation, the corresponding unit may be embodied as a device or a part of a device, such as a computer or a microprocessor. For example, the device may include a central processing unit (CPU), a graphics processing unit (GPU), programmable hardware logic (e.g., a field programmable gate array, FPGA), an application specific integrated circuit (ASIC), etc. In addition, one or more units may be implemented together in a single hardware device, and they may, for example, share memory, interfaces, etc. The unit may also be implemented in a separate hardware component.

[0081] In the present case, "one" is not necessarily to be understood as being limited to only one element. On the contrary, multiple elements, such as two, three or more, may also be provided. Any other number used herein should not be understood as limiting the number of elements to be precisely specified. On the contrary, unless otherwise specified, upward and downward numerical deviations are possible.

[0082] Another possible implementation of the present invention also encompasses the combination of features or embodiments not explicitly mentioned in the above or below description of the exemplary embodiment. In this case, those skilled in the art will also add separate aspects as improvements or supplements to the corresponding basic forms of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0083] Further advantageous configurations and aspects of the invention are the subject matter of the dependent claims and are also the subject matter of the exemplary embodiments of the invention described below.The invention will be described in detail below based on preferred embodiments and with reference to the drawings.

[0084] Figure 1 schematically illustrates a detail of a microlithography photomask having defects in a structured coating according to one embodiment;

[0085] Figure 2 shows details of a photomask firstly having a perfect structure and secondly having defects according to one embodiment;

[0086] Figure 3 Show Figure 2 A magnified image of the defect;

[0087] Figure 4 A plurality of three exemplary scanning methods are shown;

[0088] Figure 5schematically illustrates a repaired shape of a defect having two repaired sub-shapes;

[0089] Figure 6 shows the position of an electron beam as a function of time in one exemplary embodiment;

[0090] Figure 7 Two edge geometries created using different control bandwidths are compared;

[0091] Figure 8 An apparatus for processing defects of a photomask according to an exemplary embodiment is shown;

[0092] Fig. 9 Schematically showing the Figure 8 Functional interaction of several components of

[0093] Fig.9A shows the amplitude of a control signal as a function of frequency according to an exemplary embodiment;

[0094] Fig.10 An exemplary embodiment of the method in the flowchart is shown;

[0095] Fig.11 and Fig.12 shows annular repair shapes according to various exemplary embodiments;

[0096] Fig.13 shows repair sub-shapes having different spacings from each other along a scanning direction according to an exemplary embodiment;

[0097] Fig.14 shows repair sub-shapes arranged in a two-dimensional grid according to an exemplary embodiment;

[0098] Fig.15 According to an exemplary embodiment, Figure 5 The repair shape is subdivided into five repair sub-shapes;

[0099] Figures 16 to 20 shows repair shapes having different geometries according to various exemplary embodiments;

[0100] Fig.21 According to an exemplary embodiment, Figure 1 a view of the image with a properly selected scanning direction for repairing the defect;

[0101] Fig. 22 Show Figure 5 A view in which the scanning is performed according to a method with a bias effect;

[0102] Fig.23 showing a recessed outline in a repaired subshape;

[0103] Fig.24 Show Fig.23 an enlarged view of

[0104] Fig.25 Two concave contours in one repair subshape are shown.

[0105] Unless otherwise stated, identical or functionally identical elements have the same reference numerals in the figures. Furthermore, it should be noted that the illustrations in the figures are not necessarily drawn to scale. DETAILED DESCRIPTION

[0106] Figure 1 Schematically shown are details of a microlithography photomask 100. In the example shown, the photomask 100 is a transmission lithography mask 100. The photomask 100 comprises a substrate 102. The substrate 102 is optically transparent, in particular at the wavelength at which the photomask 100 is exposed. By way of example, the material of the substrate 100 comprises fused silica.

[0107] A structured coating 104 (pattern element 104) has been applied to the substrate 102. In particular, the coating 104 is a coating made of an absorbing material. For example, the material of the coating 104 comprises a chromium layer. By way of example, the thickness of the coating 104 ranges from 50 nm to 100 nm. The structure size B of the structure formed by the coating 104 on the substrate 102 of the photomask 100 may be different at different locations of the photomask 100. By way of example, the width B of the region is plotted as Figure 1 For example, the structure size B ranges from 20 to 200 nm. The structure size B may also be greater than 200 nm, such as in the micrometer range.

[0108] In other examples, other materials than those mentioned may be used for the substrate and the coating. In addition, the photomask 100 may also be a reflective photomask rather than a transmissive photomask. In this case, a reflective layer is applied instead of the absorbing layer 104.

[0109] Sometimes, defects D occur during the production of a photomask, for example, because the etching process did not run exactly as expected. Figure 1 In the example of FIG. 1 , such a defect D is indicated by hatching. This is excess material, since the coating 104 has not been removed from this area, even though two coating areas 104 adjacent to one another are envisioned as being separate in the template of the photomask 100. It can also be said that the defect D forms a connector. In this case, the size of the defect D corresponds to the structure size B. Other defects are also known which are smaller than the structure size B, for example in the range of 5 to 20 nm. In order to ensure that the structures produced in the lithography apparatus using the photomask have the desired shape on the wafer and that the semiconductor components produced in this way thus achieve the desired function, it is necessary to repair defects such as Figure 1 The defect D shown may be another defect. In this example, it is necessary to remove the connection in a targeted manner, for example by particle beam induced etching.

[0110] Figures 2 to 4 To illustrate the repair Figure 2 A possible procedure for defect D shown in . Figure 2 The "healthy" area on the left is indicated by 200. That is, the coating 104 or substrate 102 corresponds to the target specification in this area. The healthy image detail 200 is then copied and placed over the defect D, as indicated by reference numeral 200'. Figure 3 A defect D is shown in an enlarged view. In this exemplary embodiment, the latter is formed by a protruding material excess. By superimposing a healthy material area 200, the material to be removed becomes clear.

[0111] In the case of electron beam based mask repair, the region D is now scanned several thousand times with the electron beam to remove the defect. Whether this is related to a so-called transparent defect or an opaque defect is not initially important.

[0112] Figure 4 Various scanning variants are shown for moving the electron beam over the defect D, thereby relatively etching away the coating 104 under the activation of the process gas (or in other variants for depositing material from the process gas for repair purposes). For example, Figure 4 The pattern shown is repeatedly traversed or rastered 100 to 1,000,000 times until the corresponding defects are ablated or deposited.

[0113] exist Figure 4 In FIG. 4 , the serpentine x scan is indicated by 400, the serpentine y scan is indicated by 402, and the raster scan is indicated by 404. Figure 4 The central serpentine x-scan 400 begins, wherein a solid line 406 (hereinafter referred to as a "scan line") represents a row of pixels 410 that are scanned continuously or raster scanned. The particle beam is deflected in the y-direction (hereinafter referred to as a "jump" 408) at the end of the corresponding scan line 406. The particle beam then moves in the negative x-direction in a manner parallel to the previous scan line 406, and another jump 408 is arranged.

[0114] The scanning in the x direction can be easily done in the y direction as well, so here the pixels are scanned in the y direction, while the jumps are done in the x direction. Figure 4 The right side of is shown (snake y scan 402). Figure 4 The left side of 400 shows a so-called raster scan 404. In this case, there is a diagonal return jump at the end of the corresponding scan line 406, with the result that the starting point is returned to x=0 (origin O).

[0115] Pixel 410 corresponds to Figure 2 Each pixel 410 corresponds to a location on the photomask 100. There, the electron beam impinges on the process gas, thereby triggering an etching or deposition process at this location. The pitch of the pixels is, for example, less than 40, 20 or 5 nm. Figure 4 In FIG. 4 , the distance between two adjacent pixels 410 is shown by way of example and is denoted by A. In FIG.

[0116] In the region of the scan line 406, the electron beam moves at a defined speed and in the process addresses a single pixel 410, i.e. the electron beam stays on the corresponding pixel 410 for a defined period of time ("dwell time"). The electron beam moves as fast as possible in the region of the corresponding jump 408. For example, the dwell time can be between 10 and 500 nanoseconds. At the end of the dwell time, the electron beam moves to the next pixel, wherein the intermediate region between two adjacent pixels 410 within the spacing A is scanned. The electron beam is not deactivated in the intermediate region. However, due to the very short exposure time in the intermediate region, the electron beam does not produce any noticeable effect. Therefore, it is not deactivated at the first pixel at the end of the dwell time, but moves to the next pixel and is reactivated there.

[0117] The same is true for jump 408. The last pixel of scan line 406 has been denoted using reference numeral 410', for example. The first pixel of the next scan line 406 has been denoted using 410". The electron beam moves between pixels 410' and 410" as quickly as possible. For example, it does not deactivate at the end of the dwell time at pixel 410' and reactivate at the next pixel 410".

[0118] A jump between two adjacent pixels 410 is characterized by the scanning direction (in this case the positive x-direction) remaining the same. In contrast, a jump between pixels 410, 410' in different scan lines 406 is characterized by a change from one scanning direction (in this case the positive x-direction) to another scanning direction, optionally from the opposite scanning direction (in this case the negative x-direction) to another scanning direction. Between two repair shapes 500, 502 (see below), there is a jump from one repair (sub) shape to another.

[0119] Figure 5A defect D and a specified repair shape 108 determined from the image detail 200' are shown. With the aid of a computer device and an appropriate algorithm, the repair shape 108 is decomposed into, for example, two repair sub-shapes (parts) 500, 502. The repair sub-shapes (for example, a rectangle 500 and a rectangular ring 502 in this case) are spaced apart from each other in the scanning direction x. Therefore, this generates a first scan line 406 within the repair sub-area 500, followed by a jump 504, and then another scan line 406' within the repair sub-shape 502. Since a serpentine x scan 400 is used as an example here, the electron beam is offset in the y direction at the end of the scan line 406', thereby generating a jump 408. Subsequently, the electron beam moves back in the direction of the origin O in a manner parallel to the scan line 406.

[0120] The repair sub-shape 502 comprises a cutout 506. This is the area enclosed by the ring 502. For example, the width d of the cutout 506 may be at least 500 nm and less than 10 μm in the scanning direction x. Therefore, within the repair shape 502 there is a further jump 508 of the electron beam.

[0121] Figure 6 A diagram is shown with the time t plotted on the abscissa and the jump width P plotted on the ordinate. As described above, the electron beam is moved as fast as possible in the region of the jumps 408, 504, 506. To this end, the electron beam is initially strongly accelerated starting from position P0 (first pixel) and then strongly decelerated successively towards position P1 (next pixel). In the case of an electron beam column, the electron beam is moved by a deflection unit (e.g. Figure 8 As shown) deflects from position P0 to position P1.

[0122] For example, the deflection unit is an octupole (or other multipole) located at the lower end of the electron beam column. The octupole includes a plurality of coils or electrodes, which create an electric or magnetic field for beam deflection. In other embodiments, one or more capacitors (particularly capacitor plates) may be used instead of the octupole. The deflection unit is controlled by a control unit (e.g. Figure 8 As shown in FIG. 6 ). Since the control unit has a limited control bandwidth, the electron beam must initially settle at the end of the movement (settlement curve 600 ), i.e. position P1 .

[0123] If the jump width is shorter, e.g. Figure 6 As shown at point P2 in , the amplitude AP of the sedimentation curve 600' is less than the amplitude AP of the sedimentation curve 600. This first means that the dose distribution (electron dose) at the target point P1 or P2 of the jump 408, 504, 506 is different from the initial point P0. In addition, it is found that for the same control bandwidth, when the jump width is smaller, the electron dose after the jump can be better concentrated at one point (see position P2). The same is true if the control bandwidth is increased while the jump width remains unchanged.

[0124] Figure 7 A plan view of a partial detail of a photomask 100 is shown on the left. In the area shown, the photomask 100 includes two coatings 104 that are spaced apart from each other by an exposed area 102 in which the substrate is visible. In an exemplary embodiment, the electron beam jumps from point P0 to point P1. The dwell time at point P0 (corresponding to the last pixel of a scan line not shown) is, for example, 20 ns, just like the dwell time at point P1 (the first pixel of a scan line not shown). The control bandwidth is 5 MHz.

[0125] Since the sedimentation curve 600 (see Figure 6 ), the edge 702 of the structure 104 becomes blurred. The increase in the corresponding flatness of the dose profile has a negative impact on the edge steepness of the edge repair (the so-called side wall angle). The problem of the settling behavior does not occur at the jump point, so there is a sharp edge here; this also occurs at Figure 7 In the image on the left.

[0126] Figure 7 The photomask 100' is shown on the right. In this case, the structure corresponds to the structure shown on the left. However, the electron beam column used to process the photomask 100' has a higher control bandwidth, specifically 100 MHz. Therefore, the sedimentation curve (see Figure 6 600' in the figure has a smaller amplitude AP. This results in a greater edge steepness compared to the left side illustration. Figure 7 The illustration on the right has a sharp embodiment.

[0127] Figure 8 A method for detecting a defect D (eg, Figure 1 , 2 , 3, 5 and 7. D) An apparatus 800 for performing a particle beam induced treatment. For example, the apparatus 800 is a repair tool for a photomask 100 of a DUV or EUV lithography apparatus.

[0128] Figure 8 Schematically shown is a cross section through some components of an apparatus 800 that can be used for particle beam induced repair, in this case etching, of a defect D of a photomask 100. Furthermore, the apparatus 800 can also be used to image a photomask, in particular a photomask 100 with a structured coating 104 of the defect D, before, during and after carrying out the repair process.

[0129] Figure 8The device 800 shown represents a modified scanning electron microscope 800. In this case, a particle beam in the form of an electron beam 802 is used to repair the defect D. The advantage of using the electron beam 802 as the activating particle beam is that the electron beam 802 substantially does not damage or only slightly damages the photomask 100, in particular the substrate 102 thereof.

[0130] The laser beam used to activate the local particle beam induced repair process of the photomask 100 may be used instead of the electron beam 802 or in addition to the electron beam 802 in embodiments ( Figure 8 In addition, instead of an electron beam and / or a laser beam, an ion beam, an atomic beam, and / or a molecular beam may be used to activate a local chemical reaction ( Figure 8 (not shown in the figure).

[0131] The device 800 is mainly arranged in a vacuum housing 804 , and the vacuum housing 804 is maintained at a certain air pressure by a vacuum pump 806 .

[0132] The photomask 100 to be processed is arranged on the sample stage 808. For example, the sample stage 808 is configured to set the position of the photomask 100 in three spatial directions and three rotation axes with a precision of a few nanometers.

[0133] The apparatus 800 comprises an electron column 810. The electron column 810 comprises an electron source 812 for providing an activation electron beam 802. In addition, the electron column 810 comprises an electron or beam optical component 814. The electron source 812 generates the electron beam 802 and the electron or beam optical component 814 focuses the electron beam 802 and directs the latter toward the photomask 100 located at the output of the electron column 810. The electron column 810 further comprises a deflection unit 816 (scanning unit 816) configured to guide (i.e., raster scan or scan) the electron beam 802 on the surface of the photomask 100.

[0134] The apparatus 800 further includes a detector 818 for detecting secondary electrons and / or backscattered electrons created by the incident electron beam 802 at the photomask 800. For example, as shown, the detector 818 is arranged in an annular manner around the electron beam 802 within the electron cavity 810. As an alternative to and / or in addition to the detector 818, the apparatus 800 may also include other / additional detectors ( Figure 8 not shown).

[0135] In addition, the apparatus 800 may include one or more scanning probe microscopes, such as a scanning force microscope, which may be used to analyze the defects D ( Figure 8 (not shown in the figure).

[0136] The apparatus 800 further includes a gas supply device 820 for supplying a process gas to the surface of the photomask 100. For example, the gas supply device 820 includes a valve 822 and a gas line 824. The electron beam 802 directed by the electron chamber 810 to a position on the surface of the photomask 100 can perform an electron beam induced process (EBIP) together with a process gas supplied from the outside by the gas supply device 820 via the valve 822 and the gas line 824. In particular, the process includes deposition and / or etching of a material.

[0137] The device 800 further comprises a computing device 826, such as a computer, having a control unit 828, a determination unit 830 and a memory unit 832. Figure 8 In the example shown in FIG. 8 , computing device 826 is disposed outside of vacuum enclosure 804 .

[0138] Specifically, the computing device 826 controls the supply of the electron beam 802 by controlling the electron column 810. Specifically, the control unit 828 controls the electron beam 802 to perform raster scanning on the surface of the photomask 100 by controlling the deflection unit 816. In addition, the computing device 826 controls the supply of the process gas by controlling the gas supply device 820.

[0139] In addition, the computing device 826 receives measurement data from the detector 818 and / or other detectors of the device 800 and creates images from the measurement data, which images can be displayed on a monitor (not shown). In addition, the images created from the measurement data can be stored in the memory unit 832 of the computing device 826.

[0140] In order to inspect the photomask 100, in particular the structured coating 104 of the photomask 100, the apparatus 800 is particularly configured to capture the photomask 100 from the measurement data from the detector 818 and / or other detectors of the apparatus 800 ( Figure 1 ) or an image 200' of a detail of the photomask 100. By way of example, the spatial resolution of the image 300 is of the order of a few nanometers.

[0141] The computing device 826, in particular the determination unit 830, is configured to identify a defect D in the recorded image 200'. Figure 1 ), locate the defect and determine the geometric shape (repair shape 108) of the defect D. For example, the determined repair shape 108 is a two-dimensional geometric shape.

[0142] The computing device 826, in particular the determining unit 830, is configured to arrange the repair shape 108 in a grid containing m pixels 410 (see Figure 4). For example, the repair shape 108 contains 1 million pixels 304 (m=1000000). For example, the size of the pixel 304 is 1.5nm×1.5nm. During the repair method, the electron beam 802 is directed to each center of each pixel 410 multiple times by the deflection unit 816. Specifically, during the method, the intensity maximum of the Gaussian intensity distribution of the electron beam 802 is directed to each center of each pixel 410 multiple times.

[0143] Fig. 9 Schematically shows Figure 8 The control unit 828 creates a control signal XS, which is used to control the deflection unit 816. Fig.9A shows the amplitude A of the control signal XS as a function of the frequency f XS . The control unit 828 can be considered as a low-pass filter. The latter passes signals with frequencies up to a limit frequency GF (called the control bandwidth in this case) essentially unchanged. In contrast, the output signal XS of the control unit 828 is significantly attenuated above the limit frequency GF. Therefore, the control signal XS consists of frequency components below the control bandwidth GF. The control signal XS is preferably analog. The control unit 828 itself can have an analog or digital embodiment. In particular, it receives a digital signal from the determination unit 830, and the digital signal is converted into an analog signal within the control unit 828.

[0144] For example, it can be determined by examining the frequency components of the control signal XS. Fig.9A For example, the control bandwidth GF can be defined as the frequency f at which the amplitude A XS Drop to maximum amplitude A XS Less than 80% Fig.9A The control bandwidth GF is provided to the determination unit 830.

[0145] In a variant, the control bandwidth GF is read from the control unit 828 after calibration of the device 800 or during operation of the device 800, ie when raster scanning the pixels 410. Thus, the determination unit 830 may respond to changes in the control bandwidth.

[0146] In another variant, the control signal XS is measured after the device 800 is put into operation and calibrated, and the control bandwidth GF is determined (more specifically calculated) based on the measured data. The control bandwidth GF defined in this way is stored in the data memory 832 (see Figure 8). In particular, the control bandwidth GF may be stored as part of a computer program executed on the computer device 826. In particular, the computer program may be part of the determination unit 830. In the determination unit 830, the control bandwidth GF is used to determine the repair shape 108 with the defect D based on the control bandwidth.

[0147] Overall, Fig.10 A corresponding method is described in . In step S1 , an image of at least a portion of the photomask 100 is recorded and thus provided by means of the device 800 . In particular, the recording is effected by means of the detector unit 818 .

[0148] In step S2, the repair shape 108 is determined in the image 200', more precisely, in a manner that depends on the control bandwidth GF. The repair shape 108 includes the defect D, more precisely, at least partly or completely. How to determine the repair shape 108 in detail remains to be explained in detail below. It is important that the determination does not need to be implemented in a manner that directly depends on the control bandwidth GF. In particular, a value derived from the control bandwidth GF can also be used. As already described for the control bandwidth GF, this value can be read from the control unit 828 and / or provided in the memory unit 832, optionally as part of the above-mentioned computer program. This indirect use of the control bandwidth GF is also covered in this example.

[0149] In step S3 , the particle beam 802 is supplied to the m pixels 410 of the repair shape 108 by means of a deflection unit 816 and activates the process gas there in order to thereby process (more specifically etch or deposit) the defects.

[0150] Step S2 can be designed to achieve Fig.10 One or more of the variants S2-1 to S2-3 shown on the left. In this case, one of the variants S2-1 to S2-3 can be implemented in the device 800, or a plurality of variants can be implemented, wherein one of the variants S2-2 to S2-3 can be selectively selected in an automatic manner depending on the application.

[0151] The following is based on Figures 13 to 15 Variants S2-1 and S2-2 are described in detail. For variant S2-3, see Figure 22 to Figure 25 .

[0152] based on Fig.11 and 12 A possible implementation of method step S2-1 is explained. Fig.11 and 12An annular defect D or a corresponding repair shape 108, 108' is shown respectively. They comprise cutouts 1100 and 1200 respectively, in which no pixel should be scanned or the area remains unaffected by the treatment of the electron beam 802. The diameter of the cutout 1100 is denoted by d1 and the diameter of the cutout 1200 is denoted by d2. For the diameter d1, i.e. the repair shape 108, the determination unit 830 now determines that the corresponding jump width is too large and therefore does not result in an acceptable edge. This takes into account the determined control bandwidth GF. Therefore, it subdivides the repair shape 108 into two semicircular repair shapes 1102, 1104, which are then scanned by separate serpentine scans 400, 400'.

[0153] In contrast, in view of the control bandwidth GF and the smaller diameter d2 compared to the diameter d1 , the determination unit 830 evaluates the defect D or the repair shape 108 ′ so that the repair shape 108 ′ can be scanned as a whole, i.e. using a serpentine x-scan. Therefore, the scan line 406 has a jump 1202 in the region of the cutout 1200 .

[0154] To explain step S2-2, Fig.13 A repair shape 108 of a defect D is shown, which is subdivided into, for example, three repair sub-shapes 1300, 1302 and 1304 with the help of the determination unit 830. For example, the determination unit 830 may decide that the jump width 1306 in the scanning direction x is still acceptable in view of the control bandwidth GF, and therefore one scanning line 406 is used to scan the repair shape 1300 and the repair shape 1302 over a portion 1308 in the y direction (i.e. transverse to the scanning direction x).

[0155] In this case, the determination unit 830 determines that the jump width 1310 would be too large considering the control bandwidth GF. Therefore, the repair shape 1304 is scanned separately only after or before scanning the repair shapes 1300, 1302.

[0156] Fig.14 A rectangular defect D or a rectangular repair shape 108 is shown. The latter is subdivided again into rectangular repair shapes, which form a grid in the x and y directions, for example. Some repair shapes are marked 1400 to 1410, for example. The subdivision into repair shapes 1400 to 1410, i.e. the size of the individual rectangles, can be determined, for example, such that during a raster scan of the pixels (not shown) of the individual rectangles 1400 to 1410, the process gas atmosphere remains sufficient for etching or deposition. This cannot always be ensured if the repair shapes are too large.

[0157] The repair shapes 1400 to 1410 are scanned independently in each case, so that each repair shape is assigned a serpentine scan 400. The serpentine scan 400 can be repeated several thousand times for the respective repair shape 1400 to 1410, for example, until the next repair shape 1400 to 1410 changes. This change is Fig.14 1414, 1416, and 1418. These jumps or decisions about the repaired shape of the next jump are determined by the determination unit 830 based on the control bandwidth GF. In view of the control bandwidth GF, it may be found that the individual jumps here are too far to produce sufficient edge steepness. For example, the control unit 830 may decide that jumps 1414 or 1416 are too far, but jumps 1412 and 1418 are acceptable. As shown by jump 1414, it may also be decided here that the jump to pixel 1420 is too far, but the jump to pixel 1422 is still acceptable.

[0158] The determination unit 830 may also be configured to select a jump pixel (here, pixel 1424 is used as an example) and / or a target pixel 1422 in a random manner from the pixels included in the repair shape 1400 or 1406. This may prevent a repetitive (unwanted) pattern determined by constant jump and target positions from appearing on the photomask 100.

[0159] Fig.15 Shows that with Figure 5 1500, 1502, 1504, 1506, 1508. However, here a subdivision into five repair sub-shapes 1500, 1502, 1504, 1506, 1508 has been implemented. This is performed in such a way that acceptable jumps are always performed given a known control bandwidth GF.

[0160] Otherwise, it should be observed that by changing the scanning direction from x to y, it is already possible to find a repair shape 108 that is acceptable in terms of controlling the bandwidth GF. If the cutout 1510 is formed with the same dimensions in the x and y directions, this will not make any difference. However, if the cutout 1510 has a larger width in the x direction and a narrower depth in the y direction, changing the scanning direction from x to y will result in no more acceptable jump widths.

[0161] Figures 16 to 20 Various options for subdividing the repair shape 108 are shown, such that a jump width tolerated taking into account the control bandwidth GF is observed, or jumps are avoided completely.

[0162] For example, Fig.16 The ring segment 108 in is subdivided by the determination unit 830 into two semicircular ring segments.

[0163] Fig.17The kidney-shaped shape 108 in FIG. 8 is also subdivided by the determination unit 830 into two acceptable repair shapes.

[0164] for Fig.18 In the jagged edge region 1800 of the repaired shape 108, the determining unit 108 determines that the repaired shape can be scanned without jumps by the serpentine x-scan.

[0165] refer to Fig.19 , the determination unit 830 subdivides the repair shape 108 into two repair shapes, specifically, into two polygons, which are a quadrilateral 1900 and a pentagon 1902 in this example.

[0166] Fig. 20 The repair shape 108 in FIG. 1 (which is also partially kidney-shaped) is subdivided into five repair shapes so that the five repair shapes can be traversed without jumping using a snake-shaped x-scan. The separation lines 2000, 2002, 2004, and 2006 drawn in this process point to the reversal points of the outer surrounding line 2010 of the repair shape 108 (for example, one of the reversal points is indicated by reference numeral 2008).

[0167] In each case, the inpainted shape 108 may be subdivided into inpainted sub-shapes using a scanline method, as shown in the above figure.

[0168] Fig.21 The above aspect is shown in FIG. 1 , where the scanning direction is selected based on the control bandwidth GF. Reference numeral 2100 denotes the longest edge of the repair shape 108. Fig.21 In the case of the repair shape 108 shown, jumps occur in the case of scanning in the x-direction. If, on the other hand, the scanning is performed in the y-direction (i.e. parallel to the longest edge 2100), as shown by the scanning line 406, each jump can be avoided. However, such a rotation may only be implemented after the determination unit 830 determines that this is necessary based on the control bandwidth GF. Therefore, if the jump width in the scanning direction x is small, it can be managed without changing the scanning direction in the y-direction (this also includes rotating the photomask 100 by 90°).

[0169] Fig. 22 Again, it is shown that Figure 5 The repair shape 108 is known in FIG. The repair shape 108 is subdivided into a rectangle 2200 and a rectangular ring 2202 (frame). All pixels to be scanned corresponding to the defect D are located therein.

[0170] Now, to implement step S2-3 (see Fig.10 ), in the repair shape 2200 (see Fig.23) within the repair shape 2300. It includes a contour 2300 that is recessed relative to the (right) edge 2204. The edge 2204 of the repair shape 2200 adjoins a gap 2206 to be bridged within the serpentine x-scan range. Thus, a corresponding gap 2206 corresponds to a corresponding jump of the electron beam 802, which allows the scan line 406 to continue in the repair sub-region 2202.

[0171] Fig.24 Shown in an enlarged manner Fig.23 4. The electron beam 802 scans pixels 2400, 2402 and 2404 in sequence along the scanning direction x. The electron beam jumps at pixel 2404 and continues its path on scan line 406 in area 2202. This is acceptable for the repair process because the jump is not associated with smearing or settling behavior. If the electron beam travels in the opposite direction, i.e. in the negative x direction, see scan line 406' in area 2202, the electron beam jumps there and falls in the repair sub-area 2200. In principle, it would fall on pixel 2406 if the scanning pattern remained unchanged. However, due to the settling behavior, this can lead to unexpected edge flatness. Therefore, the second repair shape 2300 is recessed relative to the first repair shape 2200, so that the electron beam does not reach pixel 2406 after jumping over gap 2206, but reaches pixel 2408; in this case this is also called "bias".

[0172] Therefore, a repair shape 2500 (eg, Fig.25 ), and therefore in each case the settling behavior of the electron beam 802 under the control bandwidth GF is taken into account.

[0173] Although the present invention has been described based on exemplary embodiments, the present invention can be modified in various ways.

[0174] Reference Symbols List

[0175] 100 Photomask

[0176] 102 substrate

[0177] 104 Coating

[0178] 108 Repair shape

[0179] 108' Repair Shape

[0180] 200 healthy image details

[0181] 200' Defective Image Details

[0182] 400 Snake x Scan

[0183] 400' Snake X-Scan

[0184] 402 Snake Y Scan

[0185] 404 Raster Scan

[0186] 406 scan lines

[0187] 406' Scan Line

[0188] 408 Jump

[0189] 410 pixels

[0190] 410' pixels

[0191] 410" pixels

[0192] 410" pixels

[0193] 500 Repair subshape

[0194] 502 Fix subshape

[0195] 504 Jump

[0196] 600 Sedimentation Curve

[0197] 600' Settlement Curve

[0198] 700 Jump

[0199] 702 Edge

[0200] 702' Edge

[0201] 800 devices

[0202] 802 Electron Beam

[0203] 804 Vacuum Enclosure

[0204] 806 Vacuum Pump

[0205] 808 Sample Stage

[0206] 810 Electron Column

[0207] 812 Electron Source

[0208] 814 Electron Optical Components

[0209] 816 Deflection Unit

[0210] 818 Detection Unit

[0211] 820 Gas Supply Unit

[0212] 822 Valve

[0213] 824 Gas pipeline

[0214] 826 Computer equipment

[0215] 828 Control Unit

[0216] 830 Determine unit

[0217] 832 memory cells

[0218] 1100 cut

[0219] 1102 fix subshape

[0220] 1104 fix subshape

[0221] 1200 cuts

[0222] 1202 Jump

[0223] 1300 fix subshape

[0224] 1302 fix subshape

[0225] 1304 fix subshape

[0226] 1306 Jump

[0227] 1308 Overlap

[0228] 1310 Gap

[0229] 1400 fix subshape

[0230] 1402 fix subshape

[0231] 1404 fix subshape

[0232] 1406 fix subshape

[0233] 1408 fix subshape

[0234] 1410 fix subshape

[0235] 1412 Jump

[0236] 1413 Jump

[0237] 1414 Jump

[0238] 1416 Jump

[0239] 1418 Jump

[0240] 1420 pixels

[0241] 1422 pixels

[0242] 1424 pixels

[0243] 1500 fix subshape

[0244] 1502 fix subshape

[0245] 1504 fix subshape

[0246] 1506 fix subshape

[0247] 1508 fix subshape

[0248] 1510 incision

[0249] 1800 Edge Area

[0250] 1900 fix subshape

[0251] 1902 fix subshape

[0252] 2000 dividing line

[0253] 2002 Dividing Line

[0254] 2004 Dividing Line

[0255] 2006 Dividing Line

[0256] 2008 Turning Point

[0257] 2010 Profile

[0258] 2100 Longest Edge

[0259] 2200 fix subshape

[0260] 2202 fix subshape

[0261] 2204 Edge

[0262] 2300 repair sub shape

[0263] 2302 Profile

[0264] 2400 pixels

[0265] 2402 pixels

[0266] 2404 pixels

[0267] 2406 virtual pixels

[0268] 2408 pixels

[0269] 2410 pixels

[0270] 2500 repair subshape

[0271] 2502 Profile

[0272] 2504 Profile

[0273] A Spacing

[0274] AP amplitude

[0275] A XS amplitude

[0276] B Structure width

[0277] d Width

[0278] d1 diameter

[0279] d2 diameter

[0280] D Defect

[0281] f Frequency

[0282] GF Control Bandwidth

[0283] O origin

[0284] P Position

[0285] P0 position

[0286] P1 Position

[0287] P2 Position

[0288] S1-S3 Method Steps

[0289] T Time

[0290] x scanning direction

[0291] XS Control Signal

[0292] y scanning direction

Claims

1. A method for treating a defect (D) of a microlithography photomask (100), wherein a process gas is activated by means of a particle beam (802), wherein a control unit (828) is used to control a deflection unit (816) having a control bandwidth (GF), wherein the deflection unit (816) for deflecting the particle beam (802) is configured to direct the particle beam (802) over the photomask (100), the method comprising the following steps: a) providing (S1) an image (200') of at least a portion of the photomask (100); b) determining a repair shape (108, 500, 502, 1102, 1104, 1300-1304, 1400-1410, 1500-1508) in the image (200') based on the control bandwidth (GF), wherein the repair shape (108, 500, 502, 1102, 1104, 1300-1304, 1400-1410, 1500-1508) includes the defect (D); and c) providing the particle beam (802) at m pixels (410) of the repair shape (108, 500, 502, 1102, 1104, 1300-1304, 1400-1410, 1500-1508) by means of the deflection unit (816) and activating the process gas to treat the defect (D).

2. The method according to claim 1, wherein: Before step a), in particular before or when the particle beam column (810) is put into operation to perform steps a) to c), a control bandwidth (GF) is determined or provided, wherein preferably, before step b), the determined or provided control bandwidth (GF) or a value derived therefrom is stored in a data memory (832) and used in step b).

3. The method according to claim 1 or 2, in, Step b) comprises: b1) subdividing (S2-1) the repair shape (108) including the defect (D) into k repair sub-shapes (1102, 1104) based on the control bandwidth (GF), and selecting one of the k repair sub-shapes (1102, 1104); and / or b2) subdividing (S2-2) the repair shape (108) containing the defect (D) into k repair sub-shapes (1300-1304, 1400-1410) and selecting one of the k repair sub-shapes (1300-1304, 1400-1410), wherein the selection is performed based on the control bandwidth (GF), Wherein, step c) comprises: The particle beam (802) is provided at m pixels (410) of the selected k repair sub-shapes (1300-1304, 1400-1410) by means of the deflection unit (816), and the process gas is activated to treat the defect (D).

4. The method according to any one of claims 1 to 3, wherein: The determination according to step b) or the subdivision according to step b1) and / or the selection according to step b2) is achieved based on the spacing or jump width (d1, d2, 1202, 1306, 1310, 1412-1418) between two repair shapes (108, 2200, 2002, 2300, 2500) or between two repair sub-shapes among the k repair sub-shapes (1300-1304, 1400-1410).

5. The method according to any one of claims 1 or 4, wherein: Step c) comprises: Providing the particle beam (802) at m pixels (410) of the first repair shape (2200, 2202) or at m pixels (410) of the first repair sub-shape among the k repair sub-shapes (500) by means of the deflection unit (816), and activating the process gas to process the defect (D); The particle beam (802) is provided at n pixels (410'") of the second repair shape (2300, 2500) or at n pixels (410'") of the second repair sub-shape among the k repair sub-shapes (502) by means of the deflection unit (816), and the process gas is activated to process the defect.

6. The method according to any one of claims 1 to 5, wherein: The first pixel (1422) and / or the last pixel (1424) of the m or n pixels are selected in a random manner.

7. The method according to any one of claims 3 to 6, wherein: Each of the k repair sub-shapes (1102, 1104, 1300-1304, 1400-1410) is formed continuously in the scanning direction (x) of the particle beam (802).

8. The method according to any one of claims 3 to 7, wherein: The scan line method is used in step b1) or b2).

9. The method according to any one of claims 1 to 8, wherein: The repair shape (108) comprises a cutout (506, 1100, 1200, 1510) having a maximum dimension (d, d1, d2) of between at least 5 nm and less than 10 μm.

10. The method according to claims 1 to 9, wherein: A spacing (A) between two pixels (410) within a corresponding one of the k repair sub-shapes (500, 502, 1102, 1104, 1300-1304, 1400-1410, 1500-1508) or the repair shape (108) is less than 40, 20 or 5 nm.

11. The method according to any one of claims 1 to 10, wherein: The deflection unit (816) includes an octupole for beam deflection.

12. The method according to any one of claims 1 to 11, wherein: In step c), the particle beam (802) moves along a straight line (406, 406') and / or moves along a line (406, 406') parallel to and / or perpendicular to the line.

13. The method according to any one of claims 1 to 12, wherein: In step c), the particle beam (802) is moved parallel to one of the k repair sub-shapes (500, 502, 1102, 1104, 1300-1304, 1400-1410, 1500-1508) and / or the longest edge (2100) of the repair shape (108).

14. The method according to any one of claims 1 to 13, wherein: In step b), a first repair shape (2200, 2202) and a second repair shape (2300, 2500) containing the defect (D) are determined, wherein the second repair shape (2300, 2500) is at least partially located within the first repair shape (2200, 2202).

15. The method according to claim 14, wherein: The contour of the second repair shape (2300, 2500) is partially recessed relative to the contour of the first repair shape (2200, 2202).

16. The method according to claim 14 or 15, wherein: The second repair shape (2300, 2500) partially has the same contour as the first repair shape (2200, 2202).

17. The method according to any one of claims 14 or 16, wherein: When the first and second repair shapes (2200, 2202; 2300, 2500) overlap between two adjacent contours of the first and second repair shapes (2200, 2202; 2300, 2500), one or more pixels (2404, 2406) are positioned along a straight line (406, 406') intersecting the two adjacent contours (2204, 2302, 2502, 2504).

18. A computer program product comprising instructions which, when executed by a device (800) for processing defects (D) of a microlithography photomask (100), cause the device (800) to perform the method steps (S1-S3) according to any one of claims 1 to 17.

19. An apparatus (800) for treating a defect (D) of a microlithography photomask (100), comprising: a process gas supply device (820) for providing process gas, a particle source (812) for providing a particle beam (802), a deflection unit (816) for deflecting the particle beam (802) so as to provide the particle beam (802) at m pixels (410) of the repair shape (108, 500, 502, 1102, 1104, 1300-1304, 1400-1410, 1500-1508) and activate the process gas, a control unit (828) for controlling the deflection unit (816) using a control bandwidth (GF), a detector unit (818) for providing an image (200') of at least a portion of the photomask (100); A determination unit (830) is used for determining the repair shape (108, 500, 502, 1102, 1104, 1300-1304, 1400-1410, 1500-1508) in the image (200') based on the control bandwidth (GF), wherein the repair shape (108, 500, 502, 1102, 1104, 1300-1304, 1400-1410, 1500-1508) contains the defect (D).

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