Particle beam-induced processing method for defects of microlithographic photomasks

Abstract

A particle beam induced processing method of a defect (D, D') of a microlithographic photomask (100) comprising the steps of: a1) providing (S1) an image (300) of at least a portion of the photomask (100), b1) determining (S2) a geometry of the defect (D, D') in the image (300) as a repair shape (302, 302'), c1) subdividing (S3) the repair shape (302, 302') into n pixels (304) according to a first grid (306), d1) subdividing (S5) the repair shape into m pixels (304') according to a second grid (306') resulting from a sub-pixel displacement of the first grid (306), e1) providing (S4) an active particle beam (202) and a process gas at each of the n pixels (304) of the repair shape (302, 302') according to the first grid (306), and f1) providing (S6) the active particle beam (202) and the process gas at each of the m pixels (304') of the repair shape (302, 302') according to the second grid (306').

Description

Technical Field

[0001] This invention relates to a particle beam-induced treatment method for defects in microlithography masks.

[0002] The entire contents of priority application DE 10 2021 123 440.9 are incorporated herein by reference. Background Technology

[0003] Microlithography is used to fabricate microstructured components, such as integrated circuits. Microlithography processes are performed using lithography equipment equipped with an illumination system and a projection system. An image of a mask (mask master) illuminated by the illumination system is projected by the projection system onto a substrate (e.g., a silicon wafer) coated with a photosensitive layer (photoresist) and arranged in the image plane of the projection system, so as to transfer the mask structure onto the photosensitive coating of the substrate.

[0004] To achieve small structural dimensions and thus increase the integration density of microstructured components, light with very short wavelengths is increasingly being used, for example, light known as deep ultraviolet (DUV) or extreme ultraviolet (EUV). DUV, for example, has a wavelength of 193 nm, and EUV, for example, has a wavelength of 13.5 nm.

[0005] In this context, microlithography photomasks have structural dimensions ranging from a few nanometers to hundreds of nanometers. The fabrication of such photomasks is extremely complex and therefore very expensive. This is especially true in this case, because the photomask must be defect-free; otherwise, it is impossible to ensure that the structure fabricated on the silicon wafer using the photomask exhibits the desired functionality. In particular, the quality of the structure on the photomask is decisive for the quality of the integrated circuits fabricated on the wafer using the photomask.

[0006] For this reason, it is essential to inspect microlithography masks for defects and repair any discovered defects in a targeted manner. Typical defects include the absence of intended structures, such as due to unsuccessful etching processes, or the presence of unintended structures, such as due to etching processes proceeding too quickly or having an effect in the wrong location. These defects can be remedied by selectively etching excess material in the appropriate locations or selectively depositing additional material; as an example, this can be done in a highly targeted manner using electron beam induced processing (FEBIP, "Focused Electron Beam Induced Processing").

[0007] DE 10 2017 208 114 A1 describes a method for particle beam-induced etching of photolithographic masks. In this method, a particle beam, particularly an electron beam, and an etching gas are provided on the photolithographic mask at the locations to be etched. The particle beam activates a localized chemical reaction between the material of the photolithographic mask and the etching gas, resulting in the localized ablation of the material from the photolithographic mask. During the etching method, the electron beam is directed to a number of discrete incident points on the mask according to a grid, and the electron beam is held at the corresponding grid point for a duration of approximately 100 ns to induce a localized etching reaction before the electron beam is directed to the next incident point in the grid. In particular, edge regions of defects can only be processed inaccurately in this way with relatively coarse grids. However, refining the grid generates a large amount of data during the algorithmic processing of the data, because the amount of data increases quadratically with the number of grid points (electron beam incident points), that is, as the distance between two incident points decreases.

[0008] Furthermore, the edge resolution when processing defects with a particle beam (e.g., an electron beam) depends on the reaction distribution of the chemical reaction between the photomask material and the process gas (e.g., an etching gas). The reaction distribution specifies the region on the mask where the chemical reaction occurs (e.g., the diameter of the circle around the incident point of the particle beam on the mask). The reaction distribution depends particularly on the beam profile of the particle beam (the primary beam) and the radius of the secondary particles that appear. However, when processing defects on a photomask, improving resolution by refining the primary beam (e.g., by increasing the primary energy) is limited by the fact that the radius of the secondary beam, and therefore the radius of the reaction distribution, may increase with increasing primary beam energy. Summary of the Invention

[0009] In view of this background, the object of the present invention is to provide an improved method for particle beam-induced treatment of defects in microlithography masks.

[0010] Based on the first aspect, a method for particle beam-induced processing of defects in microlithography masks is proposed. The method includes the following steps:

[0011] a1) Provide an image of at least a portion of the photomask.

[0012] b1) Determine the geometry of the defect in the image as the repair shape.

[0013] c1) Subdivide the repair shape into n pixels based on the first grid.

[0014] d1) Subdivide the repaired shape into m pixels according to the second grid, which is generated by shifting the sub-pixels of the first grid.

[0015] e1) Provide an activation particle beam and process gas at each of the n pixels of the repaired shape according to the first grid, and

[0016] f1) Provides an activation particle beam and process gas at each of the m pixels of the repaired shape according to the second grid.

[0017] By using a particle beam to expose a photomask in the defect region according to two grids that have been shifted relative to each other by sub-pixel displacement, it is possible to scan the edge region of the defect more precisely.

[0018] As an example, the edge region of the defect can be scanned more precisely without refining the grid itself. As an example, the pixel size of the n pixels of the repair shape based on the first grid is the same as the pixel size of the m pixels of the repair shape based on the second grid. In other words, in this example, applying the second grid to the repair shape does not change the grid's refinement. Therefore, the number of pixels and thus the amount of data are not changed or substantially changed by applying the second grid to the repair shape.

[0019] However, in another example, the second grid can also be finer than the first grid so that the true shape of the defect, especially its outer contour, can be better processed by the particle beam.

[0020] Specifically, the repair shape is subdivided into n pixels, such that the n pixels are arranged in columns (X direction) and rows (Y direction, perpendicular to the X direction).

[0021] As an example, pixel size is the pixel side length and / or the distance between the centers of two adjacent pixels. As an example, pixel size is the pixel side length in the X and / or Y directions, and / or the distance between the centers of two adjacent pixels in the X and / or Y directions.

[0022] Specifically, both the first and second grids are grids with grid lines arranged in the X and Y directions, respectively. By overlaying the corresponding grids (corresponding to the first and second grids) on the repair shape, the repair shape is subdivided into n pixels or m pixels, respectively.

[0023] Defect handling specifically includes defect etching, which involves locally ablating material from a photomask within the defect area, or depositing material on a photomask in the defect region. As an example, the proposed method allows for better etching away of excess structures in the defect region, or better enhancement of missing structures in the defect region. In particular, the proposed method can better and more accurately etch away the edge regions of defects, or better and more accurately enhance missing structures in the edge regions of defects.

[0024] For example, an image of at least a portion of a photomask can be recorded using a scanning electron microscope (SEM). As an example, the image of at least a portion of the photomask has a spatial resolution on the order of several nanometers. Images can also be recorded using a scanning probe microscope (SPM) (e.g., an atomic force microscope (AFM) or a scanning tunneling microscope (STM)).

[0025] The method may specifically include the step of capturing an image of at least a portion of the photomask using a scanning electron microscope and / or a scanning probe microscope.

[0026] As an example, a microlithography photomask is a photomask used in EUV lithography equipment. In this context, EUV stands for "Extreme Ultraviolet," and refers to the wavelength of working light between 0.1 nm and 30 nm, specifically 13.5 nm. Within an EUV lithography equipment, beam shaping and illumination systems are used to guide EUV radiation onto the photomask (also called a "mask master"), which is particularly in the form of a reflective optical element (reflective photomask). The photomask has a structure that is imaged onto a wafer or the like in a reduced manner through the projection system of the EUV lithography equipment.

[0027] As an example, a microlithography photomask can also be a photomask used in DUV lithography equipment. In this case, DUV stands for "deep ultraviolet" and refers to the wavelength of working light between 30 nm and 250 nm, particularly between 193 nm and 248 nm. Within a DUV lithography equipment, beam shaping and illumination systems are used to guide DUV radiation onto the photomask, which is particularly 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 through the projection system of the DUV lithography equipment.

[0028] As an example, a microlithography photomask includes a substrate and a structure formed on the substrate by a coating. As an example, the photomask is a transmissive 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. The photomask can also be a mask used for nanoimprint lithography (NIL).

[0029] As an example, the substrate includes silicon dioxide (SiO2), such as fused silica. As an example, the structured coating includes chromium, chromium compounds, tantalum compounds, and / or compounds made of silicon, nitrogen, oxygen, and / or molybdenum. The substrate and / or coating may also include other materials.

[0030] In the case of photomasks used in EUV lithography equipment, the substrate may include alternating layers of molybdenum and silicon.

[0031] The proposed method can be used to identify, locate, and repair defects in photomasks, particularly defects in the structured coating of photomasks. Specifically, defects are (e.g., absorbing or reflecting) coatings of photomasks that have been incorrectly applied to the substrate. This method can be used to add coatings to areas of the photomask where coatings are lacking. Furthermore, this method can be used to remove coatings from areas of the photomask that have been incorrectly applied.

[0032] To this end, the geometry of the defect is determined in at least a portion of the recorded image of the photomask. As an 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.

[0033] The n pixels corresponding to the first grid are defined within the repair shape for particle beam induction processing of the repair shape. In step e1) of the method, a particle beam is directed to each of the n pixels of the repair shape. Specifically, the maximum intensity of the electron beam is directed to the respective center of each of the n pixels. In other words, the n pixels of the repair shape represent the first grid of the repair shape for particle beam induction processing, particularly a two-dimensional grid. As an example, the n pixels of the repair shape correspond to the incident area of ​​the particle beam during particle beam induction processing of the defect. As an example, the pixel size is selected such that the intensity distribution of the electron beam directed to the pixel center decreases to a predetermined intensity at the pixel edge due to the Gaussian intensity distribution of the electron beam. The predetermined intensity may correspond to a reduction to half of the maximum intensity, or any other fractional reduction of the maximum intensity of the electron beam. As an example, the pixel size and / or the full width at half maximum (FWHM) of the electron beam are in the sub-nanometer range or on the order of several nanometers.

[0034] In step d1), m pixels corresponding to the second grid are defined in the repair shape for further particle beam induction processing of the repair shape. Specifically, the second grid is calculated from the first grid based on the sub-pixel displacement. Step d1) can be performed before or after step e1). Then, in step f1) according to the method, the particle beam is directed to each of the m pixels of the repair shape according to the second grid—in a manner similar to that for the n pixels according to the first grid. In principle, labeling steps a1), b1), etc., does not specify any particular order; rather, these steps can be performed in different orders. This also applies to the method according to the second aspect.

[0035] As an example, the second grid has the same level of detail as the first grid. In this case, the number of n pixels according to the first grid is no different from the number of m pixels according to the second grid, or there is no substantial difference. As an example, in this case, the difference between the number m and the number n is less than 20%, 10%, 5%, 3%, and / or 1%. However, in other examples, the second grid may be more detailed than the first grid.

[0036] As an example, the process gas is a precursor gas and / or an etching gas. As an example, the process gas can be a mixture of multiple gas components, that is, a process gas mixture. As an example, the process gas can be a mixture of multiple gas components, where each gas component has only a specific molecular type.

[0037] In particular, alkyl compounds of main group elements, metals, or transition elements can be considered as precursor gases suitable for depositing or growing elevated structures. Examples include cyclopentadienyl(trimethyl)platinum (CpPtMe3 Me=CH4), methylcyclopentadienyl(trimethyl)platinum (MeCpPtMe3), tetramethyltin (SnMe4), trimethylgallium (GaMe3), ferrocene (Cp2Fe), diarylchromium (Ar2Cr), and / or carbonyl compounds of main group elements, metals, or transition elements (e.g., hexacarbonylchromium (Cr(CO)6), hexacarbonylmolybdenum (Mo(CO)6), hexacarbonyltungsten (W(CO)6), octacarbonyldicobalt (Co2(CO)8), dodecacarbonyltriruthenium (Ru3(CO))). 12 Iron pentacarbonyl (Fe(CO)5), and / or alkoxy compounds of group elements, metals or transition elements (e.g., tetraethoxysilane (Si(OC2H5)4), tetraisopropoxytitanium (Ti(OC3H7)4), and / or halides of group elements, metals or transition elements (e.g., tungsten hexafluoride (WF6), tungsten hexachloride (WCl6), titanium tetrachloride (TiCl4), boron trifluoride (BCl3), silicon tetrachloride (SiCl4)), and / or complexes with group elements, metals or transition elements (e.g., bis(hexafluoroacetylacetone)copper (Cu(C5F6HO2)2), trifluoroacetylacetone dimethyl gold (Me2Au(C5F3H4O2))), and / or organic compounds (e.g., carbon monoxide (CO), carbon dioxide (CO2), aliphatic hydrocarbons and / or aromatic hydrocarbons), and the like.

[0038] As an example, etching gases may include: xenon difluoride (XeF2), xenon dichloride (XeCl2), xenon tetrachloride (XeCl4), vapor (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 are defined in the applicant's U.S. patent application number 13 / 0 103281 for etching one or more deposition test structures.

[0039] Process gases may include additional gases, such as oxidizing gases like hydrogen peroxide (H₂O₂), nitrous oxide (N₂O), nitric oxide (NO), nitrogen dioxide (NO₂), nitric acid (HNO₃), and other oxygen-containing gases and / or halides (e.g., 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 like 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.

[0040] As an example, the activation of the particle beam is provided by means of a device that may include: a particle beam source for generating the particle beam; a particle beam guiding device (e.g., a scanning unit) configured to guide the particle beam to a corresponding pixel of the repair shape of the photomask; a particle beam shaping device (e.g., an electronic or beam optics) configured to shape, in particular, focus the particle beam; at least one storage container configured to store a process gas or at least one gaseous component of a process gas; and at least one gas supply device configured to supply a process gas or at least one gaseous component of a process gas to the corresponding pixel of the repair shape having a predetermined gas flow rate.

[0041] Activated particle beams include, for example, electron beams, ion beams, and / or laser beams.

[0042] As an example, an electron beam is provided using a modified scanning electron microscope. As an example, an image of at least a portion of a photomask is recorded using the same modified scanning electron microscope that provides the activation of the electron beam.

[0043] The activated particle beam specifically activates the local chemical reaction between the photomask material and the process gas, which causes the material to be locally deposited on the photomask from the gas phase or causes the photomask material to be locally transformed into the gas phase.

[0044] In step e1), for example, an activation particle beam is continuously provided at each of the n pixels of the repaired shape according to the first grid, using a particle beam guiding device. In step e1) of the method according to the first aspect, the activation particle beam is maintained at each pixel for a predetermined residence time to initiate a chemical reaction between the process gas and the mask material at the location of the corresponding pixel. As an example, the residence time is 100 ns. Furthermore, in step f1), for example, an activation particle beam is continuously provided at each of the m pixels of the repaired shape according to the second grid, using a particle beam guiding device, to initiate the chemical reaction. In step f1) of the method according to the first aspect, the activation particle beam is maintained at each pixel for a predetermined residence time, for example, 100 ns.

[0045] However, other values ​​can also be used for the dwell time. As an example, the dwell time of the activated particle beam at each pixel according to the first grid or the second grid in step e1) or f1) is less than or equal to 500 ns, less than or equal to 400 ns, less than or equal to 300 ns, less than or equal to 200 ns, less than or equal to 100 ns, and / or less than or equal to 50 ns.

[0046] According to an embodiment, subpixel displacement is a displacement of the first grid by the subpixel size, and more particularly, a lateral displacement.

[0047] Therefore, the second grid for repairing the shape can be easily determined (e.g., calculated) from the first grid.

[0048] Specifically, the subpixel size is a portion of the pixel size. As an example, the subpixel size is a portion of the pixel side length (e.g., in the X and / or Y directions) and / or the distance between the centers of two adjacent pixels (e.g., in the X and / or Y directions).

[0049] As an example, lateral displacement is displacement (especially transverse displacement) in a first direction (X direction) or in a second direction (Y direction) perpendicular to the first direction.

[0050] Specifically, the grid lines of the first grid are shifted (particularly laterally) by subpixel size relative to the repair shape to form the grid lines of the second grid. In this case, pixels according to the first grid can now, for example, be located outside the repair shape and therefore not considered according to the second grid. Furthermore, the "free grid space" of the first grid can now also be filled with pixels according to the second grid.

[0051] According to another embodiment, the method includes the following steps:

[0052] The repair shape is subdivided into l based on at least one additional grid. i 1 pixels, where the i-th additional grid is subdivided into li Each pixel and at least one additional grid are generated by displacement of subpixels from any one of the first grid, the second grid, or at least one additional grid, and

[0053] In repairing the shape according to at least one additional grid, l i Each of the pixels provides an activation particle beam and process gas.

[0054] By using a particle beam to pass through one or more additional grids different from the first and second grids, the edge regions of defects can be handled more effectively. In particular, the accuracy of edge positioning can be improved during defect repair.

[0055] According to another embodiment, step e1) is repeated for g repetition cycles and / or step f1 is repeated for h repetition cycles before step f1).

[0056] Specifically, g and h are integers greater than or equal to 2. In this case, the number of repetitions g can be equal to the number of repetitions h (g = h), or they can be different from each other (g ≠ h).

[0057] Therefore, in step e1), all pixels n of the repaired shape according to the first grid are repeatedly exposed with an electron beam (g repetition cycles), for example, before the transition for processing defects in the photomask according to the second grid. As an example, step e1) is performed with 10 or 100 repetition cycles (i.e., g = 10 or g = 100). However, the repetition cycle g can also take any other value.

[0058] Furthermore, for example, in step f1), all pixels m of the repaired shape according to the second grid are also repeatedly exposed with an electron beam (h repetition periods). As an example, the number of repetition periods h is also 10 or 100. However, the number of repetition periods h can also take any other value.

[0059] According to another embodiment, steps e1) and f1) are repeated in j repetition cycles.

[0060] Specifically, j is an integer greater than or equal to 2. As an example, the number of repetition cycles j can be on the order of 100, 1000, 10000, 100000, or one million.

[0061] As an example, defects in a photomask can be completely repaired by repeatedly processing the defects using a particle beam.

[0062] As an example, the repaired shape is thus formed by exposing each of the n pixels of the first grid to a particle beam (g×j) times. As an example, the repaired shape is formed by exposing each of the m pixels of the second grid to a particle beam (h×j) times.

[0063] According to another embodiment, in various cases, in the n pixels, m pixels and / or l pixels of the repaired shape i Activation particle beams are sequentially and continuously provided at each pixel, in which process gases are consumed uniformly over the repaired shape through chemical reactions activated by the activation particle beams.

[0064] Specifically, a row-by-row scan of the repair shape can be avoided, where every pixel is identified (home in on) within the repair shape. As an example, initially only r pixels are identified each time along a row (e.g., along the X direction), where r is an integer greater than or equal to 1. For example, one pixel (r=1), two pixels (r=2), or three pixels (r=3) are identified each time along a row. As an example, only s pixels are identified each time along a column (e.g., along the Y direction), where s is an integer greater than or equal to 1. As an example, the offset along the column is greater than the offset along the row (i.e., s is greater than r). As an example, five pixels (s=5) or ten pixels (s=10) are identified each time along a column. In further iterations, the other pixels of the repair shape are then exposed via a particle beam in a similar manner until all n pixels of the repair shape according to the first grid, or all m pixels of the repair shape according to the second grid, or all l pixels of the repair shape according to another grid. i They were all exposed once.

[0065] In the embodiment, the n pixels, m pixels and / or l pixels of the repaired shape i The order in which activation particle beams are provided sequentially at each pixel may have a random distribution.

[0066] According to the second aspect, a method for particle beam-induced processing of defects in microlithography masks is proposed. The method includes the following steps:

[0067] a2) Provide an image of at least a portion of the photomask.

[0068] b2) Determine the geometry of the defects in the image as the repair shape, and

[0069] c2) Provide process gas at least along the stretching portion of the repaired shape, and guide the activation particle beam along the stretching portion while activating the chemical reaction between the photomask material on the stretching portion and the process gas.

[0070] Because the particle beam is guided along the stretched portion of the repair shape, simultaneously activating the chemical reaction between the process gas and the mask material, discrete scanning of individual pixels of the repair shape—that is, scanning according to the grid—is avoided. Instead, the particle beam is guided along the stretched portion of the repair shape in vector form. Therefore, defects (especially their edge regions) can be repaired better and more accurately. In particular, the resolution at which defects can be processed does not depend on the grid resolution (fineness), but only on the resolution (i.e., control accuracy) of the particle beam induction processing equipment.

[0071] Steps a2) and b2) of the method according to the second aspect specifically correspond to steps a1) and b1) of the method according to the first aspect. Furthermore, for example, the provision of process gas in step c2) of the method according to the second aspect is also carried out in a similar manner to the provision of process gas in steps e1) and f1) of the method according to the first aspect.

[0072] Furthermore, for example, regarding the particle beam induction processing apparatus, and regarding the generation of the particle beam and its basic effect on the process gas, the provision of the particle beam in step c2) of the method according to the second aspect is also carried out in a manner similar to the provision of the particle beam in steps e1) and f1) of the method according to the first aspect.

[0073] According to another embodiment, the activated particle beam is guided along the entire stretching section at a velocity greater than zero and / or the activated particle beam is guided along the entire stretching section without stopping.

[0074] Since the individual pixel stop (dwelling) for dwell time is omitted in the method according to the second aspect, the desired particle beam dose (e.g., electron beam dose) can be set by selecting a speed at which the activated particle beam is guided on the surface of the defect. Furthermore, the temporal variation of the composition of the provided process gas (e.g., etching gas) may also be affected by the selection of the sweep speed. In particular, this can also prevent unfavorable gas compositions, and therefore, a significantly reduced processing rate (e.g., etching rate) due to unfavorable gas compositions. Thus, defects can be removed more effectively, for example, their outer contours can be completely removed.

[0075] As an example, the particle beam is guided from the starting point of the stretching section to the ending point of the stretching section at a velocity greater than zero and / or without stopping.

[0076] According to another embodiment, the length of the stretched portion is greater than or equal to 5 nm, greater than or equal to 10 nm, greater than or equal to 20 nm, greater than or equal to 50 nm, greater than or equal to 100 nm, greater than or equal to 200 nm, and / or greater than or equal to 500 nm.

[0077] According to another embodiment, the stretching portion extends linearly from one edge of the repair shape to the opposite edge of the repair shape.

[0078] As an example, a particle beam is guided across the repair shape in a "serpentine pattern." In this case, the particle beam is guided linearly, for example, along a first stretching section, from a first starting point at a first edge of the repair shape to a first ending point at a second edge of the repair shape opposite to the first edge. For example, the first stretching section connects the first starting point and the first ending point on the shortest path. Subsequently, the particle beam is shifted to a new second starting point at the second edge, for example, in a direction perpendicular to the first stretching section at the second edge. Then, for example, along the second stretching section, the particle beam is guided from a second starting point at the second edge of the repair shape to a second ending point at the first edge. The second stretching section connects the second starting point and the second ending point, for example, on the shortest path and is arranged parallel to the first stretching section. In a corresponding manner, the particle beam can sweep across the entire repair shape across multiple individual stretching sections.

[0079] As an example, what applies to each of the individual stretch sections is to guide the active particle beam along the entire individual stretch section at a speed greater than zero and / or to guide the active particle beam along the entire individual stretch section without stopping (dwelling).

[0080] The distance between the first endpoint and the second starting point can be selected (e.g., increased) such that there is a favorable particle beam dose and / or no adverse change in the gas composition of the process gas. If processing gaps perpendicular to the first and second stretching sections appear due to the large spacing, the particle beam can return to these processing gaps in further iterations. However, this can lead to an unfavorable particle beam dose, particularly in the edge regions of defects, and even more so in the edge regions of defects arranged perpendicular or approximately perpendicular to the first and second edges.

[0081] According to another embodiment, the stretching portion extends along the outer edge of the repair shape and / or along a parallel curve parallel to the outer edge of the repair shape.

[0082] Therefore, adverse particle beam doses can be avoided, especially in the edge regions of defects.

[0083] For example, the particle beam is guided on the repair shape in a (quasi)helical pattern. In this case, the particle beam is guided, for example, from a first starting point at the outer edge of the repair shape along a first stretch extending along the outer edge of the repair shape to a first ending point at the outer edge. In this case, the first ending point coincides with or is arranged adjacent to the first starting point. Subsequently, for example, the particle beam is shifted radially inward from the outer edge (e.g., in the central direction of the repair shape) to a second starting point. Then, for example, the particle beam is guided from the second starting point along a second stretch extending along a parallel curve parallel to the first stretch. Correspondingly, the particle beam can sweep across the entire repair shape along multiple individual stretches extending along parallel curves parallel to the outer edge.

[0084] As an example, what applies to each of the individual stretch sections is to guide the active particle beam along the entire individual stretch section at a speed greater than zero and / or to guide the active particle beam along the entire individual stretch section without stopping (dwelling).

[0085] According to another embodiment, the repair shape is subdivided into at least a first sub-repair shape and a second sub-repair shape.

[0086] Furthermore, the stretching portion extends linearly from the edge of the first sub-repair shape to the opposite edge of the first sub-repair shape, and / or

[0087] The stretching portion extends along the outer edge of the second sub-repair shape and / or along a parallel curve parallel to the outer edge of the second sub-repair shape.

[0088] For example, the first sub-repair shape is the inner region of the repair shape, and the second sub-repair shape surrounds the inner first sub-repair shape.

[0089] In this embodiment, the repair shape is subdivided into sub-repair shapes in two or more distinct subdivisions. This avoids uneven treatment of defects at the boundaries between sub-repair shapes.

[0090] According to another embodiment, the activated particle beam is guided along the stretching section at a velocity greater than or equal to 0.01 m / s, greater than or equal to 0.02 m / s, greater than or equal to 0.03 m / s, greater than or equal to 0.05 m / s, greater than or equal to 0.1 m / s, greater than or equal to 1 m / s, greater than or equal to 5 m / s, greater than or equal to 10 m / s, greater than or equal to 50 m / s, and / or greater than or equal to 100 m / s.

[0091] Therefore, the activated particle beam can be guided sufficiently fast along the stretching section to ensure that the particle beam dose is as uniform as possible throughout the entire repair shape, especially in the edge regions of the repair shape.

[0092] According to another embodiment, the activation particle beam is guided over the entire repair shape at times less than or equal to 500 ns, less than or equal to 400 ns, less than or equal to 300 ns, less than or equal to 200 ns, less than or equal to 100 ns, and / or less than or equal to 50 ns.

[0093] In other embodiments, the activation particle beam may also be guided more slowly over the entire repair shape.

[0094] According to another embodiment, the beam current activating the particle beam is greater than or equal to 0.0001 μA, greater than or equal to 0.001 μA, greater than or equal to 0.01 μA, greater than or equal to 0.1 μA, and / or greater than or equal to 1 μA.

[0095] Because of the higher beam current in the method according to the second aspect, where the repaired shape is vector-sweeped (rather than being scanned discretely and pixel-by-pixel by the particle beam as in the method according to the first aspect), the required particle beam dose (e.g., electron beam dose) can be applied even at high sweep velocities.

[0096] However, in other embodiments, the beam current activating the particle beam can also have a smaller value. For example, the beam current activating the particle beam can also be greater than or equal to 1 pA and / or greater than or equal to 10 pA.

[0097] According to another aspect, a computer program product is proposed, the computer program product comprising instructions that, when executed by a computing device of a device for controlling particle beam-induced processing of defects in a microlithography mask, prompt the device to perform the methods described above according to the first aspect and / or the methods described above according to the second aspect.

[0098] The term "one" in the present context should not be interpreted as limited to exactly one element. Of course, multiple elements can be provided, such as two, three, or more. Any other numerical values ​​used herein should not be construed as a limitation on the existence of exactly the stated number of elements. Rather, upward and downward numerical deviations are possible unless otherwise indicated.

[0099] Other possible implementations of the invention include combinations of any features or embodiments not expressly mentioned in the descriptions above or below with respect to exemplary embodiments. In such cases, those skilled in the art will also add various aspects as improvements or supplements to the corresponding basic form of the invention.

[0100] Other advantageous embodiments and aspects of the invention are the subject of the dependent claims and also the subject of exemplary embodiments of the invention described below. The invention is explained in detail below with reference to the accompanying drawings and preferred embodiments. Attached Figure Description

[0101] Figure 1 Details of a microlithography mask with defects in a structured coating, according to one embodiment, are schematically shown.

[0102] Figure 2 An example of a method for [doing something] is shown. Figure 1 Particle beam-induced processing equipment for defects in optical masks;

[0103] Figure 3 It shows Figure 1 Partial details of another example of a defect in a photomask, wherein the geometry of the defect (the repair shape) is subdivided into multiple pixels according to a first grid;

[0104] Figure 4 Shown in magnified view Figure 3 The five pixels in;

[0105] Figure 5 It shows something similar to Figure 3 The view shows that the geometry of the defect (the repair shape) is subdivided into multiple pixels according to a second grid;

[0106] Figure 6 It shows something similar to Figure 3 The view shows the geometry of the defect (the repair shape) subdivided into multiple pixels according to a third grid.

[0107] Figure 7 It shows something similar to Figure 3 The view, in which the centers of pixels according to the first grid, the second grid, and the third grid are depicted as superimposed on each other;

[0108] Figure 8 It shows the method for using the first aspect to Figures 1 to 7 A flowchart of a method for particle beam-induced processing of defects in optical masks;

[0109] Figure 9 It shows Figure 1 Another example of a defect in a photomask is that the geometry of the defect (the repair shape) is not subdivided into pixels, but rather a beam of particles travels continuously and vectorarily along multiple stretches from one edge of the repair shape to the other.

[0110] Figure 10 It shows Figure 1 Another example of photomask defects in which the geometry of the defect (repair shape) is not subdivided into pixels, but rather the particle beam travels continuously and vectorarily on the repair shape along multiple stretches that extend parallel to the outer contour of the repair shape.

[0111] Figure 11 It shows Figure 10 The defect in the repair shape is subdivided into two sub-repair shapes, among which Figure 9 The method described in the text is applied to the interior of two sub-repair shapes. Figure 10 The method described in the text is applied to the exterior of two sub-repair shapes; and

[0112] Figure 12 It shows the method for dealing with the second aspect from Figure 1 and Figures 9 to 11 The flowchart shows a method for particle beam-induced processing of defects in photomasks. Detailed Implementation

[0113] Unless otherwise stated, identical or functionally equivalent elements have the same reference numerals in the accompanying drawings. It should also be noted that the illustrations in the drawings are not necessarily to scale.

[0114] Figure 1 The details of a microlithography photomask 100 are schematically shown. In the example shown, the photomask 100 is a transmission photolithography photomask 100. The photomask 100 includes a substrate 102. The substrate 102 is optically transparent, especially at the wavelength at which the photomask 100 is exposed. As an example, the material of the substrate 100 includes fused silica.

[0115] A structured coating 104 (pattern element 104) has been applied to the substrate 102. Specifically, the coating 104 is a coating made of an absorbing material. For example, the material of the coating 104 includes a chromium layer. For example, the thickness of the coating 104 ranges from 50 nm to 100 nm. The structural dimension B of the structure formed by the coating 104 on the substrate 102 of the photomask 100 can vary depending on the location of the photomask 100. As an example, the width B of the region is drawn as... Figure 1 The structural size is defined as follows. For example, structural size B is located in the region of 20 to 200 nm. Structural size B can also be larger than 200 nm, for example, on the order of micrometers.

[0116] In other examples, other materials and other layer thicknesses relative to the mentioned materials and layer thicknesses (e.g., thinner layer thicknesses, such as "thin EUV mask absorbers") may also be used for the substrate and coating. Furthermore, the photomask 100 may also be a reflective photomask instead of a transmissive photomask.

[0117] Defect D typically occurs during photomask fabrication, for example, because the etching process does not run exactly as intended. Figure 1In this context, the defect D is represented by a cross-sectional line. This is redundant material because the coating 104 is not removed from this region, even though two adjacent coating regions 104 are envisioned to be separated within the template of the photomask 100. It can also be said that the defect D forms a network. In this case, the size of the defect D corresponds to the structural dimension B. Other defects smaller than the structural dimension B, such as those on the order of 5 to 20 nm, are also known. To ensure that the structure fabricated in a photolithography apparatus using a photomask has the desired shape on the wafer, and thus that the semiconductor component fabricated in this way achieves the desired function, defects need to be repaired, such as... Figure 1 Defect D is shown, otherwise other defects. In this example, the mesh must be removed in a targeted manner, such as by particle beam-induced etching.

[0118] Figure 2 A particle beam-induced processing apparatus 200 for defects in microlithography masks is shown, for example... Figure 1 Defect D in photomask 100. Figure 2 A cross-section of some components of device 200 is schematically shown. Device 200 can be used for particle beam-induced repair of defects D in photomask 100, in this case, etching. In addition, device 200 can also be used to image the photomask (particularly the structured coating 104 of mask 100 and defect D) before, during and after the repair process.

[0119] Figure 2 The device 200 shown represents an improved scanning electron microscope 200. In this case, a particle beam 202 in the form of an electron beam 202 is used to repair the defect D. The advantage of using an electron beam 202 as an activating particle beam is that the electron beam 202 does not substantially damage or can only slightly damage the photomask 100, especially its substrate 102.

[0120] The laser beam used to activate the local particle beam induced repair process of the photomask 100 can replace the electron beam 202 or be used as an adjunct to the electron beam 202 in the embodiments. Figure 2 (Not shown in the image). Furthermore, instead of electron beams and / or laser beams, ion beams, atomic beams, and / or molecular beams can be used to activate localized chemical reactions (…). Figure 2 (Not shown in the image).

[0121] The device 200 is generally arranged in a vacuum housing 204, which is maintained at a certain pressure by a vacuum pump 206.

[0122] As an example, device 200 is a repair tool for microlithography photomasks, such as photomasks used in DUV or EUV lithography equipment.

[0123] The photomask 100 to be processed is arranged on the sample stage 208. As an example, the sample stage 208 is configured to position the photomask 100 with an accuracy of a few nanometers in three spatial directions and, for example, additionally, on three rotational axes.

[0124] Device 200 includes an electron column 210. Electron column 210 includes an electron source 212 for providing an activation electron beam 202. Furthermore, electron column 210 includes electron or beam optics 214. Electron source 212 generates electron beam 202, and electron or beam optics 214 focuses electron beam 202 and directs electron beam 1028 to a mask 100 at the output of column 210. Electron column 210 also includes a deflection unit 216 (scanning unit 216) configured to guide (scan) electron beam 202 on the surface of photomask 100. Instead of the deflection unit 216 (scanning unit 216) disposed within column 210, a deflection unit (scanning unit) (not shown) disposed outside column 210 may also be used.

[0125] Device 200 also includes detector 218 for detecting secondary electrons and / or backscattered electrons generated by the incident electron beam 202 at photomask 200. As an example, as shown, detector 218 is arranged in a ring around electron beam 202 within electron column 210. As an alternative and / or addition to detector 218, device 200 may also contain other / additional detectors for detecting secondary electrons and / or backscattered electrons. Figure 2 (Not shown in the image).

[0126] In addition, the device 200 may include one or more scanning probe microscopes (e.g., atomic force microscopes) that can be used to analyze defects D in the photomask 100. Figure 2 (Not shown in the image).

[0127] The apparatus 200 also includes a gas supply unit 220 for supplying process gases to the surface of the photomask 100. As an example, the gas supply unit 220 includes a valve 222 and a gas line 224. An electron beam 202, guided by the electron column 210 to a location on the surface of the photomask 100, can be combined with the process gas to perform electron beam induced process (EBIP), which is supplied externally by the gas supply unit 220 via the valve 222 and the gas line 224. Specifically, the process includes material deposition and / or etching.

[0128] The device 200 also includes a computing device 226, such as a computer, having a control device 228 and a determining device 230. Figure 2 In the example, computing device 226 is arranged outside vacuum housing 204.

[0129] The computing device 226 (especially the control device 228) is used to control the device 200. Specifically, the computing device 226 (especially the control device 228) controls the supply of the electron beam 202 by driving the electron column 210. Specifically, the computing device 226 (especially the control device 228) controls the guidance of the electron beam 202 on the surface of the photomask 100 by driving the scanning unit 216. Furthermore, the computing device 226 controls the supply of process gases by driving the gas supply unit 220.

[0130] Furthermore, the computing device 226 receives measurement data from the detector 218 and / or other detectors of the device 200, and generates an image from the measurement data, which can be displayed on a monitor (not shown). Additionally, the image generated from the measurement data can be stored in a memory unit (not shown) of the computing device 226.

[0131] To inspect photomask 100 and, in particular, its structured coating 104, device 200 is configured to, specifically, capture photomask 100 based on measurement data from detector 218 and / or other detectors of device 200. Figure 1 Image 300 is a detail of image 300 or photomask 100. As an example, the spatial resolution of image 300 is on the order of a few nanometers.

[0132] The computing device 226 (particularly the determining device 230) is configured to identify defects D in the recorded image 300. Figure 1 This is used to locate the defect and determine the geometry 302 (repair shape 302) of the defect D. The determined geometry 302 (i.e., repair shape 302) of the defect D is, for example, a two-dimensional geometry.

[0133] Figures 3 to 7 It clarifies the use of the first aspect for... Figure 1 Another example of a particle beam-induced treatment method for defects D' in the structured coating 104 of the photomask 100. As an example, the method uses... Figure 2 The device shown is used for this purpose.

[0134] As mentioned above Figure 1 and Figure 2 As described above, in step S1 of the method according to the first aspect, the photomask 100 is recorded. Figure 1 At least a portion of the image 300.

[0135] As mentioned above Figure 1 and Figure 2 In step S2 of the method according to the first aspect, the geometry of defect D' is determined as repair shape 320' in image 300. Figure 3 Some details of defect D' are shown.

[0136] In step S3 of the method according to the first aspect, the repair shape 302' is determined according to the first grid 306. Figure 3 ) is subdivided into multiple n pixels 304. Specifically, the computing device 226 ( Figure 2 (More specifically, the determining device 230) is configured to determine the repair shape 302' according to the first grid 306. Figure 3 Divide it into n pixels (304).

[0137] exist Figure 3 In the figure, the three pixels 304 of the repair shape 302' are provided with reference numerals in an exemplary manner. Specifically, the pixels 304 are arranged in columns (X direction) and rows (Y direction, perpendicular to the X direction). Each pixel 304 has a center M. Figure 3 The three pixels provided are provided with reference numerals in an exemplary manner. Figure 3 Only a very small detail of the repair shape 302' is shown. As an example, the entire repair shape 302' comprises 1 million pixels 304 (n = 1,000,000). As an example, the side length 'a' of pixel 304 is a few nanometers, for example, 1.5 nm. As an example, pixel 304 has an area of ​​1.5 nm × 1.5 nm. During the repair process, the electron beam 202 ( Figure 2 The electron beam 202 is directed multiple times to the center M of each pixel 304 via the scanning unit 216. In particular, during the process of this method, the maximum intensity of, for example, a Gaussian intensity distribution of the electron beam 202 is directed multiple times to the respective center M of each pixel 304.

[0138] Figure 4 It shows Figure 3 An enlarged view of the five pixels 304 of the repair shape 302' shown. Each pixel 304 has a square shape with a side length of a. Therefore, the distance between the centers M of two adjacent pixels is also equal to a. The circle with diameter c indicated by reference numeral 308 represents the electron beam 202 ( Figure 2 The incident region is located on the surface of the photomask 100. In this case, the diameter c corresponds to the side length a. For example, the electron beam 202 has a radially symmetrical Gaussian intensity distribution. Specifically, the electron beam 202 is directed to the center M of the incident region 308 or pixel 304 such that the maximum value of its intensity distribution is incident on the center M within the technically possible range. As an example, the incident region 308 may correspond to the half-width at half-maximum (WHM) of the intensity distribution of the electron beam 202. However, the incident region 308 may also correspond to any other intensity decreasing from the maximum value of the intensity distribution of the electron beam 202.

[0139] In step S4 of the method according to the first aspect, the shape 302' is repaired. Figure 3The defect D' (whose geometry is repair shape 302') is scanned by an electron beam 202 while a process gas is provided, so that the defect D' is scanned by a computing device 226. Figure 2 More specifically, it is processed and corrected under the control of control device 228. In this case, the activation electron beam 202 is continuously directed to each of the n pixels 304 of the repair shape 302'. The electron beam 202 resides at each of the n pixels 304 of the repair shape 302' for a predetermined residence time. In this case, the electron beam 202 activates a chemical reaction of the process gas at each of the n pixels 304 of the repair shape 302'. As an example, the process gas includes an etching gas. As an example, the chemical reaction results in the appearance of volatile reaction products generated with the material of the defect D' to be etched, which are at least partially gaseous at room temperature and can be removed using a pump system (not shown).

[0140] After the electron beam 202 has been directed to each of the n pixels 304 of the repair shape 302 once (step e1), the process is repeated over g repetition cycles.

[0141] In step S5 of the method according to the first aspect, according to the second grid 306' ( Figure 5 The repaired shape 302' is subdivided into m pixels 304'. In particular, the computing device 226 (more particularly the determining device 230) is configured to calculate the second grid from the first grid.

[0142] Step S5 can be performed before or after step S4.

[0143] Figure 5 It shows the relationship with Figure 3 The same repaired shape 302' details. However, with Figure 3 Conversely, repair shape 302' according to Figure 5 The second grid 306' is subdivided into m pixels 304'. Specifically, based on the sub-pixel displacement from the first grid 306 ( Figure 3 ) Calculate the second grid 306'. Specifically, in order to form the second grid 306' ( Figure 5 ), first grid 306 ( Figure 3 )exist Figure 3 and Figure 4 The length b is shifted to the right, corresponding to the pixel length a in the example shown. In the example shown, the second grid 306' has the same level of refinement as the first grid 306. Specifically, according to pixel 304' of the second grid 306' ( Figure 5 ) has the same characteristics as according to the first grid 306 ( Figure 3 The pixels 304 have the same size (pixel side length a).

[0144] Then, in step S6 of the method according to the first aspect, the particle beam 202 is directed to each of the m pixels 304' of the repair shape 302' according to the second grid 306' in a manner similar to that for the n pixels according to the first grid 306.

[0145] In step S7 of the method according to the first aspect, step S5 is performed on one or more additional grids 306″ that are different from the first grid and the second grids 306, 306'. As an example, Figure 6 The third grid 306″ is shown, which passes through the second grid 306'. Figure 5 and 6 The upward displacement of half a pixel length 'a' is generated. That is, the repair shape 302' is subdivided into multiple 'l' pixels 304' according to the third grid 306″. In the example shown, pixel 304″ has the same characteristics as pixel 304( Figure 3 ) and pixel 304' ( Figure 5 The same size, i.e., side length a. In other examples, the second and / or third grids 306', 306″ can also be finer than the first grid 306. In this case, pixels 304' and / or 304″ will have a smaller side length than pixel 304.

[0146] In step S8 of the method according to the first aspect, step S6 is performed on one or more additional grids 306″. As an example, in repairing shape 302', one pixel 304″ of the third grid 306″ is used. Figure 6 Each of the points in the array provides an activation particle beam 202 and a process gas.

[0147] exist Figure 7 In the diagram, the centers M, M', and M″ of pixels 304, 304', and 304” are depicted in a superimposed manner. During steps S4, S6, and S8, the electron beam 202 is repeatedly directed to each center (incident point) M, M', and M″. Figure 7 As shown, the edge region 310 of defect D' can be scanned better by the second and third grids (center M' and M″) than by applying only the first grid (center M).

[0148] In the embodiment, steps S4, S6 and S8 are repeated in j repetition cycles, such that the total number of repetition cycles for each of the n, m and l pixels 304, 304', 304″ is, for example, (j×g) or (j×h).

[0149] In order to (completely) remove coating 104 from the area of ​​defect D' Figure 1Each pixel 304, 304', 304″ requires, for example, a total of j (or j×g or j×h) of 100, 1000, 10000, 100000 or 1 million repetition cycles.

[0150] Figures 9 to 12 The second aspect clarifies the use of... Figure 1 Another example of a particle beam-induced treatment method for the defect D' of the structured coating 104 of the photomask 100. As an example, the method uses... Figure 2 The device shown is used for this purpose. Figure 9 A first embodiment of the method according to the second aspect is shown.

[0151] As mentioned above Figure 1 and Figure 2 As stated, in step S1 of the method according to the second aspect, the photomask 100 is recorded. Figure 1 At least a portion of the image 300.

[0152] As mentioned above Figure 1 and Figure 2 In step S2' of the method according to the second aspect, the geometry of the defect E is determined as a repair shape 402 in the image 300. In step S2' of the method according to the second aspect, the geometry is specifically determined as a vector form based on vector representation. Figure 9 Another example of defect E' is shown.

[0153] In step S3' of the method according to the second aspect, at least along the stretch portion 404 of the repair shape 402 ( Figure 9 ) provides process gas. In addition, it activates particle beam 202 ( Figure 2 The photomask 100 is guided along the stretching section 404, while the photomask 100 is activated on the stretching section 404. Figure 1 Chemical reactions between materials and process gases.

[0154] According to the method of the second aspect, the stretching portion 404 according to the first embodiment ( Figure 9 The particle beam 202 extends linearly from edge 406 of the repair shape 402 to the opposite edge 408 of the repair shape 402. Specifically, the particle beam 202 is guided linearly along the first stretch 404 from a first starting point 410 at the first edge 406 to a first ending point 412 at the second edge 408 without stopping. Specifically, the first stretch 404 is the shortest path between the first starting point 410 and the first ending point 412. The length of the first stretch 404 is indicated by reference numeral l. A chemical reaction between the process gas and the mask material is initiated throughout the stretch 404 to achieve the purpose of repairing defect D' during the continuous guidance of the particle beam 202 along the stretch 404.

[0155] Subsequently, the particle beam 202 is offset in a direction R perpendicular to the first stretching portion 404 at the second edge 412 to a new second starting point 414 at the second edge 408. Then, the particle beam 202 is guided from the second starting point 414 to a second ending point 418 at the first edge 406 along the second stretching portion 416. For example, the second stretching portion 416 extends parallel to the first stretching portion 404.

[0156] In a corresponding manner, the entire repair shape can be achieved by particle beam 202 in multiple individual stretching sections 404, 416, 420, 422 (only four of which are in Figure 9 The particle beam 202 is swept across the entire individual stretch sections 404, 416, 420, 422 (shown and provided with reference numerals). The activated particle beam 202 is guided at a velocity greater than zero and does not stop (dwell), particularly along the entire individual stretch sections 404, 416, 420, 422 for each individual stretch section 404, 416, 420, 422.

[0157] Figure 10 A second embodiment of the method according to the second aspect is shown.

[0158] According to the second embodiment, the first stretching portion 424 extends along the outer edge 426 and / or adjacent to the outer edge 426 of the repair shape 402'. Specifically, the first stretching portion 424 extends from a first starting point 428 adjacent to the outer edge 426 along the entire outer edge 426 to a first ending point 430 adjacent to the outer edge 426. Specifically, the first ending point is arranged adjacent to the first starting point 428. Therefore, the particle beam 202 is guided along the first stretching portion 424 from the first starting point 428 to the first ending point 430 without stopping. During the guidance of the particle beam 202 along the first stretching portion 424, a chemical reaction between the process gas and the mask material is initiated throughout the first stretching portion 424.

[0159] Subsequently, the particle beam 202 is radially offset inward from the outer edge 426 in the repair shape 402' to the second starting point 432. Then, the particle beam 202 is guided from the second starting point 432 along the second stretching portion 434 to the second ending point 436 on a parallel curve that extends along a parallel curve parallel to the first stretching portion 424.

[0160] In a corresponding manner, the entire repair shape 402' can be formed by particle beam 202 in multiple individual stretching portions 424, 434, 438 (in Figure 10Only three (with reference numerals) are shown in the figure, sweeping along a parallel curve parallel to the outer edge 426. Particularly applicable to each of the individual stretches 424, 434, 438 is that the activated particle beam 202 is guided at a velocity greater than zero along the entire individual stretch 424, 434, 438 without stopping (dwelling).

[0161] As a result of this beam guiding pattern, a suitable particle beam dose for the electron beam 202 can be obtained, particularly at the edge region or outer edge 426 of the defect E″.

[0162] Figure 11 A third embodiment of the method according to the second aspect is shown.

[0163] According to the third embodiment, the repair shape 402' is subdivided into at least a first sub-repair shape and second sub-repair shapes 440, 442. In the illustrated example, the first sub-repair shape 440 is the interior region of the repair shape 402'. Furthermore, the second sub-repair shape 442 completely surrounds the interior of the first sub-repair shape 440.

[0164] Within the first sub-repair shape 440, a corresponding individual stretch portion 444 extends linearly from edge 446 to the opposite edge 448 of the first sub-repair shape 440 (similar to...). Figure 9 (As shown in the diagram). Furthermore, a first individual stretch portion 450 within the second sub-repair shape 442 extends adjacent to the outer edge 452 of the second sub-repair shape 442. Additionally, further individual stretch portions 454 and 456 extend within the second sub-repair shape 442 along a parallel curve parallel to the outer edge 452 of the second sub-repair shape 442.

[0165] In an embodiment, in the method according to the second aspect, electron beam 202 ( Figure 2 ) along the corresponding stretching part ( Figure 9 The numbers 404, 416, 420, and 422 are included. Figure 10 424, 434, 438; Figure 11 The speed at which pixels 444, 450, 454, and 456 are guided can be very high, so that the exposure time of the entire repair shape 402 and 402' reaches that of a single pixel 304 according to the method of the first aspect. Figure 3 The residence time on electron beam 202 is on the order of magnitude. As an example, the residence time on electron beam 202 is on the order of magnitude. Figure 2 ) along the corresponding stretching section ( Figure 9-11The guided velocity is greater than or equal to 1 to 100 m / s. As an example, the entire restoration shape 402, 402' is completely swept once within a time period of less than or equal to 50 to 200 ns. As an example, the particle beam 202 used for this purpose is provided with a beam current greater than or equal to 0.0001 to 0.01 μA. However, in other examples, the beam current of particle beam 202 may also take other values ​​(e.g., smaller values ​​of a few pA). Due to this quasi-simultaneous exposure of the entire restoration shape 402, 402', a particularly uniform particle beam dose can be obtained across the entire restoration shape 402, 402', thus achieving optimal performance on photomask 100 ( Figure 1 Better and more accurate repair of defects E' and E″. Figure 9-11 ).

[0166] Although the invention has been described based on exemplary embodiments, it can still be modified in a variety of ways.

[0167] List of reference numerals

[0168] 100 photomask

[0169] 102 substrate

[0170] 104 Coating

[0171] 200 devices

[0172] 202 Particle Beams

[0173] 204 vacuum enclosure

[0174] 206 Vacuum Pump

[0175] 208 Sample Stage

[0176] 210 electron column

[0177] 212 Electronic Source

[0178] 214 Electron or beam optics

[0179] 216 scanning units

[0180] 218 detector

[0181] 220 Gas Supply Unit

[0182] 222 valve

[0183] 224 Gas Pipeline

[0184] 226 Computing devices

[0185] 228 Control device

[0186] 230 Determining Device

[0187] 300 images

[0188] 302, 302' Shape Repair

[0189] 304, 304', 304″ pixels

[0190] 306, 306', 306″ grid

[0191] 308 Incident Area

[0192] 310 Edge Area

[0193] 402 Shape Repair

[0194] 404 tensile section

[0195] 406 Edge

[0196] 408 Edge

[0197] 410 Starting Point

[0198] 412 The finish line

[0199] 414 Starting Point

[0200] 416 Tension section

[0201] 418 End Point

[0202] 420 Tension section

[0203] 422 Tension section

[0204] 424 Tension section

[0205] 426 Edge

[0206] 428 Starting Point

[0207] 430 Finish Line

[0208] 432 Starting Point

[0209] 434 Tension section

[0210] 436 Finish Line

[0211] 438 Tension section

[0212] 440 Sub-shape Repair

[0213] 442 Sub-shape repair

[0214] 444 Tension section

[0215] 446 Edge

[0216] 448 Edge

[0217] 450 stretch section

[0218] 452 Edge

[0219] 454 Tension section

[0220] 456 Tension section

[0221] a length

[0222] b Length

[0223] B. Structural Dimensions

[0224] c diameter

[0225] D, D' defects

[0226] E, E', E″ defects

[0227] l length

[0228] M, M', M″ Center

[0229] R direction

[0230] S1-S8 Method Steps

[0231] S1'–S8' Method Steps

[0232] X direction

[0233] Y direction

Claims

1. A particle beam-induced treatment method for defects (D, D') in a microlithography mask (100), comprising the following steps: a1) Provides an image (300) of at least a portion of the photomask (100) (S1). b1) Determine (S2) the geometry of the defects (D, D') in the image (300) as the repair shape (302, 302'). c1) Subdivide (S3) the repaired shape (302, 302') into n pixels (304) according to the first grid (306). d1) The repaired shape is subdivided (S5) into m pixels (304') according to the second grid (306'), the second grid (306') being generated from the sub-pixel displacement of the first grid (306). e1) Provide (S4) an activation particle beam (202) and process gas at each of the n pixels (304) of the repaired shape (302, 302') according to the first grid (306), and f1) Provide (S6) the activation particle beam (202) and the process gas at each of the m pixels (304') of the repair shape (302, 302') according to the second grid (306').

2. The method of claim 1, wherein, The subpixel displacement is the displacement of the first grid (306) by the subpixel size (b).

3. The method of claim 2, wherein, The subpixel displacement is the lateral displacement of the first grid (306) by the subpixel size (b).

4. The method according to any one of claims 1 to 3, comprising the following steps: subdividing (S7) the repair shape (302') into l i pixels (304'') according to at least one further grid (306''), wherein the i-th further grid (306'') is subdivided into l i pixels (304'') and the at least one further grid (306'') is generated from a subpixel displacement of the first grid (306), the second grid (306'), or any other one of the at least one further grid (306''). providing (S8) the activated particle beam (202) and a process gas at each of the pixels (304''). i providing (S8) the activated particle beam (202) and a process gas at each of the pixels (304'').

5. The method of any one of claims 1 to 3, wherein, Step e1) is repeated for g repetition cycles before step f1) and / or step f1 is repeated for h repetition cycles.

6. The method of any one of claims 1 to 3, wherein, Steps e1 and f1 are repeated for j repetition cycles.

7. The method of claim 4, wherein, In each case, the activated particle beam (202) is provided continuously in a sequence at the n pixels (304), the m pixels (304') and / or the l i pixels (304'') of the repair shape (302'), in which sequence, by means of the chemical reaction activated by the activated particle beam (202), a uniform achievement of the consumption of the process gas on the repair shape (302') is achieved.

Images