The present invention relates to a processing arrangement, a device for particle beam-induced processing of a sample, a method for processing a sample by a particle beam-induced processing process, a flushing plate and the use of a flushing plate in a processing arrangement.

The content of the priority application DE 10 2020 120 940.1 is incorporated by reference in its entirety.

Microlithography is used for producing microstructured components, such as for example integrated circuits. The microlithography process is performed with a lithography apparatus, which has an illumination system and a projection system. The image of a mask (reticle) illuminated by means of the illumination system is in this case projected by means of the projection system onto a substrate, for example a silicon wafer, which is coated with a light-sensitive layer (photoresist) and arranged in the image plane of the projection system, in order to transfer the mask structure to the light-sensitive coating of the substrate.

The mask or lithography mask is used for a large number of exposures, which is why it is extremely important that it is free from defects. A correspondingly high effort is therefore made to examine lithography masks for defects and to repair defects that are found. Defects in the lithography mask can be on the order of a few nanometers. In order to repair such defects, devices which offer a very high spatial resolution for the repair processes are necessary.

Devices that activate local etching or depositing processes on the basis of particle beam-induced processes are suitable for this purpose.

EP 1 587 128 Bl discloses such a device which uses a beam of charged particles, in particular an electron beam of an electron microscope, to trigger the chemical processes. If charged particles are used, the sample can become charged if it is not or only poorly conductive. This can lead to uncontrolled beam deflection, which limits the process resolution that can be achieved. It is therefore proposed to arrange a shielding element very close to the processing position, so that the charging of the sample is minimized and the process resolution and control are improved.

For the desired repair processes, a process gas must be brought up to the processing position. Typical process gases may already be very reactive in their basic state; in addition, further highly reactive atoms or molecules, which may for example also attack components of the particle beam device and/or can settle on them, can arise during the processing processes. This can lead to shorter service intervals for the respective particle beam device.

The processing speed that can be achieved with such a particle beam-induced process strongly depends, among other things, on the process gas pressure at the processing position. For a high processing speed, a high process gas pressure at the processing position is desirable. This can be achieved for example by the process gas being supplied through the exit opening of the particle beam, the process gas then being able to flow unhindered into the particle beam device. On the other hand, from the point of view of the longevity of the components used, the aim is to achieve the lowest possible gas flow of the process gas from the processing position into the particle beam device.

DE 102 08 043 Al discloses a material processing system that can be used in methods for material processing by material deposition from gases, such as CVD (Chemical Vapor Deposition), or material removal by supplying reaction gases. Here, the gas reaction that leads to material deposition or material removal is triggered in particular by an energy beam which is directed onto an area of the workpiece to be processed.

Against this background, an object of the present invention is to improve the processing of a sample in a particle beam -induced processing process.

According to a first aspect, a processing arrangement with a device for providing a focused particle beam, a sample which can be processed with the aid of the particle beam and a process gas, and a flushing plate is proposed. The flushing plate comprises a first section, which has a passage opening for the particle beam to pass through to a processing area of the sample, the first section defining with the sample a first gap, which is set up for supplying process gas to the processing area, and a second section, which defines with the sample a second gap, which is set up for supplying process gas to the first gap, and a third section, which defines with the sample a third gap, which at least partially surrounds the second section. The first gap and the third gap are dimensioned smaller than the second gap.

This processing arrangement has the advantage that the process gas can be supplied via the second gap at high pressure to the first gap and thereby to the processing area. On the other hand, a leakage rate of the process gas through the passage opening against the particle beam direction can be controlled very precisely via the size of the first gap. In this way, a high processing speed can be achieved in the device for providing the focused particle beam, with at the same time a low process gas pressure.

The device for providing the focused particle beam is for example an electron column, which can provide an electron beam with an energy in the range of 10 eV - 10 keV and a current in the range of 1 pA - 1 pA. It may however also be an ion source, which provides an ion beam. The focused particle beam is preferably focused on the sample surface, for example an irradiation area with a diameter in the range of 1 nm - 100 nm being achieved.

The sample is for example a lithography mask with a structure size in the range of 10 nm - 10 gm. It may be for example a transmissive lithography mask for DUV lithography (DIT "deep ultra violet", working light wavelengths in the range of 30 - 250 nm) or a reflective lithography mask for EUV lithography (EIT "extreme ultra violet", working light wavelengths in the range of 1 - 30 nm). The processing processes that are carried out here comprise for example etching processes, in which a material is locally removed from the surface of the sample, depositing processes, in which a material is locally applied to the surface of the sample, and/or similar locally activated processes, such as the forming of a passivation layer or the compacting of a layer. Coming into consideration in particular as process gases that are suitable for depositing material or for growing raised structures are alkyl compounds of main group elements, metals or transition elements. Examples of this are cyclopentadienyl trimethyl platinum CpPtMes (Me = CH4), methylcyclopentadienyl trimethyl platinum MeCpPtMes, tetramethyl tin SnMe4, trimethyl gallium GaMes, ferrocene CpsFe, bisaryl chromium ArsCr, and/or carbonyl compounds of main group elements, metals or transition elements, such as for example chromium hexacarbonyl Cr(CO)e, molybdenum hexacarbonyl Mo(CO)@, tungsten hexacarbonyl W(CO)@, dicobalt octacarbonyl Co2(CO)s, triruthenium dodecacarbonyl Ru3(CO)i2, iron pentacarbonyl Fe(CO)5, and/or alkoxide compounds of main group elements, metals or transition elements, such as for example tetraethyl orthosilicate Si(OC2H5)4, tetraisopropoxy titanium TiCOCsH?^, and/or halide compounds of main group elements, metals or transition elements, such as for example tungsten hexafluoride WF@, tungsten hexachloride WCk, titanium tetrachloride TiCU, boron trifluoride BF3, silicon tetrachloride SiC14, and/or complexes with main group elements, metals or transition elements, such as for example copper bis(hexafluoroacetylacetonate) Cu(C5F @1102)2, dimethyl gold trifluoroacetyl acetonate Me2Au(C5FsH4O2), and/or organic compounds such as carbon monoxide CO, carbon dioxide CO2, aliphatic and/or aromatic hydrocarbons, and more of the same.

Coming into consideration for example as process gases that are suitable for etching material are: xenon difluoride XeF2, xenon dichloride XeCh, xenon tetrachloride XeC14, steam H2O, heavy water D2O, oxygen O2, ozone O3, ammonia NH3, nitrosyl chloride NOCI and/or one of the following halide compounds: XNO, XONO2, X2O, XO2, X2O2, X2O4, X2O6, where X is a halide. Further process gases for etching material are specified in the applicant's US patent application No. 13/0 103 281.

Additional gases, which can for example be added in proportions to the process gas in order to better control the processing process, comprise 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 CI2, hydrogen chloride HC1, hydrogen fluoride HF, iodine I2, hydrogen iodide HI, bromine Br2, hydrogen bromide HBr, phosphorus trichloride PCI3, phosphorus pentachloride PCI5, 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. By way of example, these additional gases can find more use for etching processes, as buffer gases, passivation means and the like.

The flushing plate is designed for example as an end plate of the device for providing the focused particle beam and closes it off in the direction of the sample. As a result, in particular an interior of the device, which contains for example beam-guiding and/or beam-shaping elements such as lenses or diaphragms and detectors for detecting backscattered particles and/or secondary particles, can be closed comparatively tightly with respect to the outside, in particular with respect to the processing area. Only the passage opening for the particle beam remains free.

For example, due to the viscosity of fluids and the adhesion of fluid molecules to delimiting walls, there is a very strong dependence of the volume flow of a fluid through an opening on the dimensions of the opening. For a laminar flow through a round opening, for example, there is a dependence of the volume flow on the opening radius to the fourth power (Hagen-Poisseuille's law). A similar dependence also applies to the gas flow through narrow gaps. Therefore, a gas flow through a gap can be influenced by reducing the gap size. In addition, the gas flow is reciprocally dependent on the length of the flow path, so that a lower gas flow occurs over a longer path.

On its side facing the sample, which is also referred to below as the underside, the flushing plate has a structuring which, in combination with the sample arranged opposite, conducts the process gas in a targeted manner to the processing area on the sample. It can be said that the underside of the flushing plate has at least two different levels. The first section defines a first level and the second section defines a second level. The third section may be on the same level as the first section, but it may also define a third level. The first section extends for example in a plane which runs perpendicular to the particle beam. The first level is for example at a greatest distance from the upper side of the flushing plate opposite from the underside and the second level is at a smaller distance from the upper side. The third level is preferably at an intermediate distance from the upper side. If the flushing plate is arranged opposite the sample, this structuring results in a first gap in the first section, a second gap in the second section and a third gap in the third section, the first gap and the third gap being dimensioned smaller than the second gap.

The first section, which with the sample forms the first gap, has for example two edges, an outer edge and an inner edge. The outer edge forms the transition from the first section to a section surrounding the first section, for example to the second or the third section. The inner edge forms the edge of the passage opening in the first section. Process gas that is supplied to the first gap has to flow through the first gap from a position at the outer edge to a position at the inner edge in order to reach the processing area. The shortest connection between two points is decisive for the resulting volume flow. The length of the flow path between two points depends on the geometry of the outer edge and the inner edge as well as the relative arrangement of the edges to one another. Both edges preferably have for example a circular geometry and the inner edge is arranged centrally in the first section, that is to say the passage opening forms a central hole in the first section. The first gap then has an annular geometry, a width of the ring in the radial direction preferably lying in a range of 1 - 100 pm. However, other geometries are also possible, for example according to a regular polygon, such as a triangle or a square or the like, or else star-shaped geometries and so on. A gas flow of the process gas through the first gap can be controlled by the design of the geometry of the outer edge and the inner edge on the one hand and by the gap size of the first gap on the other hand. It can also be said that the first section has the passage opening and a projection or collar surrounding the passage opening.

The second gap, which is formed by the second section with the opposite sample, serves in particular to conduct the process gas to the first gap. The second gap can extend over a length that is great in comparison with the first gap, for example in the range of centimeters. Due to the larger gap size of the second gap in comparison with the first gap, a relatively high gas flow can nevertheless be achieved along the second gap.

The third gap, which is formed by the third section with the opposite sample, serves in particular to seal the second gap with respect to the outside, for which the third section at least partially surrounds the second section. This is understood as meaning for example that the third section at least partially surrounds the second section in the circumferential direction in a plane that is defined by the second section. "Sealing" is understood here as meaning that a flow resistance of a flow along the third gap is increased in comparison with a flow resistance of a flow along the second gap. A gas flow along the third gap can thus be reduced. As described above, the gas flow depends greatly on the size of the gap in the third gap and the length of the flow path. The third section is preferably designed in such a way that a shortest flow path from the second gap to the outside, out of an intermediate space between the sample and the flushing plate, is at least one centimeter.

In embodiments, the first section is designed as described above in such a way that the first gap extends annularly around the processing area and the second and third sections are each designed annularly. In this embodiment, the ring of the third section has for example a width which is at least ten times, preferably a hundred times, more preferably a thousand times, the width of the ring of the first section. This contributes to the fact that a gas flow from the second gap through the first gap to the processing area is clearly preferred over a gas flow from the second gap through the third gap into a space surrounding the flushing plate and the sample.

This flow-directing effect can also in particular be achieved even if the first gap is smaller than the third gap by the width of the third section (and thus the minimum flow path through the third gap to the outside) being chosen to be correspondingly great. If the first gap and the third gap are of the same size, a width of the third section that is for example ten times that of the first section can achieve a sufficient flow- directing effect. If the third gap is twice the size of the first gap, a width of the third section that is for example a hundred times that of the first section can produce the advantageous flow- directing effect. It should be noted that these specific examples are only used for clarification. When the flushing plate is in operation, the width ratio of the third section to the first section that develops a sufficient flow-directing effect will depend both on the gases to be conducted, in particular their molecular size and tendency to adsorb on the surface of the sample and/or the underside of the flushing plate, as well as on the specific dimensions of the gaps. If the sections have a geometry other than annular, the ratio of the widths is replaced by the ratio of the respective shortest connections from an inner edge of the respective section to an outer edge of the respective section.

According to one embodiment of the processing arrangement, the third section completely surrounds the second section and is designed such that a length of a shortest connection from the second gap through the third gap to the outside is at least ten times, preferably a hundred times, more preferably a thousand times, a length of a shortest connection from the second gap through the first gap to the processing area.

According to one embodiment of the processing arrangement, the first gap has a size in the range of 1 pm - 50 pm, preferably 3 pm - 20 pm, more preferably 5 pm - 10 pm.

The first gap preferably has a constant size or an essentially constant size in the entire first section. "Essentially constant" is understood as meaning for example that there may be small differences, caused for example by a surface structure on the sample, or differences of up to 10%, 20%, 30%, or even up to 50%, on the basis of a nominal size. A respective section preferably forms an essentially flat surface. By arranging the flushing plate plane-parallel to the sample, it can be achieved that the first gap has an essentially constant size.

It may alternatively also be provided that the first section has a structure, so that the first gap varies along the first section. For example, the first gap may taper from the outer edge of the first section to the inner edge of the first section. For this purpose, the first section may have for example a conical shape, the passage opening being arranged centrally.

According to a further embodiment of the processing arrangement, the first section has a geometry such that a ratio of a smallest distance from an outer edge of the first section to an edge of the passage opening in the first section to a diameter of the passage opening is between 0.25 and 4 . The edge of the passage opening in the first section may also be referred to as the inner edge. The specified relation preferably applies to every point on the outer edge. The shortest distance is also referred to below as the width of the first section. Process gas that flows through the first gap to the processing area flows with a high probability along a route that corresponds to this shortest distance.

If the passage opening is circular, the diameter is a clear geometric variable. If the passage opening is not circular, but for example elliptical, the diameter comprises not only a single value, but a set of values delimited by the two main axes of the ellipse.

With a predetermined size of the passage opening, the width of the first section is thus determined. With a diameter of 50 gm, the shortest distance is for example in the range of 12.5 gm to 200 gm.

If the outer edge is circular and the passage opening is circular and is arranged coaxially in the first section, then all points of the outer edge have the same shortest distance. It can then also be said that the first section has a constant width.

The width of the first section preferably lies in a range of 1 gm - 100 gm, preferably 3 pm - 50 pm, more preferably 5 pm - 30 pm, even more preferably 5 pm -10 pm.

In embodiments, the flushing plate has a number of first sections arranged at a distance from one another, each of which has a passage opening for the particle beam and which each define with the sample a first gap. Different first sections can have a different geometry, in particular different sized passage openings can be provided.

According to a further embodiment of the processing arrangement, the passage opening has a diameter of at most 200 pm, preferably at most 100 pm, more preferably at most 50 pm, more preferably at most 30 pm.

The larger the passage opening, the larger the processing area can be. On the other hand, a larger passage opening leads to an increased gas flow from the processing area into the device for providing the focused particle beam, that is for example into the electron column. According to a further embodiment of the processing arrangement, the second gap has a size in the range of 30 pm - 1 mm.

This allows a gas flow that is several orders of magnitude higher along the second gap than along the first. In this way, the process gas can be conducted efficiently along the second gap to the first gap.

In the case of a plane -parallel arrangement of the flushing plate in relation to the sample, the size for the second gap is given for example by the sum of the size of the first gap together with the difference in level between the first section and the second section.

According to a further embodiment of the processing arrangement, the second gap is set up for conducting process gas along a distance of at least 300 pm, preferably at least 1 mm, preferably at least 3 mm, more preferably at least 1 cm.

It can also be said that the second gap forms a channel along which the process gas flows. The longer the channel, the further away a process gas connection can be from the first gap, which may be advantageous for reasons of space.

According to a further embodiment of the processing arrangement, the second section surrounds the first section at least partially, preferably at least from two sides, preferably at least from three sides, more preferably completely.

Enclosing means for example that a path which runs radially outward from a point in the first section crosses the second section.

In preferred embodiments, the second section directly adjoins the first section. As an alternative to this, the third section or a transitional section or the like may be arranged between the first section and the second section. A gap defined between such a transitional section and the sample has a size which lies between the size of the first gap and the size of the second gap. In a further embodiment of the processing arrangement, the third gap has a size in the range of 5 pm - 100 pm, preferably 5 pm - 50 pm, preferably 10 pm - 50 pm, more preferably 10 pm - 30 pm.

In preferred embodiments, the third gap is as large as the first gap.

The third section preferably completely encloses the second section and the first section. This means in particular that each path which originates in the first section or in the second section and leads to the outside from an intermediate space between the flushing plate and the sample crosses the third section.

The third section has in particular an extent in the range of a few millimeters. Because of this size in combination with the small gap size, a very low gas flow through the third gap can be achieved, and thus a good seal of the second gap with respect to the outside.

For example, the flushing plate is circular and has a diameter of 1 cm. The first section is for example circular (the outer edge forms a circle) and has a diameter of 100 pm.

According to a further embodiment of the processing arrangement, the second gap forms an inflow channel and the flushing plate has at least one supply channel, which runs through the flushing plate and is set up for conducting process gas to the inflow channel.

In this embodiment, the process gas is conducted through the flushing plate to the inflow channel. A gas connection for the process gas can thus be formed on the upper side of the flushing plate.

According to a further embodiment of the processing arrangement, the flushing plate has at least one discharge channel, which runs through the flushing plate and is set up for discharging process gas from the second gap and/or the third gap. In this embodiment, a constant process gas flow can be set. Excess process gas is collected again through the discharge channel. In this way, the process gas can in particular also be reused, provided that the proportion of foreign gas does not become excessively high. Additionally or alternatively, the collected process gas can be reprocessed. In this way, the process gas consumption can be reduced considerably, and consequently costs can be reduced.

The discharge channel may open directly into the second gap and/or the third gap in order to discharge process gas directly from the second gap and/or the third gap.

According to a further embodiment of the processing arrangement, the flushing plate has a fourth section, which defines with the sample a fourth gap, the fourth section at least partially surrounding the second section, and a discharge channel being set up, running through the flushing plate, for discharging process gas from the fourth gap.

The fourth gap may be set up in particular to collect and discharge process gas escaping to the outside.

A further section, for example the third section, may be arranged between the fourth section and the second section.

According to a further embodiment of the processing arrangement, the flushing plate has a fifth section, which defines with the sample a fifth gap, and has an additional supply channel, which runs through the flushing plate and is set up for conducting an additional gas to the fifth gap, the fifth section at least partially surrounding the fourth section.

In this embodiment it can advantageously be avoided even better that process gas escapes to the outside, since the additional gas generates a counter pressure in the fifth gap. This is advantageous in particular in the case of highly reactive process gases. According to a further embodiment of the processing arrangement, the flushing plate consists of a material comprising a metal, a semiconductor and/or glass.

According to a further embodiment of the processing arrangement, the flushing plate has a round shape with a diameter of 1 mm - 200 mm, preferably 2 mm - 100 mm, more preferably 3 mm - 30 mm, in the center of which the passage opening is arranged in the first section .

According to a further embodiment of the processing arrangement, the flushing plate additionally has a shielding unit, which is formed in the area of the first section, in particular forms the first section, and which is set up for electrostatic shielding from charges present in the processing area.

The shielding unit comprises in particular an electrically conductive material, such as a metal, which is connected to a predetermined potential. The shielding unit may comprise a conductive coating. The shielding unit is preferably grounded, that is to say connected to a potential of 0 V.

The shielding unit preferably forms the first section. This ensures that the shielding element is arranged as close as possible to the processing area, and thus achieves particularly good shielding.

If the passage opening in the first section has a relatively great diameter, for example more than 80 pm, the shielding unit may additionally comprise a mesh formed from a conductive material which is attached to the inner edge of the first section and spans the passage opening. The mesh itself advantageously has the narrowest possible crosspieces with the largest possible meshes. The meshes are for example in the form of a honeycomb and have a diameter in the range of 20 - 50 pm! the crosspieces preferably have a maximum width of up to 10 pm.

According to a further embodiment of the processing arrangement, the flushing plate additionally has a beam deflection unit comprising a number of poles. The beam deflection unit is preferably arranged as close as possible to the passage opening and has the smallest possible diameter. The beam deflection unit comprises a number of poles arranged opposite one another, which are each connected to an opposite potential in order to effect a beam deflection. By combining a plurality of such pairs of poles, preferably up to eight individual poles, which form four pairs of poles, a very precise deflection of the particle beam can be achieved. The beam deflection unit preferably has a circular passage opening for the particle beam. The smaller the passage opening, the lower the voltages used for beam deflection can be, since the electrical field strength, obtained as the quotient of voltage over distance, is the decisive variable for beam deflection.

The flushing plate may in particular have a multi-part structure. For example, the flushing plate comprises a first partial plate and a second partial plate. The first partial plate and the second partial plate are joined together at a joining surface. The joining surface runs in particular perpendicular to the particle beam. The first partial plate and/or the second partial plate may have a structuring at the joining surface, which in the joined'together state form for example the supply channel or the discharge channel. A system of lines running in the flushing plate is therefore designed for conducting the process gas. On its side opposite from the joining surface, the second partial plate has the various sections which form the various gaps when the sample is arranged opposite.

According to a second aspect, a device for particle beam-induced processing of a sample is proposed. The device comprises a device for providing a focused particle beam in a processing area on the sample and a flushing plate, which is designed as described with reference to the first aspect, the flushing plate being arranged on the device for providing the focused particle beam opposite the sample. Furthermore, a sensor device for detecting tilting between the flushing plate and the sample is provided. An alignment unit comprising a number of actuator elements is set up to align the flushing plate and the sample in relation to one another in dependence on the tilting detected.

The embodiments and features described for the processing arrangement apply correspondingly to the proposed device and vice versa. The sensor device comprises at least three sensor elements, each of which is set up for detecting a distance. For example, the flushing plate forms a reference plane, the sensor elements detecting the distance between the sample and the reference plane. For example, the sensor elements are arranged on the flushing plate. As an alternative to this, the flushing plate may be arranged at an exact distance from a holding element which forms the reference plane and on which the sensor elements are also arranged.

The sample is preferably aligned as parallel as possible to the flushing plate, so that the resulting gap sizes are as constant as possible.

However, it may also be provided that a certain tilting is desired in order to set certain gas flow conditions at the surface of the sample.

The device preferably comprises a housing for providing a process atmosphere and a sample stage for holding the sample in a processing position in the process atmosphere. The alignment unit is preferably set up for aligning the sample stage.

If the flushing plate itself is tilted in relation to the reference plane relative to which the sensor elements detect the distance, additional sensor elements for detecting a distance from the sample stage to the flushing plate and for detecting a distance from the sample stage to the reference plane may be provided. The reference plane is formed in particular by a holding element. By detecting the distances between the sample stage and the holding element and between the holding element and the sample, including any tilting between the sample stage and the flushing plate, it is possible to infer a tilting between the sample and the flushing plate.

The alignment unit is set up to compensate for such tilting. The alignment unit is set up for example for aligning the sample stage and comprises for example three supporting points, at least two of which can be displaced in the beam direction by means of a respective actuator element. The third supporting point has for example a joint, in order to allow the sample stage to be tilted. Alternatively, more than two supporting points may be displaceable with actuator elements, for example three, four, five or six supporting points.

The sensor elements comprise for example confocal distance sensors and/or interferometric distance sensors.

By means of the sensor device and the alignment unit, a very exact alignment of the flushing plate relative to the sample can be achieved, with which a gap size of 5 - 20 pm can be achieved for the first gap. The advantages of the flushing plate with a number of sections mentioned in relation to the first aspect can thus be achieved.

According to a third aspect, a method for processing a sample by a particle beam- induced processing process with the device according to the second aspect is proposed. In a first step, the sample is aligned relative to the flushing plate. In a second step, process gas is supplied to the second gap. The process gas is conducted through the second gap to the first gap and flows through the first gap to the processing area. In a third step, the focused particle beam is radiated onto the processing area. In this way, a local chemical reaction based on activation of the process gas by the particle beam and/or by secondary effects, such as a deposition process or an etching process, can be triggered in a targeted manner in the processing area.

The embodiments and features described for the processing arrangement apply correspondingly to the proposed method and vice versa.

According to a fourth aspect, a flushing plate is proposed. The flushing plate comprises a first section, which has a passage opening for a particle beam to pass through onto a processing area of a sample, the first section being set up to form with the sample a first gap, which is set up for supplying process gas to the processing area, a second section, which is set up to form with the sample a second gap, which is set up to supply process gas to the first gap, a third section, which is set up to form with the sample a third gap, which at least partially surrounds the second section. The first section, the second section and the third section are designed in such a way that the first gap and the third gap are dimensioned smaller than the second gap. The embodiments and features described with reference to the first aspect apply correspondingly to the proposed flushing plate.

According to a fifth aspect, the use of a flushing plate according to the fourth aspect in a processing arrangement according to the first aspect is proposed.

”A(n); one" in the present case should not necessarily be understood as restricted to exactly one element. Rather, a number of elements, such as for example two, three or more, may also be provided. Any other numeral used here should also not be understood as restricted to exactly the stated number of elements. Rather, unless indicated to the contrary, numerical upward and downward deviations are possible.

Further possible implementations of the invention also comprise not explicitly mentioned combinations of features or embodiments that are described above or below with respect to the exemplary embodiments. In this case, a person skilled in the art will also add individual aspects as improvements or supplementations to the respective basic form of the invention.

Further advantageous configurations and aspects of the invention are the subject matter of the dependent claims and also of the exemplary embodiments of the invention described below. In the text that follows, the invention is explained in more detail on the basis of preferred embodiments with reference to the accompanying figures.

Fig. 1 shows a schematic cross section through a flushing plate according to a first exemplary embodiment;

Fig. 2 schematically shows a a view from below of the flushing plate of Fig. 1;

Fig. 3 schematically shows a view from below of a second exemplary embodiment of a flushing plate;

Fig. 4 schematically shows a view from below of a third exemplary embodiment of a flushing plate; Fig. 5 schematically shows a view from below of a fourth exemplary embodiment of a flushing plate;

Fig. 6 schematically shows a view from below of a fifth exemplary embodiment of a flushing plate;

Fig. 7 schematically shows a view from below of a sixth exemplary embodiment of a flushing plate;

Fig. 8 schematically shows a view from below of a seventh exemplary embodiment of a flushing plate;

Fig. 9 schematically shows a view from below of an eighth exemplary embodiment of a flushing plate;

Fig. 10 shows a schematic cross section through a flushing plate according to a ninth embodiment;

Fig. 11 shows a schematic cross section through a flushing plate according to a tenth exemplary embodiment;

Fig. 12 shows a schematic block diagram of an exemplary embodiment of a device for particle beam-induced processing of a sample; and

Fig. 13 shows a schematic block diagram of an exemplary embodiment of a method for particle beam-induced processing of a sample.

Unless indicated to the contrary, elements that are the same or functionally the same have been provided with the same reference signs in the figures. It should also be noted that the illustrations in the figures are not necessarily true to scale.

Fig. 1 shows a schematic cross section through a flushing plate 100 according to a first exemplary embodiment with a sample 300 arranged below it. Fig. 1 shows a detail from a processing arrangement 10 (see Fig. 12). Fig. 2 shows a view from below of the flushing plate 100. As can be seen here, the flushing plate 100 has a circular shape. In this example, the flushing plate 100 has three sections 110, 120, 130, which each form a level on the underside of the flushing plate 100. As a result of the opposite arrangement of the sample 300, in each of the sections 110, 120, 130 a gap 112, 122, 132 is formed, the size of which depends on the one hand on the distance between the surface of the sample and a reference plane of the flushing plate 100, for example a virtual central plane, and on the other hand on the respective level. In this example, the first section 110 and the third section 130 have the same level, which is why the first gap 112 and the third gap 132 have the same size. The second section 120 has a different level, which is why the second gap 122 has a different size. In particular, the second gap 122 is dimensioned larger than the first gap 112 and the third gap 132. For example, the first gap 112 and the third gap 132 have a size of 20 pm and the second gap 122 has a size of 500 pm. In this example, the first section 112 is configured as circular and the second 122 and third section 132 are configured as annular. The sections 112, 122, 132 are arranged coaxially in relation to one another. The second section 120 thus completely surrounds or surrounds the first section 110 and the third section 130 completely surrounds or surrounds the second section 120.

The first section 110 comprises a passage opening 114 for the particle beam 242, so that the particle beam 242 can radiate through the flushing plate 100 onto the processing area 302 on the sample 300. In this example, the passage opening 114 has a diameter of 50 pm. The first section 110 is delimited on the outside by an outer edge 110a and furthermore has an inner edge HOi, which forms the edge of the passage opening 114. The distance from the outer edge 110a and the inner edge HOi can also be referred to as the width DI of the first section 110. In this example, the first section 110 has a width of 20 pm. Process gas can flow in the second gap 122 with a relatively low flow resistance due to the difference in the gap sizes in comparison with the first gap 112 or the third gap 132. The second gap 122 is thus set up to conduct a sufficiently great volume flow of process gas to the first gap 112 even over long distances. The gas flow through the first gap 112 to the processing area 302 is determined in particular by the width of the first section 110 and the size of the first gap 112. Since the third section 130 completely encloses the second section 120, a particularly good sealing effect is provided by the third gap 132 in relation to the second gap 122. The width of the third section 130 is identified in this example as D3. In particular, the width D3 comprises a multiple of the width Di; for example, the width D3 of the third section 130 is at least 100 pm (five times the width DI of the first section 110), preferably 200 pm (ten times), more preferably 2 mm (a hundred times) or an even higher multiple. This achieves a preferred flow of process gas from the second gap 122 through the first gap 112, since a flow resistance of a flow through the third gap 132 into the outer area 105 is significantly greater than a flow resistance through the first gap 112 in the direction of the processing area 302. It should be noted that an aim of this structuring of the flushing plate 100 in different sections is on the one hand to minimize a loss of the process gas into the outer space 105 and at the same time to control the flow of process gas to the processing area 302, in particular also to limit it.

Fig. 3 schematically shows a view from below of a second exemplary embodiment of a flushing plate 100, which has for example a circular geometry with a diameter of 30 cm. In this example, the flushing plate 100 has three sections 110, 120, 130, which each have a different level and thus define gaps 112, 122, 132 with different sizes when the sample 300 is arranged opposite (see Fig. 1, 10, or 11) . In this example, each of the sections 110, 120, 130 spans a plane extending perpendicular to the particle beam 242 (see Fig. 1 or 10 - 12), the multiple planes running essentially parallel to one another. In the case of a plane -parallel arrangement of the sample 300 and the flushing plate 100, gap sizes which differ from one another by the distance between these planes are obtained, depending on the distance from the sample 300. For example, the first section 110 has a difference in level (a distance between the planes) of 500 pm in relation to the second section 120 and of 20 pm in relation to the third section 130. With a gap size of 20 pm for the first gap 112, this gives a gap size of 520 pm for the second gap 122 and of 40 pm for the third gap 132.

The first section 110 comprises the passage opening 114, which is arranged centrally therein. The first section 110 is circular and has for example a diameter of 60 pm. The passage opening 114 is designed as circular and has for example a diameter of 30 pm. The first section 110 thus has a width, which is measured from the outer edge 110a (see Fig. 1 or 2) of the first section 110 to the edge of the passage opening 114, of 15 pm. The first section 110 is surrounded by the second section 120, which with the sample 300 forms the second gap 122, which forms a straight channel. The channel 122 has for example a length of 20 cm and a width of 2 cm. The channel 122 extends from a supply channel 124, which runs through the flushing plate 100 and is set up for supplying process gas PG to the channel 122, to a discharge channel 126, which runs through the flushing plate 100 and is set up for discharging the process gas PG from the channel 122. In this way, a predetermined process gas pressure can be set in the channel 122, whereby a specific gas flow through the first gap 112 to the processing area 302 (see Fig. 1 or 10 - 12) can be achieved. The process gas pressure in the processing area 302 can consequently be set via the parameters process gas pressure in the channel 122, width of the first section 110 and size of the first gap 112. The process gas pressure is preferably set such that on the one hand a leakage rate of process gas PG, which flows through the passage opening 114 against the particle beam 242, is kept as low as possible, but on the other hand there is enough process gas PG in the processing area 302 to achieve a high processing speed. The second section 120 is enclosed by the third section 130, as a result of which the second gap 122 is sealed with respect to the outside by the third gap 132.

The third section 130 is preferably designed in such a way that a shortest connection D3 from the second gap 122 through the third gap 132 into the outer area 105 surrounding the flushing plate 100 has at least a length that corresponds to ten times, preferably a hundred times, more preferably a thousand times, the width DI (see Fig. 1 or 2) of the first section 110, which in this example corresponds to a distance of 150 pm (ten times), 1.5 mm (a hundred times) or 1.5 cm (a thousand times).

Fig. 4 schematically shows a view from below of a third exemplary embodiment of a flushing plate 100. This corresponds to the example of Fig. 3, with the difference that three first sections 110 with a respective passage opening 114 are arranged in the channel 122. This can prolong the service life of the flushing plate 100, since, as the period of use increases, the passage opening 114 can slowly become clogged, for example due to physical-chemical processes. It is then possible to switch to one of the alternative passage openings 114, so that an exchange of the flushing plate 100 as a whole can be avoided.

Fig. 5 schematically shows a view from below of a fourth exemplary embodiment of a flushing plate 100. With the exception of the arrangement of the second section 120, this corresponds for example to that of Fig. 3. In particular, in this example there are two second sections 120, which are separated from one another by the third section 130. The supply channel 124 opens into one of the two second gaps 122. This gap 122 is also referred to as the inflow channel. The discharge channel 126 branches off from the other second gap 122. This gap 122 is also referred to as the outflow channel. In this example, the outflow channel 122 forms a circular channel, which has an interruption in the area of the inflow channel 122. The outflow channel 122 thus almost completely encompasses the inflow channel 122. Process gas PG that escapes to the outside from the inflow channel 122 through the third gap 132 can thus be almost completely collected in the outflow channel 122 and discharged via the discharge channel 126.

Fig. 6 schematically shows a view from below of a fifth exemplary embodiment of a flushing plate 100. The flushing plate 100 has for example a circular geometry and a diameter of 20 cm. The different sections 110, 120, 130, 140 have an axial symmetry. In particular, all of the sections 110, 120, 130, 140 are designed as circular or annular and are arranged coaxially in relation to one another and in relation to the flushing plate 100. A respective section 110, 120, 130, 140 here forms a level, so that, when a sample 300 is arranged opposite (see Fig. 1 or 11), a gap 112, 122, 132, 142 is in each case formed in the respective section 110, 120, 130, 140, it being possible for different gaps 112, 122, 132, 142 to have different sizes. The first section 110 with a central passage opening 114 is arranged in the middle. The first section 110 is surrounded by the third section 130. This in turn is surrounded by the second section 120, with a supply channel 124 for supplying process gas PG opening into the second gap 122. The second section 120 is surrounded by a further third section 130, which is surrounded by a fourth section 140. A discharge channel 126, through which process gas PG can be discharged through the flushing plate 100, branches off from the fourth gap 140. The fourth section 140 is surrounded by a further third section 130. This arrangement achieves the effect that a constant process gas pressure is achieved in the inner third gap 132, which surrounds the first gap 112. Any flow path that leads to the outside from the second gap 122 crosses the fourth gap 142 and can be brought together and diverted there. A loss of process gas PG into an environment can thus be almost completely ruled out.

Fig. 7 schematically shows a view from below of a sixth exemplary embodiment of a flushing plate 100. This example is similar to the structure of the fifth exemplary embodiment, the second section 120 having an additional linear part, which forms an elongate channel 122 via which the process gas PG is supplied to the circular channel 122. In this way, the supply channel 124 can be arranged radially further outward in the flushing plate 100, which may be advantageous.

Fig. 8 schematically shows a view from below of a seventh exemplary embodiment of a flushing plate 100. This example has the special feature that, in addition to the process gas PG, an additional gas ZG is fed into a fifth gap 152 via a supply channel 154.

The inner area of the flushing plate 100 has for example the same structure as the second exemplary embodiment (see Fig. 3). This inner area is enclosed by a fourth section 140, which comprises two annular channels 142 connected to one another. The fourth gap 142 is connected to a discharge channel 126, via which process gas PG and additional gas ZG, which flows into the fourth gap 142, can be discharged and collected. The fifth section 150, which forms an interrupted annular channel 152, is arranged in an intermediate area between the two connected annular channels 142 of the fourth section 140. The additional gas ZG is for example a weakly reactive gas such as a noble gas, for example argon. Since a higher gas pressure is set in the fifth gap 152 with the additional gas ZG than in the fourth gap 142, a flow is obtained from the fifth gap 152 radially inward and outward, via the third gap 132 respectively lying in between, to the fourth gap 142. In particular, the inwardly directed flow can have an even greater effect of avoiding an outward flow of process gas PG from the second gap 122 into an environment. Fig. 9 schematically shows a view from below of an eighth exemplary embodiment of a flushing plate 100. This exemplary embodiment is similar to the seventh exemplary embodiment (see Fig. 8), but the fourth section 140 does not have an outer annular channel 142. For this purpose, the fifth section 150 has a closed ring 152, that is to say that the fifth section 150 completely encloses the fourth section 140. With this structure, a flow of the additional gas ZG from the fifth area 150 into an environment can be obtained.

Fig. 10 shows a schematic cross section through a flushing plate 100 according to a ninth exemplary embodiment. The structure of the sections 110, 120, 130 corresponds for example to that of the second exemplary embodiment (see Fig. 3). In the ninth exemplary embodiment, the first section 110 is formed by an electrically conductive material, and thus forms a shielding unit 160. The shielding unit 160 is preferably connected to ground potential. An electrical field, which is caused for example by an accumulation of positive or negative charges in the processing area 302, can in this way be prevented from penetrating into the area above the passage opening 114. An unfavorable and/or uncontrolled deflection of the particle beam 242 by such an undesirable electrical field can thus be minimized. In addition, the flushing plate 100 has a beam deflection unit 170. This has for example four oppositely arranged pairs of poles (only one pair is shown in Fig. 10). By applying a voltage between the two poles of a respective pair of poles, an electrical field which can be used to deflect the particle beam 242 is formed between the two poles. With the beam deflection unit 170, the particle beam 242 can be advantageously scanned over the processing area 302. The conically running opening above the passage opening 114 is advantageous in order to be able to detect backscattered electrons and/or secondary electrons from the processing area 302, which have an inclined path.

Fig. 11 shows a schematic cross section through a flushing plate 100 according to a tenth exemplary embodiment. The flushing plate 100 has for example a structure similar to the seventh or eighth exemplary embodiment (see Fig. 8 or 9), with annular channels which are formed by the second gap 122, fourth gap 142 and fifth gap 152. The second gap 122 is fluidically connected to a supply channel 124 for supplying process gas PG. The fourth gap 142 is fluidically connected to a discharge channel 126 for discharging gases PG, ZG that collect in the fourth gap 142. The fifth gap 152 is fluidically connected to a further supply channel 154 for supplying additional gas ZG.

Only one half of the flushing plate 100 and sample 300 is shown in Fig. 11; the other half has for example the same structure of the sections 110, 120, 130, 140, 150, the channels 124, 126, 154 only being present on one side. The first section 110 comprises the passage opening 114 for the particle beam 242. As already described with reference to Fig. 10, the first section 110 is formed from an electrically conductive material or coated with an electrically conductive material, and thus serves at the same time as a shielding unit 160. A conically tapering section (without a reference sign) is arranged between the first section 110 and the second section 120, which results in a transitional area between the first section 110 and the second section 120. A beam deflection unit 170 is also arranged above the upwardly widening passage opening, as already explained with reference to Fig. 10.

The flushing plate 100 may in particular be of a multi-part construction. For example, the flushing plate 100 may comprise a number of partial plates, with depressions being formed in a respective partial plate in such a way that the channels 124, 126, 154 are formed when the partial plates are joined together to form the flushing plate 100.

Fig. 12 shows a schematic block diagram of an exemplary embodiment of a device 200 for particle beam-induced processing of a sample 300, in particular a microlitho- graphic lithography mask. The device 200 comprises a housing 210 for providing a process atmosphere which has for example a predefined gas composition, for example a nitrogen atmosphere, at a predefined pressure, for example in the range of 10 ⁵ - 10 ⁸ mbar. For this purpose, the housing 210 is for example connected to a vacuum pump 250 and may furthermore be connected to gas feeds (not shown). The curly brace indicates that the device 200 with the sample 300 arranged therein forms a processing arrangement 10.

A sample stage 220 for holding the sample 300 is arranged in the housing 210. The sample stage 220 is arranged on an alignment unit with three supporting points. One of the supporting points 221 has a fixed height and the two other supporting points each have an actuator element 222. The actuator elements 222 are set up for displacing the sample stage 220 along a z axis, which runs in the direction of the particle beam 242, as represented by the double arrows. The surface of the sample stage 220 can thus be tilted. The sample stage 220 is also arranged on a displacement unit, not shown here, by means of which the sample stage 220 can be moved in the x-y direction (perpendicular to the z axis). In addition, the sample stage 220 may also be rotatably mounted. The sample stage 220 is preferably held by the housing 210 in a vibration- decoupled and/or vibration-damped manner.

A means 230 for providing a focused particle beam 242 is also arranged in the housing 210. It is for example a column of electrons. A process atmosphere with a pressure of 10 ⁷ - 10 ⁸ mbar preferably prevails in the means 230, which has its own housing (without a reference sign). The electron column 230 has a particle beam providing unit 240, which is set up for providing the particle beam 242, in this example an electron beam. The electron beam 242 has for example a current in the range of 1 mA - 1 pA. A beam guiding means 232, a beam shaping means 234 and a detector 236 are arranged below the particle beam providing unit 240. The beam guiding means 232 and the beam shaping means 234 are set up for example for focusing the particle beam 242 on the surface of the sample. The detector 236 is designed for detecting backscattered electrons and/or secondary electrons. The detector 236 can also be referred to as an inlens detector. The flushing plate 100 is arranged on the underside of the means 230, opposite the sample stage 220 and the sample 300. This is shown here without further details! it may for example be designed as described with reference to Fig. 1 - 11 . When the device 200 is in operation, the flushing plate 100 has for example a distance from the sample 300 of 10 pm. Two gas lines 262, 252 are connected to the upper side of the flushing plate 100. The gas line 262 is supplied with process gas PG by a process gas providing unit 260. The gas line 262 opens for example into a supply channel 124 (see Fig. 3 - 11) in the flushing plate 100, which in turn opens into a second gap 122 (see Fig. 1 - 11). The gas line 252 is for example connected to a discharge channel 226 (see Fig. 3 - 11) in the flushing plate 100 and is set up for pumping process gas PG out of the discharge channel 226 by means of a vacuum pump 250. Coming into consideration in particular as process gases PG that are suitable for depositing material or for growing raised structures are alkyl compounds of main group elements, metals or transition elements. Examples of this are cyclopentadienyl trimethyl platinum CpPtMes (Me = CH4), methylcyclopentadienyl trimethyl platinum MeCpPtMes, tetramethyl tin SnMe4, trimethyl gallium GaMes, ferrocene CpsFe, bis-aryl chromium ArsCr, and/or carbonyl compounds of main group elements, metals or transition elements, such as for example chromium hexacarbonyl Cr(CO)e, molybdenum hexacarbonyl Mo(CO)e, tungsten hexacarbonyl W(CO)e, dicobalt octacarbonyl Co2(CO)s, triruthenium dodecacarbonyl Ru3(CO)i2, iron pentacarbonyl Fe(CO)5, and/or alkoxide compounds of main group elements, metals or transition elements, such as for example tetraethyl orthosilicate Si(OC2H5)4, tetraisopropoxy titanium TiCOCsH?^, and/or halide compounds of main group elements, metals or transition elements, such as for example tungsten hexafluoride WFg, tungsten hexachloride WOE, titanium tetrachloride TiCU, boron trifluoride BCI3, silicon tetrachloride SiCU, and/or complexes with main group elements, metals or transition elements, such as for example copper bis(hexafluoroacetylacetonate) OUCOBF 6HO2)2, dimethyl gold trifluoroacetyl acetonate Me2Au(C5F3H4O2), and/or organic compounds such as carbon monoxide CO, carbon dioxide CO2, aliphatic and/or aromatic hydrocarbons, and more of the same.

Coming into consideration for example as process gases PG that are suitable for etching material are: xenon difluoride XeF2, xenon dichloride XeCh, xenon tetrachloride XeC14, steam H2O, heavy water D2O, oxygen O2, ozone O3, ammonia NH3, nitrosyl chloride NOCI and/or one of the following halide compounds: XNO, XONO2, X2O, XO2, X2O2, X2O4, X2O6, where X is a halide. Further process gases for etching material are specified in the applicant's US patent application No. 13/0 103 281.

The process gas may also contain proportions of 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 CI2, hydrogen chloride HC1, hydrogen fluoride HF, iodine I2, hydrogen iodide HI, bromine Br2, hydrogen bromide HBr, phosphorus trichloride PCI3, phosphorus pentachloride PCI5, 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 gases can be used for example for etching processes, as buffer gases, as passivating agents and the like.

Also arranged on the underside of the means 230 are three sensor elements 238 (only two sensor elements 238 are shown in Fig. 12) for detecting a distance from the flushing plate 100 to the sample 300. Since the distance is detected at at least three points, a tilting of the sample 300 relative to the flushing plate 100 can be deduced, which can then be compensated for by the alignment unit by means of the actuator elements 22.

For an optimal function of the flushing plate 100, in particular for guiding the process gas on the basis of the structured underside of the flushing plate 100 with the different sections, an exact alignment of the flushing plate 100 in relation to the sample 300 is advantageous, preferably a plane-parallel alignment. Since the distance of the flushing plate 100 from the sample 300 in the area of the first section 110 (see Fig. 1 - 11) is only a few micrometers, for example of 5 - 50 pm, but the flushing plate 100 and the sample 300 are each several millimeters to centimeters in diameter, even very slight tilting can lead to the flushing plate 100 colliding with the sample 300 and/or to the formation of undesired gas flows due to inhomogeneous gap sizes. Such tilting can be compensated for by the actuator elements 222, whereby a predetermined, optimal relative arrangement of the flushing plate 100 in relation to the sample 300 is ensured.

It is explained below with reference to Fig. 13 how for example the device 200 can be operated.

Fig. 13 shows a schematic block diagram of an exemplary embodiment of a method for particle beam-induced processing of a sample 300 (see Fig. 1 or 10 - 12). The method may be carried out for example by means of the device 200 of Fig. 12. In a first step Si, the sample 300 (see Fig. 1 or 10 - 12) is aligned relative to the flushing plate 110 (see Fig. 1 - 12). This takes place for example by means of a multiple distance measurement with corresponding sensor elements 238 (see Fig. 12) and corresponding actuator elements 222 (see Fig. 12). In a second step S2, process gas PG (see Fig. 3 - 12) is supplied to a second gap 122 (see Fig. 1 - 11), which is formed by a second section 120 (see Fig. 1 - 12) of the flushing plate 100 and the sample 300. The process gas PG is conducted through the second gap 122 to a first gap 112 (see Fig. 1 - 11), which is formed by a first section 110 (see Fig. 1 - 11) of the flushing plate 100 and the sample 300. The process gas can then flow through the first gap 112 and to the processing area 302 (see Fig. 1 or 10 - 12) on the sample 300.

In a third step S3, a focused particle beam 242 (see Fig. 1 or 10 - 12) is radiated onto the processing area 302. The particle beam 242 passes through the passage opening 114 in the flushing plate 110.

By irradiating the processing area 302 with the particle beam 242, local reactions can be triggered in the presence of the process gas PG, for example etching processes or depositing processes. For this purpose, the particle beam 242 is preferably scanned over the processing area 302, which is controlled for example by means of a beam deflection unit 170 (see Fig. 10 or 11) in the flushing plate 100. The shielding unit 160 (see Fig. 10 or 11) can ensure that the particle beam 242 is not deflected in an uncontrolled manner by undesired electrical fields that may result from a charging of the sample 300 in the processing area 302.

Although the present invention has been described on the basis of exemplary embodiments, it can be modified in various ways.

LIST OF REFERENCE SIGNS

10 Processing arrangement

100 Flushing plate

105 Environment

110 Section

110a Edge

HOi Edge

112 Gap

114 Opening

120 Section

122 Gap

124 Channel

126 Channel

130 Section

132 Gap

140 Section

142 Gap

150 Section

152 Gap

154 Channel

160 Shielding unit

170 Beam deflection unit

200 Device

210 Housing

220 Sample stage

221 Fixed point

222 Actuator element

230 Means

232 Beam guiding means

234 Beam shaping means

236 Detector

238 Sensor element

240 Particle beam providing unit 242 Particle beam

250 Vacuum pump

252 Line

260 Process gas providing unit 262 Line

300 Sample

302 Processing area

DI Distance D3 Distance

PG Process gas

SI Method step

S2 Method step

S3 Method step

ZG Additional gas