Device and method for cleaning a microelectromechanical assembly

Abstract

The invention relates to a device (400) for cleaning only a first portion of a surface (421) of a microelectromechanical assembly (401) in a vacuum, said device comprising: a lower part (402); an upper part (403), wherein the upper part (403) can be sealingly and detachably connected to the lower part (402), and wherein a chamber interior (405) can be formed by the connection between the lower part (402) and the upper part (403); a suction unit (406), wherein the suction unit (406) is connected to the device (400), and a vacuum can be created in the chamber interior (405) by the suction unit (406); a gas supply unit (407), wherein the gas supply unit (407) is connected to the device (400), and a targeted gas flow (408) for particle mobilisation in the chamber interior (405) can be generated by the gas supply unit (407); characterised in that the device (400) also has a reception zone (409) for sealingly receiving at least one microelectromechanical assembly (401), wherein the reception zone (409) is designed such that only the first portion of a surface (421) of the microelectromechanical assembly (401) that can be received in the reception zone (409) can be exposed to the chamber interior (405), while a second portion of the surface of the microelectromechanical assembly can be separated from the chamber interior.

Description

[0001] Device and method for cleaning a microelectromechanical assembly

[0002] The present application claims priority from German patent application No. 102025 108 888.8, the contents of which are incorporated herein in full by reference.

[0003] Field of invention

[0004] The invention relates to a device, an arrangement, and a method for cleaning at least one microelectromechanical assembly in a vacuum environment, wherein the cleaning of the microelectromechanical assembly is supported by a controlled gas flow. The invention further relates to the cleaned microelectromechanical assembly.

[0005] State of the art

[0006] Projection exposure systems for semiconductor lithography are used to fabricate microstructured devices using a photolithographic process. In this process, a structure-bearing mask, the so-called reticulum, is projected onto a photosensitive layer using projection optics or a projection system. The minimum feature size that can be imaged using such projection optics is determined by the wavelength of the imaging light. The smaller the wavelength of the imaging light, the smaller the structures that can be imaged. Currently, imaging light with a wavelength of 193 nm or imaging light with a wavelength in the extreme ultraviolet (EUV) range, i.e., at least 5 nm and at most 30 nm, is primarily used.When using imaging light with a wavelength of 193 nm, both refractive and reflective optical assemblies are used within the projection imaging system. When using imaging light with a wavelength in the EUV range, only reflective optical assemblies, especially mirrors, are used, which are typically operated under vacuum conditions in a vacuum environment.

[0007] The reflective optical assembly for EUV projection systems can, for example, comprise a plurality of microelectromechanical assemblies, particularly in the form of individual mirror modules (“MEMS (micro-electromechanical system) mirror modules”). A basic design is described in DE 10 2014 219 770 A1. Such a reflective optical assembly has a plurality of MEMS mirror modules in a grid arrangement, which are typically actuable or tiltable about at least one, preferably two, axes. The MEMS mirror modules are very small components (size of the respective mirror surface, e.g., approximately 1 mm²). 2 .

[0008] For actuation, a single MEMS mirror module, as a microelectromechanical assembly, typically comprises a head section containing a base element, a mirror substrate, and a space between the base element and the mirror substrate. This space contains components of a suspension system for the movable mounting of the mirror substrate to the base element, such as spring-elastic or flexible sections, or components that connect the mirror substrate to the base element. The space also contains components of an actuator system for generating movements of the mirror substrate relative to the base element in response to the reception of control signals. The actuator system can be a separate system from the suspension system. Alternatively, the suspension system and the actuator system can be integrated, with sections of the suspension system also functioning as parts of the actuator system.Typically, a rod-shaped control element is attached to the base element of the MEMS mirror module and is thus integrated into the microelectromechanical assembly. The control element comprises various components, such as electronics, connecting wires, and control lines for controlling the actuator system.

[0009] To ensure the free movement of the mirror substrate during operation, the space between the MEMS mirror module and the surrounding environment is designed to be open. This allows contaminants, particularly particles, to enter the space and impair the free movement of the mirror substrate. This risk is further increased by the miniaturized design of the MEMS mirror modules. This applies generally to both the operation and manufacturing of the microelectromechanical assembly. In addition to preventing the ingress of contamination, especially particulate contamination, into the space—for example, by providing a very clean operating or manufacturing environment—it is necessary to remove any existing contamination from the space within the microelectromechanical assembly, particularly during various stages of its manufacturing process.

[0010] Due to the miniaturized structures in the interstitial space of the microelectromechanical assembly, conventional wet chemical methods known from the prior art for removing contaminants, especially particles, and which employ techniques such as ultrasound, pressure immersion, pressure variations, turbulence, or spraying, are unsuitable because they can damage the exposed, delicate micromechanical structures. Likewise, such wet chemical methods are unsuitable for previously applied functional coatings, particularly reflective coatings or adhesives, as they can alter or damage them.

[0011] Prior art cleaning methods using only a flowing or pulsating cleaning gas require a defined enclosure for the microelectromechanical assembly and are limited in terms of the possible gas flow rate due to the risk of damaging the delicate structures in the space. Contaminants, especially particles, that have penetrated areas of the space, particularly the suspension system and / or the actuator system, can therefore only be incompletely removed by such a cleaning method using only a gas flow.

[0012] Vacuum-based cleaning methods, such as plasma or ozone, cannot be used for such microelectromechanical assemblies because the components of the head area and the control element have different cleanliness requirements and achievable cleanliness classes. Since the components of the head area are designed for use inside an EUV projection system, extremely high cleanliness classes apply to them. Vacuum-based cleaning of the microelectromechanical assembly would therefore lead to cross-contamination of these components. Furthermore, vacuum-incompatible components are installed in the control element area, which poses a risk of damage.

[0013] Against this background, the object of the invention is to provide a device and a method for cleaning microelectromechanical assemblies for use in a projection exposure system. The cleaning process should be feasible for a finished microelectromechanical assembly that can be integrated into a reflective optical assembly, as well as for a microelectromechanical assembly that is being assembled in a preliminary process.

[0014] This problem is solved according to the features of independent claims 1 and 13. By integrating the microelectromechanical assembly for cleaning into the device according to the invention, an arrangement according to claim 12 is obtained.

[0015] For cleaning a microelectromechanical assembly, a device according to the invention is provided, comprising a lower part and an upper part. The upper part is sealed and detachably connected to the lower part, with the connection between the lower and upper parts forming a chamber interior. The lower part and upper part are, for example, a cylindrical or cuboid vacuum chamber with a corresponding lid. Therefore, the lower part and the upper part are typically made of a vacuum-compatible material, such as stainless steel. The device further comprises a suction unit, which is connected to the device and provides a vacuum in the chamber interior. The suction unit can be designed as an adjustable vacuum pump.The device also includes a gas supply unit, which is connected to the device and provides a targeted gas flow for particle mobilization within the chamber. The gas supply unit can be configured as a nozzle with a gas flow regulating element, such as a valve or a mass flow controller. This design enables vacuum-assisted cleaning of the microelectromechanical assembly, particularly of particulate contamination, by means of a targeted gas flow. A vacuum of 10... 2 At mbar - 200 mbar, particle mobilization in combination with a targeted gas flow in hard-to-reach areas is particularly advantageous, as a viscous gas flow is formed.

[0016] The microelectromechanical assembly to be cleaned has a first surface area and a second surface area. The first surface area is typically formed by a head region comprising a base element, a mirror substrate, and an actuated space between the base element and the mirror substrate. This space contains corresponding components and is open. Therefore, it is particularly important to remove any existing contaminants, especially particles, from the space. Particularly high cleanliness requirements apply to the first surface area of ​​the microelectromechanical assembly, especially if the assembly is designed as a MEMS mirror module, has an EUV-reflective coating, and is configured to guide EUV light.The second part of the surface is typically a control element connected to the head area. This control element comprises various components, such as electronics, connecting wires, and control lines. Significantly lower cleanliness requirements apply to this second part of the surface than to the first, or the components of the second part can only be supplied with a lower cleanliness class. Therefore, vacuum-assisted cleaning poses a risk of cross-contamination of the first part of the surface. Furthermore, vacuum-incompatible components are installed in the area of ​​the second part of the surface of the microelectromechanical assemblies, resulting in a risk of damage.

[0017] Therefore, according to the invention, the device for cleaning such a microelectromechanical assembly has a specially designed receiving area for the sealing reception of at least one microelectromechanical assembly. The receiving area is designed such that only the first part of the surface of the microelectromechanical assembly to be received by the receiving area is exposed to the interior of the chamber, and a second part of the surface of the microelectromechanical assembly is separable from the interior of the chamber. The second part of the surface of the microelectromechanical assembly can be separated from the interior of the chamber, for example, by encapsulation or by only partially receiving the microelectromechanical assembly within the chamber.This avoids both the risk of cross-contamination of the first part of the surface through vacuum-assisted cleaning and the risk of damage to individual components of the second part of the surface through vacuum-assisted cleaning using a targeted gas flow.

[0018] According to a first embodiment of the device according to the invention for cleaning a first part of a surface of a microelectromechanical assembly, the receiving area is formed by at least one recess in the upper part and / or lower part, wherein the upper part and / or the lower part is provided by at least one sealing device for the sealing reception of at least one microelectromechanical assembly. The sealing device can, for example, be a circular or rectangular elastomer seal that includes the correspondingly complementary recess in the upper part and / or lower part, thereby enabling a sealing reception of the microelectromechanical assembly.This arrangement allows the microelectromechanical assembly to be only partially inserted into the chamber interior, so that only the first part of the surface of the microelectromechanical assembly, as it is held by the receiving area, is exposed to the chamber interior. The second part of the surface of the microelectromechanical assembly can be positioned outside the chamber interior, thus enabling a dedicated and low-risk vacuum-assisted cleaning of the first part of the surface of the microelectromechanical assembly by means of a targeted gas flow.According to a second alternative embodiment of the device according to the invention for cleaning a first part of a surface of a microelectromechanical assembly, the receiving area comprises a capsule element configured such that a second part of a surface of the microelectromechanical assembly, which is sealedly received by the capsule element, can be separated from the interior of the chamber. For this purpose, the capsule element comprises a sealing device located at an opening area of ​​the capsule element. The sealing device is, for example, a circular or rectangular elastomer seal, the size of which is complementary to the size of the opening area of ​​the capsule element and the size of the microelectromechanical assembly to be received.In this embodiment according to the invention, the complete microelectromechanical assembly can advantageously be introduced into the interior of the chamber, whereby only the first part of its surface is exposed to the interior of the chamber for vacuum-assisted cleaning by means of a targeted gas flow.

[0019] According to a further embodiment of the second alternative of the device according to the invention for cleaning a first part of the surface of a microelectromechanical assembly, the capsule element is connected to a positioning element. The connection between the positioning element and the capsule element can be fixed or detachable. The positioning element is designed to position the microelectromechanical assembly, which is held by the capsule element, within the chamber interior. The positioning element allows the position of the part of the microelectromechanical assembly to be cleaned relative to the position of the provided targeted gas flow, thus enabling particularly effective cleaning. The positioning element is, for example, a perforated sheet or a grid structure with capsule elements that can be held or are permanently mounted on it.The positioning element advantageously allows a grid-like recording of a large number of microelectromechanical assemblies to be supplied for cleaning by the device according to the invention.

[0020] In another embodiment, the positioning element is permanently or detachably connected to the upper and / or lower part. The detachable connection allows multiple units of positioning elements with connected capsule elements to be used in the cleaning process, and these can be efficiently fitted with the microelectromechanical assemblies outside the device.

[0021] According to a further embodiment of the device according to the invention for cleaning a first part of the surface of a microelectromechanical assembly, the device includes a particle counter for determining the quantity of particles. Typically, an optical measuring device is used as the particle counter, which determines the number of particles for different particle size classes using a light scattering method. By arranging the particle counter in a specific area of ​​the chamber interior, a quantity of particles representative of this area can be determined. The particle counter is typically located at an outlet of the suction unit. This allows the particle counter to determine a quantity of particles representative of the entire chamber interior as well as of the microelectromechanical assembly that can be collected. Continuous measurement of the particle quantity by the particle counter enables monitoring of the cleaning process.Additionally, the particle count determined by the particle counter can be transmitted to a control unit, allowing the cleaning process to be controlled by the control unit. For example, the control unit can adjust the targeted gas flow or the suction power of the vacuum unit.

[0022] According to a further embodiment of the device according to the invention for cleaning a first part of a surface of a microelectromechanical assembly, the device comprises a plurality of suction units and / or gas supply units. By providing the plurality of suction units and / or gas supply units, the local concentration of the cleaning effect of the device according to the invention, particularly with regard to particulate contamination, can be further improved. This advantageously allows targeted treatment of areas within the chamber interior where the first part of a surface of the microelectromechanical assembly to be cleaned can be positioned or where a high contamination load is expected.

[0023] According to a further embodiment of the device according to the invention for cleaning a first part of the surface of a microelectromechanical assembly, the device comprises at least one guiding element within the chamber interior, particularly in the area of ​​the gas supply unit, which is designed to increase turbulence of the targeted gas flow within the chamber interior. Due to the turbulent gas flow, portions of the gas flow can be applied to the first part of the surface of the microelectromechanical assembly to be cleaned at different angles. The guiding element thus further increases the probability of mobilizing particulate contaminants, especially since the particulate contaminants can occur in different, difficult-to-access areas of the first part of the surface of the microelectromechanical assembly.

[0024] According to a further embodiment of the device according to the invention for cleaning a first part of the surface of a microelectromechanical assembly, the device comprises at least a plasma source, a temperature control unit, a UV light source, and / or an ozone generator as a further cleaning element. Certain types of contaminants, for example, volatile and non-volatile organic contaminants, can only be incompletely removed by a targeted gas flow in combination with the assistance of a vacuum. The removal of contaminants from the first part of the surface of the microelectromechanical assembly can be further improved by the aforementioned additional cleaning elements. This can be achieved, for example, predominantly physically through the input of energy (temperature control unit, UV light source) or predominantly chemically (ozone generator, plasma source).

[0025] According to a further embodiment of the device according to the invention for cleaning a first part of the surface of a microelectromechanical assembly, the device comprises a sensor unit for determining the cleanliness status of the first part of the surface of the microelectromechanical assembly that can be detected by the detection area. The cleanliness status corresponds, for example, to a particle concentration according to DIN EN ISO 14644 or can be converted to this quantity. In particular, the sensor unit is an optical sensor unit, for example, a high-resolution camera for inspecting particulate contamination. The camera can also be configured to acquire hyperspectral information, thereby enabling the first part of the surface to be analyzed not only for particulate contamination but also for organic contamination.The sensor unit advantageously inspects areas sensitive to contamination, such as the mirror substrate with any reflective coating that may be present, or the area of ​​the space between the microelectromechanical assembly and the suspension system and the actuator system. The sensor unit can also be configured as a mass spectrometer for residual gas analysis of the chamber interior, thereby providing indirect information regarding the cleanliness of the surface of the microelectromechanical assemblies that are to be detected or have been detected by the detection area.

[0026] According to a further embodiment of the device according to the invention for cleaning a first part of the surface of a microelectromechanical assembly, the device comprises a control unit for controlling the device based on the cleanliness level determined by the sensor unit and / or on the particle quantity determined by the particle counter. For this purpose, the control unit is connected to the particle counter and / or the sensor unit to obtain the determined information. The control unit is also connected, for example, to the suction unit, the gas supply unit, or other cleaning elements. For example, the controlled unit can adjust the targeted gas flow provided by the gas supply unit or the suction power of the suction unit. The control unit enables the device to be automated.

[0027] Another aspect of the invention relates to an arrangement for cleaning a first part of the surface of a microelectromechanical assembly. The arrangement according to the invention comprises the device according to the invention or one of the described embodiments thereof. Furthermore, the arrangement comprises at least one microelectromechanical assembly received by the device such that only the first part of the surface of the microelectromechanical assembly is exposed to the interior of the device's chamber. The advantages of the arrangement arise according to the advantages described for the device according to the invention or its embodiments.

[0028] A further object of the invention relates to the provision of a method for cleaning a first part of a surface of a microelectromechanical assembly. The method comprises the following steps:

[0029] In a first step, a device according to the invention or an embodiment thereof is provided. In a further step, at least one microelectromechanical assembly is received by the device in such a sealing manner that only the first part of the surface of the at least one microelectromechanical assembly is exposed to the interior of the chamber of the device, wherein a second part of the surface of the microelectromechanical assembly is arranged outside the interior of the chamber and / or separated from it. For this purpose, the device comprises the described receiving area. The arrangement according to the invention is obtained by receiving the microelectromechanical assembly. In this arrangement, a second part of the surface of the microelectromechanical assembly is arranged outside the interior of the chamber or separated from it.In a further step of the method according to the invention, a vacuum is provided in the chamber interior of the arrangement by means of a suction unit of the device. Typically, the vacuum is created in area 10. -2A pressure of 200 mbar is provided, which is particularly advantageous for particle mobilization in combination with a targeted gas flow in hard-to-reach areas of the first part of the surface of the microelectromechanical assembly, as a predominantly viscous gas flow is established. In a further step, a targeted gas flow is provided for cleaning, in particular particle cleaning, of the first part of the surface of the at least one microelectromechanical assembly. Typically, a gas such as nitrogen, CDA (Clean Dry Air), XCDA (Extreme Clean Dry Air), or a noble gas available in a high cleanliness class is used for the targeted gas flow. The gas flow to be set depends on the size of the chamber interior and the suction capacity of the suction unit, advantageously achieving or maintaining the pressure conditions described for a viscous flow.

[0030] This method achieves effective and low-risk cleaning of the first part of the microelectromechanical assembly's surface, which typically has extremely high cleanliness requirements. Separating the first and second parts of the surface simultaneously and advantageously prevents cross-contamination of the first part by the second, while also avoiding the risk of damage to electronic components of the second part of the surface from exposure to a vacuum environment.

[0031] According to one embodiment of the inventive method, in a further step, the cleanliness state of a first part of the surface of a microelectromechanical assembly is at least partially determined by means of a sensor unit and / or the particle quantity is determined by means of a particle counter. The cleanliness state corresponds, for example, to a particle concentration according to DIN EN ISO 14644 or can be converted into this quantity.

[0032] In particular, an optical sensor unit is used, for example, a high-resolution camera for inspecting particulate contamination, especially with the capability of acquiring hyperspectral information, which allows for the identification of further contamination classes. An optical measuring device is typically used as the particle counter, determining the number of particles for different particle size classes using a light scattering method. By positioning the particle counter in a specific area of ​​the chamber interior, a representative sample of particles for that area is determined. Typically, the particle counter is located at an outlet of the suction unit, thus obtaining a representative result for the entire chamber interior.The cleaning process according to the invention is monitored by continuously determining the cleanliness of the first part of the surface of the microelectromechanical assembly using the sensor unit and / or the particle count using the particle counter. For example, an endpoint of the cleaning process is advantageously determined based on this data, thereby avoiding unnecessary cleaning time.

[0033] According to one embodiment of the inventive method of a first part of a surface of a microelectromechanical assembly, in a further step the method is controlled, in particular terminated, on the basis of the determined cleanliness state and / or the determined particle quantity.

[0034] For this purpose, the device for carrying out the process includes a control unit. Data acquired, for example, by the particle counter or the sensor unit, are transmitted to the control unit. Based on this data, and in particular by target values ​​stored in the control unit, the cleaning process is controlled by the control unit. For this purpose, the control unit is connected, for example, to the suction unit, the gas supply unit, or other cleaning elements. For instance, the control unit modifies the targeted gas flow provided by the gas supply unit or the suction power of the suction unit. If the data within the chamber interior is acquired with a certain spatial resolution, the process can also be controlled according to specifically defined areas within the chamber interior.For example, by means of multiple suction units and / or gas supply units arranged on the device. The control of the process includes automation.

[0035] Another aspect of the invention relates to the microelectromechanical assembly cleaned with a device according to the invention.

[0036] Further features and advantages of the invention will become apparent from the following description of exemplary embodiments of the invention, with reference to the figures, which show essential details of the invention, and from the claims. The individual features can be implemented individually or in any combination in a variant of the invention.

[0037] The invention will now be explained in more detail with reference to the drawings.

[0038] This shows

[0039] Figure 1 shows an EUV projection exposure system

[0040] Figure 2 shows a reflective optical assembly for an EUV projection exposure system with three microelectromechanical assemblies. Figure 3a shows a device for cleaning only a first part of a surface of a microelectromechanical assembly in a vacuum.

[0041] Figure 3b Arrangement for cleaning a first part of a surface of a microelectromechanical assembly comprising a device according to Figure 3a and a microelectromechanical assembly received by the device

[0042] Figure 4a Device for cleaning only a first part of a surface of a microelectromechanical assembly in a vacuum

[0043] Figure 4b Arrangement for cleaning a first part of a surface of a microelectromechanical assembly comprising a device according to Figure 4a and a microelectromechanical assembly received by the device

[0044] Figure 5a Device for cleaning only a first part of a surface of a microelectromechanical assembly in a vacuum

[0045] Figure 5b Arrangement for cleaning a first part of a surface of a microelectromechanical assembly comprising a device according to Figure 5a and a microelectromechanical assembly received by the device

[0046] Figure 6 shows a method for cleaning a first part of a surface of a microelectromechanical assembly

[0047] Character description

[0048] Figure 1 shows a simplified representation of a projection exposure system 100, in particular an EUV projection exposure system, for microlithography. The projection exposure system 100 has a housing 101 enclosing an interior space and at least one, in this case several, optical components 102 to 112 arranged in the housing 101.

[0049] According to the exemplary embodiment, the projection exposure system 100 further comprises a radiation source 113, in particular an EUV light source, an illumination system 114 for illuminating an object field 115 in an object plane 116, and a projection system 117. The illumination system 114 illuminates a reticule 118 arranged or arrangable in the object field 115, which is held by a reticule holder 119. The projection system 117 serves to image the object field 115 onto an image field 120 in an image plane 121. The structure of the reticule 118 is imaged onto a photosensitive layer of a wafer 122 arranged in the image plane 121 within the area of ​​the image field 120 and held by a wafer holder 123. The wafer is made of a semiconductor material, for example silicon. The radiation source 113 emits EUV radiation 124, particularly in the range between 5 nm and 30 nm, especially 13.5 nm.To control the radiation path of the EUV radiation 124, preferably at least one of the optical components 102 to 112, in particular each of the optical components 102 to 112, is controllable, in particular for the respective alignment or positioning.

[0050] The EUV radiation 124 generated by the radiation source 113 is aligned by means of a collector mirror integrated into the radiation source 113 (not shown here) such that the EUV radiation 124 passes through an intermediate focus 125 in the region of an intermediate focus plane before the EUV radiation 124 then strikes a first of the optical components 102, in this case a field facet mirror 102. After the field facet mirror 104, the EUV radiation 124 is directed to a second of the optical components 103, in this case a pupil facet mirror 103. Subsequently, the light is guided through the further optical components 104, 105, 106 to the object field 115.

[0051] To further improve the imaging properties of the illumination system, the field facet mirror 102 is designed as a micromirror array in the form of individual microelectromechanical assemblies or mirrors (MEMS mirror modules). The microelectromechanical assemblies are arranged in a grid and are typically actuable or tiltable about at least one, preferably two, axes. The MEMS mirror modules are very small components (size of the respective mirror surface, e.g., approximately 1 mm). 2 ), which are controlled or actuated using electrodes and micromechanical structures.

[0052] The reticle 118 arranged or arrangable in the object field 115 is, for example, a reflective photomask having reflective and non-reflective, or at least less reflective, areas for generating at least one structure to be imaged. Alternatively, the reticle 118 is formed by a plurality of micromirrors arranged in a one- or multi-dimensional configuration and preferably movable about at least one axis.

[0053] The reticule 118 reflects part of the EUV radiation 124 coming from the lighting system 114 into the projection system 117 and shapes the light reflected into the projection system 117 in such a way that the information about the structure of the reticule 118 is transferred to the image plane 120 by means of the projection system 117.

[0054] In the present embodiment, the projection lens 117 has, without being limited to this number, six optical components or optical elements 107 to 112.

[0055] Figure 2 shows an embodiment of a reflective optical assembly 200 for the EUV projection exposure system 100. For example, the reflective optical assembly 200 is the field facet mirror 102 in Figure 1. The reflective optical assembly 200 comprises a substrate body 201, which is typically made of a material such as stainless steel, copper, aluminum alloy, Invar, SiC, molybdenum alloy, or a tungsten alloy and is preferably temperature-controlled. The reflective optical assembly 200 according to Figure 2 comprises three mounting areas 202, each of which contains a microelectromechanical assembly 203 designed as a MEMS mirror module. The microelectromechanical assemblies 203 comprise a head section 204, each of which has a base element 205, a mirror substrate 206, and a space between the base element 205 and the mirror substrate 206.For guiding and shaping EUV radiation 114, the mirror substrate 206 has a corresponding reflective coating and is designed to be actuated. In the space between the substrate and the base element 205 are components of a suspension system 207 for the movable mounting of the mirror substrate 206, which also connects the mirror substrate 206 to the base element 205. Also located in this space are components of an actuator system 208 for generating movements of the mirror substrate 206 relative to the base element 205 in response to the reception of control signals. The base element 205, the mirror substrate 206, the suspension system 207, and the actuator system 208 can be made of a ceramic material, silicon, or a silicon compound. A rod-shaped control element 209 is attached to the base element 205 of the microelectromechanical assembly 203 and is thus encompassed by the microelectromechanical assembly 203.The control element 209 has various components, such as electronics, connection and control lines for controlling the actuator system.

[0056] To ensure the free movement of the mirror substrate 206 during operation of the reflective optical assembly 200, the space between the mirror substrate and the microelectromechanical assembly 203 is open. This allows contaminants, particularly particles, to enter the space and impair the free movement of the mirror substrate 206, leading to a deterioration of the imaging properties of the reflective optical assembly 200. Therefore, for the operation of the reflective optical assembly 200, a correspondingly very clean environment is provided within an EUV projection exposure system 100. Additionally, it is necessary to integrate the microelectromechanical assemblies 203 into the reflective optical assembly 200 in an extremely clean condition.For this purpose, it is generally necessary to clean the microelectromechanical assemblies 203, in particular the spaces between the head region 204 and the front integration into the reflective optical assembly 200. It is also advantageous to perform this cleaning during various stages of the manufacturing process of the microelectromechanical assemblies 203, especially before coating.

[0057] For this purpose, Figure 3a shows an embodiment of a device 300 according to the invention for cleaning a first part of a surface 321 of a microelectromechanical assembly 301 in a vacuum. Figure 3b shows a corresponding arrangement 320 according to the invention, in which two microelectromechanical assemblies 301 are received by the device 300. Figures 3a and 3b are described together, and where possible, the same reference numerals are used.

[0058] The device 300 and the arrangement 320 comprise a lower part 302 and an upper part 303. The upper part 303 is sealed to the lower part 302 by means of a seal 304 and is detachably connected. The connection between the upper part 303 and the lower part 302 forms an interior chamber 305. The device 300 and the arrangement 320 also comprise a suction unit 306, which is connected to the device 300 or the arrangement 320 and provides a vacuum in the interior chamber 305. Furthermore, the device 300 and the arrangement 320 comprise a gas supply unit 307, wherein the gas supply unit 307 is also connected to the device 300 or the arrangement 320 and a targeted gas flow 308 for cleaning, in particular particle mobilization and cleaning in the chamber interior 305, can be provided by the gas supply unit 307.In the embodiments shown in Figures 3a and 3b, the suction unit 306 and the gas supply unit 307 are arranged on the lower part 302. Arrangement on the upper part 303 is equally possible.

[0059] To accommodate microelectromechanical assemblies 301 to be cleaned, the device 300 has a receiving area 309 with at least one recess for receiving at least one microelectromechanical assembly 301. In the embodiment according to Figure 3a, the recess of the receiving area 309 is formed on the upper part 303, the upper part 303 being equipped by sealing devices 312 for the sealing reception of two microelectromechanical assemblies 301. The sealing devices 312 can, for example, be circular or rectangular elastomer seals that encompass the corresponding complementary recess in the upper part and thereby enable a sealing reception of microelectromechanical assemblies 301. Of course, it is also possible for the receiving area 309 to be formed on the lower part 302.

[0060] The device 300 and the arrangement 320 further comprise a particle counter 310 for determining the quantity of particles. In the embodiments shown in Figures 3a and 3b, the particle counter 310 is arranged at the outlet of the suction unit 306. This allows the particle counter 310 to determine a quantity of particles representative of the chamber interior 305 and of any microelectromechanical assemblies 301 that can be collected or are already in place. The particle counter 310 is typically an optical measuring device that determines the number of particles 323 for different particle size classes using a light scattering method. The particle counter 310 can also be arranged in a defined area of ​​the chamber interior 305, thereby allowing the determination of a quantity of particles representative of this area. Continuous measurement of the quantity of particles by the particle counter 310 enables the monitoring of the cleaning process of the arrangement 320.Additionally, the particle quantity determined by the particle counter 310 can be transmitted to a control unit 311, enabling the control unit 311 to manage the cleaning process. For example, the control unit 311 can adjust the targeted gas flow 308 or the suction power of the suction unit based on the particle quantity determined by the particle counter 310.

[0061] The arrangement 320 according to the invention is achieved by the sealing connection of the two microelectromechanical assemblies 301. In this arrangement, only a first part of a surface 321 of the microelectromechanical assemblies 301 received by the receiving area 309 is exposed to the interior of the chamber 305. Typically, the first part of the surface 321 of the microelectromechanical assemblies 301 received by the device 300 is the head region 204 described in connection with Figure 2. A second part of a surface 322 of the microelectromechanical assemblies 301 received by the receiving area 309 is thus exposed to an area outside the interior of the chamber 305. Contaminants present on the second part of the surface 322, for example particles, are therefore separable from the interior of the chamber 305 and cannot contribute to cross-contamination of the first part of the surface 321.This advantageously allows different cleanliness requirements to be set for the first part 321 and the second part of the surface 322 of the microelectromechanical assemblies 301. Likewise, vacuum-incompatible components, such as sensitive electronics, can be used in the area of ​​the second part of the surface 322 of the microelectromechanical assemblies 301. Typically, the second part of the surface 322 of the microelectromechanical assemblies 301 held by the device 300 is the control element 209 described in connection with Figure 2.

[0062] The positioning of the microelectromechanical assemblies 301 in the arrangement 320 enables targeted vacuum-assisted cleaning of the first part 321 of the surface of the microelectromechanical assemblies 301 by means of the targeted gas flow 308. In particular, for the removal of particulate contaminants 323 from the space between the head region 204, the mobilization of the particulate contaminants 323 by the targeted gas flow 308 is advantageously supported by the vacuum provided in the chamber interior 305. The particulate contaminants 323 can then be carried out of the chamber interior 305 by the gas flow 308 towards the suction unit 306, thereby improving the cleanliness of the first part of the surface 321 of the microelectromechanical assemblies 301.

[0063] Figure 4a shows a further embodiment of a device 400 according to the invention for cleaning a first part of a surface 421 of a microelectromechanical assembly 401 in a vacuum. Figure 4b shows a corresponding arrangement 420 according to the invention, in which three microelectromechanical assemblies 401 are received by the device 400. Figures 4a and 4b are described together, and where possible, the same reference numerals are used.

[0064] The device 400 and the arrangement 420 each comprise a lower part 402 and an upper part 403. The upper part 403 is sealed to the lower part 402 by means of a seal 404 and is detachably connected. The connection between the upper part 403 and the lower part 402 forms an interior chamber 405. The device 400 and the arrangement 420 also comprise two suction units 406.1 and 406.2, which are connected to the device 400 or the arrangement 420 and by which a vacuum can be provided in the interior chamber 405.

[0065] Furthermore, the device 400 and the arrangement 420 comprise two gas supply units 407.1, 407.2, wherein the gas supply units 407.1, 407.2 are also connected to the device 400 or the arrangement 420 and each of the gas supply units 407.1, 407.2 provides two targeted and independent gas flows 408.1, 408.2 for cleaning, in particular particle mobilization, in the interior of the chamber 405. The two independent suction units 406.1, 406.2 allow the gas flows 408.1, 408.2 to be further individually controlled. For example, if in the embodiments shown in Figures 4a and 4b a gas flow 408.1 within the chamber interior 405 is provided only by the gas supply unit 407.1 and the suction unit 406.1, a cleaning effect can be localized to the left area of ​​the chamber interior 405.By providing more than two suction units and gas supply units, this local concentration of the cleaning effect, particularly with regard to particulate contamination 423, of the device 400 or the arrangement 420, can be further improved. This advantageously allows targeted addressing of areas within the chamber interior 405 in which a first part of a surface 421 of a microelectromechanical assembly 401 to be cleaned can be positioned. In the embodiments shown in Figures 4a and 4b, the suction units 406.1, 406.2 and the gas supply units 407.1, 407.2 are arranged on the lower part 402. Arrangement on the upper part 403 is equally possible.

[0066] To accommodate three microelectromechanical assemblies 401 to be cleaned, the device 400 has a receiving area for receiving the microelectromechanical assembly 401, wherein the receiving area is formed by three capsule elements 409, which are designed such that a second part of a surface 422 of the microelectromechanical assemblies 401, which are sealedly received by the capsule elements 409, is separable from the interior of the chamber 405, and only a first part of a surface 421 is exposed to the interior of the chamber for dedicated cleaning. For the sealed reception of the microelectromechanical assemblies 401, the capsule elements 409 each have sealing devices located at their lower end.The sealing devices are, for example, circular or rectangular elastomer seals whose size is complementary to the size of the opening of the capsule elements 409 and the size of the microelectromechanical assemblies 401 to be accommodated. Typically, the first part of the surface 421 of the microelectromechanical assemblies 401 that can be accommodated by or are accommodated by the device 400 is the head region 204 described in connection with Figure 2. Typically, the second part of the surface 422 of the microelectromechanical assemblies 401 that can be accommodated by or are accommodated by the device 400 is the control unit 209 described in connection with Figure 2.

[0067] The capsule elements 409 of the embodiments shown in Figures 4a and 4b are each connected to a positioning element 415. The positioning element 415 is designed to position the microelectromechanical assemblies 401, which are accommodated by the capsule element 409, within the chamber interior 405, particularly with regard to an adjustable gas flow within the chamber interior 405 and the associated cleanability of the microelectromechanical assemblies 401. In the embodiment shown in Figures 4a and 4b, the positioning element 415 is fixedly connected to the upper part 403. The positioning element 415 can also be fixedly connected to the lower part 402.The fixed combination of the upper part 403 with the positioning element 415 and the capsule elements 409 connected thereto allows the upper part 403 to be used as a component placement element, thereby advantageously reducing the integration steps required for cleaning the microelectromechanical assemblies 401. Figure 5a shows a further embodiment of a device 500 according to the invention for cleaning a first part of a surface 521 of a microelectromechanical assembly 501 in a vacuum. Figure 5b shows a corresponding arrangement 520 according to the invention in which three microelectromechanical assemblies 501 are received by the device 500. Figures 5a and 5b are described together, and where possible, the same reference numerals are used.

[0068] The device 500 and the arrangement 520 each comprise a lower part 502 and an upper part 503. The upper part 503 is sealed to the lower part 502 by means of a seal 504 and is detachably connected. The connection between the upper part 503 and the lower part 502 forms a chamber interior 505. Additionally, the device 500 and the arrangement 520 each comprise a suction unit 506, wherein the suction unit 506 is connected to the device 500 or the arrangement 520 and a vacuum can be provided in the chamber interior 505 by the suction unit 506.

[0069] Furthermore, the device 500 and the arrangement 520 each comprise a gas supply unit 507, wherein the gas supply unit 507 is also connected to the device 500 or the arrangement 520, and a targeted gas flow 508 for cleaning, in particular particle mobilization in the chamber interior 505, can be provided by the gas supply unit 507. In the embodiments shown in Figures 5a and 5b, the suction unit 506 and the gas supply unit 507 are arranged on the lower part 502. Arrangement on the upper part 503 is equally possible in each case.

[0070] To accommodate three microelectromechanical assemblies 501 to be cleaned, the device 500 has a receiving area for receiving the microelectromechanical assemblies 501, wherein the receiving area is formed by three capsule elements 509, which are designed such that a second part of a surface 522 of the microelectromechanical assemblies 501, which are sealedly received by the capsule element 509, is separable from the interior of the chamber 505, and only a first part of a surface 521 is exposed to the interior of the chamber 505 for dedicated cleaning. For the sealed reception of the microelectromechanical assembly 501, the capsule elements 509 each have sealing devices located at their lower end.The sealing devices are, for example, circular or rectangular elastomer seals whose size is complementary to the size of the opening of the capsule elements 509 and the size of the microelectromechanical assemblies 501 to be accommodated. Typically, the first part of the surface 521 of the microelectromechanical assemblies 501 that can be accommodated by or are accommodated by the device 500 is the head region 204 described in connection with Figure 2. Typically, the second part of the surface 522 of the microelectromechanical assemblies 501 that can be accommodated by or are accommodated by the device 500 is the control unit 209 described in connection with Figure 2.

[0071] The capsule elements 509 of the embodiments shown in Figures 5a and 5b are each detachably or permanently connected to a positioning element 515. The positioning element 515 is designed to position the microelectromechanical assemblies 501, which can be received by the capsule element 509, within the chamber interior 505, particularly with regard to the position of an adjustable gas flow within the chamber interior 505 and the associated cleanability of the microelectromechanical assemblies 501. In the embodiments shown in Figures 5a and 5b, the positioning element 515 is detachably connected to the lower part 503 via receptacles 513. This detachable connection allows multiple units of positioning elements 515 with connected capsule elements 509 to be used, and these units can be efficiently fitted with the microelectromechanical assemblies 501 outside the device 500.

[0072] The device 500 and the arrangement 520 each include a further cleaning element 517, for example, a plasma source, a temperature control unit, a UV light source, or an ozone generator. Likewise, the device 500 or the arrangement 520 can include several of these cleaning elements, including a combination of the examples mentioned. Certain types of contaminants, for example, volatile and non-volatile organic contaminants, can only be partially removed by a targeted gas flow in combination with the assistance of a vacuum. The removal of contaminants from the first part of the surface 521 of the microelectromechanical assemblies 501 can be further improved by the listed additional cleaning elements 517. This can be achieved, for example, predominantly physically through the input of energy (temperature control unit, UV light source) or predominantly chemically (ozone generator, plasma source).These additional cleaning elements 517 also improve the cleaning of the device 500 itself before the microelectromechanical assembly 501 is installed.

[0073] The device 500 and the arrangement 520 further comprise two guide elements 518 within the chamber interior 505. The guide elements 518 are arranged in the region of the gas supply unit 507 and are designed to increase turbulence of the targeted gas flow 508 within the chamber interior 505. Due to the turbulent gas flow 508, portions of the gas flow 508 can be applied at different angles to the first part of the surface 521 of the microelectromechanical assemblies 501 that can be received or received. The guide element 518 thus further increases the probability of mobilizing particulate contaminants 523, particularly since the particulate contaminants 523 can occur in different, difficult-to-access areas of the first part of the surface 521.

[0074] The device 500 and the arrangement 520 further comprise a sensor unit 516 for determining the cleanliness of the first part of the surface 521 of the microelectromechanical assemblies 501 that can be detected or are detected by the detection area 509. In particular, the sensor unit 516 is an optical sensor unit, for example, a high-resolution camera for inspecting particulate contamination 523. The camera can also be configured to obtain hyperspectral information, thereby enabling the first part of the surface 521 to be analyzed not only for particulate information 523 but also for organic contamination. Advantageously, the sensor unit 516 inspects areas sensitive to contamination, such as the mirror substrate with any reflective coating that may be present, or the area of ​​the space between the microelectromechanical assembly 501 with the suspension system and the actuator system.In the embodiments shown in Figures 5a and 5b, the sensor unit 516 is arranged opposite a surface of the mirror substrate for this purpose. The sensor unit 516 can also be configured as a mass spectrometer for residual gas analysis of the chamber interior 505, thereby obtaining indirect information regarding the cleanliness of the first part of the surface 521 of the microelectromechanical assemblies 501 that can be detected or have been detected by the detection area 509.

[0075] The device 500 and the arrangement 520 further comprise a control unit 511 for controlling the device 500 or the arrangement 520 based on the cleanliness status determined by the sensor unit 516. For this purpose, the control unit 511 is connected to the sensor unit 516 to receive the information determined by the sensor unit 516. The control unit 511 is also connected, for example, to the suction unit 506, the gas supply unit 507, or other cleaning elements 517. For example, the controlled unit 511 can change the targeted gas flow 508 provided by the gas supply unit 507 or the suction power of the suction unit 506. The control unit 511 enables the device 500 and the arrangement 520 to be automated.

[0076] Figure 6 shows an embodiment of the inventive method for cleaning a first part of a surface of a microelectromechanical assembly.

[0077] In a first step (a), a device according to the invention or an embodiment thereof is provided. An embodiment according to Figures 3a, 4a or 5a can already be provided as the device.

[0078] In a second step (b), the at least one microelectromechanical assembly is received by the device provided in step (a) in such a sealing manner that only the first part of the surface, which is exposed to an interior chamber of the device, is exposed. If a device according to Figures 3a, 4a, or 5a is provided in step (a), an arrangement corresponding to Figures 3b, 4b, or 5b is obtained. For receiving the microelectromechanical assembly, the device has a specially designed receiving area, for example, a recess in the upper or lower part or a capsule element, each with sealing devices. These elements are adapted to the size of the microelectromechanical assembly so that it can be received, for example, by insertion into the device.To assist with the fixing process, the sealing device can be designed as a differentially pumped double seal.

[0079] In a third step (c), a vacuum is provided in the chamber interior of the arrangement by a suction unit of the device. Typically, the vacuum is in the region of 10 -2mbar - 200 mbar is provided, which is particularly advantageous for particle mobilization in combination with a targeted gas flow in hard-to-reach areas of the first part of the surface of the microelectromechanical assembly, as a predominantly viscous gas flow is established. In a fourth step (d), a targeted gas flow is provided in the chamber interior for cleaning, in particular particle cleaning, of the first part of the surface of the at least one microelectromechanical assembly. Typically, a gas such as nitrogen, CDA (Clean Dry Air), XCDA (Extreme Clean Dry Air), or a noble gas available in a high cleanliness class is used as the gas for the targeted gas flow. The provided targeted gas flow depends on the size of the chamber interior and the suction capacity of the suction unit, advantageously achieving the pressure conditions described for a viscous flow.

[0080] In a fifth step (e), the cleanliness of the first part of the surface of the microelectromechanical assembly is determined using a sensor unit and / or the particle quantity is determined using a particle counter. The cleanliness corresponds, for example, to a particle concentration according to DIN EN ISO 14644 or can be converted into this quantity.

[0081] In particular, an optical sensor unit is used, for example, a high-resolution camera for inspecting particulate contamination. Advantageously, this unit can acquire hyperspectral information, allowing for the identification of different contamination classes among the particles. An optical measuring device is typically used as the particle counter, determining the number of particles for different particle size classes using a light scattering method. By positioning the particle counter in a specific area of ​​the chamber interior, a representative sample of particles for that area is obtained. Typically, the particle counter is located at an outlet of the suction unit, thus providing a representative result for the entire chamber interior.

[0082] The cleaning process is monitored by continuously determining the cleanliness of the first part of the surface of the microelectromechanical assembly using the sensor unit and / or the particle count using the particle counter in step (e). For example, an endpoint of the cleaning process can be advantageously determined based on this data, thus avoiding unnecessary cleaning time.

[0083] In a sixth step (f) the process is controlled, in particular terminated, based on the determined cleanliness status and / or the determined particle quantity from step (e).

[0084] The device includes a control unit for operation. Data acquired by the particle counter or sensor unit is transmitted to the control unit. Based on this data, and in particular on target values ​​stored within the control unit, the cleaning process is controlled by the control unit. For this purpose, the control unit is connected, for example, to the suction unit, the gas supply unit, and / or other cleaning elements. For instance, the control unit modifies the targeted gas flow provided by the gas supply unit or the suction power of the suction unit. If the data within the chamber interior is acquired with a certain spatial resolution, the process can also be controlled according to specifically defined areas within the chamber interior. This can be achieved, for example, by multiple suction units and / or gas supply units arranged on the device.The control of the process includes automation. Reference mark.

[0085] 100 EUV projection exposure system 101 housing

[0086] 102 - 112 optical components

[0087] 113 Radiation source

[0088] 114 Lighting system

[0089] 115 object field

[0090] 116 Object level

[0091] 117 Projection optics

[0092] 118 reticles

[0093] 119 label holders

[0094] 120 image field

[0095] 121 Image plane

[0096] 122 wafers

[0097] 123 wafer holders

[0098] 124 EUV radiation

[0099] 125 Intermediate focus

[0100] 200 Reflective Optical Assembly

[0101] 201 substrate bodies

[0102] 202 capacity

[0103] 203 microelectromechanical assembly 204 head area

[0104] 205 Basic element

[0105] 206 Mirror substrate

[0106] 207 Suspension system

[0107] 208 Actuator system

[0108] 209 Control element

[0109] 300 Cleaning device

[0110] 301 microelectromechanical assemblies 302 lower part

[0111] 303 Top

[0112] 304 Seal

[0113] 305 Chamber interior

[0114] 306 Suction unit

[0115] 307 Gas supply unit

[0116] 308 targeted gas flow

[0117] 309 Recording area

[0118] 310 particle counters

[0119] 311 Control unit

[0120] 312 Sealing devices 320 Arrangement

[0121] 321 First part of a surface of the microelectromechanical assembly 322 Second part of a surface of the microelectromechanical assembly 323 Particle

[0122] 400 Cleaning device

[0123] 401 microelectromechanical assemblies

[0124] 402 Lower part

[0125] 403 Top

[0126] 404 Seal

[0127] 405 Chamber interior

[0128] 406.1 / 406.2 Suction unit

[0129] 407.1 / 407.2 Gas supply unit

[0130] 408.1 / 408.2 targeted gas flow

[0131] 409 Recording area / Capsule element

[0132] 415 Positioning element

[0133] 420 Arrangement

[0134] 421 First part of a surface of the microelectromechanical assembly 422 Second part of a surface of the microelectromechanical assembly 423 Particles

[0135] 500 Cleaning device

[0136] 501 microelectromechanical assemblies

[0137] 502 Lower part

[0138] 503 Top

[0139] 504 Seal

[0140] 505 Chamber interior

[0141] 506 Suction unit

[0142] 507 Gas supply unit

[0143] 508 targeted gas flow

[0144] 509 Recording area / Capsule element

[0145] 511 Control unit

[0146] 513 Recording unit

[0147] 515 Positioning element

[0148] 516 Sensor unit

[0149] 517 additional cleaning element

[0150] 518 Guide element

[0151] 520 Arrangement

[0152] 521 First part of a surface of the microelectromechanical assembly 522 Second part of a surface of the microelectromechanical assembly 523 Particle

[0153] af process steps

Claims

23 Patent claims 1. Device (300, 400, 500) for cleaning only a first part of a surface (321, 421, 521) of a microelectromechanical assembly (301, 401, 501) in a vacuum comprising, - a lower part (302, 402, 502), - an upper part (303, 403, 503), wherein the upper part (303, 403, 503) is sealingly (304, 404, 504) and detachably connectable to the lower part (302, 402, 502) and wherein a chamber interior can be formed by the connection of the lower part (302, 402, 502) and the upper part (303, 403, 503) (305, 405, 505), - a suction unit (306, 406.1 , 406.2, 506), wherein the suction unit (306, 406.1 , 406.2, 506) is connected to the device (300, 400, 500) and a vacuum can be provided in the chamber interior (305, 405, 505) by the suction unit (306, 406.1 , 406.2, 506), - a gas supply unit (307, 407.1 , 407.2, 507), wherein the gas supply unit (307, 407.1 , 407.2, 507) is connected to the device (300, 400, 500) and a targeted gas flow (308, 408.1 , 408.2, 508) for particle mobilization in the chamber interior (305, 405, 505) can be provided by the gas supply unit (307, 407.1 , 407.2, 507), characterized by the fact that The device (300, 400, 500) further comprises a receiving area (309, 409, 509) for the sealing reception of at least one microelectromechanical assembly (301, 401, 501), wherein the receiving area (309, 409, 509) is configured such that only the first part of a surface (321, 421, 521) of the microelectromechanical assembly (309, 409, 509) to be received by the receiving area (309, 409, 509) is exposed to the interior of the chamber (305, 405, 505) and a second part of the surface (322, 422, 522) of the microelectromechanical assembly (309, 409, 509) is exposed to the interior of the chamber (305, 405, 505) from the interior of the chamber (405, 505) separable is 2. Device (300) according to claim 1 , characterized in that the receiving area (309) on the upper part (303) and / or lower part (302) is formed by at least one recess, wherein the upper part (303) and / or the lower part (302) is provided by at least one sealing device for the sealing reception of at least one microelectromechanical assembly (301).

3. Device (400, 500) according to claim 1 , characterized in that the receiving area comprises a capsule element (409, 509) which is designed such that a second part of a surface (322, 422) of the microelectromechanical assembly (401, 501) which can be received by the capsule element (409, 509) in a sealing manner is separable from the interior of the chamber (405, 505).

4. Device (400, 500) according to claim 3, characterized in that The capsule element (409, 509) is connected to a positioning element (415, 515), wherein the positioning element (415, 515) is designed to position the microelectromechanical assembly (401, 501) that can be received by the capsule element (409, 509) within the chamber interior (405, 505).

5. Device (400, 500) according to claim 4, characterized in that the positioning element (415, 515) is fixedly or detachably connected to the upper part (403, 503) and / or lower part (402, 502).

6. Device (300) according to one of claims 1-5, characterized in that the device (300) comprises a particle counter (321) for determining a quantity of particles.

7. Device (400) according to one of claims 1-6, characterized in that the device (400) comprises a plurality of suction units (406.1 , 406.2) and / or gas supply units (407.1 , 407.2).

8. Device (500) according to one of claims 1-7, characterized in that the device (500) comprises at least one guide element (518) within the chamber interior (505), in particular in the area of ​​the gas supply unit (507), which is designed to increase turbulence of the targeted gas flow (508) within the chamber interior (505).

9. Device (500) according to one of claims 1-8, characterized in that the device (500) comprises at least one plasma source, one temperature control unit, one UV light source and / or one ozone generator as further cleaning elements (517).

10. Device (500) according to one of claims 1-9, characterized in that the device (500) includes a sensor unit (516) for determining the cleanliness state of the first part of the surface (521), which comprises the microelectromechanical assembly (501) that can be received by the receiving area (509).

11. Device (300, 500) according to one of claims 1-10, characterized in that The device (300, 500) comprises a control unit (311, 511) for controlling the device (300, 500) based on the cleanliness status determined by the sensor unit (516) and / or on the basis of the particle quantity determined by the particle counter (310).

12. Arrangement (320, 420, 520) for cleaning a first part of a surface (321, 421, 521) of a microelectromechanical assembly (301, 401, 501) comprising a device (300, 400, 500) according to one of claims 1-11 and a microelectromechanical assembly (301, 401, 501) received by the device (300, 400, 500) such that only the first part of the surface (321, 421, 521) of the microelectromechanical assembly (301, 401, 501) is exposed to a chamber interior (305, 405, 505) of the device (300, 400, 500).

13. Method for cleaning a first part of a surface of a microelectromechanical assembly comprising the steps of:- providing a device according to one of claims 1-11 (a), - Receipt of at least one microelectromechanical assembly by the device such that only the first part of the surface of the at least one microelectromechanical assembly is exposed to a chamber interior of the device (b), and a second part of a surface of the microelectromechanical assembly is arranged outside the chamber interior and / or separated from it, - Providing a vacuum in the chamber interior (c), - Providing a targeted gas flow for cleaning, in particular particle cleaning, of the first part of the surface of the at least one microelectromechanical assembly (d) 14. Method according to claim 13, characterized in that In a further step, at least a partial cleanliness state of the first part of the surface of the microelectromechanical assembly is determined by means of an inspection element and / or a particle quantity is determined by means of a particle counter (e).

15. Method according to claim 14, characterized in that The process is controlled, in particular terminated, based on the determined cleanliness level and / or the determined particle quantity (f).

16. Microelectromechanical assembly (301 , 401 , 501) cleaned by a device (300, 400, 500) according to any one of claims 1-11 and / or according to a method according to any one of claims 13-15.

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