DE102016203666A1 - DEVICE AND METHOD FOR ANALYZING THE CONTAMINATION STATE OF A SURFACE - Google Patents

Abstract

The present invention relates to a method and a corresponding apparatus for analyzing contaminations on surfaces (11), in which a bell (5) covers at least part of the surface and a fluid is directed onto the part of the surface covered by the bell, to dislodge contaminants from the surface and to pump fluid out of the bell and analyze for contained contaminants to obtain information on the surface contamination state from the analysis of the bell-pumped fluid.

Description

BACKGROUND OF THE INVENTION

FIELD OF THE INVENTION

The present invention relates to an apparatus and method for analyzing contaminants on surfaces.

STATE OF THE ART

In microlithographic processes for the production of nanostructured or microstructured components of electrical engineering and microsystem technology, structures which are formed on a reticle are imaged onto a wafer with a projection exposure apparatus. In order to resolve small structure sizes, it is necessary that this used equipment, aids and starting materials have no impurities or contamination, but all the components involved have a high surface purity, since even the smallest contamination with particles and the like can lead to significant changes and damage. Thus, for example, both the reticle carrying the structures and the wafer must have a high surface purity, since otherwise particles can adulterate and destroy the desired structure on the wafer.

In order to be able to take suitable measures for the desired surface purity, it is important to be aware of the state of contamination of the surfaces in the picture. In particular, an analysis of contaminants can be used to identify and eliminate sources of contamination. Accordingly, components to be used in projection exposure equipment, and in particular components to be used in high resolution EUV (extreme ultraviolet) projection exposure equipment, must be characterized and monitored for particle contamination.

This is from the DE 10 2014 207 109 A1 a method and a device for determining the contamination of surfaces, in which a fluid is passed to the surface to be examined in order to detach contaminants therefrom. The detached and absorbed in the fluid contaminants can then be counted by particle counter. Although this already achieves good results, there is still room for improvement.

DISCLOSURE OF THE INVENTION

OBJECT OF THE INVENTION

It is therefore an object of the present invention to provide a method and a device for analyzing the state of contamination of surfaces, which make it possible to make quantitative and / or qualitative statements about the occupancy of the surface with contaminants, starting from which appropriate remedial measures, such as Cleaning the concrete surface affected, and / or to take measures to prevent such contamination. In this case, the corresponding method is easy to use and the device should be simple and variable for a variety of different contaminants. In particular, contaminations with different sizes of contaminant particles should be able to be analyzed with high precision.

TECHNICAL SOLUTION

This object is achieved by a method having the features of claim 1 and a device having the features of claim 9. Advantageous embodiments are the subject of the dependent claims.

In a method and a device for analyzing contaminations on surfaces of components or components, in particular of a projection exposure apparatus, the invention proposes providing a bell or hood with which a part of the surface to be analyzed can be covered. In the area covered with the bell or hood, according to the invention, contaminants located on the surface are to be removed from the surface with a fluid which is directed onto the surface, in order to absorb the contaminant which has caused the detachment and in which the contaminations are accordingly absorbed have been pumped out of the bell and fed to a corresponding analysis device. In the analyzer, the fluid extracted from the bell with the contaminants received therein can be examined to obtain quantitative and / or qualitative information about the contaminants originally contained in the fluid to be tested.

The analysis device used may be any suitable examination device and method with which quantitative and / or qualitative information about the contained contaminants can be obtained. In particular, particle counters and / or particle filters can be used to make statements about the number of the To obtain the surface to be examined detached particles and to determine the chemical composition of the filtered out particles. In addition, however, other analysis devices can be used with which the shape and / or size of the contaminants received in the fluid can be determined in the form of particles, such as optical methods.

The fluid used to remove the contaminants from the surface to be examined and to remove the contaminants to the analyzer may be a gas or a liquid or a plasma. A gaseous fluid may in particular be ionized, particle-free air or nitrogen. In addition, other high purity, inert gases can be used.

The fluid is directed in a turbulent flow to the surface to be examined in order to effect effective separation of contaminants from the surface to be examined by the turbulence within the fluid.

For this purpose, the fluid can also be directed onto the surface in a plurality of jets, the jets in particular being able to be angled relative to one another or the direction of irradiation of the fluid jets to be different from the surface to be examined.

A corresponding device for analyzing the contamination situation on a surface thus comprises a nozzle device with a plurality of nozzles, via which the fluid can be directed to the surface to be examined, wherein the nozzles are oriented such that the dispensing direction of the nozzles is directed in different directions.

At least one, preferably a plurality of the fluid jets emitted by the nozzle device, which can be directed onto the surface to be examined, can be guided in such a way that the fluid jet (s) can be changed with respect to the orientation and / or position with respect to the surface to be analyzed, so that different geometric or topographical conditions can be taken into account.

For this purpose, the nozzle device or parts thereof may be arranged to be movable, wherein in particular a rotatable arrangement of the nozzle device is possible. Moreover, the movement of the nozzle device or parts thereof and the fluid jet correspondingly discharged from the nozzle device may also comprise other types of movement, such as a reciprocating motion.

In order to generate a turbulent flow on the surface to be analyzed, one or more nozzles of the nozzle device and / or the nozzle device as a whole can also be designed such that an angular momentum is imparted to the outflowing fluid. This can be done, for example, by having a nozzle on an inner wall having one or more spiral-shaped grooves that guide outflowing fluid and output, according to the spiral shape, with an angular momentum about the central output axis of the nozzle, which is centered to the inner wall of the nozzle. In addition, a nozzle may also have a curved shape such that the center axis, i. the central output axis, the nozzle, which in each case extends centrally in the planes transverse to the wall of the nozzle, has an arcuate shape. As a result, the outflowing fluid can also be provided with an angular momentum.

Further, the nozzle device may comprise a plurality of nozzles, which may be arranged on or along the leaves of a two- or multi-bladed propeller and / or at the tips of a star shape and / or annular.

The one or more nozzles of a nozzle device can in turn be adjustably, in particular pivotably and / or rotatably accommodated within the nozzle device or with respect to a carrier in order to be able to apply a suitable fluid jet to all regions of the surface to be examined or to provide a suitable turbulent flow produce.

In particular, a nozzle can be arranged to be pivotable about an axis of rotation transversely to an axial direction of a supply line and / or rotatable about the axial direction of the supply line, so that the output end of a nozzle can be adjusted in a circular path, for example.

The nozzle device or parts thereof can be arranged eccentrically to the bell, which itself can be rotationally symmetrical, so that, for example, during a rotary movement of the eccentric nozzle device or the corresponding parts thereof, the fluid jets emerging from the nozzle device are moved in circular paths over the surface to be examined can. This makes it possible to effect a temporally variable admission of the surface to be analyzed with the fluid jets, which enables better separation of the contaminations.

The same can also be achieved by directing the fluid at intervals onto the surface to be examined and / or repeated repetitions of the corresponding processing of the surface to be examined preferably with changing the adjustable parameters is performed.

The detachment of the contaminants on the surface to be analyzed can be further supported by the fact that the surface to be examined is irradiated with electromagnetic radiation, in particular high-energy electromagnetic radiation, such as laser light, by the interaction of the electromagnetic radiation with the surface and the contaminations thereon intensify their replacement. The irradiation with electromagnetic radiation can also be carried out at intervals.

In addition, the surface to be examined can also be heated, for which purpose heating devices, such as electric heating elements and / or radiant heaters (infrared radiators) can be used. Also by increasing the temperature, the separation of the contaminants from the surface to be examined can be improved.

The fluid can be directed to the surface to be examined at a pressure which is higher than the ambient pressure, thereby also improving the detachment of contaminants.

In order to avoid that fluid escapes from the region of the surface covered with the bell, without passing to the analysis device (s), the bell covering the surface to be examined may be provided with a sealing arrangement which ensures a tight fit Allows bell on the surface to be examined, so that the introduced into the bell fluid can escape only via a suction device back out of the bell and thus can be inevitably fed to the analysis devices.

The sealing arrangement of the bell may have a sealing ring, which may be formed of a fluoroelastomer, in particular a perfluoroelastomer.

The bell may be made of a transparent material that is transparent to both the light visible to the eye and any electromagnetic radiation to be radiated from outside to aid in the removal of the contaminants. The transparency of the visible light bulb provides the advantage that during processing of the surface to be examined, it can be inspected to determine if there are any particular topographical conditions requiring special treatment.

The apparatus or the method for the analysis of contaminations can be generally used or applied to any components or components, but in addition to the already mentioned components and components of projection exposure systems in particular components and components of equipment come into question in which a particular purity of Surfaces and the knowledge of possible contamination of importance, such as components and components of mask or wafer inspection apparatuses and metrology systems, which are used, for example, in turn, for the measurement of projection exposure equipment or parts thereof.

BRIEF DESCRIPTION OF THE FIGURES

The accompanying drawings show in a purely schematic manner in FIG

1 a view of a first embodiment of a device according to the invention for the analysis of the contamination state of a surface,

2 a sectional view along the section line AA 1 .

3 1 is a representation of a second embodiment of a device according to the invention for analyzing the state of contamination of a surface;

4 a detailed view with respect to a nozzle of the device 3 .

5 a representation of another embodiment of a device according to the invention for analyzing the contamination state of a surface,

6 a detailed view of a nozzle assembly, as for example in the embodiments of the device of 1 . 3 and 5 Can be used

7 a representation of a nozzle, as used for example in the embodiments of the device of 1 . 3 and 5 Can be used, and in

8th a further illustration of a nozzle, as used for example in the embodiments of the device of 1 . 3 and 5 Can be used.

EMBODIMENTS

Further advantages, characteristics and features of the present invention will become apparent in the following detailed description of the Embodiments with reference to the accompanying drawings clearly. However, the invention is not limited to these embodiments.

The 1 shows in a purely schematic representation of a device 1 for analysis of contaminants that are located on a surface to be examined 11 For example, a component of an EUV projection exposure system can be located. For the analysis of the state of contamination, the device has a bell 5 on that with a supply line 2 is provided for a fluid in the form of ionized, particle-free air or nitrogen, so that the fluid in the bell 5 covered space above the surface 11 can be introduced.

At the feed line 2 is a nozzle device 3 provided on the supply line 2 opposite end three nozzles 4 having the star-shaped or pyramid-shaped from a central, connected to the supply line main line 13 the nozzle device 3 stand out, with the nozzles 4 each with respect to one through the main line 13 defined axis of rotation have an angular distance of 120 degrees to each other. This is in detail in the sectional view of 2 to see who made a cut along the section line AA 1 shows, where the nozzles 4 and the bell 5 can be seen. About the feed line 2 and the nozzle device 3 the fluid becomes on the surface to be examined 11 steered by the bell 5 and one between the bell 5 and the surface 11 arranged seal 6 is limited. The seal 6 DuPont, for example, by an O-ring made of fluorine elastomer, particularly a perfluoroelastomer be formed, for example, a so-called Kalrez ^® O-ring of the Fa. be formed. The seal 6 seals the space of the bell 5 and the surface to be examined 11 trapped gas-tight, so no fluid at the interface between the bell 5 and surface 11 can escape.

The nozzle device 3 is rotatable on the supply line 2 arranged so that the nozzle device 3 with the nozzles 4 around the axial axis of the feed line 2 or the main line 13 the nozzle device 3 defined rotation axis is rotatable. This results in a temporally variable loading of the surface 11 with the outflowing fluid and a uniform treatment of the entire surface to be analyzed 11 reached.

The bell 5 also has a suction line 7 on, which are adjacent to the feed line 2 at the surface 11 opposite side of the bell 5 is arranged so that fluid from the bell 5 can be sucked off, which may contain contaminants on the surface 11 have been removed by the irradiation or spraying or spraying with the fluid stream.

In the suction line 7 are a particle counter 8th as well as a particle filter 9 arranged with those of the surface 11 detached contaminations in the form of particles can be examined. With the particle counter 8th can the number of im out of the bell 5 taken from fluid containing particles are determined. In addition, further particle analysis devices (not shown) may be provided with which further properties of the contaminants contained in the fluid can be determined. For example, the shape and / or size of the particles could be determined by optical measurements. In addition, the particles filtered out in the particulate filter can be subjected to a chemical analysis, so that information about the composition of the contaminants from the surface 11 have been replaced can be obtained. With the reference number 15 is a pump called the fluid through the suction line 7 can suck.

The 3 shows a further embodiment of a device according to the invention 10 for the analysis of contaminations on a surface 11 , wherein the same components as in the embodiment of the 1 are provided with the same reference numerals, so that a repeated description of these components is unnecessary.

The embodiment of the device 10 according to 3 differs from the embodiment of the 1 in that curved nozzles 40 are provided so that through the nozzles 40 flowing fluid receives an angular momentum. As a result, a particularly turbulent flow can be set, in addition to the rotation of the nozzle device 3 around the main line 13 defined axis of rotation from the nozzles 40 outflowing fluid additionally has an internal rotation.

In addition, the nozzles can 40 rotatable on the main line 13 the nozzle device 3 be arranged so that the nozzle exit direction 41 , along which the fluid from the nozzle 40 leaking, with respect to the impact angle α on the surface 11 can be changed, as in the 4 is shown. This allows, depending on the application, a particularly intensive detachment of contaminants from the surface to be examined 11 to reach. In particular, the angle of incidence α during machining, ie during the impact of the fluid on the surface to be examined 11 , be adjusted, in particular oscillated between different positions, and / or it may in a repeated, intermittent loading of the surface to be examined 11 with the fluid one another Impact angle α can be selected so that contaminants can be detached at different angles of incidence.

The 5 shows a further embodiment of a device according to the invention 100 in which, again, the same components are denoted by the same reference numerals and will not be described again for the sake of simplicity and brevity. The embodiment of the 5 differs from the previous embodiments of the 1 and 3 in that a different nozzle device 300 with different types of nozzles 400 is provided. However, it should be mentioned that the individual components of the different embodiments of the 1 . 3 and 5 can also be used in the other embodiments, so the nozzle device of the embodiment of 5 also in embodiments of the 1 and 3 can be used and vice versa. In the same way, the nozzles can 400 the embodiment of the 5 in the embodiments of the 1 and or 3 Use and vice versa.

The nozzle device 300 the embodiment of the 5 is characterized by the fact that the main line 301 the nozzle device 300 that the feed line 2 with the nozzles 400 connects, a pipe bend 302 so that parts of the main line 301 as well as the nozzles 400 with the nozzle feed lines 401 eccentric to the central axis 200 the bell 5 are arranged so that upon rotation of the nozzle device 300 around the central axis 200 the bell, the nozzles 400 on a circular path over the surface to be examined 11 be guided. The nozzles 400 are in turn star-shaped at the ends of the blades of a three-bladed propeller passing through the nozzle feed lines 401 is formed, wherein in the embodiment of the 5 the nozzles or nozzle supply lines 401 do not run obliquely downwards, as in the embodiment of 1 but are arranged in one plane.

Further, in the device 100 according to 5 a laser 12 provided by the transparent to the laser light bell 5 Laser light, in particular pulsed laser light on the surface to be examined 11 can radiate to through the interaction of the laser light with the surface 11 or the contaminations arranged thereon to contribute to their replacement. In addition, other means for generating shock waves or the like may be provided, with which contaminations of the surface to be examined 11 can be replaced.

In the embodiment of the 5 is still a heater with heating elements 14 shown with their help the surface to be examined 11 can be heated to also by an elevated temperature, the detachment of contaminants from the surface to be examined 11 to effect. The heating elements 14 may be electrical resistance heating elements or radiant heaters, such as infrared radiators or the like.

The nozzles 400 the nozzle device 300 are in the embodiment shown the 5 at star-shaped nozzle supply lines 401 arranged, with the nozzles 400 with respect to the nozzle feed lines 401 is arranged pivotably and rotatably, as in the 6 is shown.

The 6 shows a nozzle supply line 401 , at the end of which a nozzle 400 is arranged. The nozzle feed line 401 defines a nozzle feed direction 402 , the central, axial axis of the nozzle supply line 401 equivalent. The nozzle 400 is so at the nozzle feed line 401 arranged that the nozzle 400 both around the nozzle feed direction 402 rotatable as well as about a transverse, in particular perpendicular axis 403 is pivotable, so that a central Fluidauslassrichtung 404 the nozzle 400 opposite the nozzle feed direction 402 can be pivoted by an angle β. Due to the additional rotation around the nozzle feed direction 402 can the nozzle 400 with its nozzle opening 405 be moved on a circular path. This is how the nozzle is made 400 variably set the delivered fluid flow or fluid jet.

The 7 and 8th show two examples of nozzles 410 and 420 as in the embodiment of the 5 and 6 but also in the preceding embodiments of 1 and 3 can be used.

At the nozzle 410 of the 7 are at the nozzle inner wall 407 one or more grooves 406 formed spirally along the nozzle inner wall 407 run, leaving fluid in or in the corresponding grooves 406 is guided, the nozzle 410 with an angular momentum about the central nozzle axis 408 leaves.

In the embodiment of the nozzle 420 of the 8th is the central nozzle axis 409 , which by a uniform distance to the surrounding nozzle inner wall 407 in each case perpendicular to the nozzle inner wall 407 standing plane is defined, curved, so that through the nozzle 420 the embodiment of the 8th flowing fluid also receives an angular momentum.

The devices described 1 . 10 . 100 for the analysis of the contamination state of a surface 11 can now operate in the way be that first, the bell 5 on the surface to be examined 11 attached and a fluid, such as ionized, particle-free air or nitrogen or a liquid medium through the Fluidzuführleitung 2 in the interior of the bell 5 introduced and over the nozzle device 3 . 300 with the nozzles 4 . 40 . 400 . 410 . 420 on the surface to be examined 11 is applied. By the impact of the fluid on the surface to be examined 11 be supported, if necessary, by additional heating or irradiation with electromagnetic radiation or by generating other shock waves, contamination of the surface to be examined 11 dissolved and with the fluid through the suction line 7 from the bell 5 removed and to appropriate analysis facilities 8th . 9 transported there to be examined in terms of size, shape and / or chemical composition. For the investigation of the contaminations a variety of investigation methods can be used, which can characterize the contaminants that are contained in the fluid and / or filtered out of the fluid accordingly.

The fluid can with an overpressure relative to the surrounding atmosphere on the surface to be examined 11 be consumed in order to cause a solution of contamination at the corresponding impact.

With the described apparatus and the described method for carrying out an analysis of the contamination state of a surface, an exact and accurate characterization of a surface with regard to possible contaminations can be carried out.

Although the present invention has been described with reference to the exemplary embodiments, it is obvious to a person skilled in the art that the invention is not restricted to these exemplary embodiments, but rather deviations are possible in such a way that individual features can be omitted or other types of combinations of features can be realized. without departing from the scope of the appended claims. The present disclosure includes all combinations of the features presented.

LIST OF REFERENCE NUMBERS

1, 10, 100

 Device for analyzing the state of contamination of surfaces

2

 feed

3, 300

 nozzle device

4, 40, 400, 410, 420

 jet

5

 Bell jar

6

 poetry

7

 suction

8th

 particle counter

9

 particulate Filter

11

 surface

12

 laser

13, 301

 main

14

 heating elements

15

 pump

41

 Nozzle outlet direction

200

 central axis

302

 pipe bend

401

 Düsenzuführleitung

402

 Düsenzuführrichtung

403

 axis

404

 Fluidauslassrichtung

405

 nozzle opening

406

 groove

407

 Nozzle inner wall

408, 409

 central nozzle axis

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102014207109 A1 [0004]

Claims (18)

Method for analyzing contaminations on surfaces ( 11 ), in which with a bell ( 5 ) covering at least a portion of the surface and directing a fluid to the portion of the surface covered by the bell to dislodge contaminants from the surface, and wherein fluid is pumped out of the bell and analyzed for contained contaminants to determine by analysis of the bell-pumped fluid to obtain information about the contamination state of the surface, characterized in that the fluid in a turbulent flow to the surface ( 11 ). A method according to claim 1, characterized in that the fluid in a plurality of jets on the surface ( 11 ) is directed, wherein the beams are in particular aligned at an angle to each other. Method according to one of the preceding claims, characterized in that the fluid with one or more with respect to the surface to be examined ( 11 ) moving rays is directed to the surface. Method according to one of the preceding claims, characterized in that the fluid which is deposited on the surface ( 11 ), ionized, particle-free air and / or nitrogen. Method according to one of the preceding claims, characterized in that the fluid is passed to the surface under a pressure which is increased in relation to the environment. Method according to one of the preceding claims, characterized in that the surface ( 11 ) is additionally irradiated by high-energy, electromagnetic radiation, in particular laser beams, preferably at intervals and / or is heated. Method according to one of the preceding claims, characterized in that the fluid sucked out of the bell by a particle counter ( 8th ) and / or a particulate filter ( 9 ) is passed, wherein in particular in the particulate filter filtered particles are subjected to a chemical analysis. Method according to one of the preceding claims, characterized in that the loading of the surface with fluid takes place at intervals and / or with multiple repetitions. Device for analyzing the state of contamination of a surface ( 11 ), in particular for carrying out the method according to one of the preceding claims, with a bell ( 5 ), with which at least part of the surface to be examined can be covered, and a nozzle device ( 3 . 300 ) for directing a fluid onto the surface to be examined, which can be covered by the bell to dissolve contaminations of the surface by means of the fluid, and a suction device ( 7 . 15 ) for sucking the fluid out of the bell, and an analysis device ( 8th . 9 ) for analyzing the fluid extracted from the bell with the contaminants received therein, characterized in that the nozzle device ( 3 . 300 ) several nozzles ( 4 . 40 . 400 . 410 . 420 ) aligned so that the discharge direction of the nozzles is directed in different directions. Apparatus according to claim 9, characterized in that the nozzle device ( 3 . 300 ) and / or parts thereof is arranged to be movable, in particular rotatably arranged and / or is designed to be adjustable so that a fluid jet from the nozzle at different angles (α) can impinge on the surface to be examined. Device according to one of claims 9 to 10, characterized in that a nozzle ( 410 . 420 ) of the nozzle device an inner wall ( 407 ), at the at least one curved, in particular spiral groove ( 406 ) is formed and / or has a curved shape in order to impart a corresponding angular momentum to the fluid flowing out through the nozzle. Device according to one of claims 9 to 11, characterized in that the nozzle device ( 3 . 300 ) several nozzles ( 4 . 40 . 400 . 410 . 420 ) arranged on or along the blades of a bimodal or multiblade propeller and / or in a star shape and / or in a ring shape. Device according to one of claims 9 to 12, characterized in that one or more nozzles ( 400 ) adjustable, in particular pivotable and / or rotatable in the nozzle device ( 3 . 300 ) are received, in particular pivotable about an axis of rotation transverse to an axial direction of a supply line to the nozzle and / or rotatable about the axial direction. Device according to one of claims 9 to 13, characterized in that the nozzle device ( 3 . 300 ) or parts thereof are arranged eccentrically to the bell. Device according to one of claims 9 to 14, characterized in that the device comprises at least one high-energy electromagnetic radiation device ( 12 ), in particular a laser and / or at least one heating device ( 14 ). Device according to one of claims 9 to 15, characterized in that the bell ( 5 ) is formed of a transparent material which is transparent to the human eye visible light and / or for high-energy electromagnetic radiation. Device according to one of claims 9 to 16, characterized in that the bell ( 5 ) a sealing arrangement ( 6 ) for tight contact with the surface to be examined ( 11 ) having. Apparatus according to claim 17, characterized in that the sealing arrangement ( 6 ) has a sealing ring which is formed of a fluoroelastomer, in particular a perfluoroelastomer.

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