DE102005052046A1 - Lithographic projection photo-mask, useful e.g. in structuring semiconductor wafers to form integrated circuits, includes absorber in purging gas volume above substrate to inhibit crystal formation - Google Patents

Abstract

A lithographic projection photo-mask (5) comprises: (a) a transparent substrate (10) with a pattern (14) of structural elements (16); (b) a frame (18), on the substrate outside the pattern; (c) a protective film (20) above the substrate, forming an enclosed volume filled with purging gas; and (d) an arrangement (32) of absorber within the enclosed volume, to remove harmful materials from the gas and inhibit crystal formation on the mask. A photo-mask (5) for lithographic projection comprises: (a) a transparent substrate (10), provided on its front with a pattern (14) of absorbing, partially absorbing or phase-shifting structural elements (16); (b) a frame (18), located on the front side of the substrate outside the pattern; (c) a protective film (20), located above the substrate on the frame, forming an enclosed volume filled with purging gas; and (d) an absorber arrangement (32), including absorber located in the frame region within the enclosed volume, for removing harmful materials from the purging gas to inhibit crystal formation on the mask. An independent claim is included for a method for using the mask in an exposure plant, involving: (A) supplying the mask into an exposure device from a protective container; (B) carrying out one or more exposure processes in the exposure device using light from an ultraviolet source; and (C) withdrawing the mask from the exposure device into the protective container.

Description

The The invention relates to a photomask and a method of use the photomask in an exposure system.

to Integrated circuit fabrication is commonly done on semiconductor wafers provided with different electrical properties layers applied and each lithographically structured. A lithographic Structuring step is usually in applying a photosensitive resist, this with a desired Structure for to expose and develop the relevant level, and subsequently the thus resulting resist mask in the underlying layer in an etching step transferred to or the resist mask as implantation mask for targeted change the electrical properties of the underlying layer.

For the lithographic The projection step of a circuit pattern usually becomes an exposure apparatus a wafer scanner or wafer stepper used. In the exposure apparatus, the Exposure of the photosensitive resist layer to electromagnetic Radiation of a predetermined wavelength, the current exposure technologies for example in the UV or DUV range at 256 nm, 193 nm or 157 nm is located. The exposure of the photosensitive resist layer Exposure dose present at the location of the semiconductor wafer becomes corresponding the specifications of the resist layer selected.

each single layer of the circuit pattern is usually by means of a Transfer photomask to the semiconductor wafer. The photomask comprises a transparent substrate layer provided with absorbent elements, such as. a chromium layer is provided, which simulate the circuit pattern. The photomask, also called reticle, often comes with a protective film (Pellicle) provided. The protective film serves to the structure side protect the transparent substrate layer from deposits. deposits transferred to the protective film itself usually not on the resist layer in lithography, because the protective film outside of Focus area for an image lies on the resist layer.

Of the Semiconductor wafer is generally deposited on a substrate holder and moved to a corresponding position for exposure. Then The circuit pattern arranged on a mask becomes successive transferred into individual exposure fields on the photosensitive resist layer. Usually is the size of a Exposure field about 25 mm × 35 mm.

The subject in the lithographic exposure process photomasks used through the movements inside and outside the exposure systems mechanical stresses that cause defects or contamination can. Furthermore you can Particles or contaminations on the surface due to adhesion the ambient atmosphere attach so that photomasks controlled within certain time intervals Need to become.

For example, the presence of ammonium ions and / or sulfate ions on the reticle surface leads to the formation of ammonium sulfate ((NH ₄ ) ₂ SO ₄ ) or to the formation of ammonium oxalate ((NH ₄ ) ₂ C ₂ O ₄ H ₂ O. These crystals can grow under energy irradiation by the light source.

photomasks in exposure machines with exposure wavelengths in the DUV range show a growth of these crystals, almost avalanche-like. Consequently, must The photomasks are checked regularly and be cleaned.

An effective control system for monitoring photomasks in exposure apparatus is described in US Pat DE 10352639 the same applicant described. In this process, photomasks are preventively controlled both in terms of their mechanical stress including particle deposits or electrostatically induced damage as well as their energetic loading and the associated changes in the material and surface properties of the photomasks. Also considered are the different surface distributions of the absorber layer and the properties of the exposure system.

It will be a maximum number of possible exposures from the exposure dose at the location of the resist layer, properties the lens of the exposure device, the bright-dark portion of the circuit pattern, the irradiated area, the Transmittance of the protective film, the transmittance of the absorber layer and the transmittance of the substrate to determine when the photomask must be subjected to a control. at When the control limits are reached, the photomask is then checked, wherein macro inspection or defect inspection is performed.

Macro inspections are large-scale oblique-light inspections in white light, around defect spots or particles with a size of about 10 μm in the scattered light to recognize. In order to be able to recognize also smaller defects, others must Method, for example, laser beam scanning, scatterometry or image recognition with layout comparison, used for defect control.

To When the control limits are reached, the photomasks are cleaned. This cleaning is usually in the mask house, i. at the manufacturer of the photomasks. at During cleaning, the photomasks are placed in an acid bath. It has however, revealed that the surface of freshly cleaned photomasks even more susceptible for crystal growth is. In addition to the productivity loss and the high cost of cleaning it can happen occasionally that a photomask is destroyed or damaged during cleaning. Furthermore you can For example, phase shift masks are cleaned only about five times since the characteristics of the phase shifters change.

consequently There is a need in the art for a photomask in which the time intervals between The purification steps can be further extended.

• – ein transparentes Substrat, das auf seiner Vorderseite mit einem Muster von absorbierenden, teilweise absorbierenden oder phasenschiebenden Strukturelementen versehen ist;
• – einen Rahmen, der auf der Vorderseite des transparenten Substrats außerhalb des Musters von absorbierenden, teilweise absorbierenden oder phasenschiebenden Strukturelementen angeordnet ist;
• – eine Schutzfolie, die oberhalb des transparenten Substrats auf dem Rahmen angeordnet ist, um eine abgeschlossenes Volumen zu bilden, das mit einem Spülgas gefüllt ist; und
• – eine Adsorberanordnung, die wenigstens ein adsorbierendes Material aufweist, die im Bereich des Rahmens innerhalb des Volumens angeordnet ist und die geeignet ist, Störstoffe aus dem Spülgas im Volumen zu entfernen, um Kristallbildung auf der Photomaske zu verhindern.

This object is achieved according to the invention by a photomask comprising:

• A transparent substrate provided on its front side with a pattern of absorbing, partially absorbing or phase-shifting structural elements;
• A frame disposed on the front side of the transparent substrate outside the pattern of absorbent, partially absorbing or phase shifting structural elements;
• A protective film disposed above the transparent substrate on the frame to form a closed volume filled with a purge gas; and
• An adsorber assembly comprising at least one adsorbent material disposed in the region of the frame within the volume and adapted to remove contaminants from the purge gas in the volume to prevent crystal formation on the photomask.

According to the invention become impurities in the immediate vicinity of the photomask in volume above the transparent substrate removed by means of an adsorber, so that crystal growth on the surface of the photomask is suppressed. Consequently lets the time between cleaning steps of the photomask clearly extend.

In a further embodiment the adsorber assembly is enclosed by a semi-permeable wall, the semipermeable wall being gaseous contaminants is permeable from the volume.

According to this embodiment can also powdery Adsorbents can be used without contaminating the surface of the photomask.

In a further embodiment The semi-permeable wall is made of the material of the protective film.

According to this embodiment can the techniques already used in applying the protective film can be used, so that on these materials, e.g. non-outgassing Adhesives used can be.

In a further embodiment the frame has at least one cavity in which the adsorber arrangement is arranged, wherein the semi-permeable wall the volume and the Adsorberanordnung separates.

According to this embodiment will not be additional space for the adsorber arrangement is needed.

In a further embodiment is the Adsorberanordnung on at least one side wall of the frame arranged.

According to this embodiment The adsorber can also be applied over the entire surface of the side walls become.

In a further embodiment adsorber adsorbs the ammonia.

ammonia is one of the gaseous impurities, which can form crystals when exposed to light. According to this embodiment Ammonia is removed from the volume.

In a further embodiment The adsorber arrangement adsorbs sulfur-containing gases.

hydrogen sulfide or promote sulfur dioxide also the crystal formation. According to this embodiment Sulfur-containing gases are removed from the volume.

In a further embodiment For example, the adsorbent material comprises a zeolite.

zeolites are suitable sulfur-containing gases or ammonia with high efficiency to remove from the volume.

In a further embodiment is the frame towards the volume with a nano- and macroscopic dense surface Mistake.

According to this approach, chemical stores are closed during the Using the photomask would be a constant source of outgassing.

• – Bereitstellen der Photomaske;
• – Bereitstellen eines Schutzbehälters, der geeignet ist, die Photomaske aufzunehmen;
• – Bereitstellen eines Belichtungsgeräts, das geeignet ist, die Photomaske aufzunehmen;
• – Zuführen der Photomaske von dem Schutzbehälter in das Belichtungsgerät;
• – Durchführen eines oder mehrerer Belichtungsprozesse mit dem Belichtungsgerät mit Licht einer UV-Quelle; und
• – Entnehmen der Photomaske von dem Belichtungsgerät in den Schutzbehälter.

This object is also achieved according to the invention in a further aspect by a method for using the photomask of an exposure system, which comprises the following steps:

• - Providing the photomask;
• - Providing a protective container, which is adapted to receive the photomask;
• Providing an exposure apparatus adapted to receive the photomask;
• Feeding the photomask from the protective container into the exposure apparatus;
• - Performing one or more exposure processes with the exposure device with light from a UV source; and
• - Remove the photomask from the exposure device in the protective container.

According to the invention the photomask is used in an exposure system with operated conventional loading and unloading stations and storage containers can be.

• – Bereitstellen einer weiteren Adsorberanordnung, die innerhalb des Schutzbehälters angeordnet ist und die geeignet ist, Störstoffe innerhalb des Schutzbehälters zu entfernen.

In a further embodiment, the following step is carried out:

• - Providing a further adsorber arrangement, which is arranged within the protective container and which is suitable to remove impurities within the protective container.

According to this Procedure, the photomask can be used with in a protective container, the one with additional Adsorber is provided to the surroundings of the photomask of impurities to clean.

• – Bereitstellen einer weiteren Adsorberanordnung, die innerhalb des Belichtungsgeräts angeordnet ist und die geeignet ist, Störstoffe innerhalb des Belichtungsgeräts zu entfernen.

In a further embodiment, the following step is carried out:

• Providing a further adsorber arrangement which is arranged within the exposure apparatus and which is suitable for removing impurities within the exposure apparatus.

According to this The photomask can also be used in an exposure system be used with additional Adsorber is provided to the surroundings of the photomask of impurities to clean.

preferred Further developments of the invention are specified in the subclaims.

The The invention will now be described with reference to the accompanying drawings. In show the drawing:

1 schematically a cross-sectional view through a photomask according to an embodiment of the invention;

2 schematically a plan view of a photomask according to another embodiment of the invention;

3 schematically a plan view of a photomask according to another embodiment of the invention;

4 schematically a cross-sectional view of an exposure apparatus with a photomask according to an embodiment of the invention;

5 schematically a cross-sectional view of a portion of an exposure apparatus with a photomask according to an embodiment of the invention; and

6 schematically a cross-sectional view of a portion of an exposure apparatus with a photomask according to an embodiment of the invention.

The The invention will be described below by way of example in the lithographic Structured semiconductor wafers explained, for example, in the production of microelectronic circuits is performed. The invention leaves however, apply to a variety of manufacturing technologies which a structuring step takes place by means of a photomask, such as in the manufacture of thin-film devices, e.g. TFT elements, or even in nanotechnology.

In 1 1 is a schematic cross-sectional view through a photomask for lithographic projection according to a first embodiment of the invention. The photomask 5 has a transparent substrate 10 on, which consists for example of quartz. On the front side 12 is the transparent substrate 10 with a pattern 14 of structural elements 16 Mistake. The pattern 14 corresponds to a plane of a circuit design and is usually generated by means of a suitable CAD program.

Depending on the type of mask, the structural elements are 16 absorbent, partially absorbent or phase-shifting. A mixture of these properties of the structural elements 16 is also possible. Absorbing structural elements 16 usually consist of chrome or black chrome. For partially absorbent structural elements 16 Thinned chromium or molybdenum silicide is used. Phase-shifting properties of the structural elements 16 For example, by the use of molybdenum silicide or by etching into the mask substrate 10 for the formation of trench-like structural elements can be achieved.

As in 1 is shown has the photomask 5 a frame 18 on top of that on the front 12 of the transparent substrate 10 outside the pattern 14 of structural elements 16 is arranged. Usually the frame 18 executed in a plan view rectangular or trapezoidal. The frame 18 is on the transparent substrate 10 glued and encloses the structural elements 16 of the pattern 14 ,

Furthermore, above the transparent substrate 10 a protective film 20 , also called pellicle, on the frame 18 attached, for example by sticking. This protective film 20 is forms together with the front 12 of the transparent substrate 10 and the side walls of the frame 18 a closed volume 26 , The volume 26 is filled with a purge gas, such as anhydrous air or nitrogen.

In the area of the frame 18 within the volume 26 is an adsorber arrangement 32 arranged. The adsorber arrangement 32 serves to remove impurities from the purge gas in the volume 26 to remove by adsorption. As mentioned above, these impurities are for example ammonia, carbon dioxide or sulfur-containing gases such as hydrogen sulfide or sulfur dioxide. These impurities could be on the photomask 8th Cause crystal formation, due to adsorption in the adsorber assembly 30 is prevented.

The following is an example of crystal growth under irradiation with UV light. Air normally contains hydrogen sulfide (H ₂ S) at a concentration of about 0.25 to 10 ppb (ppb = parts per billion). Together with oxygen, sulfur dioxide forms according to the reaction equation: 2H ₂ S + 3O ₂ → 2SO ₂ + 2H ₂ O. [1]

Under light irradiation during the lithographic projection with a UV light source with 193 nm wavelength free oxygen radicals are formed, which react with sulfur dioxide according to the following reaction equation: SO ₂ + O → SO ₃ . [2]

Together with (residual) water from the air, aerosol particles which are chemically stable result according to the following reaction equation: SO ₃ + H ₂ O → H ₂ SO ₄ . [3]

In the presence of impurities, in this case ammonia, these aerosol particles react to form ammonium sulfate according to the following reaction equation: H ₂ SO ₄ + 2NH ₃ → (NH ₄ ) ₂ SO ₄ . [4]

The adsorber arrangement 32 has one or more adsorbent materials to adsorb the contaminants. In the embodiment according to 1 is the filter in a cavity 40 as part of 18 the photomask 5 arranged. Of course, it is also possible to have multiple cavities at different locations of the frame 18 provided.

A semi-permeable wall 34 separates the closed volume 26 the photomask 5 and the adsorber assembly 32 , The semipermeable wall 34 is for impurities from the volume 26 permeable, components of the adsorber arrangement 32 however, can not be in the volume 26 penetration. As a semi-permeable wall 34 For example, the material of the protective film 20 be used.

To eliminate the impurities several adsorbent materials come into question. According to the reaction equations [1] to [4], crystal growth is prevented by the filter 32 Ammonia or sulfur-containing gases adsorbed.

A suitable material for the adsorption of ammonia and / or sulfur dioxide is zeolite. Zeolites are complex compounds that have an extremely large surface area (~ 1000 m ² / g) compared to the molecular volume, which consists of various channel-like structures. Within these channels, contaminants can be deposited by adsorption. A possible zeolite is, for example, clinoptilolite, which adsorbs ammonia very effectively.

For possible contamination of the photomask 5 By preventing the zeolite is the semi-permeable wall 34 intended. Additionally or alternatively, it is also possible to sinter zeolites to form a compact adsorbent that is nearly free of particulate deposits on the transparent substrate 10 in the photomask 5 can be introduced.

It is also possible instead of or in addition to the zeolites as adsorbents activated carbon or alumina which are also suitable, ammonia and / or sulfur dioxide to adsorb.

With reference to 2 In the following, a further embodiment of the invention is shown. In 2 Fig. 12 is a plan view of a photomask for lithographic projection according to a second embodiment of the invention schematically shown.

The photomask 5 again shows the transparent substrate 10 made of quartz. On the front side 12 is the photomask 5 with the pattern 14 of structural elements 16 provided according to a layer for a plane of a circuit design.

As in 2 is shown has the photomask 5 the rectangular frame 18 on, outside the pattern 14 of structural elements 16 is arranged and with the protective film 20 (not in 2 shown) is provided.

In the area of the frame 18 within the volume 26 are several Adsorberanordnungen 32 arranged. The Adsorberanordnungen 32 are composed of respective adsorbent materials, which may also be chosen differently for the adsorption of various contaminants, on each side wall of the frame 18 arranged. The Adsorberanordnungen 32 located on the top, left and right sidewall 28 are attached to the semi-permeable membrane 34 from the volume 28 separated. The Adsorberanordnungen 32 on the lower side wall 28 has no semi-permeable membrane.

According to this embodiment, different Adsorberanordnungen 32 implement in a photomask. For example, the non-semi-permeable membrane-covered adsorbent material could be sintered zeolites or alumina, since these materials are less likely to contaminate the front surface 12 of the transparent substrate 10 tend. The adsorbent material with the semi-permeable membrane 34 could for example consist of activated carbon, which is present as a powdery substance. Thus, different adsorbents can be attached, at the same time a high adsorption capacity is achieved.

Additionally is in 2 another adsorber 32 ' shown, which consists of a metal layer. In general, metals such as gold, nickel, ruthenium, platinum or copper are also suitable for adsorbing sulfur-containing gases, in particular sulfur dioxide.

As in 2 is shown, the metal layer of the adsorber 32 ' only partially on the side walls 28 appropriate. But it is also intended, the inside of the frame 18 completely covered with the metal layer. It is also possible that the front 12 of the transparent substrate 10 in some places, for example in the corners near the frame 18 to provide with the metal layer.

In 3 In the drawings, a third embodiment of the invention is again shown schematically in a plan view of the photomask. The photomask 5 again shows the transparent substrate 10 made of quartz and is with the pattern 14 of structural elements 16 provided according to a plane of a circuit design.

As in 3 is shown has the photomask 5 the rectangular frame 18 on, outside the pattern 14 of structural elements 16 is arranged and with the protective film 20 (not in 3 shown) is provided.

In the area of the frame 18 within the volume 26 are several Adsorberanordnungen 32 arranged. The Adsorberanordnungen 32 are made of the respective adsorbent materials in each corner of the frame 18 arranged and are with the semipermeable membrane 34 from the volume 28 separated. According to this embodiment, in turn, different adsorbent materials can be implemented in a photomask, for example zeolites, activated carbon or aluminum oxide.

In addition, the side walls 28 of the frame 18 with a nano- or microscopically dense surface 36 Mistake. The nano- or microscopic dense surface 36 serves to smallest cavities in the frame 18 to close, so that there can accumulate no impurities that in the course of time in the volume 28 could arrive.

Known in the art, conventional photomasks are usually provided with an anodized (anodized) Rah men, for example, consists of aluminum and has small anodization pores. These pores serve as chemical reservoirs and gase during use of the photomask. According to this embodiment of the invention, another approach is taken by the surface of the sidewalls 28 of the frame 18 on the size scale of molecules (ie on a nano- or microscopic scale) is closed.

The nano- or microscopic dense surface 36 can be formed in several ways.

For one thing, the frame 18 be made of aluminum. By means of a palladium chloride solution is subsequently a palladium layer on the side walls 28 educated. The palladium layer creates a nano- and microscopic surface on the sidewalls 28 ,

According to another possibility, the frame becomes 18 made of copper. The copper subsequently forms a copper oxide layer on the surface during thermal oxidation, which forms the nano- and microscopically dense surface 36 forms.

Furthermore, it is possible the frame 18 made of nickel, using sodium hydroxide or sodium nitride, a nickel oxide layer as a nano- and microscopically dense surface 36 is formed.

According to another possibility, the frame becomes 18 made of steel. The iron content of the steel then forms during a blackening on the surface of a blackening layer (Fe ₂ O ₃ ), the nano- and microscopic dense surface 36 forms.

The according to the 1 to 3 described photomask 5 can also be in an exposure system 5 can be used, which is provided with additional Adsorbereinrichtungen to the surroundings of the photomask 5 largely free of contaminants. This will be explained below with reference to 4 explained.

During the preparation of a lithographic patterning step, the photomask becomes 5 in a protective container 50 to the exposure device 52 brought. The protective container 50 is suitable, the photomask 5 and by means of an automatic feeder 70 the exposure device 52 supply.

The photomask is between an illumination optics 66 and a projection optics 68 in the exposure device 52 stored. Above the illumination optics 66 is the light source 53 , Below the projection optics 68 is on a substrate holder 60 the semiconductor wafer 62 stored. The semiconductor wafer 62 is with a photosensitive resist layer 64 Mistake. After completion of the lithographic patterning, the photomask 5 from the automatic feeder 70 again in the protective container 50 returned or within the exposure device 52 stored.

According to this embodiment of the invention is a further adsorber arrangement 54 provided within the exposure device 52 is arranged to remove contaminants within the exposure device 52 to remove. This is in 5 shown. The further adsorber arrangement 54 in turn comprises one or more adsorbent materials and is arranged, for example, above and below the photomask.

As in 6 can also be shown another adsorber 54 inside the protective container 50 (also called smif pod) be provided to impurities within the protective container 50 to remove. The further adsorber arrangement 54 also comprises one or more adsorbent materials and is derived from another semi-permeable membrane 58 enclosed, so that no contamination of the surfaces of the photomask can occur.

The further adsorber arrangement 54 may be similar to the embodiments according to 1 to 3 consist of adsorbent materials, such as zeolite, a metal layer or activated carbon.

According to the invention become impurities in the immediate vicinity of the photomask by means of adsorbing Materials removed, allowing crystal growth on the surface of the Photomask suppressed becomes. Accordingly, it is possible significantly increase the time between cleaning steps of the photomask.

5

photomask

10

transparent substratum

12

front

14

template

16

structural elements

18

frame

20

protector

26

volume

28

Side wall

32

adsorber

32 '

adsorber

34

semipermeable wall

40

cavity

50

protective container

52

exposure unit

53

UV source

54

Further adsorber

58

Further semi-permeable membrane

Claims (33)

A photomask for lithographic projection comprising: - a transparent substrate ( 10 ) on its front ( 12 ) with a pattern ( 14 ) of absorbing, partially absorbing or phase-shifting structural elements ( 16 ) is provided; - a frame ( 18 ), on the front ( 12 ) of the transparent substrate ( 10 ) outside the pattern ( 14 ) of absorbing, partially absorbing or phase-shifting structural elements ( 16 ) is arranged; - a protective foil ( 20 ), which are above the transparent substrate ( 10 ) on the frame ( 18 ) is arranged to hold a closed volume ( 26 ), which is filled with a purge gas; and an adsorber arrangement ( 32 ) comprising at least one adsorbent material located in the region of the frame ( 18 ) within the volume ( 26 ) is arranged and which is suitable, impurities from the purge gas in the volume ( 26 ) to prevent crystal formation on the photomask ( 8th ) to prevent. A photomask according to claim 1, wherein the adsorber assembly ( 32 ) of a semi-permeable wall ( 34 ), wherein the semi-permeable wall ( 34 ) for gaseous contaminants from the volume ( 26 ) is permeable. A photomask according to claim 2, wherein the semi-permeable wall ( 34 ) from the material of the protective film ( 20 ) is made. A photomask according to one of claims 2 or 3, wherein the frame ( 18 ) at least one cavity ( 40 ), in which the adsorber arrangement ( 32 ), wherein the semi-permeable wall ( 34 ) the volume ( 26 ) and the adsorber arrangement ( 32 ) separates. A photomask according to any one of claims 2 to 4, wherein the frame ( 18 ) a plurality of separate cavities ( 40 ), in each of which an adsorber arrangement ( 32 ), each having a semi-permeable wall ( 34 ) the volume ( 26 ) and the adsorber arrangement ( 32 ) separates. Photomask according to one of Claims 1 to 3, in which the adsorber arrangement ( 32 ) on at least one side wall ( 28 ) of the frame ( 18 ) is arranged. A photomask according to any one of claims 1 to 3, wherein the frame ( 18 ) has a substantially rectangular shape and the adsorber arrangement ( 32 ) in at least one corner of the frame ( 18 ) is arranged. Photomask according to Claim 7, in which the adsorber arrangement ( 32 ) in each corner of the frame ( 18 ) is arranged. A photomask according to claim 8, wherein the adsorber assembly ( 32 ) on each side wall ( 28 ) of the frame ( 18 ) is arranged. Photomask according to one of Claims 1 to 3, in which the adsorber arrangement ( 32 ) on the transparent substrate ( 10 ) outside the pattern ( 14 ) is arranged. A photomask according to any one of claims 1 to 5, comprising at least two adsorber assemblies, wherein the first adsorber assembly ( 32 ) on the transparent substrate ( 10 ) outside the pattern ( 14 ) and the second Adsorbera arrangement ( 32 ) in the cavity ( 40 ) of the frame ( 18 ) is arranged. Photomask according to Claim 11, in which the adsorber arrangement ( 32 ) Adsorbed ammonia. Photomask according to Claim 11, in which the adsorber arrangement ( 32 )) Sulfur-containing gases adsorbed. A photomask according to any one of claims 10 to 13, wherein the adsorber assembly ( 32 ) comprises a zeolite as adsorbent material. A photomask according to claim 14, wherein the zeolite is a clinoptilolite capable of removing gaseous contaminants from the bulk ( 26 ) to adsorb. A photomask according to any one of claims 10 to 13, wherein the adsorber assembly ( 32 ) comprises as adsorbent material alumina or activated carbon. A photomask according to any one of claims 10 to 13, wherein the adsorber assembly ( 32 ) comprises a metal layer as the adsorbent material. A photomask according to claim 17, wherein the metal layer of the adsorber assembly ( 32 ) Comprises gold, nickel, ruthenium, platinum or copper. A photomask according to any one of claims 1 to 18, further comprising the frame (16). 18 ) to volume ( 26 ) is provided with a nano- and microscopically dense surface. A photomask as claimed in claim 19, wherein the frame ( 18 ) Aluminum, which is provided with a palladium layer as a nano- and microscopically dense surface. A photomask as claimed in claim 19, wherein the frame ( 18 ) Contains copper or nickel, which is provided with an oxide layer as a nano- and microscopically dense surface. A photomask as claimed in claim 19, wherein the frame ( 18 ) Includes steel provided with a burnishing layer as a nano- and microscopically dense surface. A method of using the photomask according to any one of claims 1 to 22 in an exposure apparatus, comprising the following steps: - providing the photomask ( 5 ); - Provision of a protective container ( 50 ), which is suitable, the photomask ( 5 ); - Provision of an exposure device ( 52 ), which is suitable, the photomask ( 5 ); - feeding the photomask ( 5 ) from the protective container ( 50 ) into the exposure device ( 52 ); - Performing one or more exposure processes with the exposure device ( 52 ) with light from a UV source ( 53 ); and - removing the photomask ( 5 ) from the exposure device ( 52 ) in the protective container ( 50 ). A method according to claim 23, further comprising the steps of: - providing a further adsorber arrangement ( 54 ) inside the protective container ( 50 ) is arranged and which is suitable, impurities within the protective container ( 50 ) to remove. The method of claim 24, further comprising the steps of: - providing a further adsorber assembly ( 54 ) within the exposure device ( 52 ) and which is suitable for removing contaminants within the exposure apparatus ( 52 ) to remove. Process according to Claim 24 or 25, in which the further adsorber arrangement ( 54 ) comprises an adsorbent material. Process according to Claim 26, in which the further adsorber arrangement ( 54 ) comprises an adsorbent material derived from another semi-permeable membrane ( 58 ) is at least partially enclosed. A method according to claim 26 or 27, wherein adsorbing material, a zeolite, a metal layer or activated carbon chosen becomes. A method according to any of claims 23 to 28, wherein the step of providing the photomask ( 5 ) that the photomask ( 5 ) a frame ( 18 ) to the volume ( 26 ) is provided with a nano- and macroscopically dense surface. The method of claim 29, wherein the frame ( 18 ) is made of aluminum, wherein a palladium layer is formed by means of a palladium chloride solution to form the nano- and macroscopically dense surface. The method of claim 29, wherein the frame ( 18 ) is made of copper, wherein by means of a thermal Oxi tion a copper oxide layer is formed to form the nano- and microscopically dense surface. The method of claim 29, wherein the frame ( 18 ) is made of nickel, wherein a nickel oxide layer is formed by means of sodium hydroxide or sodium nitride to form the nano- and microscopically dense surface. The method of claim 29, wherein the frame ( 18 ) is made of steel, which is then burnished to form a burnishing layer as a nano- and microscopically dense surface.