DE102004038548A1 - Mask blank manufacturing method for photolithography processing, involves designing handling portion so that multilayered layer on front surface of substrate is exposed in each handling portion and pressed by mechanical clamp - Google Patents

Abstract

An electroconductive layer (5) is vapor-deposited to back side of substrate and silicon/molybdenum multilayered layer (6) and buffer layer (9) are vapor-deposited over front side of substrate. A handling portion is designed so that multilayered layer is exposed in each handling portion and is pressed by mechanical clamp. An independent claim is also included for mask blank.

Description

Territory of invention

The The present invention generally relates to the manufacture of a mask blank (maskblank) for photolithographic Applications, especially in EUV lithography (extreme ultraviolet lithography) in the range of about 13 nm The present invention provides a method for producing a suitable manageable mask blanks for photolithographic applications, in particular in EUV lithography, as well as such a provided mask blank.

State of technology

to Achieving ever higher Integration densities in microelectronics but also in other applications, such as microsystems technology, it is necessary to photolithographic exposure to ever shorter wavelengths use. It is already foreseeable that future wavelengths in the Range of about 13 nm can be used to structure with Structure widths of less than about 35 nm. The production of high-precision Mask blanks for photolithography plays a key role here. mask blanks have to be essentially defect-free, because otherwise even the slightest error in the photomask on each chip. All the causes leading to one Contamination or damage lead the photomask, be it during their preparation or subsequent handling with electrostatic or mechanical holding or handling devices, must as far as possible be imposed.

This requires high precision Techniques for making mask blanks and a very careful mount and handling of mask blanks to provide mechanical abrasion and to exclude the formation of particles as much as possible. in the In view of having a photomask for exposing a plurality is used by semiconductor substrates, a lot of effort in justified the production and handling of mask blanks or photomasks. Even the smallest improvements justify this in the field comparatively high effort. That's why it's not surprising that process used in the manufacture and handling of mask blanks or photomasks are used, relatively expensive and expensive could be. Because even the slightest improvements in the yield in the production of integrated circuits and the like this effort can one justify high expenditure.

Electrostatic chucks are known in the art for holding semiconductor substrates provided with an electrically conductive coating on the back. Due to the comparatively large-area contact between the holding device and the return-electrically conductive coating, only slight pressure forces act during holding, which reduces the abrasion and the mechanical stress on the back-side coating. The pending patent application DE 103 17 792.2 , "Mask Blank for Use in EUV Lithography and Method of Making", filed April 16, 2003 and corresponding US Patent Application Serial No. 10 / 825,681 filed April 16, 2004, the applicant discloses a mask blank This backside coating is applied by Ion Beam Deposition (IBD), in particular ion beam assisted sputtering, resulting in highly abrasion resistant and durable coatings The contents of the two aforementioned patent applications are hereby expressly assigned in the present application Revelation purposes included, in particular as regards the properties of the back coating and a method for its deposition.

DE 102 39 858 A1 (corresponding US 2004 041 102 A1 ) discloses a method and apparatus for compensating for unevenness in the surface of a substrate. On the front of the substrate, a multilayer reflective coating is applied. An electrically conductive backside coating of the EUV reflection mask is also disclosed.

coatings on sidewalls of substrates are comparatively rare in microelectronics, in the field of mask blanks, but not known in particular for EUV lithography. JP 03-212 916 A discloses a multilayer thin-film capacitor, at the on side surfaces an insulating layer of a protective layer is applied. JP 2001-291 661 A discloses a method for producing a Reflection mask in which on a front side of a substrate more Layers are deposited, being prevented at the Structuring the coating on the front by overetching conical Structures are formed.

US 5,756,237 discloses a method of making a projection mask in which wedge-shaped grooves are formed in the backside of a mask substrate by wet etching along which the projection masks are split by columns. In the course of the production of the projection mask side edges of the mask substrate with a Photoresist layer to be coated. This side edge coating, however, is replaced again.

To the Holding or handling mask blanks by means of mechanical devices It may be necessary, the mask blanks or later from it made photomasks from the front to handle. to Avoidance of abrasion has been proposed, for example, by the company ASML, on the front of the substrate special handling areas (Handling areas), which must remain uncoated. In Such areas thus become the mechanical holding or handling device lie directly on the front side of the mask substrate. Because the front of the mask substrate is very even and only a small one surface roughness can also be in this way a mechanical abrasion during Holding or handling the mask can be avoided.

Such a mask layout is in the 3 displayed. According to the 3 is on the front of the mask blank 1 a pattern area 20 in which the actual photomask is formed by structuring or patterning. Furthermore, a number of areas not provided with reference numerals are reserved at the edge regions. On the front is also an unstructured area 21 provided the pattern area 20 surrounds. The reference numerals 22a - 22c denotes discrete handling areas that should remain uncoated in accordance with the ASML proposal.

Summary the invention

According to one The first aspect of the present invention is intended to provide a method for producing a mask blank for photolithographic applications be provided to create a mask blank, the easier and handled more reliably can be. According to one Another aspect of the present invention is a method be provided for the production of a mask blank, which are produced inexpensively can and both during the production as well as later Use with reduced abrasion and reduced particle production can be held and handled. According to another aspect The present invention is intended to provide such a mask blank be grounded in advantageous simple and reliable manner can, especially during the handling or processing of the mask blank. According to others Aspects of the present invention are also corresponding Mask blanks are provided.

According to the present invention there is provided a method of making a mask blank for photolithographic applications, in particular in EUV lithography, comprising the following steps:
Providing a substrate having a front side and a back side;
Depositing an electrically conductive layer on the back side of the substrate;
Depositing a coating on the front side of the substrate, the coating comprising at least a first layer and a second layer; and
Patterning the coating for photolithographic applications;
wherein on the front side at at least one predetermined location, a respective handling area is formed, which is not structured for the photolithographic application and which is designed for handling the mask blank by means of a mechanical holding or handling device, and wherein
the first layer is exposed in the respective handling region, so that the mechanical holding or handling device bears against the first layer when the mask blank is handled from the front side.

Of the The present invention is therefore particularly the realization Basically, that a material-friendly and low-abrasion handling of Mask blanks can not only be achieved if, as in the state the technique suggested on the front of the mask blank uncoated handling areas are reserved, but also then, if in the handling areas suitable coatings are provided. Usually are the surfaces of mask blanks very flat and have a low residual roughness on. As the inventors have found, such surfaces are suitable for Training of low-defect and very homogeneous coatings Deposition. Such coatings will also by a high planarity and a low defect density, so that such coatings very resistant to abrasion and comparatively strong.

Advantageous is that to form the front side coating less process steps and / or simpler process steps can be used. In particular, the Front side of the mask substrate at least in some of the method steps the whole area be treated without being elaborate Masking techniques or etching techniques would be required to form handling areas.

According to a further embodiment, the coating is deposited so that side walls of the substrate at least partially covered are, wherein the coating is electrically conductive. Thus, the mask blank can also be electrically contacted on the side surfaces. This may be desirable, for example, for grounding the mask blank in order to avoid unwanted charging, for example caused by irradiation, and / or to keep the mask at a defined potential. Because then the mask blank can be held even more reliable and reproducible by means of an electrostatic holding device. This grounding applied from the side of the mask blank may also be used to prevent the occurrence of uncontrolled discharges which could destroy the mask.

According to one further embodiment, the coating is further deposited, that the electrically conductive Coating on the back of the Substrate is contacted. Thus, the front of the Mask blanks are contacted in the area of the handling zones, where the coating, in particular its first layer, is exposed. This represents another important advantage, which according to the present Invention can be achieved since the mask blank according to the invention optionally from the front, from the side wall or from the back reliable can be grounded. In particular, the same can be used for grounding Devices are used to handle the mask blank be used.

To the Depositing the electrically conductive coating on the back side of the mask substrate, this can be achieved by a mechanical holding device, that from the front or side surfaces of the mask substrate attaches to be held. When the electrically conductive layer on the back side is applied to the mask substrate, this can during subsequent Process steps reliable be held by means of an electrostatic holding device, from the back of the mask substrate. It can side walls of the Mask substrate also exposed and so for depositing a electrically conductive Layer on the sidewalls to lead.

According to one Another embodiment may be deposited on the front side First layer further comprises a buffer or stress compensation layer be formed, which the second layer of the front side coating can train. According to one embodiment can the buffer or stress compensation layer in the Handling areas are deposited. According to another embodiment however, it may also be achieved, for example, by suitably masking the front while of the deposition, prevents the buffer or stress compensation layer is deposited in the handling areas. This way you can be determined whether in the mechanical handling of the mask blank of the front side a mechanical holding or handling tool in the handling areas on the multilayer layer or on the Buffer or stress compensation layer is applied.

According to one further embodiment may be on the buffer or voltage compensation layer Furthermore, an absorber layer are deposited, for example can consist of chromium (Cr), TaN or doped TaN. For separating The absorber layer may be the mask substrate of an electrostatic or mechanical holding device are kept away. According to one Embodiment is while the front while the deposition masked so that the absorber layer is not in the handling areas is trained. According to one another embodiment the front side of the mask substrate will not be masked and become the handling areas later, for example by wet etching, re-exposed, in such a way that either the multilayer layer or the buffer or stress compensation layer in the handling areas exposed.

To the Depositing optionally one, several or all of the aforementioned layers According to the invention, an ion beam-based deposition method (Ion Beam Deposition, IBD), in particular ion beam-based sputtering, be used. In this way, can be particularly homogeneous and form low-defect layers with low residual roughness.

Consequently can according to the invention devices for handling mask blanks at the same time also for grounding a mask blank according to the invention be used, optionally from the front, the side wall or the back of the Mask blanks.

LIST OF FIGURES

following the invention will be described by way of example and with reference on the attached Drawings are described, resulting in more features, benefits and to be solved Tasks and in which:

1 in a schematic section represents a mask blank according to a first embodiment of the present invention;

2 in a schematic section shows a mask blank according to a second embodiment of the present invention;

3 in a schematic plan view shows a mask blank according to the present invention;

4 Fig. 10 is a partial plan view showing a mask blank according to a third embodiment of the present invention;

5 in a flow chart illustrates a method according to the present invention;

6 in a flow chart, a modification of the method according to the 5 represents; and

7 in a flow chart, a modification of the method according to the 6 represents.

DETAILED DESCRIPTION OF EMBODIMENTS

In the figures denote identical reference numerals identical or Substantially equal elements or groups of elements.

According to the 1 includes the total with 1 designated mask blank a substrate 2 formed from a conventional LTE material (low thermal expansion material), for example, Zerodur the applicant. The substrate 2 has a back 3 and a front side 4 on. According to the 1 is on the back 3 an electrically conductive coating 5 deposited, which the back 3 essentially completely covered. Further details of backside coating and a method of forming the same are disclosed in the pending patent application DE 103 17 792 , "Mask Blank for Use in EUV Lithography and Method of Making It", filed April 16, 2003, as well as related US Patent Application Serial No. 10 / 825,618, filed April 16, 2004, the assignee of which is incorporated herein by reference As described therein, the electrically conductive backside coating is applied by ion beam assisted deposition (IBD), in particular ion beam assisted sputtering, and is characterized by a feature of the present invention In particular, the resistance of the electrically conductive coating to abrasion with a cloth in accordance with DIN 58196-5 at least falls into the category 2 , the resistance of the electrically conductive coating against abrasion with an eraser according to DIN 58196-4 falls at least in the category 2 and corresponds to the adhesive strength of the electrically conductive coating in a test using an adhesive tape according to DIN 58196-2 a replacement of substantially 0%. Further, it is disclosed therein that the resistivity of the electroconductive coating at a film thickness of about 100 nm is at least about 10 ^-7 Ωcm, more preferably at least about 10 ^-6 Ωcm, and even more preferably at least about 10 ^-5 Ωcm. A backside coated mask blank can be held or handled rearwardly without the risk of mechanical abrasion or particles generated by handling by means of electrostatic holding devices.

According to the 1 is on the front 4 a multilayer coating 6 , in particular a Si / Mo multilayer layer, which is designed and usable in the known manner for the reflection of radiation, in particular of EUV radiation. Like in the 1 shown, covers the multilayer coating 6 in the fields of 7 also sidewalls of the substrate 2 , On the back, as shown schematically in the 1 shown contacts the multilayer layer 6 the electrically conductive backside coating 5 , This contact point 8th can of course at the bottom of the sidewall coating 7 and approximately flush with a respective sidewall of the substrate 2 be educated. According to a further embodiment (not shown), the electrically conductive backside coating 5 also slightly the lower longitudinal edge of the substrate 2 embrace so that the contact point between the electrically conductive backside coating 5 and the multilayer layer 6 also in the area of the side walls of the substrate 2 can be trained. According to the 1 covers the electrically conductive coating 5 the backside 3 of the substrate 2 not complete, but rather is an edge region of the substrate 2 at least in sections not of the electrically conductive coating 5 covered, which will be described in more detail below.

According to the 1 are on the multilayer layer 6 applied further layers, namely a buffer or stress compensation layer 9 , For example, from SiO ₂ , Si, Ru, Ta ₂ O ₅ , and an absorber layer 10 , for example, from Cr, TaN or doped TaN, in particular doped with boron, C, Ge. The absorber layer 10 and the buffer layer 9 can be photolithographically patterned in the known manner to be in the central area of the mask blank 1 a mask area 20 (see. 3 ) train. Like that 1 and 3 can be removed, according to the invention edge regions on the front of the mask blank 1 not with the buffer layer 9 and / or the absorber layer 10 Mistake. In such areas, therefore, lies in the first embodiment, the multilayer layer 6 free. According to the first embodiment, such exposed multilayer film regions are formed to form handling regions on the front side of the mask blank 1 used in the handling of the mask blank from the front side of a mechanical holding or handling device, in particular Chuck, immediately can be present. According to the invention, these exposed surface areas of the multilayer layer 6 sufficiently resistant to abrasion and stress, so that a handling from the front in the handling area 22 is permissible.

According to the first embodiment, the uppermost layer of the multilayer layer 6 a certain minimum electrical conductivity, so that in the handling of the substrate from the front side by contacting in the handling areas (see. 3 ) the mask blank 1 can be grounded. Thus, grounding currents are transmitted through the multilayer layer 6 , in particular its uppermost layer, of the handling areas 22 (see. 3 ) over the sidewall areas 7 and the contact point 8th on the electrically conductive backside coating 5 from where they can flow via the electrostatic holding device (not shown). Even in the case of uncontrolled discharges, therefore, the mask can still be securely held by the electrostatic chuck because the mask can be held at a defined potential. The grounding may also be necessary to avoid unwanted charging, for example during irradiation, in particular during electron beam writing, of a photoresist layer. Overall, the mask blank can 1 be held reliably by means of an electrostatic holding device, because the mask blank 1 always be kept at a defined potential.

At the top layer of the multilayer layer 6 it can be a silicon layer. This is applied with a sufficient thickness, for example with a thickness of at least 11 nm, so that only about the uppermost 3 nm of the silicon layer will be oxidized, but the remainder remains unoxidized and is thus sufficiently electrically conductive. Alternatively, the uppermost cover layer of the multilayer layer 6 be formed of any other suitable abrasion resistant materials, such as Ru, Ta ₂ O ₅ and the like.

The 2 shows in a schematic section a mask blank according to a second embodiment of the present invention. Deviating from the 1 is the buffer or stress compensation layer also on the side edge areas 7 of the maskblank 1 trained and extends to the rear contact points 8th , Alternatively, only the side wall areas 7 at least in sections of the buffer or stress compensation layer 9 be covered. As a buffer or stress compensation layer 9 In particular, an SiO ₂ layer is suitable. However, any other materials may be used as well, as will be apparent to those skilled in the art. According to the second embodiment, a contacting in the handling areas 22 (see. 3 ) basically be accomplished by a grounding mandrel or the like through the buffer layer 9 is pushed to contact underlying electrically conductive layers. This can be especially true on the sidewalls of the mask blank 1 respectively. According to the second embodiment, there is a mechanical holding or handling device that extends from the front side of the mask blank 1 attaches, in the handling areas directly to the buffer layer 9 at.

If this is to be avoided, then according to a third embodiment, which in the 4 is shown at the handling areas 22 in the buffer layer 9 one or more recesses 16 be formed, as described below, where the underlying multilayer layer 6 exposed. In the handling area 22 According to the third embodiment, the holding or handling device, as in the first embodiment, directly on the multilayer layer 6 issue.

The following is based on the 5 a method for producing a mask blank according to the present invention will be described. As will be apparent from the following description, the substrate is optionally held by a mechanical clamp or electrostatic chuck.

According to the 5 The mask substrate is first held by means of a mechanical holding device, which attaches from the front side of the mask substrate, in order to deposit an electrically conductive layer on the rear side. For this purpose, an ion beam-based sputtering method is preferably used. Subsequently, the back-coated mask substrate is transferred to an electrostatic chuck which abuts the electrically conductive backcoat and holds the mask substrate from the back side. Subsequently, the multilayer layer is deposited on the front side. This covers the front of the substrate over its entire surface. The uppermost layer of the multilayer layer has a certain minimum electrical conductivity, which is sufficient for grounding the front side of the mask substrate. Because the sidewalls of the mask substrate are exposed during the deposition of the multilayer layer, this inevitably results in a certain coating of the sidewalls with the multilayer layer whose uppermost cover layer has a certain minimum conductivity. Thus, inevitably results in a conductive coating of the side walls of the mask substrate.

According to the 5 The mask substrate is then connected to a mechanical holding device handed over and held by this. Subsequently, the buffer layer and the absorber layer are deposited on the front side of the mask substrate. In the area of trainee handling areas (cf. 3 ), a mask is used during the deposition of the buffer layer and the absorber layer so that the multilayer layer is not further coated in the region of the handling areas. In this way, the mask blank according to the 1 be formed.

Instead of the mask substrate for depositing the buffer and absorber layer to hand over to a mechanical holding device, according to the invention in principle also be provided to deposit the buffer and absorber layer, while the Mask substrate of the same or another electrostatic Holding device from the back is held here.

When in the 6 shown modification of the method according to the 5 For example, the buffer layer is deposited on the front side of the mask substrate while the mask substrate is still held by the electrostatic chuck. Thus, the buffer layer is also deposited on the sidewalls of the mask substrate to form the mask blank according to the second embodiment of FIG 2 train.

According to the 6 the mask substrate is subsequently transferred to a mechanical holding device and then the absorber layer is deposited on the front side. When depositing the absorber layer, a mask is again used to prevent deposition of the absorber layer in the handling areas. In this way, the mask blank according to the 4 be formed.

Of course, according to the 6 the absorber layer can be deposited on the front side of the mask substrate even when it is held by the same or another electrostatic chuck from the back side.

The 7 shows a further modification of the method according to the 6 , In this case, no mask is used in the deposition of the absorber layer on the front side, so that the front side of the mask substrate is completely covered by the absorber layer. Only in a subsequent method step, for example by wet etching at the predetermined handling areas, the buffer layer or stress compensation layer located under the absorber layer or the multilayer layer located below the buffer layer is exposed. Finally, as a mask blank can be obtained, as this in the 2 or 4 is shown. Of course, also in the method according to the 7 the absorber layer can be deposited on the front side of the mask substrate even when it is held by the same or another electrostatic chuck from the back side.

As the expert in studying the above description readily can be seen further modifications and changes be made without the general solution thought, as above or to depart from the scope of the appended claims. In particular, you can Any other than the aforementioned materials for training a mask blank for photolithography, in particular EUV photolithography used become. Furthermore, a stress compensation layer may alternatively or in addition also be provided under the multilayer layer. These and other modifications and changes should therefore explicitly from the scope of the attached claims to be included.

1

mask Blank

2

substratum

3

back

4

front

5

electrical conductive backside coating

6

Si / Mo multi-layer

7

Si / Mo multilayer layer on sidewall of the substrate 2

8th

contact point

9

buffer layer

10

absorber layer

11

Buffer layer on sidewall of the substrate 2

15

Edge of the substrate 2

16

Recess in buffer layer 9

20

pattern area

21

unstructured Area

22

handling area

22a

Handling area near the corner area of the mask blank 1

22b

centrally handling area

22c

Another handling area

Claims (25)

Method for producing a mask blank ( 1 ) for photolithographic applications, in particular in EUV lithography, comprising the following steps: providing a substrate ( 2 ), which has a front side ( 4 ) and a back ( 3 ) having; Depositing an electrically conductive layer ( 5 ) on the back of the substrate; Depositing a coating on the front of the substrate, the coating comprising at least a first layer ( 6 ) and a second layer ( 9 ); and structuring the coating ( 6 . 9 ) for photolithographic applications; being on the front ( 4 ) at at least one predetermined location a respective handling area ( 22 ; 22a - 22c ), which is not patterned for the photolithographic application and which is used to handle the mask blank ( 1 ) is designed by means of a mechanical holding or handling device, and wherein in the respective handling area ( 22 ; 22a - 22c ) the first layer ( 6 ) is exposed so that when handling the mask blank ( 1 ) from the front side, the mechanical holding or handling device on the first layer ( 6 ) is present. Process according to Claim 1, in which the coating ( 6 . 9 ) is deposited so that side walls of the substrate ( 2 ) are covered at least in sections, wherein the coating ( 6 . 9 ) is electrically conductive. Process according to Claim 2, in which the coating ( 6 . 9 ) is further deposited so that the electrically conductive coating ( 5 ) is contacted on the back side of the substrate. Method according to one of the preceding claims, in which the substrate ( 2 ) for depositing the electrically conductive layer ( 5 ) is held by means of a mechanical holding or handling device and the substrate before the deposition of the first layer ( 6 ) is transferred to an electrostatic chuck on the front side so that the first layer ( 6 ) is deposited on the front surface while the substrate is held by the electrostatic chuck. Process according to claim 4, wherein a surface of the coating ( 6 . 9 ) is formed of Si or SiO ₂ . The method of claim 5, wherein the first layer is formed as Si / Mo multilayer (6). Method according to one of Claims 4 to 6, in which on the first layer ( 6 ) a stress compensation layer ( 9 ), which forms the second layer. The method of claim 7, wherein the stress compensation layer is formed of Cr or SiO ₂ . Method according to Claim 7 or 8, in which the stress compensation layer ( 9 ) is formed so that side walls of the substrate ( 2 ) are embraced. Method according to one of claims 4 to 9, wherein on the front side of the mask blank ( 1 ) further comprises an absorber layer ( 10 ) is deposited to attenuate radiation used for photolithographic application. Method according to one of claims 4 to 10, wherein the substrate ( 2 ) before depositing the stress compensation layer ( 9 ) and the absorber layer ( 10 ) is transferred to a mechanical holding or handling device, which the substrate ( 2 ) from the back ( 3 ), wherein at least one area on the front ( 4 ) of the substrate ( 2 ) is masked so that the stress compensation layer ( 9 ) and the absorber layer ( 10 ) with at least one opening at a respective predetermined handling area ( 22 ) and the underlying first layer ( 6 ) is exposed. Method according to one of claims 4 to 10, wherein the substrate ( 2 ) before depositing the absorber layer ( 10 ) is transferred to a mechanical holding or handling device, which the substrate ( 2 ) from the back ( 3 ), wherein at least one area on the front ( 4 ) of the substrate ( 2 ) is masked, so that the absorber layer ( 10 ) with at least one opening at a respective predetermined handling area ( 22 ) and the underlying first layer ( 6 ) is exposed. Method according to one of claims 10 to 12, wherein the absorber layer ( 10 ) is formed of Cr, TaN or doped TaN. Method according to one of claims 10 to 13, wherein the absorber layer ( 10 ) is formed by ion beam assisted sputtering. Mask blank for photolithographic applications, in particular in EUV lithography, with a substrate ( 2 ), which has a front side ( 4 ) and a back ( 3 ), an electrically conductive layer ( 5 ), which is deposited on the back of the substrate so that the mask blank ( 1 ) is durable by an electrostatic chuck, and a coating ( 6 . 9 ) located on the front side of the substrate ( 2 ) is deposited, wherein on the front at at least one predetermined location a respective handling area ( 22 ; 22a - 22c ), which is not structured or intended for the photolithographic application and which is suitable for handling the mask blank ( 1 ) is designed by means of a mechanical holding or handling device, characterized in that the coating comprises at least a first layer ( 6 ) and a second one Layer ( 9 ), wherein in the respective handling area ( 22 ; 22a - 22c ) the first layer ( 6 ) is exposed so that when handling the mask blank ( 1 ) from the front side, the mechanical holding or handling device on the first layer ( 6 ) is present. Masking sheet according to Claim 15, in which the coating ( 6 . 9 ) side walls of the substrate ( 2 ) at least partially covered, wherein the coating ( 6 . 9 ) is electrically conductive Masking sheet according to Claim 16, in which the coating ( 6 . 9 ), the electrically conductive coating ( 5 ) contacted on the back of the substrate. Masking sheet according to claim 17, wherein a surface of the coating ( 6 . 9 ) is formed of Si or SiO ₂ . Masking sheet according to Claim 18, in which the coating comprises a Si / Mo multilayer ( 6 ). The mask blank of any one of claims 17 to 19, wherein the coating further comprises a stress compensation layer (16). 9 ). The mask blank according to claim 20, wherein the stress compensation layer comprises Cr or SiO ₂ . The mask blank according to claim 20 or 21, wherein the stress compensation layer ( 9 ) Side walls of the substrate ( 2 ) surrounds. The mask blank according to any of claims 20 to 22, wherein the stress compensation layer ( 9 ) has at least one opening which at a respective predetermined handling area ( 22 ) is formed so that the underlying first layer ( 6 ) is exposed. The mask blank according to any one of claims 16 to 23, on the front side of which an absorber layer ( 10 ) is deposited to attenuate radiation used for photolithographic application. Masking sheet according to Claim 24, in which the absorber layer ( 10 ) is formed of Cr, TaN or doped TaN.