NL2021649B1

NL2021649B1 - Exposure device for a photolithography method, assembly having an exposure device and method for exposing a substrate coated with a photoresist

Info

Publication number: NL2021649B1
Application number: NL2021649A
Authority: NL
Inventors: Vogler Uwe
Original assignee: Suss Microtec Lithography Gmbh
Priority date: 2018-09-17
Filing date: 2018-09-17
Publication date: 2020-05-07
Also published as: WO2020058194A1; TW202032274A

Abstract

Exposure device (12) for a photolithography method, comprising a light source (16), a lens mask (18) and a chuck (34). The lens mask (18) is provided between light source (16) and chuck (34), is disposed substantially parallel to the chuck (34) and comprises at least two focussing elements (42), each with a focal point (44). The exposure device (12) is arranged such that during exposure all focussing elements (42) of the lens mask (18) are always illuminated by the light source (16). An assembly (10) is provided with a substrate (14), in particular a wafer, and said exposure device (12). The substrate (14) is disposed on the chuck (34). The number of focussing elements (42) of the lens mask (18) corresponds to a number of the dies (48) provided on the substrate (14). A method for exposing a substrate (14) coated with a photoresist is described.

Description

Dit octrooi is verleend ongeacht het bijgevoegde resultaat van het onderzoek naar de stand van de techniek en schriftelijke opinie. Het octrooischrift wijkt af van de oorspronkelijk ingediende stukken. Alle ingediende stukken kunnen bij Octrooicentrum Nederland worden ingezien.

Exposure device for a photolithography method, assembly having an exposure device and method for exposing a substrate coated with a photoresist

The invention relates to an exposure device for a photolithography method for and an assembly with a substrate and such an exposure device. The invention further relates to a method for exposing a substrate coated with a photoresist.

Devices for treating a disc-shaped substrate are known from the prior art, which devices are used in conjunction with photolithography methods. A photolithography method can be used to produce micro-structured components, e.g. integrated circuits, semi-conductor chips or micro-electromechanical systems (MEMS). During the production process, a photomask is first loaded into the exposure device. A substrate coated with a photoresist (resist), e.g. a wafer, is then placed into the device and then exposed through the photomask. By reason of the exposure, the chemical properties of the photoresist attached to the substrate are partially changed, i.e. the photoresist is developed at these locations. The photoresist can then be removed in regions defined by the photomask. The treated substrate can then be processed further.

The biggest disadvantage of these methods is that the photomasks have a fixed, unchanging design. This means that for each new pattern to be written onto a substrate, a new photomask with the corresponding design has to be produced.

Furthermore, so-called direct write methods are known in which a light beam is passed over the substrate in order thereby to develop the photoresist in a selective manner and therefore to write the desired pattern onto the substrate directly, i.e. without a photomask. In this way, constructional changes can be carried out without a time delay and additional material costs for a photomask. However, direct write systems are comparatively slow since the light beam can write on only one point of the substrate at a time.

It is the object of the invention to provide an exposure device for a photolithography method which can both be used in a flexible manner and can also write on a large region of a substrate in a short time. It is also the object of the invention to provide a method for exposing a substrate coated with a photoresist,

-2by means of which, in a short time, substantially any pattern can be written onto a substrate.

In order to achieve the object, an exposure device for a photolithography method is provided with a light source, a lens mask and a chuck. The lens mask is disposed between the light source and the chuck, substantially parallel to the chuck, and comprises at least two focussing elements, each with a focal point. The exposure device is thus arranged in such a way that during exposure all focussing elements of the lens mask are illuminated by the light source.

The focal points of the focussing elements are each provided to write on the substrate using the direct write method. The focal points of the focussing elements thus each lie on the side - facing away from the light source - of the lens mask and are spaced apart from the chuck and so the focal points generate light points which can be used to develop the photoresist on the substrate.

By virtue of the fact that the lens mask is used to provide a plurality of focal points for writing, it is possible to write using the direct write method at different locations simultaneously. The focal points provided for writing are passed over the lens mask together and so all focal points write in parallel. In this way, the photoresist can be exposed at different locations simultaneously, whereby the writing speed is increased proportionally to the number of focussing elements compared with devices which comprise only a single focal point for writing using the direct write method. At the same time, the flexibility of the direct write method is retained and so the pattern to be written can be adapted at any time without constructional changes or fundamental process changes being necessary in order to do so.

In the sense of the invention, a deviation of up to ± 2.5 pm from parallelism is deemed to be substantially parallel¹¹, wherein ± 2.5 pm is the maximum change in spacing between the lens mask and the chuck when these are disposed substantially parallel. During exposure refers to times when a substrate on the chuck, more precisely the photoresist on the substrate, is illuminated with light from the light source.

In particular, the exposure device does not comprise any component which can block a light beam from the light source to individual focussing elements in a

- 3targeted manner such as an arrangement of movable mirrors, a pixel panel or the like.

The lens mask is flat, whereby the focussing elements are disposed in a planar array.

Furthermore, in particular, the lens mask is not a photomask, i.e. it is not a projection template and is not used as such. In particular, the lens mask does not screen any defined regions in order to reproduce a pattern as is the case with the conventional photolithography methods using photomasks, but rather bundles light into a plurality of light beams with which it is possible to write simultaneously in each case.

Furthermore, the focussing elements are not switchable independently of one another and so either all focussing elements provide a light point for writing or they do not.

The exposure device is thus particularly suitable for the production of integrated circuits since it is common in the production of integrated circuits to reproduce the same structures on a substrate multiple times.

The focussing elements can be formed of structured and/or coated material, in particular glass.

According to one embodiment, the exposure device comprises illumination optics which are disposed between the light source and the lens mask. The illumination optics are in this case designed in such a way that the light from the light source is incident on the focussing elements over the whole surface, in a collimated manner and/or with homogeneous intensity. In this way, the light beam formed by each focussing element has substantially the same properties and so, at all focal points of the lens mask which are provided for writing purposes, the photoresist can be developed in the same way, i.e. can be written directly.

The exposure device preferably comprises an adjusting device designed to move, in particular shift and/or tilt, the lens mask relative to the chuck, to move, in particular shift and/or tilt, the chuck relative to the lens mask, and/or to move, in particular shift and/or tilt the light source relative to the lens mask. In this way, by means of the adjusting device, the focal points of the lens mask which are provided

-4for writing purposes can be moved over a substrate fastened to the chuck and can therefore be used in a defined manner for direct writing.

In particular, the movement of the focal points is effected via an adjustment of the illumination angles.

The adjustment of the illumination angles can be effected by tilting the light source. In particular, the illumination angle is pivoted, i.e. the orientation of the illumination angle is changed while the angle of the illumination angle preferably remains constant.

Alternatively, the light source can be disposed in a stationary, i.e. fixed, manner and illuminate an optical element, e.g. a movable tilted mirror. In this case the adjustment of the illumination angle can be effected by tilting the optical element.

The tilting of the illumination angle can also be effected with known methods for changing the illumination angle in mask aligners as described in e.g. EP 2 253 997 A2.

For example, individual light bundles, which are generated in particular by switchable LED arrays, can be superimposed in a targeted manner in order to vary the angular distribution of the illumination angle.

The adjusting device is in this case controlled by means of a control unit in which the design to be written is stored as a template and which controls the writing process in particular in a fully automatic manner.

The focussing elements of the lens mask can be formed by Fresnel lenses, micro-lenses, e.g. a micro-lens array (MLA), in particular a monolithic micro-lens array, axicons and/or diffractive optical elements.

These focussing elements can be a micro-lens grid (micro-lens array - MLA) and/or binary/multi-level diffractive optical elements (DOEs).

According to a further embodiment, the lens mask can comprise a plurality of working cells, each with at least one focussing element. Thus the size of the at least one working cell defines the size of the die which can be produced with the working cell. Therefore, using the lens mask, the design which is identical for a

- 5plurality of - in particular all - the dies can be written in parallel onto a plurality of dies.

In particular, in this case, in each working cell, exactly one focussing element is provided and so each die is allocated a focussing element, in particular each with a focal point, which is provided to write on the die.

It is advantageous if the exposure device comprises a holder for a mask, in particular a photomask, wherein the lens mask is disposed in the holder. Therefore, both a photomask for a conventional mask exposure method and also a lens mask for the direct write method can be used in the exposure device, whereby the exposure device can be used in a particularly flexible manner.

Furthermore, provision can be made that the light source is a gas discharge lamp, in particular a mercury vapor lamp, at least one laser, in particular an excimer laser or a diode laser, or an LED array. In this way, the properties of the light source can be tailored to different requirements.

In accordance with the invention, in order to achieve the above-mentioned object, an assembly with a substrate, in particular a wafer, and an exposure device in accordance with the invention are provided. The substrate is disposed on the chuck and in particular is fastened thereto in a positionally stable manner. The number of focussing elements of the lens mask corresponds to a number of the dies provided on the substrate. In particular, each die is thus allocated a focussing element. Therefore, all dies can be written simultaneously with the same pattern using the direct write method, whereby the time required to create the design on the substrate is reduced to a fraction compared with devices in which only one die is written at any one time.

The substrate can be a silicon wafer.

The substrate is preferably coated with a photoresist.

The substrate can have a maximum diameter or a maximum edge length of 10 mm to 500 mm, preferably of 100 mm to 200 mm, in particular of 150 mm.

In one embodiment, the distance between the focal points of the focussing elements which have the largest distance from each other is at least 50%, in particular at least 75%, particularly preferably at least 90% of the maximum width

-6of the substrate, in particular of the maximum width of the useable surface of the substrate. In this way, the substrate can have the lens mask written on it substantially over its whole useable surface, i.e. the surface provided to be written on, simultaneously.

In an alternative embodiment, the distance between the focal points of the focussing elements which have the largest distance from each other is at most 50% of the maximum width of the substrate, in particular of the maximum width of the usable surface of the substrate. This is preferably the case if the lens mask has a small number of focussing elements, e.g. less than 9, in particular two focussing elements. In this case, the additional movement path of the lens mask is correspondingly at most 50% of the maximum width of the substrate, in particular at most half the maximum width of the usable surface of the substrate. The additional movement path is in this case the distance by which the focal points must be moved relative to the substrate in addition to the distance which is sufficient to write on one die completely in each case. In accordance with the invention, in order to achieve the above-mentioned object, a method for exposing a substrate coated with a photoresist, in particular for the production of integrated circuits, is also provided having the following steps:

a) providing an exposure device, in particular one in accordance with the invention, having a light source, a chuck and a lens mask with at least two focussing elements, which is disposed between the light source and the chuck,

b) placing a substrate coated with photoresist on the chuck,

c) illuminating all focussing elements of the lens mask by means of the light source so that each focussing element produces a focussed light point on and/or in the photoresist, and

d) moving the chuck, the lens mask and/or the light source in order to pass with the light points the regions of the photoresist which are to be exposed.

The method is a direct write method since the design is reproduced directly in the photoresist by means of the light points, in particular without using a photomask. By means of the lens mask, the focal points forming the light points

- 7are adjusted synchronously and in the same way, and the points which are provided to be written simultaneously are written simultaneously, i.e. are exposed or not exposed. Therefore, the substrate can have a pattern or the design written directly on it at a plurality of locations simultaneously.

Preferably, during the exposure, all focussing elements of the lens mask are always illuminated simultaneously and so all focussing elements form a focussed light point which can be used for direct writing.

It is advantageous if a plurality of dies are provided on the substrate. The light points are thus moved in a region on or in the photoresist which corresponds to a die to be produced on the substrate. In particular, each die is in this case allocated a focussing element and a focal point. In this way, the dies can be written on simultaneously in an identical manner using the direct write method, whereby the time required for this can be considerably reduced compared with other direct write methods.

In particular, the light points are moved only within a die, i.e. the scope of movement of a light point is limited to the size of a die and so a light point is not provided for writing on a plurality of dies which are disposed at different locations on the substrate.

The scope of movement can be limited to 50 mm, preferably to 20 mm, whereby a very precise movement of the light points is possible.

In one embodiment, the movement of the chuck, the lens mask and/or the light source is effected by means of an adjusting device designed to move, in particular shift and/or tilt, the lens mask relative to the chuck, to move, in particular shift and/or tilt, the chuck relative to the lens mask, and/or to move, in particular shift and/or tilt the light source relative to the lens mask. In this way, the light points can be moved in a defined manner over the substrate.

Provision can be made that the regions to be exposed are passed according to a template stored in a control unit. By means of the control unit it can be ensured that the substrate can be written on in a precise and, in particular, fully automatic manner. The template is created on the basis of the pattern or design.

- 8Preferably, the distance between the light points having the largest distance from each other corresponds to at least 50%, in particular at least 75%, particularly preferably at least 90% of the maximum width of the substrate, in particular of the maximum width of the useable surface of the substrate.

In terms of the invention, the maximum width of the useable surface is the distance between the points on the useable surface which have the largest distance from each other.

The useable surface of the substrate is thus the surface provided for writing on or for production of integrated circuits. Therefore, by means of the method, the substrate can be written substantially over its whole surface simultaneously.

Further advantages and features will be apparent from the following description and from the attached drawings, in which:

- Figure 1 is a schematic cross-sectional view of an assembly in accordance with the invention having an exposure device in accordance with the invention which comprises a lens mask,

- Figure 2 is a schematic view of the assembly with the exposure device of Figure 1,

- Figure 3 is a schematic plan view of the lens mask of Figure 1 according to a first embodiment, and

- Figure 4 is a schematic plan view of the lens mask of Figure 1 according to a second embodiment.

Figure 1 shows an assembly 10 with an exposure device 12 and a coated substrate 14, wherein the exposure device 12 is designed to expose the substrate 14 coated with a photoresist.

In the illustrated exemplified embodiment (see Figure 2), the substrate 14 is a circular wafer and has a useable surface 40. Alternatively, any substrate 14 can be exposed by means of the exposure device 12, in particular wafers which are non-circular.

- 9The useable surface 40 shown in broken lines in Figure 2 comprises a region of the substrate 14 which is formed by a concentric circle with a diameter d which amounts to 95% of the diameter of the substrate 14.

Naturally, the useable surface 40 can amount to a portion of a surface of the substrate 14 of any size.

Furthermore, the exposure device 12 can be used in any photolithography method.

In order to expose the substrate 14, the exposure device 12 comprises a light source 16, a lens mask 18 and illumination optics 20 provided to guide the light from the light source 16 to the lens mask 18.

In this case, the light source 16 is a mercury vapor lamp.

In an alternative embodiment, the light source 16 can be any light source suitable for the photolithography method, e.g. another gas discharge lamp, a laser, in particular an excimer laser or diode laser, or an LED array. Naturally, the light source 16 can also be formed of a combination of these light sources.

The illumination optics 20 are designed corresponding to the light source 16 and to the beam path on which the light is conducted from the light source 16 to the lens mask 18.

In the embodiment illustrated in Figure 1, the illumination optics 20 comprise an ellipsoidal mirror 22 which bundles the light from the light source 16, and, in the direction of the beam path, a shutter 24, a collimation lens 26, two lens plates 28, 29, which jointly form a so-called Kohler integrator, and a front lens 30. Furthermore, two mirrors 32, 33 are disposed in the beam path and deflect the light by 90° in a corresponding manner in each case.

By means of the shutter 24 the light from the light source 16 can be completely blocked, so no light from the light source 16 falls on the lens mask 18. In particular, the shutter 24 is not suitable for blocking light beams to individual parts such as focussing elements of the lens mask 18.

-10The exposure device 12 additionally comprises a chuck 34 and a platform 36, wherein the chuck 34 is disposed opposite the front lens 30 on the platform 36 (see Figure 2).

The substrate 14 is fastened to the chuck 34.

The lens mask 18 is held in a holder 38 of the exposure device 12 between the illumination optics 20 and the chuck 34 and is disposed substantially parallel to the useable surface 40 of the substrate 14.

The holder 38 is preferably a holder in which photomasks for a mask photolithography method can also be held. For example, the holder 38 can be a drawer-like holding means in which the lens mask 18 has suction applied by means of negative pressure and is thereby fixed. Alternatively, the holder 38 can also be designed especially, in particular exclusively, for holding the lens mask 18.

The lens mask 18 is e.g. flat and has a main body 41 and a plurality of, in particular identically formed, focussing elements 42 which are disposed next to one another in the form of a grid.

The main body 41 has a plurality of working cells 46. In the illustrated exemplified embodiment, the working cells 46 are disposed in a square manner and in rows and columns, in particular directly adjoining one another. In other words, the working cells 46 are distributed in a chess broad-like manner on the main body 41.

In the illustrated exemplified embodiment, the number of working cells 46 corresponds to the number of focussing elements 42, wherein in each case one focussing element 42 is allocated to a working cell 46.

The focussing elements 42 are e.g. micro-lenses, each having a focal point 44 which, in the installed condition of the lens mask 18, lies in the plane of the usable surface 40 or of the photoresist applied to the substrate 14.

The focussing elements 42 are formed in the main body 41. The focussing elements 42 and the main body 41 can thus be jointly formed as one piece.

-11 Figure 3 illustrates a lens mask 18 according to a first embodiment. The lens mask 18 is in this case a circular disc with nine focussing elements 42 disposed in the form of a 3 x 3 grid centered in the disc.

In this embodiment, each focussing element 42 comprises an individual microlens 43 with a focal point 44 which is provided for writing on the photoresist or the substrate 14.

Figure 4 illustrates a lens mask 18 according to a second embodiment. In this embodiment, the focussing elements 42 each comprise Fresnel lenses 45 instead of micro-lenses 43 as in the first embodiment. Irrespective of this, the lens mask 18 of the second embodiment is formed analogously to the first embodiment.

The following explanations apply equally to the lens mask 18 in each embodiment, i.e. regardless of the configuration of the focussing elements 42.

The focal points 44 of all focussing elements 42 lie in a plane which is parallel to the lens mask 18 (see Figure 2). Alternatively, the focal points 44 can lie in a plane which is substantially parallel to the lens mask 18, i.e. in a plane inclined by up to 2.5 pm with respect to the lens mask 18.

The distance between the focal points 44 of the focussing elements 42 disposed at diagonally opposing ends of the lens mask 18 is 90% of the diameter d of the usable surface 40 of the substrate 14. In an alternative embodiment, the distance between the focal points 44 of the focussing elements 42 having the largest distance from each other can be of any length. It is preferably at least 50%, in particular at least 75%, particularly preferably at least 90% of the maximum width of the substrate 14 or the maximum width of the usable surface 40.

The distance between the focal points 44 of the focussing elements 42 having the largest distance from each other is preferably not larger than the maximum width of the substrate 14, in particular not larger than the maximum width of the usable surface 40 of the substrate 14 since otherwise not all focal points 44 will be usable simultaneously for writing on the substrate 14.

In an alternative embodiment, the focussing elements 42 can be formed by substantially any type of lens, e.g. by Fresnel lenses, micro-lens arrays (MLAs), in

-12particular a monolithic micro-lens array, diffractive optical elements (DOEs) or axicons or combinations thereof.

The focussing elements 42 can be formed of structured and/or coated material, in particular glass.

The size of the working cells 46 is selected such that it corresponds to the size of a die 48 to be produced from the substrate 14. At the same time, the working cells 46 establish the region on the substrate 14 in which a corresponding focal point 44 of the allocated focussing element 42 can be moved.

Therefore, each die 48 is allocated a focussing element 42 with a focal point 44 which is provided to write on the corresponding working cell 46.

The lens mask 18 can generally have any number of plural, i.e. at least two, focussing elements 42. Furthermore, any number of focussing elements 42 can be allocated to a working cell 46 and/or to a die 48. Additionally or alternatively any number of dies 48 can be provided in a working cell 46.

Furthermore, a focussing element 42 can have more than one focal point 44 provided for writing purposes.

Furthermore, the focussing elements 42 can be disposed next to one another in any manner. In particular, they can form an arrangement deviating from a rectangle, e.g. in order to be able to produce the largest possible number of rectangular dies 48 on a circular wafer.

In order to move the focal points 44 relative to the substrate 14, the exposure device 12 comprises an adjusting device 50 with a first adjusting unit 52 and a second adjusting unit 54.

The first adjusting unit 52 is coupled to the light source 16 and is arranged to shift and/or tilt the light source 16.

The second adjusting unit 54 is coupled to the chuck 43 via the platform 36 and is arranged to shift and/or tilt the chuck 34 with respect to the lens mask 18.

Additionally or alternatively, the adjusting device 50 can comprise an adjusting unit which is coupled to the lens mask 18 and is arranged to shift and/or tilt the lens mask 18 relative to the chuck 34.

-13Naturally, in a further alternative embodiment, all the above-mentioned adjusting units can be combined in any manner in an adjusting device 50 in order to provide a corresponding movement of the focal points 44.

Since the focussing elements 42 are fixedly disposed in the lens mask 18, the focal points 44 are also fixedly disposed with respect to one another and are therefore all adjusted by the adjusting device 50 synchronously and in the same manner relative to the substrate 14.

In order to control the exposure device 12, a control unit 56 is provided which is connected in a signal-transmitting manner to the light source 16, the shutter 24 and the adjusting device 50.

The control unit 56 can be part of the exposure device 12 or can be designed separately e.g. as a computer.

The control unit 56 stores a template of the design or pattern which is to be written onto the dies 48 by means of the photolithography method, wherein the control unit 56 controls the movement of the focal points 44 and the opening and closing of the shutter 24 according to the template.

If the shutter 24 is opened, the light from the light source 16 is let through to the front lens 30 and broken at that location such that the light is collimated and the whole side 58 of the lens mask 18 facing the front lens 30 is illuminated at homogeneous intensity. In this way, all focussing elements 42 are also illuminated by the light from the light source 16 and, at each focal point 44, a light point is produced by means of which the photoresist can be exposed in the direct write method on the substrate 14.

In this way, regions of the substrate 14 can be exposed selectively using the exposure device 12.

If the shutter 24 is closed, the light from the light source 16 is blocked and so no light from the light source 16 falls onto the lens mask 18 and therefore no light points are formed which develop the photoresist.

The manner of operation of the assembly 10 and the exposure device 12 with the aid of an integrated circuit is described hereinunder, this circuit being produced

- 14in each case on a die 48 of the substrate 14 by means of the photolithography method.

Naturally, the method can be used for any designs or patterns.

Firstly, the lens mask 18 is inserted into the holder 38 and a substrate 14 coated with a photoresist is fastened to the chuck 34.

Then the shutter 24 is opened and all focussing elements 42 of the lens mask 18 are homogeneously illuminated by means of the light source 16 via the illumination optics 20. Each focussing element 42 then generates, at its focal point 44, a focussed light point which directly exposes the photoresist at the corresponding location in the respective die 48.

By means of the control unit 56 and with the aid of the stored template, the regions - which are to be exposed - of the photoresist on the substrate 14 are passed and exposed by the light points formed by the lens mask 18.

In this case, the control unit 56 controls, via the adjusting device 50, the relative movement of the focal points 44 with respect to the substrate 14 and, with the focal points 44 coupled to one another via the lens mask 18, and according to the template, passes the structures of the design or pattern to be written.

For this purpose, the chuck 34 is shifted with the substrate 14 by means of the second adjusting unit 54 with respect to the lens mask 18 in the X-Y direction. Additionally or alternatively, the chuck 34 can be tilted and/or rotated relative to the lens mask 18 in order to move the focal points 44 relative to the substrate 14.

In an alternative embodiment, the relative movement of the focal points 44 with respect to the substrate 14 can be generated in that the lens mask 18 is shifted and/or tilted via the corresponding adjusting unit.

Furthermore, by means of the adjusting unit 52 the light source 16 can be shifted and/or tilted, whereby the beam path of the light from the light source 16 is changed and leads to a corresponding relative movement of the focal points 44 with respect to the substrate 14.

Each focal point 44 is thus allocated each time to an individual die 48, i.e. each die 48 is written on by one focal point 44 only at any time.

-15Furthermore, each focal point 44 is disposed at the correspondingly same location of the die 48 allocated thereto and so all focal points 44 each write on the same location of the die 48.

By means of the illumination optics 20 the light from the light source 16 illuminates all focussing elements 42 simultaneously and so at all focal points 44 of the focussing elements 42 a light point is formed to develop the photoresist. By means of the shutter 24 the light from the light source 16 is let through to the lens mask 18 or is blocked corresponding to the structure to be formed and so light from the light source 16 correspondingly falls through the focussing elements 42 and light points for writing purposes are formed or no light from the light source 16 falls through the focussing elements 42 and therefore no light points for writing purposes are formed.

In this way, all focal points 44 are moved synchronously in the same way over the photoresist and each write the same structure of the design simultaneously in dependence upon the position of the shutter 24.

In this way, the design of the integrated circuit is reproduced simultaneously using the direct write method in all dies 48 by means of the light point, which is allocated to the corresponding die 48, in the photoresist on the substrate 14.

In order to produce a different design, a different template merely needs to be stored in the control unit 56 and selected for the method. The exposure device 12 and in particular the lens mask 18 do not have to be changed for this purpose, i.e. they can be used flexibly for different designs.

Naturally, different lens masks 18 can also be used for different designs, in particular lens masks 18 can be used corresponding to their optical properties, such as resolution. For example, for a design in 1 pm technology and a design in 5 pm technology, different lens masks 18 can be used.

In this way, a photolithography method is provided which is both flexible to use and can also reproduce substantially any patterns multiple times in a distributed manner over a large region of a substrate 14 in a short time.

- 16By means of the method, it is possible to produce a design common to all dies 48 using the direct write method simultaneously in all dies 48 provided on a substrate 14.

The method is thereby quicker by a multiple than in the case of conventional direct write methods in which the dies 48 are written on individually one after another or only a part of the dies 48 of a substrate 14 is ever written on at any one time.

The invention is not limited to the illustrated embodiments. In particular, individual features of an embodiment can be combined with other features as desired, independently of the other features of the corresponding embodiment.

Claims

CONCLUSIONS

An exposure device for a photolithography method, with a light source (16), a lens mask (18) and a holder (34), the lens mask (18) being provided between the light source (16) and the holder (34), substantially parallel is arranged on the holder (34) and comprises at least two focusing elements (42), each with a focal point (44), the exposure device (12) being arranged in such a way that, during exposure, all focusing elements (42) of the lens mask (18) are always ) exposed by the light source (16).

Illumination device according to claim 1, characterized in that the illumination device (12) comprises an illumination optic (20) arranged between the light source (16) and the lens mask (18), the illumination optic (20) being arranged to light from the light source (16) over the entire surface, collimated and / or with homogeneous intensity on the focusing elements (42).

Illumination device according to claim 1 or 2, characterized in that the illumination device (12) comprises an adjusting device (50), the adjusting device (50) being adapted to move the lens mask (18) relative to the holder (34) , in particular sliding and / or tilting, moving the holder (34) relative to the lens mask (18), in particular sliding and / or tilting, and / or the light source (16) relative to move, in particular slide and / or tilt the lens mask (18).

Illumination device according to one of the preceding claims, characterized in that the focusing elements (42) of the lens mask (18) are Fresnel lenses, micro lenses, Axicons and / or diffractive optical elements.

Illumination device according to one of the preceding claims, characterized in that the lens mask (18) comprises a plurality of working cells (46), each with at least one focusing element (42), the size of the at least one working cell (46) being the size of the dies (48) which can be manufactured with the working cell (46), in particular wherein exactly one focusing element (42) is provided in each working cell (46).

An exposure device according to any one of the preceding claims, characterized in that the exposure device (12) comprises a mask receiving element (38), the lens mask (18) being disposed in the receiving element (38).

Illumination device according to one of the preceding claims, characterized in that the light source (16) is a pressure lamp, in particular a mercury pressure lamp, at least one laser, in particular an excimer laser or diode laser, or an LED matrix.

Assembly with a substrate (14), in particular a wafer, and an exposure device (12) according to any of the preceding claims, wherein the substrate (14) is arranged on the holder (34), the number of focusing elements (42 ) of the lens mask corresponds to a number of the dies (48) provided on the substrate (14), in particular each of which (48) is associated with a focusing element (42).

Assembly according to claim 8, characterized in that the distance between the focal points (44) of the focusing elements (42) furthest from one another is at least 50%, in particular at least 75%, in particular preferably is at least 90% of the maximum width (d) of the useful surface (40) of the substrate.

Method for exposing a photoresist-coated substrate (14), in particular for the manufacture of integrated circuits, with the following steps:

a) providing an exposure device (12), in particular according to claim 1, having a light source (16), a holder (34) and a lens mask (18) with at least two focusing elements (42), which is between the light source (16) ) and the holder (34) is set up,

b) placing a photoresist-coated substrate (14) on the holder (34),

c) exposing all the focusing elements (42) of the lens mask (18) by means of the light source (16), so that each focusing element (42) generates a focused light point on and / or in the photoresist, and

d) moving the holder (34), the lens mask (18) and / or the light source (16), to move the area of the photoresist to be exposed with the light points.

Method according to claim 10, characterized in that during the exposure all focusing elements (42) of the lens mask (18) are always exposed simultaneously.

Method according to claim 10 or 11, characterized in that a plurality of dies (48) are provided on the substrate (14), the light points being moved in an area on or in the photoresist corresponding to one to be manufactured (48) on the substrate (14), in particular wherein each one (48) is associated with a focusing element (42) and a focal point (44).

Method according to any one of claims 10 to 12, characterized in that the movement of the holder (34), the lens mask (18) and / or the light source (16) takes place by means of an adjustment device (50) the adjusting device (50) being adapted to move, in particular displace, the lens mask (18) relative to the holder (34)

5 and / or tilting, moving the holder (34) relative to the lens mask (18), in particular sliding and / or tilting, and / or the light source (16) relative to the lens mask (18 ), in particular to shift and / or tilt.

Method according to any one of claims 10 to 13, characterized in that the

10 areas to be exposed are set according to a pattern stored in a control unit (56).

Method according to any one of claims 10 to 14, characterized in that the distance of the brightest points from each other corresponds to at least

At least 50%, in particular at least 75%, especially preferably at least 90% of the maximum width (d) of the useful surface (40) of the substrate (14).