DE10313277A1 - Photoresist outputting device for microlithography, has homogenizing device in photoresist flow between filter and outlet opening - Google Patents

Abstract

The photoresist passes through a filter (1,10)to an outlet opening (3). The photoresist continuously passes through a homogenizing device (9) provided between the filter and the outlet opening, for homogenizing the photoresist. The homogenizing device may change the orientation, extension of molecules or macromolecules dissolved in the photoresist by mixing or eddying lower regions of the photoresist flow. Independent claims are included for a method of outputting photoresist; a method of forming a thin layer of photoresist on a wafer substrate; and a mask blank.

Description

The The present invention relates generally to the formation of thin layers in microlithographic manufacturing processes and more specifically relates to an apparatus and a method for outputting a photo or Electron beam varnish for forming a layer of paint on a microlithographic process. The present invention further relates to an apparatus and a method for forming a thin photo or electron beam lacquer layer on a substrate, for example one Wafer or mask blank.

Thin layers from organic materials, especially thin layers of photoresist in microlithographic manufacturing processes in microelectronics used to create ever smaller structures, for example for the production of integrated semiconductor circuits, masks for the production of integrated circuits, liquid crystal displays or like. Because of the ever smaller dimensions find ever shorter ones wavelength Application, for that the photoresist used must be sensitive. Under Photoresist in the sense of this application is therefore equally a Understanding photoresist, which is based on exposure or writing visible wavelengths, wavelength in the ultraviolet or deep ultraviolet spectral range, electron beams, Ion beams or x-rays is sensitive.

Usually are photoresist layers on a substrate (e.g. wafer, mask blank) dispensed in doses and then by rotating the wafer at high speeds to a thin photoresist layer squandered. For the exposure of ever smaller structures increases the demands with regard to the absence of defects and homogeneity of the spin-coated photoresist layer increasingly. Contamination and disruptive particles in the photoresist to remove, ever finer filters are used. Filter, their use is preferred by the present invention have, for example, average pore sizes of 0.05 to 0.1 micrometers on. As the named inventor found out, occur below a certain pore size, depending especially the viscosity of the photoresist, for example below an average pore size of 0.2 Micrometer, increasing problems with the homogeneity of a spin-coated photoresist layer. Like the inventor in elaborate Has found out these series of problems one or the other several of the following Causes are attributed.

Photoresists, especially those for using electron or ion beam lithography from released Macromolecules those in the solvent usually a ball form. Dependent on of the solvent used is the ball widened by solvation. The balls of macromolecules can do one larger medium Have diameters as the pores of the filters used. To the filter to be able to happen the macromolecules therefore stretch, which leads to inhomogeneities in the viscosity for example through a pronounced preference orientation of stretched molecules. inhomogeneities in viscosity to lead when dispensing and spilling the photoresist to inhomogeneities spin-coated photoresist layer.

Inhomogeneities of viscosity to lead in particular that the result of the layer thickness during spin coating responsible balance of power of shear and viscous force on the rotating wafer locally varied.

Further the inventor found that fluctuations in the pore size of the filter used can be another cause of inhomogeneities.

The closest stand according to US 6,332,924 B1 discloses a device for dispensing a photoresist for use in a microlithographic process. A diaphragm pump is used between a dispensing nozzle serving as a dispensing opening and a fine filter, which is used to meter the dispensed photoresist. The pump cannot be flowed through continuously and has an active effect on the photoresist. The pump is used for metering and not for homogenizing the photoresist.

task The present invention is an apparatus and a method to create a photoresist, making it even more homogeneous Have photoresist layers formed. Furthermore, according to the present Invention an apparatus and a method for forming a even more homogeneous thin Photoresist layer can be created on a substrate. Furthermore should according to the present Invention a mask blank with a more homogeneous layer thickness distribution be created.

This Object is achieved by a device with the features of claim 1 or 13, by a method with the features of claim 14 or 25 and solved by a mask blank according to claim 26. Further advantageous embodiments are the subject of back-related Expectations.

The aforementioned task can be carried out in a surprisingly simple manner in a device for dispensing a photoresist to form a lacquer layer in a microlithographic process, which comprises a filter medium through which the lacquer flows and an output opening downstream of the filter medium for the output of the filtered photoresist, can be solved in that at least one homogenization means for homogenising the photoresist is arranged between the filter medium and the output opening which can be flowed through continuously by the photoresist and is designed such that the photoresist is homogenized when it flows through the homogenizing agent. Because the photoresist is homogenized according to the invention when it flows through the homogenizing agent, the device can be operated continuously and continuously output photoresist. Longer waiting times, which would otherwise be required, for example, so that the photoresist after the fine filtering in the filter medium, where the macromolecules are stretched, reach an equilibrium state again by relaxation or reorientation, can thus be avoided and a high throughput can thus be achieved in a microlithographic process become.

According to one first preferred embodiment is the at least one homogenizing agent designed so that on the photoresist as it flows through of the homogenizing agent is done passively. Because the The inventor has found that one is located downstream of the filter means active homogenizing agent that is active on the photoresist Do work, for example by mechanical stirring, swirling or the like, due to friction or comparable effects disruptive inhomogeneities or even a disturbing one Particle formation in the photoresist leads. Such inhomogeneities or According to the invention, particles can be surprisingly simple Avoid using a passive homogenizing agent the photoresist as it flows through mixed or swirled without further active mechanical action or solved in it preferred molecules reoriented. The work done passively on the photoresist can for example, a pressure drop in the paint flow when flowing through the Homogenizing agent, but by simple countermeasures, in particular in that the photoresist is active by means of a the filter arranged pump is pressed by the device or sucked by means of a suction device arranged downstream of the filter medium is easily compensated for. Overall, it can Homogenizing agent to increase the flow resistance in the device compared to a substantially straight line Route the hose connection between the filter medium and the dispensing opening. This However, the effect can be easily compensated for, if at all required.

The The present invention is based on an essentially laminar one flow between the filter medium and the discharge opening, which is caused by the comparatively high viscosity of the solvent flowing through with the macromolecules dissolved in it. The effect recognized by the inventor. significantly better homogenization attributed to one or more of the following effects: in that in a hose or tube-like guide means to lead the liquid Flow obstacles and / or deflection areas between the filter medium and the discharge opening to redirect the flow are provided, the orientation of the molecules or dissolved in the photoresist Macromolecules through Mixing or swirling sub-areas of the paint flow changes what overall leads to a significant reduction in inhomogeneities. On the flowing Photoresist can also be done passively on the job solvent and the solved in it molecules or macromolecules acts and can be used to filter through to reduce the stretching of the molecules caused in the filter medium. So you can the solved molecules faster back to their original Take equilibrium, in which the photoresist largely is homogeneous. Possible Reasons for the aforementioned work is in addition to the reorientation the solved molecules also due to friction effects between flow sub-areas one about the cross section of the photoresist flow prevailing flow profile.

By Matching the geometric arrangement and proportions of the homogenizing agent serving flow obstacles and / or deflection areas on the properties of the photoresist flowing through can the device in surprising easy way for designed a comparatively wide range of flow rates be without making a change the setting of active components, for example the speed of agitators or the like.

The homogenization means can comprise a plurality of deflection regions for deflecting the paint flow in another spatial direction. The deflecting means is expediently designed as a region of curvature of a hose-like or tube-like guide means, the guide means being able to have, for example, a circular, elliptical or rectangular cross section in order to allow the photoresist to flow essentially laminar therein. The deflection area is particularly preferably curved in each case by an angle of at least 90 degrees, so that sub-areas of the essentially laminar-flowing paint flow during deflection by mixing or swirling be mixed together. As is known, the exact description of flow conditions is complex. However, the present invention contemplates that individual subregions of the paint flow or so-called laminar flow threads approach each other in the deflection regions and that due to the flow profile caused in the deflection region and / or of friction between the subregions or flow threads, mixing or Whirling the same comes. The present invention also contemplates that individual flow sub-regions are swirled together, in particular when the flow is deflected by comparatively large angles, in particular angles that are significantly greater than 90 degrees. It may also be sufficient for the purposes of the present invention that, due to the flow profile occurring in the respective deflection area, frictional effects are caused between sub-areas of the flow with different flow velocities, so that overall work is done on the photoresist which leads to reorientation and / or compression of the dissolved molecules.

Prefers are deflection areas according to the invention, the the flow by angles greater than 90 degrees, more preferably by angles greater than 130 degrees, and even more preferred by angles greater than Deflect 170 degrees. The preferred upper limit for the deflection area is a Value of close to 180 degrees is provided. Of course, the leadership means or the hose also looped by more than 180 degrees be, for example, about 270 degrees or even about 360 degrees. However, the present invention is not based on the foregoing Limited angular ranges, because by suitable choice of flow parameters, in particular the flow rate and the flow cross section and by arranging further flow obstacles, can also sufficient homogenization of the photoresist at smaller angles be achieved.

On another important parameter, which the aforementioned deflection areas characterized is the radius of curvature itself. According to the invention, a comparatively small one is preferred Radius of curvature, the one with a hose or tube-like guide means to lead the paint flow through the inside diameter of the guide means are expressed can. According to the invention, a radius of curvature is preferred that only one or a few diameters of the tubular or tubular guide means corresponds and which is preferably in the range from about one to about ten inner diameters, more preferably in the range of about one to about six inner diameters, and more preferably in the range is from about one to about three inner diameters of the guide means. The deflection area can even be a kink of the guide means with a constriction area be trained.

Of course you can the hose or tube-like guide means a comparatively large radius of curvature in the deflection areas have a multiple of the inner diameter.

Prefers the deflection areas are arranged at irregular intervals and / or in different spatial directions curved so that the paint flow overall undirected and random or is even diverted chaotically. The aforesaid hose-like or tube-like guide means can even be made in the form of a chaotic hose, so the paint flow overall random or chaotic quasi to and fro when it hits the redirection areas flows through.

Of course you can the cross section of the tubular or tubular guide means at least in the deflection areas also compared to essentially rectilinear sections may be narrowed or may be in the rectilinear sections of the guide means further constriction areas can be provided to unify the flow To oppose resistance.

According to one another embodiment, which can also be claimed separately or with each of the aforementioned embodiments can be combined, the guide means comprises a flow obstacle with one or more constrictions where the cross section of the aforementioned tubular or tubular guide means is narrowed. Due to the narrowing, subregions of the paint flow, in particular laminar flow threads of the same, when flowing through of the obstacle are mixed together by swirling. Also the flow profile prevailing in the constriction area itself can be too a mixing or swirling of individual subregions of the paint flow (their. Furthermore, due to friction effects or the like Work on the flowing Photoresist are performed in the manner mentioned above to a Reorientation and / or compression of the macromolecules and thus to another Homogenize the photoresist can.

The aforementioned constrictions can be impressed on the hose-like or tube-like guide means, for example in the form of radial projections on the inner wall of the guide means, or can be provided with orifices, perforated plates or other mechanical obstacles with one or more axial openings or tortuous flow paths through the guide means be specified.

Basically can as an obstacle another one downstream of the first filter medium Filter means are used, but the average pore diameter is expediently larger than that of the first filter medium and also larger than the average diameter of the molecules of the photoresist. So be the molecules when flowing through the pores of the further filter medium are not stretched but instead the further filter medium then essentially becomes a mixture and / or swirling the paint flow after the filter medium to lead. The mean pore diameter of the further filter medium is thus preferred bigger or equal to the average diameter of the molecules of the photoresist, which of the type of solved molecules depends. Usually the average pore diameter of the further filter medium becomes larger or equal to about 0.2 microns. Because filters are made in a very pure form can be and thus will not lead to any further contamination in the paint flow, can according to this embodiment the photoresist can be homogenized in a particularly expedient manner.

Prefers the homogenizing agent is arranged directly in front of the dispensing opening, so the flow path between the filter medium and the discharge opening can be minimized as far as possible can and according to the invention the risk that on this flow path new impurities get into the photoresist, are minimized as far as possible can. According to the Duration of the photoresist at a normally for the output of the Flow rate used photoresists are a few seconds, so a time that would normally not be enough for that the photoresist and the dissolved in it macromolecules automatically, for example due to relaxation, their state of equilibrium after fine filtering can reach again.

According to one another embodiment, which are also separately independent can be claimed or with one or more of the. aforementioned embodiments can be combined; is the homogenizing agent as a container with an inlet at one end of the container and one end of the container opposite Drain of the container formed, the capacity of the container to the middle to Output of the photoresist used flow rate matched is that the average residence time of photoresist in the container in the corresponds essentially to one or more relaxation times the at least partially stretched macromolecules in their after the fine filtering original Can relax state of equilibrium, or that the middle Residence time of photoresist in the container corresponds to a period of time, which is sufficient for the preferred oriented stretched molecules to be sufficient can reorient. Thus, according to this alternative embodiment by simply specifying the geometric size of a container suitable homogenization of the photoresist can be accomplished. Works in this embodiment the container quasi like a sedimentation basin, where the photoresist essentially rests, to achieve its equilibrium state, which is used as a serving containers but can be flowed through or is flowed through continuously.

For example can according to the present Invention to be considered that the average residence time of photoresist in the container for the intended use flow rates used by photoresist at least 10 minutes, more preferably at least 20 minutes and more preferably at least about 30 minutes.

Further is according to the present Invention according to the aforementioned device features trained procedure created.

According to the invention an apparatus and a method for forming a thin photoresist layer on a substrate, for example a wafer or mask blank, for a microlithographic Process created, the device or the method by characterized the aforementioned device or a corresponding method is. The substrate is on a turntable with a Vacuum clamping device or a comparable holding device for temporary Hold the substrate on the turntable. After spending one preferred Predeterminable dose of the photoresist on the substrate is the turntable a rapid rotary movement and thereby the one on the substrate existing photoresist is thrown radially due to centrifugal forces, until there is a balance of power between shear forces and has built up a viscous force, which is essentially determines the achievable thickness of the paint layer.

following become preferred embodiments of the present invention with reference to the accompanying figures are described in which:

1 shows in a schematic cross section an embodiment of a device according to the present invention;

2 in a schematic cross-sectional view deflection areas of a homogenization by means of the device according to the 1 are shown;

3 shows a schematic cross section of an embodiment in which a first filter is followed by a further filter with a larger pore size;

4 shows a schematic cross section of an embodiment in which an aperture-like obstacle is used to homogenize the photoresist;

S represents a measured layer thickness distribution of PBS (polybutene sulfone) on a substrate, the coating application being carried out without homogenization; and

6 represents a measured layer thickness distribution on a substrate, the coating application being carried out with homogenization according to the present invention.

In the figures designate identical reference numerals identical or equivalent elements or functional groups, no further need to be described.

In the 1 a device for dispensing a photoresist according to an embodiment of the present invention is shown in a schematic cross section. The device is used in a microlithographic process in which a thin photoresist layer is to be formed on a substrate, for example on a wafer. The photoresist 5 is in a container 2 kept. The photoresist comprises a solvent in which molecules, in particular organic macromolecules, are dissolved. Via the hose or tube-like connecting line 6 , which serves as a guide, the photoresist becomes a pump 7 which sucked the photoresist 5 to a dispensing opening, for example a dispensing nozzle 3 , promotes. Between the dispensing nozzle 3 and the pump 7 is a membrane filter serving as a filter medium with a membrane 10 arranged. Between the membrane filter 1 and the dispensing nozzle 3 the photoresist in a tube, a tube or a comparable connecting line serving as a guide means 8th guided. In that area 9 is the hose 8th wound several times chaotically or accidentally, so that the tortuous hose area 9 serves as a homogenizing agent for homogenizing the photoresist.

Like in the 1 the hose shows 8th in that area 9 a plurality of deflection areas for deflecting the paint flow in another spatial direction, the hose 8th is curved in the deflection areas in each case by a comparatively large angle, for example by at least 90 degrees. The radius of curvature of the deflection areas can vary in large areas. According to the 1 the radius of curvature of the deflection areas is significantly larger than the diameter of the tube B. The radius of curvature of the deflection areas is preferably significantly smaller and corresponds in particular to one or a few diameters of the tube 8th , which, however, for reasons of simplification in the 1 is not shown. Additional flow obstacles, for example orifices, perforated plates or the like, can also be provided in the curvature regions.

In the 2 are two deflection areas of the chaotically wound hose 9 according to the 1 shown in an enlarged cross section. Overall, the hose 28 flows through from the inlet IN to the outlet OUT. During the lower deflection area 20 a comparatively large radius of curvature of several diameters of the hose 28 is the radius of curvature of the upper region of curvature 21 significantly smaller and corresponds approximately to a hose diameter.

In the 2 Two possible causes that contribute to the observed homogenization of the photoresist are shown schematically. In both cases, sub-areas of the paint flow 22 . 23 respectively. 25 . 26 considered. In the lower deflection area 20 is that of the approximately central flow thread 23 The distance to be covered is shorter than that of the flow thread 23 Distance to be covered while in the upper deflection area 21 that of the approximately central flow thread 26 The distance to be covered is longer than that of the approximately central flow thread 21 distance to be covered.

Consider the case that the lacquer flows through the tube 28 essentially in a laminar manner, the laminar flow area essentially due to the viscosity of the photoresist, through the inside diameter of the tube 28 and the flow rate is predetermined and can be easily calculated or predetermined for each photoresist. In the lower deflection area 20 are the differences in the flow threads 22 . 23 distances to be covered because of the comparatively large radius of curvature comparatively small. This leads to the lower deflection area 20 to a comparatively flat curvature profile across the cross-section of the hose 28 so the flow threads 22 . 23 be mixed together. Due to the prevailing flow profile, comparatively low frictional forces can also occur between individual sub-areas of the flow. The friction that occurs is generated passively, ie without the active influence of moving elements, and leads to an energy loss of paint flow in the hose 28 , Work is thus carried out on the photoresist, which is partially absorbed by the photoresist and to accelerate relaxation effects, to reorientate directed molecules, to compress the membrane filter 1 stretched macromolecules and lead to comparable effects.

As schematically in the 2 shown can be found in the area 24 individual flow threads also approach each other, which will lead to even greater friction effects. After leaving the lower deflection area 20 flow the two flow threads 22 ' . 23 ' continue essentially straight until it reaches the upper redirection area 21 to reach.

In the upper deflection area 21 are two streams accordingly 25 . 26 considered. It is assumed that there are differences in flow velocity between the flow threads 25 . 26 in the upper deflection area 21 becomes so large that the laminar flow there at least partially breaks down, so that the flow threads 25 . 26 mixed together or even swirled. Thus, in the upper deflection area 21 a swirling of individual flow sub-areas is achieved, which can also lead to a homogenization of the photoresist.

such Mixing or swirling effects are even more pronounced when the individual curvature or deflection areas are designed as kinks.

In the 3 a further embodiment for a homogenizing agent according to the present invention is shown in a schematic cross section. With the reference symbol 1 Let us call a fine filter, the filter pores 31 having a small diameter. The right one with the reference symbol 30 designated part contains a coarser filter, its filter pores 32 a larger diameter than the filter pores 31 exhibit. For the sake of simplicity, assume that the two filters 1 . 30 are arranged directly next to each other, although a hose is normally provided between the two filters. In the 3 the flow profiles of four sub-areas are designated schematically with the letters a to d.

For the sake of simplicity, the filter pores are assumed to be overall tubular. The straight from the fine filter pores 31 emerging flow threads a, c and d can the coarser filter pores 32 Flow unhindered while the flow thread b hits an obstacle in the filter 30 bumps around an area of the filter 30 without filter pores. This obstacle leads to a deflection or swirling of the flow thread b and thus to a homogenization of the photoresist. When the flow threads a to d are swirled or mixed, work is also done passively on the photoresist.

The 4 shows in a schematic cross section a further embodiment of a homogenizing agent 9 according to the present invention. According to the 4 there is an aperture in the hose 40 arranged, which narrows the cross section of the hose. There are three flow sub-areas or flow threads 41 . 42 and 43 considered. During the flow thread 41 the aperture 40 can flow essentially unimpeded, the outer flow threads 42 and 43 through the bezel 40 redirected and at any rate at higher flow velocities also in the swirling areas 44 and 45 swirled.

following are examples of some preferred materials and parameters cited. Organic solvents are used as photoresist or photoresist used in which molecules are solved for example polybutene sulfone (PBS) or polyimide. The molecular weights the one in the solvent dissolved molecules can several hundred to 1000 kilodaltons. Because of the organic used solvent solvent-resistant hoses are preferred, for example PTFE tubing (Polytetrafluoroethylene). PFA tubes (perfluoroalkoxide) be used with comparable solvent resistance are even easier to deform. The photoresist comes with a flow rate pumped through the device at about 1 ml / s, the inside diameter of the hoses is about 1 to 3 mm. The viscosity the photoresist ranges from 20 to 40 centiPoise up to some 100 or 1000 centiPoise.

The photoresist is pumped through a membrane filter, for example with a UPE membrane or PTFE membrane. The pore size can be below 0.2 micrometers and can be, for example, 0.05 to 0.1 micrometers. Typically the total hose length of the device between the pump is 7 and the dispensing nozzle 3 about 1.5 to 3 meters, with the hose in the area 9 is curved or kinked about 15 times, with angles of curvature of, for example, about 90 to 180 degrees or larger angles of curvature, for example about 270 to 360 degrees. The PTFE tubes can be bent manually or, for example, with a hot air dryer. Overall, the area 9 with the homogenizing agent in close proximity to the dispensing nozzle 3 arranged. The pump can be used for dosing 7 operated clocked or a suitable control valve, for example in the dispensing nozzle 3 or anywhere else in the hose 8th , be arranged.

In embodiments with obstacles in the hose 8th The constriction cross sections can be approximately in the range from 0.5 to 3.5 mm, more preferably in the range from approximately 1 to 2 mm and even more preferably in the range from approximately 1.3 to 1.7 mm. Instead of screens, suitable perforated plates, for example with perforations with a diameter of about 0.2 to 0.6 millimeters, can also be used. The orifices, perforations or constrictions can be chamfered in the direction of flow or counter to the direction of flow in order to continuously or abruptly narrow the flow of paint. The diameters of the perforations mentioned above can be even smaller.

In embodiments where the membrane filter 10 according to the 3 Another filter is arranged downstream, the average pore size of the further filter 30 be larger than the average diameter of the molecules dissolved in the photoresist, for example larger than or equal to 0.2 micrometers.

The paint is applied in the following way: from the dispensing nozzle 3 apply a predetermined dose of photoresist to the center of the substrate 4 output. The substrate 4 itself is temporarily held on a turntable, not shown, by means of a vacuum clamping device or pen holder. The turntable rotates the substrate at high speed, for example at up to 10,000 revolutions per minute, so that the applied photoresist is centrifugally thrown off radially. At the interface with the substrate, the centrifugal speed of the photoresist is zero. At the top of the photoresist, the centrifugal forces shear off the photoresist, excess photoresist ends up in a collecting chamber, not shown. The coating thickness is adjusted according to the corresponding balance of forces between the shear force and the viscous force of the photoresist, the speed of rotation determining the resulting coating thickness.

In the 5 shows the layer thickness distribution of a PBS photoresist layer on a blank of six by six inches, the coating application being carried out without homogenization in accordance with the present invention. Again 5 can be clearly seen, the thickness of the lacquer layer is inhomogeneously distributed over the B1ank, in the form of approximately concentric rings with sub-areas arranged therein. Overall, the layer thickness fluctuates in the range shown by approximately ± 10 nm.

In the 6 shows a measured layer thickness distribution of a PBS photoresist layer on a B1ank of six by six inches, the lacquer application being carried out under otherwise identical conditions, but with a homogenization according to the present invention. For this purpose the in the 1 shown chaotic hose 9 used, with a total of 15 kinks, which are arranged irregularly over a hose length of one and a half meters, the kinks are each bent by 90 to 180 degrees in irregular spatial directions. How to 6 can be seen, the layer thickness distribution on the B1ank is almost constant over the entire range shown, with an average fluctuation of less than about ± 2 nm.

The B1ank or blank according to the 5 and 6 serves, for example, as a starting substrate for the production of a photomask, for example for use in EUV lithography (extreme ultraviolet) at wavelengths down to approximately 13 nm.

The inventive method can equally for positive and negative photoresists for exposure using optical radiation, for example in the visible wavelength range, or by means of ultraviolet Light, or by means of electron beams, at wavelengths below of 0.1 microns, or by means of ion beams, at wavelengths below 0.1 micron, or using x-rays, at wavelength below about 0.01 microns. Of course, suitable the method or device described above also for the application of any other organic dissolved molecules.

Claims (27)

Device for dispensing a photoresist for forming a photoresist layer in a microlithographic process, comprising a filter means ( 1 . 10 ), through which the photoresist flows, and an output opening downstream of the filter medium ( 3 ) for outputting the filtered photoresist, characterized by at least one between the filter means ( 1 ) and the dispensing opening ( 3 ) arranged homogenizing agent ( 9 ) for homogenizing the photoresist, through which the photoresist can flow continuously and which is designed to homogenize the photoresist as it flows through the homogenizing agent. Apparatus according to claim 1, wherein the at least one homogenizing agent ( 9 ) is designed so that work is done passively on the photoresist. Device according to one of the preceding claims, in which the homogenizing agent is in each case designed to orient and / or stretch molecules or macromolecules dissolved in the photoresist by mixing or entangling buff of sub-areas ( 22 . 23 ; 25 . 26 ; b '; 44 . 45 ) to change the paint flow. Device according to one of the preceding claims, in which the homogenizing agent ( 9 ) a plurality of deflection areas ( 20 . 21 ) for redirecting the paint flow to sub-areas ( 22 . 23 . 25 . 26 ) to mix the paint flow by repeatedly deflecting it. Device according to the preceding claim, in which the paint flow in at least some of the deflection areas is deflected by at least 90 degrees in a different spatial direction, the dimensions of such deflection areas, in particular their radius of curvature, being one or a few diameters of a hose or tube-like guide means ( 28 ) for guiding the paint flow. Apparatus according to claim 4 or 5, wherein the deflection areas ( 20 . 21 ) are arranged at irregular intervals and / or are curved in different spatial directions. Device according to one of Claims 3 to 6, in which the homogenizing agent ( 9 ) is designed to cover laminar flow areas ( 22 . 23 . 25 . 26 ) to mix the paint flow with one another. Device according to one of the preceding claims, in which the homogenizing agent has one or more constrictions ( 32 ; 40 ) comprehensive obstacle ( 30 ; 40 ) includes where sub-areas ( b '; 44 . 45 ) the paint flow is mixed by swirling as it flows through the obstacle. Apparatus according to claim 8, wherein the homogenization means at least one of the filter means ( 1 ) downstream additional filter medium ( 30 ), wherein an average pore diameter of the further filter medium is larger than an average diameter of molecules or macromolecules dissolved in the photoresist, preferably greater than or equal to about 0.2 micrometers. Apparatus according to claim 8, wherein the homogenization means at least one of the filter means ( 1 ) downstream aperture ( 40 ) to reduce the cross-section of the paint flow. Device according to one of the preceding claims, in which the homogenizing agent ( 9 ) immediately before the delivery opening ( 3 ) is arranged. Device according to one of the preceding claims, in particular according to claim 1, in which the homogenizing agent ( 9 ) comprises a container with an inlet at one end of the container and an outlet opposite the one end of the container, the capacity of the container being matched to a relaxation rate of molecules dissolved in the photoresist at a flow rate used for dispensing the photoresist. Device for forming a thin layer of photoresist on a substrate, in particular on a wafer or mask blank, for a Microlithgraphic method, comprising an output device according to one of the preceding claims and a turntable with a vacuum chuck to spill the dispensed onto the substrate Photoresists to a thin Photoresist layer of essentially homogeneous layer thickness. Method for dispensing a photoresist for forming a photoresist layer in a microlithographic process, in which method the photoresist contains a filter medium ( 1 . 10 ) flows through and before dispensing a homogenizer which can be flowed through continuously and is arranged downstream of the filter medium ( 9 ) for homogenizing the filtered photoresist, the photoresist flowing through the homogenizing agent ( 9 ) is homogenized. A method according to claim 14, in which on the photoresist when flowing through the at least one homogenizing agent ( 9 ) work is done passively. Method according to Claim 14 or 15, in which the orientation and / or stretching of molecules or macromolecules dissolved in the photoresist by mixing or swirling sub-regions ( 22 . 23 ; 25 . 26 ; b '; 44 . 45 ) the paint flow is changed. Method according to one of Claims 14 to 16, in which the photoresist has a plurality of deflection regions ( 20 . 21 ) to redirect the paint flow so that sub-areas ( 22 . 23 . 25 . 26 ) the paint flow can be mixed by repeatedly deflecting it. Method according to the preceding claim, in which the paint flow in at least some of the deflection areas is deflected by at least 90 degrees in a different spatial direction, the dimensions of such deflection areas, in particular their radius of curvature, being one or a few diameters of a hose or tube-like guide means ( 28 ) for guiding the paint flow. A method according to claim 17 or 18, which the paint flow is deflected at irregular intervals and / or in different spatial directions. Method according to one of claims 16 to 19, in which laminar flow regions ( 22 . 23 . 25 . 26 ) the paint flow when flowing through the homogenizing agent ( 9 ) are mixed together. Method according to one of claims 14 to 20, in which the paint flow one or more constrictions ( 32 ; 40 ) comprehensive obstacle ( 30 ; 40 ) flows through, with sub-areas ( b '; 44 . 45 ) the paint flow is mixed by swirling as it flows through the obstacle. The method of claim 21, wherein the paint flow at least one of the filter means ( 1 ) downstream additional filter medium ( 30 ) flows through, an average pore diameter of the further filter medium being larger than an average diameter of molecules or macromolecules dissolved in the photoresist, preferably greater than or equal to about 0.2 micrometers. The method of claim 21, wherein the paint flow at least one of the filter means ( 1 ) downstream aperture ( 40 ) flows through where the cross-section of the paint flow is reduced. Method according to one of claims 14 to 23, in particular of claim 14, wherein the photoresist with a container an inlet at one end of the container and one end of the container opposite Flow flows, whereby a capacity of the container at a flow rate used to output the resist matched to a relaxation rate of molecules dissolved in the photoresist is so that the photoresist is homogenized. Process for forming a thin layer of photoresist on a Substrate, in particular on a wafer, comprising the process steps according to one of the claims 14 to 24 for dispensing photoresist on the substrate, the photoresist output on the substrate by rotating the substrate to a thin one Photoresist layer of essentially homogeneous layer thickness is thrown. Mask blank for use in a microlithographic Process, in particular in EUV lithography, being on the mask blank a photoresist layer is applied at least in sections, characterized in that an average fluctuation in a layer thickness the photoresist layer is less than or equal to approximately ± 2 nm. Maskblank according to the preceding claim, wherein the photoresist layer is a PBS layer (polybutene sulfone).