CN101430424A - Contaminant removing method, and exposure method - Google Patents

Abstract

A method for quickly removing pollutants adhered to a predetermined optical member in an optical system. To remove the pollutants adhered to a lens (32A) disposed at the upper end of a projection optical system (PL), a cylindrical protecting member (53) is disposed through the openings in a reticle stage (22) and a reticle base (23). The bottom surface of a support section (56) at the tip section of a rod section (58) is brought into contact with the surface of the lens (32A) through the inner surface of the protecting member (53). A wiping cloth soaked with a washing solution containing hydrofluoric acid is attached to the bottom surface of the support section (56). The support section (56) is reciprocated via the rod section (58) to remove the pollutants on the lens (32A) with the wiping cloth.

Description

Polluter removal method and device, and exposure method and device

The application is that application number is 200380104822.4, the applying date is on November 25th, 2003, denomination of invention is divided an application for the application for a patent for invention of " polluter removal method and device, and exposure method and device ".

Technical field

The present invention relates to removing polluter removals technology, be particularly useful for removing as the lamp optical system of the projection aligner of exposure light source use quasi-molecule laser source etc. or the polluter that the optical component surfaces in the projection optical system is adhered to attached to the polluter of optical component surfaces.

Background technology

The optics used of projection aligner not only, be categorized as among the parts of optics, because the surface exists the foreign matter that adheres to tend to make the transmissivity decline of light and cause uneven illumination, can't obtain original due optical property, thereby propose various solutions.

On the main disagreeable fuzzy parts that cause by water droplet of windscreen of eyeglass lens and automobile and so on, by adopting following various methodologies to prevent adhering to of water droplet: the anti fouling agent (opening clear 56-90876 communique) that contains interfacial agent in the coating of top layer with reference to the spy, increase surface area by coarse surface, wetting state is increased come antifouling (opening clear 55-154348 communique), form coating (opening clear 54-74291 communique) with reference to the spy with fluorine-containing material and hydrophobic polymer with reference to the spy.

In addition, for example among the etching work procedure of the device that is used for making semiconductor element or liquid crystal display cells etc., among the projection aligner that is used for the mask graph as mask copied to the various irradiation areas of the wafer that has been coated with photoresist as sensitive substrate (sense object) (or glass plate etc.), bring into use the pulse laser of excimer laser and so on as exposing light beam.If but have micro-organic substance etc. in the gas on the light path of pulse laser, will be because of a kind of optical cvd (Chemical Vapor deposition) effect, optical component surfaces on this light path is adhered to membranaceous polluter, thereby transmittance is descended gradually, or produce uneven illumination.

Therefore, among projection aligner, be attached to the optical component surfaces in lamp optical system and the projection optical system, inquiring into following (1) or the method for (2) that is used for camera work for many years of using always in order to prevent polluter.

(1) optical component surfaces of adhering to easily at polluter forms the oxidation titanium film of photocatalyst, utilizes its photocatalyst effect to make organic pollutant matter decompose (with reference to Patent Document 1).

(2) silicon oxide film of formation compactness on this optics, attempt to reduce the amount of polluter by the surface area that dwindles this optics, or have the organism film of fluoridizing carbon back and reduce adaptation with polluter, thereby reduce the adhesion amount (with reference to Patent Document 2) of organic pollutant matter by on this optics, forming.

A kind of method of always using is that the optics that has adhered to polluter is unloaded down from lamp optical system or projection optical system for many years, changes this optics.

(Patent Document 1): the spy opens flat 8-313705 communique

(Patent Document 2): the spy opens flat 6-5324 communique

Must be pointed out, above-mentioned now with there being following point in the technology.

At first, method about the formation oxidation titanium film described in (1), though oxidation titanium film has very high transmissivity to the long light of i ray (365 nanometer) and so on wavelength, but it is because the short wavelength laser of KrF and ArF excimer laser and so on is had absorption, thereby quite low to the transmissivity of this type of laser.Therefore, among the projection aligner as exposing light beam with KrF and ArF excimer laser, the time shutter that is used for obtaining the correct exposure amount is elongated, and processing power is descended.Also have, under long-term operating position,, thereby need to change optics because oxidation titanium film begins damage because of the heat energy that absorbing light produced.

In addition, on the optics of (2), form the method for fine and close silicon oxide film because the characteristic of the anti-reflection coating etc. of this optics is changed, thus not very good yet.On the other hand, it is identical with oxidation titanium film to have the organism film of fluoridizing carbon back, though the light long to i ray (365 nanometer) and so on wavelength has very high permeability, because the short laser of absorption of K rF and ArF excimer laser and so on wavelength, thereby transmissivity is very low.Also have, under the irradiation of this type of short wavelength laser, having the organism film itself of fluoridizing carbon back can be decomposed.

There is following point in addition:, then when taking place to change required cost, also need the time of changing adjustment projection optical system behind the optics if the optics in the projection optical system is set at the consumable accessory that needs are changed.

Especially use under the situation of pulse laser,, also can consider to use the irradiation that utilizes this pulse laser that the light of polluter volatilization is cleaned as the method for removing attached to the polluters such as organism of optical component surfaces.But exist because the formed polluter of a kind of optical cvd effect of pulse laser is difficult to use up the problem of removing of cleaning.In addition, because the kind difference of polluter is cleaned also and can't be removed in some cases even with organic solvents such as alcohol and ketone.

Summary of the invention

In view of above each point, the 1st purpose of the present invention is to provide a kind of polluter removal technology and the exposure technique that can remove rapidly attached to the polluter on the optics of the regulation in the optical system.

In addition, the 2nd purpose of the present invention be to provide a kind of can remove rapidly to use up clean and organic solvent cleans polluter removal technology and the exposure technique that also is difficult to the polluter removed.

The present invention can effectively remove can not remove up to now attached to the organic and inorganic polluter on the optics, the transmissivity of various opticses is recovered.

The 1st kind of polluter removal method of the present invention comprises the corrosive liquid that uses hydrofluoric acid containing, removes attached to the polluter of the polluter on the optics and removes operation and make water or organic solvent is removed above-mentioned corrosive liquid from above-mentioned optics corrosive liquid is removed operation.

If adopt the present invention, contain the corrosive liquid of the hydrofluorite of dissolved oxygen silicon by use, promptly solubilized is removed to the polluter of the silicon oxide-containing that can't remove till the present.

In addition, the optics among the present invention is the optics of handling with polluter removal method of the present invention.Optics among the present invention has very high transmissivity.

In addition, the 1st projection aligner among the present invention is to use projection optical system (500) with expose projection aligner to substrate (W) of the image projection of mask (R), this device by with vacuum ultraviolet as the lamp optical system (101) of exposure rayed mask and comprise optical element with fluoride film of the present invention, the projection optical system that forms this mask images on substrate constitutes.

In addition, the 2nd kind of projection aligner of the present invention is to use projection optical system (500) with expose projection aligner to substrate (W) of the image projection of mask (R), this device is by comprising the optical element with fluoride film of the present invention, and vacuum-ultraviolet light is constituted as the lamp optical system (101) of exposure rayed mask and the projection optical system that forms this mask images on substrate.

In addition, the 2nd kind of polluter removal method of the present invention is with the polluter removal method that removes attached to the polluter on the optics in the optical system (5, PL) (20,32A, 32B) surface, comprising: measure the optical characteristics of the regulation of this optical system, and judge the 1st operation of whether removing attached to the polluter on this optics (step 201,202) according to this measurement result; Use the cleaning fluid of regulation, remove the 2nd operation (step 205) attached to the polluter on this optics; Remove the 3rd operation (step 206,207) of cleaning fluid from this optics; Collect and polluter the 4th operation (step 208) for information about that remains on this optics.

If adopt above-mentioned the present invention,, can remove polluter rapidly with very difficult removals such as organic solvents as long as the polluter of removing this optics with the cleaning fluid of regulation is removed this cleaning fluid afterwards again.In addition, under the residual situation of polluter, can effectively remove polluter by repeating the 1st operation and the 2nd operation.

In the case, the surface that this polluter is removed object is the outside surface of the optics that is configured in this optical system (5, PL) end (20,32A, 32B), the the 1st to the 4th operation, preferably this optics separately is configured under the interior state of optical system and carries out.Like this can not will optics unload from this optical system, remove polluter rapidly.

In addition, the 3rd kind of polluter removal method of the present invention is exposing light beam illuminating the 1st object (R) of using lamp optical system (5) and coming with removing, and with this exposing light beam through this lamp optical system in the exposure device of the 1st object and projection optical system (PL) exposure the 2nd object (W) or the optics (20 in this projection optical system, 32A, the polluter removal method of the polluter that 32B) adheres on the surface, comprising: measure the optical characteristics of the regulation of this lamp optical system or this projection optical system, and judge the 1st operation (step of whether removing attached to the polluter on this optics 202 according to this measurement result, 203); Use the cleaning fluid of regulation, remove the 2nd operation (step 205) attached to the polluter on this optics; Remove the 3rd operation (step 206,207) of this cleaning fluid from this optics; And residual polluter the 4th operation (step 208) for information about on collection and this optics.

If adopt the invention described above,, can remove polluter rapidly with very difficult removals such as organic solvents as long as the polluter of removing this optics with the cleaning fluid of regulation is removed this cleaning fluid afterwards again.In addition, under the polluter residual condition, can effectively remove polluter by repeating the 1st operation and the 2nd operation.

In the case, the surface of the removal object of this polluter is the outside surface that is configured in the 1st object one side of this projection optical system or the optics of the 2nd object one side end (20,32A, 32B), and the 1st to the 4th operation preferably separately this optics is installed under this state in projection optical system and implements.Especially under the situation through the gas of exposing light beam such as nitrogen that provides high-purity to remove impurity to projection optical system inside and rare gas, often do not have polluter to adhere in the inside of this projection optical system, and on the outside surface of the optics of this projection optics end that contacts with ambient gas, have polluter to adhere to.At this moment, if adopt the present invention, will this optics do not unload and to remove this polluter rapidly from this optical system.

In addition, when this optics is under the situation of parts (32A) of end of the 1st object one side in this projection optical system, being preferably in increases together the operation (step 204) that the end optics (19,20) with the 1st object one side of lamp optical system unloads before the 2nd operation again.Unload by end optics, can guarantee to be used for to clean the space of the optics of this projection optical system this lamp optical system.In addition, owing to compare with projection optical system, the adjustment accuracy requirement of lamp optical system is lower, thereby can implement the Installation and Debugging of lamp optical system in the short time after the optics that cleans projection optical system.

In addition, also can be set at when carrying out above-mentioned cleaning, increase the operation of changing the part of the optics (20) that comprises the 1st object one side end that has adhered to polluter in this lamp optical system together at least.Because the Installation and Debugging ratio of lamp optical system is easier to, even thereby change the optics that adheres to polluter, exposure process also can will begin in a minute.

In addition, this exposure device is under the situation of scan exposure type, after the 2nd operation preferably includes and makes the parts that soaked this cleaning fluid and the surface of this optics contacts, the operation of back and forth movement on perpendicular to the non-direction of scanning of the direction of scanning of the 1st object or the 2nd object.

When polluter is under the situation that a kind of optical cvd effect forms because of exposing light beam, among the scan exposure type, especially attached to the polluter on the optical component surfaces of close the 1st object or the 2nd object, substantially attached in the elongated area on the non-direction of scanning.As long as therefore make these parts back and forth movement on non-direction of scanning, just can effectively remove polluter.

In addition, the 4th operation comprises the operation (step 208) of for example using spectrophotometer and so on to measure the reflectivity of this optical component surfaces.Because available spectrophotometry reflectivity, thereby can be according to the residual degree of the horizon check polluter of reflectivity.

In addition, also can be set at and also be included in a plurality of time enforcement of periodicity and change the operation of this optics at least after the 1st to the 4th operations.Can reduce the replacing number of times of optics by carrying out the cleaning of periodicity like this, make the processing power of exposure process maintain a high position.

In addition, the 1st kind of polluter removal device of the present invention is exposing light beam illuminating the 1st object (R) of using lamp optical system (5) and coming with removing, with the polluter removal device of this exposing light beam through the polluter of this lamp optical system in the exposure device of the 1st object and projection optical system (PL) exposure the 2nd object (W) or optics (32A) surface attachment in this projection optical system, comprising: tubular spare (53) covered at least apart from a part of space of this optical component surfaces; The immersion that can load and unload flexibly has been installed when crossing the cleaning item (59A, 59B) of stipulating cleaning fluid, has moved with the state of contact optical parts surface, disposed the supporter (56) that can move flexibly along this optical component surfaces in order to make this cleaning item; And in order to move this supporter, having disposed at least a portion can be at the inner stick-like (58) that moves flexibly of its tubular spare.

If adopt foregoing invention,, can remove polluter rapidly as long as this supporter is moved in this optical component surfaces through this stick-like.

In addition, the 2nd kind of polluter removal device of the present invention, it is exposing light beam illuminating the 1st object (R) of using lamp optical system (5) and coming with removing, with the optics of removing among the exposure device of this exposing light beam through the 1st object and projection optical system (PL) exposure the 2nd object (W) in this lamp optical system or this projection optical system (20,32B) the polluter removal device of the polluter of surface attachment, this device has been installed and can have been loaded and unloaded flexibly, when soaking the cleaning item (68) of stipulating cleaning fluid, for this cleaning item is moved with the state of contact optical parts surface, having disposed can be along the mobile flexibly supporter (67) of this optical component surfaces.

If adopt the present invention,, can remove polluter rapidly as long as this supporter is moved along this optical component surfaces.

In addition, be under the situation of scan exposure type at this exposure device, this supporter preferably is configured to and can moves flexibly on perpendicular to the non-direction of scanning of the direction of scanning of the 1st object or the 2nd object.Can effectively remove the distinctive polluter of scan exposure type like this.

In addition, the cleaning fluid removal part that soaked with the solution that removes this cleaning fluid preferably also is configured to and can loads and unloads flexibly on this supporter.Be that available shared supporter is easily removed this cleaning fluid like this.

In addition, this cleaning fluid that uses among the present invention preferably contains hydrofluorite.Because hydrofluorite solubilized monox, thereby be the polluter that solubilized is removed to the silicon oxide-containing that can not remove till the present by the cleaning fluid that use contains hydrofluorite.

In addition, this cleaning fluid preferably by add ammonium fluoride in hydrofluorite, is adjusted to pH value between 4～6, in order to remove this cleaning fluid, preferably makes a certain in water and the organic solvent at least.So both can be set at this cleaning fluid and can not cause harmful effect, can after removing polluter, effectively remove this cleaning fluid again the antireflection film beyond the polluter.

As an example, this organic solvent should be a kind of in isopropyl alcohol, methyl alcohol, ethanol, propyl alcohol, butanols, the acetone, or their potpourri.As the solvent that can at will use, preferably use methyl alcohol.

In addition, as an example, this optics is the parts that form on the parts surface that is made of quartzy, fluorite or other optical glass at least by a certain a plurality of layer films that constitute in fluoride and the oxide.That is to say that this optics forms the film of antireflection film and so in its surface.Especially in the optical cvd effect because of exposing light beam, monox promptly can worsen attached to its reflectivity Characteristics under the situation on this antireflection film surface, thereby the present invention is very effective.

As an example, this fluoride is a certain in magnesium fluoride, calcium fluoride, aluminum fluoride, cryolite, sulfo-stone, neodymium fluoride, lanthanum fluoride, gadolinium fluoride, the yttrium fluoride at least.And this oxide is a certain in aluminium oxide, hafnia, titanium dioxide, the zirconia at least.And the most surperficial (film) of this optics preferably seldom is subjected to (insoluble) fluoride of corrosive liquid (BOE) influence of hydrofluoric acid containing.

In addition, the 1st kind of exposure method of the present invention is exposing light beam illuminating the 1st object that comes using lamp optical system, among this exposing light beam exposure method, use certain polluter removal method of the present invention for the polluter of removing optics in this lamp optical system or the projection optical system (20,32A, 32B) surface through the 1st object and projection optical system (PL) exposure the 2nd object.If adopt the present invention, owing to the reflectivity or the transmissivity of this optics can be maintained kilter, thereby can under the state that always keeps high throughput, expose.

In addition, the 1st kind of exposure device of the present invention is exposing light beam illuminating the 1st object that comes using lamp optical system (5), among the exposure device of this exposing light beam through the 1st object and projection optical system (PL) exposure the 2nd object, in order to remove the polluter on optics in this lamp optical system or this projection optical system (20,32A, 32B) surface, certain polluter removal device of the present invention can be installed.If adopt the present invention, needn't unload this optics and can remove polluter rapidly.

In addition, the 4th kind of polluter removal method of the present invention is the 1st object that has figure in process, expose in the exposure device of the 2nd object (W) with exposing light beam, the optical system (5 that removal is passed through attached to this exposing light beam, PL) optics (20,32A, 32B) among the polluter removal method of Biao Mian polluter, when using the cleaning fluid of stipulating to remove attached to the polluter on this optics, remove this cleaning fluid from this optics, after periodicity is implemented the removal of this polluter and this cleaning fluid for a plurality of times, change this optics at least.

If adopt the present invention, can promptly use organic solvent also to be difficult to the polluter of removing from rapid removal on this optics.Also have,, can reduce the replacing number of times of this optics by carrying out the cleaning of periodicity.

In the case, preferably measure the optical characteristics of this optical system, and judge whether remove this polluter according to measurement result.

In addition, also can be set at when measuring the information relevant with the hot spot that produces in this optical system, removal is attached to the polluter on this optics when this hot spot exceeds permissible value.For example, when producing because of polluter under the situation of hot spot, hot spot is reduced by removing polluter.

In addition, the 5th kind of polluter removal method of the present invention is the 1st object (R) that has figure in process, expose in the exposure device of the 2nd object (W) with exposing light beam, the optical system (5 that removal is passed through attached to this exposing light beam, PL) optics (20,32A, 32B) among the polluter removal method of Biao Mian polluter, when measuring the information relevant with the hot spot that produces in this optical system, when this hot spot exceeds allowed band, when removing attached to the polluter on this optics, remove this cleaning fluid from this optics with the cleaning fluid of regulation.

If adopt the present invention,, can hot spot be reduced rapidly by removing this polluter when producing under the situation of hot spot because of polluter.

In the case, be preferably in and remove after this polluter, collect the information relevant or measure the reflectivity of this optical component surfaces with the residual polluter of this optics.

In addition, the 6th kind of polluter removal method of the present invention is the 1st object (R) that has figure in process, expose with exposing light beam and to remove the optical system of passing through attached to this exposing light beam (5 in the exposure device of the 2nd object (W), PL) optics (20,32A, 32B) among the polluter removal method of Biao Mian polluter, comprise when the cleaning fluid that uses regulation is removed attached to the polluter on this optics, from the 1st operation (step 205～207) of this optics removal cleaning fluid, and the 2nd operation (step 208) of after this removal, measuring the reflectivity of this optical component surfaces.

If adopt this invention, repeat the 1st operation by measured value according to this reflectivity, can remove polluter rapidly and effectively.

In the case, in order to measure the reflectivity of this optical component surfaces, preferably use spectrophotometer.

In addition, this cleaning fluid preferably contains hydrofluorite.Be the polluter that solubilized is removed silicon oxide-containing like this.

In addition, this cleaning fluid is preferably in and adds ammonium fluoride in the hydrofluorite, and the pH value of this cleaning fluid is preferably between 4～6.Can be set at this cleaning fluid like this and can not cause harmful effect the antireflection film beyond the polluter.In addition, in order to remove this cleaning fluid, preferably make a certain in water and the organic solvent at least from this optics.

In addition, as an example, this optical system comprises the projection optical system on image projection to the 2 objects of the 1st object, removes a side who is arranged on this projection optical system attached to the optics of lip-deep polluter at least.

In addition, as an example, removal is attached to the optics of this lip-deep polluter, at least be arranged on an end of this projection optical system of the 1st object one side, this optical system comprises that with the lamp optical system on exposing light beam illuminating to the 1 object part that preferably will be configured in this lamp optical system of the 1st object one side unloads removes this polluter afterwards.

In addition, as an example, also can be set at removal and be arranged on an end of this projection optical system of the 1st object one side at least, remove this polluter after this movable body in unloading stage system at least with the movable body (22) that keeps the 1st object attached to the optics of this surperficial polluter.By unloading this movable body, can make and remove that operation is easier to be carried out.

In addition, when this exposure device is under the situation of synchronization-moving scan exposure type on the 1st object and the 2nd object, for the depollution material that gets on from this optics, after preferably making the parts that soaked this cleaning fluid and this optical component surfaces contacting, back and forth movement on perpendicular to the non-direction of scanning of this synchronization-moving direction of scanning.Because polluter often is deposited in the elongated area on the non-direction of scanning of optical component surfaces, thereby can effectively remove polluter by back and forth movement on this non-direction of scanning.

In addition, as an example, the gas that this optical system provides the damping capacity of exposing light beam to be less than air for its inside constitutes this polluter and removes the outside surface that the face of object comprises the optics that is arranged on the unified end of this optical system at least.

In addition, in another case, this optical system comprises the lamp optical system of this exposing light beam illuminating to the 1st object, removes an end that is arranged on this lamp optical system of the 1st object one side attached to the optics (20) of this surperficial polluter.

In addition, also can be set at this optical system comprises the lamp optical system on this exposing light beam illuminating to the 1 object, in this lamp optical system, preferably change the part of the optics (20) that comprises the 1st object one side end that adheres to this polluter at least.The part of this lamp optical system that this is changed should comprise condenser.

In addition, as an example, the optics of removing attached to this lip-deep polluter forms in its surface at least by a certain a plurality of layer films that constitute in fluoride and the oxide.When this film is under the situation of antireflection film, in case its reflectivity Characteristics of film that forms polluter in the above promptly can variation, can improve reflectivity Characteristics by removing polluter.

In addition, as an example, the optics of removing attached to this lip-deep polluter can be a planopaallel plate.Planopaallel plate can make removes easier and more effective the carrying out of operation.

In addition, as an example, the wavelength of this exposing light beam is below 200 nanometers.Owing to easily produce polluter in the case, thereby effect of the present invention is bigger.

In addition, as an example, this exposure device is arranged in the decontamination chamber of device manufacturing shop, and the removal of this polluter is carried out after this exposure device decommissions.If adopt the present invention, remove operation owing to can implement polluter at short notice, thereby during can shortening it and decommissioning.

In addition, the 2nd kind of exposure method of the present invention comprises that the operation that adopts any one polluter removal method of the present invention to remove attached to the polluter on this optical component surfaces is through the 1st object, with the expose method of the 2nd object of this exposing light beam.

In addition, device making method of the present invention comprises with exposure method of the present invention component graphics (R) is copied to operation on the sense object (W).The application of the invention can make processing power maintain a high position always.

Description of drawings

Fig. 1 illustrates the various reflectivity Characteristics of optics.

Fig. 2 illustrates the various transmission characteristics of optics.

Fig. 3 illustrates the basic comprising of the projection aligner of the 1st embodiment of the present invention.

Fig. 4 is the part disappearance figure that illustrates the configuration in the decontamination chamber of the projection aligner that has disposed the 2nd embodiment of the present invention.

Fig. 5 is the oblique view of the projection aligner of the 2nd embodiment of the present invention.

Fig. 6 is the key diagram when measuring the hot spot of projection optical system.

Fig. 7 is that the polluter that illustrates in the 2nd embodiment is removed the process flow diagram of action.

Fig. 8 is the significant points under catoptron 19 and main condenser 20 states is unloaded in expression from Fig. 5 a oblique view.

Fig. 9 is the oblique view of the part disappearance of the key position of expression when removing the polluter of projection optical system PL upper end lens 32A.

Figure 10 is the front enlarged drawing of the supporter 56 of presentation graphs 9.

Figure 11 is the oblique view of the key position of expression when removing the polluter of projection optical system PL lower end lens 32B.

Figure 12 is that expression makes the rag 68 of moving member 67 and the cut-open view under the lens 32B contact condition of lower end.

Embodiment

(the 1st embodiment)

Below with reference to Fig. 1 to Fig. 3, the 1st embodiment of the present invention is described.

(embodiment 1)

As everyone knows, among the projection aligner that uses the ArF excimer laser, the pollutant component of siloxane and so on can the form with silicon oxide film be deposited on from the nearest lens surface of objective table under the decomposition synthesis of laser light for a long time.This silicon oxide film is pure Sio ₂Even be the sediment that the deep ultraviolet zone is not had yet absorption.But if deposit the different silicon oxide film of refractive index on antireflection film, its reflection characteristic promptly can worsen.

Fig. 1 illustrates the reflectivity of wavelength and optics.Be illustrated in the optics A that has implemented broadband antireflection film (MgF2/LaF3/MgF2/LaF3/MgF2/LaF3) on the quartz base plate with curve A, B, C respectively among Fig. 1, the part B of on optics A, having adhered to pollutant, and the reflectivity Characteristics of handling the parts C of part B with polluter removal method of the present invention.Concrete pollutant is for being about the monox sediment of 10 nanometers with the thickness of laser deposition.As shown in Figure 1, the reflectivity on ArF excimer laser wavelength 193 nanometers is respectively: the reflectivity of components A is 0.1%, and the reflectivity of part B is 4%.The reflectivity of parts C is 0.1%.

Thereby after the corrosive liquid that uses hydrofluoric acid containing of the present invention was removed this silica contamination thing, water and methyl alcohol were washed the corrosive liquid of hydrofluoric acid containing off again.Used corrosive liquid composition is for mixing the mixed liquor of hydrofluoric acid aqueous solution (HF:50wt%) and ammonium fluoride (NH4F:40wt%) by 1 to 10 volumetric ratio.(NH4F, mixed liquor 40wt%) are referred to as BOE (buffered oxide etch) with ammonium fluoride will to have mixed the hydrofluoric acid aqueous solution among the present invention (HF, 50wt%) by 1 to 10 volumetric ratio below.Add ammonium fluoride and be for by adjusting pH value, make it not and can cause harmful effect the magnesium fluoride layer in the optical thin film beyond the monox, lanthanum fluoride layer and the fluorite etc. that constitutes substrate.PH value is more suitable between 4～6, is the best with pH value=5.

Make after above-mentioned BOE is impregnated in the polypropylene rag, wipe optics and can remove silica contamination 10～60 seconds.Because BOE is to the rate of corrosion of monox about 70 nanometers/min 25 ℃ the time, thereby it is just enough with 10 seconds to remove the monox of 10 nanometers.Said herein rate of corrosion is meant the amount (degree of depth) of dissolved oxygen silicon in 1 minute.Water cleans optics then, washes BOE off, in case residual component causes harmful effect to optical thin film and substrate.

The measurement result of dichroism is as shown in the curve C of Fig. 1, and on ArF excimer laser wavelength (193 nanometer), reflection characteristic returns to the reflectivity of original good value-0.1% fully.In addition, as shown in Figure 1, the reflection characteristic in 180 nanometers～250 nanometer wavelength range is recovered original good reflection rate fully.Hence one can see that, optical thin film and optics do not caused harmful effect, but only removed silica contamination.Replenish one again, identical about permeability and surfaceness also characteristic with original broadband antireflection film.

Hydrofluorite herein is set at 1 to 10 with the blending ratio of ammonium fluoride, even but changing mixing ratio, effect does not have big difference yet.Also have, even the further dilute hydrofluoric acid of water also has not big harm.

As mentioned above, when knowing that polluter only is under the situation of monox, use the mixed liquor of hydrofluorite and ammonium fluoride to have very good effect.

(embodiment 2)

Yet it is not for the pollutant that wherein contains inorganicss such as organism such as hydrocarbon and ammonium sulfate, just much of that.So modulated the BOE that mixes hydrofluoric acid aqueous solution (HF:50wt%) and ammonium fluoride (NH4F:40wt%) by 1 to 10 volumetric ratio, again the corrosive liquid (BOE/IPA) that mixes with isopropyl alcohol in the ratio of 1:1.Its reason is that ammonium sulfate is dissolved in water, the monox hydrofluoric acid dissolution because hydrocarbon dissolves with isopropyl alcohol.Therefore by BOE/IPA is used as corrosive liquid, can remove all contaminations matter rapidly.

Among the projection aligner that uses the KrF excimer laser, try to remove laser is sent to the pollution of reality generation the TU Trunk Unit (optical system) of projecting lens from LASER Light Source with BOE/IPA one.Fig. 2 illustrates the transmissivity of wavelength and optics.Be illustrated in the parts E that has adhered to pollutant on optics D, the optics D that forms antireflection film (MgF2/NdF3/MgF2) on the quartz base plate among Fig. 2 respectively with curve D, E and F, and the transmissivity distribution of having handled the parts F of parts E with polluter removal method of the present invention.Concrete pollutant is that organic pollutant and the thickness that deposits because of laser light are the mixed deposit thing of the monox of 5 nanometers.As shown in Figure 2, the transmissivity on KrF excimer laser wavelength (248 nanometer) is: parts D is 100%, parts E is 72%, parts F is 99%.Pollution cause is contemplated for the potpourri of hydrocarbon and monox.This optics was soaked for 60 seconds in being full of the beaker of BOE/IPA, dissolved polluter and with pure water and methyl alcohol BOE/IPA has been rinsed out again afterwards.

As can be seen from Figure 2, the transmissivity on curve F wavelength 248 nanometers after the removal returns to more than 99%, and dichroism is also recovered original characteristic.Also will add one, reflection is identical with the surfaceness also characteristic with original optics.Also have, as shown in Figure 2, the characteristic that sees through in 190 nanometers～400 nanometer wavelength range reverts to original good transmissivity distribution fully.Hence one can see that, optical thin film and substrate do not caused harmful effect, only removed pollutant.

Among present embodiment, substrate is a quartz base plate, but is not limited thereto, and also can use fluorite and other optical glass.In addition, organic solvent is made as isopropyl alcohol, but is not limited thereto, and also can use methyl alcohol, ethanol, propyl alcohol, butanols, acetone.

In addition, the film of antireflection film constitutes and can be made of at least a in magnesium fluoride, calcium fluoride, aluminum fluoride, cryolite, sulfo-stone, neodymium fluoride, lanthanum fluoride, gadolinium fluoride, yttrium fluoride, monox, aluminium oxide, hafnia, titanium dioxide, the zirconia.And the top layer (film) of optics preferably is not subject to the fluoride of corrosive liquid (BOE) influence (indissoluble is separated) of hydrofluoric acid containing.

(embodiment 3)

Illustrate projection aligner of the present invention below.

Fig. 3 is the basic structure that adopts the projection aligner of the optics implemented the polluter removal method that the present invention relates to, especially can be applicable to the graphic projection of mask pattern be referred to as among the projection aligner of steeper or scanner and so on to the wafer of crossing with photic resist-coating.

As shown in Figure 3, projection aligner in this example comprises at least: can with in the surface coated of substrate (wafer) 801 sensitive substrate of emulsion (photoresist) 701 (below abbreviate substrate as) W be placed on the substrate objective table (wafer stage) 301 on the surperficial 301a, the vacuum-ultraviolet light of the wavelength that irradiation is prepared as exposure light, be used for the graph copying of ready mask (below be referred to as mask (reticle)) the R lamp optical system 101 to the substrate W, be used for to lamp optical system 101 provide the exposure light light source 100, for the graphic design of mask R is projected on the substrate W, have the 1st (object plane) P1 that is configured in (picture surface) below the mask R that forms this figure and the 2nd (image surface) P2 that is configured in substrate W (photographic layer 701) surface, be arranged on the projection optical system 500 on the light path that the light that exposes between mask R and the substrate W passes through.And among Fig. 3, the picture surface of the 1st and mask R all as P1, is all represented the surface of the 2nd and substrate W as P2.In addition, also be provided with and tell one by the exposure light of lamp optical system 101 as location light use, be used for regulating the location optical system 110 of the relative position of mask R and substrate W, mask R be configured in can mask objective table 190 with respect to the 1st P1 parallel motion of projection optical system 500 on.When mask replacing system 200 also is included in replacing and transmits the mask R that is installed on the mask objective table 190, drive the objective table driver (for example linear motor) of mask objective table 190 etc.Though not shown, outside projection optical system 500, also be provided with separately and use and the different location light of exposure optical wavelength, detect the location optical system of the specifically labelled deviation adjustment hole mode on the substrate W.Objective table control system 300 comprises the objective table driver (for example linear motor) that drives wafer stage 301 etc., and the whole devices of system 200 and objective table control system 300 etc. are changed in the master controller 400 unified controls that detect result etc. of exporting above-mentioned location optical system based on light source 100, mask.

And the use of the projection aligner in this example is the optics of handling with the polluter removal method in above-mentioned the example.Particularly, the projection aligner that shown in Figure 3 this is routine, as the optical lens 90 of lamp optical system 101 and or the optical lens 100 of projection optical system 500, this routine method of configurable usefulness has been removed the optics of polluter.

And among this example, though will constitute a plurality of opticses of lamp optical system 101 or projection optical system 500 is set at and has at least to remove a polluter, but be exposed in the inside of lamp optical system 101 or projection optical system 500 under the situation of the gas purification that optical transmission rate height and foreign body removed by high standard, preferably remove one side and be exposed to optics in the extraneous air, promptly be configured in the optics of lamp optical system 101 1 ends (the most close mask), and be configured in polluter on the optics at projection optical system 500 two ends.In addition, among this example, the optics (lens element) of removing polluter is not limited to optical lens, also can be aberration correcting part and planopaallel plate (glass plate outer cover) etc.

(the 2nd embodiment)

Below with reference to Fig. 4～Figure 12 the 2nd embodiment of the present invention is described.

Fig. 5 illustrates the concise and to the point formation of this routine scan exposure type projection aligner, among this Fig. 5, as exposure light source 6, has used ArF quasi-molecule laser source (wavelength 193 nanometers).And also can use the harmonic wave generation light source of KrF quasi-molecule laser source (wavelength 247 nanometers), F2 LASER Light Source (wavelength 157 nanometers), Kr2 LASER Light Source (wavelength 146 nanometers), Ar2 LASER Light Source ultraviolet pulse laser light sources such as (wavelength 126 nanometers), YAG laser, the humorous wave generating device of Solid State Laser (semiconductor laser etc.) or mercury lamp (I line etc.) etc. as exposure light source.

Exposure light (illumination light of exposure usefulness) IL as the impulse type exposing light beam that sends from exposure light source 1 during exposure passes through catoptron 7, not shown beam-shaping optical system, the 1st lens 8A, catoptron 9 and the 2nd lens 8B are shaped as section shape after the regulation shape, incident is as the fly lens 10 of optical joint assembly (monodrome device or homogenizer), and Illumination Distribution is promptly by homogenizing.The light quantity distribution that has disposed by the light that will expose on the outgoing plane of fly lens 10 (the pupil face of lamp optical system) is set at circle, a plurality of eccentric region, annular etc., have with deciding aperture diaphragm (σ aperture) 13A, the 13B of lighting condition, the illuminator opening aperture spare 11 of 13C, 13D, this diaphragm spare 11 can rotation flexibly under the driving of CD-ROM drive motor 12.Exposure light IL by the aperture diaphragm among the illuminator aperture diaphragm spare 11 via the little beam splitter 14 and relay lens 17A of reflectivity after, but successively by as the fixedly shadow shield 18A of field of excursion diaphragm and as the movable light shield plate 18B of dynamic visual field diaphragm.In the case, movable light shield plate 18B is configured in picture surface (mask face) as the mask R of mask to have on the face of same function substantially, and fixedly shadow shield 18A then is configured in this mask mask has coefficient face to depart from the diacaustic slightly.

Fixedly shadow shield 18A can be used for field of illumination 21R with the mask face and is limited in the slit-shaped zone perpendicular to the elongate strip on the non-direction of scanning of the direction of scanning of mask R.Movable light shield plate 18B disposed can with the corresponding direction in the direction of scanning of mask R and non-direction of scanning on respectively relative to the two pairs of plates that move flexibly, be used in and cover the field of illumination on the direction of scanning, so that do not need the part exposure that exposes in when stoping scan exposure to begin and the zone of respectively photographing of when end exposure object.Movable light shield plate 18B also can be used for limiting the center and the width of the non-direction of scanning of field of illumination.Exposure light IL by shadow shield 18A, 18B transfers with after catoptron 19 and the main condenser 20 via auxiliary condenser 17B, light path, with the field of illumination 21R of uniform Illumination Distribution irradiation as the graphics field of the mask R of mask.

On the other hand, by the exposure light process collector lens 15 of beam splitter 14 reflections, the associating component sensors 16 that can be made of photoelectric sensor is accepted.The detecting signal of associating component sensors 16 is provided for exposure control system 43, exposure control system 43 is used these detecting signals and is measured in advance, to the transmissivity as the optical system of the wafer W of substrate (sensitive substrate), indirect calculation goes out the exposure on the wafer W from beam splitter 14.The control information that the master control system 41 that exposure control system 43 is controlled whole device action according to the integrated value and the unification of this result of calculation provides, the luminous action of control exposure light source 6 is so that make wafer W can obtain the correct exposure amount.Catoptron 7,9, lens 8A, 8B, fly lens 10, illuminator aperture diaphragm spare 11, beam splitter 14, relay lens 17A, shadow shield 18A, 18B, auxiliary condenser 17B, catoptron 19 and main condenser 20 common formation lamp optical systems 5.

Below exposure light IL, figure in the field of illumination 21R of mask R through the projection optical system PL of both sides telecentric iris with projection multiplying power β (β be 1/4,1/5 etc.), on the non-direction of scanning on one on the wafer W that the has been coated with photoresist regional SA of photography, project in the exposure area 21W of strip.Wafer W is that the diameter of semiconductor (silicon etc.) or SOI (siliconon insulator) etc. is the substrate of the circular plate type about 200～300mm.Mask R and wafer W correspond respectively to the 1st object and the 2nd object (sense object).Below among Fig. 5, get the Z axle parallel with the optical axis AX of projection optical system PL, in the plane vertical with the Z axle, X-axis is got on the vertical non-direction of scanning in the mask R during with scan exposure and the direction of scanning of wafer W, gets Y-axis and be illustrated on this direction of scanning.

At first, mask R is maintained on the mask objective table (movable body) 22, mask objective table 22 on the mask seat 23 with certain speed when the Y direction moves, in order to revise synchronous error, by at directions X, the Y direction, finely tune on the rotation direction, carry out the scanning of mask R, the position of mask objective table 22 can be measured by side's disposed thereon moving lens (not shown) and laser interferometer (not shown), according to the control information that this measured value and master control system 41 provide, objective table drive system 42 is by the position and the speed of not shown driving member (linear motor etc.) control mask objective table 22.Among this example, aforementioned mask objective table 22, objective table drive system 42, driving member and laser interferometer constitute the mask stage system jointly.In addition, on mask objective table 22 and mask seat 23, form respectively and be used for opening 22a and 23a (with reference to Fig. 5) that exposure light IL is passed through.Disposed the mask alignment microscope (not shown) that mask alignment is used above around mask R.In addition, on the next door of mask objective table 22, though not shown mask hopper loader that is used for changing the mask on the mask objective table 22 and the mask storehouse of having accommodated a plurality of masks of also disposing.

On the other hand, wafer W is maintained on the wafer stage 28 by wafer rack 24, wafer stage 28 on the wafer holder 27 with certain speed when the Y direction moves, also on directions X, Y direction, disposed XY objective table 26 and Z inclination objective table 25 that stepping is moved.Z inclination objective table 25 carries out the focusing and the complanation of wafer W according to the position finding value on the Z direction of the wafer W of not shown automatic focus sensor determination.Position in the XY plane of wafer stage 28 is measured by laser interferometer (not shown), the control information that provides according to this measured value and master control system 41, objective table drive system 42 is by the action of not shown driving member (linear motor etc.) control wafer objective table 28. in this example, above-mentioned wafer rack 24, wafer stage (movable body) 28, objective table drive system 42, driving member and laser interferometer constitute the wafer stage system jointly, carrying out polluter described later when removing, wafer stage 28 withdraws under projection optical system, so that guarantee working space.

Also have, wafer W next door on wafer stage 28, fixing the optical sensors 29 that comprises the exposure watch-dog with sensitive surface 30B also bigger than exposure area 21W and have the illuminance transducer of pin hole shape sensitive surface 30A, two detecting signals of optical sensors 29 can offer the exposure control system.In addition, disposing the alignment sensor 36 that deviation that wafer orientation uses is adjusted the hole mode above wafer stage 28, detecting the result according to it, master control system 41 carries out the location of wafer W.

During exposure, by driving mask objective table 22 and wafer stage 28 repeatedly, the action in a photography zone under the state of irradiation exposure light on synchronous scanning mask R and wafer W on the Y direction, and drive wafer stage 28 and make the wafer W action that stepping is moved on directions X, Y direction, with the image of respectively the photograph regional exposed mask R of mode on wafer W of limit stepping scan edge.

In this example, be the ArF excimer laser as what expose light IL use.As mentioned above, if the ultraviolet pulse laser of ArF or KrF excimer laser and so on is used as exposure light, because of a kind of optical cvd effect, the siloxane pollutant component on the surface (especially outside surface) of the optics (lens or parallel panel etc.) of the wafer of close projection optical system PL and mask is promptly decomposed by laser, through long-time synthetic gradually and be deposited as silicon oxide film (the pure SiO of polluter ₂).This silicon oxide film is to the almost non-absorbent sediment of the exposure light in the vacuum ultraviolet scope as monomer, but form antireflection film in the common optical component surfaces that exposure device is used, in case deposited the different silicon oxide film of refractive index on this antireflection film, the reflection characteristic of this optics promptly worsens, thereby though makes transmissivity decline and seldom also might produce hot spot.

Fig. 1 illustrates the relation between the reflectivity of wavelength and optics.Among Fig. 1, curve A is illustrated in the reflectivity of the optics of the broadband antireflection film (MgF2/LaF3/MgF2/LaF3) that formation ArF excimer laser is used on the quartz base plate.Curve B is illustrated in the reflectivity of parts of the pollutant of the silicon oxide film that has deposited 10 nanometer thickness on the optics A.As shown in Figure 1, on the wavelength (193 nanometer) of ArF excimer laser, the reflectivity of optics itself is 0.1% (curve A), and the reflectivity when optics has adhered to silicon oxide film then is 4% (curve B), hence one can see that, and silicon oxide film descends reflectivity greatly.

In addition, among Fig. 5 under the situation of ArF excimer laser as exposure light IL, for fear of by absorptions such as oxygen, lamp optical system 5 is contained with airtight conditions substantially by auxiliary chamber 4 (with reference to Fig. 4).And the gas of nitrogen (also can use rare gas such as helium) that impurity removed by high-purity and so on, the decay of exposure light being provided for these auxiliary chamber 4 inside to be less than air (promptly exposure light IL being had the transmissivity higher than air) (below be referred to as Purge gas).Identical therewith, as to provide impurity to be removed also for the lens barrel inside of projection optical system PL Purge gas by high-purity.And at the inner sealing of lamp optical system 5 and projection optical system PL after the Purge gas, both can regularly carry out gas changes, Purge gas also can be provided and discharge Purge gas and carry out simultaneously substantially, can also not carry out mandatory discharge and providing of Purge gas only is provided.Therefore, on the optics of lamp optical system 5 and projection optical system PL inside, the deposition of pollutant seldom, the optics that the deposition of polluter becomes problem is the optics (below be referred to as the lower end lens) of the most close wafer one side of projection optical system PL and the optics of the most close mask one side (below be referred to as the upper end lens), also have the optics-main condenser 20 of the most close mask one side of lamp optical system 5.And since the deposition of polluter be by with contain contacting of impurity and atmosphere gas and produce, thereby might as well think that the deposition major part of polluter occurs in lower end lens 32B (with reference to Fig. 4), upper end lens 32A (with reference to Fig. 4) and main condenser 20 outside surface separately (with the gas of outside, for example from the decontamination chamber of projection aligner that Fig. 5 is set, air that enters via chemical purifier etc. or the face that contacts with dry-air blast described later).

Therefore, be not set in as described below the example and will from this optical system, unload by this optics, but directly remove the polluter that produces on the optics outside surface of this kind optical system end.Just because of this, whether the amount that at first needs to judge the polluter of optics has exceeded allowed band.The simplest method is the wafer stage 28 that drives among Fig. 5, the light spare 30B that is subjected to of optical sensors 29 is moved to exposure area 21W, the transmissivity of output by relatively uniting component sensors 16 and output, monitoring 28 optical system from beam splitter 14 to wafer stage with the exposure watch-dog that is subjected to light spare 30B.This transmissivity of periodicity ground monitoring for example when this transmissivity drops to allowed band than regulation when also low gradually, can be judged to be and need carry out the removal of polluter.

Illustrate the hot spot of another method-limit monitoring optical system below with reference to the process flow diagram of Fig. 7, limit monitoring pollution level, the action when removing the polluter of the lower end of projection optical system PL and upper end lens according to its result.

At first, in the step 201 of Fig. 7, measure the hot spot amount of the projection optical system PL of Fig. 5.On the mask objective table 22 of Fig. 5, do not place earlier mask R for this reason, but place the hot spot evaluation mask R2 shown in Fig. 6 (A).In the zone corresponding with the field of illumination 21R of mask R2, with transmittance section T is background, central part at non-direction of scanning (directions X) is formed with the wide a plurality of square shading graph C1 of several mm, also is formed with several mm wide a plurality of square shading graph C2 and C3 at peripheral position.In addition, on the peripheral position of the direction of scanning in the zone corresponding (Y direction), also form the wide a plurality of square shading graph of number mm respectively with the field of illumination 21R of mask R2.

Then on the wafer stage 28 of Fig. 5, place the wafer (this is also as wafer W) of the photoresist that has been coated with unexposed eurymeric, change exposure on one side gradually in the many photographies zone on this wafer W, one side scan exposure Fig. 6 (A) the figure of mask R2.Carry out the development of this wafer then, be determined at the convex-concave pattern that forms in each photography zone of this wafer W with not shown apparatus and method for measuring figure.And the alignment sensor 36 among the also available Fig. 5 of this convex-concave pattern is measured.

In addition, under the situation that apparatus and method for measuring figure and exposure device are provided with respectively, also apparatus and method for measuring figure can be arranged on the developer applicator, or be connected, also can be set at and send this measurement result to exposure device by communication line with the developer applicator is online.

In the case as shown in the sketch of Fig. 6 (B),, then, should remain as projection because image C 1P, C2P on the wafer W corresponding with shading graph C1, C2, C3, each zone of C3P are not exposed if supposition does not have a hot spot.Yet in case in projection optical system PL, it is big that the reflectivity of the outside surface of the lens of upper end and lower end becomes, produce hot spot light L2, L3, then owing on the position of image C 2P, the C3P of shading graph C2, C3, also can shine exposure light, thereby exposure is increased, also will become depression on the position of this image C 2P, C3P after the development.

Fig. 6 (C) example illustrates that mensuration by the convex-concave pattern of each irradiation area on the wafer W after this development obtains, the evaluation result of the locational hot spot amount of the directions X of each irradiation area (or Y direction) demonstrates the exposure E of the longitudinal axis when each position X (or Y) develops back initial formation depression figure among Fig. 6 (C).Therefore, exposure E1 promptly is the exposure when depression occurring after developing in the zone corresponding with the transmittance section T of Fig. 6 (A).On the other hand, corresponding with the image C 3P of periphery exposure E2 is the value of trying to achieve with following method.That is to say that if the exposure E when depression appearred in the position of the image C 3P of development rear perimeter edge is set at E23, then the locational exposure E2 of the image C 3P during exposure E1 can be represented by the formula.

E2＝E1＊(E1/E23) (1)

Therefore, the ratio of the locational hot spot light of image C 3P is E2/E1 * 100 (%).Identical therewith, the ratio of the locational hot spot light of the image C 1P of central authorities and the ratio of other peripheral locational hot spot light such as image C 2P also can be obtained.About its details, publicity is among the open EP1308991 of Europe special permission of open (WO) the 02/09163rd trumpeter's volume in the world and correspondence.And so long as home in the scope that the domestic decree of the designated state of appointment or selected selection state allows in the border application, quote open handbook in the above-mentioned world and Europe and specially permit disclosed publicity and promptly constitute a part as herein described.

And in the open handbook in this world institute's publicity, also can use the evaluation mask that has the figure of the figure confuse right and wrong of Fig. 6 (A), with the movable light shield plate 18B of Fig. 5 light quantity on the wafer stage 28 when respectively the seeing through figure light quantity during with the whole figure of illumination of only throwing light on, carry out the hot spot evaluation of the lamp optical system 5 of Fig. 5 by relatively.

Then judge in the step 202 of Fig. 7 whether the hot spot that determines exceeds allowed band, when in allowed band, advance to the normal exposure operation of step 203.In addition, when in step 202, measuring hot spot and exceed allowed band, advance to the following polluter of step 204 and remove operation.Must at first send into cleaning fluid in the decontamination chamber of the projection aligner of having accommodated Fig. 5 for this reason.

Fig. 4 illustrates the decontamination chamber in the semiconductor manufacturing shop of the projection aligner (projection aligner 3) that is provided with Fig. 5, in this decontamination chamber among this Fig. 4, ventilating duct 1B from the fan blower 1A of left end to right-hand member, shown in arrow 34A, 34B, 34C, by (high efficiency particularte air-filter: the high purity air clarifier) be subjected to temperature controlled air after the purification again such as HEPA filter cleaners with fixing substantially traffic flow.In addition, in the box-shaped chamber 2A in this decontamination chamber, be provided with exposure main part by vibration isolators 31A, 31B, nearby be provided with the auxiliary chamber 4 of the lamp optical system 5 (removing exposure light source 6) of accommodating Fig. 5 at it from the mask R of the projection aligner 3 of Fig. 5 to wafer holder 27.The top 4a of auxiliary chamber 4 (accommodating the part of catoptron 19 and the main condenser 20 of Fig. 5) adopts demountable structure.Projection optical system PL has disposed upper end lens 32A, lens 33A...... lens 33B and lower end lens 32B successively from mask one side.And be provided with the 2B of auxiliary chamber of the exposure light source 6 of accommodating Fig. 5 with chamber 2A adjacent regions.Give during exposure to provide in the chamber 2A and carried out processings of also will prevent dust completely, and temperature and humidity all are subjected to chemical that precision controls purify air (dry-air blast) than the decontamination chamber.

But just as shown in this example, remove under the situation of operation implementing polluter, the switch sections 2Aa of the downwind side of chamber 2A is opened, and on the working rig 44 of leeward one side of chamber 2A, is provided with the small-sized ventilation blower 45 of square tubular along airflow.Exhausr port one side at small-sized ventilation blower 45 is installed with chemical purifier 46, carrying is storing as cleaning fluid of the present invention on the support 47 in small-sized ventilation blower 45, and the storage bottle 48 and being used to that contains the corrosive liquid of oxygen fluoric acid is adorned the container 49 of the corrosive liquid of use.Storage bottle 48 and container 49 are made of the polypropylene (or tygon) of hydrofluoric acid resistant (HF).In addition, also be provided with the storage bottle of storage pure water and storage storage bottle (not shown) in the small-sized ventilation blower 45 as the methyl alcohol of organic solvent.

The composition of the corrosive liquid in this example is the mixed liquor that mixes hydrofluoric acid aqueous solution (HF:50wt%) and ammonium fluoride (NH4F:40wt%) by 1 to 10 volumetric ratio, i.e. BOE (bufferedoxideetch).Why sneak into ammonium fluoride and be in order to make it not and can to cause harmful effect substrates such as optical thin film such as magnesium fluoride outside the monox and lanthanum fluoride and fluorites by adjusting pH value.PH value is good between 4～6, is optimum value about PH=5.

Among Fig. 4,, thereby can prevent that this composition is diffused in the decontamination chamber owing to the composition of the BOE (corrosive liquid) that evaporates in storage bottle 48 in the small-sized ventilation blower from this example 45 and the container 49 can be removed by the chemical purifier 46 of leeward one side.

In addition, when BOE is used as cleaning fluid, be set at by the operator and will have soaked this BOE about Icc respectively, parts 51A, the 51B such as rag that is made of polypropylene is sealed to after the container 50A and 50B that is made of polypropylene, sends in the chamber 2A from switch member 2Aa.In the case, owing to purifying the air of a room always towards switch member 2A one side flow, thereby even if a small amount of BOE composition is arranged from parts 51A, 51B volatilization because this composition can be removed by not shown filter cleaner via ventilating duct 1B, thereby this composition can not be diffused in the decontamination chamber.

In the case, among the step 204 of Fig. 7, the operator unloads in the chamber 2A of Fig. 4 after the end 4a of auxiliary chamber 4 of lamp optical system, unloads catoptron 19 and the main condenser 20 of Fig. 5 again.At this moment, mask objective table 22 is located in the central part of direction of scanning, and the mask on it is removed.Among next step 205, wipe the surface of the upper end lens 32A of projection optical system PL with above-mentioned BOE.

Fig. 8 illustrates from the projection aligner of Fig. 5 and lays down key position under catoptron 19 and main condenser 20 states; among this Fig. 8, the operator inserts the tubular guard member 53 (tubular spare) with the elongated square shaped as frame section on the directions X by opening 22a, the 23a of mask objective table 22 and mask seat 23.The upper end of guard member 53 is provided with handle 54A, the 54B that is used to carry, and the side of guard member 53 is provided with and is used for guard member 53 is fixed on brake valve 53b above the mask objective table 22.Then will insert the inside surface 53a of guard member 53 with the end of the cleaner 55 that removes polluter.Cleaner 55 has following formation: the end of bar-shaped rod-like element 58 (stick-like) is installed with the supporter 56 that can rotate flexibly, on the bottom surface of supporter 56,, rag 59A, the 59B (with reference to Figure 10) that can load and unload flexibly are installed through pressing piece 57A, 57B.Guard member 53, rod-like element 58 and supporter 56 common the 1st polluter removal devices (cleaner) that constitute in this example, the projection aligner in this example adopts the structure that this polluter removal device can be installed.Guard member 53, rod-like element 58, supporter 56, pressing piece 57A, 57B and rag 59A, 59B constitute by polypropylene.Shown in Figure 10 as the front enlarged drawing of supporter 56, pressing piece 57A, 57B push rag 59A, 59B by spring 59 and are fixed on the supporter 56, and BOE has been soaked in the end of rag 59A, 59B.Return Fig. 8, because supporter 56 is elongated shape on sense of rotation, thereby by making rod-like element 58 towards the rotation of θ direction, supporter 56 can pass through inside surface 53a.

Fig. 9 is after the inside surface 53a of expression by the guard member 53 among Fig. 8, makes the cut-open view of surperficial contact condition of the upper end lens 32A of the bottom surface of supporter 56 of end of rod-like element 58 and cleaning object.Among Fig. 9, because this example is the scan exposure type, and longilineal field of illumination 21R (with reference to Fig. 5) on the directions X of the lens 32A mask face of upper end, thereby exposure light passed through is elongated oval shape zone 60 on directions X (non-direction of scanning), silicon oxide film (polluter) deposits this zone 60 in.The upper end lens 32A of this example then is that the surface that is used for revising aberration is the flat part on plane, is fixed on the upper end of projection optical system PL by fixer 62.The width setup of supporter 56 is the width of the Y direction of slightly being wider than zone 60, also is set on the bottom surface of slightly being wider than supporter 56 width in the Y direction of outstanding rag 59A, 59B simultaneously.The operator is by making rod-like element 58 back and forth movement on directions X, and the limit wipes zone 60 on the lens 32A of upper end with rag 59A, the 59B of supporter 56 bottom surfaces, and the limit comes and goes three times rag 59A, 59B on the non-direction of scanning shown in the arrow 61.

The duration of contact of the each several part in rag 59A, 59B and zone 60 is greatly about about 10 seconds therebetween.Because BOE is to the rate of etch of monox about 70 nanometers/min 25 ℃ the time, thereby wants to remove 10 nano silicon oxides, there were 10 seconds just enough.The rate of etch here is meant the amount (degree of depth) of per minute dissolved oxygen silicon.And under the situation of monox thickness, as long as prolong its duration of contact.

Then, among step 206, rag 59A, the 59B of supporter 56 are replaced by the rag that has soaked into pure water, identical with Fig. 9, make this rag back and forth movement in the zone 60 of upper end lens 32A, remove BOE.Then, among step 207, the rag of supporter 56 is replaced by the rag that has soaked ethanol (organic solvent), identical with Fig. 9, this rag is come and gone three times in the zone 60 of upper end lens 32A, BOE is removed fully.So, BOE can be washed off from the surface of upper end lens 32A, in case residual component causes harmful effect to optical thin film and substrate.

Among next step 208, whether be removed within the allowed band in order to judge polluter, use the reflection characteristic on the lens 32A surface, spectrophotometer 63 mensuration upper end of Fig. 9.What use in this example is the spectrophotometer 63 that has disposed optical fiber cohort 64 and light transmitter-receiver 65.The reflectivity Characteristics that can under the state that is combined into projection optical system PL, work as field recognition upper end lens 32A like this.By the dichroism optical curve before and after relatively the polluter removal is handled, judge the removal degree of this polluter.

Optic fibre spectrophotometer is made of three parts substantially.Be light source and beam split light quantity detector (detector) and the optical fiber cohort 64 in the spectrophotometer 63.Its formation can be selected the parts with suitable respective performances according to the wavelength of measuring as the need on the tested surface of determination object.This example for example, if with the ultraviolet range as object, the light source of available generation ultraviolet light, can detect the beam split light quantity detector of ultraviolet light, the optical fiber that can see through ultraviolet light constitutes.

As light source, want in projection aligner, to use optic fibre spectrophotometer, preferably use and can put into wherein pocket, want to increase its signal to noise ratio (S/N ratio) and preferably use high-power type.Preferably without scan mode, and be to use the detector of photodiode array mode as beam split light quantity detector.Than its biggest advantage of scan mode is the optical curve that is easy in moment acquisition broadband.The photodiode array mode does not have the grating rotating structure, only white light irradiation is subjected to inspection face, and with the grating beam splitting of fixing by this reflection or the light quantity that sees through, photodiode array can detect wide band beam split optical curve simultaneously.

Use the advantage of optical fiber to have: needn't to from light source to the inspection face of being subjected to, or adjust from being subjected to inspection face to carry out accurate position to photometric optical system, be not subject to the influence of surrounding environment, and optical system is moved freely.If can moving fiber, on required locating, freely measure the beam split optical curve, just can move (unloading) interior optics of charging apparatus, measure simply.

When determining the optical characteristics of antireflection film etc., confirm that this reflection beam splitting optical curve is very important.Thereby want to confirm that can polluter remove and what have been removed, preferably use optic fibre spectrophotometer to confirm the reflection beam splitting optical curve.When deciding the reflection beam splitting optical curve with this optical fibre light splitting degree instrumentation, the optical fiber that optical fiber cohort 64 uses from light source to the incident light of being examined face with from be subjected to inspection face to form cohort together to the photometric fiber mix that is subjected to.By cohortization in parallel, can make the incident light optical fiber of the face examined keep the state of identical configuration to move down at the same time as a cohort with the optical fiber that used by light.

If using bore, numerical aperture NA with tens μ m is about 0.1 optical fiber, make from the end face of measuring part and count mm apart to the distance on the vertical direction of being examined face, then on optical fiber cohort 64, the light that is come by incident light optical fiber is reflected on the inspection face of being subjected to, and it is that available beam split light quantity detector detects the reflection beam splitting optical curve that light enters the optical fiber that used by light.Under the situation of using optical fiber cohort 64, in order to carry out stable mensuration, keep with examined face vertical measure particularly important.Thereby can use three-decker cohortization optical fiber or use the cohort optical fiber of tens above random arrangement.The core of the cohort optical fiber of three-decker is to be used for the catoptrical optical fiber for receiving light of the face that detects, center section is to be used for making light to incide the incident light optical fiber of the face examined, and outermost layer then is the tilt adjustments optical fiber that is used for detecting the degree of tilt of cohort optical fiber.If make in the tilt adjustments optical fiber to detect light quantity consistent and revise the degree of tilt of cohort optical fiber, as long as the tip-to-face distance that then makes optical fiber measure part is examined the height unanimity of face, can carry out the mensuration under the identical conditions.

In addition, the optical fiber of the cohortization of tens above random arrangement makes the evenly distributed cohortization of optical fiber that used by optical fiber that light uses and incident light.Can make even incident of light quantity and reflection like this, relax susceptibility, thereby detect the reflection beam splitting optical curve the degree of tilt of the optical fiber of cohortization.

As mentioned above, if use optic fibre spectrophotometer, then can lightheartedly measure the reflection beam splitting optical curve.Owing to the reflection beam splitting optical curve that can measure by manual operation on the optional position, thereby the polluter that can grasp on the desired location is removed situation.In addition, among projection aligner, if being provided with moves the mensuration part of cohort optical fiber automatically towards the inspection face that is subjected to of optic fibre spectrophotometer, make apart from the height of being examined face and keep certain structure, then before removing polluter, just can grasp the situation of adhering to of this polluter at any time, before and after using polluter removal method, all can confirm its removal degree.In addition, by adopting the mapping structure, can on both direction, find out the attachment state and the polluter of the polluter in the inspection face of being subjected to and remove the removal degree of front and back.Especially among the removal of polluter, can determine not wipe clean ad-hoc location.

The illustration of measuring the result of reflection characteristic with spectrophotometer 63 in the step 208 is represented by the curve C of Fig. 1.Reflectivity on the wavelength of the ArF excimer laser of curve C (193 nanometer) returns to the reflection characteristic (curve A) of original good value-0.1%.Also have, the reflection characteristic in 180 nanometers～250 nanometer wavelength range all returns to original good reflection characteristic.Hence one can see that, optical thin film and optics do not caused harmful effect but only removed the silica contamination thing.

Among next step 209, that is afraid of that only some surpasses under the situation of allowed band when the reflectivity on the exposure wavelength of the upper end lens 32A that measures with spectrophotometer 63, return step 205 and repeat the BOE cleaning, and the removal operation of BOE.And when the reflectivity on the upper end lens 32A exposure wavelength of measuring with spectrophotometer 63 in the step 209 is all in allowed band; advance to step 210; the operator unloads behind the guard member 53 of Fig. 8 and the cleaner 55 catoptron 19 of Fig. 5 and main condenser 20 lamp optical system 5 of packing into, carries out the adjustment of optical axis etc. then.The adjustment of lamp optical system 10 is compared with projection optical system PL, can finish at short notice.

Among next step 211, the wafer stage 28 of Fig. 5 is moved to the end of directions X.Can wipe the surface of the lower end lens 32B of projection optical system PL like this.Among next step 212, wipe the surface of lower end lens 32B with above-mentioned BOE.

Figure 11 illustrates the key position of the projection optical system PL bottom of Fig. 5, and among this Figure 11, the operator moves to the dull and stereotyped moving member 67 (supporter) that is the elongated oval type on the directions X (non-direction of scanning) bottom surface one side of projection optical system PL.Within the depression 67a on the moving member of making by polypropylene 67, by the screw 69 that compacting is made with polycarbonate, installed the immersion that can load and unload flexibly the rag 68 made of the polypropylene of BOE.Moving member 67 and rag 68 common the 2nd polluter removal devices (cleaner) that constitute this example.Among Figure 11, this example is the scan exposure type, what light passed through because lower end lens 32B near the elongated exposure area 21W (with reference to Fig. 5) on the directions X, therefore exposes is the zone 66 that is elongated oblong on the directions X substantially, and silicon oxide film (polluter) is deposited in this zone 66.And this routine lower end lens 32B is that lower surface (cleaning surface) is the flat part that is used for revising aberration on plane.The width setup of moving member 67 is the width on the Y direction of being wider than zone 66 greatly, and the width of Y direction that protrudes in the rag 68 (with reference to Figure 12) of moving member 67 is also set widelyer than the width of the Y direction in zone 66.

Cut-open view as the bottom of the projection optical system PL of Figure 11 is shown in Figure 12, the operator contacts with the surface of lower end lens 32B by making the rag 68 on the moving member 67, the limit wipes zone 66 on the lens 32B of lower end with rag 68, and the limit makes moving member 67 come and go on the non-direction of scanning shown in the arrow 70 three times.The each several part in rag 68 and zone 66 can be removed the monox about 10 nanometers about duration of contact in nearly 10 seconds so fully therebetween.And under the situation of monox thickness, as long as proper extension is just passable duration of contact.

Then among step 213, the rag 68 of moving member 67 is replaced by the rag that has soaked pure water, identical with Figure 11, this rag is come and gone three times in the zone 66 of lower end lens 32B, remove BOE.Then among step 214, the rag of moving member 67 is replaced by the rag that soaked ethanol (organic solvent), identical with Figure 11, this rag is come and gone three times in the zone 66 of lower end lens 32B, further remove BOE fully.BOE all can be washed off from the lens 32B of lower end like this, in case residual component causes harmful effect to optical thin film and substrate.

Among the step 215 below, identical with step 208, whether be removed within the allowed band in order to judge polluter, measure the reflection characteristic on lens 32B surface, lower end with the spectrophotometer 63 of Fig. 9.Among next step 216, the reflectivity on the exposure wavelength of the lower end lens 32B that measures with spectrophotometer 63 when that is afraid of that only some surpasses allowed band, is return step 212, repeats the removal operation of BOE cleaning and BOE.And when the reflectivity on the exposure wavelength of the lower end lens 32B that measures with spectrophotometer 63 is all in allowed band, advance to step 217 in step 216, implement normal exposure process.

If adopt above-mentioned example, on the upper end of projection optical system PL lens 32A and lower end lens 32B, adhere under the situation of polluter, will lens 32A, 32B do not unload and can remove these polluters rapidly from projection optical system PL.Owing to neither take place to change the expense of optics,, thereby has the advantage that the processing power of exposure process does not descend substantially also almost not because of changing optic and adjust and to use the time of projection aligner.

Even and under the optics-main condenser 20 lip-deep situations of polluter attached to the end of mask one side of the lamp optical system among Fig. 55, also needn't unload main condenser 20, use the cleaner identical, can remove this polluter rapidly with the moving member 67 of Figure 11.

What the cleaning fluid in this example used is to mix hydrofluorite and amine fluoride in 1 to 10 ratio, even but changing mixing ratio, effect does not have big difference yet.In addition, also can use the liquid of the further dilute hydrofluoric acid of water.When knowing that polluter is under the situation of monox, use the mixed liquor of hydrofluorite and ammonium fluoride can obtain sufficient cleaning performance.

Below, as the another kind of use-case of the 2nd embodiment of the present invention, illustrate that polluter comprises the situation of dead matter such as organism such as hydrocarbon and ammonium sulfate.In the case, as cleaning fluid, modulate corrosive liquid (BOE/IPA) with the BOE and the isopropyl alcohol of ammonium fluoride (NH4F:40wt%) in 1 to 1 ratio mix hydrofluoric acid aqueous solution (HF:50wt%) in the volumetric ratio of 1:10.Its reason is that ammonium sulfate can be separated by water-soluble because hydrocarbon can be dissolved by isopropyl alcohol, and monox can be by hydrofluoric acid dissolution, thereby by BOE/IPA is used as corrosive liquid, can remove various polluters rapidly.

Fig. 2 illustrates with BOE/IPA and removes among the projection aligner that uses the KrF excimer laser, excimer laser is sent to the result of the interior actual pollution that takes place of TU Trunk Unit (optical system) of projection optical system from LASER Light Source.

Fig. 2 illustrates the transmissivity of wavelength and optics, the curve D of Fig. 2 is illustrated in the transmissivity of the optics of having implemented antireflection film (MgF2/NdF3/MgF2) on the quartz base plate, curve E is illustrated in the parts that adhere on the optics after the pollution, curve F represents to handle transmissivity after the polluter on these parts with the polluter removal method in this example, and concrete pollutant is that organic pollutant is the mixed deposit thing of 5 nanometers with the thickness that forms because of laser light.As shown in Figure 2, the transmissivity on the wavelength of KrF excimer laser (248 nanometer) is: the parts of contamination-free (curve D) are 100%, and it is 70% that the parts (solid line E) of pollution are arranged, and removing pollution back (curve F) is 99%.The reason of polluting can be envisioned for the potpourri of hydrocarbons and monox.Curve F soaks this optics 60 seconds in being full of the beaker of BOE/IPA, has dissolved polluter, falls BOE/IPA transmissivity afterwards with pure water and washed with methanol again.

As can be seen from Figure 2, the transmissivity on wavelength 248 nanometers after the removal returns to more than 99%, and dichroism also returns to original characteristic.Also have, as shown in Figure 2, the transmissivity in 190 nanometers～400 nanometer wavelength range returns to original good transmissivity fully.Can optical thin film and substrate not caused harmful effect like this, but only remove polluter.Mixing ratio with BOE and isopropyl alcohol in this example is decided to be 1 to 1, but mixing ratio is not limited to by this.

Be set at removal in the above-described embodiment attached to before the polluter on the upper end lens 32A of projection optical system PL, at first in step 204, mask objective table 22 is positioned the cardinal principle central part of direction of scanning, make this center unanimous on the whole with the opening 22a of mask objective table 22 and the opening 23a of mask seat 23, but also can be identical with the catoptron 19 and the main condenser 20 of lamp optical system 5, the mask objective table 22 to major general's aforementioned mask stage system unloads from mask seat 23.

In addition, remove polluter respectively, also can only remove upper end and lower end lens 32A, 32B one side's polluter though be set in the above-described embodiment on the upper end of projection optical system PL and lower end lens 32A, 32B.Also have, can on upper end and lower end lens 32A, 32B, not remove polluter yet, use the cleaner removal polluter identical with the moving member 67 of Figure 11 but only go up at the optics (being main condenser 20 in this example) of mask one side end that is arranged on lamp optical system 5.Main points are the polluters that also can be set at least one side in the optics at two ends of the optics of mask one side end of removing lamp optical system 5 and projection optical system PL.

In addition, though be set in the above-described embodiment for the depollution material that gets at the upper end of projection optical system PL lens 32A, and in step 204, the catoptron 19 and the main condenser 20 of lamp optical system 5 unloaded, but also can be set at and only unload main condenser 20, be i.e. the optics of lens one side end of lamp optical system 5.Though and Fig. 5 with main condenser 20 as an optics (lens unit) expression since actual be that a plurality of opticses constitute, thereby also can at least only unload one of them optics.In addition, also can be set at least a portion (the end 4a of Fig. 4 etc.) that constitutes the lamp optical system 5 that comprises main condenser 20 (one of them optics) with the slide construction mobility, and when wiping the optics (lens 32A) of the upper end that is arranged on projection optical system PL and being arranged at least one side in the end optics of mask one side of lamp optical system 5 surperficial with above-mentioned BOE etc., at least the part of portable lighting optical system 5 is to guarantee to clean the required space of operation.Also have, optics with mask one side end of lamp optical system 5 is set at main condenser 20 in the above-described embodiment, but also planopaallel plate (glass plate cover) can be arranged on the end of mask one side of lamp optical system 5, unload only with this planopaallel plate, or with planopaallel plate and other optics (main condenser 20 etc.) globality.

Also have, in the above-described embodiment, also can be above-mentioned cleaner remove polluter on the optics of mask one side end of lamp optical system 5, but the part of the optics that comprises mask one side end at least in the lamp optical system 5 is unloaded, be replaced by other parts.In addition, also the part of this lamp optical system 5 can be unloaded, the polluter of removing mask one side end with above-mentioned corrosive liquid reinstalls to the part of this lamp optical system 5 on the projection aligner 3 afterwards again.This is because the adjustment of the lamp optical system 5 after above-mentioned replacing or the loading and unloading is easier than projection optical system PL.Also can be set at this moment and not only carry out the replacing or the loading and unloading of the part of this lamp optical system 5, also the moving member 67 of available Figure 11 is removed the polluter of the side in the optics at projection optical system PL two ends at least.And the optics of mask one side end of the lamp optical system 5 of changing or loading and unloading is not limited to condenser 20, also can be planopaallel plate (glass plate cover) etc.

In the above-described embodiment, the optics that is arranged on projection optical system PL two ends is set at the aberration revision board respectively, but also at least one side in the optics at these two ends can be set at other parts, for example lens or planopaallel plate (glass plate cover) etc.

In addition, be set at the transmissivity of monitoring (mensuration) in the above-described embodiment from the beam splitter 14 of Fig. 5 to the optical system of wafer stage 28, or the hot spot that at least one side produces among lamp optical system 5 and the projection optical system PL, and judge according to measurement result and will not remove polluter (or the opportunity of implementing etc.), when exceeding allowed band, transmissivity or hot spot remove polluter.But the present invention is not so limited, also can be set at by other optical characteristics outside monitoring transmissivity and the hot spot (for example imaging characteristic such as the illumination on mask R or the wafer W or Illumination Distribution or aberration or constitute the reflectivity etc. on surface (cleaning face) that polluter is removed the optics of object), carry out the removal of polluter equally.Also have, also can be set at when optical characteristics such as being judged as above-mentioned hot spot according to this measurement result does not exceed allowed band as yet, according to the enforcement time of this measurement result prediction (decision) removal polluter, in that being worked, this projection aligner 3 no longer measures the removal that above-mentioned optical characteristics is promptly directly carried out polluter after the prescribed timelimit.In addition, the optical characteristics (transmissivity, hot spot etc.) of optical system that also can be set at monitoring, illumination optical system 5 not and comprise the part of projection optical system PL at least, but during certain or in the working time every regulation of projection aligner 3, carry out and the identical polluter of above-mentioned enforcement is removed.

Also have, only be set in the above-described embodiment and remove polluter with a kind of solvent (above-mentioned corrosive liquid BOE or BOE/IPA), but also available a plurality of kinds of solvents (containing pure water).At this moment also can be set at the polluter of a kind of removal of solvents optics of every usefulness, promptly measure the optical characteristics (reflectivity etc.) of this optics (or optical system that this optics has been installed).In addition, also can be set at when not knowing which kind of time-like the polluter that adheres on the optics is, when removing polluter respectively with a plurality of kinds of solvents, whenever once remove the optical characteristics of but measuring optics (or optical system that this optics has been installed), determine the kind of polluter, that is to say the decision at least a solvent of suitable this removal.Also have, during polluter on removing a plurality of kinds of opticses respectively, the solvent species (or its combination) that the part of every kind of optics or a plurality of kinds of opticses is also available to be different from the removal polluter that other optics uses carries out.

In addition, be set in the above-described embodiment in order to confirm that whether polluter remove (be residual polluter whether below permissible value) fully, after this removal operation, measure the optical characteristics (reflectivity etc.) of optics, but also can be set at needn't carry out that this optical characteristics is measured or only initial (or from from the beginning of a plurality of times within) the removal operation after measure optical characteristics, confirm the removal result of polluter, then no longer carry out optical characteristics after this and measure.Also have, the optical characteristics of removing the optics of measuring after the operation of polluter is not limited to a kind of (for example reflectivity), also can measure a plurality of kinds of optical characteristics, can the kind of the optical characteristics of measuring after this removal operation be had nothing in common with each other according to the position (in other words being a plurality of kinds of opticses) of the optics of removing polluter.In addition, also can be set at the optical property (for example resolution capability, illuminance uniformity, CD focusing etc.) of before and after polluter is removed operation, measuring projection aligner respectively, in order to verify the improve effect of this removal operation to optical property.At this moment, especially after removing operation, preferably measure the imaging characteristic (aberration etc.) of projection optical system PL, when this imaging characteristic departs from the allowed band of regulation,, adjust its imaging characteristic by the optical element of mobile projector optical system PL.

Also have, be set in the above-described embodiment in order to judge after polluter is removed whether will carry out this removal (promptly confirming the removal situation) once more, as the information relevant and measure the reflectivity of optics with residual polluter on the optics, but this determinator is not limited to spectrophotometer, and its information also is not limited to reflectivity.In addition, after removing, polluter also may not carry out the collection (mensuration of reflectivity etc.) of this information.

In addition, stop the removal that above-mentioned polluter is carried out in this running afterwards during being set at projection aligner 3 runnings in the decontamination chamber that is arranged on the device manufacturing shop in the above-described embodiment temporarily, but the present invention is not limited to by this, for example can be set at when projection aligner 3 time-based maintenances etc. to implement to remove with the identical polluter of above-mentioned embodiment yet.

In addition, in the above-described embodiment, operate above-mentioned cleaner (Fig. 9, Figure 11), but also above-mentioned cleaner can be remained on the end of mechanical arm, operate above-mentioned cleaner with the driving mechanism that has disposed CD-ROM drive motor and vapour tube etc. by the operator.

Also have, be set in the above-described embodiment and under the state that projection optical system PL is installed in projection aligner 3, use above-mentioned cleaner (Fig. 9, Figure 11) to remove the polluter of upper end and lower end lens 32A, 32B, but after having carried out above-mentioned removal, when above-mentioned optical characteristics does not reach in the allowed band yet, preferably change at least one end of whole projection optical system PL or replacing projection optical system PL, comprise the part of the projection optical system PL of the optics that should remove surperficial polluter.Combine by removal and to carry out this replacing with above-mentioned polluter, can reduce during projection aligner 3 running required, projection optical system PL is all, or comprise the replacing number of times of a part of projection optical system PL of the optics of an end at least, thereby the work efficiency of projection aligner 3 is improved.At this moment, be preferably in above-mentioned replacing carries out changing after 1 time (being generally 2 times) above-mentioned polluter removal afterwards at least next time again.And when carrying out above-mentioned replacing, be preferably in changed after, with being arranged on the pin hole projection image that photoelectric sensor on the wafer stage 28 detects lens, or by trying the corrugated aberration of mensuration projection optical system PL such as printing, according to this corrugated aberration of measuring and Cheney's gram (sound) polynomial expression, adjust its optical characteristics (imaging characteristic) by at least one lens of mobile projector optical system PL.

The optics that to remove above-mentioned polluter in the above-mentioned embodiment is set at quartz (synthetic quartz) but not limited to by this, also can use the synthetic quartz or fluorite and other optical glass that have mixed impurity such as fluorine.In addition, the optics of not only above-mentioned removal polluter, other optics that is installed in respectively among lamp optical system 5 and the projection optical system PL also is not limited to synthetic quartz, also can be other glass material (above-mentioned fluorite etc.).In addition, the organic solvent in the embodiment of Figure 11 being set at isopropyl alcohol, but being not limited thereto, also can be methyl alcohol, ethanol, propyl alcohol, butanols, acetone etc.

The composition that constitutes antireflection film can be made of a certain at least in magnesium fluoride, calcium fluoride, aluminum fluoride, cryolite, sulfo-stone, neodymium fluoride, lanthanum fluoride, gadolinium fluoride, yttrium fluoride, monox, aluminium oxide, hafnia, titanium dioxide, the aluminium oxide.But the most surperficial (film) of this optics preferably is made of (insoluble) fluoride of the mordant that is not subject to hydrofluoric acid containing (BOE, BOE/IPA) influence.

The optical system that will comprise the optics of the polluter of removing surface attachment in the above-mentioned embodiment is set at and comprises projection optical system PL at least, but also applicable the present invention when this optical system only comprises lamp optical system.In addition, lamp optical system 5 and projection optical system PL formation separately are not limited to above-mentioned embodiment, can constitute arbitrarily.For example projection optical system PL both can be a certain in dioptric system, reflected refraction system and the reflecting system, can also be reduction system, etc. a certain in times system and the amplification system.In addition, the optical joint assembly 10 of lamp optical system 5 is not limited to fly lens, also can be inner face reflection-type associating assembly (shaft-like associating assembly etc.).In addition, also can be without aperture diaphragm spare 11, be configured between light source 6 and the optical joint assembly 10 after comprising therewith combination and be to use, for the intensity distributions of the illumination light IL on the pupil face that changes lamp optical system 5 in lamp optical system a plurality of refraction optical elements of alternate configurations and about a pair of prism (cone prism or polyhedral prism etc.) of the variable spaced of the optical axis direction of lamp optical system, preferably include the shaping optical system of lens of variable focal length (single focus class).

The projection aligner of above-mentioned embodiment is after carrying out that lamp optical system, projection optical system that a plurality of lens constitute be combined into the optics adjustment of exposure device main body, mask objective table that will be made of many mechanical parts and wafer stage connect distribution and pipe arrangement after being installed on the exposure device main body, can produce through comprehensive adjust (circuit adjustment and confirming operation etc.) again.The manufacturing of this projection aligner is preferably in the decontamination chamber that temperature and degree of purification all be controlled to be carried out.

In addition, when the projection aligner that uses above-mentioned embodiment is made microdevice (electron device), for example under the situation of semiconductor devices, this semiconductor devices is made through following operation: design the function of this semiconductor devices and the step of performance, make the step of mask according to this step, make the step of wafer with silicon materials, with the step of behind the projection aligner of the above-mentioned embodiment location mask graph being exposed to wafer, form the step of etched circuit figure, the device number of assembling steps (comprises the cutting operation, welding sequence, packaging process), and checking procedure.

Device fabrication, comprise that especially the projection aligner that uses above-mentioned embodiment comprises the photo-mask process of the operation (exposure process) of graph copying to the sense object at least: the polluter of above-mentioned embodiment is removed operation; And remove the optics of polluter or comprise the replacing operation of at least a portion of the optical system of this optics; This replacing operation is carried out after being preferably in the removal operation of implementing a plurality of times.In addition,, preferably not only after changing operation, after removing operation, also comprise the operation of the mensuration (and adjustment of imaging characteristic) of the imaging characteristic (corrugated aberration etc.) that carries out projection optical system.

The present invention is not the exposure device that only is applicable to the scan exposure type, can use too when the polluter of the optics of the exposure device of removing the overall exposing type.In addition, applicable too the present invention during the polluter removal of the optics of the immersion liquid type exposure device of publicity in open (WO) No. 99/49504 communique in the world etc.Among this immersion liquid type exposure device, soaked by liquid (pure water etc.) owing to be arranged on the surface of optics of image planes one side end of projection optical system, thereby the top layer (film) of this optics material that preferably not influenced by above-mentioned corrosive liquid.Also have, under the situation of using above-mentioned corrosive liquid (BOE, BOE/IPA), the removal of the polluter that results from this liquid and produce at need, the solvent that preferably will be suitable for removing this polluter use in the lump with above-mentioned corrosive liquid or mix after carry out above-mentioned removal operation.In addition, specially permit No. 6341007 as No. the 98/24115th, the world open (WO) and the corresponding U.S., during No. 98/40791 and the corresponding U.S. specially permit No. 6262796 etc. publicity like that, because exposure actions and location action (mark detects action) basic synchronization are carried out, thereby in the exposure device of two wafer stage of above-mentioned wafer stage system configuration, remove under the situation of polluter of optics applicable too the present invention.

In addition, purposes as exposure device of the present invention, be not limited to the exposure device of semiconductor devices manufacturing usefulness, also can be widely used in the liquid crystal display cells that on the square glass plate, forms, or the exposure device used of the display device of plasma display etc. and be used for making imaging apparatus (CCD etc.), the exposure device of various devices such as micromachine, thin-film head and DNA chip.Also have the exposure process (exposure device) of the present invention during also applicable to the mask (photomask, mask etc.) of the formation mask graph of making various devices with photo-mask process.

The present invention is not limited to above-mentioned embodiment, obviously can obtain various formations in the scope that does not exceed aim of the present invention.In addition, all publicity contents that comprise patented claim 2002-350944 of Japan that files an application in 3 days Dec in 2002 of instructions, claim scope, accompanying drawing and summary and the national patented claim 2003-115098 that filed an application on April 18th, 2003 also can directly refer among the application on ground with no word changed.

Owing to adopt polluter removal method of the present invention can make the work of removing the polluter that adheres on the optics become more easy, needn't change optics etc. more as before, thereby can cut down the parts expense that relates to, the assembly and adjustment expense, and maintenance expense changed.

In addition, among the present invention,,, can dissolve the polluter of the silicon oxide-containing that removal can't remove so far rapidly by using hydrofluoric acid containing at interior liquid as cleaning fluid.

In addition, owing to adopt the present invention to be easy to just to make the transmissivity of optics remain on a high position, thereby the processing power of exposure process can be remained on a high position, the various devices of High-efficient Production.

Claims (15)

1, a kind of usefulness removes the polluter removal method attached to the polluter of the optical component surfaces in the optical system, it is characterized in that comprising:

The 1st operation is measured the optical characteristics of the regulation of above-mentioned optical system, and judges whether remove attached to the polluter on the above-mentioned optics based on this measurement result;

The 2nd operation is used the cleaning fluid of stipulating, removes attached to the polluter on the above-mentioned optics;

The 3rd operation is removed above-mentioned cleaning fluid from above-mentioned optics; With

The 4th operation, collection relates to the information that remains in the polluter on the above-mentioned optics.

2, polluter removal method according to claim 1 is characterized in that:

The surface that above-mentioned polluter is removed object is the outside surface that is configured in the optics of above-mentioned optical system end,

Above-mentioned the 1st to the 4th operation can be implemented respectively under the state in above-mentioned optics is configured in above-mentioned optical system.

3, a kind of polluter removal method that is used to remove attached to the polluter of optical component surfaces, described optics is positioned at exposing light beam illuminating 1st object of use from lamp optical system, use above-mentioned exposing light beam to expose in the above-mentioned lamp optical system or above-mentioned projection optical system in the exposure device of the 2nd object via above-mentioned the 1st object and projection optical system, described polluter removal method is characterised in that and comprises:

The 1st operation is measured the optical characteristics of the regulation of above-mentioned lamp optical system or above-mentioned projection optical system, judges whether remove attached to the polluter on the above-mentioned optics according to this measurement result;

The 2nd operation is removed attached to the polluter on the above-mentioned optics with the cleaning fluid of regulation;

The 3rd operation is removed above-mentioned cleaning fluid from above-mentioned optics; With

The 4th operation, collection relates to the information that remains in the polluter on the above-mentioned optics.

4, polluter removal method according to claim 3 is characterized in that:

The surface that above-mentioned polluter is removed object is the outside surface of optics of the end of above-mentioned the 1st object one side of above-mentioned projection optical system or above-mentioned the 2nd object one side,

Above-mentioned the 1st to the 4th operation can be installed under the state in the above-mentioned projection optical system at above-mentioned optics and implement respectively.

5, polluter removal method according to claim 4 is characterized in that:

Above-mentioned optics is the parts of above-mentioned the 1st object one side end of above-mentioned projection optical system,

Before above-mentioned the 2nd operation, also have:

The operation that the optics of above-mentioned the 1st object one side end of above-mentioned lamp optical system is unloaded.

6, according to each the described polluter removal method in the claim 3～5, it is characterized in that also comprising:

Change the operation of the part of the optics that comprises above-mentioned the 1st object one side end that has adhered to above-mentioned polluter in the above-mentioned lamp optical system at least.

7, according to each the described polluter removal method in claim 3 or 4, it is characterized in that:

The surface of the removal object of above-mentioned polluter comprises the outside surface of optics of above-mentioned the 1st object one side end of above-mentioned lamp optical system, and above-mentioned the 1st to the 4th operation can be implemented respectively under above-mentioned optics is installed in state in the above-mentioned optical system.

8, according to each the described polluter removal method in the claim 3 to 7, it is characterized in that:

Above-mentioned exposure device is the scan exposure type,

Above-mentioned the 2nd operation comprises makes the parts that soaked above-mentioned cleaning fluid contact with the surface of above-mentioned optics, the operation of back and forth movement on perpendicular to the non-direction of scanning of the direction of scanning of above-mentioned the 1st object or above-mentioned the 2nd object.

9, according to each the described polluter removal method in the claim 1 to 8, it is characterized in that:

Above-mentioned the 4th operation comprises the operation with the reverse rate of the above-mentioned optical component surfaces of spectrophotometric determination.

10, according to each the described polluter removal method in the claim 1 to 9, it is characterized in that:

Above-mentioned cleaning fluid contains hydrofluorite.

11, polluter removal method according to claim 1 is characterized in that:

Above-mentioned cleaning fluid can be adjusted to pH value between 4～6 by add ammonium fluoride in hydrofluorite,

In above-mentioned the 3rd operation,, make a certain in water or the organic solvent at least in order to remove above-mentioned cleaning fluid.

12, according to each the described polluter removal method in the claim 1 to 11, it is characterized in that:

Above-mentioned optics is the parts that form on the parts surface that is made of quartzy, fluorite or other optical glass at least by a kind of multilayer film that constitute in fluoride and the oxide.

13, according to each the described polluter removal method in the claim 1 to 12, it is characterized in that:

The optical characteristics of afore mentioned rules relates to the information of the hot spot that produces in comprising the optical system of above-mentioned optics.

14, according to each the described polluter removal method in the claim 1 to 13, it is characterized in that also comprising:

After periodicity is implemented above-mentioned the 1st to the 4th operation a plurality of times, change the operation of above-mentioned optics at least.

15, a kind ofly use exposing light beam illuminating the 1st object from lamp optical system to utilize above-mentioned exposing light beam, it is characterized in that via the expose exposure method of the 2nd object of above-mentioned the 1st object and projection optical system:

In order to remove the polluter of the optical component surfaces in above-mentioned lamp optical system or the above-mentioned projection optical system, and use the described polluter of claim 14 removal method.

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