JP2013134316A - Dimmer for exposure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately adjust a quantity of light according to a change in light output in an exposure device provided with a DMD.SOLUTION: To adjust a quantity of light, the effective mirror of the DMD is turned on, a quantity of projected light is measured, and a use ratio R, which is the ratio of a quantity of measured light to the target quantity of light, is determined. Then, on the basis of the use rate R, dimmer filter data, which indicate the arrangement of mirrors that are not in use, are created. At this time the mirrors that are not in use are arranged such that a change in the quantity of light is substantially even as the entire area.

Description

  The present invention relates to an exposure apparatus that forms a pattern on a substrate or the like, and more particularly to adjustment of the amount of light applied to a substrate.

  In the exposure apparatus, pattern light is projected onto a substrate coated with a photosensitive material such as a photoresist to form a pattern on the photosensitive material. For example, when a DMD (Digital Micro-mirror Device) in which micromirrors are two-dimensionally arranged is used, pattern light can be generated by ON / OFF control of each micromirror based on pattern data.

  In order to form a pattern with high accuracy, it is necessary to irradiate the substrate with light at a constant dose during the exposure operation. Therefore, the illuminance is measured between exposures using a photometric device, and the constant illuminance lighting control is performed by adjusting the power supplied to the discharge lamp (see, for example, Patent Document 1).

  On the other hand, unevenness in the amount of light locally occurs when one substrate is exposed due to the intensity and wavelength characteristics of illumination light or the sensitivity characteristics of the photosensitive material. Further, local light amount unevenness also occurs depending on the lamp temperature and the substrate temperature. In order to prevent the occurrence of such uneven local light quantity, a method of maintaining a uniform light quantity without using a specific mirror in the DMD mirror group is known (see Patent Document 2).

  In this case, when performing a multiple exposure operation, a mirror that is set to the OFF state during exposure in the DMD is specified for each mirror row along the scanning line. Then, mask data representing the mirror arrangement in the OFF state is created. Based on the mask data and the drawing data, the micromirror is ON / OFF controlled so that the total amount of light reaching the substrate is finally uniform in each place.

JP 2010-077251 A JP 2007-316194 A

  While a light source such as a discharge lamp is turned on, the light source output fluctuates at short-term time intervals (spans), and the output fluctuation covers the entire exposure area that is the projection area of the light modulation element array. For this unstable light output short-term fluctuation, it is necessary to adjust the light amount distribution in the entire exposure area without deviation. In particular, even in a single shot exposure operation, it is necessary to adjust the illuminance of the entire exposure area.

  However, with the method of adjusting the lamp output, it is difficult to accurately maintain the target light amount. In addition, as in the prior art, assuming a stable light output over a long period of time, the light output adjustment that locally sets the mirror OFF so as not to cause a bias in the total light amount is a short-term light output that covers the entire area. Unable to deal with fluctuations.

  Therefore, a uniform and accurate light amount adjustment is required for the entire exposure area.

  The exposure light control device of the present invention includes a light source, a plurality of light modulation elements arranged two-dimensionally, a light modulation element array that guides illumination light from the light source to an exposure target area of the drawing object, A light amount adjusting means for adjusting the light amount of the projection light irradiated to the projection area (exposure area) of the light modulation element array.

  The exposure light control device can be applied to an exposure device that adjusts the amount of light and illuminance of pattern light applied to the substrate in the exposure device, and can directly form a pattern on the substrate using a light modulation element array, for example. Alternatively, in an exposure apparatus using a mask or a reticle such as a stepper, a light modulation element array such as a DMD or LCD can be separately provided for light amount adjustment.

As the light source, various light sources such as a discharge lamp and a laser can be applied. For example, a discharge lamp having an enclosed mercury amount of 0.2 mg / mm ³ or more is used. Various light modulation devices such as DMD, LCD, and SLM can be applied to the light modulation element array.

  The light amount adjusting means of the present invention defines the unused light modulation elements over the entire element arrangement region so as to change the light amount in the exposure area as a whole. Here, “changing the amount of light in the exposure area as a whole” means that there is no substantial change in the amount of light distribution in the exposure area before and after adjustment of the amount of light regardless of the drawing data. Accordingly, when viewed from the entire light modulation element array region, the unused light modulation elements are dispersed and dissipated, and there is no local uneven distribution, part of which is blank, or the like. An unused light modulation element refers to a light modulation element that is set to the OFF state regardless of the drawing pattern.

  Therefore, when a light amount distribution tendency (two-dimensional relative light amount distribution) in the exposure area is determined for predetermined drawing data, even if the light amount is adjusted, the relative light amount distribution trend does not change. Overall light intensity increases or decreases.

  For example, it is preferable that the array of unused light modulation elements is uniformly distributed with respect to the exposure target area, that is, the light modulation elements are scattered and distributed substantially evenly over the entire element region. That is, it is possible to determine the arrangement of unused light modulation elements so that the amount of light can be increased or decreased evenly over the entire exposure target area.

  With respect to the arrangement of the unused light modulation elements, either a regular arrangement or an irregular arrangement is possible. For example, in the case of a regular arrangement, it can be arranged in a checkered pattern or in a dot form, and in the case of an irregular arrangement, it can be arranged in a snow noise pattern or a satin pattern. In an irregular arrangement, there is a bias in the element arrangement when viewed in a small area, but it is scattered substantially uniformly when viewed in a relatively large divided area, and the arrangement of distances is substantially uniform when viewed macroscopically. It has become. Further, such an arrangement resembles a distribution state in which the arrangements of unused light modulation elements regularly arranged at equal intervals are slightly shifted.

  The light control device can be provided with a light amount measuring means for measuring the light amount of the exposure area. For example, the amount of light can be measured for a part of the exposure target area or the entire area. However, measurement of illuminance, integrated dose, etc. is also included in the light quantity measurement here. For example, the amount of projection light irradiated using all the light modulation elements is measured. The method for measuring the amount of light is arbitrary, and the amount of light in each minute region in the area can be obtained by averaging.

  In the light amount adjustment based on the light modulation element array, an unused light modulation element can be set based on the determined target light amount and the light amount of the projection light measured in the exposure target area. Since the amount of projection light decreases as the number of unused light modulation elements increases, the used / unused light modulation elements may be set in accordance with the target light quantity. For example, the light amount adjusting unit can determine an unused light modulation element based on the ratio between the target light amount and the measured light amount of the projection light.

  In the maskless exposure apparatus described above, a plurality of light modulation elements provided in the light modulation element array based on scanning means for moving the exposure target area relative to the object to be drawn and pattern data corresponding to the position of the exposure target area. It is possible to provide an exposure control means for controlling the element. In this case, the exposure control means can control a plurality of light modulation elements based on exposure data obtained by combining dimming filter data indicating an array of unused light modulation elements and pattern data.

  The target light amount is a light amount required in pattern formation, and is determined based on the sensitivity characteristics of the photoreceptor, the exposure method, and the like. There are various exposure operations such as multiple exposure (overlap exposure) or single shot exposure, and light amount adjustment using the light modulation element array can be performed in accordance with the exposure method.

  The light amount adjustment based on the light modulation element array can be executed at an arbitrary timing, and the light amount measurement may be performed in accordance with the adjustment. For example, the light amount can be adjusted for each lot, for a certain elapsed time, for a certain number of processed substrates, or for each substrate.

  In the light amount adjustment based on the light modulation element array, the number of unused light modulation elements can be adjusted to be dimmed according to the required pattern resolution, the sensitivity characteristic of the photosensitive member, the exposure method, etc. There are limitations. Therefore, it is desirable that the light amount adjusting means increases the light amount of the illumination light according to the light amount adjustment range of the projection light by the light modulation element array.

  In consideration of the total number of exposures in the same area in the multiple exposure operation, the light amount adjustment range is determined such that the ratio (usage rate) of the light modulation element to be used to the entire usable light modulation element is 20% to 100%. Is possible. In this range, it is possible to prevent a difference in resolution. On the other hand, when considering devices such as DMD and general-purpose film, and photoreceptor characteristics, the light amount adjustment range is preferably set to a range of 65% to 100% in order to prevent a difference in resolution.

  For example, the light amount adjusting means can determine a substantially uniform and irregular light modulation element array according to a pseudo random number. In this case, it is better not only to automatically calculate according to the calculation method, but also to make corrections so as to obtain a more preferable arrangement. For example, when at least two or three unused light modulation elements determined according to a pseudo random number are adjacent to each other, it is preferable to reset the unused light modulation elements. In addition, when an unused light modulation element is determined according to a pseudo-random number, and the determined unused light modulation element overlaps, the unused light modulation element can be reset.

  The light amount adjusting means can store dimming filter data indicating the set array of unused light modulation elements in the memory. It is possible to combine the drawing data and the light control filter data during the exposure operation, and it is also possible to prepare the light control filter data corresponding to the measured light amount in advance.

  The light control method for exposure according to the present invention has a plurality of light modulation elements arranged two-dimensionally, and the light modulation element array that guides the illumination light from the light source to the exposure area of the drawing object. The light quantity of the projection light is adjusted by setting the unused light modulation elements in the entire element array region so as to change the light quantity as a whole, and turning off the unused light modulation elements.

  The program of the present invention has a plurality of light modulation elements in which the exposure apparatus is two-dimensionally arranged, and the light modulation element array that guides the illumination light from the light source to the exposure area of the drawing object. The amount of projection light is adjusted by turning off the unused light modulation element and the unused light modulation element setting means for determining the unused light modulation element in the entire element array region so as to change the overall light quantity. It is made to function as a light quantity adjustment means to perform.

  According to the present invention, an exposure operation can always be performed with an appropriate amount of light in an exposure apparatus.

It is a schematic block diagram of the exposure apparatus which is this embodiment. It is the flowchart which showed the light control process performed by a controller. It is the figure which showed the light control filter data without an unused mirror. It is the figure which showed the light control filter data when an unused mirror is arranged irregularly. It is the figure which showed the light control filter data when an unused mirror is arranged regularly. It is the graph which showed the light quantity of the projection light, input power, and the usage rate of DMD with the use time passage of a discharge lamp. It is the flowchart which showed the drawing process by a step & repeat system.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic block diagram of an exposure apparatus according to this embodiment.

  The exposure apparatus 10 is a maskless exposure apparatus that directly forms a pattern on a substrate SW having a photosensitive material such as a photoresist formed thereon, and includes a discharge lamp 20 that is a light source and a DMD (Digital Micro-mirror Device) 22. ing. The substrate SW is irradiated based on the illumination light radiated from the discharge lamp 20, and a pattern is formed on the photoreceptor applied or pasted on the surface of the substrate SW.

Here, the discharge lamp 20 is a short arc type mercury lamp, and 0.2 mg / mm ³ or more of mercury is contained in the discharge tube. The light emitted from the discharge lamp 20 that is always lit is guided to the DMD 22 through an illumination optical system (not shown). The DMD 22 is a light modulation element array (here, 1024 × 1280) in which micro rectangular micromirrors of several μm to several tens μm are two-dimensionally arranged in a matrix, and is driven by the DMD driving circuit 24.

  Vector data such as CAD / CAM data transmitted from a workstation (not shown) is converted into raster data of a two-dimensional dot pattern by the raster conversion circuit 26. The exposure data generation circuit 28 generates exposure data obtained by synthesizing light control filter data, which will be described later, and raster data.

  In the DMD 22, each micromirror is selectively ON / OFF controlled based on the exposure data sent from the DMD drive circuit 24. The light reflected by the micromirror in the ON state passes through a projection optical system (not shown) and is irradiated onto the substrate SW as light of a pattern image.

  The substrate SW is moved in the scanning direction by the stage driving mechanism 14. A pattern is formed on the entire substrate by performing an exposure operation at a predetermined exposure pitch while the substrate SW is relatively moved. The position of the substrate SW is detected by the position detection sensor 15.

  The exposure apparatus 10 includes a photometric device 34 that measures the amount of light projected on the stage 12, and the position is controlled by a photometric drive unit 35. When the exposure operation is not performed, the photometric drive unit 35 arranges the photometric device 34 on the optical path, and moves the photometric device 34 to the retracted position when the measurement is completed. However, it is also possible to attach the photometric device 34 to the stage 12 and measure the amount of light according to the movement of the substrate SW.

  The controller 30 controls the entire exposure operation such as exposure data generation timing, DMD drive, and the like, and data related to light control is read from the memory 32. A control program for the exposure operation is stored in a ROM (not shown) in the controller 30.

  The controller 30 also has a light control process (light quantity adjustment process), and executes the light control process by combining mirror control for the DMD 22 and output control for the discharge lamp 20. During the life cycle of the discharge lamp 20, that is, the entire period from the start of lighting until the end of lighting due to the lifetime, the controller 30 performs mirror control and lamp output control based on the measured light quantity, and projects it onto the substrate SW. Adjust the amount of light to irradiate.

  Below, the light control process is demonstrated using FIGS.

  FIG. 2 is a flowchart showing the dimming process executed by the controller.

  There are various timings for the dimming process, such as when a new discharge lamp is installed, when processing a substrate of a photosensitive material with a different sensitivity, and for each lot (product unit), when a certain number of substrates are processed, every certain period It is also possible to perform a dimming process. Here, dimming processing is executed at regular intervals.

  When the dimming process is started by a user input operation or the like, the photometry device 34 moves on the optical path while the discharge lamp 20 is lit, and the light quantity is measured (S101). At this time, all the mirrors (hereinafter referred to as effective mirrors) that can be used for drawing in the DMD 22 are turned on, and the amount of light is measured. Therefore, in the photometry device 34, the light amount of the light in the state where all the effective mirrors are in the ON state is measured for the projection area (exposure area). The effective mirror refers to a mirror excluding all mirrors of the DMD that are previously determined not to be used for drawing (such as a mirror at the periphery of the DMD).

  After the light amount is measured, it is determined whether or not the measured light amount is equal to or greater than a predetermined light amount (hereinafter referred to as a target light amount) (S102). If it is determined that the measured light quantity is equal to or greater than the target light quantity, the ratio of mirrors actually used for drawing (hereinafter referred to as usage rate) in the entire effective mirror of the DMD 22 is calculated (S104).

  When the usage rate is 100%, the entire effective mirror constituting the drawing area is in the ON state, and the usage rate decreases as the number of mirrors set to the OFF state increases (the number of used mirrors decreases). The light control processing here is to match the amount of light projected onto the substrate SW with the target amount of light, and the degree of dimming, that is, the usage rate is determined based on the measured amount of light.

  Here, when the mirror usage rate is R, the light quantity measured in the effective mirror total number ON state is L1, and the target light quantity is L0, the usage ratio R is obtained by the light quantity ratio (R = L0 / L1). When the usage rate R is determined, a mirror that is not used at the time of drawing, that is, a mirror that is turned off regardless of the pattern is specified and set (S104).

  At this time, since the amount of light projected onto the substrate SW is increased or decreased not locally but as a whole, there is no local deviation and a substantially uniform distribution as viewed from the entire effective mirror of the DMD. And extract to disperse. Specifically, the unused mirrors are selected so as to have an irregular arrangement, or the unused mirrors are selected so as to have a regular arrangement.

  In the case of an irregular unused mirror array, unused mirrors are determined so as to have a substantially uniform distribution two-dimensionally in the entire mirror region. In other words, the unused mirrors are arranged so that the unused mirrors are arranged at substantially equal distance intervals in the effective mirror area of the DMD 22 and are arranged in a dispersed state in which the unused mirrors are uniformly scattered without local concentration. It is determined. On the other hand, in order to prevent moire due to light interference, unused mirrors are randomly arranged so as not to be regular and periodic.

  According to such an arrangement, the unused mirrors are diffused and distributed to such an extent that they can be regarded as uniform when the entire exposure area is viewed from above. If the exposure area is divided into small areas (for example, 5 × 5 mirrors), even if there is a slight deviation in the number of unused mirrors in each small area, it is divided into larger areas (for example, 200 × 200 mirrors). The number of unused mirrors in each region is almost equal and distributed substantially uniformly.

In order to select an irregular array of unused mirrors, pseudorandom numbers are used here. For example, it is possible to generate a random number based on an improved Römer method using uniform random numbers. The number of active mirrors N, when the number of unused mirror and n (= N (1-R )), the effective mirror _{M 1, M 2, ···,} unused using a pseudo-random number from among the _{M N} Select and extract mirrors. An unused mirror is determined by repeating this n times. At this time, the unused mirror is determined from the entire effective mirror regardless of the pattern data.

  However, when an already extracted mirror is selected again, an unused mirror is extracted again. If a predetermined number of mirrors adjacent to each other among the mirrors extracted as unused mirrors exist, the selection is invalidated and the unused mirrors are extracted again. The number of adjacent mirrors that invalidate the selection of unused mirrors is adjusted according to the usage rate.

  Thus, data representing the array of unused mirrors (herein, dimming filter data) is calculated and created based on the usage rate R, and the dimming filter data is stored in the memory 32 (S106). Hereinafter, the dimming filter data will be described with reference to FIGS. 3A to 3C.

  FIG. 3A is a diagram showing dimming filter data without an unused mirror. FIG. 3B is a diagram illustrating dimming filter data when the unused mirrors are irregularly arranged. FIG. 3C is a diagram showing dimming filter data when the unused mirrors are regularly arranged.

  FIG. 3A shows a dimming filter when all effective mirrors are used. The black part represents the mirror ON state, and the area is black because the usage rate is 100%. FIG. 3B shows dimming filter data in the form of snow noise (sandstorm) / satin texture in which the usage rate R = 80%, that is, the ratio of unused mirrors is 20%.

  As shown in FIG. 3B, the unused mirrors are scattered in a substantially uniform distribution with respect to the mirror region at substantially equal distance intervals. On the other hand, when viewed from the entire mirror region, the unused mirrors have a regular arrangement. is not. From a macro perspective, unused mirrors are evenly diffused.

  On the other hand, instead of employing an irregular array of unused mirrors, it is possible to employ a regular unused mirror array. For example, the unused mirrors can be arranged in a checkered pattern or a dot pattern, and the unused mirrors can be arranged at equal intervals. In FIG. 3C, unused mirrors are regularly arranged in a checkered pattern.

  By superimposing the dimming filter data prepared in this way and the pattern data for drawing, it is possible to form a pattern with a reduction in the amount of light in the projection area. The dimming filter data does not depend on the pattern data.

  With the above-described dimming filter data, the amount of projection light is adjusted substantially uniformly in the entire projection area. That is, regardless of whether the array of regular or irregular unused mirrors is used, the amount of light in the exposure area changes uniformly, and the tendency of the amount of light distribution in the exposure area does not change substantially before and after adjustment of the amount of light. There is only an increase or decrease in the amount of light over the entire area.

  Or, in other words, the two-dimensional light amount distribution in the exposure area corresponding to the pattern data for drawing does not substantially change even when the dimming filter data is superimposed, and only the absolute light amount is obtained. Increase or decrease overall. The light amount can be adjusted with high accuracy without affecting the drawing pattern.

  The maintenance of the relative light quantity distribution tendency in the exposure area can also be expressed by detecting the light quantity situation. For example, when the exposure area is divided into a plurality of divided areas, each area is ordered according to the amount of light, and the areas for obtaining the maximum light quantity and the areas for obtaining the minimum light quantity are determined by comparing the light quantities of the divided areas. If the order according to the amount of light does not change before and after the adjustment, it can be said that the light amount is uniformly adjusted in the entire exposure area. Even when the ratio of the maximum light amount to the minimum light amount does not substantially change before and after the light amount adjustment, it can be said that the uniform light amount adjustment is performed.

  The dimming filter data having the irregular and regular mirror arrangement shown above is prepared according to the usage rate, and the dimming filter data is selectively read from the memory according to the usage rate obtained at the time of adjusting the light amount.

  On the other hand, when the light amount measured in step S103 is less than the target light amount, the light amount adjustment using the DMD 22 cannot be performed. That is, the measured light quantity does not reach the target light quantity even when all the effective mirrors are in the ON state, and therefore cannot be matched with the target light quantity by selecting the unused mirror.

  This is a decrease in output with use of the discharge lamp 20 and occurs after a relatively long lighting time. In such a state, the input power to the lamp is adjusted so that the output of the discharge lamp 20 is increased (S103).

  Specifically, the lamp input power is adjusted so that the amount of illumination light from the discharge lamp 20 becomes a reference amount of light that is a predetermined amount greater than the target amount of light. For example, the lamp input power is increased until the measured light quantity reaches 120% of the target light quantity. Then, dimming filter data is created again. Once the output of the discharge lamp 20 is adjusted, the input power is kept constant until the measured light quantity falls below the target light quantity again.

  FIG. 4 is a graph showing the amount of projection light, the input power, and the usage rate of DMD as the usage time of the discharge lamp elapses.

  As shown in FIG. 4, the input power (initial power) at the start of use of the discharge lamp 20 is set to a power for obtaining a reference light amount higher than the target light amount. While maintaining this input power constant, the light amount of the projection light is adjusted to the target light amount L0 by light amount adjustment (dimming) using the DMD 22.

  While the discharge lamp 20 is lit, the output of the discharge lamp 20 may fluctuate finely, and the mirror usage rate increases or decreases accordingly. However, as the lighting time becomes longer, the output of the discharge lamp 20 gradually decreases. Along with this, the mirror usage rate gradually increases.

  When the measured light quantity falls below the target light quantity L0, the lamp input power is increased, and the input power is increased by VD until the reference light quantity is reached again. While maintaining the newly set input power, the mirror usage rate is calculated to adjust the light amount.

  As a result, as shown in FIG. 4, while the mirror usage rate increases or decreases for a certain period of time, the lamp usage rate increases toward 100% and finally reaches almost 100%, and this is repeated. Note that the light amount when the mirror usage rate is 100% is indicated by a two-dot chain line L1 in FIG.

  In this way, while performing the dimming process using the DMD at predetermined time intervals, the lamp input power is increased stepwise in a span longer than the DMD dimming process time interval, and finally the maximum power that becomes the upper limit Up to. From the start of use of the discharge lamp 20 to the end of use due to its life, the light quantity and illuminance with respect to the projection area of the substrate SW are always maintained at the target light quantity L0 suitable for drawing.

  By the way, considering the resolution required for the pattern, there is a limit to dimming using the DMD 22, and it is necessary to set a lower limit value for the usage rate R. The lower limit value of the usage rate R is determined by the tilt angle of the DMD 22, the number of pixels, the pixel size, the magnification of the projection optical system, the resolution, the sensitivity of the photoreceptor, and the like. Here, an adjustment range in which there is no difference in the required resolution is determined, and the lower limit value RZ of the usage rate R is set to 65%.

  Therefore, when the output of the discharge lamp 20 is increased, it is necessary that the usage rate R does not become lower than the lower limit value RZ = 65%. In the present embodiment, the reference light amount referred to when the output increases corresponds to the lower limit value RZ, and the usage rate R decreases to the lower limit value RZ each time the lamp output increases. As a result, the light amount adjustment range in which the usage rate R is the lower limit value RZ = 65% to 100% is used during the increase of the lamp output.

  FIG. 5 is a flowchart showing drawing processing by the step & repeat method.

  While the substrate SW moves, the relative position of the projection area (exposure area) is detected, and when the exposure area reaches the area on the substrate on which the pattern corresponding to the generated pattern data is to be projected, the substrate SW stops ( S201 to S203). Then, raster data is generated from the vector data (S204).

  When the dimming filter data is read from the memory 32, exposure data is generated by superimposing (logical product) the raster data and the dimming filter data (S205, S206). The exposure light is sent to the DMD driving circuit 24, and thereby pattern light is projected (S207). Such exposure operation is repeated until drawing is completed (S208, S209).

  As described above, according to the present embodiment, when adjusting the light amount, the effective mirror of the DMD 22 is turned on, the light amount of the projection light is measured, and the usage rate R, which is the ratio between the measured light amount and the target light amount, is determined. . Based on the usage rate R, dimming filter data indicating an array of unused mirrors is generated. At this time, the unused mirrors are arranged so that the change in the amount of light is substantially uniform over the entire area.

  The array of unused mirrors is two-dimensionally distributed almost evenly over the entire area to be exposed, and the light intensity distribution in the exposure area does not change before and after the light intensity adjustment, and the light intensity increases by a fixed amount over the entire area. / Reduction can be realized.

  The ratio of the mirrors used in the light amount adjustment using the DMD 22, that is, the usage rate, can be set in a range that satisfies any of the requirements in the exposure conditions. The range of the usage rate depends on the size of the DMD, the pixel pitch, the resolution, the DMD tilt angle, the number of times of multiple exposure of the photosensitive member such as a photoresist, and the like. For example, it can be set in the range of 20% to 100%.

  The dimming filter data may be created in advance according to the usage rate and stored in the memory, and the corresponding dimming filter data may be selected from the ratio between the measured light amount and the target light amount. Furthermore, test exposure may be performed in advance, and light control filter data may be selected based on the result.

  Mirrors other than unused mirrors that are set to the OFF state based on the dimming filter data are set to ON / OFF based on the pattern data, but some of the effective mirrors are set to OFF as needed depending on the usage environment. May be.

  As for the exposure operation method, a continuous scanning method may be applied instead of step & repeat. Further, instead of the multiple exposure method, a method of performing a single shot exposure may be used. Furthermore, a light modulation element array other than DMD may be used, and a light source other than a discharge lamp can be applied. Further, in an exposure apparatus using a mask and a reticle, a light modulation element array such as a DMD may be separately provided as a dedicated filter device.

DESCRIPTION OF SYMBOLS 10 Exposure apparatus 20 Discharge lamp 21 Lamp drive part 22 DMD
28 Exposure Data Generation Circuit 30 Controller 34 Photometric Device

Claims (8)

A light source;
A plurality of light modulation elements arranged two-dimensionally, and a light modulation element array for guiding illumination light from the light source to an exposure area of a drawing object;
A light amount adjusting means for controlling the plurality of light modulation elements to adjust the light amount of the projection light,
An exposure light control device, wherein the light amount adjusting means defines unused light modulation elements in the entire element array region so that the light amount in the exposure area is changed as a whole.   The exposure light control device according to claim 1, wherein the light quantity adjusting unit defines the unused light modulation elements so as to form a regular array.   The exposure light control device according to claim 1, wherein the light amount adjusting unit defines the unused light modulation elements so that the light intensity adjusting unit has an irregular arrangement.   4. The exposure light control device according to claim 3, wherein the light intensity adjusting means arranges the unused light modulation elements so as to have a snow noise shape or a satin shape. A light amount measuring means for measuring the light amount of the projection light irradiated to the exposure area,
5. The light quantity adjusting unit sets an unused light modulation element based on a predetermined target light quantity and a measured light quantity of projection light. Light control device for exposure.   An exposure apparatus comprising the exposure light control device according to claim 1. For a light modulation element array that has a plurality of light modulation elements arranged two-dimensionally and guides the illumination light from the light source to the exposure area of the object to be drawn, so as to change the overall light amount in the exposure area, Unused light modulation elements are defined in the entire element array region,
A light amount adjustment method comprising adjusting an amount of projection light by turning off an unused light modulation element. Exposure equipment
For a light modulation element array that has a plurality of light modulation elements arranged two-dimensionally and guides the illumination light from the light source to the exposure area of the object to be drawn, so as to change the overall light amount in the exposure area, Unused light modulation element setting means for determining unused light modulation elements in the entire element array region;
A program that functions as a light amount adjusting unit that adjusts a light amount of projection light by turning off an unused light modulation element.

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