JP2010251363A - Exposure method, exposure apparatus, and device manufacturing method - Google Patents

Abstract

A reduction in throughput due to light source replacement is minimized.
An in parallel with replacement of the at least one light source 1 _k of the plurality of light sources, the plate is exposed using a different light source of the plurality of light sources except the light source 1 _k exchanged . As a result, a plurality of light sources can be exchanged without interrupting plate exposure (lot processing) for a long time, so that a reduction in throughput due to the exchange of light sources can be minimized. Further, throughput is reduced by operating an exposure system including an exposure apparatus and other ancillary apparatuses so that lot processing under exposure conditions with a small exposure amount is concentrated on an exposure apparatus whose light source _1k is being replaced. Can be avoided almost completely.
[Selection] Figure 3

Description

  The present invention relates to an exposure method, an exposure apparatus, and a device manufacturing method, and more specifically, an exposure method and an exposure apparatus used in a lithography process for manufacturing a semiconductor element, a liquid crystal display element, and the like, and a device using the exposure method It relates to a manufacturing method.

  In a lithography process for manufacturing electronic devices (microdevices) such as semiconductor elements and liquid crystal display elements, for example, a step-and-repeat projection exposure apparatus (so-called stepper) or a step-and-scan projection exposure apparatus (so-called so-called stepper). Scanning steppers (also called scanners)) are mainly used. In this type of exposure apparatus, a mask (or reticle) on which a pattern is formed is irradiated with illumination light, and a pattern image is applied to a substrate (wafer, glass plate) to which a sensitive agent (resist) is applied via a projection optical system. Etc.), the pattern is sequentially transferred to a plurality of shot areas on the substrate.

  For example, as disclosed in Patent Document 1, a plurality of light sources are mounted on the above exposure apparatus in order to generate high intensity illumination light.

Japanese Patent Laid-Open No. 11-195589

  In an exposure apparatus equipped with a plurality of light sources, the light sources have a lifetime, and therefore the light sources need to be replaced periodically. Conventionally, when replacing the light source, the exposure apparatus is stopped and all the light sources are replaced simultaneously. In this case, all the light sources can be replaced with a minimum stop time. However, although it is a minimum, the exposure apparatus is stopped for a long time, resulting in a decrease in throughput.

  In order to reduce the running cost of the exposure apparatus, in a lot with a small exposure amount, some of the plurality of light sources may be turned off and the exposure process may be performed using only the remaining light sources. However, when the light source is turned off / on, the exposure apparatus is temporarily stopped, which causes a decrease in throughput.

  The present invention has been made under such circumstances. From a first viewpoint, the present invention is an exposure method for exposing an object using a plurality of light sources, and includes at least one light source among the plurality of light sources. A step of turning off the light in a state where the light from the light source is blocked; and at least one other light source of the plurality of light sources except the one light source is turned on and the light from the other light source Measuring the illuminance on the object in the open state, and exposing the object using the other light source based on the measurement result; in parallel with the exposing step, Exchanging one light source and lighting the exchanged light source in a state where light from the light source is blocked; after the exchanged light source is stabilized, the exposure is stopped and the exchanged light source is replaced. An exposure method comprising: releasing light from a light source; That.

  According to this, it is possible to suppress a decrease in throughput due to replacement of the light source.

  According to a second aspect of the present invention, there is provided an exposure method in which a plurality of sets of objects are sequentially exposed using a plurality of light sources, and the required number of light sources to be used for each of the plurality of sets of objects. Is less than the number of light sources that are lit among the plurality of light sources, the exposure process is performed in consideration of at least the stabilization time required until the light source that is lit is stabilized and the processing time required for the exposure process. In the exposure method, when starting, the remaining light sources other than the required number of light sources among the light sources that are turned on are extinguished.

  According to this, it is possible to suppress the cost required for the exposure process without reducing the throughput.

  According to a third aspect of the present invention, there is provided a device manufacturing method comprising: a step of forming a pattern on an object using the exposure method of the present invention; and a step of processing the object on which the pattern is formed. It is.

  According to this, since the exposure method of the present invention is used, a highly integrated device can be manufactured with high productivity.

  According to a fourth aspect of the present invention, there is provided an exposure apparatus for sequentially exposing a set of a plurality of objects using a plurality of light sources, including an optical system, and passing through the optical system by light from the plurality of light sources. An exposure apparatus main body that exposes the object to form a pattern image on the object; and a required number of light sources to be used for each of the plurality of object sets is being lit among the plurality of light sources. If the number of light sources is smaller than the number of light sources, the light sources that are turned on when starting the exposure processing in consideration of at least the stabilization time required until the light sources that are turned on are stabilized and the processing time required for the exposure processing. And a control system for turning off the remaining light sources excluding the required number of light sources.

  According to this, the running cost can be suppressed without reducing the throughput.

It is a figure which shows schematic structure of the exposure apparatus which concerns on one Embodiment of this invention. FIG. 2 is a block diagram for explaining an input / output relationship of a main controller provided in the exposure apparatus of FIG. 1. It is a figure which shows schematic structure of the illumination system with which the exposure apparatus of FIG. 1 is provided. It is a flowchart (the 1) for demonstrating the light source replacement | exchange process in a main controller. It is a flowchart (the 2) for demonstrating the light source replacement | exchange process in a main controller. It is a flowchart (the 3) for demonstrating the light source replacement | exchange process in a main controller. It is a flowchart which shows the procedure of the warming-up operation | movement of the exposure apparatus for replacing | exchanging a light source. It is a timing chart for demonstrating the turning-on / off process of the light source performed by the main controller. It is a figure for demonstrating the reservation list | wrist of lot processing. It is a figure for demonstrating the relationship between exposure amount and the required number of light sources.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a schematic configuration of an exposure apparatus 110 according to an embodiment.

As shown in FIGS. 1 and 2, the exposure apparatus 110 drives _five illumination systems IOP _{1 to} IOP ₅ , a mask stage MST that holds a mask M, a plate stage PST that holds a plate P, and a mask stage MST. the mask stage driving system MSD to the projection optical system module PL containing plate stage drive system PSD, 5 one of the projection optical system _PL 1 through PL ₅ for driving the plate stages PST, and the main control for overall control of each component of the exposure apparatus 110 The apparatus 50 etc. are provided.

In the following description, the optical axis _AX 1 _{~AX 5} parallel to direction Z-axis direction of the projection optical system _PL 1 through PL _5, X-axis direction and the Y-axis the two directions perpendicular to each other in a plane perpendicular thereto The direction. Further, the rotation directions around the X, Y, and Z axes are the θx, θy, and θz directions, respectively. Note that the X-axis direction is parallel to the scanning direction of the mask stage MST and the plate stage PST in scanning exposure.

  The mask M is a rectangular mask having a pattern formed on one surface (the surface on the −Z side), and is fixed on the mask stage MST by, for example, vacuum suction.

  The plate P is a rectangular glass plate that is a substrate for a display device. A sensitive agent (resist) is applied to the surface of the plate P.

  The mask stage MST can be driven minutely in the horizontal plane (XY plane) by a mask stage drive system MSD including a linear motor and the like, and can be driven at a predetermined scanning speed with a predetermined stroke in the scanning direction (X-axis direction). is there.

  The position of the mask stage MST in the XY plane is always measured with a laser interferometer (hereinafter referred to as “mask interferometer”) 16 with a resolution of, for example, about 0.25 nm.

  Here, a movable mirror (or mirror-finished reflecting surface) 15 is provided at the end of the mask stage MST, and the mask interferometer 16 moves the movable mirror 15 by irradiating it with a laser beam (length measuring beam). By receiving the reflected light from the mirror 15, the position of the mask stage MST is measured. The measurement result here is supplied to the main controller 50.

  Main controller 50 drives and controls mask stage MST via mask stage drive system MSD based on the measurement result of mask interferometer 16. Note that an encoder (or an encoder system including a plurality of encoders) may be used instead of the mask interferometer 16 or together with the mask interferometer 16.

Each illumination system is arranged on the + Z side of the mask stage MST, and emits bright lines such as g-line (wavelength 436 nm), h-line (wavelength 405 nm), i-line (wavelength 365 nm) as shown in FIG. 3 as an example. Three light sources 1 ₁ to 1 ₃ composed of ultra-high pressure mercury lamps, three elliptical mirrors 2 ₁ to 2 ₃ that are attached to the respective light sources and collect light, and are condensed by the respective elliptical mirrors and emit light directed in the −Z direction. Each of the shutters includes three shutters 3 ₁ to ₃ 3 that are opened and closed, a light guide 4 that collects light that has passed through each shutter, and an illumination optical system 5 that shapes light transmitted from the light guide 4. Yes.

  Each light source is provided with a temperature sensor (not shown) for measuring the temperature of the light source and a luminance sensor (not shown) for measuring the luminance.

  In the illumination optical system 5, the wavelength band and intensity of light transmitted from the light guide 4 are adjusted by a wavelength selector (not shown) and a variable dimmer (not shown), and an optical integrator (not shown). Is converted into a light beam having a uniform illuminance distribution.

This light beam is further shaped by a blind (not shown) having a slit-shaped opening, and passes through a condenser lens (not shown) as illumination light IL _n (n = 1 to 5) as an illumination system IOP _n (n = 1). To 5).

  The illumination optical system 5 includes a beam splitter (not shown) that branches a part of the illumination light as monitor light, a photodetector (not shown) that receives the monitor light and measures the amount of illumination light, and the like. It is. The measurement result of the light amount by the photodetector is transmitted to the main controller 50.

  The main controller 50 constantly monitors the amount of illumination light emitted from each illumination system and controls the variable dimmer so that the target amount of light is maintained. Thereby, the illuminance on the plate P is kept constant.

  Further, main controller 50 opens and closes the shutter, and turns on and off the light source.

  Each illumination system emits illumination light in the −Z direction. Each illumination light individually illuminates five illumination areas (not shown) on the mask M. The five illumination areas are arranged in a zigzag pattern and each have an isosceles trapezoid shape defined by the blind of the illumination optical system 5.

  Each projection optical system is disposed below the mask stage MST (on the −Z side). Each projection optical system is composed of a two-stage in-mirror lens optical system that includes two sets of prisms, optical element groups (lens groups), and reflecting mirrors arranged along the optical axis, and projects both sides of an equal-magnification erect image. This is a telecentric optical system.

The five projection optical systems PL _{1 to} PL ₅ are arranged in a staggered manner in the XY plane, similarly to the five illumination areas on the mask M. Here, the projection optical systems PL ₁ , PL ₃ , PL ₅ are arranged at predetermined intervals in the Y-axis direction, and the projection optical systems PL ₂ , PL ₅ are located on the + X side from the projection optical systems PL ₁ , PL ₃ , PL _5. They are spaced apart and arranged at predetermined intervals in the Y-axis direction.

  Similar to the five illumination areas on the mask M, the five areas (projection areas) on which the image is projected on the plate P are arranged in a staggered pattern. Here, the five projection areas have the same isosceles trapezoid shape as the illumination area.

Therefore, the mask M and the plate P are scanned while projecting partial images of the patterns in the five illumination areas on the mask M onto the five projection areas on the plate P through the projection optical systems PL _{1 to} PL ₅ , respectively. By driving synchronously in the direction (X-axis direction), the partial image of the pattern projected on the plate P is synthesized into one image (synthesized image) equal to the pattern formed on the mask M. That is, the pattern of the mask M is transferred into one shot area on the plate P through the projection optical systems PL _{1 to} PL ₅ .

  Here, since each projection optical system employs an optical system that projects an equal-size erect image, the shape and arrangement (positional relationship) of the five projection areas are five illumination areas on the mask M, respectively. It is equal to the shape and arrangement (positional relationship). Details of the configuration of the projection optical system module PL are disclosed in, for example, US Pat. No. 6,552,775.

  The plate stage PST is disposed below (−Z side) the projection optical system module PL. The plate stage PST is driven with a predetermined stroke in the X-axis direction and the Y-axis direction by a plate stage drive system PSD including a linear motor and the like, and also rotates around the Z axis (θz direction) and rotates around the X axis. It is finely driven in the (θx direction) and rotation direction around the Y axis (θy direction).

  Instead of the plate stage PST, a stage movable in the XY plane (including rotation in the θz direction) and supported on the stage, holding the plate P, the Z axis direction, the θx direction, and the θy direction It is also possible to use a table that can be moved slightly.

  The position of the plate stage PST in the XY plane (including yawing (rotation θz in the θz direction)) and inclination with respect to the Z axis (pitching (rotation θx in the θx direction) and rolling (rotation θy in the θy direction)) are laser interference. It is always measured using a meter (hereinafter referred to as “plate interferometer”) 18.

  Here, a movable mirror (or mirror-finished reflecting surface) 17 is provided at the end of the plate stage PST, and the plate interferometer 18 irradiates the movable mirror 17 with a laser beam (length measuring beam) and moves. By receiving the reflected light from the mirror 17, the position of the plate stage PST is measured. The measurement result here is supplied to the main controller 50.

  Main controller 50 controls drive of plate stage PST via plate stage drive system PSD based on the measurement result of plate interferometer 18. Note that an encoder (or an encoder system including a plurality of encoders) may be used instead of the plate interferometer 18 or together with the plate interferometer 18.

  A rectangular mark plate (not shown) whose longitudinal direction is the Y-axis direction is fixed to the upper surface of the plate stage PST. The height of the mark plate is set so that the surface thereof is substantially flush with the surface of the plate P placed on the plate stage PST. On the surface of the mark plate, six reference marks (not shown) are formed side by side in the Y-axis direction.

Inside the plate stages PST, each downward (-Z side), the lens system and the imaging device (CCD, etc.) and six mark image detection system _MD 1 to MD ₆ is arranged comprising six reference marks Has been. These mark image detection systems MD _{1 to} MD ₆ simultaneously project projection images of alignment marks on the mask M by the projection optical systems PL _{1 to} PL ₅ and the lens system, and images of reference marks (not shown) by the lens system. Detect and measure the position of the alignment mark image relative to the position of the reference mark image. The measurement result is supplied to the main controller 50 and used for alignment of the mask M (mask alignment) and the like.

Further, the exposure apparatus 110 is provided with _six off-axis type alignment detection systems AL _{1 to} AL 6 in order to detect six reference marks and alignment marks on the plate P. The six alignment detection systems are sequentially arranged along the Y axis on the + X side of the projection optical system module PL.

As each alignment detection system, an image processing type FIA (Field Image Alignment) type sensor is employed. The FIA sensor, for example, irradiates a target mark with broadband detection light that does not sensitize the resist on the plate P, and the image of the target mark and an index (uncorrected) formed on the light receiving surface by the reflected light from the target mark. The image of the image is taken using an image sensor (CCD) or the like. Detection results of the alignment detection system _AL 1 _{~AL 6} is sent to main controller 50 via an alignment signal processing system (not shown).

  In addition to the FIA system, a target mark is irradiated with coherent detection light, and scattered light or diffracted light generated from the target mark is detected, or two diffracted lights (for example, of the same order) generated from the target mark. It is also possible to use an alignment sensor that detects the interference by singly or in combination. Details of alignment measurement (mark detection) using an alignment detection system are disclosed in, for example, Japanese Patent Application Laid-Open No. 2003-347184.

  The exposure apparatus 110 also has an input device 51A including at least one of a keyboard and a mouse for an operator to input various information to the main controller 50 and give instructions, and the main controller 50 displays various information. The display device 51B including the display is provided. The operator can instruct operation / stop of the exposure apparatus 110 via the input device 51A. Further, the main control device 50 can notify the operator of the replacement of the light source via the display device 51B.

  The lot processing and plate exposure in the exposure apparatus 110 will be briefly described.

  When a lot to be processed consisting of a plurality of (for example, 50 or 100) plates is loaded into a coater / developer (hereinafter referred to as “C / D”) (not shown) connected inline to the exposure apparatus 110, the lot The inner plates are sequentially coated with a resist by a coater (resist coating device) in the C / D, and are transported to the exposure device 110 by a transport system (not shown).

When the resist-coated plate P is loaded onto the plate stage PST, the main control device 50 detects the reference mark on the plate stage PST using the alignment detection systems AL _{1 to} AL ₆ , and the base Perform line measurement.

Then, main controller 50 uses the alignment detection system AL ₁ ~AL _6, detects a plurality of alignment marks granted with the pattern on the plate P, it performs the plate alignment.

  After the plate alignment is completed, main controller 50 sequentially transfers the pattern of mask M by scanning exposure into a plurality of shot areas arranged on plate P.

In the scanning exposure for each shot area, main controller 50 monitors the measurement results of mask interferometer 16 and plate interferometer 18 to move mask stage MST and plate stage PST to their respective scanning start positions (acceleration start positions). Move to. Then, both stages MST and PST are synchronously driven in the same X-axis direction (± X direction). Accordingly, the five illumination areas on the mask M are illuminated by the illumination lights IL _{1 to} IL ₅ , respectively, and the partial images of the patterns in the five illumination areas are respectively on the plate P via the projection optical systems PL _{1 to} PL _5. Are projected onto five projection areas.

When the entire surface of the pattern of the mask M is completely illuminated with the illumination lights IL _{1 to} IL ₅ , the scanning exposure for one shot region on the plate P is completed. Thereby, the pattern of the mask M is transferred into the shot area. That is, a latent image having the same pattern as the pattern of the mask M is formed on the resist layer provided on the plate.

  When the scanning exposure for one shot area is completed, main controller 50 moves (steps) plate stage PST to the scanning start position (acceleration start position) for the next shot area. Then, scanning exposure is performed on the next shot area in the same manner as described above. Thus, the pattern of the mask M is transferred to all the shot areas on the plate P by repeating the stepping between the shot areas on the plate P and the scanning exposure on the shot area.

  When the pattern transfer is completed, the plate P is unloaded from the plate stage PST and conveyed to the C / D by the conveyance system. The plate P is developed by a developer (developing device) in the C / D. After the plate P is unloaded from the plate stage PST, the next plate is loaded on the plate stage PST, the pattern is transferred by scanning exposure, and developed. The same processing is performed on all the plates in the lot, and the lot processing ends.

  The light source replacement process performed by the main controller 50 will be described with reference to FIGS. The flowcharts of FIGS. 4 to 7 correspond to a series of processing algorithms executed by the main controller 50. Note that all light sources are turned on.

  When the operator inputs a light source replacement request to the input device 51A, the light source replacement process is started. At the same time, timer interrupts are permitted, and interrupt processing is started every predetermined time (for example, 10 milliseconds).

  Here, the processes in FIGS. 4 and 5 are started when a light source replacement request is received via the input device 51A, and the processes in FIGS. 6 and 7 are started each time an interrupt process is performed. Process.

  In the first step S401, an initial value 0 is set to the replacement flag Fc for specifying the light source to be replaced. In addition, an initial value 0 is set to the sequence flag Fs indicating the progress of processing in the interrupt processing.

  In the next step S403, it is determined whether or not lot processing has been completed. If the plate in the lot is being exposed, the determination here is denied. And it waits until judgment here is affirmed. When the exposure of all the plates in the lot is completed, the determination here is affirmed, and the process proceeds to step S405.

  In step S405, an initial value 1 is set to the number k for specifying the light source.

In the next step S407, the shutter (here, shutter 3 ₁ ) attached to the light source (here, light source 1 ₁ ) corresponding to the number k is closed.

  In the next step S409, the light source corresponding to the number k is turned off.

  In the next step S411, the value of k is set in the exchange flag Fc.

In the next step S413, via the optical detector and the mark image detection system illuminance measurement instrument MD ₁ to MD _6, to measure the illumination intensity on the plate P.

  In the next step S415, an exposure amount is obtained from illuminance × scanning distance / scanning speed. Here, the scanning distance / scanning speed is equivalent to the exposure time, and adjusting at least one of the scanning distance and the scanning speed means substantially adjusting the exposure time. The scanning distance is equal to the width of the shot area arranged on the plate P in the scanning direction (X-axis direction). The scanning speed is substituted with a scanning speed that does not reduce the throughput of the entire line.

  In the next step S417, the exposure amount obtained in the above step 415 is notified to the host computer that comprehensively manages the exposure system including the exposure apparatus 110 and other attached apparatuses. As a result, the host computer selects a lot corresponding to the exposure condition where the required exposure amount is equal to or less than the exposure amount obtained in step 415, and notifies the C / D.

  In the next step S433, an exposure process is performed. When the exposure process ends, the process proceeds to step S435.

  In step S435, it is determined whether or not the value of the exchange flag Fc is zero. If the value of the exchange flag Fc is not 0, the determination here is denied and the process returns to step S433.

  Thereafter, the processes in steps S433 to S435 are repeated until the determination in step S435 is affirmed.

  If the exchange flag Fc is set to 0 in the timer interrupt process, the determination in step S435 is affirmed, and the process proceeds to step S437.

  In step S437, the shutter attached to the light source corresponding to the number k is opened. Thereby, in each illumination system, the light of the replaced light source is released, and the illumination optical system 5 forms the illumination light together with the light of other light sources.

  In the next step S439, it is determined whether or not the value of k is 3 or more. Here, since the value of k is 1, the determination here is denied, and the routine goes to Step S441.

  In step S441, 1 is added to the value of k. Then, the process returns to step S407.

  Thereafter, the processes in steps S407 to S441 are repeated until the determination in step S439 is affirmed.

  When the value of k becomes 3, the determination in step S439 is affirmed, and the process proceeds to step S451.

  In step S451, the illuminance on the plate P is measured in the same manner as in step S413.

  In the next step S453, the exposure amount is obtained in the same manner as in step S415.

  In the next step S455, the exposure amount obtained in step 453 is notified to the host computer. As a result, the host computer selects a lot corresponding to the exposure condition where the required exposure amount is equal to or less than the exposure amount obtained in step 453, and notifies the C / D. Then, the light source replacement process is terminated, and the process returns to the normal exposure process.

  Next, processing performed in the interrupt processing will be described with reference to FIGS.

  In the first step S601, it is determined whether or not the value of the exchange flag Fc is zero. If the value of the exchange flag Fc is 0, the determination here is affirmed and the routine returns without doing anything. On the other hand, if the value of the exchange flag Fc is not 0, the determination here is denied and the process proceeds to step S603.

  In step S603, it is determined whether or not the value of the sequential flag Fs is zero. Here, since the value of the sequential flag Fs is 0, the determination here is affirmed and the process proceeds to step S605.

  In step S605, the temperature Tk of the light source corresponding to the number k is obtained via the temperature sensor attached to the light source corresponding to the number k.

  In the next step S607, it is determined whether or not the obtained temperature Tk is equal to or lower than a predetermined temperature Ts (for example, 30 ° C.). If the temperature Tk is not lower than the temperature Ts, the determination here is denied and the process returns. That is, it waits until the temperature of the light source corresponding to the number k is sufficiently cooled. On the other hand, if the temperature Tk is equal to or lower than the temperature Ts, the determination here is affirmed and the process proceeds to step S609.

  In step S609, 1 is set to the sequential flag Fs.

  In the next step S611, a message indicating that the light source corresponding to the number k can be exchanged is displayed on the display device 51B.

  In the next step S613, it is determined whether or not the replacement of the light source corresponding to the number k has been completed. When the operator inputs the completion of the light source replacement to the input device 51A and there is a notification from the input device 51A, the determination here is affirmed and the process proceeds to step S631.

  In step S631, 2 is set to the sequential flag Fs.

  In the next step S633, the light source corresponding to the number k is turned on.

  In the next step S635, the luminance of the light source corresponding to the number k is obtained using the luminance sensor attached to the light source corresponding to the number k.

  In the next step S637, it is determined whether or not the luminance of the light source corresponding to the number k is greater than or equal to a desired value. If the luminance of the light source corresponding to the number k is not higher than the desired value, the determination here is denied and the process returns. That is, it waits for the lit light source to stabilize. On the other hand, if the luminance of the light source corresponding to the number k is greater than or equal to a desired value, the determination here is affirmed and the process proceeds to step S639.

  In step S639, the value of the exchange flag Fc is set to zero.

  In the next step S641, 0 is set to the sequential flag Fs. Then return.

  In step S603, if the value of the sequential flag Fs is not 0, the determination in step S603 is denied and the process proceeds to step S621.

  In step S621, it is further determined whether or not the value of the sequential flag Fs is 1. If the value of the sequential flag Fs is 1, the determination here is affirmed and the process proceeds to step S613. On the other hand, if the value of the sequential flag Fs is not 1, the determination here is denied and the process proceeds to step S635.

  If the replacement of the light source corresponding to the number k is not completed in step S613, the determination in step S613 is denied and the process returns.

  In step S607, it may be determined whether a predetermined time has elapsed since the light source corresponding to the number k is turned off.

  In step S637, it may be determined whether a predetermined time has elapsed since the light source corresponding to the number k is turned on.

  By the way, the exposure conditions in the exposure apparatus 110 are designated by a host computer that comprehensively manages the exposure system including the exposure apparatus 110 and other attached apparatuses. The host computer creates a process program (referred to as a recipe) in which specified conditions are described and transfers the process program to the exposure apparatus 110. And the main control apparatus 50 will reserve the lot process described in the recipe, if a recipe is received. Usually, multiple lot processing is reserved. The main control device 50 executes lot processing in the reserved order.

  Next, a light source on / off process performed by the main controller 50 in a normal exposure process will be described with reference to FIG. It is assumed that the time (stabilization time) required for stabilization when the light source being turned off is turned on is 30 minutes. Further, it is assumed that lot processing is reserved as shown in FIG. Further, FIG. 10 shows the relationship between the exposure amount and the number of necessary light sources. This relationship is obtained in advance and stored in the memory of the main controller 50.

1. Consider lot 0.

  In this case, since the exposure amount is 50, the required number of light sources is three. Therefore, all light sources are used in each illumination system.

2. Process lot 0.
(2-1) Turn on all light sources in each illumination system.
(2-2) The illuminance on the plate is measured using the photodetector of each illumination system and the illuminance meter of each mark image detection system.
(2-3) An exposure amount is obtained from the measurement result of illuminance, and it is confirmed that it corresponds to the exposure amount necessary for lot 0.
(2-4) Scanning exposure is started.

3. When scanning exposure of lot 0 is started, lot 1 is examined.

In this case, since the exposure amount is 30, the number of necessary light sources is two. In addition, the number of light sources currently on is 3, and the expected processing time is longer than the stabilization time. Therefore, two light sources are used in each illumination system. Here, we are assumed that the light source 1 ₃ other than the light source is used.

4). When the processing for the lot 0 is completed (time T _{1 in} FIG. 8), the processing for the lot 1 is performed.
(4-1) attached to the light source _{1 3} have been shutter _{3 3} Close.
(4-2) The light source _{1 3} turned off.
(4-3) The illuminance on the plate is measured using the photodetector of each illumination system and the illuminance measuring instrument of each mark image detection system.
(4-4) An exposure amount is obtained from the measurement result of illuminance, and it is confirmed that the exposure amount necessary for lot 1 is supported.
(4-5) Scanning exposure is started.

5. When scanning exposure of lot 1 is started, examination of lot 2 is performed.

  In this case, since the exposure amount is 50, the required number of light sources is three. Therefore, all light sources are used in each illumination system. That is, the required number of light sources is larger than the number of light sources currently on.

6). Processing 30 minutes scheduled time to end of lot 1 (stabilization time) becomes before (in Figure 8 times _T'1), the light source 1 ₃ lights.

7). When the processing of the lot 1 is completed (time T _{2 in} FIG. 8), the processing of the lot 2 is performed.
(7-1) opening the shutter _{3 3} annexed to the light source _{1 3.}
(7-2) The illuminance on the plate is measured using the photodetector of each illumination system and the illuminance meter of each mark image detection system.
(7-3) The exposure amount is obtained from the illuminance measurement result, and it is confirmed that the exposure amount necessary for the lot 2 is supported.
(7-4) Scanning exposure is started.

8). When scanning exposure of lot 2 is started, examination of lot 3 is performed.
(8-1) In this case, since the exposure amount is 30, the required number of light sources is two. In addition, the number of light sources currently on is 3, and the expected processing time is shorter than the stabilization time.
(8-2) The lot following lot 3 is examined. In this case, since the exposure amount is 50, the required number of light sources is three.
(8-3) Therefore, in the processing of lot 3, all the light sources are used in each illumination system.

9. When the processing of the lot 2 is completed (time T _{3 in} FIG. 8), the processing of the lot 3 is performed.
(9-1) The amount of illumination light is adjusted using the variable dimmer of the illumination optical system 5.
(9-2) The illuminance on the plate is measured using the photodetector of each illumination system and the illuminance meter of each mark image detection system.
(9-3) An exposure amount is obtained from the measurement result of illuminance, and it is confirmed that the exposure amount necessary for the lot 3 is supported.
(9-4) Start scanning exposure.

10. When scanning exposure of lot 3 is started, examination of lot 4 is performed.

  In this case, since the exposure amount is 50, the required number of light sources is three. Therefore, all light sources are used in each illumination system. That is, the required number of light sources is the same as the number of light sources currently on.

11. When the processing of the lot 3 is completed (time T _{4 in} FIG. 8), the processing of the lot 4 is performed.
(11-1) The illuminance on the plate is measured using the photodetector of each illumination system and the illuminance measuring instrument of each mark image detection system.
(11-2) An exposure amount is obtained from the measurement result of illuminance, and it is confirmed that it corresponds to the exposure amount necessary for the lot 4.
(11-3) Scanning exposure is started.

  When the reserved last lot processing is completed, all the light sources are turned on and all the shutters are opened. Thereby, even when a lot process with a required number of light sources of 3 is reserved, the lot process can be started immediately.

  As described above, according to the exposure apparatus 110 according to the present embodiment, the plate P is exposed using the light sources other than the light sources to be replaced in parallel with the replacement of at least one of the plurality of light sources. is doing. Therefore, it is possible to replace the light source without interrupting the exposure of the plate P for a long time, and it is possible to minimize a decrease in throughput due to the replacement of the light source.

  Further, in an exposure system including a plurality of exposure apparatuses similar to the exposure apparatus 110, throughput processing is almost completely avoided by concentrating lot processing with a small required exposure amount on the exposure apparatus whose light source is being replaced. It is also possible.

  In addition, when starting each of a plurality of lot processing, if the required number of light sources to be used is less than the number of light sources that are lit among the plurality of light sources, the required number of light sources that are lit is excluded. The light source is turned off. As a result, the cost required for lot processing, that is, the running cost of the exposure apparatus can be suppressed.

  In addition, at least the stabilization time required until the lit light source is stabilized and the processing time required for lot processing are taken into consideration when turning off the light, so that the running cost of the exposure apparatus can be suppressed without reducing the throughput. It becomes.

  In the above embodiment, the case where all the light sources of each illumination system are replaced has been described. However, the present invention is not limited to this, and only a part of the light sources may be replaced in the same manner.

  Moreover, although the said embodiment demonstrated the case where the exposure apparatus 110 was a scanning exposure apparatus, it is not limited to this. For example, the exposure apparatus 110 may be a static exposure apparatus. However, in this case, the processable exposure amount is obtained from the product of the measurement result of the illuminance on the plate and the exposure time. The exposure time is limited by the blind driving speed of the illumination optical system 5, that is, the shutter speed.

  Further, in the above embodiment, the condition determination for the light source turning-off / lighting process may be performed when the lot process is reserved. In this case, not only the newly reserved lot process but also the condition determination for the unprocessed lot process that has already been reserved may be performed again. Furthermore, the order of unprocessed lot processing may be changed.

  In the above embodiment, the order of lot 2 and lot 3 may be switched. Thereby, one light source can be turned off also in the processing of the lot 3.

  In the above-described embodiment, the projection optical system of the exposure apparatus 110 is not limited to the equal magnification system, and may be any of a reduction system and an enlargement system, or any of a catadioptric system, a reflection system, and a refraction system. The projected image may be either an inverted image or an erect image.

In the above embodiment, a KrF excimer laser (248 nm), an ArF excimer laser (193 nm), or an F ₂ laser (157 nm) can also be used as the light source.

  The exposure method in the above embodiment is not limited to the manufacture of liquid crystal display elements, but can be applied to the manufacture of semiconductor elements, organic EL, thin film magnetic heads, imaging elements (CCDs, etc.), micromachines, DNA chips, and the like. .

  An electronic device such as a semiconductor element or a liquid crystal display element includes a step of designing a function / performance of the device, a step of manufacturing a mask based on the design, a step of manufacturing a substrate of the device, an exposure apparatus similar to the above embodiment, and The step of transferring the mask pattern to the substrate by the exposure method, the step of developing the exposed substrate, the step of etching the substrate on which the resist pattern is formed, the step of removing unnecessary resist, the step of assembling the device (dicing) , Bonding, and packaging), and a device inspection step.

  In this case, in the transferring step, the exposure method described above is executed using the same exposure apparatus as in the above embodiment, and a device pattern is formed on the substrate, so that a highly integrated device can be manufactured with high productivity. Can be manufactured.

  The exposure method and apparatus of the present invention are suitable for forming a pattern on an object. The device manufacturing method of the present invention is suitable for manufacturing electronic devices such as semiconductor elements and liquid crystal display elements.

1 ₁ to 1 3 _... light _{source, 3} 1 to 3 3 _... shutter, 50 ... main control unit, 110 ... exposure apparatus (scanning exposure _apparatus), IOP 1 _~IOP 5 _... illumination system, M ... mask, MST ... mask stage , P: plate, PL (PL _{1 to} PL ₅ ): projection optical system module (projection optical system), PST: plate stage.

Claims (24)

An exposure method for exposing an object using a plurality of light sources,
Turning off at least one light source of the plurality of light sources in a state where light from the light source is blocked;
The illuminance on the object is measured in a state where at least one other light source of the plurality of light sources excluding the one light source is turned on and light of the other light source is opened, and the measurement is performed. Exposing the object using the another light source based on the results of:
In parallel with the exposing step, the one light source is exchanged, and the exchanged light source is lit in a state where light from the light source is blocked;
After the exchanged light source has stabilized, stopping the exposure and releasing the light of the exchanged light source;
An exposure method comprising:   The exposure method according to claim 1, wherein in the exposing step, an exposure condition that requires a small amount of exposure is selected based on the measurement result of the illuminance, and the object corresponding to the exposure condition is exposed.   The exposure method according to claim 2, wherein in the exposing step, the object is exposed by substantially adjusting an exposure time based on the measurement result of the illuminance.   The exposure method according to claim 1, wherein in the exposing step, a plurality of objects including the object are sequentially exposed until the exposure is stopped in the releasing step. Each of the plurality of light sources is provided with a light-shielding device that blocks light from the light sources,
The exposure method according to any one of claims 1 to 4, wherein, in the opening step, the light-shielding device attached to the replaced light source is opened to release light of the replaced light source.   6. The exposure according to claim 5, wherein, in the step of turning off the light, before turning off the one light source, the light shielding device attached to the light source is closed to block light from the one light source. Method.   The exposure method according to claim 1, wherein in the step of turning on the light source, the light source is replaced after the one light source is cooled.   After the step of opening, the step of turning off, the step of exposing, the step of turning on, and the step of opening are repeated for at least one of the plurality of light sources excluding the replaced light source. The exposure method according to claim 1, further comprising a step.   After the opening step, the illuminance on the object is measured in a state where the plurality of light sources are turned on and the light of the plurality of light sources is opened, and the plurality of the light sources are measured based on the measurement result. The exposure method according to claim 1, wherein the object is exposed using a light source. Forming a pattern on the object using the exposure method according to any one of claims 1 to 9;
Processing the object on which the pattern is formed;
A device manufacturing method including: An exposure method that sequentially exposes a set of a plurality of objects using a plurality of light sources,
When the required number of light sources to be used for each of the plurality of object sets is less than the number of light sources that are lit among the plurality of light sources, at least a stabilization time required until the lit light sources are stabilized; An exposure method that turns off the remaining light sources other than the required number of light sources among the light sources that are turned on when the exposure processing is started in consideration of the processing time required for the exposure processing.   The exposure method according to claim 11, wherein when the processing time is longer than the stabilization time, the remaining light source is turned off.   The exposure according to claim 12, wherein the remaining light sources are turned off in consideration of the necessary number and the processing time for at least one group following the target group of the exposure process among the plurality of sets of objects. Method.   The remaining number of light sources is turned off when the required number for the subsequent group is also smaller than the number of light sources that are turned on and the processing time of the target group and the subsequent group is longer than the stabilization time. Item 14. The exposure method according to Item 13.   When the required number is larger than the number of light sources that are turned on, the light sources that are turned off among the plurality of light sources that are sufficient for the required number are included before the stabilization time for starting the exposure process. The exposure method according to any one of claims 11 to 14, wherein the light is turned on in a state where the light of the light source is blocked and the light of the light source that is turned on is released when the exposure process is started.   The exposure method according to claim 15, wherein the light from the plurality of light sources is opened and closed by opening and closing a light shielding member attached to each of the plurality of light sources.   The exposure method according to claim 11, wherein the required number is determined according to at least an exposure amount required for the exposure processing. Using the exposure method according to any one of claims 11 to 17 to form a pattern on an object;
Processing the object on which the pattern is formed;
A device manufacturing method including: An exposure apparatus that sequentially exposes a set of a plurality of objects using a plurality of light sources,
An exposure apparatus main body that includes an optical system, exposes the object through the optical system with light from the plurality of light sources, and forms an image of a pattern on the object;
When the required number of light sources to be used for each of the plurality of object sets is less than the number of light sources that are lit among the plurality of light sources, at least a stabilization time required until the lit light sources are stabilized; In consideration of the processing time required for the exposure process, a control system that turns off the remaining light sources other than the required number of light sources among the light sources that are turned on when the exposure process is started;
An exposure apparatus comprising:   The exposure apparatus according to claim 19, wherein the control system turns off the remaining light sources when the processing time is longer than the stabilization time.   The control system further turns off the remaining light sources by further considering the required number and the processing time for at least one group following the target group of the exposure processing among the plurality of sets of objects. 21. The exposure apparatus according to 20.   The control system, when the required number for the subsequent group is also less than the number of light sources that are turned on, and the processing time of the target group and the subsequent group is longer than the stabilization time, The exposure apparatus according to claim 21, wherein the light source is turned off.   When the required number is larger than the number of light sources that are turned on, the control system is in the light-off state among the plurality of light sources that is sufficient for the required number before the stabilization time for starting the exposure process. The light source is turned on in a state where a light shielding member that blocks light from the light source is closed, and when the exposure process is started, the light from the lighted light source is released by opening the light shielding member. The exposure apparatus according to any one of claims 22 to 22.   The exposure apparatus according to any one of claims 19 to 23, wherein the control system determines the required number according to at least an exposure amount required for an exposure process.

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