JPH1187237A - Alignment device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an alignment device, which can readily replace a light source such as a halogen lamp. SOLUTION: A using-time control part 91 controls the laminated using time of a halogen lamp in use by measuring and storing the conducting time of the halogen lamp in use at present. A using-time display part 92 display the laminated using time of the halogen lamp in use, so that a worker can understand. A replacement requirement discriminating part 95 discriminates whether the halogen lamp in use maintains the required performance or not, based on the laminated using time of the halogen lamp in use and the output of the detection of optical quantity from an light-quantity sensor 41. When it is discriminates that the change of the halogen lamp in use is required, a lamp holder 411 is made to rotate, and the halogen lamp in use is replaced by another lamp not in the using state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alignment apparatus for positioning an exposure apparatus for transferring a mask pattern onto a photosensitive substrate, and more particularly, to an alignment apparatus having a mechanism for replacing a halogen lamp and other light source components. is there.

[0002]

2. Description of the Related Art In an exposure apparatus, a circuit pattern drawn on an original called a mask is printed on a resist layer of a semiconductor wafer by using a projection lens and developed to form a resist pattern of a desired circuit. .

At this time, it is necessary to accurately overlap the circuit pattern already formed on the wafer with the light image of the circuit pattern to be exposed.

An apparatus required for such superposition is called an alignment apparatus. The alignment apparatus optically detects an alignment mark formed in advance on a wafer and generates a photoelectric signal corresponding to the mark profile. And a signal processing system for electrically processing this photoelectric signal by an appropriate algorithm to obtain a shift amount from the original position of the alignment mark, and a position of a wafer or a mask according to the obtained shift amount. And a positioning mechanism for precisely correcting the position.

Among these, an alignment sensor comprising an alignment optical system and a signal processing system is of an on-axis type which detects an alignment mark via a projection lens, and a microscope which is separately provided at a certain distance from the projection lens. There is an off-axis type that detects an alignment mark on a wafer via an objective lens.

As the latter off-axis type alignment sensor, for example, an FIA (field image sensor) is used.
Alignment). In such an alignment sensor, light having a broad wavelength distribution is used as mark illumination light, and the position of the alignment mark is measured by performing image processing on the alignment mark illuminated with the light. Then, the circuit pattern drawn on the mask is projected to a desired position on the wafer by correcting the measured position of the alignment mark by a baseline amount corresponding to the difference from the position of the circuit pattern drawn on the mask. be able to.

In the above-described alignment apparatus, a halogen lamp is used as a light source for generating light having a broad wavelength distribution. However, since the halogen lamp has a certain life (generally, about 2000 hours), it is necessary to use an appropriate lamp. It needs to be replaced at the right time. In this case, the operator checks the operation state of the alignment device to determine whether the halogen lamp needs to be replaced. When replacing the halogen lamp, the operation of the exposure apparatus was temporarily stopped, and the used halogen lamp was manually replaced with an unused one.

[0008]

However, the operation of checking the operation state of the alignment device and replacing the halogen lamp is complicated.

Usually, this type of exposure apparatus is used continuously for 24 hours in a mass production factory, and it is not desirable to stop the exposure apparatus due to maintenance or trouble of the alignment apparatus. It is desirable that the shorter the time, the higher the operation rate.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an alignment apparatus which can easily replace a light source such as a halogen lamp.

Another object of the present invention is to provide an alignment apparatus capable of replacing a light source without stopping the operation of the exposure apparatus.

[0012]

According to the present invention, there is provided an alignment apparatus for observing an alignment mark when a mask pattern is transferred onto a photosensitive substrate. An installation device (411) for providing two light source components (20a to 20d) and for exchanging the first or second light source component (20a to 20d) between an illuminable state and an unilluminable state; A timer (91) for measuring the use time of the first or second light source component (20a) installed in a state, and the first or second light source component (20a) installed in an illuminable state include a predetermined A monitor device (416) for monitoring whether or not performance is maintained; and the monitor device (416) installed in an illuminable state based on information from the timing device and the monitor device. A determination device (95) for determining the necessity of replacement of the first or second light source component (20a) and the installation device (411) are controlled based on a result of the determination by the determination device to be installed in a lighting enabled state. The first or second light source component (20a) is replaced with the second or first light source component (20b).
-20d) and a control device (97) for replacement.

In a preferred aspect, the control device (97) does not stop an exposure operation for transferring the pattern of the mask onto the photosensitive substrate, without stopping the light source component (20).
a) is exchanged (steps S31 and S33).

In a preferred aspect, the alignment device is an off-axis system that does not allow illumination light from the light source component to pass through a projection lens (PL) that transfers the pattern of the mask onto the photosensitive substrate. The control device (97) replaces the light source component while avoiding whether the alignment device is performing calibration (step S22) or detecting a specific alignment mark (step S23). It is characterized by.

In a preferred aspect, when the control device replaces the light source component (step S31), the calibration of the alignment device is redone (step S22).

In a preferred aspect, when the control device replaces the light source component immediately after the detection of the specific alignment mark by the alignment device (step S23) (step S33), the specific alignment mark by the alignment device is replaced. (Step S23).

In a preferred aspect, among the light source components attached to the installation device, the first or second light source components (20b to 20d) in a non-illuminable state apply the mask pattern to the photosensitive substrate. It is characterized in that it can be replaced with an inconvenient third light source component without stopping the exposure operation for transfer.

In a preferred aspect, the alignment device includes an optical sensor (34) for detecting the alignment mark as image information, and the light source component includes a wide wavelength band light source lamp (20) for illuminating the alignment mark. It is characterized by including.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION

[First Embodiment] FIG. 1 is a view for explaining the overall structure of an exposure apparatus incorporating the alignment apparatus of the first embodiment. The illumination light IL for exposure irradiates a pattern area PA provided on a reticle R, which is collectively called a mask, with a uniform illuminance distribution via a condenser lens CL. Pattern area P
The illumination light IL passing through A enters the projection lens PL and reaches a wafer W as a photosensitive substrate. Here, the projection lens P
Regarding L, the reticle R and the wafer W are conjugate to each other under the wavelength of the illumination light IL. The illumination light IL is Koehler illumination, and a light source image is formed at the center of the pupil EP of the projection lens PL.

The reticle R is held on a reticle stage RS which can be finely moved two-dimensionally. This reticle R
A reticle alignment mark formed therearound is detected by a reticle alignment system including a mirror 16, an objective lens 17, and a mark detection system 18, whereby the reticle alignment mark is positioned with respect to the optical axis AX of the projection lens PL.

The wafer W is mounted on a wafer stage ST which is two-dimensionally moved by a drive system 13. The coordinate values of the wafer stage ST are sequentially measured by the interferometer 12. The stage controller 14 controls the movement and positioning of the wafer stage ST by controlling the drive system 13 based on the coordinate calculation values and the like from the interferometer 12. On the wafer stage ST, a reference mark FM used for baseline measurement or the like described later is provided.

The exposure apparatus shown in FIG. 1 uses a TTL (Thro
A first alignment optical system 50 of a high the lens (high the lens) system and a second alignment optical system 60 of an off-axis system are provided, and these are appropriately used depending on conditions such as detection accuracy and detection speed (TTL system). The detailed principle of the alignment optical system and the off-axis type alignment optical system is described in JP-A-2-5410.
No. 3).

First, the first alignment optical system 50 will be described. Beam LB output from laser light source 1
Is red light such as a He-Ne laser where the resist has no photosensitivity. The beam LB passes through a beam shaping optical system 2 including a cylindrical lens and the like, and is incident on an objective lens 6 via a mirror 3a, a lens system 4, a mirror 3b, and a beam splitter 5. The beam LB emitted from the objective lens 6 is reflected by a mirror 7 inclined at 45 ° below the reticle R, and the optical axis AX is set around the field of view of the projection lens PL.
And incident in parallel. Beam L incident on projection lens PL
B illuminates the wafer W vertically through the center of the pupil EP of the projection lens PL. The projection lens PL re-images the slit-shaped spot light SP0 condensed by the objective lens 6 on the wafer W as the spot light SP.

In order to detect an alignment mark on the wafer W by the spot light SP, the wafer stage ST is moved horizontally with respect to the spot light SP. Spot light S
When P relatively scans the alignment mark of the periodic pattern formed around the shot area on the wafer W, specular reflected light, scattered light, diffracted light, etc. are generated from the alignment mark, and depending on the relative position of the alignment mark and the spot light SP. The amount of light changes. Such optical information travels backward along the light transmission path of the beam LB, passes through the projection lens PL, the mirror 7, and the objective lens 6, is reflected by the beam splitter 5, and reaches the light receiving element 8. The light receiving surface of the light receiving element 8 is arranged on a plane EP ′ substantially conjugate to the pupil EP of the projection lens PL, receives only scattered light or diffracted light from the alignment mark, and outputs a signal corresponding to the intensity.

The photoelectric signal from the light receiving element 8 is input to an LSA (laser step alignment) operation unit 9 together with a position measurement signal PDS from the interferometer 12. The LSA calculation unit 9 samples and stores the photoelectric signal waveform from the light receiving element 8 for the spot light SP based on the position measurement signal PDS, and analyzes the waveform to determine the center of the alignment mark as the spot light S.
The mark position information AP1 is output as the coordinate position of the wafer stage ST when it coincides with the center of P.

Next, the second alignment optical system 60 will be described. Light generated from the halogen lamp 20 built in the light source device 40 is similarly focused on one end surface of the optical fiber 22 by the condenser lens 21 built in the light source device 40. The light that has passed through the fiber 22 passes through a filter 23 that cuts the photosensitive wavelength (short wavelength) region of the resist layer and the infrared wavelength region, and reaches a half mirror 25 via a lens system 24. The illumination light reflected here is substantially horizontally reflected by the mirror 26, then enters the objective lens, and is fixed to the periphery of the lower part of the barrel of the projection lens PL so as not to block the field of view of the projection lens PL. The wafer W is reflected vertically by the prism mirror 28 and irradiates the wafer W vertically. Note that the objective lens 27 is a telecentric system, and an image of the exit end of the fiber 22 is formed on the surface 27a of the aperture stop (same as the pupil), and Koehler illumination is performed. Further, the optical axis of the objective lens 27 is set to be vertical on the wafer W, so that when the alignment mark is detected, the mark position does not shift due to the tilt of the optical axis.

The reflected light from the wafer W is transmitted to the objective lens 2
7 and an image formed on the index plate 30 by the lens system 29 through the half mirror 25. The index plate 30 is arranged conjugate with the wafer W by the objective lens 27 and the lens system 29, and has a linear index mark in a rectangular transparent window. The image of the wafer W-shaped alignment mark is
An image is formed in the transparent window of No. 0. The alignment mark image and the index mark form an image on an image sensor 34 such as a CCD camera via relay systems 31 and 32 and a mirror 32. The video signal from the image sensor 34 is transmitted to the FIA operation unit 35
And a position measurement signal PDS from the interferometer 12. The FIA operation unit 35 calculates the displacement of the alignment mark image with respect to the index mark formed on the index plate 30 based on the waveform of the video signal, and obtains the position measurement signal PDS.
From the stop position of the wafer stage ST represented by
The information AP2 about the mark center detection position of the wafer stage ST when the alignment mark image is accurately located at the center of the index mark is output. In the above, the illumination light of the wafer W that has passed through the filter 23 illuminates the local area (smaller than the shot area) including the alignment mark of the wafer W with substantially uniform illuminance. At this time, the wavelength range of the illumination light is set to a width of about 200 nm.

Although FIG. 1 shows only one pair of the first alignment optical system 50 and the second alignment optical system 60, one pair of the same structural optical systems is provided in the direction perpendicular to the plane of the drawing. Have been.

The main control system 80 controls the first alignment optical system 50, the second alignment optical system 60, the stage controller 14, and the like.

The main control system 80 constantly receives position information PDS from the interferometer 12. Mark position information AP1 from LSA operation unit 9 and FIA operation unit 3
The mark position information AP2 from No. 5 is also input to the main control system 80 and is stored and held as alignment data. The alignment data stored in this manner is obtained by converting the actual shot array coordinate value from the designed shot array coordinate value to be exposed on the wafer W using a statistical calculation method (EGA; enhancement global alignment). It is used when calculating. The shot array coordinate values thus calculated are used when performing stepping control (that is, shot exposure) of the wafer stage ST via the stage controller 14.

In addition to the functions described above, the main control system 80 has a shot map data function for storing coordinate values (design values) of shot arrangements to be exposed on the wafer W, and alignment for the wafer W. It also has an alignment map data function for storing shot array coordinate values (design values), a sequence controller function for controlling movement of the wafer stage ST during alignment and during step-and-repeat shot exposure. .

The lamp control processing section 90 operates in cooperation with the main control system 80, and manages the state of the halogen lamp 20 and replaces the halogen lamp 20 at an appropriate timing, as will be described later in detail.

The reference mark FM formed on the wafer stage ST is used for baseline measurement required for calibration of the second alignment optical system 60. Here, the baseline measurement refers to the center position of the image of the reticle by the exposure light, the detection center of the spot light SP of the first alignment optical system 50, or the detection center of the second alignment optical system 60 (the center of the index plate 30). Distance in the wafer W plane (baseline amount)
Is calculated.

FIG. 2 is a view for explaining the main part of the light source device 40 of the second alignment optical system 60. FIG. 2 (a)
FIG. 2B is a diagram illustrating an internal structure of the light source device 40, illustrating an external appearance of a main part thereof.

The halogen lamp 20a used for the operation is 1
On the other hand, the lamp holder 411 holding the halogen lamp 20a has a structure in which three unused halogen lamps 20b, 20c, and 20d can be attached.

The lamp holder 411 is a turret-type device. By rotating the lamp holder 411 about a holder rotation shaft 412, the halogen lamp 20a installed in a usable state can be turned into another halogen lamp 2 other than the usable state.
0b, 20c, and 20d. The usable halogen lamp 20a is stored in the lamp houses 413 and 414 as shown.

On the inner walls of the lamp houses 413 and 414,
A light amount sensor 416 is attached, and detects an electric signal corresponding to the light amount of the halogen lamp 20a in use. The lamp control processing unit 90 determines whether or not the halogen lamp 20a in use maintains the required performance based on the detection signal of the light amount sensor 416.

Note that even while the halogen lamp 20a is being used, the halogen lamps 20b, 20c, and 20d that are not in the other usable states are in the lamp house 413,
414. For this reason, of the halogen lamps 20b, 20c, and 20d, those that have been used due to their life can be replaced with unused halogen lamps at an appropriate timing.

FIG. 3 is a view for explaining a mechanism for replacing the usable halogen lamp 20a with a used one of the halogen lamps 20b, 20c and 20d. FIG. 3A shows the appearance, and FIG. 3B shows the inside.

The movable part 41 of the lamp houses 413 and 414
Numeral 4 is slidable along the optical axis. When the halogen lamp is replaced, the movable portion 14 of the lamp house slides to expose the usable halogen lamp 20a as shown in the figure. Next, by rotating the lamp holder 411 by 90 ° or 180 ° about the rotation shaft 412 provided on the lamp holder 411, the usable halogen lamp 20a can be replaced with another halogen lamp 20b, 20c, 20d. Becomes

As described above, when the number of the halogen lamps to be mounted on the lamp holder 411 is four, the three halogen lamps 20b, 20c and 20d are spare parts in addition to the halogen lamp 20a actually used. Therefore, the halogen lamps 20b, 20c, 20
It is sufficient to replace used parts at a time after all of d has been used. This makes it possible to reduce the replacement work itself. In addition, the timing of performing such replacement work of the consumables depends on the halogen lamp 2 being used.
There is no need to match the timing when 0a becomes unusable or the timing between processing sequences of the exposure apparatus.
Since it is not necessary to stop the exposure apparatus when replacing a used halogen lamp, an operation method in which consumable parts of all the exposure apparatuses are periodically replaced becomes possible.

In recent years, as the miniaturization of semiconductors has progressed, higher cleanliness has been required for clean rooms for manufacturing semiconductors, so that humans are prevented from entering the clean rooms as much as possible. It is a situation that it is desirable to do. As described above, in this exposure apparatus, it is possible to reduce the frequency of replacement work of the light source parts for the alignment sensor, and if it is possible to replace all the key parts of all the exposure apparatuses with one replacement work, the result is As a result, the frequency of human entry into the clean room can be reduced.

FIG. 4 is a block diagram illustrating the configuration of the lamp control processing unit 15. The use time management unit 91 manages the cumulative use time of the halogen lamp 20a by measuring and storing the current supply time of the halogen lamp 20a currently in use. The use time display section 92 displays the accumulated use time of the halogen lamp 20a so that the operator can recognize it. The replacement necessity determining unit 95 determines whether or not the halogen lamp 20a maintains the required performance based on the accumulated use time of the halogen lamp 20a and the light amount detection output from the light amount sensor 416. When it is determined that the halogen lamp 20a needs to be changed, the lamp holder 411 is rotated to replace the halogen lamp 20a in use with another one.

FIG. 5 is a flowchart for explaining the sequence of the wafer exposure process of the exposure apparatus of FIG.

The wafer exposure process is usually performed continuously on a plurality of wafers W, and a position measurement process is performed on each alignment mark on the wafer W using an alignment sensor for each wafer W. After that, a shot exposure process is performed on each exposure region on the wafer W. In the following description, a wafer exposure process in the case where alignment is performed using the off-axis type second alignment optical system 60 will be described.

First, in step S20, an unexposed wafer W is set on wafer stage ST. Next, in step S21, it is determined whether calibration of the alignment sensor is necessary. For example, when the number of wafers W subjected to the exposure processing after the last calibration and the elapsed time from the last calibration exceed a predetermined upper limit, it is determined that the calibration is necessary.

If it is determined in step S21 that the alignment sensor needs to be calibrated, the process proceeds to step S21.
At 22, the alignment sensor is calibrated. Specifically, a baseline amount corresponding to the difference between the center position of the reticle image by the exposure light and the detection position of the second alignment optical system 60 is measured.

Next, in step S30, it is determined whether or not the currently used halogen lamp 20a needs to be replaced. For example, when the cumulative use time of the halogen lamp 20a currently installed in a usable state exceeds a predetermined upper limit, it is determined that the halogen lamp needs to be replaced. Also, when it is determined that the halogen lamp 20a has not completely lost its performance but it is time to replace the halogen lamp 20a based on a criterion such as a decrease in the amount of light of the halogen lamp 20a,
It is determined that the lamp needs to be replaced. Further, when the halogen lamp 20a suddenly loses its performance due to lamp burnout or the like, it is determined that the lamp needs to be replaced.

If it is determined in step S30 that the lamp needs to be replaced, then in step S31 the halogen lamp 20a installed in the currently usable state is replaced with the unused halogen lamp 20b, 20c, 20d which is not in the other usable state. Replace with one. In this case, the process returns to step S22, and the calibration of the alignment sensor is executed again. The reason why the calibration process immediately before the lamp replacement is determined to be necessary is performed again because the process performed using the halogen lamp 20a immediately before the lamp replacement may not have a normal result. This is because it is possible to continue the appropriate processing by retrieving the result that may not be normal.

If it is determined in step S32 that the lamp does not need to be replaced, then in step S23 the n-th lamp (n = n)
The position of the alignment mark (1, 2, 3 ...) is measured. Specifically, a specific image among a plurality of alignment marks is detected using the second alignment optical system 60,
The position of the alignment mark is measured.

Next, in step S32, it is determined whether or not the currently used halogen lamp 20a needs to be replaced. The criterion is the same as in step S30. When it is determined in step S32 that the lamp needs to be replaced, in step S33, the halogen lamp 20a installed in the currently usable state is replaced with the unused halogen lamp 20b, 20c, 20d among the other usable lamps. Replace with something. In this case as well, the process returns to step S23, and the position measurement of the alignment mark performed immediately before is executed again.

If it is determined in step S30 that the lamp need not be replaced, it is determined whether the alignment mark whose position has been measured immediately before is the last mark. If not, the flow returns to step S23 to return to step S23. Is measured, and if it is the last mark, the process proceeds to step S24, where the m-th (m
= 1, 2, 3 ...).

The above-described shot exposure is repeated, and if it is determined in step S35 that the immediately preceding shot exposure is the final shot, the process proceeds to step S36, where the currently exposed wafer W is the final wafer. It is determined whether or not there is. If it is not the last wafer, the flow returns to step S20 to replace the wafer W, and the above-described processing is repeated. If it is the last wafer, the process ends.

The replacement of the halogen lamp 20a can be executed in parallel with the normal operation at a timing when the alignment sensor is not used, such as when the exposure apparatus is stopped or during shot exposure. is there.

Further, among the halogen lamps 20b, 20c and 20d which are not in a usable state, those which have exceeded their lifespan, specifically those which have burned out or deteriorated in performance, remove unused halogen lamps during the operation of the exposure apparatus. Can be replaced with a lamp.

FIG. 6 is a flowchart for explaining a modification of the sequence of the exposure processing shown in FIG. This sequence corresponds to a case where the replacement of the halogen lamp 20a causes a change in the position detection characteristics of the alignment sensor.

In this sequence, if it is determined in step S32 that the lamp needs to be replaced during the alignment mark position measurement process, the lamp is replaced in step S31, and the process returns to step S22 to return to the alignment sensor calibration process. Is executed again. And
The position detection of the alignment mark shown in step S23 is repeated from the first mark. As a result, it is possible to correct the characteristic change of the sensor caused by the lamp replacement and to continue the appropriate processing.

In this case, even when the lamp is replaced while the exposure apparatus is stopped or during the shot exposure processing (step S24) in parallel with the normal operation, the alignment sensor is used for the next wafer W. Therefore, calibration of the alignment sensor is required. For this reason, in step S121, as a criterion for determining the necessity of calibration of the alignment sensor, step S21 in FIG.
In addition to the criterion in the case of, there is a matter of whether or not the lamp has been replaced since the last calibration was performed.If such a lamp replacement has been performed, the calibration is performed. Judgment is made.

FIG. 7 is a view for explaining a modified example of the lamp holder 411 shown in FIG. 2 and FIG. In the illustrated lamp holder 411, the halogen lamps 20a, 20b, 20
Status indicators 413a, 413a, 4b, 4c, and 4c indicating whether each halogen lamp is unused or used near c and 20d.
13b, 413c and 413d are added. The status indicators 413a, 413b, 413c, and 413d are:
Each shows the state of the lamps 20a, 20b, 20c, 20d. In this case, the lamp control processing unit 90 also manages the state of each of the halogen lamps 20a, 20b, 20c, and 20d, and changes the state indicator such as, for example, blue when not used and red when used. This allows the operator to recognize the state of each halogen lamp, thereby improving lamp replacement workability.

[Second Embodiment] FIG. 8 is a view for explaining the main parts of an exposure apparatus incorporating the alignment apparatus of the second embodiment. This exposure apparatus is a second alignment optical system 6 using the FIA method in the alignment apparatus of the first embodiment.
0 is diffracted by irradiating the laser beam to the alignment mark.
This is a modification of the second alignment optical system 160 of the LSA system for detecting scattered light, and the description of other common parts will not be repeated. The second alignment system has an off-axis arrangement.

The beam LB2 from the laser light source 161a
Is red light such as a He-Ne laser where the resist has no photosensitivity. The beam LB2 passes through the beam shaping optical system 162, and passes through a pair of beam splitters 165 and 169.
Through the objective lens 166. Objective lens 16
The beam LB2 emitted from 6 is reflected by a mirror 167 inclined at 45 ° below the lens barrel of the projection lens PL, enters the outside of the projection lens PL in parallel with the optical axis AX, and enters a slit on the wafer W. Of the spot light SP.

In order to detect an alignment mark on the wafer W by the spot light SP, the wafer stage ST is moved horizontally with respect to the spot light SP. Spot light S
When P relatively scans the alignment mark on the wafer W, scattered light, diffracted light, and the like are generated from the alignment mark, and the light amount changes depending on the relative position between the alignment mark and the spot light SP. Such optical information travels backward along the light transmission path of the beam LB2, passes through the mirror 167 and the objective lens 166, is reflected by the beam splitter 165, and reaches the light receiving element 168. The light receiving surface of the light receiving element 168 receives only scattered light and diffracted light from the alignment mark.

Each photoelectric signal from this light receiving element 8 is
By the same processing as that of the first alignment optical system 50 described in the embodiment, the wafer stage ST when the center of the alignment mark coincides with the center of the spot light SP
The mark position information AP2 is output as the coordinate position of.

The intensity of the beam LB2 output from the laser light source 161a is reflected by a beam splitter 169 and monitored by a light amount sensor 416 '. When the output of the light amount sensor 416 ′ detects exhaustion such as performance deterioration of the laser light source 161a, or when the usage time of the laser light source 161a reaches the upper limit, the laser light source 161 being used is
It is determined that replacement of a is necessary. When the light source needs to be replaced in this way, the laser light source 161a in use is rotated to rotate the lamp holder 411 to another laser light source 161b,
Exchange with 161c and 161d.

Although the present invention has been described with reference to the embodiment, the present invention is not limited to the above embodiment. For example, in the alignment exposure apparatus of the first embodiment, although the FIA type is used as the second alignment optical system 60, the frequency is slightly changed to a diffraction grating alignment mark formed on the wafer W. An LIA (Laser Interferometric Alignment) method (Japanese Patent Laid-Open No. 61-215905) in which laser light is irradiated from two directions and two generated diffracted lights interfere with each other to detect position information of an alignment mark from its phase reference)
It is good. In the above description, the FIA method is used as the second alignment optical system of the off-axis method,
Although the LIS system and the LIA system are used, they can be appropriately used depending on various alignment characteristics such as detection accuracy and detection speed required for alignment processing.

[0066]

As is apparent from the above description, according to the alignment device of the present invention, the control device controls the installation device based on the judgment result of the judgment device, and the first or the second device installed in the illuminable state. Since the second light source component is replaced with the second or first light source component, the workability of replacing the light source component is enhanced.
In addition, the stop time of the exposure apparatus can be reduced as compared with the case where a person performs replacement work.

According to the preferred embodiment, the operation of the exposure apparatus does not stop when the light source component is replaced, so that the operation efficiency of the exposure apparatus is increased. That is, the light source component of the alignment device is used only in a part of the exposure processing sequence of the exposure device, and in the case of such a light source component, the light source component falls within the time when the light source component is not used in the sequence. If you replace the light source parts like this,
Light source components can be replaced without stopping the exposure apparatus.

According to a preferred embodiment, the control device replaces the light source component while avoiding the case where the alignment device is performing calibration or detection of a specific alignment mark. Light source components can be automatically replaced while not in use.

Further, according to the preferred embodiment, the calibration of the alignment device is performed again after the replacement of the light source components. Therefore, even when the characteristics of the alignment device change due to the replacement of the light source components, the accuracy of the calibration can be maintained. it can.

According to a preferred embodiment, when the control device replaces the light source component immediately after the detection of the specific alignment mark, the detection of the specific alignment mark is performed again. In this case, the accuracy of position detection can be maintained.

According to the preferred embodiment, the first or second light source component in the non-illuminable state can be replaced with an unused third light source component without stopping the exposure operation. Operating time can be extended.

According to a preferred embodiment, the alignment device includes an optical sensor for detecting the alignment mark as image information, and the light source component includes a wide-wavelength light source lamp for illuminating the alignment mark. The replacement of the light source lamp of the alignment apparatus of the type performing the above is facilitated.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an overall structure of an exposure apparatus according to a first embodiment.

FIG. 2 is a diagram illustrating a main part of the exposure apparatus of FIG.

FIG. 3 is a diagram for explaining the operation of the part shown in FIG. 2;

FIG. 4 is a block diagram illustrating a configuration of a lamp control processing unit in FIG. 3;

FIG. 5 is a flowchart illustrating an exposure operation of the exposure apparatus of FIG.

FIG. 6 is a flowchart obtained by modifying the flowchart of FIG. 5;

FIG. 7 is a diagram illustrating a modification in which a status indicator is added to the lamp holder shown in FIGS. 2 and 3.

[Explanation of symbols]

 Projection lens PL Reticle R Wafer W First alignment optical system 50 Second alignment optical system 60 LSA operation unit 9 FIA operation unit 35 80 Main control system 90 Lamp control processing unit 91 Usage time management unit 92 Usage time display unit 93 Parts replacement warning Display unit 95 Effect necessity determination unit 97 Lamp holder control unit 411 Lamp holder 413 Lamp house 414 Lamp house (movable part) 416 Light intensity sensor

Claims (7)

[Claims] 1. An alignment apparatus for observing an alignment mark when a mask pattern is transferred onto a photosensitive substrate, wherein first and second light source parts for illuminating the alignment mark are provided, and the first or second light source part is provided. An installation device for exchanging the light source between an illuminable state and a non-illumination state; a timing device for measuring the use time of the first or second light source component installed in the illuminable state; A monitoring device that monitors whether the first or second light source component has maintained a predetermined performance, and installed in an illuminable state based on information from the timing device and the monitoring device. A judging device for judging the necessity of replacement of the first or second light source component; and Alignment device, characterized in that it comprises a control device for exchange with the second or first light source part of the first or second light source part was. 2. The alignment apparatus according to claim 1, wherein the control device replaces the light source components without stopping an exposure operation for transferring the pattern of the mask onto the photosensitive substrate. 3. The alignment device according to claim 1, wherein the projection lens transfers the pattern of the mask onto the photosensitive substrate.
An off-axis system that does not allow illumination light from the light source component to pass therethrough, and the control device avoids the case where the alignment device is during calibration or detection of a specific alignment mark. 3. The alignment device according to claim 2, wherein the light source component is replaced. 4. The alignment device according to claim 3, wherein when the control device replaces the light source component, calibration of the alignment device is performed again. 5. The method according to claim 3, wherein when the control device replaces the light source component immediately after the detection of the specific alignment mark by the alignment device, the detection of the specific alignment mark by the alignment device is performed again. The alignment apparatus according to any one of the preceding claims. 6. The first or second light source component in a non-illuminable state among the light source components attached to the installation device, without stopping an exposure operation of transferring the pattern of the mask onto the photosensitive substrate. 2. The alignment device according to claim 1, wherein the alignment device can be replaced with a third light source component for inconvenience. 7. The alignment apparatus according to claim 1, wherein the alignment device includes an optical sensor that detects the alignment mark as image information, and the light source component includes a light source lamp of a wide wavelength band that illuminates the alignment mark. The alignment apparatus according to any one of the preceding claims.