JPH09275058A - Projected exposure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To execute projection exposure through precise alignment of reticle pattern in a shot region on a wafer. SOLUTION: Using a sheet of reticle where shot pattern and alignment mark are drawn in the space isolating condition, only the alignment marks M1 to M8 are exposed by projection to the circumference region 61 of a wafer 12 and only the shot pattern of the first layer is exposed by projection to the shot regions S1, S2, S3,... of the wafer 12. For the exposure of the second layer, the photosensitive agent of the circumference region 61 of the wafer 12 coated with the photosensitive agent is removed to expose the alignment marks M1 to M8 and the alignment is performed using such alignment mark to expose the shot pattern of the second layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for projecting and exposing a pattern image on a photosensitive substrate using an exposure apparatus in a process of manufacturing a semiconductor device, a liquid crystal display device, or the like.

[0002]

2. Description of the Related Art In manufacturing a semiconductor element or a liquid crystal display element, a semiconductor wafer or a glass plate coated with a photoresist having an image of a fine pattern formed on a mask or reticle (hereinafter referred to as a reticle) using an exposure apparatus. Projection exposure is performed on a photosensitive substrate (hereinafter, referred to as a wafer). The pattern of the reticle is projected and exposed by aligning the reticle and the wafer with high accuracy (alignment) by using, for example, a step-and-repeat type exposure apparatus, and superimposing them on the pattern already formed on the wafer. . The requirements for the accuracy of the alignment have become more severe as the patterns have become finer, and various methods have been devised for the alignment.

As an alignment method, a laser beam is irradiated on an alignment mark in a dot row on a wafer,
LSA (Laser Step Aligmnent) method of detecting the mark position using light diffracted or scattered by the mark,
FIA (Field Image Al) that measures the position of a mark by performing image processing on image data of an alignment mark captured by illuminating with light having a wide wavelength bandwidth using a halogen lamp or the like as a light source.
Ignition) method, or irradiating a diffraction grating alignment mark on a wafer with laser light with a slightly changed frequency from two directions, causing the two generated diffraction lights to interfere, and measuring the position of the alignment mark from its phase LIA
(Laser Interferometric Alingnment) method, etc.

[0004] Alignment using exposure light has also been proposed. According to the alignment using the exposure light, the positional relationship between the reticle and the shot area on the wafer can be simultaneously measured from above the reticle. Moreover, since the aberration of the projection lens is also the exposure light, it is affected by the same effect as the image formation relationship. Therefore, the alignment by the exposure light is an alignment method having no offset for so-called chromatic aberration.

In these optical alignments,
The alignment mark on the wafer coated with the resist for exposure is detected, and the position coordinates of the alignment mark are measured to obtain the position of the shots to be overlapped. After that, the wafer is moved by the wafer stage so that the pattern image of the reticle overlaps the shot position, and the pattern image of the reticle is projected and exposed. Alignment marks are usually 20-
The alignment mark is formed by a step difference of about 300 nm, and therefore, the resist is applied on the alignment mark unless the resist is peeled off.

The optical alignment system detects alignment marks of four or more different shot areas in the wafer, calculates how the shot areas are arranged in the wafer, and obtains arrangement coordinates. Each shot is sequentially exposed in the shot area on the wafer by moving the wafer stage based on the coordinates.

[0007]

As described above, alignment is performed using a non-contact optical alignment system. In the LSA type alignment and the like, laser light is used to reduce the beam diameter. However, since a resist is applied on the alignment mark, when monochromatic light such as laser light is used as alignment light, multiple interference occurs in the resist, noise is generated, and a change in the thickness of the resist and minute marks on the mark are caused. The intensity distribution of the diffracted light generated from the alignment mark changes due to the influence of the asymmetry. As a result, the detection accuracy of the alignment mark decreases.

In order to prevent interference, the wavelength band of the alignment light is broadened.
However, when light in a broad wavelength band is used as the alignment light, the alignment optical system is restricted in terms of chromatic aberration, and it is difficult to freely design. Also, when the step of the alignment mark is low, it is difficult to obtain a contrast with light in a broad wavelength band, and it becomes difficult to detect the alignment mark.

In the exposure light alignment method, when the resist is applied on the alignment mark, the exposure light is absorbed as long as the resist has a photosensitive performance.
A sufficient alignment signal cannot be obtained. Further, as the exposure proceeds, the absorption rate of the resist changes, and the alignment signal changes with time. That is, the exposure light alignment method can be the simplest alignment method because the reticle and the wafer can be observed without an optical offset, but practical use has been difficult due to the exposure of the resist.

The present invention has been made in view of the above problems of the prior art, and it is an object of the present invention to provide a method capable of aligning a reticle pattern on a shot area on a wafer with high accuracy and performing projection exposure. To aim.

[0011]

When monochromatic light such as laser light is used as the alignment light, the alignment accuracy is lowered because the resist is applied on the alignment mark. Therefore, by removing the resist on the alignment mark, multiple interference of laser light can be eliminated, and alignment accuracy can be improved.

However, the size of the alignment mark in each shot area of the wafer is usually smaller than 100 μm square, and it is difficult to remove the resist only at the alignment mark portion. As one method of removing the resist on the alignment mark, a method of exposing only the alignment mark portion prior to the alignment and developing it once to remove the resist on the alignment mark can be considered. However, this method cannot be adopted because there is a problem in controlling the resist film thickness and deteriorating the accuracy of resist image formation because the developing solution is applied to the place where the resist is required. As another method, a method of sublimating or evaporating and removing only the resist on the alignment mark using an excimer laser has been considered, but this is disadvantageous in that the size of the apparatus becomes large and the throughput is reduced. There is also a problem of contamination by the evaporated resist.

By the way, the resist on the edge of the wafer is easily peeled off, and if the peeled resist adheres to the shot area, defective exposure of the pattern occurs in the shot area.
The resist in the peripheral area of the wafer tends to come off recently. Therefore, if an alignment mark having a known positional relationship with the shot areas arranged inside the wafer is formed in the area where the resist is removed in the peripheral area of the wafer, a new processing step is added to the exposure step. Also, the resist on the alignment mark can be removed. Then, it is possible to perform high-precision alignment using monochromatic light using the alignment marks exposed by stripping the resist. Further, a sufficient alignment signal can be obtained by the exposure light alignment method. The present invention has been made based on such a study.

That is, the projection exposure method of the present invention is the first
Using the first reticle in which the shot pattern and the alignment mark are spatially separated and drawn, only the alignment mark is projected and exposed onto the peripheral region of the substrate (for example, a wafer) coated with the photosensitive agent, and the substrate is exposed. Exposure step of the first layer for projecting and exposing only the first shot pattern onto the shot area, and after removing the photosensitizer in the peripheral area of the substrate coated with the photosensitizer, the second shot pattern is drawn. Second reticle is aligned using the alignment mark previously formed in the peripheral area of the wafer, and a second layer exposure step of projecting and exposing the second shot pattern onto the shot area of the substrate is performed. It is what

Between the exposure step of the first layer and the exposure step of the second layer, a step of developing the photosensitive agent exposed in the exposure step of the first layer and a new exposure of the substrate for the exposure of the second layer. In addition to the step of applying the agent, a film forming step necessary for device manufacturing, an ion implantation step, a substrate processing step such as a heat treatment step, etc. are interposed at any time.

The first shot pattern drawn on the first reticle and the alignment mark have a known positional relationship. In the exposure process of the first layer, the reticle blind is used to select the alignment mark and the first shot pattern. That is, the first exposure step is performed using one reticle on which the shot pattern and the alignment mark are drawn in a known positional relationship without unloading the reticle or the substrate from the projection exposure apparatus. Therefore, the positional relationship between the first shot pattern on the substrate and the alignment mark is known with sufficient accuracy.

The first reticle is used to project and expose the first shot pattern on the substrate in a predetermined arrangement, and the alignment marks are projected and exposed to at least three positions in the peripheral region of the substrate, and then the substrate is placed on the stage of the exposure apparatus. It is unloaded from above and the required processing is performed. Then, the substrate is coated with a photosensitizer for the next exposure, the photosensitizer in the peripheral region is removed, and then the substrate is loaded on the stage of the exposure apparatus.

In the exposure of the second layer, the alignment mark exposed by removing the photosensitizer is detected by the alignment system of the projection exposure apparatus, and the array coordinate value of the shot area of the substrate is determined based on the position information of the alignment mark. Is calculated to align the reticle pattern with the shot area.

According to the present invention, since there is no resist on the alignment mark, it is possible to perform highly accurate alignment using light with good monochromaticity such as laser light, and to effectively use an alignment mark with a low step. Can be detected. Further, even if the height or depth of the alignment mark has asymmetry, it is possible to correct the alignment error caused by the asymmetry of the alignment mark by measuring the step in advance. The alignment can be performed with high accuracy without being affected by the asymmetry of the alignment mark and the asymmetry of the resist coating.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic view of an example of an exposure apparatus used in the projection exposure method of the present invention. Illumination light emitted from an illumination light source 1 such as an ultra-high pressure mercury lamp is elliptical mirror 2
In response to the opening / closing operation of the shutter 3 by the shutter driving means 3a, the light is reflected by the reflecting mirror 4 and enters the wavelength selection filter 5. The wavelength selection filter 5 passes only the light of the wavelength required for exposure, and the illumination light that has passed through the wavelength selection filter 5 is adjusted by the fly-eye integrator 6 into a luminous flux having a uniform illuminance distribution and reaches the reticle blind 7. To do. The reticle blind 7 changes the size of the opening S to adjust the illumination range on the reticle 10 by the illumination light.

The illumination light that has passed through the opening S of the reticle blind 7 is reflected by the reflecting mirror 8 and enters the lens system 9, and the lens system 9 forms an image of the opening S of the reticle blind 7 on the reticle 10. , The desired area of reticle 10 is illuminated. The image of the shot pattern or alignment mark existing in the illumination range of the reticle 10 is imaged on the wafer 12 coated with the resist by the projection optical system 11, whereby the reticle 1 is formed on a specific area of the wafer 12.
The pattern image of 0 is exposed.

The wafer 12 is held on the stage 13 by vacuum suction. The stage 13 has a well-known structure in which a pair of blocks movable in directions orthogonal to each other are superposed, and the stage 13 is driven by a drive means 21 such as a motor to move the stage 13 within the stage movement coordinate system. The position, and hence the shot position on the wafer 12 that overlaps the exposure field of the projection optical system 11 is adjusted. The position of the stage 13 in the stage moving coordinate system is a laser interferometer 20 that emits a laser beam 15 toward a movable mirror 14 fixed to the stage 13 and measures a distance based on the interference between the reflected beam and the incident beam. Detected in.

The measurement value of the laser interferometer 20 is sent to the stage control system 36, and the stage control system 36 controls the stage driving means 21 based on the information. Further, information on the measurement values of the laser interferometer 20 is supplied from the stage control system 36 to the main control system 37, and the main control system 37 controls the stage control system 36 based on the information.

This projection exposure apparatus is provided with, for example, a TTR (through the reticle) type reticle alignment sensor 31 and an off-axis type wafer alignment sensor 32 for aligning the reticle 10 and the wafer 12. Has been. The alignment method of the reticle alignment sensor 31 of the TTR method includes:
An LSA method and an LIA method using a He-Ne laser or the like, or an exposure light alignment method using exposure light is preferable. Particularly, KrF (krypton fluoride), ArF
Projection optical system 11 for (argon fluoride) excimer laser
Is adopted, the He-Ne laser and KrF, Ar
Since the wavelength differs greatly from that of the F excimer laser, the exposure light alignment method is preferable in view of the chromatic aberration of the projection optical system 11. Further, when the exposure light alignment method is used, it is not necessary to consider the offset and it is not necessary to manage the so-called baseline.

The reticle alignment sensor 31 indicates the positional relationship (deviation amount) between the alignment mark formed on the reticle 10 and the reference mark on the reference mark member 33 or the wafer 12 observed through the projection optical system 11. measure. In the exposure light alignment method, an image sensor (CC
By displaying on a monitor using D), the positional relationship can be directly observed.

As an alignment method for the off-axis type wafer alignment sensor 32, an FIA method, an LSA method, an LIA method, or an exposure light alignment method using exposure light can be applied. Since the off-axis alignment method is often used for pre-alignment (simple positioning), the FIA method is preferable.

At the time of alignment, the position of the alignment mark formed on the wafer is detected by using one of these alignment sensors 31 and 32, and based on the detection result, it is formed in the shot area of the wafer 12 in the previous step. Accurately align the formed pattern with the pattern on the reticle. Detection signals from these alignment sensors 31 and 32 are processed by an alignment control system 35, and the alignment control system 35 is controlled by a main control system 37. A reference mark member 33 having a surface having the same height as the surface of the wafer 12 is fixed on the stage 13, and a mark serving as a reference for alignment is formed on the surface of the reference mark member 33.

As shown in FIG. 2, the reticle blind 7 forms a rectangular opening S by combining a pair of blades 7a and 7b bent in an L shape in a state of being orthogonal to the optical axis AX of the illumination light. The positions of the blades 7a and 7b are adjusted by the drive mechanisms 18a and 18b shown in FIG.
Change the size of

As shown in FIGS. 3 and 4, the drive mechanism 18
a and 18b are obtained by superimposing a second block 711 and a third block 712 on a first block 710 to which the blades 7a and 7b are fixed, and using a feed mechanism (not shown) combining a DC servo motor and a ball screw. ,
The first block 710 is moved along the guide grooves y1 and y2, and the second block 711 is moved along the guide grooves x1 and y2.
The blades 7a and 7b are moved along a plane perpendicular to the optical path of the illumination light by moving the blades along x2. As shown in FIG. 4, the drive mechanisms 18a and 18b are arranged on opposite sides of the blades 7a and 7b, and the third blocks 712 are integrally fixed to the main body of the exposure apparatus by a frame (not shown). .

Shutter drive means 3a and drive mechanism 18
a and 18b are controlled by the stage control system 36. The stage control system 36 instructs the drive mechanisms 18 a and 18 b to set the reticle blind 7 for the pattern area of the reticle 10 to be exposed, and the stage drive means 2
1, the stage 37 is moved to align the shot area of the wafer 12 with the exposure area of the projection optical system 11, and then the shutter drive means 3a is instructed to open the shutter 3 for a predetermined time. The shot pattern on the reticle 10 is exposed in the shot area on the upper surface 12.

FIGS. 5A and 5B are schematic views of a resist coater for applying a resist on a wafer. FIG. 5 (a)
The resist coater 40 includes a rotary support 41 for vacuum-sucking and rotating the wafer 12, and a resist jetting jet, which is located above the rotary support 41 and coaxially with the rotation axis thereof, and jets a resist solution to the central portion of the wafer 12. A nozzle 42 and a solvent jet nozzle 43 for jetting a resist solvent into the peripheral area of the wafer 12 are provided. The resist solution is ejected from the resist ejection nozzle 42 to the rotating wafer 12 fixed to the rotation support table 41, and thereby the wafer 1 is rotated.
On the surface of No. 2, a resist is spin-coated to a uniform thickness. Thereafter, the solvent in the resist is jetted and sprayed from the solvent jet nozzle 43 to the peripheral region of the wafer to perform edge rinsing, whereby the resist in the peripheral region of the wafer can be removed.

In addition to the method of spraying a solvent, it is also possible to remove the resist in the peripheral area of the wafer by using the peripheral exposure apparatus using the exposure light shown in FIG. 5B. FIG.
In (b), the resist coater 400 removes the wafer 12
Is vacuum-sucked on the rotation support table 411 and rotated by the motor 412. An exposure light beam from the exposure light source 413 is guided to an irradiation unit 415 by an optical fiber 414. A light shielding plate 416 is arranged between the irradiation unit 415 and the wafer 12, and
The region where the exposure light beam 417 is irradiated to the peripheral portion of the light emitting device 2 is adjusted. In other words, the exposure light beam 417 has the marks M1 to
A light shielding plate 4 is provided so as to irradiate the peripheral region of the wafer including M8.
16 is adjusted. Further, the irradiation area can be adjusted by moving the entire peripheral exposure apparatus in the arrow direction. The reflecting plate 418 reflects the exposure light flux not irradiated on the wafer 12 to the back side of the wafer 12 for irradiation. This makes it possible to cope with the case where the resist solution adheres to the back side of the wafer 12. The wafer 12 exposed by the peripheral exposure apparatus shown in FIG. 5B is sent to a step of performing a chemical treatment in order to remove the resist in the exposed area.

Next, the pattern exposure method according to the present invention will be described step by step. First, a method of exposing the first layer will be described. The entire surface of the wafer 12 is coated with the resist coater 40 shown in FIG. 5A or the resist coater 400 shown in FIG. 5B.
At this time, edge rinsing using the solvent ejection nozzle 43 is not performed. Therefore, the wafer 12 is also coated with a resist in its peripheral region. The wafer 12 coated with the resist is placed on the stage 13 of the exposure apparatus shown in FIG.

FIG. 6A shows a reticle used for exposing the first layer. The reticle 10a for exposing the first layer is provided with a shot pattern P1 of the first layer and a pattern M of alignment marks to be exposed in the peripheral region of the wafer 12 in a spatially separated manner. .

The stage control system 36 of the exposure apparatus controls the reticle blind drive mechanisms 18a and 18b so that the illumination range of the reticle 10a by the illumination light is the range 51 shown by the broken line in FIG. 6A, that is, the shot pattern P1. Limit to parts. Thereafter, the stage control system 36 becomes the main control system 3
By repeating the step driving of the stage 13 and the opening / closing control of the shutter 3 under the control of 7, the predetermined shot areas S1, S2, S3, ... On the wafer 12, as shown in FIG.
Are sequentially exposed to the shot pattern P1 of the first layer.

All shot areas S1, S2, S3, ...
When the exposure of the shot pattern P1 to ‥ is completed,
Subsequently, the exposure of the alignment mark M to the peripheral region of the wafer 12 is performed using the reticle 10a. The stage control system 36 includes a reticle blind drive mechanism 18a, 1
8b, the illuminating range of the reticle 10a by the illuminating light is limited to a range 52 indicated by a broken line in FIG. Next, the stage control system 36, under the control of the main control system 37,
Step drive and opening / closing control of the shutter 3 are repeated,
As shown in FIG. 7, only the alignment marks M are sequentially exposed at predetermined locations M1, M2, M3,... In the peripheral area of the wafer 12. This peripheral area is an area where the resist is removed during the exposure of the shot pattern for the second and subsequent layers.

The number of alignment marks provided on the wafer 12 is preferably three or more, and eight are provided in the example of FIG. However, the number and arrangement of the alignment marks can be changed according to the required alignment accuracy. Alternatively, exposure may be performed in many places, and an appropriate one may be selected and used depending on required alignment accuracy. When alignment is performed by an alignment method called enhanced global alignment (EGA) using alignment marks provided in the peripheral area of the wafer, the EGA method minimizes the least square error in alignment of a plurality of points on the wafer. Since this is a simple alignment method, it is possible to disperse the effects of alignment errors and stepping errors. Further, the alignment marks are arranged in the respective alignment marks M1, M
If the arrangement is such that the area of the convex polygon formed by 2, M3, ... Is maximized, so-called linear errors can be evenly distributed.

In the present invention, only the alignment mark M is drawn on a part of the reticle 10a on which the shot pattern P1 of the first layer is drawn, and the reticle blind 7 is used to select and expose the alignment mark M. Is because the reticle manufacturing error is taken into consideration. According to this method, the positional relationship between the shot pattern P1 of the first layer and the alignment mark M can be known with an accuracy of about a reticle drawing error, and in some cases, the error can be measured in advance. It is also possible to correct the position of the alignment mark formed in the above. The method of exposing only the alignment mark on a reticle different from the shot pattern reticle and exposing the alignment mark with the reticle dedicated to the alignment mark is because the unknown error when the reticle is placed on the exposure device is the alignment mark. Since it is inevitably included in the exposure position, it is not a good idea.

What is desirable in the exposure of the alignment mark is that the alignment mark is drawn on the reticle on which the shot pattern that is the most basic of the alignment target is formed. Only this alignment mark is selected by the reticle bride and transferred to the peripheral area of the wafer, but the relative positional relationship between the shot pattern and the alignment mark on the reticle is known in advance from manufacturing data (or by measurement). Therefore, by taking this into consideration, the transfer is performed to the peripheral area of the wafer, so that the alignment marks M1, M2, M3 are formed in a known positional relationship with respect to the shot area on the wafer without introducing an unknown error due to the reticle exchange. , Can be formed.

As shown in FIG. 7, the shot areas S1, S2, S3, ... On the wafer 12 are exposed with the shot pattern P1 of the first layer, and the peripheral areas thereof are exposed with the alignment marks M1 to M8. 12 is stage 13
Is unloaded and developed, and then subjected to processing necessary for device manufacturing.

Next, the method of exposing the second layer will be described. The resist for the second layer exposure is applied to the wafer 12 by the resist coater 40 shown in FIG. Next, after the resist solution is jetted from the resist jet nozzle 42 to spin-coat the resist to a uniform thickness on the surface of the wafer 12, the solvent of the resist is jetted and sprayed from the solvent jet nozzle 43 to the peripheral region of the wafer. Edge rinsing is performed to remove the resist in the peripheral region of the wafer.
In this way, the resist is removed from above the alignment marks M1 to M8 formed in the wafer peripheral area, and the alignment marks M1 to M8 are exposed. The removal of the resist in the peripheral region of the wafer can also be performed using the peripheral exposure apparatus shown in FIG.

FIG. 8 shows a wafer 12 coated with a resist.
FIG. The resist in the wafer peripheral area 61 is removed by edge rinsing or peripheral exposure, and the alignment marks M1 to M8 are exposed. A resist is uniformly applied to the inner region 62 where the first layer shot patterns S1, S2, S3,... Are formed. The wafer coated with the resist for exposure of the second layer is placed on the stage 13 of the exposure apparatus and is vacuum-adsorbed and fixed.

The reticle 10 mounted on the exposure apparatus is replaced with the reticle 10b shown in FIG. 6 (b). Only the second layer shot pattern P2 is drawn on the reticle 10b. The reticle blind 7 controls the stage control system 36 so that the illumination area of the illumination light is in a range 53 surrounding the shot pattern P2 as shown by a broken line in FIG.
Is controlled by

The alignment for the second layer shot is as follows:
Using the alignment marks M1 to M8 exposed in the peripheral region 61 of the wafer 12, the process is performed in the same manner as in the related art. For example, alignment of reticle 10b is performed using reticle alignment sensor 31. Then, the alignment marks M1 to M8 formed on the wafer 12 are detected by using the wafer
Shot areas S1, S2, S3, ...
The positions of the ... Are obtained, and the step control system 36 repeats the step drive of the stage 13 and the opening / closing control of the shutter 3 under the control of the main control system 37. Exposure is done by superimposing on.

Similarly, for the shot patterns of the third and subsequent layers, the resist in the peripheral area 61 of the wafer 12 is removed, and the reticle pattern is aligned with the shot areas by using the exposed alignment marks M1 to M8. Is accurately overlapped with the shot pattern of.
When the alignment mark is needed again, the edge rinse or the peripheral exposure by the resist coater 40 may be omitted and the alignment mark may be exposed on the wafer peripheral region, as in the case of the first layer exposure described above.

[0046]

According to the present invention, since there is no resist on the alignment mark and the exposed alignment mark can be used, the alignment accuracy is dramatically improved.

[Brief description of drawings]

FIG. 1 is a schematic view of an exposure apparatus used in the method of the present invention.

FIG. 2 is a front view of a blade portion of the reticle blind.

FIG. 3 is a schematic diagram of a reticle blind drive mechanism.

4 is a schematic configuration diagram of an AA cross section of the blade shown in FIG. 2 and a driving mechanism.

FIG. 5 is a schematic view of a resist coater.

FIG. 6 is a schematic view of a first-layer exposure reticle and a second-layer exposure reticle.

FIG. 7 is a layout diagram of shot areas and alignment marks on a wafer.

FIG. 8 is a plan view of a wafer subjected to edge rinsing or peripheral exposure after resist application.

[Description of Reference Signs] 1 ... Illumination light source, 2 ... Elliptic mirror, 3 ... Shutter, 5 ... Wavelength selection filter, 6 ... Fly eye integrator, 7 ... Reticle blind, 7a, 7b ... Blade, 10 ... Reticle, 11 ... Projection optics System, 12 ... Wafer, 13 ... Stage, 20 ... Laser interferometer, 21 ... Stage driving means, 3
DESCRIPTION OF SYMBOLS 1 ... Reticle alignment sensor, 32 ... Wafer alignment sensor, 35 ... Alignment control system, 36 ...
Stage control system, 37: Main control system, 40: Resist coater, 42: Rotary support, 42: Resist ejection nozzle, 4
3 ... Solvent ejection nozzle, 61 ... Peripheral region, 400 ... Resist coater, 411 ... Rotation support stand, 412 ... Motor, 41
3 ... Exposure light source, 414 ... Optical fiber, 415 ... Irradiation part, 416 ... Shading plate, 417 ... Exposure light flux, 418 ... Reflector plate

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location H01L 21/30 577

Claims (5)

[Claims] 1. A first reticle on which a first shot pattern and an alignment mark are spatially separated and drawn, and only the alignment mark is projected and exposed onto a peripheral region of a substrate coated with a photosensitive agent. And exposing the first shot pattern of only the first shot pattern onto the shot area of the substrate, and removing the photosensitizer in the peripheral area of the substrate coated with the photosensitizer; An exposure step of a second layer for aligning a second reticle on which a shot pattern is drawn by using the alignment mark, and projecting and exposing the second shot pattern on the shot area of the substrate. Projection exposure method. 2. The projection exposure method according to claim 1, wherein in the exposure step of the first layer, the alignment mark to be projected and exposed and the first shot pattern are switched by using a reticle blind. . 3. The first shot pattern and the alignment mark are arranged in the first positional relationship in a predetermined positional relationship.
The reticle of FIG.
The projection exposure method described. 4. In the exposure step of the first layer, the alignment mark is at least 3 in a peripheral region of the substrate.
The projection exposure method according to claim 1, wherein the projection exposure is performed on a location. 5. The alignment in the exposure process of the second layer is performed by calculating array coordinate values of shot areas of the substrate based on position information of the alignment marks. Projection exposure method.