JPH10284364A - Alignment mark for electron beam exposure, electron beam exposing method and electron beam exposing equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable obtaining an alignment mark whose discrimination ability is high, by forming a region having a potential different from the potential of a substrate region except an alignment mark region. SOLUTION: A reverse bias is applied to an alignment mark constituted of a P-N junction by a bias applying circuit 3. The alignment mark is scanned by an electron beam 4. Secondary electrons emitted form the surface of a substrate are detected with a secondary electron detector. In this case, since a bias is applied to the P-N junction of the alignment marked part, the potential of the alignment marked part is different from that of the other region to with the bias is not applied. The amount of secondary electrons emitted from the alignment marked by irradiation of electron beams 5 is different from the amount of electrons emitted from the other substrate region. The alignment marked formed of the P-N junction is recognized by measuring the inplane distribution of emitted amount of the secondary electrons.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electron beam (E).
B) An alignment mark used for exposure, an electron beam exposure method using the alignment mark, and an electron beam exposure apparatus used for the electron beam exposure method.

[0002]

2. Description of the Related Art Recognition of an alignment mark on a substrate at the time of EB direct writing is performed by scanning an EB from an EB exposure apparatus and detecting returning secondary electrons or reflected electrons. Such alignment marks include a step mark obtained by partially etching the substrate surface as shown in FIG. 8, a V-groove-shaped mark as shown in FIG. 9, and an alignment mark using a metal pattern (not shown). ) Etc. are used.

[0003]

The step mark 30 shown in FIG.
Is used to recognize the alignment mark as a contour pattern, utilizing the fact that the amount of secondary electrons emitted at the step of the alignment mark increases when the EB is scanned. Since the amount of change in the amount of secondary electrons at the step portion is small, it is difficult to accurately recognize the alignment pattern. Also,
The V-groove mark 31 in FIG. 9 can clearly recognize the alignment mark when the EB is scanned because the emission amount of the secondary electrons is very large in the slope portion in the groove. It is difficult to form an alignment mark with high precision because a long time wet etching in a chemical is required to form the mark.
Further, the alignment mark using a metal pattern can easily form a high-precision alignment mark, and the amount of reflected electrons is very large, so that the alignment mark can be clearly recognized. In the case of performing the method, since the substrate surface is contaminated with a metal used as an alignment mark when forming an alignment mark, there is a problem that the crystallinity of the grown layer is deteriorated. Accordingly, an object of the present invention is to provide an alignment mark having a high discriminating power used in an electron beam exposure step.

[0004]

Accordingly, as a result of intensive research, the present inventors have found that a predetermined alignment mark region formed of a first conductive type semiconductor layer and a second conductive type semiconductor layer stacked via a PN junction region is provided. By generating a potential, it is found that the amount of secondary electrons emitted from the alignment mark area when the electron beam is irradiated is different from other areas, and that the alignment mark can be recognized with high accuracy by detecting this. Thus, the present invention has been completed.

That is, according to the present invention, an alignment mark detected by a difference in the amount of secondary electrons emitted when an electron beam is irradiated is composed of a first conductive type semiconductor layer laminated on a substrate and a second conductive type semiconductor layer. And an electron beam exposure alignment mark formed in a region having a potential different from the potential of the substrate region other than the alignment mark region. As described above, the alignment mark is formed from the semiconductor layer of the first conductivity type and the semiconductor layer of the second conductivity type stacked via the PN junction region, and a predetermined potential is generated in the PN junction region of the alignment mark. Thereby, the potential of the alignment mark region can be made different from the potentials of the other substrate regions. As a result, when the substrate is scanned by using the electron beam, the distance from the alignment mark area is 2
Since the amount of secondary electrons emitted is different from the amount of secondary electrons emitted from other substrate areas, it is possible to recognize the alignment mark area with high accuracy by detecting such a difference in secondary electron emission. Become.

Preferably, the alignment mark is formed on the substrate by patterning. That is,
An alignment mark is formed on the substrate by patterning on a PN junction region of a convex shape region of a predetermined height, or a second conductivity type formed by diffusion or the like in a first conductivity type semiconductor layer on the substrate. By including the PN junction region composed of the semiconductor layer, for example, electrons generated by light irradiation or the like are unlikely to move from the alignment mark region to another region, and only the potential of the alignment mark region is different from the potential of the other region. This is because the alignment mark can be recognized with high accuracy.

The above-mentioned alignment mark is formed by a bias applying means for applying a bias to the PN junction.
It is preferable to have a potential different from the potential of the substrate region other than the alignment mark region. This is because, by applying a bias to the PN junction of the alignment mark by such a bias applying unit, the potential of the alignment mark area can be easily made different from the potential of other areas.

Preferably, the alignment mark is formed of a potential region different from the potential of the substrate region other than the alignment mark region formed by irradiating the PN junction region with light. By using such an alignment mark, it is not necessary to form an alignment mark dedicated to electron beam exposure, and an unnecessary alignment mark area is eliminated, so that high integration of a semiconductor element can be achieved.

Further, according to the present invention, in an electron beam exposure method for exposing a predetermined area on a substrate by scanning an electron beam, the step of recognizing an alignment mark, which is a reference for positioning the exposure area, comprises: A first conductivity type semiconductor layer;
Light is applied to an alignment mark formed by laminating a semiconductor layer of the second conductivity type provided on the semiconductor layer of the first conductivity type via a PN junction region, and the potential of the semiconductor layer of the second conductivity type is set to the above-mentioned value. A step of causing a potential different from the potential of the substrate, a step of scanning the substrate with an electron beam to emit secondary electrons from the substrate, and a step of causing the potential of the alignment mark to be different from the potential of the substrate. Detecting the difference in the amount of emitted electrons and recognizing the position of the alignment mark. This is because the use of such a method enables highly accurate recognition of the alignment mark.

According to the present invention, there is provided an electron beam exposure method for exposing a predetermined area on a substrate with an electron beam by scanning the area with an electron beam. A first conductivity type semiconductor layer;
A bias is applied to the PN junction of the alignment mark in which the semiconductor layer of the first conductivity type and the semiconductor layer of the second conductivity type provided on the semiconductor layer of the first conductivity type are stacked via a PN junction region.
Applying a potential of the conductive semiconductor layer to a potential different from the potential of the substrate; scanning an electron beam on the substrate to emit secondary electrons from the substrate; Detecting the difference in the amount of secondary electrons emitted due to the potential difference of the substrate and recognizing the position of the alignment mark. This is because the use of such a method also enables highly accurate recognition of the alignment mark.

According to the present invention, there is provided an electron beam exposure method for exposing a predetermined area on a substrate with an electron beam by scanning the area with an electron beam. A first conductive type semiconductor layer and a second conductive type semiconductor layer provided on the first conductive type semiconductor layer are stacked on a substrate via a PN junction region. Irradiating light to generate a predetermined potential in the PN junction region of the light irradiation region; scanning an electron beam on the substrate to emit secondary electrons from the substrate; Detecting a difference in the emission amount of the secondary electrons due to the potential of the irradiation region being different from the potential of the region other than the light irradiation region, and recognizing the light irradiation region as an alignment mark. You There is also an electron beam exposure method. By using such a method, it is not necessary to form an alignment mark dedicated to electron beam exposure, and unnecessary formation of an alignment mark is eliminated, whereby high integration of a semiconductor element can be achieved.

The present invention also provides an electron gun for generating an electron beam, a deflecting lens for deflecting the electron beam, an objective lens for converging the electron beam, and an arrangement for disposing a substrate. An electron beam exposure apparatus including at least a substrate stage and a secondary electron detector for detecting secondary electrons generated by irradiating the substrate with the electron beam. An electron beam exposure apparatus comprising light irradiation means for irradiating light.

The present invention also provides an electron gun for generating an electron beam, a deflecting lens for deflecting the electron beam, an objective lens for converging the electron beam, and an arrangement for disposing a substrate. An electron beam exposure apparatus comprising at least a substrate stage and a secondary electron detector for detecting secondary electrons generated by irradiating the substrate with the electron beam, further comprising a bias at a predetermined position on the substrate. An electron beam exposure apparatus comprising a bias applying means for applying a bias voltage.

An electron gun for generating an electron beam, a deflection lens for deflecting the electron beam, an objective lens for focusing the electron beam, a substrate stage for arranging a substrate, An electron beam exposure apparatus comprising at least a secondary electron detector for detecting secondary electrons generated by irradiating the substrate with a beam,
Further, reading means for optically reading the position of the optical alignment mark formed on the substrate, a coherent light source for irradiating a spot light on a predetermined position of the substrate with reference to the position of the optical alignment mark, An electron beam exposure apparatus comprising:

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. FIG. 1 is a perspective view of an alignment mark according to the first embodiment of the present invention, and FIG. 2 is a schematic view of a method for recognizing an alignment mark using such an alignment mark. In the figure, 1 is an n-type substrate, 2 is a p-type region, 3
Is a bias application circuit, 4 is an electron beam (EB), 5 is 2
Reference numeral 6 denotes a secondary electron detector. As shown in FIG. 1, the alignment mark according to the present embodiment is formed of, for example, a cross-shaped PN junction composed of a p-type region 2 laminated on an n-type substrate 1, and a bias is applied to the PN junction by an external wiring. Applied. Generally, in a semiconductor device manufacturing process, a PN junction is usually always formed. Therefore, such an alignment mark can be formed simultaneously with the formation of another PN junction. The bias is applied from outside using a probe or the like.

In the method of recognizing an alignment mark according to the present embodiment, as shown in FIG. 2, a reverse bias is first applied to the alignment mark formed of a PN junction by a bias applying circuit 3, and in this state, an electron is applied to the alignment mark. The line 4 is scanned, and secondary electrons emitted from the substrate surface are detected using a secondary electron detector. In this case, since a bias is applied to the PN junction of the alignment mark portion, the potential of the alignment mark portion is different from the potential of other regions to which no bias is applied. For this reason, the amount of secondary electrons emitted from the alignment mark portion by the irradiation of the electron beam 5 is different from the amount emitted from other substrate regions, and the in-plane distribution of the amount of emitted secondary electrons is measured. , The alignment mark portion formed by the PN junction can be recognized.
In FIG. 2, a reverse bias is applied to the PN junction, but the bias may be a forward bias.

Embodiment 2 FIG. FIG. 3 shows a method for recognizing an alignment mark according to the second embodiment of the present invention. In the drawing, the same reference numerals as those in FIG. 2 indicate the same or corresponding parts, and 7 indicates light. In the first embodiment, since a bias has to be applied to the PN junction, it is necessary to provide an electrode wiring and a voltage application circuit. In the second embodiment, the electrode wiring and the voltage application circuit are formed. The alignment mark can be recognized without any problem. That is, by irradiating the alignment mark formed from the PN junction with light 7 having an energy larger than the band gap energy of the semiconductor material forming the PN junction, an electron-hole pair is formed at the PN junction. The electrons and holes move into the n-type semiconductor and the holes move into the p-type semiconductor, respectively, due to the built-in voltage at the junction.
The holes that have moved to the p-type semiconductor side have no place to go and are accumulated, and accordingly, the forward potential applied to the PN junction increases. On the other hand, when the forward potential increases, the forward potential increases. As a result, the recombination rate of electrons and holes in the depletion layer increases. Therefore, the forward potential generated at the PN junction is determined so that the generation of electron-hole pairs due to the incidence of light is equal to the amount of recombination of electrons and holes.

FIG. 4 is a diagram showing a change in band structure when light is irradiated to an alignment mark region formed from such a PN junction. FIG. 4A shows a band when light is not irradiated. FIG. 4B shows a band structure when light is irradiated. As is clear from the figure, when light is not irradiated (FIG. 4A), the values of Fermi energies (E _Fp , E _Fn ) in the P-type and N-type regions are equal, but when light is irradiated (FIG. 4A). 4 (b)) is because, as described above, the forward potential is generated at the PN junction so that the generation of electron-hole pairs by light irradiation and the amount of recombination of electrons and holes become equal. , The band structure is as shown in FIG. 4B, and the Fermi energies (E _Fp , E _Fn ) of the P-type region and the N-type region are V _F
A difference occurs the corresponding to, i.e., such V _F becomes the potential generated in the PN junction region of the alignment mark by the light irradiation. The forward voltage V _F is smaller than the built-in voltage applied to the PN junction, about 0.5V when the semiconductor material used for the PN junction is estimated for the case of Si, GaA
In the case of s, it is about 1.0V. As described above, in the method according to the present embodiment, the potential can be generated in the alignment mark formed from the PN junction only by irradiating the light. The alignment mark can be recognized by scanning the electron beam 4 and measuring a change in the amount of secondary electrons 5 generated with the electron beam 4 using the secondary electron detector 6. Therefore, by using the method according to the present embodiment, the alignment mark can be recognized without the bias application circuit, and the alignment mark can be recognized more easily than in the first embodiment. The light 7 used to generate the electron-hole pairs is preferably continuous light because the electron lifetime is relatively short, but pulsed light can also be used. The light irradiation may be irradiation on the entire surface of the substrate or spot irradiation.

Embodiment 3 FIG. 5 shows a method for recognizing an alignment mark according to the third embodiment of the present invention. In the first and second embodiments, the PN junction pattern is formed by etching and used as an alignment mark. However, in the third embodiment, as shown in FIG. That is, by irradiating, for example, spot light to the p-type region 2 formed in a certain region on the n-type substrate 1, the potential of the spot light irradiation region 8 in the PN junction formation region is changed, and Are used as alignment marks.

In the manufacturing process of the semiconductor device, an EB exposure machine,
Several types of exposure apparatuses, such as a step-and-repeat mask aligner and a projection mask aligner, are properly used for each process, and alignment marks of different types are prepared for each of these exposure apparatuses. That is, the alignment marks used in the respective manufacturing steps have different optimum shapes and the like for each apparatus, so that it is difficult to use one alignment mark in common in a plurality of manufacturing steps. Therefore, Embodiments 1 and 2
In order to align the EB direct drawing pattern, an alignment mark for exclusive use of the EB exposure apparatus as shown in FIGS. Was needed.

On the other hand, in the third embodiment, first, an alignment mark used in another exposure process is
Reading is performed by an optical system similar to the method used by such an exposure apparatus for substrate alignment. In other words, alignment marks read by an optical system are generally difficult to recognize by a reading method that scans an EB. Therefore, using an optical reading system separately provided in advance in an EB exposure apparatus,
First, the position of the alignment mark is read. next,
A spot-like light 8 is applied to a position away from the alignment mark position by a predetermined distance, and an electron-hole pair is generated at the PN junction at the position according to the same principle as in the second embodiment. Is changed. Next, the EB is scanned by the same method as in the first and second embodiments, and the change in the amount of the secondary electrons 5 generated in the
The next electron detector 6 detects the position of the alignment mark, and performs an EB exposure process. In the present embodiment,
Since the potential generated in the spotlight irradiating section 8 is not confined as in the first and second embodiments, the potential spreads around the spotlight irradiating section 8. It is possible to recognize the position of the mark. Further, in the present embodiment, the spot-shaped light 7 ′ is emitted, but the light is not limited to the spot-shaped light, and light of another shape can be used.

As described above, in the present embodiment, the PN junction can be recognized as the alignment mark without patterning the PN junction and forming the alignment mark, so that the alignment mark forming step can be reduced, and Since it is not necessary to form an alignment mark unnecessary for the element structure on a highly integrated substrate, further higher integration can be achieved.

Embodiment 4 FIG. 6 shows a part of a method for manufacturing a semiconductor device using the alignment marks according to the second embodiment. This step is a step of providing an opening in the center of the concave portion of the exposure region 11 of the electron beam resist 12 formed on the exposure region 11. First, as shown in FIG. 6A, an alignment mark 10 having a PN junction as described above is formed on a substrate having an exposure region 11. Such an alignment mark 10 may have a p-type or n-type semiconductor material disposed thereon. Next, FIG.
As shown in FIG. 1B, an electron beam resist 12 is formed so as to cover the exposure region 11 on the substrate. After the electron beam resist 11 is formed so as to cover the entire surface of the substrate, only the alignment mark 10 may be removed. Next, as shown in FIG. 6C, the electron beam 4 is scanned while irradiating the alignment mark with light 7, and the generated secondary electrons are detected by a secondary electron detector (not shown). Recognize the alignment mark position. Next, as shown in FIG. 6D, the electron beam photoresist 12 is exposed to the electron beam photoresist 12 at a predetermined position in the exposure region 11 with reference to the recognized position of the alignment mark 10. Finally, FIG.
As shown in (e), by performing the developing step, the electron beam resist 12 at a predetermined position is removed, and the opening 13 is formed.
Is formed.

By using such a manufacturing method, alignment marks can be clearly detected, so that highly accurate pattern alignment can be performed, and a high-performance semiconductor device can be manufactured. In addition, since a metal material is not used for the alignment mark, a highly reliable semiconductor device can be manufactured without concern about metal contamination.

In the above manufacturing method, the case where the alignment mark according to the second embodiment is used has been described.
A similar process can be performed using either the alignment mark according to the first embodiment or the alignment mark according to the third embodiment. That is, when the alignment mark of the first embodiment is used, a predetermined bias of a PN junction is applied instead of the light 7 used in the present embodiment, and when the alignment mark of the third embodiment is used, By irradiating a spot light to a PN junction region, which is provided in a predetermined region on the substrate and is not patterned, it becomes possible to perform each of them.

Embodiment 5 FIG. 7A shows an EB used for detecting the alignment mark according to the second embodiment.
FIG. 7B shows an EB exposure apparatus used for detecting an alignment mark according to the third embodiment. 7A, reference numeral 20 denotes an electron gun, 21 denotes a deflection lens, 22 denotes an objective lens, 23 denotes a white light source, 25 denotes a substrate stage on which a substrate 24 is mounted, and further includes a secondary electron detector 6. . In such a structure, a white light source 23 is newly provided in a normal EB exposure apparatus so that a predetermined position on the substrate 24 can be irradiated with light using an optical system, and the electron-positive light is applied to the PN junction of the alignment mark. In this case, a pair of holes can be formed. With this light source, the PN on the substrate
A potential difference can be applied to the substrate alignment mark formed by bonding, the substrate alignment mark can be clearly recognized, and highly accurate alignment can be easily obtained.

In FIG. 7B, a coherent light source 26 made of, for example, a He—Ne gas laser or the like is provided in order to obtain the spot light irradiation unit 8 described in the third embodiment. In such a configuration, since the light irradiating section 8 has a spot shape, a simple optical system can be used as compared with the configuration of FIG. In addition, a light source (not shown) separately provided may be used to recognize an alignment mark formed for another exposure apparatus. However, in FIG. 7B, the light from the coherent light source 26 is used. Using the photodetector 27, the alignment mark formed for the other exposure apparatus can be recognized. Further, a television camera that can optically observe the alignment mark may be provided.

The recognition of the alignment mark according to the first embodiment is performed by applying a bias to the substrate arranged in a normal EB apparatus by an appropriate means (for example, a lead wire introduced from the outside through a port). It is possible to do so.

[0029]

As is clear from the above description, the use of the alignment mark according to the present invention makes it possible to easily obtain an alignment mark having a high discriminating power. In particular, in the formation of the alignment mark according to the present invention, since the contamination or the like of the substrate surface does not occur, the crystal growth step can be performed after the alignment mark is formed.

Further, by using the electron beam exposure method according to the present invention, it is possible to recognize alignment marks with high accuracy in the electron beam exposure step, and to improve the accuracy of electron beam exposure.

Further, by using the electron beam exposure apparatus according to the present invention, it is possible to easily recognize the alignment mark according to the present invention.

[Brief description of the drawings]

FIG. 1 is a perspective view of an alignment mark structure according to a first embodiment of the present invention.

FIG. 2 is a method for recognizing an alignment mark structure according to the first embodiment of the present invention;

FIG. 3 is a method for recognizing an alignment mark structure according to a second embodiment of the present invention;

FIG. 4A shows a band structure of a PN junction region of an alignment mark when light is not irradiated. (B) The band structure of the PN junction region of the alignment mark when irradiated with light.

FIG. 5 is a method for recognizing an alignment mark structure according to a third embodiment of the present invention;

FIG. 6 is a manufacturing process diagram of a semiconductor device using an alignment mark according to the present invention.

FIG. 7 is a schematic view of an EB exposure apparatus for recognizing an alignment mark according to the present invention.

FIG. 8 is a perspective view of a conventional alignment mark using a step mark.

FIG. 9 is a perspective view of an alignment mark using a conventional V-groove mark.

[Explanation of symbols]

1 n-type substrate, 2 p-type region, 3 bias application circuit,
4 electron beam, 52nd electron, 6 secondary electron detector, 7
Light, 7 'spot light, 8 spot light irradiation part, 9P
N junction, 10 alignment mark, 11 exposure area,
12 resist for electron beam, 13 opening, 20 electron gun, 21 deflection lens, 22 objective lens, 23 white light source, 24 substrate, 25 substrate stage, 26 coherent light source, 30 step mark, 31 V groove mark, 3
1 substrate.

Claims (10)

[Claims] 1. An alignment mark detected by a difference in the amount of secondary electrons emitted when an electron beam is irradiated,
A PN junction region including a first conductivity type semiconductor layer and a second conductivity type semiconductor layer laminated on a substrate, and is formed of a region having a potential different from the potential of the substrate region other than the alignment mark region. An alignment mark for electron beam exposure. 2. The alignment mark for electron beam exposure according to claim 1, wherein the alignment mark is formed on a substrate by patterning. 3. The alignment mark according to claim 2, wherein the alignment mark has a potential different from a potential of a substrate region other than the alignment mark region by a bias applying unit for applying a bias to a PN junction. Alignment mark for electron beam exposure. 4. The alignment mark according to claim 1, wherein the alignment mark is formed of a potential region different from a potential of a substrate region other than the alignment mark region formed by irradiating a light to a PN junction region. Alignment mark for electron beam exposure. 5. Scanning a predetermined area on a substrate with an electron beam,
In the electron beam exposure method for exposing the region, a step of recognizing an alignment mark serving as a reference for positioning the exposure region is provided on the first conductive type semiconductor layer and the first conductive type semiconductor layer. Irradiating light to an alignment mark formed by laminating a semiconductor layer of the second conductivity type via a PN junction region to make the potential of the semiconductor layer of the second conductivity type different from the potential of the substrate; Scanning an electron beam thereon to emit secondary electrons from the substrate; detecting a difference in the amount of secondary electrons emitted due to a potential of the alignment mark being different from a potential of the substrate; Recognizing the position of the electron beam. 6. Scanning a predetermined region on a substrate with an electron beam,
In the electron beam exposure method for exposing the region, a step of recognizing an alignment mark serving as a reference for positioning the exposure region is provided on the first conductive type semiconductor layer and the first conductive type semiconductor layer. A bias is applied to the PN junction of the alignment mark in which the semiconductor layer of the second conductivity type is stacked via the PN junction region, and the potential of the semiconductor layer of the second conductivity type is applied to a potential different from the potential of the substrate. Scanning an electron beam on the substrate to emit secondary electrons from the substrate; and detecting a difference in the amount of emitted secondary electrons due to the potential of the alignment mark being different from the potential of the substrate. And a step of recognizing the position of the alignment mark. 7. A predetermined area on a substrate is scanned with an electron beam,
In the electron beam exposure method for exposing the area, the step of recognizing an alignment mark serving as a reference for positioning the exposure area includes the steps of: forming a first conductive type semiconductor layer on the substrate; And the second conductive type semiconductor layer provided in
Irradiating light to a predetermined region on the stacked substrate via the bonding region to generate a predetermined potential in the PN junction region of the light irradiation region; and scanning an electron beam on the substrate. A step of emitting secondary electrons from the substrate; and detecting a difference in the amount of emitted secondary electrons due to a potential of the light irradiation area being different from a potential of an area other than the light irradiation area. Recognizing a mark as an alignment mark. 8. An electron gun for generating an electron beam, a deflection lens for deflecting the electron beam, an objective lens for focusing the electron beam, a substrate stage for arranging a substrate, An electron beam exposure apparatus comprising at least a secondary electron detector for detecting secondary electrons generated by irradiating the substrate with the electron beam, further comprising: irradiating a predetermined position on the substrate with light. An electron beam exposure apparatus, comprising: 9. An electron gun for generating an electron beam, a deflection lens for deflecting the electron beam, an objective lens for focusing the electron beam, a substrate stage for arranging a substrate, An electron beam exposure apparatus including at least a secondary electron detector for detecting secondary electrons generated by irradiating the substrate with the electron beam, further comprising: applying a bias to a predetermined position of the substrate. An electron beam exposure apparatus, comprising: 10. An electron gun for generating an electron beam, a deflection lens for deflecting the electron beam, an objective lens for focusing the electron beam, a substrate stage for arranging a substrate, An electron beam exposure apparatus having at least a secondary electron detector for detecting secondary electrons generated by irradiating the substrate with the electron beam, further comprising: a position of an optical alignment mark formed on the substrate. An electron beam exposure apparatus, comprising: reading means for optically reading light; and a coherent light source for irradiating spot light to a predetermined position on the substrate with reference to the position of the optical alignment mark.