JP3485071B2 - Photomask and manufacturing method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure photomask used for manufacturing a semiconductor device and a method for manufacturing the photomask.

[0002]

2. Description of the Related Art Conventionally, this type of photomask has
A circuit pattern is formed by a light shielding part on a substrate (a glass substrate such as quartz) that is substantially transparent to illumination light such as a KrF excimer laser. The light-shielding portion forming this circuit pattern is formed of a single layer of light-shielding material (chrome film or the like),
The layer of the light shielding material was made to have a film thickness that does not transmit light. Further, recently, a so-called phase shift mask in which a layer of a phase shifter (dielectric thin film) for shifting the phase of light is formed in a part of the circuit pattern has also been manufactured.

[0003]

However, in the prior art as described above, when the pattern is rough as compared with the resolution of the projection lens of the exposure apparatus, the dark portion (corresponding to the light shielding portion) of the pattern image is There was a slight distribution of light intensity near the center. For this reason,
When a positive resist is used as the projection target, the center portion of the pattern exposed on the resist may be exposed and dented, especially when the exposure amount is increased.

Further, a mask substrate G as shown in FIG.
In the mask in which a phase shifter D for shifting the phase of light is provided in a part of the upper light-shielding layer B, the intensity of transmitted light in each of the part where the phase shifter D is applied and the part where the phase shifter D is not applied is controlled. Sometimes there was a need. Therefore, in order to limit the amount of transmitted light from the opening portion (phase shifter adhered portion) of the light shielding layer B particularly in the edge emphasis type (having an auxiliary pattern) and the light shielding effect emphasis type phase shift mask, As shown in FIG. 12, the opening line width of the light shielding layer B must be narrower than that of the mask shown in FIG. However, if the opening line width of the light-shielding layer B is made too narrow, there arises a problem that the opening does not have a predetermined line width during mask manufacture, or the opening does not separate, and a mask suitable for practical use cannot be obtained. There was a problem.

Further, in general, a photomask on which a circuit pattern is drawn has a light-shielding band around the area on which the circuit pattern is drawn. When this circuit pattern has a predetermined transmittance, if the pattern is formed only by a layer of a member having a predetermined transmittance (transmissive layer), this light-shielding band is also formed of a layer having a transmittance. Will be. As a result, a light flux corresponding to the transmittance reaches the portion corresponding to the light-shielding band of the projected image on the wafer, which causes a problem that the resist is exposed.

[0006]

[Means for Solving the Problems ] To solve the above problems
In the invention of the application, on the substrate (G) which is almost transparent to the illumination light.
And a first layer having a predetermined transmittance for the illumination light.
(A), or the transmittance for the illumination light is almost zero.
To form the second layer (B) on the first layer so that
Smell of photomask having a printed circuit pattern (3)
The circuit pattern provided around the circuit pattern.
The light-shielding band (4) that defines the area where the light is formed is
The first layer so that the transmittance for
Formed by stacking the second layer (B) on (A)
To do.

In the method of manufacturing a photomask in which the circuit pattern (3) is formed on a substrate which is substantially transparent to the illumination light, the first layer (A) having a transmittance for the illumination light is formed. At least a part (3) of the circuit pattern is formed on the substrate, and the second layer (B) is formed on the first layer so that the transmittance for the illumination light becomes substantially zero. A light-shielding band (4) formed of the first layer (A) and provided on the transparent substrate around the first layer and defining a formation area of the circuit pattern includes the first and second light-shielding bands. Each of the first and second layers is partially removed to provide a multi-layer structure including two layers.

[0008]

According to the photomask of the present invention, in particular, the light-shielding band (4) is provided on the first layer (A) so that the transmittance for the illumination light is substantially zero. Since the layers are formed by stacking layers (B), the transmittance also corresponds to the portion corresponding to the shielding band of the projected image on the wafer, as in the case where the shielding band is formed of a member having a predetermined transmittance. There is no inconvenience that the luminous flux that reaches is reached.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a technique related to the present invention will be described. The circuit pattern in the photomask for manufacturing a semiconductor element is adjacent to a portion (near the center of the circuit pattern) that does not affect the image formation state (contrast of the image of the circuit pattern) and a light transmitting portion (glass substrate portion). , The part that affects the image formation state (near the edge of the circuit pattern). In order to improve the image formation state (contrast) of the image of the circuit pattern, a predetermined light transmittance may be provided near the edge of the circuit pattern. Incidentally, this light transmittance is determined by the absorbance and the film thickness of the light shielding material.

Utilizing the above-mentioned idea, the portion to be provided with a predetermined light transmittance is, as shown in FIG. 4, etched to a predetermined value in which the film thickness of the light shielding material is thinner than the other portions. A method of adjusting can be considered. However, in order to obtain a predetermined film thickness by etching or the like, it is necessary to carry out etching while measuring the film thickness with an optical film thickness measuring instrument or the like, and it is difficult to obtain the predetermined film thickness.

Therefore, if the circuit pattern is formed by a plurality of layers having different transmittances for the illumination light, the transmittance for the illumination light can be made different between the central portion and the edge portion of the circuit pattern. In addition, since the chemical properties (such as etching resistance) of the plurality of layers forming the circuit pattern are different, even if a chemical treatment is performed to adjust the film thickness, only unnecessary layers are removed, The film thickness of the layer does not change during film formation.

FIG. 1 is a diagram showing a schematic structure of a circuit pattern portion of a photomask based on the above idea.
This is an example in which a circuit pattern is formed by a plurality of layers having different chemical properties (such as etching resistance), and the first pattern having a predetermined transmittance for illumination light is formed on the glass substrate G. For example, a chromium layer is used as the layer (transparent layer) A, and a tungsten silicide (WS) layer is used as the second layer (light-shielding layer) B having a transmittance of almost zero with respect to the illumination light.
The layer i) is formed. By forming the tungsten-silicide layer B which is a light-shielding layer near the central portion 1 on the chromium layer A which is a light-transmitting layer, the edge portion 2 has a light transmittance and the central portion transmits the light. It is possible to obtain a pattern whose rate is almost zero.

FIG. 8A is a flow chart showing a method of manufacturing the photomask of FIG. In order to form this photomask, first, a chromium layer A is sputtered to a thickness such that a predetermined transmittance is obtained (step 101), and then a tungsten silicide layer B is formed on the chromium layer A so as to have a transmittance of the layer A. Depending on the (film thickness), the CVD (Chemical Vapor Depositio
A film is formed according to n) (step 102). Moreover,
A photoresist (positive type resist) is applied to this mask (step 103), and the photoresist except the portion corresponding to the central portion 1 of the pattern is exposed and removed (step 104). Next, the tungsten silicide layer B is removed using sulfur hexafluoride (SF6) gas (step 10).
5) Then, the remaining resist is peeled off (step 106).
As a result, the central portion 1 of the pattern is formed. Further, the resist is applied again (step 10).
7), expose resist other than the part corresponding to the pattern,
Remove (step 108). Then, using a mixed gas of carbon tetrachloride and oxygen, RIE (Reactive Ion Etchin
The layer A of chromium is etched by g) (step 109), and the remaining resist is peeled off to complete the process. As a result, the edge portion 2 of the circuit pattern is formed.

Alternatively, as shown in FIG. 8B, a chromium layer A is sputtered to a thickness such that a predetermined transmittance is obtained (step 111), and then a tungsten silicide layer B is formed thereon. Depending on the transmittance (film thickness) of A, the layer A,
CVD by a thickness such that the transmittance of B as a whole becomes almost zero.
To form a film (step 112). Then, a photoresist is applied to this mask (step 113),
Exposing the photoresist except the part corresponding to the pattern,
Remove (step 114). Next, the tungsten silicide layer B is etched using SF6 gas (step 115), and the chromium layer A is etched using a mixed gas of carbon tetrachloride and oxygen (step 116). Expose the surface. After that, the resist remaining in the previous process is peeled off (step 117), and the photoresist is applied again on the mask (step 11).
8), the photoresist other than the portion corresponding to the central portion 1 of the pattern is exposed and removed (step 119). Further, a method may be adopted in which the tungsten / silicide layer B is removed by etching (step 120) and the remaining resist is stripped (step 121) to complete the process.

Further, the substance used for the layer forming the pattern, the etching agent, and the combination thereof are not limited to those described above, and an etching agent for removing the light shielding layer B (second layer) can be used. On the other hand, the transparent layer A (first layer)
The substance may be a combination of substances having a higher etching resistance than the substance of the light shielding layer B.

FIG. 2 is a diagram showing a schematic structure of a circuit pattern portion of another photomask. This is because an intermediate layer (third layer) made of a material having a different chemical property from those layers is formed between the first and second layers made of a material having the same chemical properties (etching resistance, etc.). This is an example provided. That is, in the case where the intermediate layer C has the same chemical properties as the first and second layers sandwiching the intermediate layer C, the light-shielding layer B (second layer) is etched to reach the transparent layer A (first layer). It is provided to prevent the film thickness from being changed by etching. On the glass substrate G, a light-transmitting layer A is, for example, a chromium layer having a thin film thickness so as to have a predetermined transmittance, an intermediate layer C is, for example, a silicon dioxide (SiO ₂ ) layer, and a light-shielding layer. A layer of chromium, for example, is formed as B.
Similar to the photomask of FIG. 1, the light-shielding layer B of chrome is formed near the central portion 1 on the layer A of chrome, which is a light-transmitting layer, so that the edge has light transmittance. It is possible to obtain a pattern in which the light transmittance is almost zero in the central portion.

FIG. 9A is a flow chart showing a method of manufacturing the photomask of FIG. To make this photomask, first, on the glass substrate G, a layer of chromium A,
The silicon dioxide layer C and the chromium layer B are formed in this order to a predetermined thickness (steps 131 to 133). Then, apply photoresist to this mask (step 1
34), the photoresist other than the portion corresponding to the central portion 1 of the pattern is exposed and removed (step 135). Next, the layer B of chromium and the layer C of silicon dioxide are removed in this order by etching (steps 136 and 137), and the remaining resist is stripped (step 138). As a result, the central portion 1 of the pattern is formed. Further, the resist is applied again (step 139), and the resist other than the portion corresponding to the pattern is exposed and removed (step 14).
0). Then, the chromium layer A is removed by etching (step 141), and the remaining resist is peeled off (step 142) to complete the process. As a result, the edge portion 2 of the circuit pattern is formed.

Alternatively, as shown in FIG. 9 (b), a chromium layer A, a silicon dioxide layer C, and a chromium layer B are formed in this order on the glass substrate G in a predetermined film thickness ( Steps 151-153). Then, a photoresist is applied to this mask (step 154), and the photoresist other than the portion corresponding to the pattern is exposed and removed (step 155). Next, the layers A to C are removed by etching (steps 156 to 158) to expose the surface of the glass substrate G. After that, the resist remaining in the previous step is removed (step 159), the photoresist is applied again on the mask (step 160), and the resist other than the portion corresponding to the central portion 1 of the pattern is exposed and removed. (Step 161). Further, the chromium layer B and the silicon dioxide layer C are respectively removed by etching (step 16).
2, 163), a method may be adopted in which the remaining resist is peeled off to complete the process.

In the photomask of FIG. 2, the intermediate layer C
Although a portion of the pattern corresponding to the edge portion 2 of the pattern is removed by etching, this portion does not need to be particularly removed, and as shown in FIG. You may comprise the one transparent layer which has a ratio. Furthermore, if the remaining intermediate layer C is formed by a phase shift member that shifts the phase of light, it can be used as a phase shift mask (particularly, edge emphasis type or light shielding effect emphasis type). .

Although an example in which both the light-transmitting layer A and the light-shielding layer B are made of the same chemical property has been described, an intermediate layer may be necessary even if they are made of different chemical properties. For example, in the case of the combination of the photomasks shown in FIG. 1, that is, the combination of tungsten silicide and chromium, if the light-transmitting layer is formed of tungsten silicide and the light-shielding layer is formed of chromium, these layers are formed. It is necessary to provide an intermediate layer between them. This is because the resistance of tungsten silicide to the etching agent (mixed gas of carbon tetrachloride and oxygen) is lower than that of chromium. That is, when the upper layer chromium is etched, the lower layer tungsten silicide is also etched. In order to prevent this, even when the materials of the plurality of layers forming the pattern are chemically different, the intermediate layer may be provided similarly to the photomask shown in FIG. In this case, there is an effect that the respective materials and etching agents of the light transmitting layer A and the light shielding layer B can be arbitrarily determined.

In both of the photomasks shown in FIGS. 1 and 2, even if the light shielding layer B or the intermediate layer C is etched, the film thickness of the light transmitting layer A does not change from that at the time of film formation. The film thickness of the layer A, that is, the light transmittance can be controlled during film formation.

In the above description, the light-transmitting layer (first layer) and the light-shielding layer (second layer) that form the pattern each have a single layer structure, but each layer may be composed of a plurality of layers. For example, if the light-transmitting layer is formed of a plurality of layers, the transmittance can be changed by changing the number of layers constituting each of the plurality of edges of the pattern. Further, by changing the number of layers partially formed within the edge of the pattern, it is possible to change the light transmittance depending on the position within the edge. Particularly in the first embodiment, if at least one layer out of the plurality of layers forming the light transmitting layer is formed of a phase shift member that shifts the phase of light, a phase shift mask similar to the photomask of FIG. Can be used as The layer of the phase shift member may be a portion where the light transmitting layer and the glass substrate of the mask are in contact with each other, or may be between a plurality of layers forming the light transmitting layer. Furthermore, what is formed by a plurality of layers is not limited to a light-transmitting layer, but may be a light-shielding layer.

Further, at least one of the surface layer of the light shielding layer composed of a plurality of layers as described above or the layer of the light transmitting layer which is in contact with the glass substrate is formed of an antireflection material such as chromium oxide. Then, it can be used as a so-called antireflection film that reduces unnecessary reflected light in the pattern. However, when the surface layer of the light-shielding layer is the layer of the antireflection film, the portion corresponding to the edge portion of this antireflection film layer is etched when etching the portion of the light-shielding layer corresponding to the edge portion of the pattern. Will also be removed. Therefore, particularly in the photomasks of FIGS. 2 and 3, if not only the surface layer of the light shielding layer but also the intermediate layer (third layer) is formed by the antireflection film, the antireflection film is formed on the entire surface of the pattern. It can be formed and is even more effective. The intermediate layer must be formed of a material that transmits light and has a property different from that of chromium as an etching agent, and for example, silicon dioxide may be formed to a thickness such that an antireflection effect is produced.

Next, the results obtained by illuminating the conventional photomask and one of the photomasks shown in FIGS. 1 to 3 and detecting the intensities of the transmitted light will be described with reference to FIGS. 5 and 10. FIG. 5 is a diagram showing a result of illuminating the photomask of any of FIGS. 1 to 3 and detecting the light intensity of the projected image of the circuit pattern. In this case, the light transmittance at the edge is 1.0%
Stipulated in. Further, FIG. 10 is a diagram showing a result of detecting the light intensity of the projected image of the circuit pattern by illuminating the photomask according to the conventional technique. That is, this is the case where the light transmittance of the pattern portion of the photomask is zero. In each photomask, the width of the pattern portion is 0.6 μm and the duty ratio is 1: 1. In the figure, 0 ≦ X ≦
The range of 0.6 and 1.2 ≦ X ≦ 1.8 corresponds to the pattern portion of the photomask. The exposure apparatus used has a numerical aperture NA of the projection lens of 0.6, a coherence factor σ of 0.3, and an exposure wavelength of λ of 365 nm.

As can be seen from these figures, as compared with the case where the photomask according to the conventional technique (the light transmittance of the pattern portion is zero) is used, the photomask of any one of FIGS. When the ratio is about 1%), the image of the pattern portion has almost no light intensity.

It should be noted that, if the portion that contributes to the image formation (the edge portion of the pattern portion) has a predetermined light transmittance, the contrast of the formed image is improved, which can be also calculated.

Next, a photomask according to an embodiment of the present invention will be described. In general, a photomask on which a circuit pattern is drawn has a light-shielding band 4 around the area on which the circuit pattern 3 is drawn, as shown in FIG. When the circuit pattern 3 has a predetermined transmittance, if the pattern is formed only by a layer of a member having a predetermined transmittance (translucent layer), the light-shielding band 4 also has a transmittance. It will be composed of layers. As a result, the light flux corresponding to the transmittance reaches the portion corresponding to the light-shielding band of the projected image on the wafer, which causes a disadvantage that the resist is exposed. In order to prevent this, it is desirable that the light-shielding band 4 has a transmittance of zero. Therefore, as shown in FIG. 14B, the circuit pattern of the photomask and the light-shielding band should be composed of a light-shielding layer having almost zero transmittance for illumination light and a light-transmitting layer having a predetermined transmittance. To That is, almost 1 on the glass substrate G.
Forming a circuit pattern with a transparent layer A having a transmittance of
A light shielding layer B is further formed in a portion corresponding to the light shielding band.
In this method of manufacturing a photomask, the light-transmitting layer A and the light-shielding layer B are formed to have film thicknesses that give predetermined transmittances, respectively, and then the portion of the light-shielding layer B corresponding to the light-shielding band 4 is left. It is removed by etching, and is removed in the same manner, leaving a portion of the transparent layer A corresponding to the circuit pattern 3.

The circuit pattern 3 is not limited to the one formed of only the light-transmitting layer A, and has a central portion formed of the light-shielding layer B as in the photomask of FIGS. It doesn't matter.

Next, an example in which the structure of the light shielding portion of the photomask shown in FIG. 3 is applied to a phase shift mask will be described with reference to FIG. Incidentally, a conventional edge-enhancement type or light-shielding effect-enhancement type phase shift mask is a glass substrate G as shown in FIG.
A light shielding layer B having a light transmittance of zero is formed on the top. This layer B has an opening having a width of 0.5 μm, and the layer D of the phase shifter is formed in this opening.

FIG. 6 is a diagram showing a schematic structure of the pattern portion of the phase shift mask. This is one in which the intermediate layer C, which is a phase shifter, is not etched after the chromium layer B is etched during the manufacture of the photomask of FIG. This phase shift mask is an edge enhancement type,
Alternatively, it is a light-shielding effect-enhancing type mask, and the light-transmitting layer A having a predetermined light transmittance (40% in this case) on the substrate G.
And a phase shifter layer D as an intermediate layer are formed,
Further, a light-shielding layer B having an opening with a width of 0.5 μm and a light transmittance of zero is formed thereon.

The light intensity distribution of the projected image of the circuit pattern formed by illuminating the mask having the circuit pattern having such a cross-sectional structure and the mask by the conventional method, respectively, and using FIG. 7 and FIG. Explain. The exposure device has the same numerical aperture NA = 0.
6, coherence factor σ = 0.3, exposure wavelength λ =
The one with 365 nm was used.

FIG. 7 is a diagram showing the light intensity distribution of the projected image of the circuit pattern formed by illuminating the phase shift mask (edge emphasis type or light shielding effect emphasis type) of FIG. 6 and the transmitted light thereof. The light transmittance of the phase shifter portion of this mask is about 40% of the transmittance of the phase shifter portion of the conventional phase shift mask shown in FIG.

FIG. 13 is a view showing a light intensity distribution of a projected image of a circuit pattern formed by illuminating a phase shift mask (edge emphasis type or light shielding effect emphasis type) according to a conventional technique and its transmitted light. . The light transmittance of the phase shifter portion of this mask is 100%.

As shown in FIGS. 7 and 13, the image contrast is improved from 0.898 to 0.938 when the mask of FIG. 6 is used as compared with the case where the conventional mask is used. Incidentally, the contrast when the phase shifter is not provided is 0.826.

As described above, by changing the light transmittance between the central portion and the edge portion of the pattern, the intensity of light generated in the dark portion of the image of the pattern can be reduced.
Also, in a photomask in which the light transmittance differs between the central portion and the edge portion of the pattern, by forming the pattern with multiple layers with different chemical properties, only the upper layer member is removed during etching, Since the film thickness of the lower layer member having the ratio remains as it is at the time of film formation, there is no change in film thickness (change in transmittance) during etching.

Further, it is possible to change the light transmittance of the light transmitting portion depending on the position by stacking not only one layer of the light transmitting portion but also more layers. Also, by changing some of the layers to a thin film of phase shift material,
It is also possible to provide the effect of a phase shift mask (edge emphasis type or light shielding effect emphasis type). In particular, when the intermediate layer is used as a phase shifter, the film thickness control of the phase shifter and the like can be performed at the time of film formation, which is convenient. Further, at this time, since the intensity of the transmitted light in the phase shifter portion can be reduced by combining with the transparent portion having a predetermined light transmittance, it is possible to enhance the contrast of the image of the pattern. Further, since it is possible to increase the area of the phase shifter portion or the line width for obtaining the same effect as that of the phase shift mask according to the conventional technique, it is less likely that defects will occur during the manufacture of the mask pattern. There is also an advantage that

[0037]

In the photomask according to the first aspect of the present invention, the second layer is superposed on the first layer so that the light-shielding band has a transmittance of the illumination light of substantially zero. The light flux corresponding to the transmittance reaches the portion corresponding to the light shielding band of the projected image on the wafer, as in the case where the light shielding band is formed of a member having a predetermined transmittance. There is no inconvenience.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of a pattern portion of a photomask according to a technique related to the present invention.

FIG. 2 is a diagram showing a schematic configuration of a pattern portion of a photomask having an intermediate layer.

3 is a diagram showing a schematic configuration of a pattern portion in the photomask of FIG. 2 when an intermediate layer is left.

FIG. 4 is a cross-sectional view showing a state where a film thickness of a pattern portion is partially changed in a mask according to a conventional technique.

FIG. 5 is a diagram showing a result of detecting the light intensity of a projected image of the circuit pattern by illuminating the photomask of any of FIGS.

FIG. 6 is a diagram showing a schematic configuration of a pattern portion of a phase shift mask.

7 is a diagram showing a light intensity distribution of a projected image of a circuit pattern formed by illuminating the phase shift mask of FIG. 6 and transmitted light thereof.

FIG. 8 is a flowchart showing a method for manufacturing the photomask of FIG.

9 is a flowchart showing a method for manufacturing the photomask of FIG.

FIG. 10 is a diagram showing a result of detecting the light intensity of a projected image of a circuit pattern by illuminating a photomask according to a conventional technique.

FIG. 11 is a cross-sectional view showing a schematic configuration of a pattern portion of a conventional phase shift photomask.

12 is a sectional view showing a schematic configuration of a circuit pattern portion of a conventional phase shift mask for obtaining an image equivalent to that of the phase shift mask of FIG.

FIG. 13 is a diagram showing a light intensity distribution of a projected image of a circuit pattern formed by illuminating a phase shift mask according to a conventional technique and transmitted light thereof.

14A shows an example of a photomask having a light-shielding band according to the present invention. FIG. 14B shows a light-shielding band and a circuit pattern when the embodiment of the present invention is applied to a photomask having a light-shielding band. Diagram showing the configuration of

[Explanation of symbols]

1 pattern center 2 pattern edge 3 circuit patterns 4 shading zone A translucent layer B Light-shielding layer C middle layer D phase shifter G glass substrate

Claims (9)

(57) [Claims] 1. A first layer having a predetermined transmittance for the illumination light on a substrate substantially transparent to the illumination light, or
In a photomask having a circuit pattern formed by superimposing a second layer on the first layer so that the transmittance for the illumination light becomes substantially zero, a photomask having a circuit pattern formed around the circuit pattern is provided. A photomask, wherein a light-shielding band defining a formation region is formed by stacking the second layer on the first layer so that the transmittance with respect to the illumination light becomes substantially zero. 2. The photomask according to claim 1, wherein the first layer forming the circuit pattern comprises a plurality of layers. 3. The photomask according to claim 2, wherein
The photomask, wherein the first layer composed of a plurality of layers includes a phase shift layer for shifting the phase of transmitted light. 4. The photomask according to claim 2, wherein:
The photomask, wherein the first layer composed of a plurality of layers has at least one of an antireflection film as an uppermost layer and a material having a chemical property different from that of the second layer. 5. The photomask according to claim 2, wherein the lowermost layer of the plurality of first layers is an antireflection film. 6. illuminates the illumination light on a photomask according to any one of claims 1 to 5, the exposure method comprising exposing the photosensitive substrate with the illumination light via the photomask. 7. A method of manufacturing a photomask in which a circuit pattern is formed on a substrate which is substantially transparent to illumination light, wherein a first layer having a predetermined transmittance for the illumination light is formed on the substrate. At the same time, the second layer is formed so as to be superposed on the first layer so that the transmittance for the illumination light is substantially zero, and the circuit pattern is configured by the first layer,
The light-shielding band provided on the periphery of the circuit pattern on the transparent substrate and defining the formation region of the circuit pattern has a multi-layer structure including the first and second layers. A method of manufacturing a photomask, characterized in that the first and second layers are partially removed. 8. The method of manufacturing a photomask according to claim 7, wherein the first layer forming the circuit pattern is composed of a plurality of layers. 9. The photomask according to claim 8, wherein the first layer is formed, and the second layer is overlaid on the first layer before partially removing the first layer. A method of manufacturing a photomask, comprising forming and then partially removing the first and second layers, respectively.