TWI604267B - Method of manufacturing a photomask and method of manufacturing display device - Google Patents

Description

Method for manufacturing photomask and method for manufacturing display device

The present invention relates to a method of manufacturing a photomask and a method of manufacturing the display device.

A multi-step mask having a light-shielding portion, a light-transmitting portion, and a first semi-transmissive portion and a second semi-transmissive portion having different light transmittances is known.

Patent Document 1 describes a method for producing a fourth-order photomask, which is prepared by sequentially forming a first semi-transmissive film and a light-shielding film containing a material resistant to etching of each other on a light-transmitting substrate. After the light-shielding film and the first semi-transmissive film are etched, the second semi-transmissive film is formed, and further, etching is performed to form a light-transmitting portion, a light-shielding portion, a first semi-transmissive portion, and a second Semi-transmissive portion.

Further, Patent Document 2 describes an invention in which a method of manufacturing a fourth-order photomask is performed by performing surface treatment different from other regions on a partial region of the semi-transmissive film, thereby forming different light transmittances. The first and second semi-transmissive portions.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2007-249198

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2009-230126

In the method described in Patent Document 1, a plurality of semi-transmissive films each having a predetermined light transmittance are prepared and sequentially etched. The method must set the composition or film thickness of the plurality of semi-transmissive films according to the combination of the required light transmittances, and carry out a complicated film forming step, which is not only the case, but also has the following restrictions: it can be formed only before the film formation. The light transmittance.

Further, since the light transmittance of the formed laminate is substantially determined by each of the single films constituting the layer, fine adjustment of the light transmittance cannot be performed. Further, since the light caused by the interface between the semi-transmissive films of the layers is generated, the calculation of the light transmittance obtained as a result is performed in advance, and a verification load is generated in advance.

In the manufacturing method of Patent Document 2, the film thickness is adjusted so as to reduce the light transmittance by the film reduction of the semi-transmissive film, thereby making the first difference to be small with respect to the light transmittance difference. 2 The semi-transmissive portion forms a desired difference in light transmittance. However, in the film-removing step, only the direction for increasing the transmittance can be adjusted, and the light transmittance temporarily higher than the desired value cannot be corrected to the lower side. Therefore, it is difficult to determine the end point of the film-removing step. It is consistent with the light transmittance of the target.

In other words, in the light transmittance adjustment of the semi-transmissive portion, it is preferable to accurately measure the light transmittance in the film-reducing step, and to accurately grasp the film before the light transmittance reaches the target value. time.

However, in a display device represented by a liquid crystal display device or an organic EL (Electroluminescence) display device, higher quality is required for brightness, speed of operation, power saving, resolution, and the like.

In the production of the display device, for example, in order to form a three-dimensional structure such as a contact hole using a photosensitive resin such as an organic insulating film, a lithography method using a photomask is preferably applied. In particular, a three-dimensional structure in which an insulating film having a partial height is different or a plurality of photosensitive spacers having different heights from each other is complicated, and in order to efficiently produce the three-dimensional structure, multi-step light is generated. The need for a cover. In order to precisely form such a purpose The three-dimensional structure of the reticle is important for the management of the light transmittance of the reticle used.

In particular, it is estimated that it is advantageous to use a fourth-order or higher-order photomask (that is, a multi-step light having first and second semi-transmissive portions having different light transmittances of exposure, in addition to the light-transmitting portion and the light-shielding portion) cover). In order to precisely form the plurality of semi-transmissive portions having transmittances different from each other, the light transmittance control is more critical. In other words, when the light transmittance of each of the first semi-transmissive portion and the second semi-transmissive portion is not accurately formed as a design value, it is not possible to perform a function in a final device such as a display device.

The structure 1 of the present invention is a method for producing a photomask, comprising: patterning the optical film of a photomask substrate on which an optical film is formed on a transparent substrate to form a transfer pattern, comprising: a step of forming an optical film on the transparent substrate and applying a photomask substrate of the first resist film to the optical film; and a first resist pattern forming step of the first resist The first patterning step is performed by drawing a first drawing pattern on the film, and the first patterning step is to remove the optical film by using the first resist pattern as a mask to expose one surface of the transparent substrate; a step of peeling off the first resist pattern and recoating the second resist film; and a second resist pattern forming step of drawing the second drawing pattern on the second resist film and performing development And exposing one portion of the surface of the transparent substrate and a portion of the surface of the optical film to each other; and the second patterning step of etching and thinning the optical film by using the second resist pattern as a mask; Will be on a step of peeling off the second resist pattern; and exposing the exposed portion of the transparent substrate in the second resist pattern to a size smaller than an exposed portion of the transparent substrate in the first resist pattern by a specific amount square In the formula, the second drawing pattern is reduced in size.

According to a second aspect of the present invention, in a method of manufacturing a photomask, the photomask includes a transfer pattern including a light transmitting portion and a semi-transmissive portion having a desired light transmittance of exposure, and the photomask is provided on the transparent substrate. The manufacturing method includes a step of preparing a photomask substrate on which an optical film is formed on the transparent substrate and a first resist film is applied to the optical film, and a first resist pattern forming step. The first resist film is removed by drawing the first drawing pattern on the first resist film, and the first resist film is removed from the portion corresponding to the light transmitting portion. The first patterning step is to apply the first resist The etching agent pattern is used as a mask to etch away the optical film to expose the surface of the transparent substrate; the step of peeling off the first resist pattern and recoating the second resist film; and the second resist a pattern forming step of removing a second resist film corresponding to each of the light transmitting portion and the semi-light transmitting portion by drawing the second drawing pattern on the second resist film and developing the film; 2 a patterning step of the second resist a pattern as a mask, and etching and thinning the optical film to form a semi-transmissive portion having a desired light transmittance of exposure; and a step of peeling off the second resist pattern; and the second drawing The pattern is reduced in size corresponding to the light-transmitting portion by a specific size dimension with respect to the design size of the light-transmitting portion.

According to a third aspect of the present invention, in the method of manufacturing a photomask according to the second aspect, the etching rate at the time of etching and thinning the optical film is 0.3 to 5.0%/min in terms of a change in transmittance of the exposed light.

The fourth aspect of the present invention is the method for producing a photomask according to the second or third aspect, characterized in that the film thickness of the optical film subjected to the etching reduction is 50 to 2000 Å.

The fifth aspect of the present invention relates to a method of manufacturing a photomask having a light-shielding portion, a light-transmitting portion, and a transfer pattern having a semi-transmissive portion having a desired light transmittance of exposure. Further, the manufacturing method includes a photomask substrate on which a semi-transparent film, an etching stopper film, and a light shielding film are laminated on the transparent substrate, and the first resist film is coated on the laminate. a first resist pattern forming step of removing a first resist film corresponding to the light transmitting portion by drawing the first pattern on the first resist film and developing the film; a patterning step of etching the light-removing film, the etching stopper film, and the semi-transmissive film to expose a surface of the transparent substrate by using the first resist pattern as a mask; and the first resist a step of removing and recoating the second resist film; and a second resist pattern forming step of removing the second pattern by drawing the second pattern on the second resist film The light portion and the semi-transmissive portion respectively correspond to a second resist film; a second patterning step of etching the semi-transmissive film by etching and removing the light-shielding film and the etching stopper film by using the second resist pattern as a mask a first semi-transmissive portion having a light transmittance of the exposure required as described above, and a step of peeling off the second resist pattern; and the second drawing pattern pair corresponding to the light transmitting portion Partially implemented is reduced by a specific size dimension relative to the design size of the light transmitting portion.

According to a sixth aspect of the invention, in the method of manufacturing the reticle of the fifth aspect, the transfer pattern further includes a second semi-transmissive portion, and the second semi-transmissive portion has the first semi-transmissive portion a light transmittance of different exposures, and the method includes the steps of: re-coating the third resist film after peeling off the second resist pattern; a third resist pattern forming step of removing a portion corresponding to the second semi-transmissive portion different from the one semi-transmissive portion by drawing the third drawing pattern on the third resist film and developing the third resist pattern a third resist film; the third patterning step of etching the removal of the light shielding film and the etching stopper film by using the third resist pattern as a mask to form a second semi-transmissive portion; The step of peeling off the third resist pattern.

According to a seventh aspect of the invention, in the method of manufacturing the reticle of the fifth aspect, the transfer pattern further includes a second semi-transmissive portion, and the second semi-transmissive portion has the first semi-transmissive portion a light transmittance of different exposures, and the method includes: a step of recoating the third resist film after peeling off the second resist pattern; and a third resist pattern forming step by using the above The third resist film traces the third drawing pattern and develops, and removes the third resist film corresponding to the second semi-transmissive portion and the light transmitting portion; and the third patterning step The third resist pattern is used as a mask to etch away the light shielding film and the etching stopper film, and further, the semi-transmissive film is etched and thinned to form the second semi-transmissive portion; and the third resist is formed a step of peeling off the pattern of the agent; and the third drawing pattern is configured to reduce a size corresponding to the light-transmitting portion by a specific size to a portion corresponding to the light-transmitting portion.

According to a sixth aspect of the present invention, in a method of manufacturing a photomask, the photomask includes a transfer pattern including a light transmitting portion and a semi-transmissive portion having a desired light transmittance of exposure, and the photomask is provided on the transparent substrate. The manufacturing method includes the steps of: preparing a photomask substrate having a semi-transmissive film, an etching stopper film, and a light-shielding film on the transparent substrate and applying the first resist film on the laminate; a resist pattern forming step by drawing the first resist film first The first resist film is removed by drawing a pattern and developing the portion corresponding to the light transmitting portion and the semi-transmissive portion, and the first patterning step is performed by using the first resist pattern as a mask. Etching and removing the light-shielding film and the etching stopper film to expose the surface of the semi-transmissive film; peeling off the first resist pattern and recoating the second resist film; and second resist a pattern forming step of removing a second resist film corresponding to the light transmitting portion by drawing the second drawing pattern on the second resist film and performing development; and a second patterning step Etching and removing the semi-transmissive film as a mask to form the light-transmitting portion; peeling the second resist pattern and recoating the third resist film; a third resist pattern forming step of removing the third resist corresponding to the light transmitting portion and the semi-transmissive portion by drawing the third drawing pattern on the third resist film and developing the third resist pattern a film of the third patterning step of the third resist a pattern as a mask for etching and thinning the semi-transmissive film to form a first semi-transmissive portion having a desired light transmittance of exposure; and a step of peeling off the third resist pattern; The second drawing pattern includes a portion for which a portion corresponding to the light transmitting portion is increased by a specific size with respect to a design size of the light transmitting portion, and the third drawing pattern is applied to a portion corresponding to the light transmitting portion. The size of the light-transmitting portion is reduced by a specific size, and the portion corresponding to the first semi-transmissive portion is increased by a specific amount with respect to the design size of the first semi-transmissive portion. Size plus size.

The ninth aspect of the present invention is a method of manufacturing a reticle comprising a first semi-transmissive portion including a light-transmitting portion and having a desired light transmittance of light, and having a light-receiving portion a pattern for transfer of a second semi-transmissive portion having a light transmittance of exposure required to be different from the first semi-transmissive portion, and the method of manufacturing the method comprising: preparing a layer on the transparent substrate a step of applying a photomask substrate of a first resist film to the laminate, a light-transmissive film, an etching stopper film, and a light-shielding film; and a first resist pattern forming step by using the first resist The first resist pattern is formed by drawing the first drawing pattern on the film, and removing the first resist film corresponding to the light transmitting portion, the first semi-transmissive portion, and the second semi-transmissive portion; the first patterning step The light-shielding film and the etching stopper film which are portions of the first light-receiving portion, the first semi-transmissive portion, and the second semi-transmissive portion are removed by etching the first resist pattern as a mask And exposing the surface of the semi-transmissive film; removing the first resist pattern and recoating the second resist film; and forming a second resist pattern by the second The resist film traces the second drawing pattern and develops it, and removes the pair of the light transmitting portions a second resist film; a second patterning step of etching and removing the semi-transmissive film by using the second resist pattern as a mask to form the light transmitting portion; and the second resist a step of peeling off and etching the third resist film; and a third resist pattern forming step of removing the third resist pattern by the third resist film and performing development a third resist film corresponding to a portion corresponding to the first semi-transmissive portion; and a third patterning step of applying the third resist pattern as a mask to the first semi-transparent light The semi-transmissive film corresponding to the portion is etched and thinned to form the first semi-transmissive portion; and the step of peeling off the third resist pattern; and the second drawing pattern includes the pair and the light transmissive The portion corresponding to the portion is increased in size by a specific size relative to the design size of the light transmitting portion, The third drawing pattern is configured such that a portion corresponding to the light transmitting portion is reduced by a specific size with respect to a design size of the light transmitting portion, and a portion corresponding to the first semi-light transmitting portion is implemented. The size of the specific size is increased with respect to the design size of the first semi-transmissive portion.

The method of manufacturing a photomask according to any one of the first to eighth aspects of the present invention, characterized in that the transfer pattern includes the light transmitting portion surrounded by the light shielding portion.

The method of manufacturing a photomask according to any one of the items 2 to 10, wherein the transfer pattern includes the light transmitting portion surrounded by the semi-transmissive portion.

The method of manufacturing a photomask according to any one of 2 to 11, wherein the semi-transmissive portion of the transfer pattern includes a first semi-transmissive portion and an exposed light transmittance The second semi-transmissive portion is higher than the first semi-transmissive portion, and the transfer pattern includes the second semi-transmissive portion surrounded by the one semi-transmissive portion.

The present invention is directed to a method of manufacturing a display device, comprising the steps of: preparing a photomask manufactured by the constitution of any one of 1 to 12; and using the prepared photomask and exposure apparatus The transfer pattern is transferred onto the transfer target.

According to the present invention, the desired amount of film can be correctly applied to the optical film formed by one film formation.

1‧‧‧Photomask substrate

10‧‧‧Transparent substrate

20‧‧‧ Semi-transparent film

30‧‧‧etch stop film

40‧‧‧Shade film

50‧‧‧resist film

50'‧‧‧Resist film

50"‧‧‧Resist film

60‧‧‧Optical film

E‧‧‧ edge

S‧‧‧ position offset

The exposed part of the W1‧‧ transparent substrate

Design dimensions of the exposed portion of the W1a‧‧ transparent substrate 10

The exposed portion of the W2‧‧ transparent substrate 10

Dimensions of the exposed portion of the W2a‧‧ transparent substrate 10

W3‧‧‧ exposed part of transparent substrate 10

Dimensions of the exposed portion of the W3a‧‧ transparent substrate 10

Edge of X1‧‧

X2‧‧‧ edge

1(a) to 1(g) are explanatory views for explaining a first reference example of a method of manufacturing a photomask for obtaining a specific light transmittance of exposure.

2(a) to 2(g) are explanatory views for explaining a second reference example of a method of manufacturing a photomask for obtaining a specific exposure light transmittance.

3(a) to 3(h) are explanatory views for explaining a first embodiment of a method of manufacturing a photomask according to the present invention.

4(a) to 4(n) are explanatory views for explaining a second embodiment of the method of manufacturing the photomask of the present invention.

5(a) to 5(o) are explanatory views for explaining a third embodiment of the method of manufacturing a photomask according to the present invention.

6(a) to 6(n) are explanatory views for explaining a fourth embodiment of the method of manufacturing the photomask of the present invention.

7(a) to 7(o) are explanatory views for explaining a fifth embodiment of the method of manufacturing a photomask according to the present invention.

8(a) to 8(k) are explanatory views for explaining a sixth embodiment of the method of manufacturing a photomask according to the present invention.

9(a) to 9(m) are explanatory views for explaining a seventh embodiment of the method of manufacturing a photomask according to the present invention.

10(a) to 10(c) are explanatory views for explaining the configuration of a transfer pattern produced by the method for producing a photomask of the present invention.

A method of reducing the optical film of the photomask to obtain a desired light transmittance (relative to the light transmittance of the exposed light) will be described with reference to the reference examples shown in FIGS. 1 and 2.

Further, in the present application, the film-reduction film causes the film to be applied to partially disappear in the thickness direction, and the film thickness is reduced. Further, by reducing the film only to a specific region of the film to be the target, the light transmittance of the portion can be adjusted.

FIG. 1 is an explanatory view for explaining a first reference example of a step of forming a transfer pattern of a multi-step mask including a light transmitting portion, a light blocking portion, and a semi-light transmitting portion.

First, the semi-transmissive film 20, the etching stopper film 30, and the light shielding film 40 are sequentially laminated on the transparent substrate 10, and the mask substrate 1 on which the resist film 50 is formed is applied on the surface (Fig. 1(a)).

The term "resist" as used in the present application refers to a resist for a lithography method comprising a photoresist or an electron beam resist. In the following description, a positive resist is used as a resist as an example.

Here, the mask substrate 1 shown in FIG. 1(a) is a mask substrate. However, in the present application, as the photomask substrate, in addition to the mask substrate, light that has been specifically patterned and used to form a mask by performing further film formation and/or patterning may be used. Cover the middle.

Next, a specific drawing pattern for forming a semi-transmissive portion is drawn using a drawing device. The EB (Electron Beam) drawing device and the laser drawing device are exemplified as the drawing device. However, it is preferable to use a laser drawing device for the photomask for manufacturing the display device. After the resist pattern is formed by development, the resist pattern is used as an etching mask, and the exposed light shielding film 40 and the etching stopper film 30 are removed (FIG. 1(b)). Here, a film containing Cr is exemplified as the light shielding film 40, and a film containing Si is exemplified as the etching stopper film 30. Further, a wet etchant (etching solution) is used in the etching step.

Further, the exposed semi-transmissive film 20 is subjected to a film-reduction treatment to reduce the film thickness to obtain a desired film thickness (Fig. 1 (c)). The required film thickness is calculated in advance based on the light transmittance of the desired exposure to be obtained and the light transmission characteristics of the material or film quality derived from the semi-transmissive film. That is, the etching rate depending on the light transmission characteristics and the specific etchant (etching agent) can be determined in advance, whereby the necessary etching time can be grasped in advance.

The resist pattern (resist film 50) is peeled off after the film-reduction process shown in FIG. 1(c) (FIG. 1(d)).

Further, the second resist film 50' is applied to the surface, and the second drawing pattern for forming the light transmitting portion is drawn and developed, thereby forming a second resist pattern (Fig. 1(e)).

Then, the second resist pattern is used as an etching mask, and the light shielding film 40, the etching stopper film 30, and the semi-transmissive film 20 are sequentially removed by etching (FIG. 1(f)). Thereby, the surface of the transparent substrate 10 Exposed to form a light transmitting portion.

Finally, when the second resist pattern (second resist film 50') is peeled off, the multi-step mask is completed (Fig. 1 (g)).

Here, if the time for performing the etching reduction film shown in FIG. 1(c) is adjusted, a multi-step mask having various light transmittances of exposure can be manufactured from the same mask substrate. Therefore, there is no need to prepare a plurality of reticle substrates, and the degree of freedom of light transmittance of the desired multi-step reticle can be selected according to the desire of the reticle user.

However, the etching end point for obtaining the desired light transmittance of the exposure is set only based on the pre-established etching rate, and there is no mechanism for confirming the etching end point. That is, it is impossible to reflect the fluctuation of the etching rate due to a slight concentration fluctuation of the etching liquid or the temperature to the setting of the accurate etching end point. Therefore, it is useful to measure the light transmittance of the semi-transmissive film 20 and obtain the time required until the end of etching in the middle of etching and film-reduction.

In order to grasp the light transmittance of the exposure of the semi-transmissive portion of the mask, an optical transmittance detector can be used. The measuring device can indicate the light transmittance value of the semi-transmissive portion to be measured, based on the light transmittance of the transparent substrate (transmittance: 100%). Therefore, when measuring the light transmittance of the semi-transmissive portion of the reticle, the light transmittance is also measured for the light-transmitting portion of the same sample (mask substrate), and it is reasonable to use it as a reference value. The light used in the measurement is substantially the same wavelength (or wavelength region) as that used for the exposure light used in the actual exposure, or light of a representative wavelength included in the exposed light may be used. According to the measurement result of the light transmittance, the light transmittance of the actual exposure can be grasped.

However, in the first reference example, the light transmittance of the transparent substrate 10 cannot be referred to in the step of etching the film.

Therefore, as in the second reference example, the step of referring to FIG. 2 for the light transmittance of the transparent substrate in the step of etching and thinning can be studied.

In the second reference example, the same mask substrate 1 (mask base) as in Fig. 1(a) is prepared. Thereafter, the resist film 50 is drawn using a drawing pattern for forming a light transmitting portion (Fig. 2(a)). After the resist film 50 is developed to form a resist pattern, the resist pattern is used as an etching mask to sequentially remove the exposed light shielding film 40, the etching stopper film 30, and the semi-transmissive film 20.

Then, the resist pattern (resist film 50) is peeled off (FIG. 2(b)), and the second resist film 50' is applied (FIG. 2(c)).

Then, a drawing pattern for forming a semi-transmissive portion and exposing a portion of the transparent substrate 10 corresponding to the light-transmitting portion is drawn, and development is performed to form a second resist pattern (FIG. 2(d)).

The second resist pattern is used as a mask to remove the light shielding film 40 and the etching stopper film 30 (FIG. 2(e)). Further, the semi-transmissive film 20 is subjected to a desired amount of etching film reduction (Fig. 2(f)). At this time, since one of the light transmitting portions is partially exposed, the amount of etching reduction for forming the semi-transmissive portion can be adjusted and confirmed while referring to the light transmittance of the transparent substrate 10.

However, in the second reference example, it is difficult to surely shift the positional shift S (see FIG. 2(d)) of the two drawing steps performed as described above to zero. Therefore, the position of the light transmitting portion exposed from the second resist pattern is displaced from the position of the light transmitting portion exposed from the first resist pattern, and the edge of the light shielding film adjacent to the light transmitting portion is damaged. Therefore, there is a risk that a portion that transmits a light amount larger than the amount of light set for the light transmitting portion functions (resulting in a result that the light transmitting portion becomes larger than the design size).

The present inventors conducted intensive studies to suppress the occurrence of such a problem and to properly control the film reduction of the optical film.

Hereinafter, each embodiment of the method of manufacturing the photomask of the present invention will be described with reference to Figs. 3 to 10 .

[First Embodiment]

Fig. 3 is an explanatory view for explaining a first embodiment of a method of manufacturing a photomask according to the present invention.

Step 1: As shown in FIG. 3(a), the optical film 60 is formed on the transparent substrate 10, and the mask substrate 1 on which the first resist film 50 is formed is further formed. Here, the mask substrate 1 is a mask base, but it may be a part of the pattern that has been patterned as a mask substrate.

Further, the first resist film 50 in the mask substrate 1 can be directly formed on the surface of the optical film 60, and can be applied to the first resist film 50 and the optical layer within a range that does not impair the effects of the present invention. Other films are interposed between the membranes 60. The optical film 60 may be a light-shielding film, may be a semi-transmissive film, or may have a function of shifting the phase of the exposed light by a specific amount (phase shift film). Further, the surface portion of the optical film 60 may have an antireflection layer that suppresses reflection of light. Further, the optical film 60 may be laminated with a plurality of layers. For example, in FIG. 3, the case where the optical film 60 is a light-shielding film is illustrated.

The film formation of the optical film 60 can be performed by a well-known film formation method, such as a sputtering method.

The film material is not particularly limited. Although the light-shielding film is exemplified here, as a light-shielding film material, the light-shielding film which has Cr as a main component is mentioned, for example. It is preferred to have an antireflection layer such as a Cr oxide on the surface portion of the film.

Step 2: A drawing pattern (first drawing pattern) for forming a light transmitting portion is drawn using a drawing device. After the drawing, the first development is performed to form a first resist pattern (Fig. 3(b)). Here, since a positive type photoresist is used as the resist, the resist of the drawing portion is removed.

Step 3: The optical film 60 (light-shielding film) is removed by etching the first resist pattern formed in the step 1 as an etching mask (Fig. 3(c)). Here, wet etching is performed using a known etching solution. Thereby, the light transmitting portion is defined (first patterning step).

Step 4: The first resist pattern (resist film 50) is peeled off (Fig. 3(d)).

Step 5: The second resist film 50' is again coated on the surface (Fig. 3(e)).

Step 6: The second drawing pattern is drawn again using the drawing device, and the second development is performed. Thereby, the portion corresponding to the light transmitting portion and the second resist film 50' corresponding to the semi-transmissive portion are removed, and a part of the surface of the transparent substrate 10 and the surface of the optical film 60 are formed. A part of the second resist pattern is exposed (Fig. 3(f)). Further, the data of the second drawing pattern is sized so that the exposed portion W2 of the transparent substrate 10 is smaller than the exposed portion W1 of the transparent substrate in the first resist pattern. In other words, in the second drawing pattern, the portion corresponding to the light transmitting portion is reduced in size by a specific size with respect to the design size of the light transmitting portion. Thereby, even if a positional shift occurs between the first drawing pattern and the second drawing pattern, the edge E of the optical film 60 in the light shielding portion adjacent to the light transmitting portion formed in the step 2 (refer to FIG. 3 (c) ))) is not exposed from the second resist pattern.

Step 7: The second resist pattern is used as a mask to etch and reduce the exposed portion of the optical film 60 (second patterning step). Thereby, a semi-transmissive portion having a desired light transmittance of exposure is formed (Fig. 3(g)). The etching rate at the time of etching and thinning the optical film is preferably set to 0.3 to 5.0%/min in terms of the change in transmittance of the exposed light. That is, it is easy to accurately perform the desired increase in transmittance by setting a condition that is sufficiently slow compared to the case where the specific portion of the optical film is etched and removed. Further, in the second to seventh embodiments, the etching rate at the time of etching and film-reducing is also preferably set in the same manner.

At this time, since the edge of the light-shielding portion adjacent to the light-transmitting portion is covered by the second resist pattern as described above, it is not damaged, and as a result, the size of the light-transmitting portion defined in FIG. 3(c) is not Will produce an error.

Further, since the portion of the transparent substrate 10 corresponding to the light transmitting portion is exposed, the light transmittance of the transparent substrate 10 exposed by the first patterning step can be measured before the etching film is removed or in the middle of the etching film reduction. Therefore, the light transmittance of the transparent substrate 10 can be measured as a reference, and the light transmittance before the film is reduced or the light transmittance in the middle of the film can be reduced, and the end point of the film can be accurately expected. Of course, it is also confirmed whether or not the desired light transmittance is obtained at the stage of etching the film at a specific time.

Step 8: The second resist pattern is peeled off, and a third-order photomask having a light transmitting portion, a light blocking portion, and a semi-light transmitting portion is completed (FIG. 3(h)).

Further, in the first embodiment, a single layer of light shielding film is exemplified as the optical film 60. However, the present invention is not limited to such a configuration. In the embodiment shown below, a case where the optical film has a laminated structure will be described.

[Second Embodiment]

Next, a second embodiment of the present invention will be described with reference to Fig. 4 .

The manufacturing method of the reticle shown in FIG. 4 exemplifies a method of manufacturing a multi-step reticle using a laminate including a semi-transmissive film 20, an etch-stop film 30, and a light-shielding film 40 as a transparent substrate. 10 optical film.

Step 1: Prepare the optical substrate including the semi-transmissive film 20, the etching stopper film 30, and the light-shielding film 40 on the transparent substrate 10, and further form the photomask substrate 1 on which the first resist film 50 is formed (Fig. 4(a)). The semi-transmissive film 20 is a film having a specific light transmittance for partially exposing the exposed light. In the present embodiment, for example, the light transmittance of the exposure is 50 to 60%.

Further, the light shielding film 40 and the etching stopper film 30 contain materials having etching selectivity and etching resistance to each other (here, applying wet etching and thus etching liquid) to each other. Further, the semi-transmissive film 20 and the etching stopper film 30 also contain materials which are resistant to each other's etchants. The light shielding film 40 and the semi-transmissive film 20 may have an etching selectivity with each other or may have no etching selectivity. Therefore, here, the materials of the light shielding film 40 and the semi-transmissive film 20 are common to the etching characteristics including Cr.

Step 2: A drawing pattern (first drawing pattern) for forming a light transmitting portion is drawn using a drawing device. After the drawing, the first development is performed to form a first resist pattern (Fig. 4(b)).

Step 3: The first resist pattern formed in the step 2 is used as an etching mask to etch away the light shielding film 40 (Fig. 4(c)).

Step 4: The etching stopper film 30 is etched and removed by changing the etching agent for the etching stopper film 30 (Fig. 4(d)).

Step 5: The etchant is changed again, and the semi-transmissive film 20 is removed by etching with the etchant for the semi-transmissive film 20. Thereafter, the first resist pattern (first resist film 50) is peeled off (Fig. 4(e)).

Step 6: The second resist film 50' is formed again on the surface (Fig. 4(f)).

Step 7: The second drawing pattern is drawn again using the drawing device, and the second development is performed. Thereby, the portion corresponding to the light transmitting portion and the second resist film 50' corresponding to the semi-transmissive portion (first semi-transmissive portion) are removed, and a part of the surface of the transparent substrate 10 is formed and the light is blocked. The second resist pattern is exposed to one of the surfaces of the film 40 (Fig. 4(g)).

Further, the data of the second drawing pattern is sized so that the exposed portion W2 of the transparent substrate 10 is smaller than the exposed portion W1 of the transparent substrate 10 in the first resist pattern. In other words, in the second drawing pattern, the portion corresponding to the light transmitting portion is reduced in size by a specific size with respect to the design size of the light transmitting portion. Thereby, even if the first drawing pattern and the second drawing pattern are displaced from each other, the light shielding film 40, the etching stopper film 30, and the semi-transparent light in the light shielding portion adjacent to the light transmitting portion formed in the step 5 are formed. The edge E (see FIG. 4(e)) of the film 20 is also not exposed from the second resist pattern.

Step 8: etching the removed portion of the light-shielding film 40 by using the second resist pattern as a mask. Further, the etching stopper is removed by etching the etchant (Fig. 4(h)).

Step 9: Next, the etchant is changed, and the exposed semi-transmissive film 20 is etched and thinned (second patterning step). Thereby, a semi-transmissive portion (first semi-transmissive portion) having a desired light transmittance of exposure is formed (FIG. 4(i)).

At this time, as described above, the edge E (see FIG. 4(e)) of the light-shielding portion adjacent to the light-transmitting portion is covered by the second resist pattern, so that it is not damaged, and as a result, it is defined in step 5. The size of the light transmitting portion does not cause an error. Further, since the transparent substrate 10 corresponding to the light transmitting portion is exposed, the light transmittance of the transparent substrate 10 can be measured. Therefore, the light transmittance of the transparent substrate 10 can be used as a reference, and the light transmittance before the film is reduced or the light transmittance in the middle of the film can be measured, and the end point of the film can be accurately predicted. Of course, it is also confirmed that the desired light transmittance is obtained at the stage of etching and film-reduction at a specific time.

Step 10: peeling off the second resist pattern (second resist film 50') to complete The third-order photomask of the light portion, the light-shielding portion, and the semi-transmissive portion (Fig. 4(j)).

In addition to the light-transmitting portion and the light-shielding portion, the fourth-order light of the transfer pattern of the two semi-transmissive portions (the first and second semi-transmissive portions) having different light transmittances after exposure is provided. In the case of a cover, the following steps can be carried out for the mask of Fig. 4(j).

Step 11: Forming a third resist film 50" on the surface (Fig. 4(k)).

Step 12: Using a drawing device, drawing a drawing pattern (third drawing pattern) for forming an additional semi-transmissive portion (second semi-transmissive portion), and performing third development to form a third resist pattern (Fig. 4(l)).

Step 13: The third resist pattern is used as a mask, and the light shielding film 40 and the etching stopper film 30 are removed by etching to form a second semi-transmissive portion (Fig. 4(m)).

Step 14: peeling off the third resist pattern (third resist film 50"), and completing the fourth-order light including the light transmitting portion, the light blocking portion, the first semi-light transmitting portion, and the second semi-light transmitting portion Cover (Fig. 4(n)).

By the above steps, the first semi-transmissive film 20 can be used to form a plurality of first and second semi-transmissive portions having different light transmittances of the exposure.

[Third embodiment]

Next, a third embodiment of the present invention will be described with reference to Fig. 5 . According to the third embodiment, in the second semi-transmissive portion (see Fig. 4(n)) of the second embodiment, the transmittance is adjusted differently from that at the time of film formation to obtain a higher transmittance of light transmittance. By.

In the method of manufacturing the reticle according to the third embodiment shown in FIG. 5, steps 1 to 11 (see FIGS. 5(a) to 5(k)) and steps 1 to 11 in the second embodiment (see FIG. 4(a)~(k)) is the same. That is, the mask substrate 1 is prepared (Step 1: FIG. 5(a)), a first resist pattern is formed (Step 2: FIG. 5(b)), and the portion of the light-shielding film 40 corresponding to the light-transmitting portion is removed by etching. After etching the termination film 30 (steps 3 and 4: FIGS. 5(c) and (d)), the semi-transmissive film 20 is removed by etching (first patterning step), and the first resist pattern (first resist) is removed. The film 50) is peeled off (step 5: Fig. 5(e)).

Then, the second resist film 50' is reformed (step 6: FIG. 5(f)), and a second resist pattern is formed (step 7: FIG. 5(g)), and the first semi-transparent is removed by etching. Light-shielding film 40 and eclipse The film 30 is stopped (step 8: Fig. 5(h)). Further, after the semi-transmissive film 20 is etched and thinned (step 9 (second patterning step): FIG. 5 (i)), the second resist pattern (second resist film 50') is peeled off ( Step 10: Fig. 5(j)), a third resist film 50" is formed on the surface thereof (Step 11: Fig. 5(k)).

Step 12: The third drawing pattern is drawn using the drawing device and the third development is performed. Thereby, the portion corresponding to the light transmitting portion and the third resist film 50" corresponding to the second semi-light transmitting portion are removed, and a part of the surface of the transparent substrate 10 and a part of the surface of the light shielding film 40 are formed. The third resist pattern is exposed (Fig. 5(l)).

Here, the data of the third drawing pattern is also sized such that the exposed portion W3 of the transparent substrate 10 is smaller than the exposed portion W1 of the transparent substrate 10 in the first resist pattern. In other words, the third drawing pattern is a size reduction of a portion corresponding to the light transmitting portion by a specific size dimension with respect to the design size of the light transmitting portion. Therefore, even if a positional shift occurs between the first drawing pattern and the third drawing pattern, the edge E (see FIG. 5(e)) of the light blocking portion adjacent to the light transmitting portion formed in step 5 does not occur. The second resist pattern is exposed.

Step 13: The third resist pattern is used as a mask, and the light-shielding film 40 of the exposed portion corresponding to the second semi-transmissive portion is removed by etching. Further, the etchant is changed to etch away the etching stopper film 30 (Fig. 5(m)).

Step 14: Next, the exposed etchant is changed to etch and reduce the exposed semi-transmissive film 20 (third patterning step). Thereby, the second semi-transmissive portion having the desired light transmittance of the exposure is formed (Fig. 5(n)).

At this time, the edge E of the light shielding portion adjacent to the light transmitting portion shown in FIG. 5(e) is also covered by the third resist pattern, so that it is not damaged, and as a result, the light is defined in step 5. The size of the department does not produce errors. Further, similarly to the step 9 (see FIG. 5(i)), since the transparent substrate 10 corresponding to the light transmitting portion is exposed, the exposure of the transparent substrate 10 can be referred to when the semitransparent film 20 is etched and thinned. Light transmission rate.

Step 15: The third resist pattern (third resist film 50") is peeled off, and the first and second semi-transmissive portions having the light transmitting portion, the light blocking portion, and the light transmittance of the exposure are different from each other. The fourth-order reticle (Fig. 5(o)).

According to the above steps, the mask substrate (mask base) similar to that of the second embodiment can be used as a starting material, and a fourth-order mask having different specifications of the light transmittance of the exposure can be manufactured.

[Fourth embodiment]

Next, a fourth embodiment of the present invention will be described with reference to Fig. 6 .

In the fourth embodiment, the photomask substrate 1 similar to that described in FIG. 4(a) is prepared (step 1: FIG. 6(a)), and the first resist pattern is formed by drawing and first development (step 2: Figure 6(b)). Then, after the light-shielding film 40 and the etching stopper film 30 corresponding to the light-transmitting portion are removed by etching (steps 3 and 4: FIGS. 6(c) and (d)), the semi-transmissive film 20 is removed by etching and the first resist is removed. The etchant pattern (first resist film 50) is peeled off (step 5: Fig. 6(e)).

Next, the second resist film 50' is formed on the surface (step 6: FIG. 6(f)), and the second resist pattern is formed by drawing and second development (step 7: FIG. 6(g)). The portion of the light shielding film 40 and the etching stopper film 30 corresponding to the first semi-transmissive portion are removed by etching (step 8: FIG. 6(h)).

Then, after the second resist pattern (second resist film 50') is peeled off (step 9: FIG. 6(i)), a third resist film 50" is formed on the surface thereof (step 10: FIG. (j)) forming a third resist pattern by drawing and third development (step 11: FIG. 6(k)). The exposed portion W3 of the transparent substrate 10 in the third resist pattern is smaller than the first The material of the third drawing pattern is sized in such a manner that the exposed portion W1 of the transparent substrate 10 in the resist pattern.

Then, after the light-shielding film 40 and the etching stopper film 30 corresponding to the second semi-transmissive portion are removed by etching (step 12: FIG. 6(1)), the semi-transmissive film 20 is etched and thinned (step 13: 6(m)), and the third resist pattern (third resist film 50") is peeled off (step 14: FIG. 6(n)).

By the above steps, the light transmissive portion, the light shielding portion, and the first and second semi-transmissive portions are completed. The 4th order mask. Further, the first semi-transmissive portion has a light transmittance that is not exposed to the semi-transmissive film 20, and the second semi-transmissive portion has a higher light transmittance than the first semi-transmissive portion. rate.

[Fifth Embodiment]

Next, a fifth embodiment of the present invention will be described with reference to Fig. 7 .

In the fifth embodiment, the same mask substrate 1 as that described in FIG. 4(a) is prepared (step 1: FIG. 7(a)), and the first resist pattern is formed by drawing and first development ( Step 2: Figure 7(b)). Then, the light shielding film 40 and the etching stopper film 30 corresponding to the first semi-light-transmitting portion are removed by etching (step 3: FIG. 7(c)). Then, after the first resist pattern (first resist film 50) is peeled off (step 4: FIG. 7(d)), the second resist film 50' is formed again on the surface (step 5: FIG. 7 ( e)) The second resist pattern is formed by drawing and second development (step 6: FIG. 7(f)).

Then, after the light-shielding film 40 and the etching stopper film 30 corresponding to the light-transmitting portion are removed by etching (steps 7 and 8: FIGS. 6(g) and (h)), the semi-transmissive film 20 is removed by etching (step 9: 7(i)). Then, after the second resist pattern (second resist film 50') is peeled off (step 10: FIG. 7(j)), a third resist film 50" is formed on the surface thereof (step 11: FIG. 7) (k)) forming a third resist pattern by drawing and third development (step 12: FIG. 7(l)). The exposed portion W3 of the transparent substrate 10 in the third resist pattern is smaller than the first The material of the third drawing pattern is sized in such a manner that the exposed portion W1 of the transparent substrate 10 in the resist pattern.

Next, after the light-shielding film 40 and the etching stopper film 30 corresponding to the second semi-transmissive portion are removed by etching (step 13: FIG. 7(m)), the semi-transmissive film 20 is etched and thinned (step 14: 7(n)), and the third resist pattern (third resist film 50") is peeled off (step 15: FIG. 7(o)).

By the above steps, the fourth-order photomask having the light transmitting portion, the light blocking portion, and the first and second semi-transmissive portions is completed. Further, the first semi-transmissive portion has a light transmittance that is not exposed to the semi-transmissive film 20, and the second semi-transmissive portion has an exposure higher than that of the first semi-transmissive portion. Light transmission rate.

[Sixth embodiment]

Next, a sixth embodiment of the present invention will be described with reference to Fig. 8 . In the sixth embodiment, the position at which the light transmitting portion and the semi-light transmitting portion are formed is determined in the first patterning step.

Step 1: Prepare the mask substrate 1 (mask base; see FIG. 4(a)) (FIG. 8(a)) similar to that of the second embodiment.

Step 2: The first drawing pattern for forming the light transmitting portion and the first and second semi-light transmitting portions is drawn by the drawing device. After the drawing, the first development is performed to form a first resist pattern (Fig. 8(b)). Here, the first semi-transmissive portion and the second semi-transmissive portion are formed such that the light transmittances of the exposures are different from each other.

Step 3: The light-shielding film 40 and the etching stopper film 30 are removed by using the first resist pattern as a mask (Fig. 8(c)).

Step 4: The first resist pattern (first resist film 50) is peeled off, and the second resist film 50' is formed by recoating (Fig. 8 (d)).

Step 5: The second drawing pattern is drawn by the drawing device and the second development is performed. Thereby, the second resist film 50' corresponding to the portion corresponding to the light transmitting portion is removed to form a second resist pattern (Fig. 8(e)). Here, the size W2a of the exposed portion of the transparent substrate 10 in the portion of the second resist pattern corresponding to the light transmitting portion is slightly larger than the transparent substrate 10 in the portion of the first resist pattern corresponding to the light transmitting portion. The second drawing pattern is sized to expose the design size W1a of the portion. Therefore, when a positional shift occurs between the first drawing pattern and the second drawing pattern, the formation of the subsequent light transmitting portion is not affected.

Step 6: The exposed second semi-transmissive film 20 is removed by etching the second resist pattern as a mask to form a light transmitting portion (Fig. 8(f)). Further, in the second drawing pattern, the portion corresponding to the light transmitting portion is dimensioned, so that the edge X1 of the light shielding film 40 in the region of the light blocking portion adjacent to the light transmitting portion is slightly exposed. When the etching characteristics of the semi-transmissive film 20 and the light-shielding film 40 are common, when the semi-transmissive film 20 is etched, the edge X1 of the light-shielding film 40 is simultaneously affected. In the case of damage. However, by adjusting the film thickness of the semi-transmissive film 20 sufficiently small relative to the film thickness of the light-shielding film 40 or making the etching rate of the semi-transmissive film 20 sufficiently small with respect to the etching rate of the light-shielding film 40, it is substantially not correct. The shape of the final transfer pattern is affected.

Step 7: The second resist pattern (second resist film 50') is peeled off (Fig. 8(g)).

Step 8: Forming a third resist film 50" on the surface (Fig. 8(h)).

Step 9: The third drawing pattern is drawn by the drawing device and the third development is performed. Thereby, the portion corresponding to the light transmitting portion and the portion corresponding to the first semi-light transmitting portion are removed, and a portion of the surface of the transparent substrate 10 and a portion of the surface of the semi-transmissive film 20 are respectively exposed. The third resist pattern (Fig. 8(i)). Further, the portion of the resist corresponding to the second semi-transmissive portion is not removed here.

Further, the second drawing is performed such that the size W3a of the exposed portion of the transparent substrate 10 is smaller than the design size W1a of the exposed portion of the transparent substrate 10 in the portion corresponding to the light transmitting portion in the first resist pattern. The data of the pattern determines the size. In other words, the third drawing pattern is a size reduction of a portion corresponding to the light transmitting portion by a specific size dimension with respect to the design size of the light transmitting portion. Therefore, even if the first drawing pattern and the third drawing pattern are displaced from each other, the edge E (see FIG. 8(c)) of the light blocking portion adjacent to the light transmitting portion formed in the step 3 is not formed. The third resist pattern is exposed.

Here, the third drawing pattern is dimensioned so that the size of the portion corresponding to the first semi-transmissive portion of the third resist pattern is slightly larger than the design size of the first semi-transmissive portion. Thereby, even if a positional shift occurs between the first drawing pattern and the third drawing pattern, the subsequent etching of the semi-transmissive film 20 is not affected.

Step 10: etching and thinning the semi-transmissive film 20 exposed at a portion corresponding to the first semi-transmissive portion using the third resist pattern as a mask (third patterning step: FIG. 8(j)) . Thereby, the first semi-transmissive portion having the desired light transmittance of the exposure is formed. At this time, in the case where the etching characteristics of the light-shielding film and the semi-transmissive film 20 are common, the edge X2 of the exposed light-shielding film 40 is simultaneously damaged by the etching and film-reduction of the semi-transmissive film 20. But borrow The adjustment is made by making the film thickness of the semi-transmissive film 20 sufficiently smaller than the film thickness of the light shielding film 40 or making the etching rate of the semi-transmissive film 20 sufficiently small with respect to the etching rate of the light shielding film 40, and the step 6 (refer to FIG. 8 (refer to FIG. 8 f)) Similarly, the shape of the final transfer pattern is not substantially affected.

In the same manner as in the first to fifth embodiments, when the semi-transmissive film 20 is etched and thinned, the portion of the transparent substrate 10 corresponding to the light-transmitting portion is exposed. Therefore, the light transmittance of the transparent substrate 10 can be referred to.

Step 11: The third resist pattern (third resist film 50") is peeled off (Fig. 8(k)).

By the above steps, the fourth-order photomask having the light-transmitting portion, the light-shielding portion, and the first and second semi-transmissive portions whose light transmittances are different from each other is completed.

An advantage of the method of manufacturing a photomask according to the sixth embodiment shown in Fig. 8 is that even if a mutual positional shift occurs in a plurality of drawing steps, the overlap of the patterning is not caused. . In other words, in the first patterning step, since the positional relationship between the light transmitting portion, the light shielding portion, and the semi-light transmitting portion is determined, the coordinate accuracy in the final transfer pattern is extremely high.

Further, of course, in the sixth embodiment, if the step of forming the second semi-transmissive portion is omitted, the photomask having excellent positional accuracy of the pattern of the light transmitting portion, the light blocking portion, and the first semi-transmissive portion can be formed. .

[Seventh embodiment]

Next, a seventh embodiment of the present invention will be described with reference to Fig. 9 . In the transparent substrate 10 used in the seventh embodiment, an optical film which is a target for film reduction is not formed, and a pattern of another optical film or another optical film is formed. In the following description, the light shielding film 40 is formed as the above other optical film.

Step 1: A mask substrate 1 (a mask substrate) in which a light shielding film 40 and a first resist film 50 are formed on a transparent substrate 10 is prepared (FIG. 9(a)).

Step 2: Using a drawing device to draw a drawing pattern for forming a light-shielding portion (translucent portion and semi-transmissive portion), and performing a first development to form a first resist that defines a light-shielding portion Pattern (Fig. 9(b)).

Step 3: The exposed first light-shielding film 40 is removed by etching the first resist pattern as a mask (Fig. 9(c)).

Step 4: The first resist pattern (first resist film 50) is peeled off (Fig. 9(d)).

Step 5: The semi-transmissive film 20 is formed again on the entire surface of the transparent substrate 10 (Fig. 9(e)).

Step 6: A second resist film 50' is formed on the entire surface of the semi-transmissive film 20 (Fig. 9(f)).

The subsequent steps are the same as those in the second step (Fig. 3(b)) of the first embodiment. That is, the second resist pattern for forming the light transmitting portion is formed by using the drawing device (Fig. 9(g)), and the semi-transmissive film 20 is etched away as an etching mask (Fig. 9(h)). Then, the second resist pattern (second resist film 50') is peeled off (FIG. 9(i)), and the third resist film 50" is formed by surface coating again (FIG. 9(j) ).

Then, the third drawing pattern for forming the second semi-transmissive portion is drawn again by the drawing device, and then developed to form a third resist pattern (Fig. 9(k)). In the third drawing pattern, the material is dimensioned such that the exposed portion W3 of the transparent substrate 10 is smaller than the exposed portion W2 of the transparent substrate 10 in the second resist pattern.

Next, the semi-transmissive film 20 of the exposed portion is etched and thinned by using the third resist pattern as a mask to form a semi-transmissive portion having a desired light transmittance of exposure (FIG. 9(1)). . Then, when the third resist pattern (third resist film 50") is peeled off, the fourth-order photomask having the light-transmitting portion, the light-shielding portion, and the first and second semi-transmissive portions is completed (FIG. 9). (m)) Here, the first semi-transmissive portion has a light transmittance that is not exposed to the semi-transmissive film 20, and the second semi-transmissive portion has a higher transmittance than the first semi-transmissive portion. The light transmittance of the exposure of the department.

Although a plurality of embodiments of the present invention have been described above with reference to FIGS. 3 to 9, the present invention is not limited to the embodiments, and various aspects are included as long as the effects of the invention are not impaired. Further, the steps in the above embodiments or other steps may be added as long as the effects of the present invention are not impaired.

In addition, the names of "1st", "2nd", and "3rd" in the description of the first to seventh embodiments The ordering means that the order of the steps is conveniently indicated, and when the other steps are performed before or after or the like, the reading can be appropriately changed.

In all of these aspects, it is more preferred to apply wet etching during etching. In particular, in the reticle for device manufacturing, it is necessary to produce a plurality of reticle substrates having a larger size of 300 mm or more and having various aspect ratios or areas. Therefore, the effect of applying wet etching is large.

Further, the amount of the determined size (added size, reduced size) of the drawing pattern can be set to 0.2 to 2.0 μm. In other words, the size of each region is increased or decreased by 0.1 to 1.0 μm with respect to the design size of the region for the light transmitting portion, the semi-light transmitting portion, or the light shielding portion.

Further, in the first to sixth embodiments, the photomask base on which the optical film and the resist film are formed on the transparent substrate is shown as a starting material, but of course, as exemplified in the seventh embodiment. A reticle intermediate that has been subjected to some patterning or other processing is applied as a starting material.

The use as the photomask of the present invention is not particularly limited.

For example, it is also suitable as a so-called PEP (Photolithography Etching Process) which is useful as a multi-step mask (the number of masks used is reduced when manufacturing a display panel).

Further, it can be used as a photomask for forming a three-dimensional shape of a structural material (including a photosensitive resin or the like) in a display device. For example, when the photosensitive spacer of the liquid crystal display device or the insulating layer of the display device is formed, the height control of a plurality of structural materials having different heights can be precisely performed, and the effect of the invention is remarkable. It is particularly advantageous in a reticle of 4th order or more.

Further, as the transfer pattern for forming the photosensitive spacer and the insulating layer, for example, the constituents shown in FIG. 10 can be used. Specifically, a transfer pattern including a light-transmitting portion surrounded by a light-shielding portion can be used as shown in a plan view of the transfer pattern shown in FIG. 10 ( 10(a)) or a transfer pattern including a light transmitting portion surrounded by a semi-light transmitting portion (Fig. 10(b)). Further, as shown in FIG. 10(c), a plurality of semi-transmissive portions (here, first and second semi-transmissive portions) having different transmittances may be arranged adjacent to each other around the light-transmitting portion. And a pattern for transfer of the light-shielding portion. In this case, the closer the semi-transmissive portion is to the light-transmitting portion, the more the light transmittance of the exposure is increased, and a useful pattern can be formed. In addition, FIG. 10 schematically illustrates the adjacent relationship of the light-shielding portion, the light-transmitting portion, and the semi-transmissive portion, and does not necessarily indicate that the patterns of the shapes are practical. Further, a transfer pattern in which the light-transmitting portion, the light-shielding portion, and the semi-transmissive portion of FIG. 10(c) are arranged may be changed. For example, a semi-transmissive portion may be disposed adjacent to the periphery of the light-shielding portion (a plurality of semi-transmissive portions having different light transmittances may be sequentially adjacent to each other from a lower light transmittance), and The pattern for transfer of the light portion. Alternatively, the transfer pattern in which the light transmitting portion and the semi-light transmitting portion are disposed may be adjacently arranged around the light shielding portion.

Furthermore, the present invention includes a method of manufacturing a display device, comprising: using a photomask manufactured by any one of the first to seventh embodiments, and transferring the transfer pattern to a transfer by an exposure device The steps of printing.

As an exposure apparatus for transfer, a method of performing equal-fold projection exposure is mentioned, and the following are mentioned. In other words, it is used as an exposure machine for LCD (Liquid Crystal Display) (or FPD (Flat Panel Display), liquid crystal display device), and the number of openings (NA) of the optical system is 0.08 to 0.15 (the homology factor (σ) is 0.4 to 0.9), and has a light source including at least one of an i line, an h line, and a g line, preferably a light source having a wavelength region including an i line, an h line, and a g line; (also known as wide wavelength light source). As the light source, an ultrahigh pressure mercury lamp or the like can be used. Further, in the exposure apparatus in which the number of openings NA is 0.10 to 0.20, of course, the present invention can be applied to obtain the effects of the invention.

Further, as an exposure apparatus to which the photomask of the present invention is applied, an exposure apparatus of a proximity exposure (near exposure) type is also preferable. As the light for exposure, a wide-wavelength light source similar to the above can be used, and the distance between the transfer target and the reticle is set to about 20 to 300 μm to expose.

The following is exemplified as the material of the optical film used for the photomask of the present invention.

The material of the light-shielding film used herein is not particularly limited, and the following may preferably be used. For example, in addition to Cr or a Cr compound (oxide, nitride, carbide, nitrogen oxide, carbon oxynitride, etc.) of Cr, it is preferable to use a compound of Ta, Mo, W, and the like (for example, oxidation) a substance, a nitride, an oxynitride, or a nitride of a TaSi, a MoSi, a WSi (a metal telluride) or the like, an oxynitride, or the like). Further, these materials may be used alone or in combination of two or more. The film thickness of the portion used as the light shielding portion is preferably such that sufficient light blocking property (optical density OD ≧ 3, preferably OD ≧ 4) can be obtained.

As the semi-transmissive film, there may be an etching selectivity or an etching selectivity between the light-shielding film and the light-shielding film. However, in the case where etching selectivity (i.e., common etching characteristics) is not used, a common etchant can be used, and therefore, production efficiency is preferable.

Therefore, the material as the semi-transmissive film can be selected from the above-exemplified light-shielding film material. Further, in the case of etching and film-reducing, in order to easily control the etching time before reaching the target light transmittance, the film thickness of the semi-transmissive film is preferably 50 to 2000 Å.

As the etching stopper film, a material selected from the above-exemplified light shielding film materials can be used. However, it is preferable to have an etching selectivity with respect to the light-shielding film or the semi-transmissive film. Therefore, when the light-shielding film is a film containing Cr, the film may be made of a film containing Si, Ti or Ta. When the light shielding film is a film containing Si or Ta, it may be a film containing Cr.

According to the present invention, the light transmittance of the semi-transmissive portion of the photomask can be precisely controlled according to the complicated design of the device to be obtained. In particular, in the step of forming the semi-transmissive portion, the transmittance measurement can be performed and the necessary additional etching time can be accurately grasped.

Further, on the premise that such fine adjustment can be performed, the type of the mask base to be prepared can be limited. If the plurality of devices to be obtained require different orders or different transmittance values, and the reticle base to be prepared becomes a multi-variety, the payment period and cost are not appropriate. On the other hand, if the present invention is applied, the reticle base to be prepared can be predefined The type of the bottom can be adjusted to the required transmittance in the step, and therefore, a variety of display devices can be provided with advantageous production efficiency.

Further, as described in the sixth embodiment (see FIG. 8), the step of improving the coordinate accuracy of each of the light transmitting portion, the light blocking portion, and each of the semi-transmissive portions may be selected.

1‧‧‧Photomask substrate

10‧‧‧Transparent substrate

50‧‧‧resist film

50'‧‧‧Resist film

60‧‧‧Optical film

Claims (13)

A method of manufacturing a photomask, comprising: forming a transfer pattern by patterning the optical film of a photomask substrate on which an optical film is formed on a transparent substrate, comprising: preparing to be formed on the transparent substrate a step of applying a photomask substrate of a first resist film to the optical film; and a first resist pattern forming step of drawing the first drawing pattern on the first resist film a first patterning step of etching and removing the optical film by using the first resist pattern as a mask to expose one surface of the transparent substrate; and peeling off and removing the first resist pattern a step of applying a second resist pattern; and a second resist pattern forming step of drawing a second drawing pattern on the second resist film and performing development to form a portion of the surface of the transparent substrate and the above a part of the surface of the optical film is exposed; a second patterning step of etching the film by using the second resist pattern as a mask; and removing the second resist pattern Further, the second drawing pattern is reduced in such a manner that the exposed portion of the transparent substrate in the second resist pattern is smaller than a size of the exposed portion of the transparent substrate in the first resist pattern by a specific amount. size. A photomask manufacturing method comprising: a transfer pattern comprising a light transmitting portion and a semi-transmissive portion having a desired light transmittance; and the manufacturing method is characterized by comprising: a step of preparing a photomask substrate on which the optical film is formed on the transparent substrate and the first resist film is coated on the optical film; a first resist pattern forming step of removing a first resist film corresponding to the light transmitting portion by drawing the first pattern on the first resist film and developing the first resist film; the first pattern a step of etching and removing the optical film by using the first resist pattern as a mask to expose the surface of the transparent substrate; peeling off the first resist pattern and recoating the second resist a step of forming a second resist pattern forming step by drawing a second drawing pattern on the second resist film and performing development, thereby removing portions corresponding to the light transmitting portion and the semi-transmissive portion, respectively a second resist film; the second patterning step of etching and thinning the optical film by using the second resist pattern as a mask to form a light transmittance having a desired exposure a semi-transmissive portion; and a step of peeling off the second resist pattern; and the second drawing pattern is configured to reduce a design size of the light-transmitting portion by a specific size with respect to a portion corresponding to the light-transmitting portion Reduced size. The method of manufacturing a photomask according to claim 2, wherein the etching rate at the time of etching and thinning the optical film is 0.3 to 5.0%/min in the form of a change in transmittance of the exposed light. The method of manufacturing a photomask according to claim 2, wherein the film thickness of the optical film subjected to the etching and film-removing is 50 to 2000 Å. A method of manufacturing a photomask according to the present invention, comprising: a light-shielding portion, a light-transmitting portion, and a transfer pattern having a semi-transmissive portion having a desired light transmittance of exposure; and the manufacturing method The method includes the steps of: preparing a photomask substrate having a semi-transmissive film, an etching stopper film, and a light shielding film on the transparent substrate and coating the first resist film on the laminate; the first resist a pattern forming step by drawing the first resist film The first resist pattern is removed by first drawing, and the first resist film is removed from the portion corresponding to the light transmitting portion. The first patterning step is performed by etching the first resist pattern as a mask. a film, the etching stopper film and the semi-transmissive film to expose a surface of the transparent substrate; a step of peeling off the first resist pattern and recoating the second resist film; and forming a second resist pattern a second resist film that removes a portion corresponding to each of the light transmitting portion and the semi-transmissive portion by drawing the second drawing pattern on the second resist film and developing the second resist film; the second pattern a step of etching and removing the light shielding film and the etching stopper film by using the second resist pattern as a mask, and further etching and thinning the semi-transmissive film to form the light having the desired exposure And a step of peeling off the second resist pattern; and the second drawing pattern is configured to reduce a design size of the portion corresponding to the light transmitting portion with respect to the light transmitting portion Size reduction . The method of manufacturing a reticle according to claim 5, wherein, when the semi-transmissive portion is the first semi-transmissive portion, the transfer pattern further includes a second semi-transmissive portion, and the second semi-transmissive portion The light transmittance of the exposure different from the first semi-transmissive portion, and the manufacturing method includes the step of peeling off the second resist pattern and then applying the third resist film; the third resist a pattern forming step of removing the third resist film corresponding to the second semi-transmissive portion by drawing the third drawing pattern on the third resist film; and developing the third resist film; a step of etching the third resist pattern as a mask Removing the light shielding film and the etching stopper film to form a second semi-transmissive portion; and a step of peeling off the third resist pattern. The method of manufacturing a reticle according to claim 5, wherein, when the semi-transmissive portion is the first semi-transmissive portion, the transfer pattern further includes a second semi-transmissive portion, and the second semi-transmissive portion The light transmittance of the exposure different from the first semi-transmissive portion, and the manufacturing method includes the step of re-coating the third resist film after peeling off the second resist pattern; and the third resist a pattern forming step of removing the third resist corresponding to the second semi-transmissive portion and the light-transmitting portion by drawing the third drawing pattern on the third resist film and developing the pattern a third patterning step of etching and removing the light shielding film and the etching stopper film by using the third resist pattern as a mask, and further etching and thinning the semi-transmissive film to form the second half a light transmitting portion; and a step of peeling off the third resist pattern; and the third drawing pattern is configured to reduce a design size of the light transmitting portion by a specific amount by a portion corresponding to the light transmitting portion Size. A method of manufacturing a photomask comprising a light-shielding portion, a light-transmitting portion, and a transfer pattern having a semi-transmissive portion having a desired light transmittance of light, and the method of manufacturing the photomask The method includes the steps of: preparing a photomask substrate having a semi-transmissive film, an etching stopper film, and a light-shielding film on the transparent substrate and applying the first resist film on the laminate; and a first resist; a pattern forming step of removing a first resist film corresponding to the light transmitting portion and the semi-light transmitting portion by drawing the first pattern on the first resist film and developing the film; a patterning step of etching the first resist pattern as a mask Removing the light shielding film and the etching stopper film to expose the surface of the semi-transmissive film; removing the first resist pattern and recoating the second resist film; and forming a second resist pattern a step of removing a second resist film corresponding to the light transmitting portion by drawing the second drawing pattern on the second resist film and performing development; and a second patterning step The second resist pattern is used as a mask to etch away the semi-transmissive film to form the light-transmitting portion; the second resist pattern is peeled off and the third resist film is re-coated; and the third resist An etchant pattern forming step of removing a third resist film corresponding to the light transmitting portion and the semi-light transmitting portion by drawing the third drawing pattern on the third resist film and performing development; a third patterning step of etching and thinning the semi-transmissive film by using the third resist pattern as a mask to form the semi-transmissive portion having a desired light transmittance of exposure; a step of peeling off the third resist pattern; and the second The drawing pattern includes a portion for which a portion corresponding to the light transmitting portion is increased by a specific size with respect to a design size of the light transmitting portion; and the third drawing pattern is opposite to a portion corresponding to the light transmitting portion. The size of the light-transmitting portion is reduced by a specific size, and the portion corresponding to the semi-transmissive portion is increased by a specific size with respect to the design size of the semi-transmissive portion. . A method of manufacturing a photomask comprising a light-shielding portion, a light-transmitting portion, a first semi-transmissive portion having a desired light transmittance, and a first semi-transmissive portion; The manufacturing method is characterized in that: the transfer pattern of the second semi-transmissive portion of the light transmittance of the exposure required is: a step of forming a mask substrate having a semi-transmissive film, an etching stopper film, and a light-shielding film on the transparent substrate and applying the first resist film thereon; and a first resist pattern forming step; The first resist is formed by drawing the first drawing pattern on the first resist film, and removing the first resist corresponding to the light transmitting portion, the first semi-transmissive portion, and the second semi-transmissive portion. An etchant film; the first patterning step of etching and removing the portion corresponding to the light transmitting portion, the first semi-transmissive portion, and the second semi-transmissive portion by using the first resist pattern as a mask The light shielding film and the etching stopper film expose the surface of the semi-transmissive film; the step of peeling off the first resist pattern and recoating the second resist film; and forming the second resist pattern a step of removing a second resist film corresponding to the light transmitting portion by drawing the second drawing pattern on the second resist film and performing development; and a second patterning step The second resist pattern is etched as a mask to remove the semi-transmissive film, thereby forming a light transmissive portion; a step of peeling off the second resist pattern and recoating the third resist film; and a third resist pattern forming step by drawing the third resist film 3: drawing a pattern and performing development to remove a third resist film corresponding to the light transmitting portion and the first semi-transmissive portion; and a third patterning step of using the third resist pattern as a mask for etching and thinning the semi-transmissive film corresponding to the first semi-transmissive portion to form the first semi-transmissive portion; and a step of peeling off the third resist pattern; The second drawing pattern includes a portion for which a portion corresponding to the light transmitting portion is increased by a specific size with respect to a design size of the light transmitting portion, and the third drawing pattern is applied to a portion corresponding to the light transmitting portion. Relative to upper The design size of the light transmitting portion is reduced by a specific size, and the portion corresponding to the first semi-transmissive portion is increased by a specific size with respect to the design size of the first semi-transmissive portion. Plus size. The method of manufacturing a photomask according to any one of claims 5 to 9, wherein the transfer pattern includes the light transmitting portion surrounded by the light shielding portion. The method of manufacturing a photomask according to any one of claims 2 to 8, wherein the transfer pattern includes the light transmitting portion surrounded by the semi-transmissive portion. The method of manufacturing a reticle according to any one of claims 2 to 8, wherein the semi-transmissive portion of the transfer pattern includes a first semi-transmissive portion, and an exposure light transmittance is higher than the first semi-transmissive light. In the second semi-transmissive portion of the portion, the transfer pattern includes the second semi-transmissive portion surrounded by the one semi-transmissive portion. A manufacturing method of a display device, comprising the steps of: preparing a photomask manufactured by the manufacturing method according to any one of claims 1 to 9; and using the prepared photomask and exposure device on the object to be transferred The transfer pattern described above is transferred.