TWI569090B - Phase shift mask and resist pattern forming method using the phase shift mask - Google Patents

Description

Phase shift mask and resist pattern forming method using the same

The present invention relates to a phase shift mask for forming a predetermined resist pattern on a workpiece and a resist pattern forming method using the phase shift mask.

A liquid crystal display generally has a structure in which a TFT substrate having a switching active element (TFT) for driving a pixel electrode, a black matrix having a predetermined opening, and a black matrix formed thereon are formed on the opening. The color filter substrate of the colored layer is disposed opposite to each other, sealed around, and sealed and filled with a liquid crystal material in the gap.

In the liquid crystal display, the TFT or the like on the TFT substrate can be formed by performing the operation on a transparent substrate on which a thin film including the material of the gate electrode, the source electrode, the drain electrode, or the like is formed. On the film, a photoresist film having a predetermined pattern is formed, and etching is performed by using a patterned photoresist film as a mask. The black matrix or the like on the color filter substrate can also be formed in the same manner.

Further, an EL (Electro Luminescence) display has a structure in which a cathode electrode, an organic EL film, and an anode electrode are sequentially laminated on a transparent substrate, and sealed by a sealing film or the like from the above; or The structure is such that an organic EL film and a common electrode are sequentially laminated on a TFT substrate, and sealed from the above by a sealing film or the like.

In the organic EL display, similarly to the liquid crystal display, the cathode electrode, the anode electrode, the TFT, and the like can be formed by forming the film on the transparent substrate on which the thin film including the constituent materials is formed. A photoresist film having a predetermined pattern is etched by using a patterned photoresist film as a mask.

For the manufacture of image display devices such as liquid crystal displays and organic EL displays In the process of forming a predetermined resist pattern on a transparent substrate, a photolithography method is generally used, which uses a mask having a light-shielding portion including a metal chrome or the like having a predetermined pattern shape (binary mask). The mask) exposes and develops the photoresist film. Further, in order to contribute to mass production and cost reduction, a transparent substrate having such an electrode or a TFT is often laminated on a large area using a large-area transparent substrate (for example, a transparent substrate of 330 mm × 450 mm or more). Since it is produced, even if it is an exposure apparatus used for forming a predetermined resist pattern on a transparent substrate, it is generally used to have an equal-magnification projection optical system which can be uniformly or divided into a plurality of transparent substrates for exposure to a large area. Large exposure unit.

The size of the resist pattern formed by the photolithography method as described above (for example, in the case of a line-and gap-like resist pattern, the width of the short side direction of the line pattern or the gap pattern; that is, the line Width is determined by the exposure limit of the exposure device. As an exposure device for manufacturing an image display device, a resolution limit of about 3 μm is generally used. In the case of the conventional image display device resolution, there is no problem as long as the patterning degree of the exposure device is exceeded, but in recent years, it has been desired to increase the number of pixels and display images with higher resolution. The development of the device has become increasingly necessary for the patterning of the size of the resolution limit of the exposure device for manufacturing an image display device.

In such a situation, an attempt is made to use a phase shift mask which is patterned to a very small size in a manufacturing process of a semiconductor device such as a large scale integrated circuit (LSI) as an image display device. The reticle used in the manufacturing process. For example, a photomask having a light transmitting portion (exposed light transmittance of 100%) and a semi-light transmitting portion (exposure light transmittance of 20 to 60%), a light transmitting portion, and a half are provided on a transparent substrate. At least one of the light transmitting portions has a size portion of less than 3 μm (refer to Patent Document 1).

[Previous Technical Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2009-42753

However, the photomask of the above-mentioned Patent Document 1 is used for exposure and development by an exposure apparatus using a conventional image display device manufacturing, although the formed resist can be formed. The size of the agent pattern is less than the resolution limit of the exposure device for manufacturing an image display device, but the thickness of the formed resist pattern (the height of the line pattern) is thinned, so that the patterned photoresist film is difficult to exhibit. As a problem of the role of the etch mask in the subsequent etching step.

Further, by the thickness of the resist pattern being thinned, the angle of the side wall portion of the formed resist pattern (if the line and the gap-like resist pattern are the line pattern side walls in the vertical direction of the substrate surface) The angle at which the part is raised will become smaller. A decrease in the angle means that the unevenness of the thickness (aspect ratio) of the resist pattern in the surface on the substrate becomes large. As a result, there is a problem that high-precision etching in the subsequent etching step becomes difficult.

Since the light-based parallel light component obtained by the equal-projection exposure of the exposure device using the conventional image display device manufacturing device is smaller, the transmitted light of the light-transmitting portion of the photomask is bypassed directly below the semi-transmissive portion, thereby It is also irradiated onto the photoresist film directly under the semi-transmissive portion. It is considered that, as a result, the problem as described above occurs.

On the other hand, in the case of an exposure apparatus including a reduction projection exposure optical system for manufacturing a semiconductor device such as an LSI, exposure can be performed by using light having a large amount of parallel light components, and thus the exposure apparatus for manufacturing the semiconductor device can be used. It is suppressed that the light transmitted through the light transmitting portion of the photomask (phase shift mask) is turned back directly below the semi-transmissive portion.

However, since the exposure surface of the exposure apparatus for manufacturing a semiconductor device is actively small, an image display is generated when an exposure apparatus for manufacturing a semiconductor device is used to form a resist pattern on a large-area substrate used in an image display apparatus. The problem of reduced throughput of device manufacturing.

In view of such a problem, an object of the present invention is to provide an exposure apparatus for manufacturing an image display apparatus which can be formed on a workpiece such as a transparent substrate with a high precision to have a size which is less than the resolution limit of the exposure apparatus. A phase shift mask of a predetermined resist pattern and a resist pattern forming method using the phase shift mask.

In order to solve the above problems, the present invention provides a phase shift mask for forming a resist pattern of a design size that does not reach the resolution limit of the exposure device on a workpiece by exposure from an exposure device; The method comprises: a transparent substrate; a concave or convex phase displacement portion disposed on the transparent substrate, and the exposure is from the above exposure The exposure light of the device is given a predetermined phase difference; and the non-phase displacement portion is adjacent to the phase displacement portion; at least one of the phase displacement portion and the non-phase displacement portion is not at least the resolution of the exposure device The size of the limit, and the size of the phase shifting portion is different from the size of the non-phase shifting portion; and the smaller of the phase shifting portion and the non-phase shifting portion does not cause the workpiece to be processed. The function of exposing the photoresist film is the function of exposing the photoresist film on the material to be processed; and the size of the pattern region including the phase shift portion and the non-phase shift portion on the transparent substrate is one side It is 300 mm or more; at least in the pattern area, a light-shielding portion which is formed of a light-shielding film which does not reach the size of the resolution limit of the above-mentioned exposure apparatus is not provided (Invention 1).

Further, in the present invention, "transparent" means that the transmittance of light having a wavelength of 350 to 450 nm is 85% or more, more preferably 90% or more, and particularly preferably 95% or more. Further, in the present invention, "not exposing the photoresist film" means that the photoresist on the optical path of the light transmitted through the phase shift mask (phase shift portion or non-phase shift portion) is not exposed, and is set. It includes not only the case where the light is not irradiated to the photoresist film located on the light path of the transmitted light, but also the light of the intensity (low intensity) which does not cause the photoresist to be sensitive to be irradiated onto the photoresist film. Happening.

In the above invention (Invention 1), the size of the phase shifting portion and the size of the non-phase shifting portion are preferably 1:1.5 to 1:5.6 or 1.5:1 to 5.6:1 (Invention 2).

In the above inventions (Inventions 1 and 2), the total of the size of the phase shifting portion and the size of the non-phase shifting portion adjacent to the phase shifting portion is preferably equal to or higher than the resolution limit of the exposure device (Invention 3).

In the above invention (Invention 1), the size of the dark region having a smaller size among the phase shifting portion and the non-phase shifting portion is in the range of 0.6 μm to 2.75 μm, and the phase shift portion and the non-phase shift are In the case where the size of the dark region is larger than the size of the dark region in the portion, when the size of the dark region is set to 1, the size of the bright region is preferably 1.5 or more (Invention 4 ).

In the above invention (Inventions 1 to 4), a light-shielding portion having a light-shielding film having a size equal to or higher than the resolution of the exposure device may be provided in the pattern region (Invention 5).

In the above invention (Inventions 1 to 5), the concave phase displacement portion may be provided on the transparent substrate (the invention 6), or the convex phase displacement portion may be provided. A light-transmissive film formed on the above transparent substrate (Invention 7).

Moreover, the present invention provides a resist pattern forming method which is a method of forming a resist pattern having a design size which does not reach the resolution limit of an exposure apparatus on a workpiece, and is characterized by comprising the steps of: using the above An exposure apparatus that exposes a photoresist film provided on the workpiece by the phase shift mask of the invention (Inventions 1 to 7); and develops the exposed photoresist film by the exposure A predetermined resist pattern is formed on the processed material (Invention 8).

According to the present invention, it is possible to provide a phase shift capable of forming a predetermined pattern having a size that does not reach the resolution limit of the exposure device on a workpiece such as a transparent substrate by using an exposure device for manufacturing an image display device. A mask and a resist pattern forming method using the phase shift mask.

1A, 1B‧‧‧ phase shift mask

2A, 2B‧‧‧ transparent substrate

3A, 3B‧‧‧ Phase Displacement Department

4A, 4B‧‧‧ Non-phase displacement

5A, 5B‧‧‧Lighting Department

6A, 6B‧‧‧ pattern area

7A, 7B‧‧‧resist layer

11A, 11B‧‧‧Materials (substrate)

12A, 12B‧‧‧ photoresist film

13A, 13B‧‧‧resist pattern

13A _up ‧‧‧90% of the height (thickness) of the resist pattern 13A

13A _down ‧‧‧10% of the height (thickness) of the resist pattern 13A

13B _up ‧‧‧90% of the height (thickness) of the resist pattern 13B

13B _down ‧‧‧10% of the height (thickness) of the resist pattern 13B

30A, 30B‧‧‧Resist layer on transparent film

d‧‧‧Depth of the etch department

Θ‧‧‧ sidewall angle

W1, W2‧‧‧ Dimensions of dark areas

X‧‧‧Dimensions of phase displacement

Y‧‧‧Dimensions of non-phase displacement parts

T‧‧‧thickness of phase displacement

Fig. 1 is a partially cutaway end view showing a schematic configuration of a phase shift mask according to a first embodiment of the present invention.

Fig. 2 is a graph showing the light intensity of transmitted light of the phase shift mask according to the first embodiment of the present invention.

Fig. 3 is a partial plan view showing a schematic configuration of a phase shift mask according to a first embodiment of the present invention.

4(a) to 4(e) are flowcharts showing the steps of manufacturing the phase shift mask according to the first embodiment of the present invention.

5(a) to 5(c) are flowcharts showing a pattern forming method using a phase shift mask according to the first embodiment of the present invention.

Fig. 6 is a partial plan view showing a specific configuration example of a phase shift mask according to the first and second embodiments of the present invention.

Fig. 7 is a view showing a schematic configuration of a phase shift mask according to a second embodiment of the present invention; Cut off the end view.

Fig. 8 is a graph showing the light intensity of transmitted light of the phase shift mask according to the second embodiment of the present invention.

Fig. 9 is a partial plan view showing a schematic configuration of a phase shift mask according to a second embodiment of the present invention.

Fig. 10 (a) to (e) are flowcharts showing a manufacturing step (method 1) of the phase shift mask according to the second embodiment of the present invention.

11(a) to 11(f) are flowcharts showing a manufacturing step (method 2) of the phase shift mask according to the second embodiment of the present invention.

12(a) to 12(c) are flowcharts showing a pattern forming method using a phase shift mask according to a second embodiment of the present invention.

Fig. 13 is a view for explaining a dark region and a bright region of the phase shift mask in Test Example 6.

Fig. 14 is a view for explaining a dark region and a bright region of the phase shift mask in Test Example 7.

Hereinafter, a phase shift mask of the present invention and a resist pattern forming method using the phase shift mask will be described.

Further, the phase shift mask of the present invention has two aspects. Hereinafter, each aspect will be described.

1. The first aspect

The phase shift mask according to the first aspect of the present invention is for forming a resist pattern of a design size that does not reach the resolution limit of the exposure device by the exposure of the exposure device on the workpiece; and the characteristics thereof The invention comprises: a transparent substrate; a concave or convex phase displacement portion disposed on the transparent substrate to impart a predetermined phase difference to the exposed light from the exposure device; and a non-phase displacement portion adjacent to the above a phase shifting portion; at least one of the phase shifting portion and the non-phase shifting portion is a size that does not reach a resolution limit of the exposure device, and a size of the phase shifting portion is different from a size of the non-phase shifting portion; Any one of the smaller of the phase displacement portion and the non-phase displacement portion does not cause the processing to be performed. The function of exposing the photoresist film on the material, and the other function of exposing the photoresist film on the material to be processed; and the pattern region including the phase shift portion and the non-phase shift portion on the transparent substrate The size of one side is 300 mm or more; at least in the pattern area, a light-shielding portion made of a light-shielding film that does not reach the size of the resolution limit of the exposure device is not provided.

Here, the term "the phase shifting portion imparts a desired phase difference to the light emitted from the exposure device" means that the phase shifting portion causes the phase of the light transmitted through the phase shifting portion to pass through the non-phase. The phase of the light of the exposure portion of the displacement portion is reversed. Further, the case where the phase shifting portion reverses the phase of the light that has passed through the phase shifting portion with respect to the light that has passed through the non-phase shifting portion will be "2. Explain the items in the sample.

According to the first aspect, by making the size of the phase shifting portion and the size of the non-phase displacement portion into the above relationship, a phase shift mask can be formed, which can be used in a conventional transparent display device for manufacturing an image display device. On the workpiece, a predetermined pattern having a size that does not reach the resolution limit of the exposure device is formed with high precision.

Further, in the phase shift mask of the first aspect, the resist pattern can be formed with higher precision than the conventional phase shift mask including the transmissive portion and the semi-transmissive portion. The reason for this will be explained in the item "2. Second aspect" below.

The phase shift mask of the first aspect has two embodiments. Hereinafter, each embodiment of the phase shift mask facing the first aspect will be described with reference to the drawings.

<First embodiment>

[phase shift mask]

1 is a partially cut end view showing a schematic configuration of a phase shift mask according to a first embodiment, and FIG. 2 is a graph showing light intensity of transmitted light of a phase shift mask according to the first embodiment, and FIG. 3 is a view showing A partial plan view of a schematic configuration of a phase shift mask of the embodiment.

As shown in Fig. 1, the phase shift mask 1A of the first embodiment includes a transparent substrate 2A, a plurality of phase shifting portions 3A provided on the transparent substrate 2A, and a plurality of phase shifting portions 3A disposed adjacent to the phase shifting portions 3A. And a non-phase displacement portion 4A; and in the process of manufacturing an image display device such as a liquid crystal display device or an organic EL display device, Exposure with a large exposure apparatus having an equal magnification projection exposure optical system for the image display device will not reach the resolution limit of the exposure device (preferably less than 3 μm, more preferably 1.5 μm or more and less than 3 μm) A resist pattern of a design size of 1.5 to 2 μm) is formed on the material to be processed.

The transparent substrate 2A is not particularly limited, and for example, an amorphous material such as an alkali-free glass, quartz glass, Pyrex (registered trademark) glass, or a synthetic quartz plate, which is not flexible, or the like can be used.

The size of the transparent substrate 2A can be sized or used for the substrate (TFT substrate, color filter substrate, etc.) in the image display device to be manufactured by using the phase shift mask 1A of the first embodiment. The exposure mode (uniform exposure mode or split exposure mode) of a large exposure apparatus of an equal magnification projection exposure optical system in the manufacture of the image display device is appropriately set, for example, it can be set to 330 mm × 450 mm to 1600 mm × Around 1800 mm.

Further, the thickness of the transparent substrate 2A is not particularly limited. However, since it is necessary to maintain the phase shift mask 1A without bending it during exposure, it can be appropriately set by the size of the transparent substrate 2A, for example, at 5 mm. Set within ~20 mm.

The phase shifting portion 3A is provided on the transparent substrate 2A and is configured as an etched portion that is etched to a predetermined depth d. Further, the non-etched portion adjacent to the plurality of phase shift portions 3A becomes the non-phase shift portion 4A.

In the phase shift mask 1A of the first embodiment, the dimension X of the phase shifting portion 3A is different from the dimension Y of the non-phase shifting portion 4A. When the sizes X and Y of the two are the same, even if the exposure amount from the exposure device is increased, the image cannot be resolved, and the resist pattern cannot be formed.

Further, in the first embodiment, at least one of the size X of the phase shifting portion 3A and the size Y of the non-phase shifting portion 4A does not reach the equal magnification projection for manufacturing the image display device used in the prior art. The resolution limit of the exposure device of the exposure optical system (preferably less than 3 μm, more preferably 1.5 μm or more and less than 3 μm, particularly preferably 1.5 to 2 μm). Thereby, a resist pattern having a design size that does not reach the resolution limit of the exposure device can be formed.

The phase shifting portion 3A in the first embodiment has a dimension X smaller than the dimension Y of the non-phase shifting portion 4A. By forming such a configuration, the phase shifting portion 3A in the first embodiment is formed by transmitting a fine resist pattern which is difficult to form by using a photolithography technique such as a conventional binary mask. The workpiece (substrate or the like) on the optical path of the light (transmitted light) of the phase shifting portion 3A functions as a light-shielding portion corresponding to a conventional binary mask or the like.

The size X of the phase shifting portion 3A can be appropriately set depending on the design size of the resist pattern to be formed or the exposure amount from the exposure device, etc., preferably less than 3 μm, and particularly preferably 1.0 to 2.5 μm. The light transmitted through the phase shifting portion 3A is given a phase difference of about 180 degrees from the light transmitted through the non-phase shifting portion 4A. Therefore, the transmitted light of the phase shifting portion 3A and the transmitted light adjacent to the non-phase shifting portion 4A of the phase shifting portion 3A are transmitted. Interfere with each other. Further, by the dimension X of the phase shifting portion 3A not reaching the above-described exposure device resolution limit and smaller than the dimension Y of the non-phase shifting portion 4A, the phase shifting mask 1A can be irradiated to the phase shifting portion 3A. The intensity of the light (irradiation light) on the photoresist film that passes through the light path on the light is reduced to such an extent that the photoresist is not exposed (see FIG. 2). As a result, a resist pattern having a size that does not reach the resolution limit of the above exposure apparatus can be formed.

On the other hand, if the dimension X of the phase shifting portion 3A is equal to or larger than the resolution limit of the exposure device, that is, the size X of the phase shifting portion 3A and the dimension Y of the non-phase shifting portion 4A are both the above-described exposure device resolution limits. In the size, the transmitted light of the phase shifting portion 3A is effectively prevented from being disturbed by the bypass of the transmitted light of the non-phase shifting portion 4A, so that the photoresist film which is incident on the optical path of the transmitted light located in the phase shifting portion 3A cannot be made. The intensity of the illuminating light is reduced to such an extent that the photoresist is not sensitized. As a result, an undesired resist pattern is formed on the optical path of the transmitted light of the phase shifting portion 3A.

In other words, among the resist patterns to be formed by using the phase shift mask 1A of the first embodiment, a conventional binary mask (a mask having a light-shielding portion and an opening portion made of metal chromium or the like) is used. a resist pattern formed according to the light shielding portion (for example, a line pattern in the case where a line-and gap-like resist pattern is to be formed by a positive-type photoresist, by a negative-type photoresist In the case where the design size of the gap pattern in the case where it is to be formed is less than the resolution limit of the exposure device for the image display device to be used, the first embodiment is The phase shift mask 1A includes a phase displacement portion 3A for forming the resist pattern. On the other hand, if the design size of the resist pattern is equal to or higher than the resolution limit of the exposure apparatus, the phase shift mask 1A of the first embodiment includes the metal containing the resist pattern. A light shielding portion 5A composed of a light shielding film such as chrome.

Further, the size Y of the non-phase displacement portion 4A provided adjacent to the phase displacement portion 3A is appropriately set depending on the design size of the resist pattern to be formed, and may be larger than the size X of the phase displacement portion 3A. If the resolution limit of the above exposure device is not reached, it may be above the resolution limit.

Specifically, the relationship between the dimension X of the phase shifting portion 3A and the dimension Y of the non-phase shifting portion 4A will be described, and the ratio of the dimensions X and Y (X: Y) of the two is preferably 1:1.5 to 1:5.6. More preferably 1:1.8~1:4, especially 1:1.8~1:3. The ratio of the dimensions X and Y of the phase shifting portion 3A and the non-phase shifting portion 4A is the above range, and as is clear from the following embodiments, the sidewall angle θ of the formed resist pattern can be obtained (refer to the figure). 5) Good (the side wall angle θ varies depending on the type of the photoresist, etc., preferably 60 to 90 degrees, particularly preferably 70 to 90 degrees), and the exposure amount can be formed with a low exposure amount. Etch pattern.

In the first embodiment, the total length (X+Y) of the dimension X of one phase shifting portion 3A and the dimension Y of one non-phase shifting portion 4A adjacent to the phase shifting portion 3A is preferably equal to or higher than the resolution limit of the exposure device. . If the total (X+Y) does not reach the above-described exposure apparatus resolution limit, formation of a resist pattern having a good sidewall angle θ (see FIG. 5) becomes difficult.

The above-mentioned total (X+Y) is appropriately determined by the phase shift mask and the resolution limit of the exposure apparatus to be used, and is not particularly limited, but is preferably 3 μm or more, and more preferably 3.5 μm or more. .

In addition, the upper limit of the total (X+Y) is appropriately selected depending on the use of the phase shift mask, etc., and is not particularly limited. The upper limit of the total (X+Y) is, for example, preferably 17.9 μm or less, and more preferably 4.5 μm or less.

In the first embodiment, the total (X+Y) is preferably about 4 μm.

This is because the above total (X+Y) is within the above range, and it can be satisfactorily performed. The design of the phase displacement portion and the non-phase displacement portion of the desired resist pattern is obtained.

In the first embodiment, when the total (X+Y) is within the above range, the ratio of the dimension X of the phase shifting portion 3A to the dimension Y of the non-phase shifting portion 4A is preferably (X: Y) is set to the above numerical range. The reason for this is that the sidewall angle of the formed resist pattern can be made better, so that a resist pattern of a design size can be preferably formed with a lower exposure amount.

In the case where the specific example is given and described in more detail, the case where the design of the line pattern and the gap pattern is 2 μm and the gap-like resist pattern is formed using an exposure apparatus having a resolution limit of 3 μm. The size X of the phase shifting portion 3A can be preferably set in the range of 0.6 to 1.6 μm, more preferably in the range of 0.8 to 1.4 μm, and particularly preferably in the range of 1 to 1.4 μm. The size Y of the phase shifting portion 4A is preferably set in the range of 2.4 to 3.4 μm, more preferably in the range of 2.6 to 3.2 μm, and particularly preferably in the range of 2.6 to 3 μm.

The etching depth d of the phase shifting portion 3A may be set to a predetermined phase difference (phase difference of 170 to 190 degrees (about 180 degrees)) to the transmitted light of the phase shifting portion 3A, and may be based on a transparent substrate. The thickness of 2A, the wavelength of the light to be exposed, the refractive index of the material constituting the transparent substrate 2A, and the like are appropriately set.

In the phase shift mask 1A of the first embodiment, the phase shifting portion 3A and the non-phase shifting portion 4A are provided in the pattern region 6A (see FIG. 3) on the transparent substrate 2A. The pattern region 6A is set on at least one region on the transparent substrate 2A in accordance with the resist pattern to be formed on the workpiece using the phase shift mask 1A of the first embodiment, regardless of the exposure mode of the exposure device. The light is irradiated by one exposure on at least the entire surface in one of the pattern regions 6A.

As shown in FIG. 3, in the phase shift mask 1A of the first embodiment, a plurality of pattern regions 6A are set on the transparent substrate 2A, and only one pattern region 6A may be set. In addition, in FIG. 3, illustration of the phase displacement part 3A, the non-phase displacement part 4A, and the light-shielding part 5A in the pattern area 6A is abbreviate|omitted.

The size of the pattern region 6A can be based on the size (screen size) of the image display device to be manufactured using the phase shift mask 1A of the first embodiment, and the exposure package used. The exposure method or the area that can be exposed once is set as appropriate, and is set as a substantially rectangular (or substantially square) region in which the short side (one side) is 300 mm or more.

Further, in one pattern region 6A, a pattern useful for forming a configuration for use in one image display device may be formed, or a pattern useful for forming a configuration for a plurality of image display devices may be formed.

In addition, in the first embodiment, in addition to the phase shifting portion 3A and the non-phase shifting portion 4A, the pattern region 6A is provided with a size equal to or higher than the resolution limit of the exposure device, and includes a metal chromium or the like. The light-shielding portion 5A of the light-shielding film is not provided with a light-shielding portion having a light-shielding film made of metal chromium or the like having a size that does not reach the resolution limit of the exposure device. That is, the phase shift mask 1A of the first embodiment is referred to as a so-called chromium-free phase shift mask. When the size of the light shielding portion 5A in the pattern region 6A does not reach the exposure device resolution limit, the transmitted light adjacent to the phase displacement portion 3A or the non-phase displacement portion 4A of the light shielding portion 5A is returned to the lower portion of the light shielding portion 5A. And can't play the shading function.

By using the phase shift mask 1A of the first embodiment, the sidewall angle θ (see FIG. 5) of the resist pattern formed by exposure from the exposure apparatus can be made good (the sidewall angle θ is based on the photoresist) The type of the agent varies, for example, preferably 60 to 90 degrees, and particularly preferably 70 to 90 degrees. In this case, it is possible to reduce the unevenness in the resist pattern forming surface of the thickness (aspect ratio) of the resist pattern formed by the exposure of the phase shift mask 1A of the first embodiment. Therefore, according to the phase shift mask 1A of the first embodiment, even if a large exposure apparatus for a conventional image display apparatus is used, it is possible to form a resist pattern in-plane having a size that does not reach the resolution limit of the exposure apparatus. A resist pattern having a small dimensional error.

In the phase shift mask according to the first embodiment, any one of the phase shifting portion and the non-phase shifting portion has a smaller function of not exposing the photoresist film on the workpiece, and the other has a function of The function of exposing the photoresist film on the material to be processed. Therefore, in the phase shift mask of the first embodiment, in order to obtain a desired resist pattern, it is necessary to adjust the size of the dark region having a small size among the phase shift portion and the non-phase shift portion, and the phase shift portion and The size of the larger area of the non-phase displacement portion.

In the phase shift mask of the first embodiment, the phase shifting portion and the non-phase shift The size of the dark region having a smaller size in the portion is in the range of 0.6 μm to 2.75 μm, and the size of the larger portion of the phase displacement portion and the non-phase displacement portion and the size of the dark region In the case where the size of the dark region is set to 1, the size of the bright region is preferably 1.5 or more.

In addition, the details of the dark area and the bright area may be the same as those described in the item "2. Second aspect" below, and thus the description herein will be omitted.

[Manufacturing method of phase shift mask]

The phase shift mask 1A having the above configuration can be manufactured in the following manner. Fig. 4 is a flow chart showing the steps of manufacturing the phase shift mask 1A of the first embodiment.

First, as shown in FIG. 4(a), a transparent substrate 2A having a predetermined size is prepared, and a size of a resolution limit (for example, 3 μm) or more of an exposure device for a conventional image display device is used, and a metal chromium or the like is included. The light shielding portion 5A formed of the light shielding film is formed in the pattern region 6A (see FIG. 3) on the transparent substrate 2A.

Next, as shown in FIG. 4(b), the resist layer 7A is formed so as to cover the transparent substrate 2A (pattern area 6A) and the light shielding portion 5A thereon, and as shown in FIG. 4(c), Ray is used. The resist layer 7A is drawn by a laser drawing device, an electronic line drawing device, or the like to form a desired pattern. At this time, the size X of at least the phase shifting portion 3A is less than the resolution limit of the exposure device for the image display device used in the exposure by the phase shift mask 1A of the first embodiment and is smaller than the size of the non-phase shifting portion 4A. In the Y mode, the resist layer 7A is preferably drawn such that the ratio of the dimensions X and Y of the phase shifting portion 3A and the non-phase shifting portion 4A is within a predetermined range (1:1.5 to 1:5.6).

Then, as shown in FIG. 4(d), the resist layer 7A having a predetermined pattern is used as an etching mask, and the etching process of the transparent substrate 2A is performed. The etching treatment may be a wet etching treatment using an etching solution such as hydrofluoric acid, or a dry etching treatment such as reactive ion etching using a fluorine-based gas or the like. Thereby, the phase displacement portion 3A including the etching portion having a predetermined depth d is formed.

Finally, as shown in FIG. 4(e), the phase shift mask 1A of the first embodiment can be manufactured by removing the resist layer 7A remaining on the transparent substrate 2A.

[Resist pattern forming method]

Next, a method of forming a resist pattern using the phase shift mask 1A of the first embodiment will be described. Fig. 5 is a flow chart showing a method of forming a resist pattern in the first embodiment.

First, the phase shift mask 1A of the first embodiment is prepared so that the photoresist film 12A on the workpiece (substrate) 11A to be formed into a resist pattern is a positive resist in the first embodiment. The film film) is disposed at a predetermined interval from the surface of the phase displacement portion 3A or the like on which the phase shift mask 1A is formed, and is disposed to face the phase shift mask 1A (see FIG. 5(a)).

The substrate 11A to which the resist pattern is formed can be appropriately selected according to the use, etc., for example, a TFT substrate for a liquid crystal display device, a color filter substrate, a TFT substrate for an organic EL display device, or the like. As the substrate 11A, a glass substrate, a plastic substrate, a synthetic resin film, or the like can be used.

Next, light from an exposure device (not shown) of the image display device is irradiated onto the photoresist film 12A on the substrate 11A via the phase shift mask 1A of the first embodiment, and the photoresist film 12A is exposed. (Refer to Figure 5(b)). At this time, the transmitted light of the phase shifting portion 3A of the phase shifting mask 1A of the first embodiment interferes with the transmitted light of the non-phase shifting portion 4A, thereby causing the light to be incident on the optical path of the transmitted light of the phase shifting portion 3A. The intensity of the irradiation light of the resist film 12A is lowered to such an extent that the photoresist film 12A at the position is not exposed. Therefore, among the photoresist film 12A on the substrate 11A, the photoresist film 12A located on the optical path of the transmitted light of the phase shifting portion 3A is not light-sensitive, and is only located on the optical path of the transmitted light of the non-phase-shifting portion 4A. The film 12A is photosensitive.

Then, the exposed photoresist film 12A is developed using a predetermined developer to form a resist pattern 13A on which only the photoresist film 12A on the optical path of the transmitted light of the non-phase displacement portion 4A is removed. On the substrate 11A (see Fig. 5(c)).

According to the resist pattern forming method of the first embodiment, the dimension X of the phase shifting portion 3A of the phase shift mask 1A of the first embodiment is at least a size that is less than the resolution limit of the exposure device and smaller than the non-phase shifting portion. The size Y of 4A, whereby the resist pattern having a size which is less than the resolution limit of the exposure means corresponding to the phase shifting portion 3A can be formed to be faithfully formed in size.

Further, according to the resist pattern forming method in the first embodiment, the shape can be shaped The resist pattern 13A having a good sidewall angle θ (which varies depending on the type of the photoresist, etc., preferably 60 to 90 degrees, particularly preferably 70 to 90 degrees). Thereby, a resist pattern having a small dimensional error in the plane can be formed.

Further, in the first embodiment, the sidewall angle θ of the resist pattern 13A is from the substrate 13A side at a position 13A of the height (thickness) of the resist pattern 13A at a position 13A _down and the height of the resist pattern 13A. An arbitrary number (for example, 30 places) between the positions of 90% of the (thickness) and 13A _up is measured, and the angle of the side wall of the resist pattern 13A with respect to the resist pattern forming surface of the substrate 11A is measured, using the least square method as Calculated by the average value. The angle of the side wall of the resist pattern 13A can be calculated from, for example, a coordinate value of a side wall of the resist pattern 13A based on a scanning electron microscope (SEM) image, and calculated based on the coordinate value.

According to the resist pattern forming method of the first embodiment, the resist pattern 13A having a good sidewall angle θ can be formed, so that the thickness (aspect ratio) of the resist pattern 13A formed on the substrate 11A can be suppressed. As a result, as a subsequent step, in the etching step using the resist pattern 13A as an etching mask, an effect of being able to perform high-precision etching can be obtained.

For example, as an example of a phase shift mask which can be used to form a resist pattern for forming a transparent electrode containing indium tin oxide (ITO), which is formed on a glass substrate, it can be exemplified as shown in FIG. The phase shifting portion 3A, the non-phase shifting portion 4A, and the light blocking portion 5A, which are shown in the pattern, are disposed in the phase shift mask 1A in one of the pattern regions 6A.

Exposing the positive photoresist film on the ITO film provided on the glass substrate through the phase shift mask 1A shown in FIG. 6 using a large exposure apparatus having an equal magnification projection exposure optical system for an image display device And development, whereby a resist pattern (line pattern) corresponding to the phase shift portion 3A and a resist pattern corresponding to the light shielding portion 5A can be formed on the ITO film. Further, by performing an etching step on the glass substrate on which the resist pattern is formed, a transparent electrode having a size that does not reach the resolution limit of the large exposure apparatus for an image display device can be formed on the glass substrate with high precision.

Further, in addition to the use of the transparent electrode including ITO, the phase shift mask 1A of the first embodiment can also be applied to a map having a large area exposure. A large exposure apparatus such as an equal magnification projection exposure optical system for a display device is used for forming a resist pattern having a size that does not reach the resolution limit of the exposure apparatus on a large-area substrate. Examples of such a use include formation of a gate electrode, a source electrode, a gate electrode, and a contact hole on a TFT substrate such as a liquid crystal display; and a black matrix on the color filter substrate; The formation of a laminated column (layered spacer) formed by a plurality of layers or the like.

The exposure light used in the resist pattern forming method using the phase shift mask of the first embodiment can be used in a large exposure apparatus having a double projection exposure optical system for a general image display device. The same is not particularly limited, and it is preferably a mixed-wavelength light of g-ray, h-ray, or i-ray. The reason is that by using the mixed wavelength light, the amount of exposure to the photoresist film can be increased, and the station time for forming the resist pattern can be shortened. Further, the reason is that the mixed-wavelength light is irradiated onto the photoresist film via the phase shift mask of the first embodiment, and the phase shift mask having the known transmissive portion and the semi-transmissive portion is In contrast, a resist pattern having a predetermined thickness and a partition wall angle can be obtained.

<Second embodiment>

[phase shift mask]

The phase shift mask of the second embodiment will be described with reference to the drawings.

7 is a partially cut end view showing a schematic configuration of a phase shift mask according to a second embodiment, and FIG. 8 is a graph showing light intensity of transmitted light of the phase shift mask of the second embodiment, and FIG. 9 is a view showing 2 is a partial plan view showing a schematic configuration of a phase shift mask of the embodiment.

As shown in Fig. 7, the phase shift mask 1B of the second embodiment includes a transparent substrate 2B, a plurality of phase shifting portions 3B provided on the transparent substrate 2B, and a plurality of phase shifting portions 3B disposed adjacent to the phase shifting portions 3B. In the same manner as the phase shift mask 1A of the first embodiment, it is used in the process of manufacturing an image display device such as a liquid crystal display device or an organic EL display device, and is provided by the use of the phase shift mask 1A of the first embodiment. The exposure of the large exposure apparatus for the equal magnification projection exposure optical system of the image display device will not reach the resolution limit of the exposure device (preferably less than 3 μm, more preferably 1.5 μm or more and less than 3 μm, especially A resist pattern having a size of 1.5 to 2 μm is formed on the material to be processed.

The transparent substrate 2B is not particularly limited, and the same as the transparent substrate 2A of the phase shift mask 1A of the first embodiment can be used.

The phase shifting portion 3B is provided on the transparent substrate 2B and is configured as a transparent film having a predetermined thickness t formed on the transparent substrate 2B. Further, the transparent film unformed portion (the exposed portion of the transparent substrate 2B) adjacent to the plurality of phase shift portions 3B becomes the non-phase displacement portion 4B.

The transparent film constituting the phase shifting portion 3B is made of a transparent material having a transmittance of light having a wavelength of 365 nm of 80% or more, preferably 85% or more, and particularly preferably 90% or more. Examples of the transparent material include SiO, ITO, and a fluorine-based resin.

The dimension X of the phase shifting portion 3B and the dimension Y of the non-phase shifting portion 4B can be set to be the same as the dimension X of the phase shifting portion 3A of the phase shifting mask 1A of the first embodiment and the dimension Y of the non-phase shifting portion 4A.

The thickness t of the phase shifting portion 3B may be set to a predetermined phase difference (phase difference of 170 to 190 degrees (about 180 degrees)) to the transmitted light of the phase shifting portion 3B, and may be based on the transparent substrate 2B. The thickness, the wavelength of the light to be exposed, the refractive index of the material constituting the transparent substrate 2B, and the like are appropriately set.

Among the resist patterns to be formed by using the phase shift mask 1B of the second embodiment, a conventional binary mask (a mask having a light-shielding portion and an opening portion made of metal chromium or the like) is used. a resist pattern formed by the light shielding portion (for example, a line pattern in the case where a line and a gap-like resist pattern are to be formed by a positive type resist, and is formed by a negative photoresist In the case where the design of the gap pattern is less than the resolution limit of the exposure device for the image display device to be used, the phase shift mask 1B of the second embodiment includes the resist for forming the resist. The phase shifting portion 3B of the pattern. On the other hand, if the design size of the resist pattern is equal to or higher than the resolution limit of the exposure apparatus, the phase shift mask 1B of the second embodiment includes metal chromium containing the resist pattern. The light shielding portion 5B composed of a light shielding film.

In the phase shift mask 1B of the second embodiment, the phase shifting portion 3B and the non-phase shifting portion 4B are provided in the pattern region 6B (see FIG. 9) on the transparent substrate 2B. The pattern region 6B is set on at least one region on the transparent substrate 2B in accordance with the resist pattern to be formed on the workpiece by the phase shift mask 1B of the second embodiment, regardless of Regarding the exposure mode of the exposure device, light is irradiated by one exposure on at least the entire surface in one pattern region 6B.

As shown in FIG. 9, in the phase shift mask 1B of the second embodiment, a plurality of pattern regions 6B are set on the transparent substrate 2B, and only one pattern region 6B may be set. Further, in the phase shift mask 1B shown in FIG. 9, the phase shift portion 3B, the non-phase shift portion 4B, and the light blocking portion 5B in the pattern region 6B are omitted.

The size of the pattern region 6B can be determined according to the size (screen size) of the image display device to be manufactured by using the phase shift mask 1B of the second embodiment, the exposure mode of the exposure device to be used, or the area that can be exposed once. It is set as a substantially rectangular (or substantially square) area in which the short side (one side) is 300 mm or more.

Further, in one pattern region 6B, a pattern useful for forming a configuration for use in one image display device may be formed, or a pattern useful for forming a configuration for a plurality of image display devices may be formed.

In addition, in the second embodiment, in addition to the phase shifting portion 3B and the non-phase shifting portion 4B, the pattern region 6B is provided with a size having a resolution of the exposure device or more, and is shielded by a metal chromium or the like. The light-shielding portion 5B of the film is not provided with a light-shielding portion including a light-shielding film containing metal chromium or the like having a size that does not reach the resolution limit of the exposure device. That is, the phase shift mask 1B of the second embodiment is referred to as a so-called chromium-free phase shift mask. When the size of the light shielding portion 5B in the pattern region 6B does not reach the exposure device resolution limit, the transmitted light adjacent to the phase displacement portion 3B or the non-phase displacement portion 4B of the light shielding portion 5B is turned back below the light shielding portion 5B. And can't play the shading function.

Further, in the phase shift mask 1B of the second embodiment shown in Fig. 7, the transparent film having the same material as that of the transparent material constituting the phase shift portion 3B and having a size slightly larger than the size of the light shielding portion 5B can be completely shielded from light. The portion 5B is provided (see FIG. 11(f)). In this manner, the light shielding portion 5B is covered by the transparent film, and when the non-phase displacement portion 4B is adjacent to the light shielding portion 5B, the boundary portion between the non-phase displacement portion 4B and the light shielding portion 5B can be provided with The light of the predetermined phase difference increases the contrast of the illumination light at the boundary portion, so that the edge shape of the resist pattern formed by the light shielding portion 5B can be made good.

By using the phase shift mask 1B of the second embodiment, it is possible to The side wall angle θ (see FIG. 12) of the resist pattern formed by the exposure of the exposure apparatus is good (the side wall angle θ varies depending on the type of the photoresist, etc., preferably 60 to 90 degrees, and particularly preferably 70~) 90 degrees). In this case, it is possible to reduce the unevenness in the resist pattern forming surface of the thickness (aspect ratio) of the resist pattern formed by the exposure of the phase shift mask 1B of the second embodiment. Therefore, according to the phase shift mask 1B of the second embodiment, even if a large exposure apparatus for a conventional image display apparatus is used, it is possible to form a resist pattern in-plane having a size that does not reach the resolution limit of the exposure apparatus. A resist pattern having a small dimensional error.

[Method of Manufacturing Phase Displacement Mask 1]

The phase shift mask 1B having the above configuration can be manufactured in the following manner. Fig. 10 is a flow chart showing an example of a procedure for manufacturing the phase shift mask 1B of the second embodiment.

First, as shown in FIG. 10(a), a transparent substrate 2B having a predetermined size is prepared, and a size of a resolution (for example, 3 μm) or more of an exposure device for a conventional image display device is used, and a metal chromium or the like is included. The light shielding portion 5B formed of a light shielding film is formed in the pattern region 6B (see FIG. 9) on the transparent substrate 2B.

Next, as shown in FIG. 10(b), the resist layer 7B is formed so as to cover the transparent substrate 2B (pattern region 6B) and the light shielding portion 5B thereon, and as shown in FIG. 10(c), Ray is used. The resist layer 7B is drawn by a laser drawing device, an electron beam drawing device, or the like to form a desired pattern. In this case, the size X of at least the phase shifting portion 3B is less than the resolution limit of the exposure device for the image display device used in the exposure by the phase shift mask 1B of the second embodiment and is smaller than the size of the non-phase shifting portion 4B. In the Y mode, the resist layer 7B is preferably drawn such that the ratio of the dimensions X and Y of the phase shifting portion 3B and the non-phase shifting portion 4B is within a predetermined range (1:1.5 to 1:5.6).

Then, as shown in FIG. 10(d), a transparent film 30B including a transparent material (ITO or the like) constituting the phase displacement portion 3B is formed on the resist layer 7B having a predetermined pattern. At this time, since the thickness of the formed transparent film 30B becomes the thickness t of the phase shift portion 3B, the transparent film 30B can be formed to a thickness that is a predetermined phase difference (about 180 degrees) to the transmitted light of the phase shift portion 3B.

Finally, as shown in FIG. 10(e), it can be left on the transparent substrate 2B. The resist layer 7B and the transparent film 30B on the resist layer 7B are removed to produce the phase shift mask 1B of the second embodiment.

[Manufacturing method 2 of phase shift mask]

The phase shift mask 1B of the second embodiment can be manufactured in the following manner in addition to the method shown in Fig. 10 described above. Fig. 11 is a flow chart showing another example of the step of manufacturing the phase shift mask 1B of the second embodiment.

First, as shown in FIG. 11(a), a transparent substrate 2B having a predetermined size is prepared, and a size of a resolution limit (for example, 3 μm) of an exposure device for a conventional image display device is used, and a metal chromium or the like is included. The light shielding portion 5B formed of a light shielding film is formed in the pattern region 6B (see FIG. 9) on the transparent substrate 2B.

Next, as shown in FIG. 11(b), a transparent film 30B including a transparent material (ITO or the like) constituting the phase displacement portion 3B is formed so as to cover the transparent substrate 2B (pattern region 6B) and the light shielding portion 5B thereon. . At this time, the thickness of the transparent film 30B formed on the transparent substrate 2B becomes the thickness t of the phase shift portion 3B, so that a thickness which is capable of imparting a predetermined phase difference (about 180 degrees) to the transmitted light of the phase shift portion 3B is formed. Transparent film 30B.

Then, as shown in FIG. 11(c), the resist layer 7B is formed so as to cover the transparent film 30B, and as shown in FIG. 11(d), the resist is applied using a laser drawing device, an electron beam drawing device, or the like. The agent layer 7B is drawn to form a desired pattern. At this time, the resist layer 7B is drawn so that the resist layer 7B corresponding to the position of the phase shift portion 3B and the resist layer 7B on the light blocking portion 5B remain. Further, in the light shielding portion 5B, it is preferable that the resist layer 7B having a size slightly larger than the size of the light shielding portion 5B remains.

Then, as shown in FIG. 11(e), the resist layer 7B having a predetermined pattern is used as an etching mask, and the transparent film 30B is etched to form the phase shift portion 3B. The etching treatment may be a wet etching treatment using an etching solution such as hydrofluoric acid, or a dry etching treatment such as reactive ion etching using a fluorine-based gas or the like.

Finally, as shown in Fig. 11 (f), the phase shift mask 1B of the second embodiment can be manufactured by removing the resist layer 7B remaining on the transparent film 30B.

[Resist pattern forming method]

Next, a resist pattern is formed by using the phase shift mask 1B of the second embodiment described above. The method is explained. Fig. 12 is a flow chart showing a method of forming a resist pattern in the second embodiment.

First, the phase shift mask 1B of the second embodiment is prepared so that the photoresist film 12B on the workpiece (substrate) 11B to be formed into a resist pattern is a positive resist in the second embodiment. The phase film mask 1B is disposed opposite to the surface of the phase displacement portion 3B or the like provided with the phase shift mask 1B at a predetermined interval (see FIG. 12( a )).

The substrate 11B to which the resist pattern is formed can be appropriately selected according to the use, etc., for example, a TFT substrate for a liquid crystal display device, a color filter substrate, a TFT substrate for an organic EL display device, or the like. As the substrate 11B, a glass substrate, a plastic substrate, a synthetic resin film, or the like can be used.

Next, light from an exposure device (not shown) of the image display device is irradiated onto the photoresist film 12B on the substrate 11B via the phase shift mask 1B of the second embodiment, and the photoresist film 12B is exposed. (Refer to Figure 12(b)). At this time, the transmitted light of the phase shifting portion 3B of the phase shift mask 1B of the second embodiment interferes with the transmitted light of the non-phase shifting portion 4B, thereby causing the light to be incident on the optical path of the transmitted light located in the phase shifting portion 3B. The intensity of the irradiation light of the resist film 12B is lowered to the light intensity to such an extent that the photoresist film 12B at this position is not received. Therefore, among the photoresist films 12B on the substrate 11B, the photoresist film 12B located on the optical path of the transmitted light of the phase shifting portion 3B is not light-sensitive, and is only located on the optical path of the transmitted light of the non-phase-shifting portion 4B. The film 12B is photosensitive.

Then, the exposed photoresist film 12B is developed using a predetermined developer to form a resist pattern 13B of the photoresist film 12B on which only the light path of the transmitted light of the non-phase displacement portion 4B is removed. On the substrate 11B (see Fig. 12 (c)).

According to the resist pattern forming method of the second embodiment, the size X of the phase shifting portion 3B of the phase shift mask 1B of the second embodiment is at least a size that is less than the resolution limit of the exposure device and smaller than the non-phase shifting portion. The size Y of 4B, whereby the resist pattern having the size corresponding to the phase shift portion 3B and having the size of the resolution limit of the exposure device can be designed to be faithfully formed.

Further, according to the resist pattern forming method of the second embodiment, a good sidewall angle θ can be formed (the sidewall angle θ varies depending on the type of the photoresist, etc., The resist pattern 13B is preferably 60 to 90 degrees, more preferably 70 to 90 degrees. Thereby, the resist pattern 13B having a small dimensional error in the plane can be formed.

Further, in the second embodiment, the side wall angle θ of the resist pattern 13B is from the substrate 11B side at the position 13B _down of the height (thickness) of the resist pattern 13B and the height of the resist pattern 13B. The arbitrary number of positions (for example, 30 places) between the positions 13B _up of 90% of the thickness is measured, and the angle of the side wall of the resist pattern 13B with respect to the resist pattern forming surface of the substrate 11B is measured, using the least square method as Calculated by the average value. The angle of the side wall of the resist pattern 13B can be calculated from the coordinate value of the side wall of the resist pattern 13B based on the SEM image, for example, based on the coordinate value.

According to the resist pattern forming method of the second embodiment, the resist pattern 13B having a good sidewall angle θ can be formed, so that the thickness (aspect ratio) of the resist pattern 13B formed on the substrate 11B can be suppressed. As a result, as a subsequent step, in the etching step using the resist pattern 13B as an etching mask, an effect of being able to perform high-precision etching can be obtained.

For example, as an example of a phase shift mask which can be used for forming a resist pattern for forming a transparent electrode containing ITO on a glass substrate, a phase shift portion 3B having a pattern as shown in FIG. 6 can be cited. The non-phase shifting portion 4B and the light blocking portion 5B are provided in the phase shift mask 1B in one pattern region 6B.

Exposing the positive photoresist film on the ITO film provided on the glass substrate through the phase shift mask 1B shown in FIG. 6 using a large exposure apparatus having an equal magnification projection exposure optical system for an image display device And development, whereby a resist pattern (line pattern) corresponding to the phase shift portion 3B and a resist pattern corresponding to the light shielding portion 5B can be formed on the ITO film. Further, by performing an etching step on the glass substrate on which the resist pattern is formed, a transparent electrode having a size that does not reach the resolution limit of the large exposure apparatus for an image display device can be formed on the glass substrate with high precision.

Further, in addition to the use of the transparent electrode including ITO, the phase shift mask 1B of the second embodiment can be applied to a large-sized projection optical system that requires an image display device capable of large-area exposure. The exposure apparatus forms a resist pattern on a large-area substrate that does not reach the resolution limit of the exposure apparatus. Examples of such a use include formation of a gate electrode, a source electrode, a gate electrode, and a contact hole on a TFT substrate such as a liquid crystal display; and a black matrix on the color filter substrate; The formation of a laminated column (layered spacer) formed by a plurality of layers or the like.

The exposure light used in the resist pattern forming method using the phase shift mask of the second embodiment can be used in a large exposure apparatus having a double projection exposure optical system for a general image display device. The same is not particularly limited, and it is preferably a mixed-wavelength light of g-ray, h-ray, or i-ray. Further, the reason can be the same as that described in the item of the first embodiment described above, and thus the description thereof will be omitted.

<phase displacement mask of the first aspect>

In the first and second embodiments, the dimension X of the phase shifting portions 3A and 3B of the phase shift masks 1A and 1B is smaller than the dimension Y of the non-phase shifting portions 4A and 4B, and the phase shifting portions 3A and 3B function as conventional ones. The function of the light shielding portion of the binary mask is not limited to this aspect, and the dimension Y of the non-phase displacement portions 4A, 4B may be smaller than the size X of the phase displacement portions 3A, 3B, and the non-phase displacement portion. 4A and 4B function as a light-shielding portion of a conventional binary mask. In this case, at least the size Y of the non-phase shifting portions 4A, 4B is a size that does not reach the resolution limit of the large exposure device of the equal-projection exposure optical system used for the image display device, and the phase shift portion 3A, The comparison of the dimensions X and Y of the 3B and the non-phase displacement portions 4A and 4B is preferably 1.5:1 to 5.6:1, more preferably 1.8:1 to 4:1, and particularly preferably 1.8:1 to 3:1. Further, the size X of the phase displacement portions 3A, 3B adjacent to the non-phase displacement portions 4A, 4B is appropriately set depending on the design size of the resist pattern to be formed, as long as it is larger than the size Y of the non-phase displacement portions 4A, 4B. , it may not reach the resolution limit of the above exposure device, or may be above the resolution limit.

In the first and second embodiments, the light-shielding portions 5A and 5B including the light-shielding film containing metal chromium or the like are provided in the pattern regions 6A and 6B of the phase shift masks 1A and 1B. The present invention is not limited to such a case, and the design size of the resist pattern formed by the light shielding is less than the resolution limit of the large exposure apparatus having the double projection exposure optical system for the image display device used. It is not necessary to provide the light shielding portions 5A, 5B in the pattern regions 6A, 6B, as long as they correspond to the resist pattern. The phase shifting portions 3A and 3B (non-phase shifting portions 4A and 4B) may be provided in the equation.

As a method of manufacturing the phase shift masks 1A and 1B of the first and second embodiments, a phase shifting portion is provided on the transparent substrates 2A and 2B on which the light shielding portions 5A and 5B each including a light shielding film made of metal chromium or the like are formed. The method of 3A and 3B is exemplified, but in addition to such an aspect, for example, a light-shielding portion including a light-shielding film containing metal chromium or the like may be formed on the transparent substrates 2A and 2B after the phase-displacement portions 3A and 3B are formed. 5A, 5B mode setting.

2. The second aspect

A phase shift mask according to a second aspect of the present invention includes a transparent substrate, a concave or convex phase displacement portion provided on the transparent substrate, and a non-phase displacement portion adjacent to the phase displacement portion; The phase shifting portion is configured such that a phase of light that has passed through the phase shifting portion is reversed with respect to a phase of light that has passed through the non-phase shifting portion; and the phase shifting portion and the non-phase shifting portion The smaller one is used as the dark area, and the larger of the phase shifting portion and the non-phase shifting portion is used as the bright region; the size of the dark region is in the range of 0.6 μm to 2.75 μm. In the case where the size of the bright region is smaller than the size of the dark region, when the size of the dark region is set to 1, the size of the bright region is 1.5 or more; and the size of the phase shift mask is 330 mm × 450 mm or more.

In the second aspect, the "phase shifting portion is such that the phase of the light that is transmitted through the phase shifting portion is reversed with respect to the phase of the light that has passed through the non-phase shifting portion" means that the phase shifting portion is transmitted. The phase difference between the light that is exposed (the transmitted light of the phase shifting portion) and the light that is transmitted through the non-phase shifting portion (the transmitted light that is not the phase shifting portion) is a phase difference that cancels the two transmitted light to cancel the phase difference. Adjust the phase of the phase shift section. More specifically, the phase of the phase shifting portion is adjusted such that the phase difference between the transmitted light of the phase shifting portion and the transmitted light of the non-phase shifting portion is in the range of 180° ± 10°. In the second aspect, the phase difference is more preferably in the range of 180 ° ± 5 °, and particularly preferably 180 °.

Further, in the case where the light to be used together with the phase shift mask of the second aspect is a mixed-wavelength light of g-ray, h-ray or i-ray, it is preferable that the light of the phase shifting portion is transmitted through the i-ray. The phase difference between the transmitted light of the i-ray of the light and the non-phase displacement portion satisfies the above relationship Adjust the phase shifting section.

Specific examples of the phase shift mask as the second aspect include FIGS. 1 and 7 and the like described in the section "1. First aspect". In the second aspect, in the phase shift mask 1A shown in FIG. 1, the phase shift portion 3A as the etched portion is used as the dark region, and the non-phase shift portion 4A is used as the bright region. Further, in the phase shift mask 1B shown in Fig. 7, the phase shift portion 3B made of a transparent film is used as a dark region, and the non-phase shift portion 4B is used as a bright region.

According to the second aspect, the size of the dark region and the size of the bright region have the above-described dimensions, whereby the exposure device for manufacturing an image display device can be used, and the material to be processed on a transparent substrate or the like can be formed with high precision. A predetermined pattern that does not reach the size of the resolution limit of the exposure device.

Further, in the phase shift mask of the second aspect, the resist pattern can be formed with good precision as compared with the conventional phase shift mask including the transmissive portion and the semi-transmissive portion. Hereinafter, although the reason is not clear, it can be estimated as follows.

Here, as described above, a phase shift mask having a transmissive portion and a semi-transmissive portion used in a manufacturing process of a conventional semiconductor device such as an LSI is applied to a photomask in a manufacturing process of an image display device, and In the case where the exposure and development are performed by the exposure apparatus of the conventional image display device manufacturing, although the size of the obtained resist pattern may not reach the resolution limit, the thickness of the resist pattern may become small, or The side wall portion of the resist pattern is small, and there is a problem that the resist pattern does not function as an etching mask or that etching cannot be performed with high precision. The reasons for this problem can be estimated as follows.

That is, the photomask for manufacturing an image display device has a larger size than a photomask (a 6-inch scale photomask) for a general semiconductor manufacturing device. Further, with the increase in the size of image display devices in recent years, the size of the photomask for image display devices has been further increased. As a difference in size between the two, specifically, the length of the diagonal of the mask of 6 inches is 215 mm, and that of the image display device is about 495 mm to 1856 mm. Therefore, the photomask for the image display device has a diagonal ratio of 2.3 to 8.6 times with respect to the 6-inch scale mask, and further has the drawing time and the inspection time. The area ratio directly related to the manufacturing cost is expressed as 4.4 times to 72 times the area.

Therefore, in the case of the equal-projection exposure using the exposure apparatus for manufacturing an image display device of the prior art, in order to use the photomask for the image display device to perform exposure for a short period of time, a large amount of light is required, and thus, as the exposure light, for example, It is preferable to use mixed-wavelength light of g-ray, h-ray, and i-ray. Specifically, for a photomask having a pattern region having a side of 300 mm or more, or a mask having a size of 330 mm × 450 mm or more, it is preferable to use g, h, and manufacturing conditions. Mixed wavelength light of i-rays.

On the other hand, in the manufacturing process of the semiconductor device, in order to increase the exposure resolution, as the light to be exposed, for example, a short-wavelength side such as an i-ray, a KrF ray (248 nm), or an ArF ray (193 nm) is preferably used. Single-wavelength light, that is, light with a large amount of parallel light. Therefore, the phase shift mask used in the manufacturing process of the semiconductor generally adjusts the phase with respect to the single-wavelength light on the short-wavelength side with respect to the transmissive portion and the semi-transmissive portion.

Therefore, it is estimated that the phase shift mask in the manufacturing process of the semiconductor device in which the phase of the transmissive portion and the semi-transmissive portion is adjusted with respect to the light having a large amount of parallel components (single-wavelength light on the short-wavelength side) is applied as described above. In the case of using the photomask in the manufacturing process of the image display device in which the parallel light component is small (mixed-wavelength light), the transmitted light of the transmissive portion of the phase shift mask is easily directed to the semi-transmissive portion. When it is twisted back, the light transmitted through the semi-transmissive portion is not completely canceled toward the photoresist film corresponding to the semi-transmissive portion, and the exposed light is irradiated to the extent that the photoresist film is exposed. As a result, it is estimated that the thickness of the obtained resist pattern is small or the side wall portion of the resist pattern is small.

On the other hand, the phase shift mask of the second aspect is composed of a phase shifting portion and a non-phase shifting portion having different sizes of the dark region and the bright region, so that the two regions have the same transmittance of light for exposure, and each The phase of the transmitted light in the region is reversed. Therefore, it is estimated that when the mixed-wavelength light is irradiated onto the photoresist film as the exposure light through the phase shift mask of the second aspect, the transmitted light in the dark region can be made more than the conventional half-transmission. Since the light is transmitted through the portion, the transmitted light (return light) in the bright region which is returned to the dark region can be sufficiently canceled, and the extent to which the photoresist film is exposed to the photoresist film corresponding to the dark region can be suppressed. The situation of the light of exposure.

Hereinafter, details of the phase shift mask of the second aspect will be described.

[phase shift mask]

The phase shift mask of the second aspect is used as a dark region in which the smaller of the phase shifting portion and the non-phase shifting portion is used, and the larger one of the phase shifting portion and the non-phase shifting portion is larger Used as a bright area. Further, it is characterized in that the size of the dark area and the size of the bright area have a predetermined value.

Further, when the resist pattern on the workpiece is exposed by using the phase shift mask of the second aspect to form a resist pattern, the dark region is opposite to the region of the photoresist film which is not photosensitive. The area of the displacement mask (the area where the photoresist film is not exposed), the bright area is the area of the phase shift mask corresponding to the photosensitive area of the photoresist film (the area where the photoresist film is exposed).

The phase shift mask of the second aspect is characterized in that the size of the dark region is in the range of 0.6 μm to 2.75 μm. The dark areas described above are typically of a size that does not reach the resolution limit of the exposure apparatus.

The size of the specific dark region is appropriately selected depending on the pattern shape of the dark region, the use of the phase shift mask of the second aspect, and the like, and is not particularly limited, and is preferably in the range of 0.8 μm to 2.5 μm. It is preferably in the range of 1.0 μm to 2.0 μm.

More specifically, when the pattern shape of the dark region is linear, the size (line width) of the dark region is preferably 0.6 μm or more, more preferably 0.8 μm or more, and still more preferably 1.0 μm or more. Further, the size (line width) of the dark region is preferably 2.05 μm or less, more preferably 2.0 μm or less, and still more preferably 1.9 μm or less.

Further, when the pattern shape of the dark region is a square shape, the size of the dark region (the width in the short side direction of the square) is preferably 1.3 μm or more, more preferably 1.4 μm or more, and particularly preferably 1.6 μm. the above. Further, the size of the dark region (the width in the short side direction of the square) is preferably 2.75 μm or less, more preferably 2.5 μm or less, and particularly preferably 2.3 μm or less.

The reason is that when the size of the dark region is less than the above value, there is a case where the phase-reversed light that has passed through the dark region cannot obtain a good resist pattern because the amount of light that can cancel the light from the bright region is not obtained. The possibility of shape.

Further, the reason is that, in the case where the size of the dark region exceeds the above value, the amount of transmitted light in the dark region is used in the case where the phase resist mask of the second aspect is used to expose the photoresist film. As the light is transmitted through the dark region, the photoresist film is exposed, so that there is a possibility that the central portion of the resist pattern corresponding to the dark region is exposed.

Further, in the phase shift mask according to the second aspect, the ratio of the size of the bright region to the size of the dark region is such that when the size of the dark region is set to 1, The size of the bright area is 1.5 or more.

As the size of the bright region, the ratio of the size to the dark region may be equal to or greater than the above value, and may be a size that does not reach the resolution limit or a size equal to or higher than the resolution limit. The size of the specific region can be appropriately determined depending on various pattern shapes so that the ratio of the size to the size of the dark region is not less than the above value.

The phase shift mask of the second aspect is characterized in that it has a size of 330 mm × 450 mm or more. By the magnitude of the phase shift mask being equal to or higher than the above value, an image display device having a high-definition configuration can be manufactured.

Further, the size of the second phase shift mask can be appropriately selected depending on the application, and the like, for example, can be set to about 330 mm × 450 mm to 1600 mm × 1800 mm.

The transparent substrate, the phase shifting portion, the non-phase shifting portion, and other configurations of the phase shift mask of the second aspect can be the same as those described in the item "1. First aspect" described above, and thus the description is omitted. Description of the place.

Further, in the phase shift mask of the second aspect, a light-shielding portion having a size that does not reach the resolution limit of the exposure device and is formed of a light-shielding film such as metal chromium may be included. As such a light-shielding portion, for example, the phase shift mask can be preferably used as a correction pattern for correcting a mask pattern composed of a light-blocking portion of a bright region, a dark region, and an exposure device having a resolution limit or higher.

The size, pattern shape, and the like of the correction pattern can be appropriately selected according to the use of the phase shift mask of the second aspect, the exposure apparatus, and the like.

[Manufacturing method of phase shift mask]

The method of manufacturing the phase shift mask of the second aspect can be the same as the method of manufacturing the phase shift mask described in the above "1. First aspect", and thus the description thereof will be omitted.

[Resist pattern forming method]

Regarding the resist pattern forming method using the phase shift mask of the second aspect, in addition to the mask of the second aspect, the resist described in the above "1. First aspect" may be used. The content of the agent pattern forming method is the same, and thus the description herein is omitted.

The embodiments described above are described in order to facilitate the understanding of the present invention and are not intended to limit the present invention. Therefore, the subject matter disclosed in the above embodiments is intended to include all design changes or equivalents within the scope of the invention.

[Examples]

Hereinafter, the present invention will be described in detail by way of examples, and the present invention is not limited by the following examples and the like.

[Test Example 1]

A phase shift mask having a line-and-space pattern formed by alternately arranging a phase displacement portion having a size of 1 μm and a non-phase displacement portion having a size of 3 μm formed by an etched portion (Example 1) In the case of the photoresist film on the workpiece, the light intensity of the light (irradiation light) irradiated onto the photoresist film was obtained by simulation through the simulation.

This simulation was performed using a lithography simulation software. As a exposure condition in the simulation, a large exposure machine for liquid crystal display was used (resolution limit: 3.5 μm, NA: 0.083, coherence factor: 0.75), and the light source was set to 365 nm. Three wavelengths of mixed light source at 405 nm and 436 nm. Further, as the setting of the phase shift, when the light of the exposure at a wavelength of 365 nm is used as a reference and the phase is reversed by 180 degrees, the transmittance of the light of the exposure of the phase shift mask is set to 100%. Further, as the resist, a positive photoresist A (manufactured by AZ Corporation, product name; AZ1500) was used.

The results are shown in Table 1. In addition, in Table 1, Average indicates "the arithmetic mean of the intensity of the illumination light incident on the photoresist film", Max indicates "the maximum value of the intensity of the illumination light incident on the photoresist film", and Min indicates the "shooting direction". The minimum value of the light intensity of the photoresist film," Contrast said "the difference between Max and Min."

Further, a binary mask (Comparative Example 1) having the same configuration as that of Example 1 except that the phase shifting portion was changed to a light-shielding layer containing metal chromium was used, and the material was processed on the material to be processed through the binary mask. In the case where the photoresist film is exposed, the same as in the first embodiment The intensity of the light that is incident on the photoresist film is obtained by simulation. The results are combined and shown in Table 1.

Further, a halftone type phase shift mask having the same configuration as that of the first embodiment except that the phase shifting portion was changed to a phase shift film having a transmittance of 5% provided on the transparent substrate 2A was used (Comparative Example 2). When the photoresist film on the material to be processed is exposed through the halftone phase shift mask, the light that is incident on the photoresist film is obtained by simulation in the same manner as in the first embodiment. strength. The results are combined and shown in Table 1.

As shown in Table 1, it was confirmed that the phase shift mask of Example 1 can be directed to light as compared with the conventional binary mask (Comparative Example 1) or the halftone phase shift mask (Comparative Example 2). The minimum value (Min) of the intensity of the irradiation light of the resist film is remarkably lowered. The minimum value (Min) of the intensity of the illumination light incident on the photoresist film is the intensity of the illumination light that is incident on the photoresist film on the optical path of the transmitted light at the phase displacement portion, so that the phase shift mask according to Embodiment 1 The cover can make the phase shifting portion excellent in light blocking effect.

Further, it was confirmed that the phase shift mask of Example 1 can be directed to the photoresist film as compared with the conventional binary mask (Comparative Example 1) or the halftone phase shift mask (Comparative Example 2). The difference (Contrast) between the maximum value (Max) and the minimum value (Min) of the intensity of the illumination light is significantly increased. The larger the difference (Contrast), the higher the resolution can be obtained. Therefore, it is considered that the phase shift mask of the first embodiment can form a resist pattern with high resolution.

[Test Example 2]

Resist pattern formed by exposure of the phase shift mask of Example 1, the binary mask of Comparative Example 1, and the halftone phase shift mask of Comparative Example 2 by simulation of resist distribution (Line pattern size: 2 μm, gap pattern size: 2 μm) for comparison. The results are shown in Table 2. Further, the conditions related to the simulation (conditions relating to the simulation software, the exposure device, the phase shift, the resist, and the like) are the same as those in Test Example 1. The results are shown in Table 2.

As shown in Table 2, it was confirmed that the phase shift mask according to Example 1 can be made resistant to the conventional binary mask (Comparative Example 1) or the halftone type phase shift mask (Comparative Example 2). The sidewall angle of the etchant pattern is significantly increased. Therefore, the side wall angle of the resist pattern formed by the phase shift mask of the first embodiment is large, thereby suppressing the position on the visible substrate during exposure of a large area in the manufacturing process of the image display device or the like. The unevenness of the resist pattern shape or the like occurs.

Further, in the line-and-space-like resist pattern formed by using the phase shift mask of Example 1, the binary mask of Comparative Example 1, and the halftone type phase shift mask of Comparative Example 2, the line pattern Both the size and the gap pattern size are 2 μm.

[Test Example 3]

A phase shift mask (embodiments 2 to 8) having the same configuration as that of the first embodiment except that the phase shift portion and the non-phase shift portion are changed in the manner shown in Table 3, by using the phase shift In the case of forming a resist pattern having a predetermined size (line pattern size: 2 μm, gap pattern size: 2 μm) by changing the exposure conditions, the resist was exposed in the same manner as in Test Example 2 by the resist. The simulation of the distribution is compared. The results are shown in Table 3. Further, the distribution of the resist pattern formed using the phase shift mask of Example 1 is also shown in Table 3.

As shown in Table 3, it was confirmed that a good side wall angle can be formed by setting the ratio (X: Y) of the dimension X of the phase shifting portion to the dimension Y of the non-phase shifting portion to be 1:1.5 to 1:5.6. θ resist pattern. In particular, it was confirmed that by setting the ratio (X:Y) to 1:1.8 to 1:4, a resist pattern having a more favorable sidewall angle θ can be formed (Examples 1 to 4 and Example 6). By setting it as 1:1.8 to 1:3, a resist pattern having a particularly good sidewall angle θ can be formed (Examples 1 to 3).

Further, in each of Examples 1 to 8, the exposure amount was set so as to obtain a resist pattern having a pitch size of 4 μm, a line pattern size of 2 μm, and a gap pattern size of 2 μm and a gap pattern.

[Test Example 4]

In the same manner as in Test Example 2, a phase shift mask having the same configuration as that of Embodiment 1 except that the phase shift portion and the non-phase shift portion were changed in the manner shown in Table 4 was used for the simulation of the resist distribution. (Example 9) A comparison was made by a resist pattern formed by exposure through the phase shift mask. The results are shown in Table 4. Further, the distribution of the resist pattern formed using the phase shift mask of Example 1 is also shown in Table 4.

As shown in Table 4, it was confirmed that even if the total of the size X of the phase shifting portion and the dimension Y of the non-phase shifting portion (X+Y) is less than the resolution limit of the exposure apparatus (3.5 μm in Test Example 4) A resist pattern (Example 9) was formed, and a resist pattern having a good resist angle θ was formed by the total (X+Y) being equal to or higher than the resolution of the exposure apparatus (Example 1).

[Test Example 5]

Except that the positive type resist A in Test Example 2 was changed to other positive type resist B (manufactured by Tokyo Chemical Co., Ltd., product name: ip3600), the resist distribution was similarly The simulation was compared with a resist pattern formed by exposure of each of the phase shift mask of Example 1, the binary mask of Comparative Example 1, and the halftone type phase shift mask of Comparative Example 2. The results are shown in Table 5.

As shown in Table 5, it was confirmed that the sidewall angle θ of the formed resist pattern varies depending on the kind of the photoresist, but in any of the photoresists, the phase shift mask of Example 1 can be used. A resist pattern having a sidewall angle θ which is superior to the binary mask of Comparative Example 1 and the halftone type phase shift mask of Comparative Example 2 was formed.

[Test Example 6]

The phase shifting portion formed of the etched portion having the square shape (see FIG. 13) having the size shown in Table 6 below is used as the dark region, and the non-phase shifting portion is used as the phase shifting mask for the bright region ( In the examples 10 to 12 and the reference examples 1 to 3), when the photoresist film on the workpiece was exposed, the resist pattern formed by the exposure was obtained by simulation of the resist distribution. Further, the conditions related to the simulation (conditions relating to the simulation software, the exposure device, the phase shift, the resist, and the like) are the same as those in Test Example 1. Moreover, the exposure amount was changed so as to obtain the size of the resist pattern shown in Table 6 below.

Further, Fig. 13 is a view for explaining a dark region and a bright region of the phase shift mask in Test Example 6. Further, Fig. 13 shows an example in which the dark area is one square shape (isolated square). Further, the size of the dark area is the distance indicated by W1 in Fig. 13.

As shown in Table 6, it was confirmed that in Examples 10 to 12, the side wall angle θ was good.

[Test Example 7]

A phase shifting mask that is formed by using an etched portion having a line shape (see FIG. 14) having a size shown in Table 7 below as a dark region, and a non-phase-shifting portion as a bright region (implemented) In Examples 13 to 14, and Reference Examples 4 to 5), in the case of exposing the photoresist film on the workpiece, the resist pattern formed by the exposure was obtained by simulation of the resist distribution. Further, the conditions related to the simulation (conditions relating to the simulation software, the exposure device, the phase shift, the resist, and the like) are the same as those in Test Example 1. Moreover, the exposure amount was changed so as to obtain the size of the resist pattern shown in the following Table 7.

Further, Fig. 14 is a view for explaining a dark region and a bright region of the phase shift mask in Test Example 7. Further, an example in which the dark region has one line shape (isolated line) is shown in FIG. Further, the size of the dark area is the distance indicated by W2 in Fig. 14.

As shown in Table 7, it was confirmed that in Examples 13 to 14, the side wall angle θ was good.

[Test Example 8]

The phase shift masks of Examples 15 to 18 and Reference Example 6 in which the size of the isolated rectangular region in Test Example 6 was changed to the size shown in Table 8 below, and the exposure amount were used to obtain the following. The exposed resist pattern was obtained by simulation of the resist distribution in the same manner as in Test Example 6, except that the dimensions of the resist pattern shown in Table 8 were changed.

Further, the film reduction ratio in Table 8 is a ratio indicating the difference between the maximum thickness and the minimum thickness of the resist pattern in comparison with the maximum thickness of the resist pattern.

As shown in Table 8, it was confirmed that the film reduction rate was larger in Reference Example 6 than in Examples 15 to 18.

[Test Example 9]

The phase shift masks of Examples 19 to 21 and Reference Example 7 in which the size of the dark region of the isolated line in Test Example 7 was changed to the size shown in Table 9 below, and the exposure amount were obtained to obtain the following table. The exposed resist pattern was obtained by simulation of the resist distribution in the same manner as in Test Example 7, except that the dimensions of the resist pattern shown in Fig. 9 were changed.

Further, the film reduction ratio in Table 9 is a ratio indicating the difference between the maximum thickness and the minimum thickness of the resist pattern in comparison with the maximum thickness of the resist pattern.

As shown in Table 9, it was confirmed that the film reduction rate was larger in Reference Example 7 than in Examples 19 to 21.

From Test Examples 6 to 9, it was confirmed that in the formation of a linear resist pattern having a plural size of 0.6 μm or more, by the dark region and the bright region and the light-shielding film (for example, chromium) in the present invention A combination of a light-shielding portion such as a film or the like can be used to form the resist pattern by using one phase shift mask.

(industrial availability)

The phase shift mask of the present invention is useful for forming a resist pattern having a size that is less than the resolution limit of the exposure apparatus used in the manufacturing process of an image display device such as a liquid crystal display or an organic EL display.

1A‧‧‧phase shift mask

2A‧‧‧Transparent substrate

3A‧‧‧ Phase Displacement Department

4A‧‧‧ Non-phase displacement

5A‧‧‧Lighting Department

d‧‧‧Depth of the etch department

Claims (7)

A phase shift mask for forming a resist pattern of a design size that does not reach the resolution limit of the exposure device on a workpiece by exposure from an exposure device; characterized in that it comprises: a transparent substrate; a concave or convex phase displacement portion provided on the transparent substrate to impart a predetermined phase difference to the exposed light from the exposure device; and a non-phase displacement portion adjacent to the phase displacement portion; the phase shift At least one of the portion and the non-phase displacement portion is a size that does not reach the resolution limit of the exposure device, and the size of the phase displacement portion is different from the size of the non-phase displacement portion; the phase displacement portion and the non-phase One of the smaller of the phase shifting portions functions to prevent exposure of the photoresist film on the workpiece, and the other function to expose the photoresist film on the workpiece; The dimension of the phase shifting portion and the dark region having a small dimension among the non-phase shifting portions is in the range of 0.6 μm to 2.75 μm, and the size and the upper portion of the phase shifting portion and the non-phase shifting portion having a larger size are The ratio of the size of the dark region is such that the size of the bright region is 1.5 times or more the size of the dark region; and the size of the pattern region including the phase shift portion and the non-phase shift portion on the transparent substrate is 300 mm or more. At least in the pattern region, a light-shielding portion which is not sized to the resolution limit of the exposure device and is formed of a light-shielding film is not provided. The phase shift mask of claim 1, wherein the ratio of the size of the phase shifting portion to the dimension of the non-phase shifting portion is 1:1.5 to 1:5.6 or 1.5:1 to 5.6:1. The phase shift mask according to claim 1 or 2, wherein a total of a size of the phase shifting portion and a size of the non-phase shifting portion adjacent to the phase shifting portion is equal to or greater than a resolution limit of the exposure device. The phase shift mask according to claim 1 or 2, wherein the pattern region has a light-shielding portion having a size equal to or greater than a resolution limit of the exposure device and having a light-shielding film. The phase shift mask of claim 1 or 2, wherein the concave phase displacement portion is provided on the etched portion of the transparent substrate. A phase shift mask according to claim 1 or 2, wherein the convex phase displacement portion is formed of a light transmissive film provided on the transparent substrate. A resist pattern forming method for forming a resist pattern having a design size that does not reach the resolution limit of an exposure apparatus on a workpiece; characterized by comprising the steps of: using the above exposure apparatus, via Applying the phase shift mask of the first or second aspect of the patent to expose the photoresist film disposed on the material to be processed; and developing the exposed photoresist film on the material to be processed A predetermined resist pattern is formed.