KR20170117988A - Photomask and method for manufacturing display device - Google Patents

Abstract

INDUSTRIAL APPLICABILITY The present invention provides an excellent photomask which is suitable for exposure environment of a mask for manufacturing display devices and is capable of stably transferring a fine pattern and a method of manufacturing the same. Wherein the transfer pattern has a main pattern of a diameter W1 (占 퐉), an auxiliary pattern of a width d (占 퐉) arranged in the vicinity of the main pattern, Wherein the main pattern and the auxiliary pattern are formed in a region other than where the main pattern and the auxiliary pattern are formed, wherein the phase difference of the representative wavelength transmitted through the main pattern and the auxiliary pattern is approximately 180 degrees, and the diameter W1, the width d, The transmittance T3 (%) of the low transmittance portion, and the distance P (mu m) between the center of the main pattern and the center in the width direction of the auxiliary pattern have a predetermined relationship.

Description

[0001] PHOTOMASK AND METHOD FOR MANUFACTURING DISPLAY DEVICE [0002]

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a photomask, which is typified by a liquid crystal or an organic EL, which is advantageously used for manufacturing a display device, and a method of manufacturing a display device using the same.

Patent Document 1 discloses a photomask used for manufacturing a semiconductor device, in which four auxiliary light-transmitting portions are arranged parallel to the respective sides of the main light-transmitting portion (hole pattern) so that the optical phases of the main light-transmitting portion and the auxiliary light- A phase shift mask is described.

Patent Document 2 discloses a large phase shift mask having a transparent substrate and a translucent phase shift film formed on the transparent substrate.

Japanese Unexamined Patent Application Publication No. 3-15845 Japanese Patent Application Laid-Open No. 2013-148892

At present, in a display device including a liquid crystal display device and an EL display device, it is demanded to improve display performance such as high precision, high-speed display, and wide viewing angle in addition to being brighter and saving power.

For example, in the case of a thin film transistor ("TFT") used in the display device, among the plurality of patterns constituting the TFT, the contact hole formed in the interlayer insulating film surely connects upper and lower patterns If there is no action, correct operation is not guaranteed. On the other hand, in order to maximize the aperture ratio of the display device and obtain a bright display device with reduced power consumption, it is required that the diameter of the contact hole is sufficiently small. Along with this, it is desired that the diameter of the hole pattern provided in the photomask for forming such a contact hole is also reduced (for example, less than 3 mu m). For example, it is considered that a hole pattern having a diameter of 2.5 占 퐉 or less, furthermore, a diameter of 2.0 占 퐉 or less is required, and a pattern having a diameter of 1.5 占 퐉 or less which is less than this is desired in the near future. Such a background makes it necessary to manufacture a display device capable of reliably transferring a minute contact hole.

However, in the field of a photomask for manufacturing a semiconductor device (LSI) in which the degree of integration is high and pattern miniaturization is remarkably advanced as compared with a display device, in order to obtain high resolution, an exposure apparatus is required to have a high numerical aperture (NA) 0.2 or more), and exposure light has been shortened in wavelength, and excimer lasers of KrF and ArF (single wavelengths of 248 nm and 193 nm, respectively) have been used.

On the other hand, in the field of lithography for manufacturing display devices, it has not been general that the above-described method is applied to improve the resolution. Rather, the NA of an exposure apparatus known as an LCD (liquid crystal display) or the like is about 0.08 to 0.10, and the exposure light source uses a broad wavelength region including i line, h line, and g line , Production efficiency and cost rather than resolution and depth of focus.

However, as described above, also in the manufacture of a display device, a request for miniaturization of a pattern has conventionally increased. There are several problems in applying the technique for manufacturing semiconductor devices to the manufacture of display devices. For example, in the case of switching to a high-resolution exposure apparatus having a high NA (numerical aperture), a large investment is required, and compatibility with the price of the display device is not obtained. Alternatively, it is difficult to apply the present invention to a display device having a large area for changing the exposure wavelength (using a single wavelength such as an ArF excimer laser for a single wavelength), and furthermore, It is unsuitable in that it requires significant investment.

In addition, as described later, the photomask for a display device has a manufacturing constraint and various problems different from those of a photomask for manufacturing a semiconductor device.

In view of the above circumstances, it is practically difficult to devote the photomask of Patent Document 1 directly to the manufacture of a display device. The halftone phase shift mask described in Patent Document 2 has a description that the light intensity distribution is improved as compared with the binary mask, but there is also room for improvement in performance.

Therefore, in a method of manufacturing a display device using a mask for manufacturing a display device, it has been desired to overcome the above-described problems and to stably transfer the pattern on a body as a fine pattern. Therefore, an object of the present invention is to obtain an excellent photomask which is suitable for the exposure environment of a mask for manufacturing a display device and which can stably transfer a fine pattern, and a method of manufacturing the same.

In order to solve the above problems, the present invention has the following configuration. The present invention relates to a photomask having the following constitutions 1 to 14, and a manufacturing method of a display device having the following constitution (15).

(Configuration 1)

(1) A photomask having a transfer pattern formed on a transparent substrate, the transfer pattern comprising a main pattern having a diameter of W1 (mu m) and a width d ( And a low-transmittance portion disposed in a region other than the main pattern and the auxiliary pattern, wherein the representative wavelength in the wavelength range of the i-line to the g-line passing through the main pattern, And a light transmittance of the representative wavelength transmitted through the auxiliary pattern is T 1 (%), and a light transmittance of the representative wavelength transmitted through the low- %), And the distance between the center of the main pattern and the center of the auxiliary pattern in the width direction is P (占 퐉), the following expressions (1) to (4) are satisfied.

[Equation 1]

&Quot; (2) "

&Quot; (3) "

&Quot; (4) "

(Composition 2)

In the second aspect of the present invention, the auxiliary pattern is the photomask according to Structure 1, wherein a semi-light-transmitting film having a transmittance of T1 (%) with respect to the light of the representative wavelength is formed on the transparent substrate .

(Composition 3)

The constitution 3 of the present invention is the photomask according to Structure 2, characterized in that the transmittance T1 (%) of the semitransparent film satisfies the following expression (5).

&Quot; (5) "

(Composition 4)

The constitution 4 of the present invention is the photomask according to configuration 2 or 3, wherein the width d of the auxiliary pattern is 1 (탆) or more.

(Composition 5)

According to a fifth aspect of the present invention, in the main pattern, a part of the main surface of the transparent substrate is exposed, and the auxiliary pattern has the semi-light-transmitting film formed on the transparent substrate, And a low light-transmittance film having a light transmittance of T2 (%) of the representative wavelength is laminated on the transparent substrate in this order or vice versa. To (4).

(Composition 6)

According to a sixth aspect of the present invention, in the main pattern, the depressed portion is formed on the main surface of the transparent substrate, the auxiliary pattern is formed on the transparent substrate with the semitransparent film, And a low light-transmittance film having a light transmittance of T2 (%) of the representative wavelength is laminated on the transparent substrate in this order or vice versa. To (4).

(Composition 7)

In the constitution 7 of the present invention, it is preferable that the semi-light-transmitting film is made of a material containing at least one of Zr, Nb, Hf, Ta, Mo and Ti and Si or an oxide, a nitride, an oxynitride, A photomask according to any one of Structures 2 to 6, characterized in that it is made of a material containing nitride carbide.

(Composition 8)

In the structure 8 of the present invention, the auxiliary pattern is the photomask described in Structure 1, wherein the transparent substrate is exposed.

(Composition 9)

According to a ninth aspect of the present invention, in the main pattern, a depressed portion is formed on a main surface of the transparent substrate, the auxiliary pattern is formed by exposing a part of a main surface of the transparent substrate, And a low light-transmitting film having a light transmittance T3 (%) of the representative wavelength is formed on the transparent substrate.

(Configuration 10)

According to a tenth aspect of the present invention, the main pattern is formed by exposing a part of the main surface of the transparent substrate, the auxiliary pattern is formed with a depressed portion on the main surface of the transparent substrate, And a low light-transmitting film having a light transmittance T3 (%) of the representative wavelength is formed on the transparent substrate.

(Configuration 11)

The constitution 11 of the present invention is characterized in that a hole pattern having a transfer diameter W2 of not more than 3.0 (mu m) (W1 > W2) is formed on the transferred body in correspondence with the main pattern. Wherein the photomask is a photomask.

(Configuration 12)

In the constitution 12 of the present invention, when the difference W1-W2 between the diameter W1 of the main pattern and the transfer diameter W2 on the body is defined as a bias? (占 퐉)

&Quot; (6) "

Is a photomask as described in Structure 11 above.

(Composition 13)

The constitution 13 of the present invention is characterized in that the transmittance T3 (%) of light of the representative wavelength of the low-

&Quot; (7) "

Of the first aspect of the present invention.

(Composition 14)

The constitution 14 of the present invention is the photomask according to any one of constitutions 1 to 12, characterized in that the low-transmissive portion does not substantially transmit the light of the representative wavelength.

(Composition 15)

A constitution (15) of the present invention is a process for producing a photomask comprising the steps of: preparing a photomask according to any one of structures 1 to 14; exposing the photomask having a numerical aperture (NA) of 0.08 to 0.20 and containing at least one of i- And a step of exposing the transfer pattern using an exposure apparatus having a light source and forming a hole pattern having a diameter W2 of 0.6 to 3.0 mu m on the transferred body.

According to the present invention, it is possible to provide an excellent photomask which is suitable for the exposure environment of a mask for manufacturing a display device and is capable of stably transferring a fine pattern and a method of manufacturing the same.

1 is a schematic plan view of an example of a photomask of the present invention.
Fig. 2 is a schematic plan view (a) to (f) of another example of the photomask of the present invention.
Fig. 3 shows examples (a) to (f) of the layer structure of the photomask of the present invention.
4 is a schematic cross-sectional view and a schematic plan view showing an example of a manufacturing process of the photomask of the present invention.
Fig. 5 is a diagram showing a plan view, dimensions and transfer performance of the photomask of Comparative Examples 1-1 and 1-2 and Example 1, respectively, according to dimensions and optical simulation.
FIG. 6 is a graph showing the relationship between (a) the spatial phase of the light intensity formed on the transferred body and (b) the cross-sectional shape of the resist pattern formed by the photomask of Comparative Example 1-1 and 1-2 and Example 1 Fig.
FIG. 7 is a diagram showing a plan view, dimensions and transfer performance of the photomask of Comparative Examples 2-1 and 2-2 and Example 2, according to dimensions and optical simulation.
FIG. 8 is a graph showing the relationship between (a) a spatial phase of light intensity formed on a subject to be imaged and (b) a cross-sectional shape of a resist pattern formed thereby, in the case of using the photomasks of Comparative Examples 2-1 and 2-2 and Example 2 Fig.

When the CD (Critical Dimension) of the transfer pattern of the photomask is miniaturized, the step of accurately transferring the transfer medium to a transfer target body (also referred to as a thin film to be etched or a workpiece to be etched) It becomes more difficult. The marginal limit indicated as a specification in an exposure apparatus for a display device is about 2 to 3 탆 in most cases. On the other hand, among the transfer patterns to be formed, those having a size close to or below the transfer pattern already appear. In addition, since the mask for manufacturing a display device has a larger area than a mask for manufacturing a semiconductor device, there is a great difficulty in uniformly transferring a transfer pattern having a CD of less than 3 mu m in the plane in actual production.

Therefore, by designing elements other than pure resolution (due to the exposure wavelength and the numerical aperture of the exposure optical system), it becomes necessary to take out the effective transfer performance.

Further, since the area of the transferred body (flat panel display substrate) is large, it can be said that the step of pattern transfer by exposure is an environment in which defocus due to the surface flatness of the transferred body is likely to occur. Under this environment, it is very meaningful to sufficiently secure the DOF of the focus at the time of exposure.

The photomask for manufacturing a display device has a large size as known in the art. In the wet process (development or wet etching) in the photomask manufacturing process, the photomask for manufacturing a display device has uniformity of CD (line width) Is not easy to secure. In order to accommodate the final CD precision within the prescribed allowable range, it is desirable that the sufficient depth of focus (DOF) in the exposure process is critical and the performance deteriorates along with it.

The present invention is a photomask comprising a transfer pattern formed by patterning a semi-light-transmitting film and a low light-transmitting film respectively formed on a transparent substrate. A schematic plan view of the transfer pattern of the photomask of the present invention is illustrated in Fig.

As shown in Fig. 1, the transfer pattern formed on the transparent substrate includes a main pattern of a diameter W1 (占 퐉) and auxiliary patterns of a width d (占 퐉) arranged in the vicinity of the main pattern. In addition, a low light-transmitting portion is formed in a region other than the main pattern and the auxiliary pattern.

Here, let T 1 be the transmittance for the light of the representative wavelength in the i-line to g-line wavelength region that transmits the auxiliary pattern, and T 3 be the transmittance for the light of the representative wavelength transmitted through the low- The distance between the center of the main pattern and the center of the auxiliary pattern in the width direction is P (mu m). At this time, the photomask of the present invention satisfies the following relationship.

[Equation 1]

&Quot; (2) "

&Quot; (3) "

&Quot; (4) "

In the above formula, T1 is preferably T1? 30.

The light transmittances T1 and T3 referred to herein are based on the transmittance of the transparent substrate and are determined by the layer structure of the corresponding portion.

The cross-sectional schematic diagram of such transfer pattern can be, for example, as shown in Fig. 3 (a). The first embodiment of the photomask of the present invention will be described with reference to Fig. 3 (a).

In this embodiment, the main pattern includes a transparent portion in which the transparent substrate is exposed. Further, a film having a high transmittance may be formed in the main pattern. However, from the point of view of obtaining the maximum transmittance, it is preferable that the main pattern is made such that a transparent substrate is exposed without forming a film having a high transmittance.

Further, the auxiliary pattern of this embodiment includes a semi-transparent portion having a translucent film formed on a transparent substrate. This semi-light-transmitting film has a phase shift amount for shifting the light of the representative wavelength in the wavelength range of the i-line to the g-line by approximately 180 degrees, and has the transmittance T1 (%) with respect to the representative wavelength. Further, the portion surrounding the main pattern and the auxiliary pattern has a low light-transmitting portion on the transparent substrate, at least a low light-transmitting film is formed. That is, in the transfer pattern shown in Fig. 1, the region other than the region where the main pattern and the auxiliary pattern are formed is a low light-projecting portion. As shown in Fig. 3 (a), in this embodiment, the translucent film and the low translucent film are laminated on the transparent substrate in the low translucent portion. Further, the low light-transmissive portion may be laminated on the transparent substrate in the order of the semitransparent film and the low light-transmissive film having the light transmittance T2 (%) of the representative wavelength in this order or vice versa.

The low light transmitting portion of the photomask of the present invention has a predetermined low transmittance to the representative wavelength of the exposure light. That is, for the light of the representative wavelength in the wavelength range of i-line to g-line, the low-light-transmitting portion has a transmittance T3 (%) lower than the transmittance T1 (%) of the auxiliary pattern including the semi-light-transmitting portion. Therefore, in this embodiment (FIG. 3A) in which the low light transmitting portion is formed by the lamination of the translucent portion and the low transparent portion,

T3 < T1

, The transmittance T3 (%) of the low transmittance portion can be adjusted by selecting the transmittance T2 (%) of the low transmittance film.

A fine main pattern (hole pattern) having a diameter W2 (mu m) (W1 > W2) is formed on the transferred body in correspondence with the main pattern when the diameter W1 of the main pattern is 4 mu m or less. Can be formed.

Concretely, W1 (占 퐉) is expressed by the following formula 1

[Equation 1]

To be the relationship At this time, the diameter W2 (mu m) of the main pattern (hole pattern) formed on the transferred body is 3.0 mu m or less, specifically,

0.6? W2? 3.0

.

Further, the photomask of the present invention can be used for the purpose of forming a fine-size pattern useful for manufacturing a display device. For example, when the diameter W1 of the main pattern is 3.0 mu m or less, the effect of the present invention is more remarkably obtained. Preferably, the diameter of the main pattern W1 (mu m)

1.0? W1? 3.0

. The relationship between the diameter W1 and the diameter W2 may be W1 = W2, but preferably W1 > W2. That is, when? (占 퐉) is a bias value,

beta = W1-W2 > 0 (mu m)

when,

0.2??? 1.0

More preferably,

0.2??? 0.8

. In this case, as described below, advantageous effects such as reduction in the loss of the resist pattern on the transferred body can be obtained.

In the above, the diameter W1 of the main pattern means the diameter of the circle, or a numerical value approximate thereto. For example, when the shape of the main pattern is a regular polygon, the diameter W1 of the main pattern is the diameter of the inscribed circle. If the shape of the main pattern is a square as shown in Fig. 1, the diameter W1 of the main pattern is the length of one side. The diameter W2 of the transferred main pattern is also the same as the diameter of the circle or a numerical value approximate thereto.

Of course, when a finer pattern is to be formed, it is also possible to set W1 to be not more than 2.5 (mu m) or not more than 2.0 (mu m), and furthermore, have.

The preferable range of the diameter W1 of the main pattern, the diameter W2 of the main pattern on the transferred object, and the bias in the photomask of the present invention is the above-described preferred range of the present invention relating to the second to sixth embodiments The same can be applied to the mask.

The phase difference? Between the main pattern and the auxiliary pattern is approximately 180 degrees with respect to the representative wavelength of the exposure light used in the photomask exposure of the present invention having such a transfer pattern. That is, the phase difference? 1 between the light of the representative wavelength transmitted through the main pattern and the representative wavelength transmitted through the auxiliary pattern becomes approximately 180 degrees. About 180 degrees means 120 to 240 degrees. Preferably, the phase difference? 1 is 150 to 210 degrees, more preferably 170 to 190 degrees.

Further, since the photomask of the present invention is remarkably effective when using exposure light including i-line, h-line, or g-line, exposure light including at least one of i-line, h-line and g- have. In particular, it is preferable to apply broad wavelength light including i-line, h-line and g-line as exposure light. In this case, the representative wavelength can be any one of i-line, h-line, and g-line. For example, the photomask of the present invention can be constructed with the h-line as the representative wavelength.

In order to form such a phase difference, the main pattern is a translucent portion formed by exposing the main surface of the transparent substrate, and the auxiliary pattern is a semi-transparent portion formed by forming a translucent film on the transparent substrate. The phase shift amount with respect to the wavelength may be approximately 180 degrees.

The preferable range of the phase difference between the main pattern and the auxiliary pattern and the wavelength of the exposure light applied to the photomask of the present invention are the same also in the photomasks of the second to sixth embodiments of the present invention.

In the photomask of the first embodiment, that is, the photomask shown in FIG. 3A, the light transmittance T1 of the translucent portion can be obtained as follows. That is, when the transmittance of the translucent film formed on the translucent portion with respect to the representative wavelength is T1 (%),

30? T1? 80

. More preferably,

40? T1? 75

to be. The transmittance T1 (%) is defined as the transmittance of the representative wavelength with reference to the transmittance of the transparent substrate.

In the photomask of the present invention, the low-light-transmitting portion formed around the main pattern and the auxiliary pattern is arranged in a region other than the region where the main pattern and the auxiliary pattern are formed.

And the low light transmitting portion may not substantially transmit the exposure light (light of the representative wavelength in the wavelength range of i line to g line). In this case, a low light-transmitting film which does not substantially transmit the representative wavelength (that is, a light-shielding film) and satisfies T2? 0.01 or an optical density OD? 2 may be used as the single low light- As a laminated film, a substantially light-shielding film (optical density OD? 2) may be used.

Alternatively, the low light transmitting portion may transmit the exposure light within a predetermined range. However, when the exposure light is transmitted in a predetermined range and the transmittance T3 (%) of the low-transmittance portion (where the transmittance of the laminated film in the case of lamination of the semitransparent film and the low light transmittance film)

T3 < T1

. Preferably,

0.01 < T3 < 30

More preferably,

0.01 <T3? 20

. The transmittance T3 (%) is also defined as the transmittance of the above-mentioned representative wavelength based on the transmittance of the transparent substrate.

When the low light transmittance portion transmits the exposure light at the predetermined transmittance, the phase difference? 3 between the transmitted light of the low light transmittance portion and the transmitted light of the light transmitting portion is preferably 90 degrees or less, more preferably 60 degrees or less to be. Means that the phase difference is "(2n-1/2)? To (2n + 1/2)? (Where n is an integer)" in radians. Is calculated as the phase difference with respect to the representative wavelength included in the exposure light as described above.

Therefore, in this case, the property of the low light transmittance film used in the photomask of this embodiment is such that the transmittance [T2 (%)] of less than 30 (% 2 is approximately 180 degrees. About 180 degrees means 120 to 240 degrees. Preferably, the phase difference? 1 is 150 to 210 degrees, more preferably 170 to 190 degrees. As a result, the phase shift characteristics of the low transmissive portion including the lamination can be set to the above-mentioned range of? 3.

Here, similarly to the above, the transmittance is the transmittance of the representative wavelength based on the transmittance of the transparent substrate.

In the transfer pattern, when the width of the auxiliary pattern is d (占 퐉)

&Quot; (2) &quot;

The excellent effect of the invention can be obtained. That is, when the value of? (T1 / 100) 占 d is within the above range, the amount of light transmitted through the auxiliary pattern well interacts with that of the main pattern and improves the transferability of the main pattern.

At this time, the center of the main pattern and the center distance in the width direction of the auxiliary pattern are defined as the pitch P (占 퐉)

1.0 <P? 5.0

Is satisfied.

More preferably,

1.5 <P? 4.5

.

In the present invention, the auxiliary pattern has an effect of giving an optical effect such as a dense pattern to the main pattern isolated in design, but when the above relation is satisfied, the main pattern and the auxiliary pattern Can exert a good interaction with each other and exhibit excellent transferability as shown in Examples described later.

The width d (占 퐉) of the auxiliary pattern is a dimension below the resolution limit in the exposure conditions (the exposure apparatus to be used) applied to the photomask of the present invention,

d? 0.7

More preferably,

d? 0.8

More preferably, the width d (占 퐉) of the auxiliary pattern is 1 占 퐉 or more.

Further, it is preferable that d? W1, and more preferably d <W1.

More preferably, the relational expression of the expression (2) is the following expression (2-1), and more preferably, the following expression (2-2).

[Mathematical Expression 2-1]

[Equation 2-2]

As described above, the main pattern of the photomask shown in Fig. 1 is square, but the present invention is not limited thereto. For example, as illustrated in Fig. 2, the main pattern of the photomask may be a rotationally symmetric shape including an octagon or a circle. Then, the center of the rotational symmetry can be set as the center of the reference point P.

The shape of the auxiliary pattern of the photomask shown in Fig. 1 is an octagonal band, but the present invention is not limited to this. It is preferable that the shape of the auxiliary pattern be a uniform width in the shape of the object to be rotated three or more times symmetrically with respect to the center of the hole pattern. 2 (a) to 2 (f), and the design of the main pattern and the design of the auxiliary pattern are the same as those of the other patterns shown in Figs. 2 (a) to 2 May be combined.

For example, the case where the outer periphery of the auxiliary pattern is a regular polygon (preferably a regular 2n square, where n is an integer of 2 or more) or a circular shape such as a square, a regular hexagon, a regular octagon, or a tetragon. As the shape of the auxiliary pattern, it is preferable that the outer and inner peripheries of the auxiliary pattern are substantially parallel, that is, a shape such as a regular polygonal or circular band having a substantially constant width. This strip-like shape is also called a polygonal strip or a circular strip. As the shape of the auxiliary pattern, it is preferable that the regular polygonal band or the circular band surrounds the periphery of the main pattern. At this time, since the balance between the transmitted light of the main pattern and the transmitted light of the auxiliary pattern can be made substantially equal, the interaction of light can be easily obtained in order to obtain the operation and effect of the present invention.

Particularly, when the photomask of the present invention is used as a photomask for manufacturing a display device, that is, when the photomask of the present invention is used in combination with a photoresist for producing a display device, It is possible to reduce the resist loss in the portion where the resist is formed.

Alternatively, the shape of the auxiliary pattern may be such that the polygonal band or a part of the ring-shaped band is partially missing without completely surrounding the periphery of the main pattern. The shape of the auxiliary pattern may be a shape in which the corner portion of the rectangular band is missing, for example, as shown in Fig. 2 (f).

In addition to the main pattern and the auxiliary pattern of the present invention, other patterns may be used as long as the effects of the present invention are not hindered.

An example of a method of manufacturing a photomask of this embodiment will be described below with reference to Fig.

As shown in Fig. 4 (a), a photomask blank is prepared.

In this photomask blank, a semitransparent film and a low light transmittance film are formed in this order on a transparent substrate including glass or the like, and a first photoresist film is coated.

When the transmissivity is 30 to 80 (%) (T1 (%) is the transmittance), when the transmissivity is a representative wavelength of the i-line, h-line or g-line on the main surface of the transparent substrate, 30? T1? 80], more preferably 40 to 75 (%), and the phase shift amount with respect to this representative wavelength is approximately 180 degrees. With such a semi-light-transmitting film, the transmitted light phase difference between the main pattern including the light-projecting portion and the auxiliary pattern including the semi-light-projecting portion can be approximately 180 degrees. Such a semitransparent film shifts the optical phase of the representative wavelength in the wavelength range of i-line to g-line by about 180 degrees. As a film forming method of the semitransparent film, a known method such as a sputtering method can be applied.

It is preferable that the semitransparent film satisfies the transmittance and the retardation as described above and is made of a material that can be wet-etched as described below. However, if the amount of the side etching generated during the wet etching becomes too large, problems such as deterioration of the CD precision and destruction of the upper layer film due to undercut occur. Therefore, the film thickness is preferably 2000 angstroms or less. For example, in the range of 300 to 2000 angstroms, and more preferably in the range of 300 to 1800 angstroms. Here, CD is a Critical Dimension, which is used in this specification as a meaning of a pattern line width.

In order to satisfy these conditions, it is preferable that the semi-light-transmitting film material has a refractive index of 1.5 to 2.9 at a representative wavelength (for example, h line) included in the exposure light. More preferably, it is from 1.8 to 2.4.

In addition, in order to sufficiently exhibit the phase shift effect, it is preferable that the cross-section of the pattern (etched surface) by wet etching is nearly perpendicular to the main surface of the transparent substrate.

Considering the above properties, the material of the semitransparent film is preferably a material containing at least one of Zr, Nb, Hf, Ta, Mo, and Ti and Si, or an oxide, a nitride, an oxynitride, a carbide, And may be made of a material containing nitride carbide.

On the semitransparent film of the photomask blank, a low light transmittance film is formed. As a film forming method, a known means such as a sputtering method can be applied as in the case of the semitransparent film.

The low light transmitting film of the photomask blank may be a light shielding film which does not substantially transmit the exposure light. Alternatively, it is possible to have a predetermined low transmittance with respect to the representative wavelength of the exposure light. The low light transmittance film used in the production of the photomask of the present invention has a transmittance T2 (%) which is lower than the transmittance T1 (%) of the semi-light transmittance film with respect to the light of the representative wavelength in the wavelength range of i line to g line. T2 may be substantially zero (0.01 or less).

On the other hand, when the low-transmittance film can transmit the exposure light, the transmittance and the phase shift amount of the low-transmittance film with respect to the exposure light are set so that the transmittance and the phase shift amount of the low- . Preferably, the transmittance T3 (%) with respect to the light of the representative wavelength of the exposure light is 0.01 <T3 <30, preferably 0.01 <T3 20 in the laminated state of the low light transmitting film and the semitransparent film, , And the phase shift amount 3 is 90 (degrees) or less, more preferably 60 (degrees) or less.

As the solitary property of the low light transmitting film, it is preferable that substantially no light of the representative wavelength is transmitted, or that the transmittance [T2 (%)] of less than 30 (% It is preferable that the shift amount phi 2 be approximately 180 degrees. About 180 degrees means 120 to 240 degrees. Preferably, the phase difference? 1 is 150 to 210 (degrees), more preferably 170 to 190 (degrees).

The material of the low light transmitting film of the photomask blank may be Cr or a compound thereof (oxide, nitride, carbide, oxynitride, or oxynitride carbide), or a silicide of a metal including Mo, W, Ta, The above-mentioned compound of the silicide may be used. However, the material of the low light transmittance film of the photomask blank is preferably a material capable of wet etching as in the case of the semitransparent film, and having etching selectivity to the material of the semitransparent film. That is, it is preferable that the low light-transmitting film has resistance to the etching agent of the semitransparent film and the semitransparent film has resistance to the etching agent of the low light transmitting film.

On the low light transmitting film of the photomask blank, a first photoresist film is further coated. Since the photomask of the present invention is preferably drawn by a laser beam drawing apparatus, a photoresist suitable therefor is used. The first photoresist film may be a positive type or a negative type, but will be described as a positive type hereinafter.

Next, as shown in Fig. 4 (b), a drawing apparatus is used for the first photoresist film, and drawing is performed by drawing data based on the transfer pattern (first drawing). Then, using the first resist pattern obtained by the development as a mask, the low light transmittance film is subjected to wet etching. Thereby, a region to be a low-light-transmitting portion is defined, and an area of an auxiliary pattern (low-light-transmitting film pattern) surrounded by the low-light-transmitting portion is defined. As the etching solution (wet etchant) for wet etching, a known one suitable for the composition of the low light transmitting film to be used may be used. For example, if the film contains Cr, a wet etchant such as ceric ammonium nitrate can be used.

Next, as shown in Fig. 4 (c), the first resist pattern is peeled off.

Next, as shown in Fig. 4 (d), the second photoresist film is coated on the entire surface including the formed low light-transmitting film pattern.

Next, as shown in Fig. 4 (e), second imaging is performed on the second photoresist film, and a second resist pattern formed by development is formed. Using this second resist pattern and the low light transmittance film pattern as a mask, wet etching of the semitransparent film is performed. By this etching (development), a region of the main pattern including the transparent portion where the transparent substrate is exposed is formed. The second resist pattern covers the area to be the auxiliary pattern and has an opening in a region to be the main pattern including the transparent portion and is provided with an opening for exposing the edge of the low light transmittance film from the opening, It is preferable to perform sizing for the data. By doing so, it is possible to absorb the alignment deviation that occurs between the first and second imaging, and to prevent deterioration of the CD accuracy of the transfer pattern. This is an effect using the etching selectivity of the films of the low light-transmitting film and the semitransparent film with respect to each other.

In the photomask of this embodiment, the semi-light-transmitting film and the low light-transmitting film may be made of a material having no etching selectivity and having a common etching property, and an etching stopper film may be formed between both films.

In other words, when the second resist pattern is subjected to the sizing as described above, there is no positional deviation in the patterning of the light-shielding film and the semitransparent film when the isolation hole pattern is to be formed on the body. The center of gravity of the main pattern and the auxiliary pattern can be precisely and closely matched in the transfer pattern as illustrated in Fig.

The wet etchant for the semitransparent film is appropriately selected in accordance with the composition of the semitransparent film.

Next, as shown in Fig. 4 (f), the second resist pattern is peeled off to complete the photomask of the present invention shown in Fig.

In the production of a photomask for a display device, when an optical film such as a light-shielding film formed on a transparent substrate is patterned, dry etching and wet etching are applicable. Either may be employed, but wet etching is particularly advantageous in the present invention. This is because the photomask for a display device has a relatively large size and a large variety of sizes. When dry etching using a vacuum chamber is applied in the production of such a photomask, inefficiency occurs in the size and manufacturing process of the dry etching apparatus.

However, there is also a problem associated with application of wet etching at the time of manufacturing such a photomask. Since the wet etching has the property of isotropic etching, when the predetermined film is to be etched in the depth direction, the etching proceeds also in the direction perpendicular to the depth direction. For example, when a slit is formed by etching a semi-light-transmitting film having a film thickness F (nm), the opening of the resist pattern to be an etching mask is 2F (nm) (that is, one side F (nm) However, it is difficult to maintain the dimensional accuracy of the opening of the resist pattern as the slit becomes a fine width. For this reason, it is useful that the width d of the auxiliary pattern is not less than 1 (mu m), preferably not less than 1.3 (mu m).

In addition, when the film thickness F (nm) is large, the amount of side etching becomes large. Thus, it is advantageous to use a film material having a phase shift amount of about 180 degrees even if the film thickness is small. It is desired that the refractive index of the translucent film is high. For this reason, it is preferable to use a material such as 1.5 to 2.9, preferably 1.8 to 2.4 for the representative wavelength, as a semi-light-transmitting film.

Incidentally, as the photomask of the present invention shown in FIG. 1, in addition to the above-described form, there is one that exhibits similar optical and action effects by different layer structures.

The second embodiment of the present invention has a layer structure shown in cross section in Fig. 3 (b). The plan view of this photomask is similar to that of the first embodiment, as shown in Fig. 1, but has a different laminated structure when viewed in cross section. That is, in the low light-transmissive portion shown in FIG. 3 (b), the stacked layers of the low light-transmitting film and the semitransparent film are reversed upside down, and the low light-transmitting film is disposed on the substrate side.

In this case, the design of the pattern as the photomask of the present invention, the respective parameters thereof, and the optical action effects thereof are the same as those of the first type of photomask, and as a design design, The same is true. In addition, the physical properties of the membrane material used can be the same.

In the photomask of the second embodiment, however, there is a slight difference from the first embodiment in the following points in terms of the manufacturing method. Therefore, the film material used is not necessarily the same as the first embodiment .

For example, in the first embodiment, as shown in Fig. 4A, a photomask blank in which a semi-light-transmitting film and a low light-transmitting film are laminated is prepared, a photolithography process is applied twice to the photomask blank, In the second embodiment, it is necessary to prepare a photomask blank in which only a low light-transmitting film is formed on a transparent substrate.

Then, the low light-transmitting film is first etched to form a low light-transmitting film pattern. Subsequently, a semi-light-transmitting film is formed on the entire surface of the substrate on which the low light-transmitting film pattern is formed and patterned. In this case, it is preferable to select a material capable of performing patterning by wet etching as in the first embodiment. However, in this embodiment, it is not essential that the low light-transmitting film and the semitransparent film have mutual resistance to the etchant. That is, both films can be etched even if there is no etching selectivity between them. Therefore, the degree of freedom is higher in the selection of the material than in the first embodiment.

Next, a third embodiment of the photomask of the present invention will be described with reference to Fig. 3 (c). In this embodiment, the plan view is the same as in Fig. 1, and the design of the pattern, its parameters, and the optical action effects thereof are the same as those of the first embodiment except for the following points, As a design design, the modifications shown in Fig. 2 are applicable.

The third type photomask shown in FIG. 3 (c) differs from the first and second types of photomask in that the phase shift amount of the translucent film with respect to the light of the representative wavelength is approximately 180 degrees And in this connection, in the main pattern portion, the transparent substrate enters a predetermined amount of wave. That is, in the main pattern of this type, instead of exposing a part of the main surface of the transparent substrate made of the material, the depressed surface formed with a predetermined amount of depression portion by etching against the main surface is exposed. The phase difference between the representative wavelengths in the wavelength range of the i-line to the g-line passing through each other between the auxiliary pattern formed with the semitransparent film and the main pattern having the depressed portion is adjusted to about 180 degrees. Similarly to the first and second types of photomasks, the low-light-transmitting portion includes a semi-light-transmitting film and a low-light-transmitting film having a light transmittance T2 (%) of a representative wavelength on the transparent substrate in this order, As shown in FIG.

In the first or second aspect, it is necessary to satisfy both the condition of the transmittance T1 and the condition that the phase difference between the representative wavelength transmitted through the main pattern and the auxiliary pattern is approximately 180 degrees depending on the material of the semitransparent film and the film thickness In the photomask of the third embodiment, the composition of the semitransparent film and the film thickness are preferentially determined under the condition of the transmittance T1, and the phase difference can be adjusted by the amount of punching of the main pattern.

From this point, in the photomask of this embodiment, the phase shift amount of the translucent film with respect to the light of the representative wavelength may be 90 degrees or less, or 60 degrees or less. The phase difference of the representative wavelength transmitted through the main pattern and the auxiliary pattern may be adjusted to be approximately 180 degrees by the sum of the amount of projection of the main pattern and the amount of phase shift of the semitransparent film.

In the photomask of the third embodiment, wet or dry etching is used to form the depressions of the transparent substrate, but dry etching is more preferably used. Also in the photomask of this embodiment, an etching stopper film may be formed between the semi-light-transmitting film and the low light-transmitting film.

For example, a photomask blank in which a semi-light-transmitting film and a low light-transmitting film are laminated on a transparent substrate is prepared. First, both films of the main pattern portion are removed by etching, and then a step of etching the recessed portion of the transparent substrate is applied . Next, the third photomask can be manufactured by etching away the low light-transmitting film of the auxiliary pattern portion by the second photolithography process. In this case, the film material may be the same as the first embodiment.

Also in the photomask of the third embodiment, the stacking order of the semi-light-transmitting film and the low light-transmitting film may be reversed upside down, like the relationship between the first and second embodiments.

Next, a fourth embodiment of the photomask of the present invention will be described with reference to Fig. 3 (d). Also in this embodiment, the plan view is shown in Fig. The fourth embodiment differs from the third embodiment in that the transparent substrate (part of the main surface) of the auxiliary pattern portion is formed of a translucent film It is exposed. By selecting the depression depth of the main pattern portion, the optical phase difference of the representative wavelength transmitted through the main pattern and the auxiliary pattern, respectively, is approximately 180 degrees as in the first to third embodiments.

In the fourth embodiment, since the semitransparent film does not exist in the auxiliary pattern portion, the transmittance T1 becomes 100 (%). In this case, the number of times of film formation can be reduced, whereby advantages such as improvement in production efficiency and reduction in the probability of defect occurrence are obtained from the third embodiment.

In this case, T1 = 100 (%) is applied to Equation (2)

&Quot; (2) &quot;

In other words,

0.5? D? 1.5

. Preferably, d < W1.

Further, the amount of phase shift relative to the light of the representative wavelength included in the low light-transmittance film used in the photomask of the fourth embodiment need not be approximately 180 degrees, but is preferably 90 degrees or less. More preferably 60 degrees or less.

In the photomask of the fourth embodiment, the design of the pattern shown in Fig. 1, the parameters other than the special parameters, and the optical action effect by them are the same as the photomask of the first embodiment, 2 are applicable. The film material used in the low light transmitting film and its physical properties can also be made the same as those of the first embodiment. That is, the transmittance of the low-light-transmitting portion is T3 (%) at the representative wavelength, but it may be a structure in which a low light-transmittance film having a transmittance of T2 (%) of the representative wavelength is formed on the transparent substrate. That is, T2 = T3.

Incidentally, the fifth embodiment (Fig. 3 (e)) is the same as the fourth embodiment in which the cross-sectional structures of the main pattern and the auxiliary pattern are reversed. In the main pattern of the fifth aspect, a part of the main surface of the transparent substrate is exposed, and the auxiliary pattern is formed with a depressed portion on the main surface of the transparent substrate. That is, the optical phase difference of the representative wavelength transmitted through the main pattern and the auxiliary pattern is approximately 180 degrees by ripping the transparent substrate of the auxiliary pattern portion into the change of formation of the transparent substrate depression portion of the main pattern portion. In this case as well, it is a matter of course that the design in plan view or its optical action effect is the same as the fourth embodiment. Also, there is no particular difference in the manufacturing method and the applied materials. Therefore, in the low-light-transmitting portion of the fifth embodiment, a low light-transmitting film having a light transmittance of a representative wavelength of T2 (%) is formed on the transparent substrate.

The sixth embodiment of the present invention shown in Fig. 3 (f) is a modification of the first embodiment to the fifth embodiment Quot; is used), indicating the possibility of adding a light-shielding film pattern. This is worth considering if the low light transmittance film has a substantial transmittance.

That is, in the vicinity of the main pattern and the auxiliary pattern, the interference action of the opposite phase light is utilized, but in the region of the low-light-transmitting portion spaced apart from the main pattern, the light passing through the low light-transmitting film is unnecessary, There is a risk that the residual amount of the resist pattern to be formed will decrease. In order to exclude this risk, it is also useful to completely shield light by adding a light-shielding film pattern in the region of the low-light-transmitting portion spaced apart from the main pattern and the auxiliary pattern.

Therefore, in the present invention, the use of such a light-shielding film pattern is not hindered unless the action and effect are not impaired. The light-shielding film means a film having OD (optical density) 2 or more that does not substantially transmit exposure light (light having a representative wavelength in the range of i line to g line). The material includes chromium (Cr) as a main component.

The present invention includes a manufacturing method of a display device including a step of forming a hole pattern by transferring the transfer pattern onto a transfer body by exposing the photomask of the present invention by an exposure apparatus do.

In the method of manufacturing the display device of the present invention, first, the above-described photomask of the present invention is prepared. Next, the transfer pattern is exposed using an exposure apparatus having a numerical aperture (NA) of 0.08 to 0.20 and an exposure light source including at least one of i-line, h-line and g-line, , A hole pattern having a diameter W2 of 3.0 mu m or less, preferably 0.6 to 3.0 mu m is formed. It is also preferable that the exposure light source of the exposure apparatus includes i line, h line and g line. For exposure, it is general and advantageous to apply equal exposure.

As an exposure device used when transferring a transfer pattern using the photomask of the present invention, there is a method of performing projection exposure in the same direction, and the following can be given. That is, the exposure apparatus is used as an exposure apparatus for an LCD (liquid crystal display) (or FPD, liquid crystal), and has a configuration in which the numerical aperture NA of the optical system is 0.08 to 0.15 [coherence factor? , And has a light source (also referred to as a broad wavelength light source) including at least one of i line, h line and g line in the exposure light. However, it is of course possible to obtain the effect of the invention by applying the present invention to an exposure apparatus having a numerical aperture NA of 0.10 to 0.20.

The light source of the exposure apparatus to be used may be modified illumination (annular illumination or the like), but even in the case of unmodified illumination, an excellent effect of the invention can be obtained.

 The present invention relates to a photomask blank in which a semi-light-transmitting film and a low light-transmitting film (and also a light-shielding film, if necessary) are laminated on a transparent substrate as raw materials for the photomask of the first to third embodiments Lt; / RTI &gt; Then, a resist film is applied and formed on the surface, and a photomask is produced.

The physical properties, film quality and composition of the semitransparent film and the low light transmittance film are as described above.

That is, it is preferable that the transmittance T1 of the semi-light-transmitting film of the photomask blank with respect to the representative wavelength in the wavelength range of i-line to g-line is 30 to 80 (%). Further, the semi-light-transmitting film has a refractive index of 1.5 to 2.9 with respect to the representative wavelength, and has a film thickness having a phase shift amount of approximately 180 degrees. Since the film thickness of the semi-light-transmitting film having such a refractive index has a desired phase shift amount even if it is sufficiently thin, the wet etching time of the semi-light-transmitting film can be shortened. As a result, the side etching of the semitransparent film can be suppressed.

Further, in all the forms of the photomask of the present invention, a photomask blank in which a low light-transmitting film is formed can be used.

The low light-transmitting film may not transmit substantially the light of the representative wavelength, or may have a transmittance of less than 30%. The amount of phase shift relative to the representative wavelength in the i-line to the g-line range of the low light transmitting film is approximately 180 degrees in the photomask according to the first and second embodiments, In the mask, it may be 90 degrees or less, more preferably 60 degrees or less.

[Example]

The photomasks of three types (Comparative Examples 1-1 and 1-2 and Example 1) shown in Fig. 5 were evaluated by optical simulation by comparing their transfer performances. That is, for three photomasks having a transfer pattern for forming a hole pattern having a diameter of 2.0 mu m on the transferred body, optical simulation was performed to determine what transfer performance was exhibited when exposure conditions were set in common I did.

(Comparative Example 1-1)

As shown in Fig. 5, the photomask of Comparative Example 1-1 has a so-called binary mask pattern including a light-shielding film pattern formed on a transparent substrate. In the photomask of Comparative Example 1-1, the main pattern including the light transmitting portion to which the transparent substrate is exposed is surrounded by the light shielding portion. The diameter W1 (one side of the square) of the main pattern is 2.0 (占 퐉).

(Comparative Example 1-2)

5, the photomask of Comparative Example 1-2 has one side (diameter) (that is, W1 (diameter)) formed by patterning a translucent film having an exposure light transmittance (pair h line) of 5% and a phase shift amount of 180 deg. ) Is 2.0 (占 퐉), which is a halftone type phase shift mask.

(Example 1)

As shown in Fig. 5, the photomask of Example 1 has the transfer pattern of the present invention. Here, the main pattern is a square having one side (diameter) (i.e., W1) of 2.0 占 퐉, and the auxiliary pattern is an octagonal band having a width d of 1.3 占 퐉 and the center of the main pattern, The pitch P, which is the distance between the first and second electrodes, is 4 (占 퐉).

The auxiliary pattern is a photomask of the first type in which a translucent film is formed on a transparent substrate. The transmittance T1 of the exposed light (h-line) of this semi-light-transmitting film is 70 (%) and the phase shift amount is 180 degrees. Further, the low-light-transmitting portion surrounding the main pattern and the auxiliary pattern is composed of a light-shielding film (OD> 2) which does not substantially transmit the exposure light.

In both of the photomasks of Comparative Examples 1-1 and 1-2 and Example 1, the diameter W2 was 2.0 mu m (W1 = W2, that is, the diameter W2 formed on the transferred body was 2.0 mu m Which is the same as the diameter W1 of the main pattern of the transfer pattern of the mask). The exposure conditions applied by the simulation are as follows. That is, the exposure light has a broad wavelength including i-line, h-line, and g-line, and the intensity ratio is g-line: h-line: i-line = 1: 0.8: 1.

The optical system of the exposure apparatus has NA of 0.1 and coherence factor sigma of 0.5. The film thickness of the positive type photoresist for obtaining the cross-sectional shape of the resist pattern formed on the transfer target body was set to 1.5 탆.

The performance evaluation of each transfer pattern under the above conditions is shown in Fig. Fig. 6 shows a spatial image of light intensity formed on the transfer target and a cross-sectional shape of the resist pattern formed thereby.

(Optical evaluation of photomask)

For example, in order to transfer a fine light transmitting pattern with a small diameter, the profile of the space image formed on the body to be exposed, that is, the transmitted light intensity curve should be good in exposure light after the photomask has penetrated. Specifically, it is preferable that the inclination forming the peak of the transmitted light intensity is sharp and the upward direction is close to vertical and that the absolute value of the optical intensity of the peak is high (when the sub-peak is formed around the peak, Relatively high, relatively high, etc.).

More quantitatively, when the photomask is evaluated from the optical performance, the following indexes can be used.

(1) depth of focus (DOF)

For the target CD, the magnitude of the depth of focus to be in the range of ± 10%. If the numerical value of the DOF is high, it is difficult to be affected by the flatness of the transferred body (for example, a panel substrate for a display device), and a fine pattern can surely be formed, and CD (line width) deviation is suppressed.

(2) MEEF (Mask Error Enhancement Factor)

The mask error is a numerical value representing the ratio of the CD error of the pattern formed on the transferred body and the CD error. The lower the MEEF, the CD error of the pattern formed on the body can be reduced.

(3) Eop

Eop is a particularly important evaluation item in the photomask for manufacturing a display device. This is the amount of exposure light necessary to form the pattern size to be obtained on the transferred body. In the manufacture of a display device, the photomask size is large (for example, a square or a rectangle of 300 to 1,400 mm on one side of the main surface), and a photomask having a low Eop value is used, So that the production efficiency is improved.

5, the photomask of Example 1 has a depth of focus (DOF) of 55 mu m or more, as shown in Fig. 5, And shows a stable transferability of the pattern. This means a height of CD precision of a fine pattern in addition to a small value of MEEF.

In addition, the value of the photomask Eop in Example 1 is very small. This shows that the photomask of Example 1 has the advantage that the exposure time does not increase or can be shortened even in the manufacture of a large-area display device.

6, in the case of the photomask of Example 1, it is possible to raise the peak of the main pattern portion to a level Eth at which the resist becomes a critical value to be sensitized , And the inclination of the peak can be sufficiently set up (close to perpendicular to the surface of the body to be transferred). This point is superior to Comparative Examples 1-1 and 1-2. Here, the increase in the Eop and the reduction in the MEEF are achieved by using the light transmitted through the auxiliary pattern for increasing the light intensity at the main pattern position. Further, in the photomask of Example 1, side peaks were generated on both sides of the transfer position of the main pattern, but the transfer efficiency of the main pattern is not affected because it is less than Eth.

A method of reducing the loss of the resist remnant film derived from this side peak will be described below.

Simulations were conducted using the samples of Comparative Example 2-1, Comparative Example 2-2, and Example 2 shown in Fig. 7 by changing the design of the transfer pattern formed on the photomask. Here, all samples are different from the above samples (Comparative Example 1-1, Comparative Example 1-2 and Example 1) in that the diameter W1 of the main pattern is 2.5 (탆).

(Comparative Example 2-1)

As shown in Fig. 7, the photomask of Comparative Example 2-1 is a so-called binary mask pattern including a light-shielding film pattern formed on a transparent substrate. In the photomask of Comparative Example 2-1, the main pattern including the light-transmitting portion where the transparent substrate is exposed is surrounded by the light-shielding portion. The diameter W1 (one side of the square) of the main pattern is 2.5 (占 퐉).

(Comparative Example 2-2)

As shown in Fig. 7, the photomask of Comparative Example 2-1 has a main pattern having a diameter W1 (square) of a main pattern formed by patterning a semitransparent film having an exposure light transmittance (hue line) of 5% and a phase shift amount of 180 degrees 1 side) of 2.5 (占 퐉) is a half tone type phase shift mask having a main pattern including a quadrangular translucent portion.

(Example 2)

As shown in Fig. 7, the photomask of Example 2 is a transfer pattern of the present invention. The main pattern of the photomask of Example 2 is a square having a diameter W1 (one side of a square) of 2.5 (mu m) and the auxiliary pattern is an octagonal band having a width d of 1.3 (mu m) , And the pitch P, which is the distance between the centers of the widths of the auxiliary patterns, was 4 (占 퐉). Here again, the photomask of the second embodiment is assumed to be the photomask of the first embodiment.

Hole patterns having a diameter of 2.0 占 퐉 are formed on the transferred object using the photomasks of Comparative Example 2-1, Comparative Example 2-2, and Example 2. [ That is, the mask bias (? = W1-W2) of these photomasks was 0.5 (占 퐉). Exposure conditions applied by simulation are the same as those of the photomask of Comparative Examples 1-1 and 1-2 and Example 1 described above.

As is evident from the data shown in Fig. 7, when the photomask of Example 2 was used, good performance was shown for Comparative Examples 2-1 and 2-2 together with excellent DOF and MEEF. In the photomask of Example 2, in particular, the DOF has a numerical value exceeding 35 mu m.

Further, referring to the spatial image of the transmitted light intensity shown in Fig. 8 and the cross-sectional shape of the resist pattern on the transferred body, the excellent characteristics possessed by the sample of Example 2 become clear. As shown in Fig. 8, in the case of using the photomask of Example 2, the peak corresponding to the main pattern is significantly higher than the side peaks formed on both sides, and resist damage hardly occurs.

From the above results, it can be seen that, in the case of pattern transfer using the photomask of the present invention, in a transfer pattern in which the mask bias? Is in the range of about 0.5 (占 퐉), specifically in the range of 0.2 to 1.0 It is now clear that an excellent transfer can be obtained.

Thus, the excellent performance of the photomask of the present invention was confirmed. Particularly, when the photomask of the present invention is used, it is significant in the future manufacture of a display device that a MEEF value of 2.5 or less can be obtained in a fine pattern of 2 탆 or less.

The use of the photomask of the present invention is not particularly limited. The photomask of the present invention can be preferably used at the time of manufacturing a display device including a liquid crystal display device and an EL display device.

According to the photomask of the present invention, the mutual interference of the exposure light transmitted through both the main pattern and the auxiliary pattern can be controlled, and the zero-order shielding can be reduced during exposure, and the ratio of the ± first-order light can be relatively increased. As a result, the spatial image of the transmitted light can be greatly improved.

In order to obtain such an advantageous effect, it is advantageous to use the photomask of the present invention for forming an isolated hole pattern such as a liquid crystal or a contact hole widely used in an EL device. As a kind of the pattern, a plurality of patterns having a regular regularity are arranged, thereby distinguishing a dense pattern in which the mutual optical effects are mutually different from each other and an isolated pattern in which the pattern of such regular arrangement does not exist around There are many cases. The photomask of the present invention is preferably applied when it is desired to form an isolated pattern on a body to be transferred.

To the extent that the effect of the present invention is not impaired, an additional optical film or functional film may be used for the photomask of the present invention. For example, in order to prevent the problem that the light transmittance of the low light transmitting film hinders the inspection or the position detection of the photomask, the light shielding film may be formed in an area other than the transfer pattern. Further, in the semitransparent film, an antireflection layer for reducing reflection of imaging light and exposure light may be formed on the surface thereof.

Claims (14)

A photomask for manufacturing a display device having a transfer pattern formed on a transparent substrate, characterized in that the photomask has a transfer diameter (?) Formed on a transferred body by an exposure apparatus having an optical system with a numerical aperture (NA) of 0.08-0.20 W2 (占 퐉) is formed on the surface of the transfer pattern,
A main pattern (W1 > W2) of a diameter W1 (mu m)
An auxiliary pattern having a width d (占 퐉) arranged in the vicinity of the main pattern,
And a light shielding portion disposed in an area other than the main pattern and the auxiliary pattern,
Wherein the main pattern is formed by exposing the transparent substrate,
The phase difference between the light of the representative wavelength in the wavelength range of i-line through g-line passing through the main pattern and the light of the representative wavelength passing through the auxiliary pattern is 170 to 190 degrees,
Wherein the light-shielding portion has an optical density OD for light of the representative wavelength of 2 or more,
Wherein the auxiliary pattern has a regular polygonal band or a circular band shape surrounding the main pattern through the light shielding portion. The method according to claim 1,
The light transmittance of the representative wavelength transmitted through the auxiliary pattern is T1 (%),
And the distance between the center of the main pattern and the center of the auxiliary pattern in the width direction is P (mu m), the following equations 1 to 3
[Equation 1]

&Quot; (2) &quot;

&Quot; (3) &quot;

Is satisfied. The method according to claim 1,
and when? = W1-W2, satisfies 0.2??? 1.0. The method according to claim 1,
Wherein the photomask is a photomask for exposure using an exposure apparatus of the same projection exposure system. The method according to claim 1,
Wherein the transfer pattern is transferred onto a transfer body at a MEEF of 2.5 or less by exposure using a display apparatus exposure apparatus. The method according to claim 1,
Wherein the auxiliary pattern is formed on the transparent substrate with a translucent film having a transmittance T1 (%) with respect to the light of the representative wavelength,
30? T1? 80
Is satisfied. The method according to claim 1,
Wherein the auxiliary pattern is formed on the transparent substrate with a translucent film having a transmittance T1 (%) with respect to the light of the representative wavelength,
40? T1? 75
Is satisfied. The method according to claim 1,
The main pattern diameter W1 (mu m)
1.0? W1? 3.0
Is satisfied. &Lt; / RTI &gt; The method according to claim 1,
d &gt; / = 0.7. The method according to claim 1,
Wherein the auxiliary pattern is formed by forming a translucent film on the transparent substrate,
Wherein the semi-light-transmitting film is a material containing at least one of Zr, Nb, Hf, Ta, Mo and Ti and Si or an oxide, nitride, oxynitride, carbide or oxynitride carbide of these materials, And a wet-etchable material. 11. The method of claim 10,
Wherein the material of the semi-light-transmitting film has a refractive index in the range of 1.5-2.9 relative to the representative wavelength. 11. The method of claim 10,
Wherein the material of the semi-light-transmitting film has a refractive index in the range of 1.8-2.4 relative to the representative wavelength. 11. The method of claim 10,
Wherein the semi-light-transmitting film has an antireflection layer for reducing reflection of imaging light or exposure light on a surface thereof. A method for manufacturing a photomask, comprising the steps of: preparing the photomask according to any one of claims 1 to 13;
The transfer pattern is exposed using an exposure apparatus having an exposure number NA of 0.08 to 0.20 and an exposure light source including at least one of i line, h line and g line, To form a pattern.

Images