TW202132904A - Photomask, method of manufacturing a photomask, and method of manufacturing an electronic device - Google Patents

Abstract

Object: To provide a photomask capable of carrying out high-fidelity pattern transfer by using a proximate exposure apparatus. Solution: A photomask 10 is for use in proximate exposure and has a transfer pattern obtained by patterning a transmission control film formed on a transparent substrate. The transfer pattern includes a transmission control portion obtained by forming the transmission control film on the transparent substrate and a light transmitting portion in which the transparent substrate is exposed. The transmission control portion has a phase shift amount exceeding 180 degrees with respect to exposure light for exposing the photomask.

Description

Photomask, photomask manufacturing method and electronic component manufacturing method

The present invention relates to a photomask, a manufacturing method of a photomask, and a manufacturing method of electronic components.

In the production of electronic components such as flat panel displays and semiconductor integrated circuits, a photomask having a transfer pattern formed by patterning an optical film such as a light shielding film on a main surface of a transparent substrate is used.

In particular, as a mask for manufacturing a semiconductor integrated circuit (hereinafter, LSI: Large-scale Integrated Circuit), a halftone type phase shift mask is known. In this mask, the light-shielding area in the binary mask is set to have a transmittance to the extent that the pattern will not be transferred, as a structure that shifts the phase of the transmitted light by 180 degrees, and improves the resolution performance (Non-Patent Document 1) .

On the other hand, in the image display device, there is also a demand for an increase in the number of pixels and a higher resolution. Therefore, an attempt is being made to use a phase shift mask for the manufacture of the image display device (patent Literature 1).

In addition, there are known multi-stage halftone masks used in the manufacture of flat panel displays. For example, the transparent substrate is provided with a semi-transmitting film pattern and a light-shielding film pattern with a transmittance of 20-50% and a retardation of 60-90 degrees. By using such a multi-step halftone mask, a photoresist pattern with different film thickness depending on the position can be formed with one exposure, which can reduce the number of lithography steps in the manufacturing steps of flat panel displays, thereby reducing the number of manufacturing steps. cost. The half-tone mask for this purpose can use transparent substrates, semi-transmissive films, and light-shielding films to achieve 3 gray levels. In addition, it can also achieve half-tone masks with 4 gray levels or more using a plurality of semi-transmissive films with different transmittances ( Patent Document 2). [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2014-092727 [Patent Document 2] Japanese Patent Laid-Open No. 2018-005072 [Non-Patent Literature]

[Non-Patent Document 1] Tian Xie Gong, Takehana Yoichi, Homoto Morihisa, "Basic Technology of Mask Electronic Parts Manufacturing", first edition, Tokyo Denki University Publishing Bureau, April 20, 2011, p.245-246

[The problem to be solved by the invention]

In the manufacture of flat panel displays, there are situations in which proximity exposure methods are applied. Compared with the projection exposure device, the proximity exposure device is inferior to the projection exposure device in terms of analytical performance, but the imaging optical system is not installed between the mask and the transfer object (display substrate, etc.), so the device structure is simple and the device is introduced It is relatively easy and has a high cost advantage in manufacturing. For this reason, the proximity exposure device is mainly used in the manufacture of black matrix or black stripes used in the color filter (CF: Color Filter) of the liquid crystal display device, or the production of the photosensitive spacer (PS: Photo Spacer). In addition, it can also be used for the black matrix of organic EL display devices.

On the other hand, due to the increased pixel density or brightness of flat panel displays, and power saving requirements, the photomask used in the manufacturing process has a significant tendency to refine the pattern for transfer. If the projection exposure method is used for the transfer of fine patterns, the resolution is more advantageous, but the above advantages of using the proximity exposure method are lost. Therefore, it is a new issue to apply the proximity exposure method while transferring the fine patterns meticulously. [Technical means to solve the problem]

The first aspect of the present invention is a photomask for proximity exposure, which is provided with a transfer pattern formed by patterning a transmission control film formed on a transparent substrate, The transfer pattern has: a transmission control portion on which a transmission control film is formed on the transparent substrate; and a light transmission portion for exposing the transparent substrate; and the transmission control portion corresponds to the exposure for exposing the photomask The light has a phase shift of more than 180 degrees.

The second aspect of the present invention is a photomask for proximity exposure, which is provided with a transfer pattern formed by patterning a transmission control film formed on a transparent substrate, and In a photomask for close-exposure by exposure light having a wavelength in the wavelength region of 313-365 nm, the transfer pattern has a transmission control portion formed by forming a transmission control film on the transparent substrate , And the light-transmitting part for exposing the transparent substrate, and the light-transmitting control part has a phase shift of more than 180 degrees with respect to the light with a wavelength of 365 nm.

The third aspect of the present invention is the mask of the first or second aspect, which is used for exposure of negative photosensitive materials.

The fourth aspect of the present invention is the mask of any one of the first to third aspects, wherein The transmittance of the transmission control portion with respect to the exposure light is 10% or less.

The fifth aspect of the present invention is the mask of any one of the first to fourth aspects, wherein The above-mentioned transfer pattern has a linear light-transmitting portion with a width of 3 to 10 μm.

The sixth aspect of the present invention is the mask of any one of the first to fourth aspects, wherein The above-mentioned transfer pattern is formed with a linear pattern with a width of 10 μm or less on the negative photosensitive material on the transferred body.

The seventh aspect of the present invention is the mask of any one of the first to sixth aspects, wherein The transfer pattern has a repeating pattern in which the transmission control portion and the light transmission portion are regularly arranged, and the repeating pitch of the repeating pattern is 10 to 35 μm.

The eighth aspect of the present invention is the mask of any one of the first to seventh aspects, wherein The transfer pattern has a repeating pattern in which the transmission control portion and the light transmission portion are regularly arranged, and the transmission control portion has a shape surrounded by a closed line.

The ninth aspect of the present invention is the mask of any one of the first to seventh aspects, wherein The pattern for transfer has a repeating pattern in which the transmission control portion is regularly arranged, and the transmission control portion has a quadrangular shape.

The tenth aspect of the present invention is the mask of any one of the first to ninth aspects, wherein The transmission control unit has a phase shift of 255 degrees or more with respect to the exposure light.

The eleventh aspect of the present invention is the mask of any one of the first to tenth aspects, wherein The transmission control unit has a phase shift amount of 300 degrees or more with respect to the exposure light.

The twelfth aspect of the present invention is the mask of any one of the first to eleventh aspects, wherein The transmission control unit has a phase shift amount of 330 degrees or less with respect to the exposure light.

The thirteenth aspect of the present invention is the mask of any one of the first to the twelfth aspects, wherein The above-mentioned transfer pattern is a pattern for forming a black matrix or black stripes.

The fourteenth aspect of the present invention is the mask of any one of the first to thirteenth aspects, wherein The pattern for transfer is characterized in that only the transmission control film is patterned on the transparent substrate.

The fifteenth aspect of the present invention is a manufacturing method of a proximity exposure mask, which is provided with a transfer pattern formed by patterning a transmission control film formed on a transparent substrate, and the method has the following step: Prepare a mask base with the transmission control film formed on the transparent substrate; and The patterning step is to pattern the transmission control film to form the pattern for transfer; The pattern for transfer has a transmission control portion formed by forming the transmission control film on the transparent substrate, and a light transmission portion through which the transparent substrate is exposed. The transmission control section has a transmittance of more than 10% or less and a phase shift amount of 180 degrees with respect to the exposure light for exposing the photomask.

The 16th aspect of the present invention is a method of manufacturing an electronic component for a flat panel display, which includes the following steps: Prepare the mask of any one of the 1st to 14th patterns; and The transfer step includes exposing the above-mentioned photomask by a proximity exposure device, and transferring the above-mentioned transfer pattern on the negative photosensitive material film formed on the transferred body; and In the above transfer step, a close-up exposure with the close-up gap set to a range of 50-200 μm is applied. [Effects of Invention]

According to the present invention, it is possible to provide a photomask for more accurately transferring the transfer pattern of the photomask using a proximity exposure device.

When the design of electronic components to be obtained such as flat panel displays is high-definition and the density increases, it is inconvenient if only the transfer pattern of the photomask used to manufacture the electronic components is made finer. For example, if the proximity exposure method is used to expose a black matrix transfer pattern with a fine pattern width (CD: Critical Dimension), the corners of the quadrilateral pixels are likely to be curved in the transfer image. Degrade.

Fig. 1 shows an example of a transfer pattern 35 for forming a black matrix. The transfer pattern 35 is formed on the transparent substrate 21 (see FIG. 6 ), and has a transmission control portion 36 and a light transmission portion 37. The light-transmitting portion 37 is a linear portion where the surface of the transparent substrate 21 is exposed. The transmission control part 36 is formed on the transparent substrate 21 in a quadrangular shape of the transmission control film, and is arranged in a matrix with the light transmission part 37 interposed therebetween. That is, the transmission control portion 36 of a shape surrounded by a closed line (here, a quadrilateral with 4 corners) is arranged regularly in the X direction and the Y direction perpendicular to the light transmission portion 37 with a certain distance between them. . In addition to the right angle as shown in FIG. 1, the corner may also include an acute angle or an obtuse angle as shown in the following embodiments.

However, in the previous photomask, the region corresponding to the transmission control portion 36 is formed on the transparent substrate 21 as a light-shielding portion with a light-shielding film formed on the transparent substrate 21. When the photomask is exposed, it is not substantially The exposure light passes through. In this case, a tendency is observed that as the pattern becomes finer and the CD becomes smaller, the shape of the transferred image obtained by the close-exposure transfer onto the transfer target body 51 (refer to FIG. 3) deteriorates, It cannot faithfully reflect the shape of the transfer pattern 35.

As shown in FIG. 5, the previous photomask including the light-transmitting portion and the light-shielding portion is transferred to the negative photosensitive material (below For convenience, the shape of the black matrix 52 obtained when the photosensitive material is also referred to as resist). This is an example of a case where a faithful pattern transfer is not performed when exposing the transfer pattern 35 shown in FIG. 1. Compared with Fig. 1, the corners of the quadrilateral are curved, and the shape of the linear part also changes.

It is believed that the reason for this is that light is diffracted at the edge of the transfer pattern 35 during the proximity exposure, and further, the gap between the photomask and the transferred body 51 (that is, the proximity gap) causes the transfer on the transferred body 51 Produce complex light interference. That is, there is a problem that the light intensity distribution of the transmitted light formed on the transferred body 51 cannot faithfully reflect the transfer pattern 35 of the photomask. In particular, this tendency is remarkably observed in high-definition patterns.

On the other hand, the so-called halftone type phase shift mask, which has a specific range of light transmittance to the exposed light and shifts the phase of the exposed light by 180 degrees, replaces the light-shielding film in the semiconductor device manufacturing mask ( LSI mask) field application. Therefore, it is considered that the transfer pattern 35 can be transferred more accurately by using this halftone type phase shift mask as a proximity exposure mask. Therefore, improvement of the transferability of the pattern when a phase shift film that shifts the phase of transmitted light by 180 degrees is formed as the transmission control portion 36 in FIG. 1 has been studied. However, as shown in the following embodiment, the effect is not necessarily as expected.

Generally speaking, it is known that Fresnel diffraction works in the principle of forming a transfer image by close-up exposure. FIG. 21 is a schematic diagram showing a situation in which the exposure light transmitted through the mask 10 reaches any point on the transferred body 51 in the close-up exposure. In Fig. 21, the light wave is represented by the periodic structure of the solid line and the dashed line. The solid line represents the peak and the dashed line represents the trough (the peak and trough can also be inverted). It can be seen that the light passing through the slit SL (Slit) is diffracted (wrapped) on the edge side while advancing, and reaches the arrival point on the transferred body 51 in various phases.

The amplitude information U(x, y) of the light at any point (x, y) of the arrival point is approximated in the following Fresnel diffraction equation (1) (JWGoodman, Introduction to Fourier Optics (3rd Edition), Roberts & Company Publishers (2016), p. 66-67).

In the Fresnel diffraction formula (1), ξ and η represent the X coordinate and Y coordinate on the mask 10, respectively. That is, U(ξ, η) is the amplitude information of the light in the coordinates (ξ, η) on the mask 10. Also, z represents the proximity gap, λ represents the wavelength of the exposure light, k represents the wave number, and j represents the imaginary unit.

[Number 1]

In addition, the above-mentioned amplitude information U(x, y) in all positions in a specific surface on the transferred body 51 is integrated to determine the light intensity distribution of the transferred image, and is transferred to the transferred body 51.

On the other hand, it is considered that optimizing the phase and amplitude of the light on the transferred body 51 during the close exposure of the transfer pattern 35 of the photomask 10 improves the resolution and fidelity of the transferred image formed. Sexually useful. In this way, considering the possibility of generating a more favorable light intensity distribution for the Fresnel diffraction generated in the existing binary mask.

According to the research of the present inventor, when investigating the above situation, it is found that the phase shift amount (180 degrees) of the halftone type phase shift mask used in the projection exposure is not necessarily the best in the close-up exposure.

Furthermore, as a result of research, it is found that the transfer pattern 35 for proximity exposure (for example, the transmission control portion 36 in FIG. 1) is formed by a transmission control film having a phase shift effect, and the phase shift amount is set to When the value is larger than that of the existing halftone type phase shift mask, the shape deterioration of the transferred image obtained on the transferred body 51 can be reduced, and the fidelity of the transfer can be improved.

[Embodiment 1] The mask 10 of the first embodiment is constructed by arranging a specific transfer pattern 35 (FIG. 1) on one of the principal surfaces of a transparent substrate 21 (FIG. 6) with a rectangular or square plate-shaped principal surface. The transparent substrate 21 is made by processing a transparent material such as synthetic quartz and polishing the main surface to be flat and smooth. As the transparent substrate 21 used for the photomask for the flat panel display, it is preferable to use one whose main surface is 300-2000 mm and the thickness is 5-16 mm.

The pattern 35 for transfer which the photomask 10 has is shown in FIG. 1 as an example. The transfer pattern 35 includes: a transmission control part 36 formed by forming a transmission control film on the transparent substrate 21; and a light transmission part 37 through which the transparent substrate 21 is exposed.

Here, the transmission control portion 36 is a rectangle with a short side size B and a long side size C, and is arranged in a matrix with a D space in the short side direction and an E space in the long side direction. That is, each transmission control portion 36 is arranged regularly with the light transmission portion 37 interposed, and the distance between the long sides (also referred to as the long side distance) is Pm1 (=C+E), and the distance between the short sides (also referred to as the short distance) is Pm1 (=C+E). Side spacing) is a repeating pattern of Pm2 (=B+D). In the first embodiment, the transfer pattern 35 is a pattern for the black matrix 52 (refer to FIG. 4) used in flat panel displays, and the light-transmitting portion 37 extending vertically and horizontally in FIG. 1 is transferred to the transferred body 51 The above negative photosensitive material becomes the black matrix 52 to be obtained. FIG. 2 shows a cross-sectional explanatory view of a state where the black matrix 52 is formed on the glass substrate 56 constituting the transferred body 51. As shown in FIG.

That is, the photomask 10 is a two-gray mask formed on the transferred body where the photosensitive material is left and the part where the photosensitive material is not left. The control unit 36 corresponds to the light-shielding portion of the previous binary mask. .

The size (CD) of each part of the transfer pattern 35 is preferably set as follows, for example. In FIG. 1, the width D of the linear light-transmitting portion 37 (also referred to as the long-side slit) in the longitudinal direction is preferably 3≦D≦10 (μm), Better to be: 3≦D≦8(μm), Further preferably: 3≦D≦6(μm). With the above setting, a good black matrix 52 with a higher aperture ratio can be obtained in a flat panel display. Even with such a high-definition pattern with a fine CD, if the present invention is applied, the shape deterioration is reduced, and the effect is remarkable.

In addition, the width E of the linear light-transmitting portion 37 (also referred to as the short-side slit) extending in the horizontal direction in FIG. The width of the slit D. For example, it may be 3≦E≦30 (μm).

In addition, the short side spacing (repeat spacing) Pm2 of the repeating pattern in Figure 1 can be set as: 10≦Pm2≦35(μm). More preferably, it can be set as: 15≦Pm2≦35(μm). At this level, it can be suitably used for high-definition displays ranging from 250 ppi to 700 ppi.

On the other hand, the long-side pitch Pm1 is preferably larger than the aforementioned Pm2. For example, it can be set to: 30≦Pm1≦105(μm).

Furthermore, in the close-up exposure, the projection magnification is not set (that is, the same magnification), and the long-side pitch Pp1 and the short-side pitch Pp2 on the transferred body 51 are the same as the above-mentioned Pm1 and Pm2.

In addition, when performing proximity exposure using such a transfer pattern 35, the proximity gap G is preferably about 50 to 200 μm. Furthermore, according to the present invention, even when there is in-plane unevenness in the proximity of the gap G, the in-plane unevenness of the transferred image caused thereby is reduced. The collimation angle of the close-up exposure is preferably about 1.5 to 2.5 degrees.

It is considered to use the transfer pattern 35 as described above to form a linear pattern with a width of 10 μm or less on the transfer body 51 corresponding to the linear light-transmitting portion 37 of the aforementioned width D. For example, it is considered to form a pattern having a width of 3 to 10 μm, a width of 3 to 8 μm, and a width of 3 to 6 μm, to form a fine-width black matrix 52.

(度)之作用。即，透過控制膜之相位偏移量

為：

＞180(度)。In the photomask 10 of the first embodiment, the transmission control film used to form the transmission control portion 36 has a phase shift with respect to the exposure light for exposing the photomask 10

The role of (degree). That is, through controlling the phase shift amount of the film

for:

> 180 (degrees).

＞180、即超過180度之相位偏移量，表示藉由下述(2)式而定義之相位偏移量

之範圍。(2)式中之M表示非負整數。 180＋360M＜

＜360＋360M(度)   ‥‥‥ (2)Furthermore, the so-called

＞180, that is, the phase shift amount exceeding 180 degrees, which means the phase shift amount defined by the following equation (2)

The scope. (2) In the formula, M represents a non-negative integer. 180＋360M＜

＜360＋360M(degree) ‥‥‥ (2)

之基準。Here, the so-called exposing light for exposing the photomask 10 is used for exposing and transferring the transfer pattern 35 by the proximity exposure device 50 (FIG. 3), and it is preferable to use light having 313 to 365 Light of wavelength within the range of nm. In the exposure light containing a plurality of wavelengths, any wavelength (preferably a wavelength with an intensity peak) included in the above-mentioned wavelength range can be used as the representative wavelength as the above-mentioned phase shift amount

The benchmark.

For example, when using exposure light that includes a wavelength in the range of 313 to 365 nm, 313 nm on the short-wavelength side can be set as the representative wavelength, or 334 nm, which is close to the central value of the above-mentioned wavelength range, can be set as Represents the wavelength. In addition, 365 nm on the longest side of the above-mentioned wavelength range can be set as the representative wavelength.

＞180。又，對於以下記載之較佳之波長範圍亦係同樣。Furthermore, when the exposure light contains multiple wavelengths, all wavelengths included in the above-mentioned wavelength range can be set to

＞180. The same applies to the preferable wavelength range described below.

設為

＞180。進而，於使用之曝光之光之波長區域，亦可將強度最大之波長設為代表波長。於將高壓水銀燈設為曝光之光源且使用i射線、h射線、g射線之情形時，強度最大者一般而言為i射線。Therefore, for example, if the photomask 10 is used for close-exposure by exposure light of a wavelength in the wavelength range of 313 to 365 nm, the transmission control section 36 can be set to be the wavelength of 365 nm on the longest wavelength side. The light has a mask with a phase shift of more than 180 degrees. In this case, substantially, the phase shift amount transmitted through the control portion 36 exceeds 180 degrees with respect to all the wavelengths in the above-mentioned wavelength range included in the exposure light. Alternatively, when the wavelength of the exposure light is set to include 365-436 nm (i-ray, h-ray, g-ray), 436 nm on the longest wavelength side can be set as the representative wavelength, and the transmission relative to it Control the phase shift of the film

Set as

＞180. Furthermore, in the wavelength region of the exposure light used, the wavelength with the highest intensity can also be set as the representative wavelength. When a high-pressure mercury lamp is used as the light source for exposure and i-rays, h-rays, and g-rays are used, the one with the highest intensity is generally the i-ray.

所述者同樣之代表波長之透過率。In addition, the transmission control film for forming the transmission control portion 36 has a transmittance T with respect to the light to be exposed. The transmittance T is a value when the transparent substrate 21 is set to 1.0 (100%). In addition, the so-called transmittance here can be set to be relative to the above-mentioned phase shift

The same also represents the transmittance of the wavelength.

The transmittance T of the permeation control film is preferably 0.1 (10%) or less. For example, the transmittance T can be set as: 0.01≦T≦0.1. If T is too small, for the existing binary mask, the following fidelity improvement effect cannot be significantly obtained. If T is too large, there is a risk that the light-shielding property in the region far from the edge of the transmission control portion 36 will become insufficient.

之詳情，於下文中進行敍述。For the transmittance T and phase shift of the control film

The details are described below.

When using the photomask 10 to form the black matrix 52 of the flat panel display, in FIG. 1, a two-dot chain line is used to indicate the line corresponding to the boundary line between the pixels (pixels) constituting the flat panel display. In this example, one pixel includes a total of 3 sub-pixels of red, green, and blue, and the length of one side is a square of A (=Pm1). One sub-pixel is respectively formed in a portion corresponding to the transmission control unit 36 in FIG. 1.

When the flat panel display is a liquid crystal display, it is made by sealing liquid crystal between the opposing color filter substrate and the TFT (Thin-Film-Transistor) substrate. The black matrix 52 is formed on one surface of the color filter substrate. For example, red, green, and blue color filters can be formed in the portion corresponding to the transmission control portion 36 in FIG. 1.

When the flat panel display is an organic EL (electro-luminescence) display, red, green, and blue organic EL light-emitting elements are formed in the portion where the transmission control portion 36 in FIG. 1 is provided.

In any case, the black matrix 52 prevents color mixing or light leakage between sub-pixels, so that the images and images displayed on the flat panel display are clear. In order to realize a high-definition, that is, a flat panel display with small pixels, high pixel density and bright, the width of the black matrix 52 must be small (for example, 3-10 μm, more preferably 3-8 μm) and formed into a shape as designed .

Therefore, it is desirable to reflect the shape of the transfer pattern 35 of the photomask 10 as faithfully as possible (improve the fidelity) on the transferred image on the transferred body 51. Here, the so-called fidelity refers to the degree to which the shape of the transfer pattern 35 of the photomask 10 is maintained on the transferred body 51, for example, the corners of the transfer pattern 35 are on the transferred body 51 When the degree of curvature generated in the transferred image is reduced, or the linear portion of the transfer pattern 35 becomes thicker or thinner in the transferred image, the fidelity is improved.

As described above, the transmission control portion 36 surrounded by the closed line of the transfer pattern 35 is arranged with the line-shaped light transmission portion 37 interposed therebetween. With the transmission control portion 36, the photosensitive material on the transferred body 51 is eluted by exposure and development using the photomask 10, and on the other hand, the photosensitive material is formed in the portion corresponding to the light-transmitting portion 37 surrounding it. Three-dimensional structure of sexual materials (such as black matrix). Moreover, the mask 10 of the present invention has an excellent effect of improving the shape fidelity of the three-dimensional structure.

Hereinafter, a case where A to E shown in FIG. 1 are the lengths shown in Table 1 will be described as an example.

[Table 1] symbol Size (μm) A 90 B twenty four C 63 D 6 E 27

The proximity exposure device 50 is preferably used in the exposure of the photomask 10 of the present invention. FIG. 3 is an explanatory diagram schematically illustrating the structure of the proximity exposure device 50. When the proximity exposure device 50 irradiates the light emitted from the light source 57 to the back surface 12 side of the mask 10 via the illumination system 58, it passes through to the front surface 11 side on which the transfer pattern is formed, and reaches the transfer target body 51. A proximity gap G is provided between the photomask 10 and the transferred body 51.

The light source 57 can be a high-pressure mercury lamp. The high-pressure mercury lamp has strong peaks in i-rays, h-rays, and g-rays. However, in the exposure of the mask 10 of this embodiment 1, it is preferable to use i-rays (wavelength λ=365 nm) and shorter Spectral group on the wavelength side. For example, it is more useful to use a negative resist that has a good sensitivity range to exposure light having peaks of 365 nm, 334 nm, and 313 nm.

FIG. 4 illustrates the shape of the black matrix 52 formed on the transferred body 51 assuming that the transfer pattern 35 shown in FIG. 1 is faithfully transferred onto the transferred body 51. As shown in FIG. In the case of using a negative photosensitive material, the white and black are reversed with respect to Fig. 1. Here, the shape of Fig. 4 is assumed to be a black matrix in an ideal state.

On the other hand, FIG. 5 shows that when the binary mask with the transfer pattern 35 shown in FIG. 1 is subjected to close-up exposure and transferred to the transferred body 51, it is caused by light diffraction and interference. The transfer image when the shape is deteriorated. For example, in the previous mask in which the transmission control portion 36 shown in FIG. 1 is used as a light-shielding portion, such shape deterioration is likely to occur. In this case, the corners of the part corresponding to the sub-pixels are curved and the fidelity (fidelity) of the transfer is insufficient.

者時轉印像之保真度如何變化。Therefore, using optical simulation using Fresnel diffraction, it was verified that when the transmission control film used for the transmission control portion 36 is set to have a specific transmittance T and phase shift in the transfer pattern 35 shown in FIG. 1 quantity

How does the fidelity of the transfer image change?

對上述轉印像之影響。That is, when exposing the above-mentioned transfer pattern 35 by proximity exposure, the light intensity distribution of the exposure light formed on the transferred body 51 was obtained by optical simulation, and better transfer conditions were found and studied Through the control film transmittance T and phase shift

The effect on the above-mentioned transfer image.

Using FIG. 6, the photomask 10 and the transfer image formed by the close-up exposure will be described. FIG. 6(a) shows a schematic cross-sectional view obtained by cutting the photomask 10 along the short side direction of the transmission control portion 36. As shown in FIG. As explained using FIG. 1, the width of the transmission control portion 36 is set to B, and the width of the light transmission portion 37 is set to D. Here, the size of D corresponding to the width of the black matrix 52 is a fine size of 10 μm or less.

FIG. 6(b) shows the light intensity distribution formed on the transferred body 51 when exposure is performed by the proximity exposure device 50 from the back side of the photomask 10. The horizontal axis represents the position on the transferred body 51, and the vertical axis represents the light intensity.

The light intensity threshold Ith is equivalent to the light intensity threshold when the negative photosensitive material on the transferred body 51 forms the black matrix 52 with the width D by development. At this time, when considering a situation where the development behavior can be binarized into an ideal development model that is completely soluble and completely insoluble, Ith is the threshold value of the light intensity at which the negative photosensitive material is completely insoluble.

In repetitive patterns in which light and dark alternately repeat, such as line and gap patterns, generally speaking, an index called contrast is used to evaluate the quality of the transferred image. The higher the contrast value, the clearer the light intensity difference between the bright part and the dark part. The photolithography method is a method of burning the transfer information on the transferred body 51 by using the difference between light and darkness. Therefore, it is preferable to have a contrast of more than a fixed value.

There are several methods to quantify the contrast, but as a method focusing on the difference, the quantization using Michelson Contrast is widely used. Michelson Contrast is defined as {(I1-I2)/((I1+I2)} when the light intensity of the bright part is set to I1 and the light intensity of the dark part is set to I2. In the present invention, it is used as the light intensity of the bright part. The index of Ith has been defined. On the other hand, according to Figure 6(b), it can be seen that it depends greatly on the nature of the transmission control unit 36. In Figure 6(b), it is assumed that the dark part B is very dark. In the case where I2 is close to 0, but in the case where the transmission control film has a significant transmittance T as described below, the dark part is arranged according to the position on the mask or the position on the body to be transferred , And sometimes act with a light intensity that cannot be ignored.

對上述光強度分佈造成之影響。Based on the above, here, the contrast Co in the first embodiment is defined by formula (3), and the transmittance T or the phase shift amount through the control unit 36 is investigated

The impact on the above-mentioned light intensity distribution.

[Number 2]

Here, Ith corresponds to the threshold value of the light intensity at which the resist film on the transferred body 51 becomes insoluble by development as described above. Furthermore, it is assumed that a transfer image having a width D is formed on the transfer target body 51.

T is the inherent film transmittance of the transmission control film that does not consider the phase effect of the transmission control portion 36 with respect to the light exposed, and is a value that sets T to 1 when the transmittance is 100%.

In the formula (3), the contrast Co represents the Michelson Contrast of Ith and T. That is, if the value of T has a sufficient ratio that cannot be ignored with respect to Ith, the numerator becomes relatively smaller with respect to the denominator, and the contrast Co also becomes smaller. At this time, the expected and expected fidelity improvement effect is different, and the following concerns arise.

When the resist is of a negative type, the crosslinking reaction proceeds due to exposure to light, and it becomes a state where it will not be eluted due to development.

In addition to the ideal model, there are more or less halfway photoreactions or halfway development behaviors in the actual photosensitive materials. As a result, consider the risk that, on the transferred body 51, the cross-linking reaction will eventually occur locally in the part of the structure that does not need to contain the resist (for example, the part where the black matrix 52 should not be formed). Residues remain after development. That is, if the value of the transmittance T is close to Ith, there may be a situation in which the cross-linking reaction in the portion where the above-mentioned structure is not required, and the risk of residue retention may increase. In order to avoid this situation, the transmittance T of the transmission control unit 36 is preferably within a range that does not exceed 20% of the light intensity threshold Ith for exposure. The contrast Co2 when the transmittance T is 20% of the light intensity threshold Ith for exposure is calculated by equation (4).

[Number 3]

That is, the contrast Co is preferably set to 0.667 or more.

In addition, considering the possibility of variation (variation in irradiation intensity, unevenness in the development surface, etc.) that may occur during the exposure step or the subsequent development step, in order to obtain a more excellent yield, the control unit The transmittance T of 36 is more preferably less than 10% of the exposure light intensity threshold Ith. The contrast Co1 when the transmittance T is 10% of the exposure light intensity threshold Ith is calculated using the following formula (5).

[Number 4]

That is, the contrast Co is more preferably 0.818 or more. Moreover, it can be seen from the above equations (4) and (5) that the value of the better contrast Co is independent of the value of Ith.

Furthermore, in order to more directly evaluate the degree of reflection (fidelity) of the transfer pattern 35 formed on the photomask 10 on the transferred body 51, it is obtained by simulation that it is formed on the transferred body 51 by close-up exposure. The transfer image of the transfer pattern 35 on the upper part, and the difference in shape between the obtained transfer image and the transfer pattern 35 is quantified and calculated as the difference S.

The difference S corresponds to the area where the shape of the transfer pattern 35 on the photomask 10 is different from the shape of the transfer image formed on the body 51 to be transferred. The difference S system is defined by equation (6). The closer the difference S is to 0, the more faithfully the transfer pattern on the mask 10 is transferred to the so-called fidelity state of the transferred body 51.

S=S1＋S2 ‥‥‥(6) Here, S1 means that if the transfer pattern 35 of the mask 10 is faithfully transferred, it becomes the area constituting the black matrix 52. However, in the transferred image obtained by simulation, the light intensity does not satisfy the exposure light intensity threshold Ith Therefore, it refers to the area of the area that does not constitute the black matrix 52.

On the other hand, S2 is an area that does not constitute the black matrix 52 if the transfer pattern 35 of the mask 10 is faithfully transferred, but in the transferred image obtained by simulation, the light intensity exceeds the threshold Ith, and It refers to the area constituting the black matrix 52.

That is, S1 and S2 can be considered as the absolute value of the error (deviation amount) from the negative side and the positive side of the faithful transfer, respectively, and the total is evaluated here. Furthermore, the values of S1 and S2 are quantized to calculate the number of pixels of the above-mentioned deviation portion when output to a square of 680 pixels, and multiply it by u of the unit area of the pixel.

Fig. 7 is a transfer pattern 35 having the shape of Fig. 1 and the size of Table 1. The distribution of the numerical value and shape difference of the difference S (Fig. 7(b)~(f)) shows the close gap by simulation and using G is set to 100 μm and the influence on the transferred image when the phase shift amount of the transmission control section 36 is changed. Specifically, together with Comparative Example 1 of the binary mask with zero transmittance, the transmittance of the transmission control section 36 is set to 0.03 (3%), and the phase shift of the transmission control section 36 is obtained. The quantity is set to the distribution of the difference S in the case of each of 0 degrees, 90 degrees, 180 degrees, and 270 degrees, and the shape difference corresponding to the difference S. Furthermore, here, the light intensity threshold Ith for exposure is such that the portion of the transferred body 51 corresponding to the narrow black matrix 52 (the portion corresponding to the width D of the light-transmitting portion 37 in FIG. 1) becomes 6 μm The way to set.

Regarding the shape (a) of the transfer pattern 35, if the distribution of the difference in the shape of the above-mentioned S is observed and the value of S to quantify it, the following can be seen. Compared to (b) Comparative Example 1 (binary mask, hereinafter also referred to as "binary") or (c) Reference Example 1 (halftone mask without phase shift, hereinafter also referred to as "non-phase difference mask") HTM”), the value of the difference S in the first embodiment (f) where the phase shift is greater than 180 degrees is the lowest, and the fidelity is excellent.

The so-called halftone type phase-shift mask (hereinafter also referred to as "180-degree PSM") shown in (e) using the phase shift amount of 180 degrees is made into the reference example 3 of the transmission control unit 36 compared to the one shown in (b) The binary mask of Comparative Example 1 has low fidelity.

The above tendency can also be grasped visually based on the distribution of the shape difference in FIG. 7. That is, it can be seen that, by setting the phase shift amount of the transmission control unit 36 to a value exceeding 180 degrees in the photomask 10 of the first embodiment, a transfer image that is superior to any previous photomask can be obtained.

Generally speaking, the proximity exposure method is performed by setting the proximity gap to a specific value (for example, 100 μm), but in reality, it is impossible to cover the entire area of the mask 10 and set the distance from the transferred body 51 to this value. . For example, in the photomask 10 for a large-size flat panel display, bending due to its own weight occurs during close exposure. Therefore, the proximity gap between the center and the outer edge of the photomask 10 is different. Or, there are cases where a more complicated in-plane distribution (unevenness) of the proximity gap is generated due to a holding mechanism that applies a load to the mask 10 for the purpose of reducing the bending.

Therefore, in the above-mentioned simulation, the result of studying the fidelity of the case where the proximity gap G becomes 150 μm is shown in FIG. 8. In this case, the proximity gap of 150 μm is accidentally generated due to in-plane distribution, etc. Therefore, the value of Ith derived from 100 μm, which is a deliberately set specific proximity gap value, is used in the light intensity threshold of exposure.

According to Fig. 8, similar to Fig. 7, compared to the binary mask shown in (b) or the 180-degree PSM shown in (e), in the mask 10 of the second embodiment shown in (f), The shape difference is small, and it shows excellent fidelity.

Based on the above, it can be seen that when a phase shift film is applied to the proximity exposure mask 10 to obtain an improvement in resolution obtained by the phase shift effect, the phase shift amount is determined by 180 in the projection exposure method. The degree of phase shift may not be optimal. In other words, it was found that when the phase shift used in the close-up exposure method acts on the phase shift exceeding 180 degrees, the display is more excellent fidelity. In particular, it can be seen that in this case, the shape stability of the transferred image is remarkably excellent with respect to the variation of the proximity gap G. In this respect, it is understandable that the difference between Embodiment 1 and Embodiment 2 (that is, the difference between the difference S in FIG. 7(f) and FIG. 8(f)) is small.

Next, a more detailed optical simulation is shown for the fidelity of the obtained transfer image.

及透過率T分別變化時，對透過控制部36之相位偏移量

、透過率T、轉印像之對比度Co、差分S之關聯進行調查所得者。The following optical simulation is in the transfer pattern 35 in Fig. 1, with the phase shift

And the transmittance T change respectively, the phase shift amount of the transmittance control unit 36 is

, Transmittance T, the contrast Co of the transfer image, and the difference S are surveyed.

與透過率T之組合進行各種變更而實施。於圖9中，橫軸表示相位偏移量

(度)，縱軸表示透過率T。以虛線表示交界之一個個長方形框表示各者之模擬條件。Figure 9 is an explanatory diagram illustrating the display method of the simulation results. The simulation system makes the phase shift amount through the control unit 36

The combination with the transmittance T is implemented with various changes. In Figure 9, the horizontal axis represents the phase offset

(Degrees), the vertical axis represents the transmittance T. The dashed lines represent the rectangular boxes at the junctions to represent the simulation conditions of each.

為360度、即0度且無相位差之HTM。粗線包圍之M部表示180度PSM。粗線包圍之N部表示相位偏移量

超過180度且未達360度之透過控制部36。於以下說明中，將具備相當於N部之透過控制部36之光罩10亦稱為過偏移角相移光罩。The K portion enclosed by the thick line indicates that the transmittance T of the transmission control portion 36 is 0, that is, the binary mask through which the transmission control portion 36 does not transmit light. The L part enclosed by the thick line indicates the phase shift amount through the control part 36

It is an HTM of 360 degrees, that is, 0 degrees and no phase difference. The M part enclosed by the thick line represents the 180 degree PSM. The N part enclosed by the thick line indicates the phase offset

The transmission control unit 36 that exceeds 180 degrees and does not reach 360 degrees. In the following description, the mask 10 provided with the transmission control portion 36 corresponding to the N portion is also referred to as an over-offset angle phase shift mask.

藉由模擬器特性而於每個波長與特定值一致。又，近接間隙G設為100 μm。In the simulation, as the exposure light, exposure conditions in a wide wavelength region including light with wavelengths of 313 nm, 334 nm and 365 nm (intensity ratio 0.25:0.25:0.5) are applied. These are the main peak components below the i-ray in the photosensitive region of the negative resist used in the production of the black matrix 52 and the like in the emission spectrum of the high-pressure mercury lamp. Transmittance T and phase difference

By the characteristics of the simulator, each wavelength is consistent with a specific value. In addition, the proximity gap G is set to 100 μm.

In addition, the transfer pattern 35 of the photomask 10 is the same as that described with respect to FIG. 7.

In addition, in this simulation, the values of the contrast Co and the difference S in the above-mentioned simulation conditions were calculated, and corresponded to the rectangular frames shown by the dotted lines in FIG. 9.

Figures 10 to 12 are explanatory diagrams illustrating simulation results. Figure 10 shows the case where the proximity gap G is 100 μm. The part enclosed by the thick line shows that the difference S obtained by using the over-offset phase shift mask has the same transmittance (0.03) and no phase difference HTM, 180 degree PSM An area that is smaller and smaller than duality.

That is, the area within the thick line is an area where the fidelity of the transfer in the over-offset phase shift mask is better than any of the binary, non-phase difference HTM, and 180-degree PSM.

Fig. 11 shows the simulation results performed under the same conditions as Fig. 10 except that the proximity gap G is set to 150 μm. The part enclosed by the thick line represents the area where the fidelity of the over-offset phase shift mask is better than any of the binary, no phase difference HTM, and 180 degree PSM under the same reference as the above.

In general, if the proximity gap G becomes larger than the set value, the deterioration of the transferred image tends to become remarkable. This aspect can also be grasped according to Figure 7 and Figure 8. However, it can be seen that, according to the over-offset angle phase shift mask of the present invention, even if the proximity gap G changes in the plane and becomes larger than the set value, compared with the existing mask, it shows a stable fidelity High transferability.

The area enclosed by the single-dot chain line in FIG. 12 is shown in the sum set of the parts enclosed by the thick lines in FIG. 10 and FIG. 11. That is, when the proximity gap G is either 100 μm or 150 μm, the over-offset phase shift mask has a higher fidelity than other masks 10. In addition, the part enclosed by the thick line shows that in either of FIGS. 10 and 11, the part enclosed by the thick line, that is, a common set. That is, when the proximity gap G is either 100 μm or 150 μm, the region where the fidelity of the over-offset phase shift mask is higher.

超過180度，則過偏移角相移光罩具有較既有之光罩更有利之保真度。According to Fig. 12, it can be seen that if the phase shift amount of the control unit 36 is

More than 180 degrees, the over-offset phase shift mask has a more favorable fidelity than the existing mask.

為255度以上時，該近接間隙G時之保真度較有利。Also, according to FIG. 10, it can be seen that the phase shift amount of the transmission control unit 36 is

When it is 255 degrees or more, the fidelity of the close gap G is more favorable.

之選擇範圍較廣。Furthermore, according to FIG. 10, if the transmittance T of the transmission control portion 36 is 0.06 or less, the phase shift amount of the transmission control portion 36 is used to obtain good fidelity

The choice is wider.

為330度以下之較寬之過偏移角範圍內獲得良好之保真度。Furthermore, according to FIG. 11, when the proximity gap is unexpectedly enlarged due to in-plane distribution, etc., the phase shift amount of the control unit 36 is also affected.

Good fidelity can be obtained in a wider range of over-offset angle below 330 degrees.

為255度以上且330度以下時，有因近接間隙G之變動導致之對保真度之影響較小之優點，於相位偏移量

為270度以上時，該優點更顯著。In addition, according to FIGS. 10 to 12, the phase shift amount of the transmission control unit 36 is

When it is 255 degrees or more and 330 degrees or less, there is an advantage that the change in the proximity gap G has less impact on the fidelity, and the phase offset

When it is 270 degrees or more, this advantage is more significant.

之選擇範圍均較廣。Moreover, if the transmittance T is set to 0.06 or less, regardless of the variation of the proximity gap G, it is used to obtain a favorable fidelity phase shift amount

The selection range is relatively wide.

設為270度以上，則用以獲得有利之保真度之透過率T之選擇範圍較廣。Furthermore, if the phase shift amount of the phase shift mask is

If it is set to 270 degrees or more, the transmittance T to obtain favorable fidelity has a wider selection range.

Furthermore, FIG. 13 shows the result of calculating the contrast Co of the transfer image formed on the transferred body 51. The W portion surrounded by the thick line is a region where the contrast Co becomes 0.667 or more (wherein, less than 0.818), and the V portion surrounded by the thick line is a region where the contrast Co becomes 0.818 or more. That is, the region W is a preferable range obtained by the above-mentioned formula (4), and the region V is a more preferable range obtained by the above-mentioned formula (5).

或透過率T之條件以外，進而一併考慮圖13中之有利之對比度Co之範圍，可獲得更佳之轉印性。Therefore, it can be seen that by removing the above, a better phase offset with favorable fidelity can be obtained

Alternatively, in addition to the conditions of the transmittance T, the favorable contrast Co range in FIG. 13 is also considered to obtain better transferability.

為225度以上時，用以獲得對比度良好之轉印像之適用透過率T之範圍擴大，若將相位偏移量

設為270以上，則可獲得進而擴大之有利之效果。For example, it can be seen that the amount of phase shift transmitted through the control unit 36 in the over-offset phase shift mask is

When it is above 225 degrees, the range of applicable transmittance T to obtain a transfer image with good contrast is expanded. If the phase shift is

If it is set to 270 or more, the advantageous effect of further expansion can be obtained.

之較寬之範圍內獲得對比度良好之轉印像。 若透過率T為： 0.01≦T≦0.08， 則其優點更顯著。In addition, the value of the transmittance T is preferably 0.1 or less as described above. In particular, if it is: 0.01≦T≦0.09, the value of the transmittance T can be determined by the phase shift amount of the control unit 36

The transfer image with good contrast can be obtained in a wide range. If the transmittance T is: 0.01≦T≦0.08, the advantages are more significant.

之選擇範圍較高。Furthermore, if the transmittance T is: T≦0.05, then a better contrast Co can be obtained, and if: T≦0.04, the phase shift amount of the transmission control portion 36 to obtain a better contrast

The selection range is relatively high.

[Embodiment 2] FIG. 14 shows how the design shape of the transfer pattern 35 of the photomask 10 is changed from the first embodiment. That is, the transfer pattern 35 of the photomask 10 has a parallelogram repeating pattern instead of a rectangle. For example, it is assumed that the shape of the sub-pixels of the flat panel display is a parallelogram.

In FIG. 14, the transmission control portion 36 is a parallelogram with a base length of C, a height of B, an acute angle part of 45 degrees, and an obtuse angle part of 135 degrees. The transmission control portion 36 is arranged in a matrix with an interval of D in the height direction and an interval of E in the direction along the bottom side. Except for the design changes of these patterns, the transfer pattern 35 of the second embodiment is set to be the same as that of the first embodiment except for special descriptions. In addition, the dimensions from A to E here are set to be the same as those shown in Table 1. The dimensions are the same.

15 shows the shape of the black matrix 52 formed on the transferred body 51 assuming that the transfer pattern 35 shown in FIG. 14 is faithfully transferred to the transferred body 51. It is set as the black matrix 52 in an ideal state. However, in actuality, if the transfer pattern 35 of FIG. 14 is subjected to close-up exposure, the transfer image on the transfer target body 51 will experience shape deterioration due to diffraction and interference of light.

Here, in the case where the transfer pattern 35 shown in FIG. 14 is subjected to close-up exposure, the results of the same optical simulation as those performed in the above-mentioned FIGS. 7 and 8 are shown in FIGS. 16 and 17.

That is, for the transfer pattern 35 of FIG. 14, the transfer image and the difference d when the phase shift amount of the transmission control section 36 is changed with the interval D being 6 μm and the proximity gap G being 100 μm are shown. In Figure 16 (b) ~ (e). Specifically, along with the comparative example 4 of the binary mask with zero transmittance, the transmittance of the transmission control section 36 is set to 0.03 (3%), and the phase shift amount of the transmission control section 36 is set Calculate the difference d for each case of 0 degree, 90 degree, 180 degree, and 270 degree. In addition, here, Ith normalizes the light intensity so that the narrow black matrix 52 (the portion corresponding to D of the transfer pattern 35) becomes 6 μm. The collimation angle of the close-up exposure is set to 2.0 degrees. The simulation conditions are the same as those in the first embodiment.

Furthermore, FIG. 17 shows the results of a simulation performed under the same conditions as in FIG. 16 except that the proximity gap G is 150 μm.

According to Fig. 16 and Fig. 17, it can be seen that compared with binary mask or 180 degree PSM, according to the value of difference d, the transfer fidelity of the over-offset angle phase shift mask of embodiment 3 and embodiment 4 is excellent . Furthermore, according to FIG. 16, when the proximity gap G is 100 μm, the fidelity of the HTM without phase difference is slightly better than that of Embodiment 3. However, according to FIG. 17, if the proximity gap G becomes 150 μm, the embodiment The value of the difference d of 4 becomes the more excellent one. Furthermore, in the proximity exposure, when different proximity gaps G are formed according to the position in the plane, the point that the variation of the difference d is small according to the variation of the proximity gap G can also be understood from Embodiments 3 and 4. This aspect is of great significance in maintaining the in-plane uniformity of the transferred pattern, especially in the manufacture of flat panel displays.

Figs. 18 to 20 are explanatory diagrams for explaining the results of the simulation similar to those of Figs. 9 to 11 described above.

Figure 18 shows the case where the proximity gap G is 100 μm. The part enclosed by the thick line indicates that the fidelity of the over-offset phase shift mask is better than the fidelity of the binary, no phase difference HTM and 180-degree PSM area. That is, the area within the thick line is the area where the above-mentioned difference d in the phase shift mask is smaller than binary, and further smaller than any of HTM and 180-degree PSM with the same transmittance without phase difference. .

Fig. 19 shows the simulation results performed under the same conditions as Fig. 18 except that the proximity gap G is set to 150 μm. The part enclosed by the thick line indicates the area where the fidelity of the over-offset phase shift mask is better than any of the binary, no phase difference HTM, and 180 degree PSM.

The area enclosed by the single-dot chain line in FIG. 20 is represented by the sum of the parts enclosed by the thick lines in FIG. 18 and FIG. 19. That is to say, when the proximity gap G is either 100 μm or 150 μm, the over-offset phase shift mask has a high fidelity area. In addition, the part enclosed by the thick line shows that in either of FIGS. 18 and 19, it is the part enclosed by the thick line, that is, a common set. That is, when the proximity gap G is either 100 μm or 150 μm, the region where the fidelity of the over-offset phase shift mask is higher.

超過180度時，過偏移角相移光罩具有較既有之光罩更有利之保真度。又，可知，於相位偏移量

為300度以上時，可獲得尤其良好之結果。It can be seen from Fig. 20 that the phase shift amount of the transmission control unit 36 is

When it exceeds 180 degrees, the over-offset phase shift mask has a more favorable fidelity than the existing mask. Also, it can be seen that the phase offset

When it is 300 degrees or more, particularly good results can be obtained.

Also, as in the first embodiment, by simultaneously considering the range of good contrast Co obtained by using FIG. 13, conditions with more favorable fidelity can be selected.

As shown in the above-mentioned Embodiments 1 and 2, according to the over-offset angle phase shift mask, it is possible to provide a mask 10 that can use the proximity exposure device 50 to perform photolithography with good fidelity.

Furthermore, according to the above-mentioned embodiment, it is possible to provide a photomask 10 that can reduce the change in the shape of the transferred image (including CD) caused by the change in the proximity gap G due to the in-plane position of the photomask 10. In particular, in a large-scale photomask 10 used for a flat panel display, it is easy to produce bending due to its own weight or a change in the proximity gap G due to the holding means of the exposure device. Therefore, the photomask 10 of this embodiment is more effective .

Furthermore, according to the above-mentioned embodiment, it is possible to provide a photomask 10 that can combine a resist using a negative photosensitive material and a high-pressure mercury lamp to perform high-fidelity exposure.

The transmission control film constituting the transmission control section 36 is made to have a specific exposure light transmittance and phase shift amount and its composition or film thickness is determined, and its composition may be uniform in the film thickness direction, or may be Laminate films of different compositions or different physical properties to form a permeable control film.

However, in the range that does not impair the effects of the present invention, different films (light-shielding film, etching stop film, etc.) can be additionally provided, and use can be made on the upper surface side or the lower surface side of the pattern of the transmission control film. The film pattern of the additive film.

In addition, an additional film pattern (for example, a light-shielding film pattern) may also be provided on the outer peripheral side of the transfer pattern 35, and it may also be referred to when such an additional film pattern is formed when exposing the photomask 10 or during operation. Mark the pattern.

In common with the above two embodiments, the photomask 10 of the present invention can be manufactured by the following manufacturing method, for example.

First, a photomask base with a transmission control film formed on the transparent substrate 21 is prepared. When forming a film through the control film, the material and film thickness are selected in a manner that satisfies a specific transmittance and phase shift with respect to the exposed light. As the film forming method, a known film forming method such as a sputtering method can be applied.

Next, a resist-attached photomask base with a resist film formed on the transmission control film is prepared. The resist may be positive or negative, but is preferably positive.

Then, patterning is performed on the above-mentioned resist-attached photomask base. Specifically, a drawing device such as a laser drawing device is used to perform drawing using specific pattern data, and to perform development. Furthermore, the transmission control film is subjected to dry or wet etching using the resist pattern formed by development as a photomask to form the transfer pattern 35. Then, the resist pattern is peeled off.

According to the above steps, the photomask 10 can be formed by only one patterning (that is, only one drawing). That is, it is preferable to use only the photomask 10 formed by patterning the transmission control film. Optionally, additional film formation and patterning can be performed.

The material of the permeable control film can be, for example, a film containing Si, Cr, Ta, Zr, etc., or a suitable one can be selected from compounds such as these.

As the Si-containing film, Si compounds (SiON, etc.), or transition metal silicides (MoSi, TaSi, ZrSi, etc.) or their compounds (oxides, nitrides, carbides, oxynitrides, oxycarbonitrides, etc.) can be used Wait).

As the Cr-containing film, Cr compounds (oxides, nitrides, carbides, oxynitrides, carbonitrides, oxycarbonitrides) can be used.

The present invention includes a method of manufacturing electronic components for flat panel displays using the photomask 10.

That is, it is a method for manufacturing an electronic component system for a flat panel display, which includes the steps of: preparing the above-mentioned over-offset angle phase shift mask; The photomask is exposed, and the transfer pattern 35 is transferred on the transferred body 51; and in the transfer step, a proximity exposure of 50-200 μm is applied to the proximity gap.

The use of the mask 10 can be preferably used for the manufacture of the black matrix 52 or black stripes, but is not limited to them. Among them, the photomask of the present invention is particularly preferably used for the purpose of forming a three-dimensional structure obtained from a photosensitive material on the transfer body. The reason is that it is extremely meaningful to obtain excellent fidelity in the shape of the three-dimensional structure formed by the transmission control portion surrounded by the closed line and the light transmission portion surrounding it.

In addition, the present invention can be preferably applied to a transfer pattern including a so-called dense pattern that regularly repeats a unit pattern at a distance of optical mutual influence like a line and a gap pattern.

The technical features (constitutive elements) described in each embodiment can be combined with each other, and new technical features can be formed by the combination. It should be considered that the embodiments 1 and 2 disclosed this time are illustrative in all respects and not restrictive. The scope of the present invention is not the above-mentioned meaning, but is expressed by the scope of the patent application, and it is intended to include all changes within the meaning and scope equivalent to the scope of the patent application.

10: Mask 11: front 12: back 21: Transparent substrate 35: Pattern for transfer 36: Through the control department 37: Translucent part 50: Proximity exposure device 51: Transferred body 52: black matrix 56: Transferred body (glass substrate) 57: light source 58: lighting system

Fig. 1 is a diagram showing an example of a transfer pattern for forming a black matrix. Fig. 2 is a cross-sectional explanatory view showing a state in which a black matrix is formed on a glass substrate constituting a body to be transferred. Fig. 3 is an explanatory diagram schematically showing the structure of the proximity exposure device. FIG. 4 is a diagram illustrating the shape of the black matrix formed on the transfer body assuming that the transfer pattern shown in FIG. 1 is faithfully transferred onto the transfer body. Fig. 5 shows the shape deterioration due to the diffraction and interference of light when the binary mask with the transfer pattern shown in Fig. 1 is subjected to close-up exposure and transferred to the transferred body. The transfer image of the situation. 6(a) and (b) are explanatory diagrams for explaining the photomask 10 and the transfer image formed by the close-up exposure. Figures 7(a) to (f) use the distribution of the value and shape difference of the difference S to show that the proximity gap G is set to 100 μm for the transfer pattern with the shape of Figure 1 and the size of Table 1, and the control section is passed through A graph of the influence of the phase shift on the transferred image when the amount of phase shift is changed. Figures 8(a) to (f) show the results of studying the fidelity of the case where the proximity gap G becomes 150 μm in the simulation. Figure 9 is an explanatory diagram illustrating the display method of the simulation results. Fig. 10 is an explanatory diagram illustrating the simulation results. Figure 11 is an explanatory diagram illustrating the simulation results. Figure 12 is an explanatory diagram illustrating the simulation results. FIG. 13 shows the result of calculating the contrast Co of the transfer image formed on the transfer body. Fig. 14 shows another example of a transfer pattern for forming a black matrix. FIG. 15 shows the shape of the black matrix formed on the body to be transferred assuming that the transfer pattern shown in FIG. 14 is faithfully transferred to the body to be transferred. Figures 16(a) to (f) show the results of the same optical simulation as those performed in Figures 7 and 8 for the case where the transfer pattern shown in Figure 14 is subjected to close-up exposure. Figs. 17(a) to (f) are diagrams showing the results of the same optical simulation as those performed in Figs. 7 and 8 in the case where the transfer pattern shown in Fig. 14 is subjected to close-up exposure. Fig. 18 is an explanatory diagram illustrating the result of the simulation similar to that of Figs. 9-11. Fig. 19 is an explanatory diagram illustrating the result of the simulation similar to that of Figs. 9 to 11. Fig. 20 is an explanatory diagram illustrating the result of the simulation similar to that of Figs. 9 to 11. FIG. 21 is a schematic diagram showing a situation in which the exposure light passing through the mask reaches any point on the transferred body in the close-up exposure.

Claims (16)

A photomask for proximity exposure, which is provided with a transfer pattern formed by patterning a transmission control film formed on a transparent substrate, The pattern for transfer has a transmission control portion formed by forming a transmission control film on the transparent substrate, and a light transmission portion through which the transparent substrate is exposed. The transmission control unit has a phase shift amount exceeding 180 degrees with respect to the exposure light for exposing the photomask. A photomask for proximity exposure, which is provided with a transfer pattern formed by patterning a transmission control film formed on a transparent substrate, and In the mask used for close-up exposure by exposure light having a wavelength in the wavelength region of 313-365 nm, The pattern for transfer has a transmission control portion formed by forming a transmission control film on the transparent substrate, and a light transmission portion through which the transparent substrate is exposed. The transmission control unit has a phase shift of more than 180 degrees with respect to light with a wavelength of 365 nm. Such as the photomask of claim 2, which is used for exposure of negative photosensitive materials. Such as the mask of any one of claims 1 to 3, where The transmittance of the transmission control portion with respect to the exposure light is 10% or less. The photomask according to any one of claims 1 to 3, wherein the transfer pattern has a linear light-transmitting portion with a width of 3-10 μm. The photomask according to any one of claims 1 to 3, wherein the above-mentioned transfer pattern is formed on the negative photosensitive material on the transferred body to form a linear pattern with a width of 10 μm or less. The photomask according to any one of claims 1 to 3, wherein the transfer pattern has a repeating pattern in which the transmission control portion and the light transmission portion are regularly arranged, and the repeating pitch of the repeating pattern is 10 to 35 μm. The photomask of any one of claims 1 to 3, wherein the transfer pattern has a repeating pattern in which the transmission control portion and the light transmission portion are regularly arranged, and the transmission control portion has a closed line surrounded by a repeating pattern. shape. The photomask according to any one of claims 1 to 3, wherein the transfer pattern has a repeating pattern in which the transmission control portion is regularly arranged, and the transmission control portion is a quadrilateral. The photomask according to any one of claims 1 to 3, wherein the transmission control section has a phase shift of 255 degrees or more with respect to the exposed light. The photomask according to any one of claims 1 to 3, wherein the transmission control section has a phase shift of more than 300 degrees with respect to the exposed light. The photomask according to any one of claims 1 to 3, wherein the transmission control section has a phase shift amount of 330 degrees or less with respect to the exposed light. The photomask according to any one of claims 1 to 3, wherein the pattern for transfer is a pattern for forming a black matrix or black stripes. The photomask according to any one of claims 1 to 3, wherein the pattern for transfer is formed by patterning only the transmission control film on the transparent substrate. A manufacturing method of electronic components for flat panel displays, which includes the following steps: Prepare the photomask of any one of requirements 1 to 3; and The transfer step includes exposing the above-mentioned photomask by a proximity exposure device, and transferring the above-mentioned transfer pattern on the negative photosensitive material film formed on the transferred body; and In the above transfer step, a close-up exposure with the close-up gap set to a range of 50-200 μm is applied. A manufacturing method of a photomask for proximity exposure, the photomask for proximity exposure is provided with a pattern for transfer formed by patterning a transmission control film formed on a transparent substrate, and the method includes the following steps: Prepare a mask base with the transmission control film formed on the transparent substrate; and The patterning step is to pattern the transmission control film to form the pattern for transfer; and The pattern for transfer has a transmission control portion formed by forming the transmission control film on the transparent substrate, and a light transmission portion for exposing the transparent substrate, and The transmission control unit has a transmittance of less than 10% and a phase shift amount of more than 180 degrees with respect to the exposure light for exposing the photomask.

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