KR20230172419A - Transfer mask and manufacturing method for display device - Google Patents

Abstract

A transfer mask capable of realizing a PDL with a small inclination angle of an inclination portion located around an opening is provided. It is a transfer mask provided with a transfer pattern including a light-transmitting part, a first transparent part, and a second transparent part on a light-transmitting substrate. The light-transmitting part has a hole shape in which the light-transmitting substrate is exposed, and the first transparent part is annular along the outer circumference of the light-transmitting part. is provided, the second transmitting portion is provided in contact with the outer periphery of the first transmitting portion, the transmittance T1 of the first transmitting portion with respect to the exposure light is higher than the transmittance T2 of the second transmitting portion with respect to the exposure light, and the second transmitting portion is provided in contact with the outer periphery of the first transmitting portion. The absolute value of the phase difference between the exposure light and the exposure light passing through the light transmitting unit is 90 degrees or less, and the absolute value of the phase difference between the exposure light passing through the second transmitting unit and the exposure light passing through the light transmitting unit is 90 degrees or less, and the first The absolute value of the phase difference between the exposure light passing through the transmission portion and the exposure light passing through the second transmission portion is characterized in that it is 90 degrees or less.

Description

Transfer mask and manufacturing method of display device {TRANSFER MASK AND MANUFACTURING METHOD FOR DISPLAY DEVICE}

The present invention relates to a transfer mask and a method of manufacturing a display device.

Patent Document 1 discloses a photomask for manufacturing a display device that has a transfer pattern including a light-transmitting portion, a light-shielding portion, and a semi-transmissive portion in order to form a resist pattern having a plurality of different residual film values on a transfer object by exposure. It is listed. In this photomask, the light-transmitting portion is formed by exposing a transparent substrate, and the light-shielding portion is formed in contact with a completely light-shielding portion in which at least a light-shielding film is formed on the transparent substrate and the outer edge of the completely light-shielding portion, and a semi-transparent rim is formed on the transparent substrate. It has a rim portion with a width γ formed by forming a film. The semi-transmissive portion is sandwiched between the light-shielding portions, and a transparent substrate is exposed to a predetermined width α, and the width α is set so that the exposure light transmittance of the semi-transparent portion is smaller than the exposure light transmittance of the light-transmitting portion. The rim forming film has a transmittance Tr of 5 to 60% for light of a representative wavelength of exposure light, and a phase shift amount for light of a representative wavelength of 90 degrees or less.

In addition, Patent Document 2 discloses an organic EL (electroluminescence) display device in which pixels are arranged in a matrix form in a display area, including an organic EL layer disposed at each pixel, surrounding the border of the organic EL layer, and adjacent pixels. It includes a separation layer disposed between, a resin layer that seals the organic EL layer by covering the entire surface of the display area, and a frame-type bank surrounding an edge of the resin layer, and the taper angle of the separation layer and the frame-type bank An organic EL display device characterized by different taper angles is described.

Japanese Patent Publication No. 2020-140207 International Publication No. 2018/061195

In display devices with thin displays such as smartphones, tablets, and televisions, many products using organic EL display devices are being developed. Generally, in an organic EL display device, an insulating layer called a pixel dividing layer (PDL: Pixel Defining Layer) is formed to divide the pixels of the light emitting element. As will be described later, the PDL has an opening for forming a light-emitting layer and an inclined portion located around the opening.

One embodiment of the present invention aims to provide a transfer mask capable of realizing a PDL with a small inclination angle of an inclined portion located around an opening.

The first aspect of the present invention is,

It is a transfer mask provided with a transfer pattern including a light-transmissive part, a first transparent part, and a second transparent part on a light-transmissive substrate,

The light transmitting portion has a hole shape in which the light transmitting substrate is exposed,

The first transmitting portion is provided in an annular shape along the outer periphery of the light transmitting portion,

The second transparent portion is provided in contact with the outer periphery of the first transparent portion,

The transmittance T1 of the first transmitting portion with respect to the exposure light is higher than the transmittance T2 of the second transmitting portion with respect to the exposure light,

The absolute value of the phase difference between the exposure light passing through the first transmission unit and the exposure light passing through the light transmission unit is 90 degrees or less,

The absolute value of the phase difference between the exposure light passing through the second transmission unit and the exposure light passing through the second transmission unit is 90 degrees or less,

The transfer mask is characterized in that the absolute value of the phase difference between the exposure light passing through the first transmission part and the exposure light passing through the second transmission part is 90 degrees or less.

The second aspect of the present invention is,

The transfer mask according to the first aspect is characterized in that the width D of the first transparent portion is 1.5 μm or more.

The third aspect of the present invention is,

The transfer mask according to the first aspect is characterized in that the difference ΔT between the transmittance T1 and the transmittance T2 is 10% or more.

The fourth aspect of the present invention is,

The width D of the first transmitting portion and the difference ΔT between the transmittance T1 and the transmittance T2 are,

The transfer mask according to the first aspect is characterized in that it satisfies the relationship of D≥-3.14×ΔT/100+2.32.

The fifth aspect of the present invention is,

The transfer mask according to the first aspect is characterized in that the transmittance T1 is 20% or more.

The sixth aspect of the present invention is:

The transfer mask according to the first aspect is characterized in that the transmittance T2 is 10% or more.

The seventh aspect of the present invention is:

The transfer mask according to the first aspect is characterized in that the exposure light contains light with a wavelength of 313 nm or more and 436 nm or less.

The eighth aspect of the present invention is,

The transfer mask according to the first aspect, further comprising a light-shielding portion provided adjacent to the second transmission portion.

The ninth aspect of the present invention is:

The first transmissive portion includes a first semi-transmissive film formed on the translucent substrate,

The transfer mask according to the first aspect is characterized in that the second transmissive portion is formed by laminating the first semi-transmissive film and the second semi-transmissive film on the light-transmitting substrate.

The tenth aspect of the present invention is:

The transfer mask according to the ninth aspect is characterized in that the first semi-transmissive film and the second semi-transmissive film contain materials having mutual etching selectivity.

The eleventh aspect of the present invention is:

It further has a light blocking portion provided adjacent to the second transmission portion,

The transfer mask according to the ninth aspect is characterized in that the light-shielding portion is formed by laminating a light-shielding film having light-shielding properties, the first semi-transmissive film, and the second semi-transmissive film on the light-transmitting substrate.

The twelfth aspect of the present invention is:

The transfer mask according to the eleventh aspect is characterized in that the second semi-transmissive film and the light-shielding film contain materials having mutual etching selectivity.

The thirteenth aspect of the present invention is:

A process of preparing a transfer mask according to any one of the first to twelfth aspects,

A step of forming a photosensitive resin film on a substrate that is sensitive to the exposure light;

A step of irradiating the exposure light transmitted through the transfer mask to the photosensitive resin film using an exposure device and exposing and transferring the transfer pattern to the photosensitive resin film;

A process of performing development treatment on the photosensitive resin film that has been exposed and transferred.

A method of manufacturing a display device characterized by having a.

The fourteenth aspect of the present invention is:

In the step of exposing and transferring, the transfer pattern is exposed and transferred so that an inclined portion having a cross-sectional inclination angle of 30 degrees or less is formed around the opening of the photosensitive resin film after the development treatment. This is a manufacturing method of a display device.

According to one embodiment of the present invention, it becomes possible to provide a transfer mask that can realize a PDL with a small inclination angle of the inclined portion located around the opening.

1 is a plan view schematically showing a transfer mask 1 according to a first embodiment of the present invention.
FIG. 2 is a schematic cross-sectional view taken along line AA of the transfer mask 1 in FIG. 1.
3(a) to 3(e) are schematic diagrams explaining the manufacturing method of the transfer mask 1 according to the first embodiment of the present invention.
Figure 4 is a cross-sectional schematic diagram of the transfer mask 1 according to Modification 1 of the present invention.
Figure 5 is a cross-sectional schematic diagram of the transfer mask 1 according to Modification 2 of the present invention.
Figure 6 is a graph showing the relationship between the width D and the inclination angle θ according to Example 1 of the present invention.
Figure 7 is a graph showing the relationship between the width D and the inclination angle θ according to Example 2 of the present invention.
Figure 8 is a graph that picks up predetermined conditions in Examples 1 and 2 of the present invention.
Fig. 9 is a cross-sectional schematic diagram of the PDL of an organic EL display device.

<Knowledge obtained by the present inventor>

First, the knowledge obtained by the present inventor will be explained. Fig. 9 is a cross-sectional schematic diagram of the PDL of an organic EL display device. The PDL includes, for example, photosensitive polyimide (photosensitive resin), and as shown in FIG. 9, an opening 200 for forming a light-emitting layer and an inclined portion 201 located around the opening 200. It is provided with a pillar portion 202 for supporting the mask when forming the light-emitting layer, and a flat portion 203 at an intermediate height between the opening portion 200 and the pillar portion 202.

After forming the light emitting layer in the opening 200 of the PDL, it is necessary to seal the light emitting layer with a sealing material such as polyimide in order to maintain light emitting efficiency. At this time, manufacturing yield can be improved by improving the spreading of the sealing material and the flatness of the sealing material. Therefore, it is preferable that the inclination angle θ of the inclined portion 201 of the PDL is small. Specifically, the inclination angle θ is preferably, for example, 30 degrees or less, and more preferably 20 degrees or less. Additionally, the lower limit of the inclination angle θ is not particularly limited, but is preferably 10 degrees or more from the viewpoint of making it easy to secure a sufficient thickness of the flat portion 203 (for example, 0.8 μm or more and 1.5 μm or less).

Next, one embodiment of the present invention will be described below with reference to the drawings. In addition, the present invention is not limited to these examples, but is disclosed by the claims, and is intended to include all changes within the meaning and scope equivalent to the claims.

<First embodiment of the present invention>

(1) Configuration of the transfer mask (1)

First, the structure of the transfer mask of the first embodiment will be described. FIG. 1 is a plan view schematically showing the transfer mask 1 of the first embodiment, and FIG. 2 is a schematic cross-sectional view taken along line A-A in FIG. 1. As shown in FIGS. 1 and 2, the transfer mask 1 of the first embodiment includes a light transmitting portion 10, a first transmitting portion 20, and a second transmitting portion 30 on a translucent substrate 100. ) and a transfer pattern including a light blocking portion 40. The transfer mask 1 of the first embodiment can be used, for example, to form a PDL of an organic EL display device. In particular, the transfer mask 1 of the first embodiment can simultaneously form the opening 200 and the pillar portion 202 of the PDL described in FIG. 9.

The light transmitting portion 10 is a hole-shaped area where the light transmitting substrate 100 is exposed. In Fig. 1, as an example, the case where the light transmitting portion 10 has a square (rectangular) hole shape is shown, but it may also have a polygonal hole shape other than a circle or a square, for example. The light transmitting portion 10 is an area corresponding to the opening 200 of the PDL when forming the PDL, and its size is not particularly limited and may be determined according to the design of the display device to be manufactured. In addition, in this specification, the transmittance for the exposure light (hereinafter simply referred to as 'exposure light') exposing the transfer mask 1 refers to the light transmitting portion 10 (i.e., the light transmitting substrate 100). It was set to (100%).

As shown in FIG. 1, the first transparent portion 20 is an area provided in an annular shape along the outer periphery of the light transparent portion 10. In this specification, “ring” includes not only circular shapes but also shapes surrounding polygonal holes such as squares. The first transmission portion 20 is configured to partially transmit exposure light. The first transparent portion 20 is an area necessary to reduce the inclination angle θ (FIG. 9) of the inclined portion 201 (FIG. 9) located around the opening 200 of the PDL when forming the PDL. In addition, it is preferable that the first transparent part 20 surrounds the entire outer periphery of the light transparent part 10, but within the range where the effect of the invention is obtained, the first transparent part 20 has a shape in which a part of the annular area is missing ( The missing portion may be part of the second transparent portion 30). Additionally, if the first transparent portion 20 surrounds 80% or more of the outer circumference of the light transparent portion 10, it is assumed to be provided in an annular shape even if a portion is missing. The first transparent portion 20 preferably surrounds 90% or more of the outer circumference of the light transparent portion 10, and more preferably surrounds 100% (total circumference).

As shown in FIG. 1, the second transparent part 30 is an area provided to be in contact with the outer periphery of the first transparent part 20. The second transparent portion 30 is an area corresponding to the flat portion 203 (FIG. 9) of the PDL when forming the PDL. In addition, as shown in FIG. 1, the second transmitting portion 30 is an area with the largest area among the light transmitting portion 10, the first transmitting portion 20, the second transmitting portion 30, and the light blocking portion 40. .

As shown in FIG. 1, the light blocking portion 40 is an area provided adjacent to the second transparent portion 30. The light blocking portion 40 is substantially prevented from transmitting the exposure light (e.g., the optical density OD for the exposure light is greater than 2.0. Preferably, the OD is 2.5 or more, and more preferably, the OD is 3.0 or more. ) and is an area corresponding to the pillar portion 202 (FIG. 9) of the PDL when forming the PDL.

In the transfer mask 1, the transmittance T1 of the first transparent portion 20 is higher than the transmittance T2 of the second transparent portion 30. As a result, when forming the PDL, the inclination angle θ of the inclined portion 201 located around the opening 200 can be reduced.

The transfer mask 1 suppresses the phenomenon of attenuation of the amount of exposure light due to the phase difference between the exposure light passing through each of the light transmitting portion 10, the first transmitting portion 20, and the second transmitting portion 30. desirable. Specifically, the absolute value of the phase difference between the exposure light that passed through the first transmission unit 20 and the exposure light that passed through the light transmission unit 10 is 90 degrees or less, and the exposure light that passed through the second transmission unit 30 is 90 degrees or less. The absolute value of the phase difference between the exposure light that passed through the light transmitting portion 10 and the exposure light that passed through the light transmitting portion 10 is 90 degrees or less, and the exposure light that passed through the first transmitting portion 20 and the exposure light passing through the second transmitting portion 30 It is desirable that the absolute value of the phase difference is 90 degrees or less. When the phase difference between the exposure light passing through each of the light transmitting portion 10, the first transmitting portion 20, and the second transmitting portion 30 of the transfer mask 1 exceeds the above range, the inclined portion 201 of the PDL ) There is a possibility that the inclination angle θ may become large. On the other hand, by keeping the phase difference between the exposure light passing through each of the light transmitting portion 10, the first transmitting portion 20, and the second transmitting portion 30 of the transfer mask 1 within the above range, the inclined portion 201 It becomes possible to reduce the inclination angle θ of . It is more preferable that the absolute value of the phase difference between the exposure light that has passed through the first transmission portion 20 and the exposure light that has passed through the light transmission portion 10 is 80 degrees or less, and even more preferably it is 60 degrees or less. It is more preferable that the absolute value of the phase difference between the exposure light that has passed through the second transmission portion 30 and the exposure light that has passed through the light transmission portion 10 is 80 degrees or less, and even more preferably 60 degrees or less. It is more preferable that the absolute value of the phase difference between the exposure light transmitted through the first transmission portion 20 and the exposure light transmitted through the second transmission portion 30 is 80 degrees or less, and further preferably is 60 degrees or less.

The width D of the first transparent part 20 (i.e., the distance between the boundary between the light transparent part 10 and the first transparent part 20 and the border between the first transparent part 20 and the second transparent part 30) is, e.g. For example, it is preferably 1.5㎛ or more. If the width D is less than 1.5 μm, there is a possibility that the inclination angle θ of the inclined portion 201 cannot be sufficiently reduced. In contrast, by setting the width D to 1.5 μm or more, the inclination angle θ of the inclined portion 201 can be sufficiently reduced. It is more preferable that the width D is larger than 1.5 μm, and it is still more preferable that it is 1.7 μm or more. Meanwhile, the width D is preferably 10 μm or less. If the width D exceeds 10 μm, there is a possibility that the first transmission portion 20 and the light blocking portion 40 are in contact with each other or are too close to each other. On the other hand, by setting the width D to 10 μm or less, a sufficient distance between the first transmitting portion 20 and the light blocking portion 40 can be secured. As for width D, it is more preferable that it is 7 micrometers or less, and it is still more preferable that it is 5 micrometers or less. If the width D exceeds 5 μm, the effect of reducing the inclination angle θ of the inclined portion 201 may be saturated.

The width D of the first transparent portion 20 is preferably a substantially constant value (for example, within the range of ±5% of the average value). For example, if the width D has different values depending on the direction from the center of the light transmitting portion 10, there is a possibility that the inclination angle θ of the inclined portion 201 may vary depending on the direction when forming the PDL. There is. On the other hand, by setting the width D to an approximately constant value, when forming the PDL, the inclination angle θ of the inclined portion 201 can be set to an approximately constant value. As a result, the yield when manufacturing a display device can be further improved.

The difference ΔT (=T1-T2) between the transmittance T1 [%] of the first transmitting portion 20 and the transmittance T2 [%] of the second transmitting portion 30 is preferably, for example, 10% or more. If the transmittance difference ΔT is less than 10%, there is a possibility that the inclination angle θ of the inclined portion 201 cannot be sufficiently reduced. In contrast, by setting the transmittance difference ΔT to 10% or more, the inclination angle θ of the inclined portion 201 can be sufficiently reduced. On the other hand, the transmittance difference ΔT is preferably 30% or less, and more preferably 25% or less. If the transmittance difference ΔT exceeds 25%, the effect of reducing the inclination angle θ of the inclined portion 201 may become difficult to obtain. In contrast, by setting the transmittance difference ΔT to 25% or less, the inclination angle θ of the inclined portion 201 can be sufficiently reduced.

The width D [μm] of the first transparent portion 20 and the difference ΔT [%] between the transmittance T1 [%] and the transmittance T2 [%] satisfy the relationship of D ≥ -3.14 × ΔT / 100 + 2.32, for example. It is desirable to do so. As a result, the inclination angle θ of the inclined portion 201 can be made smaller (for example, 30 degrees or less). The above relational expression will be explained in detail in the examples described later.

The transmittance T1 of the first transmitting portion 20 is preferably 20% or more, more preferably 30% or more, and even more preferably greater than 30%. On the other hand, the transmittance T1 is preferably 60% or less, and more preferably 50% or less.

The transmittance T2 of the second transmitting portion 30 is preferably 10% or more, more preferably 15% or more, and even more preferably 20% or more. On the other hand, the transmittance T2 is preferably 40% or less, and more preferably 30% or less.

Exposure light is light irradiated by a light source provided in an exposure apparatus for manufacturing a display device. The exposure light of the first embodiment includes, for example, light with a wavelength of 313 nm or more and 436 nm or less. As exposure light, a single wavelength light (for example, i-line with a wavelength of 365 nm) may be used, or a broad wavelength light containing multiple wavelengths may be used. In addition, in this specification, the transmittance and phase difference are for the wavelength when the exposure light contains a single wavelength, and when broad wavelength light is used, the transmittance and phase difference are included in the wavelength range of 313 nm to 436 nm. It should be for a certain wavelength (representative wavelength).

As shown in FIG. 2, the first transparent portion 20 includes, for example, a first semi-transmissive film 101 formed on a light-transmissive substrate 100, and the second transparent portion 30 includes, for example, a light-transmissive substrate 100. It is preferable that the first semi-transmissive film 101 and the second semi-transmissive film 102 are stacked on the substrate 100. In particular, the second transparent portion 30 is formed by forming a second semi-transmissive film 102 on a light-transmissive substrate 100 and a first semi-transmissive film 101 on the second semi-transmissive film 102. desirable. With this configuration, the transmittance T1 of the first transparent portion 20 becomes equal to the transmittance HT1 of the first semi-transmissive film 101. Meanwhile, the transmittance T2 of the second transmissive portion 30 is the transmittance in the laminate structure of the first semi-transmissive film 101 and the second semi-transmissive film 102. The transmittance HT2 of the second semi-transmissive film 102 needs to be optically designed based on the transmittance T2 of the second transmissive portion 30 and the transmittance HT1 of the first semi-transmissive film 101.

The film thickness d1 of the first semi-transmissive membrane 101 is preferably 5 nm or more, and more preferably 10 nm or more. Additionally, the film thickness d1 is preferably 80 nm or less, and more preferably 60 nm or less.

The film thickness d2 of the second semi-transmissive membrane 102 is preferably 3 nm or more, and more preferably 5 nm or more. Additionally, the film thickness d2 is preferably 50 nm or less, and more preferably 40 nm or less.

The first semi-permeable membrane 101 and the second semi-permeable membrane 102 contain chromium (Cr) or at least one of chromium (Cr), oxygen (O), nitrogen (N), and carbon (C). It may be formed from a material (chromium-based material). Examples of this chromium-based material include Cr, CrO, CrN, CrF, CrCO, CrCN, CrON, CrCON, and CrCONF. Meanwhile, the first semi-transmissive film 101 and the second semi-transmissive film 102 are made of a material containing metal and silicon, or metal and silicon and at least oxygen (O), nitrogen (N), and carbon (C). It may be formed from a material containing either one (metal silicide-based material). Suitable metals for metal silicide include transition metals such as molybdenum (Mo), tantalum (Ta), tungsten (W), titanium (Ti), and zirconium (Zr). The ratio of the metal content M [atomic %] to the total content of metal and silicon (M+Si) [atomic %] in a metal silicide-based material (hereinafter referred to as the “M/[M+Si] ratio”) It is preferable that it is 0.5 or less, more preferably 1/3 or less, and even more preferably 0.3 or less. On the other hand, it is preferable that the M/[M+Si] ratio is 0.05 or more, and it is more preferable that it is 0.1 or more.

The first semi-transmissive film 101 and the second semi-transmissive film 102 preferably contain materials that have etching selectivity to each other. With this configuration, the transfer mask 1 as shown in FIG. 2 can be easily manufactured. For example, a thin film of a chromium-based material and a thin film of a metal silicide-based material have etching selectivity to each other. The above effect can be achieved by forming one of the first semi-transmissive film 101 and the second semi-transmissive film 102 with a chromium-based material and the other with a metal silicide-based material.

As shown in FIG. 2, the light-blocking portion 40 includes, for example, a light-blocking film 103, a first semi-transmissive film 101, and a second semi-transmissive film 102 on a light-transmitting substrate 100. It is preferable that these are stacked. In particular, the light blocking portion 40 includes a light blocking film 103 formed on a light transmissive substrate 100, a second semi-transmissive film 102 formed on the light blocking film 103, and a first semi-transmissive film 102 on the second semi-transmissive film 102. It is preferable that a semi-transmissive film 101 is formed. With this configuration, the transfer mask 1 as shown in FIG. 2 can be easily manufactured. The light blocking portion 40 may be formed of a chromium-based material or a metal silicide-based material.

The second semi-transmissive film 102 and the light-shielding film 103 preferably contain materials that have etching selectivity to each other. With this configuration, the transfer mask 1 as shown in FIG. 2 can be easily manufactured. For example, the above effect can be achieved by forming one of the second semi-transmissive film 102 and the light-shielding film 103 with a chromium-based material and the other with a metal silicide-based material.

The translucent substrate 100 is transparent to exposure light. The translucent substrate 100 has a transmittance of 85% or more, preferably 90% or more, to exposure light, assuming no surface reflection loss. The light-transmitting substrate 100 includes a material containing silicon and oxygen, and is made of glass materials such as synthetic quartz glass, quartz glass, aluminosilicate glass, soda lime glass, and low thermal expansion glass (SiO ₂ -TiO ₂ glass, etc.). It can be configured. The translucent substrate 100 of the transfer mask used for display devices is generally a rectangular substrate, and the short side of the translucent substrate is used to have a length of 300 mm or more.

(2) Method of manufacturing the transfer mask (1)

Next, the manufacturing method of the transfer mask 1 of the first embodiment will be described with reference to FIGS. 3(a) to 3(e). The transfer mask 1 of the first embodiment can be manufactured, for example, by the method described below.

First, a light-shielding film 103 is formed on the light-transmitting substrate 100. As the film formation method, known means (for example, film formation by sputtering method) can be applied.

After forming the light-shielding film 103 on the light-transmitting substrate 100, the light-shielding film 103 is patterned to match the shape of the light-shielding portion 40 (FIG. 2), as shown in FIG. 3(a). Patterning is performed by known means (for example, forming a resist film having a pattern of the light-shielding portion 40 on the light-shielding film 103 and performing wet etching or dry etching using the resist film as a mask to form a light-shielding portion on the light-shielding film 103. (forming the pattern of (40)) can be applied.

After patterning the light-shielding film 103, a second semi-transmissive film 102 is formed on the light-transmitting substrate 100 and the light-shielding film 103, as shown in FIG. 3(b). As the film formation method, known means (for example, film formation by sputtering method) can be applied.

After forming the second semi-transmissive film 102, as shown in (c) of FIG. 3, the second semi-transmissive film is formed according to the shape of the first transmissive part 20 and the light-transmitting part 10 (FIG. 2). The membrane 102 is patterned. Patterning is performed by known means (for example, wet etching where a resist film having a pattern of the first transparent portion 20 and the transparent portion 10 is formed on the second semi-transmissive film 102 and the resist film is used as a mask). Dry etching may be performed to form a pattern of the first transmissive portion 20 and the transmissive portion 10 to the second semi-transmissive layer 102.

After patterning the second semi-transmissive film 102, a first semi-transmissive film 101 is formed on the transmissive substrate 100 and the second semi-transmissive film 102, as shown in (d) of FIG. 3. do. As the film formation method, known means (for example, film formation by sputtering method) can be applied.

After forming the first semi-transmissive film 101, the first semi-transmissive film 101 is patterned according to the shape of the light transmitting portion 10, as shown in FIG. 3(e). Patterning is performed by known means (for example, by forming a resist film having a pattern of the light transmitting portion 10 on the first semi-transmissive film 101 and performing wet etching or dry etching using the resist film as a mask, A pattern of the light transmitting portion 10 is formed on the semi-transmissive film 101) can be applied.

By the above method, the transfer mask 1 of the first embodiment can be manufactured. Additionally, as long as the effect of the transfer mask 1 is not impaired, additional films other than those described above may be formed.

(3) Manufacturing method of display device

The present invention is also applicable as a manufacturing method for display devices such as organic EL. The display device manufacturing method of the first embodiment includes, for example, a step of preparing the transfer mask 1 of the first embodiment, and a photosensitive resin film (e.g., a photosensitive resin film (e.g., a process of forming a thin film made of photosensitive polyimide, a process of irradiating the photosensitive resin film with exposure light transmitted through the transfer mask 1 using an exposure device, and exposing and transferring the transfer pattern; This is a method of manufacturing a display device that includes a step of developing a photosensitive resin film to which a pattern has been exposed and transferred.

In the display device manufacturing method of the first embodiment, in the step of exposing and transferring the transfer pattern, the inclination angle θ of the cross section around the opening 200 (FIG. 9) of the photosensitive resin film after development is 30 degrees or less ( It is preferable to expose and transfer the transfer pattern so that the inclined portion 201 (FIG. 9) (more preferably 20 degrees or less) is formed. As described above, since the transfer mask 1 has a configuration for reducing the inclination angle θ of the inclined portion 201, the inclination angle θ can be reduced to 30 degrees or less (or 20 degrees) by appropriately selecting the exposure device and exposure conditions. It is possible to do this (degrees below). As a result, the yield when manufacturing a display device can be further improved.

(4) Modification of the first embodiment

The above-described first embodiment can be changed as needed, such as the modified example shown below. Hereinafter, only elements different from the above-described first embodiment will be described, and elements substantially the same as those described in the above-described first embodiment will be assigned the same reference numerals and their descriptions will be omitted.

(4-1) Modification 1 of the first embodiment

Fig. 4 is a cross-sectional schematic diagram of the transfer mask 1 of this modification example 1. The transfer mask 1 of this modification 1, like the first embodiment described above, is provided with a transfer pattern on a translucent substrate 100 and includes a light transmitting portion 10, a first transmitting portion 20, and , it has a second transmission part 30 and a light blocking part 40. Therefore, in the transfer mask 1 of the present modification example 1, when forming a PDL, the inclination angle θ of the inclined portion 201 located around the opening 200 illustrated in FIG. 9 can be reduced.

As shown in FIG. 4, the light-shielding portion 40 of the present modification example 1 includes, for example, a light-shielding film 103 having light-shielding properties, an etching stopper film 104, and a first semi-transmissive film on a light-transmitting substrate 100. It has a structure in which the (101) and the second semi-transmissive membrane (102) are stacked. Specifically, the light blocking portion 40 includes a second semi-transmissive film 102 formed on a light-transmissive substrate 100, an etching stopper film 104 formed on the second semi-transmissive film 102, and an etching stopper film. A light-shielding film 103 is formed on (104), and a first semi-transmissive film 101 is formed on the light-shielding film 103. The etching stopper film 104 is made of a material that has sufficient etching selectivity between the second semi-transmissive film 102 and the light-shielding film 103. With this configuration, it is possible to prepare a structure (mask blank) in which the second semi-transmissive film 102, the etching stopper film 104, and the light-shielding film 103 are previously deposited on the translucent substrate 100. As a result, the number of times the thin film is formed on the translucent substrate 100 and the patterning of the thin film is exchanged can be reduced, and the occurrence of defects resulting from this exchange can be reduced.

The transfer mask 1 of this modification example 1 can be manufactured, for example, by the following method. First, the second semi-transmissive film 102, the etching stopper film 104, and the light-shielding film 103 are formed on the translucent substrate 100 in that order. After film formation, the light-shielding film 103 and the etching stopper film 104 are patterned according to the shape of the light-shielding portion 40 (for example, a resist film having the pattern of the light-shielding portion 40 is formed on the light-shielding film 103 , using the resist film as a mask, wet etching or dry etching using another etchant is performed to form a pattern of the light-shielding portion 40 on the light-shielding film 103 and the etching stopper film 104). In addition, the second semi-transmissive film 102 is patterned according to the shape of the first transparent part 20 and the light transparent part 10 (for example, the pattern of the first transparent part 20 and the light transparent part 10 A resist film having a resist film is formed on the light shielding film 103 and the second semitransmissive film 102, and wet etching or dry etching is performed using the resist film as a mask to form the first transparent portion 20 and the second semitransmissive film 102. forming a pattern of the light transmitting portion 10). After that, a first semi-transmissive film 101 is formed on the translucent substrate 100, the second semi-transmissive film 102, and the light-shielding film 103, and the first semi-transmissive film 101 is formed in accordance with the shape of the transparent portion 10. 101 is patterned (for example, a resist film having a pattern of the light transmitting portion 10 is formed on the first semi-transmissive film 101, wet etching or dry etching is performed using the resist film as a mask, and the first semitransmissive film 101 is patterned. Forming a pattern of the light transmitting portion 10 on the semi-transmissive membrane 101).

(4-2) Modification 2 of the first embodiment

Fig. 5 is a cross-sectional schematic diagram of the transfer mask 1 of this modification example 2. The transfer mask 1 of the second modification also has a transfer pattern on a translucent substrate 100, similar to the first embodiment described above, and includes a light transmitting portion 10, a first transmitting portion 20, and , it has a second transmission part 30 and a light blocking part 40. Therefore, in the transfer mask 1 of the present modification example 2, when forming a PDL, the inclination angle θ of the inclined portion 201 located around the opening 200 illustrated in FIG. 9 can be reduced.

As shown in FIG. 5, the second transparent portion 30 of the present modification example 2 has a configuration in which, for example, a first semi-transmissive film 101 and an etching stopper film 104 are stacked on a transparent substrate 100. I have it. That is, the etching stopper film 104 serves as the second semi-transmissive film 102 of the first embodiment. Accordingly, the etching stopper film 104 is made of a material that has etching selectivity with respect to the first semi-transmissive film 101 and the light-shielding film 103. In the second modification, the etching stopper film 104 may be referred to as the second semi-transmissive film 102 of the first embodiment. Specifically, the second transparent portion 30 has a configuration in which a first semi-transmissive film 101 is formed on a light-transmissive substrate 100, and an etching stopper film 104 is formed on the first semi-transmissive film 101. . In addition, as shown in FIG. 5, the light-shielding portion 40 of the present modification example 2 includes, for example, a light-shielding film 103 having light-shielding properties, an etching stopper film 104, and a first half on a light-transmitting substrate 100. It has a structure in which transmission membranes 101 are stacked. Specifically, the light blocking portion 40 includes a first semi-transmissive film 101 formed on a light-transmissive substrate 100, an etching stopper film 104 formed on the first semi-transmissive film 101, and an etching stopper film. It has a configuration in which a light-shielding film 103 is formed on (104). Due to these structures, the first semi-transmissive film 101, the etching stopper film 104 (corresponding to the second semi-transmissive film 102), and the light-shielding film 103 are formed in advance on the transparent substrate 100 (a structure ( A mask blank) can be prepared in advance. As a result, the formation of a thin film on the translucent substrate 100 and the exchange of patterning for the thin film can be basically eliminated, and the occurrence of defects resulting from this exchange can be reduced.

The transfer mask 1 of this modification example 2 can be manufactured, for example, by the following method. First, a mask blank is prepared by depositing a first semi-transmissive film 101, an etching stopper film 104, and a light-shielding film 103 in that order on the transmissive substrate 100. After film formation, first, the light-shielding film 103 is patterned according to the shape of the light-shielding portion 40 (for example, a resist film having the pattern of the light-shielding portion 40 is provided on the light-shielding film 103, and the resist film is used as a mask. Then, wet etching or dry etching is performed to form a pattern of the light-shielding portion 40 on the light-shielding film 103). Next, the etching stopper film 104 is patterned according to the shape of the first transmission portion 20 and the light transmission portion 10 (for example, having the patterns of the first transmission portion 20 and the light transmission portion 10). A resist film is provided on the light shielding film 103 and the etching stopper film 104, and wet etching or dry etching is performed using the resist film as a mask to form the first transmitting portion 20 and the light transmitting portion 10 on the etching stopper film 104. forms a pattern). In addition, the first semi-transmissive film 101 is patterned according to the shape of the light-transmitting part 10 (for example, the resist film having the pattern of the light-transmitting part 10 is formed into a light-shielding film 103 and an etching stopper film 104). and providing it on the first semi-transmissive film 101 and performing wet etching or dry etching using the resist film as a mask to form a pattern of the light-transmitting portion 10 on the first semi-transmissive film 101.

Example

Next, an embodiment according to the present invention will be described. These examples are examples of the present invention, and the present invention is not limited by these examples.

(1) Example 1

Under the following conditions, the inclination angle θ of the inclined portion 201 when a PDL is formed by exposure transfer to a photosensitive polyimide film (photosensitive resin film) on a substrate is simulated using the transfer mask 1. It was calculated by . The results are shown in Figure 6.

Transmittance T1 of the first transmitting portion 20: 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%

Transmittance T2 of the second transmitting portion 30: 30%

Difference ΔT between transmittance T1 and transmittance T2: 0%, 5%, 10%, 15%, 20%, 25%, 30%, 35%

Width D of the first transmission part 20: 0 to 5.0㎛

Numerical aperture (NA) of exposure device: 0.11

Exposure light: i line

As shown in FIG. 6, compared to the inclination angle θ in the state in which the first transparent part 20 is not substantially provided (difference ΔT is 0%), the state in which the first transparent part 20 is provided (difference ΔT is 5%) , 10%, 15%, 20%), it was confirmed that the inclination angle θ became smaller. In particular, it was confirmed that when the difference ΔT is 10% or more and the width D is 1.5 μm or more, the inclination angle θ can be reduced by more than 5 degrees compared to the state in which the first transmission portion 20 is not substantially provided.

(2) Example 2

Additionally, under the following conditions, the inclination angle θ of the inclined portion 201 when forming the PDL using the transfer mask 1 was calculated through simulation. The results are shown in Figure 7.

Transmittance T1 of the first transmitting portion 20: 30%, 35%, 40%, 45%, 50%

Transmittance T2 of the second transmitting portion 30: 30%

Difference ΔT between transmittance T1 and transmittance T2: 0%, 5%, 10%, 15%, 20%

Width D of the first transmission part 20: 0 to 5.0㎛

Numerical aperture (NA) of exposure device: 0.1

Exposure light: Complex light including g-line, h-line, and i-line

As shown in FIG. 7, compared to the inclination angle θ in the state in which the first transparent part 20 is not substantially provided (difference ΔT is 0%), the state in which the first transparent part 20 is provided (difference ΔT is 5%) , 10%, 15%, 20%), it was confirmed that the inclination angle θ became smaller. In particular, it was confirmed that when the difference ΔT is 10% or more and the width D is 1.5 μm or more, the inclination angle θ can be reduced by more than 5 degrees compared to the state in which the first transmission portion 20 is not substantially provided.

(3) Conclusion

From the results of Example 1 and Example 2, in particular, the conditions under which the inclination angle θ could be set to 30 degrees or less, the conditions under which the inclination angle θ could be set to 25 degrees or less, and the conditions under which the inclination angle θ could be set to 20 degrees or less were picked up. So, it is shown in Figure 8. The broken line shown in FIG. 8 is a straight line approximation of the three points of the conditions in which the width D is the smallest among the picked conditions where the difference ΔT is 10%, 15%, and 20%, respectively.

As shown in Figure 8, when the difference ΔT is 10%, 15%, and 20%, the three points with the smallest width D are approximated with a straight line, and the equation is D = -3.14 × ΔT/100 It was +2.32. Therefore, by making the width D of the first transparent portion 20 and the difference ΔT between the transmittance T1 and the transmittance T2 satisfy the relationship of D ≥ -3.14×ΔT/100+2.32, the inclination angle θ of the inclined portion 201 is It was confirmed that it can be made smaller (for example, 30 degrees or less).

<Other embodiments of the present invention>

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various changes can be made without departing from the gist.

For example, in the above-described first embodiment, the transfer mask 1 having the light-shielding portion 40 provided adjacent to the second transparent portion 30 has been described, but the transfer mask 1 must have the light-shielding portion. There is no need to have (40). In this case, for example, a transfer mask for forming the pillar portion 202 (FIG. 9) is separately prepared, and a plurality of transfer masks are used to form the opening 200 and the pillar portion 202 of the PDL. It's okay too.

1: Transfer mask
10: Light transmitting part
20: first transmission part
30: second transmission part
40: light blocking part
100: Translucent substrate
101: first semi-permeable membrane
102: second semi-permeable membrane
103: Sunshade
104: Etching stopper film
200: opening
201: slope part
202: pillar part
203: Flat part

Claims (14)

It is a transfer mask provided with a transfer pattern including a light-transmissive part, a first transparent part, and a second transparent part on a light-transmissive substrate,
The light transmitting portion has a hole shape in which the light transmitting substrate is exposed,
The first transmitting portion is provided in an annular shape along the outer periphery of the light transmitting portion,
The second transparent portion is provided in contact with the outer periphery of the first transparent portion,
The transmittance T1 of the first transmitting portion with respect to the exposure light is higher than the transmittance T2 of the second transmitting portion with respect to the exposure light,
The absolute value of the phase difference between the exposure light passing through the first transmission unit and the exposure light passing through the light transmission unit is 90 degrees or less,
The absolute value of the phase difference between the exposure light passing through the second transmission unit and the exposure light passing through the second transmission unit is 90 degrees or less,
A transfer mask, wherein the absolute value of the phase difference between the exposure light passing through the first transmission unit and the exposure light passing through the second transmission unit is 90 degrees or less. According to paragraph 1,
A transfer mask, characterized in that the width D of the first transparent portion is 1.5 μm or more. According to paragraph 1,
A transfer mask, wherein the difference ΔT between the transmittance T1 and the transmittance T2 is 10% or more. According to paragraph 1,
The width D of the first transmitting portion and the difference ΔT between the transmittance T1 and the transmittance T2 are,
A transfer mask characterized by satisfying the relationship of D≥-3.14×ΔT/100+2.32. According to paragraph 1,
A transfer mask, characterized in that the transmittance T1 is 20% or more. According to paragraph 1,
A transfer mask, characterized in that the transmittance T2 is 10% or more. According to paragraph 1,
A transfer mask, characterized in that the exposure light includes light with a wavelength of 313 nm or more and 436 nm or less. According to paragraph 1,
A transfer mask further comprising a light-shielding portion provided adjacent to the second transmission portion. According to paragraph 1,
The first transmissive portion includes a first semi-transmissive film formed on the translucent substrate,
A transfer mask, wherein the second transmissive portion is formed by stacking the first semi-transmissive film and the second semi-transmissive film on the light-transmitting substrate. According to clause 9,
A transfer mask, wherein the first semi-transmissive film and the second semi-transmissive film include materials having etching selectivity to each other. According to clause 9,
It further has a light blocking portion provided adjacent to the second transmitting portion,
A transfer mask, characterized in that the light-shielding portion is formed by stacking a light-shielding film having light-shielding properties, the first semi-transmissive film, and the second semi-transmissive film on the light-transmitting substrate. According to clause 11,
A transfer mask, wherein the second semi-transmissive film and the light-shielding film include materials having etching selectivity to each other. A process of preparing the transfer mask according to any one of claims 1 to 12,
A step of forming a photosensitive resin film on a substrate that is sensitive to the exposure light;
A step of irradiating the exposure light transmitted through the transfer mask to the photosensitive resin film using an exposure device and exposing and transferring the transfer pattern to the photosensitive resin film;
A process of performing development treatment on the photosensitive resin film that has been exposed and transferred.
A method of manufacturing a display device comprising: According to clause 13,
In the exposure transfer step, the transfer pattern is exposed and transferred so that an inclined portion having a cross-sectional inclination angle of 30 degrees or less is formed around the opening of the photosensitive resin film after the development treatment.

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