KR102413012B1 - Method of manufacturing a photomask, a photomask and method of manufacturing a display device - Google Patents

Abstract

An object of the present invention is to provide a method for manufacturing a photomask having both finer and higher CD precision and transmittance precision.
A method of manufacturing a photomask having a transfer pattern including a light transmitting unit, a first transmission control unit, and a second transmission control unit on a transparent substrate. A process of preparing a photomask blank in which a first thin film having a predetermined exposure light transmittance is formed on a transparent substrate, a first patterning process of forming a first thin film pattern by etching the first thin film, a transparent substrate on which the first thin film pattern is formed and a second patterning process of forming a second thin film thereon and etching the second thin film to form a second thin film pattern. In the second patterning process, only the second thin film is etched.

Description

A method of manufacturing a photomask, a method of manufacturing a photomask and a display device

The present invention relates to a multi-gradation photomask useful for manufacturing a display device typified by a liquid crystal panel or an organic EL panel, a method for manufacturing the same, and a method for manufacturing a display device using the multi-gradation photomask.

In recent years, further refinement|miniaturization is calculated|required of the display apparatus represented by a liquid crystal panel and an organic electroluminescent panel, Also in the photomask pattern for manufacturing these, the refinement|miniaturization tendency is becoming remarkable. In particular, the reason why the miniaturization of the display device is desired is related to the fact that there is an advantage from the viewpoint of energy saving as well as the advancement of image quality such as an increase in the pixel density, an improvement in the brightness of the display, and an improvement in the response speed. Moreover, along with such a trend of miniaturization, the quality request|requirement with respect to a photomask is also increasing.

BACKGROUND ART Conventionally, a multi-gradation photomask (gray tone mask) having a transfer pattern formed by patterning a light-shielding film and a semi-transmissive film formed on a transparent substrate is known. This multi-gradation photomask is usefully used in the manufacture of a display device etc.

For example, Patent Document 1 below describes a halftone film type gray tone mask and a method for manufacturing the same.

Japanese Patent Laid-Open No. 2005-257712

This multi-gradation photomask has three or more portions with different light transmittances, such as a light-shielding portion, a light-transmitting portion, and a semi-transmissive portion, in a transfer pattern, thereby forming a resist pattern having a plurality of residual film thicknesses on a transfer object. will do This resist pattern is sometimes used as an etching mask for processing a thin film formed on a transfer object. In this case, following the first etching, a second etching is performed by reducing the resist pattern, so that the resist pattern functions as an etching mask having a different shape in the first etching and the second etching. From this point of view, the multi-gradation photomask can be said to be a photomask having a function corresponding to a plurality of photomasks. For this reason, the number of photomasks mainly required for manufacturing a display device can be reduced, and it contributes to production efficiency improvement.

The multi-gradation photomask includes, in addition to the light-shielding portion and the light-transmitting portion, a semi-transmissive portion using a semi-transmissive film that partially transmits the exposure light. By appropriately controlling the light transmittance, the phase characteristic with respect to the transmitted light, etc. in this semitransmissive part, the partial thickness of the resist pattern formed on the to-be-transferred object, its cross-sectional shape, etc. can be changed.

In addition, the multi-gradation photomask of Patent Document 1 has a transfer pattern in which a plurality of patterned films (light-shielding film, semi-transmissive film, etc.) are laminated. In such a multi-gradation photomask, a desired transmittance or phase characteristic for light used during exposure is set, a film material or a film thickness suitable for this is selected, and the film formation conditions are adjusted. There are advantages to being able to design a mask.

Here, the method described in patent document 1 which is a prior art is demonstrated.

In the method described in Patent Document 1, the gray tone mask 200 shown in Fig. 3(i) is manufactured by the process described in Fig. 3 . Specifically, first, a photomask blank 100 is prepared in which a light-shielding film 102 is formed on a transparent substrate 101, and a positive resist is applied thereon to form a resist film 103 [Fig. a) see].

And it draws on this using a laser drawing machine etc. (1st drawing), and it develops. Thereby, the resist film is removed in the region (region A in Fig. 3) where the semi-transmissive portion is formed. As a result, a resist pattern 103a in which the resist film remains is formed in the region forming the light-shielding portion (region B in Fig. 3) and in the region forming the light-transmitting portion (region C in Fig. 3) (see Fig. 3(b)). .

Next, using the formed resist pattern 103a as a mask, the light-shielding film 102 is etched (first etched) to form a light-shielding film pattern 102a in regions corresponding to the light-shielding portion (region B) and the light-transmitting portion (region C). formed (see Fig. 3(c)). Then, the resist pattern 103a is removed (refer to Fig. 3(d)).

By the first photolithography process described above, a region (region A) corresponding to the semi-transmissive portion is defined.

Next, the semi-transmissive film 104 is formed on the entire surface of the substrate with the light-shielding film pattern obtained as described above (see Fig. 3(e)). Thereby, the semi-transmissive portion of the region A is formed.

Further, a positive resist is applied to the entire surface of the semi-transmissive film 104 to form a resist film 105 (see Fig. 3(f)), and writing is performed (second writing). After development, the resist film 105 is removed from the light-transmitting portion (region C), and a resist pattern 105a in which the resist film remains in the light-shielding portion (region B) and the semi-transmissive portion (region A) is formed [Fig. see g)].

Using this as a mask, the semi-transmissive film 104 and the light-shielding film pattern 102a in the region C serving as the light-transmitting portion are etched (second etching) to remove them (see Fig. 3(h)). Here, by making the etching characteristics of the semi-transmissive film and the light-shielding film the same or similar, continuous etching is possible. Then, after the second etching, the resist pattern 105a is removed to complete the gray tone mask 200 (see FIG. 3(i) ).

By the method described above, the light-shielding film and the semi-transmissive film are respectively patterned by two lithography steps (drawing, development, and etching), and a gray-tone mask having a light-shielding portion, a light-transmitting portion, and a semi-transmissive portion is manufactured.

However, in display devices equipped with liquid crystal or organic EL, improvements in technology are increasingly demanded in many aspects, such as image brightness, sharpness, reaction speed, reduction of power consumption, and cost reduction. Under such circumstances, photomasks for manufacturing these display devices require not only to form fine patterns more precisely and densely than before, but also to transfer the patterns to an object (panel substrate, etc.) at low cost. is becoming In addition, the design of the required transfer pattern is also diversified and complicated.

Under these circumstances, the following new subjects were discovered by examination of the present inventors.

According to the process of said patent document 1, in 2nd etching, the two films|membrane of a semi-transmissive film and a light-shielding film are etched and removed in 1 process successively (refer FIG.3(h)). Here, for example, it is assumed that the light-shielding film is a film mainly composed of chromium, and the semi-transmissive film contains a chromium compound. Further, the former required time for etching the light-shielding film is X (for example, 50 seconds), and the latter required time for etching the semi-transmissive film is Y (for example, 10 seconds). In this case, in the second etching, an etching time of X+Y (for example, 60 seconds) is required, and it takes a long time compared to the case of etching a single film of the light-shielding film or the semi-transmissive film.

In addition, wet etching is applied as an etching method here. This is because wet etching can be very advantageously applied to a photomask for manufacturing a display device. This is a relatively large area (for example, 300 mm or more on one side), and in a photomask for manufacturing a display device in which substrates of various sizes exist, wet etching is more expensive than dry etching requiring a vacuum device. This is because it is also very advantageous in terms of efficiency.

In addition, wet etching has a strong isotropic etching property, and etching (W side etching) proceeds not only in the depth direction of the film to be etched but also in a direction parallel to the surface of the film to be etched. In general, when a long etching time is required, the in-plane variation of the etching amount tends to expand. As the wet etching time increases, the side etching amount increases, and the in-plane variation in the amount also increases. . For this reason, in the second etching, when the two films, the semi-transmissive film and the light-shielding film, are sequentially etched and removed in one process, the line width or dimension (CD: Critical Dimension, hereinafter, the line width of the pattern) of the transfer pattern to be formed. or used in the meaning of dimension) is prone to deterioration in precision. That is, the second etching that requires X+Y (seconds) has a problem in this respect. Moreover, with the length of etching time, the usage-amount of an etching agent also increases, and the burden of waste liquid treatment containing a heavy metal also increases.

In addition, when the design of the transfer pattern is complicated or there is a pattern with a fine dimension (CD), the following problems are more likely to occur, and the present inventors paid attention to it.

In Fig. 3(i) showing the method of Patent Document 1, a pattern including a portion adjacent to a semi-transmissive portion and a light-shielding portion is formed. In addition to these patterns, there are more recent transfer patterns for photomasks for display device manufacturing. complex is involved. For example, there exists a request|requirement of the transfer pattern etc. which have the part which a light transmitting part and a semi-transmissive part adjoin in addition to the said adjacent part.

Therefore, consider a case where, for example, in the transfer pattern shown in Fig. 3, there is a portion adjacent to the transmissive portion and the semi-transmissive portion (refer to Fig. 4(i)). In addition, the process (second photolithography process) of (f) - (i) of FIG. 4 corresponds to (f) - (i) of FIG. 3, respectively.

Here, in the step of Fig. 4(h) showing the second etching, the semi-transmissive film 104 and the light-shielding film pattern 102a are continuously etched away as in the step of Fig. 3(h) described above ( N) exists. For this reason, the etching time becomes long due to the large etching depth, and the side etching amount also becomes large according to an etching depth. As a result, a difference is likely to occur in the dimension CD of the pattern to be formed, and the distribution of the CD error within the plane tends to be large (refer to Fig. 4(h')).

In addition, in the step of FIG. 4(h), the portion N in which the semi-transmissive film 104 and the light-shielding film pattern 102a are continuously removed by etching, and the portion K where only the semi-transmissive film 104 is etched away. ) occurs. At this time, it becomes difficult to set the necessary time for the second etching. This is because, when an etching time of T (sec) is required for the latter part of (K), an etching time corresponding to T+α (sec) is required with the former part of N.

For this reason, in the step of FIG. 4(h), when the etching of the N portion is actually finished, the etching proceeds excessively in the K portion, and the translucent film 104 under the resist pattern 105a is The side etching proceeds (see Fig. 4(h')). And, as a result, the dimension of the formed semi-transmissive film pattern 104a becomes smaller in W (μm) in the K portion with respect to the dimension of the resist pattern 105a, resulting in a difference in the pattern dimension (CD), The distribution of the CD error within the plane tends to be large (see Fig. 4(i')).

In addition, management of the light transmittance of the semi-transmissive film used in such a multi-gradation photomask is very important. In the prior art method of FIG. 3, when the semi-transmissive film is formed, a pattern including the light-shielding film is already present on the transparent substrate. do. Therefore, it is not easy to measure the light transmittance of the formed semi-transmissive film. In particular, since the photomask for display device manufacturing has a large area (for example, a square with a side of 300 mm or more), a large-sized device (sputter device, etc.) is used for film formation, but it is difficult to deposit the film formation material uniformly in the plane. also have trouble For example, distribution of a film thickness may generate|occur|produce in-plane by the relative position with a sputtering target, etc. If this film thickness is measured accurately and this tendency is grasped correctly, it is thought that it is also possible to cancel the influence by the 2nd etching (patterning of a light-shielding film) in the manufacturing method of this invention mentioned later. However, in the method of the prior art described in Fig. 3, there is a problem in that it is difficult to accurately measure the transmittance of the semi-transmissive film at each position in the plane.

Therefore, it was found that, in the method of the prior art shown in Fig. 3, a problem remains in the case of manufacturing a multi-gradation photomask having both finer and higher CD accuracy and transmittance accuracy.

Accordingly, the present invention provides a method for manufacturing a photomask capable of manufacturing a multi-gradation photomask having finer, higher CD accuracy and transmittance accuracy, a photomask, and a method for manufacturing a display device using the photomask is intended to

MEANS TO SOLVE THE PROBLEM This inventor found that the said subject could be solved by invention which has the following structures, as a result of earnestly examining in order to solve the said subject, and came to complete this invention.

That is, this invention has the following structures.

(Configuration 1)

A method of manufacturing a photomask having a transfer pattern including a light transmitting unit, a first transmission control unit and a second transmission control unit on a transparent substrate, wherein a first thin film having a predetermined exposure light transmittance is formed on the transparent substrate A step of preparing a photomask blank, a first patterning step of forming a first thin film pattern by etching the first thin film, a second thin film formed on the transparent substrate on which the first thin film pattern is formed, A method of manufacturing a photomask comprising: a second patterning step of forming a second thin film pattern by etching the second thin film; wherein, in the second patterning step, only the second thin film is etched.

(Configuration 2)

The light transmitting part is made by exposing a surface of the transparent substrate, the first transmission control part has a portion where only the first thin film is formed on the transparent substrate, and the second transmission control part is on the transparent substrate and the second thin film The manufacturing method of the photomask as described in structure 1 characterized by the above-mentioned, it has the part in which the bay was formed.

(Configuration 3)

The said 1st thin film contains the material which has resistance with respect to the etching agent of the said 2nd thin film, The manufacturing method of the photomask of the structure 1 or 2 characterized by the above-mentioned.

(Configuration 4)

The method for manufacturing a photomask according to Configuration 1 or 2, wherein the first thin film contains a material that is etched by the etchant of the second thin film.

(Configuration 5)

After the first patterning step, before forming the second thin film, a step of forming an etching stopper film on the transparent substrate on which the first thin film pattern is formed is included. .

(Configuration 6)

After the second patterning step, the method for manufacturing the photomask according to Configuration 5, further comprising a step of removing the light-transmitting portion or the etching stopper film of the light-transmitting portion and the first transmission control unit.

(Configuration 7)

The method for manufacturing a photomask according to any one of Configurations 1 to 6, wherein the first thin film is a semi-transmissive film that partially transmits exposure light.

(Configuration 8)

The photomask according to any one of Configurations 1 to 6, wherein the phase difference φ (degrees) satisfies φ≤90 with respect to the representative wavelength of the exposure light passing through the first transmission control part. manufacturing method.

(Configuration 9)

The exposure light passing through the first transmission control unit has a phase difference ϕ (degrees) satisfying ϕ≤90 with respect to a representative wavelength of the exposure light passing through the light projection unit, and the light transmittance Tf (%) of the first transmission control unit is 5 ? Tf ? 60 is satisfied, The method for manufacturing the photomask according to any one of Configurations 1 to 6.

(Configuration 10)

The exposure light passing through the first transmission control unit has a phase difference ϕ (degrees) of 150≤ϕ≤210 with respect to a representative wavelength of the exposure light passing through the light transmitting unit, as described in any one of Configurations 1 to 6 A method of manufacturing a photomask.

(Configuration 11)

The exposure light passing through the first transmission control unit has a phase difference φ (degrees) of 150≤φ≤210 with respect to a representative wavelength of the exposure light passing through the light transmitting unit, and a light transmittance Tf (%) of 5≤Tf≤ 60 is satisfied, The manufacturing method of the photomask in any one of Configurations 1-6 characterized by the above-mentioned.

(Configuration 12)

The method for manufacturing a photomask according to any one of Configurations 1 to 11, wherein the second thin film is a semi-transmissive film that partially transmits exposure light.

(Configuration 13)

The exposure light passing through the second transmission control unit has a phase difference ϕ (degrees) of 0 < ϕ≤90 with respect to a representative wavelength of the exposure light passing through the light projection unit, according to any one of Configurations 1 to 11, characterized in that A method of manufacturing a photomask.

(Configuration 14)

The exposure light passing through the second transmission control unit has a phase difference φ (degrees) of 0<φ≤90 with respect to a representative wavelength of the exposure light passing through the light-transmitting unit, and has a light transmittance Tf(%) of 5≤Tf≤ 80 is satisfied, The manufacturing method of the photomask in any one of the structures 1-11 characterized by the above-mentioned.

(Configuration 15)

The exposure light passing through the second transmission control unit has a phase difference φ (degrees) of 150<φ≤210 with respect to a representative wavelength of the exposure light passing through the light-transmitting unit, and has a light transmittance Tf(%) of 5≤Tf≤ 60 is satisfied, The manufacturing method of the photomask in any one of the structures 1-11 characterized by the above-mentioned.

(Configuration 16)

The method for manufacturing the photomask according to any one of Configurations 1 to 11, wherein the second thin film is a light-shielding film.

(Configuration 17)

A photomask manufacturing method according to Configuration 16, wherein a reflection reducing layer for reducing light reflection is formed on the surface portion of the second thin film.

(configuration 18)

The photomask blanks have an additional structural film and a resist film on the first thin film, The method for manufacturing a photomask according to any one of Configurations 1 to 17, wherein the photomask blank is provided.

(Configuration 19)

The method for manufacturing a photomask according to Structure 18, wherein the adhesion between the additional constituent film and the resist film is higher than that between the first thin film and the resist film.

(Configuration 20)

Before the first patterning process, there is a preliminary patterning process of etching the additional constituent film to form an additional constituent film pattern, and in the first patterning process, etching the first thin film using the additional constituent film pattern as a mask The manufacturing method of the photomask of the structure 18 or 19 characterized by the above-mentioned.

(Configuration 21)

After the first patterning step and before the second patterning step, the additional component film pattern is removed, The method for manufacturing a photomask according to Configuration 20.

(Configuration 22)

A method of manufacturing a photomask having a transfer pattern on a transparent substrate, comprising: a light-transmitting unit, a first transmission control unit, and a second transmission control unit; , preparing a photomask blank in which a first thin film having a predetermined exposure light transmittance is formed on the transparent substrate; A first patterning process of forming a first thin film pattern by etching, a film forming process of forming a second thin film on the transparent substrate on which the first thin film pattern is formed, and a second resist pattern in a region serving as the second transmission control unit and a second patterning process of forming a second thin film pattern by etching the second thin film by forming A method of manufacturing a photomask, wherein a layered portion to be laminated with the thin film pattern is formed, and only the second thin film is etched using the second resist pattern.

(Configuration 23)

The light-transmitting part is made by exposing a surface of the transparent substrate, the first transmission control unit includes a portion where only the first thin film is formed on the transparent substrate, and the second transmission control unit is formed on the transparent substrate, and the second transmission control unit is on the transparent substrate. The method for manufacturing the photomask according to Configuration 22, comprising a portion where only a thin film is formed.

(Configuration 24)

The method for manufacturing the photomask according to Configuration 22 or 23, wherein the width M1 of the laminated portion is in the range of 0.5 to 2 µm.

(Configuration 25)

A photomask having a transfer pattern including a light transmitting unit, a first transmission control unit, and a second transmission control unit on a transparent substrate, wherein the transfer pattern includes a first thin film having a predetermined exposure light transmittance, and a second thin film Including, wherein the light-transmitting part is made by exposing the surface of the transparent substrate, the first transmission control part is made by forming the first thin film without the second thin film being formed on the transparent substrate, and the second transmission control part at least the second thin film is formed on the transparent substrate, and the boundary between the first transmission control unit and the second transmission control unit does not have an etched cross section of the first thin film, and the second thin film is etched A photomask having a cross-section.

(Configuration 26)

The light transmitting part is made by exposing a surface of the transparent substrate, the first transmission control part has a portion where only the first thin film is formed on the transparent substrate, and the second transmission control part is on the transparent substrate and the second thin film The photomask according to Configuration 25, characterized in that it has a portion formed with a bay.

(Configuration 27)

The photomask according to Configuration 25 or 26, wherein the first thin film contains a material resistant to the etching agent of the second thin film.

(Configuration 28)

wherein the first thin film contains a material etched by the etchant of the second thin film, and the second transmission control unit has a portion in which an etching stopper film and the second thin film are laminated in this order. The photomask according to configuration 25 or 26.

(Configuration 29)

The photomask according to any one of Configurations 25 to 28, wherein an edge portion of the second transmission control unit adjacent to the first transmission control unit includes a laminated portion of the first thin film and the second thin film.

(configuration 30)

The photomask according to Configuration 29, wherein the width M2 of the laminated portion is in the range of 0.5 to 2 µm.

(Configuration 31)

The photomask according to any one of Configurations 25 to 30, wherein the first thin film is a semitransmissive film, and the second thin film is a light shielding film.

(Configuration 32)

A photomask having a transfer pattern including a light transmitting unit, a first transmission control unit, and a second transmission control unit on a transparent substrate, wherein the transfer pattern is a first thin film including a first thin film having a predetermined exposure light transmittance a second thin film pattern including a pattern and a second thin film, wherein the light transmitting part is formed by exposing a surface of the transparent substrate, and the first transmission control part is a portion where only the first thin film pattern is formed on the transparent substrate and, the second transmission control unit has a portion on the transparent substrate in which only the second thin film pattern is formed, and is sandwiched between the first transmission control unit and the second transmission control unit, the first thin film pattern and the second thin film A photomask having a laminated portion on which patterns are laminated.

(Configuration 33)

The photomask according to Configuration 32, wherein the width M2 of the laminated portion is in the range of 0.5 to 2 µm.

(Configuration 34)

The photomask according to Configuration 32 or 33, wherein the edges of the first thin film pattern and the second thin film pattern have wet-etched cross sections of the first thin film and the second thin film, respectively.

(Configuration 35)

The photomask according to any one of Configurations 32 to 34, wherein the first thin film is a semi-transmissive film that partially transmits exposure light.

(Configuration 36)

The photomask according to any one of configurations 32 to 34, wherein the phase difference φ (degrees) satisfies φ≤90 with respect to the representative wavelength of the exposure light passing through the first transmission control part. .

(Configuration 37)

For the exposure light passing through the first transmission control unit, the phase difference φ (degrees) satisfies φ≤90 with respect to the representative wavelength of the exposure light passing through the light transmitting unit, and the light transmittance Tf(%) has 5≤Tf≤60. The photomask in any one of the structures 32-34 characterized by the above-mentioned satisfy|filling.

(Configuration 38)

The exposure light passing through the first transmission control unit has a phase difference ϕ (in degrees) that satisfies 150≤ϕ≤210 with respect to a representative wavelength of the exposure light passing through the light transmitting unit. photomask.

(Configuration 39)

The exposure light passing through the first transmission control unit has a phase difference φ (degrees) of 150≤φ≤210 with respect to a representative wavelength of the exposure light passing through the light transmitting unit, and a light transmittance Tf (%) of 5≤Tf≤ 60 is satisfied, The photomask in any one of the structures 32-34 characterized by the above-mentioned.

(Configuration 40)

The photomask according to any one of Configurations 32 to 39, wherein the second thin film is a light-shielding film.

(Configuration 41)

The photomask according to any one of Configurations 32 to 39, wherein the second thin film is a semi-transmissive film that partially transmits exposure light.

(Configuration 42)

The exposure light passing through the second transmission control unit has a phase difference φ (degrees) that satisfies 0<φ≤90 with respect to a representative wavelength of the exposure light passing through the light projection unit. photomask.

(Configuration 43)

The exposure light passing through the second transmission control unit has a phase difference φ (degrees) of 0<φ≤90 with respect to a representative wavelength of the exposure light passing through the light-transmitting unit, and has a light transmittance Tf(%) of 5≤Tf≤ 80 is satisfied, The photomask in any one of the structures 32-39 characterized by the above-mentioned.

(Configuration 44)

The exposure light passing through the second transmission control unit has a phase difference φ (degrees) of 150<φ≤210 with respect to a representative wavelength of the exposure light passing through the light-transmitting unit, and has a light transmittance Tf(%) of 5≤Tf≤ 60 is satisfied, The photomask in any one of the structures 32-39 characterized by the above-mentioned.

(Configuration 45)

The said transfer pattern is a pattern for display apparatus manufacture, The photomask in any one of structures 25-44 characterized by the above-mentioned.

(Configuration 46)

A method of manufacturing a display device comprising the steps of: preparing the photomask according to any one of Configurations 25 to 44; and transferring the transfer pattern onto a transfer target body using an exposure apparatus.

According to the present invention, in each etching process of the first thin film and the second thin film, since only each film is etched, compared to the case of continuously etching a plurality of stacked films, the setting of the etching time is shorter, so side etching It is possible to reduce pattern dimension (CD) fluctuations caused by In particular, in all etching processes, when a single film is etched, the etching time required previously calculated by the film quality and film thickness can be applied, so that dimensional deviation due to side etching can be minimized. In addition, if the configuration of the photomask of the present invention is adopted, the design and management of the optical characteristics (eg, transmittance) of the first transmission control unit and the second transmission control unit are simpler and more accurate, and thus energy saving is realized with high precision. It has great significance in manufacturing a high-spec display device.

That is, according to the present invention, it is possible to provide a photomask manufacturing method and a photomask capable of manufacturing a photomask having both finer and higher CD precision and optical property (transmittance, etc.) precision.

Further, according to the present invention, by manufacturing a display device using the photomask, it is possible to manufacture a high-spec display device that realizes energy saving with high precision.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the process of 1st Embodiment of the manufacturing method of the photomask which concerns on this invention.
It is a figure which shows the process of 2nd Embodiment of the manufacturing method of the photomask which concerns on this invention.
3 is a view showing a conventional photomask manufacturing process disclosed in the prior art.
Figure 4 is a reference diagram showing a manufacturing process of a conventional photomask for explaining the problem of the prior art.

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing this invention is demonstrated in detail, referring drawings.

[First embodiment]

The method for manufacturing a photomask according to the present invention is a method for manufacturing a photomask having a transfer pattern including a light transmitting unit, a first transmission control unit, and a second transmission control unit on a transparent substrate, as in the above configuration 1, A step of preparing a photomask blank in which a first thin film having a predetermined exposure light transmittance is formed on the transparent substrate; a first patterning step of forming a first thin film pattern by etching the first thin film; a second patterning process of forming a second thin film pattern by forming a second thin film on the transparent substrate on which the first thin film pattern is formed, and etching the second thin film; It is characterized in that only the thin film is etched.

In the first embodiment described below, the first transmission control unit serves as a semi-transmissive unit that partially transmits the exposure light, and the second transmission control unit serves as a light-shielding unit. Then, the first thin film is a semi-transmissive film, and the second thin film is a light-shielding film.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the process of 1st Embodiment of the manufacturing method of the photomask which concerns on this invention.

Hereinafter, each process is demonstrated in order.

First, a photomask blank (substrate with a semi-transmissive film) 10 in which a semi-transmissive film 2 having a predetermined exposure light transmittance is formed on a transparent substrate 1 is prepared (refer to Fig. 1 (a))

Here, as the transparent substrate 1, a flat and smooth transparent material made of quartz glass or the like is used. As a transparent substrate used for the photomask for display apparatus manufacture, it is preferable that a main surface is a rectangle 300 mm or more on one side, and that thickness is 5-13 mm.

A semitransmissive film 2 is formed on one main surface of the transparent substrate 1 by a known film forming means such as a sputtering method. The material and film thickness of this semi-transmissive film 2 can be determined in advance so that it may have a desired transmittance|permeability with respect to the exposure light used when exposing a photomask.

As said exposure light, the light source containing i line|wire, h line|wire, and g line|wire which the exposure apparatus for liquid crystals etc. has can be used, for example. Therefore, the standard of transmittance can be made with respect to light in these wavelength ranges, and can generally be expressed as numerical values for representative wavelengths (herein referred to as i-line) included in these wavelength ranges.

In addition, it is preferable that the light transmittance Tf of the said semi-transmissive film 2 is 5 to 60% with respect to the i line|wire (set the transparent substrate to 100%). Moreover, it is preferable that it is 10 to 40 %.

Here, Tf is the light transmittance of the semi-transmissive film 2 to be used as described above. In general, when a fine pattern is formed on the semi-transmissive film 2, it is affected by diffraction and interference of light by the light-shielding portion or light-transmitting portion disposed around it, and the effective light transmittance of the semi-transmissive portion is different from that at the time of film formation. have. Here, the light transmittance Tf refers to the transmittance inherent to the film that is not affected by the diffraction and interference of light due to the surrounding pattern. transmittance.

Moreover, the said semi-transmissive film 2 can be made into what has a desired phase shift action with respect to the representative wavelength of exposure light. As a multi-gradation photomask, when forming a resist pattern having a plurality of residual film thicknesses on an object to be transferred, the amount of phase shift ? (in degrees) of the semi-transmissive film 2 satisfies 0 < ? It is preferable, and it is more preferable to satisfy 5 ? ? ? 60 degrees. Accordingly, the phase difference generated between the portion where the semi-transmissive film 2 is formed and the light-transmitting portion is within the range of ? (degrees). This is to prevent generation of unnecessary protrusions (in the case of positive resist) of the resist pattern at positions corresponding to the translucent portion and the light transmitting portion of the multi-gradation photomask.

Of course, in order to control the shape of the resist pattern formed on the transfer object by the phase shift action, it may be set to about 150 ? ? 210 degrees, or 60 ? ? 120 degrees.

The material of the semi-transmissive film 2 can be, for example, a film containing Si, Cr, Ta, Zr, and the like, and an appropriate one can be selected from these oxides, nitrides, carbides, and the like. As the Si-containing film, a compound of Si (such as SiON) or a transition metal silicide (such as MoSi) or a compound thereof can be used. Examples of the MoSi compound include an oxide, nitride, oxynitride, oxynitride and carbide of MoSi.

Further, when the material of the semi-transmissive film 2 is a Cr-containing film, a Cr compound (oxide, nitride, carbide, oxynitride, carbonitride, oxynitride carbide) can be used.

Moreover, in this embodiment, it is preferable that the said semi-transmissive film 2 has mutual etching selectivity (etching characteristic is different) between the light-shielding film 5 mentioned later. That is, it is preferable that the semi-transmissive film 2 is resistant to the etchant of the light-shielding film 5 (specifically, it is an etchant since wet etching is applied in this embodiment). Herein, resistance means that the etching rate ratio of the semi-transmissive film 2 to the etching solution of the light-shielding film 5 with the light-shielding film 5 is 1/50 or less, preferably 1/100 or less. From this point of view, for example, if a film containing Cr is used for the light-shielding film 5 , the semi-transmissive film 2 may be Si-based (eg, one containing MoSi). Or, you can do the opposite.

A well-known method and apparatus, such as a sputtering method, can be applied to the film-forming of the said semi-transmissive film 2 . The film thickness of the semi-transmissive film 2 is set to a predetermined film thickness so as to have a desired transmittance with respect to the exposure light used when exposing the photomask.

In addition, it is preferable to set an appropriate number of measurement points in a plane after film-forming of the semitransmissive film 2, and to measure the light transmittance (absolute value and its in-plane distribution). For the measurement, for example, a spectrophotometer can be used. In the semi-transmissive film 2 after film formation, a certain film thickness distribution tendency may occur depending on the position of the main surface of the substrate due to the film formation apparatus or film formation conditions. It can be used for purposes, such as making it reflect in drawing data in a subsequent process. As described above, since the transmittance management of the semi-transmissive film is simpler and more accurate, the transmittance accuracy as a photomask can be finally improved.

Next, a resist film 3 is applied and formed on the surface of the prepared photomask blanks 10 to obtain a blank with a resist. A predetermined pattern is drawn (4) (first drawing) (refer to Fig. 1(b)). In addition, if necessary, the surface of the semi-transmissive film 2 may be subjected to a surface treatment for improving adhesion to the resist film 3 .

In addition, in order to supplement the adhesion between the semi-transmissive film 2 and the resist film, a constituent film may be further disposed between them.

The material of the constituent film can be selected so that the adhesion between the constituent film and the resist film is higher than that between the semitransmissive film and the resist film. That is, by arranging the constituent film, it is possible to make good adhesion to both the resist film and the semitransmissive film in direct contact with the film. The material of the additional constituent film has a higher adhesiveness to the resist film than that between the semitransmissive film and the resist film. For example, it can be set as a Cr compound.

A well-known thing, such as a slit coater and a spin coater, can be used for coating formation of the resist film 3. It can be suitably used with any resist of a positive type or a negative type, but the example using a positive type is demonstrated here.

A first patterning process is performed. First, with respect to the resist film 3 which was coated and formed, it draws using the drawing apparatus based on the drawing data based on the desired pattern. Although there exist apparatuses to which an electron beam or a laser is applied as a drawing apparatus, laser drawing can be used usefully for the photomask for display apparatus manufacture.

Next, the drawn resist film 3 is developed to form a resist pattern 3a (first resist pattern) (refer to Fig. 1C).

Then, using the formed resist pattern 3a as an etching mask, wet etching (first etching) of the semi-transmissive film 2 is performed to form a semi-transmissive film pattern 2a (see Fig. 1(d)). ]. Here, since the etching target is only the semi-transmissive film 2, the etching end point can be accurately set with reference to the previously grasped etching rate.

Then, the remaining resist pattern 3a is peeled off (refer to Fig. 1(e)).

Here, the pattern dimension CD of the semi-transmissive film pattern 2a is measured as needed. Since the pattern edge is only the semi-transmissive film, measurement can be performed relatively easily.

In addition, when an additional constituent film is formed between the semi-transmissive film 2 and the resist film 3, the constituent film is wet-etched (pre-etched) using the resist pattern 3 as an etching mask, and the formed additional film is formed. The semi-transmissive film pattern 2a can be formed by wet etching (first etching) the semi-transmissive film 2 using the constituent film pattern as an etching mask.

In this case, it is preferable to remove the additional constituent film pattern before the following second patterning process.

Next, a light-shielding film 5 is formed over the entire surface of the transparent substrate 1 on which the semi-transmissive film pattern 2a is formed on the main surface (refer to Fig. 1(f)). Here too, the same conventional film forming apparatus as in the case of forming the semi-transmissive film 2 can be applied.

The material of the light-shielding film 5 can be selected from the same materials as those exemplified as the material of the semi-transmissive film 2 . Or it may be a single-piece|unit of metals, such as Cr and Si mentioned above. In addition, a reflection reducing layer for reducing (suppressing) reflection of light may be provided on the surface portion of the light shielding film.

In addition, as described above, in the present embodiment, for the light-shielding film 5 , a material having a different etching characteristic is selected from the material used for the semi-transmissive film 2 . For example, in the light-shielding film 5, the etching rate ratio between the etching solution of the semi-transmissive film 2 and the semi-transmissive film 2 is 1/50 or less, preferably 1/100 or less. Therefore, for example, it is possible to use a material containing Si for the semitransmissive film 2 and use a material containing Cr for the light shielding film 5 , or vice versa.

In addition, the film thickness of the said light-shielding film 5 is set taking into consideration that light-shielding property can fully be exhibited and that an excessive time is not required for the etching mentioned later. Specifically, the optical density OD can be 3 or more, preferably 4 or more, for example, 4≤OD≤6.

Next, a resist film 6 (also referred to as a positive type) is coated on the light-shielding film 5, and a predetermined pattern is drawn 7 (second drawing) (see Fig. 1(g)). The drawing method is the same as in the case of the first drawing described above.

However, in the in-plane transmittance distribution data obtained by measuring after the formation of the semi-transmissive film 2 , there is an unacceptable degree of variation, and when it is attempted to correct this by the pattern of the light-shielding film 5 , the second Drawing data for drawing can be processed. For example, in a fine semi-transmissive portion adjacent to the light-shielding portion, the transmission intensity of the exposure light passing through the semi-transmissive portion tends to decrease. Using this principle, for example, the translucent portion of the region having a transmittance lower than the design value can be corrected in the direction of increasing the transmittance intensity of the exposure light by making the dimension larger than the design value.

Subsequently, the drawn resist film 6 is developed to form a resist pattern 6a (second resist pattern) (refer to Fig. 1(h)).

Next, using the formed resist pattern 6a as an etching mask, the light-shielding film 5 is wet-etched (second etching) to form a light-shielding film pattern 5a (refer to Fig. 1(i)). Since the etching target here is only the light-shielding film 5, the etching end point can be set easily by referring to the etching rate grasped|ascertained in advance, for example. In addition, as described above, in this embodiment, since the semi-transmissive film 2 contains a material resistant to the etching agent of the light-shielding film 5, in the second etching, on the semi-transmissive portion forming region, Only the light-shielding film 5 is etched away, and there is substantially no effect of etching on the lower semi-transmissive film pattern 2a.

Then, by peeling and removing the remaining resist pattern 6a, a photomask 20 (multi-gradation photomask) having a transfer pattern including a light-transmitting part, a light-shielding part, and a semi-transmissive part is completed (Fig. 1). see (j)].

In addition, the photomask 20 (multi-gradation photomask) illustrated here has the following structure. That is, the light-transmitting portion is made by exposing the surface of the transparent substrate, the semi-transmissive portion (first transmission control unit) has a portion where only the semi-transmissive film (the first thin film) is formed on the transparent substrate, and the light-shielding portion (second transmission control unit) has a portion on the transparent substrate in which only the light-shielding film (the second thin film) is formed.

In addition, the photomask 20 has adjacent portions of the light blocking portion and the semi-transmissive portion. In the light-shielding portion, a laminated portion of a semi-transmissive film (semitransmissive film pattern 2a) and a light-shielding film (light-shielding film pattern 5a) is provided with a predetermined constant width in the vicinity of an edge in contact with the semi-transmissive portion. This is because when an alignment misalignment in the above two drawing (first drawing and second drawing) occurs, the light-shielding portion and the semi-transmissive portion are not adjacent to each other and spaced apart from each other, taking into account the possibility of absorbing this alignment deviation. alignment margin for This alignment margin can be formed by processing the writing data of the first writing or the second writing. For example, in the vicinity of the boundary between the light-shielding portion and the semi-transmissive portion, the edge portion of the second resist pattern is partially stacked (overlapped) with the edge portion of the already formed semi-transmissive film pattern. You can set the dimensions. At this time, as processing of the drawing data, the width M of the stacked portion (see Fig. 1(j) ) is not particularly limited, but is, for example, 0.5 µm or more, preferably 0.5 to 2 µm, more preferably 0.5 It can be set as thru|or 1 micrometer.

That is, in the photomask according to the manufacturing method, only the semi-transmissive film is formed on the transparent substrate for the semi-transmissive portion, and only the light-shielding film is formed for the light-shielding portion on the transparent substrate, except for the stacked portion as the alignment margin.

Moreover, this invention provides also about a photomask.

The said photomask 20 obtained by this embodiment has the following characteristics.

That is, it is a photomask having a transfer pattern including a transmissive part, a light blocking part and a semi-transmissive part on a transparent substrate, wherein the transmissive part is made by exposing the surface of the transparent substrate, and the semi-transmissive part is the light blocking film on the transparent substrate is not formed, the semi-transmissive film is formed, the light-shielding portion is formed by forming at least the light-shielding film on the transparent substrate, and the boundary between the semi-transmissive portion and the light-shielding portion is not formed with an etched end face of the semi-transmissive film It is a photomask characterized in that the etched end face of the light-shielding film is formed.

That is, as is also clear from Fig. 1(j), the edges of the semi-transmissive film pattern 2a and the light-shielding film pattern 5a have wet-etched cross sections of the semi-transmissive film and the light-shielding film, respectively, but the semi-transmissive film pattern 2a ) and the edge position of the light-shielding film pattern 5a do not match. In addition, the cross section to be etched here is a cross section by wet etching in this embodiment.

In this way, the misalignment of the positions of the etched end surfaces of the semi-transmissive film and the light-shielding film is related to the above-described alignment margin.

The material of the semi-transmissive film or the light-shielding film in the photomask is as described above, and in the photomask of this embodiment, the semi-transmissive film is a material having resistance to the etchant of the light-shielding film. include

Further, in the edge portion adjacent to the semi-transmissive portion of the light-shielding portion, there is a laminated portion of the semi-transmissive film and the light-shielding film, and the width M of the laminated portion (see Fig. 1(j)) is, for example, 0.5 to 2 μm. range is preferred.

Moreover, in the photomask of this embodiment, the said transfer pattern is a pattern for display apparatus manufacture, for example, and is especially useful for manufacture of a display apparatus.

As described above, according to the present embodiment, in each etching step of the semi-transmissive film and the light-shielding film, only each film is etched. Therefore, since the etching time is shorter than in the case of successively etching the plurality of stacked films, it is possible to reduce the variation in the pattern dimension (CD) due to the side etching. In particular, in all etching processes, when a single film is etched, the etching time required previously calculated by the film quality and film thickness can be applied, so that dimensional deviation due to side etching can be minimized. In addition, if the configuration of the photomask of the present embodiment is adopted, the transmittance management of the semi-transmissive film is simpler and more accurate, so it is of great significance to the manufacture of a high-spec display device that realizes energy saving with high precision.

That is, according to the present embodiment, it is possible to provide a photomask manufacturing method and a photomask capable of manufacturing a multi-gradation photomask having both finer and higher CD accuracy and transmittance accuracy.

In addition, in the above embodiment, the first transmission control part is a semi-transmissive part that partially transmits the exposure light, and the second transmission control part is a light-shielding part. , the manufacturing method of the present invention is not limited thereto, and excellent effects are obtained even when other thin films are applied. For example, each of the first thin film and the second thin film may be a semi-transmissive film having a predetermined exposure light transmittance. In this case, the first thin film and the second thin film can each be a film containing Si, Cr, Ta, Zr, etc. exemplified as the material for the semi-transmissive film, and an appropriate one of these oxides, nitrides, carbides, etc. is selected. can

In the case where the first thin film and the second thin film are semi-transmissive films each having a predetermined exposure light transmittance, and to have resistance to each other's etching agents between them, for example, one is Cr-based and the other is Si. It can be set as a system thru|or a transition metal silicide system.

Further, in the photomask of the present invention, as a method of applying the first thin film and the second thin film, for example, more specifically,

a. The exposure light passing through the first transmission control unit having a portion in which only the first thin film is formed on the transparent substrate has a phase difference φ (in degrees) of φ with respect to the representative wavelength of the exposure light passing through the transparent substrate surface exposed If ≤90 is satisfied,

b. For the exposure light passing through the first transmission control unit, the phase difference φ (degrees) satisfies φ≤90 with respect to the representative wavelength of the exposure light passing through the light transmitting unit, and the light transmittance Tf(%) has 5≤Tf≤60. If it satisfies you,

c. When the phase difference ϕ (degrees) of the exposure light passing through the first transmission control unit satisfies 150≤ϕ≤210 with respect to the representative wavelength of the exposure light passing through the light transmitting unit,

d. The exposure light passing through the first transmission control unit has a phase difference φ (degrees) of 150≤φ≤210 with respect to a representative wavelength of the exposure light passing through the light transmitting unit, and a light transmittance Tf (%) of 5≤Tf≤ If 60 is satisfied,

e. The exposure light passing through the second transmission control unit having a portion in which only the second thin film is formed on the transparent substrate has a phase difference φ (degrees) of 0<φ≤90 with respect to a representative wavelength of the exposure light passing through the light transmitting unit If you let

f. The exposure light passing through the second transmission control unit has a phase difference φ (degrees) of 0<φ≤90 with respect to a representative wavelength of the exposure light passing through the light-transmitting unit, and has a light transmittance Tf(%) of 5≤Tf≤ If 80 is satisfied,

g. The exposure light passing through the second transmission control unit has a phase difference φ (degrees) of 150<φ≤210 with respect to a representative wavelength of the exposure light passing through the light-transmitting unit, and has a light transmittance Tf(%) of 5≤Tf≤ If 60 is satisfied,

etc. are mentioned as useful examples. In any case, the effect of the present invention that the CD precision is high and controllable is obtained. In addition, since the optical characteristics assigned to the first transmission control unit and the second transmission control unit can be independently designed, a high-quality photomask having a desired design value can be manufactured.

The multi-gradation photomask as the photomask according to the present invention can be suitably selected for a use by appropriately selecting configurations such as a to g. The photomask according to the present invention is, for example, in the photomask described in the first embodiment, the a. or b. and applying a light-shielding film to the second thin film. Such a multi-gradation photomask exhibits a function corresponding to a plurality of photomasks as described above. Thereby, the multi-gradation photomask has an advantage that it can increase the manufacturing efficiency of a display device, or can be used for a photomask for forming a three-dimensional structure with a level|step difference by transcription|transfer.

In addition, the photomask which concerns on this invention is the photomask demonstrated in 1st Embodiment, for example. WHEREIN: What applied said c or d to a 1st thin film may be sufficient, and in this case, it exhibits the function of a phase shift mask. In this case, a light-shielding film may be applied to the second thin film, or e. Alternatively, the semi-transmissive film described in f. may be applied. The phase shift mask has a function of improving contrast and DOF (Depth of Focus) by using interference of light generated at a boundary between a semi-transmissive portion in which the phase of transmitted light is inverted and a non-inverted transparent portion.

In particular, applying c or d to the first thin film and e. Alternatively, when f. is applied, a photomask having both a function of a multi-gradation photomask and a function of a phase shift mask can be realized.

In addition, when both the first transmission control part and the second transmission control part are semi-transmissive parts, when a laminated portion in which the first thin film and the second thin film are laminated is formed near the boundary, the width is sufficiently small, so the corresponding photomask Interference of the optical action of the practically does not occur. In this case, more preferably, the width of the laminated portion may be 1 µm or less, and more preferably 0.75 µm or less. More preferably, it is 0.25-0.75 micrometer.

In addition, the width M of the stacked portion on the writing data may be within the same range.

On the other hand, the dimensions of the first transmittance control unit and the second transmittance control unit (or light-shielding unit) exceed 2 µm, and preferably exceed 3 µm, even at the smallest portion.

[Second embodiment]

It is a figure which shows the process of 2nd Embodiment of the manufacturing method of the photomask which concerns on this invention.

Hereinafter, each process is demonstrated in order.

First, a photomask blank 10 in which a semi-transmissive film 2 having a predetermined exposure light transmittance is formed on a transparent substrate 1 is prepared (see Fig. 2(a)).

This photomask blanks 10 is the same as the photomask blanks prepared in the first embodiment described above. Therefore, the range of the light transmittance Tf of the semi-transmissive film 2 can be made similar to that of the first embodiment. The material of the semi-transmissive film 2 may also be appropriately selected from those exemplified in the first embodiment.

However, in this embodiment, since an etching stopper film is provided between the semi-transmissive film and the light-shielding film as described later, it is not necessary to make the etching characteristics different between the semi-transmissive film 2 and the light-shielding film 5 to be described later. . Therefore, for example, there is no problem at all in using a Cr-based material for the material of the semi-transmissive film 2 and making the light-shielding film 5 also a Cr-based material.

In addition, after forming the said semi-transmissive film 2, similarly to 1st Embodiment, it is preferable to set an appropriate number of measurement points in a surface, and to measure light transmittance. Since it is formed in the state of a single film on a board|substrate, it can measure easily and accurately.

Next, a resist film 3 is coated and formed on the photomask blanks 10, and a predetermined pattern is drawn (4) (first drawing) (see Fig. 2(b)). If necessary, the surface of the semi-transmissive film 2 may be subjected to a surface treatment for improving adhesion to the resist film.

As described above, the resist film 3 can be formed by using a known one such as a slit coater or a spin coater. Although it can be used suitably with any resist of a positive type and a negative type, also in this embodiment, it demonstrates with the example using a positive type.

With respect to the formed resist film 3, a writing apparatus is used and writing is performed by writing data based on a desired pattern. The drawing apparatus shall apply a laser similarly to 1st Embodiment.

Then, the drawn resist film 3 is developed to form a resist pattern 3a (first resist pattern) (see Fig. 2(c)).

Next, using the formed resist pattern 3a as an etching mask, wet etching (first etching) the semi-transmissive film 2 is performed to form a semi-transmissive film pattern 2a (see Fig. 2(d)). ]. Here too, since the etching target is only the semi-transmissive film 2, the etching end point can be accurately set with reference to the etching rate grasped|ascertained in advance.

The remaining resist pattern 3a is peeled off (refer to Fig. 2(e)).

Here, the pattern dimension CD of the semi-transmissive film pattern 2a is measured as needed. Since the pattern edge is only the semi-transmissive film, measurement can be performed relatively easily.

In the present embodiment, an etching stopper film 8 is then formed on the entire surface of the transparent substrate 1 on which the semi-transmissive film pattern 2a is formed on the main surface (see Fig. 2(f)).

The etching stopper film 8 contains a material having resistance to the etching agent of the light-shielding film 5, which will be described later. For example, in the etching stopper film 8 , the etching rate ratio between the light-shielding film 5 and the etching solution of the light-shielding film 5 is 1/50 or less, preferably 1/100 or less.

Therefore, for example, when a Cr-containing material is used for the light shielding film 5 , it is possible to use a Si-containing material for the etching stopper film 8 , or vice versa. After taking these into consideration, the material of the etching stopper film 8 can be selected from those exemplified as the material of the semi-transmissive film or the light-shielding film in the first embodiment.

Next, a light-shielding film 5 is further formed on the etching stopper film 8, that is, on the main surface of the transparent substrate 1 on which the semi-transmissive film pattern 2a and the etching stopper film 8 are formed (Fig. 2). of (g)].

In addition, the etching stopper film 8 and the light shielding film 5 can both be formed by applying the same film forming apparatus as described above.

The material of the light-shielding film 5 may also be appropriately selected from those exemplified in the first embodiment. As mentioned above, in this embodiment, the material of the light-shielding film 5 is the semitransmissive material. Reciprocal etching selectivity with the film 2 is not required.

Next, a resist film 6 (also referred to as a positive type) is coated on the light-shielding film 5, and a predetermined pattern is drawn 7 (second drawing) (see Fig. 2(h)). The drawing method is the same as in the case of the first drawing described above.

In addition, as described above, there is an unacceptable variation in the in-plane transmittance distribution data obtained by measuring after the film formation of the semi-transmissive film 2 , and this is corrected by the pattern of the light-shielding film 5 . In this case, the drawing data for the second drawing can be processed.

Then, the drawn resist film 6 is developed to form a resist pattern 6a (second resist pattern) (refer to Fig. 2(i)).

Next, using the formed resist pattern 6a as an etching mask, the light-shielding film 5 is wet-etched (second etching) to form a light-shielding film pattern 5a (refer to Fig. 2(j)). Since the etching target here is only the light shielding film 5, the etching end point can be set easily by referring to the etching rate grasped|ascertained in advance. As described above, in this embodiment, since the etching stopper film 8 contains a material resistant to the etching agent of the light-shielding film 5, only the light-shielding film 5 is etched away in the second etching. do.

Then, by peeling and removing the remaining resist pattern 6a, a photomask 30 (multi-gradation photomask) having a transfer pattern including a light-transmitting part, a light-blocking part, and a semi-transmissive part is completed [FIG. 2] see (k)].

Further, if necessary, the etching stopper film 8 exposed on the surface of the photomask 30 is removed. When the etching stopper film 8 is removed, it is assumed that there is an etching selectivity between the semi-transmissive film 2 and the etching stopper film 8 beforehand. That is, for example, both the semi-transmissive film 2 and the light-shielding film 5 may be Cr-containing films, and the etching stopper film 8 may be a Si-containing film, or vice versa. In the case where the light transmittance in the translucent portion or the light transmitting portion of the photomask 30 is not particularly affected, the etching stopper film 8 may be left without being removed.

Moreover, the photomask 30 (multi-gradation photomask) illustrated in this embodiment also has the adjacent part of a light-shielding part and a semi-transmissive part. In the light-shielding portion, a laminated portion of a semi-transmissive film (semitransmissive film pattern 2a) and a light-shielding film (light-shielding film pattern 5a) is provided with a predetermined constant width in the vicinity of an edge in contact with the semi-transmissive portion. This is to absorb this alignment misalignment in consideration of the possibility that the light-shielding portion and the semi-transmissive portion are not adjacent to each other and spaced apart due to the occurrence of misalignment in the above two drawing (first drawing and second drawing). alignment margin for This alignment margin can be formed by processing the writing data of the first writing or the second writing. For example, although the width M in particular of the lamination part (refer FIG.2(k)) is not restrict|limited, For example, it is 0.5-2 micrometers, Preferably, it can be 0.5-1 micrometer. This is similar to the first embodiment.

Moreover, also about the said photomask 30 obtained by this embodiment, it has the following characteristics similarly to 1st Embodiment.

That is, it is a photomask having a transfer pattern including a transmissive part, a light blocking part and a semi-transmissive part on a transparent substrate, wherein the transmissive part is made by exposing the surface of the transparent substrate, and the semi-transmissive part is the light blocking film on the transparent substrate is not formed, the semi-transmissive film is formed, the light-shielding portion is formed by forming at least the light-shielding film on the transparent substrate, and the boundary between the semi-transmissive portion and the light-shielding portion is not formed with an etched end face of the semi-transmissive film It is a photomask characterized in that the etched end face of the light-shielding film is formed.

The material of the semi-transmissive film and the light-shielding film in the photomask is as described above, and in the photomask of the present embodiment, etching selectivity between the semi-transmissive film and the light-shielding film is not required.

In addition, in the edge portion adjacent to the semi-transmissive portion of the light-shielding portion, there is a laminated portion of the semi-transmissive film and the light-shielding film, and the preferred range of the width M of the laminated portion (see Fig. 2(k)) is, for example, 0.5 to It is also the same as that of 2 micrometers.

Moreover, also about the photomask of this embodiment, the said transfer pattern is a pattern for display apparatus manufacture, for example, and is useful especially for manufacture of a display apparatus.

As explained above, also in this embodiment, in each etching process of a semitransmissive film and a light-shielding film, only each film|membrane is etched. Therefore, since the etching time is shorter than in the case of successively etching the plurality of stacked films, it is possible to reduce the variation in the pattern dimension (CD) due to the side etching. In particular, in all etching processes, when a single film is etched, the etching time required previously calculated by the film quality and film thickness can be applied, so that dimensional deviation due to side etching can be minimized. In addition, if the photomask configuration of the present embodiment is adopted, the transmittance management of the semi-transmissive film is simpler and more accurate, so it is of great significance to the manufacture of a high-spec display device that realizes energy saving with high precision.

That is, according to the present embodiment, it is possible to provide a photomask manufacturing method and a photomask capable of manufacturing a multi-gradation photomask having both finer and higher CD accuracy and transmittance accuracy.

Also in the present embodiment described above, the first transmission control unit uses a semi-transmissive unit that partially transmits the exposure light, and the second transmission control unit serves as a light-shielding unit. However, the manufacturing method of the present invention is not limited thereto, and excellent effects are obtained even when other thin films are applied. For example, each of the first thin film and the second thin film may be a semi-transmissive film having a predetermined exposure light transmittance.

Moreover, also in the photomask of this embodiment, as an application method of these 1st thin film and 2nd thin film, for example, more specifically,

a. The exposure light passing through the first transmission control unit having a portion in which only the first thin film is formed on the transparent substrate has a phase difference φ (in degrees) of φ with respect to the representative wavelength of the exposure light passing through the transparent substrate surface exposed If ≤90 is satisfied,

b. For the exposure light passing through the first transmission control unit, the phase difference φ (degrees) satisfies φ≤90 with respect to the representative wavelength of the exposure light passing through the light transmitting unit, and the light transmittance Tf(%) has 5≤Tf≤60. If it satisfies you,

c. When the phase difference ϕ (degrees) of the exposure light passing through the first transmission control unit satisfies 150≤ϕ≤210 with respect to the representative wavelength of the exposure light passing through the light transmitting unit,

d. The exposure light passing through the first transmission control unit has a phase difference φ (degrees) of 150≤φ≤210 with respect to a representative wavelength of the exposure light passing through the light transmitting unit, and a light transmittance Tf (%) of 5≤Tf≤ If 60 is satisfied,

e. The exposure light passing through the second transmission control unit having a portion in which only the second thin film is formed on the transparent substrate has a phase difference φ (degrees) of 0<φ≤90 with respect to a representative wavelength of the exposure light passing through the light transmitting unit If you let

f. The exposure light passing through the second transmission control unit has a phase difference φ (degrees) of 0<φ≤90 with respect to a representative wavelength of the exposure light passing through the light-transmitting unit, and has a light transmittance Tf(%) of 5≤Tf≤ If 80 is satisfied,

g. The exposure light passing through the second transmission control unit has a phase difference φ (degrees) of 150<φ≤210 with respect to a representative wavelength of the exposure light passing through the light-transmitting unit, and has a light transmittance Tf(%) of 5≤Tf≤ If 60 is satisfied,

etc. are mentioned as useful examples. In any case, the effect of the present invention that CD precision is high and controllable is obtained. In addition, since the optical characteristics assigned to the first transmission control unit and the second transmission control unit can be independently designed, a high-quality photomask having a desired design value can be manufactured.

Moreover, also about the photomask of this invention by 2nd Embodiment, similarly to 1st Embodiment, structures a to g etc. can be appropriately selected and it can be made suitable for a use.

As mentioned above, 1st Embodiment and 2nd Embodiment of this invention are demonstrated.

In addition, in the above embodiment, within the range that does not impair the effects of the present invention, the other constituent film is above, below, or below any one of the semi-transmissive film 2 , the light-shielding film 5 , and the etching stopper film 8 , or It may exist in the middle.

Further, the present invention also relates to a method for manufacturing a display device, comprising, for example, a step of preparing a photomask according to the above embodiment and transferring a transfer pattern onto a transfer target object using an exposure apparatus. will provide According to the present invention, by manufacturing a display device using the photomask, it is possible to manufacture a high-spec display device that realizes energy saving with high precision.

That is, there is no restriction on the use of the photomask of the present invention. For example, it is set as it is for manufacturing the panel board|substrate of a display apparatus (for example, a liquid crystal display or organic electroluminescent display), and can be provided with the pattern for transcription|transfer used for various layers.

For example, what is provided with the pattern for transcription|transfer for TFT(Thin Film Transistor: thin film transistor) manufacture is illustrated. In a bottom-gate TFT using amorphous Si or an oxide semiconductor, it is advantageously applied as a photomask used in a process of forming a semiconductor layer and a source/drain layer by one exposure.

Alternatively, the photomask of the present invention is advantageously applied even when a spacer for liquid crystal is manufactured by a photosensitive insulating layer. It can be used in a step of forming a stepped structure on a photosensitive insulating film by one exposure, and a spacer for forming a cell gap and a spacer with a slightly lower height to prevent breakdown during application of pressure are formed in one exposure etc. can be done efficiently.

As an exposure apparatus for use in photomask exposure of the present invention, for example, an equal-magnification projection exposure method having a numerical aperture (NA) of 0.08 to 0.15 and a coherence factor (σ) of 0.5 to 0.9 can be used. Alternatively, a proximity exposure method may be applied. Of course, it can be applied to an exposure apparatus of reduced exposure or enlarged exposure.

1: transparent substrate
2: semi-transmissive film
3, 6: resist film
4, 7: Drawing
5: light shield
8: etching stopper film
10: photomask blanks (substrate with semi-transmissive film)
20, 30: photo mask

Claims (47)

A method of manufacturing a photomask having a transfer pattern including a light transmitting unit, a first transmission control unit, and a second transmission control unit on a transparent substrate,
preparing a photomask blank in which a first thin film having a predetermined exposure light transmittance is formed on the transparent substrate;
a first patterning process of forming a first thin film pattern by wet etching the first thin film;
a second patterning process of forming a second thin film pattern by wet etching a second thin film formed on the transparent substrate on which the first thin film pattern is formed;
The material of the first thin film is a transition metal silicide or a compound thereof,
The light-transmitting part is made by exposing the surface of the transparent substrate,
The first transmission control unit has a portion on the transparent substrate in which only the first thin film is formed,
The second transmission control unit has a portion on the transparent substrate in which only the second thin film is formed,
In an adjacent portion of the first transmission control unit and the second transmission control unit, the second thin film is laminated on the first thin film,
The exposure light passing through the second transmission control part of the portion where only the second thin film is formed has a phase difference φ (degrees) that satisfies 0<φ≦90 with respect to the representative wavelength of the exposure light passing through the transparent part A method of manufacturing a mask. delete The method of claim 1 , wherein the first thin film comprises a material having resistance to the etching agent of the second thin film. delete delete delete The method of claim 1 or 3, wherein the first thin film is a semi-transmissive film that partially transmits exposure light. The photo according to claim 1 or 3, wherein the phase difference ϕ (degrees) satisfies ϕ≤90 with respect to a representative wavelength of the exposure light passing through the first transmission control unit. A method of manufacturing a mask. The exposure light passing through the first transmission control unit has a phase difference ϕ (degrees) that satisfies ϕ≤90 with respect to a representative wavelength of the exposure light passing through the light projection unit, and the first A method of manufacturing a photomask, characterized in that the light transmittance Tf (%) of the transmission control unit satisfies 5≤Tf≤60. The method according to claim 1 or 3, wherein the phase difference φ (degrees) satisfies 150≦φ≦210 with respect to the representative wavelength of the exposure light passing through the first transmission control part. A method for manufacturing a photomask. 4. The exposure light according to claim 1 or 3, wherein the phase difference φ (degrees) satisfies 150≤φ≤210 with respect to the representative wavelength of the exposure light passing through the light transmitting unit, and A method for manufacturing a photomask, wherein transmittance Tf (%) satisfies 5≤Tf≤60. The method of claim 1 or 3, wherein the second thin film is a semi-transmissive film that partially transmits exposure light. delete The method for manufacturing a photomask according to claim 1 or 3, wherein the light transmittance Tf (%) of the exposure light passing through the second transmission control unit satisfies 5≤Tf≤80. delete The method of claim 1 or 3, wherein the second thin film is a light-shielding film. delete delete delete delete delete delete delete delete It is a photomask having a transfer pattern including a light transmitting unit, a first transmission control unit, and a second transmission control unit on a transparent substrate,
The transfer pattern includes a first thin film and a second thin film having a predetermined exposure light transmittance,
The light-transmitting part is made by exposing the surface of the transparent substrate,
The first transmission control unit has a portion on the transparent substrate in which only the first thin film is formed,
The second transmission control unit has a portion on the transparent substrate in which only the second thin film is formed,
The material of the first thin film is a transition metal silicide or a compound thereof,
In an adjacent portion of the first transmission control unit and the second transmission control unit, the second thin film is laminated on the first thin film,
The exposure light passing through the second transmission control part of the portion where only the second thin film is formed has a phase difference φ (degrees) that satisfies 0<φ≦90 with respect to the representative wavelength of the exposure light passing through the transparent part mask. delete 26. The photomask of claim 25, wherein the first thin film comprises a material resistant to the etchant of the second thin film. delete delete delete delete delete delete delete The photomask of claim 25 or 27, wherein the first thin film is a semi-transmissive film that partially transmits exposure light. The photo according to claim 25 or 27, wherein the phase difference φ (degrees) satisfies φ≤90 with respect to the representative wavelength of the exposure light passing through the first transmission control section. mask. The light transmittance Tf according to claim 25 or 27, wherein the phase difference ? (degrees) satisfies ? (%) satisfies 5≤Tf≤60. The method according to claim 25 or 27, wherein the phase difference ϕ (degrees) satisfies 150≤ϕ≤210 with respect to a representative wavelength of the exposure light passing through the first transmission control unit. a photomask. 28. The method according to claim 25 or 27, wherein the phase difference φ (degrees) satisfies 150≤φ≤210 with respect to a representative wavelength of the exposure light passing through the light transmitting unit, and the light A photomask having a transmittance Tf (%) satisfying 5≤Tf≤60. 28. The photomask of claim 25 or 27, wherein the second thin film is a light blocking film. The photomask of claim 25 or 27, wherein the second thin film is a semi-transmissive film that partially transmits exposure light. delete The photomask according to claim 25 or 27, wherein a light transmittance Tf (%) of the exposure light passing through the second transmission control unit satisfies 5≤Tf≤80. delete delete A method of manufacturing a display device, comprising:
A method of manufacturing a display device, comprising the steps of: preparing the photomask according to claim 25 or 27; and transferring the transfer pattern onto a transfer target body using an exposure apparatus. A method of manufacturing a display device, comprising:
The process of preparing the photomask obtained by the manufacturing method of Claim 1 or 3;
A method of manufacturing a display device, comprising the step of transferring the transfer pattern onto a transfer target using an exposure apparatus.

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