Blank mask and method for manufacturing a blank mask

Abstract

To provide a blank mask from which a photomask that is precisely patterned and has less optical strains can be provided, and a method for manufacturing the same.SOLUTION: A blank mas includes a light-transmitting substrate, an optical substrate which is arranged on the light-transmitting substrate and includes a light-shielding film, and a photoresist layer arranged on the optical substrate, wherein the photoresist layer includes 49 regions which are divided into 7 at equal intervals in a lateral direction and divided into 7 at equal intervals in a longitudinal direction, the 49 regions include a first region corresponding to the center of the optical substrate, a second region arranged along the periphery of the first region, a third region arranged along the periphery of the second region, and a fourth region corresponding to the contour of the optical substrate, and the density of the optical unevenness in the fourth region is larger than the density of the optical unevenness in the first region, the second region and the third region.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD

[0001] The embodiments relate to a blank mask and a method for manufacturing the blank mask.

BACKGROUND ART

[0002] With higher integration of semiconductor devices and the like, miniaturization of circuit patterns of semiconductor devices is required. As a result, the importance of lithography technology, which is a technique for developing circuit patterns on the wafer surface using a photomask, has been further emphasized.

[0003] In order to develop a miniaturized circuit pattern, it is required to shorten the wavelength of the exposure light source used in the exposure process. In recent years, examples of exposure light sources in use include ArF excimer lasers (wavelength 193 nm).

[0004] On the other hand, photomasks include binary masks and phase shift masks, and the like.

[0005] The binary mask has a configuration in which a light-shielding layer pattern is formed on a light-transmissive substrate. On the patterned surface of the binary mask, the transmissive portion that does not include the light-shielding layer transmits exposure light, and the light-shielding portion that includes the light-shielding layer blocks exposure light, thereby exposing a pattern onto the resist film on the wafer surface. However, as the pattern of the binary mask is miniaturized, problems in developing fine patterns may occur due to light diffraction generated at the edge of the transmissive portion during the exposure process.

[0006] Phase shift masks include Levenson type, outrigger type, and half-tone type. Of these, the half-tone type phase shift mask has a configuration in which a pattern formed by a semi-transparent film is formed on a light-transmitting substrate 20. In the half-tone type phase shift mask, on the surface in which the pattern is formed, the transparent parts that do not contain the semi-transparent layer transmit exposure light, while the semi-transparent parts that contain the semi-transparent layer transmit attenuated exposure light. The attenuated exposure light has a phase difference compared to the exposure light that has passed through the transparent parts. As a result, the diffracted light generated at the edges of the transparent parts is canceled out by the exposure light that has passed through the semi-transparent parts, and the phase shift mask can form an even more intricate fine pattern on the wafer surface. [Prior art documents] [Patent Documents]

[0007] The relevant prior literature is as follows: [Patent Document 1] Republic of Korea Published Patent No. 10-2012-0057488 [Patent Document 2] Republic of Korea Published Patent No. 10-2014-0130420 [Overview of the project] [Problems that the invention aims to solve]

[0008] The embodiment aims to provide a blank mask and a method for manufacturing the same, which can be precisely patterned to provide a photomask with low optical distortion. [Means for solving the problem]

[0009] The blank mask according to the embodiment includes a light-transmitting substrate, a light-shielding film disposed on the light-transmitting substrate, and a photoresist layer disposed on the light-shielding film, wherein the photoresist layer is divided into 7 equally spaced regions in the transverse direction and 7 equally spaced regions in the vertical direction, and the thickness deviation in the 49 regions is less than 100 Å.

[0010] In one embodiment of the blank mask, the 49 regions include a first region corresponding to the center of the optical substrate, a second region arranged around the periphery of the first region, a third region arranged around the periphery of the second region, and a fourth region corresponding to the outer edge of the optical substrate, wherein the average thickness in the fourth region may be even greater than the average thickness in the third region.

[0011] In one embodiment of the blank mask, the average thickness in the fourth region may be about 3 Å to about 10 Å greater than the average thickness in the third region.

[0012] In one embodiment of the blank mask, the average thickness in the fourth region may be even greater than the average thickness in the second region.

[0013] In one embodiment of the blank mask, the average thickness in the first region may be even greater than the average thickness in the second region.

[0014] In one embodiment of the blank mask, the average thickness in the first region may be even greater than the average thickness in the third region.

[0015] The method for manufacturing a blank mask according to the embodiment includes the steps of forming an optical substrate including a light-shielding film disposed on a transparent substrate, and forming a photoresist layer on the light-shielding film while rotating the optical substrate, wherein the step of forming the photoresist layer includes the steps of: rotating the optical substrate for the first time; rotating the optical substrate for the second time at a speed faster than the first time; rotating the optical substrate for the third time at a speed faster than the second time; rotating the optical substrate for the fourth time at a speed faster than the third time; rotating the optical substrate for the fifth time at a speed slower than the fourth time; and rotating the optical substrate for the sixth time at a speed slower than the fifth time.

[0016] In a method for manufacturing a blank mask according to one embodiment, the first rotational speed may be 30 rpm to 70 rpm, the second rotational speed may be 50 rpm to 100 rpm, the third rotational speed may be 100 rpm to 150 rpm, the fourth rotational speed may be 800 rpm to 3000 rpm, the fifth rotational speed may be 500 rpm to 2500 rpm, and the sixth rotational speed may be 100 rpm to 500 rpm.

[0017] In the method for manufacturing a blank mask according to one embodiment, the first rotation step, the second rotation step, the third rotation step, the fourth rotation step, the fifth rotation step, and the sixth rotation step can be carried out at a temperature of 20°C to 30°C.

[0018] In the method for manufacturing a blank mask according to one embodiment, the fourth rotation step can be performed for 0.5 to 2 seconds.

[0019] A blank mask according to an embodiment includes a light-transmitting substrate, an optical substrate disposed on the light-transmitting substrate and including a light-shielding film, and a photoresist layer disposed on the optical substrate. The photoresist layer includes 49 regions divided into 7 parts at equal intervals in the horizontal direction and 7 parts at equal intervals in the vertical direction. The 49 regions include a first region corresponding to the center of the optical substrate, a second region arranged along the periphery of the first region, a third region arranged along the periphery of the second region, and a fourth region corresponding to the outer contour of the optical substrate. The density of optical asperities in the fourth region may be even greater than the density of optical asperities in the first region, the second region, and the third region.

[0020] In the blank mask according to an embodiment, the optical asperities are detected by a 532 nm laser, and on the light-shielding film 30 pieces per 152.4mm x 152.4mm area may be arranged to be less than.

[0021] In the blank mask according to an embodiment, the density of optical asperities in the fourth region is 15 to 25 pieces per 152.4 mm x 152.4 mm area may be.

[0022] In the blank mask according to an embodiment, the density of optical asperities in the first region, the second region, and the third region is 5 to 20 pieces per 152.4mm x 152.4mm area may be.

[0023] In the blank mask according to an embodiment, the diameter of the optical asperities may be 10 nm to 500 nm.

[0024] In the blank mask according to an embodiment, the difference between the density of optical asperities in the fourth region and the density of optical asperities in the first region, the second region, and the third region is 1 to 15 pieces per 152.4mm x 152.4mm area may be.

[0025] In the blank mask according to an embodiment, the number of optical asperities in each fourth region may be 3 or less.

[0026] In one embodiment of the blank mask, the photoresist layer includes a flat portion disposed on the light-shielding portion, and the optical irregularities may have different optical thicknesses from the light-shielding portion.

[0027] In one embodiment of the blank mask, the optical irregularities may include light path changing portions.

[0028] In one embodiment, the blank mask is such that the optical path changing portion has a different refractive index from the flat portion.

[0029] The method for manufacturing a semiconductor device according to the embodiment includes the steps of: preparing a blank mask including an optical substrate and a photoresist layer disposed on the optical substrate; forming a photomask using the blank mask; and patterning a semiconductor substrate using the photomask, wherein the optical substrate includes a light-transmitting substrate and a light-shielding film disposed on the light-transmitting substrate, and the photoresist layer includes 49 regions divided into 7 equally spaced regions in the transverse direction and 7 equally spaced regions in the vertical direction, wherein the 49 regions include a first region corresponding to the center of the optical substrate, a second region arranged around the periphery of the first region, a third region arranged around the periphery of the second region, and a fourth region corresponding to the outer edge of the optical substrate, wherein the density of optical irregularities in the fourth region is even greater than the density of optical irregularities in the first, second, and third regions.

[0030] A blank mask according to one embodiment includes a light-transmitting substrate, a light-shielding film disposed on the light-transmitting substrate, and a photoresist layer disposed on the light-shielding film, wherein the photoresist layer is divided into 7 equally spaced regions in the transverse direction and 7 equally spaced regions in the vertical direction, and the thickness deviation in the 49 regions may be less than 100 Å.

[0031] In one embodiment of the blank mask, the 49 regions include a first region corresponding to the center of the optical substrate, a second region arranged around the periphery of the first region, a third region arranged around the periphery of the second region, and a fourth region corresponding to the outer edge of the optical substrate, wherein the average thickness in the fourth region may be even greater than the average thickness in the third region.

[0032] In one embodiment of the blank mask, the average thickness in the fourth region may be about 3 Å to about 10 Å greater than the average thickness in the third region.

[0033] In one embodiment of the blank mask, the average thickness in the fourth region may be even greater than the average thickness in the second region.

[0034] In one embodiment of the blank mask, the average thickness in the first region may be even greater than the average thickness in the second region.

[0035] In one embodiment of the blank mask, the average thickness in the first region may be even greater than the average thickness in the third region.

[0036] The method for manufacturing a blank mask according to the embodiment includes the steps of forming an optical substrate including a light-shielding film disposed on a transparent substrate, and forming a photoresist layer on the light-shielding film while rotating the optical substrate, wherein the step of forming the photoresist layer includes the steps of first rotating the optical substrate, second rotating the optical substrate at a speed faster than the first rotation, third rotating the optical substrate at a speed faster than the second rotation, fourth rotating the optical substrate at a speed faster than the third rotation, fifth rotating the optical substrate at a speed slower than the fourth rotation, and sixth rotating the optical substrate at a speed slower than the fifth rotation.

[0037] In a method for manufacturing a blank mask according to one embodiment, the first rotational speed may be 30 rpm to 70 rpm, the second rotational speed may be 50 rpm to 100 rpm, the third rotational speed may be 70 rpm to 150 rpm, the fourth rotational speed may be 800 rpm to 3000 rpm, the fifth rotational speed may be 500 rpm to 2500 rpm, and the sixth rotational speed may be 100 rpm to 500 rpm.

[0038] In the method for manufacturing a blank mask according to one embodiment, the first rotation step, the second rotation step, the third rotation step, the fourth rotation step, the fifth rotation step, and the sixth rotation step can be carried out at a temperature of 20°C to 30°C.

[0039] In the method for manufacturing a blank mask according to one embodiment, the fourth rotation step can be performed for 0.5 to 2 seconds. [Effects of the Invention]

[0040] The blank mask according to the embodiment may include a photoresist layer with high overall thickness uniformity. This allows the photoresist layer to be precisely patterned during the exposure and development process. As a result, the blank mask according to the embodiment can be precisely patterned with a light-shielding film, providing a precise photomask.

[0041] In particular, in the blank mask according to the embodiment, the photoresist layer may have a relatively thicker outer region. That is, the process conditions may be adjusted so that the outer region of the photoresist layer is formed to be relatively a little thicker, so that the photoresist layer has a uniform thickness overall.

[0042] Furthermore, the process for forming the photoresist layer may include first to sixth rotation steps. This may result in the photoresist layer having a uniform thickness overall. In addition, the photoresist layer formed by the above process may have a relatively slightly thicker outer region.

[0043] Furthermore, the photoresist layer may include optical irregularities. In particular, the photoresist layer may be formed with an even higher optical density in the outer region. This allows the overall number of optical irregularities in the photoresist layer to be reduced.

[0044] In particular, the blank masks in the examples are Less than 30 pieces per 152.4mm x 152.4mm area The optical surface may include the aforementioned optical irregularities.

[0045] As a result, the method for manufacturing a blank mask according to the embodiment can embody a photoresist layer that has optical flatness as a whole. This allows the photoresist layer to be precisely patterned with the light-shielding film.

[0046] In particular, since the photoresist layer has the number of optical irregularities detectable by a 532nm laser as described above, it can be precisely developed using ultraviolet light.

[0047] As a result, the blank mask according to the example can provide a photomask with a precise pattern.

[0048] In particular, in the blank mask according to the embodiment, the photoresist layer may have a relatively thicker outer region. That is, the process conditions may be adjusted so that the outer region of the photoresist layer is formed to be relatively a little thicker, so that the photoresist layer has a uniform thickness overall.

[0049] Furthermore, the process for forming the photoresist layer may include first to sixth rotation steps. This may result in the photoresist layer having a uniform thickness overall. Also, because the photoresist layer is formed by the process described above, it may have a relatively slightly thicker outer region.

[0050] Furthermore, the photoresist layer may include optical irregularities. In particular, the photoresist layer may be formed with an even higher optical density in the outer region. This allows the overall number of optical irregularities in the photoresist layer to be reduced.

[0051] In particular, the blank masks in the examples are 30 pieces per 152.4mm x 152.4mm area It may include the aforementioned optical irregularities if it is less than [a certain value].

[0052] As a result, the method for manufacturing a blank mask according to the embodiment can embody a photoresist layer that has optical flatness as a whole. This allows the photoresist layer to be precisely patterned with the light-shielding film.

[0053] In particular, since the photoresist layer has the number of optical irregularities detectable by a 532nm laser as described above, it can be precisely developed using ultraviolet light.

[0054] As a result, the blank mask according to the example can provide a photomask with a precise pattern. [Brief explanation of the drawing]

[0055] [Figure 1] This is a cross-sectional view showing one cross-section of an optical substrate according to one embodiment. [Figure 2] This is a cross-sectional view showing one cross-section of an optical substrate according to another embodiment. [Figure 3] This is a cross-sectional view showing a cross-section of an optical substrate according to another embodiment. [Figure 4]This is a schematic diagram showing a blank mask manufacturing apparatus according to an example. [Figure 5] This is a cross-sectional view showing one cross-section of a blank mask according to the example. [Figure 6] This is a cross-sectional view showing an enlarged view of one cross-section of the blank mask according to the example. [Figure 7] This is a plan view showing the photoresist layer divided into 49 regions. [Figure 8] This is a cross-sectional view showing one cross-section of a photomask according to one embodiment. [Modes for carrying out the invention]

[0056] The following descriptions detail embodiments so that they can be easily implemented by a person with ordinary skill in the art to which the embodiments belong. However, embodiments can be embodied in a variety of different forms and are not limited to the embodiments described herein.

[0057] Terms such as “approximately” and “substantially” as used herein are used to mean, in or near the numerical value of the tolerances for manufacture and material inherent to the meaning referred to, and are used to prevent unscrupulous infringers from unfairly exploiting disclosures that refer to precise or absolute numerical values ​​in order to understand the specific examples.

[0058] Throughout this specification, the term “these combinations” as used in a Markush expression means one or more mixtures or combinations selected from the group of components described in the Markush expression, and includes one or more selected from the group of components.

[0059] Throughout this specification, the phrase "A and / or B" means "A, B, or A and B."

[0060] Throughout this specification, terms such as “First,” “Second,” or “A,” “B” are used to distinguish between the same terms unless otherwise specified.

[0061] In this specification, the meaning of B being located on A means that B is located on A, or that B may be located on A while other layers are located between them, and is not limited to B being located in contact with the surface of A.

[0062] In this specification, singular expressions are to be interpreted as including singular or plural, as interpreted in the context, unless otherwise specified.

[0063] Figure 1 is a cross-sectional view showing a cross-section of an optical substrate according to one embodiment. Figure 2 is a cross-sectional view showing a cross-section of an optical substrate according to another embodiment. Figure 3 is a cross-sectional view showing a cross-section of an optical substrate according to yet another embodiment. Figure 4 is a schematic diagram showing a blank mask manufacturing apparatus according to an embodiment. Figure 5 is a cross-sectional view showing a cross-section of a blank mask according to an embodiment. Figure 6 is an enlarged cross-sectional view showing a cross-section of a blank mask according to an embodiment. Figure 7 is a plan view showing a photoresist layer divided into 49 regions. Figure 8 is a cross-sectional view showing a cross-section of a photomask according to one embodiment.

[0064] The blank masks used in the examples may be manufactured by the following manufacturing process.

[0065] First, as shown in Figures 1 to 3, an optical substrate 10 can be provided. The optical substrate 10 includes a light-transmitting substrate 20 and a light-shielding film 30 located on the light-transmitting substrate 20.

[0066] The light-transmitting substrate 20 may have light transmittance to exposure light. The light-transmitting substrate 20 may have a transmittance of more than about 85% to exposure light with a wavelength of about 193 nm. The transmittance of the light-transmitting substrate 20 may be more than about 87%. The transmittance of the light-transmitting substrate 10 may be less than 99.99%. The light-transmitting substrate 20 may include a synthetic quartz substrate. In such a case, the light-transmitting substrate 20 can suppress the attenuation of transmitted light.

[0067] The light-transmitting substrate 20 has surface characteristics such as appropriate flatness and appropriate illuminance, so that distortion of transmitted light can be suppressed.

[0068] The light-shielding film 30 may be placed on the top surface of the light-transmitting substrate 20.

[0069] The light-shielding film 30 can selectively block at least some exposure light incident on the bottom side of the light-transmitting substrate 20.

[0070] Furthermore, as shown in Figure 3, when a phase-shift film 40 or the like is placed between the light-transmitting substrate 20 and the light-shielding film 30, the light-shielding film 30 can be used as an etching mask in the process of etching the phase-shift film 40 or the like according to the pattern shape.

[0071] The light-shielding film 30 may contain at least one of a transition metal, oxygen, and nitrogen.

[0072] The light-shielding film 30 may contain chromium, oxygen, nitrogen, and carbon. The elemental content of the entire light-shielding film 30 may differ in the thickness direction. If the light-shielding film 30 consists of multiple layers, the elemental content may differ for each layer.

[0073] The light-shielding film 30 may contain chromium in an amount of approximately 44 atom% to approximately 60 atom%. The light-shielding film 30 may contain chromium in an amount of approximately 47 atom% to approximately 57 atom%.

[0074] The light-shielding film 30 may contain carbon in an amount of approximately 5 atom% to 30 atom%. The light-shielding film 30 may contain carbon in an amount of approximately 7 atom% to approximately 25 atom%.

[0075] The light-shielding film 30 may contain nitrogen in an amount of approximately 3 atom% to approximately 20 atom%. The light-shielding film 30 may contain nitrogen in an amount of approximately 5 atom% to approximately 15 atom%.

[0076] The light-shielding film 30 may contain oxygen in an amount of approximately 20 atom% to approximately 45 atom%. The light-shielding film 30 may contain oxygen in an amount of approximately 25 atom% to approximately 40 atom%.

[0077] In such a case, the light-shielding film 30 may have sufficient light-extinguishing properties.

[0078] As shown in Figure 2, the light-shielding film 30 may include a first light-shielding layer 31 and a second light-shielding layer 32 disposed on the first light-shielding layer 31.

[0079] The second light-shielding layer 32 contains a transition metal. The second light-shielding layer 32 may also contain at least one of oxygen, nitrogen, and carbon. The second light-shielding layer 32 may contain a transition metal in a content of about 50 atom% to about 80 atom%. The second light-shielding layer 32 may contain a transition metal in a content of about 55 atom% to about 75 atom%. The second light-shielding layer 32 may contain a transition metal in a content of about 60 atom% to about 70 atom%.

[0080] The content of at least one element corresponding to oxygen, nitrogen, or carbon in the second light-shielding layer 32 may be about 10 atom% to about 35 atom%. The content of at least one element corresponding to oxygen, nitrogen, or carbon in the second light-shielding layer 32 may be about 15 atom% to about 25 atom%.

[0081] The second light-shielding layer 32 may contain nitrogen in an amount of approximately 5 atom% to approximately 20 atom%. The second light-shielding layer 32 may contain nitrogen in an amount of approximately 7 atom% to approximately 13 atom%.

[0082] The second light-shielding layer 32 may contain oxygen in an amount of approximately 5 atom% to approximately 20 atom%. The second light-shielding layer 32 may contain oxygen in an amount of approximately 7 atom% to approximately 13 atom%.

[0083] The second light-shielding layer 32 may contain carbon in an amount of about 2 atom% to about 10 atom%. The second light-shielding layer 32 may contain nitrogen in an amount of about 37 atom% to about 8 atom%.

[0084] The second light-shielding layer 32 may contain nitrogen, oxygen, and carbon.

[0085] In such a case, the light-shielding film 30 can form a laminate together with the phase-shift film 40, thereby assisting in substantially blocking the exposure light.

[0086] The first light-shielding layer 31 may contain a transition metal. The first light-shielding layer 31 may contain oxygen and nitrogen. The first light-shielding layer 31 may contain a transition metal in an amount of 30 atom% to 60 atom%. The light-shielding layer 21 may contain a transition metal in an amount of 35 atom% to 55 atom%. The first light-shielding layer 31 may contain a transition metal in an amount of 40 atom% to 50 atom%.

[0087] The sum of the oxygen and nitrogen content of the first light-shielding layer 31 may be between 40 atom% and 70 atom%. The sum of the oxygen and nitrogen content of the first light-shielding layer 31 may be between 45 atom% and 65 atom%. The sum of the oxygen and nitrogen content of the first light-shielding layer 31 may be between 50 atom% and 60 atom%.

[0088] The first light-shielding layer 31 may contain oxygen in an amount of 20 atom% to 40 atom%. The first light-shielding layer 31 may contain oxygen in an amount of 23 atom% to 33 atom%. The first light-shielding layer 31 may contain oxygen in an amount of 25 atom% to 30 atom%.

[0089] The first light-shielding layer 31 may contain nitrogen in an amount of 5 atom% to 20 atom%. The first light-shielding layer 31 may contain nitrogen in an amount of 7 atom% to 17 atom%. The first light-shielding layer 31 may contain nitrogen in an amount of 10 atom% to 15 atom%.

[0090] In such a case, the first light-shielding layer 31 can help the light-shielding film 30 to have excellent quenching properties.

[0091] The transition metal may include at least one of Cr, Ta, Ti, and Hf. The transition metal may also be Cr.

[0092] The thickness of the first light-shielding layer 31 may be approximately 250 Å to approximately 650 Å. The thickness of the first light-shielding layer 31 may be approximately 350 Å to approximately 600 Å. The thickness of the first light-shielding layer 31 may be approximately 400 Å to approximately 550 Å. In such cases, the first light-shielding layer 31 can assist the light-shielding film 30 in effectively blocking exposure light.

[0093] The thickness of the second light-shielding layer 32 may be about 30 Å to about 200 Å. The thickness of the second light-shielding layer 32 may be about 30 Å or more to about 100 Å. The thickness of the second light-shielding layer 32 may be about 40 Å to about 80 Å. In such cases, the second light-shielding layer 32 can improve the quenching characteristics of the light-shielding film 30 and help to further refine the surface profile of the side surface of the light-shielding pattern film 35 formed during the patterning of the light-shielding film 30.

[0094] The ratio of the thickness of the second light-shielding layer 32 to the thickness of the first light-shielding layer 31 may be about 0.05 to about 0.3. The ratio of the thickness of the second light-shielding layer 32 to the thickness of the first light-shielding layer 31 may be about 0.07 to about 0.25. The ratio of the thickness of the second light-shielding layer 32 to the thickness of the first light-shielding layer 31 may be about 0.1 to about 0.2.

[0095] In such a case, the light-shielding film 30 has sufficient quenching properties, and the surface profile of the side surface of the light-shielding pattern film 35 formed during the patterning of the light-shielding film 30 can be controlled with even greater precision.

[0096] The transition metal content of the second light-shielding layer 32 may be even greater than the transition metal content of the first light-shielding layer 31.

[0097] To further refine the surface profile of the side surface of the light-shielding pattern film 35 formed by patterning the light-shielding film 30, and to ensure that the surface reflectance of the light-shielding film 30 to inspection light in defect inspection is at a value suitable for inspection, the second light-shielding layer 32 may be required to have a higher transition metal content than the first light-shielding layer 31.

[0098] However, in such a case, during the heat treatment process of the formed light-shielding film 30, the transition metal contained in the second light-shielding layer 32 may undergo recovery, recrystallization, and grain growth. If grain growth occurs in the second light-shielding layer 32, which contains a high content of transition metal, the surface illuminance characteristics of the light-shielding film 30 may fluctuate excessively due to the overgrown transition metal particles. This can increase the number of false defects detected when inspecting the surface of the light-shielding film 30 for defects with high sensitivity.

[0099] The light-shielding film 30 may have a transmittance of approximately 1% to approximately 2% for light with a wavelength of 193 nm. The light-shielding film 30 may have a transmittance of approximately 1.3% to approximately 2% for light with a wavelength of 193 nm. The light-shielding film 30 may have a transmittance of approximately 1.4% to approximately 2% for light with a wavelength of 193 nm.

[0100] The light-shielding film 30 may have an optical density of approximately 1.8 to approximately 3. The light-shielding film 30 may have an optical density of approximately 1.9 to approximately 3.

[0101] In such a case, the thin film including the light-shielding film 30 can effectively suppress the transmission of exposure light.

[0102] As shown in Figure 3, the optical substrate 10 may further include a phase-shift film 40.

[0103] The phase-shift film 40 may be placed between the light-transmitting substrate 20 and the light-shielding film 30. The phase-shift film 40 may be a thin film that attenuates the intensity of the transmitted exposure light to adjust the phase difference and substantially suppresses diffracted light generated at the edges of the pattern.

[0104] The phase-shift film 40 may have a phase difference of approximately 170° to approximately 190° with respect to light with a wavelength of 193 nm. The phase-shift film 40 may have a phase difference of approximately 175° to approximately 185° with respect to light with a wavelength of 193 nm.

[0105] The phase-shift film 40 may have a transmittance of approximately 3% to approximately 10% for light with a wavelength of 193 nm. The phase-shift film 40 may have a transmittance of approximately 4% to approximately 8% for light with a wavelength of 193 nm. In such cases, the resolution of the photomask 200 containing the phase-shift film 40 can be improved.

[0106] The phase-shift film 40 may contain a transition metal and silicon. The phase-shift film 40 may contain a transition metal, silicon, oxygen, and nitrogen. The transition metal may be molybdenum.

[0107] A hard mask (not shown) may be positioned on the light-shielding film 30. The hard mask can act as an etching mask film when etching the pattern of the light-shielding film 30. The hard mask may contain silicon, nitrogen, and oxygen.

[0108] The method for manufacturing the optical substrate 10 includes the step of forming the light-shielding film 30 on the light-transmitting substrate 20. The light-shielding film 30 may be formed by a sputtering process.

[0109] After the sputtering process is performed, a heat treatment process can be carried out.

[0110] The aforementioned heat treatment step can be carried out at a temperature of approximately 200°C to approximately 400°C.

[0111] The aforementioned heat treatment step can be carried out for approximately 5 to 30 minutes.

[0112] Furthermore, the method for manufacturing the optical substrate 10 may further include a step of cooling the light-shielding film 30 that has undergone the heat treatment step.

[0113] The sputtering target can be selected considering the composition of the light-shielding film 30 to be formed. The sputtering target can be one target containing a transition metal. The sputtering target can include one target containing a transition metal, and two or more targets can be applied. The target containing a transition metal may contain 90 atom% or more of the transition metal. The target containing a transition metal may contain 95 atom% or more of the transition metal. The target containing a transition metal may contain 99 atom% of the transition metal.

[0114] The transition metal may include at least one of Cr, Ta, Ti, and Hf. The transition metal may also include Cr.

[0115] The aforementioned atmosphere gas may include an inert gas, a reactive gas, and a sputtering gas. The inert gas is a gas that does not contain the elements that constitute the deposited thin film. The reactive gas is a gas that contains the elements that constitute the deposited thin film.

[0116] The sputtering gas is a gas that is ionized in a plasma atmosphere and collides with the target. The inert gas may contain helium.

[0117] The reactive gas may include a gas containing the element nitrogen. Examples of the gas containing the element nitrogen may be N2, NO, NO2, N2O, N2O3, N2O4, or N2O5. The reactive gas may also include a gas containing the element oxygen.

[0118] The gas containing the element of oxygen may, for example, be O2. The reactive gas may contain a gas containing the element of nitrogen and a gas containing the element of oxygen. The reactive gas may contain a gas containing both the element of nitrogen and the element of oxygen. The gas containing both the element of nitrogen and the element of oxygen may, for example, be NO, NO2, N2O, N2O3, N2O4, or N2O5.

[0119] Furthermore, the reactive gas containing carbon and oxygen may be CO2.

[0120] The sputtering gas may be Ar gas.

[0121] The power supply used to apply power to the sputtering target can be a DC power supply or an RF power supply.

[0122] The cooled light-shielding film 30 can then be washed. The washing step may include an ultraviolet irradiation step and / or a rinsing step.

[0123] The ultraviolet irradiation step may include a step of irradiating the light-shielding film 30 with ultraviolet light.

[0124] The rinsing step includes a step of treating the light-shielding film 30 with a cleaning solution. The cleaning solution may contain at least one of deionized water, hydrogen water, ozonated water, or carbonated water. The cleaning solution may also contain carbonated water.

[0125] As shown in Figure 4, a coating apparatus is provided to form a photoresist layer 50 on the optical substrate 10. The coating apparatus includes a chamber 100, a chuck 200, an exhaust unit 400, a photoresist resin composition supply unit 500, and a spindle motor 700.

[0126] The chamber 100 houses the chuck 200. The chamber 100 can house an optical substrate 10 for manufacturing a blank mask. The chamber 100 can be isolated from the outside. The inside of the chamber 100 can be sealed. The internal pressure of the chamber 100 can be a vacuum lower than atmospheric pressure.

[0127] Furthermore, the chamber 100 may include a door or cover that can be opened and closed. The chamber 100 may also be equipped with a heater or the like that can adjust the internal temperature of the chamber 100.

[0128] The chuck 200 may include a support portion 210 and a guide portion 220.

[0129] The support portion 210 can support the guide portion 220 and the by-product removal portion 230. The support portion 210 supports the optical substrate 10. The support portion 210 may be positioned below the optical substrate 10.

[0130] The support portion 210 can temporarily fix the optical substrate 10. The support portion 210 can temporarily fix the optical substrate 10 by vacuum pressure or electrostatic force.

[0131] The guide portion 220 may be connected to the support portion 210. The guide portion 220 may be formed integrally with the support portion 210. The guide portion 220 may be positioned on the side surface 12 of the optical substrate 10. The guide portion 220 may surround the side surface 12 of the optical substrate 10.

[0132] The support portion 210 and the guide portion 220 can form a housing portion 240 for housing the optical substrate 10. That is, the support portion 210 may be positioned on the lower surface 13 of the optical substrate 10, and the guide portion 220 may be positioned on the side surface 12 of the optical substrate 10 to constitute the housing portion 240.

[0133] The housing portion 240 can correspond to the planar shape of the optical substrate 10. The planar shape of the housing portion 240 may be substantially similar to the planar shape of the optical substrate 10. The planar shape of the optical substrate 10 is square, and the planar shape of the housing portion 240 may also be square.

[0134] The outer casing of the guide portion 220 may be circular. The guide portion 220 and the support portion 210 may both be circular.

[0135] The exhaust unit 400 can exhaust the internal gas of the chamber 100. Furthermore, the exhaust unit 400 can discharge any photoresist composition remaining after coating the optical substrate 10. The exhaust unit 400 can also discharge any photoresist resin composition scattered to the side of the chuck 200.

[0136] The photoresist resin composition supply unit 500 can supply the photoresist resin composition 510 to the upper surface of the optical substrate 10. The photoresist resin composition 510 may include an injection nozzle 520 located within the chamber 100. The photoresist resin composition 510 can be dropped onto the optical substrate 10 via the injection nozzle 520. In other words, the photoresist resin composition supply unit 500 can spray the photoresist resin composition 510 onto the upper surface of the optical substrate 10.

[0137] The photoresist resin composition may be a negative-type photosensitive or radiation-sensitive resin composition. The photoresist composition is a resist composition for negative-type pattern formation and may be a negative-type resist composition for organic solvent development or a negative-type resist composition for alkaline development. The photoresist resin composition may typically be a chemically amplified resist composition.

[0138] The aforementioned photoresist resin composition may contain a binder resin, a photosensitive agent, and an organic solvent.

[0139] Examples of the binder resin include novolac resin, phenolic resin, epoxy resin, or polyimide resin. Examples of the binder resin include polyvinyl pyrolidone or poly(acrylamide-co-diacetoneacrylamide).

[0140] In the example of the photosensitive agent, at least one can be selected from the group consisting of 4,4'-diazido-2,2'-stilbendisulfonate sodium salt, 4,4'-diazo-2,2'-dibenzalacetone disodium salt, 2,5-bis(4-azido-2-sulfobenzylidene)cyclopentanone disodium salt, or 4,4'-diazido-2,2'-stilbendisulfonate sodium salt (DACA).

[0141] The aforementioned solvents include ethyl acetate, butyl acetate, diethylene glycol dimethyl ether, diethylene glycol dimethyl ethyl ether, dipropylene glycol dimethyl ether, methyl methoxypropionate, ethyl ethoxypropionate (EEP), ethyl lactate, propylene glycol methyl ether acetate (PGMEA), propylene glycol methyl ether, propylene glycol propyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, diethylene glycol methyl acetate, diethylene glycol ethyl acetate, acetone, methyl isobutyl ketone, and cyclohexyl At least one can be selected from the group consisting of sanone, dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), N-methyl-2-pyrrolidone (NMP), γ-butyrolactone, diethyl ether, ethylene glycol dimethyl ether, diglyme, tetrahydrofuran (THF), methanol, ethanol, propanol, isopropanol, methyl cellosolve, ethyl cellosolve, diethylene glycol methyl ether, diethylene glycol ethyl ether, dipropylene glycol methyl ether, toluene, xylene, hexane, heptane, and octane.

[0142] The solid content of the photoresist resin composition, excluding the solvent, may be about 3 wt% to about 20 wt% based on the total weight. The solid content of the photoresist resin composition, excluding the solvent, may be about 3 wt% to about 15 wt% based on the total weight. The solid content of the photoresist resin composition, excluding the solvent, may be about 5 wt% to about 10 wt% based on the total weight.

[0143] The photoresist resin composition may contain the binder resin in an amount of approximately 2 wt% to approximately 50 wt% based on the total weight. The photoresist resin composition may also contain the binder resin in an amount of approximately 3 wt% to approximately 15 wt%.

[0144] The photoresist composition may contain the photosensitive agent in an amount of about 0.5 wt% to about 40 wt%. The photoresist composition may contain the photosensitive agent in an amount of about 0.5 wt% to about 20 wt%. The photoresist composition may contain the photosensitive agent in an amount of about 0.5 wt% to about 10 wt%. The photoresist composition may contain the photosensitive agent in an amount of about 0.5 wt% to about 5 wt%.

[0145] The viscosity of the photoresist composition may be about 0.5 cPs to about 10 cPs. The viscosity of the photoresist composition may be about 1 cPs to about 5 cPs. The viscosity of the photoresist composition may be about 0.5 cPs to about 5 cPs.

[0146] The aforementioned photoresist resin composition may further contain additives such as labeling agents or adhesion aids.

[0147] The optical substrate 10 may be placed inside the chamber 100. The optical substrate 10 may be temporarily fixed to the chuck 200. The optical substrate 10 may be placed inside the housing. The optical substrate 10 can be securely attached to the chuck 200.

[0148] The photoresist layer 50 is formed on the optical substrate 10 using the coating apparatus.

[0149] Since the photoresist layer 50 is formed, the inside of the chamber 100 is isolated from the outside by the cover of the chamber 100. Then, with the chuck 200 rotating at high speed, the photoresist resin composition is dropped and coated onto the upper surface of the optical substrate 10 by the photoresist resin composition supply unit 500. This may form a photoresist resin composition layer on the optical substrate 10.

[0150] At this time, the chuck 200 can rotate the optical substrate 10 in the following manner.

[0151] First, the optical substrate 10 can undergo a first rotation step. This first rotation step can be performed at a temperature of approximately 20°C to approximately 30°C. This first rotation step can also be performed at a temperature of approximately 20°C to approximately 27°C.

[0152] The first rotational stage may have a first rotational speed. The first rotational speed may be about 30 rpm to about 70 rpm or about 40 rpm to about 60 rpm. The first rotational stage can be performed for about 1 second to about 5 seconds or about 2 seconds to about 4 seconds.

[0153] Furthermore, during the first rotation stage, the photoresist resin composition may be dropped onto the optical substrate 10. The dropping rate of the photoresist composition may be about 0.5 ml / second to about 5 ml / second or about 1 ml / second to about 4 ml / second.

[0154] The optical substrate 10 may undergo a second rotation stage after the first rotation stage. The second rotation stage can be performed at a temperature of approximately 20°C to approximately 30°C. The second rotation stage may have a second rotation speed. The second rotation speed may be approximately 50 rpm to approximately 100 rpm or approximately 60 rpm to approximately 90 rpm. The second rotation speed may be even greater than the speed of the first rotation stage. The second rotation speed may be even greater than the first rotation speed by approximately 5 rpm to approximately 70 rpm, approximately 10 rpm to approximately 70 rpm, or approximately 20 rpm to approximately 70 rpm. The second rotation stage can be performed for approximately 3 seconds to approximately 10 seconds.

[0155] The optical substrate 10 may undergo a third rotation stage after the second rotation stage. The third rotation stage can be performed at a temperature of approximately 20°C to approximately 30°C. The third rotation stage may have a third rotation speed. The third rotation speed may be approximately 100 rpm to approximately 150 rpm, approximately 110 rpm to approximately 140 rpm, or approximately 110 rpm to approximately 130 rpm. The third rotation speed may be even greater than the speed of the second rotation stage. The third rotation speed may be even greater than the second rotation speed by approximately 5 rpm to approximately 70 rpm, approximately 10 rpm to approximately 70 rpm, or approximately 20 rpm to approximately 70 rpm. The third rotation stage can be performed for approximately 5 seconds to approximately 13 seconds or approximately 6 seconds to approximately 12 seconds.

[0156] The optical substrate 10 may undergo a fourth rotation stage after the third rotation stage. The fourth rotation stage may be performed at a temperature of approximately 20°C to approximately 30°C. The fourth rotation stage may have a fourth rotation speed. The fourth rotation speed may be approximately 800 rpm to approximately 3000 rpm. The fourth rotation speed may be approximately 800 rpm to approximately 1500 rpm. The fourth rotation speed may be approximately 1500 rpm to approximately 2500 rpm. The fourth rotation speed may be approximately 2000 rpm to approximately 3000 rpm. The fourth rotation speed may be even higher than the third rotation speed. The fourth rotation speed may be approximately 700 rpm to approximately 2800 rpm higher than the third rotation speed. The speed in the fourth rotation stage may be approximately 500 rpm to approximately 2500 rpm higher than the speed in the third rotation stage. The fourth rotation stage may be performed for approximately 0.5 seconds to approximately 2 seconds.

[0157] The optical substrate 10 can undergo a fifth rotation after the fourth rotation stage. The fifth rotation stage can be performed at a temperature of approximately 20°C to approximately 30°C. The fifth rotation speed may be approximately 500 rpm to approximately 2500 rpm. The fifth rotation speed may be approximately 500 rpm to approximately 1200 rpm. The fifth rotation speed may be approximately 1000 rpm to approximately 2000 rpm. The fifth rotation speed may be approximately 1500 rpm to approximately 2500 rpm. The fifth rotation speed may be even lower than the fourth rotation speed. The fifth rotation speed may be even lower than the fourth rotation speed by approximately 300 rpm to approximately 1500 rpm. The fifth rotation stage can be performed for approximately 1 second to approximately 5 seconds.

[0158] The optical substrate 10 may undergo a sixth rotation stage after the fifth rotation stage. The sixth rotation stage may be performed at a temperature of approximately 20°C to approximately 30°C. The sixth rotation stage may have a sixth rotation speed. The sixth rotation speed may be approximately 100 rpm to approximately 500 rpm. The sixth rotation speed may be approximately 100 rpm to approximately 400 rpm. The sixth rotation speed may be approximately 100 rpm to approximately 300 rpm. The sixth rotation speed may be approximately 200 rpm to approximately 400 rpm. The sixth rotation speed may be lower than the fifth rotation speed. The sixth rotation speed may be even lower than the fifth rotation speed by approximately 200 rpm to approximately 2300 rpm. The sixth rotation time may be approximately 30 seconds to approximately 60 seconds.

[0159] During the six rotation steps, the photoresist resin composition layer formed on the optical substrate 10 dries, and the solvent can be removed.

[0160] As a result, the photoresist layer 50 may be formed on the optical substrate 10, as shown in Figure 5. This makes it possible to manufacture a blank mask including the optical substrate 10 and the photoresist layer 50.

[0161] As shown in Figure 6, the photoresist layer 50 may include a flat portion 51 and optical irregularities 52, 53.

[0162] The flat portion 51 may have a uniform thickness overall. Alternatively, the flat portion 51 may have a thickness deviation of less than approximately 100 Å overall. The flat portion 51 may have a thickness deviation of less than approximately 90 Å overall. The flat portion 51 may have a thickness deviation of less than approximately 80 Å overall. The flat portion 51 may have a thickness deviation of less than approximately 50 Å overall. The thickness deviation may be the difference between the maximum thickness and the minimum thickness of the flat portion 51.

[0163] The thickness of the flat portion 51 can be measured using a spectroscopic ellipsometer. The thickness of the flat portion 51 can be measured using Nano-View's SE MG series, SE MF series, SE MH series, or SE MI series, etc.

[0164] The thickness of the flat portion 51 may be approximately 1000 Å to approximately 10000 Å. The thickness of the flat portion 51 may be approximately 1000 Å to approximately 5000 Å. The thickness of the flat portion 51 may be approximately 1000 Å to approximately 4000 Å.

[0165] The optical irregularities 52 and 53 may have different optical thicknesses than the flat portion 51. The optical thickness of the flat portion 51 can be derived from the refractive index of the flat portion 51 and twice the thickness of the flat portion 51. Also, the optical thickness of the optical irregularities 52 and 53 can be derived from the refractive index of the optical irregularities 52 and 53 and twice the thickness of the optical irregularities 52 and 53.

[0166] The difference between the optical thickness of the flat portion 51 and the optical thickness of the optical irregularities 52 and 53 can exceed approximately 5 nm. The difference between the optical thickness of the flat portion 51 and the optical thickness of the optical irregularities 52 and 53 can exceed approximately 10 nm. The difference between the optical thickness of the flat portion 51 and the optical thickness of the optical irregularities 52 and 53 can exceed approximately 15 nm. The difference between the optical thickness of the flat portion 51 and the optical thickness of the optical irregularities 52 and 53 can exceed approximately 20 nm. The difference between the optical thickness of the flat portion 51 and the optical thickness of the optical irregularities 52 and 53 can exceed approximately 30 nm. The difference between the optical thickness of the flat portion 51 and the optical thickness of the optical irregularities 52 and 53 can exceed approximately 40 nm. The difference between the optical thickness of the flat portion 51 and the optical thickness of the optical irregularities 52 and 53 can exceed approximately 50 nm.

[0167] The maximum difference between the optical thickness of the flat portion 51 and the optical thickness of the optical irregularities 52 and 53 may be approximately 500 nm.

[0168] The diameters of the optical surface irregularities 52 and 53 can exceed approximately 10 nm. The diameters of the optical surface irregularities 52 and 53 can exceed approximately 20 nm. The diameters of the optical surface irregularities 52 and 53 can exceed approximately 30 nm. The diameters of the optical surface irregularities 52 and 53 can exceed approximately 40 nm. The diameters of the optical surface irregularities 52 and 53 can exceed approximately 50 nm. The diameters of the optical surface irregularities 52 and 53 can exceed approximately 70 nm. The diameters of the optical surface irregularities 52 and 53 can exceed approximately 100 nm.

[0169] The maximum diameter of the optical irregularities 52 and 53 may be approximately 500 nm.

[0170] Furthermore, the optical irregularities 52, 53 may include an optical path changing section. The optical path changing section can change the path of incident light. The optical path changing section distorts the path of light incident on the optical irregularities 52, 53, and the angle of incidence of the light and the angle of reflection at the optical irregularities 52, 53 may change relative to each other.

[0171] In other words, for light incident at the same angle, the reflection angle of the flat portion 51 and the reflection angles of the optical irregularities 52 and 53 may be different from each other.

[0172] The optical irregularities 52, 53 may include curved surfaces. The optical path changing portion may include the curved surfaces of the optical irregularities 52, 53.

[0173] As shown in Figure 8, the optical irregularities 52, 53 may include the first optical irregularities 52. The first optical irregularities 52 may be arranged within the photoresist layer 50. The first optical irregularities 52 may be arranged in a form immersed within the photoresist layer 50.

[0174] The first optical surface 52 may have a different refractive index than the flat portion 51. The difference between the refractive index of the first optical surface 52, 53 and the refractive index of the flat portion 51 may be approximately 0.05 to approximately 0.7, 0.03 to approximately 0.5, 0.01 to approximately 0.3, 0.1 to approximately 0.9, or approximately 0.1 to approximately 0.8. This can change the optical path at the interface between the first optical surface 52 and the flat portion 51. In other words, the reflection angle can be changed at the interface between the first optical surface 52 and the flat portion 51.

[0175] In other words, the optical path changing portion may include the interface between the first optical irregularities 52 and the flat portion 51. In other words, the optical path changing portion may include the curved surface of the first optical irregularities 52.

[0176] Furthermore, the second optical irregularities 53 may protrude from the upper surface of the photoresist layer 50. That is, the second optical irregularities 53 may cause irregularities to be generated in the photoresist layer 50. In other words, the height of the upper surface of the second optical irregularities 53 may be even higher than the height of the upper surface of the flat portion 51. The difference between the height of the upper surface of the second optical irregularities 53 and the height of the upper surface of the flat portion 51 may be about 1 nm to about 100 nm.

[0177] Furthermore, the portion of the second optical surface 53 that protrudes from the upper surface of the photoresist layer 50 may have a curved surface. That is, the upper surface of the second optical surface 53 may protrude from the photoresist layer 50 and have a curved surface.

[0178] The optical path changing portion may include the curved surface of the second optical surface 53. The optical path changing portion may also include the exposed upper surface of the second optical surface 53.

[0179] The optical irregularities 52 and 53 can be detected by light of approximately 532 nm. The optical irregularities 52 and 53 can be detected by a laser of approximately 532 nm. The laser is irradiated onto the photoresist layer 50, and the optical irregularities 52 and 53 can be detected by analyzing the light reflected from the photoresist layer 50.

[0180] After the laser irradiates the photoresist layer 50, the reflected light can be sensed via an image sensor. The light reflected from the photoresist layer 50 can be sensed by the image sensor via a confocal and a spatial filter. Subsequently, the signal sensed by the image sensor can be processed into an 8-beat, 256-level grayscale image. The image can be processed at 640 x 480 pixels.

[0181] Furthermore, when a difference exceeding approximately 3 tones occurs in the pixels of the image, it can be detected by the optical surface irregularities 52, 53. When a difference exceeding approximately 5 tones occurs in the pixels of the image, it can be detected by the optical surface irregularities 52, 53. When a difference exceeding approximately 7 tones occurs in the pixels of the image, it can be detected by the optical surface irregularities 52, 53. When a difference exceeding approximately 10 tones occurs in the pixels of the image, it can be detected by the optical surface irregularities 52, 53.

[0182] Furthermore, the average area of ​​the optical surface irregularities 52 and 53 can be calculated based on the number of pixels detected in the optical surface irregularities 52 and 53 in the image.

[0183] The optical irregularities 52, 53 can be detected by optical surface inspection equipment. The optical irregularities 52, 53 can be detected by LASERTEC's M6640S or M6641S.

[0184] The number of optical irregularities 52, 53 in the photoresist layer 50 is Approximately 50 pieces per 152.4mm x 152.4mm area. It may be less than the number of optical irregularities 52, 53 in the photoresist layer 50. Approximately 40 pieces per 152.4mm x 152.4mm area. It may be less than the number of optical irregularities 52, 53 in the photoresist layer 50. Approximately 30 pieces per 152.4mm x 152.4mm area. It may be less than the number of optical irregularities 52, 53 in the photoresist layer 50. Approximately less than 20 pieces per 152.4mm x 152.4mm area. It may also be the case that the number of optical irregularities 52, 53 in the photoresist layer 50 is Approximately 10 pieces per 152.4mm x 152.4mm area. It is acceptable to be less than [a certain value].

[0185] The number of optical irregularities 52, 53 in the photoresist layer 50 is Approximately 1 to less than 50 pieces per 152.4mm x 152.4mm area It may also be the case that the number of optical irregularities 52, 53 in the photoresist layer 50 is Approximately 1 to less than 40 pieces per 152.4mm x 152.4mm area It may also be the case that the number of optical irregularities 52, 53 in the photoresist layer 50 is Approximately 1 to less than 30 pieces per 152.4mm x 152.4mm area It may also be the case that the number of optical irregularities 52, 53 in the photoresist layer 50 is Approximately 1 to less than 20 pieces per 152.4mm x 152.4mm area It may also be the case that the number of optical irregularities 52, 53 in the photoresist layer 50 is Approximately 1 to less than 10 items per 152.4mm x 152.4mm area. That's fine.

[0186] Since the photoresist layer 50 contains the optical irregularities 52 and 53 in the number described above, the photoresist layer 50 can be precisely developed. That is, since the photoresist layer 50 contains the optical irregularities 52 and 53 in the number described above, the precision of the photoresist layer 50 in the exposure process can be improved. As a result, the method for manufacturing a blank mask according to the embodiment can provide a precise photomask.

[0187] As shown in Figure 7, the photoresist layer 50 may include 49 regions.

[0188] The 49 regions can be defined by seven virtual lines arranged horizontally at regular intervals and seven virtual lines arranged vertically at regular intervals. That is, the 49 regions may be formed by dividing the photoresist layer 50 into seven horizontally at regular intervals and seven vertically at regular intervals when viewed from above. In other words, the 49 regions have a square shape and can divide the photoresist into sections of the same size. For example, the 49 regions may be squares with a horizontal length and a vertical length of 6 / 7 inch.

[0189] Furthermore, the 49 regions may include a first region (1-1), a second region (2-1, 2-2 ... 2-8), a third region (3-1, 3-2 ... 3-16), and a fourth region (4-1, 4-2 ... 4-24).

[0190] The first region (1-1) may be located in the central part of the photoresist layer 50. More specifically, the first region (1-1) may be located in the middle of the photoresist layer 50.

[0191] The second region (2-1, 2-2 ... 2-8) may be arranged around the first region (1-1). The second region (2-1, 2-2 ... 2-8) may surround the first region (1-1). The second region (2-1, 2-2 ... 2-8) may be directly adjacent to the first region (1-1).

[0192] The third region (3-1, 3-2 ... 3-16) may be arranged around the second region (2-1, 2-2 ... 2-8). The third region (3-1, 3-2 ... 3-16) may surround the second region (2-1, 2-2 ... 2-8). The third region (3-1, 3-2 ... 3-16) may be directly adjacent to the second region (2-1, 2-2 ... 2-8).

[0193] The fourth region (4-1, 4-2 ... 4-24) may be arranged around the third region (3-1, 3-2 ... 3-16). The fourth region (4-1, 4-2 ... 4-24) may surround the third region (3-1, 3-2 ... 3-16). The fourth region (4-1, 4-2 ... 4-24) may be directly adjacent to the third region (3-1, 3-2 ... 3-16). The fourth region (4-1, 4-2 ... 4-24) may be located on the outermost edge of the photoresist layer 50.

[0194] In the 49 regions, the thickness deviation of the photoresist layer 50 may be less than approximately 100 Å. The thickness deviation may be the difference between the maximum thickness and the minimum thickness in the 49 regions. In the 49 regions, the thickness deviation of the photoresist layer 50 may be less than approximately 90 Å. In the 49 regions, the thickness deviation of the photoresist layer 50 may be less than approximately 80 Å. In the 49 regions, the thickness deviation of the photoresist layer 50 may be less than approximately 70 Å. In the 49 regions, the thickness deviation of the photoresist layer 50 may be less than approximately 60 Å. In the 49 regions, the thickness deviation of the photoresist layer 50 may be less than approximately 50 Å.

[0195] In the aforementioned 49 regions, the minimum value of the thickness deviation of the photoresist layer 50 may be approximately 3 Å.

[0196] In the photoresist layer 50, the average thickness of the fourth region (4-1, 4-2 ... 4-24) may be greater than the average thickness of the third region (3-1, 3-2 ... 3-16). In the photoresist layer 50, the average thickness of the fourth region (4-1, 4-2 ... 4-24) may be about 3 Å to about 10 Å greater than the average thickness of the third region (3-1, 3-2 ... 3-16). In the photoresist layer 50, the average thickness of the fourth region (4-1, 4-2 ... 4-24) may be about 4 Å to about 10 Å greater than the average thickness of the third region (3-1, 3-2 ... 3-16). In the photoresist layer 50, the average thickness of the fourth region (4-1, 4-2 ... 4-24) may be about 5 Å to about 10 Å greater than the average thickness of the third region (3-1, 3-2 ... 3-16).

[0197] In the photoresist layer 50, the average thickness of the fourth region (4-1, 4-2 ... 4-24) may be greater than the average thickness of the second region (2-1, 2-2 ... 2-8). In the photoresist layer 50, the average thickness of the fourth region (4-1, 4-2 ... 4-24) may be about 3 Å to about 10 Å greater than the average thickness of the second region (2-1, 2-2 ... 2-8). In the photoresist layer 50, the average thickness of the fourth region (4-1, 4-2 ... 4-24) may be about 4 Å to about 10 Å greater than the average thickness of the second region (2-1, 2-2 ... 2-8). In the photoresist layer 50, the average thickness of the fourth region (4-1, 4-2 ... 4-24) may be about 5 Å to about 10 Å greater than the average thickness of the second region (2-1, 2-2 ... 2-8).

[0198] In the photoresist layer 50, the average thickness of the fourth region (4-1, 4-2 ... 4-24) may be greater than the average thickness of the first region (1-1). In the photoresist layer 50, the average thickness of the fourth region (4-1, 4-2 ... 4-24) may be about 3 Å to about 10 Å greater than the average thickness of the first region (1-1). In the photoresist layer 50, the average thickness of the fourth region (4-1, 4-2 ... 4-24) may be about 4 Å to about 10 Å greater than the average thickness of the first region (1-1). In the photoresist layer 50, the average thickness of the fourth region (4-1, 4-2 ... 4-24) may be about 5 Å to about 10 Å greater than the average thickness of the first region (1-1).

[0199] In the photoresist layer 50, the average thickness of the first region (1-1) may be greater than the average thickness of the second region (2-1, 2-2 ... 2-8). In the photoresist layer 50, the average thickness of the first region (1-1) may be greater by about 3 Å to about 10 Å than the average thickness of the second region (2-1, 2-2 ... 2-8). In the photoresist layer 50, the average thickness of the first region (1-1) may be greater by about 4 Å to about 10 Å than the average thickness of the second region (2-1, 2-2 ... 2-8). In the photoresist layer 50, the average thickness of the first region (1-1) may be greater by about 5 Å to about 10 Å than the average thickness of the second region (2-1, 2-2 ... 2-8).

[0200] In the photoresist layer 50, the average thickness of the first region (1-1) may be greater than the average thickness of the third region (3-1, 3-2 ... 3-16). In the photoresist layer 50, the average thickness of the first region (1-1) may be greater than the average thickness of the third region (3-1, 3-2 ... 3-16) by about 3 Å to about 10 Å. In the photoresist layer 50, the average thickness of the first region (1-1) may be greater than the average thickness of the third region (3-1, 3-2 ... 3-16) by about 4 Å to about 10 Å. In the photoresist layer 50, the average thickness of the first region (1-1) may be greater than the average thickness of the third region (3-1, 3-2 ... 3-16) by about 5 Å to about 10 Å.

[0201] The density of optical irregularities in the fourth region (4-1, 4-2 ... 4-24) may be even greater than the density of optical irregularities in the first region (1-1), the second region (2-1, 2-2 ... 2-8), and the third region (3-1, 3-2 ... 3-16). The density of optical irregularities is the value obtained by dividing the number of optical irregularities by the area of ​​the region in which the optical irregularities are arranged.

[0202] In other words, the density of optical irregularities in the fourth region (4-1, 4-2 ... 4-24) may be the value obtained by dividing the total number of optical irregularities arranged in the fourth region (4-1, 4-2 ... 4-24) by the total area of ​​the fourth region (4-1, 4-2 ... 4-24).

[0203] Furthermore, the density of optical irregularities in the first region (1-1), the second region (2-1, 2-2 ... 2-8), and the third region (3-1, 3-2 ... 3-16) is the value obtained by dividing the total number of optical irregularities arranged in the first region (1-1), the second region (2-1, 2-2 ... 2-8), and the third region (3-1, 3-2 ... 3-16) by the total area of ​​the first region (1-1), the second region (2-1, 2-2 ... 2-8), and the third region (3-1, 3-2 ... 3-16).

[0204] The density of optical surface irregularities in the aforementioned fourth region (4-1, 4-2 ... 4-24) is: Approximately 15 to 25 pieces per 152.4mm x 152.4mm area It may also be the case that the density of optical surface irregularities in the fourth region (4-1, 4-2 ... 4-24) is Approximately 10 to 30 pieces per 152.4mm x 152.4mm area It may also be the case that the density of optical surface irregularities in the fourth region (4-1, 4-2 ... 4-24) is Approximately 17 to 22 pieces per 152.4mm x 152.4mm area That's fine.

[0205] The density of optical surface irregularities in the first region (1-1), the second region (2-1, 2-2 ... 2-8), and the third region (3-1, 3-2 ... 3-16) is: Approximately 5 to 20 pieces per 152.4mm x 152.4mm area It may also be the case that the density of optical surface irregularities in the first region (1-1), the second region (2-1, 2-2 ... 2-8), and the third region (3-1, 3-2 ... 3-16) is Approximately 3 to 25 pieces per 152.4mm x 152.4mm area. It may also be the case that the density of optical surface irregularities in the first region (1-1), the second region (2-1, 2-2 ... 2-8), and the third region (3-1, 3-2 ... 3-16) is Approximately 7 to 15 pieces per 152.4mm x 152.4mm area That's fine.

[0206] The difference between the density of optical surface irregularities in the fourth region (4-1, 4-2 ... 4-24) and the density of optical surface irregularities in the first region (1-1), the second region (2-1, 2-2 ... 2-8), and the third region (3-1, 3-2 ... 3-16) is: Approximately 1 to 20 pieces per 152.4mm x 152.4mm area It may also be the case that the difference between the density of optical surface irregularities in the fourth region (4-1, 4-2 ... 4-24) and the density of optical surface irregularities in the first region (1-1), the second region (2-1, 2-2 ... 2-8), and the third region (3-1, 3-2 ... 3-16) is Approximately 1 to 15 pieces per 152.4mm x 152.4mm area It may also be the case that the difference between the density of optical surface irregularities in the fourth region (4-1, 4-2 ... 4-24) and the density of optical surface irregularities in the first region (1-1), the second region (2-1, 2-2 ... 2-8), and the third region (3-1, 3-2 ... 3-16) is Approximately 3 to 15 pieces per 152.4mm x 152.4mm area It may also be the case that the difference between the density of optical surface irregularities in the fourth region (4-1, 4-2 ... 4-24) and the density of optical surface irregularities in the first region (1-1), the second region (2-1, 2-2 ... 2-8), and the third region (3-1, 3-2 ... 3-16) is Approximately 5 to 10 pieces per 152.4mm x 152.4mm area That's fine.

[0207] Furthermore, the number of optical irregularities in each of the fourth regions may be three or less. The number of optical irregularities in each of the fourth regions may be two or less.

[0208] Furthermore, the number of optical irregularities in each of the third regions may be three or less. The number of optical irregularities in each of the third regions may be two or less.

[0209] Furthermore, the number of optical irregularities in each second region may be 3 or less. The number of optical irregularities in each second region may be 2 or less.

[0210] Furthermore, the number of optical irregularities in the first region (1-1) may be 3 or less. The number of optical irregularities in the first region (1-1) may be 2 or less.

[0211] Furthermore, the total number of optical irregularities in the fourth region (4-1, 4-2 ... 4-24) may be approximately 1 to approximately 20. The total number of optical irregularities in the fourth region (4-1, 4-2 ... 4-24) may be approximately 3 to approximately 15.

[0212] Furthermore, the total number of optical irregularities in the first region (1-1), the second region (2-1, 2-2 ... 2-8), and the third region (3-1, 3-2 ... 3-16) may be 0 to approximately 15. The total number of optical irregularities in the first region (1-1), the second region (2-1, 2-2 ... 2-8), and the third region (3-1, 3-2 ... 3-16) may be 1 to approximately 10. The total number of optical irregularities in the first region (1-1), the second region (2-1, 2-2 ... 2-8), and the third region (3-1, 3-2 ... 3-16) may be 2 to approximately 7.

[0213] The photoresist layer 50 may be selectively irradiated with light, and the light-shielding film may be selectively etched to form a light-shielding pattern film 35. This may form a photomask 2 including the light-transmitting substrate 20 and the light-shielding pattern film 35 disposed on the light-transmitting substrate 20, as shown in Figure 9.

[0214] The light-shielding pattern film 35 contains at least one of a transition metal, oxygen, and nitrogen.

[0215] The light-shielding pattern film 35 may be formed by patterning the light-shielding film 30 of the blank mask 100 described above.

[0216] The description of the physical properties, composition, and structure of the light-shielding pattern film 35 is omitted as it overlaps with the description of the light-shielding film 30 of the blank mask 1.

[0217] The method for manufacturing a semiconductor device according to the embodiment includes a preparation step of arranging a light source, a photomask 2, and a semiconductor wafer coated with a resist film; an exposure step of selectively transmitting and emitting light incident from the light source through the photomask 2 onto the semiconductor wafer; and a development step of developing a pattern on the semiconductor wafer.

[0218] The photomask 2 includes a light-transmitting substrate 20 and a light-shielding pattern film 35 disposed on the light-transmitting substrate 20.

[0219] The light-shielding pattern film 35 contains at least one of a transition metal, oxygen, nitrogen, and carbon.

[0220] In the preparation stage described above, the light source is a device capable of generating short-wavelength exposure light. The exposure light may have a wavelength of 200 nm or less. The exposure light may also be ArF light with a wavelength of 193 nm.

[0221] A lens may be further placed between the photomask 2 and the semiconductor wafer. The lens has the function of reducing the shape of the circuit pattern on the photomask 2 and transferring it onto the semiconductor wafer. The lens is not limited as long as it can be generally applied to the exposure process of ArF semiconductor wafers. For example, the lens may be made of calcium fluoride (CaF2).

[0222] In the exposure step, exposure light can be selectively transmitted onto the semiconductor wafer through the photomask 2. In this case, chemical modification may occur in the portion of the resist film that is incident on by the exposure light.

[0223] In the development step, the semiconductor wafer after the exposure step can be treated with a developing solution to develop a pattern on the semiconductor wafer. If the coated resist film is a positive resist, the portion of the resist film that has been exposed to light can be dissolved by the developing solution. If the coated resist film is a negative resist, the portion of the resist film that has not been exposed to light can be dissolved by the developing solution. The developing solution treatment forms a resist pattern in the resist film. The resist pattern can then be used as a mask to form a pattern on the semiconductor wafer.

[0224] The explanation regarding the aforementioned photomask 2 is omitted as it overlaps with the content above.

[0225] The method for manufacturing a blank mask according to the example includes the step of maintaining a state in which the inside of the nozzle 520, which sprays the photoresist composition, is filled with the photoresist composition. The method for manufacturing a blank mask according to the example also includes the step of removing the photoresist composition from inside the nozzle 520. This makes it possible to easily remove any residue adhering to the inside of the nozzle 520.

[0226] As a result, the method for manufacturing a blank mask according to the example can prevent the residue 513 from flowing into the photoresist layer 50.

[0227] As a result, the blank mask according to the embodiment can reduce the number of optical irregularities 52, 53 that may be caused by the aforementioned residues, etc. The blank mask according to the embodiment is Less than 30 pieces per 152.4mm x 152.4mm area The optical surface 52, 53 may also be included.

[0228] As a result, the method for manufacturing a blank mask according to the embodiment can embody a photoresist layer 50 that has optical flatness as a whole. This allows the photoresist layer 50 to precisely pattern the light-shielding film.

[0229] The blank mask according to the embodiment may include a photoresist layer 50 with high overall thickness uniformity. This allows the photoresist layer 50 to be precisely patterned during the exposure and development process. As a result, the blank mask according to the embodiment can be precisely patterned as a light-shielding film, providing a precise photomask.

[0230] In particular, in the blank mask according to the embodiment, the photoresist layer 50 may have a relatively thicker outer region. That is, the process conditions may be adjusted so that the outer region of the photoresist layer 50 is formed to be relatively a little thicker, so that the photoresist layer 50 has a uniform thickness overall.

[0231] Furthermore, the process for forming the photoresist layer 50 may include first to sixth rotation steps. This may result in the photoresist layer 50 having a uniform thickness overall. Also, because the photoresist layer 50 is formed by the process described above, it may have a relatively slightly thicker outer region.

[0232] Furthermore, the photoresist layer 50 may include optical irregularities. In particular, the photoresist layer 50 may be formed with an even higher optical density in its outer region. This allows the photoresist layer 50 to reduce the overall number of optical irregularities.

[0233] In particular, the blank masks in the examples are Less than 30 pieces per 152.4mm x 152.4mm area The optical surface may include the aforementioned optical irregularities.

[0234] As a result, the method for manufacturing a blank mask according to the embodiment can embody a photoresist layer 50 that has optical flatness as a whole. This allows the photoresist layer 50 to precisely pattern the light-shielding film.

[0235] In particular, since the photoresist layer 50 has the number of optical irregularities that can be detected by a 532nm laser as described above, it can be precisely developed by ultraviolet light.

[0236] As a result, the blank mask according to the example can provide a photomask with a precise pattern.

[0237] As a result, the blank mask according to the embodiment can reduce the number of optical irregularities 52, 53 that may be caused by the residue 513, etc. The blank mask according to the embodiment is Less than 30 pieces per 152.4mm x 152.4mm area The optical surface 52, 53 may also be included.

[0238] As a result, the method for manufacturing a blank mask according to the embodiment can embody a photoresist layer 50 that has optical flatness as a whole. This allows the photoresist layer 50 to precisely pattern the light-shielding film.

[0239] As a result, the blank mask according to the example can provide a photomask with a precise pattern.

[0240] The blank mask manufacturing apparatus and manufacturing method according to the embodiment can provide a blank mask with improved performance.

[0241] As described above, preferred embodiments of the present invention have been explained in detail, but the scope of the present invention is not limited thereto. Various modifications and improvements made by those skilled in the art, utilizing the basic concepts of the present invention as defined in the following claims, also fall within the scope of the present invention.

[0242] Manufacturing example Photoresist composition #1 FEP171 solution (FUJIFILM Arch Co, Ltd.) was used, with PGMEA (propylene glycol monomethyl ether acetate) and PGME (propylene glycol monomethyl ether) used as solvents in an 8:2 ratio. The solid content of the FEP171 solution was approximately 8.5 wt%. The viscosity of the FEP171 solution was approximately 3 cP.

[0243] Photoresist composition #2 XFP255 solution (FUJIFILM Arch Co, Ltd.) was used, with PGMEA (propylene glycol monomethyl ether acetate) and PGME (propylene glycol monomethyl ether) used as solvents in an 8:2 ratio. The solid content of the XFP255 solution was approximately 6.5 wt%. The viscosity of the XFP255 solution was approximately 1.5 cP.

[0244] Example 1 about 152.4mm x approx. 152.4mm A quartz substrate having the following dimensions is used, and the quartz substrate is 6.35mm The substrate has a thickness of approximately (600-1000 Å) of MoSi and approximately (500-900 Å) of Cr film. A MoSi film was formed on the quartz substrate by sputtering. Subsequently, the quartz substrate on which the MoSi and Cr films were formed was fixed to a chuck.

[0245] After the FEP171 solution was dropped onto the quartz substrate from a nozzle at a height of approximately 0.5 cm, the quartz substrate was rotated for approximately 3 seconds at a temperature of approximately 23 degrees Celsius and a speed of approximately 50 rpm (stage 1). Subsequently, the quartz substrate was rotated for 5 seconds at a temperature of approximately 23 degrees Celsius and a speed of approximately 80 rpm (stage 2), then for 8 seconds at a temperature of approximately 23 degrees Celsius and a speed of approximately 100 rpm (stage 3), then for 1 second at a temperature of approximately 23 degrees Celsius and a speed of approximately 2200 rpm (stage 4), and finally for 3 seconds at a temperature of approximately 23 degrees Celsius and a speed of approximately 1750 rpm (stage 5).

[0246] Subsequently, the quartz substrate was rotated for over 40 minutes at a speed of approximately 300 rpm and a temperature of approximately 23°C (in 6 stages).

[0247] This resulted in the manufacture of an optical substrate on which a photoresist layer was formed.

[0248] Examples 2-5 and Comparative Examples The nozzle height, resist composition, and coating conditions were adjusted as shown in Tables 1 and 2 below. Other steps refer to Example 1.

[0249] [Table 1]

[0250] [Table 2]

[0251] Evaluation example 1. Thickness of the resist layer The resist layer was divided into seven equally spaced sections in both the horizontal and vertical directions, resulting in a total of 49 regions. The thickness of each region in the resist layer was measured. The thickness was measured using a spectroscopic elliptic analyzer (manufacturer: Nano-View CO.,LTD, brand: MG-PRO).

[0252] 2. Number of optical surface irregularities In the optical substrates manufactured in the examples and comparative examples, the number of optical irregularities in each region of the resist layer was measured using optical surface inspection equipment (LASERTEC M6641S). The optical irregularities have a diameter of 0.01 μm to 10 μm.

[0253] As shown in Table 3 below, the thickness of the resist layer produced in Example 1 was measured in 49 regions. In Table 3, Figure 8 is referenced, and each region is divided into columns and rows, with the unit being Å.

[0254] [Table 3]

[0255] As shown in Table 4 below, the thickness of the resist layer produced in Example 2 was measured in 49 regions. In Table 4, Figure 8 is referenced, and each region is divided into columns and rows, with the unit being Å.

[0256] [Table 4]

[0257] As shown in Table 5 below, the thickness of the resist layer produced in Example 3 was measured in 49 regions. In Table 5, Figure 8 is referenced, and each region is divided into columns and rows, with the unit being Å.

[0258] [Table 5]

[0259] As shown in Table 6 below, the thickness of the resist layer produced in Example 4 was measured in 49 regions. In Table 6, Figure 8 is referenced, and each region is divided into columns and rows, with the unit being Å.

[0260] [Table 6]

[0261] As shown in Table 7 below, the thickness of the resist layer produced in Example 5 was measured in 49 regions. In Table 7, Figure 8 is referenced, and each region is divided into columns and rows, with the unit being Å.

[0262] [Table 7]

[0263] As shown in Table 8 below, the thickness of the resist layer produced in Comparative Example 1 was measured in 49 regions. In Table 8, reference is made to Figure 8, each region is divided into columns and rows, and the unit was Å.

[0264]

Table 8

[0265] As shown in Table 9 below, the thickness of the resist layer produced in Comparative Example 2 was measured in 49 regions. In Table 9, reference is made to Figure 8, each region is divided into columns and rows, and the unit was Å.

[0266]

Table 9

[0267] As shown in Table 10 below, the thickness of the resist layer produced in Comparative Example 3 was measured in 49 regions. In Table 10, reference is made to Figure 8, each region is divided into columns and rows, and the unit was Å.

[0268]

Table 10

[0269] As shown in Table 11 below, the thickness of the resist layer produced in Comparative Example 4 was measured in 49 regions. In Table 11, reference is made to Figure 8, each region is divided into columns and rows, and the unit was Å.

[0270]

Table 11

[0271] As shown in Table 12 below, in the resist layer produced in Example 1, the number of optical asperities was measured in 49 regions. In Table 12, reference is made to Figure 8, and each region was divided into columns and rows.

[0272]

Table 12

[0273] As shown in Table 13 below, in the resist layer produced in Example 2, the number of optical asperities was measured in 49 regions. In Table 13, reference is made to Figure 8, and each region was divided into columns and rows.

[0274]

Table 13

[0275] As shown in Table 14 below, in the resist layer produced in Example 3, the number of optical asperities was measured in 49 regions. In Table 14, reference is made to Figure 8, and each region was divided into columns and rows.

[0276]

Table 14

[0277] As shown in Table 15 below, in the resist layer produced in Example 4, the number of optical asperities was measured in 49 regions. In Table 15, reference is made to Figure 8, and each region was divided into columns and rows.

[0278]

Table 15

[0279] As shown in Table 16 below, in the resist layer produced in Example 5, the number of optical asperities was measured in 49 regions. In Table 16, reference is made to Figure 8, and each region was divided into columns and rows.

[0280]

Table 16

[0281] As shown in Table 17 below, in the resist layer manufactured in Comparative Example 1, the number of optical irregularities was measured in 49 regions. In Table 17, Figure 8 is referenced, and each region is divided into columns and rows.

[0282] [Table 17]

[0283] As shown in Table 18 below, in the resist layer manufactured in Comparative Example 2, the number of optical irregularities was measured in 49 regions. Table 18 refers to Figure 8, where each region is divided into columns and rows.

[0284] [Table 18]

[0285] As shown in Table 19 below, in the resist layer manufactured in Comparative Example 3, the number of optical irregularities was measured in 49 regions. In Table 19, Figure 8 is referenced, and each region is divided into columns and rows.

[0286] [Table 19]

[0287] As shown in Table 20 below, the number of optical irregularities in the resist layer manufactured in Comparative Example 4 was measured in 49 regions. In Table 20, Figure 8 is referenced, and each region is divided into columns and rows.

[0288] [Table 20]

[0289] As shown in Tables 12 to 20, the photoresist layers in the examples contain optical irregularities with a small number of particles. [Explanation of Symbols]

[0290] 10 Optical substrate 30 shading film 50 フォトレジストlayer 51 Flat section 52,53 Optical Convexity

Claims

1. A light-transmitting substrate and an optical substrate including a light-shielding film disposed on the light-transmitting substrate, The optical substrate includes a photoresist layer disposed on the optical substrate, The photoresist layer includes 49 regions, each divided into seven equally spaced regions in the horizontal direction and seven equally spaced regions in the vertical direction. The aforementioned 49 regions are, A first region corresponding to the center of the optical substrate, A second region is arranged along the periphery of the first region, A third region is arranged along the periphery of the second region, A fourth region corresponding to the outer casing of the optical substrate, Includes, The thickness deviation in the aforementioned 49 regions is less than 100 Å, The aforementioned photoresist layer includes optical irregularities, The optical irregularities are detected by a 532 nm laser and arranged on the light-shielding film at a rate of less than 30 per 152.4 mm × 152.4 mm area. The average thickness in the fourth region is 3 Å to 10 Å greater than the average thickness in the third region. Blank mask.

2. The diameter of the optical surface is 10 nm to 500 nm. The blank mask according to claim 1.

3. The average thickness in the fourth region is even greater than the average thickness in the second region. The blank mask according to claim 1.

4. The number of optical surface features in each of the fourth regions is three or less. The blank mask according to claim 1.

5. The photoresist layer includes a flat portion disposed on the light-shielding portion, The optical irregularities have different optical thicknesses from the flat portion. The blank mask according to claim 1.

6. The optical irregularities include an optical path changing portion. The blank mask according to claim 5.

7. The optical path changing section has a refractive index different from that of the flat section. The blank mask according to claim 6.

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