JP5588633B2 - Phase shift mask manufacturing method, flat panel display manufacturing method, and phase shift mask - Google Patents

Description

  The present invention relates to a method of manufacturing a phase shift mask, a method of manufacturing a flat panel display, and a phase shift mask capable of forming a fine and highly accurate exposure pattern.

  In the flat panel display, the line width size has been made finer by improving the patterning accuracy, and the image quality has been greatly improved. As the line width accuracy of the photomask and the line width accuracy of the substrate on the transfer side become finer, the gap between the photomask and the substrate during exposure becomes smaller. Since the glass substrate used for the flat panel has a large size exceeding 300 mm, the waviness or surface roughness of the glass substrate becomes a large value, and it is easily affected by the depth of focus.

  For flat panel display exposure, since the glass substrate is a large size, a 1x proxy proximity exposure method is used using a composite wavelength of g-line (436 nm), h-line (405 nm), and i-line (365 nm). (See, for example, Patent Document 1).

  On the other hand, semiconductors are patterned with a single wavelength of ArF (193 nm), and a halftone phase shift mask is used as a technique for achieving further miniaturization (see, for example, Patent Document 2). According to this method, when the phase is 180 ° at 193 nm, it is possible to set the location where the light intensity becomes zero and improve the patterning accuracy. Further, since there is a portion where the light intensity becomes zero, it is possible to set a large depth of focus, and it is possible to ease exposure conditions or improve patterning yield.

JP 2007-271720 A (paragraph [0031]) JP 2006-78953 A (paragraphs [0002] and [0005])

  With the recent miniaturization of the wiring pattern of a flat panel display, there is an increasing demand for fine line width accuracy in a photomask used for manufacturing a flat panel display. However, it has become very difficult to deal with only the exposure conditions and development conditions for photomask miniaturization, and new techniques for achieving further miniaturization have been demanded.

  In view of the circumstances as described above, an object of the present invention is to provide a method of manufacturing a phase shift mask, a method of manufacturing a flat panel display, and a phase shift mask capable of forming a fine and highly accurate exposure pattern. is there.

  In order to achieve the above object, a method of manufacturing a phase shift mask according to an aspect of the present invention includes a step of patterning a light shielding layer on a transparent substrate. A phase shift layer is formed on the transparent substrate so as to cover the light shielding layer. The phase shift layer is formed by sputtering a chromium-based target in an atmosphere of a mixed gas containing a nitriding gas of 40% to 90% and an oxidizing gas of 10% to 35%. The phase shift layer is formed with a thickness capable of giving a phase difference of 180 ° to any light in a wavelength region of 300 nm or more and 500 nm or less. The formed phase shift layer is patterned into a predetermined shape.

  Moreover, in order to achieve the said objective, the manufacturing method of the flat panel display which concerns on one form of this invention includes the process of forming a photoresist layer on a board | substrate. A phase shift mask is disposed in proximity to the photoresist layer. The phase shift mask has a phase shift layer made of a chromium oxynitride-based material capable of giving a phase difference of 180 ° to any light in a wavelength region of 300 nm to 500 nm. The photoresist layer is exposed by irradiating the phase shift mask with light having a composite wavelength of 300 nm to 500 nm.

  Furthermore, in order to achieve the above object, a phase shift mask according to one embodiment of the present invention includes a transparent substrate, a light shielding layer, and a phase shift layer. The light shielding layer is formed on the transparent substrate. The phase shift layer is formed of a chromium oxynitride material that is formed around the light shielding layer and can have a phase difference of 180 ° with respect to light in any of the composite wavelength regions of 300 nm to 500 nm.

It is process drawing explaining the manufacturing method of the phase shift mask which concerns on the 1st Embodiment of this invention. It is an experimental result which shows the relationship between the film-forming conditions and optical characteristic of the phase shift layer of the said phase shift mask. It is process drawing explaining the manufacturing method of the phase shift mask which concerns on the 2nd Embodiment of this invention.

  The manufacturing method of the phase shift mask which concerns on one Embodiment of this invention includes the process of patterning the light shielding layer on a transparent substrate. A phase shift layer is formed on the transparent substrate so as to cover the light shielding layer. The phase shift layer is formed by sputtering a chromium-based target in an atmosphere of a mixed gas containing a nitriding gas of 40% to 90% and an oxidizing gas of 10% to 35%. The phase shift layer is formed with a thickness capable of giving a phase difference of 180 ° to any light in a wavelength region of 300 nm or more and 500 nm or less. The formed phase shift layer is patterned into a predetermined shape.

  The phase shift mask manufactured by the above method has a phase shift layer capable of giving a phase difference of 180 ° to any light in a wavelength region of 300 nm or more and 500 nm or less. Therefore, according to the phase shift mask, by using the light in the wavelength region as the exposure light, it is possible to form a region where the light intensity is minimized by the phase reversal action, and to make the exposure pattern clearer. . By such a phase shift effect, the pattern accuracy is greatly improved, and a fine and highly accurate pattern can be formed. The above effect becomes more prominent by using an exposure technique in which light having different wavelengths (for example, g-line (436 nm), h-line (405 nm), i-line (365 nm)) in the wavelength range is combined.

  By forming the phase shift layer from a chromium oxynitride material, a sputtered film having a desired refractive index can be stably formed. If the nitriding gas is less than 40%, target oxidation cannot be suppressed, and stable sputtering becomes difficult. On the other hand, if the nitriding gas exceeds 90%, the oxygen concentration in the film is too low and it becomes difficult to obtain a desired refractive index. On the other hand, when the oxidizing gas is less than 10%, the oxygen concentration in the film is too low to obtain a desired refractive index. On the other hand, if the oxidizing gas exceeds 35%, target oxidation cannot be suppressed, and stable sputtering becomes difficult. By forming a film in a mixed gas atmosphere under the above conditions, for example, a phase shift layer having a transmittance of 1 to 20% with respect to i-line can be obtained.

The thickness of the phase shift layer can be set to a thickness that gives a phase difference of about 180 ° to the i-line.
However, the present invention is not limited to this, and the phase shift layer may be formed with a thickness capable of giving a phase difference of about 180 ° with respect to the h-line or g-line.
Here, “substantially 180 °” means 180 ° or near 180 °, and is, for example, 180 ° ± 10 ° or less.

The thickness of the phase shift layer can be set such that the difference between the phase difference applied to the i-line and the phase difference applied to the g-line is 40 ° or less.
As a result, a constant phase shift effect can be obtained for each wavelength light, thereby ensuring a fine and highly accurate pattern formation.

The mixed gas may further contain an inert gas.
Thereby, stable formation of plasma becomes possible. Further, the concentrations of the nitriding gas and the oxidizing gas can be easily adjusted.

  A flat panel display manufacturing method according to an embodiment of the present invention includes a step of forming a photoresist layer on a substrate. A phase shift mask is disposed in proximity to the photoresist layer. The phase shift mask has a phase shift layer made of a chromium oxynitride-based material capable of giving a phase difference of 180 ° to any light in a wavelength region of 300 nm to 500 nm. The photoresist layer is exposed by irradiating the phase shift mask with light having a composite wavelength of 300 nm to 500 nm.

  The phase shift mask has a phase shift layer capable of giving a phase difference of 180 ° to any light in a wavelength region of 300 nm to 500 nm. Therefore, according to the manufacturing method, the pattern accuracy based on the phase shift effect can be improved by using the light in the wavelength region, and a fine and highly accurate pattern can be formed. Thereby, a high-quality flat panel display can be manufactured.

  For example, g-line (436 nm), h-line (405 nm), and i-line (365 nm) can be used as the light having the composite wavelength.

  A phase shift mask according to an embodiment of the present invention includes a transparent substrate, a light shielding layer, and a phase shift layer. The light shielding layer is formed on the transparent substrate. The phase shift layer is formed of a chromium oxynitride material that is formed around the light shielding layer and can have a phase difference of 180 ° with respect to light in any of the composite wavelength regions of 300 nm to 500 nm.

  According to the phase shift mask, by using the light in the wavelength region, the pattern accuracy based on the phase shift effect can be improved, and a fine and highly accurate pattern can be formed. The above effect becomes more prominent by using an exposure technique in which light having different wavelengths (for example, g-line (436 nm), h-line (405 nm), i-line (365 nm)) in the wavelength range is combined.

The thickness of the phase shift layer can be set such that the difference between the phase difference applied to the i-line and the phase difference applied to the g-line is 30 ° or less.
As a result, a constant phase shift effect is obtained for each wavelength light, and fine and highly accurate pattern formation can be ensured.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a process diagram illustrating a method of manufacturing a phase shift mask according to an embodiment of the present invention. The phase shift mask of this embodiment is configured as a patterning mask for a glass substrate for flat panel displays, for example. As will be described later, for the patterning of the glass substrate using the mask, a composite wavelength of i-line, h-line and g-line is used for exposure light.

  First, the light shielding layer 11 is formed on the transparent substrate 10 (FIG. 1A).

  As the transparent substrate 10, a material excellent in transparency and optical isotropy is used, and for example, a quartz glass substrate is used. The magnitude | size in particular of the transparent substrate 10 is not restrict | limited, It selects suitably according to the board | substrate (For example, a board | substrate for flat panel displays, a semiconductor substrate) exposed using the said mask. In this embodiment, a rectangular substrate having a side of 300 mm or more is used, and more specifically, a quartz substrate having a length of 450 mm, a width of 550 mm, and a thickness of 8 mm is used.

  Further, the surface roughness of the transparent substrate 10 may be reduced by polishing the surface of the transparent substrate 10. The surface roughness of the transparent substrate 10 can be 50 μm or less, for example. As a result, the depth of focus of the mask is increased, and it is possible to greatly contribute to the formation of a fine and highly accurate pattern.

  The light shielding layer 11 is made of metal chromium or a chromium compound (hereinafter also referred to as a chromium-based material), but is not limited thereto, and is a metal silicide-based material (for example, MoSi, TaSi, TiSi, WSi) or an oxide thereof. Nitride and oxynitride are applicable. The thickness of the light shielding layer 11 is not particularly limited, and may be any thickness that provides a predetermined or higher optical density (for example, 800 to 2000 angstroms). As a film forming method, an electron beam vapor deposition method, a laser vapor deposition method, an atomic layer film formation method (ALD method), an ion assist sputtering method, or the like can be applied. Especially in the case of a large substrate, the film thickness is uniform by a DC sputtering method. It is possible to form a film with excellent properties.

  Next, a photoresist layer 12 is formed on the light shielding layer 11 (FIG. 1B). The photoresist layer 12 may be a positive type or a negative type. As the photoresist layer 12, a liquid resist is used, but a dry film resist may be used.

  Subsequently, by exposing and developing the photoresist layer 12, a resist pattern 12P1 is formed on the light shielding layer 11 (FIG. 1C). The resist pattern 12P1 functions as an etching mask for the light shielding layer 11, and the shape is appropriately determined according to the etching pattern of the light shielding layer 11.

  Subsequently, the light shielding layer 11 is etched into a predetermined pattern shape. Thereby, the light shielding layer 11P1 patterned into a predetermined shape is formed on the transparent substrate 10 (FIG. 1D).

  A wet etching method or a dry etching method can be applied to the etching process of the light shielding layer 11, and in particular, when the substrate 10 is large, an etching process with high in-plane uniformity can be realized by adopting the wet etching method. Become.

  The etching solution for the light shielding layer 11 can be appropriately selected. When the light shielding layer 11 is a chromium-based material, for example, an aqueous solution of ceric ammonium nitrate and perchloric acid can be used. Since this etching solution has a high selection ratio with the glass substrate, the substrate 10 can be protected when the light shielding layer 11 is patterned. On the other hand, when the light shielding layer 11 is made of a metal silicide material, for example, ammonium hydrogen fluoride can be used as the etchant.

  After the patterning of the light shielding layer 11P1, the resist pattern 12P1 is removed (FIG. 1E). For example, a sodium hydroxide aqueous solution can be used for removing the resist pattern 12P1.

  Next, the phase shift layer 13 is formed. The phase shift layer 13 is formed on the transparent substrate 10 so as to cover the light shielding layer 11P1 (FIG. 1F).

  As a film formation method of the phase shift layer 13, an electron beam (EB) vapor deposition method, a laser vapor deposition method, an atomic layer film formation (ALD) method, an ion assisted sputtering method, or the like can be applied. By adopting the DC sputtering method, it is possible to form a film with excellent film thickness uniformity. Note that the present invention is not limited to the DC sputtering method, and an AC sputtering method or an RF sputtering method may be applied.

  The phase shift layer 13 is made of a chromium-based material. In particular, in the present embodiment, the phase shift layer 13 is made of chromium nitride oxide. According to the chromium-based material, good patternability can be obtained particularly on a large substrate. In addition, it is not restricted to chromium system material, For example, metal silicide system materials, such as MoSi, TaSi, WSi, CrSi, NiSi, CoSi, ZrSi, NbSi, TiSi, or these compounds, may be used. Furthermore, Al, Ti, Ni, or a compound thereof may be used.

  When the phase shift layer 13 made of chromium oxynitride is formed by sputtering, a mixed gas of a nitriding gas and an oxidizing gas, or a mixed gas of an inert gas, a nitriding gas, and an oxidizing gas is used as a process gas. be able to. The film forming pressure can be set to 0.1 Pa to 0.5 Pa, for example.

The oxidizing gas includes CO, CO ₂ , NO, N ₂ O, NO ₂ , O _{2 and the} like. The nitriding gas includes NO, N ₂ O, NO ₂ , N _{2 and the} like. Ar, He, Xe or the like is used as the inert gas, but typically Ar is used. Note that the mixed gas may further contain a carbonizing gas such as CH ₄ .

  The flow rate (concentration) of the nitriding gas and the oxidizing gas in the mixed gas is an important parameter for determining the optical properties (transmittance, refractive index, etc.) of the phase shift layer 13. In the present embodiment, the mixed gas is adjusted under the conditions that the nitriding gas concentration is 40% to 90% and the oxidizing gas concentration is 10% to 35%. By adjusting the gas conditions, it is possible to optimize the refractive index, transmittance, reflectance, thickness and the like of the phase shift layer 13.

  If the nitriding gas is less than 40%, target oxidation cannot be suppressed, and stable sputtering becomes difficult. On the other hand, if the nitriding gas exceeds 90%, the oxygen concentration in the film is too low and it becomes difficult to obtain a desired refractive index. On the other hand, when the oxidizing gas is less than 10%, the oxygen concentration in the film is too low to obtain a desired refractive index. On the other hand, if the oxidizing gas exceeds 35%, target oxidation cannot be suppressed, and stable sputtering becomes difficult.

  The thickness of the phase shift layer 13 is set to a thickness capable of giving a phase difference of 180 ° to any light in a wavelength region of 300 nm or more and 500 nm or less. The light to which the phase difference of 180 ° is given is inverted in phase, so that the intensity of the light is canceled by the interference action with the light that does not pass through the phase shift layer 13. By such a phase shift effect, a region where the light intensity is minimum (for example, zero) is formed, so that the exposure pattern becomes clear and a fine pattern can be formed with high accuracy.

  In the present embodiment, the light in the wavelength region is a composite light (polychromatic light) of i-line (wavelength 365 nm), h-line (wavelength 405 nm), and g-line (wavelength 436 nm). Thus, the phase shift layer 13 is formed with a thickness that can give a phase difference of 180 °. The light having the target wavelength may be any of i-line, h-line, and g-line, or light in a wavelength region other than these. As the light whose phase is to be inverted has a shorter wavelength, a finer pattern can be formed.

  In the present embodiment, the phase shift layer 13 can be formed with a thickness such that the difference between the phase difference applied to the i-line and the phase difference applied to the g-line is 40 ° or less. Thereby, a fixed phase shift effect can be obtained for light of each wavelength. For example, the phase shift layer can be formed to a film thickness that can give a phase difference of about 180 ° (180 ° ± 10 °) to the h-line that is the intermediate wavelength region of the composite wavelength. As a result, a phase difference close to 180 ° can be imparted to any of the i-line and g-line light, and the same phase shift effect can be obtained for each light.

  The film thickness of the phase shift layer 13 is preferably uniform in the plane of the transparent substrate 10. In the present embodiment, the phase shift layer 13 is formed with a film thickness difference such that the difference in phase difference in the substrate plane is 20 ° or less for each single wavelength light of g-line, h-line, and i-line. . If the difference in phase difference exceeds 20 °, the intensity of light intensity decreases due to the effect of superimposing the light intensity at the composite wavelength, and the patterning accuracy decreases. By setting the difference of the phase difference to 15 ° or less, further 10 ° or less, the patterning accuracy can be further improved.

  The transmittance of the phase shift layer 13 can be in the range of 1% to 20% for i-line, for example. When the transmittance is less than 1%, it is difficult to obtain a sufficient phase shift effect, and it becomes difficult to expose a fine pattern with high accuracy. On the other hand, when the transmittance exceeds 20%, the film forming rate is lowered and the productivity is deteriorated. In the above range, the transmittance can be in the range of 2% to 15%. Further, in the above range, the transmittance can be 3% or more and 10% or less.

  The reflectance of the phase shift layer 13 is 40% or less, for example. Thereby, it is difficult to form a ghost pattern when patterning a substrate to be processed (flat panel substrate or semiconductor substrate) using the phase shift mask, and good pattern accuracy can be ensured.

  The transmittance and reflectance of the phase shift layer 13 can be arbitrarily adjusted according to the gas conditions during film formation. According to the mixed gas conditions described above, a transmittance of 1% to 20% and a reflectance of 40% or less can be obtained with respect to i-line.

  The thickness of the phase shift layer 13 can be appropriately set within a range where the above-described optical characteristics can be obtained. In other words, the optical characteristics described above can be obtained by optimizing the thickness of the phase shift layer 13. For example, the film thickness of the phase shift layer 13 that can obtain the optical characteristics depending on the gas conditions is, for example, 100 nm or more and 130 nm or less. In this range, the thickness of the phase shift layer 13 can be in the range of 110 nm to 125 nm.

For example, when the flow rate ratio of the mixed gas at the time of sputtering film formation is Ar: N ₂ : CO ₂ = 2.5: 6: 1.5 and the film thickness is 114 nm, the transmittance for i-line is 5 0.5%, the phase difference in the i-line can be 173 °, and the phase difference in the g-line can be 146 °. Further, when the flow ratio of the mixed gas is Ar: N ₂ : CO ₂ = 2: 7: 1 and the film thickness is 120 nm, the transmittance for i-line is 4.8% and the phase difference for i-line is 185 °. , The phase difference in the g-line can be 153 °.

FIG. 2 shows the experimental results showing the relationship between the film forming conditions when forming the phase shift layer 13, the phase difference of each wavelength component, and the i-line transmittance. In this example, N ₂ was used as the nitriding gas, CO ₂ was used as the oxidizing gas, and Ar was used as the inert gas. The film forming pressure was 0.2 Pa.

  As shown in FIG. 2, in the condition of the mixed gas containing 40% or more and 90% or less nitriding gas and 10% or more and 35% or less oxidizing gas (sample No. 1 to 5), 300 nm or more and 500 nm or less. A phase difference of 180 ° can be provided in the wavelength region. In addition, by forming a phase shift layer with a thickness that can give a phase difference of 180 ° ± 10 ° to the i-line, the difference in phase difference between the i-line and the g-line is 40 ° (30 °) or less. Can be suppressed. Furthermore, the transmittance of i-line can be suppressed to 1% or more and 10% or less.

  On the other hand, under the condition that the nitriding gas exceeds 90% and the oxidizing gas is less than 10% (sample No. 6), the excess of acid in the film is small, and even if the film thickness is increased, it is necessary. Phase difference and transmittance were not obtained. In addition, in the condition where the oxidizing gas exceeds 35% (sample No. 7) and the atmosphere condition containing only the oxidizing gas (sample No. 8), the degree of oxidation of the film becomes too large and the necessary phase difference is obtained. The increase in transmittance could not be suppressed. Furthermore, under these conditions, the oxidation of the target surface progressed, resulting in a low film formation rate, and a sufficient film thickness could not be obtained.

  Subsequently, a photoresist layer 14 is formed on the phase shift layer 13 (FIG. 1G). The photoresist layer 14 may be a positive type or a negative type. As the photoresist layer 14, a liquid resist is used.

  Next, by exposing and developing the photoresist layer 14, a resist pattern 14P1 is formed on the phase shift layer 13 (FIG. 1H). The resist pattern 14 </ b> P <b> 1 functions as an etching mask for the phase shift layer 13, and the shape is appropriately determined according to the etching pattern for the phase shift layer 13.

  Subsequently, the phase shift layer 13 is etched into a predetermined pattern shape. Thereby, the phase shift layer 13P1 patterned in a predetermined shape is formed on the transparent substrate 10 (FIG. 1 (I)).

  A wet etching method or a dry etching method can be applied to the etching process of the phase shift layer 13, and when the substrate 10 is large, an etching process with high in-plane uniformity can be realized by adopting the wet etching method. It becomes.

  The etching solution for the phase shift layer 13 can be selected as appropriate. In this embodiment, an aqueous solution of ceric ammonium nitrate and perchloric acid can be used. Since this etching solution has a high selectivity with respect to the glass substrate, the substrate 10 can be protected when the phase shift layer 13 is patterned.

  After the patterning of the phase shift layer 13P1, the resist pattern 14P1 is removed (FIG. 1 (J)). For example, a sodium hydroxide aqueous solution can be used to remove the resist pattern 14P1.

  As described above, the phase shift mask 1 according to this embodiment is manufactured. According to the phase shift mask 1 of the present embodiment, the phase shift layer 13P1 having the above-described configuration is formed around the light shielding layer pattern 11P1. As a result, the pattern accuracy can be improved based on the phase shift effect when an exposure pattern is formed on the substrate to be exposed using light in the wavelength region of 300 nm to 500 nm, and a fine and highly accurate pattern can be formed. It becomes. In particular, according to the present embodiment, it becomes more prominent by using an exposure technique in which light (g-line, h-line, and i-line) having different wavelengths in the above wavelength range is combined.

  Hereinafter, a method for manufacturing a flat panel display using the phase shift mask 1 according to the present embodiment will be described.

  First, a photoresist layer is formed on the surface of the glass substrate on which the insulating layer and the wiring layer are formed. For example, a spin coater is used to form the photoresist layer. The photoresist layer is subjected to a heating (baking) process and then subjected to an exposure process using the phase shift mask 1. In the exposure process, the phase shift mask 1 is disposed in the vicinity of the photoresist layer. Then, the surface of the glass substrate is irradiated with a composite wavelength of 300 nm or more and 500 nm or less through the phase shift mask 1. In the present embodiment, composite light of g-line, h-line, and i-line is used as the light of the composite wavelength. Thereby, the exposure pattern corresponding to the mask pattern of the phase shift mask 1 is transferred to the photoresist layer.

  According to this embodiment, the phase shift mask 1 includes the phase shift layer 13P1 that can give a phase difference of 180 ° to any light in the wavelength region of 300 nm or more and 500 nm or less. Therefore, according to the manufacturing method, since the pattern accuracy based on the phase shift effect can be improved by using the light in the wavelength region, and the depth of focus can be increased, a fine and highly accurate pattern can be obtained. Formation is possible. Thereby, a high-quality flat panel display can be manufactured.

  According to the experiments by the present inventors, when exposure was performed using a mask that does not have the phase shift layer, a pattern width deviation of 30% or more with respect to the target line width (2 μm) occurred. When exposure was performed using the phase shift mask 1 of the present embodiment, it was confirmed that the deviation was suppressed to about 7%.

(Second Embodiment)
FIG. 3 is a process diagram for explaining a method of manufacturing a phase shift mask according to the second embodiment of the present invention. In FIG. 3, parts corresponding to those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The phase shift mask 2 (FIG. 3 (J)) of the present embodiment has alignment marks for alignment at the periphery, and this alignment mark is formed by the light shielding layer 11P2. Hereinafter, a method for manufacturing the phase shift mask 2 will be described.

  First, the light shielding layer 11 is formed on the transparent substrate 10 (FIG. 3A). Next, a photoresist layer 12 is formed on the light shielding layer 11 (FIG. 3B). The photoresist layer 12 may be a positive type or a negative type. Subsequently, by exposing and developing the photoresist layer 12, a resist pattern 12P2 is formed on the light shielding layer 11 (FIG. 3C).

  The resist pattern 12P2 functions as an etching mask for the light shielding layer 11, and the shape is appropriately determined according to the etching pattern of the light shielding layer 11. FIG. 3C shows an example in which a resist pattern 12P2 is formed so that the light shielding layer remains within a predetermined range of the periphery of the substrate 10.

  Subsequently, the light shielding layer 11 is etched into a predetermined pattern shape. Thereby, the light shielding layer 11P2 patterned in a predetermined shape is formed on the transparent substrate 10 (FIG. 3D). After the patterning of the light shielding layer 11P2, the resist pattern 12P2 is removed (FIG. 3E). For example, an aqueous sodium hydroxide solution can be used to remove the resist pattern 12P2.

  Next, the phase shift layer 13 is formed. The phase shift layer 13 is formed on the transparent substrate 10 so as to cover the light shielding layer 11P2 (FIG. 3F). The phase shift layer 13 is made of a chromium oxynitride material and is formed by a DC sputtering method. In this case, a mixed gas of a nitriding gas and an oxidizing gas, or a mixed gas of an inert gas, a nitriding gas, and an oxidizing gas can be used as the process gas. The phase shift layer 13 is formed under the same film formation conditions as in the first embodiment described above.

  Subsequently, a photoresist layer 14 is formed on the phase shift layer 13 (FIG. 3G). Next, by exposing and developing the photoresist layer 14, a resist pattern 14P2 is formed on the phase shift layer 13 (FIG. 3H). The resist pattern 14P2 functions as an etching mask for the phase shift layer 13, and the shape is appropriately determined according to the etching pattern for the phase shift layer 13.

  Subsequently, the phase shift layer 13 is etched into a predetermined pattern shape. Thereby, the phase shift layer 13P2 patterned in a predetermined shape is formed on the transparent substrate 10 (FIG. 3I). After the patterning of the phase shift layer 13P2, the resist pattern 14P2 is removed (FIG. 3J). For example, a sodium hydroxide aqueous solution can be used to remove the resist pattern 14P2.

  As described above, the phase shift mask 2 according to this embodiment is manufactured. According to the phase shift mask 2 of the present embodiment, since the alignment mark is formed of the light shielding layer 11P2, the alignment mark can be easily recognized optically, and high-accuracy alignment is possible. This embodiment can be implemented in combination with the first embodiment described above.

  Further, the phase shift layer 13 can function as a halftone layer (semi-transmissive layer). In this case, it is possible to make a difference in exposure amount between light transmitted through the phase shift layer 13 and light not transmitted.

  As mentioned above, although embodiment of this invention was described, of course, this invention is not limited to this, A various deformation | transformation is possible based on the technical idea of this invention.

  For example, in the above embodiment, the phase shift layer is formed and patterned after the light shielding layer is patterned. However, the present invention is not limited to this. After the phase shift layer is formed and patterned, the light shielding layer is formed and patterned. May be performed. That is, it is possible to change the stacking order of the light shielding layer and the phase shift layer.

  In the above embodiment, the light shielding layer 11 is formed on the entire surface of the substrate 10 and then the necessary portions are etched to form the light shielding layers 11P1 and 11P2. However, instead of this, the light shielding layers 11P1 and 11P2 are formed. The light shielding layer 11 may be formed after forming a resist pattern having an opening in the formation region. By removing the resist pattern after the formation of the light shielding layer 11, the light shielding layers 11P1 and 11P2 can be formed in the necessary regions (lift-off method).

DESCRIPTION OF SYMBOLS 1, 2 ... Phase shift mask 10 ... Transparent substrate 11, 11P1, 11P2 ... Light shielding layer 12P1, 12P2, 14P1, 14P2 ... Resist pattern 13P1, 13P2 ... Phase shift layer

Claims (8)

Pattern the light shielding layer on the transparent substrate,
Sputtering a chromium-based material target in an atmosphere of a mixed gas containing 49.4% or more and 86.2% or less of N ₂ gas and 10% or more and 35% or less of CO ₂ gas allows a wavelength of 300 nm or more and 500 nm or less. A phase shift layer made of a chromium oxynitride chromium carbide material capable of having a phase difference of approximately 180 ° with respect to any light in the region is applied to the i-line so as to cover the light shielding layer And a film thickness such that the difference between the phase difference applied to the g-line is 40 ° or less and formed on the transparent substrate,
A method for manufacturing a phase shift mask, wherein the phase shift layer is patterned. It is a manufacturing method of the phase shift mask according to claim 1,
The step of forming the phase shift layer includes forming the phase shift layer with a film thickness that gives a phase difference of about 180 ° with respect to i-line. It is a manufacturing method of the phase shift mask according to claim 1,
The step of forming the phase shift layer includes forming the phase shift layer with a film thickness that has a phase difference of about 180 ° with respect to the h-line. It is a manufacturing method of the phase shift mask according to claim 1,
The mixed gas further includes an inert gas. A method of manufacturing a phase shift mask. Forming a photoresist layer on the substrate;
It is formed by sputtering a chromium-based material target in an atmosphere of a mixed gas containing 49.4% or more and 86.2% or less of N ₂ gas and 10% or more and 35% or less of CO ₂ gas. A phase shift layer capable of having a phase difference of approximately 180 ° with respect to light in any of the following wavelength regions , and a phase difference applied to the i-line and a phase difference applied to the g-line A phase shift mask having a phase shift layer made of a chromium oxynitride chromium carbide-based material having a thickness such that the difference is 40 ° or less is disposed close to the photoresist layer,
A method for manufacturing a flat panel display, wherein the photoresist layer is exposed by irradiating the phase shift mask with light having a composite wavelength of 300 nm to 500 nm. It is a manufacturing method of the flat panel display according to claim 5 ,
In the step of exposing the photoresist layer, a flat panel display manufacturing method using combined exposure light of g-line, h-line and i-line. A transparent substrate;
A light shielding layer formed on the transparent substrate;
Sputtering a chromium-based material target in an atmosphere of a mixed gas formed around the light shielding layer and containing 49.4% to 86.2% N ₂ gas and 10% to 35% CO ₂ gas. It is formed by, der possible to have a phase difference of about 180 ° with respect to one light 500nm or less of the composite wavelength region of 300nm is, and the phase difference and the g-line to be applied to the i-line A phase shift mask comprising: a phase shift layer made of a chromium oxynitride chromium carbide-based material having a thickness such that the difference from the applied phase difference is 40 ° or less . The phase shift mask according to claim 7 , wherein
The light in the composite wavelength region is composite light of g-line, h-line, and i-line. Phase shift mask.

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