JP4364546B2 - Resist pattern forming method and resist pattern forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of forming a resist pattern on a substrate by contrast enhancement lithography (CEL = Contrast Enhancement Lithography). Further, the present invention relates to a resist pattern, a resist pattern forming apparatus, or the resist pattern formed by this method. The present invention relates to a method of manufacturing a device such as a semiconductor device, a magnetic head, an optical disk, and a patterned medium (magnetic recording medium) that has been developed recently.
[0002]
[Prior art]
In the manufacture of semiconductor integrated circuits and magnetic disks (such as hard disks), magnetic heads, optical disk masters, and optical disk molding stampers, photolithography techniques are used to etch the substrate.
[0003]
In the photolithography technique, etching is performed using an etching mask having the same shape as the resist pattern. That is, a photoresist is applied on a substrate, a photoresist on the substrate is exposed with light of a specific wavelength through a photomask on which a pattern is drawn, a photochemical reaction is caused in the exposed portion, and then an alkali is generated. A resist film having a desired resist pattern is formed on the substrate by developing with a developer (aqueous solution). At this time, if the photoresist is a positive resist, only the exposed portion is dissolved, and if the photoresist is a negative resist, only the exposed portion remains undissolved, and only the dissolved portion is removed by the development process. A resist film having a resist pattern corresponding to the photomask pattern is formed.
[0004]
In addition, for optical discs such as digital audio discs (so-called compact discs) and video discs, an aluminum reflective film is formed on a transparent substrate on which phase pits are previously formed according to information signals, and a protective film or the like is formed thereon. In general, the photolithography technique is also used to form the phase pits. In this case, an optical disk master is produced by laser exposure of a photoresist applied on a glass substrate by a so-called mastering process.
[0005]
In recent years, the recording density of such discs has increased, or the integrated circuit has been miniaturized and highly integrated. Thus, when forming the resist film, it is desired to form a very fine pattern. It was.
[0006]
In order to form an extremely fine pattern on the resist film, it is necessary to reduce the spot diameter of the laser beam irradiated to the resist film. This is because the fineness of the resist pattern (in the mastering process, the size of the phase pit formed in the resist film by exposure) is limited by the spot diameter.
[0007]
The spot diameter of the laser beam is proportional to λ / NA (where λ is the wavelength of the laser beam and NA is the numerical aperture of the objective lens). Therefore, in order to reduce the spot diameter of the laser beam, a method of shortening the wavelength λ of the laser beam used for exposure or increasing the numerical aperture NA of the objective lens has been conventionally known.
[0008]
However, the numerical aperture NA of the objective lens has already been increased to a value close to the limit. As for the wavelength λ of the laser beam, a blue laser beam with a short wavelength has already been used, and in order to perform higher density mastering, a laser beam with a shorter wavelength, for example, a laser beam in the ultraviolet region is used. However, it is difficult to dramatically improve the recording density even if laser light in the ultraviolet region is used. Thus, in order to reduce λ / NA, there are restrictions on the wavelength λ of the laser beam and the numerical aperture NA of the objective lens, so it is difficult to reduce the spot diameter further.
[0009]
Therefore, in order to form a finer resist pattern, the “optical disk master manufacturing method” disclosed in Patent Document 1 transmits light containing a substance that transmits only light having a predetermined intensity or more, such as a saturable dye, in the resist film. A method of forming a resist pattern by irradiating laser light through a limiting layer is disclosed. The laser beam is focused on the resist film by the objective lens and has a concentric light intensity distribution, but this method utilizes the fact that the laser light has a concentric intensity distribution and transmits the laser light. When passing through the light limiting layer, a portion where the intensity of the laser light is strong at the center of the laser spot is transmitted, and the laser light around the laser spot is absorbed by the transmitted light limiting layer and is not transmitted. As a result, the result is that the spot diameter of the laser light transmitted through the transmitted light limiting layer is significantly smaller than the spot diameter of the laser light before transmitting through the transmitted light limiting layer.
[0010]
FIG. 8 shows a beam profile at the time of focus exposure when the above-mentioned transmitted light limiting layer is formed on a normal water-insoluble resist. The alternate long and short dash line shows the beam light before entering the transmittance changing layer, but it can be seen that the light intensity is high even at a point 0.2 μm away from the focal point (spot radius 0) and the beam light diameter is widened. . On the other hand, the beam transmitted through the transmitted light limiting layer (saturable dye film) indicated by the broken line has a beam light diameter of about 0.1 μm. As a result, the width of the phase pits and groove grooves can be reduced, and a fine photoresist pattern can be formed.
[0011]
A method of enhancing the contrast of the beam spot by increasing the resolution of the beam spot by providing such a transmission light limiting layer and increasing the resolution is called contrast enhancement lithography (hereinafter abbreviated as CEL).
[0012]
[Patent Document 1]
JP-A-7-287874 (release date: October 31, 1995)
[0013]
[Problems to be solved by the invention]
As described above, in the resist pattern forming step in the optical disc mastering process or the like, in order to make the photoresist pattern fine (to reduce the phase pit of the optical disc), it is necessary to reduce the spot diameter of the beam light. The spot diameter of the beam light is limited by the wavelength λ of the laser light and the numerical aperture NA of the objective lens, but through the transmitted light limiting layer that transmits only the central portion of the beam light using the method of Patent Document 1. By irradiating the beam, the spot diameter of the laser beam irradiated on the resist film can be reduced.
[0014]
However, in the transmitted light limiting layer made of a saturable dye, the spot diameter of the beam light is not sufficiently small, and a fine photoresist pattern corresponding to high recording density cannot be formed. Therefore, it has been a problem to form a finer photoresist pattern.
[0015]
The present invention has been proposed in view of such conventional problems, and an object thereof is to provide a resist pattern forming method capable of forming a fine photoresist pattern capable of high-density recording.
[0016]
[Means for Solving the Problems]
In order to solve the above problems, a resist pattern forming method of the present invention includes a resist film forming step of forming a resist film on a substrate surface, a dye film forming step of forming a dye film comprising a dye aggregate, It has the exposure process which irradiates a laser beam to the said resist film through the said pigment | dye film | membrane, and the image development process which develops the resist film irradiated with the said laser beam.
[0017]
According to the above method, a resist film and a dye film comprising a dye aggregate are formed, and the resist film is irradiated with light through the dye film. At this time, the dye film may be provided between the light source of the laser beam and the resist film, and may be provided directly on the resist film or may be formed by sandwiching the layer between the resist layer and the dye film. I do not care.
[0018]
Since the above-mentioned dye film contains a dye aggregate, it has a property of causing a photochemical change when exposed to light of a certain intensity or more and increasing the transmittance of light in a specific range. Therefore, when a laser beam whose intensity is weakened concentrically is irradiated to the dye film, the transmittance increases with the dye film irradiated by the central part of the laser beam, and the transmittance is increased with the dye film irradiated by the peripheral part of the laser beam. Remains low. By utilizing such a phenomenon, by irradiating the laser beam through the dye film, only the light at the center of the laser beam is transmitted and the light at the periphery of the laser beam is not transmitted. Contrast can be enhanced. Therefore, the spot diameter of the laser beam transmitted through the dye film is smaller than that before transmission.
[0019]
The spot diameter of the laser beam is limited by the wavelength of the laser beam and the aperture of the objective lens that generates the laser beam, so it was difficult to reduce the spot diameter. Can be irradiated.
[0020]
As described above, by irradiating the resist film with laser light having a small spot diameter, pattern exposure corresponding to a fine pattern can be performed on the resist film, so that a fine resist pattern can be formed.
[0021]
In order to solve the above problems, the resist pattern forming method of the present invention includes an intermediate layer forming step of forming an intermediate layer on the resist film surface, and the resist film and the intermediate layer in addition to the above method. A baking process for heating the substrate, a dye film forming process for forming a dye film containing a dye aggregate on the surface of the intermediate layer after the baking process, and irradiating the resist film with laser light through the dye film It has an exposure process and a development process for developing a resist film irradiated with a laser beam.
[0022]
According to the above method, an intermediate layer is formed on the surface of the resist film, further baked, and then a dye film is formed on the surface of the intermediate layer, so that the resist film and the dye film are prevented from coming into direct contact. Even when a liquid containing an organic solvent or the like is applied at the time of forming the dye film, the resist film components are not dissolved in the organic solvent at the time of forming the dye film.
[0023]
In other words, when the dye film is dissolved in an organic solvent and the resist film surface is formed by spin coating or the like, the resist material is also dissolved in the organic solvent, so the dye film dissolved in the organic solvent is applied onto the resist film. At that time, the resist film may be dissolved in the organic solvent. In this case, the resist film and the dye film are mixed, and an accurate resist pattern cannot be formed.
[0024]
In order to prevent this mixing, an intermediate layer is provided. However, simply by inserting the intermediate layer, the organic solvent enters the inside and reaches the resist film below. Therefore, by forming an intermediate layer and further performing a baking treatment, the intermediate layer serves as a reaction preventing layer so that the organic solvent in forming the dye film does not attack the resist film. The dye diffuses inside the resist film and prevents mixing.
[0025]
In order to solve the above problems, the resist pattern forming method of the present invention performs, in addition to the above method, a removal step for removing the dye film and the intermediate layer after the exposure step, and develops after the removal step. It is characterized by performing a process.
[0026]
In the above method, after the exposure step, the layer formed on the surface opposite to the substrate of the resist film by the removal step, that is, the dye film, or the dye film and the intermediate layer is removed to expose the resist film. Then, a pattern is formed on the resist film by removing the solubilized portion of the resist film that has been exposed and solubilized or insolubilized so as to correspond to an arbitrary pattern in the development process. According to the above method, since the development is performed in a state where only the resist film is formed on the upper surface of the substrate, the development is favorably performed.
[0027]
In order to solve the above-mentioned problem, the resist pattern forming method of the present invention, in addition to the above method, is that the dye film formed in the dye film forming step is irradiated with laser light in the exposure step, It is characterized in that it has a characteristic that the transmittance of light including the wavelength region of laser light is increased.
[0028]
According to the above method, since the light irradiated in the exposure process has the property of increasing the transmittance of light in a specific wavelength range, the light intensity is weakened concentrically on the dye film. When light is irradiated, the transparency increases with the dye film irradiated by the laser light central portion, and the transmittance remains low with the dye film irradiated by the laser light peripheral portion. By utilizing such a phenomenon, by irradiating the laser beam through the dye film, only the light at the center of the laser beam is transmitted and the light at the periphery of the laser beam is not transmitted. Contrast can be enhanced. Therefore, the spot diameter of the laser beam transmitted through the dye film is smaller than that before transmission.
[0029]
The spot diameter of the laser beam is limited by the wavelength of the laser beam and the aperture of the objective lens that generates the laser beam, so it was difficult to reduce the spot diameter. Can be irradiated.
[0030]
As described above, by irradiating the resist film with laser light having a small spot diameter, pattern exposure corresponding to a fine pattern can be performed on the resist film, so that a fine resist pattern can be formed.
[0031]
In order to solve the above problems, the resist pattern forming method of the present invention is characterized in that, in addition to the above method, the wavelength range of the laser light irradiated in the exposure step is from 300 nm to 400 nm.
[0032]
In the present invention, the spot light is reduced by transmitting the laser light through the dye film, but it is preferable to reduce the laser light before passing through the dye film as much as possible. Since the spot diameter of the laser beam is proportional to λ / NA, the spot diameter of the laser beam becomes smaller as the wavelength of the laser beam is shorter. According to the above method, the wavelength range of the laser light irradiated in the exposure process is 300 nm or more and 400 nm or less, and ultraviolet light having a short wavelength is used, so that the spot diameter of the laser light during irradiation can be reduced.
[0033]
Further, since the transmittance of light having a wavelength of 300 nm or more and 400 nm or less of the dye aggregate is increased by the laser light irradiation, the contrast of the light intensity of the laser light can be enhanced, and the spot diameter at the time of irradiation can be further reduced.
[0034]
In order to solve the above-mentioned problem, the resist pattern forming method of the present invention forms a dye film comprising a dye aggregate comprising an ionic dye in the dye film forming step in addition to the above method. It is a feature.
[0035]
Since the ionic dyes have a strong tendency to bind to each other and easily form aggregates, the ionic dye is stable in the dye film if the dye film contains a dye aggregate of the ionic dye as in the above method. Can form aggregates. Therefore, the spot diameter can be reduced by favorably enhancing the contrast of the light intensity.
[0036]
In order to solve the above problems, the resist pattern forming method of the present invention includes a dye aggregate comprising a cyanine dye compound represented by the general formula (1) in the dye film forming step in addition to the above method. It is characterized by forming a dye film consisting of
[0037]
According to the above method, since the dye film comprises a dye aggregate comprising a cyanine dye compound, film formation by spin coating is easy, methine chain, peripheral functional group showing good film formability without a binder. It has the advantages that it can be easily modified and its properties can be changed easily, the dye film is a single layer film with a metallic luster and high reflectivity, and has extremely low toxicity.
[0038]
In addition, a molecular film consisting only of a cyanine dye or a mixed film of a cyanine dye and one kind of matrix molecule (using fatty acids such as arachidic acid) can be regularly aligned on the film surface by spin coating. Since it forms an associated body that is oriented and associated with several to several hundreds, it is suitable for forming a dye film made of a dye aggregate. Further, the cyanine dye compound absorbs light in the range of 300 nm to 400 nm, and when irradiated with this light, the transmittance of light in the range of 300 nm to 400 nm increases. The spot diameter can be further reduced by enhancing the contrast of the light intensity.
[0039]
In order to solve the above problems, the resist pattern forming method of the present invention is a dye comprising an indolenine carbocyanine dye compound represented by the general formula (2) in the dye film forming step in addition to the above method. It is characterized by forming a dye film comprising an aggregate.
[0040]
According to the above method, since the dye film comprises a dye aggregate comprising an indolenine carbocyanine dye compound, the light transmittance in the range of 300 nm to 400 nm is 30 when irradiated with light in the range of 300 nm to 400 nm. Since it rapidly increases from about% to about 80%, in the case of laser light having a short wavelength and a small spot diameter, the contrast of the light intensity can be enhanced well and the spot diameter can be further reduced.
[0041]
In order to solve the above problems, a resist pattern forming method of the present invention includes a resist film forming step of forming a resist film on a substrate surface, an intermediate layer forming step of forming an intermediate layer on the resist film surface, and the resist A baking process for heating the film and the substrate on which the intermediate layer is formed; a dye film forming process for forming a dye film on the surface of the intermediate layer after the baking process; and irradiating the resist film with laser light through the dye film It has an exposure process and a development process for developing a resist film irradiated with a laser beam.
[0042]
According to the above method, an intermediate layer is formed on the surface of the resist film, further baked, and then a dye film is formed on the surface of the intermediate layer, so that the resist film and the dye film are prevented from coming into direct contact. Even when a liquid containing an organic solvent or the like is applied at the time of forming the dye film, the resist film components are not dissolved in the organic solvent at the time of forming the dye film.
[0043]
In other words, when the dye film is dissolved in an organic solvent and formed on the resist film surface by spin coating or the like, the resist material is also dissolved in the organic solvent, and the dye dissolved in the organic solvent is applied onto the resist film. At the time, the resist film may be dissolved in an organic solvent. In this case, the resist film and the transmitted light limiting layer are mixed, and an accurate resist pattern cannot be formed.
[0044]
In order to prevent this mixing, an intermediate layer is provided. However, simply by inserting the intermediate layer, the organic solvent enters the inside and reaches the resist film below. Therefore, by forming an intermediate layer and further performing a baking treatment, the intermediate layer serves as a reaction preventing layer so that the organic solvent in forming the dye film does not attack the resist film. The dye diffuses inside the resist film and prevents mixing.
[0045]
According to this, since the dye film is formed on the resist film via the intermediate layer, the resist film is not mixed with the dye film, and a high-density and accurate resist pattern can be formed.
[0046]
In order to solve the above problems, the resist pattern forming method of the present invention is characterized in that, in addition to the above method, heat treatment is performed in an atmosphere of 80 ° C. or higher and 100 ° C. or lower in the baking step.
[0047]
According to the above method, since the intermediate layer is formed on the resist film surface and the baking treatment is performed in an atmosphere of 80 ° C. or higher and 100 ° C. or lower, the dye film formed on the surface of the intermediate layer is in direct contact with the resist film. In addition, even when a liquid containing an organic solvent or the like is applied at the time of forming the dye film, the components of the resist film are not dissolved in the dye film. When the intermediate layer is baked in an atmosphere of 80 ° C. or higher and 100 ° C. or lower, the role of a reaction preventing layer that prevents the organic solvent from attacking the resist film when forming the dye film is improved. The coating dye is prevented from diffusing into the resist film and mixing.
[0048]
In order to solve the above problems, the resist pattern forming method of the present invention is characterized in that, in addition to the above method, the resist film is water-insoluble and the intermediate layer is water-soluble.
[0049]
According to the above method, since the resist film is water-insoluble and the intermediate layer is water-soluble, even if the intermediate layer is dissolved in an aqueous solvent and formed on the resist film surface, it is difficult to mix with the resist film. Further, many of the dye films are water-insoluble or sparingly water-soluble, but when such a dye film is formed on the surface of the intermediate layer, it is difficult to mix with the intermediate layer.
[0050]
In order to solve the above problems, a resist pattern forming apparatus of the present invention includes a resist film forming unit that forms a resist film on a substrate surface, an intermediate layer forming unit that forms an intermediate layer on the resist film surface, and a substrate. A heating means for heating and baking the laminated substrate on which the resist film and the intermediate layer are formed, a dye film forming means for forming a dye film on the surface of the heated laminated substrate, and a laminated substrate on which the dye film is formed And an exposure means for irradiating beam light from the dye film side, and a developing means for developing the resist film.
[0051]
According to the above configuration, since the intermediate layer is formed on the resist film surface and further subjected to the baking treatment, the dye film is formed on the surface of the intermediate layer, so that the resist film and the dye film are in direct contact with each other. And a resist pattern can be formed. Even when the dye film forming means is formed by applying a liquid containing an organic solvent or the like on the surface of the intermediate layer, the components of the resist film are not dissolved in the dye film.
[0052]
If the intermediate layer is merely between the resist film and the dye film, the organic solvent may enter the intermediate layer and reach the resist below. Therefore, by forming an intermediate layer that has been baked, the intermediate layer serves as a reaction preventing layer that prevents the organic solvent from attacking the resist film when forming the dye film, and the dye of the dye film Is prevented from diffusing into the resist film and mixing.
[0053]
Moreover, since the resist pattern of this invention is produced by the resist pattern formation method mentioned above, while being able to form a resist film favorably, a fine unevenness | corrugation can be formed on a resist film.
[0054]
The optical disk manufacturing method of the present invention is to manufacture an optical disk by forming the above resist pattern as irregularities that form phase pits or grooves. As a result, a fine phase pit or groove mold can be formed, and an optical disk capable of recording information with high density can be manufactured. The resist pattern may be formed on any of a stamper that is a direct mold of the optical disk, a mold for molding the stamper, an optical disk master, and the like.
[0055]
In the semiconductor device manufacturing method of the present invention, the above-described resist pattern is formed as a highly integrated circuit such as an IC or LSI. Therefore, a semiconductor device having a high-density integrated circuit in which a fine integrated circuit is drawn can be manufactured.
[0056]
Further, in the magnetic head manufacturing method of the present invention, the magnetic head is formed using the above-described resist pattern, so that a magnetic head capable of recording and reproducing fine and high-density information can be manufactured.
[0057]
Further, in the magnetic recording medium manufacturing method of the present invention, since the magnetic recording medium is formed using the resist pattern described above, a magnetic recording medium capable of recording or reproducing information with high density can be manufactured.
[0058]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, a resist pattern forming method according to the present embodiment will be described with reference to FIGS.
[0059]
The resist pattern forming method of the present embodiment includes a resist film forming step, an intermediate layer forming step, a baking step, a dye film forming step, an exposure step, a removing step, and a developing step. A fine resist pattern is formed on the resist film 2. It is a method of forming. Hereinafter, a method for producing an optical disc master will be described as an example.
[0060]
First, in the resist film forming step, as shown in FIG. 1, a transparent glass substrate (substrate) 1 is prepared, and a photoresist is applied on the glass substrate 1 by a technique such as a spin coating method. Membrane 2 was formed. Although any photoresist can be used as the photoresist used for the resist film 2, a positive photoresist is used here.
[0061]
Next, in the intermediate layer forming step, as shown in FIG. 2, an aqueous solution of polyvinyl alcohol (PVA) is applied onto the resist film 2 by a technique such as spin coating, and the intermediate layer made of a water-soluble polymer. 3 was formed. The film thickness of the intermediate layer 3 was about 100 nm.
[0062]
Here, the substrate 1 on which the resist film 2 and the intermediate layer 3 were laminated by the baking process was placed in a heating atmosphere of 80 to 100 ° C. and dried to solidify the film quality (baking process).
[0063]
In the dye film forming step, the indolenine carbocyanine dye is dissolved in an organic solvent, and as shown in FIG. A transmittance changing layer (dye film) 4 containing an association of carbocyanine dyes was formed. The film thickness of the transmittance changing layer 4 was about 300 nm.
[0064]
The glass substrate 1 thus provided with the resist film 2, the intermediate layer 3, and the transmittance changing layer 4 is shown in FIG. 4 by an optical recording apparatus (exposure means) 18 using laser light described later in the exposure process. Thus, it exposed from the transmittance | permeability change layer 4 side. At this time, when an arbitrary pattern is exposed, only the exposed portion is dissolved.
[0065]
After the exposure step described above, in the removal step, the transmittance changing layer 4 and the intermediate layer 3 shown in FIG. 3 are removed by washing with water or an alkaline developer.
[0066]
Then, the resist film 2 was developed with an alkaline developer in the development step, that is, the exposed and dissolved portion was removed, and a resist pattern 21 and a groove portion 22 were formed on the glass substrate 1 as shown in FIG.
[0067]
Next, the optical recording device 18 used in the exposure process will be described with reference to FIG. Here, an optical recording apparatus 18 for producing an optical disc master will be described as an example. The optical recording device 18 has a configuration as shown in FIG. That is, the optical recording device 18 includes a laser light source 11, a mirror 12 that guides the laser light L emitted from the laser light source 11 to a subsequent optical system, a filter element 13 that adjusts the light intensity of the laser light L, a laser An electro-optic modulator (EOM) 14 that modulates the intensity of the light L according to an input recording signal, mirrors 15 and 16 that guide the intensity-modulated laser light L to the objective lens 17, and a predetermined laser light L. And an objective lens 17 that irradiates with a reduced spot diameter.
[0068]
The objective lens 17 and the mirror 16 disposed immediately before the objective lens 17 are installed on a movable member (not shown), and are arranged so that the objective lens 17 faces the transmittance changing layer 4 on the glass substrate 1 with a minute interval. The movable member is movable in the radial direction of the glass substrate 1 by a known moving mechanism. Therefore, while rotating the glass substrate 1 and moving the movable member in the radial direction of the glass substrate 1, the laser beam L is irradiated (exposure) through the objective lens 17 and developed, whereby the phase pits are applied to the resist film 2. Are formed concentrically or spirally.
[0069]
The EOM 14 is an optical modulator that utilizes a change in the refractive index of the medium due to an electro-optic effect (an effect in which the refractive index of the medium changes according to an applied signal electric field). The laser light is normally linearly polarized by the Brewster window, but in this embodiment, the optical phase difference between two orthogonal polarization components in the medium is changed using the EOM 14 in the incident laser light L. Controlled by the applied electric field, the polarization state is changed. Specifically, the laser light L that has passed through the EOM 14 becomes elliptically polarized light, and is converted into intensity-modulated light by an analyzer including a quarter-wave plate and an analyzer at the subsequent stage.
[0070]
In the present embodiment, using such an optical recording apparatus, the glass substrate 1 provided with the resist film 2, the intermediate layer 3, and the transmittance changing layer 4 is set to have a linear velocity of 1.0 m / sec at the exposure position. The laser beam was irradiated toward the transmittance changing layer 4. At this time, the wavelength λ of the laser beam was 351 nm, and the numerical aperture NA of the condenser objective lens 17 was 0.9. Further, the input power of the irradiated laser beam L was 0.4 mW. The laser light that has passed through the transmittance changing layer 4 has a light intensity that is reduced to about 80% before transmission, but is sufficient to expose the photoresist.
[0071]
By forming the resist pattern by the above method, the resist film 2 is exposed through the transmittance changing layer 4 in the exposure step, so that the diameter of the beam light is reduced and a fine resist pattern can be formed. This is because the transmittance changing layer 4 contains a dye aggregate, and the dye aggregate hardly absorbs light having a low intensity due to an absorption saturation phenomenon at the time of light irradiation, and only transmits light having a certain level or more. This is because it has a characteristic of transmitting. As a result, when laser light having a concentric intensity distribution is irradiated onto the transmittance changing layer 4, the laser light is transmitted at the center of the laser spot because the intensity of the laser light is strong. In the peripheral portion, the laser light is absorbed by the transmitted light limiting layer and is not transmitted. As a result, the spot diameter of the laser light that has passed through the transmitted light limiting layer is significantly smaller than the spot diameter of the laser light before being transmitted through the transmitted light changing layer 4.
[0072]
Therefore, when the resist film is irradiated with laser light through the transmittance changing layer 4, the resist film is exposed with a very small spot diameter, and a resist pattern such as a small phase pit is formed.
[0073]
In the present embodiment, as described above, in order to form the transmittance changing layer 4 on the resist film 2 without being mixed, the intermediate layer 3 is formed and the baking process is performed.
[0074]
In the conventional resist pattern forming method as described in Patent Document 1, a water-soluble photobleachable dye (aryl nitrone compound, diazonium salt, etc.) or a part of saturable color is formed as a transmittance changing layer 4 on the resist. Dyes (porphyrin, phthalocyanine, etc.) are used.
[0075]
The water-soluble photobleachable dye is weak against heat and easily deteriorates, so that it is difficult to form a film by a sputtering method or a vapor deposition method. Usually, it is dissolved in water together with a hydrophilic resin and formed by a spin coating method. Some saturable dyes have heat resistance and plasma resistance, so that they can be easily formed by sputtering or vapor deposition. However, there is a problem when forming a film on a resist by spin coating or the like. That is, since the dye is soluble in an organic solvent and hardly soluble in water, it is necessary to dissolve the dye in an organic solvent in order to form a dye film. On the other hand, since the resist material is also soluble in an organic solvent, the resist film dissolves in the organic solvent when a dye such as a photobleachable dye dissolved in the organic solvent is applied onto the resist film. An accurate resist pattern cannot be formed by mixing with the transmitted light limiting layer.
[0076]
Therefore, it is conceivable that the intermediate layer 3 is sandwiched between them. However, when only the intermediate layer 3 is formed, the organic solvent penetrates into the water-soluble polymer of the intermediate layer 3 when the transmittance changing layer 4 is formed. The resist film 2 may be affected by reaching the film 2. However, if the heat treatment is performed in the baking step, the surface of the intermediate layer 3 is solidified, and the organic solvent used to form the upper transmitted light change layer 4 does not attack the resist film 2. It plays a role and also prevents the dye of the transmitted light changing layer 4 from diffusing into the resist film 2 and mixing. The effect of preventing the resist layer 2 and the transmitted light changing layer 4 from being mixed by baking the intermediate layer at this time is not limited to the case where the transmittance changing layer 4 includes a dye aggregate, but also in the conventional example. It is also effective when the various dye coatings described are used.
[0077]
Further, in the dye film forming step of the present embodiment, the dye forming the aggregate is dissolved in an organic solvent, and the film is formed by a technique such as a spin coating method. However, the organic solvent is hardly water-soluble. preferable. This is to prevent the transmittance changing layer 4 from dissolving in the water contained in the intermediate layer for a few seconds during the spin coating on the intermediate layer 3 made of hydrophilic resin. The organic solvent is desirably poorly water-soluble. However, it may have a slight solubility in water.
[0078]
Examples of the hardly water-soluble solution include a methyl ethyl ketone solution (MEK). MEK has a pigment solubility as high as acetone, and has relatively little penetration into the polyvinyl alcohol hydrogel film used in the intermediate layer compared to low molecular organic solvents such as methanol. There is no problem that the organic solvent penetrates into the intermediate layer 3 and reaches the resist film 2 to dissolve the resist film 2. Moreover, since the drying speed is high in a room temperature atmosphere, it is suitable for spin coating of a dye film.
[0079]
If a phase pit or groove groove is formed as the groove 22 on the disk substrate using the resist pattern forming method as described above, an optical disk master having a fine phase pit or groove groove mold can be manufactured.
[0080]
An optical disc in which minute phase pits are formed at a high density can be manufactured by performing Ni electroforming on the obtained optical disc master to obtain a stamper and using this to injection-mold a substrate material such as polycarbonate. .
[0081]
Further, a phase pit or groove groove mold formed by the resist pattern forming method may be used as the above stamper directly as an optical disk mold.
[0082]
Next, the transparency of the transmittance changing layer 4 will be described in detail. The above-described characteristic of the transmittance changing layer 4 that “low intensity light is hardly transmitted and only light having a certain level or more is transmitted” is due to the transmission characteristics of the dye aggregate constituting the transmittance changing layer 4. It is.
[0083]
The transmittance changing layer 4 of the present embodiment is made of an indolenine carbocyanine dye. The indolenine carbocyanine dye is a cyanine dye represented by the chemical formula of the general formula (1), wherein X = C, two methyl groups Me, and n = 1 (trimethylene). ) Is a compound represented by the chemical formula
[0084]
What represents the wavelength dependence of the transmittance of the transmittance changing layer 4 made of the dye is shown by a broken line in FIG. Here, the horizontal axis is the wavelength λ of light, and the vertical axis is the transmittance of the transmittance changing layer 4 for each wavelength. When an indolenine carbocyanine dye is spin-coated, the dye forms a J-aggregate within the film surface, and the monomer and the aggregate are mixed. The J-aggregate has a sharp absorption peak at a wavelength of 351 nm (indicated by A) and about 650 nm (indicated by A ′), and the monomer has an absorption peak indicated by C at about 570 nm.
[0085]
The J-aggregate is a substance in which polar dyes (for example, ionic dyes such as cyanine dyes and merocyanine dyes) are regularly aligned and several to several hundreds are associated. The J aggregate has an aggregate peak on the long wavelength side of the absorption peak of the monomer. In addition to the J aggregates, there are dimers that form an absorption peak on the short wavelength side of the monomer and films formed from H aggregates, but the aggregate quality is relatively unstable. It is desirable to use it.
[0086]
Since the dye reacts with temperature to cause a photochemical change, the transmittance of the transmittance changing layer 4 changes to the transmittance characteristic indicated by the solid line portion in FIG. 6 after exposure to light having the wavelength. According to FIG. 6, the transmittance with respect to the exposure wavelength of 351 nm greatly changes from about 30% (shown by A) to about 80% (shown by B) at the time before exposure. The transmittance change at this time is caused by the shift of the absorption peak (A ′ → B ′) in the visible region on the right side of FIG.
[0087]
That is, the transmittance changing layer 4 has a temperature distribution as shown in FIG. 9 according to the light intensity distribution inside the beam spot by exposure of the beam light. That is, the irradiation part at the center of the beam light is at a high temperature of about 160 ° C., and at the point 0.1 μm away from the central part, only the central part is locally high at 20 ° C. When the dye aggregate reaches a certain temperature or higher, the orientation of the internal molecules changes thermally instantaneously, and the orientation angle between the dye molecules shifts from a metastable state to a more thermally stable state. As a result, the distance between the dye molecules is clogged, and the absorption peak of the transmission layer changing layer 4 is shifted to the short wavelength side (indicated by A ′ → B ′). Such clogging of the distance between the dye molecules varies in various ways, such as when the residual solvent or matrix molecules inside the aggregate are detached, or when the aggregate has multiple orientation angles due to the arrangement of the functional groups of the dye molecules. It occurs in conditions.
[0088]
As the distance between the dye molecules is clogged, the π-electron cloud contributing to near-ultraviolet absorption changes in the aggregate, and the transmittance in the ultraviolet region at 300 to 400 nm increases as A → B as shown in FIG. To do.
[0089]
On the other hand, the change in transmittance is also caused by another fading mechanism. For example, when the functional group of the dye is decomposed and released by heat, the π electron cloud of the dye molecule aggregate may change and the ultraviolet absorption may decrease, and the change in the absorption spectrum as shown in FIG. It is also the result of a complex reaction of the change in permeability that occurs due to two functional group changes.
[0090]
FIG. 7 is a graph showing how the transmittance of the dye aggregate changes depending on the irradiation light intensity. The horizontal axis indicates the intensity (mW) of irradiation light at 351 nm, and the vertical axis indicates the transmittance of irradiation light of the dye film at each irradiation light intensity. Here, as the transmittance changing layer 4, a conventional dye film (◯) using porphyrin and a dye film (indolenin-based carbocyanine dye) (●) containing a dye aggregate are used. According to FIG. 7, the transmittance of the porphyrin film gradually increases from 0 mW as the irradiation light intensity increases, whereas the dye film has a transmittance of approximately 0% up to about 0.3 mW of the irradiation light. When the light exceeds 0.3 mW, the transmittance increases rapidly. Therefore, the film containing the dye aggregate hardly transmits 0.2 mW irradiation light, but has a transmittance of about 50% for 0.4 mW irradiation light.
[0091]
This is because, as described above, the temperature of the dye aggregate increases due to light irradiation, and the transmittance of light in the wavelength range of 300 to 400 nm rapidly increases. In other words, the transmittance of a conventional pigment film using porphyrin increases in proportion to the increase in irradiation light when it exceeds a certain predetermined irradiation light intensity (threshold) (it changes linearly). ing). In contrast, the dye aggregate undergoes a photochemical reaction when irradiated with light of about 0.3 mW, and the absorption spectrum changes rapidly. That is, most of the films containing the dye aggregate show the transmittance characteristics shown by the solid line in FIG. 6 when irradiated with light of 0.2 mW, while the broken line shown in FIG. 6 shows most of the film when irradiated with light of 0.4 mW. It is considered that the transmittance characteristic indicated by Therefore, when light stronger than 0.3 mW is irradiated, the transmittance of light having a wavelength of around 350 nm suddenly increases compared to when light weaker than 0.3 mW is irradiated. That is, the change in light transmittance has a non-linear property with respect to the light intensity.
[0092]
Therefore, when comparing the irradiation light intensity-transmittance change characteristics of the conventional saturable dye film (using porphyrin) and the dye aggregate film of the present invention (using cyanine dye) as shown in FIG. 7, the porphyrin film In contrast, the dye aggregate coating film has a higher threshold of irradiation light intensity (or dye coating temperature) necessary for the transmittance to begin to increase. In this way, the transmittance of the dye aggregate suddenly increases due to the high threshold value of the above-mentioned irradiation light intensity (dye coating temperature) and the property of obtaining an appropriate transmittance change rate, that is, the irradiation light intensity exceeding the threshold value. Depending on the nature of the light beam, it is possible to transmit only the center of the light beam using the temperature difference between the central part and the peripheral part of the light beam due to the heat generated from the center of the beam spot. Got.
[0093]
More specifically, as shown in FIG. 9, the beam light has a rapid temperature rise between 20 ° C. and 160 ° C. in the range of about 0.1 μm diameter from the center of the beam spot. A remarkable thermal fading effect is caused, which causes an increase in the transmittance of light having a wavelength of 350 nm. Then, by passing through a film containing such a dye aggregate, the light intensity at the center of the beam light is 0.1 μm away from the center as in the beam profile shown by the solid line in FIG. The position is about 10%, which is the Pth value. The Pth value is the intensity (threshold value) of the beam light at which the transmittance starts to increase. Therefore, the laser light after passing through the dye film becomes a beam light with a small spot diameter that falls within a circle having a radius of about 0.1 μm. Therefore, the dye film of the dye aggregate produces a sharp contrast enhancement effect. In FIG. 8, the one-dot chain line indicates the irradiated light beam, and the broken line indicates the light beam after passing through the conventional porphyrin film. The radius of the spot diameter of the beam is 0.2 μm at the time of irradiation and about 0.15 μm when transmitted through the porphyrin film. Therefore, according to the chromophoric association film of the present embodiment, it can be reduced to half the spot radius of the irradiation beam light, and is smaller than the beam light after passing through the conventional porphyrin film. Yes.
[0094]
As described above, the property that the transmittance changing layer 4 made of the dye aggregate reduces the spot diameter of the beam light has been described with reference to an example using an indolenine carbocyanine dye as a dye. The dye is not limited, and any dye that forms a dye aggregate may be used. However, in order to utilize the photobleaching effect and thermal fading effect of the dye, it is preferable to use an organic dye-based heat mode material used for the recording material of the optical disk. Organic dye-based heat mode materials include polymethine dyes, anthraquinone dyes, cyanine dyes, dicarbocyanine dyes, phthalocyanine dyes, naphthalocyanine dyes, xanthene dyes, triphenylmethane dyes, pyrylium dyes, An azulene dye, a metal-containing azo dye or the like, or a mixture thereof can be used.
[0095]
In order to effectively reduce the spot diameter of the beam light as described above, it is more preferable to use a cyanine dye represented by the general formula (1), which is represented by the general formula (2). Most preferred are indolenine carbocyanine dyes of the formula
[0096]
Moreover, the pigment | dye used for this transmittance | permeability change layer 4 is selected according to an exposure wavelength so that the transmittance | permeability change of the wavelength of the irradiated light may be caused as mentioned above by the light irradiated at an exposure process. Is preferred. For example, when the exposure wavelength is 351 nm, it is preferable that the wavelength λ exhibits absorption with respect to light in the range of 300 nm to 400 nm, and the transmittance changes. A cyanine dye having the chemical formula represented by (1) may be used. Further, it is desirable that the wavelength irradiated in the exposure process be as short as possible in order to make the spot diameter of the light beam proportional to λ / NA as small as possible.
[0097]
The cyanine dye is a general term for a dye having a cation structure in which two nitrogen-containing heterocycles are bonded with methine or a chain thereof, and is used as a recording material for a write-once optical disc. In addition, cyanine dyes can be easily formed by spin coating, show good film formability without a binder, easily modify molecules such as methine chains and peripheral functional groups, and can easily change properties. The single layer film has advantages such as having a metallic luster and high reflectivity, and extremely low toxicity, and is preferably applied to the transmittance changing layer 4.
[0098]
The transmittance changing layer 4 is preferably composed of a molecular film made only of a cyanine dye, or a mixed film of a cyanine dye and one kind of matrix molecule (using fatty acid such as arachidic acid), and only spin coating. Particularly preferred is a case where a J aggregate is formed in the film plane.
[0099]
As described above, the embodiment of the present invention has been described. However, the present invention is not limited to the above-described embodiment. For example, the thickness of the transmittance changing layer can be arbitrarily set according to the power of the laser beam or the like. Can be set to
[0100]
In addition, the resist pattern of the present invention is not limited to the manufacture of optical discs, and can be used in a method of manufacturing devices such as semiconductor devices, magnetic heads, and magnetic recording media (patterned media) by further adding mask exposure. be able to.
[0101]
In addition, this invention can also be set as the following structures.
[0102]
A method for forming a resist pattern on a substrate, comprising: a step of forming a water-insoluble resist film on a substrate; and a step of forming a dye film composed of a dye aggregate.
[0103]
In the first resist pattern forming method, a step of forming a water-insoluble resist film on the substrate, a step of forming a water-soluble intermediate layer on the resist film, and a step of forming a dye film comprising a dye aggregate, A resist pattern forming method, comprising: exposing the resist film and the intermediate layer and the dye film; removing the dye film after the exposure; then removing the intermediate layer; and developing the resist film.
[0104]
In the first resist pattern forming method, a second resist pattern forming method including a step of forming a water-insoluble resist film on a substrate and a step of forming a dye film composed of a dye aggregate having absorption in a specific wavelength region.
[0105]
In the second method for forming a resist pattern, a dye aggregate having a characteristic that absorption in a wavelength region of 300 to 400 nm and absorption on the left side are reduced by exposure in the same wavelength region, and a step of forming a water-insoluble resist film on a substrate A third resist pattern forming method comprising a step of forming a dye film comprising:
[0106]
In the third resist pattern forming method, a step of forming a water-insoluble resist film on the substrate, a step of forming a water-soluble intermediate layer on the resist film, and then absorption in the wavelength region of 300 to 400 nm A step of forming a dye film comprising a dye aggregate having the property of decreasing absorption by exposure in the region, the step of exposing the resist film and the intermediate layer, the dye film, the dye film after exposure, and then the intermediate A method for forming a resist pattern, comprising a step of removing a layer and a step of developing the resist film.
[0107]
A first resist pattern forming method includes a step of forming a water-insoluble resist film on a substrate and a step of forming a dye film made of an ionic dye forming a dye aggregate. Forming method.
[0108]
In a fourth resist pattern forming method, a step of forming a water-insoluble resist film on a substrate and a step of forming a dye film made of a cyanine dye compound represented by the general formula (1) that forms a dye aggregate 5th resist pattern formation method characterized by including.
[0109]
In a fifth resist pattern forming method, a step of forming a water-insoluble resist film on a substrate and a dye film comprising an indolenine carbocyanine dye compound represented by the general formula (2) that forms a dye aggregate A method of forming a resist pattern, comprising a step of forming.
[0110]
In a method of forming a resist pattern on a substrate, a step of forming a water-insoluble resist film on the substrate, a step of forming a water-soluble intermediate layer on the resist film, and baking after forming the resist film and the intermediate layer And a step of forming a dye film, and a sixth resist pattern forming method.
[0111]
In the sixth resist pattern forming method, a step of forming a water-insoluble resist film on the substrate, a step of forming a water-soluble intermediate layer on the resist film, and 80-100 after forming the resist film and the intermediate layer A step of baking at 0 ° C., a step of forming a dye film, a step of exposing the resist film and the intermediate layer and the dye film, a step of removing the dye film and then the intermediate layer after exposure, and the resist film A method for forming a resist pattern, comprising a step of developing.
[0112]
A resist pattern forming apparatus, wherein a resist pattern is formed according to the above forming method.
[0113]
A device manufactured using the above formation method.
A semiconductor device manufactured using the above formation method.
A magnetic head manufactured by using the above forming method.
Patterned media produced using the above formation method.
An optical disc master, a disc stamper, and an optical disc produced using the above forming method.
[0114]
【The invention's effect】
As described above, the resist pattern forming method of the present invention includes a resist film forming step of forming a resist film on a substrate surface, a dye film forming step of forming a dye film containing a dye aggregate, and the above-described dye film. And an exposure step of irradiating the resist film with a laser beam, and a developing step of developing the resist film irradiated with the laser beam.
[0115]
According to the above method, by irradiating the laser beam through the dye film, only the light at the center of the laser beam is transmitted and the light at the periphery of the laser beam is not transmitted, and the contrast of the light intensity of the laser beam is increased. Can be strengthened. Therefore, the spot diameter of the laser beam transmitted through the dye film is smaller than that before transmission.
[0116]
Then, by irradiating the resist film with laser light having a small spot diameter, pattern exposure corresponding to a fine pattern can be performed on the resist film, so that a fine resist pattern can be formed.
[0117]
In the resist pattern forming method of the present invention, as described above, in addition to the above steps, an intermediate layer forming step of forming an intermediate layer on the resist film surface, and the substrate on which the resist film and the intermediate layer are formed are heated. A baking process, a dye film forming process for forming a dye film containing a dye aggregate on the surface of the intermediate layer following the baking process, an exposure process for irradiating the resist film with laser light through the dye film, And a development step of developing the resist film irradiated with the laser beam.
[0118]
According to the above method, an intermediate layer is formed on the surface of the resist film, further baked, and then a dye film is formed on the surface of the intermediate layer, so that the resist film and the dye film are prevented from coming into direct contact. Even when a liquid containing an organic solvent or the like is applied at the time of forming the dye film, the resist film components are not dissolved in the organic solvent at the time of forming the dye film.
[0119]
In addition, the intermediate layer is further baked after the intermediate layer is formed, so that the intermediate layer serves as a reaction preventing layer so that the organic solvent in forming the dye film does not attack the resist film. The dye diffuses inside the resist film and prevents mixing.
[0120]
As described above, the resist pattern forming method of the present invention is a method in which, in addition to the above steps, after the exposure step, a removal step of removing the dye film and the intermediate layer is performed, and a development step is performed after the removal step. It is.
[0121]
According to the above method, since the development is performed in a state where only the resist film is formed on the upper surface of the substrate, the development is favorably performed.
[0122]
In the resist pattern forming method of the present invention, as described above, in addition to the above method, the dye film formed in the dye film forming step is irradiated with the laser beam in the exposure step, so that the wavelength of the laser beam is increased. This is a method having a characteristic that the transmittance of light including a region is increased.
[0123]
According to the above method, by irradiating the laser beam through the dye film, only the light at the center of the laser beam is transmitted and the light at the periphery of the laser beam is not transmitted, and the contrast of the light intensity of the laser beam is increased. Can be strengthened. Therefore, the spot diameter of the laser beam transmitted through the dye film is smaller than that before transmission.
[0124]
Then, by irradiating the resist film with laser light having a small spot diameter, pattern exposure corresponding to a fine pattern can be performed on the resist film, so that a fine resist pattern can be formed.
[0125]
As described above, the resist pattern forming method of the present invention is a method in which the wavelength range of the laser light irradiated in the exposure step is 300 nm or more and 400 nm or less in addition to the above steps.
[0126]
Since the spot diameter of the laser beam is proportional to λ / NA, the shorter the wavelength of the laser beam, the smaller the spot diameter of the laser beam. According to the above method, the wavelength range of the laser beam irradiated by the exposure process is set to 300 nm. Since ultraviolet light having a wavelength as short as 400 nm or less is used, the spot diameter of the laser beam during irradiation can be reduced.
[0127]
As described above, the resist pattern forming method of the present invention is a method of forming a dye film comprising a dye aggregate composed of an ionic dye in the dye film forming process in addition to the above process.
[0128]
According to the above method, since the ionic dyes have a strong tendency to bond with each other and easily form an aggregate, if the dye film contains a dye aggregate of an ionic dye as in the above method, the ionic dye Can stably form aggregates in the dye film. Therefore, the spot diameter can be reduced by favorably enhancing the contrast of the light intensity.
[0129]
As described above, the resist pattern forming method of the present invention includes, in addition to the above steps, a dye film comprising a dye aggregate comprising a cyanine dye compound represented by the general formula (1) in the dye film forming step. It is a method of forming.
[0130]
According to the above method, since the cyanine dye forms an aggregate in the film surface only by spin coating, it is suitable for the formation of a dye film composed of the dye aggregate. Further, the cyanine dye compound absorbs light in the range of 300 nm to 400 nm, and when irradiated with this light, the transmittance of light in the range of 300 nm to 400 nm increases. The spot diameter can be further reduced by enhancing the contrast of the light intensity.
[0131]
As described above, the resist pattern forming method of the present invention includes a dye aggregate comprising an indolenine carbocyanine dye compound represented by the general formula (2) in the dye film forming step in addition to the above method. Is a method of forming a dye film.
[0132]
According to the above method, the light transmittance in the range of 300 nm to 400 nm is rapidly increased from about 30% to about 80% by irradiation with light in the range of 300 nm to 400 nm. The spot diameter can be further reduced by favorably enhancing the contrast of the light intensity.
[0133]
As described above, the resist pattern forming method of the present invention is a method of performing heat treatment in an atmosphere of 80 ° C. or higher and 100 ° C. or lower in the baking step in addition to the above method.
[0134]
According to the above method, the role of the reaction preventing layer in which the organic solvent does not attack the resist film when forming the dye film of the intermediate layer becomes better, and the dye of the dye film diffuses into the resist film and is mixed. To prevent it.
[0135]
As described above, the resist pattern forming method of the present invention is a method in which, in addition to the above steps, the resist film is water-insoluble and the intermediate layer is water-soluble.
[0136]
According to the above method, since the resist film is water-insoluble and the intermediate layer is water-soluble, the resist film is dissolved in the organic solvent and the intermediate layer is dissolved in the aqueous solvent at the time of film formation.
[0137]
As described above, the resist pattern forming apparatus of the present invention includes a resist film forming means for forming a resist film on the substrate surface, an intermediate layer forming means for forming an intermediate layer on the resist film surface, and a resist film and an intermediate on the substrate. A heating unit for heating and baking the laminated substrate on which the layer is formed; a pigment coating forming unit for forming a pigment coating on the surface of the laminated substrate that has been subjected to the heat treatment; and a pigment coating side on the multilayer substrate on which the pigment coating is formed And a developing unit for developing the resist film.
[0138]
According to the said structure, a resist pattern can be formed, without a resist film and a pigment | dye film | membrane contacting directly. Therefore, even when the dye film forming means is formed by applying a liquid containing an organic solvent or the like to the surface of the intermediate layer, the resist film components are not dissolved in the dye film.
[0139]
Furthermore, the intermediate layer is baked to serve as a reaction prevention layer that prevents the organic solvent from attacking the resist film when forming the dye film, and the dye in the dye film diffuses into the resist film and mixes. To prevent it.
[0140]
Since the resist pattern of the present invention is formed according to the above resist pattern forming method, a resist film can be formed satisfactorily and fine irregularities can be formed on the resist film.
[0141]
In the semiconductor device manufacturing method of the present invention, since the resist pattern described above is used for highly integrated circuits such as ICs and LSIs, a semiconductor device having a fine and high density integrated circuit can be manufactured.
[0142]
In the magnetic head manufacturing method of the present invention, a magnetic head is formed using the above-described resist pattern, so that a magnetic head capable of recording and reproducing fine and high-density information can be manufactured.
[0143]
Further, in the magnetic recording medium manufacturing method of the present invention, since the magnetic recording medium is formed using the resist pattern described above, a magnetic recording medium capable of recording or reproducing information with high density can be manufactured.
[0144]
As is clear from the above description, in the present invention, a transmittance changing layer containing a substance that transmits only light having a predetermined intensity or more is provided on the resist film, and the resist film is formed through this transmittance changing layer. Since the exposure is performed, it is possible to form a phase pit that is dramatically smaller than the limits of λ / NA and the light intensity distribution.
[0145]
In addition, the above effect makes it possible to perform fine device processing, and to manufacture a highly integrated semiconductor device, a fine magnetic head, a patterned medium capable of high-density recording, and an optical disc.
[Brief description of the drawings]
FIG. 1 is a drawing showing a resist film forming step according to an embodiment of the present invention.
FIG. 2 is a drawing showing an intermediate layer forming step according to an embodiment of the present invention.
FIG. 3 is a drawing showing a dye film forming step according to an embodiment of the present invention.
FIG. 4 is a drawing showing an exposure process according to an embodiment of the present invention.
FIG. 5 is a view showing a substrate on which a resist pattern is formed by a resist pattern forming method according to an embodiment of the present invention.
FIG. 6 is a diagram showing transmittance characteristics of a transmittance changing layer according to an embodiment of the present invention.
FIG. 7 shows the change in transmittance according to the light intensity of the transmittance changing layer according to one embodiment of the present invention with ●, and the change in transmittance with the light intensity of the layer prepared by the conventional method is indicated by ○. It is a drawing.
FIG. 8 is a beam profile showing the correspondence between the distance from the center portion of the light beam and the light intensity, where the alternate long and short dash line indicates the beam light at the time of irradiation, and the broken line after passing through the layer produced by the conventional method. The solid line represents the beam light after passing through the transmittance changing layer according to the embodiment of the present invention.
FIG. 9 is a drawing showing a temperature distribution on a film surface when a light beam is irradiated on a transmittance changing layer according to an embodiment of the present invention.
[Explanation of symbols]
1 Glass substrate (substrate)
2 resist film
3 middle class
4 Transmittance change layer (dye coating)
11 Laser light source
12 Mirror
13 Filter element
14 Electro-optic modulator
15 Mirror
16 Mirror
17 Objective lens
18 Optical recording device (exposure means)
21 resist pattern
22 Groove

Claims (16)

A resist film forming step of forming a resist film on the substrate surface;
A dye film forming step of forming a dye film comprising a dye aggregate;
An exposure step of irradiating the resist film with laser light through the dye film;
And a developing step of developing the resist film irradiated with the laser beam. An intermediate layer forming step of forming an intermediate layer on the resist film surface;
A baking step of heating the substrate on which the resist film and the intermediate layer are formed;
A dye film forming step of forming a dye film comprising a dye aggregate on the surface of the intermediate layer after the baking step;
An exposure step of irradiating the resist film with laser light through the dye film;
The resist pattern forming method according to claim 1, further comprising a developing step of developing the resist film irradiated with the laser beam. 3. The resist pattern forming method according to claim 2 , wherein after the exposure step, a removal step of removing the dye film and the intermediate layer is performed, and a development step is performed after the removal step.   The dye film formed in the dye film forming step has a characteristic that light transmittance including a wavelength region of the laser light is increased by being irradiated with laser light in the exposure step. The resist pattern forming method according to any one of claims 1 to 3.   The resist pattern forming method according to claim 4, wherein the wavelength range of the laser light irradiated in the exposure step is 300 nm or more and 400 nm or less.   6. The method of forming a resist pattern according to claim 1, wherein in the dye film forming step, a dye film containing a dye aggregate made of an ionic dye is formed. In the dye film forming step, the general formula (1)

(Wherein R1 and R2 represent any functional group)
A method for forming a resist pattern according to any one of claims 1 to 6, wherein a dye film comprising a dye aggregate comprising a cyanine dye compound represented by formula (1) is formed. In the dye film forming step, the general formula (2)

(Wherein R1 and R2 represent any functional group)
8. A method of forming a resist pattern according to claim 7, wherein a dye film comprising a dye aggregate comprising an indolenine carbocyanine dye compound represented by the formula: is formed. The resist pattern forming method according to claim 2, wherein in the baking step, heat treatment is performed in an atmosphere of 80 ° C. or higher and 100 ° C. or lower. The resist pattern forming method according to claim 2 , wherein the resist film is water-insoluble and the intermediate layer is water-soluble. A resist film forming means for forming a resist film on the substrate surface;
An intermediate layer forming means for forming an intermediate layer on the resist film surface;
A heating means for heating and baking the laminated substrate in which the resist film and the intermediate layer are formed on the substrate;
A dye film forming means for forming a dye film comprising a dye aggregate on the heat-treated laminated substrate surface;
An exposure means for irradiating the laminated substrate on which the dye film is formed with the beam light from the dye film side;
And a developing means for developing the resist film. Resist pattern, characterized in that it is made according to the resist pattern forming method according to any one of claims 1 to 10. An optical disk manufacturing method using the resist pattern according to claim 12 . A method for manufacturing a semiconductor device, comprising using the resist pattern according to claim 12 . A magnetic head manufacturing method using the resist pattern according to claim 12 . A method for producing a magnetic recording medium, comprising using the resist pattern according to claim 12 .

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