JP2006003422A - Method for forming pattern, and tft array substrate, and liquid crystal display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for forming a pattern suitable for the manufacture of a liquid crystal display (LCD) or a plasma display (PDP) for a large screen, and to provide a TFT array substrate and a liquid crystal display element. <P>SOLUTION: The method includes: a positive photosensitive layer forming step to form at least a positive photosensitive layer on the surface of a substrate by using a positive photosensitive composition; an exposure step to expose the positive photosensitive layer to light from a light irradiating means, the light modulated by a light modulating means having n of drawing elements which receive the light from the light irradiating means and exit the light and then made to pass a microlens array having arrangement of microlenses having aspheric surfaces which can correct aberration due to the exiting faces of the drawing elements; and a developing step to develop the positive photosensitive layer exposed in the exposure step. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a pattern forming method, a TFT array substrate, and a liquid crystal display element suitable for manufacturing a liquid crystal display (LCD) for large screens and a plasma display (PDP).

  With the trend toward larger and higher definition substrates such as liquid crystal displays (LCDs) and plasma display panels (PDPs), etching photoresists used in the manufacture of thin film transistors (TFTs) and electrode plates have increased sensitivity. Focusing on uniformity and resist saving, adhesion to various substrates, dry etching resistance (heat resistance), and the like are desired. In particular, with regard to the above uniformity, the demand for strictness in various parts such as the uniformity of the coating film thickness in the central part and the peripheral part of the substrate and the dimensional uniformity, the film thickness, and the shape due to higher resolution is increased due to the increase in size of the substrate. Yes.

As a conventional etching photoresist, for example, a liquid composition containing an alkali-soluble phenol novolak resin, a 1,2-quinonediazide compound, and a solvent, and further containing an adhesion promoter, a coating aid, a colorant and the like as necessary. Has been proposed (see Patent Documents 1 and 2).
In this case, the TFT array substrate and PDP electrode plate are manufactured by applying an etching photoresist onto a conductive substrate or an insulating substrate sputtered on a glass substrate or a transparent plastic substrate, followed by drying, pattern exposure, and development. Etching and resist stripping steps (hereinafter sometimes referred to as “photoetching steps”) are performed on the thin films of the respective layers.
For the etching, a wet etching method using various liquid etchants and dry etching that vaporizes and removes the film on the substrate using ions and radicals (active species) generated by decomposing gas with plasma in a decompression device. There is a law.

In order to form such a fine pattern by photoetching, two components from a photosensitive substance having a 1,2-quinonediazide group as a photosensitive group and an alkali-soluble novolac resin having a phenolic hydroxyl group are mainly used. Photoresist compositions are commonly used. The coating thickness of the photoresist film is generally 0.5 to several μm.
Using such a photoresist composition, an image having a wide range of dimensions from a sub-half micron region having an image pattern dimension of about 0.3 μm to a considerably large width of several tens to several hundreds of μm. Is formed, which enables fine processing of various substrate surfaces.

This type of photoresist composition is a positive photoresist that can be developed with alkaline water, and is more widely used than, for example, a rubber-based negative photoresist. This is because (1) the positive photoresist has better resolution than the negative rubber photoresist, (2) the acid / etching resistance is better, and (3) non- The problem of waste liquid treatment is not as great as solvent type due to solvent development. (4) The biggest difference is that in the positive type, the image dimensional change due to swelling during development is extremely small, and dimensional controllability is relatively easy. There is a reason for this.
Also, in the field of LCD and the like, with the progress of technologies such as TFT and STN, the line width tends to become narrower and finer. For example, in an element using conventional TN and STN liquid crystal, about 200 μm to several hundred μm. The minimum design dimension has been reduced to 100 μm or less by the development of new technology, and the TFT display element with good response or image quality has been miniaturized to the level of several μm.

On the other hand, as a characteristic expected for a photoresist material, it is necessary to deal with a large area while maintaining the above-mentioned fine processing capability. Realization of in-plane film thickness uniformity is becoming an important technology for substrates oriented toward a large screen from the beginning, such as a large-sized substrate of a liquid crystal display and a plasma display (PDP).
Further, as a common problem in large-area displays, it is necessary to further reduce the cost, and it is also a problem to reduce the amount of photoresist used. In addition, in order to improve the in-plane film thickness uniformity and reduce the amount of photoresist used, the coating system has been studied, and a new slit coater has been developed from the conventional spin coater. ing.
However, as a technique required for TFT processing of LCD, first, resolution is as high as 2 to 10 μm, metaion-free development, peeling with an organic peeling solution, metal thin film such as ITO, Ta, Al, SiNx, This is an etching process for inorganic thin films such as ITO. To cope with this, a photoresist layer having a thickness of several microns, adhesion to various sputtered metal films and inorganic thin film materials, film thickness uniformity, and the like are main problems.

Conventionally, as an exposure apparatus used for the photolithography method, an exposure method using a photomask is generally used. However, mask exposure due to uniform exposure technology in response to an increase in the size of the substrate, misalignment of the photomask, and adhesion of foreign matters during the process is a problem.
In recent years, as a solution to the problems based on these exposure machines and photomasks, laser light in the ultraviolet to visible region such as a semiconductor laser or a gas laser is applied to the photosensitive layer based on an exposure pattern formed from digital data such as a wiring pattern. An exposure apparatus using a laser direct imaging (hereinafter, also referred to as “LDI”) system that performs patterning by directly scanning an image is being studied.

  For example, when a large screen LCD of about 1 m square or more is manufactured by photolithography, it is necessary to form fine TFTs on a large substrate without many defects. For example, a panel that displays 1024 × 1024 pixels of the HDTV standard needs 1.97 million pixels. In other words, a TFT panel required for tens of thousands to millions of pixels is required to have strict quality so that no defect is allowed on any one panel on the same substrate. In this respect, the situation is greatly different from that for photolithography for semiconductors, VLSI chips, etc., which can be produced on a silicon substrate having a diameter of 30 cm at most for a CPU and can be manufactured by fractionating only good chips. .

As an exposure machine in such a so-called giant microlithography, a type using an optical system such as a huge lens has already become difficult for a large-screen LCD, and a split exposure system has been proposed. Yes. However, in this divided exposure, there is a problem in the accuracy of the connecting part of the pattern of the divided part, and a decisive one has not yet appeared.
In order to promote cost reduction in the TFT manufacturing process, it is advantageous to reduce the number of processes. However, as a method for realizing this, a technique using a halftone mask has attracted attention (see Patent Documents 3 and 4). . The bottleneck of this technology is a problem of cost increase due to the use of an expensive halftone mask.

  Therefore, direct patterning is possible without using a photomask, functions equivalent to the halftone mask method can be realized at low cost, and the number of TFT array substrate manufacturing processes can be reduced, resulting in high productivity and low cost production. In addition, a system that can realize high-yield production has not been provided yet, and its rapid development is desired.

JP-A-6-27657 JP 2000-105466 A JP 2000-206571 A JP 2001-324725 A

  This invention is made | formed in view of this present condition, and makes it a subject to solve the said various problems in the past and to achieve the following objectives. That is, according to the present invention, direct patterning is possible without using a photomask, functions equivalent to the halftone mask method can be realized at low cost, the number of TFT manufacturing processes can be reduced, high productivity and low cost. It is an object of the present invention to provide a pattern formation method, a TFT array substrate, and a liquid crystal display device using the TFT array substrate, which can realize production and high yield production.

  As a result of intensive studies to solve the above problems, the inventors of the present invention, in lithography pattern formation using a positive photoresist, an exposure step receives a drawing unit that receives and emits light from a light irradiation unit. After the light from the light irradiating means is modulated by the n light modulating means, the light passes through a microlens array in which microlenses having aspherical surfaces capable of correcting aberration due to distortion of the exit surface in the drawing unit are arranged. It has been found that a pattern forming method in which the photosensitive layer is exposed with the applied light is extremely advantageous. Further, in the exposure step in the pattern forming method of the present invention, by performing control to change the amount of irradiation light in at least two stages, exposure equivalent to that of a halftone mask can be advantageously realized at low cost. It was found that the number of processes in the manufacturing process can be reduced.

The present invention is based on the above findings of the present inventors, and means for solving the above problems are as follows. That is,
<1> A positive photosensitive layer forming step of forming at least a positive photosensitive layer on the surface of a substrate using a positive photosensitive composition;
After modulating the light from the light irradiation means by the light modulation means having n picture elements for receiving and emitting light from the light irradiation means, it is possible to correct aberration due to distortion of the emission surface in the picture element. An exposure step of exposing the positive photosensitive layer with light that has passed through a microlens array in which microlenses having aspherical surfaces are arranged;
And a development step of developing the positive photosensitive layer exposed in the exposure step.
<2> The pattern forming method according to <1>, wherein the positive photosensitive layer is formed by applying a positive photosensitive composition to a surface of a substrate and drying.
<3> The pattern forming method according to any one of <1> to <2>, wherein the positive photosensitive composition contains a novolak type phenol resin, a 1,2-quinonediazide compound, and a dissolution accelerator.
<4> The method according to any one of <1> to <3>, wherein at least two steps of intensity-modulated exposure are performed in the exposure step, and development is performed using two or more types of developers having different development intensities in the development step. This is a pattern forming method. In the pattern forming method of <4>, by performing intensity modulation control that changes the amount of irradiation light in at least two stages in the exposure process, exposure equivalent to that of a halftone mask can be advantageously realized at low cost. By performing development using two or more kinds of developers having different development strengths in the development process, the number of processes in the manufacturing process of the TFT array substrate can be reduced.
<5> The pattern forming method according to any one of <1> to <4>, wherein the aspherical surface is a toric surface.
<6> The <1> to <5, wherein the light modulation unit can control any less than n number of the pixel parts arranged continuously from the n picture elements according to the pattern information. > The pattern forming method according to any one of the above.
<7> The pattern forming method according to any one of <1> to <6>, wherein the light modulation unit is a spatial light modulation element.
<8> The pattern forming method according to <7>, wherein the spatial light modulator is a digital micromirror device (DMD).
<9> The pattern forming method according to any one of <1> to <8>, wherein the exposure is performed through an aperture array.
<10> The pattern forming method according to any one of <1> to <9>, wherein the exposure is performed while relatively moving the exposure light and the photosensitive layer.
<11> The pattern forming method according to any one of <1> to <10>, wherein the light irradiation unit can synthesize and irradiate two or more lights.
<12> The light irradiation unit includes a plurality of lasers, a multimode optical fiber, and a collective optical system that collects and couples the laser beams irradiated from the plurality of lasers to the multimode optical fiber. <1> to the pattern forming method according to any one of <11>.
<13> The pattern forming method according to <12>, wherein the wavelength of the laser beam is 395 to 415 nm.
<14> A TFT array substrate formed by the pattern forming method according to any one of <1> to <13>.
<15> A liquid crystal display element using the TFT array substrate according to <14>.

  The pattern forming method of the present invention comprises at least a positive photosensitive layer forming step, an exposure step, and a developing step. In the positive photosensitive layer forming step, at least a positive photosensitive layer is formed on the surface of the substrate using the positive photosensitive composition. In the exposing step, after the light from the light irradiation means is modulated by the light modulation means having n picture elements for receiving and emitting the light from the light irradiation means, the distortion of the emission surface in the picture element is performed. The positive photosensitive layer is exposed to light that has passed through a microlens array in which microlenses having aspherical surfaces capable of correcting the aberration due to the above are arranged. In the developing step, the positive photosensitive layer exposed in the exposing step is developed. As a result, a high tact can be achieved, a highly accurate pattern can be formed, and a TFT array can be produced densely and without defects in a large screen.

According to the present invention, conventional problems can be solved, patterning can be performed directly without using a photomask, and problems due to the photomask are eliminated, so that the yield is improved. In addition, functions equivalent to the halftone mask method can be realized at low cost, and the number of TFT manufacturing processes can be reduced. Therefore, by using the exposure apparatus of the present invention and a highly sensitive positive photosensitive composition, a system capable of realizing high productivity, low cost production and high yield production can be constructed.
In addition, according to the present invention, since contamination due to a photomask does not occur, the yield is improved, high productivity can be realized by using a high-sensitivity positive photoresist, and a function equivalent to that of a halftone mask is expensive. This can be realized without using a mask.

(Pattern forming method, TFT array substrate and liquid crystal display element)
The pattern forming method of the present invention includes at least a positive photosensitive layer forming step, an exposure step, and a developing step, and further includes other steps appropriately selected as necessary.
The TFT array substrate of the present invention is manufactured by the pattern forming method of the present invention.
The liquid crystal display element of the present invention uses the TFT array substrate of the present invention, and further includes other members as necessary.
Hereinafter, the details of the TFT array substrate and the liquid crystal display element of the present invention will be clarified through the description of the pattern forming method of the present invention.

[Positive photosensitive layer forming process]
The positive photosensitive layer forming step is a step of forming at least a positive photosensitive layer on the surface of a substrate using a positive photosensitive composition containing at least a binder and further forming other appropriately selected layers. is there.

The method for forming the positive photosensitive layer and other layers is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a method for forming by coating, pressing and heating each sheet-like layer By performing at least one of the above, a laminating method, a combination thereof and the like can be mentioned.
Preferred examples of the positive photosensitive layer forming step include the positive photosensitive layer forming step of the first aspect and the positive photosensitive layer forming step of the second aspect described below.

  In the positive photosensitive layer forming step of the first aspect, at least a positive photosensitive layer is formed on the surface of the substrate by applying the positive photosensitive composition to the surface of the substrate and drying. Furthermore, there is a step of forming other layers appropriately selected.

  In the positive photosensitive layer forming step of the second aspect, a photosensitive film obtained by forming the positive photosensitive composition into a film is laminated on the surface of the substrate under at least one of heating and pressing. Thus, there is a step of forming at least a positive photosensitive layer on the surface of the substrate and further forming other layers appropriately selected.

  In the positive photosensitive layer forming step of the first aspect, the coating and drying method is not particularly limited and can be appropriately selected depending on the purpose. For example, the positive type photosensitive layer is formed on the surface of the substrate. Examples include a method in which a photosensitive composition is dissolved, emulsified or dispersed in water or a solvent to prepare a positive photosensitive composition solution, and the solution is directly applied and dried for lamination.

  There is no restriction | limiting in particular as a solvent of the said positive photosensitive composition solution, According to the objective, it can select suitably, For example, methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, for example Alcohols such as n-hexanol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, diisobutyl ketone; ethyl acetate, butyl acetate, n-amyl acetate, methyl sulfate, ethyl propionate, dimethyl phthalate, benzoate Esters such as ethyl acid and methoxypropyl acetate; aromatic hydrocarbons such as toluene, xylene, benzene and ethylbenzene; carbon tetrachloride, trichloroethylene, chloroform, 1,1,1-trichloroethane, methylene chloride and monochlorobenze Halogenated hydrocarbons such as tetrahydrofuran, diethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 1-methoxy-2-propanol, and the like; dimethylformamide, dimethylacetamide, dimethylsulfoxide, sulfolane, etc. It is done. These may be used alone or in combination of two or more.

The coating method is not particularly limited and can be appropriately selected depending on the purpose. For example, using a spin coater, a slit spin coater, a roll coater, a die coater, a curtain coater, etc. The method of apply | coating is mentioned.
The drying conditions vary depending on each component, the type of solvent, the use ratio, and the like, but are usually about 60 to 110 ° C. for about 30 seconds to 15 minutes.

  There is no restriction | limiting in particular as thickness of the said positive photosensitive layer, According to the objective, it can select suitably, 0.5-10 micrometers is preferable, 0.75-6 micrometers is more preferable, and 1-3 micrometers is especially preferable.

Other layers formed in the positive photosensitive layer forming step of the first aspect are not particularly limited and can be appropriately selected depending on the purpose. For example, a cushion layer, an oxygen blocking layer, a release layer, an adhesion layer Examples thereof include a layer, a light absorption layer, and a surface protective layer.
There is no restriction | limiting in particular as a formation method of the said other layer, According to the objective, it can select suitably, For example, the method of apply | coating on the said positive type photosensitive layer etc. are mentioned.

In the positive photosensitive layer forming step of the second aspect, as a method of forming a photosensitive layer on the surface of the base material and other layers appropriately selected as necessary, a support and A photosensitive film having a photosensitive layer in which a positive photosensitive composition is laminated on a support and other layers appropriately selected as necessary is laminated while performing at least one of heating and pressing. A photosensitive film obtained by laminating a positive photosensitive composition on a support is laminated so that the positive photosensitive layer is on the surface side of the substrate. Next, a method of peeling the support from the positive photosensitive layer is preferably exemplified.
By peeling the support, it is possible to prevent a blurred image from being formed on the image formed on the positive photosensitive composition layer due to light scattering, refraction or the like by the support, and to increase the predetermined pattern. Obtained with resolution.
In addition, when the said photosensitive film has a protective film mentioned later, it is preferable to peel this protective film and to laminate | stack so that the said positive photosensitive layer may overlap with the said base material.

There is no restriction | limiting in particular as said heating temperature, Although it can select suitably according to the objective, For example, 70-130 degreeC is preferable and 80-110 degreeC is more preferable.
There is no restriction | limiting in particular as a pressure of the said pressurization, Although it can select suitably according to the objective, For example, 0.01-1.0 MPa is preferable and 0.05-1.0 MPa is more preferable.

  There is no restriction | limiting in particular as an apparatus which performs at least any one of the said heating and pressurization, According to the objective, it can select suitably, For example, heat press, a heat roll laminator (For example, Taisei Laminator Co., Ltd. make, VP- II), a vacuum laminator (for example, MVLP500 manufactured by Meiki Seisakusho) and the like are preferable.

  The support is not particularly limited and may be appropriately selected depending on the intended purpose. However, it is preferable that the positive photosensitive layer can be peeled off and the light transmittance is good, and further the surface It is more preferable that the smoothness is good.

  There is no restriction | limiting in particular as thickness of the said support body, According to the objective, it can select suitably, For example, 4-300 micrometers is preferable, 5-175 micrometers is more preferable, and 10-100 micrometers is especially preferable.

  There is no restriction | limiting in particular as a shape of the said support body, Although it can select suitably according to the objective, A long shape is preferable. There is no restriction | limiting in particular as the length of the said elongate support body, For example, the thing of length 10m-20000m is mentioned.

The support is preferably made of a synthetic resin and transparent, for example, a cellulose film such as cellulose triacetate or cellulose diacetate; polyethylene terephthalate, polyethylene naphthalate, polypropylene, polyethylene, poly (meth) acrylic Acid alkyl ester, poly (meth) acrylic acid ester copolymer, polyvinyl chloride, polyvinyl alcohol, polycarbonate, polystyrene, cellophane, polyvinylidene chloride copolymer, polyamide, polyimide, vinyl chloride / vinyl acetate copolymer, polytetra Various plastic films such as fluoroethylene, polytrifluoroethylene, nylon and the like can be mentioned, and among these, polyethylene terephthalate is particularly preferable. These may be used alone or in combination of two or more.
As the support, for example, the support described in JP-A-4-208940, JP-A-5-80503, JP-A-5-173320, JP-A-5-72724, or the like is used. You can also.

Formation of the positive photosensitive layer in the photosensitive film is performed by the same method as the application of the positive photosensitive composition solution to the substrate and drying (the photosensitive layer forming method of the first aspect). Examples thereof include a method of applying the positive photosensitive composition solution using a spin coater, a slit spin coater, a roll coater, a die coater, a curtain coater, or the like.

The protective film is a film having a function of preventing and protecting the positive photosensitive layer from being stained and damaged.
There is no restriction | limiting in particular as thickness of the said protective film, According to the objective, it can select suitably, For example, 5-100 micrometers is preferable, 8-50 micrometers is more preferable, 10-40 micrometers is especially preferable.

  There is no restriction | limiting in particular as a location provided in the said photosensitive film of the said protective film, Although it can select suitably according to the objective, Usually, it provides on the said positive photosensitive layer.

  When the protective film is used, the relationship between the adhesive force A of the positive photosensitive layer and the support and the adhesive force B of the positive light layer and the protective film is that adhesive force A> adhesive force B. Is preferred.

The coefficient of static friction between the support and the protective film is preferably 0.3 to 1.4, and more preferably 0.5 to 1.2.
When the coefficient of static friction is less than 0.3, slipping is excessive, so that winding deviation may occur when the roll is formed, and when it exceeds 1.4, it is difficult to wind into a good roll. Sometimes.

The protective film is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include those used for the support, silicone paper, polyethylene, polypropylene laminated paper, polyolefin or polytetrafluoro. An ethylene sheet etc. are mentioned, Among these, a polyethylene film, a polypropylene film, etc. are mentioned as a particularly preferable thing.
Examples of the combination of the support and the protective film (support / protective film) include polyethylene terephthalate / polypropylene, polyethylene terephthalate / polyethylene, polyvinyl chloride / cellophane, polyimide / polypropylene, polyethylene terephthalate / polyethylene terephthalate, and the like. .

The protective film is preferably subjected to a surface treatment in order to adjust the adhesiveness between the protective film and the positive photosensitive layer in order to satisfy the above-described adhesive force relationship.
The surface treatment method of the support is not particularly limited and may be appropriately selected depending on the purpose.For example, coating of a primer layer, corona discharge treatment, flame treatment, ultraviolet irradiation treatment, high-frequency irradiation treatment, Examples include glow discharge irradiation treatment, active plasma irradiation treatment, and laser beam irradiation treatment.
As a specific example of the method for applying the undercoat layer, for example, an undercoat layer made of a polymer such as polyorganosiloxane, fluorinated polyolefin, polyfluoroethylene, or polyvinyl alcohol is formed on the surface of the protective film. The undercoat layer may be formed by applying the polymer coating solution on the surface of the protective film and then drying it at 30 to 150 ° C. (especially 50 to 120 ° C.) for 1 to 30 minutes. .

  There is no restriction | limiting in particular as said other layer, According to the objective, it can select suitably, For example, a thermoplastic resin layer, an intermediate | middle layer, etc. are mentioned.

-Thermoplastic resin layer-
The thermoplastic resin layer can be alkali-developed, and can be alkali-soluble from the viewpoint of preventing the transferred material from being contaminated by the alkali-soluble thermoplastic resin layer protruding during transfer. Preferably, when the photosensitive film is transferred onto the transfer target, the photosensitive film has a function as a cushioning material that effectively prevents transfer defects caused by unevenness existing on the transfer target. It is more preferable that the photosensitive film can be deformed in accordance with the unevenness present on the transferred body when the photosensitive film is heated and adhered onto the transferred body.

As a material used for the thermoplastic resin layer, for example, an organic polymer substance described in JP-A-5-72724 is preferable, and the Viker Vicat method (specifically, American Materials Testing Method ASTM D1235) is used. It is particularly preferred that the softening point by the method of measuring the softening point of polymer is selected from organic polymer substances having a temperature of about 80 ° C. or lower. Specifically, polyolefins such as polyethylene and polypropylene, ethylene copolymers such as ethylene and vinyl acetate or saponified products thereof, ethylene and acrylic acid esters or saponified products thereof, polyvinyl chloride, vinyl chloride and vinyl acetate or saponified products thereof. Vinyl chloride copolymer such as fluoride, polyvinylidene chloride, vinylidene chloride copolymer, polystyrene, styrene copolymer such as styrene and (meth) acrylic acid ester or saponified product thereof, polyvinyl toluene, vinyl toluene and (meta ) Vinyl toluene copolymer such as acrylic ester or saponified product thereof, poly (meth) acrylic ester, (meth) acrylic ester copolymer such as (meth) acrylic acid butyl and vinyl acetate, vinyl acetate copolymer Combined nylon, copolymerized nylon, N-alkoxymethylated Nylon, and organic polymers of the polyamide resins, such as N- dimethylamino nylon and the like. These may be used alone or in combination of two or more.
The dry operation thickness of the thermoplastic resin layer is preferably 2 to 30 μm, more preferably 5 to 20 μm, and particularly preferably 7 to 16 μm.

-Intermediate layer-
The intermediate layer is provided on the positive photosensitive layer, and when the photosensitive film has an alkali-soluble thermoplastic resin layer, the intermediate layer includes the positive photosensitive layer and the alkali-soluble thermoplastic resin layer. Between. In forming the positive photosensitive layer and the alkali-soluble thermoplastic resin layer, an organic solvent is used. Therefore, when the intermediate layer is located between them, the layers can be prevented from being mixed with each other.

The intermediate layer is preferably one that is dispersed or dissolved in water or an aqueous alkali solution.
As the material for the intermediate layer, known materials can be used. For example, polyvinyl ether / maleic anhydride polymer, carboxyalkyl described in JP-A No. 46-2121 and JP-B No. 56-40824 Water-soluble salt of cellulose, water-soluble cellulose ether, water-soluble salt of carboxyalkyl starch, polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylamide, water-soluble polyamide, water-soluble salt of polyacrylic acid, gelatin, ethylene oxide polymer, various Water soluble salts of the group consisting of starch and the like, styrene / maleic acid copolymers, maleate resins, and the like. These may be used alone or in combination of two or more. Among these, it is preferable to use a hydrophilic polymer, and among these hydrophilic polymers, it is preferable to use at least polyvinyl alcohol, and a combination of polyvinyl alcohol and polyvinyl pyrrolidone is particularly preferable.

There is no restriction | limiting in particular as said polyvinyl alcohol, Although it can select suitably according to the objective, The saponification rate is 80% or more.
When using the said polyvinyl pyrrolidone, as content, 1-75 volume% is preferable with respect to solid content of this intermediate | middle layer, 1-60 volume% is more preferable, 10-50 volume% is especially preferable.
When the content is less than 1% by volume, sufficient adhesion to the photosensitive layer may not be obtained, and when it exceeds 75% by volume, the oxygen blocking ability may be lowered, which is not preferable.

  The intermediate layer preferably has a low oxygen permeability. When the oxygen permeability of the intermediate layer is large and the oxygen blocking ability is low, it may be necessary to increase the amount of light at the time of exposure to the positive photosensitive layer, or it may be necessary to lengthen the exposure time, and the resolution may also be increased. May fall.

There is no restriction | limiting in particular as thickness of the said intermediate | middle layer, According to the objective, it can select suitably, 0.1-5 micrometers is preferable and 0.5-2 micrometers is more preferable.
If the thickness is less than 0.1 μm, the oxygen permeability may be too high, and if it exceeds 5 μm, it takes a long time for development or removal of the intermediate layer, which is not preferable.

  The structure of the photosensitive film is not particularly limited and may be appropriately selected depending on the purpose. For example, the photosensitive film may be appropriately selected on the temporary support, the thermoplastic resin layer, the intermediate layer, and the positive film. The form which has a type | mold photosensitive layer in this order is mentioned. The positive photosensitive layer may be a single layer or a plurality of layers.

  The photosensitive film is preferably stored, for example, wound around a cylindrical core, wound in a long roll shape. There is no restriction | limiting in particular as the length of the said elongate photosensitive film, For example, it can select from the range of 10-20000 m suitably. In addition, slitting may be performed so that the user can easily use, and a long body in the range of 100 to 1000 m may be formed into a roll. In this case, it is preferable that the support is wound up so as to be the outermost side. Moreover, you may slit the said roll-shaped photosensitive film in a sheet form. From the viewpoint of protecting the end face and preventing edge fusion during storage, it is preferable to install a separator (especially moisture-proof and desiccant-containing) on the end face, and use a low moisture-permeable material for packaging. Is preferred.

The said photosensitive film can be used suitably for the pattern formation method of this invention demonstrated in detail below.
In addition, there is no restriction | limiting in particular as an exposure method to the laminated body which has the positive photosensitive layer formed by the photosensitive layer forming method of the said 2nd aspect, According to the objective, it can select suitably, For example, a support body In the case of a film comprising a photosensitive layer present on a cushion layer, it is preferable that the positive photosensitive layer is exposed via the oxygen-blocking layer after the support and the cushion layer are peeled off.

<Positive photosensitive layer>
The positive photosensitive layer formed in the positive photosensitive layer forming step contains a 1,2-quinonediazide compound, a novolak type phenol resin, and a dissolution accelerator, and a solvent, and other components as necessary. It contains.

-1,2-quinonediazide compound-
The 1,2-quinonediazide compound is a compound that suppresses the solubility of an alkali-soluble resin in an alkaline aqueous solution, generates an acid by receiving radiation, and promotes the solubility of an alkali-soluble carboxylic acid group-containing resin in an alkaline aqueous solution. It is.

Examples of the 1,2-quinonediazide compound include 1,2-benzoquinonediazidesulfonic acid esters, 1,2-naphthoquinonediazidesulfonic acid esters, 1,2-benzoquinonediazidesulfonic acid amides, 1,2-naphtho And quinonediazide sulfonic acid amides.
Examples of the 1,2-naphthoquinone diazide sulfonic acid esters include 1,2-naphthoquinone diazide sulfonic acid ester of trihydroxybenzophenone, 1,2-naphthoquinone diazide sulfonic acid ester of tetrahydroxybenzophenone, and 1,1 of naphthoquinone diazide sulfonic acid ester of pentahydroxybenzophenone. Examples include 2-naphthoquinone diazide sulfonate, 1,2-naphthoquinone diazide sulfonate of hexahydroxybenzophenone, and 1,2-naphthoquinone diazide sulfonate of (polyhydroxyphenyl) alkane.

Examples of the 1,2-naphthoquinone diazide sulfonic acid ester of trihydroxybenzophenone include, for example, 2,3,4-trihydroxybenzophenone-1,2-naphthoquinone azido-4-sulfonic acid ester, 2,3,4-trihydroxy Benzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,4,6-trihydroxybenzophenone-1,2-naphthoquinonediazide-4-sulfonic acid ester, 2,4,6-trihydroxybenzophenone-1, Examples include 2-naphthoquinonediazide-5-sulfonic acid ester.
Examples of the 1,2-naphthoquinone diazide sulfonic acid ester of tetrahydroxybenzophenone include 2,2 ′, 4,4′-tetrahydroxybenzophenone-1,2-naphthoquinone diazide-4-sulfonic acid ester, and 2,2 ′. , 4,4′-tetrahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,3′-tetrahydroxybenzophenone-1,2-naphthoquinonediazide-4-sulfonic acid ester, 2, , 3,4,3′-Tetrahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,4′-tetrahydroxybenzophenone-1,2-naphthoquinonediazide-4-sulfonic acid ester 2,3,4,4′-tetrahydroxybenzophenone-1 2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,2′-tetrahydroxy-4′-methylbenzophenone-1,2-naphthoquinonediazide-4-sulfonic acid ester, 2,3,4,2 ′ -Tetrahydroxy-4'-methylbenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,4'-tetrahydroxy-3'-methoxybenzophenone-1,2-naphthoquinonediazide-4- Examples thereof include sulfonic acid esters and 2,3,4,4′-tetrahydroxy-3′-methoxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid esters.
Examples of the 1,2-naphthoquinone diazide sulfonic acid ester of pentahydroxybenzophenone include, for example, 2,3,4,2 ′, 6′-pentahydroxybenzophenone-1,2-naphthoquinone diazide-4-sulfonic acid ester, Examples include 3,4,2 ′, 6′-pentahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester.
Examples of the 1,2-naphthoquinone diazide sulfonic acid ester of hexahydroxybenzophenone include, for example, 2,4,6,3 ′, 4 ′, 5′-hexahydroxybenzophenone-1,2-naphthoquinone diazide-4-sulfonic acid ester. 2,4,6,3 ′, 4 ′, 5′-hexahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 3,4,5,3 ′, 4 ′, 5′-hexahydroxy Examples include benzophenone-1,2-naphthoquinonediazide-4-sulfonic acid ester, 3,4,5,3 ′, 4 ′, 5′-hexahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, and the like. .
Examples of the 1,2-naphthoquinone diazide sulfonic acid ester of the (polyhydroxyphenyl) alkane include bis (2,4-dihydroxyphenyl) methane-1,2-naphthoquinone diazide-4-sulfonic acid ester, bis (2, 4-Dihydroxyphenyl) methane-1,2-naphthoquinonediazide-5-sulfonic acid ester, bis (p-hydroxyphenyl) methane-1,2-naphthoquinonediazide-4-sulfonic acid ester, bis (p-hydroxyphenyl) methane -1,2-naphthoquinonediazide-5-sulfonic acid ester, tri (p-hydroxyphenyl) methane-1,2-naphthoquinonediazide-4-sulfonic acid ester, tri (p-hydroxyphenyl) methane-1,2-naphtho Quinonediazide-5-sulfonic acid ester 1,1,1-tri (p-hydroxyphenyl) ethane-1,2-naphthoquinonediazide-4-sulfonic acid ester, 1,1,1-tri (p-hydroxyphenyl) ethane-1,2-naphthoquinonediazide- 5-sulfonic acid ester, bis (2,3,4-trihydroxyphenyl) methane-1,2-naphthoquinonediazide-4-sulfonic acid ester, bis (2,3,4-trihydroxyphenyl) methane-1,2 -Naphthoquinonediazide-5-sulfonic acid ester, 2,2-bis (2,3,4-trihydroxyphenyl) propane-1,2-naphthoquinonediazide-4-sulfonic acid ester, 2,2-bis (2,3 , 4-trihydroxyphenyl) propane-1,2-naphthoquinonediazide-5-sulfonic acid ester, 1,1,3-tris ( , 5-Dimethyl-4-hydroxyphenyl) -3-phenylpropane-1,2-naphthoquinonediazide-4-sulfonic acid ester, 1,1,3-tris (2,5-dimethyl-4-hydroxyphenyl) -3 -Phenylpropane-1,2-naphthoquinonediazide-5-sulfonic acid ester, 4,4 '-[1- [4- [1- [4-hydroxyphenyl] -1-methylethyl] phenyl] ethylidene] bisphenol-1 , 2-Naphthoquinonediazide-4-sulfonic acid ester, 4,4 '-[1- [4- [1- [4-hydroxyphenyl] -1-methylethyl] phenyl] ethylidene] bisphenol-1,2-naphthoquinonediazide -5-sulfonic acid ester, bis (2,5-dimethyl-4-hydroxyphenyl) -2-hydroxyphenylmethane 1,2-naphthoquinonediazide-4-sulfonic acid ester, bis (2,5-dimethyl-4-hydroxyphenyl) -2-hydroxyphenylmethane-1,2-naphthoquinonediazide-5-sulfonic acid ester, 3,3, 3 ′, 3′-tetramethyl-1,1′-spirobiindene-5,6,7,5 ′, 6 ′, 7′-hexanol-1,2-naphthoquinonediazide-4-sulfonic acid ester, 3, 3,3 ′, 3′-tetramethyl-1,1′-spirobiindene-5,6,7,5 ′, 6 ′, 7′-hexanol-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,2,4-trimethyl-7,2 ′, 4′-trihydroxyflavan-1,2-naphthoquinonediazide-4-sulfonic acid ester, 2,2,4-trimethyl-7,2 ′, 4′-tri Hydroxy flava 1,2-naphthoquinonediazide-5-sulfonic acid esters, and the like.
These may be used alone or in combination of two or more.
Among these, 2,3,4,4′-tetrahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 3,3,3 ′, 3′-tetramethyl-1,1′-spirobiindane- 5,6,7,5 ′, 6 ′, 7′-Hexanol-1,2-naphthoquinonediazide-5-sulfonic acid ester is preferred.

  The content of the 1,2-quinonediazide compound is preferably 5 to 90% by mass, more preferably 10 to 70% by mass, and particularly preferably 15 to 50% by mass based on the total solid content in the positive photosensitive composition. . When the content is less than 5% by mass, the amount of acid generated by light irradiation is small, so the difference in solubility in the alkaline aqueous solution that is the developer between the light-irradiated part and the unirradiated part is small and accurate. Patterning may be difficult, and if it exceeds 90% by mass, a large amount of unreacted novolak-type phenol resin remains after light irradiation for a short time, so that the solubility in the alkaline aqueous solution is insufficient and development is performed. Can be difficult.

-Novolac type phenol resin-
The novolak-type phenol resin is preferably alkali-soluble, and the alkali-soluble novolak phenol resin is an addition-condensation of 0.6 to 1.0 mol of an aldehyde with 1 mol of phenol under an acidic catalyst. Is obtained.

Examples of the phenols include phenol, p-cresol, m-cresol, o-cresol, 2,3-dimethylphenol, 2,4-dimethylphenol, 2,5-dimethylphenol, 2,6-dimethylphenol, 3,4-dimethylphenol, 3,5-dimethylphenol, 2,3,4-trimethylphenol, 2,3,5-trimethylphenol, 3,4,5-trimethylphenol, 2,4,5-trimethylphenol, Methylene bisphenol, methylene bis p-cresol, resorcin, catechol, 2-methyl resorcin, 4-methyl resorcin, o-chlorophenol, m-chlorophenol, p-chlorophenol, 2,3-dichlorophenol, p-methoxyphenol, m -Methoxyphenol, p-bu Xylphenol, o-ethylphenol, m-ethylphenol, p-ethylphenol, 2,3-diethylphenol, 2,5-diethylphenol, p-isopropylphenol, p-tert-butylphenol, α-naphthol, β-naphthol -4-phenylphenol etc. are mentioned, These may be used individually by 1 type and may use 2 or more types together.
Among these, it is particularly preferable to use a plurality of mixtures of alkylphenols such as cresol, dimethylphenol and trimethylphenol. In addition, monomethylolated products and dimethylolated products of these phenols can also be used as substituted phenols.

  Examples of the aldehydes include formalin, paraformaldehyde, acetaldehyde, benzaldehyde, hydroxybenzaldehyde, glyoxal, chloroacetaldehyde, dichloroacetaldehyde, bromoaldehyde and the like, and these may be used alone. Two or more kinds may be used in combination.

Examples of the acidic catalyst include hydrochloric acid, sulfuric acid, formic acid, oxalic acid, acetic acid, and the like.
In addition, a novolak resin having a relatively narrow molecular weight distribution is particularly preferable in order to obtain a photoresist having a wide development latitude. Such spread of the molecular weight distribution of the polymer can be generally expressed by the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn), that is, the Mw / Mn value (dispersion degree). The wider the molecular weight distribution, the larger the numerical value, and the value of this ratio is 1 when there is no molecular weight distribution. The novolak resin used in a typical positive type photoresist has a relatively wide molecular weight distribution. For example, as shown in Japanese Patent Publication No. 62-172341, the degree of dispersion is generally 5-10. Between. Also, in SPIE Brocade Dink “Advanceds in Resist Technology and Processing V”, Volume 920, page 349, the value of 4.55 to 6.75 is higher than that of 3.0. It has been suggested to give value.

  In order for the novolac type phenol resin to achieve the object and effect of the present invention, the degree of dispersion is different from these, and is preferably 1.5 to 4.0, more preferably 2.0 to 3.5. If the degree of dispersion is too large, the wide development latitude that is the effect of the present invention may not be obtained. If it is too small, a high purification step is required for synthesizing the novolac-type phenol resin, which is practical. It is inappropriate because of lack of reality.

Various methods are conceivable for producing the novolac type phenol resin having the small degree of dispersion.
For example, it can be obtained by a method such as selection of a specific phenolic monomer, selection of condensation reaction conditions, and fractional precipitation of a normal novolak type phenol resin having a high degree of dispersion. In order to acquire the effect of this invention, what was manufactured using any of these methods may be used.

  There is no restriction | limiting in particular in the weight average molecular weight (Mw) of the novolak-type phenol resin of this invention, It can select suitably according to the objective, 1000-6000 are preferable and 2000-4500 are more preferable. If the weight average molecular weight (Mw) is too large, the effect of the present invention for obtaining a wide development latitude may not be obtained as described above.

  The use ratio of the 1,2-quinonediazide compound and the novolak type phenol resin is preferably from 5 to 100 parts by weight, more preferably from 10 to 50 parts by weight, based on 100 parts by weight of the novolak type phenol resin. When this use ratio is less than 5 parts by mass, the remaining film ratio may be remarkably reduced, and when it exceeds 100 parts by mass, the sensitivity and solubility in a solvent may be reduced.

-Dissolution promoter-
The dissolution accelerator is used for the purpose of improving sensitivity, and many examples of addition to the positive photosensitive composition are disclosed. For example, JP-A-61-141441 discloses a positive photoresist composition containing trihydroxybenzophenone. The positive photoresist containing trihydroxybenzophenone improves sensitivity and developability, but has a problem that heat resistance and profile deteriorate.
JP-A-64-44439, JP-A-1-17732, JP-A-1-280748, JP-A-2-10350, JP-A-3-200251, JP-A-3-191351. JP-A-3-200255, JP-A-4-299348, and JP-A-5-204144 do not deteriorate the heat resistance by adding an aromatic polyhydroxy compound other than trihydroxybenzophenone. A device to increase sensitivity is shown. However, when such a compound is added, the film thickness of the unexposed area is increased, and as a result, the resist shape is usually deteriorated. Further, since the developing speed is increased, the developing latitude is generally lowered. Accordingly, preferred structure selections have been made to minimize these.
As a typical example, a compound having a total number of carbon atoms in the molecule of 12 to 50 and a total number of phenolic hydroxyl groups of 2 to 8 is used. Of these compounds, compounds that increase the alkali dissolution rate of the novolac phenol resin when added to the novolac phenol resin used in the present invention are particularly desirable. Moreover, the effect of this invention may reduce remarkably in the compound of carbon number 51 or more. In addition, a compound having 11 or less causes new defects such as a decrease in heat resistance. In order to exert the effect of the present invention, it is preferable to have at least two hydroxyl groups in the molecule. However, when the number is 9 or more, the development latitude improving effect may be lost.

  Examples of the dissolution accelerator include phenols, resorcin, phloroglucin, 2,3,4-trihydroxybenzophenone, 2,3,4,4′-tetrahydroxybenzophenone, 2,3,4,3 ′, 4 ′. , 5′-hexahydroxybenzophenone, acetone-pyrogallol condensed resin, prologurside, 2,4,2 ′, 4′-biphenyltetrol, 4,4′-thiobis (1,3-dihydroxy) benzene, 2,4,2 ', 4'-tetrahydroxydiphenyl ether, 2,4,2', 4'-tetrahydroxydiphenyl sulfoxide, 2,4,2 ', 4'-tetrahydroxydiphenyl sulfone, tris (4-hydroxydiphenyl) methane, 1, 1-bis (4-hydroxydiphenyl) cyclohexane, 4,4 ′-(α-methylbenzylidene) bisph , Α, α ′, α ″ -tris (4-hydroxydiphenyl) -1-1,3,5-triisopropylbenzene, α, α ′, α ″ -tris (4-hydroxydiphenyl) -1-ethyl- 4-isopropylbenzene, 1,2,2-tris (hydroxydiphenyl) propane, 1,1,2-tris (3,5-dimethyl-4-hydroxydiphenyl) propane, 2,2,5,5-tetrakis (4 -Hydroxydiphenyl) hexane, 1,1,2,2-tetrakis (4-hydroxydiphenyl) ethane, 1,1,3-tris (hydroxydiphenyl) butane, para [α, α, α ′, α′-tetrakis ( 4-hydroxydiphenyl) -xylene and the like. These may be used alone or in combination of two or more.

  2-30 mass% is preferable with respect to the said novolak-type phenol resin, and, as for the addition amount of the said dissolution accelerator, 5-25 mass% is more preferable. When the added amount exceeds 30% by mass, a new defect that the pattern is deformed during development may occur. When the added amount is less than 2% by mass, it is difficult to achieve an object such as an improvement in sensitivity. Sometimes.

-Other ingredients-
In addition to the above components, other additives may be added to the positive photosensitive composition of the present invention as needed for various purposes. Examples of the other additives include adhesion promoters, solvents, surfactants, thermal crosslinking agents, plasticizers, and colorants.

As the adhesion promoter, in the positive photosensitive composition of the present invention, an adhesion promoter can be added as an additive in order to improve the adhesion to the substrate. As such an adhesion promoter, a functional silane coupling agent can be suitably used.
The functional silane coupling agent means a silane compound having a reactive substituent such as a carboxyl group, a methacryloyl group, an isocyanate group, and an epoxy group. Examples of the functional silane coupling agent include trimethoxysilylbenzoic acid, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, vinyltrimethoxysilane, γ-isocyanatopropyltriethoxysilane, and γ-glycidoxy. Examples thereof include propyltrimethoxysilane and β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane.
The amount of the adhesion promoter used is preferably 10% by mass or less, more preferably 7% by mass or less, based on the total solid content of the positive photosensitive composition.

  Other adhesion promoters include, for example, benzimidazoles and polybenzimidazoles (Japanese Patent Laid-Open No. 6-27657), lower hydroxyalkyl-substituted pyridine derivatives (Japanese Patent No. 3024695), nitrogen-containing heterocyclic compounds (Japanese Patent Laid-Open No. 7-333841), urea or thiourea (JP-A-8-62847), organic phosphorus compounds (JP-A-11-84644), 8-oxyquinoline, 4-hydroxypteridine, 1,10-phenanthroline, 2 , 2′-bipyridine derivatives (Japanese Patent Laid-Open No. 11-223937), benzotriazoles (Japanese Patent Laid-Open No. 2000-171968), organic phosphorus compounds and phenylenediamine compounds, 2-amino-1-phenylethanol, N-phenylethanol Amine, N-ethyldiethanolamine, -Ethyldiethanolamine, N-ethylethanolamine or a derivative thereof (Japanese Patent Laid-Open No. 9-15852), benzothiazole having a cyclohexyl ring or a morpholine ring, a benzoatizolamine salt (Japanese Patent Laid-Open No. 8-76373), and the like. .

-Thermal crosslinking agent-
The thermal crosslinking agent can be added to the photoresist film to improve dry etching resistance. The dry etching resistance is improved by adding a thermal cross-linking agent and performing post-baking. However, the addition amount and post-baking conditions must be selected in consideration of suitability for the peeling treatment.
The thermal crosslinking agent that can be used is selected in consideration of storage stability.
Examples of the polymer type thermal crosslinking agent include a copolymer of 3-chloro-2-hydroxypropyl methacrylate and methacrylic acid, a copolymer of 3-chloro-2-hydroxypropyl methacrylate, cyclohexyl methacrylate and methacrylic acid, 3 -A copolymer of chloro-2-hydroxypropyl methacrylate, benzyl methacrylate and methacrylic acid.
Examples of the low molecular weight crosslinking agent include bisphenol A-di (3-chloro-2-hydroxypropyl) ether, poly (3-chloro-2-hydroxypropyl) ether of phenol novolac resin, pentaerythritol tetra (3 -Chloro-2-hydroxypropyl) ether, trimethylol methane tri (3-chloro-2-hydroxypropyl) ether phenol, bisphenol A-di (3-acetoxy-2-hydroxypropyl) ether, poly (3 -Acetoxy-2-hydroxypropyl) ether, pentaerythritol tetra (3-acetoxy-2-hydroxypropyl) ether, pentaerythritol poly (3-chloroacetoxy-2-hydroxypropyl) ether, trimethylo Metantori (3-acetoxy-2-hydroxypropyl) ether.
The addition amount of the thermal crosslinking agent compound is preferably 1 to 50% by mass, more preferably 1.5 to 30% by mass, and still more preferably 3 to 10% by mass in the total solid content of the positive photosensitive composition.

Examples of the plasticizer include dioctyl phthalate, didodecyl phthalate, triethylene glycol dicaprylate, dimethyl glycol phthalate, tricresyl phosphate, dioctyl adipate, dibutyl sebacate, and triacetyl glycerin.
The amount of the plasticizer added is preferably 30% by mass or less, more preferably 20% by mass or less, and still more preferably 10% by mass or less, based on the total solid content of the positive photosensitive composition.

When the positive photosensitive layer is used, the colorant is preferably used for coloring the surface of the positive photosensitive layer after coating or for inspection of coating defects. The colorant is selected so that the sensitivity of the positive photosensitive layer is not inhibited by its own light absorption.
The colorant is preferably a triarylmethane dye or an organic pigment. The organic pigment is added in a state where fine particles are dispersed in the resin. Preferred dyes include, for example, crystal violet, methyl violet, ethyl violet, oil blue # 603, Victoria pure blue BOH, malachite green, diamond green and the like. As other dyes, colorants described in JP-A-10-97061, JP-A-10-104827, JP-B-3-68375 and the like can be used.
Examples of the organic pigment include phthalocyanine pigments, azo pigments, carbon black, titanium oxide, brilliant green dye (CI 42040), Victoria Linebrow FGA, and Victoria Linebrow BO (C.I). 42595), Victoria Blau BO (C.I. 44045), rhodamine 6G (C.I. 45160), which can be added as a stable dispersion.
The amount of the colorant used is preferably 10% by mass or less, more preferably 7% by mass or less, and still more preferably 5% by mass or less, based on the total solid content of the positive photosensitive composition.

  In the above-mentioned solvent, the positive photosensitive composition of the present invention is uniformly mixed with 1,2-quinonediazide compound, novolac-type phenolic resin, and other components contained as needed. In general, each component is dissolved or dispersed in an organic solvent to prepare a composition solution. The organic solvent herein may be any organic solvent that dissolves and uniformly disperses other components as required and does not react with these components.

Examples of the organic solvent include alcohols such as methanol and ethanol; ethers such as tetrahydrofuran; glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, ethylene glycol methyl ethyl ether, and ethylene glycol monoethyl ether; methyl cellosolve Ethylene glycol alkyl ether acetates such as acetate and ethyl cellosolve acetate; diethylene glycols such as diethylene glycol monomethyl ether, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, diethylene glycol monoethyl ether, and diethylene glycol monobutyl ether; propylene glycol Propylene glycol alkyl ether acetates such as rumethyl ether acetate and propylene glycol ethyl ether acetate; Aromatic hydrocarbons such as toluene and xylene; Ketones such as acetone, methyl ethyl ketone, cyclohexanone and 4-hydroxy-4-methyl-2-pentanone Class: ethyl 2-hydroxypropionate, methyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-2-methylbutanoate, 3 -Lactic acid esters such as methyl methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, ethyl acetate, butyl acetate, methyl lactate, ethyl lactate And esters of ethers, and the like.
Further, N-methylformamide, N, N-dimethylformamide, N-methylformanilide, N-methylacetamide, N, N-dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, benzylethyl ether, dihexyl ether, acetonylacetone , Isophorone, caproic acid, caprylic acid, 1-octanol, 1-nonanol, benzyl alcohol, benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate, γ-butyrolactone, ethylene carbonate, propylene carbonate, phenyl cellosolve acetate, etc. A high boiling point solvent can also be added. These may be used alone or in combination of two or more.
Among these, methoxypropylene glycol acetate, ethyl 2-hydroxypropionate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl lactate, ethyl lactate, cyclohexanone, methyl isobutyl ketone and the like are particularly preferable.

The surfactant can be used to improve coating properties and smoothness of the resulting coating film. Specific examples thereof include BM-1000 (manufactured by BM Chemie), Megafax F142D, F172, F173, F183, F176PF, F177PF (manufactured by Dainippon Ink & Chemicals, Inc.), Florard FC-135, FC-170C, Florard FC-430, FC-431 (Sumitomo 3M Co., Ltd.), Surflon S-112, S-113, S-131, S-141, S-145 (above, manufactured by Asahi Glass Co., Ltd.), SH-28PA, SH-190, SH-193 , SZ-6032, SF-8428, DC-57, DC-190 (above, manufactured by Toray Silicone Co., Ltd.) It may be used corn-based surfactant.
The amount of the surfactant used is preferably 0.05 to 10% by mass, more preferably 0.08 to 5% by mass, and 0.1 to 3% by mass based on the total solid content of the positive photosensitive composition. Particularly preferred. If the amount used is less than 0.05% by mass, it may not be effective, and if it exceeds 10% by mass, the adhesion of the resist pattern may deteriorate.

  Further, in the preparation of the positive photosensitive composition solution of the present invention, for example, the 1,2-quinonediazide compound of the present invention, a novolac type phenol resin, a dissolution accelerator, and other components as required are specified. It can be prepared by dissolving at a predetermined ratio in at least one of the solvent and the mixture thereof. The solution of the positive photosensitive composition can be used after being filtered using, for example, a microfiltration filter having a pore size of 0.2 μm.

  The positive photosensitive layer is formed by a well-known coating method such as dip coating, air knife coating, curtain coating, wire bar coating, gravure coating, extrusion coating, and the like. It can form by apply | coating a composition coating liquid.

  The positive photosensitive layer contains a novolak type phenol resin, a 1,2-quinonediazide compound, and a dissolution accelerator, and when exposed in a desired pattern, the positive photosensitive layer is removed by development with an alkaline aqueous solution or the like. It is formed from a mold photosensitive composition. That is, the 1,2-quinonediazide compound acts as a dissolution inhibitor for alkali-soluble novolak-type phenol resins, but when it receives light, 3-indenecarboxylic acid is produced and the dissolution-inhibiting effect is lost. For this reason, the positive photosensitive layer containing a novolac-type phenol resin and a 1,2-quinonediazide compound functions as a positive resist in which only the light irradiation part is dissolved by alkali development.

  The thickness of the positive photosensitive layer is usually preferably 0.2 to 30 μm, more preferably 0.5 to 10 μm, and particularly preferably 1 to 6 μm. When the film thickness is less than 0.2 μm, the etching resistance may be inferior, and when it exceeds 30 μm, the resolution may deteriorate.

<Base material>
There is no restriction | limiting in particular as the said base material used at the said positive type photosensitive layer formation process, According to the objective, it selects suitably from what has a highly smooth surface to what has an uneven surface from well-known materials. However, a plate-like base material (substrate) is preferable. Specifically, a glass plate (for example, a soda glass plate, a glass plate sputtered with silicon oxide, a quartz glass plate, etc.), a synthetic resin film, Examples include paper and metal plates.
After cleaning the substrate having the preceding pattern or thin film, the substrate surface is treated with a solvent such as HMDS (hexamethylphosphoramide) to remove moisture on the substrate surface. The positive photosensitive composition is applied and dried using a spin coater. The drying temperature is preferably 100 to 150 ° C.

[Exposure process]
In the exposure step, the light from the light irradiating means is modulated by the light modulating means having at least n picture elements for receiving and emitting the light from the light irradiating means, and then the emission surface of the picture element portion. A photosensitive layer formed by the positive photosensitive layer forming step is exposed to light that has passed through a microlens array in which microlenses having aspherical surfaces capable of correcting aberrations due to distortion are arranged.

In the exposure step, the light emitted from the light irradiation means is not particularly limited and may be appropriately selected depending on the purpose. For example, an electromagnetic wave that activates a photopolymerization initiator or a sensitizer, Examples include ultraviolet to visible light, electron beams, X-rays, and laser beams. Among these, laser beams that can perform on / off control of light in a short time and easily control light interference are preferable.
There is no restriction | limiting in particular as the wavelength of the light of the said ultraviolet to visible light, Although it can select suitably according to the objective, 330-650 nm is preferable from the objective of shortening the exposure time of a positive photosensitive composition. 395 to 415 nm is more preferable, and 405 nm is particularly preferable.
The light irradiation method by the light irradiation means is not particularly limited and can be appropriately selected according to the purpose. For example, a high pressure mercury lamp, a xenon lamp, a carbon arc lamp, a halogen lamp, a cold cathode tube for a copying machine, The method of irradiating with well-known light sources, such as LED and a semiconductor laser, is mentioned. In addition, it is preferable to synthesize and irradiate two or more light beams from these light sources, and to irradiate a laser beam (hereinafter sometimes referred to as “combined laser beam”) composed of two or more light beams. Is particularly preferred.
There is no restriction | limiting in particular as the irradiation method of the said combined laser beam, Although it can select suitably according to the objective, A laser irradiated from a several laser light source, a multimode optical fiber, and this several laser light source There is a method of forming and irradiating a combined laser beam with a collective optical system that collects light and couples it to the multimode optical fiber.

In the exposure step, the method for modulating light is not particularly limited as long as it is a method for modulating light by means of light modulation means having n number of pixel parts for receiving and emitting light from the light irradiation means. Although it can select suitably according to this, The method of controlling the arbitrary less than n image-element parts arrange | positioned continuously from n image element parts according to pattern information is mentioned suitably.
There is no restriction | limiting in particular as the number (n) of said picture element parts, According to the objective, it can select suitably.
The arrangement of the picture element portions in the light modulation means is not particularly limited and may be appropriately selected according to the purpose. For example, it is preferably arranged two-dimensionally and arranged in a lattice pattern. Is more preferable.
The light modulation method is not particularly limited and may be appropriately selected depending on the intended purpose. A preferable example is a method using a spatial light modulation element as the light modulation means.
The spatial light modulation element is not particularly limited and may be appropriately selected depending on the intended purpose. However, a digital micromirror device (DMD) or a MEMS (Micro Electro Mechanical Systems) type spatial light modulation element (SLM) may be used. A Special Light Modulator), an optical element that modulates transmitted light by an electro-optic effect (PLZT element), a liquid crystal light shutter (FLC), and the like. Among these, a DMD is particularly preferable.

In the exposure step, the light modulated by the modulation means is allowed to pass through a microlens array in which microlenses having aspherical surfaces capable of correcting aberrations due to distortion of the exit surface in the picture element portion are arranged.
The microlens arranged in the microlens array is not particularly limited as long as it has an aspheric surface, and can be appropriately selected according to the purpose. However, the microlens is a microlens having a toric surface. Preferably there is.
Furthermore, in the exposure step, it is preferable that the light modulated by the modulation means is allowed to pass through an aperture array, a coupling optical system, other optical systems selected as appropriate.

In the exposure step, the method for exposing the photosensitive layer is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include digital exposure and analog exposure, but digital exposure is preferred. .
The digital exposure method is not particularly limited and may be appropriately selected depending on the purpose. For example, the digital exposure method is performed using laser light modulated according to a control signal generated based on predetermined pattern information. Is preferred.
Furthermore, in the exposure step, the method for exposing the photosensitive layer is not particularly limited and can be appropriately selected according to the purpose. From the viewpoint of enabling high-speed exposure in a short time, It is preferably carried out while relatively moving the photosensitive layer, and particularly preferably used in combination with the digital micromirror device (DMD).
In the present invention, exposure equivalent to that of a halftone mask can be advantageously realized at low cost by performing intensity-modulated exposure control that changes the amount of irradiation light in at least two stages.

  Hereinafter, a pattern forming apparatus suitably used in the pattern forming method of the present invention will be described with reference to the drawings.

FIG. 7 is a schematic perspective view showing an appearance of a pattern forming apparatus suitably used in the pattern forming method of the present invention.
As shown in FIG. 7, the pattern forming apparatus including the light modulation means adsorbs the sheet-like pattern forming material 150 on the upper surface of a thick plate-like installation table 156 supported by four legs 154. A flat plate-like stage 152 is provided.
The stage 152 is arranged so that the longitudinal direction thereof faces the stage moving direction, and is supported by a guide 158 formed on the upper surface of the installation table 156 so as to be reciprocally movable. The pattern forming apparatus has a drive device (not shown) for driving the stage 152 along the guide 158.

  A downward C-shaped gate 160 is provided at the center of the installation table 156 so as to straddle the movement path of the stage 152. Each end portion of the gate 160 is fixed to both side surfaces in the longitudinal center portion of the installation table 156. A scanner 162 is provided on one side of the gate 160, and a plurality of (for example, two) detection sensors 164 that detect the front and rear ends of the pattern forming material 150 are provided on the other side. ing. The scanner 162 and the detection sensor 164 are respectively attached to the gate 160 and fixedly arranged above the moving path of the stage 152. The scanner 162 and the detection sensor 164 are connected to a controller (not shown) that controls them.

FIG. 8 is a schematic perspective view showing the configuration of the scanner. FIG. 9A is a plan view showing an exposed region formed on the photosensitive layer, and FIG. 9B is a diagram showing an arrangement of exposure areas by the exposure head.
As shown in FIGS. 8 and 9B, the scanner 162 includes a plurality of (for example, 14) exposure heads 166 arranged in a substantially matrix of m rows and n columns (for example, 3 rows and 5 columns). ing. In this example, four exposure heads 166 are arranged in the third row in relation to the width of the pattern forming material 150. In addition, when showing each exposure head arranged in the m-th row and the n-th column, it is expressed as an exposure head 166 _mn .
An exposure area 168 by the exposure head 166 has a rectangular shape with a short side in the sub-scanning direction. Accordingly, as the stage 152 moves, a strip-shaped exposed region 170 is formed in the pattern forming material 150 for each exposure head 166. In addition, when showing the exposure area by each exposure head arranged in the m-th row and the n-th column, it is expressed as an exposure area 168 _mn .

Further, as shown in FIGS. 9A and 9B, each of the exposure heads in each row arranged in a line so that the strip-shaped exposed regions 170 are arranged in the direction orthogonal to the sub-scanning direction without gaps. These are arranged with a predetermined interval (natural number times the long side of the exposure area, twice in this example) in the arrangement direction. Therefore, can not be exposed portion between the exposure area _{168 11} in the first row and the exposure area _{168 12,} it can be exposed by the second row of the exposure area _{168 21} and the exposure area _{168 31} in the third row.

FIG. 10 is a perspective view showing a schematic configuration of the exposure head.
As shown in FIG. 10, each of the exposure heads 166 _{11 to} 166 _mn serves as the light modulation means (spatial light modulation element for modulating each pixel) that modulates a light beam according to pattern information. A digital micromirror device (hereinafter also referred to as “DMD”) 50 manufactured by Instruments Co., Ltd. A fiber array light source 66 as a light irradiating means 66 provided with laser emitting portions 68 arranged in a line along a direction corresponding to the side direction, and a laser beam emitted from the fiber array light source 66 are corrected and placed on the DMD. A condensing lens system 67, a mirror 69 that reflects laser light transmitted through the lens system 67 toward the DMD 50, and a laser reflected by the DMD 50 The B, and an image forming optical system 51 forms an image on the pattern forming material 150. In FIG. 10, the lens system 67 is schematically shown.

FIG. 12 shows a controller that controls the DMD based on the pattern information.
As shown in FIG. 12, the DMD 50 is connected to a controller 302 having a data processing unit, a mirror drive control unit, and the like. The data processing unit of the controller 302 generates a control signal for driving and controlling each micromirror in the area to be controlled by the DMD 50 for each exposure head 166 based on the input pattern information. The area to be controlled will be described later. The mirror drive control unit controls the angle of the reflection surface of each micromirror of the DMD 50 for each exposure head 166 based on the control signal generated by the pattern information processing unit.

FIG. 1 is a partially enlarged view showing a configuration of a digital micromirror device (DMD) as the light modulation means.
As shown in FIG. 1, in the DMD 50, a large number (for example, 1024 × 768) of micromirrors (micromirrors) 62 each constituting a pixel (pixel) are arranged on a SRAM cell (memory cell) 60 in a lattice shape. This is a mirror device arranged in a row. In each pixel, a micromirror 62 supported by a support column is provided at the top, and a material having high reflectance such as aluminum is deposited on the surface of the micromirror 62. The reflectance of the micromirror 62 is 90% or more, and the arrangement pitch is 13.7 μm as an example in both the vertical and horizontal directions. A silicon gate CMOS SRAM cell 60 manufactured in a normal semiconductor memory manufacturing line is disposed directly below the micromirror 62 via a support including a hinge and a yoke. The entire structure is monolithically configured. ing.

2A and 2B are diagrams for explaining the operation of the DMD.
When a digital signal is written in the SRAM cell 60 of the DMD 50, the micromirror 62 supported by the support is tilted in a range of ± α degrees (for example, ± 12 degrees) with respect to the substrate side on which the DMD 50 is disposed with the diagonal line as the center. It is done. 2A shows a state in which the micromirror 62 is tilted to + α degrees when the micromirror 62 is in an on state, and FIG. 2B shows a state in which the micromirror 62 is tilted to −α degrees that is in an off state.
Therefore, by controlling the tilt of the micromirror 62 in each pixel of the DMD 50 according to the pattern information, the laser light incident on the DMD 50 is reflected in the tilt direction of each micromirror 62.
FIG. 1 shows an example of a state in which the micromirror 62 is controlled to + α degrees or −α degrees. On / off control of each micromirror 62 is performed by the controller 302 connected to the DMD 50. A light absorber (not shown) is arranged in the direction in which the laser beam B reflected by the micromirror 62 in the off state travels.

The DMD 50 is preferably arranged with a slight inclination so that the short side forms a predetermined angle θ (for example, 0.1 ° to 5 °) with the sub-scanning direction.
3A shows the scanning trajectory of the reflected light image (exposure beam) 53 by each micromirror when the DMD 50 is not tilted, and FIG. 3B shows the scanning trajectory of the exposure beam 53 when the DMD 50 is tilted. Is shown.
As shown in FIG. 3B, the DMD 50 has a plurality of micromirror arrays (for example, 756 pairs) arranged in the short direction, in which a large number (for example, 1024) of micromirrors are arranged in the longitudinal direction. and which is, by inclining the DMD 50, the pitch P ₂ of the scanning locus of the exposure beams 53 from each micromirror (scan line), it becomes narrower than the pitch P ₁ of the scanning line in the case of not tilting the DMD 50, significant resolution Can be improved. On the other hand, the inclination angle of the DMD 50 is small, the scanning width _{W 2} in the case of tilting the DMD 50, which is substantially equal to the scanning width _{W 1} when not inclined DMD 50.

Next, a method for increasing the modulation speed in the light modulation means (hereinafter sometimes referred to as “high-speed modulation”) will be described.
When the laser light B is irradiated from the fiber array light source 66 to the DMD 50, the laser light emitted from the fiber array light source 66 is turned on and off for each pixel, and the pattern forming material 150 has approximately the same number of pixels as the DMD 50 used. Exposure is performed in elementary units (exposure area 168). Further, when the pattern forming material 150 is moved at a constant speed together with the stage 152, the pattern forming material 150 is sub-scanned in the direction opposite to the stage moving direction by the scanner 162, and a strip-shaped exposed region 170 is provided for each exposure head 166. Is formed.
Here, the data processing speed of the entire DMD 50 is limited, and the modulation speed per line is determined in proportion to the number of pixels to be used. Therefore, one line can be obtained by using only a part of the micromirror array. The modulation speed per hit is increased. On the other hand, in the case of an exposure method in which the exposure head is continuously moved relative to the exposure surface, it is not necessary to use all the pixels in the sub-scanning direction.
In the DMD 50, 768 micromirror rows in which 1024 micromirrors are arranged in the main scanning direction are arranged in the subscanning direction, but a part of micromirror rows (eg, 1024 × 256 rows) is arranged by the controller 302. Only is controlled to drive.
4 (A) and 4 (B) are diagrams showing areas where DMD is used.
As shown in FIG. 4 (A), the DMD use area may be a micromirror array arranged at the center of the DMD 50. As shown in FIG. 4 (B), the end of the DMD 50 may be used. Arranged micromirror rows may be used. In addition, when a defect occurs in some of the micromirrors, the micromirror array to be used may be appropriately changed depending on the situation, such as using a micromirror array in which no defect has occurred.
For example, when only 384 sets of 768 sets of micromirror arrays are used, modulation can be performed twice as fast per line as compared with the case of using all 768 sets. Also, when only 256 pairs are used in the 768 sets of micromirror arrays, modulation can be performed three times faster per line than when all 768 sets are used.

  As described above, according to the pattern forming method of the present invention, the micromirror array in which 1,024 micromirrors are arranged in the main scanning direction includes the DMD in which 768 sets are arranged in the subscanning direction. By controlling so that only a part of the micromirror rows are driven by the controller, the modulation rate per line becomes faster than when all the micromirror rows are driven.

  In addition, an example in which the DMD micromirror is partially driven has been described, but the length of the direction corresponding to the predetermined direction is reflected on the substrate longer than the length of the direction intersecting the predetermined direction according to the control signal. Even if a long and narrow DMD in which a large number of micromirrors capable of changing the surface angle are arranged in a two-dimensional manner is used, the number of micromirrors for controlling the angle of the reflecting surface is reduced. Can do.

As the exposure method, as shown in FIG. 5, the entire surface of the pattern forming material 150 may be exposed by a single scan in the X direction by a scanner 162.
As the exposure method, as shown in FIGS. 6A and 6B, after the pattern forming material 150 is scanned in the X direction by the scanner 162, the scanner 162 is moved one step in the Y direction. The entire surface of the pattern forming material 150 may be exposed by a plurality of scans by repeating scanning and movement, such as scanning in the direction.

  The exposure is performed on a partial area of the photosensitive layer to cure the partial area, and uncured areas other than the cured partial area are removed in a development step described later. A pattern is formed.

Next, the lens system 67 and the imaging optical system 51 will be described.
FIG. 11 is a cross-sectional view in the multiple scanning direction along the optical axis showing the details of the configuration of the exposure head in FIG.
As shown in FIG. 11, the lens system 67 includes a condensing lens 71 that condenses the laser light B as illumination light emitted from the fiber array light source 66, and a rod that is inserted in the optical path of the light that has passed through the condensing lens 71. And an imaging lens 74 disposed in front of the rod integrator 72, that is, on the mirror 69 side.
The condensing lens 71, the rod integrator 72, and the imaging lens 74 cause the laser light emitted from the fiber array light source 66 to enter the DMD 50 as a light beam that is close to parallel light and has a uniform beam cross-sectional intensity.

  The laser beam B emitted from the lens system 67 is reflected by the mirror 69 and irradiated to the DMD 50 via the TIR (total reflection) prism 70. In FIG. 10, the TIR prism 70 is omitted.

  As shown in FIG. 11, the imaging optical system 51 includes a first imaging optical system including lens systems 52 and 54, a second imaging optical system including lens systems 57 and 58, and these imaging optical systems. And an aperture array 59. The microlens array 55 is inserted between the microlens array 55 and the aperture array 59.

The microlens array 55 is formed by two-dimensionally arranging a large number of microlenses 55a corresponding to the pixels of the DMD 50. In this example, as described later, only 1024 × 256 rows of the 1024 × 768 rows of micromirrors of the DMD 50 are driven, and accordingly, 1024 × 256 rows of microlenses 55a are arranged.
The arrangement pitch of the micro lenses 55a is 41 μm in both the vertical direction and the horizontal direction. The focal length of the micro lens 55a is 0.19 mm, and the NA (numerical aperture) is 0.11.
Further, the microlens 55a is formed from the optical glass BK7.
The beam diameter of the laser beam B at the position of each microlens 55a is 41 μm.

  In the aperture array 59, a large number of apertures (openings) 59a corresponding to the respective microlenses 55a of the microlens array 55 are formed. The diameter of each aperture 59a is 10 μm.

The first imaging optical system forms an image on the microlens array 55 by enlarging the image by the DMD 50 three times.
The second image-forming optical system enlarges the image that has passed through the microlens array 55 by 1.6 times, and forms and projects the image on the pattern forming material 150.
Accordingly, in the entire optical system, an image formed by the DMD 50 is magnified 4.8 times and formed on the pattern forming material 150 and projected.

  A prism pair 73 is disposed between the second imaging optical system and the pattern forming material 150. By moving the prism pair 73 in the vertical direction in FIG. 11, an image on the pattern forming material 150 is obtained. The focus can be adjusted. In the figure, the pattern forming material 150 is sub-scanned in the direction of arrow F.

  Next, the microlens array, the aperture array, the imaging optical system, and the like will be described with reference to the drawings.

FIG. 13A is a cross-sectional view along the optical axis showing the configuration of the exposure head.
As shown in FIG. 13A, the exposure head includes a light irradiating means 144 for irradiating the DMD 50 with laser light, and a lens system (imaging optical system) 454 for enlarging the laser light reflected by the DMD 50 to form an image. 458, a microlens array 472 in which a large number of microlenses 474 are arranged corresponding to each pixel portion of the DMD 50, and an aperture array 476 in which a large number of apertures 478 are provided corresponding to each microlens of the microlens array 472. , And lens systems (imaging optical systems) 480 and 482 for forming an image of the laser beam that has passed through the aperture on the exposed surface 56.

FIG. 14 is a diagram showing a result of measuring the flatness of the reflecting surface of the micromirror 62 constituting the DMD 50.
In FIG. 14, the same height positions of the reflecting surfaces are shown connected by contour lines, and the pitch of the contour lines is 5 nm. In the drawing, the x direction and the y direction are two diagonal directions of the micromirror 62, and the micromirror 62 rotates around the rotation axis extending in the y direction as described above.
FIGS. 15A and 15B show the height position displacement of the reflecting surface of the micromirror 62 along the x direction and the y direction in FIG. 14, respectively.
As shown in FIGS. 14 and 15, there is distortion on the reflection surface of the micromirror 62, and when attention is particularly paid to the center of the mirror, distortion in one diagonal direction (y direction) is different from that in the other diagonal line. It is larger than the distortion in the direction (x direction). For this reason, the problem that the shape in the condensing position of the laser beam B condensed with the micro lens 55a of the micro lens array 55 may be distorted may occur.

FIGS. 16A and 16B are views showing the front and side shapes of the entire microlens array 55, respectively.
As shown in FIG. 16A, the microlens array 55 is configured by arranging 1024 rows of microlenses 55a in the horizontal direction and 256 rows in the vertical direction corresponding to the micromirrors 62 of the DMD 50.
The long side dimension of the microlens array 55 is 50 mm, and the short side dimension is 20 mm.
In FIG. 9A, the arrangement order of the micro lenses 55a is indicated by j for the horizontal direction and k for the vertical direction.

FIGS. 17A and 17B are diagrams showing a front shape and a side shape of the microlens constituting the microlens array. Note that FIG. 17A also shows the contour lines of the microlens 55a.
As shown in FIGS. 17A and 17B, the end surface of the microlens 55a on the light emission side has an aspherical shape that corrects aberration due to distortion of the reflection surface of the micromirror 62.
Specifically, the aspherical microlens 55a is a toric lens having a radius of curvature Rx in the x direction of −0.125 mm and a radius of curvature Ry in the y direction of −0.1 mm.
FIG. 18 is a schematic diagram showing a condensing state by the microlens in one cross section (A) and another cross section (B).
As shown in FIG. 18, since a toric lens having an aspherical end surface on the light emission side is used as the microlens 55a constituting the microlens array, the laser beam B in a cross section parallel to the x and y directions is used. In the light condensing state, when the parallel cross section in the x direction is compared with the parallel cross section in the y direction, the radius of curvature of the microlens 55a is smaller in the latter cross section, and the focal length becomes shorter. .

The shape of the microlens 55a may be a secondary aspherical shape or a higher order (4th order, 6th order,...) Aspherical shape. By adopting the higher order aspherical shape, the beam shape can be further refined.
In addition to making the end surface shape of the light exit side of the microlens 55a a toric surface, it is also possible to form a microlens array from microlenses having one of two light passing end surfaces as a spherical surface and the other as a cylindrical surface. It is.

19A, 19B, 19C, and 19D are diagrams showing the results of simulating the beam diameter in the vicinity of the condensing position (focal position) of the microlens 55a by a computer.
For comparison, FIGS. 20a, 20b, 20c, and 20d show the results of a similar simulation performed when the microlens has a spherical shape with a radius of curvature Rx = Ry = −0.1 mm. In addition, the value of z in each figure has shown the evaluation position of the focus direction of the micro lens 55a with the distance from the beam emission surface of the micro lens 55a.
The surface shape of the microlens 55a used for the simulation is calculated by the following calculation formula.

In the above formula, Cx is the curvature in the x direction (= 1 / Rx), Cy is the curvature in the y direction (= 1 / Ry), X is the distance from the lens optical axis O in the x direction, Y Indicates the distance from the lens optical axis O in the y direction, respectively.

  19A to 19D and FIGS. 20A to 20D, in the pattern forming method of the present invention, the microlens 55a has a focal length in the cross section parallel to the y direction that is greater than the focal distance in the cross section parallel to the x direction. Since the toric lens is also small, distortion of the beam shape in the vicinity of the condensing position is suppressed. Therefore, it is possible to expose the pattern forming material 150 with a higher definition image without distortion.

  In addition, when the magnitude relation of the distortion of the center part in the x direction and the y direction of the micromirror 62 is opposite to the above, the focal length in the parallel section in the x direction is the focal length in the parallel section in the y direction. If the microlens is formed of a smaller toric lens, the pattern forming material 150 can be similarly exposed to a higher-definition image without distortion.

The aperture array 59 is disposed in the vicinity of the light collection position of the microlens array 55. Only the light that has passed through the corresponding microlens 55 a is incident on each aperture 59 a provided in the aperture array 59. Therefore, it is possible to prevent light from the adjacent micro lens 55a not corresponding to one aperture 59a corresponding to the one micro lens 55a from entering, and to increase the extinction ratio.
If the diameter of the aperture 59a is reduced to some extent, an effect of suppressing distortion of the beam shape at the condensing position of the microlens 55a can be obtained. However, the amount of light blocked by the aperture array 59 increases, and the light utilization efficiency decreases. . In this case, the microlens 55a having the aspherical shape prevents light from being blocked and keeps light use efficiency high.

  The micro lens array 55 and the aperture array 59 correct the aberration caused by the distortion of the reflection surface of the micro mirror 62 constituting the DMD 50. In the pattern forming method of the present invention using a spatial light modulation element other than the DMD. However, if there is distortion on the surface of the picture element portion of the spatial light modulator, the present invention can be applied to correct the aberration due to the distortion and prevent the beam shape from being distorted.

  As shown in FIG. 13A, the imaging optical system includes lenses 480 and 482, and the light passing through the aperture array 59 is imaged on the exposed surface 56 by the imaging optical system.

As described above, in the pattern forming apparatus, the laser light reflected by the DMD 50 is magnified several times by the magnifying lenses 454 and 458 of the lens system and projected onto the exposed surface 56, so that the entire image area is Become wider. At this time, if the microlens array 472 and the aperture array 476 are not arranged, as shown in FIG. 13B, one pixel size (spot size) of each beam spot BS projected onto the exposed surface 56 is set. MTF (Modulation Transfer Function) characteristics representing the sharpness of the exposure area 468 are reduced depending on the size of the exposure area 468.
On the other hand, since the pattern forming apparatus includes the micro lens array 472 and the aperture array 476, the laser light reflected by the DMD 50 corresponds to each pixel part of the DMD 50 by each micro lens of the micro lens array 472. Focused. As a result, as shown in FIG. 13C, even when the exposure area is enlarged, the spot size of each beam spot BS can be reduced to a desired size (for example, 10 μm × 10 μm). It is possible to perform high-definition exposure while preventing deterioration of characteristics.
The exposure area 468 is inclined because the DMD 50 is inclined and disposed in order to eliminate the gap between the pixels.
In addition, the aperture array can shape the beam so that the spot size on the surface to be exposed 56 is constant even if the beam is thick due to the aberration of the micro lens. Thus, crosstalk between adjacent picture elements can be prevented by passing through the aperture array.
Further, by using a high-intensity light source for the light irradiating means 144, the angle of the light beam incident from the lens 458 to each microlens of the microlens array 472 is reduced, so that a part of the light flux of the adjacent pixel enters. Can be prevented. That is, a high extinction ratio can be realized.

FIGS. 22A and 22B are views showing the front shape and side shape of another microlens array.
As shown in FIG. 22, as another microlens array, each microlens has a refractive index distribution for correcting aberration due to distortion of the reflection surface of the micromirror 62.
As illustrated, the external shape of the other microlens 155a is a parallel plate. The x and y directions in the figure are as described above.
FIG. 23 is a schematic view showing a condensing state of the laser beam B in the cross section parallel to the x direction and the y direction by the micro lens 155a of FIG.
As shown in FIG. 23, the micro lens 155a has a refractive index distribution that gradually increases outward from the optical axis O. In FIG. 23, the broken line shown in the micro lens 155a indicates that the refractive index is light. A position changed from the axis O at a predetermined equal pitch is shown. As shown in the drawing, when the parallel cross section in the x direction is compared with the parallel cross section in the y direction, the ratio of the refractive index change of the microlens 155a is larger in the latter cross section, and the focal length is shorter. It has become. Even when a microlens array composed of such a gradient index lens is used, it is possible to obtain the same effect as when the microlens array 55 is used.
In addition, in the microlens 55a shown in FIGS. 17 and 18, the refractive index distribution is given together, and the aberration due to the distortion of the reflecting surface of the micromirror 62 can be corrected by both the surface shape and the refractive index distribution. Is possible.

In the pattern forming method of the present invention, it may be used in combination with other optical systems appropriately selected from known optical systems, for example, a light amount distribution correcting optical system composed of a pair of combination lenses.
The light amount distribution correcting optical system changes the light flux width at each exit position so that the ratio of the light flux width at the peripheral portion to the light flux width at the central portion close to the optical axis is smaller on the exit side than on the incident side. When the DMD is irradiated with the parallel light flux from the light irradiation means, the light amount distribution on the irradiated surface is corrected so as to be substantially uniform. Hereinafter, the light quantity distribution correcting optical system will be described with reference to the drawings.

FIG. 24 is an explanatory diagram showing the concept of correction by the light quantity distribution correction optical system.
As shown in FIG. 24A, the case where the entire luminous flux width (total luminous flux width) H0 and H1 is the same for the incident luminous flux and the outgoing luminous flux will be described. In FIG. 24A, the portions denoted by reference numerals 51 and 52 virtually indicate the entrance surface and the exit surface in the light amount distribution correcting optical system.
In the light quantity distribution correcting optical system, it is assumed that the light flux widths h0 and h1 of the light beam incident on the central portion near the optical axis Z1 and the light beam incident on the peripheral portion are the same (h0 = hl). The light quantity distribution correcting optical system expands the light flux width h0 of the incident light beam in the central portion with respect to the light having the same light flux widths h0 and h1 on the incident side, and conversely changes the incident light flux in the peripheral portion. On the other hand, the light beam width h1 is reduced. That is, the width h10 of the outgoing light beam at the center and the width h11 of the outgoing light beam at the periphery are set to satisfy h11 <h10. In terms of the ratio of the luminous flux width, the ratio “h11 / h10” of the luminous flux width in the peripheral portion to the luminous flux width in the central portion on the emission side is smaller than the ratio on the incident side (h1 / h0 = 1) ( (H11 / h10) <1).

  By changing the light flux width in this way, the light flux in the central part, which normally has a large light quantity distribution, can be utilized in the peripheral part where the light quantity is insufficient, and the overall light utilization efficiency is not reduced. In addition, the light quantity distribution on the irradiated surface is made substantially uniform. The degree of uniformity is, for example, such that the unevenness in the amount of light in the effective area is within 30%, preferably within 20%.

  The operations and effects of the light quantity distribution correcting optical system are the same when the entire luminous flux width is changed between the incident side and the exit side (FIGS. 24B and 24C).

  FIG. 24B shows a case where the entire light flux width H0 on the incident side is “reduced” to the width H2 and emitted (H0> H2). Even in such a case, the light quantity distribution correcting optical system has the same light beam width h0, h1 on the incident side, and the light beam width h10 in the central part is larger than that in the peripheral part on the emission side. Conversely, the luminous flux width h11 at the peripheral part is made smaller than that at the central part. Considering the reduction rate of the light beam, the reduction rate with respect to the incident light beam in the central part is made smaller than that in the peripheral part, and the reduction rate with respect to the incident light beam in the peripheral part is made larger than that in the central part. Also in this case, the ratio “H11 / H10” of the light flux width in the peripheral portion to the light flux width in the central portion is smaller than the ratio (h1 / h0 = 1) on the incident side ((h11 / h10) <1). .

  FIG. 24C shows a case where the entire light flux width H0 on the incident side is “enlarged” by the width Η3 and emitted (H0 <H3). Even in such a case, the light quantity distribution correcting optical system has the same light beam width h0, h1 on the incident side, and the light beam width h10 in the central part is larger than that in the peripheral part on the emission side. Conversely, the luminous flux width h11 at the peripheral part is made smaller than that at the central part. Considering the expansion rate of the light beam, the expansion rate for the incident light beam in the central portion is made larger than that in the peripheral portion, and the expansion rate for the incident light beam in the peripheral portion is made smaller than that in the central portion. Also in this case, the ratio “h11 / h10” of the light flux width in the peripheral portion to the light flux width in the central portion is smaller than the ratio (h1 / h0 = 1) on the incident side ((h11 / h10) <1). .

  As described above, the light quantity distribution correcting optical system changes the light beam width at each emission position, and the ratio of the light beam width in the peripheral part to the light beam width in the central part near the optical axis Z1 is larger on the outgoing side than on the incident side. Since the light having the same luminous flux width on the incident side is larger on the outgoing side, the luminous flux width in the central portion is larger than that in the peripheral portion, and the luminous flux width in the peripheral portion is smaller than that in the central portion. Become smaller. As a result, it is possible to make use of the light beam at the center part to the peripheral part, and it is possible to form a light beam cross-section with a substantially uniform light amount distribution without reducing the light use efficiency of the entire optical system.

Next, an example of specific lens data of a pair of combination lenses used as the light quantity distribution correcting optical system will be shown. In this example, lens data in the case where the light amount distribution in the cross section of the emitted light beam is a Gaussian distribution as in the case where the light irradiation means is a laser array light source is shown. When one semiconductor laser is connected to the incident end of the single mode optical fiber, the light quantity distribution of the emitted light beam from the optical fiber becomes a Gaussian distribution. The pattern forming method of the present invention can be applied to such a case. Further, the present invention can be applied to a case where the light amount in the central portion near the optical axis is larger than the light amount in the peripheral portion, for example, by reducing the core diameter of the multi-mode optical fiber and approaching the configuration of the single mode optical fiber.
Table 1 below shows basic lens data.

  As can be seen from Table 1, the pair of combination lenses is composed of two rotationally symmetric aspherical lenses. If the light incident side surface of the first lens disposed on the light incident side is the first surface and the light exit side surface is the second surface, the first surface is aspherical. In addition, when the surface on the light incident side of the second lens disposed on the light emitting side is the third surface and the surface on the light emitting side is the fourth surface, the fourth surface is aspherical.

In Table 1, the surface number Si indicates the number of the i-th surface (i = 1 to 4), the curvature radius ri indicates the curvature radius of the i-th surface, and the surface interval di indicates the i-th surface and the i + 1-th surface. The distance between surfaces on the optical axis is shown. The unit of the surface interval di value is millimeter (mm). The refractive index Ni indicates the value of the refractive index with respect to the wavelength of 405 nm of the optical element having the i-th surface.
Table 2 below shows the aspheric data of the first surface and the fourth surface.

  The aspheric data is expressed by a coefficient in the following formula (A) that represents the aspheric shape.

In the above formula (A), each coefficient is defined as follows.
Z represents the length (mm) of a perpendicular line drawn from a point on the aspheric surface at a height ρ from the optical axis to the tangential plane (plane perpendicular to the optical axis) of the apex of the aspheric surface. ρ represents a distance (mm) from the optical axis. K represents a conical coefficient. C represents a paraxial curvature (1 / r, r: paraxial radius of curvature). ai represents the i-th order (i = 3 to 10) aspheric coefficient.
In the numerical values shown in Table 2, the symbol “E” indicates that the subsequent numerical value is a “power exponent” with a base of 10, and the numerical value represented by an exponential function with the base 10 is “ Indicates that the value before E ″ is multiplied. For example, “1.0E-02” indicates “1.0 × 10 ⁻² ”.

FIG. 26 shows a light amount distribution of illumination light obtained by the pair of combination lenses shown in Tables 1 and 2. Here, the horizontal axis represents coordinates from the optical axis, and the vertical axis represents the light amount ratio (%). For comparison, FIG. 25 shows a light amount distribution (Gaussian distribution) of illumination light when correction is not performed.
As shown in FIGS. 25 and 26, the light amount distribution correction optical system performs a correction to obtain a substantially uniform light amount distribution as compared with the case where the correction is not performed. Thereby, it is possible to perform exposure with uniform laser light without reducing the use efficiency of light, without causing any unevenness.

Next, the fiber array light source 66 as a light irradiation means will be described.
27A (A) is a perspective view showing a configuration of a fiber array light source, FIG. 27A (B) is a partially enlarged view of (A), and FIGS. 27A (C) and (D) are laser emitting portions. It is a top view which shows the arrangement | sequence of the light emission point in. FIG. 27 b is a front view showing the arrangement of the light emitting points in the laser emission part of the fiber array light source.

  As shown in FIG. 27 a, the fiber array light source 66 includes a plurality of (for example, 14) laser modules 64, and one end of the multimode optical fiber 30 is coupled to each laser module 64. An optical fiber 31 having the same core diameter as that of the multimode optical fiber 30 and a smaller cladding diameter than the multimode optical fiber 30 is coupled to the other end of the multimode optical fiber 30. As shown in detail in FIG. 27b, seven end portions of the multimode optical fiber 31 opposite to the optical fiber 30 are arranged along the main scanning direction orthogonal to the sub-scanning direction, and they are arranged in two rows to form a laser. An emission unit 68 is configured.

  As shown in FIG. 27b, the laser emitting portion 68 is sandwiched and fixed between two support plates 65 having a flat surface. In addition, a transparent protective plate such as glass is preferably disposed on the light emitting end face of the multimode optical fiber 31 for protection. The light exit end face of the multimode optical fiber 31 has high light density and is likely to collect dust and easily deteriorate. However, the protective plate as described above prevents the dust from adhering to the end face and deteriorates. Can be delayed.

  Further, in order to arrange the emission ends of the optical fibers 31 having a small cladding diameter in a row without any gaps, the multi-mode optical fibers 30 are stacked between two adjacent multi-mode optical fibers 30 in a portion having a large cladding diameter, The exit end of the optical fiber 31 coupled to the stacked multi-mode optical fiber 30 is between the two exit ends of the optical fiber 31 coupled to the two adjacent multi-mode optical fibers 30 at a portion where the cladding diameter is large. It is arranged to be sandwiched between.

  In such an optical fiber, as shown in FIG. 28, an optical fiber 31 having a length of 1 to 30 cm and having a small cladding diameter is coaxially provided at the tip of the multimode optical fiber 30 having a large cladding diameter on the laser light emission side. It can be obtained by bonding. In the two optical fibers, the incident end face of the optical fiber 31 is fused and joined to the outgoing end face of the multimode optical fiber 30 so that the central axes of both optical fibers coincide. As described above, the diameter of the core 31 a of the optical fiber 31 is the same as the diameter of the core 30 a of the multimode optical fiber 30.

  In addition, a short optical fiber in which an optical fiber having a short cladding diameter and a large cladding diameter is fused to an optical fiber having a short cladding diameter and a large cladding diameter may be coupled to the output end of the multimode optical fiber 30 via a ferrule or an optical connector. Good. By detachably coupling using a connector or the like, the tip portion can be easily replaced when an optical fiber having a small cladding diameter is broken, and the cost required for exposure head maintenance can be reduced. Hereinafter, the optical fiber 31 may be referred to as an emission end portion of the multimode optical fiber 30.

  The multimode optical fiber 30 and the optical fiber 31 may be any of a step index type optical fiber, a graded index type optical fiber, and a composite type optical fiber. For example, a step index type optical fiber manufactured by Mitsubishi Cable Industries, Ltd. can be used. In the present embodiment, the multimode optical fiber 30 and the optical fiber 31 are step index type optical fibers, and the multimode optical fiber 30 has a cladding diameter = 125 μm, a core diameter = 25 μm, NA = 0.2, an incident end face. The transmittance of the coat is 99.5% or more, and the optical fiber 31 has a cladding diameter = 60 μm, a core diameter = 25 μm, and NA = 0.2.

  In general, in the laser light in the infrared region, the propagation loss increases as the cladding diameter of the optical fiber is reduced. For this reason, a suitable cladding diameter is determined according to the wavelength band of the laser beam. However, the shorter the wavelength, the smaller the propagation loss. In the case of laser light having a wavelength of 405 nm emitted from a GaN-based semiconductor laser, the cladding thickness {(cladding diameter−core diameter) / 2} is set to an infrared light having a wavelength band of 800 nm. The propagation loss hardly increases even if it is about ½ of the case of propagating infrared light and about ¼ of the case of propagating infrared light in the 1.5 μm wavelength band for communication. Therefore, the cladding diameter can be reduced to 60 μm.

  However, the cladding diameter of the optical fiber 31 is not limited to 60 μm. The clad diameter of the optical fiber used in the conventional fiber array light source is 125 μm, but the depth of focus becomes deeper as the clad diameter becomes smaller. Therefore, the clad diameter of the multimode optical fiber is preferably 80 μm or less, preferably 60 μm or less. More preferably, it is 40 μm or less. On the other hand, since the core diameter needs to be at least 3 to 4 μm, the cladding diameter of the optical fiber 31 is preferably 10 μm or more.

  The laser module 64 includes a combined laser light source (fiber array light source) shown in FIG. This combined laser light source includes a plurality of (for example, seven) chip-like lateral multimode or single mode GaN-based semiconductor lasers LD1, LD2, LD3, LD4, LD5, LD6, arrayed and fixed on the heat block 10. And LD7, collimator lenses 11, 12, 13, 14, 15, 16, and 17 provided corresponding to each of the GaN-based semiconductor lasers LD1 to LD7, one condenser lens 20, and one multi-lens. Mode optical fiber 30. The number of semiconductor lasers is not limited to seven. For example, as many as 20 semiconductor laser beams can be incident on a multimode optical fiber having a cladding diameter = 60 μm, a core diameter = 50 μm, and NA = 0.2. In addition, the number of optical fibers can be further reduced.

  The GaN-based semiconductor lasers LD1 to LD7 all have the same oscillation wavelength (for example, 405 nm), and the maximum output is also all the same (for example, 100 mW for the multimode laser and 30 mW for the single mode laser). As the GaN-based semiconductor lasers LD1 to LD7, lasers having an oscillation wavelength other than the above 405 nm in a wavelength range of 350 nm to 450 nm may be used.

  As shown in FIGS. 30 and 31, the combined laser light source is housed in a box-shaped package 40 having an upper opening together with other optical elements. The package 40 includes a package lid 41 created so as to close the opening thereof. After the deaeration process, a sealing gas is introduced, and the package 40 and the package lid 41 are closed by closing the opening of the package 40 with the package lid 41. 41. The combined laser light source is hermetically sealed in a closed space (sealed space) formed by 41.

  A base plate 42 is fixed to the bottom surface of the package 40, and the heat block 10, a condensing lens holder 45 that holds the condensing lens 20, and the multimode optical fiber 30 are disposed on the top surface of the base plate 42. A fiber holder 46 that holds the incident end is attached. The exit end of the multimode optical fiber 30 is drawn out of the package from an opening formed in the wall surface of the package 40.

  Further, a collimator lens holder 44 is attached to the side surface of the heat block 10, and the collimator lenses 11 to 17 are held. An opening is formed in the lateral wall surface of the package 40, and wiring 47 for supplying a driving current to the GaN-based semiconductor lasers LD1 to LD7 is drawn out of the package through the opening.

  In FIG. 31, in order to avoid complication of the figure, only the GaN-based semiconductor laser LD7 among the plurality of GaN-based semiconductor lasers is numbered, and only the collimator lens 17 among the plurality of collimator lenses is numbered. is doing.

  FIG. 32 shows the front shape of the attachment part of the collimator lenses 11-17. Each of the collimator lenses 11 to 17 is formed in a shape obtained by cutting a region including the optical axis of a circular lens having an aspherical surface into an elongated shape on a parallel plane. This elongated collimator lens can be formed, for example, by molding resin or optical glass. The collimator lenses 11 to 17 are closely arranged in the arrangement direction of the light emitting points so that the length direction is orthogonal to the arrangement direction of the light emitting points of the GaN-based semiconductor lasers LD1 to LD7 (left and right direction in FIG. 32).

  On the other hand, each of the GaN-based semiconductor lasers LD1 to LD7 includes an active layer having a light emission width of 2 μm, and each of the laser beams B1 to B1 has a divergence angle of, for example, 10 ° and 30 ° in a direction parallel to and perpendicular to the active layer. A laser emitting B7 is used. These GaN-based semiconductor lasers LD1 to LD7 are arranged so that the light emitting points are arranged in a line in a direction parallel to the active layer.

In the laser beams B1 to B7 emitted from the respective light emitting points, the direction in which the divergence angle is large coincides with the length direction and the direction in which the divergence angle is small with respect to the elongated collimator lenses 11 to 17 as described above. Incident light is incident in a state that coincides with the width direction (direction orthogonal to the length direction). That is, the collimator lenses 11 to 17 have a width of 1.1 mm and a length of 4.6 mm, and the horizontal and vertical beam diameters of the laser beams B1 to B7 incident thereon are 0.9 mm and 6 mm. Each of the collimator lenses 11 to 17 has a focal length f ₁ = 3 mm, NA = 0.6, and a lens arrangement pitch = 1.25 mm.

The condensing lens 20 is obtained by cutting a region including the optical axis of a circular lens having an aspherical surface into an elongated shape in a parallel plane so as to be long in the arrangement direction of the collimator lenses 11 to 17, that is, in a horizontal direction and short in a direction perpendicular thereto. Is formed. This condenser lens 20 has a focal length f ₂ = 23 mm and NA = 0.2. This condensing lens 20 is also formed by molding resin or optical glass, for example.

Since the fiber array light source uses a high-intensity fiber array light source in which the output ends of the optical fibers of the combined laser light source are arranged in an array as the light irradiating means for illuminating the DMD, it has a high output and a deep focus. A pattern forming apparatus having a depth can be realized. Furthermore, since the output of each fiber array light source is increased, the number of fiber array light sources required to obtain a desired output is reduced, and the cost of the pattern forming apparatus can be reduced.
Further, since the cladding diameter of the output end of the optical fiber is smaller than the cladding diameter of the incident end, the diameter of the light emitting portion is further reduced, and the brightness of the fiber array light source can be increased. Thereby, a pattern forming apparatus having a deeper depth of focus can be realized. For example, even in the case of ultra-high resolution exposure with a beam diameter of 1 μm or less and a resolution of 0.1 μm or less, a deep depth of focus can be obtained, and high-speed and high-definition exposure is possible. Therefore, it is suitable for a thin film transistor (TFT) exposure process that requires high resolution.

  The light irradiating means is not limited to a fiber array light source including a plurality of the combined laser light sources. For example, a single laser beam that emits laser light incident from a single semiconductor laser having one light emitting point is emitted. A fiber array light source obtained by arraying fiber light sources including optical fibers can be used.

  As the light irradiation means having a plurality of light emitting points, for example, as shown in FIG. 33, a laser array in which a plurality of (for example, seven) chip-shaped semiconductor lasers LD1 to LD7 are arranged on the heat block 100 is used. Can be used. A chip-shaped multicavity laser 110 in which a plurality of (for example, five) light emitting points 110a shown in FIG. 34A are arranged in a predetermined direction can also be used. Since the multicavity laser 110 can arrange the light emitting points with higher positional accuracy than the case where the chip-shaped semiconductor lasers are arranged, it is easy to multiplex laser beams emitted from the respective light emitting points. However, as the number of light emitting points increases, the multicavity laser 110 is likely to be bent at the time of laser manufacturing. Therefore, the number of light emitting points 110a is preferably 5 or less.

  As the light irradiation means, the multi-cavity laser 110 or a plurality of multi-cavity lasers 110 on the heat block 100 as shown in FIG. 34 (B) has the same direction as the arrangement direction of the light emitting points 110a of each chip. A multi-cavity laser array arranged in the above can be used as a laser light source.

The combined laser light source is not limited to one that combines laser beams emitted from a plurality of chip-shaped semiconductor lasers.
For example, as shown in FIG. 21, a combined laser light source including a chip-shaped multicavity laser 110 having a plurality of (for example, three) light emitting points 110a can be used. This combined laser light source is configured to include a multi-cavity laser 110, one multi-mode optical fiber 130, and a condensing lens 120. The multi-cavity laser 110 can be composed of, for example, a GaN-based laser diode having an oscillation wavelength of 405 nm.

  In the above configuration, each of the laser beams B emitted from each of the plurality of light emitting points 110 a of the multicavity laser 110 is collected by the condenser lens 120 and enters the core 130 a of the multimode optical fiber 130. The laser light incident on the core 130a propagates in the optical fiber, is combined into one, and is emitted.

  A plurality of light emitting points 110 a of the multicavity laser 110 are arranged in parallel within a width substantially equal to the core diameter of the multimode optical fiber 130, and a focal point substantially equal to the core diameter of the multimode optical fiber 130 is formed as the condenser lens 120. By using a convex lens of a distance or a rod lens that collimates the outgoing beam from the multicavity laser 110 only in a plane perpendicular to the active layer, the coupling efficiency of the laser beam B to the multimode optical fiber 130 can be increased. it can.

  As shown in FIG. 35, a multi-cavity laser 110 having a plurality of (for example, three) emission points is used, and a plurality of (for example, nine) multi-cavity lasers 110 are equidistant from each other on the heat block 111. A combined laser light source including the laser array 140 arranged in (1) can be used. The plurality of multi-cavity lasers 110 are arranged and fixed in the same direction as the arrangement direction of the light emitting points 110a of each chip.

  This combined laser light source includes a laser array 140, a plurality of lens arrays 114 arranged corresponding to each multi-capability laser 110, and a single lens arranged between the laser array 140 and the plurality of lens arrays 114. A rod lens 113, one multimode optical fiber 130, and a condenser lens 120 are provided. The lens array 114 includes a plurality of microlenses corresponding to the emission points of the multi-capability laser 110.

  In the above configuration, each of the laser beams B emitted from each of the plurality of light emitting points 10a of the plurality of multi-cavity lasers 110 is condensed in a predetermined direction by the rod lens 113 and then each microlens of the lens array 114. Is collimated. The collimated laser beam L is condensed by the condenser lens 120 and enters the core 130a of the multimode optical fiber 130. The laser light incident on the core 130a propagates in the optical fiber, is combined into one, and is emitted.

  Furthermore, as another combined laser light source, as shown in FIGS. 36A and 36B, a heat block 182 having an L-shaped cross section in the optical axis direction is mounted on a heat block 180 having a substantially rectangular shape. A storage space is formed between the two heat blocks. On the upper surface of the L-shaped heat block 182, a plurality of (for example, two) multi-cavity lasers 110 in which a plurality of light emitting points (for example, five) are arranged in an array form the light emitting points 110a of each chip. It is arranged and fixed at equal intervals in the same direction as the arrangement direction.

  A concave portion is formed in the substantially rectangular heat block 180, and a plurality of (for example, two) light emitting points (for example, five) are arranged in an array on the upper surface of the space side of the heat block 180. The multi-cavity laser 110 is arranged such that its emission point is located on the same vertical plane as the emission point of the laser chip arranged on the upper surface of the heat block 182.

  On the laser beam emission side of the multi-cavity laser 110, a collimator lens array 184 in which collimator lenses are arranged corresponding to the light emission points 110a of the respective chips is arranged. In the collimating lens array 184, the length direction of each collimating lens coincides with the direction in which the divergence angle of the laser beam is large (fast axis direction), and the width direction of each collimating lens is in the direction in which the divergence angle is small (slow axis direction). They are arranged to match. Thus, by collimating and integrating the collimating lenses, the space utilization efficiency of the laser light can be improved, the output of the combined laser light source can be increased, and the number of parts can be reduced and the cost can be reduced. .

  Further, on the laser beam emitting side of the collimating lens array 184, there is one multimode optical fiber 130, and a condensing lens 120 that condenses and combines the laser beam at the incident end of the multimode optical fiber 130. Is arranged.

  In the above configuration, each of the laser beams B emitted from each of the plurality of light emitting points 10a of the plurality of multi-cavity lasers 110 arranged on the laser blocks 180 and 182 is collimated by the collimating lens array 184 and collected. The light is condensed by the optical lens 120 and enters the core 130 a of the multimode optical fiber 130. The laser light incident on the core 130a propagates in the optical fiber, is combined into one, and is emitted.

  As described above, the combined laser light source can achieve particularly high output by the multistage arrangement of multicavity lasers and the array of collimating lenses. By using this combined laser light source, a higher-intensity fiber array light source or bundle fiber light source can be configured, so that it is particularly suitable as a fiber light source constituting the laser light source of the pattern forming apparatus of the present invention.

  It should be noted that a laser module in which each of the combined laser light sources is housed in a casing and the emission end of the multimode optical fiber 130 is pulled out from the casing can be configured.

  In addition, the other end of the multimode optical fiber of the combined laser light source is coupled with another optical fiber having the same core diameter as the multimode optical fiber and a cladding diameter smaller than the multimode optical fiber. However, for example, a multimode optical fiber having a cladding diameter of 125 μm, 80 μm, 60 μm or the like may be used without coupling another optical fiber to the emission end.

  In each exposure head 166 of the scanner 162, laser beams B1, B2, B3, B4, B5, and B6 emitted in a divergent light state from each of the GaN-based semiconductor lasers LD1 to LD7 constituting the combined laser light source of the fiber array light source 66. , And B7 are collimated by corresponding collimator lenses 11-17. The collimated laser beams B <b> 1 to B <b> 7 are collected by the condenser lens 20 and converge on the incident end face of the core 30 a of the multimode optical fiber 30.

The condensing optical system includes collimator lenses 11 to 17 and a condensing lens 20. Also, the converging optical system and the multimode optical fiber 30 constitute a multiplexing optical system.
The laser beams B1 to B7 condensed as described above by the condenser lens 20 are incident on the core 30a of the multimode optical fiber 30, propagate through the optical fiber, and are combined into one laser beam B. The light exits from the optical fiber 31 coupled to the exit end of the multimode optical fiber 30.

  In each laser module, when the coupling efficiency of the laser beams B1 to B7 to the multimode optical fiber 30 is 0.85 and each output of the GaN-based semiconductor lasers LD1 to LD7 is 30 mW, the light arranged in an array For each of the fibers 31, a combined laser beam B with an output of 180 mW (= 30 mW × 0.85 × 7) can be obtained. Therefore, the output from the laser emitting unit 68 in which the six optical fibers 31 are arranged in an array is about 1 W (= 180 mW × 6).

  In the laser emitting section 68 of the fiber array light source 66, high-luminance light emitting points are arranged in a line along the main scanning direction. A conventional fiber light source that couples laser light from a single semiconductor laser to a single optical fiber has a low output, so that a desired output cannot be obtained unless multiple rows are arranged. Since the laser light source has a high output, a desired output can be obtained even with a small number of columns, for example, one column.

For example, in a conventional fiber light source in which a semiconductor laser and an optical fiber are coupled on a one-to-one basis, a laser having an output of about 30 mW (milliwatt) is usually used as the semiconductor laser, and the core diameter is 50 μm and the cladding diameter is 125 μm. Since a multimode optical fiber having a numerical aperture (NA) of 0.2 is used, if an output of about 1 W (watt) is to be obtained, 48 multimode optical fibers (8 × 6) must be bundled. Since the area of the light emitting region is 0.62 mm ² (0.675 mm × 0.925 mm), the luminance at the laser emitting portion 68 is 1.6 × 10 ⁶ (W / m ² ) and one optical fiber is used. The luminance per hit is 3.2 × 10 ⁶ (W / m ² ).

On the other hand, when the light irradiating means is a means capable of irradiating a combined laser, an output of about 1 W can be obtained with six multimode optical fibers, and the area of the light emitting region at the laser emitting portion 68 can be obtained. Is 0.0081 mm ² (0.325 mm × 0.025 mm), the luminance at the laser emitting portion 68 is 123 × 10 ⁶ (W / m ² ), which is about 80 times higher than the conventional luminance. be able to. Further, the luminance per optical fiber is 90 × 10 ⁶ (W / m ² ), and the luminance can be increased by about 28 times compared with the conventional one.

  Here, with reference to FIGS. 37A and 37B, the difference in depth of focus between the conventional exposure head and the exposure head of the present embodiment will be described. The diameter of the light emission region of the bundled fiber light source of the conventional exposure head in the sub-scanning direction is 0.675 mm, and the diameter of the light emission region of the fiber array light source of the exposure head in the sub-scanning direction is 0.025 mm. As shown in FIG. 37A, in the conventional exposure head, since the light emitting area of the light irradiating means (bundle-shaped fiber light source) 1 is large, the angle of the light beam incident on the DMD 3 is increased, and as a result, the scanning surface 5 is moved. The angle of the incident light beam increases. For this reason, the beam diameter tends to increase with respect to the light condensing direction (shift in the focus direction).

  On the other hand, as shown in FIG. 37B, in the exposure head in the pattern forming apparatus of the present invention, the diameter of the light emitting region of the fiber array light source 66 in the sub-scanning direction is small, so that it passes through the lens system 67 and enters the DMD 50. As a result, the angle of the light beam incident on the scanning surface 56 is reduced. That is, the depth of focus becomes deep. In this example, the diameter of the light emitting region in the sub-scanning direction is about 30 times that of the conventional one, and a depth of focus substantially corresponding to the diffraction limit can be obtained. Therefore, it is suitable for exposure of a minute spot. This effect on the depth of focus is more prominent and effective as the required light quantity of the exposure head is larger. In this example, the size of one pixel projected on the exposure surface is 10 μm × 10 μm. The DMD is a reflective spatial light modulator, but FIGS. 37A and 37B are developed views for explaining the optical relationship.

Next, the pattern forming method of the present invention using the pattern forming apparatus will be described.
First, pattern information corresponding to the exposure pattern is input to a controller (not shown) connected to the DMD 50 and temporarily stored in a frame memory in the controller. This pattern information is data representing the density of each pixel constituting the image as binary values (whether or not dots are recorded).
Next, the stage 152 having the pattern forming material 150 adsorbed on the surface thereof is moved at a constant speed from the upstream side to the downstream side of the gate 160 along the guide 158 by a driving device (not shown). When the leading edge of the pattern forming material 150 is detected by the detection sensor 164 attached to the gate 160 when the stage 152 passes under the gate 160, the pattern information stored in the frame memory is sequentially read out for a plurality of lines. Then, a control signal is generated for each exposure head 166 based on the pattern information read by the data processing unit. Then, each of the micromirrors of the DMD 50 is on / off controlled for each exposure head 166 based on the generated control signal by the mirror drive control unit.
Next, when the DMD 50 is irradiated with laser light from the fiber array light source 66, the laser light reflected when the micromirrors of the DMD 50 are turned on is exposed to the exposed surface 56 of the pattern forming material 150 by the lens systems 54 and 58. Imaged on top.
In this way, the laser light emitted from the fiber array light source 66 is turned on / off for each pixel, and the pattern forming material 150 is exposed in approximately the same number of pixel units (exposure area 168) as the number of used pixel elements of the DMD 50. The
Further, when the pattern forming material 150 is moved at a constant speed together with the stage 152, the pattern forming material 150 is sub-scanned in the direction opposite to the stage moving direction by the scanner 162, and a strip-shaped exposed region 170 is provided for each exposure head 166. Is formed.

[Development process]
The developing step includes a step of developing the photosensitive layer by exposing the photosensitive layer by the exposing step and removing an unexposed portion.
There is no restriction | limiting in particular as the removal method of the said unhardened area | region, According to the objective, it can select suitably, For example, the method etc. which remove using a developing solution are mentioned.
In the present invention, the number of steps in the manufacturing process of the TFT array substrate is combined with the intensity-modulated exposure in the exposure step by performing development using two or more types of developers having different development intensities in the development step. Reduction is possible.

There is no restriction | limiting in particular as said developing solution, Although it can select suitably according to the objective, For example, alkaline aqueous solution, an aqueous developing solution, an organic solvent etc. are mentioned, Among these, weakly alkaline aqueous solution is preferable.
As the alkaline aqueous solution, a dilute aqueous solution of an alkaline substance is used, but a solution obtained by adding a small amount of an organic solvent miscible with water may be used. Examples of the alkaline substance include alkali metal hydroxides (for example, sodium hydroxide, potassium hydroxide), alkali metal carbonates (for example, sodium carbonate, potassium carbonate), alkali metal bicarbonates (for example, hydrogen carbonate) Sodium, potassium bicarbonate), alkali metal silicates (eg, sodium silicate, potassium silicate), alkali metal metasilicates (eg, sodium metasilicate, potassium metasilicate), ammonia, ethylamine, n-propylamine, Diethylamine, triethylamine, methyldiethylamine, dimethylethanolamine, triethanolamine, diethanolamine, monoethanolamine, morpholine, tetraalkylammonium hydroxides (for example, tetramethylammonium hydroxide) Droxide, tetraethylammonium hydroxide), pyrrole, piperidine, 1,8-diazabicyclo [5,4,0] -7-undecene, 1,5-diazabicyclo [4,3,0] -5-nonane or trisodium phosphate. Can be mentioned.
The concentration of the alkaline substance is 0.01% by mass to 30% by mass, and the pH is preferably 8-14.
Examples of suitable organic solvents miscible with water include methanol, ethanol, 2-propanol, 1-propanol, butanol, diacetone alcohol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono- Mention of n-butyl ether, benzyl alcohol, acetone, methyl ethyl ketone, cyclohexanone, ε-caprolactone, γ-butyrolactone, dimethylformamide, dimethylacetamide, hexamethylphosphoramide, ethyl lactate, methyl lactate, ε-caprolactam, N-methylpyrrolidone Can do. The concentration of the organic solvent miscible with water is generally 0.1% by mass to 30% by mass.
A known anionic or nonionic surfactant can be further added to the developer. The concentration of the surfactant is preferably 0.01% by mass to 10% by mass.
The temperature of the developer can be appropriately selected according to the developability of the photosensitive layer, and is preferably about 25 ° C. to 40 ° C., for example.

There is no restriction | limiting in particular as said image development system, According to the objective, it can select suitably, For example, paddle image development, shower image development, shower & spin image development, dip image development, etc. are mentioned.
The shower development will be described. The uncured portion can be removed by spraying a developer onto the exposed photosensitive layer by shower. Prior to development, it is preferable to spray an alkaline solution having a low solubility in the photosensitive layer with a shower or the like to remove the thermoplastic resin layer, the intermediate layer, and the like. Further, after development, it is preferable to remove the development residue while spraying a cleaning agent or the like with a shower and rubbing with a brush or the like.

[Other processes]
There is no restriction | limiting in particular as said other process, Although selecting suitably from the process in well-known pattern formation is mentioned, For example, a hardening process process, an etching process, etc. are mentioned. These may be used alone or in combination of two or more.

-Curing process-
It is preferable to provide a curing treatment step for performing a curing treatment on the positive photosensitive layer after the development step.
There is no restriction | limiting in particular as said hardening process, Although it can select suitably according to the objective, For example, a whole surface exposure process, a whole surface heat processing, etc. are mentioned suitably.

Examples of the entire surface exposure processing method include a method of exposing the entire surface of the laminate on which the pattern is formed after the developing step. The entire surface exposure accelerates the curing of the resin in the photosensitive composition forming the photosensitive layer, and the surface of the pattern is cured.
There is no restriction | limiting in particular as an apparatus which performs the said whole surface exposure, Although it can select suitably according to the objective, For example, UV exposure machines, such as an ultrahigh pressure mercury lamp, are mentioned suitably.

Examples of the entire surface heat treatment method include a method of heating the entire surface of the laminate on which the pattern is formed after the developing step. The whole surface heating increases the film strength of the surface of the pattern.
As heating temperature in the said whole surface heating, 120-250 degreeC is preferable and 120-200 degreeC is more preferable. When the heating temperature is less than 120 ° C., the film strength may not be improved by heat treatment. When the heating temperature exceeds 250 ° C., the resin in the positive photosensitive composition is decomposed and the film quality is weak. May become brittle.
The heating time in the entire surface heating is preferably 10 to 120 minutes, and more preferably 15 to 60 minutes.
There is no restriction | limiting in particular as an apparatus which performs the said whole surface heating, According to the objective, it can select suitably from well-known apparatuses, For example, a dry oven, a hot plate, IR heater etc. are mentioned.

-Etching process-
The etching step can be performed by a method appropriately selected from known etching treatment methods, and is performed to remove a base portion not covered with a resist pattern, thereby obtaining a thin film pattern.
Either a treatment with an etchant (wet etching) or a reaction by gas discharge under reduced pressure to form a gas (dry etching) is performed.
When performing the wet etching, it is desirable to perform post-baking in order to prevent undercut due to the penetration of the etchant. Usually, these post-baking is performed at about 110 ° C. to 140 ° C., but is not necessarily limited thereto. As etchants used, many etchants have been developed and used, with ferric chloride / hydrochloric acid systems, hydrochloric acid / nitric acid systems, hydrobromic acid systems, and the like as representative examples. Cerium ammonium nitrate solution for Cr, diluted hydrofluoric acid for Ti and Ta, hydrogen peroxide solution for Mo, phosphorous nitric acid for MoW, Al, diluted aqua regia, ferric chloride solution for ITO, Buffered hydrofluoric acid is used for hydrogen iodide water, SiNx and SiO ₂ , and hydrofluoric acid is used for a-Si and n + a-Si.

In the photosensitive composition of the present invention, the dry etching resistance of the resist pattern can be improved by adding a thermal crosslinking agent to the positive photosensitive layer and performing post-baking.
As an etchant gas used in the dry etching, an etchant gas suitable for each film type is used. Carbon tetrafluoride (chlorine) + oxygen, carbon tetrafluoride (sulfur hexafluoride) + hydrogen chloride (chlorine) for a-Si / n ⁺ and s-Si, carbon tetrafluoride for a-SiNx + Oxygen, carbon tetrafluoride + oxygen for a-SiOx, carbon trifluoride + oxygen, carbon tetrafluoride (sulfur hexafluoride) + oxygen for Ta, carbon tetrafluoride for MoTa / MoW Examples include + oxygen, chlorine + oxygen for Cr, boron trichloride + chlorine for Al, and methane, hydrogen bromide, hydrogen bromide + chlorine, hydrogen iodide, etc. for ITO.

-Resist stripping-
Finally, remove the resist used for pattern formation with a stripping solution (wet stripping), or remove it by oxidizing it with oxygen gas discharge under reduced pressure (dry stripping / ashing). Alternatively, the resist is removed by several peeling methods such as oxidation with ozone and UV light to remove it in a gaseous state (dry peeling / UV ashing). As the stripping solution, an aqueous solution system such as an aqueous sodium hydroxide solution and an aqueous potassium hydroxide solution and an organic solvent system such as a mixture of an amine and dimethyl sulfoxide or N-methylpyrrolidone are generally known. As an example of the latter, a monoethanolamine / dimethyl sulfoxide mixture (mass mixing ratio = 7/3) is well known.

  The pattern forming method of the present invention requires high-definition exposure because the pattern can be formed with high definition and efficiency by suppressing distortion of the image formed on the pattern forming material. It can be suitably used for forming various patterns, and can be particularly suitably used for forming a large-area TFT array substrate.

(TFT array substrate)
The TFT array substrate can be formed by the pattern forming method of the present invention. That is, a positive photosensitive layer comprising the positive photosensitive composition of the present invention is formed on a TFT (Thin Film Transistor) active matrix substrate (TFT array substrate), exposed and developed, and then on the same TFT array substrate. A plurality of pixel electrodes are formed.
In this case, the formation, exposure, development, etching, and the like of the positive photosensitive layer are the same as those in the pattern forming method of the present invention.

Here, the TFT array substrate for LCD will be described with reference to FIG.
FIG. 38 shows a basic cross-sectional structure diagram of an LCD TFT array substrate. In this TFT array substrate, (1) First, a gate electrode 2a and a Cs electrode 2b are provided on a glass substrate 1 with molybdenum tantalum (MoTa) or the like. (2) Next, a gate oxide film is formed on the gate electrode by a silicon oxide film (SiOx) 3 or a silicon nitride film (SiNx) 4, and (3) a semiconductor active layer is formed on the gate oxide film. An amorphous silicon layer (a-Si) 5 is formed. (4) Further, an a-Si layer 6 in which N ⁺ impurities are mixed to reduce the junction resistance is provided. (5) Thereafter, the drain electrode 7a and the source electrode 7b are formed of a metal such as aluminum. The drain electrode 7 a is connected to the data signal line, and the source electrode 7 b is connected to the pixel electrode (or sub-pixel electrode) 9. (6) Finally, a protective film such as a nitride film (SiNx) 8 that protects the semiconductor layer (a-Si layer), drain electrode, and source electrode is provided.

Next, a manufacturing process of the TFT array substrate will be described with reference to FIG.
First, as shown in FIG. 39A, a metal film 22 to be a gate electrode is formed on the insulating substrate 21 by sputtering on the entire surface of the glass substrate. Examples of the metal in the metal film include alloys such as tantalum (Ta), molybdenum tantalum (MoTa), molybdenum tungsten (MoW), aluminum (Al), and the like.
Next, as shown in the step of FIG. 39B, a metal pattern 22a is formed by applying a photoresist, drying, mask exposure, development, and etching (hereinafter, this series of steps may be referred to as a “photo etching step”). is there). This photoetching step is performed by the pattern forming method of the present invention.
Next, as shown in FIG. 39C, a gate oxide film (SiOx) 23 is formed by the CVD technique.
Next, as shown in FIG. 39D, a semiconductor film (a-Si) 24 is deposited by CVD technology.
Further, as shown in FIG. 39E, a semiconductor film 25 to which a small amount of phosphorus (N ⁺ ) is added is formed. Thereafter, only a portion to be a TFT is patterned by the photoetching process of the present invention as shown in FIG. 39F to form a semiconductor layer (a-Si film) 24a.
Thereafter, the ITO film 26, which is a transparent conductive film, is sputtered on the portion to be the pixel electrode as shown in FIG. 39 (G), and as shown in FIG. 39 (H) by the photoetching process of the present invention, Pixel electrode 26a is formed.
On the other hand, in order to form the power supply portion of the storage capacitor Cs, a part of the gate oxide film on Cs is removed by patterning as shown in FIG. 39 (I) by the photoetching process of the present invention (23a). .
Next, a metal layer 27 such as aluminum or titanium is formed by sputtering as shown in the step of FIG. Next, the source electrode 27a and the drain electrode 27b are formed by patterning as shown in FIG. 39K by the photoetching process of the present invention.
Finally, a protective film such as a nitride film (SiNx) is grown by a CVD method in order to protect elements such as TFTs. After this protective film is grown, the protective film is formed by patterning through the photoetching process of the present invention. As described above, a TFT array substrate can be manufactured.

(Liquid crystal display element)
The liquid crystal display element of the present invention includes the TFT array substrate of the present invention manufactured by the pattern forming method of the present invention described above, and further includes other members as necessary.

  The basic configuration of the liquid crystal display element is as follows: (1) TFT array substrate of the present invention in which drive elements such as thin film transistors (hereinafter referred to as “TFTs”) and pixel electrodes (conductive layers) are arrayed. (Drive-side substrate) and a color filter-side substrate provided with a color filter and a counter electrode (conductive layer) are arranged to face each other with a spacer interposed therebetween, and a liquid crystal material is sealed in the gap portion, (2 ) A color filter-integrated TFT array substrate in which a color filter is directly formed on the TFT array substrate of the present invention and a counter substrate having a counter electrode (conductive layer) are arranged to face each other with a spacer interposed therebetween, and in the gap portion Examples include a liquid crystal material encapsulated.

Examples of the conductive layer include an ITO film; a metal film such as Al, Zn, Cu, Fe, Ni, Cr, and Mo; and a metal oxide film such as SiO _2. Is preferable, and an ITO film is particularly preferable.
The TFT array substrate, the color filter side substrate, and the counter substrate of the present invention have, as their base materials, for example, a known glass plate such as a soda glass plate, a low expansion glass plate, a non-alkali glass plate, a quartz glass plate, or a plastic. It is configured using a film or the like.

  Since the liquid crystal display element of the present invention uses a TFT array substrate in which fine TFTs formed by the pattern forming method of the present invention are densely formed without defects, a large-screen LCD of about 1 m square or more can be produced with high quality. Yes, and can be provided at low cost.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto.

Example 1
An aluminum (Al) film was formed on the front surface of a 1160 mm × 980 mm glass substrate by magnetron DC sputtering. On the aluminum (Al) film, a positive photosensitive composition having the following composition was applied at 2500 rpm for 20 seconds using a spin coater and dried in an oven at 120 ° C. for 2 minutes to obtain a thickness of 1.5 μm. A positive photosensitive layer (photoresist film) was formed.

-Composition of positive photosensitive composition (solution)-
m-cresol / o-ethoxyphenol molar ratio 70/30) (reacted with novolak resin from formalin, reprecipitated, weight average molecular weight = 11600, Mw / Mn = 3.1)... 70 parts by mass α , Α ′, α ″ -tris (4-hydroxyphenyl) -1-ethyl-4-isopropylbenzene, 1,2-naphthoquinonediazide-5-sulfonic acid ester: 35 parts by mass 4,4 ′-(1- α-methylbenzylidene) bisphenol 30 parts by weight Fluorosurfactant (F176PF, manufactured by Dainippon Ink & Chemicals, Inc.) 1 part by weight 1-cyclohexyl-3- (2-morpholinoethyl) -2- Thiourea ... 3.6 parts by mass Propylene glycol monomethyl ether acetate ... 425 parts by mass

<Development process>
Next, the positive photosensitive layer on the substrate was exposed to a laser beam having a TFT pattern with an irradiation amount of 50 mJ / cm ² and patterned using a pattern forming apparatus described below.

-Pattern forming device-
29-34 as the light irradiating means, and 768 sets of micromirror arrays in which 1024 micromirrors are arranged in the main scanning direction shown in FIG. 8 as the light modulating means are arranged in the sub-scanning direction. Among the optical modulation means, the DMD 50 controlled to drive only 1024 × 256 rows, and the microlens array in which the microlenses shown in FIG. 15 whose one surface is a toric surface are arranged in an array. A pattern forming apparatus having 472 and optical systems 480 and 482 for forming an image of light passing through the microlens array on the photosensitive layer was used.

  As the microlens, a toric lens 55a is used as shown in FIGS. 19 and 20, and a radius of curvature Rx = −0.125 mm in a direction optically corresponding to the x direction, corresponding to the y direction. The radius of curvature Ry in the direction to travel is −0.1 mm.

  In addition, the aperture array 59 disposed in the vicinity of the condensing position of the microlens array 55 is disposed so that only light that has passed through the corresponding microlens 55a is incident on each aperture 59a.

<Development process>
After developing for 1 minute at 25 ° C. with a developer composed of a 0.5 mass% tetramethylammonium hydroxide aqueous solution, it was rinsed with ultrapure water for 1 minute.

<Etching process>
The aluminum (Al) portion not covered with the resist was removed with a phosphoric nitrate etchant to form an aluminum (Al) gate electrode pattern.
The above process is called the photoetching process of the present invention.

<Production of TFT array substrate>
A TFT array substrate was produced according to the TFT array substrate manufacturing method shown in the steps of FIG. 39A to FIG. 39K. That is, a gate oxide film (SiOx having a thickness of about 400 nm) was formed by plasma CVD.
Next, a semiconductor film (a-Si having a thickness of about 100 nm) is deposited by plasma CVD technique, and a small amount of phosphorus (N ⁺ ) is further added. Thereafter, only the portion that becomes the TFT is positive-type photosensitive as described above. Patterning was performed by the photoetching process of the present invention using the composition to form a semiconductor layer (a-Si film).
Thereafter, an ITO film (about 100 nm thick), which is a transparent conductive film, was sputtered on a portion to be a pixel electrode, and a pixel electrode was formed by a photoetching process.
On the other hand, in order to form the power supply portion of the storage capacitor Cs, a part of the gate oxide film on Cs was removed by patterning by the photoetching process of the present invention using the positive photosensitive composition as described above.
Next, aluminum (Al) is sputtered on the portion to be the drain electrode and source electrode of the TFT, and patterning is performed by the photoetching process of the present invention using the positive photosensitive composition in the same manner as described above to form each electrode. did.
Finally, a protective film of a nitride film (SiNx) was grown by the CVD method. After this growth, patterning was performed by the photoetching process of the present invention using a positive photosensitive composition in the same manner as described above to form a protective film, thereby producing a TFT array.
In any of the photoetching steps, the pattern edge was cut well.

  In addition, when 100 TFT array substrates were processed and the TFT chip on the substrate was evaluated, there were two substrates having one or more defective TFTs on the same substrate, and a defective product as a TFT array substrate. The occurrence rate of was 2%.

(Comparative Example 1)
In Example 1, the pattern forming apparatus of Example 1 was not used, but positive exposure was performed in the same manner as in Example 1 except that UV exposure was performed at 50 mJ / cm ² using a quartz glass photomask and an ultrahigh pressure mercury lamp exposure machine. The mold photosensitive layer was exposed and then developed with an aqueous tetramethylammonium hydroxide solution.
At that time, the photomask was soiled and a failure occurred in the pattern of the portion. Therefore, the exposure operation was continued after cleaning the photomask.
When 100 TFT array substrates were processed and the TFT chips on the substrate were evaluated, the number of substrates having one or more defective TFTs on the same substrate was 25. The incidence of non-defective products was 25%.

(Example 2)
In Example 1, the same positive photosensitive composition as in Example 1 was applied onto a silicon wafer, dried, and subjected to pattern exposure and development in the same manner as in Example 1, followed by post-baking at 180 ° C. for 30 minutes, A TFT array substrate was produced in the same manner as in Example 1 except that the etching process was changed as follows.
When 100 substrates of the TFT array substrate were processed and defects on the substrate were evaluated, there were 3 substrates having one or more defective TFTs, and the defect rate was 3%.

<Dry etching process>
The post-baked wafer was subjected to oxygen plasma etching under the following dry etching conditions using a plasma etching apparatus (manufactured by Tokyo Vacuum Co., Ltd., SUPER COAT N400 type). After the etching process, the dry etching resistance was evaluated as follows.
[Dry etching conditions]
Power supply method: Cathode couple,
Electrode size: Diameter 80mm
Process gas: oxygen,
Pressure: 0.065 Torr
rf applied voltage: 85 W
rf power density: 1.69 W / cm ²
Processing time: 5 minutes

<Evaluation of dry etching resistance>
The film thickness after the etching was measured, and the thickness of the film disappeared by the etching was divided by the etching time to obtain an oxygen plasma rate (O ₂ -RIE Rate, unit: Å / sec). The oxygen plasma velocity (O ₂ -RIE Rate) of Example 2 was 40 Å / sec. In addition, it was shown that oxygen plasma resistance is so high that the value of oxygen plasma velocity is small, and it was recognized that the resist of Example 2 has the outstanding dry etching resistance.

<Resist stripping process>
When resist stripping was performed by immersion at 80 ° C. for 3 minutes using a monoethanolamine / dimethylsulfoxide mixed stripping solution, the stripping residue was not recognized and the stripping was clean.

Example 3
In Example 1, as a positive photosensitive composition (photoresist), a positive photoresist (manufactured by Fujifilm Arch, FTLS-C4) was used, and a silicon substrate subjected to hexamethyldisilazane (HMDS) treatment was used. A positive photosensitive layer (photoresist film) having a thickness of 1.5 μm was produced by applying it at 2500 rpm for 20 seconds using a spin coater and drying it in an oven at 120 ° C. for 2 minutes.
It was exposed to laser light having patterns having various l / s widths (50 mJ / cm ² ), developed with 2.38% by mass of tetramethylammonium hydroxide (TMAH) aqueous solution for 80 seconds, and ultrapure water Wash with water and dry.
The resolution obtained was 1 / s = 3 μm / 3 μm.

Next, exposure, development, and etching were performed in the same manner as in Example 1 except that the positive photoresist (FLS-C4, manufactured by Fuji Film Arch Co., Ltd.) of Example 3 was used to produce a TFT array substrate. .
When 100 TFT array substrates were processed and defects on the substrate were evaluated, there were 3 TFT array substrates having one or more defective TFTs, and the defect rate was 3%.

(Example 4 and Comparative Example 2)
In steps H to I shown in FIG. 39, two layers of the transparent electrode film 26 and the gate oxide film 23 are formed by sputtering, and pattern formation is performed for each layer. The pattern formation was performed as follows.

  Example 4 includes an intensity-modulated exposure method that includes two-step intensity-modulated exposure and develops using two types of developing strength developing solutions. One photoresist coating and one intensity-modulated exposure, 2 Pattern formation is performed by two developments and two etchings. Specifically, in step a2 in FIG. 41, a photoresist was applied, the exposure intensity was changed, and the exposure was performed. Then, the resist was developed with an aqueous 1.69 mass% tetramethylammonium hydroxide (TMAH) solution for 20 seconds and washed with water. Next, as shown in step b2 of FIG. 41, resist images having different thicknesses were obtained. Next, as shown in step c2 of FIG. 41, etching was performed on 26 parts and 23 parts whose surfaces were not covered with the resist. Next, as shown in step d2 in FIG. 41, development is performed with an aqueous 2.38 mass% tetramethylammonium hydroxide (TMAH) solution to remove a thin resist portion, and etching of 26 portions whose surfaces are not covered with the resist. Went. As a result, as shown in the step e2 in FIG. 41, a pattern having a good shape with good resolution could be formed.

Comparative Example 2 is a conventional pattern forming method. As shown in FIG. 40, two photomasks are formed by six steps of a1 step, b1 step, c1 step, d1 step, e1 step, and f1 step. It requires two photo-etching operations (photoresist application + exposure + development + etching).
Therefore, in Example 4, which employs an intensity-modulated exposure method and develops using two types of developing strength developers, a pattern can be formed in five steps: a2, step b2, step c2, step d2, and step e2. Compared with the six steps in the conventional comparative example 2, the TFT array substrate can be efficiently manufactured with fewer manufacturing steps.

(Example 5)
[Production and Evaluation of Liquid Crystal Display]
Using the TFT array substrates of Examples 1 to 3 and Comparative Example 1, a liquid crystal panel was prepared by a known method (Japanese Patent Laid-Open No. 11-248922), and the display performance was evaluated. The liquid crystal display device of Comparative Example 1 It was confirmed that the liquid crystal display devices of Examples 1 to 3 showed good display characteristics as compared with.

  The pattern forming method of the present invention requires high-definition exposure because the pattern can be formed with high definition and efficiency by suppressing distortion of the image formed on the pattern forming material. Suitable for manufacturing TFT array substrates and plasma display (PDP) electrode plates, TFT array substrates manufactured by the pattern forming method of the present invention are for large liquid crystal display devices (LCD) such as notebook computers and TV monitors, It is suitably used for PALC (plasma address liquid crystal) and plasma display (PDP).

FIG. 1 is an example of a partially enlarged view showing a configuration of a digital micromirror device (DMD). 2A and 2B are examples of explanatory diagrams for explaining the operation of the DMD. FIGS. 3A and 3B are examples of plan views showing the arrangement of the exposure beam and the scanning line in a case where the DMD is not inclined and in a case where the DMD is inclined. 4A and 4B are examples of diagrams illustrating examples of DMD usage areas. FIG. 5 is an example of a plan view for explaining an exposure method in which the photosensitive layer is exposed by one scanning by the scanner. 6A and 6B are examples of plan views for explaining an exposure method for exposing a photosensitive layer by a plurality of scans by a scanner. FIG. 7 is an example of a schematic perspective view illustrating an appearance of an example of the pattern forming apparatus. FIG. 8 is an example of a schematic perspective view illustrating the configuration of the scanner of the pattern forming apparatus. FIG. 9A is an example of a plan view showing an exposed region formed on the photosensitive layer, and FIG. 9B is an example of a diagram showing an array of exposure areas by each exposure head. FIG. 10 is an example of a perspective view showing a schematic configuration of an exposure head including light modulation means. FIG. 11 is an example of a sectional view in the sub-scanning direction along the optical axis showing the configuration of the exposure head shown in FIG. FIG. 12 is an example of a controller that controls DMD based on pattern information. FIG. 13A is an example of a cross-sectional view along the optical axis showing the configuration of another exposure head having a different coupling optical system, and FIG. 13B shows the exposure when a microlens array or the like is not used. FIG. 13C is an example of a plan view showing a light image projected on the surface to be exposed when a microlens array or the like is used. FIG. 14 is an example of a diagram showing the distortion of the reflection surface of the micromirror constituting the DMD with contour lines. FIG. 15 is an example of a graph showing distortion of the reflection surface of the micromirror in two diagonal directions of the mirror. FIG. 16 is an example of a front view (A) and a side view (B) of a microlens array used in the pattern forming apparatus. FIG. 17 is an example of a front view (A) and a side view (B) of the microlens constituting the microlens array. FIG. 18 is an example of a schematic diagram illustrating a condensing state by a microlens in one cross section (A) and another cross section (B). FIG. 19a is an example of a diagram showing a result of simulating the beam diameter in the vicinity of the condensing position of the microlens. FIG. 19B is an example of a diagram showing the same simulation result as that in FIG. 19A at another position. FIG. 19c is an example of a diagram showing the same simulation result as in FIG. 19a at another position. FIG. 19d is an example of a diagram showing the same simulation result as in FIG. 19a at another position. FIG. 20a is an example of a diagram showing the result of simulating the beam diameter in the vicinity of the condensing position of the microlens in the conventional pattern forming method. FIG. 20b is an example of a diagram showing the same simulation result as in FIG. 20a at another position. FIG. 20c is an example of a diagram showing the same simulation result as in FIG. 20a for another position. FIG. 20d is an example of a diagram illustrating simulation results similar to those in FIG. 20a at different positions. FIG. 21 is an example of a plan view showing another configuration of the combined laser light source. FIG. 22 shows an example of a front view (A) and an example of a side view (B) of the microlens constituting the microlens array. FIG. 23 is an example of a schematic diagram illustrating a light condensing state by the microlens of FIG. 22 in one cross section (A) and another cross section (B). FIG. 24 is an example of an explanatory diagram about the concept of correction by the light amount distribution correction optical system. FIG. 25 is an example of a graph showing the light amount distribution when the light irradiation means has a Gaussian distribution and the light amount distribution is not corrected. FIG. 26 is an example of a graph showing the light amount distribution after correction by the light amount distribution correcting optical system. 27A (A) is a perspective view showing the configuration of the fiber array light source, FIG. 27A (B) is an example of a partially enlarged view of (A), and FIGS. 27A (C) and (D) are lasers. It is an example of the top view which shows the arrangement | sequence of the light emission point in an emission part. FIG. 27 b is an example of a front view showing the arrangement of light emitting points in the laser emission part of the fiber array light source. FIG. 28 is an example of a diagram illustrating a configuration of a multimode optical fiber. FIG. 29 is an example of a plan view showing the configuration of the combined laser light source. FIG. 30 is an example of a plan view showing the configuration of the laser module. FIG. 31 is an example of a side view showing the configuration of the laser module shown in FIG. 32 is a partial side view showing the configuration of the laser module shown in FIG. FIG. 33 is an example of a perspective view showing a configuration of a laser array. FIG. 34A is an example of a perspective view showing a configuration of a multi-cavity laser, and FIG. 34B is a perspective view of a multi-cavity laser array in which the multi-cavity lasers shown in FIG. It is an example. FIG. 35 is an example of a plan view showing another configuration of the combined laser light source. FIG. 36A is an example of a plan view illustrating another configuration of the combined laser light source, and FIG. 36B is an example of a cross-sectional view along the optical axis of FIG. FIGS. 37A and 37B are examples of cross-sectional views along the optical axis showing the difference between the depth of focus in the conventional exposure apparatus and the depth of focus by the permanent pattern forming method (pattern forming apparatus) of the present invention. . FIG. 38 is a diagram showing a typical cross-sectional structure of an LCD TFT substrate. FIG. 39 is a cross-sectional view showing the manufacturing process of the TFT array for LCD. FIG. 40 is a diagram showing manufacturing steps in the conventional pattern forming method for steps H to I in FIG. FIG. 41 is a diagram showing manufacturing steps in the pattern forming method of the present invention for Steps H to I in FIG.

Explanation of symbols

LD1 to LD7 GaN-based semiconductor laser 1 Glass substrate 2a Gate electrode 2b Cs electrode 3 Silicon oxide film 4 Silicon nitride film 5 Amorphous silicon layer (a-Si)
6 a ⁺ Si layer mixed with N ⁺ impurity 7a Drain electrode 7b Source electrode 8 Protective layer 9 Image electrode 10 Heat block 11-17 Collimator lens 20 Condensing lens 21 Insulating substrate 22a Metal pattern 23 Gate oxide film 24 Semiconductor film 25 N ⁺ impurity mixed a-Si layer 26 ITO film 27a Drain electrode 27b Source electrode 30-31 Multimode optical fiber 44 Collimator lens holder 45 Condensing lens holder 46 Fiber holder 50 Digital micromirror device (DMD)
52 Lens system 53 Reflected light image (exposure beam)
54 Lens of second imaging optical system 55 Micro lens array 56 Surface to be exposed (scanning surface)
55a Micro lens 57 Lens of second image forming optical system 58 Lens of second image forming optical system 59 Aperture array 64 Laser module 66 Fiber array light source 67 Lens system 68 Laser emitting portion 69 Mirror 70 Prism 73 Combination lens 74 Imaging lens 100 Heat block 110 Multicapacity laser 111 Heat block 113 Rod lens 120 Condensing lens 130 Multimode optical fiber 130a Core 140 Laser array 144 Light irradiation means 150 Photosensitive layer 152 Stage 155a Micro lens 156 Installation table 158 Guide 160 Gate 162 Scanner 164 Sensor 166 Exposure head 168 Exposure area 170 Exposed area 180 Heat block 184 Collimating lens array 302 Controller 30 4 Stage Drive Device 454 Lens System 468 Exposure Area 472 Micro Lens Array 476 Aperture Array 478 Aperture 480 Lens System

Claims (15)

A positive photosensitive layer forming step of forming at least a positive photosensitive layer on the surface of the substrate using the positive photosensitive composition;
After modulating the light from the light irradiation means by the light modulation means having n picture elements for receiving and emitting light from the light irradiation means, it is possible to correct aberration due to distortion of the emission surface in the picture element. An exposure step of exposing the positive photosensitive layer with light that has passed through a microlens array in which microlenses having aspherical surfaces are arranged;
And a development step of developing the positive photosensitive layer exposed in the exposure step.   The pattern forming method according to claim 1, wherein the positive photosensitive layer is formed by applying a positive photosensitive composition to the surface of a substrate and drying.   The pattern forming method according to claim 1, wherein the positive photosensitive composition contains a novolak type phenol resin, a 1,2-quinonediazide compound, and a dissolution accelerator.   The pattern forming method according to claim 1, wherein at least two steps of intensity-modulated exposure are performed in the exposure step, and development is performed using two or more kinds of developers having different development intensities in the development step.   The pattern forming method according to claim 1, wherein the aspheric surface is a toric surface.   6. The light modulation means is capable of controlling any less than n number of image elements arranged continuously from n image elements in accordance with pattern information. Pattern forming method.   The pattern forming method according to claim 1, wherein the light modulation means is a spatial light modulation element.   The pattern formation method according to claim 7, wherein the spatial light modulation element is a digital micromirror device (DMD).   The pattern forming method according to claim 1, wherein the exposure is performed through an aperture array.   The pattern forming method according to claim 1, wherein the exposure is performed while relatively moving the exposure light and the photosensitive layer.   The pattern forming method according to claim 1, wherein the light irradiation means can synthesize and irradiate two or more lights.   The light irradiation means includes a plurality of lasers, a multimode optical fiber, and a collective optical system for condensing and coupling the laser beams irradiated from the plurality of lasers to the multimode optical fiber. The pattern forming method according to any one of 11.   The pattern forming method according to claim 12, wherein the wavelength of the laser light is 395 to 415 nm.   A TFT array substrate formed by the pattern forming method according to claim 1. A liquid crystal display element using the TFT array substrate according to claim 14.