JPH09265186A - Resist material and method for manufacturing thin film multilayer circuit board - Google Patents

Abstract

(57) Abstract: [PROBLEMS] To provide a resist material capable of forming a resist pattern excellent in heat resistance and cross-sectional shape when used for manufacturing a thin film multilayer circuit board. A cycloolefin resin modified with an epoxy group and a crosslinking agent capable of photocrosslinking the cycloolefin resin are configured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resist material for pattern formation and a method of manufacturing a semiconductor device using the resist material. More specifically, the present invention relates to a resist material for pattern formation suitable for a lift-off method, and a method for manufacturing a thin film multilayer circuit board using the same.

[0002]

2. Description of the Related Art As is well known, a thin film multilayer circuit board is manufactured by alternately laminating insulating layers and wiring layers on the board. Here, as the insulating layer, it is common to use polyimide having excellent heat resistance, solvent resistance, and strength, and as the wiring layer, low electrical resistance and relatively inexpensive copper are used. It is common to do. However, when the polyimide thin film and the copper thin film are directly laminated, a phenomenon called migration in which copper of the wiring layer gradually diffuses into the polyimide film of the insulating layer is caused, and as a result, the wiring may be short-circuited. Often. In order to avoid the problem of migration, a chromium thin film as a protective metal is usually interposed between a polyimide thin film and a copper thin film, that is, a wiring layer has a three-layer structure of chromium-copper-chrome. Is being done.

A thin film multilayer circuit board having a wiring layer having a three-layer structure of chromium-copper-chromium has been conventionally manufactured by various methods. For example, as shown in the cross section in order of FIG. 1, it is manufactured by the following steps. Step A: Fabrication of the substrate 11 having a polyimide thin film (not shown) as an insulating layer.

Step B: Chromium layer 1 having a film thickness of about 800 Å
2. Forming a solid film composed of a copper layer 13 having a thickness of about 5 μm and a chromium layer 14 having a thickness of about 800 Å. Three layers are sequentially formed using a conventional film forming method. Step C: Formation of a patterning resist film 15 used as a mask for etching the solid film. For example, use of novolac-based resist.

Step D: Etching of solid film. Either wet etching or dry etching may be used. Step E: Exposing the wiring layer by removing the resist film 15. Further, instead of the above-described method, as shown in the cross section of FIG.

Step A: After preparing the substrate 11 with an insulating layer as in Step A of FIG. 1, a chromium layer 12 having a film thickness of about 800 Å is prepared.
And forming a solid film consisting of a copper layer 13 having a film thickness of about 5 μm.
Two layers are sequentially formed using a conventional film forming method. Step B: The resist film 25 for plating, which is exposed in order to perform copper plating on the wiring pattern formation portion of the solid film
Formation.

Step C: Copper plating using the plating resist film 25 as a mask. Step D: Removal of the resist film 25 and subsequent removal of the solid film other than the wiring pattern formation site by dry etching. Step E: Formation of a patterning resist film 35 and subsequent formation of a chromium layer 14 having a film thickness of about 800 Å.

Step F: Exposing the wiring layer by removing the resist film 35. However, in the thin-film multilayer circuit board manufactured by these methods, the chromium thin films 12 and 14 are present on the upper and lower sides of the copper thin film 13, but not on the side faces, so that the copper and the polyimide are in direct contact with each other. Therefore, there is still a possibility of migration in which the copper of the wiring layer diffuses into the polyimide film of the insulating layer.

Solving the problem of copper migration potential
In order to make a decision, the laminated arrangement shown in FIGS. 1 (E) and 2 (F) is used.
Chromate (Cr_TwoO_Three・ C
rO _Three・ XH_TwoA method of covering with a film of O) is also known. I
However, this method does not depend on the reliability or chemical properties of the chromate film.
There is a problem with, and it is not a sufficient solution. Further
In addition, the method described above has a long turn and is expensive.
Therefore, a method for forming fine wiring at low cost is desired.
ing.

The present inventors recently invented an improved method for forming a laminated wiring using a combination of a lift-off method and a sputtering method as a solution to the above-mentioned various problems, and applied for a patent. Yes (October 11, 1994)
(See Japanese Patent Application No. 6-245296).
This wiring forming method includes the following steps as shown in the cross section of FIG. 3 in order.

Step A: A resist film 45 having an opening corresponding to a wiring pattern is formed on the surface of the substrate 11 having an insulating layer (polyimide film; not shown). A lift-off resist material is used for the resist film. Step B: Sputtering of the protective metal (chromium) layer 12. The distance between the chromium target (not shown) and the substrate 11 is shortened to about 15 cm, and at least chromium is deposited on the bottom surface and the wall surface of the opening of the resist film 45.

Step C: Formation of a copper thin film 13 and a chromium layer 12 by sputtering or vapor deposition. This film formation is performed sequentially with the distance between the target and the substrate being longer than that in step B and approximately 40 cm or more (similar to a general electron beam evaporation apparatus). Step D: Peeling off the resist film 45 by the lift-off method. Although the wiring layer is exposed, the side surface of the copper thin film 13 is covered with the protective chrome layer 12.

By the way, in the method combining the lift-off method with the sputtering method, the heat resistance of the lift-off resist material to be deposited on the substrate 11 in the step A and the cross-sectional shape of the resist film are particularly important. For example, as an index of heat resistance, in the subsequent step of forming a metal film,
There are no cracks or pattern sagging, no thermal transformation (kogation) that makes separation from the substrate difficult in the last step, and the film thickness is sufficient as an index of the cross-sectional shape. Large (for example, if the wiring is 5 μm thick, the resist film thickness is about 10 μm),
High resolution (wiring width is about 10 μm), the opening corresponding to the wiring pattern has a reverse taper cross section,
To ensure the final resist film peeling reliably and easily,
and so on. However, none of the commercially available resist materials satisfy all of these requirements at present, and thus the development of new resist materials is required.

On the other hand, the present inventors have found that a resin composition containing a cyclic olefin resin having an epoxy group and a crosslinking agent is useful as an insulating material, and have already filed a patent application (1995). See Japanese Patent Application No. 7-28766 filed on January 25, 2014). This resin composition is easy to apply to a film thickness of about 10 μm,
High heat resistance and high resolution can be obtained by using a crosslinking agent. In completing the present invention, it is important that such a resin composition has already been found by the present inventors.

[0015]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems of the prior art and is excellent in heat resistance and cross-sectional shape when used in the manufacture of a thin film multilayer circuit board. An object of the present invention is to provide a resist material capable of forming a resist pattern. In addition, another one of the present invention
One object is to provide a method of manufacturing a thin film multilayer circuit board to which the lift-off method can be applied.

Other objects of the present invention will be easily understood from the detailed description of the present invention given below.

[0017]

According to the present invention, part 1
In one aspect, there is provided a resist material for pattern formation, which comprises a cyclic olefin resin modified with an epoxy group and a crosslinking agent capable of photocrosslinking the cyclic olefin resin. The epoxy-modified cyclic olefin-based resin that can be used in the practice of the present invention is preferably an epoxy-modified thermoplastic norbornene-based resin obtained by introducing an epoxy group into the thermoplastic norbornene-based resin. Here, the epoxy modification rate of the epoxy-modified cyclic olefin-based resin is represented by the weight% of oxygen of the epoxy group with respect to the weight of the polymer or resin,
Preferably 0.05 to 2% by weight, more preferably 0.1.
It is from 08 to 1% by weight.

The cross-linking agent used in combination with the epoxy-modified cyclic olefin resin and capable of photo-crosslinking the cyclic olefin resin is preferably a bisazide compound, and the epoxy contained in the cyclic olefin resin. 0.05 to 10 times the molar amount of the group,
More preferably, it is used in an amount of 0.15 to 4 times the molar amount. In addition, the resist material of the present invention can preferably further contain a dye. Furthermore, in the resist material of the present invention, when forming a resist pattern using it, by adjusting the wavelength of the exposure light source used,
The taper angle of the obtained resist pattern can be adjusted.

The resist material of the present invention can be advantageously used in the manufacture of semiconductor devices and other devices, but above all, it is advantageously used in the manufacture of thin film multilayer circuit boards using the lift-off method. be able to. According to the invention, in another of its aspects:
A thin film multilayer circuit board having a structure in which insulating layers and wiring layers are alternately laminated and having a structure capable of preventing the layer constituent material of the included wiring layer from diffusing into the insulating layer adjacent to the wiring layer is manufactured. A method comprising the step of forming a resist pattern by a lift-off method using a resist material containing a cyclic olefin resin modified with an epoxy group and a crosslinking agent capable of photo-crosslinking the cyclic olefin resin. A method of manufacturing a featured thin film multilayer circuit board is provided.

The method for manufacturing a thin film multilayer circuit board according to the present invention preferably comprises the following steps: forming an insulating layer on the substrate, applying the resist material on the insulating layer to form a resist film, By removing the wiring pattern forming portion of the resist film while adjusting the taper angle, a resist pattern having an inversely tapered window-like opening is formed, and the bottom and side surfaces of the opening of the pattern are also covered on the resist pattern. To form a first wiring material layer, and form a second wiring material layer on the first wiring material layer so as to cover at least the bottom surface of the opening of the resist pattern. A second wiring material layer made of the same or different wiring material as the first wiring material is further formed on the second wiring material layer, and the resist pattern is formed above the third wiring material layer. Removing with a layer of linear material includes.

In carrying out the method of the present invention, preferably:
The epoxy modification rate of the cyclic olefin-based resin modified with the epoxy group is 0.05 to 2% by weight, particularly 0.08 to 1
The taper angle of the inversely tapered window-like opening of the obtained resist pattern can be adjusted by adjusting in the range of wt%. Further, a bisazide compound is used as the cross-linking agent, and the amount of the bisazide compound used is 0.05 to 10 times the molar amount of the epoxy group contained in the cyclic olefin resin, particularly 0.15 to 0.15 times. It is also possible to adjust the taper angle of the inversely tapered window-like opening of the obtained resist pattern by adjusting the molar amount in the range of 4 times.

Furthermore, by further using a dye in the resist material and adjusting the type and amount of the dye, it is possible to adjust the taper angle of the inverse tapered window-like opening of the obtained resist pattern. . Furthermore,
By adjusting the wavelength of the exposure light source used when forming the resist pattern, it is also possible to adjust the taper angle of the inversely tapered window-like opening of the obtained resist pattern. Here, for the wavelength adjustment, a light source having a desired wavelength may be used, or a desired wavelength may be selected using an appropriate filter.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION The resist material for pattern formation according to the present invention is capable of crosslinking a cyclic olefin resin modified with an epoxy group and this epoxy-modified cyclic olefin resin by the action of light, that is, photocrosslinking is possible. Or a photo-crosslinkable crosslinking agent. The epoxy-modified cyclic olefin-based resin used as the main component of this resist material has excellent heat resistance, and when combined with a crosslinking agent, higher heat resistance and resolution can be achieved. The cyclic olefin resin can be formed as a thin film having a film thickness of about 10 μm.

The epoxy-modified cyclic olefin-based resin includes various resin materials, but is preferably an epoxy-modified thermoplastic norbornene-based resin obtained by introducing an epoxy group into the thermoplastic norbornene-based resin. Suitable epoxy modified thermoplastic norbornene-based resins include, but are not limited to, those listed below. It should be understood that in the present specification, the terms “polymerization” and “polymer” also include “copolymerization” and “copolymer” unless otherwise specified.

(1) A product obtained by graft-reacting an epoxy group-containing unsaturated monomer with a thermoplastic norbornene-based resin. The graft reaction is a method of reacting a resin with an epoxy group-containing unsaturated monomer in a solution using a radical generator such as peroxide (solution method) or melting a resin, an epoxy group-containing unsaturated monomer and a radical generator. It can be performed by a method of kneading and reacting (melting method).

(2) A product obtained by reacting a thermoplastic norbornene-based resin having a double bond with an epoxidizing agent. The epoxidation reaction can be carried out by a known method by reacting a thermoplastic norbornene-based resin having a double bond with an epoxidizing agent in an organic solvent.
The above-mentioned and other epoxy-modified thermoplastic norbornene-based resins can be produced from various known starting materials. For example, although the thermoplastic norbornene-based resin as a starting material is not limited to the ones listed below, the following may be mentioned.

(1) A ring-opening polymer obtained by ring-opening polymerization of at least one norbornene type monomer or a hydrogenated product of this polymer. As the norbornene type monomer,
For example, norbornene, dicyclopentadiene, dimethanooctahydronaphthalene, dimethanocyclopentadienonaphthalene and derivatives thereof can be mentioned. (2) at least one kind of norbornene-type monomer,
An addition copolymer of this monomer and an unsaturated monomer copolymerizable with it, or a hydrogenated product of this copolymer. Examples of the copolymerizable unsaturated monomer include ethylene, propylene, 1
Examples include α-olefins such as octene, alicyclic olefins such as cyclopentene and cyclohexene, vinyl aromatic compounds such as styrene, and the like.

(3) An addition polymer of at least one norbornene-type monomer or a hydrogenated product of the polymer. (4) at least one norbornene-type monomer,
Addition copolymers with non-conjugated dienes. Examples of the non-conjugated diene include 1,4-hexadiene, 1,6-octadiene and norbornadiene.

(5) An addition copolymer of at least one norbornene-type monomer, a non-conjugated diene and another copolymerizable unsaturated monomer. (6) Addition copolymer of dimethanooctahydronaphthalene and ethylene. (7) A hydrogenated product of a ring-opening copolymer of dimethanooctahydronaphthalene and dicyclopentadiene.

(8) dimethanooctahydronaphthalene,
Random addition copolymer of ethylene and 5-ethylidene-2-norbornene. As the epoxy group-containing unsaturated monomer, glycidyl ester, monoglycidyl ether or polyglycidyl ether of unsaturated polycarboxylic acid, unsaturated glycidyl ether, alkylene oxide group-containing unsaturated monomer, glycidyl group-containing vinyl aromatic compound, epoxy Examples thereof include a group-containing vinyl monomer and an epoxy group-containing cyclic unsaturated monomer. Furthermore, examples of the epoxidizing agent include peracid and hydroperoxide.

These epoxy-modified thermoplastic norbornene-based resins have an epoxy group in their molecular chains or in their side chains or terminal portions, and are usually 50
00-200000, preferably 8000-10000
Number average molecular weight of 0 (GPC using cyclohexane as solvent
Measured by analysis). Further, in the epoxy-modified cyclic olefin-based resin as described above, the content of the epoxy group contained therein, in other words, the epoxy modification rate can be widely changed according to various factors, but is preferably 0. It is within the range of 0.05 to 2% by weight. In particular, in the resist material of the present invention, by adjusting the epoxy modification rate of the epoxy modified resin contained as the main component in the material in the range of 0.05 to 2% by weight, the reverse taper window shape of the obtained resist pattern is obtained. The taper angle of the opening can be adjusted arbitrarily. Further, in the practice of the present invention, the epoxy modification rate of the epoxy modified resin may be made larger than 2% by weight, if necessary.

The epoxy-modified thermoplastic norbornene-based resin as described above may be used alone in the preparation of the resist composition of the present invention, or else two or more resins may be used in combination. Good. Further, such an epoxy-modified thermoplastic norbornene-based resin may be used in combination with a thermoplastic norbornene-based resin containing no epoxy group. Further, as will be readily understood by those skilled in the art, the epoxy-modified thermoplastic norbornene-based resin may be any functional group other than the epoxy group, such as a hydroxyl group, an ester group, an organic silicon group, and a carboxylic acid group, as necessary. It may have a group.

In the resist composition for pattern formation according to the present invention, a photo-crosslinkable cross-linking agent defined by the term "photo-crosslinking" is used in combination with such an epoxy-modified cyclic olefin resin. The photo-crosslinkable crosslinking agent acts on the cyclic olefin resin as the main component to crosslink the resin, thereby further improving the heat resistance and resolution of the resulting resist material. More specifically, this photo-crosslinkable cross-linking agent reacts with a cyclic olefin resin by irradiation with actinic rays such as g-rays, h-rays, i-rays, far-ultraviolet rays, X-rays, and electron rays. , A substance capable of forming a crosslinked product thereof. Preferred crosslinking agents that can be used in the present invention include, for example, bisazide compounds, especially aromatic bisazide compounds.

Aromatic bisazide compounds that may be advantageously used in the practice of this invention include, but are not limited to, those described below, 4,4'-diazidochalcone, 2,6-bis ( 4'-azidobenzal)
Cyclohexanone, 2,6-bis (4'-azidobenzal) -4-methylcyclohexanone, 4,4'-diazidodiphenyl sulfone, 4,4'-diazidobenzophenone, 4,4'-diazidodiphenyl, 4,4 '-Bisazidostilbene, 2,2'-bisazidostilbene,
4,4'-diazide-3,3'-dimethyldiphenyl,
2,7-diazidofluorene, 4,4'-diazidophenylmethane and the like can be mentioned. These bisazide compounds may be used alone or in combination of two or more compounds.

The above-mentioned bisazide compound as a crosslinking agent is usually used in an amount of 0.05 to 10 times the molar amount of the epoxy group contained in the polymer or resin,
It is preferably used in a molar amount of 0.15 to 4 times. If the amount of this bisazide compound is less than 0.05 times the molar amount, the desired crosslinking effect cannot be obtained, and conversely, if it exceeds 10 times the molar amount, a superior crosslinking effect cannot be obtained. . The resist material of the present invention can be obtained by adjusting the amount of the bisazide compound to be used within a range of 0.15 to 4 times the molar amount of the epoxy group contained in the polymer or resin. The taper angle of the inversely tapered window opening of the resist pattern to be formed can be arbitrarily adjusted.

Alternatively, the photo-crosslinkable cross-linking agent may be replaced with or in combination with the cross-linking agent, if it is possible to obtain the same cross-linking effect, by adding another photo-reactive substance or heating. A curing agent capable of exerting its ability may be used. As an example of the photoreactive substance, a photoamine generator, that is, a compound capable of generating an amine upon irradiation with active rays as described above can be mentioned. Examples of suitable photoamine generators include aliphatic amines, cycloaliphatic amines or aromatic amines o-nitrobenzyloxycarbonyl carbamate. Further, as another example of the photoreactive substance, a photoacid generator (PAG), that is, a compound capable of generating a Bronsted acid or a Lewis acid upon irradiation with an actinic ray can be mentioned. Examples of suitable photoacid generators include onium salts, halogenated organic compounds, quinonediazide compounds, organic acid amide compounds, organic acid imide compounds and the like. Furthermore, as a curing agent capable of exhibiting its ability by heating, aliphatic polyamines, alicyclic polyamines, aromatic polyamines, bisazides, acid anhydrides, dicarboxylic acids, polyhydric phenols known as epoxy resin curing agents are used. , Polyamide, and the like.

The pattern-forming resist material according to the present invention may optionally contain additives known in this technical field, in addition to the epoxy-modified cyclic olefin resin and the photo-crosslinkable crosslinking agent. Suitable additives include, for example, benzophenone, anthraquinone,
Examples thereof include sensitizers such as nitrobenzene, nitroaniline and diphenyl sulfide, storage stabilizers such as hydroquinone, and the like.

In the pattern forming material of the present invention, preferably, a dye is further used in the material, and the kind and the amount of the dye are adjusted, whereby the inverse tapered window-like opening of the obtained resist pattern is formed. The taper angle can be adjusted arbitrarily. The dye that can be used here, when it is mixed in the resist material, selectively absorbs the actinic ray from the exposure light source due to the difference in the absorption band of the dye, and thus the inverse taper of the obtained resist pattern can be obtained. It is a dye that can adjust the taper angle of the window-shaped opening. Suitable dyes include various light-absorbing dyes, specifically, EAB (trade name, manufactured by Hodogaya Chemical Co., Ltd.), Kayacol C (trade name, manufactured by Shinryo Corporation), Oil Yellow GGS (trade name, Orient). Industrial products) and the like. These dyes are
They may be used alone or in combination of two or more dyes. The content of the dye in the resist material can be widely changed depending on the desired effect, particularly the degree of inverse taper to be obtained, but usually 0.5 to 15% by weight based on the total amount of the resist material. %, And more preferably 0.5 to 5.0% by weight.

The resist material of the present invention can be prepared from the above-mentioned components by a conventional method. That is, an epoxy-modified cyclic olefin resin, a cross-linking agent and optionally a dye, and other additives can be uniformly mixed to obtain a resin composition. In order to uniformly disperse the crosslinking agent and the like in the resin, for example, a method of dissolving or dispersing these components in a solvent capable of dissolving the resin and then removing only the solvent can be used. As a solvent for dispersion, an organic solvent such as toluene, xylene, ethylbenzene, trimethylbenzene, chlorobenzene,
Decalin, tetralin and the like can be advantageously used. Further, instead of using the solvent, a method of melt-kneading the above components can be used.

The obtained resist material is usually formed on a substrate on which a pattern is to be formed, using a known coating method such as spin coating, to form a semiconductor device and other devices. It can be used advantageously in manufacturing. The resist material of the present invention can be advantageously used, inter alia, for manufacturing a thin film multilayer circuit board using a lift-off method, as described in detail below.

According to the present invention, on the other side thereof, the layer constituent material of the wiring layer having the insulating layers and the wiring layers alternately laminated and contained therein is diffused into the insulating layer adjacent to the wiring layer. A method for producing a thin film multilayer circuit board having a structure capable of preventing the formation of a resist material of the present invention, that is, a cyclic olefin resin modified with an epoxy group as described above and a photocrosslinkable crosslinking agent. There is provided a method of manufacturing a thin film multilayer circuit board, comprising a step of forming a resist pattern by a lift-off method using the resist material containing.

Here, the "structure capable of preventing the layer constituent material of the included wiring layer from diffusing into the insulating layer adjacent to the wiring layer" means that the wiring layer and the insulating layer adjacent thereto are directly connected to each other. The structure not in contact, specifically, the wiring layer has a double structure, the wiring material of the core portion (hereinafter, also referred to as the second wiring material), and the wiring material for protection surrounding the wiring material. (Hereinafter, also referred to as the first and sometimes the third wiring material)
It refers to the structure consisting of and. The wiring material for forming the second main conductor can be preferably formed from a metal such as copper, gold, silver, or aluminum, or an alloy thereof. Further, the first and third protective wiring materials can preferably be formed from a metal such as chromium, titanium, zirconium, hafnium, nickel, cobalt, platinum, gold, palladium or an alloy thereof.
In particular, chromium is useful as a protective wiring material because it prevents migration of wiring metals such as copper to the insulating layer and has excellent compatibility with such wiring metals. Further, the insulating layer to be laminated alternately with the wiring layer is not particularly limited, but from the viewpoint of excellent properties such as heat resistance, it can be preferably composed of polyimide. However, if necessary, the insulating layer may be formed of a thin film such as a silicon oxide film, a silicon nitride film, or an alumina film, as is generally performed in this technical field.

The thin film multilayer circuit board according to the present invention can be preferably manufactured by the following series of steps. (1) Formation of Insulating Layer on Substrate For example, a substrate made of a semiconductor material such as silicon is prepared, and the above-mentioned polyimide thin film is applied to form an insulating layer. A spin coating method or the like can be used for applying the polyimide, and the film thickness thereof is usually 5 to 10 μm. In some cases, for example, the silicon substrate may be thermally oxidized to form an insulating layer made of a silicon oxide film.

(2) Formation of Resist Film The resist material of the present invention is applied on the insulating layer formed in the previous step to form a resist film. A spin coating method or the like can be used to apply the resist material, and the film thickness thereof is usually 5 to 15 μm. (3) Formation of Resist Pattern The wiring pattern forming portion of the resist film is removed while adjusting the taper angle to form a resist pattern having an inversely tapered window-shaped opening. Conventional photolithography techniques can be used for this patterning. To expose the resist film corresponding to the wiring pattern, either selective exposure using a mask or direct drawing can be used depending on the type of exposure light source used. In particular, when performing selective exposure for patterning, it is preferable to adjust the taper angle of the inversely tapered window-like opening of the obtained resist pattern by adjusting the wavelength of the exposure light source used. Here, for the adjustment of the wavelength, a light source having a desired wavelength may be used, or otherwise, a desired light-absorbing dye or a suitable light-absorbing filter may be used to obtain the desired wavelength. The resist film may be irradiated with only actinic rays having a wavelength. Here, suitable light absorbing dyes include those described above, and
Suitable absorptive filters include U360 filters, 407 filters, 436 filters, etc., as also used in the Examples section below.

(4) Formation of Protective Wiring Material Layer (First Wiring Material Layer) A protective wiring material, such as chromium, is deposited on a resist pattern having an inversely tapered opening (window) to form a first wiring material layer. Form a layer of wiring material. The thickness of the first wiring material layer is usually 0.5 to 1.0 μm. For forming the wiring layer, the sputtering method can be preferably used, and the oblique sputtering method can be more preferably used. In forming the protective wiring layer, it is necessary to completely cover at least the bottom surface and the side surface of the opening of the resist pattern in order to prevent the migration of the wiring material to the adjacent insulating layer. It is preferable that the distance between the target and the substrate is short, usually about 15 cm.

(5) Formation of Main Wiring Material Layer (Second Wiring Material Layer) The main wiring material, for example, copper is applied to the resist pattern in which the wiring material for protection is applied to the bottom and side surfaces of the opening. A layer of wiring material 2 is formed. The film thickness of the second wiring material layer is usually 3 to 5 μm. To form this wiring layer,
Preferably, the sputtering method, more preferably the oblique sputtering method or the vertical sputtering method, or the vapor deposition method can be used. When the oblique sputtering apparatus is used in such a sputtering method, in this example, it is possible to prevent the wiring material from being formed on the side surface of the opening of the resist pattern. That is, when using an oblique sputtering device, by adjusting the distance between the sputtering target and the substrate, if it can be used as the original oblique sputtering of the device, it can also be used as an oblique sputtering that is almost vertical sputtering. You can In forming the main wiring layer, it is necessary to fill the main wiring material in at least the bottom surface of the opening of the resist pattern,
Therefore, it is preferable that the distance between the target of the wiring material and the substrate is long, usually 40 cm or more.

(6) Formation of Protective Wiring Material Layer (Third Wiring Material Layer) On the resist pattern after coating the first and second wiring material layers, the same wiring material as the above first wiring material is formed. Alternatively, a different protective wiring material, such as chromium, is deposited to form a third wiring material layer. For forming the wiring layer, preferably, a sputtering method, more preferably an oblique sputtering method, a vertical sputtering method, or a vapor deposition method can be used. In forming the protective wiring layer, it is necessary to completely surround the main wiring material together with the protective wiring layer that was previously formed. Therefore, the distance between the target of the wiring material and the substrate should be reduced. long,
Usually, it is preferably 40 cm or more.

(7) Peeling of resist pattern After the above-mentioned series of processing is completed, the resist pattern is peeled and removed together with the wiring material layer formed thereabove. The peeling of the resist pattern in this manner is called "lift-off" and can be carried out according to a conventional method. As the processing liquid for lift-off, for example, toluene or the like can be used.

The manufacture of the thin film multilayer circuit board according to the present invention is as follows.
It will be more easily understood from the following description, which will be explained with reference to FIGS. 4 and 5. Formation of Substrate: FIG. 4 (A) The substrate 1 is formed for the formation of laminated wiring. In this example, a silicon substrate is prepared and subjected to surface treatment according to a conventional method. Formation of Insulating Layer: FIG. 4B An insulating layer 2 is formed on the entire surface of the silicon substrate 1. Here, polyimide is spin-coated to a film thickness of 10 μm.
Was applied and cured. Formation of resist film: FIG. 4 (C) The resist material of the present invention is formed on the polyimide insulating layer 2 formed in the previous step by spin coating to a film thickness of 15 μm (about 3 times the thickness of the wiring to be formed). The film thickness is applied to form the resist film 3. Then, the wiring pattern formation portion of the obtained resist film 3 is removed according to a usual photolithography technique while adjusting the taper angle to form a resist pattern having an inversely tapered window-shaped opening 7. Formation of first wiring material layer: FIG. 4D: A protective wiring material, here chromium, is deposited on the resist pattern 3 having the inversely tapered opening 7 to form a layer 4 of the first wiring material. The thickness is about 800Å. When a chrome target (not shown) is placed at a distance of about 15 cm from the substrate 1 and the oblique sputtering method is performed, not only the upper surface of the resist pattern 3 but also the bottom and side surfaces of the opening of the pattern are completely covered with chrome. be able to. Formation of Second Wiring Material Layer: FIG. 4 (E) A main wiring material, here copper, is deposited on the resist pattern 3 in which the protective chromium layer 4 is deposited on the bottom and side surfaces of the opening 7, and the second wiring material layer is formed. The wiring material layer 5 is formed to have a film thickness of about 5 μm. When a copper target (not shown) is placed at a distance of about 40 cm from the substrate 1 and the oblique sputtering method is performed, a copper thin film 5 can be formed as shown in the figure. Formation of third wiring material layer: FIG. 4 (F) First wiring material layer (chrome) 4 and second wiring material layer (copper)
Further, the same wiring material for protection as the above-mentioned first wiring material, chromium, is deposited on the resist pattern 3 after coating 5 to form a layer 6 of the third wiring material with a film thickness of about 800 Å. Form. In forming this wiring layer, a chromium target (not shown) is arranged at a distance of about 40 cm from the substrate 1 and the oblique sputtering method is carried out, as in the case of forming the second wiring material layer described above. It is possible to form a thin film 6 of chrome. In this example, the first wiring material layer (chrome) 4, the second wiring material layer (copper) 5, and the third wiring material layer (chrome) 6 are collectively referred to as a metal wiring layer 10. Stripping of resist pattern: FIG. 4 (G) After completing the series of processes described above, resist pattern 3
Is removed by elution with a treatment liquid such as toluene. The unnecessary metal wiring layer 10 formed above the resist pattern 3 is peeled off (lifted off), and the metal wiring layer 10 corresponding to the desired wiring pattern is completed on the polyimide insulating layer 2 as illustrated. The metal wiring layer 10 is, as shown in the figure, the second wiring material layer 5 made of copper that constitutes the core thereof.
And a top surface of the second wiring material layer 5 and a first wiring material layer 4 which separates this layer from the underlying polyimide insulating layer 2 and also from an insulating layer (not shown) to be formed on the side surface. And a third insulating layer (not shown) for separating the second wiring material layer from the insulating layer (not shown) to be formed on the upper surface of the third wiring material layer.
And a wiring material layer 6.

After the metal wiring layer 10 is formed, the following steps such as the formation of an insulating layer can be carried out by a conventional method for forming the thin film multilayer circuit board of the present invention.

[0051]

The present invention will be described below with reference to its preferred embodiments. It should be understood that the present invention is not limited to the examples described below. Example 1 : Polyimide film thickness of 10 μm on a silicon wafer
Covered. Next, a cyclic olefin resin (manufactured by Zeon Corporation) having an epoxy modification rate of 1% by weight and containing a 4-fold molar amount of bisazide was applied in a film thickness of 15 μm. After placing a mask on the wiring pattern formation site of the obtained resist film,
Actinic rays from the exposure light source (365 nm: 80 mJ, 415
nm: 197 mJ, 436 nm: 150 mJ of ultraviolet light) 3
Irradiated for 0 seconds and developed with α-pinene. The wiring pattern forming portion of the film was dissolved and removed to obtain a groove having a width of 15 μm for forming a wiring.
Then, a 800 Å-thick chromium layer, a 3 μm-thick copper layer and a 800 Å-thick chromium layer were formed by oblique sputtering. As shown in FIG. 6A, on the resist film 3 having the opening 7 formed on the upper surface of the polyimide insulating layer 2 on the silicon wafer 1, the metal wiring layer including the opening 7 of the film is also included. 10 were formed. Metal wiring layer 1
Although not shown here, 0 is composed of three layers of a chromium layer, a copper layer, and a chromium layer, as shown in FIG. 5 (F). Subsequently, when the resist film used as the mask was peeled off with toluene and removed, only the wiring layer 10 remained on the polyimide insulating layer 2 as shown in FIG. 6 (B). Example 2 : The method described in Example 1 was repeated to form a resist pattern. However, in this example, one of the resist materials is used.
To evaluate how the degree of reverse taper of the opening of the resulting resist pattern changes by the change in the epoxy modification rate of the cyclic olefin resin used as a component and the change in the amount of bisazide used as a crosslinking agent,
When the epoxy modification rate is 0.08% by weight, the amount of bisazide used is 2.5 times or 4 times the molar amount of the epoxy group, and when the epoxy modification rate is 0.3% by weight, the amount of bisazide is the epoxy group. 0.625 times the molar amount, when the epoxy modification rate is 0.6% by weight, the amount of bisazide used is 0.312 times or 0.875 times the molar amount of the epoxy group, and the epoxy modification rate is 1.0% by weight. At that time, a resist pattern was formed by applying a combination in which the amount of bisazide used was 0.178 times the molar amount of the epoxy group. The cross-sectional shape of the obtained resist pattern was observed by a scanning electron microscope (SEM, 15
The result observed with (00 times) is shown in FIG. In the figure, the shaded area means the resist pattern, and E and BA respectively indicate the epoxy modification rate of the olefin resin and the amount of bisazide used. Example 3 : The resist pattern was formed by repeating the method described in Example 1 above. However, in this example, by additionally adding a dye capable of selectively absorbing actinic rays from the exposure light source into the resist material, it is examined how the degree of reverse taper of the opening of the obtained resist pattern is changed. For evaluation, resist patterns were formed by adding the following three kinds of dyes in an amount of 10% by weight based on the weight of the polymer or resin.

Dye A: EAB (λ _max = 345 nm) Dye B: Kayacol C (λ _max = 355 nm) Dye C: Oil Yellow GGS (λ _max = 415 nm) The cross-sectional shape of the obtained resist pattern was observed by a scanning electron microscope (SEM). , 150 times) and the results are shown in FIG. The shaded portion in the drawing means a resist pattern as in FIG. 7. Example 4 : The method described in Example 1 was repeated to form a resist pattern. However, in this example, in order to evaluate how the degree of reverse taper of the opening of the obtained resist pattern is changed by changing the wavelength of the actinic ray from the exposure light source before irradiating the resist film with the actinic ray. A resist pattern was formed by changing the wavelength of light rays as described using the following three types of filters.

U360 filter: 365 nm: 95 mJ,
415 nm: 54 mJ, 436 nm: 0 mJ) 407 Filter: 365 nm: 0 mJ, 415 nm: 234
mJ, 436 nm: 145 mJ) 436 filter: 365 nm: 0 mJ, 415 nm: 571
mJ, 436 nm: 808 mJ) FIG. 9 shows the results of observing the cross-sectional shape of the obtained resist pattern with a scanning electron microscope (SEM, 150 times). The shaded portion in the drawing means a resist pattern as in FIG. 7.

[0054]

As described above, according to the present invention, it is possible to easily form a thin film having a film thickness of about 10 μm, high heat resistance, high resolution, and an inversely tapered opening in the resist film. When opened, a resist material for pattern formation whose taper angle can be adjusted can be obtained. Further, since this resist material is suitable for the lift-off method, it can be advantageously used for manufacturing a thin film multilayer circuit board.

[Brief description of drawings]

1A to 1C are cross-sectional views sequentially showing formation of a metal wiring layer by a conventional method.

2A to 2C are cross-sectional views sequentially showing formation of a metal wiring layer by another conventional method.

3A to 3C are cross-sectional views sequentially showing formation of a metal wiring layer by still another conventional method.

4A to 4C are cross-sectional views sequentially showing a first half portion of formation of a metal wiring layer by the method of the present invention.

FIG. 5 is a cross-sectional view showing the latter half of the formation of a metal wiring layer by the method of the present invention step by step.

FIG. 6 is a cross-sectional view showing a resist pattern obtained in the step of forming a metal wiring layer of Example 1 of the present specification before and after the peeling.

FIG. 7 is a cross-sectional view showing various resist patterns obtained in the metal wiring layer forming step of Example 2 of the present specification.

FIG. 8 is a cross-sectional view showing various resist patterns obtained in the metal wiring layer forming step of Example 3 of the present specification.

FIG. 9 is a cross-sectional view showing various resist patterns obtained in the metal wiring layer forming step of Example 4 of the present specification.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Substrate 2 ... Insulating layer 3 ... Resist film 4 ... 1st wiring material layer 5 ... 2nd wiring material layer 6 ... 3rd wiring material layer 7 ... Window-shaped opening 10 ... Metal wiring layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshikatsu Ishizuki 1015 Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Within Fujitsu Limited (72) Inventor Minoru Takeshi, 1015 Kamiodanaka, Nakahara-ku, Kawasaki, Kanagawa Prefecture Fujitsu Limited (72) Inventor Masami Koshiyama 1-2-1, Yokou, Kawasaki-ku, Kawasaki-shi, Kanagawa Inside Zeon Corporation R & D Center (72) Eiko Yuda 1-2-1, Yokou, Kawasaki-ku, Kawasaki, Kanagawa Japan (72) Inventor Hideaki Kataoka 1-2-1 Yokou, Kawasaki-ku, Kawasaki-shi, Kanagawa Inside Zeon Corporation, R & D Center

Claims (13)

[Claims] 1. A resist material for pattern formation, comprising a cyclic olefin resin modified with an epoxy group and a crosslinking agent capable of photo-crosslinking the cyclic olefin resin. 2. The resist material according to claim 1, wherein the cyclic olefin-based resin is an epoxy-modified thermoplastic norbornene-based resin obtained by introducing an epoxy group into a thermoplastic norbornene-based resin. 3. The epoxy modification rate of the cyclic olefin-based resin is 0.05 to 2% by weight, which is expressed by weight% of oxygen of epoxy group based on the weight of the resin.
The resist material according to 1. 4. The cross-linking agent is a bisazide compound,
The resist material according to any one of claims 1 to 3, which is contained in a molar amount of 0.05 to 10 times the molar amount of epoxy groups contained in the cyclic olefin resin. 5. The resist material according to claim 1, further comprising a dye. 6. The resist material according to claim 1, wherein when forming a resist pattern, the taper angle of the obtained resist pattern can be adjusted by adjusting the wavelength of the exposure light source used. . 7. The resist material according to claim 1, which is used for producing a thin film multilayer circuit board by using a lift-off method. 8. A thin film multi-layer having a structure in which insulating layers and wiring layers are alternately laminated and having a structure capable of preventing the layer constituent material of the wiring layers included therein from diffusing into the insulating layer adjacent to the wiring layers. A method of manufacturing a circuit board, comprising the step of forming a resist pattern by a lift-off method using a cyclic olefin resin modified with an epoxy group and a resist material containing a crosslinking agent capable of photocrosslinking the cyclic olefin resin. A method for manufacturing a thin film multilayer circuit board, comprising: 9. The following steps: forming an insulating layer on a substrate, applying the resist material on the insulating layer to form a resist film, and adjusting a taper angle at a wiring pattern forming portion of the resist film. To form a resist pattern having an inversely tapered window-like opening, and forming a layer of the first wiring material on the resist pattern so as to cover the bottom surface and the side surface of the opening of the pattern, A second wiring material layer is formed on the first wiring material layer so as to cover at least the bottom surface of the opening of the resist pattern, and the second wiring material layer is further formed on the second wiring material layer. Forming a layer of a third wiring material made of the same or different wiring material as the first wiring material, and removing the resist pattern together with the wiring material layer formed thereabove. 8 Method of manufacturing a thin film multi-layer circuit board according. 10. The epoxy modification rate of the cyclic olefin resin modified with the epoxy group is 0.05 to 2% by weight.
10. The taper angle of the inverse taper window-shaped opening of the obtained resist pattern is adjusted by adjusting in the range of (weight% of oxygen of epoxy group to weight of cyclic olefin resin). Method for manufacturing thin film multilayer circuit board. 11. A bisazide compound is used as the cross-linking agent, and the bisazide compound is used in an amount of 0.05 to 10 times the molar amount of the epoxy group contained in the cyclic olefin resin. By adjusting
The method for manufacturing a thin film multilayer circuit board according to claim 8 or 9, wherein the taper angle of the inversely tapered window-like opening of the obtained resist pattern is adjusted. 12. The taper angle of an inversely tapered window-like opening of a resist pattern to be obtained is adjusted by further using a dye in the resist material and adjusting the type and amount of the dye used. Or a method of manufacturing the thin-film multilayer circuit board according to item 9. 13. The taper angle of an inversely tapered window-like opening of the obtained resist pattern is adjusted by adjusting the wavelength of the exposure light source used when forming the resist pattern. Method for manufacturing thin film multilayer circuit board.