JPH07161935A - Inductor and its manufacture - Google Patents

Abstract

PURPOSE:To simplify a formation process of a magnetic substance layer when forming an inductor comprised of lamination of a conductor layer and a magnetic substance layer on a semiconductor substrate. CONSTITUTION:A photopolymerizing organic monomer layer 2 having side chains of an electron donating group and/or an electron accepting group, which supplies or accepts electrons when irradiated with light, is provided on a semiconductor substrate 1. A required pattern of light is cast on the layer 2 to harden by photopolymerization and a conductor layer 5 of a required pattern is formed on the set layer 3 to overlap each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inductor formed of a conductor on a semiconductor substrate in a coil shape, and more particularly to an inductor having a ferromagnetic material layer on both upper and lower surfaces or one surface of a conductor and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, it has been known to provide an inductor composed of a coil-shaped conductor and a ferromagnetic layer laminated on both sides or one side of the conductor on a semiconductor substrate. A metal layer is used as the conductor layer, a sendust alloy or ferrite vapor-deposited layer is used as the ferromagnetic layer, or an ink layer in which ferromagnetic powder is dispersed in a binder is used. The pattern is provided on the substrate.

[0003]

In order to form a conductor layer or a ferromagnetic material layer by photolithography, several steps are required for each layer, and therefore, for example, ferromagnetic material layer-conductor layer-ferromagnetic material. Manufacturing an inductor having a three-layer structure of three layers requires ten steps or more, which is extremely troublesome.
The present invention is intended to reduce the number of manufacturing steps of an inductor having a three-layer structure of a ferromagnetic layer-a conductor layer-a ferromagnetic layer, or a two-layer structure of a conductor layer-a ferromagnetic layer. .

[0004]

The present invention is characterized in that a photo-curable magnetic material is used as a ferromagnetic layer laminated on a conductor layer forming a current path of an inductor. Materials suitable for this application include photopolymerizable monomers containing at least one of an electron donating group or an electron accepting group as a functional group in the molecule.

Examples of the above-mentioned photopolymerizable monomer include those containing a diacetylene group or a vinyl group which is polymerized by light to form a polydiacetylene bond. This photopolymerizable monomer can be used as any photoreactive group as long as it photopolymerizes. However, a compound that forms a π-conjugated bond such as a polydiacetylene bond is a magnetic substance in an organic ferromagnetic material. Desirable from the standpoint of functional function.

The functional group which emits an electron upon irradiation with light, that is, an electron-donating group, which is used in the present invention, releases an electron upon irradiation with light, and the cation radical formed by releasing the electron is used during the photopolymerization reaction. Any functional group can be used as long as it can exist stably. Specifically, a functional group having a triphenyl group, dibutylamine,
Aliphatic typified by substituted amines such as dipropylamine and diisopropylamine, anthracene, benzoanthracene, substituted benzoanthracene, dibenzanthracene, bicene, pyrene, benzopyrene, dibenzopyrene,
Carbocyclic aromatic functional groups such as phenylenediamine, heterocyclic functional groups such as pyrocholine, thiophene, substituted thiophene, furan, substituted furan, pyrrole, and substituted pyrrole, carbazole, and charge transfer complexes such as tetrathiafulvalene and its derivatives. And a functional group that forms Of course, the compounds are not limited to these compounds, and derivatives of these functional groups or functional groups obtained by combining two or more kinds of these functional groups may be used.

The functional group that accepts electrons upon irradiation with light, that is, the electron-accepting group used in the present invention, accepts electrons emitted upon irradiation with light, and the anion radicals formed by accepting the electrons undergo photopolymerization. Any functional group can be used as long as it can exist stably during the reaction. Specifically, aliphatic functional groups such as acrylic acid, acetamide, and ethylene oxide, carbocyclic aromatic functional groups such as nitrobenzene, and functional groups composed of benzoquinone derivatives such as benzoquinone and tetracyano-P-benzoquinone, tetracyanoethylene. And a functional group forming a charge transfer complex such as a functional group formed of tetracyanoquinodimethane and a derivative thereof. Of course, the functional groups are not limited to these functional groups, and a derivative of these functional groups or a functional group formed by combining two or more kinds of these functional groups and combining them may be used.

In the present invention, it is desirable that both the electron donating group and the electron accepting group cause electron donation and acceptance by light irradiation, but at least one of the functional groups is responsible for electron donation or acceptance. You can wake it up. Therefore, at least one of an electron-donating or electron-accepting functional group may be included in the molecule.

In the present invention, an uncured material such as the above-mentioned photo-curable ferromagnetic organic monomer is applied on a semiconductor substrate or a conductor layer formed on the semiconductor substrate to apply a light having a required pattern thereto. By irradiating and curing only that portion and removing the uncured portion with a solvent or the like, a magnetic material layer having a required pattern is formed.

[0010]

[Function] When a thin layer of the above-mentioned photo-curable ferromagnetic organic material is provided on a semiconductor substrate and exposed in a desired pattern by photoengraving technology, only the required portion is cured, so the uncured portion should be removed with a solvent. Thus, the first ferromagnetic material layer having a required pattern is formed.

Next, a well-known photoresist material is applied to the entire surface of the semiconductor substrate including the ferromagnetic material layer, and a mask is formed by photolithography to form a coil-shaped conductor layer on the first ferromagnetic material layer. To form.

Again, a thin layer of a photocurable ferromagnetic organic material is provided on the entire surface of the semiconductor substrate, and this is exposed in a desired pattern,
By removing the unexposed portion and forming the second ferromagnetic material layer, a coil made of a conductor sandwiched between layers of a ferromagnetic organic material can be obtained. One of the first and second ferromagnetic material layers can be omitted.

Therefore, when forming the first and second ferromagnetic material layers having a desired pattern, the desired pattern can be obtained by exposing itself, and thus the conventionally required pattern is obtained. Therefore, the step of applying the photoresist layer, which has been adopted for this purpose, can be omitted.

In the above-described photosensitization process, the electron-donating group and the electron-accepting group of the photopolymerizable monomer are irradiated with light having an appropriate wavelength to release electrons from the former and change into cation radicals, and the latter to It accepts the electron and changes into an anion radical. Since the irradiation light is required to selectively cause such a photoelectron transfer reaction, a laser beam light excellent in monochromaticity, directivity and time controllability is desirable. Further, when applying an electric field or a magnetic field during the above-mentioned light irradiation,
The presence of the generated cation radical and anion radical can be stabilized.

Simultaneously with or after irradiation with light for the above-mentioned photoelectron transfer reaction, the monomer is photopolymerized while retaining the above-mentioned cation radicals and anion radicals by irradiating with light having another appropriate wavelength. It reacts and hardens. Continuing to apply the above-mentioned electric field or magnetic field from the time when the above-mentioned photoelectron transfer reaction is performed to the time when the photopolymerization reaction is completed is useful in fixing the state of holding cation radicals and anion radicals.

The organic matter polymerized and cured as described above is
Since it holds cation radicals and anion radicals in a stable state, it has a high magnetic function and contributes to increasing the inductance of the conductor coil.

[0017]

EXAMPLE A photopolymerizable diacetylene monomer having an electron-donating group and an electron-accepting group was diluted with a suitable solvent and coated on a semiconductor substrate 1, which was then dried to obtain an uncoated layer as shown in FIG. Make a hardened layer 2. When this layer 2 is irradiated with a required pattern of light for photoelectron transfer reaction and light for polymerization reaction, only the irradiated portion is polymerized and converted into a polydiacetylene compound, which is hardened. By washing away with a solvent, the hardened layers 3, 3, ... With a required pattern as shown in FIG. 1B are obtained.

The uncured layer 2 causes the following reaction by irradiation with light. The diacetylene compound monomer molecules 21, 21 ... Shown in FIG. 3A are each composed of a diacetylene group 24 having an electron donating group 22 and an electron accepting group 23 as side chains. When this is irradiated with light for photoelectron transfer, as shown in FIG.
Emits an electron and changes into a cation radical 25, and the electron accepting group 23 receives the released electron and changes into an anion radical 26.

Next, when it is irradiated with light for photopolymerization,
As shown in FIG. 3C, the diacetylene group 24 undergoes a polymerization reaction while retaining the cation radical 25 and the anion radical 26, and is converted into a polydiacetylene compound 27. The polydiacetylene compound 27 has a cation radical 25 and an anion radical 26,
Since the cation radical 25 and the anion radical are located at the side chain positions of the compound 27, they can exist stably even after the light irradiation is stopped, and exhibit a high magnetic function.

The light for the photoelectron transfer reaction and the light for the polymerization reaction may be simultaneously irradiated. Further, if a strong electric field or magnetic field is applied during irradiation, the retained state of the generated cation radicals and anion radicals can be further stabilized by the Zeeman effect or the like.

On the substrate 1, mask layers 4, 4 ... With a required pattern are formed as shown in FIG. 1 (d) and 2 through the mask layer by plating
The conductor layers 5, 5 ... Shown in FIG.
4 ... is removed. Note that FIG. 1D is a cross-sectional view taken along the line D-D in FIG.

An insulating layer 6 is placed at the intersection of the conductors, a mask is again made of photoresist, and as shown in FIG. 1 (e), it overlaps most of the conductor layers 5, 5 ... The conductor layers 7, 7 ... Are made. Then, the uncured layer 2 is formed on the entire surface of the substrate 1 from above, as shown in FIG.
1 (g) and FIG. 1 (g) and FIG. 1 (g) are obtained by forming an uncured layer 8 similar to that of FIG. The cured layers 9, 9 ... Having a pattern as shown in FIG.
Is obtained. It should be noted that FIG. 1 (g) corresponds to G in FIG. 2 (b).
It is sectional drawing which follows the -G line.

As is apparent from FIGS. 1 (g) and 2 (b), the coil made of the conductor layers 7, 7 ... Has both sides of the ferromagnetic organic material layers 3, 3 and 9, 9.・ Because it is sandwiched by ・ ・, its inductance can be increased.

FIG. 4 shows another example of the photo-curable ferromagnetic organic material. In FIG. 4 (a), the diacetylene compound monomers 31, 31 ... Include the diacetylene group 32, the electron donating group 33, the electron accepting group 34, and the diacetylene group 32 as the electron donating group 33 and the electron accepting group, respectively. It consists of spacers 35 and 36 which are attached to a base 34.

The spacers 35 and 36 carry the electrons emitted from the electron donating group 33 to the electron accepting group 34 only when irradiated with light for photoelectron transfer reaction, and specifically, include oxygen, sulfur and selenium. Group 6 elements such as and carbon number 6
The following are single-bonding functional groups such as methylene group.

This diacetylene compound monomer has an electron donating group 33 unless the light for photoelectron transfer reaction is irradiated.
It is impossible to transfer the electrons emitted by the electron acceptor group 34. However, when it is irradiated with light for a photoelectron transfer reaction having an appropriate wavelength, the electron released from the electron donating group 33 is carried to the electron accepting group 34, and as shown in FIG. Radicals 38 are generated.

Then, when light for photopolymerization reaction having an appropriate wavelength is irradiated, the diacetylene group 32 becomes a cation radical 37 and an anion radical 3 as shown in FIG. 4 (c).
Polydiacetylene compound 39 polymerized to retain 8
Changes to. Similar to the compound shown in FIG. 3, this compound also exhibits excellent magnetic performance due to the cation radicals and anion radicals that are stably present.

[0028]

As described above, according to the present invention,
Since a photo-curable organic material was used as the ferromagnetic material layer for increasing the inductance of the coil formed of the conductor layer, the process for directly applying the photoengraving technique to obtain the ferromagnetic material layer of the desired pattern. Can be simplified.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing each manufacturing process of an inductor embodying the present invention.

FIG. 2 is a plan view of the inductor during manufacturing and a finished product.

FIG. 3 is an explanatory diagram of a changed state of the photopolymerizable ferromagnetic organic material used in the examples of the present invention by light irradiation.

FIG. 4 is an explanatory view of a change state of a photopolymerizable ferromagnetic organic material used in another example of the present invention by light irradiation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Semiconductor substrate 3 Hardened layer of photopolymerizable ferromagnetic organic material 5 Conductor layer 7 Conductor layer 9 Hardened layer of photopolymerizable ferromagnetic organic material 21 Diacetylene compound monomer 22 Electron donating group 23 Electron accepting group 24 Diacetylene group 25 Cation radical 26 Anion radical 27 Diacetylene compound polymer

Claims (4)

[Claims] 1. A conductor layer formed in a coil pattern on a semiconductor substrate, and a magnetic material layer laminated on both upper and lower surfaces of the conductor layer or on one surface thereof. The magnetic material layer is a photocurable strong layer. An inductor characterized by being a photo-cured layer of a magnetic organic material. 2. A step of applying an uncured material of a photocurable ferromagnetic organic material on a semiconductor substrate, and a step of exposing the coating layer to a desired pattern to cure it and removing the uncured portion,
And a step of forming a conductor layer having a coil-shaped pattern on the remaining hardened layer. 3. A step of forming a conductor layer having a coil-shaped pattern on a semiconductor substrate, a step of covering the conductor layer and applying an uncured material of a photocurable ferromagnetic organic material on the semiconductor substrate, A method of manufacturing an inductor, comprising the steps of exposing at least a portion of the coating layer overlapping the conductive layer to cure and removing an uncured portion. 4. The uncured product of the photocurable ferromagnetic organic material is a photocurable compound having a photoelectron-donating group that emits an electron upon irradiation with light and an electron-accepting group that accepts an electron upon irradiation with light in a side chain. 4. The method for manufacturing an inductor according to claim 2, wherein the inductor is a polymerizable organic monomer.