JPH0817656A - Magnetic shielding method and magnetic shielding film forming method of semiconductor device - Google Patents

Abstract

PURPOSE:To minimize the external magnetic effect from inductor conductors formed on a semiconductor substrate. CONSTITUTION:Two inductor conductors 12, 14 are formed on the adjacent positions on the surface of a semiconductor substrate 10. The inductor conductors 12, 14 are respectively covered with magnetic bodies 16, 18. In such a constitution, the magnetic fluxes generated by respective inductor conductors 12, 14 are distributed using the magnetic bodies 16, 18 respectively covering said conductors 12, 14 as the magnetic paths so that the magnetic fluxes of the magnetic bodies 16, 18 may be hardly leaked externally thereby enabling the magnetic effect of respective inductor conductors 12, 14 on any external elements as well as the magnetic coupling with mutual inductor conductors 12, 14 to be avoided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic shield system and a magnetic shield film forming method for a semiconductor device for magnetically shielding an inductor conductor formed on a semiconductor substrate.

[0002]

2. Description of the Related Art Generally, a coil is an important circuit component, and it can be said that it is an indispensable component depending on the circuit to be configured. For example, an oscillation circuit utilizing LC resonance and a tuning circuit included in a transceiver can be realized only by using a coil.

By the way, since the magnetic flux is generated by the coil included in the circuit described above, it is necessary to design so that the generated magnetic flux does not affect the surrounding components. For example, when it is necessary to dispose two coils apart from each other or to dispose two or more coils close to each other on a printed wiring board, it is necessary to devise a coil disposition in consideration of the magnetic flux direction. There is.

FIG. 11 is a view in which the arrangement direction is devised when the three coils are arranged adjacent to each other. As shown in the figure, adjacent coils are arranged such that the coils differ from each other by 90 degrees, that is, the magnetic fluxes generated by the adjacent coils are orthogonal to each other. Thus, by making the magnetic fluxes generated by the adjacent coils orthogonal to each other, the magnetic coupling between the coils can be minimized.

[0005]

By the way, as described above, the conventional method for making the magnetic fluxes generated by making the arrangement direction of the coils orthogonal to each other and minimizing the magnetic coupling between the coils is a printed wiring board. Only when the coil is placed on top.

On the other hand, when a spiral inductor conductor is formed on a semiconductor substrate by using a thin film forming technique, the direction of magnetic flux generation is limited to the direction perpendicular to the semiconductor substrate. Therefore, the coils formed by the inductor conductors formed close to each other are magnetically coupled to each other, which is not preferable when the circuit elements are to be electrically separated. In particular, when forming a passive element such as an inductor conductor together with various active elements using a semiconductor substrate, the entire circuit is downsized by semiconductor manufacturing technology. It is difficult to place them apart.

FIG. 12 is a diagram for explaining the magnetic flux generated by the inductor conductor formed on the semiconductor substrate. As shown in the figure, for example, spiral inductor conductors 102 and 104 are formed on the surface of the semiconductor substrate 100. Therefore, when a predetermined current is applied to the coil formed by the inductor conductor 102, a magnetic flux is generated in a direction substantially perpendicular to the surface of the semiconductor substrate 100 as indicated by an arrow a in the figure. Also, the two inductor conductors 102, 10
Since 4 is formed adjacent to the surface of the semiconductor substrate 100, the magnetic flux generated by the inductor conductor 102 intersects the inductor conductor 104 almost vertically.
The two inductor conductors 102 and 104 are magnetically coupled to each other.

Therefore, when a plurality of adjacent inductor conductors are arranged adjacent to each other on the semiconductor substrate as described above, it is desired to perform some magnetic shield between the inductor conductors. Further, even when one inductor conductor is formed, it is still desirable to minimize the magnetic influence on other elements and the like.

The present invention has been made in view of the above points, and an object thereof is a semiconductor capable of minimizing a magnetic influence from an inductor conductor formed on a semiconductor substrate to the outside. The present invention relates to a magnetic shield method and a magnetic shield film forming method for an apparatus.

[0010]

In order to solve the above-mentioned problems, a magnetic shield system for a semiconductor device according to claim 1 is
The inductor conductor formed in a substantially flat shape on the semiconductor substrate is covered with an insulating magnetic material to magnetically shield the inductor conductor.

According to a second aspect of the magnetic shield system of the semiconductor device, the inductor conductor formed on the semiconductor substrate in a substantially planar shape is covered with a conductive magnetic material via an insulating film to shield the inductor conductor from the magnetic field. It is characterized by performing.

According to a third aspect of the magnetic shield system of the semiconductor device, the plurality of inductor conductors formed in a substantially flat shape at the adjacent positions on the semiconductor substrate are individually covered with an insulating magnetic material to form the plurality of inductor conductors. The magnetic insulation between the inductor conductors is performed.

According to another aspect of the magnetic shield method of the semiconductor device of the present invention, each of the plurality of inductor conductors formed in a substantially flat shape at adjacent positions on the semiconductor substrate is individually covered with a conductive magnetic material via an insulating film. Thus, magnetic insulation is performed between the plurality of inductor conductors.

According to a fifth aspect of the present invention, there is provided a magnetic shield system for a semiconductor device according to any one of the first to fourth aspects, wherein the magnetic body is
A first magnetic film formed on the surface of the semiconductor substrate and between the inductor conductor and a first magnetic film formed on the surface of the inductor conductor and substantially opposite to the first magnetic film. It is characterized in that it is composed of a second magnetic film.

According to a sixth aspect of the present invention, there is provided a magnetic shield system for a semiconductor device according to any one of the first to fourth aspects.
It is characterized in that it is formed of a first magnetic film formed on the surface of the semiconductor substrate and between the inductor conductor.

A magnetic shield system for a semiconductor device according to a seventh aspect is the magnetic shield method according to any one of the first to fourth aspects, wherein:
It is characterized by comprising a second magnetic film formed further on the front surface side of the inductor conductor formed on the semiconductor substrate.

A magnetic shield system for a semiconductor device according to claim 8 is the magnetic shield system according to claim 3 or 4, wherein the plurality of magnetic bodies covering the plurality of inductor conductors are the surface of the semiconductor substrate and the semiconductor substrate and the plurality of magnetic bodies. And a plurality of second magnetic material films formed so as to individually cover the respective surface sides of the plurality of inductor conductors. It is characterized by

According to a ninth aspect of the present invention, there is provided a magnetic shield system for a semiconductor device according to the third or fourth aspect, wherein the plurality of magnetic bodies covering the plurality of inductor conductors are the surface of the semiconductor substrate and the semiconductor substrate and the plurality of magnetic bodies. A first magnetic film formed individually between the inductor conductor and each of the inductor conductors,
And a second magnetic film formed so as to commonly cover the front surfaces of the plurality of inductor conductors.

According to a tenth aspect of the present invention, there is provided a magnetic shield film forming method for a semiconductor device, wherein a first step of forming a first insulating magnetic material film on a semiconductor substrate and a step of adjoining the surface of the first insulating magnetic material film. A second step of forming one or a plurality of inductor conductors at the selected positions, a third step of forming a second insulating magnetic film so as to cover the one or a plurality of inductor conductors, and the one or more A fourth step of removing both the first and second insulating magnetic material films or only the second insulating magnetic material film formed on the peripheral portions of the inductor conductor of Alternatively, magnetic shielding is performed by the insulating magnetic film formed corresponding to each of the plurality of inductor conductors.

The method of forming a magnetic shield film for a semiconductor device according to claim 11 includes a first step of forming one or a plurality of inductor conductors at adjacent positions on a semiconductor substrate directly or via a first insulating film. Second, forming an insulating magnetic film to cover the one or more inductor conductors
And a third step of removing the insulating magnetic film formed on the peripheral portion of each of the one or more inductor conductors, and corresponding to each of the one or more inductor conductors. Magnetic shielding is performed by the insulating magnetic film formed as described above.

According to a twelfth aspect of the present invention, there is provided a method of forming a magnetic shield film for a semiconductor device, comprising: a first step of forming an insulating magnetic material film on a semiconductor substrate; A second step of forming one or a plurality of inductor conductors; and a third step of removing the insulating magnetic film formed on the peripheral portions of the one or a plurality of inductor conductors, respectively. It is characterized in that magnetic shielding is performed by the insulating magnetic film formed corresponding to each of one or a plurality of inductor conductors.

According to a thirteenth aspect of the present invention, there is provided a magnetic shield film forming method for a semiconductor device, comprising: a first step of forming a first conductive magnetic material film on a semiconductor substrate; and a surface of the first conductive magnetic material film. A second step of forming a first insulating film; a third step of forming one or a plurality of inductor conductors on the surface of the first insulating film and adjacent to each other; A fourth step of forming a second insulating film on the surface of the inductor conductor, and a second conductive magnetic film so that the second insulating film covers the one or more inductor conductors formed on the surface. The fifth step of forming
Alternatively, a sixth step of removing both the first and second conductive magnetic films or only the second conductive magnetic film formed on the peripheral portions of the plurality of inductor conductors, Magnetic shielding is performed by the conductive magnetic film formed corresponding to each of the one or a plurality of inductor conductors.

According to a fourteenth aspect of the present invention, there is provided a method of forming a magnetic shield film for a semiconductor device, which comprises a first step of forming one or a plurality of inductor conductors at adjacent positions on a semiconductor substrate directly or via a first insulating film. A second step of forming a second insulating film on the surface of the one or more inductor conductors, and a conductive magnetic layer so as to cover the one or more inductor conductors formed on the surface of the second insulating film. The method further comprises a third step of forming a body film and a fourth step of removing the insulating magnetic film formed on the peripheral portion of each of the one or more inductor conductors. It is characterized in that magnetic shielding is performed by the conductive magnetic film formed corresponding to each of the inductor conductors.

According to a fifteenth aspect of the present invention, there is provided a method of forming a magnetic shield film for a semiconductor device, comprising: a first step of forming a conductive magnetic film on a semiconductor substrate; and a step of forming an insulating film on a surface of the conductive magnetic film. The second step, the third step of forming one or a plurality of inductor conductors on the surface of the insulating film at a position adjacent to the insulating film, and the third step of forming one or a plurality of inductor conductors around the inductor conductors. And a fourth step of removing the conductive magnetic material film, wherein the magnetic shielding is performed by the conductive magnetic material film formed corresponding to each of the one or the plurality of inductor conductors.

A method for forming a magnetic shield film for a semiconductor device according to a sixteenth aspect is the method according to any one of the tenth to fifteenth aspects, wherein the insulating magnetic substance film or the conductive magnetic substance film is formed by a thin film forming technique. Characterize.

A magnetic shield film forming method for a semiconductor device according to a seventeenth aspect is the method according to any one of the tenth to fifteenth aspects, wherein the insulating magnetic substance film or the conductive magnetic substance film is removed by etching or laser light irradiation. It is characterized by performing.

[0027]

According to the invention of claim 1 or 3, the inductor conductor formed in a substantially flat shape on the semiconductor substrate is covered with the insulating magnetic material. Therefore, the magnetic flux generated when the inductor conductor is energized will be distributed as a magnetic path through this insulating magnetic material, and will not leak to the outside of the insulating magnetic material that covers the inductor conductor. The magnetic effect of can be minimized. Particularly, in the third aspect, since the plurality of inductor conductors are formed on the semiconductor substrate and are individually magnetically shielded, it is possible to prevent magnetic coupling between the adjacent inductors.

Further, in the invention of claim 2 or 4, the inductor conductor formed on the semiconductor substrate is covered with the conductive magnetic material via the insulating film. Therefore, the electrical insulation between the inductor conductor and the conductive magnetic body is ensured by the insulating film, and the magnetic flux generated when the inductor conductor is energized should be distributed as a magnetic path through the conductive magnetic body. Therefore, the conductive magnetic material covering the inductor conductor hardly leaks to the outside, so that the magnetic influence on the outside can be minimized. In particular, claim 4
In, since a plurality of inductor conductors are formed on the semiconductor substrate and are individually magnetically shielded, it is possible to prevent magnetic coupling between adjacent inductors.

Further, in the invention of claim 5, the above-mentioned insulating or conductive magnetic body is constituted by the first and second magnetic body films, and the inductor is formed by these first and second magnetic body films. The conductor is sandwiched. Therefore, a magnetic path is formed by these first and second magnetic films, and the magnetic flux generated by energizing the inductor conductor causes the magnetic flux of the first magnetic film and the second magnetic film forming the magnetic path. It returns to the inductor conductor again through the inside, and the leakage of magnetic flux to the outside is almost eliminated.

Further, in the invention of claim 6, the above-mentioned insulating or conductive magnetic material is constituted only by the first magnetic material film used in claim 5, and the first magnetic material film is formed. It is interposed between the inductor conductor and the semiconductor substrate. Therefore, a magnetic path is formed so as to pass through the first magnetic film formed along the inductor conductor, and the magnetic flux is not distributed to the portion far from the inductor conductor, so that the magnetic flux from the inductor conductor to the outside is not distributed. Almost no leakage.

Further, in the invention of claim 7, the above-mentioned insulating or conductive magnetic material is constituted only by the second magnetic material film used in claim 5, and the second magnetic material film is formed. It is formed further on the front surface side of the inductor conductor formed on the semiconductor substrate. Therefore, as in the sixth aspect, a magnetic path is formed so as to pass through the second magnetic film formed along the inductor conductor, and the magnetic flux is not distributed to a portion distant from the inductor conductor. There is almost no leakage of magnetic flux from the conductor to the outside.

According to the invention of claim 8 or 9, when a plurality of inductor conductors are formed on a semiconductor substrate, one of the first and second magnetic substance films formed so as to sandwich each inductor conductor is provided. Are formed so as to be continuous along each inductor conductor. As described above, even when one magnetic material film is continuous without interruption, by covering each inductor conductor individually with the other magnetic material film, the other magnetic material formed so as to be covered individually. A magnetic path is formed through the membrane. Therefore, there is almost no leakage of magnetic flux from the inductor conductors to the outside, and the inductor conductors are not magnetically coupled to each other.

According to the tenth aspect of the invention, after the first insulating magnetic film is formed on the semiconductor substrate, one or a plurality of inductor conductors are formed, and the second conductor is formed so as to cover the whole of them. By forming an insulating magnetic film, and finally removing the insulating magnetic film around the inductor conductor,
An insulating magnetic film is formed to cover each inductor conductor individually. Therefore, regardless of the number of inductor conductors arranged adjacent to each other, the first and second inductor conductors that entirely cover the inductor conductors are provided.
It suffices to form the insulative magnetic material film, and the manufacturing process can be simplified.

In the eleventh aspect of the present invention, after forming one or a plurality of inductor conductors on the semiconductor substrate, an insulating magnetic film is formed so as to cover the whole of them, and finally, insulation around the inductor conductors is performed. By removing the conductive magnetic material film, an insulating magnetic material film is formed by individually covering each inductor conductor from one side. Therefore, regardless of the number of inductor conductors arranged adjacent to each other, it suffices to form the insulating magnetic film that entirely covers one side of the inductor conductors, and the manufacturing process can be simplified.

According to the twelfth aspect of the invention, after the insulating magnetic film is formed on the semiconductor substrate, one or a plurality of inductor conductors are formed thereon, and finally the insulating magnetic film around the inductor conductor is formed. Is removed to form an insulating magnetic film individually interposed on one side of each inductor conductor. Therefore, regardless of the number of inductor conductors arranged adjacent to each other, it suffices to form the insulative magnetic film covering the surface of the semiconductor substrate over a wide range, and the manufacturing process can be simplified.

In the inventions of claims 13 to 15, the insulating magnetic film used in claims 10 to 12 is replaced with a conductive magnetic film, and the conductive magnetic film is formed on the surface of the inductor conductor. An insulating film for electrical insulation is interposed. Therefore, as in the case of claims 10 to 12, regardless of the number of inductor conductors arranged adjacent to each other, it is sufficient to form the conductive magnetic film covering the whole or one side of the inductor conductors, which simplifies the manufacturing process. Is possible.

In the sixteenth aspect of the invention, the above-mentioned insulating magnetic substance film or conductive magnetic substance film is formed by the thin film forming technique. Therefore, even when a microminiature inductor conductor is formed on a semiconductor substrate such as an IC or LSI, the film can be easily formed.

According to the seventeenth aspect of the invention, the insulating magnetic film or the conductive magnetic film described above is removed by etching or laser light irradiation, so that fine processing can be easily performed.

[0039]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A semiconductor device according to an embodiment to which the magnetic shield method and the magnetic shield film forming method for a semiconductor device of the present invention are applied will be specifically described below with reference to the drawings.

FIG. 1 is a diagram schematically showing an embodiment of magnetically shielding two inductor conductors formed at adjacent positions on a semiconductor substrate.

In the semiconductor substrate 10 of this embodiment, two inductor conductors 12 and 14 are formed at adjacent positions on the surface thereof. Moreover, one inductor conductor 12 is covered with the insulating magnetic material 16, and the other inductor conductor 14 is covered with the insulating magnetic material 18.

For the semiconductor substrate 10 described above, for example, an n-type silicon substrate (n-Si substrate) or another semiconductor material (for example, an amorphous material such as germanium or amorphous silicon) is used. Further, each of the inductor conductors 12 and 14 is formed of a metal thin film such as aluminum or gold or a semiconductor material such as polysilicon in a spiral shape or a meandering shape.

The semiconductor substrate 10 shown in FIG.
In addition to the two inductor conductors 12 and 14, active elements such as transistors and diodes and passive elements such as resistors and capacitors are formed.
Although 14 and other elements are wired to form an IC, LSI or the like, for simplicity of explanation, only the inductor conductors 12 and 14 are shown in the drawing.

FIG. 2 is a view showing a cross section of the inductor conductor portion shown in FIG.

In FIG. 2, one inductor conductor 12
Focusing on the vicinity, the inductor conductor 12 is formed on the surface of the semiconductor substrate 10 via the insulating magnetic film 16a, and the insulating magnetic film 16b is further formed on the surface of the inductor conductor 12. The magnetic body 16 shown in FIG. 1 is configured by these two magnetic body films 16a and 16b.

Similarly, focusing on the vicinity of the other inductor conductor 14, the insulating magnetic film 1 is formed on the surface of the semiconductor substrate 10.
An inductor conductor 14 is formed via 8a, and an insulating magnetic film 18b is formed on the surface of the inductor conductor 14 so as to cover it. These two magnetic films 18a and 18b form the magnetic body 18 shown in FIG.

FIG. 3 is a diagram showing the flow of magnetic flux in the vicinity of the inductor conductor shown in FIG.
It is the figure which expanded the cross section of 2 vicinity.

As shown in the figure, the inductor conductor 12 is covered with the magnetic films 16a and 16b formed on both sides, and the magnetic path is formed by these two magnetic films 16a and 16b. Therefore, the inductor conductor 12
The magnetic flux generated in a direction almost perpendicular to the inductor conductor 1 passes through the insides of these two magnetic films 16a and 16b again.
Come back to 2. Therefore, the leakage of the magnetic flux to the outside of the magnetic films 16a and 16b can be reduced, and the external influence of the magnetic flux generated by the inductor conductor 12 can be minimized.

The same applies to the other inductor conductor 14, and the magnetic flux generated in a direction substantially perpendicular to the inductor conductor 14 returns to the inductor conductor 14 again through the inside of these two magnetic films 18a and 18b. come. Therefore, the leakage of the magnetic flux to the outside of the magnetic films 18a and 18b can be reduced, and the influence of the magnetic flux generated by the inductor conductor 14 on the outside can be minimized.

Further, in each of the two inductor conductors 12 and 14 formed at the positions adjacent to each other on the surface of the semiconductor substrate 10, the leakage flux to the outside can be suppressed to the minimum as described above, so that the two inductors. Conductor 1
The degree of magnetic coupling between 2 and 14 can also be minimized. Therefore, it is possible to prevent the inductor conductors operating separately in the circuit configured by using the semiconductor substrate 10 from being transformer-coupled to each other and malfunctioning.

FIG. 4 is a diagram showing a manufacturing process for forming magnetic films on both sides of the inductor conductor. As an example, when both surfaces of the two inductor conductors shown in FIG. 2 are separately covered with magnetic films. It is shown.

(1) First, the insulative magnetic film 20 is formed on the surface of the semiconductor substrate 10 by using various thin film forming techniques (FIG. 9A).

For example, as the magnetic film 20, gamma
Various magnetic films such as ferrite, barium and ferrite can be used. In particular, gamma-ferrite, which is generally used as a magnetic storage medium, has a magnetization direction in which micro magnets are arranged in a plane direction parallel to a substrate on which a gamma-ferrite thin film is formed, as shown in FIG. This is convenient when forming a simple magnetic path. When gamma-ferrite is used, the magnetic film can be formed by coating, which facilitates manufacturing.

Various materials and methods for forming the magnetic film can be considered. For example, a method of forming a magnetic film by vacuum deposition of FeO or the like, other molecular beam epitaxy method (MBE method), chemical method. A method of forming a magnetic film using a vapor phase growth method (CVD method), a sputtering method, or the like can be considered.

(2) Next, each of the inductor conductors 12 and 14 is formed on the surface of the magnetic film 20 (FIG. 2B).

In the most general case, the inductor conductors 12 and 14 are formed in a spiral shape and have a predetermined inductance.

Although each inductor conductor 12 and 14 is generally formed of a metal thin film, it may be formed of a semiconductor material such as polysilicon. For example, after forming a metal thin film of aluminum or the like on almost the entire surface of the insulating magnetic film 20, the metal thin film is partially removed by photolithography to form a spiral inductor conductor 1.
2, 14 are formed.

(3) Next, the insulating magnetic film 22 is formed on the surfaces of the inductor conductors 12 and 14 and the exposed magnetic film 20.
Are formed ((C) in the figure).

(4) Finally, the magnetic films 20 and 22 are partially removed, leaving the portions covering the inductor conductors 12 and 14 (FIG. 7D). Magnetic film 2 remaining in this way
0 and 22 form magnetic material films 16a and 16b covering one inductor conductor 12 and magnetic material films 18a and 18b covering the other inductor conductor 14, respectively.

As a method of partially removing the magnetic films 20 and 22, a method of etching or a method of laser light irradiation, which is widely used as part of the semiconductor manufacturing process, can be considered. Since the method by etching can be included in the semiconductor manufacturing process, I including the inductor conductors 12 and 14 and other components may be included in the semiconductor manufacturing process.
There is an advantage that the magnetic films 20, 22 can be partially removed at the same time when C or LSI is manufactured, and the manufacturing process can be simplified. In addition, the method using laser light irradiation is
There is an advantage that a part of the magnetic films 20 and 22 can be removed with accurate dimensional accuracy.

In this way, the large magnetic material films 20 and 22 are formed so as to cover the entire two inductor conductors 12 and 14 formed on the semiconductor substrate 10, and then these magnetic material films 20 and 22 are formed. By removing part of
The inductor conductors 12 and 14 are individually connected to the magnetic film 16a,
It is covered with 16b or 18a, 18b. Therefore, regardless of the number of the inductor conductors 12 and the like, the magnetic film that individually covers each inductor conductor can be easily formed, and the manufacturing process can be simplified.

FIG. 5 is a view showing a modified example of this embodiment, and shows a cross section corresponding to FIGS. 2 and 3.

FIG. 5A shows one inductor conductor 12
Focusing on (1), the inductor conductor 12 is formed directly on the surface of the semiconductor substrate 10, and the surface of the inductor conductor 12 is covered with an insulating magnetic film 16b. Focusing on the other inductor conductor 14, the inductor conductor 14 is formed directly on the surface of the semiconductor substrate 10, and the surface of the inductor conductor 14 is covered with an insulating magnetic film 18b. Therefore, the magnetic films 16a and 18a shown in FIG. 2 are omitted, and the magnetic films 16b and 18b are formed on only one surface of the inductor conductors 12 and 14 on the front surface side.

Such a structure can be manufactured by using, for example, the steps shown in FIG. 4, and only the step of forming the magnetic film 20 shown in FIG. .

FIG. 5B is a diagram showing the flow of magnetic flux in the vicinity of the inductor conductor shown in FIG. 5A, and is an enlarged cross-section in the vicinity of one inductor conductor 12. As shown in FIG. 3B, since the magnetic film 16b formed only on the front surface side of the inductor conductor 12 serves as a magnetic path, the magnetic flux distribution is along this magnetic path, and the magnetic flux generated by the inductor conductor 12 is It returns to the inductor conductor 12 through a region near this magnetic path. Therefore, the magnetic film 1
The leakage of the magnetic flux to the space adjacent to 6b can be reduced, and the influence of the magnetic flux generated by the inductor conductor 12 on the outside can be minimized.

The same applies to the inductor conductor 14, and in each of the two inductor conductors 12 and 14 formed at the adjacent positions on the surface of the semiconductor substrate 10, the leakage flux to the outside is minimized as described above. Since it can be suppressed, the degree of magnetic coupling between the two inductor conductors 12 and 14 can also be suppressed to the minimum.

FIG. 6 is a diagram showing another modification of this embodiment, which is opposite to the case shown in FIG. 5, and is formed so as to be sandwiched between the semiconductor substrate 10 and the inductor conductors 12 and 14. It is shown that only the body films 16a and 18a are left and the magnetic film 16b and 18b shown in FIG. 2 are omitted.

FIG. 6A shows one inductor conductor 12
Focusing on, the insulating magnetic film 16a is formed on the surface of the semiconductor substrate 10, and the inductor conductor 12 is further formed thereon. At this time, as shown in FIG. 6B, it is desirable that the inductor conductor 12 be formed after the magnetic film 16a is partially dug down to form a recess.
In addition, the other inductor conductor 14 is also the same, in which the magnetic film 18a is formed on the surface of the semiconductor substrate 10, and the inductor conductor 14 is further formed thereon.

Such a structure can be manufactured by using, for example, the steps shown in FIG. 4, and only the step of forming the magnetic film 22 shown in FIG. . When a part of the magnetic film 16a is to be dug, after forming the magnetic film 20 shown in FIG. 4A, only the portion corresponding to the inductor conductor 12 or the like may be dug to some extent by etching or the like.

FIG. 6C is a diagram showing the flow of magnetic flux in the vicinity of the inductor conductor shown in FIG. 6B, and is an enlarged cross-section in the vicinity of one inductor conductor 12.

As shown in FIG. 7C, the semiconductor substrate 10
Film 16 formed between the inductor and the inductor conductor 12
Since a is a magnetic path, a magnetic flux is distributed along this magnetic path, and the magnetic flux generated by the inductor conductor 12 returns to the inductor conductor 12 through a region near this magnetic path. Therefore, it is possible to reduce the leakage of the magnetic flux to the space adjacent to the magnetic film 16a and minimize the external influence of the magnetic flux generated by the inductor conductor 12.

The same applies to the inductor conductor 14, and in each of the two inductor conductors 12 and 14 formed at the adjacent positions on the surface of the semiconductor substrate 10, the leakage flux to the outside is minimized as described above. Since it can be suppressed, the degree of magnetic coupling between the two inductor conductors 12 and 14 can also be suppressed to the minimum.

FIG. 7 is a diagram showing another modification of the present embodiment. FIG. 7A shows each inductor conductor 1 shown in FIG.
The case is shown in which the magnetic films 16a and 18a formed for every 2 and 14 are replaced with one common insulating magnetic film 24. Such a structure can be manufactured by using, for example, the process shown in FIG. 4, and in the process of removing a part of the magnetic film 20, 22 shown in FIG. It suffices to remove only one magnetic film 22.

FIG. 6B is a diagram showing the flow of magnetic flux in the vicinity of the inductor conductor shown in FIG. 4A, and is an enlarged cross-section in the vicinity of one inductor conductor 12.
As shown in FIG. 3B, the magnetic flux distribution is determined so that the magnetic film 16b formed on the surface of the inductor conductor 12 serves as a magnetic path. Therefore, the magnetic flux generated by the inductor conductor 12 is generated by the magnetic film 16b. And 24 and back to the inductor conductor 12. Therefore, the magnetic film 16
The leakage of the magnetic flux to the space adjacent to b can be reduced, and the influence of the magnetic flux generated by the inductor conductor 12 on the outside can be minimized.

FIG. 8 is a diagram showing another modification of the present embodiment. In FIG. 8A, contrary to the case shown in FIG. 4, the inductor conductors 12 and 14 shown in FIG. The case is shown in which the magnetic films 16b and 18b formed for each of them are replaced with a common single insulating magnetic film 26. Such a structure can be manufactured by using, for example, the process shown in FIG. 4, and the process of finally removing a part of the magnetic film is performed by the magnetic film shown in FIG. It may be performed after the step of forming 20.

FIG. 7B is a diagram showing the flow of magnetic flux in the vicinity of the inductor conductor shown in FIG. 7A, and is an enlarged cross-section in the vicinity of one inductor conductor 12. As shown in FIG. 2B, since the magnetic flux distribution is determined so that the magnetic film 16 a formed between the inductor conductor 12 and the semiconductor substrate 10 serves as a magnetic path, the magnetic flux generated by the inductor conductor 12 is generated. Are magnetic films 16a and 1
It returns to the inductor conductor 12 through the inside of 6b.
Therefore, the leakage of the magnetic flux to the space adjacent to the magnetic film 16b can be reduced, and the external influence of the magnetic flux generated by the inductor conductor 12 can be minimized.

By the way, the inductor conductor 12 and the like of the present embodiment described above are provided with the magnetic body 16 formed in the peripheral portion thereof.
The inductance changes depending on the magnetic permeability, volume, etc. of the (magnetic film 16a, 16b). Therefore, if the magnetic permeability is not uniform over the entire magnetic film or the volume of the magnetic film fluctuates slightly, the inductance of each inductor conductor 12 or the like can be adjusted after the magnetic film is formed. It is convenient.

FIG. 9 is a diagram showing a mechanism for adjusting the inductance of the inductor conductor formed in a plane on the semiconductor substrate.

As shown in the figure, the inductor conductor 12 has a spiral shape, and an adjusting conductor 28 having a predetermined number of turns (for example, 2 turns) is formed so as to circulate the outer circumference thereof. A bias power supply 30 capable of variably controlling the applied voltage is connected to both ends of the adjusting conductor 28. Bias power supply 30 to adjustment conductor 2
By applying a predetermined DC bias voltage to 8 and passing a constant current i, the inductance determined by the magnetic films 16a and 16b formed on the inductor conductor 12 and its peripheral portion can be adjusted within a certain range. .

As described above, by providing the mechanism for adjusting the inductance of the inductor conductor 12 and the like, it is possible to prevent the variation of the inductance due to the variation of the characteristics of the magnetic film 16a and the like, and to secure the stable characteristic of the inductor conductor. can do.

The present invention is not limited to the above embodiment, and various modifications can be made within the scope of the gist of the present invention.

For example, in the above-described embodiment, the case where the two inductor conductors 12 and 14 are formed at the adjacent positions on the semiconductor substrate 10 has been described as an example, but when three or more inductor conductors are formed, or The same applies to the case of forming one inductor conductor. When forming only one inductor conductor, by forming the magnetic film so as to cover only this inductor conductor,
The leakage of the magnetic flux to the outside can be prevented, and the influence of the magnetic flux on other parts can be minimized.

Further, although the shape of each inductor conductor is a spiral shape, it is not necessarily limited to the spiral shape when a high frequency signal is used, and it may be a meandering shape, a curved shape or a substantially linear shape. It suffices if the inductance can be obtained.

Although the adjusting conductor 28 shown in FIG. 9 is formed so as to circulate outside the inductor conductor 12,
It may be formed so as to overlap the inductor conductor 12.

In the above-mentioned embodiment, the magnetic film 16 is used.
Although an insulating material is used as a, 16b, 18a, 18b, a conductive material such as metal powder (MP) may be used. However, if such a conductive magnetic film is used by replacing it with the above-described insulating magnetic film 16a or the like, each winding portion of the inductor conductor 12 or the like is short-circuited and does not function as an inductor conductor. It is necessary to electrically insulate between the conductor and the conductive magnetic film. Examples of this insulating method include a method of oxidizing the inductor conductor 12 and the like to form an insulating oxide film, a method of forming a silicon oxide film or a nitride film by a chemical vapor deposition method, and the like. To form an insulating film by such various methods, for example, the insulating magnetic film is replaced with a conductive magnetic film in the manufacturing process described with reference to FIG. 4, and the step of forming the magnetic film and the inductor conductor are performed. A step of manufacturing an insulating film may be inserted between the step of forming and the step of forming.

In particular, a conductive material such as metal powder has a larger magnetic permeability than an insulating material such as gamma-ferrite, and therefore has an advantage that a large inductance can be secured.

In the above-described embodiment, the case where the inductor conductor 12 and the like are formed on the surface of the semiconductor substrate 10 has been described as an example. However, for each inductor conductor 12 and the like, a part of the semiconductor substrate 10 is dug down by etching or the like. It may be buried, and in this case, by forming a magnetic film so as to cover it further, leakage of magnetic flux from each inductor conductor 12 or the like to the outside can be minimized. .

The inductor conductor 12 and the like may be realized by forming a p-region or an n-region having a spiral shape or a meandering shape in the vicinity of the surface of the semiconductor substrate 10 by thermal diffusion or ion implantation. In this case as well, by forming a magnetic film thereon, leakage of magnetic flux from each inductor conductor to the outside can be minimized.

Further, although each of the inductor conductors 12 and the like described above is formed in the shape of one coil, two conductors are formed in a spiral shape so that the winding portions are parallel to each other, and these two conductors are transformer-coupled. You may make it use it.

FIG. 10 is a diagram showing a modified example in which two conductors are transformer-coupled. As shown in the figure, the two inductor conductors 32 and 34 are combined as a transformer to form a transformer, and a magnetic film 36 is formed so as to cover all of them. Therefore, these two inductor conductors 3
Since the magnetic fluxes generated by the inductor conductors 32 and 34 do not leak to the outside of the magnetic film 36 while the magnetic fluxes 2 and 34 are magnetically coupled to each other, the magnetic flux with respect to other inductor conductors or other components not shown Can be eliminated.

[0091]

As described above, according to the invention of claim 1 or 3, the inductor conductor formed in a substantially flat shape on the semiconductor substrate is covered with the insulating magnetic material, and the generated magnetic flux has this insulating property. Since the magnetic material is distributed as a magnetic path and hardly leaks outside, the magnetic influence on the outside can be minimized. Particularly, in the third aspect, since the plurality of inductor conductors are formed on the semiconductor substrate and are individually magnetically shielded, it is possible to prevent magnetic coupling between the adjacent inductors.

According to the invention of claim 2 or 4,
The inductor conductor formed in a substantially flat shape on the semiconductor substrate is covered with a conductive magnetic material via an insulating film, and the insulating film ensures electrical insulation between the inductor conductor and the conductive magnetic material. The generated magnetic flux is distributed through the conductive magnetic material as a magnetic path and hardly leaks to the outside, so that the magnetic influence on the outside can be minimized. In particular, according to claim 4, since a plurality of inductor conductors are formed on the semiconductor substrate and are individually magnetically shielded, it is possible to prevent magnetic coupling between adjacent inductors.

According to the fifth aspect of the present invention, the inductor is sandwiched between the magnetic body described above by the first and second magnetic body films, and the magnetic path is formed by the first and second magnetic body films. Therefore, the magnetic flux generated by energizing the inductor conductor is generated by the first magnetic flux forming the magnetic path.
It returns to the inductor conductor again through the inside of the magnetic film and the second magnetic film, and the leakage of the magnetic flux to the outside is almost eliminated.

According to the invention of claim 6, the above-mentioned magnetic body is constituted only by the first magnetic film used in claim 5, and the first magnetic film formed along the inductor conductor is used. Since the magnetic path is formed so as to pass through the magnetic film, the magnetic flux is not distributed in the portion far from the inductor conductor, and the leakage of the magnetic flux from the inductor conductor to the outside is almost eliminated.

Further, according to the invention of claim 7, the above-mentioned magnetic body is individualized only by the second magnetic film used in claim 5, and like the sixth aspect, along the inductor conductor. Since the magnetic path is formed so as to pass through the formed second magnetic film, the magnetic flux is not distributed in the portion far from the inductor conductor, and the leakage of the magnetic flux from the inductor conductor to the outside is almost eliminated. .

According to the invention of claim 8 or 9,
When forming a plurality of inductor conductors on a semiconductor substrate, one of the first and second magnetic material films formed so as to sandwich each inductor conductor is formed so as to be continuous along each inductor conductor. There is. Therefore, even when one magnetic material film is continuously formed in this manner, by covering each inductor conductor individually with the other magnetic material film, the other magnetic film formed so as to be covered individually Since the magnetic path is formed through the body membrane,
It is possible to prevent leakage of magnetic flux from the inductor conductor to the outside and magnetic coupling between the inductor conductors.

According to the tenth aspect of the invention, the first insulating magnetic film, the inductor conductor, and the second conductor are formed on the semiconductor substrate.
After forming the insulative magnetic substance film of, the insulating magnetic substance film around the inductor conductor is finally removed to form the insulative magnetic substance film individually covering each inductor conductor. Regardless of the number of inductor conductors arranged, it is sufficient to form the first and second insulative magnetic material films that cover the entire inductor conductors, and the manufacturing process can be simplified.

According to the eleventh aspect of the present invention, after the inductor conductor and the insulating magnetic material film are formed on the semiconductor substrate, the insulating magnetic material film around the inductor conductor is finally removed, whereby each inductor is formed. An insulating magnetic film is formed by covering the conductors individually from one side, and regardless of the number of inductor conductors arranged adjacently, it is sufficient to form an insulating magnetic film that covers one side of the inductor. It is possible to simplify the manufacturing process.

According to the twelfth aspect of the invention, after the insulating magnetic material film and the inductor conductor are formed on the semiconductor substrate, the insulating magnetic material film around the inductor conductor is finally removed so that each inductor is formed. Insulating magnetic material films are formed separately on one side of the conductor, and regardless of the number of inductor conductors arranged adjacent to each other, it is possible to form an insulating magnetic material film that covers a wide range of the semiconductor substrate surface. Well, the manufacturing process can be simplified.

Further, according to the inventions of claims 13 to 15,
The insulating magnetic film used in claims 10 to 12 is replaced with a conductive magnetic film, and an insulating film for electrically insulating the conductive film from the inductor conductor is provided on the surface of the inductor conductor. Similar to the case of claims 10 to 12, regardless of the number of inductor conductors arranged adjacent to each other, it is sufficient to form a conductive magnetic film covering the whole or one side of the inductor conductors, which simplifies the manufacturing process. Becomes

According to the sixteenth aspect of the present invention, the magnetic film described above is formed by the thin film forming technique, and in the case of forming a microminiature inductor conductor on a semiconductor substrate such as an IC or LSI. Even if there is, a film can be easily formed.

According to the seventeenth aspect of the invention, the insulating magnetic material film or the conductive magnetic material film is removed by etching or laser light irradiation, so that fine processing can be easily performed.

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of a magnetic shield system of a semiconductor device of this embodiment.

FIG. 2 is a diagram showing a cross section of an inductor conductor portion shown in FIG.

FIG. 3 is a diagram showing a magnetic flux distribution in the vicinity of an inductor conductor.

FIG. 4 is a diagram showing a step of forming a magnetic film for magnetically shielding the inductor conductor of the present embodiment.

FIG. 5 is a diagram showing a modification of the present embodiment.

FIG. 6 is a diagram showing another modification of the present embodiment.

FIG. 7 is a diagram showing another modification of the present embodiment.

FIG. 8 is a diagram showing another modification of the present embodiment.

FIG. 9 is a diagram showing another modification of the present embodiment in which an inductance adjusting mechanism is added.

FIG. 10 is a view showing a modified example in which two inductor conductors are used as one set to perform magnetic shielding.

FIG. 11 is a diagram showing an arrangement of a plurality of coils on the printed wiring board in consideration of magnetic influence.

FIG. 12 is a diagram for explaining a magnetic flux generated by an inductor conductor on a semiconductor substrate.

[Explanation of symbols]

 10 Semiconductor Substrate 12,14 Inductor Conductor 16,18 Magnetic Material 16a, 16b, 18a, 18b Magnetic Material Film

Claims (17)

[Claims] 1. A method for covering an inductor conductor formed in a substantially planar shape on a semiconductor substrate with an insulating magnetic material,
A magnetic shield method for a semiconductor device, which magnetically shields the inductor conductor. 2. A magnetic field of a semiconductor device, wherein the inductor conductor formed in a substantially flat shape on a semiconductor substrate is covered with a conductive magnetic material via an insulating film to magnetically shield the inductor conductor. Shield method. 3. Magnetic insulation is provided between the plurality of inductor conductors by individually covering each of the plurality of inductor conductors formed in a substantially planar shape at adjacent positions on the semiconductor substrate with an insulating magnetic material. A magnetic shield method for semiconductor devices, which is characterized in that 4. A plurality of inductor conductors formed in a substantially planar shape at adjacent positions on a semiconductor substrate are individually covered with a conductive magnetic material via an insulating film,
A magnetic shield system for a semiconductor device, wherein magnetic insulation is performed between the plurality of inductor conductors. 5. The magnetic body according to claim 1, wherein the magnetic body includes a first magnetic body film formed on a surface of the semiconductor substrate and between the inductor body and the inductor conductor. A magnetic shield system for a semiconductor device, comprising a second magnetic film formed on the front surface side and substantially facing the first magnetic film. 6. The magnetic body according to claim 1, wherein the magnetic body is formed of a first magnetic body film formed on the surface of the semiconductor substrate and between the inductor conductor. Characteristic magnetic shield method for semiconductor devices. 7. The magnetic body according to claim 1, wherein the magnetic body is formed of a second magnetic body film formed further on the front surface side of the inductor conductor formed on the semiconductor substrate. Magnetic shield method for semiconductor devices. 8. The magnetic body according to claim 3, wherein the plurality of magnetic bodies covering the plurality of inductor conductors are
A first magnetic film formed on the surface of the semiconductor substrate between the semiconductor substrate and the plurality of inductor conductors and the front surface side of each of the plurality of inductor conductors are individually formed. A magnetic shield method for a semiconductor device, comprising: a plurality of second magnetic films. 9. The magnetic body according to claim 3, wherein the plurality of magnetic bodies that cover the plurality of inductor conductors are
A first magnetic film that is formed on the surface of the semiconductor substrate and individually between the semiconductor substrate and the plurality of inductor conductors, and the front surface side of the plurality of inductor conductors are commonly covered. A magnetic shield method for a semiconductor device, comprising: the formed second magnetic film. 10. A first step of forming a first insulating magnetic material film on a semiconductor substrate, and forming one or a plurality of inductor conductors at adjacent positions on the surface of the first insulating magnetic material film. A second step and a second step to cover the one or more inductor conductors.
The third step of forming the insulative magnetic film, and both or the second insulation of the first and second insulative magnetic films formed on the peripheral portions of the one or more inductor conductors. A fourth step of removing only the conductive magnetic material film, wherein magnetic shielding is performed by the insulating magnetic material film formed corresponding to each of the one or more inductor conductors. Method for forming magnetic shield film of device. 11. A first step of forming one or a plurality of inductor conductors at adjacent positions on a semiconductor substrate directly or via a first insulating film, and insulating so as to cover the one or a plurality of inductor conductors. A second step of forming a conductive magnetic material film, and a third step of removing the insulating magnetic material film formed on the peripheral portion of each of the one or more inductor conductors. A method of forming a magnetic shield film for a semiconductor device, wherein magnetic shielding is performed by the insulating magnetic film formed corresponding to each of a plurality of inductor conductors. 12. A first step of forming an insulating magnetic film on a semiconductor substrate, and a second step of forming one or a plurality of inductor conductors at positions adjacent to the surface of the first insulating magnetic film. A third step of removing the insulating magnetic film formed on the peripheral portion of each of the one or more inductor conductors, and corresponding to each of the one or more inductor conductors. A method of forming a magnetic shield film for a semiconductor device, wherein magnetic shielding is performed by the formed insulating magnetic film. 13. A first step of forming a first conductive magnetic film on a semiconductor substrate, and a second step of forming a first insulating film on the surface of the first conductive magnetic film. And a third step of forming one or a plurality of inductor conductors on the surface of the first insulating film and adjacent to each other, and forming a second insulating film on the surface of the one or a plurality of inductor conductors. And a fifth step of forming a second conductive magnetic film so as to cover the one or more inductor conductors formed on the surface of the second insulating film, A sixth step of removing both the first and second conductive magnetic films or only the second conductive magnetic film formed on the peripheral portions of the plurality of inductor conductors, respectively; For each of one or more inductor conductors A method of forming a magnetic shield film for a semiconductor device, wherein magnetic shielding is performed by the conductive magnetic film formed correspondingly. 14. A first step of forming one or a plurality of inductor conductors at adjacent positions on a semiconductor substrate directly or via a first insulating film, and a second step on the surface of the one or more inductor conductors. A second step of forming an insulating film, a third step of forming a conductive magnetic film so as to cover the one or more inductor conductors formed on the surface of the second insulating film, A fourth step of removing the insulating magnetic film formed on the peripheral portion of each of the one or more inductor conductors, and the step of forming the insulating magnetic film corresponding to each of the one or more inductor conductors. A method of forming a magnetic shield film for a semiconductor device, which comprises magnetically shielding with a conductive magnetic film. 15. A first step of forming a conductive magnetic film on a semiconductor substrate, a second step of forming an insulating film on a surface of the conductive magnetic film, and a further surface of the insulating film. And a third step of forming one or a plurality of inductor conductors at adjacent positions, and a fourth step of removing the conductive magnetic film formed on the peripheral portions of the one or a plurality of inductor conductors. And a magnetic shield film forming method for a semiconductor device, wherein magnetic shielding is performed by the conductive magnetic film formed corresponding to each of the one or more inductor conductors. 16. The method for forming a magnetic shield film of a semiconductor device according to claim 10, wherein the insulating magnetic film or the conductive magnetic film is formed by a thin film forming technique. 17. The magnetic shield film for a semiconductor device according to claim 10, wherein the insulating magnetic film or the conductive magnetic film is removed by etching or laser light irradiation. Forming method.