JP2000232202A - High q inductor for high frequency - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to form a high Q inductor having a low series resistance component, which is not subjected to skin effect on an IC by a method wherein an inductor part, which is composed of one layer of wiring layer is multilayered. SOLUTION: Multilayered inductors 11 and 14 are arranged, they are connected with each other, and using a part of the second layer of wiring layer 1r as an inductor, a series resistance component is reduced by increasing the cross sectional area where the current of inductor flows. Also, by having the inductors in double layer, they are not subjected to the affection of the skin effect in a high frequency region.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of an inductor having a high Q value used at a high frequency on a semiconductor IC.

[0002]

2. Description of the Related Art A conventional technique will be described with reference to FIG. In FIG. 9, reference numeral 1 denotes an inductor part, 2 denotes an extraction wiring in a first layer, 3 denotes an extraction wiring in a second layer,
Reference numeral 5 denotes a connection portion between the first and second layers, 7 denotes an interlayer film, and 8 denotes a flattening film.

[0003] As described above, in the conventional inductor, the inductor portion is constituted by a single layer, and the second layer is used for the lead-out wiring for connection with other parts.

In this case, as a generally known characteristic of the inductor, it is necessary to increase the line length in order to obtain a large inductance value.

[0005]

However, in the above-described configuration, the line length is long in order to obtain a large inductance value. Therefore, the series resistance component increases due to the resistance of the wiring material forming the inductor, and the inductance of the inductor increases. Q
There was a problem that the value deteriorated.

Further, when the line length is increased, the overall size of the inductor tends to increase.

An object of the present invention is to provide an inductor having a high Q value without increasing the resistance in consideration of the above-described problems of the conventional inductor.

Another object of the present invention is to obtain an inductor whose size does not increase even if the line length is increased.

[0009]

Means for Solving the Problems The first invention (claim 1)
(Corresponding to (1)) is characterized in that one inductor has a plurality of inductor elements respectively arranged in a plurality of IC wiring layers, and the directions of magnetic fields formed by the respective inductor elements are substantially the same. This is a high-Q inductor for high frequency.

[0010] The second invention (corresponding to claim 2) is:
A high-frequency high-Q inductor according to a first aspect of the present invention, wherein the plurality of inductor elements are connected in series.

A third aspect of the present invention (corresponding to claim 3) is:
A high-frequency high-Q inductor according to a first aspect of the present invention, wherein the plurality of inductor elements are connected in parallel.

A fourth aspect of the present invention (corresponding to claim 4) is:
The first inductor of the present invention is characterized in that the plurality of inductor elements have a circuit portion connected in series and a circuit portion connected in parallel.

A fifth aspect of the present invention (corresponding to claim 5) is:
A high-frequency high-Q inductor according to a first aspect of the present invention, wherein at least one of the inductor elements is arranged in a meander shape or a spiral shape.

A sixth aspect of the present invention (corresponding to claim 6) is:
The connection according to any one of claims 1 to 5, wherein the connection part between the plurality of inductor elements is formed in an interlayer film formed between IC wiring layers in which the respective inductor elements are arranged. This is a high-Q inductor for high frequency.

A seventh aspect of the present invention (corresponding to claim 7) is:
The wiring from the inductor element is a high-frequency high-Q inductor according to the first aspect of the present invention, wherein the wiring is arranged on an IC wiring layer on which the inductor element is arranged (corresponding to FIG. 1).

An eighth aspect of the present invention (corresponding to claim 8) is:
The plurality of inductor elements are respectively arranged in a spiral shape and connected in parallel with each other, and one of the extraction wirings is connected to the center of the spiral of the inductor element and uses one of the IC wiring layers. The spiral-shaped inductor element disposed on the IC wiring layer used for the extraction is interrupted at each portion intersecting the extraction wiring, and each of the interrupted ends is separated from each other. A high-frequency high-Q inductor according to a seventh aspect of the present invention, wherein the inductors are connected to each other by being connected to a part of the spiral-shaped inductor element arranged in another IC wiring layer ( (Corresponding to FIG. 3).

According to a ninth aspect of the present invention (corresponding to claim 9),
The wiring according to any one of the first to sixth aspects of the present invention, wherein the wiring taken out from the inductor element is arranged not on the IC wiring layer on which the inductor element is arranged but on a separately provided wiring layer. High-Q inductor (corresponding to FIG. 2).

Tenth invention (corresponding to claim 10)
Is provided in an interlayer film between a wiring layer on which the extraction wiring is disposed and an IC wiring layer on which the inductor element is disposed, between the extraction wiring and the inductor element connected thereto. A ninth high-frequency inductor according to the present invention, which is connected at a connection portion (corresponding to FIG. 2).

The eleventh invention (corresponding to claim 11)
The plurality of inductor elements are each arranged in a spiral shape, and the plurality of inductor elements are connected to each other adjacent to each other, and the connection is performed by connecting the central portions and connecting the outermost portions. The first aspect, wherein the spiral windings of the adjacent inductor elements are connected in series with each other, and the directions of the magnetic fields generated by the inductor elements are substantially the same. Of the present invention (corresponding to FIGS. 4 and 5).

Twelfth invention (corresponding to claim 12)
The plurality of inductor elements are each arranged in a spiral shape, and the plurality of inductor elements are connected to each other every other way, and the connection method is to connect the central parts and connect the outermost parts. Thus, the spiral winding of each adjacent inductor element is oriented in the same direction, and the direction of the magnetic field generated by each inductor element is oriented substantially in the same direction. This is a high-frequency high-Q inductor according to the first aspect of the invention (corresponding to FIG. 6).

[0021]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) FIG. 1 shows a first embodiment of a high-Q inductor for high frequency waves according to the present invention. In the figure, reference numeral 11 denotes an inductor portion in a meander type first layer (corresponding to an inductor element of the present invention; hereinafter the same), 1
Reference numerals 2 and 13 denote a first-layer lead-out wiring, 14 denotes an inductor part in a second layer, and 15 and 16 denote connection parts of the first and second layers.
7 is an interlayer film and 18 is a flattening film.

For example, one of the connecting parts 15 and 16 is one.
Nine contact portions of about μm square are collected and formed.

As described above, the inductor portion which has conventionally been constructed using only one layer is arranged in the first and second layers, respectively, and has a two-layer structure in which the inductor portions are connected in parallel with each other. did.

As a result, the conventional series having a large series resistance component at a low frequency and a high frequency and having a low Q value has a large cross-sectional area, and further has a high frequency range at which a deterioration of the Q value due to a skin effect at a high frequency is suppressed. A Q value inductor can be obtained.

The present invention includes a case where the first layer and the second layer are connected in parallel over the entire inductor portion.

(Embodiment 2) FIG. 2 shows a second embodiment of the high-Q inductor for high frequency of the present invention. In the figure, reference numeral 21 denotes a spiral-shaped first-layer inductor portion;
Denotes a first-layer lead wiring, 23 denotes a spiral-shaped second-layer inductor portion, 24 denotes a third-layer lead-out wiring from the second-layer inductor portion 23, and 25 and 26 denote first and second layers.
The connection portion of the layer, 27 and 28 are interlayer films, 29 is a planarization film,
Reference numeral 210 denotes a connection portion between the second layer and the third layer. The first-layer inductor portion 22 and the second-layer inductor portion 23 have a spiral shape wound in the same direction.

As described above, the inductor portion conventionally using only one layer is arranged on the first and second layers, respectively, and the inductor portions 22 and 23 are connected in parallel to each other. It has a layer structure.

As a result, the conventional series having a large series resistance component at a low frequency and a high frequency and having a low Q value has a large cross-sectional area, and further has a high frequency range having a reduced Q value due to a skin effect at a high frequency. A Q value inductor can be obtained.

The present invention includes a case where the first layer and the second layer are connected in parallel over the entire inductor portion.

Although three layers are used here, four or more layers having the same structure may be provided, and the lowermost layer may have a lead-out wiring.

(Embodiment 3) FIG. 3 shows a third embodiment of the high-Q inductor for high frequency of the present invention. In the figure, 31 is a spiral-shaped first-layer inductor portion, 32 is a first-layer lead-out wire, 33 is a spiral-shaped second-layer inductor portion, 34 is a second-layer lead-out wire, and 35 is a first-layer and a second-layer wire. , 37 is an interlayer film, and 38 is a flattening film.

These inductor sections 31 and 33 are connected in parallel.

The third embodiment is characterized in that the second-layer extraction wiring 34 uses the layer itself in which the second-layer inductor section 33 is provided. Therefore, the inductor section 33 in the second layer is interrupted once so as not to be in contact with each other at a portion where the inductor section 33 intersects with the extraction wiring 34 in the same layer. The configuration is such that it is connected to the inductor 31 of the first layer. As a result, the second-layer inductor section 33
Becomes one inductor part having a substantially spiral shape.

As described above, the inductor portion, which has conventionally been constructed using only one layer, has a two-layer structure in which the first layer and the second layer are connected in parallel, and the same layer as the lead-out wiring is used. By forming an inductor in the process, even in a process in which the number of wiring layers is small, conventionally, the series resistance component at a low frequency and a high frequency is large and the Q value is low. It is possible to obtain a high-frequency high-Q inductor in which deterioration of the Q value due to the skin effect is suppressed.

In the second embodiment, the layer for forming the lead-out wiring is provided separately. However, the third embodiment is characterized in that the lead-out wiring is formed using the wiring layer of the inductor portion.

The present invention includes a case where the first and second layers are connected in parallel over the entire inductor.

Although two layers are used here, the present invention also includes providing three or more layers having the same structure and providing an extraction wiring in any one of the layers. At this time, the inductor portion that intersects with the extraction wiring can be freely connected to any of the upper and lower inductor portions.

7 and 8 are graphs comparing the performance of a conventional inductor using only one layer with the performance of the inductor of the present embodiment.

FIG. 7 is a graph plotting the change of R with respect to L. In the two-layer type of the present embodiment, R is smaller.

FIG. 8 plots the change of Q with respect to L. The Q is higher in the two-layer type of the present embodiment.

(Embodiment 4) FIG. 4 shows a high-frequency high-Q inductor according to a fourth embodiment of the present invention. In the figure, reference numeral 41 denotes a first-layer spiral-shaped inductor portion;
Is a first layer extraction wiring, 43 is a first layer second layer connection part,
4 is a spiral-shaped second-layer inductor portion, 45 is a second-layer and third-layer connection portion, 46 is a spiral-shaped third-layer inductor portion, 47 is a third-layer and fourth-layer connection portion, and 48 is A spiral-shaped fourth-layer inductor portion, 49 is a fourth-layer extraction wiring, 410, 411, and 412 are interlayer films, and 413 is a flattening film.

Here, adjacent ones of the inductor portions are connected to each other. That is, the central portions are connected to each other, and the outermost portions are connected to each other. Therefore, it can be said that these inductor units are connected in series.

At this time, the shape of the inductor is inverted between the odd and even layers.

By doing so, the directions of the magnetic fields formed by the respective inductor portions become the same, and the coupling is effectively performed.

As described above, in order to increase the Q value, a conventional 1
There is a problem that the size of the inductor portion is increased by simply increasing the total length of the inductor portion that is configured using only the layers. However, in the fourth embodiment, the length of the inductor portion is three-dimensionally reduced as a whole. Because it is long, the size becomes compact.

Although the case of four layers is shown here, FIG.
As shown in FIG. 5, the present invention further provides a similar structure with five layers,
The number of layers may be increased. When there are an even number of these layers, the extraction wiring can be easily extracted from the outermost part of the inductor section.

When there are an odd number of these layers, a lead-out wiring can be provided by the method described with reference to FIGS.

Further, as shown in FIG. 6, the spiral of one pair of inductors may be wound in the same direction, and the coil of adjacent inductors may be reversed. In that case, skip one and connect in series as shown in the figure.

Even in this case, the directions of the magnetic fields formed by the inductor portions are the same, and the coupling is effective.

[0051]

As described above, according to the present invention, the wiring layer 1
Since the inductor portion composed of only the layers has a multilayer structure, an inductor having a low series resistance component and a high Q value which is not affected by the skin effect can be formed on the IC.

[Brief description of the drawings]

FIG. 1 is an inductor diagram showing a first embodiment of the present invention.

FIG. 2 is an inductor diagram showing a second embodiment of the present invention.

FIG. 3 is an inductor diagram showing a third embodiment of the present invention.

FIG. 4 is an inductor diagram showing a fourth embodiment of the present invention.

FIG. 5 is a schematic view of an inductor showing another embodiment of the present invention.

FIG. 6 is a schematic view of an inductor showing another embodiment of the present invention.

FIG. 7 is a graph showing a comparison of performance between the embodiment of the present invention and a conventional example.

FIG. 8 is a graph showing a comparison of performance between the embodiment of the present invention and a conventional example.

FIG. 9 is a diagram of a conventional inductor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 1st layer inductor part 12 1st layer extraction wiring 13 1st layer extraction wiring 14 2nd layer inductor part 15, 16 1st layer 2nd layer connection part 17 Interlayer film 22 1st layer inductor part 23 2nd layer inductor part 24 Second-layer extraction wiring 25, 26 First-layer second-layer connection part 27, 28 Interlayer film 210 Second-layer third-layer connection part 31 First-layer inductor part 32 First-layer extraction wiring 33 Second-layer inductor part 34 Second-layer extraction wiring 35 First-layer second-layer connection part 37 Interlayer film 41 First-layer inductor part 42 First-layer extraction wiring 43 First-layer second-layer connection part 44 Second-layer inductor part 45 Second-layer third-layer connection Part 46 third-layer inductor part 47 third-layer fourth-layer connection part 48 fourth-layer inductor part 49 fourth-layer lead-out wiring 410-412 interlayer film 18, 29, 38 planarization film

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Toshifumi Nakatani 1006 Kadoma, Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. 72) Inventor Yukio Hiraoka 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (12)

[Claims] 1. One inductor has a plurality of inductor elements arranged on a plurality of IC wiring layers, respectively.
A high-frequency high-frequency inductor for high frequencies, wherein directions of magnetic fields formed by the respective inductor elements are substantially the same. 2. The high-frequency high-Q inductor according to claim 1, wherein said plurality of inductor elements are connected in series. 3. The high-frequency high-Q inductor according to claim 1, wherein said plurality of inductor elements are connected in parallel. 4. The high-frequency high-Q inductor according to claim 1, wherein the plurality of inductor elements include a circuit portion connected in series and a circuit portion connected in parallel. 5. The high-frequency high-Q inductor according to claim 1, wherein at least one of the inductor elements is arranged in a meander shape or a spiral shape. 6. A connection part between the plurality of inductor elements is formed in an interlayer film formed between IC wiring layers on which the respective inductor elements are arranged. 7. The high-Q inductor for high frequency waves according to any one of the above. 7. The high-frequency high-Q inductor according to claim 1, wherein the wiring from the inductor element is disposed on an IC wiring layer on which the inductor element is disposed. 8. The plurality of inductor elements are respectively arranged in a spiral shape and connected in parallel with each other. One of the lead-out lines is connected to a center of a spiral of the inductor element, and the plurality of inductor elements are connected to each other in the IC wiring layer. The spiral-shaped inductor element disposed on the IC wiring layer used for the extraction is interrupted at each portion intersecting with the extraction wiring. End portions are connected to a part of the spiral-shaped inductor element arranged on another IC wiring layer,
8. The high-frequency high-Q inductor according to claim 7, wherein the inductors are connected to each other. 9. The wiring according to claim 1, wherein the wiring from the inductor element is disposed not on an IC wiring layer on which the inductor element is disposed but on a separately provided wiring layer. A high-frequency inductor for high frequencies according to any one of the above. 10. A wiring layer on which the lead-out wiring is disposed and an I-layer on which the inductor element is disposed, between the lead-out wiring and the inductor element connected thereto.
10. The high-frequency high-Q inductor according to claim 9, wherein the inductor is connected to a connection portion provided in an interlayer film between the C wiring layer and the C wiring layer. 11. The plurality of inductor elements are respectively arranged in a spiral shape, the plurality of inductor elements are connected to each other adjacently, and the connection method is to connect a central portion and connect an outermost portion. In this manner, the spiral windings of the adjacent inductor elements are opposite to each other, and the directions of the magnetic fields generated by the inductor elements are substantially in the same direction. The high-frequency inductor for high frequencies according to claim 1. 12. The plurality of inductor elements are each arranged in a spiral shape, and the plurality of inductor elements are connected to every other one of the inductor elements. Are connected in series, and the spiral winding of each adjacent inductor element repeats the same direction and the opposite direction sequentially, and the direction of the magnetic field generated by each inductor element is substantially the same direction. 2. The high-frequency high-Q inductor according to claim 1, wherein the inductor is oriented.