JP3373267B2 - LC element and semiconductor device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an LC element, a semiconductor device and a method for manufacturing an LC element, which can be incorporated in a semiconductor device or the like or can attenuate a predetermined frequency band by itself.

[0002]

2. Description of the Related Art With the development of electronic technology in recent years, electronic circuits have been widely used in various fields. Therefore, it is desirable to operate these electronic circuits stably and reliably without being affected by the outside. Be done.

However, noise enters the electronic circuit directly or indirectly from the outside. For this reason,
There is a problem that various electronic devices using electronic circuits often cause malfunctions.

In particular, electronic circuits often use a switching regulator as a DC power source. Therefore, a large amount of noise having various frequency components is often generated in the power supply line of the switching regulator due to a transient current such as switching or due to a load change caused by the switching operation of the digital IC used. Then, these noises are propagated to other circuits in the same device through the power supply line or by radiation to cause malfunction or S / S.
This may have a bad effect such as a decrease in N ratio, and may cause malfunction of other electronic devices that are being used even closer.

In order to remove such noise, various noise filters are generally used in electronic circuits.
In particular, since many electronic devices with various configurations are used in recent years, regulations on noise have become more and more stringent, and as a small, high-performance noise filter that can reliably remove generated noise. Development of a functional LC element is desired.

As one of such LC elements, the LC noise filter disclosed in Japanese Patent Laid-Open No. 3-259608 is known. This LC noise filter has an L component and a C component in a distributed constant, and can obtain good attenuation characteristics over a relatively wide band as compared with a lumped constant type LC noise filter. is there.

[0007]

By the way, the above-mentioned L
The C noise filter is manufactured by forming a capacitor conductor on one surface of an insulating sheet and an inductor conductor on the other surface, and then folding the insulating sheet. However, there is a problem that the manufacturing process becomes complicated because such processes are required.

Also, this LC noise filter is used as an IC or L
When used by inserting directly into the SI power supply line or signal line, the LC noise filter and the IC, etc. must be wired, and there is the problem that it takes time to assemble the components.

Further, since this LC noise filter is formed as a single component, there is a problem that it is almost impossible to include it in an IC or LSI circuit, that is, to insert it in an internal conduit of the IC or LSI. there were.

Furthermore, the capacitor formed in a distributed constant in this LC noise filter is determined by the shape and arrangement of each of the inductor conductor and the capacitor conductor, so that the capacitance is constant after the component is completed. Therefore, there is a problem that the characteristics as a whole are fixed and there is no versatility. For example, when it is desired to change only the capacitance, it is necessary to change the shape of the capacitor conductor, and it is difficult to arbitrarily change and use the capacitance in the incorporated circuit.

Therefore, the present invention was created in view of the above-mentioned points, and its purpose is to simplify the manufacturing process and to eliminate the work of assembling parts in the subsequent steps, and further to realize the IC and LSI. An object of the present invention is to provide an LC element that can be formed as a part, a semiconductor device, and a method for manufacturing the LC element.

Another object of the present invention is to provide an LC element, a semiconductor device and a method for manufacturing an LC element, the characteristics of which can be arbitrarily changed by changing the capacitance existing in a distributed constant as required. To do.

[0013]

In order to solve the above-mentioned problems, the LC element according to claim 1 is in the same plane,
Two spiral-shaped electrodes that are arranged substantially concentrically and adjacent to each other, and a p region is formed at a position along the two electrodes, and a p region is electrically connected to one of these two electrodes and an n region is electrically connected to the other. A spiral-shaped pn junction layer connected to each other, and an inductor formed by each of the two electrodes and a capacitor formed by the pn junction layer between these two electrodes exist in a distributed constant manner. However, at least one of the two electrodes is used as a signal input / output path .

According to another aspect of the LC element of the present invention, two spirally-shaped electrodes having different lengths, which are arranged concentrically and adjacent to each other in the same plane, are arranged along the shorter side of the two electrodes. Is formed at a position, and p is formed on either one of the two electrodes.
A spiral-shaped pn junction layer in which an n region is electrically connected to the other region, the inductor formed by each of the two electrodes, and the pn junction layer between the two electrodes. a capacitor is present in distributed constant to be, Shin at least one of the two electrodes
It is used as a signal input / output path .

The LC element of claim 3 is the same as that of claim 1 or 2.
In the LC element, one of the two electrodes is divided into a plurality of pieces, or the corresponding pn junction layer is divided into a plurality of pieces together with one of the two electrodes, and each of a plurality of divided electrode pieces is divided. It is characterized in that a part of is electrically connected.

An LC element according to a fourth aspect is the LC element according to any one of the first to third aspects, wherein the first and second LC elements are provided near both ends of one of the two spiral electrodes.
The input / output electrode and a ground electrode provided near one end of the other of the two spiral electrodes,
And a signal is output from the other of the second input / output electrodes and a signal is output from the other, and the earth electrode is connected to a fixed potential power source or grounded.

The LC element of claim 5 is the same as claim 1 or 2
In the LC element, the first and second input / output electrodes provided near both ends of one of the two electrodes, and the third and fourth input / output electrodes provided near both ends of the other of the two electrodes. And an input / output electrode, and each of the two electrodes is used as a common mode type element as a signal input / output path.

An LC element according to a sixth aspect is the LC element according to any one of the first to fifth aspects, wherein a signal of a reverse bias voltage level of the pn junction layer is input to the two spiral electrodes. It is characterized by performing.

An LC element according to a seventh aspect is the LC element according to any one of the first to fifth aspects, wherein the bias circuit applies a predetermined reverse bias voltage to the pn junction layer, and a signal obtained by removing a DC component from an input signal. Is further input to at least one of the two electrodes, and a direct current component removing circuit is further included.

An LC element according to claim 8 is the LC element according to any one of claims 1 to 5, wherein an insulating layer is formed between at least one of the two spiral electrodes and the pn junction layer, A bias circuit for applying a predetermined reverse bias voltage is provided to the pn junction layer.

The LC device according to claim 9 is the LC device according to claim 7 or 8.
In the LC element, the bias circuit can change the reverse bias voltage applied to the pn junction layer,
The capacitance of the pn junction layer is arbitrarily changed by changing the reverse bias voltage applied to the n junction layer.

A semiconductor device according to claim 10 is the semiconductor device according to any one of claims 1 to 9.
One of the LC elements is formed as a part of the substrate, and at least one of the two spiral electrodes is inserted into a signal line or a power supply line for integral molding.

The LC element according to claim 11 is the LC element according to any one of claims 1 to 3, wherein the pn is formed on a semiconductor substrate.
A bonding layer is further formed on the bonding layer, and the two spiral electrodes are formed on the entire surface of the semiconductor substrate by a chemical liquid phase method.
It is characterized in that an insulating film is formed, a part of the insulating film is removed by etching or laser light irradiation to form a hole, and the hole is sealed with solder so that it is raised to the surface for terminal attachment.

According to a twelfth aspect of the present invention, there is provided a method of manufacturing an LC device, comprising: a first step of forming a spiral p-type region or an n-type region on a semiconductor substrate;
A second step of forming a spiral pn junction layer by forming an n region or a p region which is an inversion layer on a part of the surface of the region or the n region, and the surface of the pn junction layer. , A third step of forming two spiral-shaped electrodes electrically connected to each of the p-region and the n-region, and a fourth step of forming a wiring layer connected to each of the two spiral-shaped electrodes The process of and is included.

[0025]

In the LC device of the first aspect, the two spiral electrodes are formed so as to be substantially concentric, that is, to circulate substantially in parallel. Therefore, each of these two electrodes functions as an inductor. Further, a pn junction layer is formed between these two electrodes along these two electrodes, and a distributed constant capacitor is formed between the two electrodes by this pn junction layer.

Therefore, the signal input to at least one of the above-mentioned two electrodes is propagated through the inductor and the capacitor existing in a distributed constant, and a good attenuation characteristic can be obtained over a wide band.

In particular, the LC element of claim 1 can be manufactured by forming a spiral pn junction layer on a semiconductor substrate and further forming two spiral electrodes on the surface side thereof. Very easy to manufacture.
Further, since this LC element is formed on a semiconductor substrate, it can be formed as a part of an IC or an LSI. Assembly work can be omitted.

Further, in the LC element of the second aspect, either one of the above-mentioned two spiral electrodes is formed short. Even in this case, similarly, each of the two electrodes having different lengths functions as an inductor, and a capacitor formed by the pn junction layer exists between these electrodes in a distributed constant manner. Therefore, this LC element has an effect that it has good attenuation characteristics over a wide band, is easy to manufacture, and can be formed as a part of a substrate.

The LC element according to claim 3 has the above-mentioned 2
Either one of the two electrodes is divided into a plurality of electrode pieces, and a part of these is electrically connected for use. In this case, by using the other undivided spiral-shaped electrode as a signal input / output path, a distributed constant type LC element having characteristics different from those of the LC element described above is obtained.

In particular, in claim 4, the first and second input / output electrodes are provided near both ends of one of the spiral electrodes of each of the LC elements described above, and one end of the other spiral electrode is provided. By providing the ground electrode in the vicinity, a three-terminal type LC element in which the spiral electrode on the side where the first and second input / output electrodes are provided is used as a signal input / output path is formed.

Further, in the present invention, a four-terminal common mode type LC element is formed by providing the third and fourth input / output electrodes at both ends of the other spiral electrode.

Further, in the LC element according to the sixth aspect, a signal having a voltage level such that a reverse bias is applied to the pn junction layer is input to each of the above-mentioned two spiral electrodes, so that the two electrodes are formed. Capacitors are surely formed in the distribution constant.

That is, since the pn junction layer can function as a capacitor when a reverse bias is applied, by inputting a signal such that the spiral pn junction layer functions as a capacitor, a wide band is obtained as a whole. Therefore, it can operate as an LC element having good attenuation characteristics.

Further, in the LC element of the seventh aspect, the reverse bias voltage to the pn junction layer is applied by the bias circuit. Further, a DC component removing circuit is provided corresponding to this, and the signal from which the DC component has been removed from the input signal is input while being superimposed on the reverse bias voltage applied from the bias circuit. As a result, the pn junction layer can be used with a complete reverse bias, and the spiral-shaped 2
A capacitor can be reliably formed between two electrodes.

Further, in the LC element of claim 8, an insulating layer is formed between at least one of the two spiral electrodes and the pn junction layer, and a reverse bias voltage is applied to the pn junction layer by a bias circuit. is doing. Therefore, also in this case, the pn junction layer can be surely operated as a capacitor, and as a whole, it operates as an LC element having a good attenuation characteristic in a wide band. Further, in this case, since the spiral electrode and the pn junction layer are separated from each other in terms of direct current by the insulating layer, it is not necessary to add the direct current component removing circuit as used in the above-mentioned claim 7.

Further, in the LC element of the ninth aspect, the reverse bias voltage applied by the bias circuit described above can be variably set. As a result, the capacitance of the capacitor formed between the two spiral electrodes can be arbitrarily changed, and the attenuation characteristic can be variably controlled as necessary.

According to a tenth aspect of the semiconductor device, the LC element according to each of the above-mentioned aspects is formed so as to be inserted into a signal line or a power supply line in a part of the substrate. As a result, it can be manufactured integrally with other components on the semiconductor substrate, which facilitates the manufacturing and eliminates the work of assembling the components in the subsequent process.

In the LC element of claim 11, an insulating film is formed on the entire surface by a chemical liquid phase method after the LC element of any of claims 1 to 3 described above is formed on a semiconductor substrate. After that, a hole is formed in a part of the insulating film by etching or laser light irradiation, and solder is put in the hole to attach a terminal. Therefore, it is possible to easily manufacture the surface mount type LC element, and the surface mount type LC element also facilitates the assembling work of the LC element.

A method of manufacturing an LC element according to a twelfth aspect is a method for manufacturing each of the above-mentioned LC elements by applying a semiconductor manufacturing technique. That is, a spiral p-type region or n-type region is formed in the first step, and then an inversion layer n-type region or p-type region is formed in a part of it in the second step to have a spiral shape as a whole. A pn junction layer is formed. Then, in the third step, the two electrodes having a spiral shape are formed to complete the LC element described above. Further, if necessary, a wiring layer connected to each of the two spiral electrodes is formed in a subsequent step.

As described above, the above-mentioned LC element can be manufactured by applying a general semiconductor manufacturing technique, and it is possible to reduce the size and cost, and
It is possible to mass-produce a plurality of pieces at the same time.

[0041]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An LC device of one embodiment to which the present invention is applied will be specifically described below with reference to the drawings.

First Embodiment FIG. 1 is a plan view of an LC device of a first embodiment to which the present invention is applied. 2 is an enlarged sectional view taken along the line AA of FIG.

As shown in these figures, the LC of this embodiment is
The device 100 is a p-type silicon substrate (p
And -Si substrate) of spiral shape formed in the vicinity of 24 the surface of the n ⁺ regions 22, it includes further and its p ⁺ region 20 of the part which is formed in a spiral shape, these n ⁺ regions 2
2 and the p + region 20 form a pn junction layer 26.
Further, as compared with the p-Si substrate 24 described above, the n ⁺ region 2
2 and the p ⁺ region 20 are set to have a high impurity concentration, and the p-Si substrate 24 and the n ⁺ region 22 are
A reverse bias voltage is applied between and to function as an isolation region. Actually, the reverse bias voltage may be surely applied by setting the same potential as that of the ground electrode 18 described later.

Further, the LC element 100 of this embodiment is on the surface side of the above-mentioned n ⁺ region 22, and the n ⁺ region 22 is
Spiral-shaped first spiral electrode 10 at a position along the
Are formed. Similarly, a surface side of the p ⁺ region 20, the second spiral electrode 12 is formed at a position along the p ⁺ region 20. Two input / output electrodes 14 and 16 are connected to both ends of the first spiral electrode 10. A ground electrode 18 is provided at one end (for example, the outer peripheral side) of the second spiral electrode 12. As described above, the attachment of the input / output electrodes 14 and 16 or the ground electrode 18 to the first and second spiral electrodes 10 and 12 is performed by using the thin n ⁺ region 22 or p as shown in FIG.
⁺ Outside the active area so as not to damage the area 20.

In the LC element 100 of this embodiment having such a structure, the spiral first and second spiral electrodes 10 and 12 respectively function as inductor conductors. In addition, the pn electrically connected to each of the first and second spiral electrodes 10 and 12
When the bonding layer 26 is used in the reverse bias state, it functions as a spiral capacitor. Therefore, the LC element 100 in which the inductor formed by the first and second spiral electrodes 10 and 12 and the capacitor formed by the pn junction layer 26 exist in a distributed constant is formed.

FIG. 3 is a diagram showing an equivalent circuit of the LC element 100 of this embodiment. As shown in FIG. 3A, the first spiral electrode 10 functions as an inductor having an inductance L1, and a signal input from one of the input / output electrodes 14 is propagated through the first spiral electrode 10. It is output from the other input / output electrode 16. Also, the second
The spiral electrode 12 functions as an inductor having the inductance L2, and the ground electrode 18 provided at one end is grounded or is used by being connected to the power supply of the fixed potential E.

In such a connection state, when the voltage level input to the input / output electrode 14 is set higher than the voltage level of the ground electrode 18 (0 V or fixed potential E), the n ⁺ region 22 and the p + region 22 are connected. Since a reverse bias voltage is applied to the pn junction layer 26 including the region 20, the pn junction layer 26 functions as a capacitor having the capacitor C. In addition, this capacitor is formed in a distributed constant over the entire length of the first spiral electrode 10 and the second spiral electrode 12, and is a conventional lumped constant LC.
It is possible to exhibit excellent damping characteristics that the element does not have.

In FIG. 3B, a reverse bias voltage is forcibly applied to the pn junction layer 26, which allows the pn junction layer 26 to reliably operate as a capacitor. Specifically, a bias power supply 28 for applying a predetermined reverse bias voltage is connected between the input / output electrode 14 and the ground electrode 18, and a capacitor for removing only the DC component in the input signal. 30 is connected to the input / output electrode 14 side. By adding such a circuit, a constant reverse bias voltage can be constantly applied to the pn junction layer 26, and a signal superimposed on this reverse bias voltage is input to the LC element 100 of this embodiment. can do.

Since the signal output from the input / output electrode 16 is applied with a reverse bias voltage, it is desirable to remove the reverse bias voltage by connecting a capacitor 32 to the outside of the signal.

Further, in FIG. 3C, instead of the bias power source 28 described above, a variable bias power source 34 capable of arbitrarily changing the reverse bias voltage level is connected. In general, the width of the depletion layer generated at the pn junction surface changes according to the magnitude of the reverse bias voltage applied to the pn junction layer 26, and the capacitance C also changes accordingly. Therefore, more varying the reverse bias voltage applied to the pn junction layer 26 via the two output electrodes 14 and 16, distributed constant arbitrarily varying the capacitance C present, LC element 100 as a whole The damping characteristics can be adjusted or changed.

FIG. 4 is a view showing the manufacturing process of the LC element 100 of this embodiment, and shows the state of each manufacturing process of the cross section taken along the line BB of FIG.

Growth of Epitaxial Layer: First of all,
After removing the oxide film on the surface of the p-Si substrate 24 (wafer), the n ⁺ -type epitaxial layer 25 is grown on the entire surface of the p-Si substrate 24 (FIG. 8A).

Formation of isolation region: Next, p-type impurities are diffused or ions are implanted to make the region other than the n ⁺ region 22 and the p ⁺ region 20 shown in FIG. 1 into an isolation region.

Specifically, first, the surface of the epitaxial layer 25 is thermally oxidized to form the oxide film 70. Then, after removing the oxide film 70 at the position where the p region is to be formed by photolithography, the p region is selectively formed by selectively adding p-type impurities by thermal diffusion or ion implantation. The p region thus formed becomes a part of the p-Si substrate 24 to form an isolation region (FIG. 2 (B)).

As a result of forming the isolation region in this way, the spiral-shaped n ⁺ region 22 is formed by the remaining epitaxial layer 25.

Formation of pn junction layer: Next, a p-type impurity is introduced into a part of the spirally formed n ⁺ region 22 by thermal diffusion or ion implantation to form a spiral p ⁺ region 20. To do.

Specifically, first, p- containing the n ⁺ region 22
The surface of the Si substrate 24 is thermally oxidized to form an oxide film 72. Then, the p ⁺ region 20 is formed by photolithography.
After removing the oxide film 72 at the position where the p ⁺ region is to be formed, the p ⁺ region 20 is selectively formed by selectively adding p-type impurities by thermal diffusion or ion implantation.

The p ⁺ region 20 is formed by the n ⁺ formed previously.
Since it needs to be formed in the region 22, the p ⁺ region 20 is formed by adding the p-type impurity in an amount equal to or larger than the amount of the n-type impurity that has already been introduced (FIG. 7C).

In this way, the spiral pn junction layer 26 consisting of the n ⁺ region 22 and the p ⁺ region 20 is formed.

Formation of spiral electrode: Next, an oxide film 74 is formed on the surface by thermal oxidation, and then spiral holes are formed on the respective surfaces of the n ⁺ region 22 and the p ⁺ region 20 by photolithography. The first and second spiral electrodes 10 and 12 are formed by, for example, vapor-depositing aluminum on the spirally formed portion.
Are formed ((D) in the figure). Further, thereafter, each of the two input / output electrodes 14 and 16 and the ground electrode 18 is formed by vapor deposition of aluminum.

Finally, P-glass is deposited on the entire surface and then heated to form a flat surface, whereby the LC element 100 is completed.

The process of manufacturing the LC element 100 of this embodiment is basically similar to the process of manufacturing a normal bipolar transistor or diode, and the shape of the pn junction layer 26 and the isolation region between them are different. It is different. Therefore, it can be dealt with by changing the shape of the photomask in the process of manufacturing a general bipolar transistor, which facilitates manufacturing and is suitable for downsizing. Further, it can be formed on the same substrate as semiconductor components such as general bipolar transistors and MOS-FETs, and can be formed as a part of IC or LSI. Moreover, when it is formed as a part of an IC or an LSI, it is possible to omit the work of assembling the parts in the subsequent process.

In the above-described manufacturing process of the present embodiment, the case where the n ⁺ region is first formed on the entire surface by epitaxial growth and then isolation is performed has been described as an example. However, on the surface of the p-Si substrate 24, After forming the oxide film, the spiral n-shaped film is formed by photolithography.
⁺ Performs Apertures corresponding to the region 22, formed directly p ⁺ region 20 after formation of the n ⁺ region 22 by introducing n-type impurities by thermal diffusion or ion implantation in this part, in the same manner You may. Further, as a method of forming the pn junction layer, a general semiconductor manufacturing technique can be used.

As described above, the LC device 100 of this embodiment is used.
Each of the first and second spiral electrodes 10 and 12 forms an inductor, and the spiral pn junction layer 26 formed between these electrodes functions as a capacitor by being used in reverse bias. . Moreover, since the pn junction layer 26 is formed over the entire length of the first and second spiral electrodes 10 and 12, the inductances L1 and L2 formed in the first and second spiral electrodes 10 and 12 and the pn junction layer are formed. The capacitance C formed by 26 exists in a distributed constant.

Therefore, when the ground electrode 18 provided at one end of the second spiral electrode 12 is connected to ground or a fixed potential and the first spiral electrode 10 is used as a signal input / output path, The LC element has a good attenuation characteristic in a wide band with respect to the input signal.

Further, as described above, this LC device 100
Can be manufactured by applying the manufacturing technology of a general bipolar transistor and the like, and is therefore easy to manufacture and suitable for miniaturization. In addition, when this LC element is manufactured as a part of a semiconductor substrate, wiring with other components can be performed at the same time, which eliminates the need for assembling work in a subsequent process.

In addition, the LC element 100 of this embodiment has a pn
By changing the value of the reverse bias voltage applied to the junction layer 26, the capacitance C of the capacitor formed in a distributed constant can be variably controlled, and the overall frequency characteristic of the LC element 100 can be adjusted or changed. it can.

Second Embodiment Next, an LC element according to a second embodiment of the present invention will be specifically described with reference to the drawings.

The LC device 100 of the first embodiment described above is
Parallel over the entire length first and second spiral electrode 10, 12 is substantially, ie, those that are formed on substantially the same length, LC element 200 of this embodiment, the second as shown in FIG. 1 The spiral electrode 12 is shortened by about 1 turn, and the corresponding pn junction layer 26 is shortened by about 1 turn.

FIG. 5 is a plan view of the LC device 200 of the second embodiment. As shown in FIG. 5, the second spiral electrode 1
2 and the corresponding pn junction layer 26 are partially omitted, the inductor formed by the shortened second spiral electrode 12 and the shortened pn junction layer 26
Since the capacitor formed by the above is formed in a distributed constant, it has a good attenuation characteristic as in the LC element 100 shown in FIG.

FIG. 6 is a diagram showing an equivalent circuit of the LC element 200 of this embodiment. As shown in FIG. 7A, the inductance L3 is reduced by the number of turns of the second spiral electrode 12, and correspondingly the capacitance C1 existing in a distributed constant is also reduced.

Further, as shown in FIGS. 6B and 6C, a capacitor 30 is connected between the input / output electrode 14 and the ground electrode 18 together with the bias power source 28 or the variable bias power source 34. As a result, the pn junction layer 26
It is possible to reliably realize the reverse bias of
As in the first embodiment, the characteristic value can be changed by variably controlling the value of the reverse bias voltage.

As described above, the LC device 200 of this embodiment
Is the first and second spiral electrodes 10, 1 whose one is short.
In addition, by forming the pn junction layer 26 between them, the inductor and the capacitor exist in a distributed constant manner and can function as an element having a good attenuation characteristic. The first described above the LC element 200 and that can be produced by using a semiconductor manufacturing technique, the points can be omitted wiring process in a subsequent step in this case or the like it is possible to form a part such as an LSI L of the embodiment
It is the same as the C element 100.

[0074]Third embodiment Next, a diagram of the LC element 300 of the third embodiment of the present invention is shown.
A specific description will be given with reference to the surface.

Although the LC element 100 of the first embodiment and the LC element 200 of the second embodiment described above function as a three-terminal type normal mode element, the LC element 300 of this embodiment is It is characterized in that it is formed so as to function as a 4-terminal common mode element.

FIG. 7 is a plan view of the LC device of the third embodiment. As shown in the figure, the LC device 300 of the third embodiment.
The input / output electrodes 3 on both ends of the second spiral electrode 12.
6 and 38 are provided, and this point shows the LC shown in FIG.
Different from the element 100.

FIG. 8 is a diagram showing an equivalent circuit of the LC element of the third embodiment. As shown in FIG. 3A, the first spiral electrode 10 formed between the two input / output electrodes 14 and 16 functions as an inductor having an inductance L1 and the space between the two input / output electrodes 36 and 38. The second spiral electrode 12 formed on the
2 functions as an inductor. Moreover, the LC element 10 of the first embodiment is provided between these two inductors.
A capacitor having a capacitance C similar to 0 is pn
The bonding layer 26 is formed in a distributed constant manner.

As described above, in the LC device 300 of this embodiment, the two input / output electrodes 36 and 38 are provided not only on the first spiral electrode 10 but also on the opposite ends of the second spiral electrode 12, so that good attenuation is achieved. It can function as a 4-terminal common mode element having characteristics.

Further, since the pn junction layer 26 operates as a capacitor when the first spiral electrode 10 has a high relative potential with respect to the second spiral electrode 12 in reverse bias, the above-mentioned four-terminal common mode element is used. In order to operate as, the signal level input to the first spiral electrode 10 side needs to be set higher than the signal level input to the second spiral electrode 12 side.

In FIG. 8B, the reverse bias voltage is forcibly applied between the first and second spiral electrodes 10 and 12. The application of the reverse bias voltage is performed by the bias power supply 28. Done by. In addition, L of this embodiment
In the C element 300, since signals are input to both the input / output electrodes 14 and 36, the capacitor 40 is connected to the input / output electrode 36 side in addition to the capacitor 30 used in the first embodiment.

Thus, the two capacitors 30, 40
By using, the DC component is removed from the signals input to the two input / output electrodes 14 and 36, and only the AC component of each signal is superimposed on the reverse bias voltage applied from the bias power supply 28. LC of this example
It is input to the element 300.

Therefore, the LC device 300 of the present embodiment.
Can surely apply a reverse bias voltage to the pn junction layer 26, and a capacitor is formed in a distributed constant manner together with the inductor. As a result, good damping characteristics can be obtained.

Further, FIG. 8C is a diagram in which the bias power source 28 in FIG. 8B is replaced with a variable bias power source 34. That is, the reverse bias voltage can be variably set by the variable bias power supply 34, which allows the capacitance C of the pn junction layer 26 to be changed, that is, the characteristic value of the entire LC element 300 to be changed.

Fourth Embodiment Next, an LC device according to a fourth embodiment of the present invention will be specifically described with reference to the drawings.

The LC elements 100 and 20 of the above-mentioned respective embodiments
In each of 0 and 300, the second spiral electrode 12 was formed of one conductor, but the LC element 40 of the present embodiment was used.
0 is a plurality of second spiral electrodes 12 (for example, 3
It is characterized in that it is divided into (piece) divided electrode pieces 12-1, 12-2, 12-3.

FIG. 9 is a plan view of the LC device of the fourth embodiment. As shown in the figure, the LC device 400 of the fourth embodiment
Is a second element used in the LC device 100 shown in FIG.
The spiral electrode 12 of the three divided electrode pieces 12-1, 1
It has a structure replaced with 2-2, 12-3. These divided electrode pieces 12-1 having a spiral shape as a whole
The ground electrode 18 is connected to each of ~ 12-3, and by grounding the three ground electrodes 18,
One end of the inductor formed by each of the divided electrode pieces 12-1 to 12-3 is grounded. Alternatively,
By connecting the three ground electrodes 18 to a power source having a fixed potential, one end of the inductor formed by each of the divided electrode pieces 12-1 to 12-3 has the fixed potential.

FIG. 10 is a diagram showing an equivalent circuit of the LC element 400 of the fourth embodiment. As shown in FIG. 4A, the entire first spiral electrode 10 functions as an inductor having an inductance L1, and each of the divided electrode pieces 12-1, 12-2, 12-3 has an inductance L3. It functions as an inductor having L4 and L5. The pn junction layer 26 between the first spiral electrode 10 and each of the divided electrode pieces 12-1 to 12-3 functions as a capacitor having capacitances C1, C2, C3, and these capacitors are distributed. There is a constant number.

Further, in FIG. 10 (B) and FIG. 10 (C),
A circuit for applying a forced reverse bias voltage or a variably settable reverse bias voltage is shown. These drawings correspond to FIGS. 3B and 3C. With such a circuit configuration, the pn junction layer 26 can be reliably operated as a capacitor,
Or by changing the capacity of this capacitor, LC
The characteristics of the element 400 as a whole can be changed.

In the LC element 400 of this embodiment, the self-inductances L3, L4, L5 of the divided electrode pieces 12-1, 12-2, 12-3 are small. Therefore,
The influence of the characteristics of the entire LC element 400 due to these self-inductances is reduced, and the first spiral electrode 10
The characteristic of the LC element as a whole is substantially determined by the inductance L1 and the capacitances C1, C2, C3 formed in a distributed constant.

Other Examples Next, LC elements according to other examples of the present invention will be specifically described with reference to the drawings.

FIG. 11 and FIG. 12 are diagrams showing the outline of the case where terminals are attached using the chemical liquid phase method. Figure 11
FIG. 3 is a plan view of the LC element 500 of this embodiment corresponding to FIG. 1 and the like. As shown in the figure, input and output are provided at both ends of the first and second spiral electrodes 10 and 12 of the LC element 500. The electrode 14 and the like are not provided. After separating the semiconductor substrate including the first and second spiral electrodes 10 and 12 having such a shape, as shown in FIG. 12 showing a cross section taken along the line CC of FIG. A silicon oxide film 42 is formed as an insulating film on the entire surface of (1) by a chemical liquid phase method. After that, the silicon oxide film 42 on the end portions of the first and second spiral electrodes 10 and 12 is removed by etching to make a hole, and the hole is sealed with solder 44 to the extent that it rises on the surface, so that the protruding solder 44
Can be brought into direct contact with the land of the printed wiring board, which is convenient for surface mounting.

Incidentally, another insulating material such as synthetic resin may be used for the protective film on the surface of the element, and a laser beam may be used for perforating the protective film.

FIG. 13 shows the LC element 1 of each of the above-mentioned embodiments.
It is explanatory drawing at the time of forming 00 etc. as a part of LSI etc. As shown in the figure, each of the LC elements 10 described above is connected to a line 48 of various signals or a power source on the semiconductor chip 46.
Incorporate by inserting 0 etc. In particular, the LC element 100 and the like of each of the above-described embodiments can be manufactured at the same time in the process of forming various circuits on the semiconductor chip 46, so that there is an advantage that the wiring process and the like in the subsequent process are unnecessary.

FIG. 14 shows the LC element 1 of each of the above-mentioned embodiments.
It is a figure which shows the example which connected the buffer to the output side, such as 00. FIG. 1A shows a case where a source follower circuit 50 including a MOS-FET and a resistor is used as a buffer. MOS-F which constitutes this source follower circuit 50
Although the ET has a configuration slightly different from that of the LC element of each of the above-described embodiments, it can be formed on the same semiconductor substrate, so that the entire source-follower circuit 50 is integrally formed as an LC element. be able to.

Further, FIG. 6B shows a case where an emitter follower circuit 52 composed of two bipolar transistors and a resistor is used as a buffer. Since the bipolar transistor forming the emitter follower circuit 52 has the same structure as the LC element of each of the above-described embodiments, the whole including the emitter follower circuit 52 can be integrally formed as an LC element. .

14A and 14B show the case where the LC element 100 of the first embodiment is used as an example,
The same applies when the LC elements 200 to 400 of the other examples are used. However, the LC element 300 of the third embodiment
Since both the first and second spiral electrodes 10 and 12 are used as signal input / output paths, the source follower circuit 50 or the emitter follower circuit 52 described above is connected to the output side of the second spiral electrode 12 as well. .

By thus providing the buffer on the output side, the frequency component of a relatively wide band is removed by the LC element 100 and the like, and the first spiral electrode 1
A signal level attenuated by passing through 0 or the like is restored by amplification, and it becomes possible to obtain an output signal having a good SN ratio.

FIG. 15 is a diagram showing an example in which a level conversion circuit is connected to the output side of the LC element of each of the above-mentioned embodiments.
FIG. 1A shows a case where two emitter follower circuits 54 and 56 are connected in series as a level conversion circuit. FIG. 2B shows a case where two source follower circuits 58 and 60 are connected in series as a level conversion circuit. By connecting the level conversion circuit to the output side in this way, the signal level attenuated by the first spiral electrode 10 of the LC element and the like is amplified, and predetermined level conversion or level correction is easily performed. be able to.

Note that the level conversion circuits can be integrally formed on the same semiconductor substrate as the LC element of each embodiment, as in the case of the buffer described above.

In the LC element 300 of the third embodiment, the circuit shown in FIGS. 15A and 15B is also connected to the output side of the second spiral electrode 12 in the case of the buffer described above. Is the same as.

FIG . 16 shows the LC element 1 of each of the above-mentioned embodiments .
It is a figure which shows an example at the time of comprising a voltage control oscillator (VCO) using 00 etc. As shown in the figure, an amplifier 61 is connected to the output side of the LC element of each of the above-described embodiments, and the output of this amplifier is fed back to the input side of the LC element. The oscillation operation is performed by forming such a feedback loop. Moreover, the oscillation frequency is arbitrarily set within a certain range by using the control voltage applied from the outside to the input / output electrode 14 side as the reverse bias voltage, that is, by changing the capacitance existing in a distributed constant accordingly. Can be changed to

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

For example, in each of the above-mentioned embodiments, p
The first and second spiral electrodes 1 are formed on the surface of the n-junction layer 26.
0 and 12 are formed in direct contact with each other, but an insulating layer 6 such as SiO ₂ is formed between at least one of the first and second spiral electrodes 10 and 12 and the pn junction layer 26.
2 may be interposed.

FIG. 17 shows the pn junction layer 26 and the first and second layers.
Absolute between at least one of the spiral electrodes 10, 12 and the
It is a figure which shows the cross-section structure in the case of forming an edge layer .

FIG. 10A shows two spiral electrodes 1
This is a case where both 0 and 12 are formed via the insulating layer 62. In this case, a reverse bias voltage is directly applied to the pn junction layer 26, and an input provided at one end of the first spiral electrode 10 is also applied. A signal can be directly input to the output electrode 14. That is, between the first spiral electrode 10 and the n ⁺ region 22 arranged via the insulating layer 62,
Alternatively, the part between the second spiral electrode 12 and the p ⁺ region 20 functions as a capacitor, and the capacitor 3 for removing the DC component as shown in FIG.
0 becomes unnecessary.

Further, FIG. 17B shows the case where the insulating layer 62 is formed only on the second spiral electrode 12 side, and conversely, FIG. 17B shows the case where the insulating layer 62 is formed only on the first spiral electrode 10 side. In each case, the case is formed. Also in these cases, as in the case of FIG. 7A, a reverse bias voltage is directly applied to the pn junction layer 26, and a signal is directly applied to the input / output electrode 14 provided on one end side of the first spiral electrode 10. You can enter.

In each of the above-described embodiments, the first step is performed by depositing aluminum or the like in the last step.
Since the second spiral electrodes 10 and 12 are formed as shown in FIG.
As shown in FIG. 18, a spiral groove is formed in a part of the pn junction layer 26 by etching or the like, so that the spiral electrodes 10 are formed on the pn junction layer 26 as shown in FIG. 12 may be embedded. By doing so, it is possible to form a substantially flat LC element without unevenness on the surface side, and the assembling work and the like become easy.

In each of the above embodiments, p-S
Although the LC element was formed using the pnp structure including the i-substrate 24, the npn structure may be used in the same manner.
FIG. 19 is a diagram showing a partial cross section of an LC element having an npn structure. With such a structure, pn
It is necessary to reverse the polarity of the reverse bias voltage applied to the bonding layer. FIG. 20 is a diagram showing a configuration in which the polarities of the reverse bias voltage applied in this manner are reversed.
A circuit corresponding to FIG. 3C is shown.

Further, in each of the above-described embodiments, the first and second spiral electrodes 10 and 12 and the pn junction layer 26 having a substantially circular spiral shape were considered, but the spiral shape as a whole may be used. For example, it may be a square or other spiral shape.

However, generally, by forming the first and second spiral electrodes 10 and 12 and the pn junction layer 26 in a spiral shape, these electrodes function as an inductor conductor having an inductance component. When the frequency band of the generated signal is limited to high frequency, it functions as an inductor conductor having an inductance component even if it has a shape other than the spiral shape, for example, an arbitrary meandering shape such as a waveform, a simple linear shape or a curved shape. As a result, the LC element has a good attenuation characteristic.

In each of the above embodiments, LC
Although the advantage that the element 100 or the like can be formed as a part of the LSI or the like has been described, it is not always necessary to form it as a part of the LSI or the like, and the input / output electrodes 14, Terminals may be attached to each of 16 and the ground electrode 18, or may be attached using the chemical liquid phase method as shown in FIG. 12 to form a single element. In this case, if a plurality of LC elements 100 etc. are formed simultaneously on the same semiconductor substrate and then the semiconductor substrate is separated and each LC element 100 etc. is terminal-attached, mass production is easily possible. Becomes

Further, in the above-described first embodiment and the like, the second spiral electrode 12 located outside is grounded or connected to a fixed potential. However, the first and second spiral electrodes 10, The arrangement of 12 may be reversed. Although the ground electrode 18 is provided at one end on the outer peripheral side of the second spiral electrode 12, the ground electrode 18 may be provided at one end on the inner peripheral side. Further, the input / output electrodes 14 and 16 and the ground electrode 18 are not always required.
Does not have to be provided at the extreme end, and its mounting position may be shifted as necessary.

Further, the LC element 100 of each of the above-mentioned embodiments
Etc., the capacitance of a capacitor existing in a distributed constant also changes by changing the reverse bias voltage.
The frequency characteristics of the element can be variably controlled. Therefore, by using the LC element 100 or the like as a part of the circuit, it is possible to easily configure a tuning circuit, a modulation circuit, an oscillation circuit, a filter and the like.

Further, the LC device 100 of each of the above-mentioned embodiments.
In the above, the case where the pn junction layer 26 is formed on the p-Si substrate 24 has been described as an example. However, when another type of semiconductor such as germanium is used, or when an amorphous material such as amorphous silicon is used. May be

Further, the LC device 100 of each of the above-mentioned embodiments.
And the like, both the first and second spiral electrodes 10 and 12 are provided on one surface (front surface) side of the pn junction layer 26, but these two electrodes 10 and 12 are substantially opposed to each other. It may be arranged so that a pn junction layer is inserted between them.

[0116]

As described above, according to the first aspect of the present invention, the signal input to at least one of the two spiral electrodes is propagated through the inductor and the capacitor existing in a distributed constant, Good attenuation characteristics can be obtained over a wide band. Further, this LC element can be manufactured by forming a spiral pn junction layer on a semiconductor substrate and further forming two spiral electrodes on the surface side thereof, which is extremely easy to manufacture. Become. Moreover, since this LC element is formed on the semiconductor substrate,
It is also possible to form it as part of an IC or LSI,
When it is formed as a part of such a component, the work of assembling the component in the subsequent process can be omitted.

According to the second aspect of the present invention, each of the two spiral-shaped electrodes, one of which is shortened, functions as an inductor, and the capacitor formed by the pn junction layer exists in a distributed constant manner. Therefore, as in the case of claim 1 described above, good attenuation characteristics can be obtained over a wide band, and the manufacturing is easy, and it is possible to manufacture as a part of the substrate.

Further, according to the invention of claim 3, one of the above-mentioned two electrodes is divided into a plurality of electrode pieces and a part of these is electrically connected for use.
By using the other undivided spiral-shaped electrode as the signal input / output path, a distributed constant type LC element having characteristics different from those of the above-described LC element can be obtained.

According to the fourth aspect of the invention, the first and second input / output electrodes are provided near both ends of one of the spiral electrodes of each of the LC elements described above, and the other spiral electrode is provided. By providing a ground electrode near one end of the electrode, the spiral electrode on the side where the first and second input / output electrodes are provided is used as a signal input / output path.
It can be a terminal type LC element.

According to the fifth aspect of the invention, a four-terminal common mode type LC element can be obtained by providing the third and fourth input / output electrodes also at both ends of the other spiral-shaped electrode. it can.

According to the sixth aspect of the present invention, by inputting a signal of a voltage level such that a reverse bias is applied to the pn junction layer to each of the two spiral-shaped electrodes described above, two electrodes are input. Capacitors can be reliably formed between electrodes in a distributed constant manner.

According to the seventh aspect of the invention, the reverse bias voltage to the pn junction layer is applied by the bias circuit, and the DC component removing circuit is provided corresponding to this, and the DC component is removed from the input signal. Since the removed signal is input by being superimposed on the reverse bias voltage applied from the bias circuit, the pn junction layer can be used with a complete reverse bias, and a capacitor is reliably formed between two spiral electrodes. can do.

Further, according to the invention of claim 8, an insulating layer is formed between at least one of the two spiral electrodes and the pn junction layer, and a reverse bias voltage is applied to the pn junction layer by the bias circuit. ing. Therefore, also in this case, the pn junction layer can be surely operated as a capacitor, and can be operated as an LC element having good attenuation characteristics in a wide band as a whole. In this case, the insulating layer and the spiral electrode and p
Since the n-junction layer is DC-separated, it is not necessary to add the DC component removing circuit as used in the above-mentioned claim 7.

According to the ninth aspect of the invention, since the reverse bias voltage applied by the bias circuit described above can be variably set, the capacitance of the capacitor formed between the two spiral electrodes can be reduced. It can be arbitrarily changed, and the damping characteristic can be variably controlled as needed.

According to the invention of claim 10, the LC element of each of the above-mentioned claims is formed so as to be inserted into a signal line or a power supply line in a part of the substrate, and other parts on the semiconductor substrate. Since it can be manufactured integrally, the manufacturing is facilitated and the work of assembling parts in the subsequent process is not required.

According to the eleventh aspect of the present invention, after the LC element is formed on the semiconductor substrate, the insulating film is formed by the chemical liquid phase method, and then a hole is formed in a part of the insulating film. Terminals are formed by placing solder, and a surface mount type LC element can be easily manufactured. By using the surface mount type, the assembling work of this LC element becomes easy.

According to the twelfth aspect of the present invention, each of the above-mentioned LC elements can be manufactured by applying a general semiconductor manufacturing technique, and it is possible to reduce the size and cost, and at the same time, to reduce a plurality of elements. It is also possible to mass-produce individual pieces at the same time.

[Brief description of drawings]

FIG. 1 is a plan view of an LC device according to a first embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view taken along the line AA of FIG.

FIG. 3 is a diagram showing an equivalent circuit of the LC element of the first embodiment.

FIG. 4 is a diagram showing a manufacturing process of the LC element of the first embodiment.

FIG. 5 is a plan view of an LC device according to a second embodiment.

FIG. 6 is a diagram showing an equivalent circuit of the LC element of the second embodiment.

FIG. 7 is a plan view of an LC device according to a third embodiment.

FIG. 8 is a diagram showing an equivalent circuit of the LC element of the third embodiment.

FIG. 9 is a plan view of an LC device according to a fourth embodiment.

FIG. 10 is a diagram showing an equivalent circuit of an LC element of the fourth embodiment.

FIG. 11 is a diagram schematically showing a case where terminals are attached using a chemical liquid phase method.

FIG. 12 is a diagram schematically showing a case where terminals are attached using a chemical liquid phase method.

FIG. 13 is an explanatory diagram when the LC element of each example is formed as a part of an LSI or the like.

FIG. 14 is a diagram showing an example in which a buffer is connected to the output side of the LC element of each example.

FIG. 15 is a diagram showing an example in which a level conversion circuit is connected to the output side of the LC element of each example.

FIG. 16 is a diagram showing an example of a case where a voltage controlled oscillator is configured using the LC element of each example.

FIG. 17 is a diagram showing a cross-sectional structure when an insulating film is formed between the pn junction layer and at least one of the first and second spiral electrodes.

FIG. 18 is a diagram showing a cross-sectional structure when a spiral electrode is embedded.

FIG. 19 is a diagram showing a partial cross section of an LC element having an npn structure.

FIG. 20 is a diagram showing a configuration in which the reverse bias voltage to be applied has opposite polarities.

[Explanation of symbols]

10 First spiral electrode 12 Second spiral electrode 14, 16 Input / output electrodes 18 Earth electrode 20 p + area 22 n + area 24 p-Si substrate 25 Epitaxial layer 26 pn junction layer 28 Bias power supply 30, 32 capacitors 34 Variable bias power supply

Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01L 21/822 H01F 27/00 H01L 27/04 H03H 7/075

Claims (10)

(57) [Claims] 1. An LC device formed on a semiconductor substrate.
To form a spiral shape on the surface side of the semiconductor substrate.
And n in one polarity region, and one in the one polarity region.
The other pole of p and n formed along the region of one polarity
Of the pn junction layer including a conductive region and the one-polarity region and the other-polarity region.
It comprises two electrodes adjacent to arranged spiral shape, for the two electrodes, the reverse bias of the pn junction layer
By inputting the signal of the voltage level of
The pn junction layer between the two electrodes divides the capacitor.
Cloth constant manner to form an inductor formed by respective front SL two electrodes, these two capacitors formed by the pn junction layer between the electrodes is present distributed constant type, of the two electrodes An LC element using at least one of them as a signal input / output path. 2. An LC device formed on a semiconductor substrate.
To form a spiral shape on the surface side of the semiconductor substrate.
And n in one polarity region, and one in the one polarity region.
The other pole of p and n formed along the region of one polarity
Of the pn junction layer including a conductive region and the one-polarity region and the other-polarity region.
Two spirally-shaped electrodes that are placed adjacent to each other and have different lengths
Comprising a pole, the said to the two electrodes, the reverse bias of the pn junction layer
By inputting the signal of the voltage level of
The pn junction layer between the two electrodes divides the capacitor.
Cloth constant manner to form an inductor formed by respective front SL two electrodes, these two capacitors formed by the pn junction layer between the electrodes is present distributed constant type, of the two electrodes An LC element using at least one of them as a signal input / output path. 3. The method according to claim 1, wherein either one of the two electrodes is divided into a plurality of pieces, or the corresponding pn junction layer is divided into a plurality of pieces together with one of the two electrodes. L, characterized in that a part of each of the plurality of electrode pieces is electrically connected
C element. 4. The first and second input / output electrodes according to claim 1, wherein the first and second input / output electrodes are provided near both ends of one of the two spiral electrodes, and the two spiral electrodes are provided. A ground electrode provided in the vicinity of the other end of the electrode, and a signal is input from one of the first and second input / output electrodes and a signal is output from the other,
An LC element, wherein the ground electrode is connected to a power source having a fixed potential or grounded. 5. The first and second input / output electrodes according to claim 1, wherein the first and second input / output electrodes are provided near both ends of one of the two electrodes, and the two input and output electrodes are provided near both ends of the other of the two electrodes. An LC element having a third and a fourth input / output electrodes and used as a common mode type element using each of the two electrodes as a signal input / output path. 6. The bias circuit for applying a predetermined reverse bias voltage to the pn junction layer according to claim 1, and a signal obtained by removing a DC component from an input signal to at least one of the two electrodes. An LC device further comprising: a DC component removing circuit for inputting. 7. The method according to claim 1, wherein at least one of the two spiral electrodes and the p
An insulating layer is formed between the n-junction layer and
An LC element, comprising a bias circuit for applying a predetermined reverse bias voltage to the bonding layer. 8. The system of claim 6 or 7, wherein the bias circuit is capable of changing the reverse bias voltage applied to the pn junction layer, the pn junction layer by varying the reverse bias voltage applied to the pn junction layer L characterized by arbitrarily changing the capacitance of
C element. Any of the LC element 9. claims 1-8 formed as part of the substrate, that is integrally formed by inserting at least one of the two electrodes of spiral shape signal lines or power lines Characteristic semiconductor device. 10. The pn junction layer according to claim 1, wherein the pn junction layer is further formed on the semiconductor substrate, and the two spiral electrodes are formed on the pn junction layer, and the chemical liquid phase is formed on the entire surface of the semiconductor substrate. Characterized in that an insulating layer is formed by a method, a part of this insulating film is removed by etching or laser light irradiation to form a hole, and the hole is sealed to the extent that it rises on the surface for terminal attachment. LC
element.