JP3482004B2 - Sine wave oscillation circuit - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sine wave oscillating circuit for obtaining a sine wave signal having a predetermined frequency by utilizing LC resonance.

[0002]

2. Description of the Related Art Conventionally, a sine wave has been used in various fields such as communication, and various oscillation circuits for obtaining this sine wave are known. For example, various typical sine wave oscillating circuits utilizing LC resonance such as Colpitts type, Hartley type or base tuning type are known as typical circuits capable of obtaining high frequency sine waves.

In principle, each of these various sine wave oscillator circuits is constructed by combining an amplifier such as a transistor and an LC circuit, and determines each element constant in order to obtain a sine wave of a desired oscillation frequency. There is a need.

[0004]

By the way, in the conventional sine wave oscillation circuit, the inductor and the capacitor constituting the LC circuit are individually prepared and combined, so that the degree of freedom in design is increased, but the designer or the like is Many element constants are determined, which complicates the design. In particular, depending on the device using the sine wave, it is convenient if the desired oscillation frequency can be easily achieved by combining fewer types of components.

Further, many of the inductors forming the LC circuit have windings on the core or bobbin, and are generally unsuitable for integration. Therefore, even if the entire sine wave oscillation circuit including the LC circuit is to be integrated into an IC, there is a disadvantage that only the inductor has to be externally attached, and the entire circuit can be integrally formed on the semiconductor substrate. There was a problem that I could not.

The present invention has been made in view of the above points, and an object thereof is to provide a sine wave oscillation circuit capable of easily generating a sine wave by combining fewer types of components. It is in.

Another object of the present invention is to provide a sine wave oscillator circuit in which the entire circuit can be integrally formed on a semiconductor substrate.

[0008]

To solve SUMMARY OF THE INVENTION (1) the above-described problems, a sine wave oscillating circuit of the present invention includes an inverting amplifier for performing phase inversion amplifies an input signal, the shape formed on a semiconductor substrate by having two inductor conductor having a function as a primary and secondary winding, the with these two two by inductor conductor of the inductor and LC element and the capacitor Ru is formed distributed constant therebetween And connecting the output side of the inverting amplifier to the primary side of the LC element, and connecting the secondary side of the LC element to the input side of the inverting amplifier so as to be in antiphase with the primary side. Characterize.

(2) In the sine wave oscillating circuit of (1) , the inverting amplifier may be composed of an inverter logic circuit .
Yes .

(3) In the sine wave oscillating circuit of (1) , the inverting amplifier may be configured by a source-grounded circuit or a grounded-emitter circuit.

[0011] (4) a sine-wave oscillator of the invention, the
In the sine wave oscillator circuit according to any one of (1) to (3) ,
The LC elements are arranged substantially concentrically and adjacent to each other in the same plane, and the two spiral electrodes functioning as the two inductor conductors, and the two electrodes near the surface of the semiconductor substrate. A spiral shape that is formed along the electrodes and has one of these two electrodes electrically connected to the p region and the other to the n region, and acts as the capacitor by applying a reverse bias voltage. and pn junction layer may be configured to include a.

(5) In the sine wave oscillating circuit according to any one of (1) to (3) , the LC elements are arranged to face each other with the semiconductor substrate interposed therebetween, and the two inductor conductors are disposed. Two electrodes having a spiral shape functioning as an electric field and a position sandwiched by the two electrodes in the semiconductor substrate. One of these two electrodes has a p region and the other has an n region. are connected, the configuration and a pn junction layer of the spiral operating as the capacitor by applying a reverse bias voltage
You may .

(6) In the sine wave oscillating circuit according to any one of (1) to (3) , the LC elements are arranged substantially parallel and adjacent to each other in the same plane, and the two inductor conductors are arranged. Which are formed in a meandering shape and which are formed near the surface of the semiconductor substrate and along the two electrodes.
Region, n region are electrically connected to the other, a structure comprising a pn junction layer serpentine operating as the capacitor by applying a reverse bias voltage
Good .

(7) In the sine wave oscillation circuit according to any one of (1) to (3) , the LC elements are arranged to face each other with the semiconductor substrate interposed therebetween, and the two inductor conductors are disposed. Two meandering electrodes that function as
It is formed in the semiconductor substrate at a position sandwiched by the two electrodes, and one of these two electrodes is electrically connected to the p region and the other is electrically connected to the n region. a pn junction layer of the spiral operating as the capacitor by applying to, a structure comprising
Good .

(8) In the sine wave oscillating circuit according to any one of (4) to (7) , one of the two electrodes may be formed to be shorter than the other.

(9) In the sine wave oscillation circuit according to any one of (4) to (8) , the reverse bias voltage applied to the pn junction layer is changed to form the LC element in a distributed constant manner. It may be configured to change the capacitance value of the formed capacitor.

(10) In the sine wave oscillation circuit according to any one of (1) to (3) , the LC element includes a spiral electrode forming a gate in a MOS structure, the spiral electrode, and the semiconductor. An insulating layer formed between the substrate and the first and first insulating layers formed in the semiconductor substrate near both ends of a channel formed corresponding to the spiral-shaped electrode and functioning as a source and a drain. Two diffusion regions may be provided, and each of the spiral electrode and the channel formed corresponding thereto may be used as the two inductor conductors.

(11) In the sine wave oscillation circuit according to any one of (1) to (3) , the LC element includes a serpentine electrode that forms a gate in a MOS structure, the serpentine electrode, and the semiconductor. An insulating layer formed between the substrate and the first and first insulating layers formed in the semiconductor substrate near both ends of a channel formed corresponding to the meandering electrode and functioning as a source and a drain. Two diffusion regions may be provided, and each of the serpentine electrode and the channel formed corresponding thereto may be used as the two inductor conductors.

(12) In the sine wave oscillation circuit according to any one of (1) to (3) , the LC element includes a spiral first electrode forming a gate in a MOS structure,
An insulating layer formed between the spiral-shaped first electrode and the semiconductor substrate, and a spiral-shaped insulating layer formed on the surface of the semiconductor substrate and concentrically adjacent to the first electrode. Second electrode, and first and second diffusion regions formed in the semiconductor substrate near both ends of a channel formed corresponding to the spiral-shaped first electrode and functioning as a source and a drain. And a channel formed corresponding to the spiral-shaped first electrode and the second electrode may be used as the two inductor conductors.

(13) In the sine wave oscillation circuit according to any one of (1) to (3) , the LC element includes a serpentine first electrode forming a gate in a MOS structure, and the serpentine first electrode. And an insulating layer formed between the first electrode and the semiconductor substrate, and a meandering second electrode formed on the surface of the semiconductor substrate and adjacent to each other substantially parallel to the first electrode. And first and second diffusion regions formed in the semiconductor substrate near both ends of a channel formed corresponding to the meandering first electrode and functioning as a source and a drain. A channel formed corresponding to the first electrode having a meandering shape and the second electrode.
Each of the electrodes may be used as the two inductor conductors.

(14) In the sinusoidal oscillator circuit according to any one of (1) to (3) , the LC element is formed on one surface side of the semiconductor substrate and has a spiral shape forming a gate in a MOS structure. A first electrode, an insulating layer formed between the spiral-shaped first electrode and the semiconductor substrate, and formed on the other surface side of the semiconductor substrate and substantially facing the first electrode. And a second electrode having a spiral shape formed at a position corresponding to the first electrode having a spiral shape in the semiconductor substrate, the source and drain being formed near both ends of the channel formed corresponding to the first electrode having the spiral shape. configuration with the first and second diffusion regions functioning, comprising a, each of the channel formed in correspondence to said first electrode of the spiral shaped second electrode as said two inductor conductor age May be .

(15) In the sine wave oscillation circuit according to any one of (1) to (3) , the LC element is formed on one surface side of the semiconductor substrate and has a meandering shape that forms a gate in a MOS structure. A first electrode, an insulating layer formed between the meandering first electrode and the semiconductor substrate, and the insulating layer formed on the other surface side of the semiconductor substrate,
Second serpentine shape formed at a position substantially opposite to the electrode of
Electrode, and first and second diffusion regions formed in the semiconductor substrate near both ends of a channel formed corresponding to the meandering first electrode and functioning as a source and a drain. the provided, configured to use each of the channel formed in correspondence to the first electrode of the serpentine shape said second electrode as said two inductor conductor
It may be done .

(16) In the sine wave oscillating circuit according to any one of (10) to (11) , carriers are preliminarily injected into at least a part of a position near the surface of the semiconductor substrate where the channel is formed. by setting a longer or shorter length of the channel relative to the spiral shape or the electrode of the meandering, and the channel and the electrodes of spiral shape or meander shape it may be configured to be partially opposed.

(17) In the sine wave oscillating circuit according to any one of (12) to (15) , one of the first and second electrodes is formed to have a shorter length than the other. also with the second electrode of the spiral shape or meander shape and said channel as a to partially face
Good .

(18) The above (10) to (15), (1
In any one of 7) , the sine wave oscillation circuit may be configured such that carriers are injected in advance at a position near the surface of the semiconductor substrate where the channel is formed.

(19) In the sine wave oscillation circuit according to any one of (10) to (18) , the resistance value of the channel is made variable by changing the gate voltage applied to the electrode forming the gate. It can be configured to control
Yes .

(20) In the sine wave oscillating circuit according to any one of (1) to (3) , the LC element has a spiral shape formed directly on the semiconductor surface or with a first insulating layer sandwiched therebetween. A first electrode, a second insulating layer formed on the surface of the first electrode, and a spiral-shaped second electrode formed at a position substantially opposite to the first electrode with the second insulating layer interposed therebetween. comprising a second electrode, and to use each of the first and second electrode as said two inductor conductor structure
It may be done .

(21) In the sinusoidal oscillator circuit according to any one of (1) to (3) , the LC element has a meandering shape formed directly on the semiconductor surface or with a first insulating layer sandwiched therebetween. A first electrode, a second insulating layer formed on the surface of the first electrode, and a serpentine-shaped first insulating layer sandwiching the second insulating layer at a position substantially opposite to the first electrode. comprising a second electrode, and to use each of the first and second electrode as said two inductor conductor arrangement and
You may .

(22) Any of the above (20) to (21)
In either of the sine wave oscillator circuit, the second insulating layer may have a structure which is an oxide film formed by oxidizing the first electrode.

(23) Any of (20) to (21) above
In either of the sine wave oscillator circuit, the second insulating layer may have a structure which is a semiconductor oxide film or a nitride film formed by chemical vapor deposition.

[0031] (24) wherein (20) - In any of the sine wave oscillator circuit (23), configured to form shorter than either of the length of said first and second electrodes on the other
It may be done .

[0032] (25) wherein (1) In any of the sine wave oscillator to (24), and configured to be integrally formed on the semiconductor substrate which is common to the inverting amplifier and the LC element
You may .

[0033]

In the sine wave oscillating circuit of the above (1) , the output of the inverting amplifier is input to the primary side of the LC element formed on the semiconductor substrate, and the opposite phase of the reverse phase output from the secondary side of the LC element is output. The signal is input to the inverting amplifier again. Therefore, paying attention only to the phase of the signal, the LC element has 1
80 degrees out of phase, and the phase is 1 by the inverting amplifier
Since the phase is shifted by 80 degrees, the phase of the output signal and the phase of the signal returning in one cycle match. Moreover, since the above-described LC element is arranged such that the two inductor conductors are substantially parallel to each other and the distributed constant capacitor is formed between them, the specific frequency determined by these inductances and capacitances is high. Are selectively transmitted, and only the signal of this specific frequency is amplified to perform sine wave oscillation.

As described above , according to the invention of (1) ,
The sine wave oscillation is performed only by connecting the inverting amplifier and the LC element, and the sine wave can be easily generated by combining fewer types of components.

Further, since the above-mentioned LC element is formed on the semiconductor substrate, it is possible to form all the components including the inverting amplifier on the semiconductor substrate, and mass production using a semiconductor manufacturing technique or circuit Miniaturization is possible. In particular, each of these components can be formed on one semiconductor substrate, and in this case, the entire circuit is integrally formed on the semiconductor substrate, which facilitates mass production and miniaturization of the circuit.

In the sine wave oscillating circuit of (2) or (3) , the inverting amplifier described above is formed by a source ground circuit or an emitter ground circuit using an inverter logic circuit or a transistor. That is, each of these is to invert the logic of an input signal and output it, and at the same time, to amplify the voltage level of the input signal. Such a structure can be easily combined with a simple inverting amplifier and an LC element. Can generate waves. In particular,
The above-described inverter logic circuit, source grounded circuit, or grounded emitter circuit is generally formed on a semiconductor substrate, which is more convenient when integrally formed with other components.

The sine wave oscillator circuits (4) to (7) are
1 is a first example showing a specific configuration of the LC element used in (1) to (3) above .

According to the invention of the above (4) , two spiral electrodes arranged concentrically and adjacently on the semiconductor substrate, and a spiral pn formed along these two electrodes. The LC element described above is formed by the bonding layer. By applying a reverse bias voltage to this pn junction layer, a spiral capacitor is formed. Therefore, the inductor formed by each of the two electrodes and this capacitor are formed on the semiconductor substrate in a distributed constant manner. In particular, since this LC element is formed on a semiconductor substrate using a semiconductor manufacturing technique, it is convenient when integrally formed on a semiconductor substrate together with other components such as an inverting amplifier.

According to the invention of (5) above,
In (4) , two spiral electrodes, which are concentrically provided on the semiconductor substrate, are arranged so as to face each other with the semiconductor substrate sandwiched therebetween, thereby forming an LC element. As a result, an inductor formed by each electrode and a space between them are formed. The capacitor formed of the pn junction layer is formed in a distributed constant manner.
Similar to the LC element of claim 4, since this LC element is formed on the semiconductor substrate by using the semiconductor manufacturing technique, it is convenient when integrally formed with other components such as an inverting amplifier.

According to the inventions of (6) and (7) , the LC element is formed by replacing the spiral shape with the meandering shape of the electrodes in (4) and (5) . Generally, the conductor can be formed into a spiral shape to function as an inductor, but depending on the frequency band used, the conductor can also function as an inductor even when the conductor is formed in a meandering shape. That is,
When the electrode is formed in a meandering shape, one of each uneven portion 1
Since one coil has about 1/2 turn and these are connected in series, the entire electrode functions as an inductor having a predetermined inductance. In particular, when the frequency of the signal to be used reaches a high frequency region, a small inductance is sufficient, and thus a serpentine inductor may be sufficient.

In particular, when the electrode is formed in a meandering shape, there is an advantage in that when wiring is provided at one end or both ends of the electrode, this wiring can be drawn out without intersecting a part of the electrode. It is possible to simplify the entire manufacturing process.

Further, according to the invention of the above (8) , by forming one of the two electrodes to be short, the LC element in which the inductor conductors are partially opposed to each other is formed. Generally, the oscillation frequency of the entire sine wave oscillation circuit is determined by the inductance and the capacitance formed in a distributed constant. Therefore, if one electrode is made short to reduce the capacitance, the oscillation frequency is also increased. It will be changed. Therefore, the oscillation frequency can be adjusted within a certain range by changing the ratio of the electrodes which are partially opposed to each other, and the degree of freedom in designing the sine wave oscillation circuit is increased.

Further, when the lengths of the two electrodes are changed as described above, particularly when the electrodes on the secondary side are relatively lengthened to form an LC element having a winding ratio of 1: n (n> 1). Since the voltage level of the signal is amplified when the signal is fed back through the LC element that operates as a transformer, an inverting amplifier with a low amplification factor can be used, and the range of component selection can be expanded. Become.

Further, according to the invention of the above (9) , by changing the reverse bias voltage applied to the pn junction layer,
An LC element in which the capacitance value of a capacitor formed in a distributed constant can be changed is formed. Generally, the pn junction layer acts as a varicap by applying a variable reverse bias voltage. Therefore, by variably controlling the reverse bias voltage to be applied and operating the entire region of the pn junction layer having a spiral shape or a meandering shape as a varicap, an LC element whose frequency characteristic can be changed within a certain range can be obtained. . Therefore, the frequency selected by this LC element is also changed, and a voltage-controlled sine wave oscillation circuit can be easily realized.

The sine wave oscillating circuits (10) to (15) described above show a second example showing a specific configuration of the LC element used in the above (1) to (3) .

According to the invention of the above (10) or (11) , the gate has a spiral shape or a meandering shape.
An LC element having an S structure is formed, and a gate electrode and a channel formed corresponding thereto function as inductor conductors, respectively, and a distributed constant capacitor is formed between them. Each of these LC elements
It can be manufactured by using the usual process for manufacturing a MOS transistor simply by changing the shape of the mask and the like, which is convenient when integrally formed on a semiconductor substrate together with other components such as an inverting amplifier. In particular, when the inverting amplifier also has a MOS structure, for example, a MOS transistor or CMOS
When the inverter logic circuit such as the above is used, the entire sine wave oscillating circuit can have a MOS structure, which simplifies the manufacturing process and enables high-density mounting of each component, and a part of the IC or LCI. It is particularly convenient when incorporated as.

According to the inventions (12) to (15) ,
The LC element of MOS structure is formed by providing the second electrode so as to be substantially parallel to or substantially opposite to the gate electrode of the LC element of (10) or (11) , and the gate electrode is independent. It is used for reverse bias application. Therefore, it is possible to separate the voltage application to the gate electrode from the signal transmission via the channel or the second electrode, and it becomes easy to control the bias of the LC element.

According to the invention of (16) above,
The LC element is formed by partially facing the gate electrode and the channel in (10) or (11) . Generally, a channel is formed on the surface of the semiconductor substrate corresponding to the gate electrode, but by injecting carriers into at least a part of the position where the channel is formed in advance, when a predetermined gate voltage is applied. The channel may be formed only in a part of the region corresponding to the gate electrode.

According to the invention of (17) above,
An LC element is formed by shortening one of the two electrodes in (12) to (15) so that the channel and the electrode partially face each other.

As described above, also in the LC element having the MOS structure, the inductor conductors formed by the channels or the electrodes can be partially opposed to each other, and the oscillation frequency can be set within a certain range by changing the ratio of the partial opposition. The degree of freedom in designing the sine wave oscillator circuit can be increased.

Further, the channel or the electrode corresponding to the secondary winding is relatively lengthened so that the winding ratio is 1: n (n> n).
When the LC element of 1) is formed, since the voltage level of the signal is amplified when the signal is fed back through the LC element that operates as a transformer, an inverting amplifier with a low amplification factor can be used. The range of parts selection will be expanded.

According to the invention of (18) , the LC element is formed by previously injecting carriers into the position where the above-mentioned channel is formed, and the LC element has a depletion type MOS structure. It is an element. In particular, since the channel resistance and the current between the source and drain can be changed by adjusting the amount of carriers to be injected in advance, the characteristics of the LC element can be adjusted within a certain range, and the sine wave oscillator circuit can be designed freely. It will also increase the frequency.

According to the invention of (19) above,
An LC element having a variable channel resistance is formed by changing each gate voltage of (10) to (18) .
When the channel resistance, which is the resistance of one inductor conductor, is variably controlled in this manner, the frequency characteristic of the LC element is also changed according to the degree of the change.
It is possible to easily realize a voltage control type sine wave oscillation circuit.

According to the invention of (20) or (21) , the first electrode, the second insulating layer, and the second electrode are formed directly or after the first insulating layer is formed on the semiconductor substrate. The LC element is formed by stacking the layers. Moreover, by making these first and second electrodes substantially face each other, a distributed constant capacitor is formed between these two electrodes functioning as inductor conductors. This LC element is different from the LC element shown in the above (4) to (19) in that the inside of the semiconductor substrate is used, but the surface of the semiconductor substrate is used. In addition, it can be integrally formed with other components such as an inverting amplifier, which is suitable for mass production and miniaturization of a sine wave oscillation circuit.

Further, according to the invention of (22) or (23) , an LC element in which the insulating layer formed between the two electrodes is composed of an oxide or a nitride by electrode oxidation or chemical vapor deposition is provided. Has been formed. The step of forming the insulating layer and the step of forming the spiral or meandering electrode in this manner are realized by a general semiconductor manufacturing technique, and the entire sinusoidal oscillator circuit is integrally formed with other components. It will be convenient.

According to the invention of (24) above,
An LC element is formed by shortening one of the two electrodes in (20) to (23) and making these electrodes partially face each other.

As described above, also in the LC element formed by utilizing the surface of the semiconductor substrate, the inductor conductors formed by the two electrodes can be partially opposed to each other, and the ratio of partial opposition is changed. As a result, the oscillation frequency can be adjusted within a certain range and the signal to be fed back can be amplified at the same time, which also increases the degree of freedom in designing the sine wave oscillation circuit.

According to the invention of (25) , it is clarified that the entire sine wave oscillator circuit is integrally formed on the semiconductor substrate. That is, as described above, the LC element of each claim is formed by using a semiconductor substrate, and one of them is provided with an inverter logic circuit, an inverting amplifier composed of a source ground circuit and an emitter ground circuit, and other parts. It is easy to realize a sinusoidal oscillator circuit integrally formed on a semiconductor substrate.

[0059]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A sine wave oscillator circuit according to an embodiment of the present invention will be specifically described below with reference to the drawings.

[First Embodiment] FIG. 1 is a diagram showing a detailed configuration of a sine wave oscillation circuit 1 of a first embodiment to which the present invention is applied.

As shown in the figure, the sine wave oscillation circuit 1 of the first embodiment has an inverter logic circuit 10 functioning as an inverting amplifier and two inductors corresponding to primary and secondary windings when considered as a transformer. An LC element 12 having a conductor and in which a capacitor using a pn junction is formed between these two inductor conductors in a distributed constant manner, and a capacitor 14 for AC-grounding the input side of the inverter logic circuit 10. And a feedback resistor 16 for applying a predetermined bias voltage to the input side of the inverter logic circuit 10.

The inverter logic circuit 10 inverts the logic of the input signal, that is, shifts the phase by 180 degrees and outputs it, and also operates as an amplifier. This inverter logic circuit 10 can be realized by using any logic such as TTL logic, but it is a CMOS logic with a high input impedance and easy circuit design, and among them, a high-speed type for oscillating a high-frequency sine wave. Is 74HC
CMOS logic such as series is suitable.

The LC element 12 has two inductor conductors on a semiconductor substrate, these inductor conductors are two electrodes, and a pn junction layer between them forms a distributed constant capacitor. . In addition, the LC element 12
The electromagnetic coupling of these two inductor conductors also serves as a transformer as a whole, and one inductor conductor corresponds to the primary winding and the other inductor conductor corresponds to the secondary winding. The detailed structure of the LC element 12 will be described later.

The capacitor 14 is for connecting the inductor conductor on the secondary side of the LC element 12 and the input side of the inverter logic circuit 10 in an AC manner and separating them in a DC manner. It has a large capacitance that does not cause the deviation of

The resistor 16 is for applying a predetermined bias voltage to the input side of the inverter logic circuit 10. In general, the inverter logic circuit 10 operates as an inverting amplifier by using the input voltage so that the input voltage is close to a predetermined threshold value. Therefore, the bias voltage corresponding to this predetermined threshold value is applied by the resistor 16.

One end of the inductor conductor on the primary side of the LC element 12 described above is connected to the output end of the inverter logic circuit 10.
The other end is connected to the power line. Further, one end of the inductor conductor on the secondary side of the LC element 12 is connected to the capacitor 1
The other end is directly grounded to the input end of the inverter logic circuit via 4. By the way, in the pn junction layer formed between the inductor conductors of the LC element 12, an n region is formed corresponding to the primary side and a p region is formed corresponding to the secondary side (details will be described later). When a predetermined positive voltage is applied from the power supply line to the primary side of the LC element 12, this p
A reverse bias voltage is applied to the n-junction layer, and this pn-junction layer operates as a capacitor. In addition, between the output terminal and the input terminal of the inverter logic circuit 10,
That is, the resistor 16 is connected in parallel with the inverter logic circuit 10.

Next, a specific example of the LC element 12 of this embodiment formed on the semiconductor substrate will be described in detail.

FIG. 2 is a plan view of the case where the LC element 12 is formed by forming spiral spiral electrodes on the semiconductor substrate. Further, FIG. 3 shows A- shown in FIG.
It is an A line expanded sectional view.

The LC element 12 of this embodiment is formed in a spiral n ⁺ region 32 formed in the vicinity of the surface of a p-type silicon substrate (p-Si substrate) 34 which is a semiconductor substrate, and in a part thereof. And a p ⁺ region 30 having a spiral shape, and the n ⁺ region 32 and the p ⁺ region 30 form a pn junction layer 36. Further, the impurity concentration of each of the n ⁺ region 32 and the p ⁺ region 30 is set to be higher than that of the p-Si substrate 34 described above.
By applying a reverse bias voltage between the i substrate 34 and the n ⁺ region 32, the p-Si substrate 34 functions as a good isolation region. Actually, by setting the p-Si substrate 34 and the second spiral electrode 22 described later to the same potential, the p-Si substrate 34 is
The reverse bias voltage may be reliably applied between the n ⁺ region 32 and the n ⁺ region 32.

[0070] In addition, LC elements 12 of the present embodiment is a surface side of the n ⁺ regions 32 described above, the first spiral electrode spiral shape corresponding to the primary winding to a position along the n ⁺ region 32 20 are formed. Similarly, a surface side of the p ⁺ region 30, the second spiral electrode 22 corresponding to the secondary winding at a position along the p ⁺ region 30 is formed. Then, two input / output electrodes 24 and 26 are provided at both ends of the first spiral electrode 20. Two input / output electrodes 28 are provided on both ends of the second spiral electrode 22,
29 are provided. Input / output electrodes 24, 26, 28, 2 for the first and second spiral electrodes 20, 22
The attachment of 9 is done outside the active area so as not to damage the thin n ⁺ region 32 or p ⁺ region 30 as shown in FIG.

In the LC element 12 of this embodiment having such a structure, each of the spirally shaped first and second spiral electrodes 20 and 22 functions as an inductor conductor. When the pn junction layer 36 electrically connected to each of the first and second spiral electrodes 20 and 22 is used in a reverse bias state, it functions as a spiral capacitor. Therefore, the first
Further, the LC element 12 in which the inductor formed by the second spiral electrodes 20 and 22 and the capacitor formed by the pn junction layer 36 exist in a distributed constant manner is formed.

FIG. 4 shows an LC device 1 having the above structure.
It is a figure which shows the equivalent circuit of 2. As shown in FIG. 3A, the first spiral electrode 20 functions as an inductor having an inductance L1, and the second spiral electrode 22 functions as an inductor having an inductance L2. Further, since the first and second spiral electrodes 20 and 22 are wound concentrically,
Each also has a function as a transformer corresponding to the primary winding and the secondary winding.

LC element 12 having such an equivalent circuit
In the case where the potential on the first spiral electrode 20 side is set higher than the potential on the second spiral electrode 22 side, a reverse bias is applied to the spirally formed pn junction layer 36. The entire bonding layer 36 functions as a capacitor having a capacitance C. Further, this capacitor is formed in a distributed constant manner over the entire length of the first spiral electrode 20 and the second spiral electrode 22.

FIG. 4B shows a structure for applying the above-mentioned reverse bias. Specifically, a bias power supply 38 for applying a predetermined reverse bias voltage is connected between the input / output electrodes 24 and 28.

Further, as shown in FIG. 6C, a spiral bias shape is obtained by connecting a variable bias power source 44 capable of arbitrarily changing the reverse bias voltage level, instead of the bias power source 38. It is also possible to arbitrarily change the capacitance C of the pn junction layer 36 formed in.

In general, the width of the depletion layer generated at the pn junction surface changes depending on the magnitude of the reverse bias voltage applied to the pn junction layer 36, and the value of the capacitance C also changes accordingly. Therefore, by changing the reverse bias voltage applied to the pn junction layer 36 via the first and second spiral electrodes 20 and 22, the capacitance C formed in a distributed constant is arbitrarily changed, and the LC element 12 is obtained. The frequency characteristic as a whole can be changed.

To apply a fixed or variable reverse bias voltage to the pn junction layer 36 in an actual circuit, the method shown in FIG. 1 or FIG. 6 described later may be used.

FIG. 5 is a diagram showing the manufacturing process of the LC element 12 of this embodiment. The state of each cross-section along the line BB in FIG. 2 is shown.

(1) Growth of epitaxial layer: First, the oxide film on the surface of the p-Si substrate 34 (wafer) is removed, and then the n ⁺ type epitaxial layer 35 is grown on the entire surface of the p-Si substrate 34. ((A) of the same figure).

(2) Formation of isolation region: Next, in order to make the region other than the n ⁺ region 32 and the p ⁺ region 30 shown in FIG. 2 an isolation region, diffusion of p-type impurities or ion implantation is performed. To do.

Specifically, first, the surface of the epitaxial layer 35 is thermally oxidized to form an oxide film 40. Then, after removing the oxide film 40 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 34 to form an isolation region (FIG. 2 (B)).

As a result of the formation of the isolation region in this way, a spiral-shaped n ⁺ region 32 is formed by the remaining epitaxial layer 35.

(3) Formation of pn junction layer: Next, by introducing a p-type impurity into a part of the n ⁺ region 32 formed in a spiral shape by thermal diffusion or ion implantation, the spiral p ⁺ area is formed. 30 is formed ((D) in the figure).

Specifically, first, p- containing the n ⁺ region 32 is formed.
The surface of the Si substrate 34 is thermally oxidized to form an oxide film 42. Then, the p ⁺ region 30 is formed by photolithography.
After removing the oxide film 42 at the position where the p ⁺ region is to be formed, the p ⁺ region 30 is selectively formed by selectively adding p-type impurities by thermal diffusion or ion implantation.

This p ⁺ region 30 is formed by the n ⁺ formed previously.
Since it needs to be formed in the region 32, the p ⁺ region 30 is formed by adding the p-type impurity in an amount equal to or more than the amount of the n-type impurity already introduced.

In this way, the spiral pn junction layer 36 composed of the n ⁺ region 32 and the p ⁺ region 30 is formed.

(4) Formation of spiral electrode: Next, after forming an oxide film 43 on the surface by thermal oxidation, a spiral-shaped hole is formed on each surface of the n ⁺ region 32 and the p ⁺ region 30 by photolithography. Then, the first and second spiral electrodes 20, for example, are formed by vapor-depositing aluminum on the spirally formed portion.
22 is formed ((D) in the figure). Further, thereafter, each of the input / output electrodes 24, 26, 28, 29 is formed by vapor deposition of aluminum.

The process of manufacturing the LC element 12 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 36 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.

In the manufacturing process of the LC element 12 of the present embodiment described above, the case where isolation is performed after first forming the n ⁺ region on the entire surface by epitaxial growth has been described, but the p-Si substrate is used. after forming the oxide film 34 the surface of the perform Apertures corresponding to n ⁺ region 32 of the spiral shape by photolithography, the n ⁺ region 32 by introducing n-type impurities by thermal diffusion or ion implantation into the portion After the formation, the p ⁺ region 30 may be directly formed by the same method. Further, as a method of forming the pn junction layer, a general semiconductor manufacturing technique can be used.

As described above, the LC element 12 of this embodiment is
Each of the first and second spiral electrodes 20 and 22 forms an inductor, and the spiral pn junction layer 36 formed between these electrodes functions as a capacitor by being used in reverse bias. Moreover, since the pn junction layer 36 is formed over the entire length of the first and second spiral electrodes 20 and 22, the first
Also, the inductances L1 and L2 formed in the second spiral electrodes 20 and 22 and the capacitance C formed by the pn junction layer 36 exist in a distributed constant manner.

In the sine wave oscillating circuit 1 of the present embodiment, the LC element 12 having such a structure is used as a transformer, and moreover, the signals input to and output from the primary side and the secondary side of the transformer are used. Wiring is performed so that the phase is inverted.

Specifically, the input / output electrode 24 provided at one end of the first spiral electrode 20 is at the output end of the inverter logic circuit 10 and the input / output electrode 26 provided at the other end.
Is connected to a predetermined voltage line, and the input / output electrode 2 is provided at one end of the second spiral electrode 22.
8 is grounded and the input / output electrode 2 provided at the other end
9 is connected to the input terminal of the inverter logic circuit 10.

As described above, since the LC element 12 is wired such that the primary side and the secondary side are in opposite phases to each other, L
When the output signal of the inverter logic circuit 10 is input to the primary side (first spiral electrode 20 side) of the C element 12, a signal having a phase opposite to that of the output signal is generated by the capacitor 14
Will be fed back to the input side of the inverter logic circuit 10 via.

By the way, the above-mentioned LC element 12 is the first
And the second spiral electrodes 20 and 22 are inductor conductors having inductances L1 and L2, respectively, and at the same time, a spiral p-shape is provided between these inductor conductors.
The n-junction layer 36 is formed. Moreover, the first spiral electrode 20 side is connected to the power supply line via the input / output electrode 26, and the second spiral electrode 22 side is grounded via the input / output electrode 28.
A fixed reverse bias voltage is applied to 6. Therefore, a distributed constant capacitor having a capacitance C is formed by the pn junction layer 36 between the first and second spiral electrodes 20 and 22.

Therefore, the LC element 12 constitutes a resonance circuit composed of the inductors L1 and L2 and the inductor or the capacitor having the capacitance C, and has a characteristic that only a signal of a specific frequency is easily propagated. .

Therefore, the LC element 12 selects the signal of this characteristic frequency and inverts the phase, and the signal inverted in phase from the output signal, that is, 180 degrees out of phase, is input to the inverter logic circuit 10 again. It The inverter logic circuit 10 further inverts the phase of the input signal and shifts the phase by 180 degrees and outputs it. Therefore, when the amplification factor of the inverter logic circuit 10 is set to a certain value or more and the loop gain is set to 1 or more, the phase shift of the specific frequency signal returning in one cycle becomes 0 degree or 360 degrees and oscillates. Is done. That is, the oscillation is performed at the specific frequency selected by the LC element 12.

As described above, the sine wave oscillation circuit 1 of this embodiment
In principle, the inverter logic circuit 10 and the LC element 12 are
You can easily generate a sine wave by combining a small number of parts such as. In particular, the LC element 12 functioning as a resonance circuit is different from the conventional LC series resonance circuit or LC parallel resonance circuit in that an inductor and a capacitor are formed in one element in a distributed constant manner, so that the oscillation occurs. There is no need to separately prepare an inductor and a capacitor, determine the element constants, and connect them when forming a circuit.

For example, when an inductor having a predetermined L and C and a capacitor are individually prepared to form an LC resonance circuit to manufacture a sine wave oscillation circuit, different materials and different processes are used. Since each part can be arbitrarily combined by the circuit designer, it gives the circuit designer a lot of freedom, but also imposes a heavy burden on the design and manufacturing.

On the other hand, in the LC element 12 shown in FIG. 2, the inductor and the capacitor can be manufactured at the same time in the same process, so that there is an advantage that the burden on the circuit designer can be reduced and the manufacturing can be facilitated. Further, since the inductor and the capacitor are integrally formed in the same step, the wiring work can be reduced, but the characteristics are also stabilized.

Therefore, if a sine wave oscillating circuit can be constructed by using the LC element 12 having various advantages as described above, the merits of the sine wave oscillating circuit as a whole are the same. It can be said that the oscillator circuit 1 is easier to design and manufacture than the conventional sinusoidal oscillator circuit and has stable characteristics.

The LC element 12 of this embodiment also has the function of a transformer, and the sine wave oscillation circuit 1 of this embodiment is used.
By using the LC element 12 to separate the input and output terminals of the inverter logic circuit 10, it is possible to obtain a large output amplitude, for example, an output amplitude as large as the power supply voltage. Therefore, the sine wave oscillating circuit 1 of the present embodiment is suitable for applications that require a sine wave having a particularly large amplitude.

Further, in the sine wave oscillating circuit 1 of the present embodiment, the LC element 12 having the inductor component has the semiconductor substrate (p-
A major feature is that it is formed on the Si substrate 34). Moreover, as a matter of course, the inverter logic circuit 10 and the capacitor 14 shown in FIG. 1 can be formed on the same semiconductor substrate, so that the entire sine wave oscillation circuit 1 can be integrally formed on one semiconductor substrate. It enables mass production and miniaturization of the entire circuit. In addition, the circuit is integrally formed on this semiconductor substrate by using the current semiconductor manufacturing technology,
Since it can be easily performed only by changing the shape of the photomask, it is possible to significantly reduce the cost due to mass production and miniaturization.

Further, the LC whose structure is shown in FIG. 2 and FIG.
The element 12 can change the value of the capacitance C formed in a distributed constant only by changing the value of the reverse bias voltage applied to the pn junction layer 36. LC in general
Since the resonance characteristic of the element 12 is determined based on the inductances L1 and L2 of the first and second spiral electrodes 20 and 22 and the capacitance C of the pn junction layer 36, p
By changing the reverse bias voltage applied to the n-junction layer 36 and changing the capacitance C, the oscillation frequency itself of the sine wave oscillation circuit 1 changes according to the degree of the change.

Thus, the sine wave oscillator circuit 1 of this embodiment is
Can be easily made into a voltage-controlled oscillation circuit by changing the reverse bias voltage applied to the pn junction layer 36 of the LC element 12. Moreover, even in the case of such a voltage control type oscillation circuit, it is not necessary to add an element for changing the frequency, and the constituent parts of the sine wave oscillation circuit 1 can be minimized.

FIG. 6 is a diagram showing a modified example of this embodiment, and shows the configuration in the case of a frequency-controlled voltage-controlled oscillator. In the sine wave oscillation circuit 1 shown in FIG. 1, LC
Since the secondary side of the element 12 was grounded, the LC element 12
While the voltage applied from the power supply line was directly applied to the pn junction layer 36 as the reverse bias voltage, the sine wave oscillation circuit shown in FIG. Control, and thus the pn junction layer 36
It is characterized in that the reverse bias voltage applied to the can be changed.

Specifically, the input / output electrode 28 provided at one end of the second spiral electrode 22 of the LC element 12 is grounded via the capacitor 18 having a sufficiently large capacitance, and the input / output electrode is variable. A bias circuit including a resistor 52 and a resistor 54 having a sufficiently large resistance value is connected. That is, the variable resistor 52 causes 0
A predetermined bias voltage between V and the power supply line is generated, and this bias voltage is applied to the input / output electrode 28 via the resistor 54. Since the resistor 54 has a sufficiently large resistance, it is possible to apply a predetermined bias voltage without affecting the AC component of the signal flowing through the second spiral electrode 22, which is the secondary side of the LC element 12. Becomes

As described above, the second electrode is formed through the input / output electrode 28.
By variably raising and lowering the potential on the side of the spiral electrode 22 of, the reverse bias voltage determined by the difference between this potential and the potential of the first spiral electrode 20 changes, and accordingly, p
The capacitance C of the n-junction layer 36 is also a voltage control type sine wave oscillation circuit that can be arbitrarily changed within a certain range.

[Second Embodiment] FIG. 7 is a diagram showing a configuration of a sine wave oscillator circuit 2 according to a second embodiment of the present invention. The sine wave oscillating circuit 2 of the present embodiment shown in FIG. 6A is an inverting amplifier, whereas the sine wave oscillating circuit 1 of the first embodiment uses the inverter logic circuit 10 as an inverting amplifier. MOS type FE
The feature is that a source grounded circuit by T is used.

That is, the sine wave oscillating circuit 2 includes the inverter logic circuit 10 shown in FIG.
This FET3 has a configuration replaced with ET56.
2 and the first spiral electrode 20 of the LC element 12 connected to the drain side thereof form a source ground circuit that functions as an inverting amplifier. In addition, the resistor 46,
A predetermined bias voltage is applied to the gate of the FET 56 by the voltage dividing circuit by 48, and an appropriate operating point is secured.

The operating principle of the sine wave oscillating circuit 2 is the same as that of the sine wave oscillating circuit 1 described above, and the phase shift of the signal that makes a round through the LC element 12 and the source grounded circuit is 0 degree or 360 degree. At the same time, the LC element 12 selects a signal of a specific frequency and oscillates at this frequency.

The LC element 12 is formed by forming the first and second spiral electrodes 20 and 22 and the pn junction layer 36 on the p-Si substrate 34 as shown in FIGS. The connection method in the circuit is the same as that of the sine wave oscillating circuit 1 shown in FIG. 1 except that the source grounded circuit by the FET 56 is used as an inverting amplifier.

As described above, the FET 56 is used as the inverting amplifier.
And the LC element 12
Is used as a resonance circuit and a transformer for extracting an inverted signal, and a sine wave can be generated with a simple configuration.

In particular, when the inverting amplifier is composed of the source-grounded circuit, the sine wave oscillation circuit 2 of the present embodiment can be manufactured entirely by a general semiconductor technique, so that it is integrally formed on a semiconductor substrate. This is more convenient, and is suitable for high-density packaging of circuits, IC, and LSI.

FIG. 7B is a diagram showing a modification of this embodiment. The sine wave oscillation circuit shown in FIG.
The reverse bias voltage applied to is changed. That is, in the sine wave oscillator circuit 2 shown in FIG. 7A, the second spiral electrode 22 side of the LC element 12 is grounded, whereas in the sine wave oscillator circuit shown in FIG. Second
A fixed bias voltage is applied to the side of the spiral electrode 22 by a voltage dividing circuit composed of resistors 46 and 48, and
The second spiral electrode 22 side is grounded via a capacitor 50 that functions as a DC component separation circuit. Therefore, the reverse bias voltage applied to the pn junction layer 36 becomes small, but the point that the capacitor is formed in a distributed constant is the same.

As described above, the pn junction layer 3 of the LC element 12 is formed.
Although various methods can be considered for applying the reverse bias voltage to the transistor 6, any method may be used as long as the reverse bias voltage is surely applied to the pn junction layer 36.

FIG. 8 is a diagram showing another modification of this embodiment. In the sine wave oscillator circuit 2 shown in FIG. 7A, the reverse bias voltage applied to the pn junction layer 36 of the LC element 12 is fixed, whereas in the sine wave oscillator circuit shown in FIG. The feature is that the reverse bias voltage can be variably controlled. Specifically, similarly to the sine wave oscillation circuit shown in FIG. 6, the second spiral electrode 22 side of the LC element 12 is grounded via the capacitor 18 and is variable with respect to the second spiral electrode 22. A variable voltage generated by the resistors 42 and 54 is applied. Therefore,
The reverse bias applied to the pn junction layer 36 of the LC element 12 is changed, and a voltage-controlled sine wave oscillation circuit can be easily realized.

FIG. 9 is a diagram showing another modification of this embodiment. The sine wave oscillation circuit shown in FIGS. 7 and 8 is a MOS.
9 is used, the junction type FET 58 is used in the sine wave oscillation circuit shown in FIG. 9, and a parallel circuit composed of a resistor 60 and a capacitor 62 is inserted on the source side of the FET 58. The feature is that a predetermined bias voltage is applied to the gate relatively.

The resistor 60 forming this parallel circuit has a relatively small resistance value. This is because if the resistance value is too large, the voltage drop due to the resistor 60 becomes large, so the voltage between the source and drain of the FET 58 becomes small, and it may not be possible to secure an appropriate operating point. In addition, the capacitor 62 is an alternating current FET5.
8 is for grounding the source.

Further, FIG. 9A shows the case where a fixed reverse bias voltage is applied to the pn junction layer 36 of the LC element 12, and the FET 58 is gated via the second spiral electrode 22 of the LC element 12. Is grounded in a direct current manner, and the potentials of the source and drain are higher than the potential of the gate, so that an appropriate reverse bias state is established.

Further, in the same figure (B), the second spiral electrode 22 side of the LC element 12 is grounded via the capacitor 18, as in the sine wave oscillation circuit shown in FIG.
A variable voltage generated by the variable resistor 52 and the resistor 54 is applied to the second spiral electrode 22 side, whereby a variable reverse bias voltage is applied to the pn junction layer 36 to form a voltage-controlled sine wave oscillation circuit. Has been realized.

The capacitor 14 is for separating the second spiral electrode 22 of the LC element 12 from the gate of the FET 58 in terms of direct current, and the gate of the FET 58 is grounded in direct current via the resistor 60. ing. Also,
This resistor 60 has a sufficiently large resistance value,
The AC component of the feedback signal input to the gate of 58 is not affected.

[Third Embodiment] FIG. 10 is a diagram showing a configuration of a sine wave oscillation circuit 3 according to a third embodiment of the present invention. In the sine wave oscillating circuit 3 of the present embodiment shown in FIG. 7A, the sine wave oscillating circuit 1 of the first embodiment described above is an inverter logic circuit 10 as an inverting amplifier.
In contrast to the sine wave oscillator circuit 2 of the second embodiment, which uses a source-grounded circuit using FETs 56 and 58 as an inverting amplifier, a grounded-emitter circuit using a bipolar transistor 66 is used as an inverting amplifier. Is characterized by.

That is, the sine wave oscillating circuit 3 has a structure in which the FET 56 of the sine wave oscillating circuit 2 shown in FIG. 7 is replaced with a bipolar transistor 66, and the bipolar transistor 66 and the LC connected to the collector side thereof are connected.
The primary-side inductor conductor of the element 12 constitutes a grounded-emitter circuit that functions as an inverting amplifier.

The operating principle of the sine wave oscillator circuit 3 is the same as that of the sine wave oscillator circuit 2 of the second embodiment shown in FIG.
The phase shift of the signal which makes a round through the element 12 and the grounded-emitter circuit becomes 0 degree or 360 degrees, and LC
A signal having a specific frequency is selected by the element 12 and oscillation is performed at this frequency.

Regarding the LC element 12, as in the first and second embodiments, the first and second spiral electrodes 20, 20 are formed on the p-Si substrate 34 as shown in FIGS. 22 and a pn junction layer 36, and the circuit connection method is the same as the sine wave oscillation circuit 2 shown in FIG. There is no change.

As described above, the grounded emitter circuit by the bipolar transistor 66 is used as the inverting amplifier, and the LC element 12 is used as the resonance circuit and the transformer for taking out the inverted signal, and a sine wave is generated by a simple structure. be able to.

Further, the LC device 1 shown in FIGS. 2 and 3 is used.
2 has a sectional structure similar to that of a bipolar transistor, it is possible to form the entire sine wave oscillation circuit 3 including the LC element 12 and the bipolar transistor 66 by using the same semiconductor manufacturing technique. Yes, it is more convenient for mass production and miniaturization by integral formation.

Further, in the sine wave oscillation circuit shown in FIG. 10B, the bias voltage applied to the base of the bipolar transistor 66 is directly applied to the second spiral of the LC element 12 by the voltage dividing circuit including the resistors 46 and 48. Electrode 2
The voltage is also applied to the second side, which corresponds to FIG. 7 (B).

FIG. 11 is a diagram showing a modification of this embodiment. The sine wave oscillator circuit 3 shown in FIG.
While a stable bias voltage is applied to the base of the bipolar transistor 66 by using a voltage divider circuit composed of the following as a bias circuit, the sine wave oscillation circuit shown in FIG. A resistor 68 is inserted between the base and collector of the bipolar transistor 66, and a parallel circuit including a resistor 70 and a capacitor 72 is inserted between the first spiral electrode 20 of the LC element 12 and the power supply line. Is applied.

This resistor 68 is a feedback resistor for applying a predetermined bias voltage to the base of the transistor 66, but since the primary resistance of the LC element 12 is small (as shown in FIG. In some cases, the primary side (the first spiral electrode 20 is formed by winding a metal material for a predetermined number of turns), so that the primary side does not work effectively. Therefore, a parallel circuit including a resistor 70 for detecting a bias current and a capacitor 72 that operates as a bypass capacitor is inserted between the primary side of the LC element 12 and the power supply line. With such a configuration, the current flowing through the collector of the transistor 66 is detected by the resistor 70 and fed back to the base via the resistor 68 to set a predetermined bias. In particular, according to this configuration, a self-bias is performed in which the bias is adjusted according to the voltage fluctuation of the power supply line, so that stable operation of the transistor 66 is ensured.

In addition, FIG. 11B shows LC in FIG.
While the reverse bias applied to the pn junction layer 36 of the element 12 was fixed, the reverse bias applied to this pn junction layer 36 was variably controlled, thereby realizing a voltage control type sine wave oscillation circuit. It is a thing. The method of changing the reverse bias is the same as that shown in FIG.
The second resistor of the LC element 12 is formed by the variable resistor 52 and the resistor 54.
The potential on the spiral electrode 22 side is raised and lowered to variably control the reverse bias voltage applied to the pn junction layer 36.

Other Examples Next, other examples to which the present invention is applied will be described.
Various embodiments described below are realized by the LC element 12 used in the above-described first to third embodiments with other structures.

FIG. 12 is a plan view showing a schematic structure of an LC element in another embodiment. 13 is an enlarged cross-sectional view taken along the line AA shown in FIG.

The LC element 12 of this embodiment shown in these figures.
In a, the n region 130 is formed in the vicinity of the surface of the p-Si substrate 134 which is a semiconductor substrate, so that the pn junction layer 136 including the n region 130 and the p region 132 is formed.

Further, in the LC element 12a of the present embodiment, the spiral first spiral electrode 120 is formed on the surface side of the n region 130 described above. Similarly, p region 13
The second spiral electrode 122 is formed on the surface side of the second spiral electrode 120, that is, on the opposite side of the first spiral electrode 120 with the pn junction layer 136 interposed therebetween, and at a position substantially facing the first spiral electrode 120. There is. Then, two input / output electrodes 24, are provided on both ends of the first spiral electrode 120.
26 are provided. Two input / output electrodes 28 and 29 are provided at both ends of the second spiral electrode 122.

The LC element 12a of this embodiment having such a structure is similar to the LC element 12 shown in FIGS. 2 and 3 in that each of the spirally shaped first and second spiral electrodes 120 and 122, respectively. Will function as an inductor conductor.

Further, the first and second spiral electrodes 1
When the pn junction layer 136 formed between 20 and 122 is used in a reverse bias state, it operates as a capacitor. Note that, as shown in FIG. 13, the pn junction layer 136 is considered to be one capacitor having a large counter electrode (each of the n region 130 and the p region 132 corresponds to the counter electrode). However, in general, n region 130 and p region 132
Each of the first and second spiral electrodes 120,
Since the specific resistance is larger than that of the first and second spiral electrodes 122, 122, when an AC signal is applied between the first and second spiral electrodes 120 and 122, the first and second spiral electrodes 12 facing each other.
AC signal flows only through the spiral-shaped capacitor between 0 and 122, and the first and first spiral electrodes 12
Almost no AC signal flows through the capacitors formed between the different circulating portions of 0 and 122. Therefore, the pn junction layer 136 other than the surrounding portions of the first and second spiral electrodes 120 and 122 hardly functions as a capacitor, and the first and second spiral electrodes 12 do not function.
It can be considered that only the spiral-shaped portion along the circumference of 0,122 substantially operates as a capacitor.

Therefore, the inductor formed by the first and second spiral electrodes 120 and 122 and the pn
The LC element 12a in which the spiral-shaped capacitor formed by the bonding layer 136 and the spiral-shaped capacitor exist in a distributed constant is configured.

As the equivalent circuit of the LC element 12a having such a structure, the equivalent circuit shown in FIG. 4 can be applied as it is. Further, by connecting a bias power supply 38 or a variable bias power supply 44 for applying a fixed or variable reverse bias voltage, a fixed or variable predetermined reverse bias voltage can be applied, whereby a predetermined capacitor can be set. Is also the same.

In the LC element formed by making the first and second spiral electrodes 120 and 122 substantially face each other, the p-Si substrate 134 is entirely formed of the pn junction layer 136 composed of the n region 130 and the p region 132. However, as shown in FIG. 14, the n region 130 (or the p region 132 may be used) may have a spiral shape along the first spiral electrode 120. In this case, since a depletion layer is generated at the boundary surface (pn junction surface) between the n region 130 and the p region 132 formed along the spiral shape, a spiral capacitor is formed, and thus FIG. It is possible to more reliably form the spiral capacitor than the structure shown in FIG.

When the p-Si substrate 134 is actually used as the pn junction layer 136 composed of the n region 130 and the p region 132, the thickness of the p-Si substrate 134 needs to be smaller than that of the wafer. is there. Further, considering that an n-type wafer is generally easier to obtain, the structure shown in FIG. 15 may be used.

That is, as shown in FIG.
P is formed on the surface of the Si substrate 144 by epitaxial growth or the like.
After forming the region 132, etching is performed on the back surface side of the n-Si substrate 144, and the first and second spiral electrodes 120 and 122 are formed on the etched portion. Further, as shown in FIG. 3B, the p ⁺ region 146 and the n ⁺ region 1 are sequentially arranged on the surface side of the n-Si substrate 144.
After forming 48, the n-Si substrate 144 is etched, and the first and second spiral electrodes 120 and 122 are formed in the etched portions. In addition, as shown in FIG.
The spiral p ⁺ region 146 is formed so as to be substantially along the spiral electrode 120, and then the spiral n ⁺ region 148 is further formed thereon, and then the n-Si substrate 1 is formed.
A portion of the back surface of 44 corresponding to the second spiral electrode 122 is etched, and the etched portion is covered with the first and second spiral electrodes 120, 12.
Form 2.

The LC element of each of the above-mentioned modified examples is the first
Spiral electrode 120 and second spiral electrode 122
Although it is shown that and are completely opposite to each other, the first and second
Since the spiral electrodes 120 and 122 need to function as the electrodes of the capacitor formed by the pn junction layer 136, the spiral electrodes 120 and 122 may be arranged so as to be slightly opposed to each other.

FIG. 16 is a diagram showing another example of the LC element. The LC element 12b shown in the figure is characterized in that the shapes of the first and second spiral electrodes 20 and 22 of the LC element 12 shown in FIG. 2 are changed. Specifically, the LC element 12b of the present example has first and second electrodes 150 and 152 having a meandering shape instead of the first and second spiral electrodes 20 and 22 having a spiral shape in FIG. A pn junction layer 154 having a meandering shape is formed along the two electrodes 150 and 152.

FIG. 17 is a diagram showing the principle of an inductor formed by the first and second electrodes 150 and 152 having a meandering shape. As shown in the figure, when an electric current is applied to the electrode 150 or 152 having a meandering shape that is bent in a concavo-convex shape, magnetic fluxes having opposite directions are alternately generated in adjacent concavo-convex portions, and it is as if The coils of / 2 turns are connected in series. Therefore,
Each of the first and second electrodes 150 and 152 functions as an inductor having a predetermined inductance, and the equivalent circuit shown in FIG. 4 can be applied as it is.

In the case of the spiral electrode, one of both ends of the electrode is located at the center and the other is located at the periphery, whereas the meandering electrodes 150, 15 are formed.
In the case of No. 2, both ends thereof are located in the peripheral portion, which is convenient when the input / output electrodes 24, 26, 28, 29 are pulled out to the outside.

FIG. 18 is a diagram showing another example of the LC element. In the LC element 12c shown in FIG. 18, the first and second electrodes 160 and 162 having a meandering shape are formed of p-Si.
It is formed so as to face each other with the substrate 134 interposed therebetween, and corresponds to FIG. That is, FIG.
In the LC element 12a shown in FIG. 1, the spiral first and second spiral electrodes 120 and 122 are opposed to each other, whereas the LC element 12c of the present embodiment has the first and second electrodes 160 and 122. The feature is that the shape of 162 is a meandering shape. Therefore, each of the first and second electrodes 160 and 162 having a meandering shape functions as an inductor having a predetermined inductance, and the meandering pn junction layer 136 sandwiched between them (the cross-sectional structure is shown in FIG. 13 is shown. The same as the one described above) functions as a capacitor formed in a distributed constant.

As described above, even when the serpentine first and second electrodes 160 and 162 are opposed to each other with the p-Si substrate 134 having the pn junction layer 136 formed therebetween,
L in which the inductor and the capacitor are formed in a distributed constant
A C element can be formed, and the LC element can be used to form the sine wave oscillation circuit shown in FIG.
Moreover, the p-Si substrate 13 on which the LC element 12c is formed
It is also possible to form the inverter logic circuit 10 and the like on the upper part of the circuit 4, and it is possible to easily realize mass production and miniaturization by integral formation.

FIG. 19 is a diagram showing another example of the LC element. 20 is an enlarged sectional view taken along line AA of FIG.
1 is an enlarged sectional view taken along line BB of FIG. 19, and FIG. 22 is C of FIG.
It is a C line expanded sectional view.

The LC element 12d of the present embodiment shown in these figures has a p-S
The connection between the source 212 and the drain 214, which are diffusion regions formed at spaced positions near the surface of the i-substrate 34, by a channel 222 formed by applying a voltage to the spiral-shaped spiral electrode 210 functioning as a gate. Is characterized by.

The source 212 and the drain 21 described above
4 is formed as a diffusion region of the n ⁺ layer by inverting the p-Si substrate 34. For example, it is formed by implanting As ⁺ ions by thermal diffusion or ion implantation to increase the impurity concentration.

The spiral electrode 210 functioning as a gate has a p-Si substrate so that one end of the spiral shape overlaps a part of the source 212 and the other end overlaps a part of the drain 214. It is formed so as to sandwich the insulating layer 226 formed on the surface of 34. The spiral electrode 210 is formed, for example, by forming a thin film of aluminum, copper, silver or the like, or by heavily doping P by diffusion or ion implantation.

The insulating layer 226 is formed on the p-Si substrate 34.
The surface of the p-Si substrate 34 and the spiral electrode 210 are insulated from each other. The entire surface of the p-Si substrate 34 (or at least the spiral electrode 21
The portion corresponding to 0) is covered with this insulating layer 226, and the spiral electrode 210 described above is formed on the surface of this insulating layer 226. The insulating layer 226 is formed of, for example, P-added SiO ₂ (P-glass).

Further, the spiral electrode 210, the source 212, and the drain 214 described above are respectively provided in FIGS.
As shown in FIG. 22, the input / output electrodes 24, 26, 28, 2
9 is connected. That is, the spiral electrode 210
The input / output electrodes 24 and 26 are attached to the outside of the active region so as not to damage the thin gate film (insulating layer 226) as shown in FIG. Also, the source 21
2, the input / output electrode 28 is attached, and the drain 21
As shown in FIG. 22 or 20, the input / output electrode 29 is attached to the source 4 and the drain 214.
Is partially exposed, and then a metal film of aluminum, copper, gold, silver or the like is applied. Further, as shown in FIG. 21, the input / output electrode 29 connected to the drain 214 located substantially at the center of the spiral shape and the input / output electrode 26 drawn out from the inner end portion of the spiral electrode 210 are connected to the spiral electrode 210. It is drawn out to the outer peripheral side so as to maintain an insulating state with each lap portion.

L of this embodiment having the above-mentioned MOS structure
Assuming that the C element 12d has an n-channel enhancement type structure, the n-type channel 22 is not provided until a positive voltage is applied to the spiral electrode 210.
2 will be formed. And this channel 22
2 and the spiral electrode 210 described above each function as a spiral inductor conductor, and a distributed constant capacitor is formed between the channel 222 and the spiral electrode 210.

FIG. 23 is a cross-sectional view showing a state in which the channel 222 is formed, and shows a cross section taken in a direction perpendicular to the spiral direction of the spiral electrode 210. When no positive gate voltage is applied to the spiral electrode 210, that is, to the input / output electrode 24 or 26 connected to the spiral electrode 210, the surface of the p-Si substrate 34 as shown in FIG. Does not show the channel 222. Therefore, in this state, the source 212 and the drain 214 shown in FIG. 19 are in an insulated state.

However, when a positive gate voltage is applied to the spiral electrode 210, as shown in FIG. 23B, the p-Si substrate 34 corresponding to the spiral electrode 210 is formed.
A channel 222 consisting of an n region appears near the surface of the. Since the channel 222 is formed over the entire length of the spiral electrode 210, the charge accumulated in each of the spiral electrode 210 and the channel 222 forms a distributed constant capacitor between them.

FIG. 24 shows the cross-sectional structure of the LC element 12d of this embodiment, and shows the cross section of the spiral electrode 210 along the spiral direction. As shown in the figure, a channel 222 is formed parallel to the spiral electrode 210, and the source 222 and the drain 214 are formed by the channel 222.
And become conductive. For example, in the case of the enhancement type, the channel 222 is formed and the source 212 and the drain 214 are brought into conduction only after the voltage corresponding to the gate voltage is applied to the spiral electrode 210, but the channel is applied to the spiral electrode 210. Since the width and depth of the channel 222 are changed by changing the gate voltage, the resistance value of the channel 222 between the source 212 and the drain 214 can be changed.

FIG. 25 is a diagram showing an equivalent circuit of the LC element 12d of this embodiment. The equivalent circuit shown in FIG.
It is shown that the channel 222 is formed by applying a predetermined bias voltage to the spiral electrode 210, and each of them functions as an inductor having the inductances L1 and L2. Further, the spiral electrode 210 and the channel 222 form a spiral capacitor having the capacitor C.

As will be described later, a depletion type structure in which n-type carriers are preliminarily injected into the position where the channel 222 is formed may be adopted.

L of this embodiment having such an equivalent circuit
The C element 12d functions as an inductor conductor having the inductance L1 because the channel 222 serving as a signal input / output path is formed in a spiral shape. Similarly, the spiral electrode 210 functions as an inductor conductor having an inductance L2. Further, since these two inductor conductors are arranged with the insulating layer 226 sandwiched therebetween, the spiral electrode 210 and the channel 222 form a capacitor having a predetermined capacitance C in a distributed constant manner. However, since the spiral electrode 210 and the channel 222 are wound concentrically, they are electromagnetically coupled, and the LC element 12d also has a function as a transformer.

Therefore, this LC element 12d is similar to that shown in FIG.
Like the LC element shown in FIG. 1 and the like, the inductor and the capacitor are formed in a distributed constant manner, and can be used by replacing with the LC element 12 such as the sine wave oscillation circuit 1 shown in FIG. In particular, since the LC element 12d has a MOS structure, the manufacturing process is simple, and I
It is convenient for C or LSI.

Further, FIG. 25B shows the spiral electrode 2
10 shows a configuration in which a variable gate voltage Vg is applied to 10. Since the gate voltage Vg applied to the spiral electrode 210 (more accurately, the gate voltage applied between the spiral electrode 210 and the substrate 224 in FIG. 24) is relatively changed, the depth of the channel 222 is changed. , The mobility of the channel 222 is changed, and as a result, the resistance value of the channel 222 can be arbitrarily converted.

As a result, the frequency characteristic of the LC element 12d also changes. Therefore, when the sine wave oscillation circuit shown in FIG. 1 or FIG. Accordingly, it is possible to easily realize a voltage-controlled sine wave oscillation circuit whose oscillation frequency changes accordingly.

When the LC element 12d of this embodiment is actually applied to the sine wave oscillation circuit 1 shown in FIG. 1, the input / output electrode 2 provided at one end of the spiral electrode 210 is used.
Since 6 is connected to the power supply line whose voltage is fixed,
The substrate 224 side shown in FIG. 4 is grounded or connected to a fixed power supply having a voltage lower than that of the power supply line described above.
By making such a connection, the spiral electrode 21
A fixed reverse bias voltage is applied relatively to 0 to form the channel 222. When controlling the channel resistance, for example, a variable resistor 52 and a resistor 54 shown in FIG. 6 are added to raise and lower the potential on the side of the substrate 224 so that the substrate 224 and the spiral electrode 2 can be controlled.
The relative reverse bias voltage between 10 and 10 may be variably controlled.

In the above-described LC element 12d, the case where the n channel is formed between the source 212 and the drain 214 has been described, but in this case, since electrons are used as carriers, the mobility is large and the channel 222 of the channel 222 is used. The resistance decreases. On the other hand, the LC element 12d described above may be formed by forming a p channel on the n-Si substrate. In this case, since holes are used as carriers, the resistance of the channel 222 becomes relatively large, and it has different characteristics compared to the case of the n channel described above.

However, in this case, the spiral electrode 210
It is necessary to reverse the polarity of the reverse bias voltage applied between the substrate and the substrate 224.
When the C element is applied to the sine wave oscillation circuit 1 shown in FIG. 1, the potentials on the input / output electrode 28 and the substrate 224 side of the LC element 12d may be set higher than the potential of the spiral electrode 210. Alternatively, an n-Si substrate may be used instead of the p-Si substrate 34 without changing the polarity of the reverse bias voltage.

Further, in the LC element 12d described above, the channel 222 is formed with the spiral electrode 210 side as the primary winding.
Although the side is used as the secondary winding, conversely, the spiral electrode 210 side may be used as the secondary winding and the channel 222 side may be used as the primary winding. However, if this LC element is directly applied to the sine wave oscillation circuit shown in FIG.
The potential on the side of the spiral electrode 210, which is the secondary side of the LC element, is applied to the input / output electrodes 28 provided at both ends of the channel 222.
Since it becomes lower than the potentials of 29 and the substrate 224, it is necessary to use an n-Si substrate instead of the p-Si substrate 34, or to set the potential on the spiral electrode 210 side relatively high.

Further, in the above-described LC element 12d, since the spiral electrode 210 is long in the spiral direction, the potential on the substrate 224 side is set to be higher than that of the spiral electrode 210 in order to surely form the channel 222. It is necessary to set it low.

FIG. 26 is a diagram showing a manufacturing process of the LC element 12d of this embodiment, and shows an enhancement type case as an example. It should be noted that the drawing shows a cross section in the spiral direction of the spiral electrode 210.

(1) Formation of oxide film: First, p-S
Silicon dioxide is formed by thermally oxidizing the surface of the i-substrate 34 (FIG. 9A).

(2) Opening of source / drain windows:
The source 212 and the drain 21 are formed by photoetching the oxide film on the surface of the p-Si substrate 34.
The window corresponding to 4 is opened ((B) in the same figure).

(3) Source / drain formation: Next, the source 212 and the drain 214 are formed by implanting an n-type impurity from the portion where the window is opened (FIG. 7C). For example, As ⁺ is used as the n-type impurity, and this impurity is implanted by thermal diffusion. Further, when implanting this n-type impurity by ion implantation, the window opening in (2) described above is not necessary.

(4) Removal of gate region: Next, the opening of the gate region is formed by removing the oxide film in the portion where the spiral electrode 210 is to be formed (FIG. 7D). In the case of the LC element 12d of this embodiment, since the spiral electrode 210 needs to be formed in a spiral shape, the gate region opening is also formed in a spiral shape. In this way, the p-Si substrate 34 is exposed only at the portion corresponding to the spiral electrode 210.

(5) Formation of Gate Oxide Film: Next, a new oxide film, that is, an insulating layer 226 is formed on the p-Si substrate 34 which is partially exposed in this way (FIG. 8E). ).

(6) Formation of gate and electrode: Next, the spiral electrode 210 functioning as a gate is formed by vapor-depositing aluminum, for example, and
An input / output electrode 28 connected to the source 212 and an input / output electrode 29 connected to the drain 214 are formed (FIG. 4F).

The process for manufacturing the LC element 12d in this manner is basically similar to the process for manufacturing a normal MOS-FET, and it can be said that only the shape of the spiral electrode 210 is different. Therefore, the inverter logic circuit 1 is provided on one semiconductor substrate together with the LC element 12d.
This is convenient when forming a sine wave oscillation circuit in which other components such as 0 are integrally formed.

Further, the LC element 12d shown in FIG.
The enhancement-type element in which the channel 222 is formed when the voltage level applied to the spiral electrode 210 is made relatively higher than that of the substrate 224 has been described, but it may be a depletion type. That is, the n-type region is formed in advance by injecting carriers into the region of the channel 222 shown in FIG. Thus, the channel 222 can be formed without relatively increasing the voltage level applied to the spiral electrode 210, or the relationship between the voltage level applied to the spiral electrode 210 and the channel width can be changed. The carrier to be injected is the spiral electrode 2
It may be implanted only in a part of the region along 10.

FIG. 27 is a diagram showing another example of the LC element, showing a case where the gate electrode of the LC element of the MOS structure described above is formed in a meandering shape. Specifically, FIG.
The LC element 12e shown in FIG. 7 has a structure in which the spiral spiral electrode 210 shown in FIG. 19 is replaced with a meandering electrode 210a.

As described above, even when the electrode 210a and the channel 222 are formed in a meandering shape, each of the electrode 210a and the channel 222 functions as an inductor as shown in FIG. There is no difference in that a distributed constant capacitor is formed, and the sine wave oscillation circuit 1 and the like shown in FIG. 1 can be configured by using the LC element having such a structure. Moreover, these LC elements are MOS-mounted on the p-Si substrate 34.
The sine wave oscillation circuit can be formed by using a manufacturing technique and is suitable when integrally formed with other components (for example, the inverter logic circuit 10) such as the sine wave oscillation circuit 1 shown in FIG. Mass production and miniaturization of the whole can be easily realized.

FIG. 28 is a diagram showing another example of the LC element. 29 is an enlarged sectional view taken along line AA of FIG. 28, and FIG.
0 is an enlarged sectional view taken along line BB of FIG. 28, and FIG. 31 is C of FIG.
-C line expanded sectional view, FIG. 32 is the DD sectional expanded view of FIG.

The LC element 12f shown in these figures is the same as that shown in FIG.
The LC element 12d shown in FIG. 9 uses the spiral electrode 210 as both the function of the inductor conductor and the function of the gate electrode, but is characterized in that these functions are separated.

Specifically, the LC element 12f of this embodiment is
A source 212 and a drain 214 formed at spaced positions near the surface of a p-Si substrate 34 which is a semiconductor substrate are connected by a channel 222 formed by applying a voltage to a spiral-shaped first spiral electrode 310. It is formed by

The source 212 and the drain 21 described above
4 is formed as an n ⁺ region obtained by inverting the p-Si substrate 34. For example, it is formed by implanting As ⁺ ions by thermal diffusion or ion implantation to increase the impurity concentration.

The first spiral electrode 310 functions as a gate, and one end portion (outer peripheral side) of the spiral shape is a part of the source 212 and the other end portion (center side).
So that it overlaps part of the drain 214,
The insulating layer 226 formed on the surface side of the p-Si substrate 34 is sandwiched. First spiral electrode 310
Is formed, for example, by molding an aluminum film or by heavily doping P by diffusion or ion implantation.

The first spiral electrode 31 described above is also used.
The second spiral electrode 312 is formed substantially concentrically with 0. A channel 222 is formed on the surface of the p-Si substrate 34 facing the first spiral electrode 310 by applying a predetermined gate voltage between the second spiral electrode 312 and the first spiral electrode 310. It has become so.

The first spiral electrode 31 described above is also used.
0, the source 212, the drain 214, and both ends of the second spiral electrode 312, respectively, as shown in FIGS.
4, 26, 28 and 29 are connected. That is, the attachment of the control electrode 228 to the first spiral electrode 310 is performed outside the active region so as not to damage the thin gate film, as shown in FIG. Further, the input / output electrode 24 is attached to the source 212 and the drain 2
As shown in FIGS. 32 and 30, the input / output electrode 26 is attached to the source 212 and the drain 214.
Is partially exposed, and then a metal film such as aluminum is attached. Furthermore, the attachment of the input / output electrodes 28 and 29 to the second spiral electrode 312 is
Similar to the control electrode 228, it is performed at a position separated from the active region so as not to damage the thin gate film.

Assuming that the LC element 12f of the present embodiment having the above-mentioned structure has an n-channel enhancement type structure, a positive voltage (the second spiral electrode 312) is applied to the first spiral electrode 310. Higher voltage than)
The channel 222 will only be formed when is applied.

FIGS. 29A and 29B show channel 2
It is a figure which shows the state in which 22 is formed. When no positive gate voltage is applied to the first spiral electrode 310, that is, to the control electrode 228 connected to the first spiral electrode 310, as shown in FIG. The channel 222 does not appear on the surface of the substrate 34. Therefore, in this state, the source 2 shown in FIG.
12 and the drain 214 are in an insulated state.

However, when a relatively positive gate voltage is applied to the first spiral electrode 310, FIG.
As shown in (B), a channel 222 consisting of an n region appears near the surface of the p-Si substrate 34 corresponding to the first spiral electrode 310. Further, inside the p-Si substrate 34 and outside the channel 222, a depletion layer in which holes are eliminated by the positive gate voltage applied to the first spiral electrode 310 is formed. Therefore, the electrons in the channel 222 and the holes in the p-Si substrate 34 are arranged to face each other with the depletion layer in between, and the channel 222 and the p-Si substrate 34 existing outside the channel 222 with the depletion layer in between. Form a capacitor. In addition, since this capacitor is formed over substantially the entire length of the first spiral electrode 310, the second spiral electrode 312 connected to the p-Si substrate 34 and the channel 222 have a spiral shape in a distributed constant manner. A capacitor will be formed.

FIG. 33 is a diagram showing an equivalent circuit of the LC element 12f of this embodiment. The equivalent circuit shown in the figure shows that a channel 222 is formed by applying a predetermined gate voltage to the control electrode 228, and this channel resistance can be variably controlled by changing the gate voltage.

When the LC element 12f is used in the reverse bias state, the potential of the control electrode 228 is set to the second value.
It may be set higher than the potential of the spiral electrode 312 of the input / output electrodes 2 provided at both ends of the channel 222.
The potential of the electrodes 4, 26 may be the same as that of the intermediate or the second spiral electrode 312.

FIG. 34 is a diagram showing a specific example in which the LC element f of the present embodiment is applied to the sine wave oscillation circuit shown in FIG. 1 in consideration of the potentials of the electrodes as described above.

As shown in the figure, the control electrode 228 connected to the first spiral electrode 310, which is a gate, is connected to the power supply line, and the input / output electrode 28 is grounded. Further, by connecting the input / output electrode 26 provided in the drain 214 (or the source 212) to the input / output electrode 28 via the resistor 84, the drain 2
14 and source 212 to the second spiral electrode 312
Set to the same potential as the side. The resistor 84 has a sufficiently large resistance value that does not allow an AC component to pass therethrough. Further, the two capacitors 80 and 82 provided at both ends of the channel 222 are for separating a DC component and have a sufficiently large capacity.

In this way, the LC element 12f, to which an appropriate reverse bias voltage is applied between the first and second spiral electrodes 310 and 312, can be inserted into the feedback loop. By combining the element 12f and the inverter logic circuit 10 etc., a sine wave oscillation circuit with a simple structure can be configured. Note that the same applies to the sine wave oscillation circuit 2 and the like shown in FIG.
ET56, bipolar transistor 66 and LC element 12
An appropriate reverse bias voltage may be applied to the LC element 12f by inserting a DC separation capacitor between the capacitor and the capacitor.

In the sine wave oscillation circuit shown in FIG. 34, a fixed reverse bias voltage applied from the power supply line is applied between the first and second spiral electrodes 310 and 312 of the LC element 12f. When variably controlling the reverse bias voltage, the variable resistor 52 shown in FIG.
The potential of the control electrode 228 or the potential of the input / output electrode 28 may be variably controlled by using a bias circuit including the resistor 54 and the resistor 54.

In the LC element 12f of this embodiment having such a structure, the channel 222 functions as an inductor conductor having the inductance L1, and the second spiral electrode 312 functions as an inductor conductor having the inductance L2. Further, a capacitor having a predetermined capacitance C is formed in a distributed constant manner between these two inductor conductors. Therefore, this LC
The element 12f has basically the same characteristics as the LC element shown in FIG. 2 and the like, and the sine wave oscillation circuit 1 shown in FIG.
Etc. can be used. Further, since it has a MOS structure like the LC element 12d shown in FIG. 19,
The process can be simplified by the MOS manufacturing technique, and further, it can be integrally formed on the p-Si substrate 34 together with other components, and mass production and miniaturization can be easily realized.

In the sine wave oscillating circuit shown in FIG. 34, the channel 222 side of the LC element 12f was used as the primary winding and the second spiral electrode 312 side was used as the secondary winding. It may be replaced.

FIG. 35 is a diagram showing a partially modified example of the LC element shown in FIG. 28 and subsequent figures, and shows a cross-sectional structure corresponding to FIG. 29. Specifically, as shown in FIG. 35A, an inversion layer 232 formed of a spiral p region along the first and second spiral electrodes 310 and 312 is formed in a part of the n-Si substrate 144. Has been done. In the LC element having such a cross-sectional structure, when a predetermined gate voltage is applied to the control electrode 228 provided at one end of the first spiral electrode 310, as shown in FIG. N corresponding to the first spiral electrode 310
A channel 222 is formed near the surface of the Si substrate 144. Moreover, by applying a reverse bias voltage between the n-Si substrate 144 and the inversion layer 232, the spiral inversion layer 232 is electrically separated from each other in each winding portion, and the channel 222 and the second layer are separated from each other. Spiral electrode 3
A distributed constant capacitor is surely formed between the capacitor 12 and the capacitor 12.

FIG. 36 is a view showing a modified example of the LC element shown in FIG. 28 and subsequent figures, and the first LC elements arranged substantially parallel to each other.
And the second spiral electrodes 310 and 312 with p-Si.
A case is shown in which they are arranged so as to face each other with the substrate 34 interposed therebetween. 37 is an enlarged sectional view taken along the line AA of FIG. 36 and corresponds to the sectional structure shown in FIG.

The LC element 12g of this embodiment is formed such that the first and second spiral electrodes 310 and 312 are substantially opposed to each other with the p-Si substrate 34 interposed therebetween, as shown in the sectional structure of FIG. And the first spiral electrode 3
And the second spiral electrode 312 formed on the back surface of the p-Si substrate 34.
And form a spiral capacitor in a distributed constant manner.

FIG. 38 is a diagram showing a partial modification of the LC element in which the first and second spiral electrodes 310 and 312 are arranged substantially opposite to each other with the p-Si substrate 34 interposed therebetween. Specifically, the first and second spiral electrodes 3
A spiral-shaped inversion layer is formed between the circumferential portions of 10, 312. That is, as shown in FIG.
A spiral inversion layer composed of an n region 234 is formed on a part of the i substrate 34. In the LC element having such a structure, the second spiral electrode 312 having a different lap portion is provided.
Focusing on the p-Si substrates 34 connected to each other, since the n regions 234 are formed between them, they are electrically separated from each other, so that it is possible to reliably perform the isolation of each lap portion.

In addition, p-Si which is actually in a wafer state
In the case of manufacturing the above-described LC element using the substrate 34, the thickness of the p-Si substrate 34 is set to be smaller than the thickness of the wafer in consideration of the fact that the specific resistance of the p-Si substrate 34 is higher than that of a general metal. It needs to be thinner than the condition. Further, as described above, the structure shown in FIG. 39 may be used in consideration of the fact that the n-type wafer is generally more easily available.

That is, as shown in FIG.
Spiral etching is performed on one surface of the Si substrate 144, and the first or second etching is performed on the etched portion.
Spiral electrodes 310 and 312 are formed. Further, as shown in FIG. 6B, ap ⁺ region 236 is formed on a part of the n-Si substrate 144 so as to substantially follow the first and second spiral electrodes 310 and 312, respectively, and then n
-A portion of the back surface of the Si substrate 144 corresponding to the second spiral electrode 312 is etched, and finally the first and second spiral electrodes 310 and 312 are formed.

By shortening the interval between the first and second spiral electrodes 310 and 312 formed so as to face each other in this manner, the channels 222 which face each other are substantially faced.
A distributed constant capacitor is formed only between the second spiral electrode 312 and the second spiral electrode 312. Moreover, as shown in FIG. 3B, the first and second spiral electrodes 3
When the inversion layer is formed in the portion sandwiched between 10, 312, the pnp structure is formed in contact with different winding portions of the second spiral electrode 312, so that good isolation is performed in each winding portion. .

Further, in the LC element described in each of the drawings after FIG. 28 mentioned above, the first and second spiral electrodes 310 and 312 are both formed in a spiral shape, but these are formed in a meandering shape. You may. Figure 40
And FIG. 41 replaces the above-mentioned first and second spiral electrodes 310 and 312 with first and second electrodes 310a and 312a having a meandering shape, and corresponds to the first electrode 310a having a meandering shape. The channel 222 and the second electrode 312a thus formed each function as an inductor conductor, and a distributed constant capacitor is formed between them.

Specifically, in FIG. 40, first and second electrodes 310a, 310a having substantially the same length and formed in parallel,
312a is an L formed on one surface of the p-Si substrate 34.
C element 12h is shown, and in FIG. 41, these first and second electrodes 310a and 312a are formed on the p-Si substrate 34.
LC element 12i formed so as to face each other across
It is shown.

Each LC element described above is characterized in that a distributed constant capacitor is formed by partially utilizing the inside of the semiconductor substrate, and the entire LC element can be manufactured by using a semiconductor manufacturing technique. is there. On the other hand, although the semiconductor substrate is used in the same manner, the LC element can be formed by stacking a plurality of inductor conductors on the surface without using the inside thereof.

FIG. 42 is a schematic diagram showing another modification of the LC element.

The LC element 12i shown in the figure comprises a high-purity semiconductor substrate 320 and two spiral electrodes 322 and 324 which are formed substantially on the surface of the semiconductor substrate 320. The first spiral electrode 322 corresponds to the first spiral electrode 20 shown in FIG. 2, for example, and the second spiral electrode 324 corresponds to the second spiral electrode 22 shown in FIG. An insulating film (not shown) is formed between the first and second spiral electrodes 322 and 324.

Therefore, the first spiral electrode 322
By providing terminals corresponding to the input / output electrodes 24 and 26 shown in FIG. 2 at both ends of the first spiral electrode 32,
2 can be made to function as one inductor conductor. Further, since the second spiral electrode 324 is formed so as to overlap the first spiral electrode 322, a distributed constant capacitor is formed between these two spiral electrodes 322 and 324, and these inductor components The relationship between the capacitor component and the capacitor component is shown in FIG.
It is exactly the same as 2.

Therefore, by using the spiral electrodes 322 and 324 of the LC element 12j shown in FIG. 42 as the primary winding and the secondary winding, respectively, a sine wave oscillation similar to that of the sine wave oscillating circuit 1 shown in FIG. The circuit can be obtained.

In particular, the LC element 12j shown in FIG.
Since it is formed by using the semiconductor substrate 320, it is possible to integrally form the other components (for example, the inverter logic circuit 10 etc.) shown in FIG. 1 on the semiconductor substrate 320 as well. Miniaturization can be easily realized.

FIG. 43 shows an LC whose schematic structure is shown in FIG.
It is a figure which shows an example of the manufacturing process of an element. The figure shows the sectional structure of the LC element 12j in the order of each step.

(1) A high-purity semiconductor substrate 320 is prepared ((A) in the figure). When the semiconductor substrate 320 has a low purity, it can be used as an insulating substrate by forming an oxide film or the like on the surface thereof.

(2) A metal film is formed on this semiconductor substrate 320, and, for example, an aluminum film 324a is deposited (FIG. 9B). Note that the metal film may be formed of another material such as gold or copper.

(3) A spiral photoresist pattern 330a is formed on the aluminum film 324a (FIG. 7C). The formation of this pattern can be performed by, for example, a photo-etching method.

(4) Using the photoresist 330a as a mask, the aluminum film 324a is partially removed to form a second spiral electrode 324 (FIG. 7 (D)). Then, the photoresist 324a is washed off.

(5) Both ends of the second spiral electrode 324 thus formed are masked by the photoresist 330b (FIG. 11E).

(6) Anodizing is performed to form an insulating oxide film 326 on the surface of the remaining portion (the portion which is not masked) of the second spiral electrode 324 ((F) in the figure).

(7) Again, a metal film is formed on the entire surface, for example, an aluminum film 322a is vapor-deposited ((G) in the same figure).

(8) A spiral photoresist pattern 330c and a photoresist pattern 330d corresponding to the extraction electrodes 328 formed at both ends of the second spiral electrode 324 are formed on the aluminum film 322a (see FIG. H)). The formation of this pattern can be performed, for example, by the photolithography method as in the case of the photoresist 330a described above.

(9) These photoresists 330c,
The first spiral electrode 322 is formed by partially removing the aluminum film 332a using 330d as a mask.
And the extraction electrodes 328 are formed at both ends of the lower second spiral electrode 324. Then, the photoresists 330c and 330d are washed off.

FIG. 44 is a diagram showing a planar shape of the LC element 12j formed on the semiconductor substrate 320 through these steps. As shown in the figure, the LC element 1 of the present embodiment
In 2j, the first spiral electrode 322 is formed on the surface, and the two extraction electrodes 328 provided at both ends of the second spiral electrode 324 are exposed. The two extraction electrodes 328 correspond to the input / output electrodes 28 and 29 shown in FIG. 2, and both ends of the first spiral electrode 322 respectively correspond to the input / output electrodes 24 and 26 shown in FIG. It corresponds.

FIG. 45 shows an LC whose schematic structure is shown in FIG.
It is a figure which shows the other example of the manufacturing process of an element. According to the manufacturing process shown in FIG. 43, the two spiral electrodes 322, 3
Insulating oxide film 3 formed between 24 by anodic oxidation
An LC element for insulation is manufactured by 26.
According to the manufacturing process shown in FIG.
A different point is that an LC element is manufactured in which is replaced with a silicon oxide film (or a nitride film) formed by a chemical vapor deposition method (CVD). The manufacturing process will be described below.

(1) A high-purity semiconductor substrate 320 is prepared ((A) in the figure). Then, a first silicon oxide film 340 is formed on the semiconductor substrate 320 by the chemical vapor deposition method (FIG. 2B). However, a high-purity semiconductor substrate 320
Since the specific resistance is high in the case of using, the first silicon oxide film 340 can be omitted.

(2) On the first silicon oxide film 340,
A metal film 324b made of a metal, such as gold, tungsten, molybdenum, tantalum, or niobium, which can withstand the next chemical vapor deposition process is vapor-deposited (FIG. 7C).

(3) A spiral photoresist pattern 330a is formed on the metal film 324b (FIG. 3D). The formation of this pattern can be performed by, for example, a photo-etching method.

(4) Using the photoresist 330a as a mask, the metal film 324b is partially removed to form the second spiral electrode 324 (FIG. 7E). Then, the photoresist 330a is washed off.

(5) A second silicon oxide film 342 is formed on the second spiral electrode 324 and the exposed first silicon oxide film 340 by a chemical vapor deposition method (see FIG. 9F). .

(6) A metal film 322b is vapor-deposited on the second silicon oxide film 342 ((G) of the same figure). Since there is no chemical vapor deposition process in the subsequent process, this metal film 322b
Can be an aluminum film, but may be formed of another metal material such as gold or copper.

(7) A spiral photoresist pattern 330c is formed on the metal film 322b (FIG. 7 (H)). The formation of this pattern can be performed, for example, by the photolithography method as in the case of the photoresist 330a described above.

(8) Using the photoresist 330c as a mask, the first spiral electrode 322 is formed (FIG. 11 (I)). Then, the photoresist 330c is washed off. Further, the second silicon oxide film corresponding to both end portions of the second spiral electrode 324 is removed by etching to expose both end portions thereof. This exposed end is used as an input / output electrode.

By using such a process,
The LC element 12j having the planar structure shown in FIG. 42 can be manufactured. As described above, since the LC element 12j of the present embodiment described above is formed on the surface of the semiconductor substrate 320, other components such as the sine wave oscillation circuit 1 shown in FIG. For example, the inverter logic circuit 10) can be formed, and mass production and miniaturization of the entire circuit can be easily realized by integral formation.

The LC element 12j whose schematic structure is shown in FIG. 42 has the first and second spiral electrodes 322, 3
Although 24 is formed in a spiral shape, these two electrodes may be formed in a meandering shape as shown in FIG. Further, these electrodes are not only opposed to each other, but may be partially overlapped with each other so that the center of each of the surrounding portions of the other electrode is located between the surrounding portions of the one electrode.

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, the LC element in each of the above-described embodiments has two conductors (two electrodes or a combination of electrodes and channels) functioning as a primary winding and a secondary winding.
Although the lengths of the two conductors are set to be substantially the same, the two conductors may be set to different lengths. In this case as well, each conductor functions as an inductor, a capacitor is formed between each conductor in a distributed constant manner, and the two conductors are electromagnetically coupled to operate as a transformer. It can be applied to the sine wave oscillation circuit 1 of FIG. 1 and the like. Further, when the two conductors are made to partially correspond to each other, the capacitance formed in a distributed constant becomes small, so that the oscillation frequency when the sine wave oscillating circuit is configured also changes, and the two conductors The oscillation frequency can be adjusted by changing the relative length.

Furthermore, when the length of the conductor corresponding to the secondary winding is relatively long and the winding ratio is set to 1 or more, the voltage level of the signal input to the primary side can be boosted. Since an inverting amplifier having a lower amplification factor can be used, the degree of freedom in component selection increases accordingly.

In addition, in each of the LC elements described above, the electrodes and channels functioning as inductor conductors are formed in a spiral shape or a meandering shape. This spiral shape also includes ones having a number of turns of about one turn or less than one turn. The meandering shape also includes a non-linear shape with a waveform or the number of irregularities of 1 or 2, depending on the size of the inductance.
The electrode shape of the LC element used can be appropriately selected.

Although the LC element of each of the above-mentioned embodiments is formed mainly by using the p-Si substrate, it is similarly formed by using the n-type semiconductor substrate (n-Si substrate). Good. The semiconductor substrate may be made of a material other than silicon such as germanium, or amorphous silicon which is an amorphous material.

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[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a sine wave oscillator circuit of a first embodiment to which the present invention is applied.

FIG. 2 is a diagram showing an example of an LC element.

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

FIG. 4 is a diagram showing an equivalent circuit of the LC element shown in FIG.

FIG. 5 is a diagram showing a manufacturing process of the LC element shown in FIG.

FIG. 6 is a diagram showing a modification of the first embodiment.

FIG. 7 is a diagram showing a configuration of a sine wave oscillator circuit according to a second embodiment of the present invention.

FIG. 8 is a diagram showing a modification of the second embodiment.

FIG. 9 is a diagram showing another modification of the second embodiment.

FIG. 10 is a diagram showing a configuration of a sine wave oscillator circuit according to a third embodiment of the present invention.

FIG. 11 is a diagram showing a modification of the third embodiment.

FIG. 12 is a diagram showing a modification of the LC element.

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

14 is a diagram showing a partial modification of the cross-sectional structure of the LC element shown in FIG.

15 is a diagram showing a partial modification of the cross-sectional structure of the LC element shown in FIG.

FIG. 16 is a diagram showing another modification of the LC element.

FIG. 17 is a diagram for explaining the operation of the inductor conductor having a meandering shape.

FIG. 18 is a diagram showing another modification of the LC element.

FIG. 19 is a diagram showing another modification of the LC element.

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

21 is an enlarged cross-sectional view taken along the line BB of FIG.

22 is an enlarged cross-sectional view taken along the line CC of FIG.

23 is a diagram for explaining a state in which a channel is formed in the LC element shown in FIG.

FIG. 24 is a view showing a cross section taken along a spiral electrode of the LC element shown in FIG.

25 is a diagram showing an equivalent circuit of the LC element shown in FIG.

FIG. 26 is a diagram showing a manufacturing process of the LC element shown in FIG.

FIG. 27 is a diagram showing another modification of the LC element.

FIG. 28 is a diagram showing another modification of the LC element.

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

30 is an enlarged cross-sectional view taken along the line BB of FIG.

31 is an enlarged cross-sectional view taken along line CC of FIG. 28.

32 is an enlarged cross-sectional view taken along the line DD of FIG. 28.

FIG. 33 is a diagram showing an equivalent circuit of the LC element shown in FIG. 28.

FIG. 34 is a diagram showing a specific configuration when the LC element shown in FIG. 28 is applied to a sine wave oscillation circuit.

FIG. 35 is a diagram showing a partial modification of the cross-sectional structure of the LC element shown in FIG. 28.

FIG. 36 is a diagram showing another modification of the LC element.

FIG. 37 is a diagram for explaining a state in which a channel is formed in the LC element shown in FIG.

FIG. 38 is a diagram showing a partial modification of the cross-sectional structure of the LC element shown in FIG. 36.

39 is a diagram showing a partial modification of the cross-sectional structure of the LC element shown in FIG.

FIG. 40 is a diagram showing another modification of the LC element.

FIG. 41 is a diagram showing another modification of the LC element.

FIG. 42 is a diagram schematically showing another modification of the LC element.

FIG. 43 is a diagram showing an example of a manufacturing process of the LC element shown in FIG. 42.

FIG. 44 is a plan view of the LC element shown in FIG. 42.

FIG. 45 is a diagram showing another example of the manufacturing process of the LC element shown in FIG. 42.

[Explanation of symbols]

1 Sine wave oscillator 10 Inverter logic circuit 12 LC element 14 Capacitor 16 resistance 20 First spiral electrode 22 Second spiral electrode 24, 26, 28, 29 Input / output electrodes 34 p-Si substrate (p-type silicon substrate) 36 pn junction layer

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification symbol FI H03B 5/18 (56) References JP-A-7-321554 (JP, A) JP-A-54-56753 (JP, A) Kaihei 6-77711 (JP, A) JP-A-2-26115 (JP, A) JP-A-3-259608 (JP, A) JP-A 4-2108 (JP, A) Actual Kaisho Sho 63-140707 ( (58) Fields investigated (Int.Cl. ⁷ , DB name) H03B 5/08 H01F 27/00 H01G 4/40 H03B 5/18 H01L 27/04

Claims (14)

(57) [Claims] And 1. A inverting amplifier for performing phase inversion amplifies an input signal, having two inductor conductor having a function as a primary and secondary winding is made form on a semiconductor substrate, these two the two inductor according inductor conductor and a capacitor between them and LC elements that will be formed distributed constant type, wherein the inverting amplifier to one end of the primary side of the LC elements
Of the LC element by connecting the other end to the first potential side and the output side of
Reversing one end of the secondary side of the child so that it is in reverse phase with the primary side
The input side of the amplifier and the second end of which the other end is different from the first potential
Connected to the potential side of the LC element , the LC elements are arranged adjacent to each other in parallel in the same plane.
Spiral or meandering shape that functions as an inductor conductor of
The two electrodes and the two electrodes near the surface of the semiconductor substrate.
One of these two electrodes
Is electrically connected to the p region, and the other is electrically connected to the n region,
By applying a reverse bias voltage to the capacitor
And a pn junction layer having a spiral or meandering shape that operates as described above . 2. Amplifying an input signal and performing phase inversion
And an inverting amplifier for performing primary and secondary windings formed on a semiconductor substrate.
It has two inductor conductors that have a function, and these two
Inductor with two inductors and between them
And an LC element in which the capacitor of the LC element is formed in a distributed constant manner, and one end of the LC element on the primary side is connected to the inverting amplifier.
Of the LC element by connecting the other end to the first potential side and the output side of
Reversing one end of the secondary side of the child so that it is in reverse phase with the primary side
The input side of the amplifier and the second end of which the other end is different from the first potential
Connected to the potential side of the LC element , the LC elements are arranged substantially opposite to each other with the semiconductor substrate interposed therebetween,
Spirals or snakes that function as the two inductor conductors
Two electrodes in a row shape and a position between the two electrodes in the semiconductor substrate.
And the p region on either one of these two electrodes.
And the n region is electrically connected to the other
Acts as the capacitor by applying an ass voltage.
And a pn junction layer for making the sine wave oscillation circuit. 3. In any of claims 1, 2, wherein the two sine wave oscillator circuit, and forming shorter than either the length to the other electrode. 4. The capacitance value of a capacitor formed in a distributed constant in the LC element according to claim 1, wherein a reverse bias voltage applied to the pn junction layer is changed. A sine wave oscillator circuit characterized by. 5. Amplifying an input signal and performing phase inversion
And an inverting amplifier for performing primary and secondary windings formed on a semiconductor substrate.
It has two inductor conductors that have a function, and these two
Inductor with two inductors and between them
Comprising an LC element and the capacitor are formed distributed constant type, the said inverting amplifier to one end of the primary side of the LC elements
Of the LC element by connecting the other end to the first potential side and the output side of
Reversing one end of the secondary side of the child so that it is in reverse phase with the primary side
The input side of the amplifier and the second end of which the other end is different from the first potential
Connected to the potential side of the LC element , the LC element is a spiral or meandering type that forms a gate in a MOS structure.
-Shaped electrode, between the spiral or meandering electrode and the semiconductor substrate
And an insulating layer formed on the semiconductor substrate and having the spiral or meandering shape in the semiconductor substrate.
Formed near both ends of the channel formed corresponding to the electrode
First and second to function as a source and a drain
Two diffusion regions, and the spiral or meandering electrode and the corresponding
Each of the two channels formed by
Sine wave oscillator characterized by being used as a conductor
Road. 6. Amplifying an input signal and performing phase inversion
And an inverting amplifier for performing primary and secondary windings formed on a semiconductor substrate.
It has two inductor conductors that have a function, and these two
Inductor with two inductors and between them
Comprising an LC element and the capacitor are formed distributed constant type, the said inverting amplifier to one end of the primary side of the LC elements
Of the LC element by connecting the other end to the first potential side and the output side of
Reversing one end of the secondary side of the child so that it is in reverse phase with the primary side
The input side of the amplifier and the second end of which the other end is different from the first potential
Connected to the potential side of the LC element , the LC element is a spiral or meandering type that forms a gate in a MOS structure.
-Shaped first electrode, the first electrode having a spiral or meandering shape, and the semiconductor substrate
And an insulating layer formed between the first electrode and the surface of the semiconductor substrate.
A second electrode having a spiral or meandering shape, and the spiral or meandering second electrode in the semiconductor substrate.
Near both ends of the channel formed corresponding to the first electrode
A first layer formed to function as a source and a drain
And a second diffusion region , corresponding to the first electrode having a spiral or meandering shape.
Each of the second electrode and the channel formed by
Characterized by being used as two inductor conductors
Sine wave oscillator circuit. 7. Amplifying an input signal and performing phase inversion
And an inverting amplifier for performing primary and secondary windings formed on a semiconductor substrate.
It has two inductor conductors that have a function, and these two
Inductor with two inductors and between them
Comprising an LC element and the capacitor are formed distributed constant type, the said inverting amplifier to one end of the primary side of the LC elements
Of the LC element by connecting the other end to the first potential side and the output side of
Reversing one end of the secondary side of the child so that it is in reverse phase with the primary side
The input side of the amplifier and the second end of which the other end is different from the first potential
Connected to the potential side of the semiconductor device , the LC element is formed on one surface side of the semiconductor substrate and has a MOS structure.
Swirl or meandering first electrode forming a gate in
A pole, the first electrode having a spiral or meandering shape, and the semiconductor substrate
And an insulating layer formed between the first electrode and the other surface of the semiconductor substrate.
Spiral or serpentine shape formed at a position almost facing the pole
Of the second electrode of the semiconductor substrate and the second electrode of the spiral or meandering shape in the semiconductor substrate.
Near both ends of the channel formed corresponding to the first electrode
A first layer formed to function as a source and a drain
And a second diffusion region , corresponding to the first electrode having a spiral or meandering shape.
Each of the second electrode and the channel formed by
Characterized by being used as two inductor conductors
Sine wave oscillator circuit. 8. The carrier according to claim 5 , wherein carriers are previously injected into at least a part of a position where the channel is formed in the vicinity of the surface of the semiconductor substrate, and the spiral or meandering electrode is provided with the carrier. A sinusoidal oscillation circuit characterized in that the spiral or meandering electrode and the channel are partially opposed to each other by setting the channel length to be long or short. 9. The spiral or meandering shape of the second electrode according to claim 6 , wherein one of the first and second electrodes is formed to have a shorter length than the other. A sine wave oscillator circuit characterized in that the electrode and the channel are partially opposed to each other. 10. The sine wave oscillation circuit according to claim 5 , wherein carriers are injected in advance at a position near the surface of the semiconductor substrate where the channel is formed. 11. The sinusoidal wave according to claim 5 , wherein a resistance value of the channel is variably controlled by changing a gate voltage applied to an electrode forming the gate. Oscillator circuit. 12. The claim 1 to 11, a sine wave oscillating circuit, characterized in that configuring the inverting amplifier by an inverter logic circuit. 13. claimed in any one of claims 1 to 11, a sine wave oscillating circuit, characterized in that configuring the inverting amplifier by the source grounded circuit or grounded-emitter circuit. 14. claimed in any one of claims 1 to 13, a sine wave oscillating circuit, characterized in that integrally formed on the semiconductor substrate which is common to the inverting amplifier and the LC element.