JP2005244084A - Spiral high-frequency coil and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a cost and a thickness as a whole by simplifying a working process of a micro high-frequency coil of low loss. <P>SOLUTION: There are provided a silicon substrate 100 formed with a recess 102, a plurality of first gold wires 201-207 almost parallel to one another without contacting the bottom surface of the recess 102, and a plurality of second cold wires 302-307 bridged almost parallel to one another on the opening surface. Ends of the first and the second gold wires are connected to each other to constitute a continuous spiral high-frequency coil. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a spiral high-frequency coil by a microfabrication technique and a manufacturing method thereof.

A conventional high-frequency coil is formed in a spiral shape by arranging a plurality of loop-shaped lines so that their axes are common. Both ends of the spiral body are bent in the axial direction to form an input portion and an output portion, and these input / output portions are held by the substrate.
Next, the operation will be described.
The high-frequency signal input from the signal input unit is transmitted to the loop-shaped line and output from the signal output unit. At this time, the direction of the magnetic field generated around one loop-shaped line is the same as the direction of the magnetic field generated by the other loop-shaped lines, and a potential is generated in a direction that prevents the current from changing in the entire loop-shaped line. Works as an inductor. In addition, since the electromagnetic field is concentrated inside the loop-shaped line, it is not easily affected by the substrate, so that the loss due to the dielectric loss tangent of the substrate is small and the coil works as a low-loss coil.
Next, a conventional method for processing a high-frequency coil will be described.
After laminating a polyimide film having a thickness of 30 μm on the alumina substrate, a groove is formed by etching using aluminum as a mask, and copper plating is performed to form an input / output portion. Further, a polyimide film is laminated, a groove is formed by etching using aluminum as a mask, and copper plating is performed to form a lower portion of the loop-shaped line. Next, a polyimide film is laminated, a groove is formed by etching using aluminum as a mask, and copper plating is performed to create a vertical portion of the loop-shaped line. Finally, a polyimide film is laminated, a groove is formed by etching using aluminum as a mask, and copper plating is performed to form an upper portion of the loop-shaped line (for example, Non-Patent Document 1, FIG. 9a to e). reference).
In other conventional high-frequency coils, a silicon substrate on which silicon is deposited is provided on a ground conductor, a thin dielectric film is formed on the silicon substrate, and a spiral coil and spiral coil input / output are formed on the dielectric film. And an air bridge connecting the terminal portion of the spiral coil and the input / output portion, and silicon below the spiral coil is removed by etching to form a void.
Next, the operation will be described.
The signal input from the input unit is guided to the spiral coil, and further the signal is guided to the output unit via the air bridge. Since the lower part of the spiral silicon is formed as a hole, silicon dielectric loss and silicon conductor loss do not occur, so that a small and low-loss coil can be realized (see, for example, Non-Patent Document 2, especially FIG. 2).

The publication “IEEE Transactions on Components, Packaging and Manufacturing Technology”, January 1998 PART C, VOL. 21, NO. 1. Yongjun Kim and Mark G. Title “All-in-One Solenoid Inductor by Surface Micromachining for High Frequency” by Allen Publication "IEEE Transactions on Microwave Theory and Technology", April 1995 VOL. 43, NO. 4. Chain utility and Gabriel M. Title by Leviz "Elements and coupled wire filters for microwaves and millimeter waves using microfabrication technology"

In the technique described in Non-Patent Document 1, since the high-frequency coil is sequentially formed from the lower part by stacking multiple layers of polyimide films on the substrate using a fine processing technique, there is a problem that the processing process is complicated and expensive. there were.
Moreover, in the technique described in Non-Patent Document 2, since a plurality of wafers are bonded and processed, there is a problem that the thickness of the component is increased.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to obtain a high-frequency coil and a method for manufacturing the same that can simplify the machining process, reduce the cost, and realize a thinner part. .

  The spiral high-frequency coil according to the present invention includes a substrate having a recess, a plurality of first conductor lines provided substantially in parallel without contacting the surface of the recessed portion of the recess, and the upper surface portion of the recess. An insulator provided on the opening surface, a plurality of second conductor lines installed substantially parallel to the top surface of the insulator, and one end of the first conductor line connected to one end of the second conductor line And a second connection portion for connecting the other end of the first conductor line to one end of the second conductor line adjacent to the second conductor line to which one end is connected. It is.

According to the present invention, more than half of the helical conductor line is provided in the recessed portion of the inner surface of the concave portion of the substrate, and the other portion of the conductor line is installed on the opening surface of the concave portion. The whole is held inside the concave portion of the substrate. Therefore, it is possible to form a high-frequency coil even if the strength and rigidity of the spiral conductor itself are somewhat low, and thus the spiral conductor line is made thinner. Since it can be formed thin, the size can be reduced, and the entire thickness of the high-frequency coil is substantially equal to the height of the substrate, and therefore the overall thickness can be reduced.
In addition, since the first conductor line does not contact the surface of the recessed portion of the recess, the first conductor line is surrounded by air, so that the first conductor line is formed on the surface of the recessed portion of the recess. Even when compared with the case of contact, the loss can be further reduced.

An embodiment of the present invention will be described below.
Embodiment 1 FIG.
1 is a perspective view of a high-frequency coil according to Embodiment 1 of the present invention, and FIGS. 2 and 3 are perspective views showing the middle of a manufacturing process. FIG. 4 is a cross-sectional view along the first conductor line showing the manufacturing process. FIG. 6 is a cross-sectional view showing a cross section AA ′ of FIG. An insulating film 105 is provided on the surface of the silicon substrate 100, and a minute recess 102 is formed on the surface provided with the insulating film 105 by etching. The surface on which the recess 102 is provided is composed of an etched recess, that is, an inner surface of the recess, and an upper surface of the upper portion of the recess that is not etched, that is, a recess. A plurality of first gold wires 201 to 207 which are a plurality of first conductor lines provided substantially in parallel with each other without being in contact with the surface of the recessed portion inside the recess are arranged.
In addition, an insulating film 106 is provided on the opening surface that is flush with the upper upper surface portion of the recess 102, and the upper surface of the insulating film 106 is made up of a plurality of second conductor lines that are arranged substantially in parallel. A plurality of second gold lines and gold lines 301 to 308 to be input / output portions are formed. And the 1st connection part 401 which connects the end of 1st gold | metal wires 201-207 to the end of 2nd gold | metal wires 301-308, and the other end of the 1st gold | metal | money line are connected to one end. By providing a plurality of second connection portions 402 connected to one end of the second gold line adjacent to the second gold line, the adjacent first gold lines are electrically connected by the second gold line. Connected. The first connection part and the second connection part are provided on the upper surface of the upper part of the recess so as to facilitate connection. The plurality of first gold wires and the plurality of second gold wires serve as one conductor, and the gold wires are formed in a spiral coil. The core portion of the spiral coil formed of gold wire is hollow.
Measurement ground pads 501 and 502 extending in a direction substantially orthogonal to the second gold wires 302 to 307 are provided on the upper surface of the insulating film 105 and in the vicinity of the recess 102.

Next, the manufacturing method of the high frequency coil which concerns on the said structure is demonstrated.
First, as shown in FIG. 2, the surface of the silicon substrate 100 provided with the insulating film 105 is wet-etched to form the recess 102 having a depth of about 30 μm. Next, as shown in FIG. 3, gold is sputtered from the inner surface of the recess 102 to the upper surface of the substrate 100, and a plurality of first gold wires 201 to 207 having a thickness of about 1 μm are left by photoetching. At this time, both ends of each of the first gold wires 201 to 207 are left slightly on the upper surface of the upper portion of the recess of the silicon substrate 100 (see FIG. 4A).

Next, as a sacrificial layer, for example, a photoresist 1000 is filled in the recess 102 and planarized on the same surface as the upper surface of the recess of the silicon substrate 100. At this time, both end portions of the first gold wires 201 to 207 are exposed from the sacrificial layer (FIG. 4B).
Next, a first insulator film 106 made of a silicon nitride thin film is sputtered and patterned by photoetching to be slightly larger than the opening surface of the recess 102. Next, etching is performed so that both ends of the first gold wires 201 to 207 formed in the previous process are exposed from the insulator, and at the same time, holes (not shown) for removing the sacrificial layer are formed in the insulator (FIG. 4 ( c)). Next, gold is sputtered on the first insulator film 102, and a second gold line having a thickness of about 1 μm, gold lines 301 to 308 serving as input / output portions, and a measurement ground pad 501 are formed by photoetching. And 502 are patterned.
At this time, first and second gold wires and first and second gold wires 301 to 308 serving as input / output portions are joined to both end portions of the first gold wires 201 to 207, respectively. Two connection portions 401 and 402 are formed (FIG. 4D). By forming the first and second connection portions 401 and 402 as described above, the adjacent first gold wires are electrically connected to each other by the second gold wire.

Finally, the photoresist 1000 filled in the recess 102 as a sacrificial layer is removed by wet etching, and the substrate material 103 below the first gold line is removed by dry etching, whereby the first and second gold lines 301, 201, 302, 202, 303, 203, 304, 204, 305, 205, 306, 206, 307, 207, 308 are one continuous spiral conductor, and the inside of the spiral conductor as a whole is hollow, A coil is obtained in which the portions excluding both ends of one gold wire 201 to 207 are held in the air without contacting the substrate 100. FIGS. 4E and 5 are views showing a state in which only the sacrificial layer is removed. FIGS. 4F and 6 show not only the sacrificial layer but also the substrate material 103 below the first gold line. It is a figure which shows the condition from which also was removed.
The sacrificial layer is filled in the recess, and after the first insulator film 102 and the second gold wire are formed on the sacrificial layer, the sacrificial layer filled in the recess is removed, thereby simplifying the process. As a result, the cost can be reduced and the overall thickness can be reduced.
Since the first conductor line is surrounded by air in a state where the first gold wire is tangled in the air without contacting the substrate 100, the first conductor line is in contact with the surface of the recessed portion of the recess. Even if compared with the case where it is, it can be set as a lower loss.

Next, the operation will be described.
When a high-frequency signal is input from a gold wire 305 serving as an input terminal of the spiral conductor, the high-frequency signal passes through the gold wire 201, 302, 202, 303, 203, 304, 204, 305, 205, 306, 206. , 307 and 207 in this order and output from the gold line 308. Since the current flows in a spiral manner, the direction of the current flowing through the second gold lines 302 to 307 is equal, and the direction of the current flowing through the first gold lines 201 to 207 is also equal. As a result, the magnetic field is confined in the recess 102, but this portion is hollow, and there is almost no loss because the first gold wire is not in contact with the substrate. For this reason, this minute helical conductor has a low loss.
Even if the opening area of the concave portion 102 is large, the second gold wire and the gold wires 301 to 308 to be the input / output portions are supported by the first insulator film 104, so that the helical conductor can be easily manufactured. become.

  The substrate 100 is not limited to silicon, and any material that can be finely processed such as glass, GaAs, or aluminum can be used. Further, the gold line is not limited to gold, and any gold line can be used as long as a pattern can be created by, for example, photolithography. The thickness of the gold wire is preferably equal to or greater than the skin depth in consideration of the conductivity of the metal used and the frequency used.

In the first embodiment, the second gold wire and the gold wires 301 to 308 to be input / output portions are formed on the first insulator film 102. However, the present invention is not limited to this. The gold wires 301 and 308 serving as input / output portions may be provided directly on the sacrificial layer without being provided on the first insulator film 106. FIG. 7 is a perspective view showing a helical coil device formed by performing the steps of providing the second gold wire directly on the sacrificial layer and removing the sacrificial layer thereafter.
The step of providing the first insulator film and the like can be omitted, and the first insulator can be formed more easily.
In addition, when etching the substrate on the inner surface of the recessed portion of the recess, an unetched thin film, for example, an oxide film 104 is provided on the inner inclined surface of the recess, thereby reducing the etching area of the substrate slightly, It is possible to obtain a structure with increased strength. FIG. 8 is a cross-sectional view showing a state where only the sacrificial layer is removed, and FIG. 9 is a cross-sectional view showing a state where not only the sacrificial layer but also the substrate material 103 under the first gold line is removed. As can be seen from a comparison between FIGS. 7 and 9, since the substrate below the oxide film 104 is not etched, it can be seen that the mechanical strength of the substrate is higher than that of the embodiment of FIG.
In addition, when it is not easy to etch the substrate that is in contact with the first gold line in the recessed portion inside through the sacrificial layer removal hole, the first gold line formed in the recessed portion in the recessed portion is not easily etched. The substrate in between may be pre-etched to have a structure having a trench 105 under the first gold line. FIG. 10 is a cross-sectional view of what was made by the method of filling the sacrificial layer after etching the substrate between the first gold lines.
1 to 7, in the method for producing the embodiment described above, before the filling layer is filled, the step of creating the trench described above is added, and the lower part of the first gold line in the step after the sacrifice layer is removed A spiral coil having a trench as shown in FIG. 10 can be formed by simply not performing the process of removing the substrate material 103. Although the loss is larger than that in which the lower part of the first gold line as shown in FIG. 7 is completely removed, even if the material is relatively difficult to etch, such as when the substrate is glass. Can be produced easily.
Although the description has been given of the case where seven and six first and second gold wires are used, the number of the first and second gold wires may be changed as appropriate depending on the application.
Although the example of removing the substrate material 103 under the first gold line and all the portions (except for the upper upper surface portion of the substrate) has been shown, it is configured to be held by a part of the substrate instead of all the portions. Also good. In that case, a part of the first gold wire is held on the substrate, and the coil has a sturdy structure.

  In addition, one end of the gold wire formed in the recess is extended in one direction or alternately symmetrically, and a part of the extended tip and the measurement ground pad 501 or 502 are sandwiched between dielectrics such as silicon nitride 1001, so that the capacitor is It is also possible to provide it. FIG. 11 shows an example in which one end of a gold wire is extended, a silicon nitride 1001 is formed on a part of the tip, and a measurement ground pad 501 is provided on the silicon nitride 1001 to form a capacitor 1002. A capacitor may be formed by providing silicon nitride on the measurement ground pad and providing a gold wire on the silicon nitride.

Embodiment 2. FIG.
FIG. 12 is a perspective view of a high-frequency coil according to Embodiment 2 of the present invention. An insulating film 105 is provided on the surface of the silicon substrate 100, and a minute recess 102 is formed on the surface provided with the insulating film 105 by etching. The surface on which the recess 102 is provided is composed of an etched recess, that is, an inner surface of the recess, and an upper surface of the upper portion of the recess that is not etched, that is, a recess. A plurality of first gold lines 701, 703, and 705, which are a plurality of first conductor lines provided substantially in parallel without contacting the surface of the recessed portion inside the recess, respectively, and substantially in parallel with each other. A plurality of third gold lines 702, 704, and 706, which are a plurality of third conductor lines provided, are alternately arranged.
In addition, an insulating film 106 is provided on the opening surface that is flush with the upper upper surface portion of the recess 102, and the upper surface of the insulating film 106 is made up of a plurality of second conductor lines that are arranged substantially in parallel. A plurality of second gold lines 603 and 605 and a plurality of fourth gold lines 604 and 606, which are a plurality of fourth conductor lines laid substantially in parallel, are alternately arranged. .
Then, a first connecting portion 403 that connects one end of the first gold wire to one end of the second gold wire, and a second gold wire that connects the other end of the first gold wire. By providing a plurality of second connection portions 404 connected to one end of the adjacent second gold wire, the adjacent first gold wires are connected by the second gold wire. Also, a third connecting portion 405 for connecting one end of the third gold wire to one end of the fourth gold wire, and a fourth gold wire having one end connecting the other end of the third gold wire. By providing a plurality of fourth connection portions 406 that are connected to one end of the fourth gold line adjacent to each other, the adjacent third gold lines are connected by the fourth gold line.
The 1st-4th connection part is provided in the upper stage upper surface of the recessed part so that a connection may become easy. The plurality of first gold wires and the plurality of second gold wires serve as one conductor and are formed in the first spiral coil. The plurality of third gold wires and the plurality of fourth gold wires serve as one conductor and are formed in the second spiral coil. And if it forms with the gold | metal | money wire, the core part of the 1st and 2nd helical coil will be comprised hollow.

Next, the manufacturing method of the high frequency coil which concerns on the said structure is demonstrated.
Similar to the first embodiment, first, wet etching in which an insulating film 105 is provided on a silicon substrate 100 is performed to form a recess 102 having a depth of about 30 μm. Next, as shown in FIG. 3, gold is sputtered from the inner surface of the recess 102 to the upper surface of the substrate 100, and a plurality of first and third gold lines 701 to 706 having a thickness of about 1 μm are left by photoetching. At this time, both ends of each of the first and third gold lines 701 to 706 are slightly left on the upper surface of the upper portion of the recess of the silicon substrate 100.

Next, as a sacrificial layer, for example, a photoresist 1000 is filled in the recess 102 and planarized on the same surface as the upper surface of the silicon substrate 100. At this time, both end portions of the first and third gold wires 701 to 706 provided alternately are exposed from the sacrificial layer.
Next, a first insulator film 106 made of a silicon nitride thin film is sputtered and patterned by photoetching to be slightly larger than the opening surface of the recess 102. Next, etching is performed so that both end portions of the first and third gold wires 701 to 706 formed in the previous step are exposed from the insulator, and at the same time, holes (not shown) for removing the sacrificial layer are formed in the insulator.
Next, gold is sputtered on the first insulator film 106, and by photoetching, second and fourth gold lines having a thickness of about 1 μm, gold lines 601 to 608 serving as input / output portions, and measurement The ground pads 501 and 502 are patterned. In that case, the 1st and 2nd junction part for joining the both ends of each of the 2nd gold | metal wire 603,605 to each both ends of the 1st gold | metal wires 701,703,705 is provided. Also, third and fourth joints are provided for joining the ends of each of the fourth gold wires 604, 606 to the ends of each of the third gold wires 702, 704, 706. By forming the first to fourth joints, the adjacent first gold lines are the second gold lines, and the adjacent third gold lines are the fourth gold lines, respectively. Electrically connected.

Finally, the photoresist 1000 filled in the recess 102 as a sacrificial layer is removed by wet etching, and the substrate material 103 below the first gold line is removed by dry etching, so that the gold lines 601 and 701 are removed. , 603, 703, 605, 705, and 607 and another helical conductor in which the gold wire is continuous with 602, 702, 604, 704, 606, 706, and 608, As a whole, a coil in which the inside of the spiral conductor is hollow and the portions excluding both ends of the first and third gold wires 701 to 706 are held in the air without contacting the substrate 100 is obtained.
The sacrificial layer is filled in the recess, and after the second and fourth gold lines are formed on the sacrificial layer, the sacrificial layer filled in the recess is removed, so that the process can be simplified and the cost can be reduced. In addition, the overall thickness can be reduced.
Since the first conductor line is surrounded by air in a state where the first and third gold wires are tangled in the air without contacting the substrate 100, the first conductor is formed on the surface of the recessed portion of the recess. Even if compared with the case where it is in contact with the line, the loss can be further reduced.
Measurement ground pads 501 and 502 extending in a direction substantially perpendicular to the second and fourth gold lines 603 to 606 are provided on the upper surface of the insulating film 105 and in the vicinity of the recess 102.

Next, the operation will be described.
When a high-frequency signal is input from a gold wire 601 serving as an input terminal of a spiral conductor, the high-frequency signal is transmitted in the order of gold wires 701, 603, 703, 605, and 705, and output from the gold wire 607. Is done. Since the current flows in a spiral shape in this way, the direction of the current flowing through the gold lines 603 and 605 is equal, and the direction of the current flowing through the gold lines 701, 703 and 705 is also equal. As a result, the magnetic field is confined in the recess 102, but this portion is hollow, and there is almost no loss because the first gold wire is not in contact with the substrate. For this reason, this minute helical conductor has a low loss.
Even if the opening area of the recess 102 is large, the second and fourth gold wires and the gold wires 601 to 608 serving as the input / output portions are supported by the first insulator film 104, so Easy to manufacture.

  When a high frequency signal is input from a gold wire 602 serving as an input terminal of another spiral conductor, the high frequency signal is transmitted in the order of the gold wires 702, 604, 704, 606, and 706, Output from line 608. Since the current flows spirally in this way, the direction of the current flowing through the gold lines 604 and 606 is equal, and the direction of the current flowing through the gold lines 702, 704 and 706 is also equal. This occurs so that the magnetic field is confined in the recess, but this portion is hollow, and there is almost no loss because the first gold wire is not in contact with the substrate. For this reason, this other small helical conductor has a low loss.

  Further, since the second and fourth gold lines 603 to 606 are arranged in substantially the same direction, and the first and third gold lines 701 to 706 are arranged in substantially the same direction, the two helical conductors are arranged. Are electromagnetically coupled, and when a current is passed through one spiral conductor, a current is also induced in the other spiral conductor, and thus the high-frequency coil shown in FIG. 12 functions as a coupler.

  As in the first embodiment, the material of the substrate 100 is not limited to silicon, and any material that can be finely processed, such as glass, GaAs, or aluminum, can be used. The gold line can be used as long as it can form a pattern by, for example, photolithography. The thickness of the gold wire is preferably equal to or greater than the skin depth in consideration of the conductivity of the metal used and the frequency used.

In the second embodiment, the second and fourth gold lines and the gold lines 601 to 608 serving as the input / output portions are formed on the first insulator film 106. However, the present invention is not limited to this. The second gold lines and the gold lines 601 to 608 to be the input / output portions may be provided directly on the sacrificial layer without being provided on the first insulator film 106. FIG. 13 is a perspective view showing a helical coil device formed by performing substantially the same processes such as providing the second and fourth gold wires directly on the sacrificial layer and then removing the sacrificial layer thereafter. .
The step of providing the first insulator film and the like can be omitted, and the first insulator can be formed more easily.
In the second embodiment, the description has been given of the case where two coils can be formed. However, fifth and sixth gold wires may be provided to form three coils, and further, a gold wire may be provided. The desired number of coils may be obtained.
As in the first embodiment, the number of the first to fourth gold wires can be changed as appropriate depending on the application.
Similarly to the first embodiment, when etching the substrate on the inner surface of the recessed portion of the recess, an unetched thin film such as an oxide film 104 is provided on the inner inclined surface of the recess so that the etching area of the substrate is slightly increased. The structure can be reduced and the mechanical strength of the microcoil can be increased.
As in the first embodiment, when it is not easy to etch the substrate that is in contact with the first gold line in the recessed portion inside through the sacrificial layer removal hole, the first formed in the recessed portion in the recessed portion. The substrate between one gold line may be pre-etched to have a structure having a trench 105 below the first gold line.
Before the filling layer is filled, the above-described trench forming step is added, and the step of removing the substrate material 103 below the first gold line in the step after removing the sacrificial layer is not performed. A spiral coil can be created. Compared to the one where the lower part of the first gold wire is completely removed, the loss is greater, but even if the material is relatively difficult to etch, such as when the substrate is glass, it is easy to produce. Can do.
As in the first embodiment, the example in which the substrate material 103 under the first and third gold lines and all the portions (except the upper upper surface portion of the substrate) are removed has been shown, but not all the portions. Alternatively, a part of the substrate may be held. In that case, a part of the first gold wire is held on the substrate, and the coil has a sturdy structure.
Similarly to the first embodiment, one end of the gold wire formed in the recess is extended in one direction or alternately symmetrically, and the extended part and the measurement ground pad 501 or 502 are made of a dielectric such as silicon nitride 1001. It is also possible to provide a capacitor by sandwiching it. Silicon nitride may be provided on the measurement ground pad, and a capacitor may be provided on the silicon nitride by extending one end of the gold wire in one direction or alternately symmetrically.

Embodiment 3 FIG.
14 is a perspective view of a high-frequency coil according to Embodiment 3 of the present invention, and FIG. 15 is a cross-sectional view of FIG. An insulating film 105 is provided on the surface of the silicon substrate 100, and a minute recess 102 is formed on the surface provided with the insulating film 105 by etching. The surface on which the recess 102 is provided is composed of an etched recess, that is, an inner surface of the recess, and an upper surface of the upper portion of the recess that is not etched, that is, a recess. A plurality of first gold wires 701, 703, and 705, which are a plurality of first conductor lines provided in parallel with each other without contacting the surface of the recessed portion inside the recess, are provided in substantially parallel to each other. A plurality of third gold lines 702, 704, and 706, which are the plurality of third conductor lines formed, are alternately arranged.
In addition, two layers of first and second insulators 905 and 906 are provided on the opening surface that is flush with the upper upper surface portion of the recess 102, and the first and second insulators 905 and 906 are provided. A plurality of second gold lines 803 and 805, which are a plurality of second conductor lines laid in parallel with each other, and a plurality of fourth conductor lines laid in a substantially parallel manner, respectively. The fourth gold lines 804 and 806 are alternately arranged.
Then, a first connecting portion 403 that connects one end of the first gold wire to one end of the second gold wire, and a second gold wire that connects the other end of the first gold wire. By providing a plurality of second connection portions 404 connected to one end of the adjacent second gold wire, the adjacent first gold wires are connected to each other by the second gold wire. Also, a third connecting portion 405 for connecting one end of the third gold wire to one end of the fourth gold wire, and a fourth gold wire having one end connecting the other end of the third gold wire. By providing a plurality of fourth connection portions 406 connected to one end of the fourth gold line adjacent to each other, the adjacent third gold lines are connected by the fourth gold line.
The first to fourth connection portions 403 to 406 are provided on the upper surface of the upper portion of the recess so as to facilitate connection. The plurality of first gold wires and the plurality of second gold wires serve as one conductor and are formed in the first spiral coil. The plurality of third gold wires and the plurality of fourth gold wires serve as one conductor and are formed in the second spiral coil. And the core part of the 1st and 2nd helical coil formed with the gold | metal | money wire is comprised hollow.
A first magnetic body 902 is provided on the lower surface of the first insulator 905, and a second magnetic body 901 is provided on the upper surface of the second insulator 906 provided on the upper surface of the first insulator 905. In addition, the third and fourth magnetic bodies 903 and 904 passing through the first and second insulators 905 and 906 connect the end portions of the first and second magnetic bodies 901 and 902, and the two layers The first and second insulators 905 and 906 support a hollow body made of the first to fourth magnetic bodies 901 to 904, and some of the plurality of second and fourth gold wires 803 to 806 are hollow. It has a shape inserted through the body in a non-contact state.
On the upper surface of the insulating film 105 and in the vicinity of the recess 102, measurement ground pads 501 and 502 extending in a direction substantially orthogonal to the second and fourth gold lines 803 to 806 are provided.

Next, a method for producing the high frequency coil according to the above configuration will be described.
Similar to the first embodiment, first, wet etching in which an insulating film 105 is provided on a silicon substrate 100 is performed to form a recess 102 having a depth of about 30 μm. Next, gold is sputtered and first and third gold lines 701 to 706 having a thickness of about 1 μm are left by photoetching. At this time, both ends of each of the first and third gold lines 701 to 706 are slightly left on the upper surface of the upper portion of the recess of the silicon substrate 100.

  Next, for example, a photoresist 1000 is filled in the recess 102 as a sacrificial layer, and planarized on the same surface as the upper surface of the silicon substrate 100. At this time, both ends of each of the first and third gold lines 701 to 706 are exposed from the sacrificial layer. Next, the first magnetic body 902 is sputtered on the sacrificial layer and patterned so as to be positioned at the center of the recess 102 by photoetching.

  Next, a first insulator film 905 made of a silicon nitride thin film is sputtered and patterned to be slightly larger than the opening surface of the recess 102 by photoetching. Next, etching is performed so that both ends of the first and third gold wires 701 to 706 formed in the previous step are exposed from the insulator, and at the same time, holes (not shown) for removing the sacrificial layer are made in the insulator. Next, gold is sputtered on the first insulator film 905, and the second and fourth gold lines having a thickness of about 1 μm, the gold lines 801 to 808 serving as the input / output portions, and the measurement are performed by photoetching. The ground pads 501 and 502 are patterned.

  Subsequently, a second insulator film 906 made of a silicon nitride thin film is sputtered on the second and fourth gold lines and the gold lines 801 to 808 serving as input / output portions, and the recess 102 is formed by photoetching. Patterning is slightly larger than the opening surface. Next, grooves connected to both ends of the first magnetic body 902 are formed in the first and second insulator films 905 and 906 by dry etching, and the third and fourth magnetic bodies 903 and 904 are formed in these grooves. Is provided.

Thereafter, a second magnetic body 901 is sputtered on the second insulator film 906, and is patterned by photo-etching so as to be positioned between the third and fourth magnetic bodies 903 and 904. A hollow body having a shape in which a rectangular parallelepiped is hollowed out is formed inside the rectangular parallelepiped by the magnetic bodies 901 to 904.
Finally, the photoresist 1000 filled in the recess 102 as a sacrificial layer is removed by wet etching, and the substrate material 103 below the first gold line is removed by dry etching, whereby the first and second gold lines 801 are removed. , 701, 803, 703, 805, 705, 807, and the third and fourth gold lines are continuous with 802, 702, 804, 704, 806, 706, 808. A state in which one spiral conductor is hollow inside as a whole, and the portions excluding both ends of the first and third gold wires 701 to 706 are in the air without contacting the substrate 100. A coil is obtained.
The sacrificial layer is filled in the recess, and after the second and fourth gold lines are formed on the sacrificial layer, the sacrificial layer filled in the recess is removed, so that the process can be simplified and the cost can be reduced. In addition, the overall thickness can be reduced.
Since the first conductor line is surrounded by air in a state where the first and third gold wires are tangled in the air without contacting the substrate 100, the first conductor is formed on the surface of the recessed portion of the recess. Even if compared with the case where it is in contact with the line, the loss can be further reduced.

Next, the operation will be described.
When a high frequency signal is input from a gold wire 801 serving as an input terminal of a spiral conductor, the high frequency signal is transmitted in the order of gold wires 701, 803, 703, 805, and 705 and output from a gold wire 807. Is done. Since the current flows spirally in this way, the directions of the currents flowing through the gold lines 803 and 805 are equal, and the directions of the currents flowing through the gold lines 701, 703 and 705 are also equal.

  As a result, the magnetic field is confined in the recess 102, but this portion is hollow, and there is almost no loss because the first gold wire is not in contact with the substrate. For this reason, this minute coil has low loss. When a high-frequency signal is input from a gold line 802 serving as an input terminal of another spiral conductor, the high-frequency signal is transmitted in the order of gold lines 702, 804, 704, 806, and 706. Output from line 808.

  Since the current flows in a spiral manner, the direction of the current flowing through the gold lines 804 and 806 is equal, and the direction of the current flowing through the second gold lines 702, 704 and 706 is also equal. As a result, the magnetic field is confined in the recess 102, but since this portion is hollow, there is almost no loss. For this reason, this other small helical conductor has a low loss.

  Further, since the second and fourth gold lines 804 to 806 are arranged in substantially the same direction, and the first and third gold lines 701 to 706 are arranged in substantially the same direction, the two spirals are arranged. The conductors are electromagnetically coupled, and when a current is passed through one spiral conductor, a current is also induced in the other spiral conductor to function as a coupler.

  Further, since the hollow body composed of the first to fourth magnetic bodies 901 to 904 is provided, the coupling of the magnetic field is strengthened, and as a result, a helical conductor having a large inductance and a strong coupling can be obtained.

  As in the first embodiment, the material of the substrate 100 is not limited to silicon, and any material that can be finely processed, such as glass, GaAs, or aluminum, can be used. The gold line can be used as long as it can form a pattern by, for example, photolithography. The thickness of the gold wire is preferably equal to or greater than the skin depth in consideration of the conductivity of the metal used and the frequency used.

In the third embodiment, the description has been given of the case where two coils are formed. However, the fifth and sixth gold wires may be provided to form three coils, and further, the gold wire may be provided. The desired number of coils may be obtained.
As in the first embodiment, the number of the first to fourth gold wires can be changed as appropriate depending on the application.
Similarly to the first embodiment, when etching the substrate on the inner surface of the recessed portion of the recess, an unetched thin film such as an oxide film 104 is provided on the inner inclined surface of the recess so that the etching area of the substrate is slightly increased. The structure can be reduced and the mechanical strength of the microcoil can be increased.
As in the first embodiment, when it is not easy to etch the substrate that is in contact with the first gold line in the recessed portion inside through the sacrificial layer removal hole, the first formed in the recessed portion in the recessed portion. The substrate between one gold line may be pre-etched to have a structure having a trench 105 below the first gold line.
Before the filling layer is filled, the above-described trench forming step is added, and the step of removing the substrate material 103 below the first gold line in the step after removing the sacrificial layer is not performed. A spiral coil can be created. Compared to the one where the lower part of the first gold wire is completely removed, the loss is greater, but even if the material is relatively difficult to etch, such as when the substrate is glass, it is easy to produce. Can do.
As in the first embodiment, the example in which the substrate material 103 under the first and third gold lines and all the portions (except the upper upper surface portion of the substrate) are removed has been shown, but not all the portions. Alternatively, a part of the substrate may be held. Part of the first gold wire is held on the substrate, and the coil has a sturdy structure.
Similarly to the first embodiment, one end of the gold wire formed in the recess is extended in one direction or alternately symmetrically, and the extended part and the measurement ground pad 501 or 502 are made of a dielectric such as silicon nitride 1001. It is also possible to provide a capacitor by sandwiching it. Silicon nitride may be provided on the measurement ground pad, and a capacitor may be provided on the silicon nitride by extending one end of the gold wire in one direction or alternately symmetrically.

1 is a perspective view of a high frequency coil according to Embodiment 1. FIG. It is a perspective view which shows after processing the recessed part of the high frequency coil of Embodiment 1. FIG. It is a perspective view which shows the state which affixed the 1st gold | metal wire of the high frequency coil of Embodiment 1. FIG. 5 is a cross-sectional view showing a method for producing the high-frequency coil according to Embodiment 1. FIG. It is sectional drawing which shows after removing the sacrificial layer of the high frequency coil of Embodiment 1. FIG. FIG. 2 is a cross-sectional view showing an AA ′ cross section in FIG. 1 according to the first embodiment. FIG. 6 is a cross-sectional view of a modification of the first embodiment. FIG. 10 is a cross-sectional view showing a state after the sacrificial layer of the high-frequency coil is removed in the modification of the first embodiment. In the modification of Embodiment 1, it is sectional drawing which shows after removing the board | substrate material of the lower part of the 1st gold | metal wire of a high frequency coil. FIG. 6 is a cross-sectional view of another modification of the first embodiment. FIG. 6 is a cross-sectional view showing a modification in which the capacitor according to Embodiment 1 is provided. 6 is a perspective view showing a high-frequency coil according to Embodiment 2. FIG. FIG. 12 is a perspective view showing a high frequency coil according to a modification of the second embodiment. 6 is a perspective view showing a high-frequency coil according to Embodiment 3. FIG. FIG. 6 is a cross-sectional view showing a high-frequency coil according to a third embodiment.

Explanation of symbols

  100 silicon substrate, 102 recess, 103 substrate material to be removed under the first or third gold line, 106 insulating film, 201-207 first gold line, 302-307 second gold line, 301,308 Gold lines for input / output parts, 701,703,705 First gold lines, 702,704,706 Third gold lines, 601,602,607,608 Gold lines for input / output parts Wire, 603, 605 second gold wire, 604, 606 fourth gold wire, 701, 703, 705 first gold wire, 702, 704, 706 third gold wire, 801, 802 807, 808 Gold line serving as an input / output unit, 803, 805 Second gold line, 804, 806 Fourth gold line, 901, 902, 903, 904 magnetic body, 1000 sacrificial layer, 1001 silicon nitride, 1002 Capacitors.

Claims (21)

  A substrate having a recess, a plurality of first conductor lines provided substantially in parallel without contacting the surface of the recessed portion of the recess, and an opening surface on the same plane as the upper surface portion of the recess An insulator, a plurality of second conductor lines installed substantially parallel to the upper surface of the insulator, and a first connection for connecting one end of the first conductor line to one end of the second conductor line And a second connecting portion for connecting the other end of the first conductor line to one end of the second conductor line adjacent to the second conductor line to which one end is connected. .   A substrate having a recess, a plurality of first conductor lines provided substantially in parallel without contacting the surface of the recessed portion of the recess, and substantially parallel to the opening surface on the same plane as the upper surface portion of the recess A plurality of second conductor lines, a first connection portion connecting one end of the first conductor line to one end of the second conductor line, and the other end of the first conductor line. A spiral high-frequency coil comprising: a second connection portion connected to one end of a second conductor line adjacent to the second conductor line to which one end is connected.   A substrate having a recess, a plurality of first and third conductor lines provided substantially in parallel without contacting the surface of the recessed portion of the recess, and an opening surface on the same plane as the upper surface portion of the recess A plurality of second and fourth conductor lines each extending substantially in parallel; a first connection portion for connecting one end of the first conductor line to one end of the second conductor line; and the first A second connection portion for connecting the other end of the second conductor line to one end of the second conductor line adjacent to the second conductor line to which one end is connected; and one end of the third conductor line to the fourth conductor line. A third connection portion connected to one end of the second conductor line, and a fourth connection portion connected to one end of the fourth conductor line adjacent to the fourth conductor line to which the other end of the third conductor line is connected. Spiral high frequency coil with connection.   A substrate having a recess, a plurality of first and third conductor lines provided substantially in parallel without contacting the surface of the recessed portion of the recess, and an opening surface on the same plane as the upper surface portion of the recess A first insulator provided; a plurality of second and fourth conductor lines each extending substantially parallel to an upper surface of the first insulator; and one end of the first conductor line connected to the first conductor A first connecting portion connected to one end of the second conductor line, and the other end of the first conductor line connected to one end of the second conductor line adjacent to the second conductor line to which one end is connected. A second connection portion; a third connection portion for connecting one end of the third conductor line to one end of the fourth conductor line; and the other end of the third conductor line connected to one end. A spiral high-frequency coil having a fourth connection portion connected to one end of the fourth conductor line adjacent to the fourth conductor line .   A substrate having a recess, a plurality of grooves provided substantially in parallel in the recessed portion of the recess, and a plurality of first ones provided substantially in parallel on the upper surface of the convex step between the plurality of grooves. A conductor line, a plurality of second conductor lines laid on the opening surface on the same plane as the upper surface portion of the recess, and one end of the first conductor line as one end of the second conductor line A first connection portion connected to the second conductor line, and a second connection portion connecting the other end of the first conductor line to one end of the second conductor line adjacent to the second conductor line to which one end is connected; With spiral high frequency coil.   A substrate having a recess, a plurality of grooves provided substantially in parallel in the recessed portion of the recess, and a plurality of first ones provided substantially in parallel on the upper surface of the convex step between the plurality of grooves. A conductor line; an insulator provided on an opening surface that is flush with an upper surface portion of the recess; a plurality of second conductor lines each extending substantially parallel to the upper surface of the insulator; and the first A first connecting portion for connecting one end of the conductor line to one end of the second conductor line, and a second connection next to the second conductor line to which the other end of the first conductor line is connected. A spiral high-frequency coil including a second connection portion connected to one end of the conductor line.   A substrate having a recess, a plurality of grooves provided substantially in parallel in the recessed portion of the recess, and a plurality of first and second parts provided substantially in parallel on the upper surface of the convex step between the plurality of grooves. A third conductor line, a plurality of second and fourth conductor lines each extending substantially in parallel on an opening surface on the same plane as the upper surface portion of the recess, and one end of the first conductor line A first connecting portion connected to one end of the second conductor line, and the other end of the first conductor line connected to one end of the second conductor line adjacent to the second conductor line to which one end is connected A second connecting portion, a third connecting portion connecting one end of the third conductor line to one end of the fourth conductor line, and a first connecting the other end of the third conductor line. A spiral high frequency coil comprising: a fourth connection portion connected to one end of a fourth conductor line adjacent to the four conductor lines.   A substrate having a recess, a plurality of grooves provided substantially in parallel in the recessed portion of the recess, and a plurality of first and second parts provided substantially in parallel on the upper surface of the convex step between the plurality of grooves. A third conductor line; a first insulator provided on an opening surface that is flush with an upper surface portion of the recess; and a plurality of second conductors that are provided substantially parallel to the upper surface of the first insulator. The first conductor line, one end of the first conductor line connected to one end of the second conductor line, and the other end of the first conductor line are connected at one end. A second connection portion connected to one end of the second conductor line adjacent to the second conductor line; and a third connection portion connecting one end of the third conductor line to one end of the fourth conductor line. The connecting portion and the other end of the third conductor line are connected to one end of the fourth conductor line adjacent to the fourth conductor line to which one end is connected. Fourth helical high-frequency coil having a connecting portion for.   A second insulator is provided on the top surfaces of the second and fourth conductor lines, a hollow body made of a magnetic material is supported on the first and second insulators, and a plurality of second and fourth conductor lines are provided. The helical high-frequency coil according to claim 4 or 8, wherein the coil is inserted through the hollow body in a non-contact state.   The helical high-frequency coil according to any one of claims 1 to 9, wherein a thin film is provided on an inner inclined surface of the recess.   A capacitor is formed by a conductor line provided either above or below an insulator film and a ground line provided on the other surface of the insulator film. The helical high frequency coil according to any one of claims 1 to 10.   The spiral high-frequency coil according to any one of claims 1 to 11, wherein a substrate made of any one of silicon, glass, GaAs, and aluminum is used.   A step of providing a plurality of first conductor lines on the surface of the concave portion of the substrate, a step of filling a sacrificial layer in the concave portion, and a plurality of second conductors on the upper surface of the sacrificial layer, respectively. Providing a line; connecting one end of the first conductor line to one end of the second conductor line; and the second conductor line having one end connected to the other end of the first conductor line. And a step of removing the sacrificial layer and the lower substrate material of the first conductor line, and a step of removing the lower substrate material of the first conductor line.   Providing a plurality of first conductor lines substantially parallel to the surface of the concave portion of the substrate; filling a sacrificial layer in the concave portion; providing an insulating layer on the upper surface of the sacrificial layer; Providing a plurality of second conductor lines substantially parallel to the upper surface of the insulating layer, connecting one end of the first conductor line to one end of the second conductor line, and the first conductor Connecting the other end of the line to one end of the second conductor line adjacent to the second conductor line to which one end is connected; and removing the sacrificial layer and the lower substrate material of the first conductor line The manufacturing method of the spiral high frequency coil which has.   Providing a plurality of first and third conductor lines substantially parallel to the surface of the recess of the substrate; filling a sacrificial layer in the recess; and a plurality of first conductor lines substantially parallel to the upper surface of the sacrificial layer. Providing the second and fourth conductor lines, connecting one end of the first conductor line to one end of the second conductor line, and connecting the other end of the first conductor line to one end. Connecting to one end of the second conductor line adjacent to the second conductor line; connecting one end of the third conductor line to one end of the fourth conductor line; and the third conductor Connecting the other end of the line to one end of the fourth conductor line adjacent to the fourth conductor line to which one end is connected, and removing the sacrificial layer and the lower substrate material of the first conductor line Method for manufacturing helical high-frequency coil having   Providing a plurality of first and third conductor lines substantially parallel to the surface of the concave portion of the substrate, filling a sacrificial layer in the concave portion, and providing a first magnetic body on the upper surface of the sacrificial layer; Providing a first insulating layer on the sacrificial layer and the top surface of the first magnetic body; and providing a plurality of second and fourth conductor lines substantially parallel to the top surface of the first insulating layer, respectively. Providing a step, providing a second insulating layer on the top surface of the first insulating layer and the second conductor line, and first and second insulating layers provided on the top surface of the first magnetic body. Removing a part of the layer and providing two grooves; providing a third and fourth magnetic bodies in the two grooves; and a second magnetic material connected to the third and fourth magnetic bodies Providing a body on the second insulating layer; and the first conductor line Connecting one end to one end of the second conductor line; and connecting the other end of the first conductor line to one end of the second conductor line adjacent to the second conductor line to which one end is connected. Connecting one end of the third conductor line to one end of the fourth conductor line; and adjoining the other end of the third conductor line to the fourth conductor line to which one end is connected. A method for manufacturing a spiral high-frequency coil, comprising: connecting to one end of a fourth conductor line; and removing the sacrificial layer and a lower substrate material of the first conductor line.   Providing a plurality of first conductor lines substantially parallel to the surface of the concave portion of the substrate, removing a surface of the recessed portion of the concave portion between the plurality of first conductor lines, and in the concave portion Filling the sacrificial layer with each other, providing a plurality of second conductor lines substantially parallel to the upper surface of the sacrificial layer, and connecting one end of the first conductor line to one end of the second conductor line Connecting the other end of the first conductor line to one end of the second conductor line adjacent to the second conductor line to which one end is connected, and removing the sacrificial layer. A method for manufacturing a spiral high-frequency coil.   Providing a plurality of first conductor lines substantially parallel to the surface of the concave portion of the substrate, removing a surface of the recessed portion of the concave portion between the plurality of first conductor lines, and in the concave portion Filling the sacrificial layer, providing an insulating layer on the upper surface of the sacrificial layer, providing a plurality of second conductor lines substantially parallel to the upper surface of the first insulating layer, and the first Connecting one end of the second conductor line to one end of the second conductor line, and connecting the other end of the first conductor line to the second conductor line adjacent to the second conductor line. A method for manufacturing a spiral high-frequency coil, comprising: connecting to one end; and removing the sacrificial layer.   A step of providing a plurality of first and third conductor lines substantially parallel to the surface of the concave portion of the substrate, and removing a surface of the recessed portion of the concave portion between the plurality of first and third conductor lines; A step of filling a sacrificial layer in the recess, a step of providing a plurality of second and fourth conductor lines substantially parallel to the upper surface of the sacrificial layer, and one end of the first conductor line Connecting to one end of a second conductor line; connecting the other end of the first conductor line to one end of a second conductor line adjacent to the second conductor line to which one end is connected; Connecting one end of the third conductor line to one end of the fourth conductor line; and a fourth terminal adjacent to the fourth conductor line having one end connected to the other end of the third conductor line. Connecting to one end of the conductor line and removing the sacrificial layer Helical RF coil production method and a step that.   A step of providing a plurality of first and third conductor lines substantially parallel to the surface of the concave portion of the substrate, and removing a surface of the recessed portion of the concave portion between the plurality of first and third conductor lines; Filling a sacrificial layer in the recess; providing a first magnetic body on the top surface of the sacrificial layer; and providing a first insulating layer on the top surface of the sacrificial layer and the first magnetic body. Providing a plurality of second and fourth conductor lines substantially parallel to the upper surface of the first insulating layer, and forming an upper surface on the upper surfaces of the first insulating layer and the second conductor line, respectively. A step of providing two insulating layers, a step of removing a part of the first and second insulating layers provided on the upper surface of the first magnetic body and providing two grooves, and a third of the two grooves. And providing a fourth magnetic body, and the third and fourth magnets Providing a second magnetic body connected to the second insulating layer on the second insulating layer, connecting one end of the first conductor line to one end of the second conductor line, and the first Connecting the other end of the conductor line to one end of the second conductor line adjacent to the second conductor line to which one end is connected; and connecting one end of the third conductor line to one end of the fourth conductor line Connecting the other end of the third conductor line to one end of the fourth conductor line adjacent to the fourth conductor line to which one end is connected, and removing the sacrificial layer The manufacturing method of the spiral high frequency coil which has.   21. The method for manufacturing a spiral high-frequency coil according to claim 13, further comprising a step of providing a thin film on the inclined inner inclined surface of the recess.

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