JP2009302316A - Spiral inductor and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide spiral inductor in which not only a size is small, but also a self-resonant frequency is high, and a loss and a leakage electromagnetic field are reduced. <P>SOLUTION: The spiral inductor is provided with: an insulating layer 21 formed on a substrate 11; and an inductor coil 31. The insulating layer 21 has a projection 24, and the inductor coil 31 is formed on the side wall of the projection 24. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a spiral inductor and a manufacturing method thereof, and more particularly, to a spiral inductor used for a high frequency circuit and the manufacturing method thereof.

  In recent years, along with the progress of wireless communication technology, development of small and high-performance communication devices has been promoted. Such communication equipment uses a high-frequency circuit such as a low-noise amplifier that handles a high-frequency electromagnetic wave signal. In addition to active elements such as transistors, high-frequency circuits require passive elements such as inductor elements (L), resistance elements (R), and capacitive elements (C).

  In general, passive elements are manufactured separately from active elements and combined. However, it has been integrated on the same substrate as the active element because of the demand for cost reduction and miniaturization. For example, a low-noise amplifier (LNA) using BiCMOS (Bipolar Complementary Metal Oxide Semiconductor) technology is mounted with a spiral on-chip inductor (spiral inductor) as an inductor element. Since the on-chip spiral inductor is formed on the same substrate together with other elements constituting the circuit, it is advantageous for miniaturization.

  On-chip spiral inductors pattern the wiring formed on the interlayer insulating film that forms the top layer of the integrated circuit or the wiring formed on the resin film that forms the chip size package (CSP) in a spiral pattern (For example, refer to Patent Documents 1 and 2).

  In a spiral inductor, an inductor coil made of spiral wiring is generally formed on an interlayer insulating film flattened by chemical mechanical polishing (CMP) or the like or a resin film formed flat by spin coating or the like. It is. In this way, the inductor coil can be easily formed by lithography.

  However, the spiral inductor formed on a plane has the following problems. First, when an inductor coil made of spiral wiring is formed on a plane, a magnetic field and an electric field leak to the integrated circuit or the substrate side. The leakage of the magnetic field and electric field generates an induced current or parasitic capacitance, and the induced current and parasitic capacitance cause loss. Loss causes the Q value to decrease, the inductance to decrease, and the self-resonance frequency to decrease. Moreover, in order to reduce resistance loss, it is necessary to form an inductor coil by wiring with a large width and thickness, and the spiral inductor occupies a large area. Furthermore, since it is necessary to avoid the influence of the leaked electric and magnetic fields, other elements cannot be arranged in the vicinity of the spiral inductor. Thus, the spiral inductor formed in a plane is disadvantageous for integration. In addition, since the wires are arranged close to each other in the inductor coil, a parasitic capacitance is generated between the wires during high frequency operation, and the self-resonant frequency is lowered.

  In order to solve the problem that occurs when spiral inductors are integrated in this way, for example, a method of forming an inductor coil 103 on a slope of a V-shaped groove 108 formed in a semiconductor substrate 101 as shown in FIG. Has been proposed (see, for example, Patent Document 3).

Thus, by forming the inductor coil on the slope of the V-shaped groove, the inner diameter of the inner coil can be increased without reducing the width of the coil. For this reason, when forming an inductor having the same inductance as the planar inductor, the outer peripheral length can be shortened without increasing the resistance loss. Even with the same peripheral length and number of turns as the planar inductor, the inner diameter of the inner coil of the inductor can be increased, so that an inductor with a large inductance can be formed without significantly increasing the resistance loss. Furthermore, even if the outer peripheral length and the number of turns are the same as those of the planar inductor, an inductor with less resistance loss can be formed by widening the width of each coil.
Japanese Patent No. 3488164 JP 2006-59959 A Japanese Patent Laid-Open No. 2005-79286

  However, the conventional spiral inductor has the following problems. The outer peripheral length can be reduced by forming the inductor coil on the slope of the V-shaped groove. However, since the inductor coil and the silicon substrate are close to each other, the magnetic field and electric field existing around the inductor coil reach the silicon substrate without being attenuated. The fluctuating magnetic field generates an induced current in the silicon substrate, and the induced current flows in the silicon substrate having a specific resistivity, which causes a problem of so-called substrate loss.

  In addition, since the capacitance between the inductor coil and the substrate, which is a parasitic capacitance of the inductor, increases, there arises a problem that the self-resonant frequency is lowered. Furthermore, the generation of an induced current and an electromagnetic field means that a signal leaks through the substrate, which causes a problem that it adversely affects other elements formed around the spiral inductor.

  In addition to functional problems, it is necessary to perform crystal anisotropic etching on the silicon substrate to form a V-shaped groove, or to flatten the V-shaped groove after forming a spiral inductor. There is also a problem that the method is complicated.

  An object of the present invention is to solve the above-mentioned conventional problems, and to realize a spiral inductor that not only has a small size but also has a high self-resonance frequency and reduced loss and leakage electromagnetic field.

  In order to achieve the above object, the present invention has a spiral inductor in which an inductor coil is formed on a side wall of a convex portion formed in an insulating layer.

  Specifically, a first spiral inductor according to the present invention includes an insulating layer formed on a substrate and having a convex portion, and an inductor coil formed on a side wall of the convex portion. To do.

  In the first spiral inductor, an inductor coil is formed on the side wall of the convex portion formed in the insulating film. For this reason, the spiral inductor can be reduced in size as compared with the case where the inductor coil is formed on a flat insulating film, and the magnetic field reaching the substrate can be reduced. Thereby, it is possible to realize a spiral inductor that hardly affects other elements formed in the periphery. In addition, the capacitance between the inductor coil and the substrate can be reduced, and the decrease in the self-resonance frequency can be reduced. Thereby, a spiral inductor that can be used at a wide frequency can be realized.

  In the first spiral inductor, the convex portion may have a configuration in which an upper area is smaller than a lower area. By setting it as such a structure, the side wall of a convex part turns into an inclined surface. Thereby, the substantial line width of the inductor coil can be increased, and the resistance can be reduced.

  A second spiral inductor according to the present invention is formed on a substrate, and includes an insulating film having a recess and a coil formed on a side wall of the recess.

  In the second spiral inductor, an inductor coil is formed on the side wall of the recess formed in the insulating film. For this reason, the spiral inductor can be reduced in size as compared with the case where the inductor coil is formed on a flat insulating film, and the magnetic field reaching the substrate can be reduced. Thereby, it is possible to realize a spiral inductor that hardly affects other elements formed in the periphery. In addition, the capacitance between the inductor coil and the substrate can be reduced, and the decrease in the self-resonance frequency can be reduced. Thereby, a spiral inductor that can be used at a wide frequency can be realized.

  In the second spiral inductor, the concave portion may have a mortar shape. By setting it as such a structure, the side wall of a recessed part turns into an inclined surface. Thereby, the substantial line width of the inductor coil can be increased, and the resistance can be reduced.

  The first and second spiral inductors may further include a lower structure formed between the substrate and the insulating layer and having an interlayer film and a passivation film.

  In this case, the lower structure may have a mesa-shaped region surrounded by the groove, and the convex portion may be formed on the mesa-shaped region.

  In the first and second spiral inductors, the lower structure may have a shield layer that reduces the influence of the magnetic field generated in the inductor coil on the substrate.

  In this case, the shield layer may be a lower wiring formed in the lower structure.

  In the first and second spiral inductors, the insulating layer includes a first insulating layer and a second insulating layer formed on the first insulator, and the second insulating layer includes: The structure which consists of material with a small thermal contraction rate compared with 1 insulating layer may be sufficient.

  The first and second spiral inductors further include an upper wiring for supplying power to the inductor coil, and the insulating layer includes a first insulating layer and a second insulating layer formed on the first insulator. The upper wiring may be formed between the first insulating layer and the second insulating layer.

  The spiral inductor manufacturing method according to the present invention includes a step (a) of forming an insulating layer having a convex portion surrounded by a concave portion on a substrate, and a step (b) of forming an inductor coil on a side wall of the convex portion. It is characterized by having.

  In the method for manufacturing a spiral inductor according to the present invention, a convex portion surrounded by a concave portion is formed in an insulating layer, and an inductor coil is formed on a side wall of the formed convex portion. Therefore, as compared with the case where the inductor coil is formed on the flat insulating film, not only the size can be reduced, but also the magnetic field reaching the substrate can be reduced. In addition, parasitic capacitance can be reduced.

  In the method for manufacturing a spiral inductor according to the present invention, the step (a) includes a step (a1) of forming a lower structure having an interlayer film and a passivation film on a substrate, and selectively removing the lower structure, Forming a mesa region surrounded by the groove (a2) and forming an insulating layer on the lower structure so as to fill the groove, thereby forming a recess on the groove; The structure including the process (a3) which forms a convex part may be sufficient. With such a configuration, an insulating layer having a convex portion surrounded by the concave portion can be easily formed.

  In the method for manufacturing a spiral inductor according to the present invention, the step (a) includes a step (a4) of forming a first insulating layer on the substrate and a step (a4) compared with the first insulating layer on the first insulating layer. Forming a second insulating layer made of a material having a high thermal contraction rate (a5), and forming a convex portion surrounded by the concave portion by selectively removing the second insulating layer (a6). And a step (a7) of shrinking the second insulating layer by performing a heat treatment after the step (a6). Even in such a configuration, an insulating layer having a convex portion surrounded by the concave portion can be easily formed.

  In the spiral inductor manufacturing method of the present invention, in the step (b), after forming a metal film on the insulating layer, the inductor coil may be formed by patterning the formed metal film. In addition, after the insulating sheet on which the wiring pattern is formed is adhered to the insulating layer, the inductor coil may be formed by curing the adhered insulating sheet.

  According to the inductor and the manufacturing method thereof according to the present invention, it is possible to realize a spiral inductor that not only has a small size but also has a high self-resonance frequency and reduced loss and leakage electromagnetic field.

  A spiral inductor and a manufacturing method thereof according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a cross-sectional configuration of a spiral inductor according to an embodiment. In FIG. 1, the description of the lead-out wiring that connects the spiral inductor and other elements is omitted.

  As shown in FIG. 1, a lower structure 17 is formed on the substrate 11. The lower structure 17 includes a polysilicon layer 12, an interlayer film 13, and a passivation film 14 formed on the substrate 11. The polysilicon layer 12 functions as a PGS (Patterned Ground Shield) that is a shield layer that prevents an induced current from flowing through the substrate 11 due to a magnetic field generated in the spiral inductor. The polysilicon layer 12 may be silicided. Further, a metal film may be used instead of polysilicon.

  The interlayer film 13 is, for example, silicon oxide, and the passivation film 14 is, for example, silicon nitride. The interlayer film 13 and the passivation film 14 have a mesa region 16 surrounded by the groove 15. The mesa region 16 may be a planar square shape, a polygonal shape, or a circular shape. The interlayer film 13 and the passivation film 14 may be shared with a lower wiring layer provided in a region of the substrate 11 where elements other than the spiral inductor are formed.

  An insulating layer 21 made of polyimide or the like is formed on the passivation film 14 so as to fill the groove 15. A portion formed on the groove 15 in the insulating layer 21 becomes a concave portion 23, and a portion formed on the mesa-shaped region 16 becomes a convex portion 24. For this reason, the shape of the mesa region 16 is reflected in the planar shape of the convex portion 24. The planar shape of the convex portion 24 may be any shape such as a square shape, a polygonal shape, or a circular shape. However, when there is no corner, electric field concentration on the inductor coil is less likely to occur.

  An inductor coil 31 is formed on the side wall of the convex portion 24. The inductor coil 31 is a metal film formed continuously in a spiral shape. The metal film may be made of any material, but is preferably easy to form and has a low resistance. For example, it may be formed of aluminum, an aluminum alloy, gold, copper, or the like.

  What is necessary is just to determine suitably the height of the convex part 24, a magnitude | size, the distance from a board | substrate, etc. according to the characteristic of the required spiral inductor. In the present embodiment, the depth A of the groove 15, that is, the distance from the upper surface of the polysilicon layer 12 to the upper surface of the passivation film 14 is 4 μm. Thereby, the height difference B between the concave portion 23 and the convex portion 24 is also set to 4 μm. The inclination angle θ of the side wall of the convex portion 24 is 30 °. As the thickness of the insulating layer 21 is larger, the influence of the magnetic field on the substrate can be reduced, but it may be determined as appropriate in consideration of the size and characteristics of the spiral inductor. In the present embodiment, the distance from the upper surface of the polysilicon layer 12 to the upper surface of the convex portion 24 in the insulating layer 21 is 15 μm.

  The larger the line width and film thickness of the inductor coil 31, the more the resistance can be reduced. However, since it affects the size of the spiral inductor, it is preferable to make it as small as possible within an allowable range. In the present embodiment, the line width D of the inductor coil 31 is 3 μm and the film thickness is 2 μm. However, since the inductor coil 31 is formed on the inclined surface, the substantial line width of the inductor coil is 3 μm × 1 / cos θ, and when θ is 30 °, it is about 3.5 μm. Thus, since the substantial width of the inductor coil can be increased, the resistance can be reduced as compared with a spiral inductor formed on a plane. Further, since the overlap between wirings is reduced, the parasitic capacitance is also reduced.

  The spiral inductor according to the present embodiment can reduce not only the size and resistance but also the magnetic field reaching the substrate 11.

  FIG. 2 shows the relationship between the distance from the bottom surface of the convex portion 24 and the magnetic field, calculated based on the basic equations of electromagnetism. The calculation is performed assuming that the convex portion 24 has a truncated cone shape with a bottom surface radius of 11.9 μm and a top surface radius of 5 μm, the number of turns of the inductor coil 31 is two, and the current flowing through the inductor coil 31 is 1 mA. It was.

  As the inclination angle θ of the side wall of the convex portion 24 increases, the magnetic field decreases. That is, the magnetic field reaching the substrate 11 is reduced. Here, the calculation is performed on the assumption that the current flowing through the inductor coil 31 is a constant current, but the same result is expected even in an actual AC current.

  By reducing the magnetic field reaching the substrate 11, the induced current flowing through the substrate 11 can be reduced. As a result, loss can be reduced and the Q value can be increased. In addition, the parasitic capacitance can be reduced by increasing the distance between the inductor coil 31 and the substrate 11. As a result, the self-resonant frequency can be improved and the operating frequency range can be widened.

  In the present embodiment, an example in which the shield layer is a PGS made of a polysilicon layer or the like formed on the substrate 11 is shown. However, as shown in FIG. 3, the shield layer may be formed by a lower wiring formed in the lower structure 17. Specifically, the first lower wiring 18A is formed on the first interlayer film 13A, and the second lower wiring is formed on the second interlayer film 13B formed on the first interlayer film 13A. 18B is formed. The first lower wiring 18A and the second lower wiring 18B are connected by a plug 19A, and the first lower wiring 18A is grounded to the substrate 11 by a plug 19B.

  In this case, the lower structure 17 may be shared with a wiring layer provided in a region of the substrate 11 where elements other than the spiral inductor are formed. In particular, the wiring formed in the uppermost layer of the wiring layer is generally a metal wiring having a thick film in order to reduce resistance. Accordingly, the second lower wiring 18B is a metal wiring having a large film thickness. By using a thick metal wiring as the shield layer, the effect of blocking the magnetic field from the inductor coil can be improved. Further, if the thickness of the second lower wiring 18B is about 2 μm, the depth of the groove 15 can be increased by 2 μm. Thereby, the inclination angle θ of the side wall of the convex portion 24 can be increased, and the magnetic field reaching the substrate can be further reduced.

  Further, as shown in FIG. 4, an upper wiring for a spiral inductor may be formed on the lower structure 17. For example, the wiring 32 formed on the lower side of the inductor coil 31 may be connected to the inductor coil 31 to supply power to the inductor coil 31. In this case, the insulating layer 21 may be a stacked structure of the first insulating layer 26 and the second insulating layer 27, and the wiring 32 may be formed between the first insulating layer 26 and the second insulating layer 27. . The wiring 32 may be connected to the lower wiring 18 formed in the lower structure 17. An adhesion layer 33 is preferably formed between the wiring 32 and the first insulating layer 26 in order to prevent the wiring 32 from peeling off. If the convex portion 24 surrounded by the concave portion 23 is formed in the second insulating layer 27 and an opening that exposes the wiring 32 is formed at the center of the convex portion 24, the lead wiring connecting the inductor coil 31 and the wiring 32. 34 can be formed easily.

  In addition, since the distance between the inductor coil 31 and the substrate can be increased by forming the wiring 32, the shield layer can be omitted. Moreover, the shielding effect by the wiring 32 can also be expected. However, a separate shield layer may be formed.

  Below, the manufacturing method of the spiral inductor which concerns on this embodiment is demonstrated with reference to drawings. First, as shown in FIG. 5A, the lower structure 17 is formed on the substrate 11. Specifically, a polysilicon layer 12 made of PGS is formed, and an interlayer film 13 made of a silicon oxide film and a passivation film 14 made of a silicon nitride film are formed on the polysilicon layer 12. The interlayer film 13 and the passivation film 14 may have the same configuration as the wiring layer formed in a region other than the spiral inductor forming region and may be formed in common. The shield layer may be a lower wiring formed in the lower structure 17 instead of the polysilicon layer 12.

  Subsequently, a part of the interlayer film 13 and the passivation film 14 is selectively removed to form a groove 15 surrounding the mesa region 16. In the present embodiment, the sum of the film thickness of the interlayer film 13 and the film thickness of the passivation film 14 is about 4 μm, the mesa-shaped region 16 is a planar circle, and the diameter is about 24 μm.

  Next, as shown in FIG. 5B, an insulating layer 21 is formed on the passivation film 14 so as to fill the groove 15. The insulating layer 21 is preferably formed of a resin having a low dielectric constant and excellent insulating properties such as polyimide. By applying a resin having an appropriate viscosity by a spin coating method, a concave portion 23 is formed on the groove portion 15 and a convex portion 24 is formed on the mesa-shaped region 16. Subsequently, a heat treatment at 400 ° C. is performed to cure the resin.

  Next, as shown in FIG. 5C, a metal layer 41 to be the inductor coil 31 is formed on the insulating layer 21 by sputtering, MOCVD, or the like. The metal layer 41 may be formed of a low resistance metal such as aluminum, an aluminum alloy, copper, or gold. In the present embodiment, aluminum having a thickness of 2 μm is used. Subsequently, a resist film 42 is formed on the metal layer 41, and a resist pattern is formed by a technique such as electron beam exposure. Use of electron beam exposure with a very deep focal depth is preferable because the resist film 42 having unevenness can be accurately exposed.

  Next, as shown in FIG. 5C, the metal layer 41 is etched using the formed resist pattern as an etching mask to form the inductor coil 31. Thereafter, although not shown, formation of an upper insulating layer covering the inductor coil 31, formation of a lead wiring connected to the inductor coil 31, and the like are performed.

  In the present embodiment, the resist pattern is formed by electron beam exposure, but may be formed by direct drawing or the like. Further, although the inductor coil 31 is formed by patterning the metal layer 41, it may be formed as follows.

  As shown in FIG. 6A, a convex portion 24 surrounded by the concave portion 23 is formed in the same manner as described above. An insulator sheet 43 having a metal wiring pattern 44 is prepared. The prepared insulator sheet 43 and the insulating layer 21 are pressure-bonded. The pressure bonding between the insulating layer 21 and the insulating sheet 43 may be performed by applying pressure from above the insulating sheet 43 by air or liquid. Moreover, you may apply force uniformly along the surface of an insulator using the softness | flexibility of the insulator sheet 43. FIG.

  Next, as shown in FIG. 6B, after the insulating sheet 43 and the insulating layer 21 are pressure-bonded, the insulating sheet 43 is cured by heat treatment at 400 ° C. Thereby, the inductor coil 31 can be formed. Further, the hardened insulating sheet 43 becomes an insulating film that covers the inductor coil 31. The insulator sheet 43 may be a resin film such as polyimide. The insulating layer 21 may be cured at the same time as the insulating sheet 43 is cured.

  Further, in the present embodiment, the lower structure 17 is patterned to form the mesa region 16 surrounded by the groove 15, and the insulating layer 21 is formed thereon to form the convex portion 24 surrounded by the concave portion 23. An example of forming was shown. However, the convex portion 24 surrounded by the concave portion 23 may be formed in the insulating layer 21 as follows.

  First, as shown in FIG. 7A, a polysilicon layer 12, an interlayer film 13, and a passivation film 14 are formed on a substrate 11.

  Next, as shown in FIG. 7B, the first insulating layer 28 is formed on the passivation film 14.

  Next, as shown in FIG. 7C, a second insulating layer 29 having a thermal contraction rate larger than that of the first insulating layer 28 is formed on the first insulating layer 28. Subsequently, the convex portion 24 surrounded by the concave portion 23 is formed by selectively removing the second insulating layer 29. At this time, the side wall of the convex portion 24 has no inclination.

  Next, heat treatment is performed as shown in FIG. Since the thermal contraction rates of the first insulating layer 28 and the second insulating layer 29 are different, the portion of the second insulating layer 29 in contact with the first insulating layer 28 does not contract. On the other hand, since the upper part of the second insulating layer 29 contracts, a concave portion 23 having a tapered side wall and a convex portion 24 having a frustum shape are formed. Thereafter, the inductor coil 31 may be formed in the same manner as described above.

  The first insulating layer 28 and the second insulating layer 29 may be formed by combining insulating materials having different shrinkage rates. For example, the first insulating layer 28 is formed of silicon oxide to form a second insulating layer. The layer 29 may be formed of polyimide.

  In addition to these methods, the insulating layer 21 may be processed by etching or the like to form the convex portion 24 surrounded by the concave portion 23. Moreover, although the convex part 24 enclosed by the recessed part 23 is formed by forming a part lower than another part in the insulating layer 21, a part higher than another part is formed on the insulating layer 21. Thus, the convex portion 24 may be formed.

  The example which forms the inductor coil 31 on the side wall of the convex part 24 was shown. However, when the convex portion 24 is surrounded by the concave portion 23, the inductor coil 31 may be formed on the side wall of the concave portion 23 opposite to the convex portion 24. Further, instead of the convex portion 24 surrounded by the concave portion 23, a planar rectangular, polygonal or circular concave portion may be formed, and the inductor coil 31 may be formed on the side wall of the concave portion.

  As described above, the larger the inclination angle θ of the concave portion or the convex portion, the smaller the magnetic field that reaches the substrate is preferable. However, when the inclination angle θ increases, it becomes difficult to form the inductor coil. Therefore, the inclination angle θ is preferably in the range of about 30 ° to 60 °. However, even if θ is 90 °, there is no problem with the function as an inductor coil.

  When the magnetic field reaching the substrate is sufficiently small, a shield such as PGS may not be formed. There is no problem even if other elements are formed on the substrate.

  The substrate 11 may be a compound semiconductor substrate or a silicon substrate used for a high frequency integrated circuit. By using and integrating the spiral inductor of the present embodiment in a low noise amplifier (LNA) or the like, it is possible to realize miniaturization and high performance of the high frequency circuit.

  The spiral inductor and the manufacturing method thereof according to the present invention can realize a spiral inductor that not only has a small size but also has a high self-resonance frequency and a reduced loss and leakage electromagnetic field. This is useful as a production method.

It is sectional drawing which shows the spiral inductor which concerns on one Embodiment of this invention. It is a graph which shows the result of having calculated | required the magnetic field strength of the spiral inductor which concerns on one Embodiment of this invention by calculation. It is sectional drawing which shows the modification of the spiral inductor which concerns on one Embodiment of this invention. It is sectional drawing which shows the modification of the spiral inductor which concerns on one Embodiment of this invention. It is sectional drawing which shows the manufacturing method of the spiral inductor which concerns on one Embodiment of this invention to process order. It is sectional drawing which shows the modification of the manufacturing method of the spiral inductor which concerns on one Embodiment of this invention to process order. It is sectional drawing which shows the modification of the manufacturing method of the spiral inductor which concerns on one Embodiment of this invention to process order. The spiral inductor which concerns on a prior art example is shown, (a) is a top view, (b) is sectional drawing in the VIIIb-VIIb line | wire of (a).

Explanation of symbols

11 Substrate 12 Polysilicon layer 13 Interlayer film 14 Passivation film 15 Groove portion 16 Mesa region 17 Lower structure 21 Insulating layer 23 Recessed portion 24 Protruding portion 26 First insulating layer 27 Second insulating layer 28 First insulating layer 29 Second Insulating layer 31 Inductor coil 32 Wiring 33 Adhesion layer 34 Lead-out wiring 41 Metal layer 42 Resist film 43 Insulator sheet 44 Metal wiring pattern

Claims (15)

An insulating layer formed on the substrate and having a convex portion;
A spiral inductor comprising: an inductor coil formed on a side wall of the convex portion.   The spiral inductor according to claim 1, wherein the convex portion has an upper area smaller than a lower area. An insulating film formed on the substrate and having a recess;
And a coil formed on a side wall of the recess.   The spiral inductor according to claim 3, wherein the recess has a mortar shape.   5. The spiral inductor according to claim 1, further comprising a lower structure formed between the substrate and the insulating layer and having an interlayer film and a passivation film. 6. The lower structure has a mesa region surrounded by a groove,
The spiral inductor according to claim 5, wherein the convex portion is formed on the mesa region.   The spiral inductor according to claim 5 or 6, wherein the lower structure includes a shield layer that reduces an influence of a magnetic field generated in the inductor coil on the substrate.   The spiral inductor according to claim 7, wherein the shield layer is a wiring formed in the lower structure. The insulating layer has a first insulating layer and a second insulating layer formed on the first insulator;
The spiral inductor according to any one of claims 1 to 8, wherein the second insulating layer is made of a material having a smaller thermal shrinkage rate than the first insulating layer. Further comprising an upper wiring for supplying power to the inductor coil;
The insulating layer has a first insulating layer and a second insulating layer formed on the first insulator;
The spiral inductor according to any one of claims 1 to 9, wherein the upper wiring is formed between the first insulating layer and the second insulating layer. Forming an insulating layer having a convex portion surrounded by a concave portion on the substrate;
And (b) forming an inductor coil on the side wall of the convex portion. The step (a)
Forming a lower structure having an interlayer film and a passivation film on the substrate (a1);
A step (a2) of forming a mesa-like region surrounded by the groove by selectively removing the lower structure;
Forming the insulating layer on the lower structure so as to fill the groove, thereby forming the recess on the groove and forming the protrusion on the mesa-shaped region (a3); The method of manufacturing a spiral inductor according to claim 11, comprising: The step (a)
Forming a first insulating layer on the substrate (a4);
A step (a5) of forming a second insulating layer made of a material having a thermal contraction rate larger than that of the first insulating layer on the first insulating layer;
A step (a6) of forming a convex portion surrounded by the concave portion by selectively removing the second insulating layer;
The method of manufacturing a spiral inductor according to claim 11, further comprising a step (a7) of shrinking the second insulating layer by performing a heat treatment after the step (a6).   14. The inductor coil according to claim 11, wherein, in the step (b), the inductor coil is formed by patterning the formed metal film after forming a metal film on the insulating layer. A method for manufacturing a spiral inductor according to claim 1.   In the step (b), after the insulator sheet on which the wiring pattern is formed is adhered on the insulating layer, the inductor coil is formed by curing the adhered insulator sheet. The manufacturing method of the spiral inductor of any one of Claims 11-13.

Images