Composite passive component and manufacturing method thereof

Abstract

The present disclosure provides a composite passive component, comprising a substrate, an epitaxial structure, and a passive component body. The epitaxial structure is disposed on the substrate, a two-dimensional electron gas having a specific pattern is formed in the epitaxial structure, and the passive component body is in ohmic contact with the two-dimensional electron gas. The composite passive component includes a metal capacitor structure. The metal capacitor structure includes a first metal plate and a second metal plate, the second metal plate being located on one side of the first metal plate away from the substrate, and the first metal plate being insulated from the two-dimensional electron gas. The passive component body includes an inductor structure. The inductor structure includes a first connection metal layer in ohmic contact with a first end of the two-dimensional electron gas, an inductor metal line disposed on one side of the epitaxial structure away from the substrate, and a first connection metal having a first end electrically connected to the first connection metal layer and a second end electrically connected to a first end of the inductor metal line.

Description

[Technical field]

[0001] TECHNICAL FIELD Embodiments of the present disclosure relate to capacitor technology, and more particularly to composite passive components and methods for making the same. [Background technology]

[0002] On-chip composite passive components are one of the main building blocks of modern RF / MM circuits and have important applications in modern electronic technology.

[0003] However, with the trend towards miniaturization of electronic devices, the requirements for the integration density of passive components are becoming higher and higher, while the integration density of traditional passive components is low, limiting the applications of passive components. Summary of the Invention [Means for solving the problem]

[0004] In a first aspect, an embodiment of the present disclosure provides a composite passive component, the composite passive component comprising: a substrate; an epitaxial structure disposed on the substrate in which a specific pattern of two-dimensional electron gas is formed; and a passive component body disposed on one side of the epitaxial structure away from the substrate and in ohmic contact with the two-dimensional electron gas.

[0005] In one embodiment, an isolation is formed in the epitaxial structure, the isolation defining a region corresponding to the two-dimensional electron gas.

[0006] In one embodiment, the particular pattern of the two-dimensional electron gas is adapted to conform to the passive component body.

[0007] In one embodiment, the composite passive component includes a composite capacitor, and the passive component body includes a metal capacitor structure disposed on one side of the epitaxial structure away from the substrate, the metal capacitor structure including a first metal plate and a second metal plate, the second metal plate being located on one side of the first metal plate away from the substrate, and the first metal plate being insulated from the two-dimensional electron gas; Along a thickness direction of the composite capacitor, a total projection of the first metal plate and the second metal plate on the substrate at least partially overlaps a projection of the two-dimensional electron gas on the substrate.

[0008] In one embodiment, the two-dimensional electron gas is set to an equipotential with the second metal plate; Along a thickness direction of the composite capacitor, a projection of the first metal plate on the substrate at least partially overlaps a projection of the two-dimensional electron gas on the substrate.

[0009] In one embodiment, the composite capacitor further comprises a connection structure; The connection structure is in ohmic contact with the two-dimensional electron gas and is electrically connected to the second metal plate.

[0010] In one embodiment, the composite capacitor comprises: a first interlayer dielectric layer overlying the epitaxial structure; The metal capacitor structure is disposed on one side of the first interlayer dielectric layer away from the substrate, and the metal capacitor structure includes the first metal plate, the second metal plate, and a second interlayer dielectric layer.

[0011] In one embodiment, the epitaxial structure is a III-V compound based semiconductor material.

[0012] In one embodiment, along a thickness direction of the composite capacitor, a projection of the two-dimensional electron gas on the substrate covers a projection of the first metal plate on the substrate and a projection of the second metal plate on the substrate.

[0013] In one embodiment, the two-dimensional electron gas is insulated from the second metal plate.

[0014] In one embodiment, the passive component body includes an inductor structure, the inductor structure comprising: a first connection metal layer in ohmic contact with a first end of the two-dimensional electron gas; an inductor metal line disposed on one side of the epitaxial structure away from the substrate, the inductor metal line being a second planar spiral; a first connection metal having a first end electrically connected to the first connection metal layer and a second end electrically connected to a first end of the inductor metal line; a first end of the inductor metal wire corresponding to a center point of the second planar spiral, and a first end of the two-dimensional electron gas corresponding to a center point of the first planar spiral; The two-dimensional electron gas is in the shape of the first planar helix.

[0015] In one embodiment, the first planar spiral and the second planar spiral have opposite spiral directions.

[0016] In one embodiment, an isolation is formed in the epitaxial structure, the isolation defining a region corresponding to the two-dimensional electron gas.

[0017] In one embodiment, the width of the two-dimensional electron gas is greater than the width of the inductor metal line.

[0018] In one embodiment, the number of turns of the two-dimensional electron gas is greater than the number of turns of the inductor metal wire.

[0019] In one embodiment, the composite inductor further includes a first interlayer dielectric layer, a first electrode metal, a second electrode metal, a second connection metal layer, and a second connection metal; the first interlayer dielectric layer is disposed on one side of the epitaxial structure away from the substrate, and the inductor metal line is disposed on one side of the first interlayer dielectric layer away from the substrate; the first electrode metal, the second electrode metal and the inductor metal line are disposed in the same layer, and the first electrode metal is electrically connected to a second end of the inductor metal line; the second connection metal layer and the first connection metal layer are disposed on the same layer, the second connection metal layer being in ohmic contact with a second end of the two-dimensional electron gas; The second connection metal penetrates the first interlayer dielectric layer, a first end of the second connection metal is electrically connected to the second connection metal layer, and a second end of the second connection metal is electrically connected to the second electrode metal.

[0020] In one embodiment, the composite inductor further includes a second interlayer dielectric layer, a first ohmic metallization through hole, and a second ohmic metallization through hole, the second interlayer dielectric layer being disposed between the first interlayer dielectric layer and the epitaxial structure, the first ohmic metallization through hole penetrating the second interlayer dielectric layer, and the second ohmic metallization through hole penetrating the second interlayer dielectric layer; The first connecting metal layer makes ohmic contact with a first end of the two-dimensional electron gas via a first ohmic metallization through hole, and the second connecting metal layer makes ohmic contact with a second end of the two-dimensional electron gas via a second ohmic metallization through hole.

[0021] In one embodiment, the composite inductor further comprises a protection layer, the protection layer covering the inductor metal lines. In a second aspect, an embodiment of the present disclosure further provides a method for manufacturing a composite passive component, comprising: The method includes the steps of providing a substrate, epitaxially forming an epitaxial structure layer on the substrate, implanting ions into the epitaxial structure layer to form an isolation portion, thereby defining a region corresponding to the two-dimensional electron gas, and placing a passive component body on one side of the epitaxial structure layer away from the substrate, and making ohmic contact with the two-dimensional electron gas.

[0022] In one embodiment, the method comprises the steps of: epitaxially forming an epitaxial structure on a substrate, the epitaxial structure having a two-dimensional electron gas formed therein; forming a metal capacitor structure on one side of the epitaxial structure away from the substrate, the metal capacitor structure including a first metal plate and a second metal plate, the second metal plate being located on one side of the first metal plate away from the substrate, and the first metal plate being insulated from the two-dimensional electron gas; Along a thickness direction of the composite capacitor, a total projection of the first metal plate and the second metal plate on the substrate at least partially overlaps a projection of the two-dimensional electron gas on the substrate.

[0023] In one embodiment, the step of forming a metal capacitor structure on one side of the epitaxial structure away from the substrate comprises: forming the first metal plate such that a projection of the first metal plate on the substrate at least partially overlaps a projection of the two-dimensional electron gas on the substrate along a thickness direction of the composite capacitor; The step of forming a metal capacitor structure on a side of the epitaxial structure away from the substrate further includes forming a connection structure in ohmic contact with the two-dimensional electron gas and electrically connected to the second metal plate.

[0024] In one embodiment, the method comprises the steps of: forming an epitaxial structure on a substrate, the epitaxial structure including a first planar spiral two-dimensional electron gas; forming a first contact metal layer on a side of the epitaxial structure away from the substrate, the first contact metal layer being in ohmic contact with a first end of the two-dimensional electron gas; forming a first connecting metal and an inductor metal line on one side of the epitaxial structure away from the substrate, the inductor metal line being a second planar spiral, a first end of the first connecting metal electrically connected to the first connecting metal layer, a second end of the first connecting metal electrically connected to a first end of the inductor metal line, the first end of the inductor metal line being one end corresponding to a center point of the second planar spiral, and a first end of the two-dimensional electron gas being one end corresponding to a center point of the first planar spiral.

[0025] In one embodiment, the step of forming an epitaxial structure containing a planar spiral two-dimensional electron gas on a substrate comprises: epitaxially forming an epitaxial structure layer on the substrate; and performing ion implantation into the epitaxial structure layer to form an isolation portion, thereby defining a region corresponding to the two-dimensional electron gas.

[0026] In one embodiment, prior to the step of forming a first connection metal and an inductor metal line on one side of the epitaxial structure away from the substrate, forming a first interlayer dielectric layer on a side of the epitaxial structure away from the substrate, the first interlayer dielectric layer having a first through hole formed therein, the first through hole exposing the first connection metal layer; The step of forming a first connection metal on a side of the epitaxial structure away from the substrate includes forming a first connection metal by metallizing the first through holes.

[0027] In one embodiment, prior to the step of forming a first connection metal layer on one side of the epitaxial structure facing away from the substrate, The method further includes forming a second interlayer dielectric layer on a surface of the epitaxial structure away from the substrate, the first ohmic through hole and the second ohmic through hole being formed in the second interlayer dielectric layer, the first ohmic through hole exposing a first end of the two-dimensional electron gas, and the second ohmic through hole exposing a second end of the two-dimensional electron gas; forming a first connection metal layer on a side of the epitaxial structure away from the substrate; The method further includes the steps of metallizing the first ohmic through hole to form a first ohmic metallization through hole, forming a second connection metal layer on one side of the epitaxial structure away from the substrate, and metallizing the second ohmic through hole to form a second ohmic metallization through hole, wherein the first connection metal layer makes ohmic contact with a first end of a two-dimensional electron gas via the first ohmic metallization through hole, and the second connection metal layer makes ohmic contact with a second end of the two-dimensional electron gas via the second connection metal layer; forming a first interlayer dielectric layer on one side of the epitaxial structure away from the substrate further comprises forming a first interlayer dielectric layer having a second through hole exposing the second connection metal layer; The step of metallizing the first through hole to form a first connection metal and forming an inductor metal line on one side of the first interlayer dielectric layer away from the substrate comprises: The method further includes the steps of forming a first electrode metal on one side of the first interlayer dielectric layer away from the substrate, metallizing the second through hole to form a second connection metal, and forming a second electrode metal on one side of the first interlayer dielectric layer away from the substrate, wherein the first electrode metal is electrically connected to a second end of the inductor metal line, a first end of the second connection metal is electrically connected to the second connection metal layer, and a second end of the second connection metal is electrically connected to the second electrode metal.

[0028] In the technical solution of this embodiment, the passive component body can be a capacitor structure or an inductor structure.

[0029] In the technical solution of this embodiment, the composite capacitor used includes a substrate, an epitaxial structure on the substrate, in which a two-dimensional electron gas is formed, and a metal capacitor structure disposed on one side of the epitaxial structure away from the substrate, the metal capacitor structure including a first metal plate and a second metal plate, the second metal plate being located on one side of the first metal plate away from the substrate, the first metal plate being insulated from the two-dimensional electron gas, and along the thickness direction of the composite capacitor, the total projection of the first metal plate and the second metal plate on the substrate at least partially overlaps with the projection of the two-dimensional electron gas on the substrate. The two-dimensional electron gas can be equivalent to one plate of the capacitor, and this embodiment can increase the number of capacitors without increasing the occupied area of ​​the wafer, and increase the integration density of the capacitor.

[0030] In the technical solution of the present embodiment, the composite inductor used includes a substrate, an epitaxial structure disposed on the substrate, in which a two-dimensional electron gas having a first planar spiral shape is formed, a first connection metal layer in ohmic contact with a first end of the two-dimensional electron gas, an inductor metal wire disposed on one side of the epitaxial structure away from the substrate, inductor metal wire having a second planar spiral shape, a first end electrically connected to the first connection metal layer and a second end electrically connected to a first end of the inductor metal wire, the first end of the inductor metal wire being an end corresponding to the center point of the second planar spiral shape, and the first end of the two-dimensional electron gas being an end corresponding to the center point of the first planar spiral shape. If the wafer size occupied by the composite inductor remains unchanged, the first inductor and the second inductor of the composite inductor are disposed on different layers, which further increases the integration degree of the inductors, and increases the inductor amount of the composite inductor by series connection, i.e., increases the current path length per unit wafer area, and further increases the inductor density of the composite inductor. [Brief description of the drawings]

[0031] [Figure 1] FIG. 2 is a structural schematic diagram of a composite capacitor according to an embodiment of the present disclosure. [Diagram 2]FIG. 13 is a structural schematic diagram of another composite capacitor according to an embodiment of the present disclosure. [Diagram 3] FIG. 13 is a structural schematic diagram of another composite capacitor according to an embodiment of the present disclosure. [Figure 4] FIG. 13 is a structural schematic diagram of another composite capacitor according to an embodiment of the present disclosure. [Diagram 5] 4 is a flow chart of a method for manufacturing a composite capacitor according to an embodiment of the present disclosure. [Figure 6-15] 1A to 1C are schematic diagrams illustrating the structure of a product corresponding to a main flow of a manufacturing method for a composite capacitor according to an embodiment of the present disclosure. [Figure 16] FIG. 2 is a plan view of a composite inductor according to an embodiment of the present disclosure. [Figure 17] 17 is a cross-sectional view taken along the A1A2 direction in FIG. 16. [Figure 18] 17 is another cross-sectional view taken along the A1A2 direction in FIG. 16. [Figure 19] 17 is another cross-sectional view taken along the A1A2 direction in FIG. 16. [Figure 20] 1 is a flowchart of a method for manufacturing a composite inductor according to an embodiment of the present disclosure. [Figure 21-29] 1A to 1C are schematic diagrams of a product structure corresponding to the main flow of a manufacturing method for a composite inductor according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] The present disclosure will be described in more detail below with reference to the drawings and examples. It is to be understood that the specific examples described herein are merely for the purpose of interpreting the present disclosure, and are not intended to limit the present disclosure. For ease of description, the drawings show only some structures related to the present disclosure, rather than all structures.

[0033] An embodiment of the present disclosure provides a composite passive component, The composite passive component includes a substrate, an epitaxial structure disposed on the substrate and having a specific pattern of two-dimensional electron gas formed thereon, and a passive component body disposed on one side of the epitaxial structure away from the substrate and in ohmic contact with the specific pattern of two-dimensional electron gas. Interaction between the two-dimensional electron gas of the epitaxial structure and the passive component body improves the integration density and performance of the composite passive component. The passive component may be a capacitor structure or an inductor structure.

[0034] Specifically, the substrate 11 may be, for example, one or a combination of gallium nitride, aluminum gallium nitrogen, indium gallium nitrogen, aluminum indium gallium nitrogen, indium phosphide, gallium carbide, silicon carbide, diamond, sapphire, germanium, silicon, or any other material on which a group III nitride can be grown. The epitaxial structure 12 may be formed by growing on the substrate 11. The growth method may be, for example, any of metal organic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), and hydride vapor phase epitaxy (HVPE). The epitaxial structure 12 may include multiple layers, and each layer structure may be a semiconductor material based on a group III-V compound. The epitaxial structure 12 may be, for example, a heterojunction. This embodiment is not limited thereto. When the epitaxial structure 12 is grown and formed, a layer of high concentration free charges (Two Dimensional Electron In other words, one layer of two-dimensional electron gas 121 is formed. The surface density of the two-dimensional electron gas 121 is usually 1e 13 / cm 2 It is considered that the resistivity of the two-dimensional electron gas 121 is larger and its resistivity is low, and that the resistivity of the two-dimensional electron gas 121 is similar to that of a metal.

[0035] The composite passive component according to the embodiment of the present disclosure provides an isolation region around a specific pattern of two-dimensional electron gas, i.e., an isolation region is formed around a specific pattern of two-dimensional electron gas in the epitaxial structure 12, and the isolation region is used to define a specific pattern region corresponding to the two-dimensional electron gas.

[0036] Optionally, the composite passive component according to the embodiment of the present disclosure is configured such that the specific pattern exhibited by the two-dimensional electron gas is conformed to the passive component body, for example, if the passive component body is a flat capacitor, the specific pattern of the two-dimensional electron gas is flat, for example, if the passive component body is a spiral inductor, the specific pattern of the two-dimensional electron gas is spiral.

[0037] When the passive component has a capacitor structure FIG. 1 is a structural schematic diagram of a composite capacitor according to an embodiment of the present disclosure. Referring to FIG. 1, the composite capacitor includes a substrate 11, an epitaxial structure 12 disposed on the substrate 11 and having a two-dimensional electron gas 121 formed therein, a first interlayer dielectric layer 13 covering the epitaxial structure 12, and a metal capacitor structure 14 disposed on one side of the epitaxial structure 12 away from the substrate 11, the metal capacitor structure 14 including a first metal plate 141 and a second metal plate 143, the second metal plate 143 being located on one side of the first metal plate 141 away from the substrate 11, the first metal plate 141 being insulated from the two-dimensional electron gas 121, and along the thickness direction X of the composite capacitor, the total projection of the first metal plate 141 and the second metal plate 143 on the substrate 11 at least partially overlaps with the projection of the two-dimensional electron gas 121 on the substrate 11.

[0038] The areal density of the two-dimensional electron gas 121 is usually 1e 13 / cm 2The resistivity of the two-dimensional electron gas 121 is larger than that of the first metal plate 141, and its resistivity is low. It is considered that the resistivity of the two-dimensional electron gas 121 is similar to that of a metal. That is, the two-dimensional electron gas 121 can be equivalent to a metal plate of a capacitor. As shown in FIG. 1, the first metal plate 141 and the second metal plate 143 each need to have an electrode, so the projection of the first metal plate 141 on the substrate 11 and the projection of the second metal plate 143 on the substrate 11 can be set so as not to completely overlap. That is, the total projection of the first metal plate 141 and the second metal plate 143 on the substrate 11 is located in three regions on the substrate 11, and the projection of the first region 111 only includes the projection of the first metal plate 141, and the projection of the second region 112 not only includes the projection of the first metal plate 141, but also includes the projection of the second metal plate 143. , and the projection of the third region 113 includes only the projection of the second metal plate 143. When the projection of the two-dimensional electron gas 121 on the substrate 11 is located in the first region 111 and / or the second region 112, the two-dimensional electron gas 121 and the first metal plate 141 form a capacitor. When the projection of the two-dimensional electron gas 121 on the substrate 11 is located in the third region 113 and is not connected to the second metal plate 143, the two-dimensional electron gas 121 and the second metal plate 143 form a capacitor. The two-dimensional electron gas 121 is disposed in the thickness direction of the metal capacitor structure 14, without increasing the area occupied on the wafer. Therefore, this embodiment can increase the number of capacitors and increase the integration density of the capacitors without increasing the occupied area of ​​the wafer.

[0039] In the technical solution of this embodiment, the composite capacitor used includes a substrate, an epitaxial structure on the substrate, in which a two-dimensional electron gas is formed, and a metal capacitor structure disposed on one side of the epitaxial structure away from the substrate, the metal capacitor structure including a first metal plate and a second metal plate, the second metal plate being located on one side of the first metal plate away from the substrate, the first metal plate being insulated from the two-dimensional electron gas, and along the thickness direction of the composite capacitor, the total projection of the first metal plate and the second metal plate on the substrate at least partially overlaps with the projection of the two-dimensional electron gas on the substrate. The two-dimensional electron gas can be equivalent to one plate of the capacitor, and this embodiment can increase the number of capacitors without increasing the occupied area of ​​the wafer, and increase the integration density of the capacitor.

[0040] With continued reference to FIG. 1, in one embodiment, isolation 122 is formed in epitaxial structure 12 , isolation 122 defining a region corresponding to two-dimensional electron gas 121 .

[0041] Specifically, in this embodiment, the separation portion 122 may be formed in all parts of the epitaxial structure other than the part where the two-dimensional electron gas 121 needs to be retained. For example, when the projection of the first metal plate 141 on the substrate and the projection of the second metal plate 143 on the substrate 11 overlap along the thickness direction of the composite capacitor, the projection of the two-dimensional electron gas 121 on the substrate 11 completely overlaps, and the separation portion 122 may be formed in other parts of the epitaxial structure 12. The separation portion 122 may be formed, for example, by an ion implantation method, for example, by injecting argon ions, etc., thereby extremely increasing the resistance of the separation portion 122 and further reducing the loss of the substrate.

[0042] In one embodiment, with continued reference to FIG. 1, the composite capacitor further includes a protective layer 17 covering second metal plate 143 .

[0043] Specifically, the protective layer 17 may be, for example, one or more combinations of silicon oxide, alumina, silicon nitride, silicon oxynitride, or any other materials that can be insulating dielectrics. The protective layer 17 can protect the composite capacitor, prevent the composite capacitor from being corroded by external water, oxygen, etc., and extend the service life of the composite capacitor.

[0044] In one embodiment, as shown in FIG. 1, the two-dimensional electron gas 121 is insulated from the second metal plate 143. In this embodiment, the two-dimensional electron gas 121 can form a capacitor with a metal plate that overlaps its projection. Preferably, the projection of the two-dimensional electron gas 121 on the substrate 11 is located in the first region 111 and / or the second region 112, but may not be located in the third region 113. In this case, the first metal plate 141 and the two-dimensional electron gas 121 form a capacitor, and the first metal plate 141 is closer to the two-dimensional electron gas 121 than the second metal plate 143. Therefore, the performance of the capacitor is better, and the first metal plate 141 and the second metal plate 143 form one capacitor. The composite capacitor includes two capacitors, and the integration degree of the capacitor is high. The two-dimensional electron gas 121 can be electrically connected to an external circuit by installing an electrode that is in ohmic contact with the two-dimensional electron gas 121. The position of the electrode is not specifically limited, and may be, for example, installed on one side of the two-dimensional electron gas 121 away from the substrate 11, or installed on one side of the two-dimensional electron gas 121 close to the substrate 11, or installed on some other side. In some embodiments, when the projection of the two-dimensional electron gas 121 on the substrate 11 is located in the third region 113 and is not present in either the first region 111 or the second region 112, then the two-dimensional electron gas 121 and the second metal plate 143 form a capacitor, and the composite capacitor still includes two capacitors; in other embodiments, when the projection of the two-dimensional electron gas 121 on the substrate 11 is not only located in the third region 113 but also located in at least one of the first region 111 and the second region 112, then the two-dimensional electron gas 121 and The first metal plate 141 forms a capacitor, and the two-dimensional electron gas 121 and the second metal plate 143 also form a capacitor, so that the composite capacitor includes three capacitors, which further increases the integration density of the capacitors. In this case, preferably, the projection of the two-dimensional electron gas 121 on the substrate 11 covers the projection of the first metal plate 141 on the substrate 11 and the projection of the second metal plate 143 on the substrate 11, so that the capacitance values ​​of the two capacitors formed by the two-dimensional electron gas 121 in the composite capacitor are both large, and the capacitance density of the composite capacitor is also large.

[0045] In one embodiment, the two-dimensional electron gas 121 is set to be equipotential with the second metal plate 143, and along the thickness direction of the composite capacitor, the projection of the first metal plate 141 on the substrate 11 at least partially overlaps with the projection of the two-dimensional electron gas 121 on the substrate 11. By setting in this way, the two-dimensional electron gas 121 and the second metal plate 143 correspond to one plate and respectively overlap with two surfaces of the first metal plate 141, which on the one hand can improve the integration degree of the capacitor, and on the other hand is equivalent to increasing the capacitance value of the composite capacitor, and can further increase the capacitance density.

[0046] 2 is a structural schematic diagram of another composite capacitor according to an embodiment of the present disclosure. In this embodiment, the composite capacitor further includes a connection structure 15, which is in ohmic contact with the two-dimensional electron gas 121 and is electrically connected to the second metal plate 143. The connection structure 15 forms an ohmic contact with the two-dimensional electron gas 121, and the contact resistance is extremely low, so that charges can be introduced from the two-dimensional electron gas 121 to the connection structure 15. The connection structure 15 is electrically connected to the second metal plate 143 and insulated from the first metal plate 141. Along the thickness direction X of the composite capacitor, the projection of the two-dimensional electron gas 121 on the substrate 11 overlaps with the projection of the first metal plate 141 on the substrate 11, and the two-dimensional electron gas 121 is insulated from the first metal plate 141. Therefore, the two-dimensional electron gas 121 and the first metal plate 141 form a capacitor, which is referred to as a capacitor C1. The capacitor structure 14 is a capacitor C2, and the capacitors C2 and C1 share one plate (the first metal plate 141, and there is a movable charge on both the upper and lower surfaces of the first metal plate 141 during the operation of the composite capacitor), and the plates (the two-dimensional electron gas 121 and the second metal plate 143) that are not shared by the capacitors C1 and C2 are electrically connected via a connection structure 15, which is equivalent to the parallel connection of the capacitors C1 and C2, that is, the capacitance value of the composite capacitor is equal to the sum of the capacitance value of the capacitors C1 and C2, which is equivalent to increasing the opposing area of ​​the capacitor plates, and the two-dimensional electron gas 121 is provided in the thickness direction of the metal capacitor structure 14, without increasing the area occupied on the wafer, so that this embodiment can improve the capacitance value of the composite capacitor without increasing the occupied area of ​​the wafer. In addition, since fewer metal layers are required, the difficulty of manufacturing can be reduced and the cost can be reduced.

[0047] Of course, in some other embodiments, other solutions may be used to achieve equipotential between the two-dimensional electron gas 121 and the second metal plate 143, for example, the two-dimensional electron gas 121 and the second metal plate 143 may be electrically connected outside the composite capacitor.

[0048] 1 and 2, in one embodiment, the composite capacitor further includes a first interlayer dielectric layer 13, which covers the epitaxial structure 12, and the metal capacitor structure 14 includes a first metal plate 141, a second metal plate 143, and a second interlayer dielectric layer 142, which is disposed between the first metal plate 141 and the second metal plate 143, and by disposing the first interlayer dielectric layer 141 and the second interlayer dielectric layer 142, the performance of the capacitor can be improved. In this case, the metal capacitor structure 14 is a MIM capacitor.

[0049] In one embodiment, still referring to FIG. 2 , along the thickness direction X of the composite capacitor, the projection of the two-dimensional electron gas 121 on the substrate 11 covers the projection of the first metal plate 141 on the substrate 11 and the projection of the second metal plate 143 on the substrate 11.

[0050] Specifically, the larger the overlapping area between the two-dimensional electron gas 121 and the first metal plate 141, the larger the capacitance value of the capacitor C1. Therefore, along the thickness direction X of the composite capacitor, the projection of the two-dimensional electron gas 121 on the substrate 11 may be set to cover the projection of the first metal plate 141 on the substrate 11, thereby greatly increasing the capacitance value of the capacitor C1. In the metal capacitor structure 14, since it is necessary to install the lead-out electrode of the MIM capacitor, along the thickness direction X of the composite capacitor, the projection of the second metal plate 143 on the substrate 11 and the orthogonal projection of the first metal plate 143 on the substrate 11 do not completely overlap. Therefore, along the thickness direction X of the composite capacitor, the projection of the two-dimensional electron gas 121 on the substrate 11 may be set to cover the orthogonal projection of the second metal plate 143 on the substrate 11, thereby making it easier to install the connection structure 15.

[0051] In addition, as shown in Figures 1 and 2, the composite capacitor may further include a first electrode 16, which is located on one side of the first metal plate 141 away from the substrate 11 and is electrically connected to the first metal plate 141, and the portion of the connection structure 15 penetrating the second interlayer dielectric layer 142 can be the second electrode of the composite capacitor.

[0052] For example, as shown in FIG. 2 , the connection structure 15 includes a connection metal layer 151 and a connection metallized through hole, where the connection metal layer 151 contacts the surface of the two-dimensional electron gas, and the connection metallized through hole penetrates the first interlayer dielectric layer 13 and the second interlayer dielectric layer 142 and is electrically connected to the connection metal layer 151 and the second metal plate 143.

[0053] Specifically, in this embodiment, the connection metal layer 151 is in direct ohmic contact with the two-dimensional electron gas 121, and the connection metal layer 151 can be directly manufactured after epitaxially forming the epitaxial structure 12 during the manufacture of the composite capacitor, so that the contact performance between the connection metal layer 151 and the two-dimensional electron gas 121 is better, which is more favorable for improving the performance of the composite capacitor. The first through hole penetrates the first interlayer dielectric layer 13, the second through hole penetrates the second interlayer dielectric layer 142, and the connection metallization through hole includes a first sub-through hole 153 and a second sub-through hole 154, where the first sub-through hole 153 is the first through hole 153 after metallization, and the second sub-through hole 154 is the second through hole 154 after metallization. The connection metal layer 151 may be, for example, a connection metal layer formed by first depositing a composite metal using an electron beam evaporation system and then using a rapid thermal annealing (RTA) process. The connecting metallized through-holes may be produced by first etching a through-hole and then metallizing the through-hole.

[0054] In some other embodiments, as shown in FIG. 3, FIG. 3 is a structural schematic diagram of another composite capacitor according to an embodiment of the present disclosure, and the difference from the structure shown in FIG. 2 is that the connection structure 15 of this embodiment includes a connection metal layer 151, an ohmic metallized through hole 152 and a connection metallized through hole, the connection metal layer 151 and the first metal plate 141 are disposed in the same layer, the connection metal layer 151 is in ohmic contact with the two-dimensional electron gas 121 through the ohmic metallized through hole 152 penetrating the first interlayer dielectric layer 13, and the connection metallized through hole is electrically connected to the connection metal layer 151 and the second metal plate 143 through the second interlayer dielectric layer 142.

[0055] Specifically, in this embodiment, the connection metal layer 151 and the first metal plate 141 are disposed on the same layer, and after epitaxially forming the epitaxial structure 12, the first interlayer dielectric layer 13 is grown first, and then a through hole is etched in the first interlayer dielectric layer 13, and then the connection metal layer 151 and the ohmic metallized through hole 152 can be simultaneously manufactured using the manufacturing process of the ohmic metal. The fourth through hole penetrates the second interlayer dielectric layer 142, and the connection metallized through hole only includes the second sub-through hole 154, which is the fourth through hole after metallization in this embodiment.

[0056] In some other embodiments, as shown in FIG. 4, FIG. 4 is a structural schematic diagram of another composite capacitor according to an embodiment of the present disclosure. The difference from the structures shown in FIG. 2 and FIG. 3 is that the connection structure 15 of this embodiment includes a connection metal layer 151, an ohmic metallization through hole 152 and a connection metallization through hole, the first interlayer dielectric layer 13 includes a first sub-dielectric layer 131 and a second sub-dielectric layer 132 stacked on the epitaxial structure 12, the connection metal layer 151 is disposed on the surface of the first sub-dielectric layer 131 away from the epitaxial structure 12, and is in ohmic contact with the two-dimensional electron gas 121 through the ohmic metallization through hole 152 penetrating the first sub-dielectric layer 131, and the connection metallization through hole is electrically connected to the connection metal layer 151 and the second metal plate 143 through the second interlayer dielectric layer 142 and the second sub-dielectric layer 132.

[0057] Specifically, in this embodiment, the first interlayer dielectric layer 13 includes a first sub-dielectric layer 131 and a second sub-dielectric layer 132, and the material of the first sub-dielectric layer 131 and the material of the second sub-dielectric layer 132 can be, for example, one or more combinations of silicon oxide, alumina, silicon nitride, silicon oxynitride, or any other material that can be an insulating dielectric, and the composite capacitor can be fabricated on the same wafer with other thin-film devices, such as thin-film transistors, and the connection metal layer 151 is placed on the first sub-dielectric layer 131 to make it compatible with other devices on the wafer and further improve the compatibility of the manufacturing process of the composite capacitor. The sixth through hole passes through the second sub-dielectric layer 132, the seventh through hole passes through the second interlayer dielectric layer 142, and the connection metallization through holes include a first sub-through hole 153 and a second sub-through hole 154, and in this embodiment, the first sub-through hole 153 is the sixth through hole after metallization, and the second sub-through hole 154 is the seventh through hole after metallization.

[0058] An embodiment of the present disclosure further provides a method for manufacturing a composite capacitor. As shown in FIG. 5, FIG. 5 is a flow chart of a method for manufacturing a composite capacitor according to an embodiment of the present disclosure, the method includes steps S301 to S302, Step S301: epitaxially forming an epitaxial structure on a substrate, and forming a two-dimensional electron gas in the epitaxial structure; Specifically, FIGS. 6 to 15 are schematic diagrams of product structures corresponding to the main flow of the manufacturing method of the composite capacitor according to the embodiment of the present disclosure. As shown in FIG. 6, a substrate 11 can be provided first. Then, as shown in FIG. 7, an epitaxial structure 12 is epitaxially formed on the substrate 11. The growth method can be, for example, any of metal-organic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), and hydride vapor phase epitaxy (HVPE). The epitaxial structure 12 can include multiple layers, and each layer structure can be a semiconductor material based on III-V group compounds. The epitaxial structure 12 can be formed by epitaxy. The epitaxial structure 12 may be, for example, a heterojunction. When the epitaxial structure 12 is grown and formed, a layer of two-dimensional electron gas 121 is formed therein, and the two-dimensional electron gas 121 can be used to form one plate of a capacitor. Then, as shown in FIG. 8, in order to reduce loss in the substrate, a separation portion 122 can be formed in a portion of the epitaxial structure other than the portion where the two-dimensional electron gas 121 needs to be retained. The separation portion 122 may be formed, for example, by an ion implantation method, for example, by injecting argon ions or the like, thereby extremely increasing the resistance of the separation portion 122 and further reducing loss in the substrate.

[0059] Step S302: Form a metal capacitor structure on one side of the epitaxial structure away from the substrate, the metal capacitor structure including a first metal plate and a second metal plate, the second metal plate being located on one side of the first metal plate away from the substrate, the first metal plate being insulated from the two-dimensional electron gas, and along the thickness direction of the composite capacitor, the total projection of the first metal plate and the second metal plate on the substrate at least partially overlaps with the projection of the two-dimensional electron gas on the substrate.

[0060] In the composite capacitor manufactured by the composite capacitor manufacturing method of this embodiment, the two-dimensional electron gas and the first metal plate and / or the second metal plate form a capacitor, and the two-dimensional electron gas is disposed in the stacking direction of the first metal plate and the second metal plate. Therefore, the number of capacitors in the composite capacitor can be increased without increasing the area of ​​the wafer occupied by the composite capacitor, and therefore the integration degree of the capacitor can be improved.

[0061] In one embodiment, the step of forming a metal capacitor structure on one side of the epitaxial structure away from the substrate comprises: The method includes forming a first metal plate such that a projection of the first metal plate on the substrate at least partially overlaps a projection of the two-dimensional electron gas on the substrate along a thickness direction of the composite capacitor, and further includes forming a connection structure in ohmic contact with the two-dimensional electron gas and electrically connected to the second metal plate when forming a metal capacitor structure on one side of the epitaxial structure away from the substrate.

[0062] Exemplarily, a first interlayer dielectric layer can also be formed when forming the metal capacitor structure, the first interlayer dielectric layer covers the epitaxial structure, the metal capacitor structure is located on one side of the first interlayer dielectric layer away from the substrate, the metal capacitor structure includes a first metal plate, a second metal plate and a second interlayer dielectric layer, the second metal plate is located on one side of the first metal plate away from the substrate, the connection structure includes a connection metal layer and a connection metallized through hole, and the steps of forming the first interlayer dielectric layer, the metal capacitor structure and the connection structure include: As shown in FIG. 9, a connecting metal layer 151 is formed on the surface of the epitaxial structure 12 away from the substrate 11, specifically, a composite metal is first deposited using an electron beam evaporation system, and then a connecting metal layer is formed using a rapid thermal annealing (RTA) process; then, as shown in FIG. 10, a layer of dielectric layer material is first grown, which can be, for example, one or more combinations of silicon oxide, alumina, silicon nitride, silicon oxynitride, or any other material that can be an insulating dielectric; then, as shown in FIG. 11, As shown, a first through-hole 201 is formed by exposure, development and etching, and the first through-hole 201 exposes the connecting metal layer 151; then, as shown in FIG. 12, a first metal plate 141 is formed on the surface of the first interlayer dielectric layer 13 away from the substrate, and the first through-hole is metallized, which can be manufactured by, for example, sputtering, deposition, etc., and the first metal plate 141 is formed by a mask, and the first through-hole is metallized at the same time to form a first sub-through-hole 153; then, as shown in FIG. 13, a layer of dielectric layer material 1420 is completely covered. 14, the dielectric layer material 1420 can be one or a combination of silicon oxide, alumina, silicon nitride, silicon oxynitride, or any other material that can be an insulating dielectric, and can be used as an isolation layer of the metal capacitor structure. Then, as shown in FIG. 14, a second through hole 202 is formed by exposure, development, etching, etc., and the second through hole 202 exposes the first through hole. Furthermore, an electrode through hole 301 can be formed at the same time, and the electrode through hole 301 can be used to subsequently form a metal electrode, thereby forming the structure shown in FIG. 15, a second interlayer dielectric layer 142 of the connection structure 15 is formed, and then, as shown in FIG. 15, a method such as sputtering, deposition, etc. is used to form a second metal plate 143. At the same time, the second through-hole 202 and the electrode through-hole 301 are metallized to form a second sub-through-hole 154, a second metal plate 143, an electrode metal through-hole 161, and an electrode 162. The electrode metal through-hole 161 and the electrode 162 constitute a first electrode of the composite capacitor, and the part of the connection structure 15 that penetrates the second interlayer dielectric layer 142 can be the second electrode of the composite capacitor.Finally, as shown in Fig. 2, a layer of protective layer 17 is completely covered, thereby forming the structure shown in Fig. 2, and the protective layer 17 can be, for example, one or more combinations of silicon oxide, alumina, silicon nitride, silicon oxynitride, or any other materials that can be insulating dielectrics. The protective layer 17 can protect the composite capacitor, prevent the composite capacitor from being corroded by external water and oxygen, etc., and extend the service life of the composite capacitor.

[0063] In one embodiment, the difference from the above manufacturing method is that the connection structure of this embodiment includes a connection metal layer, an ohmic metallization through hole and a connection metallization through hole, and the steps of forming a first interlayer dielectric layer, a metal capacitor structure and a connection structure include: After forming the structure shown in FIG. 8, a material 1301 of the first interlayer dielectric layer can be deposited on the epitaxial structure 12, for example, the material of the first interlayer dielectric layer can be one or more combinations of silicon oxide, alumina, silicon nitride, silicon oxynitride, or any other material that can be an insulating dielectric; then, a third through hole 203 is formed by exposure, development, etching, etc., and the third through hole 203 exposes an area corresponding to the connecting metal layer; then, a connecting metal layer 151 is formed on the surface of the first interlayer dielectric layer 13 that is away from the substrate; and then, a third through hole 203 is formed by exposure, development, etching, etc., and the third through hole 203 exposes an area corresponding to the connecting metal layer. The ohmic metallization through hole 152 is formed by metallizing the 3 through hole, and the connection metal layer 151 is in ohmic contact with the two-dimensional electron gas 121 through the ohmic metallization through hole 152. The connection metal layer 151 and the ohmic metallization through hole 152 are simultaneously manufactured using an ohmic metal manufacturing process. The ohmic metal manufacturing process may be to first deposit a composite metal using an electron beam evaporation system, and then form an ohmic metal using a rapid thermal annealing process. Secondly, since a high temperature process is required during the manufacturing of the connection metal layer, Therefore, the first metal plate 161 may be manufactured after the connection metal layer is manufactured. The first metal plate 161 may be manufactured by sputtering, deposition, etc. In addition, if the entire layer of metal needs to be manufactured when manufacturing the metal plate, in order to avoid the electrical connection between the first metal plate and the connection metal layer, a sacrificial layer may be first manufactured on the connection metal layer before the entire layer of metal is deposited, and then the metal layer is etched to form the first metal plate 141, and then the sacrificial layer is etched, so that the first metal plate 141 and the connection metal layer 151 are formed in the same layer, and then the sacrificial layer is etched. The dielectric layer material 1420 of the layer is completely covered, and the dielectric layer material 1420 can be one or a combination of silicon oxide, alumina, silicon nitride, silicon oxynitride, or any other material that can be an insulating dielectric, and serves as an isolation layer of the metal capacitor structure. Then, a fourth through hole 204 is formed by exposure, development, etching, etc., and the fourth through hole 204 exposes the connection metal layer 151. An electrode through hole 301 can be formed at the same time, and the electrode through hole 301 can be used to subsequently form a metal electrode.This forms the second interlayer dielectric layer 142 in FIG. 20, which can then be manufactured by sputtering, deposition, etc., and the second metal plate 143 is formed by a mask, and the fourth through hole 204 and the electrode through hole 301 are simultaneously metallized to form the second sub-through hole 154, the second metal plate 143, the electrode metal through hole 161, and the electrode 162. Finally, as shown in FIG. 2, a layer of protective layer 17 is fully covered, thereby forming the structure shown in FIG. 3, and the protective layer 17 can be, for example, one or more combinations of silicon oxide, alumina, silicon nitride, silicon oxynitride, or any other material that can be an insulating dielectric. The protective layer 17 can protect the composite capacitor, prevent the composite capacitor from being corroded by external water and oxygen, etc., and extend the service life of the composite capacitor.

[0064] In one embodiment, the difference from the above manufacturing method is that the connection structure of this embodiment includes a connection metal layer, an ohmic metallization through hole and a connection metallization through hole, the first interlayer dielectric layer includes a first sub-dielectric layer and a second sub-dielectric layer, and the steps of forming the first interlayer dielectric layer, the metal capacitor structure and the connection structure include: After forming the structure shown in FIG. 8, a first sub-dielectric layer material 1310 can be deposited on the epitaxial structure 12, and the first sub-dielectric layer material 1310 can be, for example, one or more combinations of silicon oxide, alumina, silicon nitride, silicon oxynitride, or any other material that can be an insulating dielectric. A fifth through hole 205 is formed by exposure, development, etching, etc., and the fifth through hole 205 exposes an area corresponding to the connecting metal layer. A connecting metal layer 151 is formed on the surface of the first sub-dielectric layer 131 that is away from the substrate. A fifth through hole 205 is formed by exposure, development, etching, etc., and the ... exposes an area corresponding to the connecting metal layer. A connecting metal layer 151 is formed on the surface of the first sub-dielectric layer 131 that is away from the substrate. The ohmic metallization through hole 152 is formed by metallizing the 5 through hole, and the connection metal layer 151 is in ohmic contact with the two-dimensional electron gas 121 through the ohmic metallization through hole 152. The connection metal layer 151 and the ohmic metallization through hole 152 are simultaneously manufactured using an ohmic metal manufacturing process. The ohmic metal manufacturing process may be to first deposit a composite metal using an electron beam evaporation system, and then form an ohmic metal using a rapid thermal annealing process. The material 1320 forming the second sub-dielectric layer is completely covered. The material of the second sub-dielectric layer can be, for example, one or more combinations of silicon oxide, alumina, silicon nitride, silicon oxynitride, or any other material that can be an insulating dielectric. The sixth through-hole 206 is formed by a method such as exposure, development, etching, etc., and the sixth through-hole 206 exposes the connecting metal layer 151. The first metal plate 141 is formed on the surface of the second sub-dielectric layer 132 that is away from the substrate. The sixth through-hole is metallized, for example, by a method such as sputtering, deposition, etc., and the first metal plate 141 is formed by a mask, and the same At the same time, the sixth through-hole is metallized to form a first sub-through-hole 153, which completely covers a layer of dielectric layer material 1420, which may be one or more combinations of silicon oxide, alumina, silicon nitride, silicon oxynitride, or any other materials that can be insulating dielectrics, and serves as a separation layer of the metal capacitor structure; and a seventh through-hole 207 is formed by exposure, development, etching, etc., which exposes the sixth through-hole, and can also simultaneously form an electrode through-hole 301;The electrode through-hole 301 can then be used to form a metal electrode, thereby forming the second interlayer dielectric layer 142, which can be manufactured by sputtering, deposition, etc., and a mask is used to form the second metal plate 143, and the seventh through-hole 207 and the electrode through-hole 301 are simultaneously metallized to form the second sub-through-hole 154, the second metal plate 143, the electrode metal through-hole 161, and the electrode 162. Finally, as shown in FIG. 4, a layer of a protective layer 17 is fully covered, thereby forming the structure shown in FIG. 3. The protective layer 17 can be, for example, one or more combinations of silicon oxide, alumina, silicon nitride, silicon oxynitride, or any other material that can be an insulating dielectric. The protective layer 17 can protect the composite capacitor, prevent the composite capacitor from being corroded by external water and oxygen, etc., and extend the service life of the composite capacitor.

[0065] When the passive component has an inductor structure FIG. 16 is a plan view of a composite inductor according to an embodiment of the present invention, and FIG. 17 is a cross-sectional view along the A1A2 direction of FIG. 16. Referring to FIG. 16 and FIG. 17, the composite inductor includes a substrate 11, an epitaxial structure 12 disposed on the substrate 11 and having a first planar spiral two-dimensional electron gas 121 formed therein, a first connection metal layer 13' in ohmic contact with a first end of the two-dimensional electron gas 121, an inductor metal wire 15' disposed on one side of the epitaxial structure 12 away from the substrate 11 and having a second planar spiral shape, and a first connection metal 16' having a first end electrically connected to the first connection metal layer 13' and a second end electrically connected to a first end of the inductor metal wire 15', where a first end 151' of the inductor metal wire 15' is one end corresponding to the center point of the second planar spiral shape, and a first end 1211 of the two-dimensional electron gas 121 is one end corresponding to the center point of the first planar spiral shape.

[0066] The two-dimensional electron gas 121 can be equivalent to a metal wire of an inductor. By setting the two-dimensional electron gas 121 in a first planar spiral shape, the two-dimensional electron gas 121 can be equivalent to one inductor, and this inductor is a first inductor. Furthermore, the first connecting metal layer 13' and the two-dimensional electron gas 121 are in ohmic contact and the contact resistance is extremely low, so that a current can be transferred from the first connecting metal 16' to the two-dimensional electron gas 121 or a current can be transferred from the two-dimensional electron gas 121 to the first connecting metal 16'. Since the inductor metal wire 15' is set in a second planar spiral shape, the inductor metal wire 15' is also equivalent to one inductor, and this inductor is a second inductor. The spiral directions of the first inductor and the second inductor are opposite, and the total inductor of the composite inductor is a series connection of the first inductor and the second inductor, and therefore is equivalent to increasing the inductor amount of the composite inductor. In addition, because the first planar spiral extends spirally outward from its center point and the second planar spiral extends spirally outward from its center point, if the wafer size occupied by the composite inductor remains unchanged, the first inductor and the second inductor of the composite inductor are installed on different layers and connected in series to increase the inductor amount of the composite inductor, i.e., to increase the current path length per unit wafer area, and further increase the inductor density of the composite inductor.

[0067] In the technical solution of the present embodiment, the composite inductor used includes a substrate, an epitaxial structure disposed on the substrate, in which a two-dimensional electron gas having a first planar spiral shape is formed, a first connection metal layer in ohmic contact with a first end of the two-dimensional electron gas, an inductor metal wire disposed on one side of the epitaxial structure away from the substrate, inductor metal wire having a second planar spiral shape, a first end electrically connected to the first connection metal layer and a second end electrically connected to a first end of the inductor metal wire, the first end of the inductor metal wire being an end corresponding to a center point of the second planar spiral shape, the first end of the two-dimensional electron gas being an end corresponding to a center point of the first planar spiral shape, and the spiral directions of the first planar spiral shape and the second planar spiral shape are opposite. If the wafer size occupied by the composite inductor is not changed, the first inductor and the second inductor of the composite inductor are disposed on different layers, and the inductor amount of the composite inductor is increased by series connection, i.e., the current path length per unit wafer area is increased, and the inductor density of the composite inductor is further increased.

[0068] Optionally, the spiral directions of the first planar spiral and the second planar spiral are opposite to each other, thereby further increasing the total inductor amount of the inductor made of the inductor metal wire and the inductor made of the two-dimensional electron gas, thereby further increasing the inductor density of the composite inductor.

[0069] Note that FIG. 32 illustrates an example in which the first planar spiral shape and the second planar spiral shape are both rectangular spiral shapes, but in some other embodiments, the first planar spiral shape and the second planar spiral shape may both be other shapes, and may be the same or different. For example, the first planar spiral shape may further be a circular spiral shape, and the second planar spiral shape may also be a circular spiral shape.

[0070] Optionally, with continued reference to FIGS. 16 and 17, isolations 122 are formed in the epitaxial structure 12, the isolations 122 defining regions corresponding to the two-dimensional electron gas 121.

[0071] Specifically, the two-dimensional electron gas 121 needs to be formed in a first planar spiral shape, and after the epitaxial structure 12 is formed, the two-dimensional electron gas exists in the entire layer and cannot be formed in a first planar spiral shape, so a separation portion 122 can be provided to define a region corresponding to the two-dimensional electron gas 121. The separation portion 122 may be formed, for example, by injecting argon ions into the epitaxial structure 12, and the resistance of the separation portion 122 is extremely high and is equivalent to an insulator, thereby defining the first planar spiral two-dimensional electron gas 121.

[0072] 16, the width of the two-dimensional electron gas is wider than the width of the inductor metal line along the thickness direction of the composite inductor, which is advantageous in reducing the resistance of the two-dimensional electron gas 121, making the inductor formed by the two-dimensional electron gas 121 closer to an ideal inductor, and improving the performance of the inductor formed by the two-dimensional electron gas 121.

[0073] Alternatively, still referring to FIG. 16, the number of turns of the two-dimensional electron gas 121 is greater than the number of turns of the inductor metal line 15'.

[0074] Specifically, the number of turns of the two-dimensional electron gas 121 is the number of turns of the first planar spiral, and the number of turns of the inductor metal wire 15' is the number of turns of the second planar spiral. In FIG. 32, the number of turns of the first planar spiral is 2, and the number of turns of the second planar spiral is 3. The two-dimensional electron gas 121 needs to connect one electrode metal as one electrode of the composite inductor, and the layer where the inductor metal wire 15' is located is a metal layer, which makes it easier to manufacture the electrode of the composite inductor in the layer. Therefore, the number of turns of the two-dimensional electron gas 121 is set to be larger than the number of turns of the inductor metal wire 15', the length of the two-dimensional electron gas 121 is longer than the length of the inductor metal wire 15', and the two-dimensional electron gas 121 has an extra part that makes it easier to introduce the current from the second end into the layer where the inductor metal wire 15' is located, which further makes it easier to manufacture the composite inductor electrode. In addition, in Figure 32, an example is described in which the wafer area required for two-dimensional electron gas 121 is larger than the wafer area required for inductor metal wire 15', but in some other embodiments, the wafer area required for two-dimensional electron gas 121 may be set smaller than the wafer area required for inductor metal wire 15', the number of turns of two-dimensional electron gas 121 may be smaller than the number of turns of inductor metal wire 15', and the projection of two-dimensional electron gas 121 onto substrate 11 and the projection of inductor metal wire 15' onto substrate 11 may or may not overlap, except for the overlapping area that is unavoidable because the spiral directions of the two are opposite, and this embodiment is not specifically limited.

[0075] Optionally, still referring to FIG. 16 and FIG. 17, the composite inductor further includes a first interlayer dielectric layer 14′, a first electrode metal 21, a second electrode metal 22, a second connection metal layer 23 and a second connection metal 24, the first interlayer dielectric layer 14′ is disposed on one side of the epitaxial structure 12 away from the substrate 11, the inductor metal line 15′ is disposed on one side of the first interlayer dielectric layer 14′ away from the substrate 11, and the first electrode metal 21, the second electrode metal 22 and the inductor metal line 15′ are provided in the same layer, the first electrode metal 21 is electrically connected to the second end of the inductor metal line 15', the second connecting metal layer 23 and the first connecting metal layer 13' are provided in the same layer, the second connecting metal layer 23 is in ohmic contact with the second end of the two-dimensional electron gas 121, the second connecting metal 24 penetrates the first interlayer dielectric layer 14', the first end of the second connecting metal 24 is electrically connected to the second connecting metal layer 23, and the second end of the second connecting metal 24 is electrically connected to the second electrode metal 22.

[0076] Specifically, the first electrode metal 21, the second electrode metal 22, the inductor metal line 15', the first connecting metal 16' and the second connecting metal 24 may all be aluminum and may be formed simultaneously, and the first connecting metal layer 13' and the second connecting metal layer 23 may be formed simultaneously, for example, by first depositing a composite metal using an electron beam evaporation system, and then forming the first connecting metal layer 13' and the second connecting metal layer 23 using a rapid thermal annealing (RTA) process. The first electrode metal 21 is the first electrode of the composite inductor, and the second electrode metal 22 is the second electrode of the composite inductor. The current path of the composite inductor is as follows: from the first electrode metal 21 to the second end of the inductor metal line 15', through the second planar spiral inductor metal line 15', through the first end 151' of the inductor metal line 15' into the first connecting metal 16', then through the first connecting metal layer 13' into the first end 1211 of the two-dimensional electron gas 121, through the first planar spiral two-dimensional electron gas 121, through the second end of the two-dimensional electron gas 121 into the second connecting metal layer 23, and then through the second connecting metal 24 into the second electrode metal 22; of course, in some other embodiments, the current path may be the opposite, i.e., from the second electrode metal 22 and from the first electrode metal 21.

[0077] Optionally, FIG. 18 is another cross-sectional view along the A1A2 direction of FIG. 16. Please refer to FIG. 16 and FIG. 18 for the differences from the structure shown in FIG. 17, in that the composite inductor of this embodiment further includes a second interlayer dielectric layer 25, a first ohmic metallization through hole 26 and a second ohmic metallization through hole 27, the second interlayer dielectric layer 25 is disposed between the first interlayer dielectric layer 14' and the epitaxial structure 12, the first ohmic metallization through hole 26 penetrates the second interlayer dielectric layer 25, the second ohmic metallization through hole 27 penetrates the second interlayer dielectric layer 25, the first connecting metal layer 13' is in ohmic contact with the first end 1211 of the two-dimensional electron gas 121 through the first ohmic metallization through hole 26, and the second connecting metal layer 23 is in ohmic contact with the second end of the two-dimensional electron gas 121 through the second ohmic metallization through hole 27.

[0078] Specifically, the second interlayer dielectric layer 25 may be, for example, one or a combination of silicon oxide, alumina, silicon nitride, silicon oxynitride, or any other material that can be an insulating dielectric, and the composite inductor may be fabricated on the same wafer as other thin-film devices, such as thin-film transistors, and the first connecting metal layer and the second connecting metal layer are disposed on the second interlayer dielectric layer 25, making the composite inductor compatible with other devices on the wafer and further improving the compatibility of the manufacturing process.

[0079] Optionally, referring to FIGS. 16-18, the composite inductor further includes a protective layer 28, which covers the inductor metal line 15'.

[0080] Specifically, the protective layer 28 may be, for example, one or more combinations of silicon oxide, alumina, silicon nitride, silicon oxynitride, or any other materials that can be insulating dielectrics. The protective layer 28 can protect the composite inductor, prevent the composite inductor from being corroded by external water and oxygen, etc., and extend the service life of the composite inductor.

[0081] 19 is another cross-sectional view taken along the A1A2 direction in FIG. 16. In this embodiment, the inductor metal wire 15' has a multi-layer structure, and correspondingly, the protective layer 28 also has a multi-layer structure, which is equivalent to increasing the thickness of the inductor metal wire 15', and is therefore advantageous in reducing the resistance of the inductor metal wire 15'.

[0082] An embodiment of the present invention further provides a method for manufacturing a composite inductor. FIG. 20 is a flowchart of a method for manufacturing a composite inductor according to an embodiment of the present invention. Referring to FIG. 20, the method includes steps S301 to S303, Step S301: forming an epitaxial structure on a substrate, the epitaxial structure including a first planar spiral two-dimensional electron gas; Specifically, FIGS. 21 to 29 are schematic diagrams of the structure of a product corresponding to the main flow of the manufacturing method of the composite inductor according to the embodiment of the present invention. As shown in FIG. 21, a substrate 11 can be provided first. Then, as shown in FIG. 22, an epitaxial structure 12 is epitaxially formed on the substrate 11. The growth method can be, for example, any of metal-organic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), and hydride vapor phase epitaxy (HVPE). The epitaxial structure 12 can include multiple layers, and each layer structure can be a III-V group compound. The epitaxial structure 12 may be a semiconductor material based on a compound, and the epitaxial structure 12 may be, for example, a heterojunction. When the epitaxial structure 12 is grown and formed, a layer of two-dimensional electron gas 121 is formed therein. Then, as shown in FIG. 23, since the two-dimensional electron gas 121 has a full-layer structure, a separation portion 122 can be formed in a portion of the epitaxial structure other than the portion where the two-dimensional electron gas 121 needs to be retained in order to form a first planar spiral two-dimensional electron gas. The separation portion 122 may be formed, for example, by an ion implantation method, for example, by injecting argon ions or the like.

[0083] Step S302: forming a first connection metal layer on one side of the epitaxial structure away from the substrate, the first connection metal layer being in ohmic contact with a first end of the two-dimensional electron gas; Specifically, before forming the first connection metal layer, a second interlayer dielectric layer may be first formed on the surface of the epitaxial structure away from the substrate, and a first ohmic through hole and a second ohmic through hole may be formed in the second interlayer dielectric layer, the first ohmic through hole may expose a first end of the two-dimensional electron gas, and the second ohmic through hole may expose a second end of the two-dimensional electron gas. As shown in FIG. 24, first, one layer of the material 250 of the second interlayer dielectric layer may be formed on the entire surface, and the material of the second interlayer dielectric layer 250 may be, for example, one or a combination of silicon oxide, alumina, silicon nitride, silicon oxynitride, or any other material that can be an insulating dielectric. Then, as shown in FIG. 25, a first ohmic through hole 401 and a second ohmic through hole 402 are formed by a method such as exposure, development, and etching, and then As shown in FIG. 26, a first connection metal layer 13′ and a second connection metal layer 23 are formed on the surface of the second interlayer dielectric layer 25 away from the substrate, the first ohmic through hole is metallized to form a first ohmic metallized through hole 26, and the second ohmic through hole is metallized to form a second ohmic metallized through hole 27. The first connection metal layer is in ohmic contact with a first end of the two-dimensional electron gas 121 through the first ohmic metallized through hole, and the second connection metal layer is in ohmic contact with a second end of the two-dimensional electron gas 121 through the second connection metal layer. The connection metal layer and the ohmic metallized through hole are simultaneously manufactured using an ohmic metal manufacturing process. The ohmic metal manufacturing process may be to first deposit a composite metal using an electron beam evaporation system, and then form an ohmic metal using a rapid thermal annealing process. Step S303: forming a first connection metal and an inductor metal line on one side of the epitaxial structure away from the substrate; Specifically, the step of forming the first connecting metal and the inductor metal line on one side of the epitaxial structure away from the substrate may further include: forming a first interlayer dielectric layer on one side of the epitaxial structure away from the substrate, and forming a first through hole in the first interlayer dielectric layer, the first through hole exposing the first connecting metal layer; first, as shown in FIG. 27, a layer of the material 140 of the first interlayer dielectric layer can be fully covered, and the material of the first interlayer dielectric layer can be, for example, one or more combinations of silicon oxide, alumina, silicon nitride, silicon oxynitride, or any other material that can be an insulating dielectric; then, as shown in FIG. 28, forming a first through hole 403 and a second through hole 404 by a method such as exposure, development, etching, etc., the first through hole 403 exposing the first connecting metal layer 13', and the second through hole 404 exposing the second connecting metal layer 23; The step of forming a first connection metal on the side of the epitaxial structure away from the substrate includes forming the first connection metal by metallizing the first through hole. The first connection metal and the inductor metal line may be formed simultaneously, the inductor metal line being a second planar spiral, a first end of the first connection metal being electrically connected to the first connection metal layer, a second end of the first connection metal being electrically connected to the first end of the inductor metal line, the first end of the inductor metal line being one end corresponding to a center point of the second planar spiral, and the first end of the two-dimensional electron gas being one end corresponding to the center point of the first planar spiral.

[0084] Specifically, as shown in FIG. 29 , the step of metallizing the first through-hole to form a first connecting metal 16′ further includes: forming a first electrode metal 21 on one side of the first interlayer dielectric layer 14′ away from the substrate; metallizing the second through-hole to form a second connecting metal 24; and forming a second electrode metal 22 on one side of the first interlayer dielectric layer 14′ away from the substrate 11, the first electrode metal 21 being electrically connected to a second end of the inductor metal line 15′; a first end of the second connecting metal 24 being electrically connected to a second connecting metal layer 23; a second end of the second connecting metal 24 being electrically connected to the second electrode metal 22; the first electrode metal 21 being a first electrode of the composite inductor; and the second electrode metal 22 being a second electrode of the composite inductor. As the second electrode, the current path of the composite inductor is from the first electrode metal 21 to the second end of the inductor metal line 15', through the second planar spiral inductor metal line 15', through the first end 151' of the inductor metal line 15' into the first connecting metal 16', then through the first connecting metal layer 13' into the first end 1211 of the two-dimensional electron gas 121, through the first planar spiral two-dimensional electron gas 121, through the second end of the two-dimensional electron gas 121 into the second connecting metal layer 23, and then through the second connecting metal 24 into the second electrode metal 22; of course in some other embodiments the current path may be the opposite, i.e., in from the second electrode metal 22 and out from the first electrode metal 21.

[0085] Then, one more protective layer 28 can be fully covered, thus forming the structure shown in Fig. 18, and the protective layer 28 can be, for example, one or more combinations of silicon oxide, alumina, silicon nitride, silicon oxynitride, or any other material that can be an insulating dielectric. The protective layer 28 can protect the composite inductor, prevent the composite inductor from being corroded by external water and oxygen, etc., and extend the service life of the composite inductor.

[0086] It should be noted that the above is merely a preferred embodiment of the present disclosure and the technical principles used. As can be understood by those skilled in the art, the present disclosure is not limited to the specific embodiments described herein, and those skilled in the art can make various obvious modifications, adjustments and substitutions without departing from the scope of protection of the present disclosure. Therefore, although the present disclosure has been described in detail by the above embodiments, the present disclosure is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present disclosure, and the scope of the present disclosure is determined by the appended claims.

Claims

1. A composite passive component, comprising: A substrate; an epitaxial structure disposed on the substrate, the epitaxial structure having a specific pattern of two-dimensional electron gas formed thereon; a passive component body disposed on one side of the epitaxial structure away from the substrate and in ohmic contact with the two-dimensional electron gas.

2. 2. The composite passive component of claim 1, wherein an isolation is formed in the epitaxial structure, the isolation defining a region corresponding to the two-dimensional electron gas.

3. 3. A composite passive component according to claim 1, wherein the specific pattern of the two-dimensional electron gas is provided to conform to the passive component body.

4. the composite passive component includes a composite capacitor, the passive component body includes a metal capacitor structure disposed on one side of the epitaxial structure away from the substrate, the metal capacitor structure includes a first metal plate and a second metal plate, the second metal plate is located on one side of the first metal plate away from the substrate, and the first metal plate is insulated from the two-dimensional electron gas; A composite passive component described in any one of claims 1 to 3, characterized in that along the thickness direction of the composite passive component, the total projection of the first metal plate and the second metal plate on the substrate at least partially overlaps with the projection of the two-dimensional electron gas on the substrate.

5. the two-dimensional electron gas is set at an equipotential with the second metal plate; 5. A composite passive component as claimed in claim 4, characterized in that along the thickness direction of the composite passive component, the projection of the first metal plate on the substrate at least partially overlaps with the projection of the two-dimensional electron gas on the substrate.

6. The composite passive component comprises: a first interlayer dielectric layer overlying the epitaxial structure; 6. The composite passive component of claim 4 or 5, wherein the metal capacitor structure is located on one side of the first interlayer dielectric layer away from the substrate, and the metal capacitor structure includes the first metal plate, the second metal plate and a second interlayer dielectric layer.

7. A composite passive component described in any one of claims 4 to 6, characterized in that along the thickness direction of the composite passive component, the projection of the two-dimensional electron gas on the substrate covers the projection of the first metal plate on the substrate and the projection of the second metal plate on the substrate.

8. 8. The composite passive component according to claim 4, wherein the two-dimensional electron gas is insulated from the second metal plate.

9. The composite passive component includes a composite inductor, and the passive component body includes: a first contact metal layer in ohmic contact with a first end of the two-dimensional electron gas; a second planar spiral inductor metal line disposed on one side of the epitaxial structure away from the substrate; a first connection metal having a first end electrically connected to the first connection metal layer and a second end electrically connected to a first end of the inductor metal line; a first end of the inductor metal wire corresponding to a center point of the second planar spiral, and a first end of the two-dimensional electron gas corresponding to a center point of the first planar spiral; 4. The composite passive component according to claim 1, wherein the two-dimensional electron gas is in the shape of the first planar spiral.

10. 10. The composite passive component according to claim 9, wherein the first planar spiral and the second planar spiral have opposite spiral directions.

11. 11. The composite passive component according to claim 9, wherein the width of the two-dimensional electron gas is greater than the width of the inductor metal line.

12. The composite passive component further includes a first interlayer dielectric layer, a first electrode metal, a second electrode metal, a second connection metal layer, and a second connection metal; the first interlayer dielectric layer is disposed on one side of the epitaxial structure away from the substrate, and the inductor metal line is disposed on one side of the first interlayer dielectric layer away from the substrate; the first electrode metal, the second electrode metal and the inductor metal line are disposed in the same layer, and the first electrode metal is electrically connected to a second end of the inductor metal line; the second connection metal layer and the first connection metal layer are disposed on the same layer, the second connection metal layer being in ohmic contact with a second end of the two-dimensional electron gas; A composite passive component as described in any one of claims 9 to 11, characterized in that the second connection metal penetrates the first interlayer dielectric layer, a first end of the second connection metal is electrically connected to the second connection metal layer, and a second end of the second connection metal is electrically connected to the second electrode metal.

13. The composite passive component further includes a second interlayer dielectric layer, a first ohmic metallization through hole, and a second ohmic metallization through hole, the second interlayer dielectric layer being disposed between the first interlayer dielectric layer and the epitaxial structure, the first ohmic metallization through hole penetrating the second interlayer dielectric layer, and the second ohmic metallization through hole penetrating the second interlayer dielectric layer; A composite passive component as described in any one of claims 9 to 12, characterized in that the first connecting metal layer is in ohmic contact with a first end of the two-dimensional electron gas via a first ohmic metallization through hole, and the second connecting metal layer is in ohmic contact with a second end of the two-dimensional electron gas via a second ohmic metallization through hole.

14. The composite passive component according to any one of claims 9 to 13, further comprising a protective layer, the protective layer covering the inductor metal line.

15. A method for manufacturing a composite passive component, comprising the steps of: Providing a substrate; epitaxially forming an epitaxial structure layer on the substrate; implanting ions into the epitaxial structure layer to form an isolation region, thereby defining a region corresponding to the two-dimensional electron gas; and placing a passive component body on one side of the epitaxial structure layer away from the substrate and in ohmic contact with the two-dimensional electron gas.

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