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] FIELD OF THE DISCLOSURE Embodiments of the present disclosure relate to capacitor technology, and more particularly to composite passive components and methods for fabricating 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 electronics.

[0003] However, with the trend toward miniaturization of electronic devices, the requirements for the integration density of passive components are becoming higher and higher, while the integration density of conventional passive components is low, limiting the application 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 and having a specific pattern of two-dimensional electron gas formed therein; 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 fit 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, 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.

[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: further comprising 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 semiconductor material based on III-V compounds.

[0012] In one embodiment, along the thickness direction of the composite capacitor, 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.

[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; 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; The two-dimensional electron gas is in the shape of the first planar spiral.

[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, and the second connection metal layer is 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, wherein the second interlayer dielectric layer is disposed between the first interlayer dielectric layer and the epitaxial structure, the first ohmic metallization through hole penetrates the second interlayer dielectric layer, and the second ohmic metallization through hole penetrates the second interlayer dielectric layer; The first connection 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 connection 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 line. 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 manufacturing method comprises: 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, 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.

[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 one 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 manufacturing method comprises: 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 one side of the epitaxial structure away from the substrate, the first contact metal layer making ohmic contact with a first end of the two-dimensional electron gas; forming a first connection metal and an inductor metal line on one side of the epitaxial structure away from the substrate, the inductor metal line having a second planar spiral shape, a first end of the first connection metal electrically connected to the first connection metal layer, a second end of the first connection metal 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 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 one side of the epitaxial structure away from the substrate, a first through hole formed in the first interlayer dielectric layer, the first through hole exposing the first connecting 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, before the step of forming a first connection metal layer on one side of the epitaxial structure 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, wherein a first ohmic through hole and a second ohmic through hole are 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 one side of the epitaxial structure away from the substrate; 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 the 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 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 may 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 disposed on the substrate and having a two-dimensional electron gas formed therein, 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, and the first metal plate being insulated from the two-dimensional electron gas, wherein the total projection of the first metal plate and the second metal plate on the substrate along the thickness direction of the composite capacitor 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 and improve the capacitor integration density without increasing the occupied wafer area.

[0030] In the technical solution of this embodiment, the composite inductor used includes a substrate, an epitaxial structure disposed on the substrate and having a first planar spiral-shaped two-dimensional electron gas formed thereon, 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 having a second planar spiral-shaped inductor, and a first connection metal, the first end of which is electrically connected to the first connection metal layer and the second end of which is electrically connected to a first end of the inductor metal line, the first end of the inductor metal line being one end corresponding to the 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. While 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, further increasing the inductor integration degree and increasing the inductor volume of the composite inductor by series connection, i.e., lengthening the current path length per unit wafer area and further increasing the inductor density of the composite inductor. [Brief explanation of the drawings]

[0031] [Figure 1] 1 is a structural schematic diagram of a composite capacitor according to an embodiment of the present disclosure. [Figure 2]FIG. 10 is a structural schematic diagram of another composite capacitor according to an embodiment of the present disclosure. [Figure 3] FIG. 10 is a structural schematic diagram of another composite capacitor according to an embodiment of the present disclosure. [Figure 4] FIG. 10 is a structural schematic diagram of another composite capacitor according to an embodiment of the present disclosure. [Figure 5] 1 is a flowchart 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 the main flow of a manufacturing method for a composite capacitor according to an embodiment of the present disclosure. [Figure 16] FIG. 1 is a plan view of a composite inductor according to an embodiment of the present disclosure. [Figure 17] FIG. 17 is a cross-sectional view taken along the A1A2 direction in FIG. [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 illustrating the structure of a product 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 INVENTION

[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 relevant 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 therein, 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. The interaction between the two-dimensional electron gas in the epitaxial structure and the passive component body improves the integration density and performance of the composite passive component. The passive component may have 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 nitride, indium gallium nitride, aluminum indium gallium nitride, indium phosphide, gallium 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 may be a semiconductor material based on a group III-V compound. The epitaxial structure 12 may be, for example, a heterojunction, but this embodiment is not limited thereto. When the epitaxial structure 12 is grown and formed, a layer of high concentration free charges (two dimensional electrons) may be formed therein. In other words, one layer of two-dimensional electron gas 121 is formed, and 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 similar to that of a metal.

[0035] The composite passive component according to the embodiment of the present disclosure establishes 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 shown in the specific pattern of the two-dimensional electron gas is adapted 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 thereon, 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, and the first metal plate 141 being insulated from the two-dimensional electron gas 121. 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 typically 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. The resistivity of the two-dimensional electron gas 121 is considered to be similar to that of a metal. That is, the two-dimensional electron gas 121 can be equivalent to the metal plates of a capacitor. As shown in FIG. 1, the first metal plate 141 and the second metal plate 143 each need to be connected to an electrode. Therefore, 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 that they do not 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. The projection of the first region 111 includes only the projection of the first metal plate 141, and the projection of the second region 112 includes not only the projection of the first metal plate 141 but also 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 arranged in the thickness direction of the metal capacitor structure 14, and does not increase the area occupied on the wafer. Therefore, this embodiment can increase the number of capacitors and improve the capacitor integration density without increasing the occupied wafer area.

[0039] In the technical solution of this embodiment, the composite capacitor used includes a substrate, an epitaxial structure disposed on the substrate and having a two-dimensional electron gas formed therein, 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, and the first metal plate being insulated from the two-dimensional electron gas, wherein the total projection of the first metal plate and the second metal plate on the substrate along the thickness direction of the composite capacitor 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 and improve the capacitor integration density without increasing the occupied wafer area.

[0040] In one embodiment, with continued reference to FIG. 1, 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 any part 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 electrode plate 141 on the substrate and the projection of the second metal electrode plate 143 on the substrate 11 overlap along the thickness direction of the composite capacitor, they completely overlap with the projection of the two-dimensional electron gas 121 on the substrate 11, 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 ion implantation, for example, by implanting argon ions, thereby extremely increasing the resistance of the separation portion 122 and further reducing substrate loss.

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

[0043] Specifically, the protective layer 17 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. 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.

[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 the 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, and 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 for example, it may be installed on one side of the two-dimensional electron gas 121 that is farther from the substrate 11, or on one side of the two-dimensional electron gas 121 that is closer to the substrate 11, or on any 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, 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 in at least one of the first region 111 and the second region 112, the two-dimensional electron gas 121 and the second metal plate 143 form a capacitor. 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, further increasing the degree of integration 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 at the same potential as the second metal plate 143, and the projection of the first metal plate 141 on the substrate 11 at least partially overlaps the projection of the two-dimensional electron gas 121 on the substrate 11 along the thickness direction of the composite capacitor. By setting it in this way, the two-dimensional electron gas 121 and the second metal plate 143 correspond to one plate and respectively overlap 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, further increasing 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 electrically connected to the second metal plate 143. The connection structure 15 forms 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, so that 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 capacitor C1. The capacitor structure 14 is capacitor C2. Capacitors C2 and C1 share one electrode plate (first metal electrode plate 141, which has mobile charge on both the top and bottom surfaces of first metal electrode plate 141 during operation). The remaining electrodes (two-dimensional electron gas 121 and second metal electrode plate 143) are electrically connected via connection structure 15. This is equivalent to connecting capacitors C1 and C2 in parallel. That is, the capacitance of the composite capacitor is equal to the sum of the capacitances of capacitors C1 and C2, which is equivalent to increasing the facing area of ​​the capacitor's electrodes. Two-dimensional electron gas 121 is disposed in the thickness direction of metal capacitor structure 14, without increasing the area occupied on the wafer. Therefore, this embodiment can improve the capacitance of the composite capacitor without increasing the occupied wafer area. Furthermore, because fewer metal layers are required, manufacturing is easier and costs can be reduced.

[0047] Of course, in some other embodiments, other solutions may be used to achieve equipotentiality 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, 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. The presence of the first interlayer dielectric layer 141 and the second interlayer dielectric layer 142 can improve the performance of the capacitor. 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 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 significantly increasing the capacitance of the capacitor C1. In the metal capacitor structure 14, since it is necessary to install the lead-out electrodes 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 facilitating the installation of the connection structure 15.

[0051] 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 that penetrates 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 to be electrically connected to the connection metal layer 151 and the second metal plate 143.

[0053] Specifically, in this embodiment, the connecting metal layer 151 makes direct ohmic contact with the two-dimensional electron gas 121. When fabricating a composite capacitor, the connecting metal layer 151 can be directly fabricated after epitaxially forming the epitaxial structure 12. This provides better contact between the connecting metal layer 151 and the two-dimensional electron gas 121, which is more beneficial to improving the performance of the composite capacitor. The first through-hole penetrates the first interlayer dielectric layer 13, and the second through-hole penetrates the second interlayer dielectric layer 142. The connecting metallized through-hole includes a first sub-through-hole 153 and a second sub-through-hole 154. 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 connecting metal layer 151 may be formed, for example, 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. 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 metallization through hole 152, and a connection metallization through hole, the connection metal layer 151 and the first metal electrode plate 141 are disposed on the same layer, the connection metal layer 151 is in ohmic contact with the two-dimensional electron gas 121 through the ohmic metallization through hole 152 penetrating the first interlayer dielectric layer 13, and the connection metallization through hole is electrically connected to the connection metal layer 151 and the second metal electrode 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. 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. After that, the connection metal layer 151 and the ohmic metallized through hole 152 can be simultaneously fabricated using an ohmic metal fabrication process. 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 in this embodiment is the fourth through hole after metallization.

[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 differences from the structures shown in FIGS. 2 and 3 are 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. The materials of the first sub-dielectric layer 131 and the second sub-dielectric layer 132 may be, for example, one or a combination of silicon oxide, alumina, silicon nitride, silicon oxynitride, or any other insulating dielectric material. The composite capacitor may be fabricated on the same wafer as other thin-film devices, such as thin-film transistors. The connection metal layer 151 is located on the first sub-dielectric layer 131 to ensure compatibility with other devices on the wafer and further improve the compatibility of the composite capacitor fabrication process. A sixth through-hole penetrates the second sub-dielectric layer 132, and a seventh through-hole penetrates the second interlayer dielectric layer 142. The connection metallization through-holes include a first sub-through-hole 153 and a second sub-through-hole 154. 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 flowchart of a method for manufacturing a composite capacitor according to an embodiment of the present disclosure, the method including 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, metal organic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), or hydride vapor phase epitaxy (HVPE). The epitaxial structure 12 can include multiple layers, and each layer can be a semiconductor material based on a III-V compound. The epitaxial structure 12 may be, for example, a heterojunction. When the epitaxial structure 12 is grown, a layer of two-dimensional electron gas 121 is formed therein. The two-dimensional electron gas 121 can be used to form one electrode plate of a capacitor. Then, as shown in FIG. 8, in order to reduce substrate loss, a separation region 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 region 122 can be formed, for example, by ion implantation, for example, by implanting argon ions, thereby extremely increasing the resistance of the separation region 122 and further reducing substrate loss.

[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 single 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 wafer area occupied by the composite capacitor, thereby improving the degree of capacitor integration.

[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 the thickness direction of the composite capacitor, and further includes forming a connection structure that is in ohmic contact with the two-dimensional electron gas and is electrically connected to the second metal plate when forming the metal capacitor structure on one side of the epitaxial structure away from the substrate.

[0062] For example, when forming the metal capacitor structure, a first interlayer dielectric layer can be formed, 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, by first depositing a composite metal using an electron beam evaporation system, and then using a rapid thermal annealing (RTA) process to form the connecting metal layer. Then, as shown in FIG. 10, a layer of dielectric layer material is first grown, which may 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. Next, as shown in FIG. 12, a first metal plate 141 is formed on the surface of the first interlayer dielectric layer 13 facing away from the substrate, and the first through-hole is metallized. This can be manufactured by methods such as 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. Next, as shown in FIG. 13, a layer of dielectric layer material 1420 is completely covered. The dielectric layer material 1420 may 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 a separation layer for the metal capacitor structure. Then, as shown in FIG. 14, a second through-hole 202 is formed by exposure, development, etching, etc., so that the second through-hole 202 exposes the first through-hole. At the same time, an electrode through-hole 301 can be formed, which can then be used to form a metal electrode, as shown in FIG. 15, a second interlayer dielectric layer 142 is formed, which can be manufactured by sputtering, deposition, or other methods, and a second metal plate 143 is formed using a mask. 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 the first electrode of the composite capacitor, and the portion 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, one protective layer 17 is completely covered, thereby forming the structure shown in Fig. 2. The protective layer 17 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. The protective layer 17 protects the composite capacitor and prevents the composite capacitor from being corroded by external water and oxygen, etc., thereby extending 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. The material of the first interlayer dielectric layer can 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, 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 faces away from the substrate. The through-holes are metallized to form ohmic metallized through-holes 152, and the connection metal layer 151 makes ohmic contact with the two-dimensional electron gas 121 through the ohmic metallized through-holes 152. The connection metal layer 151 and the ohmic metallized through-holes 152 are simultaneously manufactured using an ohmic metal manufacturing process. The ohmic metal manufacturing process may involve first depositing a composite metal using an electron beam evaporation system, and then forming an ohmic metal using a rapid thermal annealing process. Secondly, since a high-temperature process is required when manufacturing the connection metal layer, Therefore, the first metal plate 161 may be manufactured after manufacturing the connection metal layer, and the first metal plate 161 may be manufactured by sputtering, deposition, etc. In addition, if the entire metal layer must 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 depositing the entire metal layer, and then the metal layer may be etched to form the first metal plate 141, and then the sacrificial layer may be 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 may be etched. a dielectric layer material 1420 is entirely covered on the layer, 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 a separation layer of the metal capacitor structure; and then, by means of exposure, development, etching, etc., a fourth through hole 204 is formed, the fourth through hole 204 exposes the connecting metal layer 151, and 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 shown in FIG. 20 , which can then be fabricated by sputtering, deposition, or other methods. A second metal plate 143 is then formed using a mask. At the same time, the fourth through-hole 204 and electrode through-hole 301 are 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 protective layer 17 is completely covered, thereby forming the structure shown in FIG. 3 . The protective layer 17 can be, for example, one or more of silicon oxide, alumina, silicon nitride, silicon oxynitride, or any other material capable of acting as an insulating dielectric. The protective layer 17 protects the composite capacitor and prevents corrosion of the composite capacitor due to external factors such as water and oxygen, thereby extending 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. The first sub-dielectric layer material 1310 can 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, 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. The connecting metal layer 151 is formed on the surface of the first sub-dielectric layer 131 that faces away from the substrate. The through-holes are metallized to form ohmic metallized through-holes 152, and the connection metal layer 151 makes ohmic contact with the two-dimensional electron gas 121 through the ohmic metallized through-holes 152. The connection metal layer 151 and the ohmic metallized through-holes 152 are simultaneously manufactured using an ohmic metal manufacturing process. The ohmic metal manufacturing process may involve first depositing a composite metal using an electron beam evaporation system, and then forming an ohmic metal using a rapid thermal annealing process. The material 1320 forming the second sub-dielectric layer is then completely covered. The material of the second sub-dielectric layer 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. The sixth through-hole 206 is formed by 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 faces away from the substrate. The sixth through-hole is metallized, and can be manufactured by, for example, sputtering, deposition, etc., and the first metal plate 141 is formed by a mask. At the same time, the sixth through-hole is metallized to form a first sub-through-hole 153, which is completely covered with a layer of dielectric layer material 1420, which may 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 a separation layer of the metal capacitor structure. A seventh through-hole 207 is formed by exposure, development, etching, etc., which exposes the sixth through-hole, and an electrode through-hole 301 can also be formed at the same time.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, or other methods. The second metal plate 143 is formed using a mask, 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 protective layer 17 is completely covered, thereby forming the structure shown in FIG. 3. The protective layer 17 can be, for example, one or more of silicon oxide, alumina, silicon nitride, silicon oxynitride, or any other material capable of serving as an insulating dielectric. The protective layer 17 protects the composite capacitor and prevents corrosion of the composite capacitor due to external factors such as water and oxygen, thereby extending the service life of the composite capacitor.

[0065] When the passive component has an inductor structure 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 FIGS. 16 and 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 thereon, 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 the first end of the inductor metal wire 15′, wherein a first end 151′ of the inductor metal wire 15′ is one end corresponding to the center point of the second planar spiral, 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.

[0066] The two-dimensional electron gas 121 can be equivalent to an inductor metal wire. By setting the two-dimensional electron gas 121 in a first planar spiral shape, the two-dimensional electron gas 121 can be equivalent to an inductor, and this inductor is referred to as 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 current can be transferred from the first connecting metal 16′ to the two-dimensional electron gas 121, or 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 an inductor, and this inductor is referred to as a second inductor. The spiral directions of the first inductor and the second inductor are opposite, and the total inductance of the composite inductor is the series connection of the first inductor and the second inductor, which is therefore equivalent to increasing the inductance of the composite inductor. Furthermore, 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 the same, the first inductor and the second inductor of the composite inductor are installed on different layers and connected in series to increase the inductance of the composite inductor, i.e., 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 this embodiment, the composite inductor includes a substrate, an epitaxial structure disposed on the substrate and having a first planar spiral-shaped two-dimensional electron gas formed thereon, 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 having a second planar spiral shape, and a first connection metal, the first end of which is electrically connected to the first connection metal layer and the second end of which is electrically connected to a first end of the inductor metal line, the first end of the inductor metal line being one end corresponding to the 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, the spiral directions of the first and second planar spirals being opposite. If the wafer size occupied by the composite inductor remains the same, the first inductor and the second inductor of the composite inductor are disposed on different layers and connected in series to increase the inductor volume of the composite inductor, i.e., to lengthen the current path length per unit wafer area and further increase the inductor density of the composite inductor.

[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 inductance 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] Although FIG. 32 illustrates an example in which the first and second planar spirals are both rectangular spirals, in some other embodiments, the first and second planar spirals may have other shapes, and may be the same or different. For example, the first planar spiral may also be a circular spiral, and the second planar spiral may also be a circular spiral.

[0070] Optionally, with continued reference to FIGS. 16 and 17, isolation regions 122 are formed in the epitaxial structure 12, the isolation regions 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. 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. Therefore, a separation region 122 can be installed to define the region corresponding to the two-dimensional electron gas 121. The separation region 122 may be formed, for example, by injecting argon ions into the epitaxial structure 12. The resistance of the separation region 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 wire 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] Optionally, 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 wire 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 is one electrode of the composite inductor and needs to connect one electrode metal. The layer where the inductor metal wire 15′ is located is a metal layer, which makes it easier to fabricate the electrode of the composite inductor on this 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′, and the length of the two-dimensional electron gas 121 is longer than the length of the inductor metal wire 15′. The two-dimensional electron gas 121 has an extra portion 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 facilitates fabrication of the composite inductor electrode. Note that Figure 32 illustrates an example 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 also 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 FIGS. 16 and 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′ being disposed on one side of the epitaxial structure 12 away from the substrate 11, the inductor metal line 15′ being 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′ The first electrode metal 21 is electrically connected to the second end of the inductor metal line 15', the second connection metal layer 23 and the first connection metal layer 13' are arranged in the same layer, the second connection metal layer 23 is in ohmic contact with the second end of the two-dimensional electron gas 121, the second connection metal 24 penetrates the first interlayer dielectric layer 14', the first end of the second connection metal 24 is electrically connected to the second connection metal layer 23, and the second end of the second connection 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′, into the first connecting metal 16′ via the first end 151′ of the inductor metal line 15′, then through the first connecting metal layer 13′ to the first end 1211 of the two-dimensional electron gas 121, through the first planar spiral two-dimensional electron gas 121, into the second connecting metal layer 23 via the second end of the two-dimensional electron gas 121, and then through the second connecting metal 24 to the second electrode metal 22. Of course, in some other embodiments, the current path may be reversed, i.e., flowing in from the second electrode metal 22 and out from the first electrode metal 21.

[0077] Optionally, Figure 18 is another cross-sectional view along the A1A2 direction of Figure 16. Please refer to Figures 16 and 18 for differences from the structure shown in Figure 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 located 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 and second connecting metal layers are placed on the second interlayer dielectric layer 25, which makes the composite inductor compatible with other devices on the wafer and further improves 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 a combination 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.

[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 multilayer structure, and correspondingly, the protective layer 28 also has a multilayer 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 the 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; 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 made of III-V group metals. 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 region 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 region 122 may be formed, for example, by ion implantation, for example, by implanting 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 making 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 can 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 can be 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. As shown in FIG. 24, first, a layer of second interlayer dielectric layer material 250 can be formed on the entire surface, and the material of second interlayer dielectric layer 250 can 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. Next, as shown in FIG. 25, a first ohmic through hole 401 and a second ohmic through hole 402 are formed by exposure, development, etching, etc., 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 facing away from the substrate; the first ohmic through hole is metallized to form a first ohmic metallized through hole 26; 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; 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; and the connection metal layer and the ohmic metallized through hole are simultaneously manufactured using an ohmic metal manufacturing process, which may be to first deposit a composite metal using an electron beam evaporation system and then form the 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; 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 first interlayer dielectric layer material 140 can be entirely 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 means of exposure, development, etching, etc., respectively, 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 one side of the epitaxial structure away from the substrate includes metallizing a first through hole to form the first connection metal. The first connection metal and the inductor metal line may be formed simultaneously, the inductor metal line having a second planar spiral shape, a first end of the first connection metal electrically connected to the first connection metal layer, a second end of the first connection metal electrically connected to the first end of the inductor metal line, the first end of the inductor metal line being one end corresponding to the 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 the 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, wherein the first electrode metal 21 is electrically connected to the second end of the inductor metal line 15′; a first end of the second connecting metal 24 is electrically connected to the second connecting metal layer 23; and a second end of the second connecting metal 24 is electrically connected to the second electrode metal 22, the first electrode metal 21 being the first electrode of the composite inductor; and the second electrode metal 22 being the second electrode of the composite inductor. The current path of the composite inductor as the second electrode 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' to 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 to the second electrode metal 22; of course, in some other embodiments, the current path may be reversed, i.e., from the second electrode metal 22 and from the first electrode metal 21.

[0085] 18, the protective layer 28 may be, for example, one or more 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 and prevent it from being corroded by external water and oxygen, etc., thereby extending 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 various obvious modifications, adjustments, and substitutions can be made by those skilled in the art 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, A substrate; an epitaxial structure disposed on the substrate, in which a specific pattern of two-dimensional electron gas is formed; 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; 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 two-dimensional electron gas is insulated from the first metal plate adjacent to the two-dimensional electron gas; 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 along a thickness direction of the composite passive component; When the composite passive component includes a composite capacitor, the two-dimensional electron gas is insulated from the second metal plate; Alternatively, 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; A composite passive component, wherein the two-dimensional electron gas has the first planar spiral shape.

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

3. 2. The 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. When the composite passive component includes a composite capacitor, the two-dimensional electron gas is set to an equipotential with the second metal plate; 2. A composite passive component as described in claim 1, wherein 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.

5. When the composite passive component includes a composite capacitor, the composite passive component comprises: further comprising a first interlayer dielectric layer overlying the epitaxial structure; 2. The composite passive component of claim 1, 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.

6. 2. The composite passive component of claim 1, wherein when the composite passive component includes a composite capacitor, 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.

7. 2. The composite passive component according to claim 1, wherein when the composite passive component includes a composite inductor, the spiral directions of the first planar spiral and the second planar spiral are opposite to each other.

8. 2. The composite passive component according to claim 1, wherein when the composite passive component includes a composite inductor, the width of the two-dimensional electron gas is wider than the width of the inductor metal line.

9. When the composite passive component includes a composite inductor, 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, and the second connection metal layer is in ohmic contact with a second end of the two-dimensional electron gas; A composite passive component as described in any one of claims 1, 7 to 8, 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.

10. When the composite passive component includes a composite inductor, the composite passive component further includes a second interlayer dielectric layer, a first ohmic metallization through hole, and a second ohmic metallization through hole, wherein the second interlayer dielectric layer is disposed between the first interlayer dielectric layer and the epitaxial structure, the first ohmic metallization through hole penetrates the second interlayer dielectric layer, and the second ohmic metallization through hole penetrates the second interlayer dielectric layer; A composite passive component as described in any one of claims 1, 7 to 8, characterized in that the first connection 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 connection metal layer makes ohmic contact with a second end of the two-dimensional electron gas via a second ohmic metallization through hole.

11. A composite passive component as described in any one of claims 1, 7 to 8, characterized in that when the composite passive component includes a composite inductor, the composite passive component further includes a protective layer, the protective layer covering the inductor metal wire.

12. 2. A method for manufacturing a composite passive component according to claim 1, comprising: 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 a two-dimensional electron gas; and placing a passive component body on one side of the epitaxial structure layer away from the substrate, the passive component body being in ohmic contact with the two-dimensional electron gas.

Images