CN116093084A - Switching plate structure and forming method thereof - Google Patents

Abstract

The invention relates to an adapter plate structure, which comprises two bonded first adapter plates, wherein the first adapter plates comprise: a substrate; a plurality of interconnected trench capacitor structures located on a front side of the substrate, wherein the trench capacitor structures comprise: a plurality of trenches located on the front side of the substrate; a capacitor lower electrode covering an inner wall of the trench; the capacitor medium is positioned on one side surface of the capacitor lower electrode, which is away from the inner wall of the groove; the capacitor upper electrode is positioned on one side surface of the capacitor medium, which is away from the capacitor lower electrode; and the inductor is positioned on the back surface of the substrate and is electrically connected with the groove capacitor structure. The capacitor is integrated in the adapter plate, the inductor is integrated on the surface of the adapter plate, the occupied space of two devices is greatly reduced, the distance between the inductor and the groove capacitor structure is far, the isolation degree is high, the interference between the inductor and the groove capacitor structure is reduced, the dielectric loss is reduced, and the Q value of the inductor is improved; and the trench capacitor structure is used, so that the capacitor density is improved, and the capacitance value can be effectively improved.

Description

An adapter plate structure and its forming method

technical field

The invention relates to the technical field of semiconductor packaging, in particular to an adapter plate structure and a forming method thereof.

Background technique

In recent years, with the rapid development of the wireless communication market, the demand for low-cost, high-performance on-chip radio frequency devices is also increasing. In order to meet the requirements of low loss and high integration, on-chip integrated inductors have become voltage-controlled oscillators, Important components in many communication modules such as low noise amplifiers, mixers, and filters. Capacitors are indispensable components in microwave radio frequency circuits, and have the functions of DC isolation, filtering, coupling, tuning, and rectification. As the operating frequency of integrated circuits is getting higher and higher, the speed is getting faster and faster, and the noise problem of the circuit power supply network in the electronic system is becoming more and more serious, and the demand for the decoupling effect of the capacitor is also rapidly increasing.

Conventional IPD capacitors are mainly in the form of MIM, realized by two layers of planar metal electrodes, but due to the limited planar space, this capacitor structure usually cannot obtain a large capacitance value. In the prior art, the adapter board contains inductors and capacitors in the form of M I M . Capacitors and inductors are usually integrated together. The distance between the two is relatively close, and there is greater interference between them. The inductor has a dielectric loss, which limits the Inductive performance.

Contents of the invention

In order to solve at least some of the above-mentioned problems in the prior art, the present invention provides an adapter plate structure, including two bonded first adapter plates, wherein the first adapter plate includes:

Substrate;

A plurality of interconnected trench capacitor structures located on the front side of the substrate, wherein the trench capacitor structures include: a plurality of trenches located on the front side of the substrate; a capacitor bottom electrode covering the trenches The inner wall of the groove; the capacitance medium, which is located on the side surface of the lower electrode of the capacitance away from the inner wall of the groove; the upper electrode of the capacitance, which is located on the surface of the side of the capacitance medium away from the lower electrode of the capacitance;

An inductor is located on the backside of the substrate and is electrically connected to the trench capacitor structure.

Further, it also includes:

a conductive member positioned on a side of the trench capacitor structure and spaced from the trench capacitor structure;

a first redistribution layer, which is electrically connected to the conductive member and the trench capacitance structure;

The second redistribution layer is electrically connected to the conductive element and the inductor.

Further, the substrate has a through hole, and the conductive member is located in the through hole.

Further, it also includes:

The first insulating layer is located between the lower electrode of the capacitor and the inner wall of the trench;

The second insulating layer is located on the surface of the capacitor upper electrode away from the capacitor medium;

The third insulating layer is located between the inner wall of the through hole and the conductive member;

A fourth insulating layer is located on the backside of the substrate.

Further, the capacitor lower electrode extends to the upper surface of the first insulating layer away from the substrate; the capacitor lower electrodes of the multiple trench capacitor structures are electrically connected;

The first redistribution layer is electrically connected to the lower electrode of the capacitor.

Further, the first redistribution layers of the two first riser boards are bonded, so that the two first riser boards are bonded to form a riser board structure.

The present invention also provides a method for forming an adapter plate structure, comprising: first forming a first adapter plate, and then bonding two first adapter plates to form an adapter plate structure, wherein forming the first adapter plate includes :

forming trenches on the front side of the substrate;

Forming a capacitor lower electrode on the inner wall of the trench;

A capacitor medium is formed on the side surface of the capacitor lower electrode away from the inner wall of the trench;

Form the upper electrode of the capacitor on the surface of the capacitor medium away from the lower electrode of the capacitor;

forming via holes on the front side of the substrate;

forming conductive elements in the via holes;

forming a first redistribution layer connecting the conductive member and the lower electrode of the capacitor on the front surface of the substrate;

Thinning the back of the substrate to expose the conductive parts;

The inductor and the second redistribution layer are arranged on the backside of the substrate to finally obtain the first interposer board.

Further, it also includes:

Before forming the capacitor bottom electrode on the inner wall of the trench, a first insulating layer is formed on the front surface of the substrate and the inner wall of the trench;

Before forming a through hole on the front side of the substrate, a second insulating layer is formed on the surface of the capacitor upper electrode away from the capacitor medium;

Before forming the conductive member in the through hole, a third insulating layer is formed on the inner wall of the through hole.

Further, an interposer structure is obtained by bonding the first redistribution layers of the two first interposers.

Further, firstly, a fourth insulating layer is formed on the back side of the substrate, and the fourth insulating layer is etched to form an inductor pattern and a rewiring pattern, and then metal is filled in the inductor pattern and the rewiring pattern to form an inductor and a second rewiring layer, Wherein the inductor and the second redistribution layer are integrally formed.

The present invention has at least the following beneficial effects: an adapter plate structure disclosed by the present invention and its forming method, in which the capacitor is integrated inside the adapter plate, and the inductance is integrated on the surface of the adapter plate, The space occupied by the two devices is greatly reduced, and the distance between the inductor and the trench capacitor structure is relatively long, the isolation is high, the interference between the two is reduced, the dielectric loss is reduced, and the Q value of the inductor is improved; compared with Compared with general planar MIM capacitors, the trench capacitor structure is used to increase the capacitance density and effectively increase the capacitance value.

Description of drawings

In order to further clarify the above and other advantages and features of various embodiments of the present invention, a more particular description of various embodiments of the present invention will be presented with reference to the accompanying drawings. It is understood that the drawings depict only typical embodiments of the invention and therefore are not to be considered limiting of its scope. In the drawings, the same or corresponding parts will be denoted by the same or similar symbols for clarity.

FIG. 1 shows a schematic cross-sectional view of an adapter plate structure according to an embodiment of the present invention; and

2A to 2N are schematic cross-sectional views showing the process of forming the interposer structure according to an embodiment of the present invention.

Detailed ways

It should be noted that components in the various figures may be shown exaggerated for the purpose of illustration and are not necessarily true to scale.

In the present invention, each embodiment is only intended to illustrate the solutions of the present invention, and should not be construed as limiting.

In the present invention, unless otherwise specified, the quantifiers "a" and "an" do not exclude the scene of multiple elements.

It should also be pointed out here that in the embodiments of the present invention, for the sake of clarity and simplicity, only a part of parts or components may be shown, but those skilled in the art can understand that under the teaching of the present invention, specific The scene needs to add the required parts or components.

It should also be pointed out that within the scope of the present invention, expressions such as "same", "equal", and "equal to" do not mean that the two values are absolutely equal, but allow a certain reasonable error, that is, the Wording also covers "substantially the same", "substantially equal", "substantially equal to".

It should also be noted that in the description of the present invention, the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", The orientations or positional relationships indicated by "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplified descriptions, rather than explicitly or implying that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and thus should not be construed as limiting the invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and should not be interpreted as expressing or implying relative importance.

In addition, the embodiments of the present invention describe the process steps in a specific order, but this is only for the convenience of distinguishing the steps, and does not limit the order of the steps. In different embodiments of the present invention, it can be adjusted according to the process Adjust the sequence of steps.

At present, the integration of capacitor and inductor structures mainly has the following methods:

1. Use on-chip capacitive elements to achieve integration. The capacitors used in this method are mostly planar capacitors in the form of M I M. The M I M capacitor structure is formed by sandwiching the capacitor dielectric layer between two layers of metal electrode plates in the horizontal direction.

2. Use on-chip inductance elements to achieve integration. Most of the inductance used in this method is a planar spiral inductance structure. The redistribution layer with a thickness of less than 10um is used as the inductance metal coil, and the capacitor and inductance are integrated in the existing technology adapter board Together, the distance between the two is relatively short, and there is greater interference between them, and the inductance will have a dielectric loss, which limits the performance of the inductance.

In the integration method of the above-mentioned capacitor and inductor structure, the capacitor is limited by the area cost, the capacitance is limited, the capacitor density is low, and the integrated use of the capacitor and inductor will occupy a large plane area cost.

The present invention provides an adapter board structure and its forming method. A trench capacitance structure array is formed in the substrate, and the capacitor is formed by the conductor on the side wall of the groove-high K value medium-intermediate conductor wall, and the inductance is formed on the back of the adapter board. , using several layers of rewiring layers above to lead out the lower electrode of the capacitor and the inductor to construct a series/parallel capacitor and inductor structure. The capacitor is integrated inside the adapter board, and the inductor is integrated on the surface of the adapter board, which greatly reduces the space occupied by the two devices, and the distance between the inductor and the trench capacitor structure is relatively long, and the isolation is high, reducing the The interference between the two reduces the dielectric loss and improves the Q value of the inductor; compared with the general planar MIM capacitor, the use of the trench capacitor structure increases the capacitance density and can effectively increase the capacitance value.

The structure of the adapter board will be described below in combination with specific embodiments.

FIG. 1A shows a schematic cross-sectional view of an adapter plate structure according to an embodiment of the present invention. FIG. 1B shows a schematic top view of an adapter plate structure according to an embodiment of the present invention.

As shown in FIGS. 1A and 1B , an interposer structure includes two bonded first interposer plates, wherein the first interposer plate includes a substrate 101, a trench capacitor structure, an inductor 105, a conductive member 106, and a first interposer plate. A redistribution layer 107 and a second redistribution layer 108 .

A plurality of interconnected trench capacitor structures are located on the front side of the substrate 101 . The trench capacitor structure comprises a plurality of grooves located on the front of the substrate 101; the capacitor lower electrode 102, which covers the inner wall of the groove; the capacitor medium 103, which is located on the side surface of the capacitor lower electrode 102 away from the inner wall of the groove; the capacitor upper electrode 104, which is located on the surface of the capacitor medium 103 facing away from the capacitor lower electrode 102. The capacitor bottom electrodes 102 of the plurality of trench capacitor structures are electrically connected, so that the plurality of trench capacitor structures are connected in series. A plurality of interconnected trench capacitor structures form a capacitor array.

The inductor 105 is located on the backside of the substrate 101 . The inductor 105 is electrically connected to the trench capacitor structure.

The conductive member 106 is located on the side of the trench capacitor structure and spaced from the trench capacitor structure. The conductive member 106 runs through the substrate 101 . The substrate 101 has a through hole, and the conductive element 106 is located in the through hole. The via hole penetrates through the substrate 101 , is located on a side of the trench capacitor structure and is spaced from the trench capacitor structure.

The first redistribution layer 107 is electrically connected to the conductive element 106 and the trench capacitor structure. The first redistribution layer 107 is electrically connected to the capacitor bottom electrode 102 of the trench capacitor structure. The first redistribution layer 107 is located on the front side of the substrate 101 .

The second redistribution layer 108 is electrically connected to the conductive element 106 and the inductor 105 . The second redistribution layer 108 is located on the backside of the substrate 101 . The second redistribution layer 108 is integrally formed with the inductor 105 .

The above adapter plate structure also includes: a first insulating layer 109 located between the capacitor lower electrode 102 and the inner wall of the groove; a second insulating layer 110 located on the side surface of the capacitor upper electrode 104 away from the capacitor medium 103; located on the inner wall of the through hole The third insulating layer 111 between the conductive member 106 ; the fourth insulating layer 112 located on the back of the substrate 101 . The fourth insulating layer 112 surrounds the second redistribution layer 108 .

The first insulating layer 109 covers the front surface of the substrate 101 and the inner wall of the trench.

The capacitor lower electrode 102 extends to the upper surface of the first insulating layer away from the substrate 101 .

The first redistribution layers 107 of the two first interposer boards are bonded, so that the two first interposer boards are bonded to form an interposer board structure. There is face-to-face bonding between the two first adapter plates.

In the adapter plate structure, the upper and lower inductors are connected in parallel to form a three-dimensional inductor, and the upper and lower capacitor arrays are connected in parallel. In the above adapter board structure, the capacitor structure is integrated inside the adapter board, and the inductor is integrated on the surface of the adapter board, which greatly reduces the space occupied by the two devices, and the distance between the inductor and the trench capacitor structure is relatively long , high isolation, reducing the interference between the two, reducing the dielectric loss, and improving the Q value. Compared with general planar M I M capacitors, the trench capacitor structure is used to increase the capacitance density, which can effectively increase the capacitance value, and can be freely placed near the required circuit, which can effectively optimize the power quality. When the above adapter board structure is in use, chips can be flexibly integrated on the adapter board structure.

2A to 2N are schematic cross-sectional views showing the process of forming the interposer structure according to an embodiment of the present invention.

The first riser board is formed first, and then the two first riser boards are bonded to form the riser board structure.

The process of forming the first adapter plate is as follows:

Step 1.1, as shown in FIG. 2A , a trench 202 is formed on the front surface of the substrate 201 by etching.

Step 1.2, as shown in FIG. 2B , a first insulating layer 203 is formed on the front surface of the substrate 201 and the inner wall of the trench 202 . For example, the first insulating layer 203 is formed by deposition.

In step 1.3, as shown in FIG. 2C , a capacitor bottom electrode 204 is formed on the inner wall of the trench 202 . For example, the bottom electrode of the capacitor is formed by electroplating a metal layer on the inner wall of the trench 202 . The capacitor lower electrode 204 also extends to the upper surface of the first insulating layer on the front of the substrate 201 away from the substrate 201 .

Step 1.4, as shown in FIG. 2D , a capacitor medium 205 is formed on the surface of the capacitor bottom electrode 204 facing away from the inner wall of the trench 202 . For example, the capacitive medium 205 is formed by deposition.

In step 1.5, as shown in FIG. 2E , a capacitor upper electrode 206 is formed on the surface of the capacitor medium 205 facing away from the capacitor lower electrode 204 . For example, the capacitor bottom electrode 206 is formed by electroplating a metal layer on the surface of the capacitor medium 205 facing away from the capacitor bottom electrode 204 . The capacitor lower electrode 204, the capacitor medium 205 and the capacitor lower electrode 206 in each trench 202 form a trench capacitor structure, and the capacitor lower electrodes between each trench capacitor structure are electrically connected, so that between multiple trench capacitor structures in series.

Step 1.6, as shown in FIG. 2F , a second insulating layer 207 is formed on the surface of the capacitor upper electrode 206 facing away from the capacitor medium 205 . For example, the second insulating layer 207 is formed by deposition.

In step 1.7, as shown in FIG. 2G , a through hole 208 is formed on the front surface of the substrate 201 . The vias 208 are located on the side of the trench 202 and spaced apart from the trench 202 . The depth of the via 208 is greater than the depth of the trench 202 .

In step 1.8, as shown in FIG. 2H , a third insulating layer 209 is formed on the inner wall of the via hole 208 .

In step 1.9, as shown in FIG. 2I , a conductive element 210 is formed in the through hole 208 .

In step 1.10, as shown in FIG. 2J , a first redistribution layer 211 connecting the conductive element 210 and the capacitor bottom electrode 204 is formed on the front surface of the substrate 201 .

Step 1.11, as shown in FIG. 2K , thinning the back surface of the substrate 201 to expose the conductive member 210 .

Step 1.12, as shown in FIGS. 2L and 2M , arrange the inductor 212 and the second redistribution layer 213 on the back of the substrate 201 , and finally obtain the first interposer board. Wherein the inductor 212 and the second redistribution layer 213 are integrally formed. The second redistribution layer 213 is electrically connected to the inductor 212 and the conductive element 210 . Firstly, the fourth insulating layer 214 is formed on the back side of the substrate 201, and the fourth insulating layer 214 is etched to form the inductor pattern and the rewiring pattern, and then metal is filled in the inductor pattern and the circuit pattern to form the inductor 212 and the second rewiring layer 213 .

Step 2, as shown in FIG. 2N , is to obtain an adapter plate structure by bonding the front surfaces of two first adapter plates. The first redistribution layers 211 of the two first interposer boards are bonded, so that the two first interposer boards are bonded to form an interposer board structure. The capacitance value and the inductance Q value are further improved by bonding the two first interposer boards.

While certain embodiments of the present invention have been described in this specification, those skilled in the art will appreciate that these embodiments have been presented by way of example only. Those skilled in the art can think of numerous modification schemes, substitution schemes and improvement schemes under the teaching of the present invention without departing from the scope of the present invention. It is intended that the scope of the invention be defined by the appended claims and that methods and structures within the scope of such claims themselves and their equivalents be covered thereby.

Claims (10)

1. An adapter plate structure, characterized in that it comprises two bonded first adapter plates, wherein the first adapter plate comprises: Substrate; A plurality of interconnected trench capacitor structures located on the front side of the substrate, wherein the trench capacitor structures include: a plurality of trenches located on the front side of the substrate; a capacitor bottom electrode covering the trenches The inner wall of the groove; the capacitance medium, which is located on the side surface of the lower electrode of the capacitance away from the inner wall of the groove; the upper electrode of the capacitance, which is located on the surface of the side of the capacitance medium away from the lower electrode of the capacitance; An inductor is located on the backside of the substrate and is electrically connected to the trench capacitor structure. 2. The adapter plate structure according to claim 1, further comprising: a conductive member positioned on a side of the trench capacitor structure and spaced from the trench capacitor structure; a first redistribution layer, which is electrically connected to the conductive member and the trench capacitance structure; The second redistribution layer is electrically connected to the conductive element and the inductor. 3. The interposer structure according to claim 2, wherein the substrate has a through hole, and the conductive member is located in the through hole. 4. The adapter plate structure according to claim 3, further comprising: The first insulating layer is located between the lower electrode of the capacitor and the inner wall of the trench; The second insulating layer is located on the surface of the capacitor upper electrode away from the capacitor medium; The third insulating layer is located between the inner wall of the through hole and the conductive member; A fourth insulating layer is located on the backside of the substrate. 5. The interposer structure according to claim 2, wherein the capacitor lower electrode extends to the upper surface of the first insulating layer away from the substrate; the capacitor lower electrodes of a plurality of the trench capacitor structures electrical connection between The first redistribution layer is electrically connected to the lower electrode of the capacitor. 6. The interposer structure according to claim 5, wherein the first redistribution layers of the two first interposers are bonded so that the two first interposers are bonded to form an interposer. Board structure. 7. A method for forming an adapter plate structure, comprising: first forming a first adapter plate, and then bonding two first adapter plates to form an adapter plate structure, wherein the first adapter plate is formed include: forming trenches on the front side of the substrate; Forming a capacitor lower electrode on the inner wall of the trench; A capacitor medium is formed on the side surface of the capacitor lower electrode away from the inner wall of the trench; Form the upper electrode of the capacitor on the surface of the capacitor medium away from the lower electrode of the capacitor; forming via holes on the front side of the substrate; forming conductive elements in the via holes; forming a first redistribution layer connecting the conductive member and the lower electrode of the capacitor on the front surface of the substrate; Thinning the back of the substrate to expose the conductive parts; The inductor and the second redistribution layer are arranged on the backside of the substrate to finally obtain the first interposer board. 8. The method for forming the adapter plate structure according to claim 7, further comprising: Before forming the capacitor bottom electrode on the inner wall of the trench, a first insulating layer is formed on the front surface of the substrate and the inner wall of the trench; Before forming a through hole on the front side of the substrate, a second insulating layer is formed on the surface of the capacitor upper electrode away from the capacitor medium; Before forming the conductive member in the through hole, a third insulating layer is formed on the inner wall of the through hole. 9 . The method for forming the interposer structure according to claim 7 , wherein the interposer structure is obtained by bonding the first redistribution layers of the two first interposers. 10. The forming method of the interposer structure according to claim 7, characterized in that, at first, a fourth insulating layer is formed on the back side of the substrate, and the fourth insulating layer is etched to form inductance patterns and rewiring patterns, and then Filling metal in the inductor pattern and the redistribution pattern forms the inductor and the second redistribution layer, wherein the inductor and the second redistribution layer are integrally formed.

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