Micro-coaxial transmission structure, preparation method and electronic device

Abstract

The invention discloses a micro-coaxial transmission structure, a preparation method and an electronic device, and the structure comprises a substrate which comprises a central part and a peripheral part surrounding the central part; the first conductor layer is positioned between the central part and the peripheral part, surrounds the central part and wraps the side surface of the central part; a first barrier layer between the first conductor layer and the central portion; the second conductor layer is located between the first conductor layer and the peripheral part and surrounds the first conductor layer; the insulating layer is located between the first conductor layer and the second conductor layer and surrounds the first conductor layer; and a second barrier layer between the second conductor layer and the peripheral portion. According to the micro-coaxial transmission structure, the substrate is divided into the central part, the peripheral part surrounding the central part, the first conductor layer located between the central part and the peripheral part and the side face surrounding the central part and wrapping the central part, the first conductor layer is of an annular structure, a cavity structure influencing signal transmission quality cannot be generated, and stable quality of the transmission structure is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of chip packaging, and in particular to a micro-coaxial transmission structure, a preparation method and an electronic device. Background Art

[0002] With the development of chip technology, packaging technology based on through silicon via (TSV) transmission structure has broad application prospects.

[0003] The existing through silicon via transmission structure uses a central copper pillar for device signal transmission. During preparation, a barrier layer is first deposited on the inner wall of the deep hole of the silicon wafer, and then a conductive medium is electroplated and filled in the central hole surrounded by the barrier layer to form a central copper pillar. Finally, both sides of the silicon wafer are polished flat to obtain the through silicon via transmission structure.

[0004] In this preparation method, when the conductive medium is filled with the electroplating process, the conductive medium grows radially inward based on the barrier layer, which is very easy to be described in the attached manual. Figure 1 As shown in FIG. 1 , the axial end of the central hole is closed to form a cavity, which leads to a decrease in the quality of the through silicon via transmission structure. Summary of the invention

[0005] In view of the above problems, the present application is proposed to provide a micro-coaxial transmission structure, a preparation method and an electronic device that overcome the above problems or at least partially solve the above problems.

[0006] In a first aspect, a micro-coaxial transmission structure is provided, comprising:

[0007] A substrate including a central portion and a peripheral portion surrounding the central portion;

[0008] The first conductor layer is located between the central portion and the peripheral portion, is disposed around the central portion, and wraps around the side of the central portion;

[0009] a first barrier layer, located between the first conductor layer and the central portion;

[0010] A second conductor layer is located between the first conductor layer and the peripheral portion and is disposed around the first conductor layer;

[0011] An insulating layer is located between the first conductor layer and the second conductor layer and is disposed around the first conductor layer;

[0012] The second barrier layer is located between the second conductor layer and the peripheral portion.

[0013] Optionally, the orthographic projection of the first conductor layer on the plane where the substrate surface is located is an annular area.

[0014] Optionally, the orthographic projection of the central portion on the plane where the substrate surface is located is a circular, elliptical or polygonal area.

[0015] Optionally, along the thickness direction of the substrate, the central portion includes a first surface and a second surface arranged opposite to each other, and the peripheral portion includes a third surface and a fourth surface arranged opposite to each other, the first surface and the third surface are located on a first plane, the second surface and the fourth surface are located on a second plane, and the first plane is parallel to the second plane.

[0016] Optionally, along a direction perpendicular to the thickness of the substrate, the cross-sectional shape of the first conductor layer is a circular ring, and the cross-sectional shape of the second conductor layer is a circular ring; the first conductor layer and the second conductor layer satisfy the following mathematical relationship:

[0017]

[0018] Among them, ε r is the relative dielectric constant of the insulating layer, d is the outer diameter of the first conductor layer; D is the inner diameter of the second conductor layer, and Z0 is the preset characteristic impedance.

[0019] Optionally, the micro-coaxial transmission structure further includes:

[0020] a first seed layer, located between the first conductor layer and the first barrier layer;

[0021] The second seed layer is located between the second conductor layer and the second barrier layer.

[0022] Optionally, in a direction toward the center portion, the first conductor layer and the second conductor layer have the same thickness; in a direction toward the center portion, the first barrier layer and the second barrier layer have the same thickness.

[0023] In a second aspect, the present application provides a method for preparing a micro-coaxial transmission structure, which is used to prepare the micro-coaxial transmission structure of the first aspect, and the method comprises:

[0024] An annular hole is formed on the surface of the substrate, wherein the depth of the annular hole is less than the thickness of the substrate along a direction perpendicular to the surface of the substrate;

[0025] forming a barrier material layer on a side wall of the annular hole;

[0026] forming a conductive material layer on a surface of the barrier material layer away from the substrate;

[0027] Filling an insulating layer in the annular hole formed with the conductive material layer to obtain a micro-coaxial structure, wherein the micro-coaxial structure has a first surface and a second surface, and the first surface and the second surface are arranged opposite to each other in a direction perpendicular to the surface of the substrate base material;

[0028] The first surface and the second surface of the micro-coaxial structure are thinned respectively to obtain a micro-coaxial transmission structure.

[0029] Optionally, the conductive material layer includes a seed material layer and a conductor material layer; forming the conductive material layer on a surface of the barrier material layer away from the substrate base material includes:

[0030] forming a seed material layer on a surface of the barrier material layer away from the substrate;

[0031] A conductor material layer is formed on a surface of the seed material layer away from the barrier material layer.

[0032] In a third aspect, the present application provides an electronic device comprising the micro-coaxial transmission structure of the first aspect.

[0033] The technical solution provided by this application has at least the following technical effects or advantages:

[0034] The present application provides a micro-coaxial transmission structure, a preparation method and an electronic device. The micro-coaxial transmission structure divides a substrate into a central portion and a peripheral portion surrounding the central portion. A first conductor layer is located between the central portion and the peripheral portion, and is arranged around the central portion and wraps the side of the central portion. The first conductor layer adopts an annular structure and will not generate a hollow structure that affects the signal transmission quality, thereby ensuring the stable quality of the transmission structure.

[0035] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0037] Figure 1 A schematic diagram of the existing through silicon via processing process;

[0038] Figure 2 For existing through silicon via structure Figure 1 ;

[0039] Figure 3 For existing through silicon via structure Figure 2 ;

[0040] Figure 4 The micro-coaxial transmission structure in the embodiment of the present application Figure 1 ;

[0041] Figure 5 The micro-coaxial transmission structure in the embodiment of the present application Figure 2 ;

[0042] Figure 6 This is an example diagram of a circular micro-coaxial transmission structure in an embodiment of the present application;

[0043] Figure 7 This is an example of a square ring micro-coaxial transmission structure in the embodiment of the present application. Figure 1 ;

[0044] Figure 8 This is an example of a square ring micro-coaxial transmission structure in the embodiment of the present application. Figure 2 ;

[0045] Fig. 9 This is an example of a square ring micro-coaxial transmission structure in the embodiment of the present application. Figure 3 ;

[0046] Fig.10 This is an example of a square ring micro-coaxial transmission structure in the embodiment of the present application. Figure 4 ;

[0047] Fig.11 This is a flow chart for preparing the micro-coaxial transmission structure in the embodiment of the present application;

[0048] Fig.12 The micro-coaxial transmission structure preparation process in the embodiment of the present application Figure 1 ;

[0049] Fig.13 The micro-coaxial transmission structure preparation process in the embodiment of the present application Figure 2 ;

[0050] Fig.14 The micro-coaxial transmission structure preparation process in the embodiment of the present application Figure 3 ;

[0051] Fig.15 The micro-coaxial transmission structure preparation process in the embodiment of the present application Figure 4 ;

[0052] Fig.16 The micro-coaxial transmission structure preparation process in the embodiment of the present application Figure 5 ;

[0053] Fig.17 The micro-coaxial transmission structure preparation process in the embodiment of the present application Figure 6 ;

[0054] Fig.18 The micro-coaxial transmission structure preparation process in the embodiment of the present application Figure 7 ;

[0055] Fig.19 The micro-coaxial transmission structure preparation process in the embodiment of the present application Figure 8 ;

[0056] Fig. 20 The micro-coaxial transmission structure preparation process in the embodiment of the present application Figure 9 ;

[0057] Fig.21 This is the characteristic impedance curve of the micro-coaxial transmission structure with a circular ring structure in the embodiment of the present application;

[0058] Fig. 22 This is the reflection loss curve of the micro-coaxial transmission structure with a circular ring structure in the embodiment of the present application;

[0059] Fig.23 This is the insertion loss curve of the micro-coaxial transmission structure with a circular ring structure in the embodiment of the present application;

[0060] Fig.24 This is the characteristic impedance curve of the square ring structure micro-coaxial transmission structure in the embodiment of the present application;

[0061] Fig.25 This is the reflection loss curve of the micro-coaxial transmission structure with a square ring structure in the embodiment of the present application;

[0062] Fig.26 This is the insertion loss curve of the square ring structure micro-coaxial transmission structure in the embodiment of the present application. DETAILED DESCRIPTION

[0063] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings.

[0064] Various structural schematic diagrams according to embodiments of the present application are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may further design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0065] In the context of the present disclosure, when a layer / element is referred to as being "on" another layer / element, the layer / element may be directly on the other layer / element, or there may be an intervening layer / element therebetween. Additionally, if a layer / element is "on" another layer / element in one orientation, the layer / element may be "below" the other layer / element when the orientation is reversed. In the context of the present disclosure, similar or identical components may be denoted by the same or similar reference numerals.

[0066] In order to better understand the above-mentioned technical scheme, the above-mentioned technical scheme will be described in detail below in combination with specific implementation methods. It should be understood that the embodiments of the present disclosure and the specific features in the embodiments are detailed descriptions of the technical scheme of the present application, rather than limitations on the technical scheme of the present application. In the absence of conflict, the embodiments of the present application and the technical features in the embodiments can be combined with each other.

[0067] With the development of chip technology, packaging technology based on through silicon via (TSV) transmission structure has broad application prospects. At present, the preparation process of through silicon via transmission structure can include: Figure 1 As shown in FIG. 1 , a deep hole is processed on a silicon wafer 101, a barrier layer 102 is deposited on the inner wall of the deep hole, and then a conductive medium is electroplated in the central hole surrounded by the barrier layer 102 to form a conductive column 103. Finally, both sides of the silicon wafer 101 along the thickness direction are ground flat to expose both sides of the conductive column 103, thereby obtaining a structure as shown in FIG. Figure 2 The through silicon via transfer structure shown.

[0068] In this preparation method, when the conductive medium is filled with the electroplating process, the conductive medium grows in the direction toward the central axis of the central hole, and the growth rate at the axial end of the central hole is faster than the growth rate at the axial middle of the central hole, resulting in premature shrinkage and closure of the axial end of the central hole, thereby forming a conductive column 103 as shown in the appendix of the specification. Figure 3 The void 301 shown, the hollow structure of the void 301 and the electroplating solution enclosed in the void 301 will reduce the conductive function of the conductive pillar 103, thereby reducing the quality of the through silicon via transmission structure.

[0069] Based on the above technical problems, the inventive concept of the present application is to divide the substrate into a central portion and a peripheral portion surrounding the central portion, and a first conductor layer located between the central portion and the peripheral portion is arranged around the central portion and wraps the side of the central portion. The first conductor layer of the structure of the present application adopts a ring structure, which will not generate a hollow structure that affects the signal transmission quality, thereby ensuring the stable quality of the transmission structure.

[0070] The following is a detailed description of the technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0071] See also Figure 4 , 5 The present application provides a micro-coaxial transmission structure, including: a substrate 401, a first conductor layer 402, a first barrier layer 403, a second conductor layer 404, an insulating layer 405 and a second barrier layer 406.

[0072] The substrate 401 includes a central portion 4011 and a peripheral portion 4012 surrounding the central portion 4011. The substrate 401 can be a silicon substrate or a glass substrate.

[0073] The first conductor layer 402 is located between the central portion 4011 and the peripheral portion 4012, and is disposed around the central portion 4011, and wraps the side surface of the central portion 4011. The first conductor layer 402 is mainly used for signal transmission.

[0074] The first conductor layer 402 may include: a metal element and its alloys, wherein the metal element includes copper, silver, gold, aluminum, zinc, iron, tin or platinum, and the alloys include copper alloy, silver alloy, gold alloy, aluminum alloy, zinc alloy, iron alloy, tin alloy and platinum alloy.

[0075] The first barrier layer 403 is located between the first conductor layer 402 and the central portion 4011. The first barrier layer 403 located between the first conductor layer 402 and the central portion 4011 is used to prevent metal ions in the first conductor layer 402 from diffusing into the central portion 4011.

[0076] The material of the first barrier layer 403 may include at least one of silicon nitride, titanium nitride and tantalum nitride.

[0077] The second conductor layer 404 is located between the first conductor layer 402 and the peripheral portion 4012, and is disposed around the first conductor layer 402. The second conductor layer 404 located between the first conductor layer 402 and the peripheral portion 4012 is used as a signal shielding layer, which can reduce the dissipation and radiation loss of the first conductor layer 402 when transmitting high-frequency signals, thereby improving the transmission bandwidth of the micro-coaxial transmission structure.

[0078] The material of the second conductor layer 404 may include: metal elements and their alloys. The metal elements include copper, silver, gold, aluminum, zinc, iron, tin or platinum. The alloys include copper alloy, silver alloy, gold alloy, aluminum alloy, zinc alloy, iron alloy, tin alloy and platinum alloy.

[0079] The insulating layer 405 is located between the first conductor layer 402 and the second conductor layer 404, and is disposed around the first conductor layer 402. The insulating layer 405 is used to isolate the first conductor layer 402 from the second conductor layer 404, and the insulating layer 405 may include at least one of silicon oxide, silicon nitride, silicon oxynitride, tantalum oxide, aluminum oxide, polyimide, benzocyclobutene, polybutylene terephthalate, acrylic glue, and epoxy resin.

[0080] The second barrier layer 406 is located between the second conductor layer 404 and the peripheral portion 4012. The second barrier layer 406 located between the second conductor layer 404 and the peripheral portion 4012 is used to block the metal ions in the second conductor layer 404 from diffusing toward the peripheral portion 4012.

[0081] The second barrier layer 406 may include at least one of silicon nitride, titanium nitride, and tantalum nitride.

[0082] In some embodiments, the orthographic projection of the first conductor layer 402 on the plane where the surface of the substrate 401 is located is a ring area. The first conductor layer 402 adopts a ring structure, which does not generate a hollow structure that affects the signal transmission quality, ensuring the stability of the transmission structure quality.

[0083] Exemplarily, the orthographic projection of the first conductor layer 402 on the plane where the surface of the substrate 401 is located is as follows: Figure 6 The circular ring area shown, or the elliptical ring area, or Figure 7 , 8 The square ring area shown in FIG. 1 , wherein the corners of the square ring area can be right angles or can be as shown in FIG. Fig. 9 , 10 The orthographic projection of the first conductor layer 402 on the plane where the surface of the substrate 401 is located can also be other polygonal annular areas.

[0084] It is understandable that in Figures 6 to 10 The first barrier layer 403 and the second barrier layer 406 are omitted, and the orthographic projections of the first barrier layer 403 and the second barrier layer 406 on the plane where the surface of the substrate 401 is located are annular regions, specifically including circular annular regions, elliptical annular regions, square annular regions, etc.

[0085] Under the condition that the cross-sectional shape of the first conductor layer 402 is a circular ring and the cross-sectional shape of the second conductor layer 404 is a circular ring, along the direction perpendicular to the thickness of the substrate, the first conductor layer 402 and the second conductor layer 404 satisfy the following mathematical relationship:

[0086]

[0087] Among them, ε r is the relative dielectric constant of the insulating layer 405, d is the outer diameter of the first conductor layer 402; D is the inner diameter of the second conductor layer 404, and Z0 is the preset characteristic impedance.

[0088] It can be understood that the insulating layer 405 is to ensure the electrical isolation between the first conductor layer 402 and the second conductor layer 404, so that the second conductor layer 404 can properly play the role of signal shielding. The use of a softer insulating medium can alleviate the thermal and mechanical stress between metal and silicon. According to the above formula, the use of a low-loss, low-dielectric-constant insulating medium can reduce dielectric loss and help reduce the size of the micro-coaxial.

[0089] In some embodiments, the orthographic projection of the center portion 4011 on the plane where the surface of the substrate 401 is located is a circular, elliptical or polygonal area. Figure 4 , 6 As shown, the orthographic projection of the center portion 4011 on the plane where the surface of the substrate 401 is located is a circle. Figure 7 , 8 As shown, the orthographic projection of the central portion 4011 on the plane where the surface of the substrate 401 is located is a square.

[0090] In some embodiments, Figure 5 As shown, along the thickness direction of the substrate 401, the central portion 4011 includes a first surface 501 and a second surface 502 that are oppositely arranged, and the peripheral portion 4012 includes a third surface 503 and a fourth surface 504 that are oppositely arranged, the first surface 501 and the third surface 503 are located on a first plane, the second surface 502 and the fourth surface 504 are located on a second plane, and the first plane is parallel to the second plane.

[0091] In some embodiments, Figure 4 , 5 As shown, the micro-coaxial transmission structure further includes: a first seed layer 407 and a second seed layer 408. The first seed layer 407 is located between the first conductor layer 402 and the first barrier layer 403; the second seed layer 408 is located between the second conductor layer 404 and the second barrier layer 406.

[0092] Considering that the first conductor layer 402 and the second conductor layer 404 are usually prepared by electroplating, a deposition method can be used to form the first seed layer 407 on the first barrier layer 403, and a deposition method can be used to form the second seed layer 408 on the second barrier layer 406. The first seed layer 407 and the second seed layer 408 can be made of metal films with a thickness of less than 1 micron.

[0093] It can be understood that the first seed layer 407 and the second seed layer 408 can be prepared at the same time, and thus the thicknesses can be the same.

[0094] Along the direction of the center line toward the center portion 4011, the thickness of the first barrier layer 403 is greater than or equal to 50 nanometers; the thickness of the second barrier layer 406 is greater than or equal to 50 nanometers. For example, along the direction of the center line toward the center portion 4011, the thickness of the first barrier layer 403 can be 50 nanometers, 55 nanometers, 60 nanometers, 80 nanometers, and the thickness of the second barrier layer 406 can be 50 nanometers, 55 nanometers, 60 nanometers, 80 nanometers.

[0095] It is understandable that the first barrier layer 403 and the second barrier layer 406 can be prepared at the same time, and thus can have the same thickness.

[0096] In some embodiments, along the direction toward the center portion 4011 , the first conductor layer 402 and the second conductor layer 404 have the same thickness; and along the direction toward the center portion 4011 , the first barrier layer 403 and the second barrier layer 406 have the same thickness.

[0097] It can be understood that the first conductor layer 402 and the second conductor layer 404 can be prepared at the same time, and thus can have the same thickness.

[0098] Based on the same inventive concept, the embodiment of the present application also provides a method for preparing a micro-coaxial transmission structure. It should be noted that the basic principle and technical effects of the method for preparing a micro-coaxial transmission structure provided in the embodiment of the present application are the same as those in the above embodiment. For the sake of brief description, for matters not mentioned in the embodiment of the present application, reference may be made to the corresponding contents in the above embodiment.

[0099] like Fig.11 As shown, the method for preparing the micro-coaxial transmission structure provided in the embodiment of the present application may include the following steps S1101 to S1104.

[0100] S1101, forming an annular hole on the first surface of the substrate base material, wherein the depth of the annular hole 1201 along a direction perpendicular to the surface of the substrate base material is less than the thickness of the substrate base material.

[0101] Specifically, the substrate substrate may be a silicon substrate substrate, a glass substrate substrate 1200 or a sapphire substrate substrate. An annular hole 1201 is processed on the front surface of the substrate substrate 1200 by etching.

[0102] Please refer to 12, 13, Fig.12Figure (a) shows the substrate 1200, and Figure (b) shows the substrate 1200 with the annular hole 1201 processed therein, and the annular hole 1201 is a blind hole that does not penetrate the substrate 1200. The method for forming the annular hole 1201 may be an etching method: first, a silicon dioxide layer is formed on the first surface of the substrate 1200, and a silicon dioxide layer of a desired thickness may be formed on the first surface of the substrate 1200 by thermal oxidation or chemical deposition; then, a vacant area with a preset pattern is formed on the silicon dioxide layer by a first etching method, and the bottom of the vacant area exposes the substrate 1200; and then, a second etching method is used to form the annular hole 1201 on the substrate 1200 in the vacant area.

[0103] Among them, the first etching method can adopt dry etching, such as reactive ion etching or plasma etching to etch silicon dioxide, thereby forming a new hard MASK covered with silicon dioxide on the substrate base material 1200; the second etching method can adopt a deep hole etching method, such as Bosch BOSCH deep hole variable parameter method for high aspect ratio hole etching, and the etching depth is slightly less than the thickness of the substrate base material 1200.

[0104] After the annular hole 1201 is etched, the excess photoresist and silicon dioxide film layer can be stripped off to expose the surface of the substrate base material 1200 .

[0105] It can be understood that the area at the center of the substrate 1200 surrounded by the inner circle of the annular hole 1201 constitutes Figure 4 The central part 4011 of the substrate 401 of the micro-coaxial transmission structure shown in the figure, the periphery of the substrate base material 1200, and the area surrounding the outer ring of the annular hole 1201 constitute as shown in the figure. Figure 4 The peripheral portion 4012 of the substrate 401 of the micro-coaxial transmission structure is shown.

[0106] It is understandable that the bottom of the annular hole 1201 will be ground off through a thinning operation to separate the central portion 4011 and the peripheral portion 4012 of the substrate 401. The thinning operation will be specifically described in the following operations and will not be repeated here.

[0107] S1102 , forming a barrier material layer 1401 on the side wall of the annular hole 1201 .

[0108] Specifically, using atomic layer deposition technology, such as Fig.14 , 15As shown in the figure, a barrier material layer 1401 thin film is deposited on the side wall of the blind hole and the surface of the substrate 1200. The material of the barrier material layer 1401 thin film can be at least one of silicon nitride, titanium nitride, and tantalum nitride. The thickness of the barrier material layer 1401 is not less than 50 nanometers. Among them, the barrier material layer 1401 covers the part of the side wall of the central part 4011, which serves as the first barrier layer 403 in the aforementioned embodiment. The barrier material layer 1401 covers the part of the inner wall of the peripheral part 4012, which serves as the second barrier layer 406 in the aforementioned embodiment.

[0109] S1103 , forming a conductive material layer on the surface of the barrier material layer 1401 away from the substrate base material 1200 .

[0110] Specifically, Figures 16 to 19 As shown, the conductive material layer includes a seed material layer 1601 and a conductor material layer 1801. Using the atomic layer deposition technology and the adhesion effect of the barrier material layer 1401, as shown in FIG. Fig.16 , 17 As shown in the figure, a metal film is formed on the surface of the barrier material layer 1401 as a seed material layer 1601. The thickness of the seed material layer 1601 can be less than 1 micron. The seed material layer 1601 covers a portion of the surface of the first barrier layer 403, serving as the first seed layer 407 in the aforementioned embodiment. The seed material layer 1601 covers a portion of the surface of the second barrier layer 406, serving as the second seed layer 408 in the aforementioned embodiment.

[0111] Using electroplating technology, such as Fig.18 , 19 As shown in the figure, a conductor material layer 1801 is formed on the surface of the seed material layer 1601, and the conductor material layer 1801 covers a portion of the surface of the first seed layer 407, which serves as the first conductor layer 402 in the aforementioned embodiment. The first conductor layer 402 is mainly used for signal transmission. The first barrier layer 403 is used to block the metal ions in the first conductor layer 402 and the first seed layer 407 from diffusing into the central portion 4011.

[0112] The conductor material layer 1801 covers a portion of the surface of the second seed layer 408, serving as the second conductor layer 404 in the aforementioned embodiment. The second conductor layer 404 is used as a signal shielding layer, which can reduce the dissipation and radiation loss of the first conductor layer 402 when transmitting high-frequency signals, thereby improving the transmission bandwidth of the micro-coaxial transmission structure. The second barrier layer 406 is used to block the metal ions of the second conductor layer 404 and the second seed layer 408 from diffusing to the peripheral portion 4012.

[0113] The conductor material layer 1801 may include: metal elements and their alloys, the metal elements include copper, silver, gold, aluminum, zinc, iron, tin or platinum, and the alloys include copper alloys, silver alloys, gold alloys, aluminum alloys, zinc alloys, iron alloys, tin alloys, and platinum alloys.

[0114] S1104 , filling the annular hole 1201 formed with the conductive material layer with an insulating layer 405 to obtain a micro-coaxial structure.

[0115] like Fig. 20 As shown, the micro-coaxial structure has a first surface 2001 and a second surface 2002 , and the first surface 2001 and the second surface 2002 are arranged opposite to each other in a direction perpendicular to the surface of the substrate base material 1200 .

[0116] The insulating layer 405 fills the gap between the first conductive layer 402 and the second conductive layer 404. The insulating layer 405 may include at least one of silicon oxide, silicon nitride, silicon oxynitride, tantalum oxide, aluminum oxide, polyimide, benzocyclobutene, polybutylene terephthalate, acrylic glue, and epoxy resin.

[0117] Optionally, an inkjet printer is used to print acrylic glue or epoxy resin into the gap between the first conductor layer 402 and the second conductor layer 404 as a filling and insulating medium, which also plays a certain stress buffering role. Alternatively, a deposition or spin coating process is used to form an insulating layer 405 on the surface of the conductive material layer located in the annular hole 1201.

[0118] Under the condition that the cross-sectional shape of the first conductor layer 402 is a circular ring and the cross-sectional shape of the second conductor layer 404 is a circular ring, along the direction perpendicular to the thickness of the substrate 1200, the first conductor layer 402 and the second conductor layer 404 satisfy the following equation relationship:

[0119]

[0120] Among them, ε r is the relative dielectric constant of the insulating layer 405, d is the outer diameter of the first conductor layer 402; D is the inner diameter of the second conductor layer 404, and Z0 is the preset characteristic impedance.

[0121] It can be understood that the insulating layer 405 is to ensure the electrical isolation between the first conductor layer 402 and the second conductor layer 404, so that the second conductor layer 404 can properly play the role of signal shielding. The use of a softer insulating medium can alleviate the thermal and mechanical stress between metal and silicon. According to the above formula, the use of a low-loss, low-dielectric-constant insulating medium can reduce dielectric loss and help reduce the size of the micro-coaxial.

[0122] It can be understood that the insulating layer 405 is disposed between the first conductor layer 402 and the second conductor layer 404, and is filled after the first conductor layer 402 and the second conductor layer 404 are prepared, and there is no subsequent lithography, etching and other steps after filling, and the dielectric material used for filling has more selectivity; the insulating layer 405 mainly has two functions, the first is to play an insulating role, as the insulating medium of the first conductor layer 402 and the second conductor layer 404, to achieve electrical isolation between the first conductor layer 402 and the second conductor layer 404. The second is to play a role in thermal and mechanical stress buffering. Compared with silicon and metal, the softer insulating layer 405 can be used as a buffer layer between metals to relieve thermal, compressive and tensile stresses during the process and reduce the risk of wafer splitting. At the same time, the insulating layer 405 can select materials with low dielectric constant and low loss tangent to increase signal transmission speed, reduce structural size and reduce loss.

[0123] S1105, thinning the first surface and the second surface of the substrate base material 1200 until the insulating layer is exposed. The second surface is the opposite surface of the first surface along the thickness direction.

[0124] Chemical mechanical polishing is used to grind the front side, i.e., the first surface, of the substrate 1200 flat, and the back side, i.e., the second surface, of the substrate 1200 is thinned to expose the insulating layer 405, while disconnecting the first conductor layer 402 and the second conductor layer 404. The insulating layer 405 isolates the first conductor layer 402 from the second conductor layer 404. Figure 4 , 5 The micro-coaxial transmission structure shown is completed.

[0125] In the method for preparing the micro-coaxial transmission structure provided in the embodiment of the present application, the first conductor layer 402 for device signal transmission only needs to grow to a set thickness along the first barrier layer 403. Compared with the existing through-silicon via preparation process, it eliminates the need to electroplating a conductive medium in the center hole to form a central copper column, thereby avoiding the formation of voids and ensuring the quality stability of the transmission structure. Secondly, the insulating layer 405 is processed after the conductor material layer 1801 is prepared. Since there are no subsequent lithography, etching and other steps, the dielectric material of the filling layer has more selectivity.

[0126] In some feasible implementations, the annular hole 1201 processed in S1101 is as follows: Fig.13 The circular shape shown, corresponding to the barrier material layer 1401, the seed material layer 1601, the conductor material layer 1801, and the insulating layer 405, has an orthographic projection on the plane where the surface of the substrate base material 1200 is located as an annular area.

[0127] For example, the annular region may be formed as follows: Figure 4The characteristic impedance, reflection loss and insertion loss of the prepared micro-coaxial transmission structure are tested in the circular ring area as shown in FIG. Figures 21 to 23 The results, among which, Fig.21 From the curve of the characteristic impedance of the micro-coaxial transmission structure varying with frequency, it can be seen that the characteristic impedance of the micro-coaxial transmission structure is maintained at 50 ohms and changes very little, which proves that the micro-coaxial transmission structure is very stable in the frequency range of 1 to 100 GHz.

[0128] Fig. 22 The curve of reflection loss of the micro-coaxial transmission structure changing with frequency shows that the reflection loss of the micro-coaxial transmission structure is very small. Fig.23 From the curve of the insertion loss of the micro-coaxial transmission structure varying with frequency, it can be seen that the insertion loss of the micro-coaxial transmission structure is close to 0, which further proves that the performance of the micro-coaxial transmission structure is stable in the frequency range of 1 to 100 GHz.

[0129] For example, the annular region may be formed as follows: Fig. 9 , 10 The characteristic impedance, reflection loss and insertion loss of the prepared micro-coaxial transmission structure are tested in the circular ring area as shown in FIG. Figures 24-26 The results, among which, Fig.24 From the curve of the characteristic impedance of the micro-coaxial transmission structure varying with frequency, it can be seen that the characteristic impedance of the micro-coaxial transmission structure is maintained at 50 ohms and changes very little, which proves that the micro-coaxial transmission structure is very stable in the frequency range of 1 to 100 GHz.

[0130] Fig.25 The curve of reflection loss of the micro-coaxial transmission structure changing with frequency shows that the reflection loss of the micro-coaxial transmission structure is very small. Fig.26 From the curve of the insertion loss of the micro-coaxial transmission structure varying with frequency, it can be seen that the insertion loss of the micro-coaxial transmission structure is close to 0, which further proves that the performance of the micro-coaxial transmission structure is stable in the frequency range of 1 to 100 GHz.

[0131] In the micro-coaxial transmission structure prepared by the method provided in the above embodiment, the orthographic projection of the first conductor layer 402 on the plane where the surface of the substrate 1200 is located is a ring area. The first conductor layer 402 adopts a ring structure, and does not generate a hollow structure that affects the signal transmission quality, thereby ensuring that the quality of the transmission structure is stable and has good signal transmission performance.

[0132] Based on the same inventive concept, the embodiment of the present application also provides an electronic device, including the micro-coaxial transmission structure of the above embodiment. The electronic device applies the micro-coaxial transmission structure of the above embodiment, and divides the substrate base material 1200 into a central part 4011 and a peripheral part 4012 surrounding the central part 4011 through the annular hole 1201. The first conductor layer 402 located between the central part 4011 and the peripheral part 4012 is arranged around the central part 4011 and wraps the side of the central part 4011. The first conductor layer 402 of the structure of the present application adopts an annular structure, which will not generate a hollow structure that affects the signal transmission quality, thereby ensuring the stable quality of the transmission structure.

[0133] Illustratively, the electronic device can be used for high-density interconnection of high-frequency and high-speed chips (artificial intelligence AI chips, data centers, cloud computing chips), or for various miniaturized, high-performance, highly integrated, reconfigurable microwave and millimeter-wave devices and subsystems, such as filters, resonators, couplers, and antennas, etc., which can be applied to navigation, communication, radar, and many other fields.

[0134] Since the electronic device introduced in this embodiment is an electronic device using the micro-coaxial transmission structure in the embodiment of the present invention, based on the micro-coaxial transmission structure introduced in the embodiment of the present application, the technicians in this field can understand the specific implementation of the electronic device in this embodiment and its various variations, so how the electronic device uses the micro-coaxial transmission structure in the embodiment of the present application is not described in detail here. As long as the technicians in this field implement the electronic device with the micro-coaxial transmission structure in the embodiment of the present application, it belongs to the scope of protection of this application.

[0135] An embodiment of the present application also provides an electronic device, comprising the electronic device of the above embodiment.

[0136] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

[0137] In the description provided herein, a large number of specific details are described. However, it is understood that the embodiments of the present application can be practiced without these specific details. In some instances, well-known methods, structures and techniques are not shown in detail so as not to obscure the understanding of this description.

Claims

1. A micro-coaxial transmission structure, characterized in that: include: A substrate including a central portion and a peripheral portion disposed around the central portion; A first conductor layer is located between the central portion and the peripheral portion, is disposed around the central portion, and wraps around the side surface of the central portion; a first barrier layer, located between the first conductor layer and the central portion; A second conductor layer is located between the first conductor layer and the peripheral portion and is disposed around the first conductor layer; an insulating layer, located between the first conductor layer and the second conductor layer, and arranged around the first conductor layer; The second barrier layer is located between the second conductor layer and the peripheral portion.

2. The micro-coaxial transmission structure according to claim 1, characterized in that: The orthographic projection of the first conductor layer on the plane where the substrate surface is located is an annular area.

3. The micro-coaxial transmission structure according to claim 1, characterized in that: The orthographic projection of the central portion on the plane where the substrate surface is located is a circular, elliptical or polygonal area.

4. The micro-coaxial transmission structure according to claim 1, characterized in that: Along the thickness direction of the substrate, the central portion includes a first surface and a second surface arranged opposite to each other, and the peripheral portion includes a third surface and a fourth surface arranged opposite to each other, the first surface and the third surface are located on a first plane, the second surface and the fourth surface are located on a second plane, and the first plane is parallel to the second plane.

5. The micro-coaxial transmission structure according to claim 1, characterized in that: Along a direction perpendicular to the thickness of the substrate, the cross-sectional shape of the first conductor layer is a circular ring, and the cross-sectional shape of the second conductor layer is a circular ring; the first conductor layer and the second conductor layer satisfy the following mathematical relationship: Among them, ε r is the relative dielectric constant of the insulating layer, d is the outer diameter of the first conductor layer; D is the inner diameter of the second conductor layer, and Z0 is the preset characteristic impedance.

6. The micro-coaxial transmission structure according to claim 1, characterized in that: Also includes: a first seed layer, located between the first conductor layer and the first barrier layer; The second seed layer is located between the second conductor layer and the second barrier layer.

7. The micro-coaxial transmission structure according to claim 1, characterized in that: In a direction toward the central portion, the first conductor layer and the second conductor layer have the same thickness; in a direction toward the central portion, the first barrier layer and the second barrier layer have the same thickness.

8. A method for preparing a micro-coaxial transmission structure, characterized in that: The micro-coaxial transmission structure according to any one of claims 1 to 7 is prepared by application, the method comprising: An annular hole is formed on the surface of the substrate, wherein the depth of the annular hole is less than the thickness of the substrate along a direction perpendicular to the surface of the substrate; forming a barrier material layer on the sidewall of the annular hole; forming a conductive material layer on a surface of the barrier material layer away from the substrate; Filling an insulating layer in the annular hole formed with the conductive material layer to obtain a micro-coaxial structure, wherein the micro-coaxial structure has a first surface and a second surface, and the first surface and the second surface are arranged opposite to each other in a direction perpendicular to the surface of the substrate base material; The first surface and the second surface of the micro-coaxial structure are thinned respectively to obtain the micro-coaxial transmission structure.

9. The method for preparing a micro-coaxial transmission structure according to claim 8, characterized in that: The conductive material layer comprises a seed material layer and a conductor material layer; and forming the conductive material layer on the surface of the barrier material layer away from the substrate base material comprises: forming the seed material layer on the surface of the barrier material layer away from the substrate base material; The conductor material layer is formed on a surface of the seed material layer away from the barrier material layer.

10. An electronic device, characterized in that: The micro-coaxial transmission structure comprises the micro-coaxial transmission structure described in any one of claims 1 to 7.

Images