Semiconductor device and manufacturing method thereof

Abstract

The embodiment of the invention discloses a semiconductor device and a manufacturing method thereof. The semiconductor device comprises a first bonding structure, a second bonding structure, a filling layer and a connecting layer, the first bonding structure is arranged on the surface of the first wafer and comprises a first bonding part and a second bonding part, and the sectional dimension of the first bonding part is smaller than that of the second bonding part; the second bonding structure is arranged on the surface, facing the first wafer, of the second wafer, the surface, deviating from the second wafer, of the second bonding structure is provided with a first groove, the section size of the first groove is larger than that of the second bonding part, and the second bonding part is embedded into the first groove; the filling layer is arranged between the second bonding structure and the first wafer; the connecting layer comprises a first connecting part and a second connecting part, the first connecting part is arranged between the first groove and the second bonding part, and the second connecting part is arranged between the filling layer and the second bonding part.

Description

Technical Field

[0001] The embodiments of the present disclosure relate to the field of semiconductor technology, and more particularly to a semiconductor device and a method for manufacturing the same. Background Art

[0002] Traditional metal bonding solutions have bonding strength limitations in micro-electro-mechanical system (MEMS) wafer-level vacuum packaging. Specifically, the metal bumps of the upper and lower wafers are pressed together at high temperature to form a stable intermetallic compound (IMC). Due to the inherent brittleness of IMC, the bonding strength of the upper and lower wafers is limited.

[0003] Therefore, how to enhance the metal bonding strength becomes a technical problem that needs to be solved urgently. Summary of the invention

[0004] The present disclosure provides a semiconductor device and a method for manufacturing the same.

[0005] The first aspect of the present disclosure provides a semiconductor device. The semiconductor device includes: a first bonding structure, a second bonding structure, a filling layer and a connecting layer; the first bonding structure is arranged on the surface of the first wafer and includes a first bonding portion and a second bonding portion, wherein the cross-sectional size of the first bonding portion is smaller than the cross-sectional size of the second bonding portion; the second bonding structure is arranged on the surface of the second wafer facing the first wafer, wherein the surface of the second bonding structure facing away from the second wafer has a first groove, the cross-sectional size of the first groove is larger than the cross-sectional size of the second bonding portion, and the second bonding portion is embedded in the first groove; the filling layer is arranged between the second bonding structure and the first wafer; the connecting layer includes a first connecting portion and a second connecting portion, wherein the first connecting portion is arranged between the first groove and the second bonding portion, and the second connecting portion is arranged between the filling layer and the second bonding portion.

[0006] In some embodiments, the connection layer further includes a third connection portion, and the third connection portion is disposed between the filling layer and the first bonding portion.

[0007] In some embodiments, the surface of the second bonding portion facing away from the first bonding portion has at least one second groove; the second bonding structure includes at least one third bonding portion, and the third bonding portion is arranged in the first groove, wherein the height of the third bonding portion is smaller than the height of the first groove, and the third bonding portion and the second groove are embedded.

[0008] In some embodiments, the width of the filling layer is greater than the distance between the outer wall of the second bonding structure and the first groove, and less than or equal to the distance between the outer wall of the second bonding structure and the first bonding portion; the height of the filling layer is less than or equal to the distance between the second bonding structure and the first wafer.

[0009] In some embodiments, a width of the filling layer is greater than a distance between an outer sidewall of the second bonding structure and the first groove, and less than twice a distance between an outer sidewall of the second bonding structure and the first groove.

[0010] In some embodiments, the thermal expansion coefficient of the filling layer is greater than 15×10 -6 / ℃.

[0011] In some embodiments, the material of the filling layer includes a metamaterial.

[0012] The second aspect of the present disclosure provides a method for manufacturing a semiconductor device. The manufacturing method includes: forming a first bonding structure on the surface of a first wafer, the first bonding structure including a first bonding portion and a second bonding portion, wherein the cross-sectional size of the first bonding portion is smaller than the cross-sectional size of the second bonding portion; forming a second bonding structure on the surface of a second wafer, the second bonding structure having a first groove on the surface facing away from the second wafer, wherein the cross-sectional size of the first groove is larger than the cross-sectional size of the second bonding portion; forming a connection layer covering the first groove; forming an initial filling layer on the second bonding structure and the connection layer; bonding the first wafer and the second wafer based on the first bonding structure, the second bonding structure, the connection layer and the initial filling layer, so that the second bonding portion is embedded in the first groove and the initial filling layer expands into a filling layer, wherein the connection layer extends between the filling layer and the second bonding portion.

[0013] In some embodiments, during the bonding process between the first wafer and the second wafer, the connection layer further extends to between the filling layer and the first bonding portion.

[0014] In some embodiments, the first bonding structure is formed on the surface of the first wafer, including: forming an initial second bonding portion on the surface of the first bonding portion away from the first wafer; etching the initial second bonding portion to form at least one second groove on the surface of the initial second bonding portion away from the first bonding portion, wherein the retained initial second bonding portion constitutes the second bonding portion; the second bonding structure is formed on the surface of the second wafer, including: forming at least one third bonding portion in the first groove, the height of the third bonding portion being less than the height of the first groove, wherein the third bonding portion and the second groove are interlocked.

[0015] In some embodiments, the width of the filling layer is greater than the distance between the outer wall of the second bonding structure and the first groove, and less than or equal to the distance between the outer wall of the second bonding structure and the first bonding portion; the height of the filling layer is less than or equal to the distance between the second bonding structure and the first wafer.

[0016] In some embodiments, a width of the filling layer is greater than a distance between an outer sidewall of the second bonding structure and the first groove, and less than twice a distance between an outer sidewall of the second bonding structure and the first groove.

[0017] In some embodiments, the thermal expansion coefficient of the filling layer is greater than 15×10 -6 / ℃.

[0018] In some embodiments, the material of the filling layer includes a metamaterial.

[0019] In the embodiment of the present disclosure, by setting the first bonding structure to include the first bonding part and the second bonding part, the cross-sectional size of the first bonding part is smaller than the cross-sectional size of the second bonding part, a gap can be formed between the second bonding part and the first bonding part, the filling layer is filled in the gap, and the connecting layer is not only arranged between the first groove and the second bonding part, but also extends to between the filling layer and the second bonding part. In this way, the present disclosure provides a new design of the bonding structure, which can increase the contact area between the first bonding structure and the second bonding structure, thereby enhancing the bonding strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the multiple drawings represent the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in the present application and should not be regarded as limiting the scope of the present application.

[0021] Figure 1A is a schematic diagram of bonding a first wafer and a second wafer to each other provided by an embodiment of the present disclosure; Figure 1B is a schematic diagram of a first bonding structure on a surface of a first wafer provided by an embodiment of the present disclosure; Figure 1C is a schematic diagram of a second bonding structure on a second wafer surface provided by an embodiment of the present disclosure; Figure 2A is a schematic diagram of a first wafer and a second wafer bonded to each other provided by another embodiment of the present disclosure; Figure 2B is a schematic diagram of a first bonding structure on a surface of a first wafer provided by another embodiment of the present disclosure; Figure 2Cis a schematic diagram of a second bonding structure on a second wafer surface provided by another embodiment of the present disclosure; Figure 3A is a schematic diagram of a first filling layer after expansion provided by an embodiment of the present disclosure; Figure 3B is a schematic diagram of a second filling layer after expansion provided by an embodiment of the present disclosure; Figure 3C is a schematic diagram of the dimensions of the first filling layer after expansion provided by an embodiment of the present disclosure; Figure 4 is a flow chart of a method for manufacturing a semiconductor device provided by an embodiment of the present disclosure; Figure 5A is a schematic diagram of a first wafer provided by an embodiment of the present disclosure; Figure 5B is a schematic diagram of forming a first bonding portion provided by an embodiment of the present disclosure; Figure 5C is a schematic diagram of forming an initial first sacrificial layer provided by an embodiment of the present disclosure; Figure 5D is a schematic diagram of forming a first sacrificial layer provided by an embodiment of the present disclosure; Figure 5E is a schematic diagram of forming an initial second bonding portion provided by an embodiment of the present disclosure; Fig. 5F is a schematic diagram of removing a first sacrificial layer provided by an embodiment of the present disclosure; Figure 5G is a schematic diagram of forming a second bonding portion provided by an embodiment of the present disclosure; Fig. 6A is a schematic diagram of forming a second sacrificial layer provided by another embodiment of the present disclosure; Figure 6B is a schematic diagram of forming an opening provided by another embodiment of the present disclosure; Figure 6C is a schematic diagram of forming a plurality of second grooves provided by another embodiment of the present disclosure; Fig.6D is a schematic diagram of forming a second bonding portion provided by another embodiment of the present disclosure; Fig. 7A is a schematic diagram of a second wafer provided by an embodiment of the present disclosure; Figure 7B is a schematic diagram of forming an initial second bonding structure provided by an embodiment of the present disclosure; Figure 7C is a schematic diagram of forming a second bonding structure provided by an embodiment of the present disclosure; Figure 8is a schematic diagram of forming a first connecting portion provided by an embodiment of the present disclosure; Fig. 9 It is a schematic diagram of forming an initial filling layer provided by an embodiment of the present disclosure. DETAILED DESCRIPTION

[0022] In order to facilitate the understanding of the present disclosure, the exemplary embodiments of the present disclosure will be described in more detail below with reference to the relevant drawings. Although the exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the specific embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0023] In the following description, a large number of specific details are given to provide a more thorough understanding of the present disclosure. However, it is obvious to those skilled in the art that the present disclosure can be implemented without one or more of these details. In some embodiments, in order to avoid confusion with the present disclosure, some technical features known in the art are not described; that is, all features of the actual embodiment may not be described here, and well-known functions and structures may not be described in detail.

[0024] The present disclosure will be described in more detail below by way of example with reference to the accompanying drawings. The advantages and features of the present disclosure will become clearer according to the following description. It should be noted that the accompanying drawings are in a very simplified form and are not in exact proportions, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present disclosure.

[0025] It will be understood that the meaning of “on,” “over,” and “over” of the present disclosure should be interpreted in the broadest manner, such that “on” not only means that it is “on” something with no intervening features or layers (i.e., directly on something), but also includes the meaning that it is “on” something with intervening features or layers.

[0026] In the embodiments of the present disclosure, the terms "first", "second", "third", etc. are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0027] In the disclosed embodiments, the term "layer" refers to a material portion including an area having a thickness. A layer may extend over the entirety of a lower or upper structure, or may have an extent less than the extent of a lower or upper structure. In addition, a layer may be an area of ​​a homogeneous or inhomogeneous continuous structure having a thickness less than the thickness of a continuous structure. For example, a layer may be located between the top and bottom surfaces of a continuous structure, or a layer may be between any horizontal faces at the top and bottom surfaces of a continuous structure. A layer may extend horizontally, vertically, and / or along an inclined surface. A layer may include multiple sublayers.

[0028] It should be noted that the technical solutions described in the embodiments of the present disclosure can be arbitrarily combined without conflict.

[0029] Figures 1A to 1C is a schematic diagram of a semiconductor device provided by an embodiment of the present disclosure, wherein: Figure 1A is a schematic diagram of bonding the first wafer and the second wafer to each other, Figure 1B is a schematic diagram of a first bonding structure on the surface of a first wafer, Figure 1C is a schematic diagram of a second bonding structure on the surface of a second wafer. Figures 1A to 1C As shown, the semiconductor device 300 includes: a first bonding structure 120 , a second bonding structure 220 , a filling layer 240 and a connecting layer 230 .

[0030] Reference Figure 1A and Figure 1B As shown, the first bonding structure 120 is arranged on the surface of the first wafer 110, and the first bonding structure 120 includes a first bonding portion 121 and a second bonding portion 122, wherein the cross-sectional dimension of the first bonding portion 121 is smaller than the cross-sectional dimension of the second bonding portion 122. Here, the first bonding structure 120 is arranged on the surface of the first wafer 110 facing the second wafer 210, and the first bonding portion 121 is arranged between the first wafer 110 and the second bonding portion 122, and the cross-sectional dimension of the first bonding portion 121 and the cross-sectional dimension of the second bonding portion 122 are equal to or greater than the cross-sectional dimension of the first bonding portion 121. Figure 1B In the figure, they are represented as W1 and W2, that is, W1<W2. The materials of the first bonding part 121 and the second bonding part 122 both include conductive materials, for example, at least one of metal materials such as copper, silver, gold, aluminum, and tin.

[0031] Reference Figure 1A and Figure 1C As shown, the second bonding structure 220 is disposed on the surface of the second wafer 210 facing the first wafer 110, wherein the surface of the second bonding structure 220 facing away from the second wafer 210 has a first groove 220T, the cross-sectional dimension of the first groove 220T is larger than the cross-sectional dimension of the second bonding portion 122, and the second bonding portion 122 is embedded in the first groove 220T. Here, the cross-sectional dimension of the first groove 220T is Figure 1C The second bonding portion 122 is preferably W3, that is, W3>W2, which can ensure that the second bonding portion 122 is smoothly embedded in the first groove 220T. The material of the second bonding structure 220 includes a conductive material, for example, at least one of metal materials such as copper, silver, gold, aluminum and tin.

[0032] Reference Figure 1A As shown, the filling layer 240 is disposed between the second bonding structure 220 and the first wafer 110. Figure 1BAs shown, since W1<W2, the second bonding portion 122 protrudes horizontally compared to the first bonding portion 121, so that a gap is formed between the horizontally protruding portion of the second bonding portion 122 and the first wafer 110. Figure 1B The structure shown and Figure 1C During the bonding process of the structure shown in FIG. 1 , the filling layer 240 may be embedded in the gap, that is, the filling layer 240 is disposed between the second bonding structure 220 and the first wafer 110. Here, the cross-sectional size of the filling layer 240 is less than or equal to the cross-sectional size of the gap. Figure 3C Detailed introduction is given in , so I will not repeat it here.

[0033] It should be noted that in the embodiment of the present disclosure, the filling layer 240 may be made of a material with a high thermal expansion coefficient. For example, the thermal expansion coefficient of the filling layer 240 is greater than 15×10 -6 / ℃. Specifically, Figure 1C An initial filling layer 240S is formed on the second bonding structure 220 and the first connecting portion 231. During the bonding process, the initial filling layer 240S undergoes thermal expansion, thereby forming a Figure 1A Here, the cross-sectional dimension of the initial filling layer 240S is smaller than the cross-sectional dimension of the filling layer 240 .

[0034] In one example, the material of the filling layer 240 includes a metamaterial. Since the metamaterial has a combination of excellent isotropic / anisotropic thermal expansion coefficients, large thermal deformation with linear behavior, high filling rate, and relatively fast thermal response, the filling layer 240 can better fill the above gap, thereby enhancing the bonding strength. Of course, in other examples, the material of the filling layer 240 also includes an alloy with a high thermal expansion coefficient, for example, at least one of Cu60Zn40, FeNi22Cr3, FeNi20Mn6, FeNi13Mn7, and Mn72Cr18Ni10.

[0035] Reference Figure 1A and Figure 1C As shown, the connection layer 230 includes a first connection portion 231 and a second connection portion 232, wherein the first connection portion 231 is disposed between the first groove 220T and the second bonding portion 122, and the second connection portion 232 is disposed between the filling layer 240 and the second bonding portion 122. It should be noted that, Figure 1C Only the first connection portion 231 is shown. Figure 1B The structure shown and Figure 1CDuring the bonding process of the structure shown, due to the thermal expansion of the initial filling layer 240S, a gap may be formed between the expanded initial filling layer 240S and the second bonding portion 122, and the first connecting portion 231 extends into the gap between the expanded initial filling layer 240S and the second bonding portion 122, that is, the first connecting portion 231 extends between the filling layer 240 and the second bonding portion 122, thereby forming the second connecting portion 232 between the filling layer 240 and the second bonding portion 122, thereby increasing the contact area between the first bonding structure 120 and the second bonding structure 220.

[0036] In the embodiment of the present disclosure, the first bonding structure 120 includes a first bonding portion 121 and a second bonding portion 122, and the cross-sectional size of the first bonding portion 121 is smaller than the cross-sectional size of the second bonding portion 122, so that a gap can be formed between the second bonding portion 122 and the first bonding portion 121, and the filling layer 240 is filled in the gap, and the connecting layer 230 is not only provided between the first groove 220T and the second bonding portion 122, but also extends between the filling layer 240 and the second bonding portion 122. In this way, the present disclosure provides a new design of a bonding structure, which can increase the contact area between the first bonding structure 120 and the second bonding structure 220, thereby enhancing the bonding strength.

[0037] In some embodiments, the connection layer 230 further includes a third connection portion 233, which is disposed between the filling layer 240 and the first bonding portion 121. It should be noted that, when the initial filling layer 240S expands to a low degree, the first connection portion 231 may only extend to the gap between the filling layer 240 and the second bonding portion 122; and when the initial filling layer 240S expands to a high degree (i.e., the initial filling layer 240S is closer to the first bonding portion 121), a gap may also be formed between the expanded initial filling layer 240S and the first bonding portion 121, and the first connection portion 231 extends to the gap between the expanded initial filling layer 240S and the first bonding portion 121, i.e., the first connection portion 231 extends between the filling layer 240 and the first bonding portion 121, thereby forming the third connection portion 233 between the filling layer 240 and the first bonding portion 121, further increasing the contact area between the first bonding structure 120 and the second bonding structure 220, which is conducive to further enhancing the bonding strength.

[0038] In some embodiments, the material of the connection layer 230 includes an intermetallic compound, for example, at least one of Cu—Au, Cu—Sn, Cu—Ni, and Cu—Fe.

[0039] FIG. 2A to FIG. 2C is a schematic diagram of another semiconductor device provided by an embodiment of the present disclosure, wherein: Figure 2A is a schematic diagram of bonding the first wafer and the second wafer to each other, Figure 2Bis a schematic diagram of a first bonding structure on the surface of a first wafer, Figure 2C is a schematic diagram of the second bonding structure on the surface of the second wafer. It should be noted that: FIG. 2A to FIG. 2C The same reference numerals are used for the same structures in the embodiment shown and in the above embodiment, and the same structures can refer to the relevant descriptions of the above embodiment and will not be described in detail. Only the different structures are described in detail in this embodiment.

[0040] Reference Figure 2A and Figure 2B As shown, the surface of the second bonding portion 122 facing away from the first bonding portion 121 has at least one second groove 122T, and the depth of the second groove 122T is less than the height of the second bonding portion 122. Figure 2B As shown, the surface of the second bonding portion 122 facing away from the first bonding portion 121 has a plurality of protrusions 122P and a plurality of second grooves 122T, and the plurality of protrusions 122P and the plurality of second grooves 122T are arranged alternately, so that the second bonding portion 122 is in a "comb-tooth shape". Of course, the number of protrusions 122P and second grooves 122T is not limited to Figure 2B As shown, other quantities are also possible.

[0041] Reference Figure 2A and Figure 2C As shown, the second bonding structure 220 includes at least one third bonding portion 221P, and the third bonding portion 221P is disposed in the first groove 220T, wherein the height of the third bonding portion 221P is less than the height of the first groove 220T. Figure 2C As shown, a plurality of third bonding portions 221P and a plurality of third grooves 221T are provided on the bottom surface of the first groove 220T, and the plurality of third bonding portions 221P and the plurality of third grooves 221T are arranged alternately, so that the second bonding structure 220 also presents a "comb-shaped" shape. Of course, the number of the third bonding portions 221P and the third grooves 221T is not limited to Figure 2C Here, the depth of the third groove 221T is less than the depth of the first groove 220T.

[0042] In some embodiments, the number of protrusions 122P is the same as the number of third grooves 221T, and the number of third keying portions 221P is the same as the number of second grooves 122T. Figure 2B The structure shown and Figure 2CAfter the structure shown is bonded, a protrusion 122P is engaged with a corresponding third groove 221T, and a third bonding portion 221P is engaged with a corresponding second groove 122T, so that the "comb-shaped" second bonding structure 220 and the first bonding structure 120 are engaged with each other. It should be noted that the "comb-shaped" bonding structure design can increase the contact area between the two bonding structures, thereby further enhancing the bonding strength.

[0043] FIG. 3A to FIG. 3C is a schematic diagram of two expanded filling layers provided by an embodiment of the present disclosure, wherein: Figure 3A This is a schematic diagram of the first filling layer after expansion. Figure 3B is a schematic diagram of the second filling layer after expansion. Figure 3C is a schematic diagram of the dimensions of the first filling layer after expansion. It should be noted that FIG. 3A to FIG. 3C The same reference numerals are used for the same structures in the embodiment shown and in the above embodiment, and the same structures can refer to the relevant descriptions of the above embodiment and will not be described in detail. Only the different structures are described in detail in this embodiment.

[0044] Reference Figure 3A As shown, the connection layer includes a first connection portion 231 and a second connection portion 232. The first connection portion 231 is disposed between the second bonding structure 220 and the second bonding portion 122, and the second connection portion 232 is disposed between the filling layer 240 and the second bonding portion 122. It can be understood that Figure 3A The expansion degree of the first filling layer 240 is relatively low, so the first connecting portion 231 only extends into the gap between the filling layer 240 and the second bonding portion 122, that is, forming Figure 3A The second connecting portion 232 is shown.

[0045] Reference Figure 3B As shown, the connection layer includes a first connection portion 231, a second connection portion 232 and a third connection portion 233. The first connection portion 231 is disposed between the second bonding structure 220 and the second bonding portion 122, the second connection portion 232 is disposed between the filling layer 240 and the second bonding portion 122, and the third connection portion 233 is disposed between the filling layer 240 and the first bonding portion 121. It can be understood that Figure 3B The second filling layer 240 shown in the figure has a higher expansion degree, so the first connecting portion 231 not only extends to the gap between the filling layer 240 and the second bonding portion 122, but also extends to the gap between the filling layer 240 and the first bonding portion 121, that is, forming Figure 3B The second connection portion 232 and the third connection portion 233 are shown.

[0046] It should be noted that during the bonding process, the first connecting part 231 will overflow, thereby forming a second connecting part 232 at the interconnection interface between the filling layer 240 and the second bonding part 122, and even forming a third connecting part 233 at the interconnection interface between the filling layer 240 and the first bonding part 121. The first connecting part 231 and the second connecting part 232 constitute a connecting layer, or the first connecting part 231, the second connecting part 232 and the third connecting part 233 constitute a connecting layer, which can increase the contact area between the bonding structures.

[0047] In some embodiments, reference Figure 3C As shown, the width of the filling layer 240 is greater than the distance between the outer wall of the second bonding structure 220 and the first groove 220T, and is less than or equal to the distance between the outer wall of the second bonding structure 220 and the first bonding portion 121. The distance between the outer wall of the second bonding structure 220 and the first bonding portion 121, the width of the filling layer 240, and the distance between the outer wall of the second bonding structure 220 and the first groove 220T are Figure 3C denoted as L1, L2 and L3, i.e., L3<L2≤L1, thereby ensuring that the expanded initial filling layer 240S can extend above the second bonding portion 122 to form a gap between the expanded initial filling layer 240S and the second bonding portion 122, and will not cause compression to the first bonding portion 121.

[0048] In some embodiments, the width of the filling layer 240 is greater than the distance between the outer wall of the second bonding structure 220 and the first groove 220T, and less than twice the distance between the outer wall of the second bonding structure 220 and the first groove 220T, that is, L3<L2≤2L3, thereby ensuring that the expanded initial filling layer 240S can extend close to the first bonding portion 121 to form a gap between the expanded initial filling layer 240S and the first bonding portion 121.

[0049] In some embodiments, reference Figure 3C As shown, the height of the filling layer 240 is less than or equal to the distance between the second bonding structure 220 and the first wafer 110. The distance between the second bonding structure 220 and the first wafer 110 and the height of the filling layer 240 are equal to or less than the distance between the second bonding structure 220 and the first wafer 110. Figure 3C They are respectively represented as H1 and H2, that is, H2≤H1, so as to ensure that the expanded initial filling layer 240S does not cause compression to the first wafer 110.

[0050] In practical applications, by controlling the thermal expansion coefficient of the filling layer (i.e., selecting a suitable material for the filling layer), the film thickness of the filling layer, and the distance between the second bonding structure and the first wafer, the filling of the high thermal expansion coefficient material can be controlled, that is, the expansion degree of the filling layer can be regulated to achieve optimization of the bonding strength.

[0051] Based on the above semiconductor device, an embodiment of the present disclosure provides a method for manufacturing a semiconductor device. The manufacturing method can be used to form the semiconductor device in any of the above embodiments.

[0052] Figure 4 is a flow chart of a method for manufacturing a semiconductor device provided by an embodiment of the present disclosure. It should be noted that: Figure 4 The steps shown in the operation are not exclusive, and other steps may be performed before, after or between any steps in the operation shown; Figure 4 The steps shown in the figure can be adjusted in order according to actual needs. Figure 4 As shown, the manufacturing method comprises the following steps: Step 410: forming a first bonding structure on a surface of a first wafer, the first bonding structure comprising a first bonding portion and a second bonding portion, wherein a cross-sectional dimension of the first bonding portion is smaller than a cross-sectional dimension of the second bonding portion; Step 420: forming a second bonding structure on the surface of the second wafer, wherein the surface of the second bonding structure facing away from the second wafer has a first groove, wherein the cross-sectional dimension of the first groove is greater than the cross-sectional dimension of the second bonding portion; Step 430: forming a connection layer covering the first groove; Step 440: forming an initial filling layer on the second bonding structure and the connecting layer; Step 450: Based on the first bonding structure, the second bonding structure, the connecting layer and the initial filling layer, the first wafer and the second wafer are bonded so that the second bonding part is embedded in the first groove and the initial filling layer expands into a filling layer, wherein the connecting layer extends between the filling layer and the second bonding part.

[0053] FIG. 5A to FIG. 5G It is a schematic diagram of forming a first wafer having a first bonding structure provided by an embodiment of the present disclosure.

[0054] In step S410, refer to Figure 5G As shown, a first bonding structure 120 is formed on the surface of the first wafer 110 .

[0055] Specifically, provide Figure 5A The first wafer 110 shown in FIG. 1 is formed on the surface of the first wafer 110. Figure 5B The first bonding portion 121 shown in FIG. 1 is formed on the surface of the first bonding portion 121 away from the first wafer 110. Figure 5GThe second bonding part 122 shown, the second bonding part 122 and the first bonding part 121 constitute the first bonding structure 120. The first wafer 110 includes but is not limited to a silicon wafer. The formation process of the first bonding part 121 includes but is not limited to physical vapor deposition (Physical Vapor Deposition, PVD), electron beam evaporation, electrochemical Plating (Electro chemical Plating, ECP), etc.

[0056] In some embodiments, reference Figure 5E to Figure 5G As shown, the above step S410 includes: forming an initial second bonding portion 122S on the surface of the first bonding portion 121 away from the first wafer 110; etching the initial second bonding portion 122S to form at least one second groove 122T on the surface of the initial second bonding portion 122S away from the first bonding portion 121, wherein the retained initial second bonding portion 122S constitutes the second bonding portion 122.

[0057] Reference Figure 5C As shown, an initial first sacrificial layer 501S covering the first wafer 110 and the first bonding portion 121 is formed, and a planarization process is performed on the initial first sacrificial layer 501S until the first bonding portion 121 is exposed. The retained initial first sacrificial layer 501S is formed as shown in Figure 5D The first sacrificial layer 501 is shown. The material of the first sacrificial layer 501 includes at least one of silicon oxide, silicon nitride and silicon oxynitride. The planarization process includes but is not limited to a chemical mechanical polishing process.

[0058] On the exposed first bonding portion 121, a Figure 5E The initial second bonding portion 122S shown in FIG. 1 is etched to form a Figure 5G The plurality of protrusions 122P and the plurality of second grooves 122T shown in FIG. 1 and the retained initial second bonding portion 122S constitute as follows: Figure 5G The second bonding portion 122 is shown. It can be understood that Figure 5D The exposed surface of the first bonding portion 121 is the surface of the first bonding portion 121 facing away from the first wafer 110. The formation process of the initial second bonding portion 122S includes but is not limited to PVD, electron beam evaporation, ECP, etc. Here, before etching the initial second bonding portion 122S, the first sacrificial layer 501 can be removed first, such as Fig. 5F The etching of the initial second bonding portion 122S includes: forming a hard mask including a mask pattern on the initial second bonding portion 122S, etching the initial second bonding portion 122S based on the mask pattern on the hard mask to obtain a target etching pattern, that is, Figure 5G A plurality of second grooves 122T are shown.

[0059] FIG. 6A to FIG. 6Dis a schematic diagram of forming a first wafer having a first bonding structure provided by another embodiment of the present disclosure. It should be noted that: FIG. 6A to FIG. 6D The same reference numerals are used for the same structures in the embodiment shown and those in the above embodiment, and the steps for forming the same structures can refer to the relevant descriptions in the above embodiment and will not be described in detail again.

[0060] exist Figure 5E Based on the structure shown, the deposition is formed as Fig. 6A The second sacrificial layer 502 shown covers the initial second bonding portion 122S and the first sacrificial layer 501 exposed on both sides of the initial second bonding portion 122S. The material of the second sacrificial layer 502 includes at least one of silicon oxide, silicon nitride and silicon oxynitride.

[0061] Through processes such as photomask, development, and etching, a second sacrificial layer 502 may be formed above the initial second bonding portion 122S. Figure 6B The opening 503 shown in FIG. 1 exposes the initial second bonding portion 122S. The initial second bonding portion 122S is etched based on the opening 503 to form a Figure 6C The second sacrificial layer 502 and the first sacrificial layer 501 are removed, and the retained initial second bonding portion 122S is formed as shown in FIG. Fig.6D The second bonding portion 122 is shown.

[0062] 7A to 7C is a schematic diagram of forming a second wafer having a second bonding structure provided by an embodiment of the present disclosure, Figure 8 is a schematic diagram of forming a first connecting portion provided by an embodiment of the present disclosure, Fig. 9 It is a schematic diagram of forming an initial filling layer provided by an embodiment of the present disclosure.

[0063] In step S420, refer to Figure 7C As shown, a second bonding structure 220 is formed on the surface of the second wafer 210 .

[0064] Specifically, provide Fig. 7A The second wafer 210 shown in FIG. 1 is formed on the surface of the second wafer 210 as shown in FIG. Figure 7B The initial second bonding structure 220S is etched to form a second bonding structure 220S on the surface of the initial second bonding structure 220S away from the second wafer 210 as shown; Figure 1C The first groove 220T shown in the figure and the retained initial second bonding structure 220S constitute the second bonding structure 220. The second wafer 210 includes but is not limited to a silicon wafer. The formation process of the initial second bonding structure 220S includes but is not limited to PVD, electron beam evaporation, ECP, etc.

[0065] In some embodiments, the above step S420 includes: forming at least one third bonding portion 221P in the first groove 220T, wherein the height of the third bonding portion 221P is less than the height of the first groove 220T. The formation process of the third bonding portion 221P includes: Figure 7B A hard mask including a mask pattern is formed on the initial second bonding structure 220S shown in FIG. 1 , and the initial second bonding structure 220S is etched based on the mask pattern on the hard mask to obtain a target etching pattern, that is, as shown in FIG. Figure 7C The multiple third grooves 221T shown, the initial second bonding structure 220S between adjacent third grooves 221T is the third bonding portion 221P, and the retained initial second bonding structure 220S constitutes the second bonding structure 220. It can be understood that the first groove 220T includes the third groove 221T, and the depth of the third groove 221T is less than the depth of the first groove 220T.

[0066] In step S430, a connection layer 230 covering the first groove 220T is formed. Taking the first groove 220T including the third groove 221T as an example, a first connection portion 231 covering the first groove 220T may be formed. Figure 8 As shown, the first connection portion 231 conformally covers the first groove 220T. Of course, in other examples, the first connection portion 231 covering the sidewall and the bottom of the first groove 220T may be formed. Figure 1C shown.

[0067] In step S440, an initial filling layer 240S is formed on the second bonding structure 220 and the connection layer 230. Figure 8 The first connecting portion 231 and the second bonding structure 220 at the edge are formed as shown in FIG. Fig. 9 The initial filling layer 240S shown in FIG. Figure 8 A barrier layer having an opening is formed on the structure shown, the opening of the barrier layer exposing the first connection portion 231 and the second bonding structure 220 at the edge, an initial filling layer 240S is deposited in the opening by PVD, and then the barrier layer is removed.

[0068] In step S450, based on the first bonding structure 120, the second bonding structure 220, the connecting layer 230 and the initial filling layer 240S, the first wafer 110 and the second wafer 210 are bonded, so that the second bonding portion 122 is embedded in the first groove 220T and the initial filling layer 240S expands to become the filling layer 240, wherein the connecting layer 230 extends between the filling layer 240 and the second bonding portion 122. Figure 1B The structure shown and Figure 1C The structure shown in the figure is face-to-face aligned and bonded, so that the second bonding portion 122 is embedded in the first groove 220T, thereby forming Figure 1AAs another example, Fig. 9 The structure shown and Figure 5G or Fig.6D The structure shown in the figure is face-to-face aligned and bonded, so that the third bonding portion 221P is embedded in the second groove 122T, that is, the third bonding portion 221P is embedded in the second groove 122T, thereby forming Figure 2A , Figure 3A or Figure 3B The structure shown.

[0069] It should be noted that during the bonding process, the initial filling layer 240S is embedded in the gap formed between the horizontal protruding portion of the second bonding portion 122 and the first wafer 110, and the initial filling layer 240S undergoes thermal expansion at a certain temperature, that is, the initial filling layer 240S expands into the filling layer 240; and the first connecting portion 231 will overflow, thereby forming a second connecting portion 232 at the interconnection interface between the filling layer 240 and the second bonding portion 122, and the first connecting portion 231 and the second connecting portion 232 constitute the connecting layer 230.

[0070] In some embodiments, during the bonding process of the first wafer 110 and the second wafer 210, the connection layer 230 also extends between the filling layer 240 and the first bonding portion 121. For example, when the initial filling layer 240S has a high expansion degree, a third connection portion 233 may be formed at the interconnection interface between the filling layer 240 and the first bonding portion 121, and the first connection portion 231, the second connection portion 232 and the third connection portion 233 constitute the connection layer 230.

[0071] The above description is only a specific implementation mode of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present disclosure, which should be included in the protection scope of the present disclosure.

Claims

1. A semiconductor device, characterized in that: include: A first bonding structure, which is disposed on a surface of the first wafer and includes a first bonding portion and a second bonding portion, wherein a cross-sectional dimension of the first bonding portion is smaller than a cross-sectional dimension of the second bonding portion; A second bonding structure, wherein the second bonding structure is disposed on a surface of the second wafer facing the first wafer, and a surface of the second bonding structure facing away from the second wafer has a first groove, wherein a cross-sectional dimension of the first groove is greater than a cross-sectional dimension of the second bonding portion, and the second bonding portion is engaged with the first groove; a filling layer, the filling layer being arranged between the second bonding structure and the first wafer; The connecting layer includes a first connecting portion and a second connecting portion, wherein the first connecting portion is arranged between the first groove and the second bonding portion, and the second connecting portion is arranged between the filling layer and the second bonding portion.

2. The semiconductor device according to claim 1, wherein: The connection layer further includes a third connection portion, and the third connection portion is arranged between the filling layer and the first bonding portion.

3. The semiconductor device according to claim 1 or 2, characterized in that: The surface of the second bonding portion facing away from the first bonding portion has at least one second groove; The second bonding structure includes at least one third bonding portion, and the third bonding portion is disposed in the first groove, wherein the height of the third bonding portion is smaller than the height of the first groove, and the third bonding portion is embedded in the second groove.

4. The semiconductor device according to claim 1, wherein: The width of the filling layer is greater than the distance between the outer side wall of the second bonding structure and the first groove, and is less than or equal to the distance between the outer side wall of the second bonding structure and the first bonding portion; A height of the filling layer is less than or equal to a distance between the second bonding structure and the first wafer.

5. The semiconductor device according to claim 1, wherein: The width of the filling layer is greater than the distance between the outer sidewall of the second bonding structure and the first groove, and less than twice the distance between the outer sidewall of the second bonding structure and the first groove.

6. The semiconductor device according to claim 1, wherein: The thermal expansion coefficient of the filling layer is greater than 15×10 -6 / ℃.

7. The semiconductor device according to claim 1, wherein: The material of the filling layer includes metamaterial.

8. A method for manufacturing a semiconductor device, characterized in that: include: Forming a first bonding structure on a surface of a first wafer, wherein the first bonding structure comprises a first bonding portion and a second bonding portion, wherein a cross-sectional dimension of the first bonding portion is smaller than a cross-sectional dimension of the second bonding portion; forming a second bonding structure on the surface of the second wafer, wherein the surface of the second bonding structure facing away from the second wafer has a first groove, wherein the cross-sectional dimension of the first groove is greater than the cross-sectional dimension of the second bonding portion; forming a connection layer covering the first groove; forming an initial filling layer on the second bonding structure and the connecting layer; Based on the first bonding structure, the second bonding structure, the connecting layer and the initial filling layer, the first wafer and the second wafer are bonded so that the second bonding part is embedded in the first groove and the initial filling layer expands into a filling layer, wherein the connecting layer extends between the filling layer and the second bonding part.

9. The method for manufacturing a semiconductor device according to claim 8, wherein: During the bonding process of the first wafer and the second wafer, the connection layer also extends between the filling layer and the first bonding portion.

10. The method for manufacturing a semiconductor device according to claim 8 or 9, characterized in that: The forming of a first bonding structure on the surface of the first wafer includes: forming an initial second bonding portion on a surface of the first bonding portion facing away from the first wafer; Etching the initial second bonding portion to form at least one second groove on a surface of the initial second bonding portion facing away from the first bonding portion, wherein the remaining initial second bonding portion constitutes the second bonding portion; The forming of a second bonding structure on the surface of the second wafer comprises: At least one third bonding portion is formed in the first groove, and the height of the third bonding portion is smaller than the height of the first groove, wherein the third bonding portion is embedded in the second groove.

11. The method for manufacturing a semiconductor device according to claim 8, wherein: The width of the filling layer is greater than the distance between the outer side wall of the second bonding structure and the first groove, and is less than or equal to the distance between the outer side wall of the second bonding structure and the first bonding portion; A height of the filling layer is less than or equal to a distance between the second bonding structure and the first wafer.

12. The method for manufacturing a semiconductor device according to claim 8, wherein: The width of the filling layer is greater than the distance between the outer sidewall of the second bonding structure and the first groove, and less than twice the distance between the outer sidewall of the second bonding structure and the first groove.

13. The method for manufacturing a semiconductor device according to claim 8, wherein: The thermal expansion coefficient of the filling layer is greater than 15×10 -6 / ℃.

14. The method for manufacturing a semiconductor device according to claim 8, wherein: The material of the filling layer includes metamaterial.

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