Semiconductor structure and method for manufacturing the same

Abstract

The present invention relates to a semiconductor structure and a preparation method thereof; comprising: a support layer, including a pad region; a plurality of grooves are formed in the pad region of the support layer, and the width of the bottom of the groove is greater than the width of the groove opening; a pad is located on the support layer and in the pad region, and the pad is partially embedded in the groove. In the semiconductor structure, there may be an air cavity between the portion of the pad embedded in the groove and the side wall of the lower portion of the groove. During the wire bonding process, even if the pad is flat and most of the pads will be squeezed out under the action of the bonding pressure, the squeezed pad will enter the air cavity, which can prevent the protective layer from being lifted up or cracked, and prevent the pad from overflowing, thereby ensuring the quality of the product; at the same time, because the pad will enter the air cavity during the wire bonding process, the contact area between the pad and the support layer will be increased, thereby enhancing the stability of the overall structure.

Description

Technical Field

[0001] The present application relates to the technical field of semiconductor device manufacturing, and in particular to a semiconductor structure and a preparation method thereof. Background Art

[0002] In the existing process, when the wire bonding process is performed on the pad, since the pad is generally made of aluminum with relatively soft hardness, the pad will be quickly flattened under the bonding force during the wire bonding process; if the opening in the protective layer is too small or the wire is crooked so that the wire is close to the protective layer, the pad layer that is squeezed outward will lift up or crack the protective layer, or cause the pad to overflow, thereby causing quality problems. Summary of the invention

[0003] Based on this, it is necessary to provide a semiconductor structure and a method for preparing the same in order to solve the above problems in the prior art.

[0004] In order to achieve the above object, on the one hand, the present invention provides a semiconductor structure, comprising:

[0005] A support layer, comprising a pad region; a plurality of grooves are formed in the pad region of the support layer, and a width of a bottom of the groove is greater than a width of an opening of the groove;

[0006] A welding pad is located on the support layer and in the pad area, and a portion of the welding pad is embedded in the groove.

[0007] In the above-mentioned semiconductor structure, a support layer with several grooves is formed in the pad area below the welding pad, and the width of the bottom of the groove is greater than the width of the top of the groove. An air cavity can be provided between the portion of the welding pad embedded in the groove and the side wall of the lower portion of the groove. During the wire bonding process, even if the welding pad is flat and most of the welding pads will be squeezed out under the action of the bonding pressure, the squeezed welding pads will enter the air cavity, which can prevent the protective layer from being lifted up or cracked, and prevent the welding pads from overflowing, thereby ensuring the quality of the product. At the same time, because the welding pad will enter the air cavity during the wire bonding process, the contact area between the welding pad and the support layer will be increased, thereby enhancing the stability of the overall structure.

[0008] In one embodiment, the support layer is a single-layer structure.

[0009] In one embodiment, the support layer is a laminated structure, and the support layer includes:

[0010] a first material layer;

[0011] The second material layer is located on the upper surface of the first material layer; the groove is formed in the second material layer.

[0012] In one embodiment, the longitudinal cross-section of the groove includes a bottle shape or a trapezoidal shape.

[0013] In one of the embodiments, the inclination angle of the side wall of the groove relative to the upper surface of the support layer is 30° to 65°.

[0014] In the above semiconductor structure, by limiting the inclination angle of the side wall of the groove to 30° to 65° compared to the upper surface of the support layer, the pad can fill the air cavity during the wire bonding process, so that the contact area between the pad and the support layer is maximized, thereby maximizing the stability of the overall structure.

[0015] In one example, the support layer is a laminated structure, and the support layer includes:

[0016] a first material layer;

[0017] The second material layer is located on the upper surface of the first material layer; wherein,

[0018] A through hole penetrating along the thickness direction is formed in the second material layer, and a recessed groove is formed in the first material layer. The width of the recessed groove is greater than the width of the through hole. The recessed groove is connected to the through hole and together with the through hole constitutes the groove.

[0019] In one example, the width of the recessed groove is 1.5 to 6 times the width of the through hole.

[0020] In one example, the support layer is a laminated structure, and the support layer includes:

[0021] a first material layer;

[0022] a second material layer, located on an upper surface of the first material layer;

[0023] The third material layer is located on the upper surface of the second material layer; wherein,

[0024] A first through hole is formed in the third material layer and penetrates along its thickness direction, and a second through hole is formed in the second material layer and penetrates along its thickness direction; the width of the second through hole is greater than the width of the first through hole, the second through hole is connected to the first through hole, and together with the first through hole, constitutes the groove.

[0025] In one example, the width of the second through hole is 1.5 to 6 times the width of the first through hole.

[0026] In one example, the semiconductor structure further includes:

[0027] A protective layer, located on the upper surface of the support layer and the welding pad; the protective layer has an opening, and the opening exposes the welding pad;

[0028] A welding wire has one end located in the opening and connected to the welding pad.

[0029] The present invention also provides a method for preparing a semiconductor structure, comprising the following steps:

[0030] Forming a support layer, the support layer comprising a pad region; a plurality of grooves are formed in the pad region of the support layer, and the width of the bottom of the groove is greater than the width of the opening of the groove;

[0031] A welding pad is formed in the pad area of ​​the support layer, and the welding pad is partially embedded in the groove.

[0032] In the preparation method of the above-mentioned semiconductor structure, a support layer having a plurality of grooves is formed in the pad area below the welding pad, and the width of the bottom of the groove is greater than the width of the top of the groove. An air cavity can be provided between the portion of the welding pad embedded in the groove and the side wall of the lower portion of the groove. During the wire bonding process, even if the welding pad is flat and most of the welding pads will be squeezed out under the action of the bonding pressure, the squeezed welding pads will enter the air cavity, which can prevent the protective layer from being lifted up or cracked, and prevent the welding pads from overflowing, thereby ensuring the quality of the product. At the same time, because the welding pad will enter the air cavity during the wire bonding process, the contact area between the welding pad and the support layer will be increased, thereby enhancing the stability of the overall structure.

[0033] In one embodiment, forming the support layer comprises the following steps:

[0034] forming a material layer;

[0035] The material layer is etched to form the groove in the material layer.

[0036] In one embodiment, forming the support layer comprises the following steps:

[0037] forming a first material layer;

[0038] forming a second material layer on the upper surface of the first material layer;

[0039] The second material layer is etched to form the groove in the second material layer.

[0040] In one embodiment, forming the support layer comprises the following steps:

[0041] forming a first material layer;

[0042] forming a second material layer on the upper surface of the first material layer;

[0043] Etching the second material layer to form a through hole penetrating the second material layer along a thickness direction thereof;

[0044] The first material layer is etched based on the through hole to form a recessed groove in the first material layer, wherein the width of the recessed groove is greater than the width of the through hole, the recessed groove is connected to the through hole, and the recessed groove and the through hole together constitute the groove.

[0045] In one embodiment, forming the support layer comprises the following steps:

[0046] forming a first material layer;

[0047] forming a second material layer on the upper surface of the first material layer;

[0048] forming a third material layer on the upper surface of the second material layer;

[0049] Etching the third material layer to form a first through hole penetrating the third material layer along a thickness direction thereof;

[0050] The second material layer is etched based on the first through hole to form a second through hole in the second material layer. The width of the second through hole is greater than that of the first through hole. The second through hole is connected to the first through hole and together with the first through hole constitutes the groove.

[0051] In one embodiment, after forming the welding pad, the following steps are also included:

[0052] forming a protective layer on the upper surface of the support layer and the upper surface of the welding pad, wherein the protective layer covers the welding pad;

[0053] forming an opening in the protective layer, wherein the opening exposes the welding pad;

[0054] A welding wire is provided, and one end of the welding wire is connected to the welding pad. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 A flowchart of a method for preparing a semiconductor structure according to an embodiment of the present invention;

[0056] Figures 2 to 19 It is a schematic diagram of the cross-sectional structure of the structure obtained in each step of the method for preparing a semiconductor structure in one embodiment of the present invention; wherein, Figures 16 to 19 It is also a schematic cross-sectional structural diagram of a different semiconductor structure provided in another embodiment of the present invention.

[0057] In the figure, 10-support layer, 101-first material layer, 102-second material layer, 103-third material layer, 11-groove, 111-through hole, 112-depressed groove, 113-first through hole, 114-second through hole, 12-soldering pad, 13-protective layer, 131-opening, 14-soldering wire, 15-air cavity, α-inclination angle of the side wall of the groove compared to the upper surface of the support layer. DETAILED DESCRIPTION

[0058] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present application are given in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0059] It should be noted that when an element is considered to be "connected" to another element, it may be directly connected to another element and integrated therewith, or there may be an intermediate element at the same time. The terms "installed", "one end", "the other end" and similar expressions used herein are for illustrative purposes only.

[0060] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0061] In one embodiment, Figure 1 As shown, the present invention provides a method for preparing a semiconductor structure, comprising the following steps:

[0062] S11: forming a support layer, the support layer including a pad region; a plurality of grooves are formed in the pad region of the support layer, and the width of the bottom of the groove is greater than the width of the groove opening;

[0063] S12: forming a soldering pad in the soldering pad area of ​​the support layer, wherein the soldering pad is partially embedded in the groove.

[0064] In the preparation method of the above-mentioned semiconductor structure, a support layer having a plurality of grooves is formed in the pad area below the welding pad, and the width of the bottom of the groove is greater than the width of the top of the groove. An air cavity can be provided between the portion of the welding pad embedded in the groove and the side wall of the lower portion of the groove. During the wire bonding process, even if the welding pad is flat and most of the welding pads will be squeezed out under the action of the bonding pressure, the squeezed welding pads will enter the air cavity, which can prevent the protective layer from being lifted up or cracked, and prevent the welding pads from overflowing, thereby ensuring the quality of the product. At the same time, because the welding pad will enter the air cavity during the wire bonding process, the contact area between the welding pad and the support layer will be increased, thereby enhancing the stability of the overall structure.

[0065] In one example, the support layer 10 may be formed on a substrate (not shown), and the substrate may be any substrate that can play a supporting role.

[0066] In an optional example, step S11 may include the following steps:

[0067] S111: forming a material layer, where the material layer is the support layer 10, such as Figure 2 As shown; specifically, the material layer may be formed by a physical vapor deposition process, a chemical vapor deposition process or an atomic layer deposition process; the material layer may include but is not limited to at least one of a silicon oxide layer, a silicon nitride layer, a silicon oxynitride layer, a silicon carbonitride layer, a tungsten layer, a titanium layer, a titanium nitride layer and a tantalum layer;

[0068] S112: Etching the material layer to form a groove 11 in the material layer. Figure 3 As shown; specifically, first, a patterned mask layer (not shown) can be formed on the upper surface of the material layer, and the patterned mask layer may include but is not limited to a patterned photoresist layer; then, the material layer is dry-etched based on the patterned mask layer, and the protection of the lower side wall is reduced during the etching process to cause lateral etching (under cut) to form a groove 11 in the material layer; finally, the patterned mask layer is removed.

[0069] In one example, the depth of the groove 11 may be less than the thickness of the support layer 10. Figure 3 As shown, at this time, the depth of the groove 11 can be set according to actual needs. For example, the depth of the groove 11 can be 1 / 3, 2 / 3 or 3 / 4 of the thickness of the support layer 10.

[0070] In one example, the longitudinal cross-sectional shape of the groove 11 may be bottle-shaped (eg Figure 3 as shown) or trapezoidal, etc.

[0071] In one example, if Figure 3As shown, the inclination angle α of the side wall of the groove 11 compared to the upper surface of the support layer 10 can be 30° to 65°, specifically, 30°, 40°, 50°, 60° or 65°, etc. By limiting the inclination angle α of the side wall of the groove 11 compared to the upper surface of the support layer 10 to 30° to 65°, the pad 12 can fill the air cavity during the wire bonding process, so that the contact area between the pad 12 and the support layer 10 is maximized, and the stability of the overall structure is maximized.

[0072] In another optional example, step S11 may include the following steps:

[0073] S111: forming a first material layer 101, such as Figure 4 As shown; the first material layer 101 may be formed by a physical vapor deposition process, a chemical vapor deposition process or an atomic layer deposition process; the first material layer 101 may include but is not limited to at least one of a silicon oxide layer, a silicon nitride layer, a silicon oxynitride layer, a silicon carbonitride layer, a tungsten layer, a titanium layer, a titanium nitride layer and a tantalum layer;

[0074] S112: forming a second material layer 102 on the upper surface of the first material layer 101, such as Figure 4 As shown; the second material layer 102 may be formed by a physical vapor deposition process, a chemical vapor deposition process or an atomic layer deposition process; the second material layer 102 may include but is not limited to at least one of a silicon oxide layer, a silicon nitride layer, a silicon oxynitride layer, a silicon carbonitride layer, a tungsten layer, a titanium layer, a titanium nitride layer and a tantalum layer; it should be noted that the material of the second material layer 102 is different from that of the first material layer 101, and under the same etching conditions, the second material layer 102 has a higher etching selectivity than the first material layer 101, so as to ensure that the first material layer 101 can be used as an etching stop layer for the second material layer 102;

[0075] S113: Etching the second material layer 102 to form a groove 11 in the second material layer 102. Figure 5 As shown; specifically, first, a patterned mask layer (not shown) can be formed on the upper surface of the second material layer 102, and the patterned mask layer may include but is not limited to a patterned photoresist layer; then, the second material layer 102 is dry-etched based on the patterned mask layer, and during the etching process, since the first material layer 101 is an etching stop layer, the second material layer 102 is etched through and then the etching is continued for a certain time to create lateral etching to form a groove 11 in the second material layer 102; finally, the patterned mask layer is removed.

[0076] In one example, the depth of the groove 11 may be less than or equal to the thickness of the second material layer 102. Figure 5As shown, the depth of the groove 11 is equal to the thickness of the second material layer 102 .

[0077] In one example, the longitudinal cross-sectional shape of the groove 11 may be bottle-shaped or trapezoidal (eg Figure 5 shown) and so on.

[0078] In one example, if Figure 5 As shown, the inclination angle α of the side wall of the groove 11 compared to the upper surface of the support layer 10 can be 30° to 65°, specifically, 30°, 40°, 50°, 60° or 65°, etc. By limiting the inclination angle α of the side wall of the groove 11 compared to the upper surface of the support layer 10 to 30° to 65°, the pad 12 can fill the air cavity during the wire bonding process, so that the contact area between the pad 12 and the support layer 10 is maximized, and the stability of the overall structure is maximized.

[0079] In yet another example, step S11 includes the following steps:

[0080] S111: forming a first material layer 101, such as Figure 6 As shown; the first material layer 101 can be formed by a physical vapor deposition process, a chemical vapor deposition process or an atomic layer deposition process; the first material layer 101 can include but is not limited to at least one of a silicon oxide layer, a silicon nitride layer, a silicon oxynitride layer, a silicon carbonitride layer, a tungsten layer, a titanium layer, a titanium nitride layer and a tantalum layer;

[0081] S112: forming a second material layer 102 on the upper surface of the first material layer 101, such as Figure 6 As shown; the second material layer 102 may be formed by a physical vapor deposition process, a chemical vapor deposition process or an atomic layer deposition process; the second material layer 102 may include but is not limited to at least one of a silicon oxide layer, a silicon nitride layer, a silicon oxynitride layer, a silicon carbonitride layer, a tungsten layer, a titanium layer, a titanium nitride layer and a tantalum layer; it should be noted that the material of the second material layer 102 is different from that of the first material layer 101, and under the same etching conditions, the first material layer 101 has a higher etching selectivity than the second material layer 102;

[0082] S113: Etching the second material layer 102 to form a through hole 111 penetrating the second material layer 102 along the thickness direction thereof. Figure 7 Specifically, first, a patterned mask layer (not shown) may be formed on the upper surface of the second material layer 102, and the patterned mask layer may include but is not limited to a patterned photoresist layer; then, the second material layer 102 is dry-etched based on the patterned mask layer to form a through hole 111 in the second material layer 102; finally, the patterned mask layer is removed;

[0083] S114: etching the first material layer 101 based on the through hole 111. Specifically, a wet etching process is used to etch the first material layer 101 based on the through hole 111 to form a recessed groove 112 in the first material layer 101. The width of the recessed groove 112 is greater than the width of the through hole 111. The recessed groove 112 is connected to the through hole 111. The recessed groove 112 and the through hole 111 together constitute a groove 11. Figure 8 shown.

[0084] In one example, the depth of the recessed groove 112 may be less than the thickness of the first material layer 101. Figure 8 As shown, at this time, the depth of the recessed groove 112 can be set according to actual needs. For example, the depth of the recessed groove 112 can be 1 / 3, 2 / 3 or 3 / 4 of the thickness of the first material layer 101, etc.

[0085] In one example, the width of the recessed groove 112 may be 1.5 to 6 times the width of the through hole 111 .

[0086] In yet another example, step S11 may include the following steps:

[0087] S111: forming a first material layer 101, such as Figure 6 As shown; the first material layer 101 may be formed by a physical vapor deposition process, a chemical vapor deposition process or an atomic layer deposition process; the first material layer 101 may include but is not limited to at least one of a silicon oxide layer, a silicon nitride layer, a silicon oxynitride layer, a silicon carbonitride layer, a tungsten layer, a titanium layer, a titanium nitride layer and a tantalum layer;

[0088] S112: forming a second material layer 102 on the upper surface of the first material layer 101, such as Figure 6 As shown; the second material layer 102 may be formed by a physical vapor deposition process, a chemical vapor deposition process or an atomic layer deposition process; the second material layer 102 may include but is not limited to at least one of a silicon oxide layer, a silicon nitride layer, a silicon oxynitride layer, a silicon carbonitride layer, a tungsten layer, a titanium layer, a titanium nitride layer and a tantalum layer;

[0089] S113: forming a third material layer 103 on the upper surface of the second material layer 102, such as Fig. 9 As shown; the third material layer 103 may include but is not limited to at least one of a silicon oxide layer, a silicon nitride layer, a silicon oxynitride layer, a silicon carbonitride layer, a tungsten layer, a titanium layer, a titanium nitride layer and a tantalum layer; it should be noted that the material of the second material layer 102 is different from the material of the first material layer 101, and under the same etching conditions, the third material layer 103 has a higher etching selectivity than the second material layer 102, so as to ensure that the third material layer 103 can be used as an etching stop layer for the second material layer 102;

[0090] S114: etching the third material layer 103 to form a first through hole 113 penetrating the third material layer 103 along the thickness direction thereof. Fig.10 Specifically, first, a patterned mask layer (not shown) may be formed on the upper surface of the third material layer 103, and the patterned mask layer may include but is not limited to a patterned photoresist layer; then, the third material layer 103 is dry-etched based on the patterned mask layer to form a first through hole 113 in the third material layer 103; finally, the patterned mask layer is removed;

[0091] S115: etching the second material layer 102 based on the first through hole 113. Specifically, a wet etching process is used to etch the first material layer 101 based on the through hole 111 to form a second through hole 114 in the second material layer 102. The width of the second through hole 114 is greater than the width of the first through hole 113. The second through hole 114 is connected to the first through hole 113 and together with the first through hole 113, forms a groove 11. Fig.11 In this embodiment, by providing the support layer 10 of the first material layer 101, the second material layer 102 and the third material layer 103, and the first material layer 101 is used as an etching stop layer of the groove 11, the depth of the groove 11 can be controlled.

[0092] In one example, the width of the second through hole 114 may be 1.5 to 6 times the width of the first through hole 113 .

[0093] In one example, the shape of the opening of the groove 11 in the above examples may include but is not limited to a rectangular strip, a cross, a circle or a star (a six-pointed star or a five-pointed star, etc.), etc.

[0094] In one example, in step S12, Figures 12 to 15 As shown, the solder pad 12 may be formed by, but not limited to, electroplating or other processes; the solder pad 12 may include, but not limited to, an aluminum solder pad. After the solder pad 12 is formed, there is a gap between the portion of the solder pad 12 embedded in the groove 11 and the side wall of the lower portion of the groove 11, that is, there is an air cavity 15 between the portion of the solder pad 12 embedded in the groove 11 and the side wall of the lower portion of the groove 11, as shown in FIG. Figures 12 to 15 During the subsequent bonding process of the welding wire 14, the air cavity 15 can be used to accommodate the welding pad 12 displaced by the welding wire 14, and can prevent the displaced welding pad 12 from entering under the protective layer 13, and prevent the protective layer 13 from being lifted up or cracked, and prevent the welding pad 12 from overflowing, thereby ensuring the quality of the product.

[0095] like Figures 16 to 19 As shown, after step S12, the following steps are also included:

[0096] S13: forming a protective layer 13 on the upper surface of the support layer 10 and the upper surface of the welding pad 12, wherein the protective layer 13 covers the welding pad 12;

[0097] S14: forming an opening 131 in the protective layer 13 , wherein the opening 131 exposes the bonding pad 1 ;

[0098] S15 : providing a welding wire 14 , and connecting one end of the welding wire 14 to the welding pad 12 .

[0099] In one example, the protection layer 13 may include but is not limited to a silicon oxide layer, a silicon nitride layer, a silicon oxynitride layer, or the like.

[0100] In one example, the bonding wire 14 may include, but is not limited to, a copper wire, an aluminum wire, a gold wire, or the like.

[0101] It should be noted that during the wire bonding process, the pad 12 will be displaced under the action of the bonding pressure, and the displaced pad 12 will enter the air cavity 15. Figures 16 to 19 As shown, the protective layer 13 can be prevented from being lifted up or cracked, and the solder pad 12 can be prevented from overflowing, thereby ensuring the quality of the product.

[0102] In another embodiment, please combine Figures 2 to 15 Continue reading Figures 16 to 19 The present invention also provides a semiconductor structure, including: a support layer 10, the support layer 10 includes a pad area (not shown); a plurality of grooves 11 are formed in the pad area of ​​the support layer 10, and the width of the bottom of the groove 11 is greater than the width of the opening of the groove 11; a pad 12, the pad 12 is located on the support layer 10 and in the pad area, and the pad 12 is partially embedded in the groove 11.

[0103] In the above-mentioned semiconductor structure, a support layer having a plurality of grooves 11 is formed in the pad area below the welding pad 12, and the width of the bottom of the groove 11 is greater than the width of the top of the groove 11. An air cavity can be provided between the portion of the welding pad 12 embedded in the groove 11 and the side wall of the lower portion of the groove 11. During the wire bonding process, even if the welding pad 12 is flat and most of the welding pad 12 will be squeezed out under the action of the bonding pressure, the squeezed welding pad 12 will enter the air cavity, which can prevent the protective layer from being lifted up or cracked, and prevent the welding pad 12 from overflowing, thereby ensuring the quality of the product. At the same time, because the welding pad will enter the air cavity during the wire bonding process, the contact area between the welding pad 12 and the support layer 10 will be increased, thereby enhancing the stability of the overall structure.

[0104] In one example, the support layer 10 may be formed on a substrate (not shown), and the substrate may be any substrate that can play a supporting role.

[0105] In an alternative example, Fig.16As shown, the support layer 10 may be a single layer structure. The support layer 10 may include but is not limited to at least one of a silicon oxide layer, a silicon nitride layer, a silicon oxynitride layer, a silicon carbonitride layer, a tungsten layer, a titanium layer, a titanium nitride layer and a tantalum layer.

[0106] In one example, the longitudinal cross-sectional shape of the groove 11 may be bottle-shaped (eg Fig.16 as shown) or trapezoidal, etc.

[0107] In one example, if Fig.16 As shown, the inclination angle α of the side wall of the groove 11 compared to the upper surface of the support layer 10 can be 30° to 65°, specifically, 30°, 40°, 50°, 60° or 65°, etc. By limiting the inclination angle α of the side wall of the groove 11 compared to the upper surface of the support layer 10 to 30° to 65°, the pad 12 can fill the air cavity during the wire bonding process, so that the contact area between the pad 12 and the support layer 10 is maximized, and the stability of the overall structure is maximized.

[0108] In another alternative example, Fig.17 As shown, the support layer 10 is a laminated structure, and the support layer 10 may include: a first material layer 101 ; a second material layer 102 , the second material layer 102 is located on the upper surface of the first material layer 101 ; and a groove 11 is formed in the second material layer 102 .

[0109] In one example, the first material layer 101 may include but is not limited to at least one of a silicon oxide layer, a silicon nitride layer, a silicon oxynitride layer, a silicon carbonitride layer, a tungsten layer, a titanium layer, a titanium nitride layer and a tantalum layer; the second material layer 102 may include but is not limited to at least one of a silicon oxide layer, a silicon nitride layer, a silicon oxynitride layer, a silicon carbonitride layer, a tungsten layer, a titanium layer, a titanium nitride layer and a tantalum layer; it should be noted that the material of the second material layer 102 is different from that of the first material layer 101, and under the same etching conditions, the second material layer 102 has a higher etching selectivity than the first material layer 101, so as to ensure that the first material layer 101 can serve as an etching stop layer for the second material layer 102.

[0110] In one example, the depth of the groove 11 may be less than or equal to the thickness of the second material layer 102. Fig.17 As shown, the depth of the groove 11 is equal to the thickness of the second material layer 102 .

[0111] In one example, the longitudinal cross-sectional shape of the groove 11 may be bottle-shaped or trapezoidal (eg Fig.17 shown) and so on.

[0112] In one example, if Fig.17As shown, the inclination angle α of the side wall of the groove 11 compared to the upper surface of the support layer 10 can be 30° to 65°, specifically, 30°, 40°, 50°, 60° or 65°, etc. By limiting the inclination angle α of the side wall of the groove 11 compared to the upper surface of the support layer 10 to 30° to 65°, the pad 12 can fill the air cavity during the wire bonding process, so that the contact area between the pad 12 and the support layer 10 is maximized, and the stability of the overall structure is maximized.

[0113] In yet another alternative example, Fig.18 As shown, the support layer 10 is a laminated structure, and the support layer 10 may include: a first material layer 101; a second material layer 102, and the second material layer 102 is located on the upper surface of the first material layer 101; wherein a through hole 111 is formed in the second material layer 102 and penetrates along the thickness direction thereof, and a recessed groove 112 is formed in the first material layer 101, and the width of the recessed groove 112 is greater than the width of the through hole 111, and the recessed groove 112 is connected to the through hole 111, and together with the through hole 111, constitutes a groove 11.

[0114] In one example, the first material layer 101 may include but is not limited to at least one of a silicon oxide layer, a silicon nitride layer, a silicon oxynitride layer, a silicon carbonitride layer, a tungsten layer, a titanium layer, a titanium nitride layer and a tantalum layer; the second material layer 102 may include but is not limited to at least one of a silicon oxide layer, a silicon nitride layer, a silicon oxynitride layer, a silicon carbonitride layer, a tungsten layer, a titanium layer, a titanium nitride layer and a tantalum layer; it should be noted that the material of the second material layer 102 is different from that of the first material layer 101, and under the same etching conditions, the first material layer 101 has a higher etching selectivity than the second material layer 102.

[0115] In one example, the depth of the recessed groove 112 may be less than the thickness of the first material layer 101. Figure 8 As shown, at this time, the depth of the recessed groove 112 can be set according to actual needs. For example, the depth of the recessed groove 112 can be 1 / 3, 2 / 3 or 3 / 4 of the thickness of the first material layer 101, etc.

[0116] In one example, the width of the recessed groove 112 may be 1.5 to 6 times the width of the through hole 111 .

[0117] In yet another alternative example, Fig.19As shown, the support layer 10 is a laminated structure, and the support layer 10 may include: a first material layer 101; a second material layer 102, the second material layer 102 is located on the upper surface of the first material layer 101; a third material layer 103, the third material layer 103 is located on the upper surface of the second material layer 102; wherein, a first through hole 113 is formed in the third material layer 103 and penetrates along the thickness direction thereof, and a second through hole 114 is formed in the second material layer 102 and penetrates along the thickness direction thereof; the width of the second through hole 114 is greater than the width of the first through hole 113, the second through hole 114 is connected to the first through hole 113, and together with the first through hole 113, forms a groove 11.

[0118] In an example, the first material layer 101 may include but is not limited to at least one of a silicon oxide layer, a silicon nitride layer, a silicon oxynitride layer, a silicon carbonitride layer, a tungsten layer, a titanium layer, a titanium nitride layer and a tantalum layer; the second material layer 102 may include but is not limited to at least one of a silicon oxide layer, a silicon nitride layer, a silicon oxynitride layer, a silicon carbonitride layer, a tungsten layer, a titanium layer, a titanium nitride layer and a tantalum layer; the third material layer 103 may include but is not limited to at least one of a silicon oxide layer, a silicon nitride layer, a silicon oxynitride layer, a silicon carbonitride layer, a tungsten layer, a titanium layer, a titanium nitride layer and a tantalum layer; it should be noted that the material of the second material layer 102 is different from that of the first material layer 101, and under the same etching conditions, the third material layer 103 has a higher etching selectivity than the second material layer 102 to ensure that the third material layer 103 can serve as an etching stop layer for the second material layer 102.

[0119] In one example, the width of the second through hole 114 may be 1.5 to 6 times the width of the first through hole 113 .

[0120] In one example, the shape of the opening of the groove 11 in the above examples may include but is not limited to a rectangular strip, a cross, a circle or a star (a six-pointed star or a five-pointed star, etc.), etc.

[0121] For an example, see Figures 16 to 19 The semiconductor structure further includes: a protective layer 13, the protective layer 13 is located on the upper surface of the support layer 10 and the pad 12; an opening 131 is provided in the protective layer 13, and the opening 131 exposes the pad 12; a welding wire 14, one end of the welding wire 14 is located in the opening 131 and connected to the pad 12.

[0122] In one example, the protection layer 13 may include but is not limited to a silicon oxide layer, a silicon nitride layer, a silicon oxynitride layer, or the like.

[0123] In one example, the bonding wire 14 may include, but is not limited to, a copper wire, an aluminum wire, a gold wire, or the like.

[0124] It should be noted that during the wire bonding process, the pad 12 will be displaced under the action of the bonding pressure, and the displaced pad 12 will enter the air cavity 15. Figures 16 to 19 As shown, the protective layer 13 can be prevented from being lifted up or cracked, and the solder pad 12 can be prevented from overflowing, thereby ensuring the quality of the product.

[0125] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features of the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0126] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A semiconductor structure, characterized in that: include: A support layer, comprising a pad region; a plurality of grooves are formed in the pad region of the support layer, and a width of a bottom of the groove is greater than a width of an opening of the groove; A soldering pad is located on the support layer and in the pad area. The soldering pad is partially embedded in the groove. An air cavity is formed between the portion of the soldering pad embedded in the groove and the side wall of the lower portion of the groove.

2. The semiconductor structure according to claim 1, characterized in that: The supporting layer is a single-layer structure.

3. The semiconductor structure according to claim 1, characterized in that: The support layer is a laminated structure, and the support layer includes: a first material layer; The second material layer is located on the upper surface of the first material layer; the groove is formed in the second material layer.

4. The semiconductor structure according to claim 2 or 3, characterized in that: The longitudinal cross-sectional shape of the groove includes a bottle shape or a trapezoidal shape.

5. The semiconductor structure according to claim 4, characterized in that: The inclination angle of the side wall of the groove compared to the upper surface of the support layer is 30° to 65°.

6. The semiconductor structure according to claim 1, characterized in that The support layer is a laminated structure, and the support layer includes: a first material layer; a second material layer, located on an upper surface of the first material layer; A through hole penetrating along the thickness direction is formed in the second material layer, and a recessed groove is formed in the first material layer. The width of the recessed groove is greater than the width of the through hole. The recessed groove is connected to the through hole and together with the through hole constitutes the groove.

7. The semiconductor structure according to claim 6, characterized in that: The width of the concave groove is 1.5 to 6 times the width of the through hole.

8. The semiconductor structure according to claim 1, characterized in that: The support layer is a laminated structure, and the support layer includes: a first material layer; a second material layer, located on an upper surface of the first material layer; a third material layer, located on an upper surface of the second material layer; Among them, a first through hole is formed in the third material layer and penetrates along its thickness direction, and a second through hole is formed in the second material layer and penetrates along its thickness direction; the width of the second through hole is greater than the width of the first through hole, the second through hole is connected to the first through hole, and together with the first through hole constitutes the groove.

9. The semiconductor structure according to claim 8, characterized in that: The width of the second through hole is 1.5 to 6 times the width of the first through hole.

10. The semiconductor structure according to claim 1, characterized in that The semiconductor structure further comprises: A protective layer, located on the upper surface of the support layer and the welding pad; the protective layer has an opening, and the opening exposes the welding pad; A welding wire has one end located in the opening and connected to the welding pad.

11. A method for preparing a semiconductor structure, characterized in that: The steps include: Forming a support layer, the support layer comprising a pad region; a plurality of grooves are formed in the pad region of the support layer, and the width of the bottom of the groove is greater than the width of the opening of the groove; A welding pad is formed in the pad area of ​​the support layer, and a portion of the welding pad is embedded in the groove. An air cavity is formed between the portion of the welding pad embedded in the groove and the side wall of the lower portion of the groove.

12. The method for preparing a semiconductor structure according to claim 11, characterized in that: Forming the support layer comprises the following steps: forming a material layer; The material layer is etched to form the groove in the material layer.

13. The method for preparing a semiconductor structure according to claim 11, characterized in that: Forming the support layer comprises the following steps: forming a first material layer; forming a second material layer on the upper surface of the first material layer; The second material layer is etched to form the groove in the second material layer.

14. The method for preparing a semiconductor structure according to claim 11, characterized in that: Forming the support layer comprises the following steps: forming a first material layer; forming a second material layer on the upper surface of the first material layer; Etching the second material layer to form a through hole penetrating the second material layer along a thickness direction thereof; The first material layer is etched based on the through hole to form a recessed groove in the first material layer, wherein the width of the recessed groove is greater than the width of the through hole, the recessed groove is connected to the through hole, and the recessed groove and the through hole together constitute the groove.

15. The method for preparing a semiconductor structure according to claim 11, characterized in that: Forming the support layer comprises the following steps: forming a first material layer; forming a second material layer on the upper surface of the first material layer; forming a third material layer on the upper surface of the second material layer; Etching the third material layer to form a first through hole penetrating the third material layer along a thickness direction thereof; The second material layer is etched based on the first through hole to form a second through hole in the second material layer. The width of the second through hole is greater than that of the first through hole. The second through hole is connected to the first through hole and together with the first through hole constitutes the groove.

16. The method for preparing a semiconductor structure according to any one of claims 11 to 15, characterized in that: After forming the welding pad, the following steps are also included: forming a protective layer on the upper surface of the support layer and the upper surface of the welding pad, wherein the protective layer covers the welding pad; forming an opening in the protective layer, wherein the opening exposes the welding pad; A welding wire is provided, and one end of the welding wire is connected to the welding pad.

Images