Semiconductor device and method of forming the same

Abstract

The application discloses a semiconductor device and a forming method thereof. The forming method comprises the following steps: providing a substrate, forming an insulating layer and a first conductive contact pad separated by the insulating layer in the substrate; forming a plurality of convex columns on the substrate; forming a semiconductor structure between two adjacent convex columns, the semiconductor structure being in contact with the first conductive contact pad, the semiconductor structure comprising a first U-shaped conductive layer covering the upper surface of the first conductive contact pad and the sidewall of each convex column, a second U-shaped conductive layer located in the first U-shaped conductive layer, a first dielectric layer arranged in the second U-shaped conductive layer, and a second conductive contact pad located above the first dielectric layer. The application can inhibit the leakage problem of the semiconductor device and improve the semiconductor performance.

Description

Technical Field

[0001] This application relates to the field of semiconductor technology, specifically to a semiconductor device and a method for forming the same. Background Technology

[0002] Interconnect structures are common in semiconductor devices, enabling the interconnection of multiple objects within the device, allowing them to communicate, cooperate, and perform corresponding functions. The inventors researched interconnect structures in semiconductor devices and discovered that using... Figure 1 When the interconnect structure shown (such as a ring interconnect structure) connects the lower object 1 and the upper object 2, leakage current is likely to occur, which will affect the performance of the corresponding semiconductor device. Summary of the Invention

[0003] In view of this, this application provides a semiconductor device and a method for forming the same, to solve the problem that the interconnect structure is prone to leakage, which affects the performance of the corresponding semiconductor device.

[0004] This application provides a method for forming a semiconductor device, comprising:

[0005] A substrate is provided in which an insulating layer and a first conductive contact pad separated by the insulating layer are formed;

[0006] Multiple protrusions are formed on the substrate;

[0007] A semiconductor structure is formed between two adjacent protrusions, the semiconductor structure being in contact with the first conductive contact pad, the semiconductor structure including a first U-shaped conductive layer covering the upper surface of the first conductive contact pad and the sidewalls of each of the protrusions, a second U-shaped conductive layer located inside the first U-shaped conductive layer, a first dielectric layer disposed within the second U-shaped conductive layer, and a second conductive contact pad located above the first dielectric layer.

[0008] Optionally, forming a semiconductor structure between two adjacent protrusions includes: forming a first U-shaped conductive layer conformally covering the upper surface of the first conductive contact pad and the sidewalls of each protrusion; forming a second U-shaped conductive layer on the surface of the first U-shaped conductive layer, wherein the conductivity of the second U-shaped conductive layer is lower than that of the first U-shaped conductive layer; filling a first dielectric layer in a first groove within the second U-shaped conductive layer, wherein the top surface of the first dielectric layer is not higher than the top surface of the second U-shaped conductive layer; and forming a second conductive contact pad on the upper surface of the first dielectric layer, so that the first U-shaped conductive layer and the second U-shaped conductive layer connect the first conductive contact pad and the second conductive contact pad.

[0009] Optionally, filling the first dielectric layer in the first groove within the second U-shaped conductive layer includes: forming a first dielectric layer that fills the first groove within the second U-shaped conductive layer and covers the surface of the second U-shaped conductive layer; etching the first dielectric layer and the second U-shaped conductive layer so that the surfaces of the first dielectric layer and the second U-shaped conductive layer are flush and lower than the top of the first U-shaped conductive layer.

[0010] Optionally, etching the first dielectric layer and the second U-shaped conductive layer includes: etching the first dielectric layer such that the surface of the first dielectric layer is located within the first groove; and etching the second U-shaped conductive layer such that the second U-shaped conductive layer is aligned with the first dielectric layer.

[0011] Optionally, a second dielectric layer is provided within the protrusion; the first U-shaped conductive layer further covers the top surface of the protrusion; a second conductive contact pad is formed on the upper surface of the first dielectric layer, including: forming a first doped semiconductor layer that fills the sidewall of the first U-shaped conductive layer and the upper surface of the second U-shaped conductive layer and the first dielectric layer, and covers the sidewall of the first U-shaped conductive layer and the upper surface of the second U-shaped conductive layer and the first dielectric layer; etching the first doped semiconductor layer and the first U-shaped conductive layer to expose the second dielectric layer within the protrusion, and making the first doped semiconductor layer serve as the second conductive contact pad, aligned with the second dielectric layer.

[0012] Optionally, a second dielectric layer is provided within the protrusion; the first U-shaped conductive layer further covers the top surface of the protrusion, and the second U-shaped conductive layer further covers the top surface of the first U-shaped conductive layer; a second conductive contact pad is formed on the upper surface of the first dielectric layer, including: forming a third groove that fills the sidewall of the second U-shaped conductive layer and the upper surface of the first dielectric layer, and a first doped semiconductor layer that covers the sidewall of the second U-shaped conductive layer and the upper surface of the first dielectric layer; etching the first doped semiconductor layer, the first U-shaped conductive layer, and the second U-shaped conductive layer to expose the second dielectric layer within the protrusion, and making the first doped semiconductor layer serve as the second conductive contact pad, aligned with the second dielectric layer.

[0013] Optionally, the first doped semiconductor layer is doped with a first type of particles.

[0014] Optionally, the top of the first dielectric layer is aligned with the top of the second U-shaped conductive layer.

[0015] Optionally, the first conductive contact pad comprises polycrystalline silicon doped with a first type of particles.

[0016] Optionally, the first U-shaped conductive layer includes a second doped semiconductor layer; the second U-shaped conductive layer includes a third doped semiconductor layer; the second doped semiconductor layer is doped with a first type of particles, and the third doped semiconductor layer is doped with a second type of particles.

[0017] Optionally, the first type of particles includes N-type particles; the second type of particles includes P-type particles.

[0018] Optionally, the second doped semiconductor layer includes an N-type doped polysilicon layer; the third doped semiconductor layer includes a germanium-silicon layer doped with boron ions.

[0019] This application also provides a semiconductor device, including:

[0020] A substrate, wherein a plurality of first conductive contact pads separated by an insulating layer are provided therein;

[0021] Multiple protrusions are located on the substrate;

[0022] A semiconductor structure located between two adjacent protrusions, the semiconductor structure being in contact with the first conductive contact pad, the semiconductor structure including a first U-shaped conductive layer covering the upper surface of the first conductive contact pad and the sidewalls of each of the protrusions, a second U-shaped conductive layer located inside the first U-shaped conductive layer, a first dielectric layer disposed within the second U-shaped conductive layer, and a second conductive contact pad located above the first dielectric layer.

[0023] Optionally, the conductivity of the second U-shaped conductive layer is lower than that of the first U-shaped conductive layer.

[0024] Optionally, the top surface of the second U-shaped conductive layer is aligned with the top surface of the first dielectric layer.

[0025] Optionally, the top surface of the first dielectric layer is lower than the top surface of the second U-shaped conductive layer.

[0026] Optionally, the protrusion has a second dielectric layer inside; the surface of the second conductive contact pad is aligned with the surface of the second dielectric layer.

[0027] Optionally, the second U-shaped conductive layer forms a first groove, and the first groove is filled with the first dielectric layer.

[0028] Optionally, the sidewall of the first U-shaped conductive layer and the upper surface of the second U-shaped conductive layer and the first dielectric layer form a second groove, and the second groove is filled with the second conductive contact pad.

[0029] Optionally, the sidewall of the second U-shaped conductive layer and the upper surface of the first dielectric layer form a third groove, and the third groove is filled with the second conductive contact pad.

[0030] The aforementioned semiconductor device and its formation method form a semiconductor structure between two adjacent protrusions. The semiconductor structure is in contact with a first conductive contact pad. The semiconductor structure includes a first U-shaped conductive layer covering the upper surface of the first conductive contact pad and the sidewalls of each protrusion, a second U-shaped conductive layer located inside the first U-shaped conductive layer, a first dielectric layer disposed within the second U-shaped conductive layer, and a second conductive contact pad located above the first dielectric layer. In this way, the first U-shaped conductive layer and the second U-shaped conductive layer can connect the first conductive contact pad and the second conductive contact pad, realizing the interconnection between the first conductive contact pad and the second conductive contact pad, which can improve the leakage current condition.

[0031] Furthermore, the conductivity of the second U-shaped conductive layer is lower than that of the first U-shaped conductive layer. For example, the first U-shaped conductive layer is N-type doped, and the second U-shaped conductive layer is P-type doped, etc. In this way, a PN junction can be formed between the second U-shaped conductive layer and the first U-shaped conductive layer, which can more effectively suppress the leakage problem of the first U-shaped conductive layer.

[0032] It is evident that this application can improve the leakage current condition of the interconnect layer from multiple aspects, thereby enhancing the performance of the resulting semiconductor device. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a schematic diagram of the interconnection structure during the inventor's research process;

[0035] Figure 2 This is a flowchart of a method for forming a semiconductor device according to an embodiment of this application;

[0036] Figure 3a , Figure 3b and Figure 3c This is a schematic diagram of the structure obtained in each step of an embodiment of this application;

[0037] Figure 4a , Figure 4b and Figure 4c This is a schematic diagram of the structure obtained in each step of an embodiment of this application;

[0038] Figure 5a , Figure 5b and Figure 5c This is a schematic diagram of the structure obtained in each step of an embodiment of this application;

[0039] Figure 6a , Figure 6b , Figure 6c and Figure 6d This is a schematic diagram of the structure obtained in each step of an embodiment of this application. Detailed Implementation

[0040] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. In the absence of conflict, the following embodiments and their technical features can be combined with each other.

[0041] This application provides a method for forming a semiconductor device in its first aspect, with reference to... Figure 2 As shown, the forming method includes steps S110 to S130.

[0042] S110, Reference Figure 3a As shown, a substrate 210 is provided, in which an insulating layer 212 and a first conductive contact pad 211 separated by the insulating layer 212 are formed.

[0043] The first conductive contact pad 211 may include contact elements such as contact plugs, functional regions such as source regions, and other interconnection objects located inside the substrate that need to be interconnected with other objects.

[0044] Optionally, the material of the first conductive contact pad 211 may include a conductive material, a semiconductor material, and / or a doped semiconductor material. For example, the first conductive contact pad 211 may be formed using polycrystalline silicon, doped polycrystalline silicon, or other silicon-containing conductive materials. Optionally, the material of the first conductive contact pad 211 may include polycrystalline silicon to give the first conductive contact pad 211 better conductivity. Optionally, the first conductive contact pad 211 may also include polycrystalline silicon doped with a first type of particles.

[0045] S120, Reference Figure 3b As shown, a plurality of protrusions 221 are formed on the substrate 210.

[0046] The aforementioned protrusion 221 has a dielectric layer inside, which can also be called an insulating sidewall layer. There is a third groove 222 between two adjacent protrusions 221. The insulating layer 212 is located at the bottom of the protrusion 221. The third groove 222 exposes the top surface of the first conductive contact pad 211.

[0047] S130, a semiconductor structure 220 is formed between two adjacent protrusions. The semiconductor structure 220 contacts the first conductive contact pad 211. The semiconductor structure 220 includes a first U-shaped conductive layer 223 covering the upper surface of the first conductive contact pad 211 and the sidewalls of each protrusion, a second U-shaped conductive layer 224 located inside the first U-shaped conductive layer 223, a first dielectric layer 225 disposed within the second U-shaped conductive layer 224, and a second conductive contact pad 228 located above the first dielectric layer 225.

[0048] The above-described method for forming a semiconductor device involves forming a semiconductor structure 220 between two adjacent protrusions. The semiconductor structure 220 contacts a first conductive contact pad 211. The semiconductor structure 220 includes a first U-shaped conductive layer 223 covering the upper surface of the first conductive contact pad 211 and the sidewalls of each protrusion, a second U-shaped conductive layer 224 located inside the first U-shaped conductive layer 223, a first dielectric layer 225 disposed within the second U-shaped conductive layer 224, and a second conductive contact pad 228 located above the first dielectric layer 225. In this way, the first U-shaped conductive layer 223 and the second U-shaped conductive layer 224 can connect the first conductive contact pad 211 and the second conductive contact pad 228, realizing the interconnection between the first conductive contact pad 211 and the second conductive contact pad 228, which can improve the leakage current condition.

[0049] In one embodiment, step S130 above, forming a semiconductor structure 220 between two adjacent protrusions, includes steps S131 to S134.

[0050] S131, Reference Figure 4a As shown, a first U-shaped conductive layer 223 is formed to conformally cover the upper surface of the first conductive contact pad 211 and the sidewalls of each of the protrusions 221.

[0051] S132, a second U-shaped conductive layer 224 is formed on the surface of the first U-shaped conductive layer 223, the conductivity of the second U-shaped conductive layer 224 being lower than that of the first U-shaped conductive layer 223. A first groove is formed within the second U-shaped conductive layer 224. The second U-shaped conductive layer 224 can conformally cover the bottom surface and sidewalls of the first U-shaped conductive layer 223. Optionally, if the first U-shaped conductive layer 223 also covers the top surface of the protrusion 221, the second U-shaped conductive layer 224 can also cover the top surface of the first U-shaped conductive layer 223.

[0052] The aforementioned first U-shaped conductive layer 223 includes a second doped semiconductor layer, and the second U-shaped conductive layer 224 may include a third doped semiconductor layer. The second doped semiconductor layer is doped with a first type of particle, and the third doped semiconductor layer is doped with a second type of particle. The first type of particle can move faster in the second doped semiconductor layer than the second type of particle can move faster in the third doped semiconductor layer. For example, the first type of particle includes N-type particles, and the second type of particle includes P-type particles, so that the conductivity of the first U-shaped conductive layer 223 is higher than that of the second U-shaped conductive layer 224. Preferably, the second doped semiconductor layer includes an N-type doped polysilicon layer, that is, the first U-shaped conductive layer 223 is N-type doped; the third doped semiconductor layer includes a germanium-silicon layer doped with boron ions, so that the second U-shaped conductive layer 224 is P-type doped. In this way, a PN junction can be formed between the second U-shaped conductive layer 224 and the first U-shaped conductive layer 223, effectively suppressing the leakage problem of the first U-shaped conductive layer 223.

[0053] S133, Reference Figure 4b As shown, a first dielectric layer 225 is filled in the first groove within the second U-shaped conductive layer 224, and the top surface of the first dielectric layer 225 is not higher than the top surface of the second U-shaped conductive layer 224; in one example, such as Figure 4b As shown, the top of the first dielectric layer 225 can be aligned with the top of the second U-shaped conductive layer 224; in another example, as Figure 4c As shown, the top of the first dielectric layer 225 may be lower than the top of the second U-shaped conductive layer 224.

[0054] The first dielectric layer 225 can be obtained by deposition of dielectric materials such as oxides.

[0055] Optionally, step S133 may further include: forming a first dielectric layer 225 that fills the first groove formed by the second U-shaped conductive layer 224 and covers the top surface of the second U-shaped conductive layer 224; etching the first dielectric layer 225 so that the etched first dielectric layer 225 is lower than the first U-shaped conductive layer 223, that is, the top surface of the first dielectric layer 225 is located in the first groove; etching the second U-shaped conductive layer 224 so that the top of the second U-shaped conductive layer 224 is aligned with the top of the first dielectric layer 225 (e.g., ...). Figure 4b (as shown), or the top of the second U-shaped conductive layer 224 is higher than the top of the first dielectric layer 225 (not shown in the figure).

[0056] S134, a second conductive contact pad 228 is formed on the upper surface of the first dielectric layer 225, resulting in... Figure 4c Or such as Figure 3cThe semiconductor structure shown is configured such that the first U-shaped conductive layer 223 and the second U-shaped conductive layer 224 connect the first conductive contact pad 211 and the second conductive contact pad 228.

[0057] In this embodiment, the conductivity of the second U-shaped conductive layer 224 is lower than that of the first U-shaped conductive layer 223. For example, the first U-shaped conductive layer 223 is N-type doped, and the second U-shaped conductive layer 224 is P-type doped, etc. In this way, a PN junction can be formed between the second U-shaped conductive layer 224 and the first U-shaped conductive layer 223, which can more effectively suppress the leakage problem of the first U-shaped conductive layer 223.

[0058] In one example, step S133, filling the first dielectric layer 225 in the first groove within the second U-shaped conductive layer 224, includes:

[0059] refer to Figure 5a As shown, a first dielectric layer 225 is formed to fill the first groove in the second U-shaped conductive layer 224 and cover the surface of the second U-shaped conductive layer 224;

[0060] refer to Figure 5b As shown, the first dielectric layer 225 and the second U-shaped conductive layer 224 are etched so that the surfaces of the first dielectric layer 225 and the second U-shaped conductive layer 224 are flush with each other and lower than the top of the first U-shaped conductive layer 223. At this time, the sidewall of the first U-shaped conductive layer 223 and the top surfaces of the first dielectric layer 225 and the second U-shaped conductive layer 224 form a second groove 229a.

[0061] In this example, both the first U-shaped conductive layer 223 and the second U-shaped conductive layer 224 can contact the subsequently formed second conductive contact pad 228, which can improve the corresponding interconnection capability and further enhance the conductivity.

[0062] In another example, step S133, filling the first dielectric layer 225 into the first groove within the second U-shaped conductive layer 224, may also include:

[0063] refer to Figure 5a As shown, a first dielectric layer 225 is formed to fill the first groove in the second U-shaped conductive layer 224 and cover the surface of the second U-shaped conductive layer 224;

[0064] refer to Figure 5cAs shown, the first dielectric layer 225 is etched so that it is lower than the tops of the first U-shaped conductive layer 223 and the second U-shaped conductive layer 224, at which point the tops of the first U-shaped conductive layer 223 and the second U-shaped conductive layer 224 are aligned. At this point, the first groove formed by the second U-shaped conductive layer 224 can form a new groove after the formation of the first dielectric layer 225; this new groove can be referred to as the fourth groove 229b.

[0065] The etching process used in this example is relatively simple and can simplify the process steps.

[0066] In one example, etching the first dielectric layer 225 and the second U-shaped conductive layer 224 includes:

[0067] The first dielectric layer 225 is etched so that the surface of the first dielectric layer 225 is located within the first groove, at which point the following can be obtained: Figure 5c The structure shown;

[0068] The second U-shaped conductive layer 224 is etched to align it with the first dielectric layer 225, at which point the following can be obtained: Figure 5b The structure shown.

[0069] In one example, the protrusion 221 contains a second dielectric layer 226. The second dielectric layer 226 may include dielectric materials such as an oxide layer and / or a oxynitride layer. Optionally, the second dielectric layer 226 may include a single-layer structure or a multi-layer structure.

[0070] Optionally, during the formation of the first U-shaped conductive layer 223, the first U-shaped conductive layer 223 may also cover the top surface of the protrusion 221. Subsequently, the first U-shaped conductive layer 223 may be etched through a related etching process to remove the unnecessary parts and retain the final required first U-shaped conductive layer 223.

[0071] Further, a second conductive contact pad 228 is formed on the upper surface of the first dielectric layer 225, comprising:

[0072] refer to Figure 6a As shown, a second groove 229a is formed that fills the sidewall of the first U-shaped conductive layer 223 and the upper surface of the second U-shaped conductive layer 224 and the first dielectric layer 225, and covers the first U-shaped conductive layer 223 and the second U-shaped conductive layer 224 with a first doped semiconductor layer 228'.

[0073] refer to Figure 6bAs shown, the first doped semiconductor layer 228' and the first U-shaped conductive layer 223 are etched to expose the second dielectric layer 226 within the protrusion 221, and the first doped semiconductor layer 228' serves as the second conductive contact pad 228, aligning with the second dielectric layer 226.

[0074] In one example, the protrusion 221 contains a second dielectric layer 226. The second dielectric layer 226 may include dielectric materials such as an oxide layer and / or a oxynitride layer. Optionally, the second dielectric layer 226 may include a single-layer structure or a multi-layer structure.

[0075] Optionally, during the formation of the first U-shaped conductive layer 223, the first U-shaped conductive layer 223 may also cover the top surface of the protrusion 221. Subsequently, the first U-shaped conductive layer 223 can be etched using a relevant etching process to remove unwanted portions, retaining the final required first U-shaped conductive layer 223. During the formation of the second U-shaped conductive layer 224, the second U-shaped conductive layer 224 may also cover the top surface of the first U-shaped conductive layer 223. Subsequently, the second U-shaped conductive layer 224 can be etched using a relevant etching process to remove unwanted portions, retaining the final required second U-shaped conductive layer 224.

[0076] Further, a second conductive contact pad 228 is formed on the upper surface of the first dielectric layer 225, comprising:

[0077] refer to Figure 6c As shown, a fourth groove 229b is formed, which fills the sidewall of the second U-shaped conductive layer 224 and the upper surface of the first dielectric layer 225, and a first doped semiconductor layer 228' is formed covering the sidewall of the second U-shaped conductive layer 224 and the upper surface of the first dielectric layer 225.

[0078] refer to Figure 6d As shown, the first doped semiconductor layer 228', the first U-shaped conductive layer 223 and the second U-shaped conductive layer 224 are etched to expose the second dielectric layer 226 within the protrusion 221, and the first doped semiconductor layer 228' serves as the second conductive contact pad 228, aligning with the second dielectric layer 226.

[0079] Optionally, the first doped semiconductor layer 228' is doped with a first type of particle, which is an N-type particle.

[0080] In one embodiment, the first U-shaped conductive layer 223 includes a second doped semiconductor layer; the second U-shaped conductive layer 224 includes a third doped semiconductor layer; the second doped semiconductor layer is doped with a first type of particles, and the third doped semiconductor layer is doped with a second type of particles, so that the conductivity of the second U-shaped conductive layer 224 is lower than that of the first U-shaped conductive layer 223.

[0081] Optionally, the first type of particles includes N-type particles; the second type of particles includes P-type particles.

[0082] Optionally, the second doped semiconductor layer includes an N-type doped polysilicon layer; the third doped semiconductor layer includes a germanium-silicon layer doped with boron ions.

[0083] The above method for forming a semiconductor device involves forming a semiconductor structure 220 between two adjacent protrusions. The semiconductor structure 220 contacts a first conductive contact pad 211. The semiconductor structure 220 includes a first U-shaped conductive layer 223 covering the upper surface of the first conductive contact pad 211 and the sidewalls of each protrusion, a second U-shaped conductive layer 224 located inside the first U-shaped conductive layer 223, a first dielectric layer 225 disposed within the second U-shaped conductive layer 224, and a second conductive contact pad 228 located above the first dielectric layer 225. In this way, the first U-shaped conductive layer 223 and the second U-shaped conductive layer 224 can connect the first conductive contact pad 211 and the second conductive contact pad 228, realizing the interconnection between the first conductive contact pad 211 and the second conductive contact pad 228, which can improve the leakage current condition. The conductivity of the second U-shaped conductive layer 224 is lower than that of the first U-shaped conductive layer 223. For example, the first U-shaped conductive layer 223 may be N-type doped, while the second U-shaped conductive layer 224 may be P-type doped. In this way, a PN junction can be formed between the second U-shaped conductive layer 224 and the first U-shaped conductive layer 223, which can more effectively suppress the leakage current problem of the first U-shaped conductive layer 223. It can be seen that the above-described semiconductor device formation method can improve the leakage current condition of the interconnect layer from multiple aspects and enhance the performance of the resulting semiconductor device.

[0084] In a second aspect, this application provides a semiconductor device, with reference to... Figure 3c and Figure 4c As shown, the above-mentioned semiconductor device includes:

[0085] Substrate 210, wherein a plurality of first conductive contact pads 211 are provided in the substrate 210 and separated by insulating layer 212;

[0086] Multiple protrusions 221 are located on the substrate 210;

[0087] A semiconductor structure 220 is located between two adjacent protrusions 221. The semiconductor structure 220 is in contact with the first conductive contact pad 211. The semiconductor structure 220 includes a first U-shaped conductive layer 223 covering the upper surface of the first conductive contact pad 211 and the sidewalls of each of the protrusions 221, a second U-shaped conductive layer 224 located inside the first U-shaped conductive layer 223, a first dielectric layer 225 disposed in the second U-shaped conductive layer 224, and a second conductive contact pad 228 located above the first dielectric layer 225.

[0088] The first conductive contact pad 211 may include contact elements such as contact plugs, functional regions such as source regions, and other interconnection objects located inside the substrate that need to be interconnected with other objects.

[0089] Optionally, the material of the first conductive contact pad 211 may include a conductive material, a semiconductor material, and / or a doped semiconductor material. For example, the first conductive contact pad 211 may be formed using polycrystalline silicon, doped polycrystalline silicon, or other silicon-containing conductive materials. Optionally, the material of the first conductive contact pad 211 may include polycrystalline silicon to give the first conductive contact pad 211 better conductivity. Optionally, the first conductive contact pad 211 may also include polycrystalline silicon doped with a first type of particles.

[0090] The aforementioned protrusion 221 has a dielectric layer inside, which can also be called an insulating sidewall layer. There is a third groove 222 between two adjacent protrusions 221. The insulating layer 212 is located at the bottom of the protrusion 221. The third groove 222 exposes the top surface of the first conductive contact pad 211.

[0091] In one embodiment, the conductivity of the second U-shaped conductive layer 224 is lower than that of the first U-shaped conductive layer 223, which can more effectively suppress the leakage problem of the first U-shaped conductive layer 223.

[0092] In one embodiment, the top surface of the second U-shaped conductive layer 224 is aligned with the top surface of the first dielectric layer 225.

[0093] In one embodiment, the top surface of the first dielectric layer 225 is lower than the top surface of the second U-shaped conductive layer 224.

[0094] In one embodiment, the protrusion 221 is provided with a second dielectric layer 226; the surface of the second conductive contact pad 228 is aligned with the surface of the second dielectric layer 226.

[0095] In one embodiment, the second U-shaped conductive layer 224 forms a first groove, and the first groove is filled with the first dielectric layer 225.

[0096] In one embodiment, the sidewall of the first U-shaped conductive layer 223 and the upper surface of the second U-shaped conductive layer 224 and the first dielectric layer 225 form a second groove 229a, and the second groove 229a is filled with the second conductive contact pad 228.

[0097] In one embodiment, the sidewall of the second U-shaped conductive layer 224 and the upper surface of the first dielectric layer 225 form a fourth groove 229b, and the fourth groove 229b is filled with the second conductive contact pad 228.

[0098] The semiconductor device described above can be formed using the semiconductor device formation method described in any of the above embodiments, and has all the beneficial effects of the semiconductor device formation method described in any of the above embodiments, which will not be repeated here.

[0099] Although this application has been shown and described with respect to one or more implementations, equivalent variations and modifications will occur to those skilled in the art based on a reading and understanding of this specification and the accompanying drawings. This application includes all such modifications and variations and is limited only by the scope of the appended claims. In particular, with respect to the various functions performed by the aforementioned components, the terminology used to describe such components is intended to correspond to any component (unless otherwise indicated) that performs the specified function of said component (e.g., is functionally equivalent to it), even if it is not necessarily structurally equivalent to the disclosed structure that performs the functions in the exemplary implementations of this specification shown herein.

[0100] That is, the above description is only an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural changes made using the content of this application’s specification and drawings, such as the combination of technical features between different embodiments, or direct or indirect application in other related technical fields, are similarly included within the patent protection scope of this application.

[0101] Furthermore, it should be understood that in the description of this application, the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Additionally, for structural elements with the same or similar characteristics, this application may use the same or different reference numerals for identification. Moreover, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0102] In this application, the term "exemplary" is used to mean "serving as an example, illustration, or description." Any embodiment described as "exemplary" in this application is not necessarily to be construed as more preferred or advantageous than other embodiments. This application has been provided above to enable any person skilled in the art to implement and use it. Various details have been set forth in the above description for purposes of explanation. It should be understood that those skilled in the art will recognize that this application can be implemented without using these specific details. In other embodiments, well-known structures and processes will not be described in detail to avoid obscuring the description of this application with unnecessary detail. Therefore, this application is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed herein.

Claims

1. A method for forming a semiconductor device, characterized in that, The forming method includes: A substrate is provided in which an insulating layer and a first conductive contact pad separated by the insulating layer are formed; Multiple protrusions are formed on the substrate; A semiconductor structure is formed between two adjacent protrusions. The semiconductor structure is in contact with the first conductive contact pad. The semiconductor structure includes a first U-shaped conductive layer covering the upper surface of the first conductive contact pad and the sidewalls of each protrusion, a second U-shaped conductive layer located inside the first U-shaped conductive layer, a first dielectric layer disposed within the second U-shaped conductive layer, and a second conductive contact pad located above the first dielectric layer. The bottom surface of the first U-shaped conductive layer is in direct contact with the first conductive contact pad, and the sidewall of the first U-shaped conductive layer is in direct contact with the second conductive contact pad. The conductivity of the second U-shaped conductive layer is lower than that of the first U-shaped conductive layer.

2. The method for forming a semiconductor device according to claim 1, characterized in that, The formation of a semiconductor structure between two adjacent protrusions includes: A first U-shaped conductive layer is formed to conformally cover the upper surface of the first conductive contact pad and the sidewalls of each of the protrusions; A second U-shaped conductive layer is formed on the surface of the first U-shaped conductive layer; A first dielectric layer is filled in the first groove within the second U-shaped conductive layer, wherein the top surface of the first dielectric layer is not higher than the top surface of the second U-shaped conductive layer; A second conductive contact pad is formed on the upper surface of the first dielectric layer so that the first U-shaped conductive layer and the second U-shaped conductive layer are connected to the first conductive contact pad and the second conductive contact pad.

3. The method for forming a semiconductor device according to claim 2, characterized in that, The step of filling the first groove within the second U-shaped conductive layer with a first dielectric layer includes: A first dielectric layer is formed to fill the first groove in the second U-shaped conductive layer and cover the surface of the second U-shaped conductive layer; The first dielectric layer and the second U-shaped conductive layer are etched so that the surfaces of the first dielectric layer and the second U-shaped conductive layer are flush with each other and lower than the top of the first U-shaped conductive layer.

4. The method for forming a semiconductor device according to claim 3, characterized in that, The etching of the first dielectric layer and the second U-shaped conductive layer includes: The first dielectric layer is etched so that the surface of the first dielectric layer is located within the first groove; The second U-shaped conductive layer is etched to align it with the first dielectric layer.

5. The method for forming a semiconductor device according to claim 3, characterized in that, The protrusion has a second dielectric layer inside; the first U-shaped conductive layer also covers the top surface of the protrusion. A second conductive contact pad is formed on the upper surface of the first dielectric layer, including: A second groove is formed by filling the sidewall of the first U-shaped conductive layer and the upper surface of the second U-shaped conductive layer and the first dielectric layer, and a first doped semiconductor layer is formed covering the sidewall of the first U-shaped conductive layer and the upper surface of the second U-shaped conductive layer and the first dielectric layer; The first doped semiconductor layer and the first U-shaped conductive layer are etched to expose the second dielectric layer within the protrusion, and the first doped semiconductor layer is used as the second conductive contact pad to align with the second dielectric layer.

6. The method for forming a semiconductor device according to claim 5, characterized in that, The first doped semiconductor layer is doped with particles of the first type.

7. The method for forming a semiconductor device according to claim 2, characterized in that, The top of the first dielectric layer is aligned with the top of the second U-shaped conductive layer.

8. The method for forming a semiconductor device according to claim 1, characterized in that, The first conductive contact pad comprises polycrystalline silicon doped with a first type of particles.

9. The method for forming a semiconductor device according to claim 1, characterized in that, The first U-shaped conductive layer includes a second doped semiconductor layer; the second U-shaped conductive layer includes a third doped semiconductor layer; the second doped semiconductor layer is doped with a first type of particles, and the third doped semiconductor layer is doped with a second type of particles.

10. The method for forming a semiconductor device according to claim 6 or 8, characterized in that, The first type of particle includes N-type particles.

11. The method for forming a semiconductor device according to claim 9, characterized in that, The second type of particle includes P-type particles.

12. The method for forming a semiconductor device according to claim 9, characterized in that, The second doped semiconductor layer includes an N-type doped polycrystalline silicon layer; the third doped semiconductor layer includes a germanium-silicon layer doped with boron ions.

13. A semiconductor device, characterized in that, include: A substrate, wherein a plurality of first conductive contact pads separated by an insulating layer are provided therein; Multiple protrusions are located on the substrate; A semiconductor structure is located between two adjacent protrusions, and the semiconductor structure is in contact with the first conductive contact pad. The semiconductor structure includes a first U-shaped conductive layer covering the upper surface of the first conductive contact pad and the sidewalls of each of the protrusions, a second U-shaped conductive layer located inside the first U-shaped conductive layer, a first dielectric layer disposed within the second U-shaped conductive layer, and a second conductive contact pad located above the first dielectric layer. The bottom surface of the first U-shaped conductive layer is in direct contact with the first conductive contact pad, and the sidewall of the first U-shaped conductive layer is in direct contact with the second conductive contact pad. The conductivity of the second U-shaped conductive layer is lower than that of the first U-shaped conductive layer.

14. The semiconductor device according to claim 13, characterized in that, The top surface of the second U-shaped conductive layer is aligned with the top surface of the first dielectric layer.

15. The semiconductor device according to claim 13, characterized in that, The top surface of the first dielectric layer is lower than the top surface of the second U-shaped conductive layer.

16. The semiconductor device according to claim 13, characterized in that, The protrusion has a second dielectric layer inside; the surface of the second conductive contact pad is aligned with the surface of the second dielectric layer.

17. The semiconductor device according to claim 13, characterized in that, The sidewall of the first U-shaped conductive layer, together with the upper surface of the second U-shaped conductive layer and the first dielectric layer, forms a second groove, and the second groove is filled with the second conductive contact pad.

18. The semiconductor device according to claim 13, characterized in that, The sidewall of the second U-shaped conductive layer and the upper surface of the first dielectric layer form a third groove, and the third groove is filled with the second conductive contact pad.

19. A semiconductor device, characterized in that, include: A substrate, wherein a plurality of first conductive contact pads separated by an insulating layer are provided therein; A plurality of protrusions are located on the substrate, the protrusions are located on the insulating layer and extend upward in a direction perpendicular to the top surface of the substrate; A semiconductor structure is located between two adjacent protrusions, and the semiconductor structure is in contact with the first conductive contact pad. The semiconductor structure includes a first U-shaped conductive layer covering the upper surface of the first conductive contact pad and the sidewalls of each of the protrusions, a second U-shaped conductive layer located inside the first U-shaped conductive layer, a first dielectric layer disposed within the second U-shaped conductive layer, and a second conductive contact pad located above the first dielectric layer. The bottom surface of the first U-shaped conductive layer is in direct contact with the first conductive contact pad, and the sidewall of the first U-shaped conductive layer is in direct contact with the second conductive contact pad. The conductivity of the second U-shaped conductive layer is lower than that of the first U-shaped conductive layer.

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