Titanium-nickel-silver multilayer composite metal mesh for semiconductor device electrode

Abstract

The utility model discloses a kind of titanium nickel silver multilayer composite metal net for semiconductor device electrode, belong to semiconductor device technical field, it is applicable to electrode conductivity, adhesion and stability have high request high-performance integrated circuit, power semiconductor device etc. Scene. For the problems of insufficient adhesion, conductivity and stability contradiction, structural strength defects etc. of existing semiconductor device electrode material, the present application adopts titanium metal layer, nickel metal layer and silver metal layer sequentially laminated to form composite structure, and each layer is net-shaped. Among them, titanium metal layer is connected with semiconductor silicon wafer to improve adhesion, nickel metal layer is used as transition layer to block atomic diffusion and enhance interlayer bonding, silver metal layer realizes efficient current transmission, each layer grid pattern is adapted, the composite metal net is synergistically designed by three-layer structure, with high adhesion, high stability, high conductivity and high structural strength.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor device technology, specifically a titanium-nickel-silver multilayer composite metal mesh for semiconductor device electrodes. Background Technology

[0002] In the manufacturing process of semiconductor devices, electrodes are key components for current transmission, and their performance directly affects the overall efficiency, reliability, and lifespan of the device. Currently, commonly used metallic materials for semiconductor device electrodes include single metals or metal alloys such as aluminum, copper, and silver. However, these materials have significant drawbacks in practical applications:

[0003] Metals such as aluminum and copper have weak bonding forces with the silicon substrate of semiconductor devices, and are prone to peeling under long-term high temperature and high voltage operating conditions, leading to device failure. Although silver has excellent conductivity, silver atoms are prone to diffuse into the silicon wafer, forming metallic impurity defects that affect the electrical performance of semiconductor devices. Metals such as titanium and nickel have strong stability, but their conductivity is much lower than that of silver, and they are difficult to meet the requirements of high current transmission when used alone.

[0004] To address these issues, this invention provides a titanium-nickel-silver multilayer composite metal mesh for semiconductor device electrodes. Utility Model Content

[0005] To address the shortcomings of existing technologies, this invention provides a titanium-nickel-silver multilayer composite metal mesh for semiconductor device electrodes, thus solving the aforementioned problems.

[0006] To achieve the above objectives, this utility model is implemented through the following technical solution: a titanium-nickel-silver multilayer composite metal mesh for semiconductor device electrodes, comprising a titanium metal layer, a nickel metal layer and a silver metal layer stacked sequentially, wherein one side surface of the titanium metal layer is directly connected to the silicon wafer of the semiconductor device, the other side surface is connected to one side surface of the nickel metal layer, and the other side surface of the nickel metal layer is connected to one side surface of the silver metal layer, and the titanium metal layer, nickel metal layer and silver metal layer are all mesh structures.

[0007] Preferably, the thickness of the titanium metal layer is 50-200 nm, the thickness of the nickel metal layer is 100-300 nm, and the thickness of the silver metal layer is 200-500 nm.

[0008] Preferably, the purity of the titanium metal layer is not less than 99.99%, the purity of the nickel metal layer is not less than 99.99%, and the purity of the silver metal layer is not less than 99.99%.

[0009] Preferably, the grid patterns of the titanium metal layer, nickel metal layer and silver metal layer are compatible, and the grid line width is 100-500nm, and the shape of the grid holes is square or regular hexagonal.

[0010] Preferably, the bonding surface between the titanium metal layer and the silicon wafer is a mesh-like bonding surface, and the bonding area accounts for 60%-80% of the corresponding surface area of ​​the silicon wafer.

[0011] Preferably, the overall thickness of the multilayer composite metal mesh is 350-1000nm, and the thickness ratio of the titanium metal layer, nickel metal layer and silver metal layer is 1:(2-3):(2-4).

[0012] Beneficial effects

[0013] This invention provides a titanium-nickel-silver multilayer composite metal mesh for semiconductor device electrodes. Compared with the prior art, it has the following advantages:

[0014] 1. The electrodes of this semiconductor device use a titanium-nickel-silver multilayer composite metal mesh. The titanium metal layer has excellent chemical affinity with the silicon substrate, which can significantly improve the bonding force between the composite metal mesh and the silicon wafer and avoid peeling under high temperature and high stress conditions. The nickel metal layer, as a transition layer, can effectively block the diffusion of titanium atoms to the silver layer and silver atoms to the silicon wafer, avoid metal impurity defects, and improve the long-term working stability of the device.

[0015] 2. The electrodes of this semiconductor device use a titanium-nickel-silver multilayer composite metal mesh. The silver metal layer has excellent conductivity, which can meet the requirements of high current transmission. At the same time, the mesh structure reduces the resistance loss of the current transmission path. The suitable multilayer mesh structure improves the flexibility and impact resistance of the electrodes, and can withstand the external force and thermal stress during device packaging, transportation and use, thus extending the service life of the device. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a perspective view of the external structure of this utility model;

[0018] Figure 2 This is a three-dimensional view of the overall bottom structure of this utility model;

[0019] Figure 3 This is a three-dimensional view of the overall disassembled structure of this utility model.

[0020] In the diagram: 1. Titanium metal layer; 2. Nickel metal layer; 3. Silver metal layer; 4. Silicon wafer. Detailed Implementation

[0021] It should be noted that in the description of the embodiments of this application, the terms "front," "rear," "left," "right," "up," "down," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and 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. The terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0022] The present application will be further described in detail below with reference to the accompanying drawings and embodiments.

[0023] Reference Figures 1 to 3 This application provides a titanium-nickel-silver multilayer composite metal mesh for semiconductor device electrodes, and the specific technical solution is as follows:

[0024] Overall structural design

[0025] The multi-layer composite metal mesh includes a titanium metal layer 1, a nickel metal layer 2, and a silver metal layer 3 stacked sequentially. Each layer has a mesh structure, and the layers are directly and tightly connected.

[0026] One side surface of the titanium metal layer 1 is directly connected to the silicon wafer 4 of the semiconductor device, serving as an "adhesion layer" responsible for enhancing the bonding force between the composite metal mesh and the silicon wafer;

[0027] The other side of the titanium metal layer 1 is connected to one side of the nickel metal layer 2. The nickel metal layer 2 serves as a "transition layer," which on the one hand prevents the mutual diffusion of titanium atoms and silver atoms, and on the other hand enhances the interfacial bonding strength between the titanium metal layer and the silver metal layer.

[0028] The other side of the nickel metal layer 2 is connected to one side of the silver metal layer 3. The silver metal layer 3, as a "conductive layer", is responsible for achieving efficient current transmission.

[0029] Key parameter limitations

[0030] Thickness parameters: The thickness of titanium layer 1 is 50-200 nm, the thickness of nickel layer 2 is 100-300 nm, and the thickness of silver layer 3 is 200-500 nm; the overall thickness of the multilayer composite metal mesh is 350-1000 nm, and the thickness ratio of titanium layer 1, nickel layer 2, and silver layer 3 is 1:2-3:2-4. This thickness ratio design ensures synergistic performance of each layer: the titanium layer thickness is sufficient to guarantee adhesion, the nickel layer thickness effectively blocks atomic diffusion, and the silver layer thickness meets the requirements for high conductivity.

[0031] Purity requirements: The purity of titanium metal layer 1, nickel metal layer 2, and silver metal layer 3 shall not be less than 99.99%. High-purity metals can avoid interference from impurity atoms on the electrical performance of semiconductor devices, while improving the conductivity and chemical stability of each layer.

[0032] Mesh structure parameters: The mesh patterns of titanium layer 1, nickel layer 2, and silver layer 3 are compatible, meaning the mesh lines of each layer are aligned, the apertures are consistent, the mesh linewidth is 100-500 nm, and the mesh apertures are square or regular hexagonal. This compatible mesh structure reduces the "edge effect" during current transmission, while also improving the electrode's flexibility and impact resistance; the 100-500 nm linewidth reduces the electrode's parasitic resistance while ensuring structural strength.

[0033] Bonding area requirements: The bonding surface between the titanium metal layer 1 and the silicon wafer 4 is a mesh bonding surface, and the bonding area accounts for 60%-80% of the corresponding surface area of ​​the silicon wafer 4. This bonding area design can reduce the coverage of the metal layer on the silicon wafer surface while ensuring adhesion, and reserve space for other functional layers of semiconductor devices such as passivation layers and insulating layers.

[0034] In this embodiment, the preparation process

[0035] Step 1: Silicon wafer pretreatment. Semiconductor silicon wafer 4 is sequentially subjected to ultrasonic cleaning with acetone, ultrasonic cleaning with ethanol, and rinsing with deionized water. Then it is dried at 120°C to remove surface oil and impurities.

[0036] Step 2: Prepare titanium metal layer 1. Titanium metal is deposited on the surface of silicon wafer 4 using magnetron sputtering. The sputtering power is 150W, the sputtering pressure is 0.5Pa, and the deposition time is 30s, forming a titanium metal mesh with a thickness of 100nm and a purity of 99.99%. The titanium metal mesh is prepared by photolithography-etching process, with a mesh linewidth of 200nm, square mesh holes with a side length of 5μm, and the bonding area accounts for 70% of the corresponding surface area of ​​the silicon wafer.

[0037] Step 3: Prepare nickel metal layer 2. Nickel metal is deposited on the surface of titanium metal layer 1 using electron beam evaporation process. The evaporation power is 200W and the vacuum degree is 5×10⁻⁶. -4 Pa, deposition time of 60s, forming a nickel metal mesh with a thickness of 200nm and a purity of 99.99%; the mesh pattern of the nickel metal mesh is adapted to the titanium metal layer with a line width of 200nm and a square hole side length of 5μm;

[0038] Step 4: Prepare silver metal layer 3. Deposit silver metal on the surface of nickel metal layer 2 using magnetron sputtering process. The sputtering power is 180W, the sputtering pressure is 0.3Pa, and the deposition time is 120s, forming a silver metal mesh with a thickness of 400nm and a purity of 99.99%. The mesh pattern of the silver metal mesh is adapted to the nickel metal layer with a linewidth of 200nm and a square hole side length of 5μm.

[0039] Step 5: Post-treatment. The prepared multilayer composite metal mesh is annealed at 200℃ for 30 minutes to eliminate interlayer stress and enhance interlayer bonding.

[0040] Performance testing

[0041] Adhesion test: The cross-cut test was used with a grid spacing of 1mm. The test results showed no peeling phenomenon, and the adhesion level was 0, the highest level.

[0042] Conductivity test: The resistivity was measured using the four-probe method and was 1.8 × 10⁻⁶. -8 Ω·m, close to the resistivity of pure silver 1.59×10 -8 Ω·m;

[0043] Stability testing: The device was placed in a high-temperature environment of 150℃ for 1000 hours. The test results showed that the diffusion of silver atoms into the silicon wafer was less than 1×10⁻⁶. 15 atoms / cm 2 This is far below the industry-permitted 5×10 15 atoms / cm 2 ;

[0044] Impact resistance test: A 10g steel ball was used for the drop impact test, with a drop height of 5cm. After the test, the metal mesh showed no cracking or peeling, and the electrical properties did not change significantly.

[0045] Furthermore, all contents not described in detail in this specification are existing technologies known to those skilled in the art, and all electrical components mentioned in this document are powered by external power supply lines.

[0046] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0047] Although embodiments of this application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A titanium-nickel-silver multilayer composite metal mesh for semiconductor device electrodes, characterized in that, It includes a titanium metal layer (1), a nickel metal layer (2) and a silver metal layer (3) stacked in sequence. One side of the titanium metal layer (1) is directly connected to the silicon wafer (4) of the semiconductor device, and the other side is connected to one side of the nickel metal layer (2). The other side of the nickel metal layer (2) is connected to one side of the silver metal layer (3). The titanium metal layer (1), the nickel metal layer (2) and the silver metal layer (3) are all mesh structures.

2. The titanium-nickel-silver multilayer composite metal mesh for semiconductor device electrodes according to claim 1, characterized in that, The thickness of the titanium metal layer (1) is 50-200 nm, the thickness of the nickel metal layer (2) is 100-300 nm, and the thickness of the silver metal layer (3) is 200-500 nm.

3. The titanium-nickel-silver multilayer composite metal mesh for semiconductor device electrodes according to claim 1, characterized in that, The purity of the titanium metal layer (1) is not less than 99.99%, the purity of the nickel metal layer (2) is not less than 99.99%, and the purity of the silver metal layer (3) is not less than 99.99%.

4. The titanium-nickel-silver multilayer composite metal mesh for semiconductor device electrodes according to claim 1, characterized in that, The grid patterns of the titanium metal layer (1), nickel metal layer (2) and silver metal layer (3) are compatible, and the grid line width is 100-500nm. The shape of the grid holes is square or regular hexagon.

5. The titanium-nickel-silver multilayer composite metal mesh for semiconductor device electrodes according to claim 1, characterized in that, The connection surface between the titanium metal layer (1) and the silicon wafer (4) is a mesh bonding surface, and the bonding area accounts for 60%-80% of the corresponding surface area of ​​the silicon wafer (4).

6. The titanium-nickel-silver multilayer composite metal mesh for semiconductor device electrodes according to claim 1, characterized in that, The overall thickness of the multilayer composite metal mesh is 350-1000nm, and the thickness ratio of the titanium metal layer (1), nickel metal layer (2), and silver metal layer (3) is 1:(2-3):(2-4).

Images