Method for producing silicon-coated copper, silicon-coated copper for antioxidant use using the same, and semiconductor device using the same

Abstract

The present invention relates to a method for manufacturing silicon-coated copper, silicon-coated copper for oxidation prevention using the same, and a semiconductor device using the same, and more particularly to copper having a surface coated with silicon (Si) that has oxidation resistance while maintaining electrical properties by forming a protective film of a silicon (Si)-oxygen (O)-copper (Cu) mixed layer by depositing silicon (Si). The silicon-coated copper of the present invention is characterized in that a silicon (Si)-oxygen (O) mixed layer is formed by depositing silicon (Si). The silicon-coated copper is characterized by comprising a copper layer (10), a psychox layer (20) formed on the copper layer (10) by mixing silicon (Si)-oxygen (O)-copper (Cu), a first silicon (Si)-oxygen (O) mixed layer (30) formed on the psychox layer (20), a silicon (Si) layer (40) formed on the first silicon (Si)-oxygen (O) mixed layer (30), and a second silicon (Si)-oxygen (O) mixed layer (50) formed on the silicon (Si) layer (40). The method for manufacturing silicon-coated copper according to the present invention is characterized by depositing silicon (Si) in a single sputtering process.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing silicon-coated copper, silicon-coated antioxidant copper using the same, and a semiconductor device using the same. More specifically, the present invention relates to copper including a surface coated with silicon (Si) having oxidation resistance while maintaining electrical properties by depositing silicon (Si) to form a protective film of a silicon (Si)-oxygen (O)-copper (Cu) mixed layer.

Background Art

[0002] Generally, copper is a conductive material with high utilization value and is widely used. Such copper is used as a thin film, foil, or massive structure. However, since copper has weak oxidation resistance, it cannot be used when extremely high reliability is required, when long-term use is necessary, or when it is used at a high temperature. Gold, which has a higher resistance and a higher price than copper, is used instead.

[0003] Therefore, in order to more efficiently utilize copper, which is economically advantageous and has excellent physical properties, a technique for solving such oxidation problems is required.

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present invention has been made to solve the above problems, and an object of the present invention is to provide a method for manufacturing a copper thin film, foil, or massive structure that prevents oxidation by forming an Si—O—Cu protective layer by depositing Si and is stable against oxidation even at high temperatures.

[0005] The technical problems to be solved by the invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those having ordinary knowledge in the technical field to which the present invention pertains from the following description.

Means for Solving the Problems

[0006] The present invention relates to copper for antioxidant coated with silicon, characterized in that silicon (Si) is vapor-deposited to form a silicon (Si)-oxygen (O) and silicon (Si)-oxygen (O)-copper (Cu) mixed layer.

[0007] Further, the copper coated with silicon has an electrical resistance value between that of copper on which silicon (Si) is not vapor-deposited and gold (Au).

[0008] Further, the copper coated with silicon has an electrical resistance value of 1.68×10 -6 ~2.2×10 -6 Ω·cm.

[0009] Further, the copper coated with silicon comprises a copper layer 10, a coccox layer 20 formed by mixing silicon (Si)-oxygen (O)-copper (Cu) on the copper layer 10, a first silicon (Si)-oxygen (O) mixed layer 30 formed on the coccox layer 20, a silicon (Si) layer 40 formed on the first silicon (Si)-oxygen (O) mixed layer 30, and a second silicon (Si)-oxygen (O) mixed layer 50 formed on the silicon (Si) layer 40.

[0010] Further, the silicon (Si) layer 40 has a thickness of 3 to 20 nm.

[0011] Further, the first silicon (Si)-oxygen (O) mixed layer 30 and the second silicon (Si)-oxygen (O) mixed layer 50 have a thickness of 1 to 10 nm.

[0012] Further, the coccox layer 20 has a thickness of 0.8 to 1.2 nm.

[0013] The present invention relates to a method for manufacturing silicon-coated copper, characterized in that silicon (Si) is deposited on copper (Cu) in a single sputtering process.

[0014] Also, the sputtering is characterized by being performed in an argon atmosphere.

[0015] Also, the sputtering is characterized by being performed at room temperature to 350 °C for 1 to 5 minutes.

[0016] The present invention relates to a semiconductor device, characterized in that it contains copper provided with a silicox layer 20 which is a silicon (Si)-oxygen (O)-copper (Cu) mixed layer formed by depositing silicon (Si).

[0017] Also, the silicox layer 20 is characterized by having a thickness of 0.8 to 1.2 nm.

Advantages of the Invention

[0018] By the means for solving the above problems, the present invention can produce copper free from oxidation only by depositing silicon (Si), has high production efficiency, and can replace gold by using copper (Cu) and silicon (Si) which are the most abundant on the earth, so it has high economic value.

[0019] Also, the present invention can produce copper (Cu) having oxidation resistance while maintaining its electrical properties by forming a silicon (Si)-oxygen (O)-copper (Cu) protective film by depositing silicon (Si).

[0020] Also, the present invention can produce antioxidant copper that can be used semi-permanently at room temperature while the manufacturing method is very simple and inexpensive.

[0021] Also, when the present invention produces a pattern and performs surface treatment, it can produce a circuit that is not oxidized despite heat generation, and can prevent fires and explosions caused by heat generation.

Brief Description of the Drawings

[0022]

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Mode for Carrying Out the Invention

[0023] The terms used in this specification will be briefly explained, and the present invention will be specifically described.

[0024] In the present invention, the terms used are selected as generally widely used terms as much as possible while considering the functions of the present invention. However, this may change depending on the intention of those skilled in the art, precedents, the emergence of new technologies, etc. Therefore, the terms used in the present invention are not defined by simple term names, but are defined based on the meaning of the terms and the overall content of the present invention.

[0025] Throughout the specification, when a certain part states that a certain component "includes", unless there is a description to the contrary, it does not exclude other components, but means that other components can be further included.

[0026] Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those having ordinary knowledge in the technical field to which the present invention pertains can easily implement them. However, the present invention can be embodied in various different forms and is not limited to the embodiments described herein.

[0027] Specific matters including the problems to be solved by the present invention, the means for solving the problems, and the effects of the invention are included in the embodiments and drawings described below. The advantages and features of the present invention, and the methods for achieving them, will become clear by referring to the embodiments described in detail below together with the accompanying drawings.

[0028] Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

[0029] The present invention relates to a method for manufacturing silicon-coated copper, in which silicon is vapor-deposited to form a silicon (Si)-oxygen (O)-copper (Cu) mixed layer.

[0030] More specifically, silicon is vapor-deposited on the surface of copper in a single sputtering process to coat the silicon. The sputtering is performed in an argon atmosphere and is preferably performed at a normal temperature to 350°C for 1 to 5 minutes. When performing the sputtering, if it is higher or lower than the range of temperature and execution time, crystal grains boundaries and potential etc. are formed, resulting in a decrease in crystallinity. Therefore, it is preferably performed within the above temperature range. In the embodiments of the present invention, it was performed at 190°C for 75 seconds, 150 seconds, and 300 seconds.

[0031] The silicon-coated copper manufactured by the method for manufacturing silicon-coated copper is characterized in that a silica layer 20, which is a silicon (Si)-oxygen (O)-copper (Cu) mixed layer, is formed by vapor-depositing silicon.

[0032] The silicon-coated copper of the present invention is characterized in that the RGB values are 250 to 260 (red), 210 to 220 (green), and 155 to 165 (blue), respectively. Figure 1 is a photograph of a single crystal copper thin film (hereinafter referred to as SCCF) with a thickness of 185 nm, and Figure 2 is a photograph of copper after coating with silicon and heat-treated in air at 350 °C for 30 minutes. When manufactured to the same size, the single crystal copper thin film in Figure 1 shows RGB values of 254 (red), 220 (green), and 182 (blue), and the copper heat-treated in air after silicon coating in Figure 2 of the present invention was observed to have RGB values of 255 (red), 216 (green), and 159 (blue). In view of the fact that the known RGB values of copper are 185 (red), 115 (green), and 51 (blue), it can be seen that the silicon-coated copper manufactured according to the present invention is prevented from oxidation, and it can be confirmed that, despite being heat-treated at 350 °C for 30 minutes, it is maintained similar to the single crystal copper thin film and oxidation is prevented.

[0033] Figures 5 to 8 show a comparison of photographs of copper foil and silicon-coated copper foil before and after heat treatment in air. When the copper foil in Figure 5 was heat-treated at 250 °C for 30 minutes (Figure 7) and compared, it was confirmed that the general copper foil changed to a darker color. On the other hand, when the silicon-coated copper foil in Figure 6 was heat-treated at 250 °C for 30 minutes (Figure 8) under the same conditions and compared, it was confirmed that the silicon-coated copper foil maintained its original color.

[0034] Figures 3 and 4 show the XRD measurement results of a single crystal copper thin film (SCCF) and a single crystal copper thin film heat-treated after coating with silicon. As shown in Figure 4, after coating with silicon and heat-treatment in air at 350 °C for 30 minutes, the crystal structure remains completely unchanged. Rather, crystallization occurs better in one direction, and it can be predicted that the surface is not oxidized.

[0035] Figures 9 to 10 show the XRD measurement results of the copper foil after heat treatment in air and the silicon-coated copper foil. When the copper foil in Figure 9 was heat-treated in air at 250 °C for 30 minutes (Figure 10) and compared, it was found that the copper foil showed a Cu2O phase in Figure 9, while the silicon-coated copper foil retained the original copper structure as shown in Figure 10.

[0036] In addition, as shown in Figure 11, the silicon-coated copper of the present invention has a resistance value between 1.68×10 -6 Ω·cm, which is the resistance value of bulk Cu, and 2.2×10 -6 Ω·cm, which is the resistance value of bulk Au.

[0037] The silicon-coated copper of the present invention maintains an electrical resistance value similar to that of the copper without the silicon deposited thereon.

[0038] The silicon-coated copper of the present invention is prevented from being oxidized even when heated at 200 °C for 60 hours.

[0039] Figure 11 shows the change in resistance depending on the heat treatment temperature and the coating thickness of silicon of the SiCu / Al2O3 sample. Zone A is the change in resistance due to the heat treatment of a single-crystalline copper thin film (SCCF) sample with a thickness of 185 nm, and Zone B is the change in resistance of a silicon-coated single-crystalline copper thin film (SCCF) sample (Si5SCCF) and after its heat treatment. Zone C is the change in resistance of a single-crystalline copper thin film (SCCF) sample coated with silicon thicker than 5 nm. Zone D shows the resistance of bulk Cu and bulk Au and is compared with Zones B and C.

[0040] In Zone A, the pristine SCCF sample has a resistance value almost the same as 1.68×10 -6 Ω·cm, which is the resistance value of bulk Cu, and 2.2×10 -6It shows a resistance value smaller than Ω·cm. However, in zone A, when a single-crystal copper thin film (SCCF) sample is heat-treated at 200 to 250 °C, a sharp increase in resistance is observed. This means that copper is oxidized and turned into Cu2O.

[0041] On the other hand, in zone B, it can be seen that a sample (Si5SCCF) in which a 185-nm single-crystal copper thin film (SCCF) is coated with 5 nm of silicon also has a resistance value almost equal to that of a copper block (Cu) even when heat-treated at 400 °C for 30 minutes.

[0042] Also, in zone C, the change in resistance associated with the increase in the thickness of the silicon layer can be confirmed. A single-crystal copper thin film (SCCF) coated with silicon until the silicon thickness reaches 30 nm has a value between the resistance value of a copper block (bulk Cu) and the resistance value of a gold block (bulk Au), and it can be confirmed that it becomes approximately the same as the resistance of a gold block (bulk Au) only after the silicon thickness reaches 30 nm.

[0043] The silicon-coated copper can be manufactured as a single-crystal thin film, a polycrystalline thin film, a foil, or a block. As confirmed in FIG. 11, when the silicon-coated copper is a single-crystal thin film, oxidation is prevented even when heated at 400 °C for 30 minutes. When the silicon-coated copper is a polycrystalline thin film, a foil, or a block, oxidation is prevented even when heated at 300 °C for 30 minutes.

[0044] The silicon-coated copper manufactured by the manufacturing method of the silicon-coated copper is composed of a copper layer 10, a silicox layer 20 in which silicon (Si) - oxygen (O) - copper (Cu) is mixed on the copper layer 10, a first silicon (Si) - oxygen (O) mixed layer 30 formed on the silicox layer 20, a silicon (Si) layer 40 formed on the first silicon (Si) - oxygen (O) mixed layer 30, and a second silicon (Si) - oxygen (O) mixed layer 50 formed on the silicon (Si) layer 40, as shown in FIG. 12.

[0045] FIG. 12 shows the results of cross-sectional measurement by transmission electron microscope (TEM) of a sample in which a single-crystalline copper thin film is coated with 10 nm of silicon (Si10Cu / Al2O3). It can be confirmed that the silicon coated in the present invention does not exist as a single layer, and a silicon (Si)-oxygen (O) mixed layer is formed on the copper layer 10, and it is formed of a silicon (Si) layer and further the silicon (Si)-oxygen (O) mixed layer.

[0046] More specifically, the first silicon (Si)-oxygen (O) mixed layer 30, the silicon (Si) layer 40, and the second silicon (Si)-oxygen (O) mixed layer 50, which are layers in which silicon (Si) is coated on copper, are characterized by having a thickness of 5 to 30 nm. If the silicon (Si) coating layer is thinner than 5 nm, it is easily oxidized, and if it is thicker than 30 nm, problems such as insulation or a decrease in electrical conductivity occur. Therefore, it is preferable that it is the above conditions.

[0047] The silicon (Si) layer 40 is characterized by having a thickness of 3 to 20 nm.

[0048] The first silicon (Si)-oxygen (O) mixed layer 30 and the second silicon (Si)-oxygen (O) mixed layer 50 are characterized by having a thickness of 1 to 10 nm.

[0049] The coccox layer 20 is characterized by having a thickness of 0.8 to 1.2 nm.

[0050] FIG. 13 shows the change in the distance between copper atoms according to the depth observed by high-resolution TEM. As shown in FIG. 13, it can be seen that the distance between copper (Cu)-copper (Cu) on the surface has shrunk, which can confirm that a mixed layer of silicon (Si) and copper (Cu) exists on the surface, and the presence of the mixed layer of silicon (Si) and copper (Cu) can be confirmed again by the XPS analysis in FIG. 14.

[0051] Figure 14 shows the XPS analysis results for confirming the component distribution on the surface of an SCCF (Si10SCCF) sample coated with 10 nm of silicon. It can be confirmed that the oxygen on the surface gradually decreases, increases again in the mixed layer, and then decreases. It can be seen that the distribution of silicon (Si) shows the largest distribution at the locations where oxygen forms valleys. Also, there are locations where oxygen, silicon, and copper form a mixed layer, and it is expected that this mixed layer plays an important role in preventing oxidation. That is, on the surface of copper, there is a silicon (Si)-oxygen (O)-copper (Cu) mixed layer (the psychox layer 20, SiCuO x ), a silicon (Si)-oxygen (O) mixed layer (SiO x ), and a silicon (Si) layer 40.

[0052] Figure 15 can more accurately confirm the surface morphology of silicon-coated copper and shows the surface structure (TEM) of an SCCF (Si10SCCF) sample surface coated with 10 nm of silicon. Figure 15(b) also shows that, in the component analysis results of the TEM, similar to the TEM in Figure 12 and the XPS measurement results in Figure 14, a silicon (Si)-oxygen (O) mixed layer (SiO x ), a silicon (Si) layer 40, a silicon (Si)-oxygen (O) mixed layer (SiO x ), a silicon (Si)-oxygen (O)-copper (Cu) mixed layer (the psychox layer 20, SiCuO x ), and copper (Cu) are formed in this order on the thin film surface. The formed silicon (Si)-oxygen (O) mixed layer (SiO x ) has an amorphous structure and thus cannot be seen in the image of Figure 15(a). The silicon atoms directly above the copper thin film fix the freely moving oxygen on the copper surface at an optimal position (site). Generally, oxygen moves relatively freely on the flat surface of copper, while silicon plays the role of fixing this oxygen. The thickness of the silicon (Si) layer 40 is not very important for preventing oxidation, and the most important structure is determined by the top 1-2 layers of atoms directly above the copper thin film.

[0053] At the location indicated by the key in Fig. 15(b), there is a silicon (Si)-oxygen (O)-copper (Cu) mixed layer (the Sycox layer 20, SiCuO x ) where oxygen, silicon, and copper form a mixed layer, and this mixed layer is expected to play an important role in preventing oxidation.

[0054] Fig. 16 shows a predicted distribution diagram of oxygen (O) and silicon (Si) in the Sycox layer 20 on a copper thin film. Fig. 16(a) is a side view of the oxygen (O) and silicon (Si) forming the Sycox layer 20 on the copper thin film, and Fig. 16(b) is a plan view. It is predicted that the silicon (Si) binds to the oxygen (O) on the copper surface and plays a role in fixing it on the copper surface. At this time, the most basic structure is configured as shown in Fig. 16. As shown in the side view of Fig. 16(a) and the plan view of Fig. 16(b), if the oxygen (O) covers the surface of the copper and is fixed by the silicon (Si), it is predicted that other oxygen (O) cannot enter the copper, thus playing a role in preventing entry.

[0055] Also, the present invention can manufacture a semiconductor device including silicon-coated copper manufactured by the method for manufacturing the silicon-coated copper. This semiconductor device is characterized by including copper on which silicon (Si) is deposited to form a silicon (Si)-oxygen (O)-copper (Cu) mixed layer. The semiconductor device includes the same configuration as the silicon-coated copper.

[0056] Specifically, the semiconductor device is connected to the semiconductor chip pad and terminals, and since the surface has a silicon (Si)-oxygen (O)-copper (Cu) mixed layer of the present invention formed thereon to prevent oxidation, compared with the case of using gold, it has low electrical resistance and rigidity, is low-cost, and has the effect that its lifespan can be extended at a high ambient temperature and it can be used for a long time. Also, while maintaining the advantages provided by general copper, it has the effects of improving electrical characteristics due to oxidation suppression and increasing strength.

[0057] More specifically, the first silicon (Si)-oxygen (O) mixed layer 30, the silicon (Si) layer 40 and the second silicon (Si)-oxygen (O) mixed layer 50 are layers in which silicon (Si) is coated on copper, and are characterized in that the thickness is 5 to 30 nm. If the layer coated with silicon (Si) is thinner than 5 nm, it is easily oxidized, and if it is thicker than 30 nm, problems such as insulation or a decrease in electrical conductivity occur. Therefore, it is preferable that the layer satisfies the above conditions.

[0058] Also, in the semiconductor device, the thickness of the cockscomb layer 20 is characterized in that it is 0.8 to 1.2 nm.

[0059] By the means for solving the above problems, the present invention can produce copper free from oxidation only by silicon (Si) vapor deposition, has high production efficiency, and can replace gold using the most abundant copper (Cu) and silicon (Si) on earth. Therefore, it has high economic value.

[0060] Further, the present invention can form a silicon (Si)-oxygen (O)-copper (Cu) protective film by silicon (Si) vapor deposition to produce copper (Cu) having oxidation resistance while maintaining its electrical characteristics as they are.

[0061] Further, the present invention corresponds to a substance that can withstand the highest temperature for the longest time, the manufacturing method is very simple and inexpensive, and it corresponds to antioxidant copper that can be used semi-permanently at room temperature.

[0062] Further, the present invention can produce a circuit that is not oxidized despite heat generation when producing a pattern and performing surface treatment, can prevent fires and explosions due to heat generation, and can greatly improve the current density. Therefore, it can cause a very large response in the semiconductor process.

[0063] As described above, it can be understood that the technical configuration of the present invention described above can be implemented in other specific forms without changing the technical idea and essential features of the present invention by those skilled in the technical field to which the present invention belongs.

[0064] Therefore, all of the embodiments described above are exemplary in all respects and not restrictive. The scope of the present invention is defined by the following claims rather than the above detailed description, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts belong to the scope of the present invention.

Explanation of Reference Numerals

[0065] 10 Copper layer 20 Psychox layer 30 First silicon (Si)-oxygen (O) mixed layer 40 Silicon (Si) layer 50 Second silicon (Si)-oxygen (O) mixed layer

Claims

1. Copper for oxidation prevention coated with silicon, on which a SiCux layer (20), which is a silicon (Si)-oxygen (O)-copper (Cu) mixed layer, is formed by depositing silicon (Si), having an electrical resistance value between the copper on which the silicon (Si) is not deposited and gold (Au). Copper for oxidation prevention coated with silicon, characterized by the above.

2. Copper for oxidation prevention coated with silicon, on which a SiCux layer (20), which is a silicon (Si)-oxygen (O)-copper (Cu) mixed layer, is formed by depositing silicon (Si), preventing oxidation even when heated at 200°C for 60 hours. Copper for oxidation prevention coated with silicon, characterized by the above.

3. Copper for oxidation prevention coated with silicon, on which a SiCux layer (20), which is a silicon (Si)-oxygen (O)-copper (Cu) mixed layer, is formed by depositing silicon (Si), comprising a copper layer (10), on the copper layer (10), the SiCux layer (20) formed by mixing silicon (Si)-oxygen (O)-copper (Cu), a first silicon (Si)-oxygen (O) mixed layer (30) formed on the SiCux layer (20), a silicon (Si) layer (40) formed on the first silicon (Si)-oxygen (O) mixed layer (30), and a second silicon (Si)-oxygen (O) mixed layer (50) formed on the silicon (Si) layer (40). Copper for oxidation prevention coated with silicon, characterized by the above.

4. The copper for oxidation prevention coated with silicon is a single-crystalline thin film, polycrystalline thin film, foil, or bulk, the copper for oxidation prevention coated with silicon according to any one of Claims 1 to 3.

5. When the copper for oxidation prevention coated with silicon is a single-crystalline thin film, oxidation is prevented even when heated at 400°C for 30 minutes. The copper for oxidation prevention coated with silicon according to Claim 4.

6. When the copper for oxidation prevention coated with silicon is a polycrystalline thin film, foil, or bulk, oxidation is prevented even when heated at 300°C for 30 minutes. The copper for oxidation prevention coated with silicon according to Claim 4.

7. The silicon-coated copper for antioxidant has an electrical resistance value of 1.68×10 －６ to 2.2×10 －６ Ω·cm The copper for oxidation prevention coated with silicon according to any one of Claims 1 to 3.

8. The first silicon (Si)-oxygen (O) mixed layer (30) and the second silicon (Si)-oxygen (O) mixed layer (50) have a thickness of 5 to 30 nm. The copper for oxidation prevention coated with silicon according to claim 3.

9. The first silicon (Si)-oxygen (O) mixed layer (30) and the second silicon (Si)-oxygen (O) mixed layer (50) have a thickness of 1 to 10 nm. The copper for oxidation prevention coated with silicon according to claim 3.

10. The coccox layer (20) has a thickness of 0.8 to 1.2 nm. The copper for oxidation prevention coated with silicon according to claim 3.

11. Comprising the copper for oxidation prevention coated with silicon according to claim 3. A semiconductor device characterized by this.

12. The coccox layer (20) has a thickness of 0.8 to 1.2 nm. The semiconductor device according to claim 11.

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