A semiconductor structure based on molybdenum metal wires and a method of manufacturing the same
By using a mixed gas containing oxygen, chlorine, and hydrocarbon gases to form a carbon-containing protective layer during the etching process of molybdenum metal lines, and combining this with an oxidation-dissolution cycle, the problems of sidewall depressions and poor roughness of molybdenum metal lines were solved, resulting in molybdenum metal lines with higher aspect ratios and lower resistance, thus meeting the technical requirements of advanced nodes.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SHANGHAI BANGXIN SEMI TECHNOLOGY CO LTD
- Filing Date
- 2026-04-30
- Publication Date
- 2026-07-07
AI Technical Summary
At advanced nodes, during the etching process of molybdenum metal lines, byproducts may not adequately protect the sidewalls of the etched structure, leading to sidewall depressions and poor roughness, which affects resistance and interconnect stability.
A first plasma dry etching process is performed using a mixture of oxygen-containing gas, chlorine-containing gas, and hydrocarbon-containing gas to form a carbon-containing protective layer to protect the sidewalls. A soluble molybdenum trioxide layer is generated by oxidizing gas, and an oxidation-dissolution cycle is performed in combination with an alkaline solution to gradually reduce the sidewall roughness.
This achieves a vertical morphology and higher aspect ratio for the sidewalls of the molybdenum metal wire, reduces resistance, improves interconnect density and stability, and meets the technical requirements of advanced nodes.
Smart Images
Figure CN122121651B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of semiconductor processing technology, and in particular to a semiconductor structure based on molybdenum metal wire and a method for manufacturing the same. Background Technology
[0002] At advanced nodes, when forming metal interconnect layers on substrates, the industry is exploring subtractive patterning processes (depositing metal first, then etching the pattern) to create the most critical and densely patterned bottom metal layers (such as M1 and M2). Molybdenum (Mo) has the advantages of good adhesion to oxide dielectric materials and does not require a diffusion barrier layer, making it a promising candidate material for the subtractive method's bottom metal layers. However, when molybdenum is etched in a conventional oxygen and chlorine-containing gas system, byproducts (MoO) are generated. x Cl y The high sensitivity to lateral bombardment by free radicals results in insufficient protection of the etched structure's sidewalls by byproducts, leading to isotropic etching and a tendency to fail to achieve vertical profiles due to severe sidewall depressions. Furthermore, existing dry etching processes also produce poor sidewall roughness. These issues affect the fabrication of high aspect ratio molybdenum metal lines, making it difficult to reduce resistivity. Therefore, it is necessary to investigate a process method that can significantly improve these problems. Summary of the Invention
[0003] The purpose of this application is to overcome the aforementioned problems in the prior art and to provide a semiconductor structure based on molybdenum metal wire and its manufacturing method.
[0004] To achieve the above objectives, the technical solution of this application is as follows:
[0005] According to a first aspect of this application, embodiments of this application provide a method for manufacturing a semiconductor structure based on molybdenum metal wires, including:
[0006] Provide substrate;
[0007] A front dielectric layer, a molybdenum metal layer, and a mask are sequentially formed on the surface of the substrate;
[0008] Through the mask, at a first temperature, a first gas is used to perform a first plasma dry etching on the molybdenum metal layer, and the molybdenum metal layer is etched through to form a molybdenum metal line on the surface of the preceding dielectric layer;
[0009] The mask is removed, and at a second temperature, the sidewalls of the molybdenum metal wire are oxidized using a second gas to generate a molybdenum trioxide layer on the surface of the sidewalls.
[0010] At a third temperature, the molybdenum trioxide layer on the sidewall is dissolved and removed using a dissolving solution.
[0011] The process of generating the molybdenum trioxide layer and dissolving and removing the molybdenum trioxide layer is repeated until the surface roughness of the sidewall is reduced.
[0012] The first gas includes a mixture of oxygen-containing gas, chlorine-containing gas, and hydrocarbon-containing gas; the second gas includes an oxidizing gas; and the solution includes an alkaline solution.
[0013] The second temperature is above 150°C and below 250°C, and the first temperature and the third temperature are lower than the second temperature.
[0014] In some embodiments, during the first plasma dry etching, carbon-containing active groups generated by the dissociation of the hydrocarbon gas in the plasma are adsorbed and reacted on the sidewall surface of the forming molybdenum metal wire to form a carbon-containing protective layer to protect the sidewall.
[0015] In some embodiments, the carbon-containing protective layer comprises an amorphous hydrocarbon thin film layer.
[0016] In some embodiments, the oxygen-containing gas includes oxygen, the chlorine-containing gas includes chlorine, and the hydrocarbon-containing gas includes methane.
[0017] In some embodiments, the oxidizing gas includes ozone.
[0018] In some embodiments, the alkaline solution comprises an ammonium hydroxide solution.
[0019] In some embodiments, the volume ratio of ammonium hydroxide to water in the ammonium hydroxide solution is: ammonium hydroxide:water = 1:8 to 1:20.
[0020] In some embodiments, when performing the first plasma dry etching, the first temperature is 10°C to 60°C, the total flow rate of the mixed gas containing oxygen, chlorine, and hydrocarbon gases is 50 sccm to 500 sccm, wherein the flow rate of oxygen-containing gas accounts for 10% to 30%, the flow rate of chlorine-containing gas accounts for 40% to 60%, the flow rate of hydrocarbon-containing gas accounts for 10% to 30%, the pressure is 5 mTorr to 10 mTorr, the source power is 500 W to 800 W, and the bias power is 20 W to 200 W.
[0021] In some embodiments, the second temperature is 150°C to 230°C, and the time for each generation of the molybdenum trioxide layer is 2 min to 10 min.
[0022] In some embodiments, the third temperature is 20°C to 100°C, and the time for each dissolution and removal of the molybdenum trioxide layer is 2 min to 6 min.
[0023] In some embodiments, the process of generating the molybdenum trioxide layer and dissolving and removing the molybdenum trioxide layer is repeated 10 to 30 times.
[0024] In some embodiments, after removing the mask, the carbon-containing protective layer is first subjected to a second plasma dry etching at a fourth temperature using a third gas to remove the carbon-containing protective layer, and then the sidewalls of the molybdenum metal line after the carbon-containing protective layer has been removed are oxidized. The third gas includes a reducing gas and a diluting gas.
[0025] In some embodiments, the reducing gas includes hydrogen, and the diluting gas includes nitrogen.
[0026] In some embodiments, when performing the second plasma dry etching, the fourth temperature is 100°C to 300°C, the flow rate of the reducing gas in the third gas is 4% to 50%, the pressure is 100 mTorr to 3000 mTorr, the source power is 300 W to 3000 W, and the bias power is 0 W.
[0027] According to a second aspect of this application, embodiments of this application also provide a semiconductor structure based on molybdenum metal wires, which is obtained using a semiconductor structure manufacturing method based on molybdenum metal wires as provided in any of the embodiments of the first aspect above.
[0028] The embodiments of this application may have, or at least have, the following advantages:
[0029] (1) By adding a hydrocarbon-containing gas to the first gas used for the first plasma dry etching of the molybdenum metal layer, the carbon-containing active groups generated by the dissociation of the hydrocarbon-containing gas in the plasma can be used to adsorb and react on the sidewall surface of the forming molybdenum metal wire, forming a carbon-containing protective layer for sidewall protection. This carbon-containing protective layer is sensitive to longitudinal ion bombardment (removed by sputtering) but insensitive to lateral free radical attacks (retained), thus achieving "in-situ sidewall protection." This effectively solves the problem of byproducts (MoO₂) generated during the etching of molybdenum in conventional oxygen and chlorine gas systems. x Cl y The insufficient protection of the sidewalls makes the etching isotropic and prone to severe sidewall depressions, thus enabling the acquisition of a more vertical sidewall morphology.
[0030] (2) By further using a second gas to oxidize the sidewall of the molybdenum metal wire, the surface of the protrusions on the rough sidewall of the molybdenum metal wire is preferentially oxidized by the oxidizing gas, and the oxidation temperature (second temperature) is controlled to be less than 250°C. A soluble molybdenum trioxide layer can be selectively generated on the sidewall surface. The generated molybdenum trioxide layer can be easily dissolved and removed by an alkaline solution. Thus, the surface roughness of the sidewall of the molybdenum metal wire can be gradually reduced through the alternating oxidation-dissolution cycle.
[0031] (3) By using oxidizing gas and dry oxidation of the sidewalls of the molybdenum metal wire at a certain baking temperature (second temperature), the rough sidewall surface can be finely treated, and the surface stress of the sidewall can be changed without affecting it, while maintaining the hydrophilicity and hydrophobicity of the sidewall surface. Furthermore, by using an alkaline solution, the molybdenum trioxide layer generated on the sidewall can be dissolved and removed, while organic residues can also be effectively removed, achieving good cleaning of the sidewall surface and thus obtaining a better overall treatment effect.
[0032] The process steps in this application are highly compatible. By first using dry etching to define the pattern outline and then using oxidation-dissolution cycle processing to refine the sidewall surface, molybdenum metal lines with higher aspect ratio and higher interconnect density can be obtained, which helps to achieve lower resistance and interconnect stability, and well meets the technical requirements of advanced nodes.
[0033] Other advantages of this application will be described in the following detailed description. Attached Figure Description
[0034] Figure 1 This is a flowchart of a semiconductor structure manufacturing method based on molybdenum metal wires, provided as a preferred embodiment of this application.
[0035] Figure 2 This is a schematic diagram of a preferred embodiment of the present application after forming a front dielectric layer, a molybdenum metal layer and a mask on the surface of a substrate.
[0036] Figure 3 This is a schematic diagram of a molybdenum metal layer after patterning etching to form molybdenum metal lines, provided as a preferred embodiment of this application.
[0037] Figure 4 This is a schematic diagram of a preferred embodiment of the present application after mask removal.
[0038] Figure 5 This is a schematic diagram of a preferred embodiment of the present application after removing the carbon-containing protective layer on the sidewall of a molybdenum metal wire.
[0039] Figure 6This is a schematic diagram of a preferred embodiment of the present application showing the formation of a molybdenum trioxide layer on the sidewall surface of a molybdenum metal wire after oxidation.
[0040] Figure 7 This is a schematic diagram of a preferred embodiment of the present application after dissolving and removing the molybdenum trioxide layer on the sidewall of a molybdenum metal wire.
[0041] In the figure: 10. Substrate; 11. Molybdenum metal layer; 111. Molybdenum metal line; 12. Mask; 13. Front dielectric layer; 14. Carbon-containing protective layer; 15. Molybdenum trioxide layer. Detailed Implementation
[0042] This relates to the byproduct (MoO) generated during the etching of molybdenum (Mo) in a conventional gas system containing oxygen and chlorine. x Cl y The insufficient protection of the etched structure sidewalls makes the etching process isotropic, easily leading to severe sidewall depressions that prevent the acquisition of a vertical profile. Furthermore, existing dry etching processes result in poor sidewall roughness. This application provides a method for manufacturing a semiconductor structure based on molybdenum metal lines, including:
[0043] Provide substrate;
[0044] A front dielectric layer, a molybdenum metal layer, and a mask are sequentially formed on the surface of the substrate;
[0045] Through the mask, at a first temperature, a first gas is used to perform a first plasma dry etching on the molybdenum metal layer, and the molybdenum metal layer is etched through to form a molybdenum metal line on the surface of the preceding dielectric layer;
[0046] The mask is removed, and at a second temperature, the sidewalls of the molybdenum metal wire are oxidized using a second gas to generate a molybdenum trioxide layer on the surface of the sidewalls.
[0047] At a third temperature, the molybdenum trioxide layer on the sidewall is dissolved and removed using a dissolving solution.
[0048] The process of generating the molybdenum trioxide layer and dissolving and removing the molybdenum trioxide layer is repeated until the surface roughness of the sidewall is reduced.
[0049] The first gas includes a mixture of oxygen-containing gas, chlorine-containing gas, and hydrocarbon-containing gas; the second gas includes an oxidizing gas; and the solution includes an alkaline solution.
[0050] The second temperature is above 150°C and below 250°C, and the first temperature and the third temperature are lower than the second temperature.
[0051] This application embodiment uses a mixed gas comprising oxygen-containing gas, chlorine-containing gas, and hydrocarbon-containing gas to pattern the molybdenum metal layer. This allows for the formation of a carbon-containing protective layer on the sidewall surface of the forming molybdenum metal line, resisting lateral free radical attacks, thus achieving "in-situ sidewall protection" and resulting in a more vertical sidewall morphology. Furthermore, by using an oxidizing gas to oxidize the sidewall of the etched molybdenum metal line, the surface of protrusions on the rough sidewall is preferentially oxidized. A soluble molybdenum trioxide layer is selectively formed on the sidewall surface by temperature control, which can be easily dissolved and removed using an alkaline solution. This alternating oxidation-dissolution cycle gradually reduces the surface roughness of the molybdenum metal line sidewall, facilitating the acquisition of molybdenum metal lines with higher aspect ratios and higher interconnect density, resulting in lower resistance and better interconnect stability.
[0052] This application also provides a semiconductor structure based on molybdenum metal wires, which is obtained using the above-described method for manufacturing semiconductor structures based on molybdenum metal wires.
[0053] The specific embodiments of this application will now be described in detail with reference to the accompanying drawings.
[0054] refer to Figure 1 In a first aspect, embodiments of this application provide a method for manufacturing a semiconductor structure based on molybdenum metal wires, which may sequentially include the following steps:
[0055] Step S11: Provide a substrate.
[0056] refer to Figure 2 In some embodiments, a substrate 10 is used for further forming molybdenum metal lines on the substrate 10 to form the molybdenum metal line-based semiconductor structure provided in the embodiments of this application. The substrate 10 may include any suitable type of semiconductor substrate and material. For example, the substrate 10 may include a silicon (Si) substrate, a germanium (Ge) substrate, or a germanium-silicon (SiGe) substrate, or a III / V compound semiconductor substrate, such as a gallium arsenide (GaAs) substrate, an indium gallium arsenide (InGaAs) substrate, or similar materials.
[0057] In some embodiments, substrate 10 may include a wafer.
[0058] Step S12: Sequentially form a front dielectric layer, a molybdenum metal layer, and a mask on the surface of the substrate.
[0059] refer to Figure 2 In some embodiments, a deposition process may be used to sequentially form a front dielectric layer 13 and a molybdenum metal layer 11 (a metal layer of molybdenum material) on the surface of the substrate 10.
[0060] In some embodiments, a plurality of masks 12 are formed on the surface of the molybdenum metal layer 11, and an opening serving as an etching window is provided between any two adjacent masks 12.
[0061] In some embodiments, mask 12 may include a hard mask. The material of the hard mask may include TiN, etc.
[0062] In some embodiments, the mask 12 is a TiN hard mask, and silicon dioxide hard masks or silicon nitride hard masks are avoided on the surface of the molybdenum metal layer 11. If a silicon dioxide hard mask or a silicon nitride hard mask is used for patterning etching of the molybdenum metal layer, byproducts (Mo-Si phase and Mo-Si-O-Cl complex) are extremely difficult to remove, due to the redeposition of the silicon dioxide hard mask or silicon nitride hard mask material during the etching process. Therefore, by using a TiN hard mask (without using a silicon dioxide hard mask or a silicon nitride hard mask) as the mask 12 for patterning etching of the molybdenum metal layer 11, the problem of byproduct residue caused by the reaction between the sputtered Si-containing mask material and Mo can be solved, and the generation of the above-mentioned residues can be avoided while achieving anisotropic etching.
[0063] In some embodiments, the method of forming a hard mask (mask 12) may include:
[0064] A hard mask layer and a photoresist layer are sequentially formed on the surface of the molybdenum metal layer 11 (figure omitted).
[0065] Photolithography is used to lithographically shape the photoresist layer, forming multiple photoresist patterns on the surface of the hard mask layer.
[0066] The hard mask layer exposed on the surface is patterned by photoresist patterning to form multiple hard masks 12 on the surface of the molybdenum metal layer 11; then, the photoresist pattern is removed.
[0067] Thus, the exposed molybdenum metal layer 11 can be patterned and etched using a hard mask, and molybdenum metal lines can be formed on the surface of the previous dielectric layer 13.
[0068] In some embodiments, when the mask 12 is a TiN hard mask (the hard mask layer is a TiN layer), a plasma of a mixture of a first chlorine-containing gas, a second chlorine-containing gas, a first nitrogen-containing gas, a first hydrocarbon-containing gas, and a first dilution gas (a fourth gas) can be used. Anisotropic third plasma dry etching is performed on the surface of the exposed TiN layer through the openings between the photoresist patterns. The etching can be stopped on the surface of the molybdenum metal layer 11 by detecting the etching endpoint, thereby forming a TiN hard mask formed by the patterned TiN layer on the surface of the molybdenum metal layer 11.
[0069] In some embodiments, the first chlorine-containing gas may include chlorine gas, etc.
[0070] In some embodiments, the second chlorine-containing gas may include boron trichloride (BCl3), etc.
[0071] In some embodiments, the first nitrogen-containing gas may include nitrogen or the like.
[0072] In some embodiments, the first hydrocarbon-containing gas may include methane (CH4) or the like. By adding the first hydrocarbon-containing gas to the fourth gas, the sidewalls of the photoresist pattern and the TiN hard mask during etching can be passivated for protection, improving pattern transfer accuracy and the sidewall quality of the TiN hard mask, maintaining the vertical sidewall morphology, which helps to improve the dimensional uniformity of the molybdenum metal lines formed by subsequent etching, and reducing sidewall roughness.
[0073] In some embodiments, the first diluting gas may include argon or the like.
[0074] In some embodiments, when etching the TiN layer, the flow rate percentage of the first chlorine-containing gas (chlorine) in the fourth gas (first chlorine-containing gas, second chlorine-containing gas, first nitrogen-containing gas, first hydrocarbon-containing gas, and first dilution gas) is 20%–50%, the flow rate percentage of the second chlorine-containing gas (boron trichloride) is 0%–10%, the flow rate percentage of the first nitrogen-containing gas (nitrogen) is 9%–11%, the flow rate percentage of the first hydrocarbon-containing gas (methane) is 10%–20%, and the flow rate percentage of the first dilution gas (argon) is 30%–40%. For example, the flow rate percentage of the first chlorine-containing gas (chlorine) can be 20%, 21%, 22%, 25%, 28%, 30%, 33%, 36%, 39%, 40%, 42%, 44%, 45%, 47%, 49%, or 50%, or any value between any two of the aforementioned flow rate percentages. The flow rate percentage of the second chlorine-containing gas (boron trichloride) can be 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10%, or any value between any two of the aforementioned flow rate percentages. The flow rate percentage of the first nitrogen-containing gas (nitrogen) can be 9%, 10%, or 11%, or any value between any two of the aforementioned flow rate percentages. The flow rate percentage of the first hydrocarbon-containing gas (methane) can be 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, or 20%, or any value between any two of the aforementioned flow rate percentages. The flow rate percentage of the first diluting gas (argon) can be 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, or 40%, or any value between any two of the aforementioned flow rate percentages.
[0075] In some embodiments, when etching the TiN layer, the total flow rate of the fourth gas is 50 sccm to 500 sccm. For example, the total flow rate of the fourth gas can be 50 sccm, 60 sccm, 90 sccm, 100 sccm, 115 sccm, 155 sccm, 185 sccm, 200 sccm, 215 sccm, 250 sccm, 275 sccm, 290 sccm, 300 sccm, 310 sccm, 345 sccm, 375 sccm, 380 sccm, 400 sccm, 425 sccm, 450 sccm, 488 sccm, or 500 sccm, or any value between any two of the aforementioned flow rate values.
[0076] In some embodiments, the temperature for etching the TiN layer is 10°C to 60°C. For example, the temperature can be 10°C, 15°C, 18°C, 20°C, 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, or 60°C, or any value between any two of the aforementioned temperature values.
[0077] In some embodiments, the pressure during etching of the TiN layer is 5 mTorr to 15 mTorr. For example, the pressure can be 5 mTorr, 6 mTorr, 7 mTorr, 8 mTorr, 9 mTorr, 10 mTorr, 11 mTorr, 12 mTorr, 13 mTorr, 14 mTorr, or 15 mTorr, or any value between any two of the aforementioned pressure values.
[0078] In some embodiments, when etching the TiN layer, the source power is 400W to 600W (frequency 13.56MHz). For example, the source power can be 400W, 410W, 430W, 450W, 480W, 500W, 520W, 550W, 590W, or 600W, or any value between any two of the aforementioned power values.
[0079] In some embodiments, when etching the TiN layer, the bias power is 20W to 100W (frequency 13.56MHz). For example, the bias power can be 20W, 30W, 40W, 50W, 60W, 70W, 80W, 90W or 100W, or any value between any two of the aforementioned power values.
[0080] Thus, by coordinating the control of the above-mentioned flow rate ratio, flow rate, temperature, pressure, source power, bias power, etc., a TiN hard mask with high pattern accuracy and vertical sidewall morphology can be obtained. This is beneficial for improving the pattern transfer accuracy and obtaining a vertical sidewall morphology when performing the first plasma dry etching of the molybdenum metal layer 11 through the TiN hard mask.
[0081] In some embodiments, a plasma of a mixture of a first oxygen-containing gas and a carbon-containing gas (the fifth gas), and a plasma of a mixture of a second nitrogen-containing gas and a nitrogen-hydrogen-containing gas (the sixth gas) can be used for dry photoresist stripping to remove the photoresist pattern and clean the surface of the TiN hard mask.
[0082] In some embodiments, the first oxygen-containing gas may include oxygen or the like.
[0083] In some embodiments, the carbon-containing oxygen gas may include carbon monoxide, etc.
[0084] In some embodiments, the second nitrogen-containing gas may include nitrogen or the like.
[0085] In some embodiments, the nitrogen-containing hydrogen gas may include ammonia (NH3) or the like.
[0086] In some embodiments, the dry photoresist stripping process can be divided into two steps. The first step uses a plasma of a mixture of oxygen-containing gas (oxygen) and carbon-containing oxygen gas (carbon monoxide) to remove most of the photoresist pattern (the timing of the first step can be controlled by detecting the CO signal). The second step uses a plasma of a mixture of nitrogen-containing gas (nitrogen) and nitrogen-hydrogen gas (ammonia) (which does not contain oxygen-containing gas) to thoroughly remove the remaining photoresist pattern while cleaning the surface of the TiN hard mask. This can improve the surface condition of TiN and remove any O free radicals or O dangling bonds that may exist on the TiN surface.
[0087] In some embodiments, when removing the photoresist pattern, the flow rate percentage of the first oxygen-containing gas (oxygen) in the fifth gas is 70% to 90%, and the flow rate percentage of the nitrogen-hydrogen gas (ammonia) in the sixth gas is 70% to 90%. For example, the flow rate percentage of the first oxygen-containing gas (oxygen) in the fifth gas can be 70%, 71%, 75%, 77%, 79%, 80%, 83%, 86%, 88%, 89%, or 90%, or any value between any two of the aforementioned flow rate percentages. The flow rate percentage of the nitrogen-hydrogen gas (ammonia) in the sixth gas can be 70%, 71%, 73%, 75%, 78%, 79%, 80%, 81%, 84%, 87%, 89%, or 90%, or any value between any two of the aforementioned flow rate percentages.
[0088] In some embodiments, the temperature for removing the photoresist pattern is 100°C to 300°C. For example, the temperature may be 100°C, 105°C, 120°C, 125°C, 130°C, 150°C, 180°C, 200°C, 220°C, 250°C, 255°C, 285°C, or 300°C, or any value between any two of the aforementioned temperature values.
[0089] In some embodiments, the pressure is 100 mTorr to 2000 mTorr when removing the photoresist pattern. For example, the pressure can be 100 mTorr, 200 mTorr, 500 mTorr, 800 mTorr, 1000 mTorr, 1100 mTorr, 1300 mTorr, 1500 mTorr, 1700 mTorr, 1900 mTorr, or 2000 mTorr, or any value between any two of the aforementioned pressure values.
[0090] In some embodiments, when removing the photoresist pattern, the source power during the first step is 500W to 4000W (frequency of 60MHz). For example, the source power during the first step can be 500W, 600W, 800W, 1000W, 1500W, 2000W, 2500W, 3000W, 3500W, or 4000W, or any value between any two of the aforementioned power values. The source power during the second step is 500W to 4000W (frequency of 13.56MHz). For example, the source power during the second step can be 500W, 550W, 750W, 990W, 1000W, 1100W, 1500W, 2000W, 2500W, 3000W, 3500W, or 4000W, or any value between any two of the aforementioned power values.
[0091] In some embodiments, bias power is turned off when removing the photoresist pattern.
[0092] By coordinating the control of the above-mentioned flow rate ratio, temperature, pressure, source power, etc., the surface of the TiN hard mask can be cleaned while completely removing the photoresist pattern, ensuring the critical dimensions of the TiN hard mask and the molybdenum metal lines formed by subsequent etching, and preventing the distortion of the line pattern.
[0093] Step S13: Pattern the molybdenum metal layer using a mask to form molybdenum metal lines on the surface of the previous dielectric layer, and then remove the mask.
[0094] refer to Figure 3 In some embodiments, a plasma of a mixture of oxygen-containing gas (second oxygen-containing gas), chlorine-containing gas (third chlorine-containing gas), and hydrocarbon-containing gas (second hydrocarbon-containing gas) (first gas) can be used. At a first temperature, anisotropic first plasma dry etching is performed on the surface of the exposed molybdenum metal layer 11 through the openings between the masks 12. By patterning the molybdenum metal layer 11, the molybdenum metal layer 11 is etched through, and molybdenum metal lines 111 formed by the patterned molybdenum metal layer 11 are formed on the surface of the front dielectric layer 13.
[0095] Molybdenum metal undergoes severe isotropic etching in a plasma of pure chlorine and oxygen, thus failing to achieve a vertical profile. In this embodiment, this problem is effectively solved by adding a hydrocarbon-containing gas (second hydrocarbon-containing gas) to both the oxygen-containing gas (second oxygen-containing gas) and the chlorine-containing gas (third chlorine-containing gas). During etching of the molybdenum metal layer 11, carbon-containing active groups generated by the dissociation of the hydrocarbon-containing gas in the plasma are adsorbed and reacted on the sidewall surface of the forming molybdenum metal line 111, forming a carbon-containing protective layer 14 to protect the sidewalls of the forming molybdenum metal line 111. Figure 3 As shown (the carbon-containing protective layer 14 is also formed on the side of the mask 12). This carbon-containing protective layer 14 is sensitive to ion bombardment from the vertical direction (and is removed by sputtering), but is insensitive to free radical attacks from the side (and is retained), thereby achieving "in-situ sidewall protection" for the sidewalls of the forming molybdenum metal line 111, thus obtaining a relatively vertical sidewall morphology of the molybdenum metal line 111. After etching to form the molybdenum metal line 111, the carbon-containing protective layer 14 may still remain on the sidewalls of the molybdenum metal line 111.
[0096] In some embodiments, the oxygen-containing gas (the second oxygen-containing gas) may include oxygen or the like.
[0097] In some embodiments, the chlorine-containing gas (the third chlorine-containing gas) may include chlorine gas, etc.
[0098] In some embodiments, the hydrocarbon-containing gas (the second hydrocarbon-containing gas) may include methane (CH4) and the like.
[0099] In some embodiments, the carbon-containing protective layer 14 includes an amorphous hydrocarbon thin film layer (aC:H thin film layer).
[0100] In some embodiments, the carbon-containing protective layer 14 is mainly composed of CC bonds and CH bonds, and may also contain a small amount of Mo-C complex and / or Mo-OC complex. The carbon-containing protective layer 14 can cover the grain boundaries and grain surfaces of Mo on the sidewalls, suppressing the lateral attack of Cl / O free radicals on the sidewalls. During etching, the carbon-containing protective layer 14 located in the bottom region can be removed by high-energy ion sputtering, exposing the surface of the underlying Mo, enabling further etching downwards.
[0101] In some embodiments, when etching the molybdenum metal layer 11, the first temperature is 10°C to 60°C. For example, the temperature may be 10°C, 12°C, 15°C, 18°C, 20°C, 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, or 60°C, or any value between any two of the aforementioned temperature values.
[0102] In some embodiments, when etching the molybdenum metal layer 11, the flow rate percentage of the oxygen-containing gas (oxygen) in the first gas is 10%–30%, the flow rate percentage of the chlorine-containing gas (chlorine) is 40%–60%, and the flow rate percentage of the hydrocarbon-containing gas (methane) is 10%–30%. For example, the flow rate percentage of the oxygen-containing gas can be 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, or 30%, or any value between any two of the aforementioned flow rate percentages. The flow rate percentage of the chlorine-containing gas can be 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, or 60%, or any value between any two of the aforementioned flow rate percentages. The percentage of hydrocarbon-containing gas flow can be 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, or 30%, or any value between any two of the aforementioned percentage values.
[0103] In some embodiments, when etching the molybdenum metal layer 11, the total flow rate of the first gas is 50 sccm to 500 sccm. For example, the total flow rate of the first gas can be 50 sccm, 55 sccm, 60 sccm, 80 sccm, 95 sccm, 100 sccm, 110 sccm, 150 sccm, 180 sccm, 200 sccm, 220 sccm, 250 sccm, 270 sccm, 290 sccm, 300 sccm, 310 sccm, 340 sccm, 360 sccm, 380 sccm, 400 sccm, 430 sccm, 450 sccm, 480 sccm, or 500 sccm, or any value between any two of the aforementioned flow rate values.
[0104] In some embodiments, the pressure for etching the molybdenum metal layer 11 is 5 mTorr to 10 mTorr. For example, the pressure can be 5 mTorr, 5.5 mTorr, 6 mTorr, 6.4 mTorr, 7 mTorr, 7.6 mTorr, 8 mTorr, 8.3 mTorr, 9 mTorr, 9.8 mTorr, or 10 mTorr, or any value between any two of the aforementioned pressure values.
[0105] In some embodiments, when etching the molybdenum metal layer 11, the source power is 500W to 800W. For example, the source power can be 500W, 515W, 520W, 555W, 575W, 600W, 630W, 650W, 680W, 700W, 720W, 750W, 760W, 780W, or 800W, or any value between any two of the aforementioned power values.
[0106] In some embodiments, when etching the molybdenum metal layer 11, the bias power is 20W to 200W. For example, the bias power can be 20W, 30W, 40W, 60W, 80W, 95W, 100W, 120W, 135W, 155W, 190W, or 200W, or any value between any two of the aforementioned power values.
[0107] In some embodiments, when etching the molybdenum metal layer 11, the bias power can be set to alternately turn on and off (pulse bias mode) to form periodic pulse etching, with a duty cycle of 10% to 30%. During the period when the bias power (bias voltage) is off, ion bombardment is stopped, which allows the carbon-containing protective layer 14 to be better retained on the sidewall, achieving continuous and effective protection of the sidewall.
[0108] By coordinating the control of temperature, flow rate ratio, flow rate, pressure, source power, and bias power, anisotropic etching is achieved on the surface of the molybdenum metal layer 11 in the opening. This forms a well-formed, uniformly sized trench with vertical sidewalls that penetrates the molybdenum metal layer 11 at the bottom of the opening, exposing the surface of the underlying dielectric layer 13. Furthermore, by defining the pattern outline through dry etching, multiple well-formed, uniformly sized molybdenum metal lines 111 with vertical sidewalls are formed on the surface of the dielectric layer 13, segmented by trenches.
[0109] Then, the mask 12 and the carbon-containing protective layer 14 are removed to allow for further processing of the sidewalls of the molybdenum metal line 111.
[0110] refer to Figure 4 In some embodiments, the mask 12 on the top of the molybdenum wire 111 can be removed first. After removing the mask 12, the sidewalls of the molybdenum wire 111 also have a carbon-containing protective layer 14, which also needs to be removed subsequently to obtain a completely exposed molybdenum wire 111.
[0111] In some embodiments, when the mask 12 on top of the molybdenum metal line 111 is a TiN hard mask, an aqueous solution comprising a fluorinated etchant, an oxidant, an organic solvent, and a corrosion inhibitor can be used as a wet etching solution to perform wet etching treatment on the TiN hard mask, so as to selectively remove the TiN hard mask (the corrosion rate of this wet etching solution on molybdenum is much lower than the corrosion rate on TiN). The fluorine ions contained in the fluorinated etchant attack the TiN lattice, the oxidant maintains the reactivity, and the corrosion inhibitor selectively protects Mo, thereby achieving the purpose of highly selective removal of TiN.
[0112] In some embodiments, the fluorine-containing etchant may include NH4F, etc.
[0113] In some embodiments, the oxidant may include hydrogen peroxide (H2O2) or the like.
[0114] In some embodiments, the organic solvent may include DMSO (dimethyl sulfoxide (C2H6OS)) or the like.
[0115] In some embodiments, corrosion inhibitors may include 2-aminopyridine (C5H6N2), etc.
[0116] In some embodiments, the wet etching solution contains 0.5% to 3% (wt%) of fluorinated etchant (NH4F), 1% to 4% of oxidant (hydrogen peroxide (concentration 30%)), 20% to 50% of organic solvent (DMSO), 0.3% to 3% of corrosion inhibitor (2-aminopyridine), and the remainder is deionized water.
[0117] In some embodiments, when selectively removing the TiN hard mask using a wet etching solution, the temperature is between 20°C and 60°C. For example, the temperature can be 20°C, 22°C, 25°C, 28°C, 30°C, 31°C, 35°C, 38°C, 40°C, 43°C, 45°C, 47°C, 50°C, 52°C, 55°C, 59°C, or 60°C, or any value between any two of the aforementioned temperature values.
[0118] refer to Figure 5 In some embodiments, after removing the mask 12, the carbon-containing protective layer 14 on the sidewall of the molybdenum metal wire 111 is further removed to obtain the molybdenum metal wire 111 with its surface fully exposed.
[0119] In some embodiments, at a fourth temperature, a third gas is used to perform a second plasma dry etching on the carbon-containing protective layer 14 remaining on the sidewall of the molybdenum metal line 111 to remove the carbon-containing protective layer 14.
[0120] In some embodiments, the third gas may include a reducing gas and a diluting gas (second diluting gas). The reducing gas may include hydrogen, etc., and the diluting gas (second diluting gas) may include nitrogen, etc.
[0121] In some embodiments, when performing the second plasma dry etching, the fourth temperature is 100°C to 300°C. For example, the fourth temperature may be 100°C, 110°C, 120°C, 135°C, 140°C, 150°C, 175°C, 200°C, 210°C, 245°C, 265°C, 280°C, or 300°C, or any value between any two of the aforementioned temperature values.
[0122] In some embodiments, during the second plasma dry etching, the flow rate of the reducing gas (hydrogen) in the third gas is 4% to 50%. For example, the flow rate percentage of the reducing gas (hydrogen) can be 4%, 5%, 7%, 9%, 10%, 11%, 13%, 16%, 19%, 20%, 22%, 25%, 28%, 30%, 34%, 37%, 40%, 45%, 49%, or 50%, or any value between any two of the aforementioned flow rate percentages.
[0123] In some embodiments, the pressure during the second plasma dry etching is 100 mTorr to 3000 mTorr. For example, the pressure can be 100 mTorr, 200 mTorr, 500 mTorr, 800 mTorr, 1000 mTorr, 1100 mTorr, 1500 mTorr, 2000 mTorr, 2500 mTorr, or 3000 mTorr, or any value between any two of the aforementioned pressure values.
[0124] In some embodiments, when performing the second plasma dry etching, the source power is 300W to 3000W. For example, the source power can be 300W, 310W, 500W, 750W, 900W, 1000W, 1220W, 1550W, 1790W, 2000W, 2220W, 2550W, 2800W, or 3000W, or any value between any two of the aforementioned power values.
[0125] In some embodiments, when performing the second plasma dry etching, the bias power is 0W (i.e., the bias power is turned off).
[0126] Thus, through the coordinated control of the above-mentioned temperature, flow rate ratio, pressure, source power, etc., the carbon-containing protective layer 14 left on the sidewall of the molybdenum metal wire 111 can be removed (the time for the second plasma dry etching can be determined according to the removal effect of the carbon-containing protective layer 14).
[0127] Step S14: The sidewalls of the molybdenum metal wire are baked and oxidized using an oxidizing gas to generate a molybdenum trioxide layer on the surface of the sidewalls.
[0128] Using the first plasma dry etching process described in the present application embodiment to etch the molybdenum metal layer 11 can yield a molybdenum metal line 111 with uniform size and vertical sidewalls and a good morphology. However, the sidewall roughness may still be poor. Therefore, the sidewalls of the molybdenum metal line 111 can be further surface-treated by the surface treatment process described in the following embodiment of the present application to improve the sidewall roughness of the molybdenum metal line 111.
[0129] refer to Figure 6 In some embodiments, a second gas including an oxidizing gas may be used, and the sidewalls of the molybdenum wire 111 may be oxidized at a second temperature to achieve shallow oxidation of the sidewalls of the molybdenum wire 111 by baking the sidewall surfaces. During baking, the oxidizing gas preferentially oxidizes the surfaces of protrusions present on the rough sidewalls of the molybdenum wire 111, and at the controlled second temperature, a soluble molybdenum trioxide layer 15 is selectively generated on the sidewall surface of the molybdenum wire 111 (a soluble molybdenum trioxide layer 15 is also generated on the top surface of the molybdenum wire 111 after the mask 12 is removed).
[0130] In some embodiments, the oxidizing gas may include ozone (O3) or the like.
[0131] In some embodiments, the second temperature is 150°C or higher and less than 250°C. Preferably, the second temperature is 150°C to 230°C. For example, the second temperature may be 150°C, 160°C, 170°C, 180°C, 190°C, 193°C, 200°C, 201°C, 205°C, 210°C, 215°C, 220°C, 225°C, 230°C, 235°C, 238°C, 240°C, or 245°C, or any value between any two of the aforementioned temperature values. Within the second temperature range, easily soluble amorphous molybdenum trioxide (amorphous molybdenum trioxide layer 15) can be formed by baking on the sidewall surface of the molybdenum metal wire 111.
[0132] Step S15: Use an alkaline solvent to dissolve and remove the molybdenum trioxide layer.
[0133] refer to Figure 7In some embodiments, after the soluble molybdenum trioxide layer 15 is generated, an alkaline dissolving solution can be used to treat the sidewall surface of the oxidized molybdenum metal wire 111 at a third temperature to dissolve and remove the soluble molybdenum trioxide layer 15 (the molybdenum trioxide layer 15 located on the top surface of the molybdenum metal wire 111 will also be dissolved and removed). Specifically, by preferentially oxidizing the surface of the protrusions present on the rough sidewall of the molybdenum metal wire 111 with an oxidizing gas, and then dissolving and removing the oxidized molybdenum trioxide layer 15 with an alkaline dissolving solution, the surface roughness of the sidewall of the molybdenum metal wire 111 can be reduced.
[0134] By using oxidizing gases and dry oxidation of the sidewalls of the molybdenum wire 111 at a specific baking temperature (second temperature), the rough sidewall surface of the molybdenum wire 111 can be finely treated, avoiding changes in surface stress and maintaining the hydrophilic and hydrophobic properties of the sidewall surface. Furthermore, by using an alkaline solution, the molybdenum trioxide layer 15 formed on the sidewall can be dissolved and removed, while organic residues can also be effectively removed, achieving good cleaning of the sidewall surface and thus obtaining a better overall treatment effect.
[0135] In some embodiments, the alkaline solution may include ammonium hydroxide (NH4OH) solution (an aqueous solution of ammonia), etc.
[0136] In some embodiments, the volume ratio of ammonium hydroxide to water in the alkaline solution can be NH4OH:H2O = 1:8 to 1:20. For example, the volume ratio of ammonium hydroxide to water can be 1:8, 1:9, 1:10, 1:11, 1:12, 1:13, 1:14, 1:15, 1:16, 1:17, 1:18, 1:19, or 1:20, but is not limited to these.
[0137] In some embodiments, the third temperature is 20°C to 100°C. For example, the third temperature may be 20°C, 22°C, 25°C, 27°C, 30°C, 34°C, 38°C, 40°C, 41°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, or 100°C, or any value between any two of the aforementioned temperature values.
[0138] Step S16: Repeat steps S14 to S15 until the surface roughness of the sidewall is reduced.
[0139] In some embodiments, steps S14 to S15 can be repeated, i.e., the process of generating the molybdenum trioxide layer 15 and dissolving and removing the molybdenum trioxide layer 15 can be repeated. This alternating oxidation-dissolution cycle can gradually reduce the surface roughness of the sidewalls of the molybdenum metal line 111 until a molybdenum metal line 111 with effectively reduced surface roughness is obtained. This results in a semiconductor structure with surface-treated molybdenum metal lines 111 on the substrate 10.
[0140] In some embodiments, the number of times the process of generating the molybdenum trioxide layer 15 and dissolving and removing the molybdenum trioxide layer 15 is repeated (the number of times steps S14 to S15 are repeated) is 10 to 30 times. For example, steps S14 and S15 can be alternately and cyclically performed 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 times, and are not limited thereto.
[0141] In some embodiments, when steps S14 to S15 are executed alternately, the time for each execution of step S14 (generating molybdenum trioxide layer 15) is 2 min to 10 min. For example, the time for each execution of step S14 can be 2 min, 3 min, 4 min, 5 min, 6 min, 7 min, 8 min, 9 min, or 10 min, or any value between any two of the aforementioned time values.
[0142] In some embodiments, when steps S14 to S15 are executed alternately, the time for each execution of step S15 (dissolving and removing the molybdenum trioxide layer 15) is 2 min to 6 min, limited to completely dissolving the molybdenum trioxide generated each time. For example, the time for each execution of step S15 can be 2 min, 2.5 min, 3 min, 3.5 min, 4 min, 4.5 min, 5 min, 5.5 min, or 6 min, or any value between any two of the aforementioned time values.
[0143] By repeatedly performing the process of generating and dissolving the molybdenum trioxide layer 15, the degree of oxidation and the degree of removal of the protrusions can be precisely controlled each time. Thus, the sidewall surface is refined through oxidation-dissolution cycle treatment, effectively reducing the surface roughness of the molybdenum metal line 111 sidewall. This gradually smooths the sidewall of the molybdenum metal line 111, improves the linewidth uniformity, reduces the risk of short circuits or open circuits, ensures good connection with the upper metal via, and helps to improve the aspect ratio of the molybdenum metal line 111 to reduce resistance.
[0144] Therefore, by using a plasma containing a mixture of oxygen-containing gas, chlorine-containing gas, and hydrocarbon-containing gas to pattern the molybdenum metal layer 11, molybdenum metal lines 111 with vertical sidewall profiles can be formed on the surface of the substrate 10 (previous dielectric layer 13). Further surface treatment of the sidewalls of the molybdenum metal lines 111, based on an alternating oxidation-dissolution cycle, can effectively reduce the surface roughness of the sidewalls. Thus, by defining the profile of the molybdenum metal lines 111 through plasma dry etching and refining the sidewall surface through oxidation-dissolution treatment, molybdenum metal lines 111 with higher aspect ratios and higher interconnect density can be obtained, achieving lower resistance and better interconnect stability.
[0145] In a second aspect, embodiments of this application also provide a semiconductor structure based on molybdenum metal wires, which is obtained using the semiconductor structure manufacturing method based on molybdenum metal wires provided in any of the embodiments of the first aspect above.
[0146] refer to Figure 7 In some embodiments, the molybdenum-based semiconductor structure includes a substrate 10, a front dielectric layer 13 disposed on the surface of the substrate 10, and molybdenum metal lines 111 disposed on the surface of the front dielectric layer 13. The molybdenum metal lines 111 are obtained using a method for manufacturing a molybdenum-based semiconductor structure as provided in any of the embodiments of the first aspect described above. The molybdenum metal lines 111 can be used to form the most densely patterned bottom metal layer (such as M1, M2) in a metal interconnect layer.
[0147] The molybdenum metal line 111 is obtained by patterning the molybdenum metal layer 11 using a plasma of a mixed gas containing oxygen (oxygen), chlorine (chlorine), and hydrocarbon (methane). The surface roughness is reduced by further performing oxidation and dissolution-based surface treatment on the sidewalls of the molybdenum metal line 111 after etching.
[0148] In a third aspect, embodiments of this application also provide a plasma processing apparatus for performing the semiconductor structure manufacturing method based on molybdenum metal wires corresponding to the above embodiments to form the semiconductor structure based on molybdenum metal wires corresponding to the above embodiments. The plasma processing apparatus includes inductively coupled plasma (ICP) processing equipment or capacitively coupled plasma (CCP) processing equipment, etc.
[0149] In other aspects, embodiments of this application also provide an electronic device, including a molybdenum-based semiconductor structure obtained using the molybdenum-based semiconductor structure manufacturing method described above. The electronic device can be a storage device, mobile phone, computer, tablet computer, electronic instrument, television, artificial intelligence device, etc.
[0150] In summary, this embodiment of the application uses a plasma containing a mixture of oxygen-containing gas, chlorine-containing gas, and hydrocarbon-containing gas (the first gas) to pattern the molybdenum metal layer 11. This allows for the formation of a carbon-containing protective layer 14 on the sidewall surface of the forming molybdenum metal line 111, which is resistant to lateral free radical attacks, achieving "in-situ sidewall protection" and thus obtaining a more vertical sidewall morphology. Furthermore, by performing a surface treatment based on oxidation and dissolution cycles on the sidewall of the etched molybdenum metal line 111, the surface roughness of the sidewall is effectively reduced. This facilitates the obtaining of molybdenum metal lines 111 with higher aspect ratios and higher interconnect density, achieving lower resistance and interconnect stability, which well meets the technical requirements of advanced nodes.
[0151] The above are merely preferred embodiments of this application. These embodiments are not intended to limit the scope of protection of this application. Therefore, any equivalent changes made based on the description and drawings of this application should also be included within the scope of protection of this application.
Claims
1. A method for manufacturing a semiconductor structure based on molybdenum metal wires, characterized in that, include: Provide substrate; A front dielectric layer, a molybdenum metal layer, and a mask are sequentially formed on the surface of the substrate; Through the mask, at a first temperature, a first gas is used to perform a first plasma dry etching on the molybdenum metal layer, and the molybdenum metal layer is etched through, forming a molybdenum metal line on the surface of the previous dielectric layer; The mask is removed, and at a second temperature, the sidewalls of the molybdenum metal wire are oxidized using a second gas to generate a molybdenum trioxide layer on the surface of the sidewalls. At a third temperature, the molybdenum trioxide layer on the sidewall is dissolved and removed using a dissolving solution. The process of generating the molybdenum trioxide layer and dissolving and removing the molybdenum trioxide layer is repeated until the surface roughness of the sidewall is reduced. The first gas includes a mixture of oxygen-containing gas, chlorine-containing gas, and hydrocarbon-containing gas; the second gas includes an oxidizing gas; and the solution includes an alkaline solution. The second temperature is above 150°C and below 250°C, and the first temperature and the third temperature are lower than the second temperature.
2. The semiconductor structure manufacturing method based on molybdenum metal wires according to claim 1, characterized in that, During the first plasma dry etching process, carbon-containing active groups generated by the dissociation of the hydrocarbon gas in the plasma are adsorbed and reacted on the sidewall surface of the forming molybdenum metal wire to form a carbon-containing protective layer to protect the sidewall.
3. The semiconductor structure manufacturing method based on molybdenum metal wires according to claim 2, characterized in that, The carbon-containing protective layer includes an amorphous hydrocarbon thin film layer.
4. The semiconductor structure manufacturing method based on molybdenum metal wire according to claim 1, characterized in that, The oxygen-containing gas includes oxygen, the chlorine-containing gas includes chlorine, the hydrocarbon-containing gas includes methane; and / or, the oxidizing gas includes ozone; and / or, the alkaline solution includes ammonium hydroxide solution.
5. The semiconductor structure manufacturing method based on molybdenum metal wire according to claim 4, characterized in that, In the ammonium hydroxide solution, the volume ratio of ammonium hydroxide to water is: ammonium hydroxide:water = 1:8 to 1:
20.
6. The semiconductor structure manufacturing method based on molybdenum metal wire according to claim 1, characterized in that, During the first plasma dry etching process, the first temperature is 10℃~60℃, the total flow rate of the mixed gas containing oxygen, chlorine, and hydrocarbon gases is 50sccm~500sccm, wherein the flow rate of oxygen-containing gas accounts for 10%~30%, the flow rate of chlorine-containing gas accounts for 40%~60%, and the flow rate of hydrocarbon-containing gas accounts for 10%~30%, the pressure is 5mTorr~10mTorr, the source power is 500W~800W, and the bias power is 20W~200W; and / or, the second temperature is 150℃~230℃, and the time for each generation of the molybdenum trioxide layer is 2min~10min; and / or, the third temperature is 20℃~100℃, and the time for each dissolution and removal of the molybdenum trioxide layer is 2min~6min.
7. The semiconductor structure manufacturing method based on molybdenum metal wire according to claim 1, characterized in that, The process of generating the molybdenum trioxide layer and dissolving and removing the molybdenum trioxide layer is repeated 10 to 30 times.
8. The semiconductor structure manufacturing method based on molybdenum metal wire according to claim 2, characterized in that, After removing the mask, the carbon-containing protective layer is first subjected to a second plasma dry etching at a fourth temperature using a third gas to remove the carbon-containing protective layer. Then, the sidewalls of the molybdenum metal line after the carbon-containing protective layer has been removed are oxidized. The third gas includes a reducing gas and a diluting gas.
9. The semiconductor structure manufacturing method based on molybdenum metal wire according to claim 8, characterized in that, The reducing gas includes hydrogen, and the diluting gas includes nitrogen; and / or, during the second plasma dry etching, the fourth temperature is 100°C to 300°C, the flow rate of the reducing gas in the third gas is 4% to 50%, the pressure is 100 mTorr to 3000 mTorr, the source power is 300 W to 3000 W, and the bias power is 0 W.
10. A semiconductor structure based on molybdenum metal wire, characterized in that, It is obtained using the semiconductor structure manufacturing method based on molybdenum metal wire as described in any one of claims 1-9.