Capacitor manufacturing method, capacitor and semiconductor device

Abstract

The invention provides a capacitor manufacturing method, a capacitor and a semiconductor device. The method comprises the steps that a substrate is provided, a first metal layer, a first insulating layer and a second metal layer are sequentially stacked on the substrate, a capacitor structure is obtained, the material of a target metal layer comprises active metal, and the target metal layer comprises at least one of the first metal layer and the second metal layer; at least forming a first dielectric layer on the exposed surface of the capacitor structure, and at least removing a part of the first dielectric layer to form a first groove enabling a first part of the surface of the first metal layer to be exposed and a second groove enabling a part of the surface of the second metal layer to be exposed, and oxidizing the part, including the exposed surface, of the target metal layer into an oxide layer; in a predetermined environment, reducing the oxide layer by using a predetermined gas including a reducing gas, and at least forming a protective layer on the exposed surface of the reduced target metal layer; and filling a metal material in the first groove and the second groove to obtain the lead structure.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, and in particular, to a method for manufacturing a capacitor, a capacitor, and a semiconductor device. Background Art

[0002] A capacitor is an essential electronic component in a circuit. During the manufacturing process of existing capacitors, it is found that when certain metals are selected as the electrode plate materials, an open circuit will occur between the formed leads and the upper and lower electrode plates, thereby affecting the performance of the capacitor. Summary of the Invention

[0003] The main purpose of the present application is to provide a method for manufacturing a capacitor, a capacitor, and a semiconductor device, so as to at least solve the problem of the risk of open circuit between the upper and lower electrode plates and the leads of the capacitor in the prior art.

[0004] To achieve the above object, according to one aspect of the present application, a method for manufacturing a capacitor is provided, including: providing a substrate, and sequentially stacking a first metal layer, a first insulating layer, and a second metal layer on the exposed surface of the substrate to obtain a capacitive structure, wherein the material of the target metal layer includes an active metal, the target metal layer includes at least one of the first metal layer and the second metal layer, and the projection of the second metal layer on the first metal layer covers a part of the surface of the first metal layer; forming a first dielectric layer at least on the exposed surface of the capacitive structure, and at least removing a part of the first dielectric layer to form a first trench exposing a first part of the surface of the first metal layer and a second trench exposing a part of the surface of the second metal layer, the first part of the surface being the part not covered by the second metal layer, and the part of the target metal layer including the exposed surface is oxidized to form an oxide layer; in a predetermined environment, reducing the oxide layer with a predetermined gas including a reducing gas, and forming a protective layer at least on the exposed surface of the reduced target metal layer to obtain an intermediate structure, the predetermined environment not containing a gas capable of oxidizing the target metal layer; filling a metal material in the first trench and the second trench of the intermediate structure to obtain a lead structure.

[0005] Optionally, reducing the oxide layer with a predetermined gas including a reducing gas in a predetermined environment includes: placing the structure with the oxide layer formed therein in a reaction chamber in a vacuum environment or a protective gas environment; introducing the predetermined gas into the reaction chamber at a predetermined temperature for a predetermined duration, so that the predetermined gas reacts with the oxide layer to reduce the oxide layer.

[0006] Optionally, the predetermined temperature is 25°C to 100°C, and the predetermined duration is 10 seconds to 40 seconds.

[0007] Optionally, a first metal layer, a first insulating layer, and a second metal layer are sequentially stacked on the exposed surface of the substrate to obtain a capacitor structure, including: sequentially stacking a first metal nitride sub-layer, a first active metal material sub-layer, and a second metal nitride sub-layer on a partial exposed surface of the substrate to obtain the first metal layer; forming the first insulating layer on the first metal layer and the exposed surface of the substrate; sequentially stacking a third metal nitride sub-layer, a second active metal material sub-layer, and a fourth metal nitride sub-layer on a second partial surface of the first insulating layer to obtain the second metal layer, and the projection of the second partial surface on the substrate overlaps with the projection of the first metal layer on the substrate.

[0008] Optionally, at least a part of the first dielectric layer is removed to form a first trench exposing a first partial surface of the first metal layer and a second trench exposing a partial surface of the second metal layer, including: sequentially etching and removing a part of the first dielectric layer, a part of the first insulating layer, and a part of the second metal nitride sub-layer to expose the first active metal material sub-layer to obtain at least one first trench; sequentially etching and removing a part of the first dielectric layer and a part of the fourth metal nitride sub-layer to expose the second active metal material sub-layer to obtain the second trench.

[0009] Optionally, a protective layer is formed at least on the exposed surface of the reduced target metal layer, including: growing a first metal nitride material with a first thickness on the exposed surface of the reduced target metal layer, on the exposed inner walls of the first trench and the second trench, and on the exposed surface of the first dielectric layer to obtain the protective layer.

[0010] Optionally, before filling the first trench and the second trench in the intermediate structure with a metal material to obtain a lead structure, the method further includes: growing a second metal nitride material with a second thickness on the exposed surface of the protective layer, and the second thickness is greater than the first thickness.

[0011] Optionally, the active metal and the metal material respectively include at least one of the following: aluminum, potassium, calcium, sodium, magnesium, zinc, iron, tin, lead, nickel, hafnium, tantalum, titanium.

[0012] Optionally, the material of the first insulating layer includes silicon nitride, the material of the first dielectric layer includes silicon oxide, the reducing gas includes at least one of the following: hydrogen, hydrogen sulfide, methane, sulfur monoxide, carbon monoxide, and the predetermined gas further includes an inert gas.

[0013] According to another aspect of the present application, a capacitor is provided, and the capacitor is manufactured by using any one of the methods.

[0014] According to another aspect of the present application, there is also provided a semiconductor device including the capacitor described above.

[0015] Applying the technical solution of the present application, first, a substrate, a capacitor structure, and a first dielectric layer are sequentially stacked. The capacitor structure includes a first metal layer, a first insulating layer, and a second metal layer. At least one of the first metal layer and the second metal layer includes an active metal material. Then, a first trench exposing the first metal layer and a second trench exposing the second metal layer are formed, and the active metal material on the exposed surface is oxidized into an oxide layer. After that, in a predetermined environment without a gas that can oxidize the active metal material, the oxide layer is reduced. In this way, the reduction of the oxide layer is achieved, and a protective layer is covered on the surface of the reduced exposed active metal material, realizing the isolation of the active metal material from the outside, avoiding the re-oxidation of the reduced active metal material, and ensuring that there is no oxide layer on the surfaces of the first metal layer and the second metal layer serving as the capacitor electrodes. Finally, a lead structure is filled in the first trench and the second trench of the intermediate structure, realizing normal contact conduction between the lead structure and the electrodes of the capacitor structure, avoiding the contact between the lead structure and the oxide layer of the electrode plate, resulting in a large contact resistance between the lead structure and the capacitor electrode plate and being prone to open circuit problems, and ensuring that the device performance of the manufactured capacitor is good. Description of the Drawings

[0016] The specification drawings forming a part of the present application are used to provide a further understanding of the present application. The schematic embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation of the present application. In the drawings:

[0017] Figure 1 A flowchart showing a method for manufacturing a capacitor according to an embodiment of the present application is shown;

[0018] Figures 2 to 5 Structural schematic diagrams after each process step of the method for manufacturing a capacitor according to an embodiment of the present application are respectively shown;

[0019] Figure 6 A structural schematic diagram of a capacitor according to an embodiment of the present application is shown.

[0020] Among them, the above-mentioned drawings include the following reference numerals:

[0021] 10. Substrate; 11. First metal layer; 12. First insulating layer; 13. Second metal layer; 14. Target metal layer; 15. First dielectric layer; 16. First trench; 17. Second trench; 18. Oxide layer; 19. Protective layer; 20. Lead structure; 21. First metal nitride sub-layer; 22. First active metal material sub-layer; 23. Second metal nitride sub-layer; 24. Third metal nitride sub-layer; 25. Second active metal material sub-layer; 26. Fourth metal nitride sub-layer; 27. Second insulating layer. Detailed implementation manners

[0022] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other. The present application will be described in detail below with reference to the drawings and in conjunction with the embodiments.

[0023] In order to enable those skilled in the art to better understand the solution of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0024] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the drawings are used to distinguish similar objects, and do not necessarily need to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so as to describe the embodiments of the present application here. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units does not necessarily have to be limited to those clearly listed steps or units, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0025] As introduced in the background art, there is a risk of open circuit between the upper and lower electrodes and the leads of the capacitor in the prior art. To solve the above technical problems, the embodiments of the present application provide a method for manufacturing a capacitor, a capacitor, and a semiconductor device.

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention.

[0027] In this embodiment, a method for manufacturing a capacitor is provided. It should be noted that although the logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than here.

[0028] Figure 1 is a flowchart of a method for manufacturing a capacitor according to an embodiment of the present application. As Figure 1 shown, the method includes the following steps:

[0029] Step S201, provide a substrate 10, and sequentially stack a first metal layer 11, a first insulating layer 12, and a second metal layer 13 on the exposed surface of the substrate 10 to obtain a capacitor structure as Figure 2 shown, wherein the material of the target metal layer 14 includes an active metal, the target metal layer 14 includes at least one of the first metal layer 11 and the second metal layer 13, and the projection of the second metal layer 13 on the first metal layer 11 covers a part of the surface of the first metal layer 11;

[0030] Specifically, the materials of the first metal layer and the second metal layer may be the same or different. When the first metal layer includes an active metal, the target metal layer includes the first metal layer. When the second metal layer includes an active metal, the target metal layer includes the second metal layer. Usually, in order to ensure better performance of the capacitor structure, the first metal layer and the second metal layer are formed of the same material, that is, the materials of both the first metal layer and the second metal layer include active metals.

[0031] Step S202, as Figure 2 shown, form a first dielectric layer 15 at least on the exposed surface of the capacitor structure, and as Figure 3 shown, at least remove a part of the first dielectric layer 15 to form a first trench 16 exposing a first part of the surface of the first metal layer 11 and a second trench 17 exposing a part of the surface of the second metal layer 13. The first part of the surface is the part not covered by the second metal layer 13. As Figure 4 shown, the part of the target metal layer 14 including the exposed surface is oxidized to an oxide layer 18 ( Figure 4 shows the case where both the first metal layer 11 and the second metal layer 13 are the target metal layer 14, that is, the exposed surfaces of both the first metal layer 11 and the second metal layer 13 are oxidized to the oxide layer 18);

[0032] Specifically, the surface of the first part is specifically the part of the first metal layer that is not covered by the projection of the second metal layer on the first metal layer. When the first insulating layer only covers a part of the surface of the first metal layer away from the substrate, the first dielectric layer is formed on the exposed surfaces of the capacitive structure and the substrate, and a part of the first dielectric layer covers the surface of the first part. By removing this part of the first dielectric layer, the surface of the first part is exposed to obtain the first trench; when the first insulating layer completely covers the surface of the first metal layer away from the substrate, the first dielectric layer covers the surface of the first insulating layer away from the first metal layer and the surface of the second metal layer away from the first metal layer. At this time, by removing a part of the first dielectric layer and a part of the first insulating layer, the surface of the first part is exposed. When a part of the surface of the target metal layer is exposed, due to the unstable characteristics of the active metal, the part of the target metal layer including the exposed surface is oxidized to form an oxide layer. The grooving directions of the first trench and the second trench are both from the surface of the first dielectric layer away from the substrate to the substrate direction.

[0033] Step S203, in a predetermined environment, use a predetermined gas including a reducing gas to reduce the oxide layer 18, and form a protective layer 19 on at least the exposed surface of the target metal layer 14 after reduction, to obtain an intermediate structure as shown in Figure 5 wherein the predetermined environment does not contain a gas that can oxidize the target metal layer;

[0034] Specifically, the gas that can oxidize the target metal layer is specifically an oxidizing gas, such as oxygen, ozone, fluorine, and chlorine, etc. It should be noted that the process of forming the protective layer on at least the exposed surface of the target metal layer after reduction is also carried out in a predetermined environment.

[0035] Step S204, fill the first trench and the second trench in the intermediate structure with a metal material to obtain a lead structure 20 as shown in Figure 6 wherein.

[0036] Through the above embodiments, a substrate, a capacitive structure, and a first dielectric layer are provided in sequence and stacked. The capacitive structure includes a first metal layer, a first insulating layer, and a second metal layer. At least one of the first metal layer and the second metal layer includes an active metal material. Then, a first trench exposing the first metal layer and a second trench exposing the second metal layer are formed. The active metal material on the exposed surface is oxidized to form an oxide layer. After that, in a predetermined environment without a gas capable of oxidizing the active metal material, the oxide layer is reduced, thereby realizing the reduction of the oxide layer and covering a protective layer on the surface of the reduced exposed active metal material, achieving the isolation of the active metal material from the outside world, preventing the reduced active metal material from being oxidized again, and ensuring that there is no oxide layer on the surfaces of the first metal layer and the second metal layer serving as capacitor electrodes. Finally, a lead structure is filled in the first trench and the second trench of the intermediate structure, realizing normal contact conduction between the lead structure and the electrodes of the capacitive structure, avoiding the contact between the lead structure and the oxide layer of the electrode plate, which may cause a large contact resistance between the lead structure and the capacitor electrode plate and easily lead to an open circuit problem, and ensuring that the fabricated capacitor has good device performance.

[0037] In order to further solve the problem of the risk of open circuit between the upper and lower electrodes of the capacitor and the lead, in an alternative solution, in a predetermined environment, a predetermined gas including a reducing gas is used to reduce the oxide layer, including: placing the structure with the oxide layer formed therein in a reaction chamber in a vacuum environment or a protective gas environment; introducing the predetermined gas into the reaction chamber at a predetermined temperature for a predetermined duration, so that the predetermined gas reacts with the oxide layer to reduce the oxide layer. The semiconductor structure with the oxide layer formed thereon is placed in a reaction chamber in a vacuum environment or a reaction chamber with a protective gas, and then the predetermined gas is introduced into the reaction chamber, so that the predetermined gas bombards the oxide layer, replacing the oxygen atoms in the oxide layer, thereby realizing the reduction of the oxide layer and obtaining active metal, further solving the problem that the exposed part of the capacitor electrode plate cannot conduct electricity normally after being oxidized, and further avoiding the capacitor open circuit problem.

[0038] In a specific application, the predetermined gas may only include the reducing gas or may further include other gases for adjusting the ratio of the reducing gas. For example, in addition to the reducing gas, it further includes inert gases such as helium and argon. The reducing gas includes at least one of the following: hydrogen, hydrogen sulfide, methane, sulfur monoxide, and carbon monoxide. The oxide layer is reduced by at least one of the reducing gases, and the insulating oxide layer is reduced to a conductive active metal.

[0039] It should be noted that the protective gas is a gas that does not react with the active metal, the predetermined gas, and the oxide layer, and may specifically be an inert gas or other inactive gases.

[0040] In the actual application process, those skilled in the art can set the specific values of the predetermined temperature and the predetermined duration according to the specific predetermined gas to ensure that the predetermined gas can completely reduce the oxide layer. In an exemplary embodiment of the present application, to ensure the reduction effect and reduction efficiency, the predetermined temperature is 25°C to 100°C, and the predetermined duration is 10 seconds to 40 seconds. To further accelerate the reduction reaction, during the reduction of the oxide layer with a predetermined gas including a reducing gas, some catalysts can also be added to the reaction chamber.

[0041] According to some further alternative embodiments of the present application, a first metal layer, a first insulating layer, and a second metal layer are sequentially stacked on the exposed surface of the substrate to obtain a capacitor structure, including: as Figure 2 shown, a first metal nitride sub-layer 21, a first active metal material sub-layer 22, and a second metal nitride sub-layer 23 are sequentially stacked on a partial exposed surface of the substrate to obtain the first metal layer 11; the first insulating layer 12 is formed on the exposed surfaces of the first metal layer 11 and the substrate 10; a third metal nitride sub-layer 24, a second active metal material sub-layer 25, and a fourth metal nitride sub-layer 26 are sequentially stacked on a second partial surface of the first insulating layer 12 to obtain the second metal layer 13, and the projection of the second partial surface on the substrate overlaps the projection of the first metal layer 11 on the substrate. In this embodiment, both the first metal layer and the second metal layer adopt a multi-layer stack structure, which can protect the active metal material while realizing the normal conduction of the upper and lower electrodes of the capacitor using the active metal material.

[0042] Specifically, the projection of the second partial surface on the substrate does not overlap the projection of the first partial surface on the substrate.

[0043] After a first metal layer, a first insulating layer, and a second metal layer are sequentially stacked on the exposed surface of the substrate to obtain a capacitor structure, and before at least forming a first dielectric layer on the exposed surface of the capacitor structure, the method further includes: as Figure 2 shown, at least a second insulating layer 27 is covered on the exposed surface of the second metal layer 13.

[0044] To further ensure the relatively simple and rapid formation of the first trench and the second trench, in the actual application process, at least part of the first dielectric layer is removed to form a first trench that exposes a first partial surface of the first metal layer and a second trench that exposes a partial surface of the second metal layer, including: as Figure 2 and Figure 3As shown, part of the first dielectric layer 15, part of the first insulating layer 12, and part of the second metal nitride sub-layer 23 are sequentially etched away, exposing the first active metal material sub-layer 22 to obtain at least one first trench 16. When there are multiple first trenches 16, the multiple first trenches 16 are spaced apart; part of the first dielectric layer 15 and part of the fourth metal nitride sub-layer 26 are sequentially etched away, exposing the second active metal material sub-layer 25 to obtain the second trench 17.

[0045] In another exemplary solution, as Figure 3 shown, there are two first trenches 16, and the two first trenches 16 are located on both sides of the second trench 17.

[0046] In addition, after forming the first trench that exposes the surface of the first part of the first metal layer and the second trench that exposes part of the surface of the second metal layer, before reducing the oxide layer with a predetermined gas including a reducing gas in a predetermined environment, the method further includes: cleaning the structure formed with the first trench and the second trench to remove the etching residues generated during the etching of the first trench and the second trench.

[0047] Optionally, the materials of the first metal nitride sub-layer, the second metal nitride sub-layer, the third metal nitride sub-layer, and the fourth metal nitride sub-layer may be the same or different. Considering the process difficulty and process cost, the same material is selected to form the first metal nitride sub-layer, the second metal nitride sub-layer, the third metal nitride sub-layer, and the fourth metal nitride sub-layer. In one embodiment, the materials of the first metal nitride sub-layer, the second metal nitride sub-layer, the third metal nitride sub-layer, and the fourth metal nitride sub-layer respectively include tantalum nitride. Further, the materials of the first metal nitride sub-layer, the second metal nitride sub-layer, the third metal nitride sub-layer, and the fourth metal nitride sub-layer are respectively tantalum nitride.

[0048] Optionally, a protective layer is formed at least on the exposed surface of the target metal layer after reduction, including: as Figures 3 to 5As shown, a first metal nitride material with a first thickness is grown on the exposed surface of the reduced target metal layer 14, on the exposed inner walls of the first trench 16 and the second trench 17, and on the exposed surface of the first dielectric layer 15 to obtain the protective layer 19. The target metal layer is isolated from the outside air through the protective layer, further preventing the target metal layer from being oxidized again. Moreover, by forming the protective layer on the exposed inner walls of the first trench and the second trench and on the exposed surface of the first dielectric layer, the protective layer can prevent the subsequently filled lead structure from diffusing into the first dielectric layer, further ensuring normal conduction between the lead structure and the first metal layer and between the lead structure and the second metal layer.

[0049] Before the step S204: filling a metal material into the first trench and the second trench of the intermediate structure to obtain a lead structure, the method further includes: growing a second metal nitride material (not shown in the figure) with a second thickness on the exposed surface of the protective layer, where the second thickness is greater than the first thickness.

[0050] The step S204: filling a metal material into the first trench and the second trench of the intermediate structure to obtain a lead structure includes: as Figure 5 and Figure 6 shown, filling the metal material into the remaining first trench and the remaining second trench to obtain the lead structure 20.

[0051] In actual application, the first metal nitride material and the second metal nitride material may be the same or different. Those skilled in the art can select suitable materials as the first metal nitride material and the second metal nitride material according to actual needs. In an exemplary embodiment of the present application, the first metal nitride material and the second metal nitride material are the same, both being tantalum nitride. The step forms a tantalum nitride layer with a required thickness by means of two growths.

[0052] Specifically, those skilled in the art can flexibly set the formation thicknesses of the first metal nitride material and the second metal nitride material according to actual needs, and the present application does not make specific limitations thereon.

[0053] In this embodiment, the active metal and the metal material each include at least one of the following: aluminum, potassium, calcium, sodium, magnesium, zinc, iron, tin, lead, nickel, hafnium, tantalum, titanium.

[0054] In this application, aluminum is used as the metal material of the active metal and the lead structure, that is, aluminum is used as the electrode plate and the lead structure of the capacitor. Compared with the commonly used copper, the cost of aluminum is lower. By using the manufacturing method of this application, not only the manufacturing cost of the capacitor is ensured to be low, but also the problem that the active metal is easily oxidized and causes an open circuit can be overcome, and a capacitor structure with good electrical contact is obtained.

[0055] Those skilled in the art can use any suitable material as the first insulating layer, such as one or a combination of silicon dioxide, silicon nitride, silicon carbide, silicon carbon oxide, silicon carbide doped with nitrogen, etc. In a specific embodiment of this application, the material of the first insulating layer includes silicon nitride. Similarly, those skilled in the art can use any suitable material as the first dielectric layer. In this application, the material of the first dielectric layer includes silicon oxide. In a more specific embodiment, the material of the first insulating layer is silicon nitride, and the material of the first dielectric layer is silicon oxide.

[0056] Specifically, the silicon oxide can be grown by any suitable method, including but not limited to being generated by tetraethyl orthosilicate (TEOS for short).

[0057] It should be noted that each step in the above-described embodiment of forming the capacitor can be implemented by a feasible method in the prior art. The substrate can be selected according to the actual requirements of the device, and can include a silicon substrate, a germanium substrate, a silicon germanium substrate, an SOI (Silicon-On-Insulator) substrate or a GOI (Germanium-On-Insulator) substrate, and can also be other feasible substrate structures in the prior art. In this application, the substrate is a high-resistance substrate. The substrate includes a substrate and a second dielectric layer (not shown in the figure) stacked in sequence, and the first metal layer is located on the second dielectric layer. The material of the second dielectric layer can be the same as or different from that of the first dielectric layer. In this application, the materials of the first dielectric layer and the second dielectric layer are the same.

[0058] The various structural layers can be formed using a thin film deposition process, including but not limited to one or more of chemical vapor deposition (CVD for short), physical vapor deposition (PVD for short), atomic layer deposition (ALD for short), and / or other suitable crystal growth processes.

[0059] To enable those skilled in the art to more clearly understand the technical solution of this application, the implementation process of the manufacturing method of the capacitor of this application will be described in detail below in conjunction with specific embodiments.

[0060] This embodiment relates to a specific manufacturing method of a capacitor, including the following steps:

[0061] Step S1: Provide a substrate, and sequentially stack a first metal nitride sub-layer TaN, a first active metal material sub-layer Al, and a second metal nitride sub-layer TaN on a partially exposed surface of the substrate to obtain a first metal layer. Form a first insulating layer SiN on the exposed surface of the first metal layer and the exposed surface of the substrate; sequentially stack a third metal nitride sub-layer TaN, a second active metal material sub-layer Al, and a fourth metal nitride sub-layer TaN on a partially exposed surface of the first insulating layer to obtain a second metal layer, thereby obtaining a capacitor structure. The projection of the second metal layer on the first metal layer covers a partial surface of the first metal layer, and the part of the first metal layer not covered by the projection of the second metal layer is the first partial surface;

[0062] Step S2: Sequentially form a second insulating layer SiN and a first dielectric layer silicon oxide on the exposed surface of the capacitor structure. The surface of the first dielectric layer silicon oxide away from the substrate is a plane;

[0063] Step S3: Sequentially etch and remove a part of the first dielectric layer silicon oxide, a part of the second insulating layer SiN, a part of the first insulating layer SiN, and a part of the second metal nitride sub-layer TaN, so that the first active metal material sub-layer Al is exposed, forming a first trench. The exposed part of the first active metal material sub-layer Al is oxidized by air to Al 2 O 3 , sequentially etch and remove a part of the first dielectric layer silicon oxide, a part of the second insulating layer SiN, a part of the second insulating layer SiN, and a part of the fourth metal nitride sub-layer TaN, so that the second active metal material sub-layer Al is exposed, obtaining the second trench. The exposed part of the second active metal material sub-layer Al is oxidized by air to an oxide layer Al 2 O 3 ;

[0064] Step S3: Place the semiconductor structure with the formed oxide layer Al 2 O 3 in a vacuum environment, introduce a predetermined gas including a reducing gas H 2 for 27s, bombard the oxide layer of the semiconductor structure, so that the Al-O chemical bond in Al 2 O 3 is broken, and the insulating oxide layer Al2 O 3 Restore to conductive Al. The specific reaction formula is as follows. Then, deposit a protective layer TaN on the reduced first trench, the reduced second trench, and the exposed surface of the first dielectric layer silicon oxide to isolate Al from air. The thickness of the protective layer is

[0065] 2Al 2 O 3 +3H 2 →4Al+3H 2 O;

[0066] Step S4: Deposit another layer of second metal nitride material TaN on the exposed surface of the protective layer TaN. The thickness of the second metal nitride material TaN is

[0067] Step S5: Fill the remaining first trench and second trench with a 28K metal material Al to obtain the lead structure.

[0068] According to another aspect of the present application, a capacitor is provided, and the capacitor is fabricated by using any one of the methods described above.

[0069] The capacitor is fabricated by using any one of the methods described above. The method first provides a substrate, a capacitor structure, and a first dielectric layer stacked in sequence. The capacitor structure includes a first metal layer, a first insulating layer, and a second metal layer. At least one of the first metal layer and the second metal layer includes an active metal material. Then, form a first trench exposing the first metal layer and a second trench exposing the second metal layer, and the active metal material on the exposed surface is oxidized to an oxide layer. After that, in a predetermined environment without a gas that can oxidize the active metal material, reduce the oxide layer, thereby realizing the reduction of the oxide layer and covering a protective layer on the exposed active metal material after reduction, achieving the isolation of the active metal material from the outside world, avoiding the re-oxidation of the active metal material after reduction, and ensuring that there is no oxide layer on the surfaces of the first metal layer and the second metal layer serving as the capacitor electrodes. Finally, fill the first trench and the second trench in the intermediate structure with a lead structure, realizing the normal contact conduction between the lead structure and the electrodes of the capacitor structure, avoiding the contact between the lead structure and the oxide layer of the electrode plate, resulting in a large contact resistance between the lead structure and the capacitor electrode plate and being prone to open circuit problems, and ensuring that the device performance of the capacitor is good and the manufacturing yield is high.

[0070] Specifically, the capacitor can be a MIM (Metal-Insulator-Metal) capacitor or other types of capacitors.

[0071] In a specific embodiment, the materials of the capacitor plates and the lead structures electrically connected to the plates are both Al. Compared with using Cu, the cost of Al is lower, thus ensuring a relatively low manufacturing cost of the capacitor.

[0072] The embodiment of the present application further provides a semiconductor device, and the semiconductor device includes the capacitor described above.

[0073] In this embodiment, the semiconductor device includes the capacitor, and this capacitor overcomes the problem of device open circuit caused by using active metals as the lead structure and capacitor plates, ensuring better device performance.

[0074] It should also be noted that the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of another identical element in the process, method, commodity or device including the element.

[0075] From the above description, it can be seen that the embodiments described in the present application achieve the following technical effects:

[0076] 1) In the manufacturing method of the capacitor of the present application, first, a substrate, a capacitive structure and a first dielectric layer are provided in sequence. The capacitive structure includes a first metal layer, a first insulating layer and a second metal layer. At least one of the first metal layer and the second metal layer includes an active metal material. Then, a first trench for exposing the first metal layer and a second trench for exposing the second metal layer are formed, and the active metal material on the exposed surface is oxidized to an oxide layer. After that, in a predetermined environment without a gas capable of oxidizing the active metal material, the oxide layer is reduced. In this way, the reduction of the oxide layer is achieved, and a protective layer is covered on the surface of the reduced exposed active metal material, realizing the isolation of the active metal material from the outside world, avoiding the re-oxidation of the reduced active metal material, and ensuring that there is no oxide layer on the surfaces of the first metal layer and the second metal layer serving as the capacitor plates. Finally, the lead structures are filled in the first trench and the second trench of the intermediate structure, realizing normal contact conduction between the lead structures and the plates of the capacitive structure, avoiding the contact between the lead structures and the oxide layers of the plates, resulting in a large contact resistance between the lead structures and the capacitor plates and being prone to open circuit problems, and ensuring better device performance of the manufactured capacitor.

[0077] 2) The capacitor of the present application is fabricated by any of the described methods. The method first provides a substrate, a capacitive structure, and a first dielectric layer stacked in sequence. The capacitive structure includes a first metal layer, a first insulating layer, and a second metal layer. At least one of the first metal layer and the second metal layer includes an active metal material. Then, a first trench exposing the first metal layer and a second trench exposing the second metal layer are formed, and the active metal material on the exposed surface is oxidized to an oxide layer. After that, in a predetermined environment without a gas capable of oxidizing the active metal material, the oxide layer is reduced, thus achieving the reduction of the oxide layer and covering a protective layer on the surface of the reduced exposed active metal material, realizing the isolation of the active metal material from the outside, avoiding the re-oxidation of the reduced active metal material, and ensuring that there is no oxide layer on the surfaces of the first metal layer and the second metal layer serving as the capacitor electrodes. Finally, a lead structure is filled in the first trench and the second trench of the intermediate structure, realizing the normal contact conduction between the lead structure and the electrodes of the capacitive structure, avoiding the contact between the lead structure and the oxide layer of the electrode plate, resulting in a large contact resistance between the lead structure and the capacitor electrode plate and being prone to open circuit problems, and ensuring that the device performance of the capacitor is good and the manufacturing yield is high.

[0078] 3) The semiconductor device of the present application includes a capacitor, which overcomes the device open circuit problem caused by using an active metal as the lead structure and the capacitor electrode plate, and ensures good device performance.

[0079] The above are only the preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for manufacturing a capacitor, characterized in that: include: Providing a substrate, and sequentially stacking a first metal layer, a first insulating layer, and a second metal layer on an exposed surface of the substrate to obtain a capacitor structure, wherein the material of the target metal layer includes an active metal, the target metal layer includes at least one of the first metal layer and the second metal layer, and a projection of the second metal layer on the first metal layer covers a portion of the surface of the first metal layer; forming a first dielectric layer at least on the exposed surface of the capacitor structure, and removing at least a portion of the first dielectric layer to form a first groove that exposes a first portion of the surface of the first metal layer and a second groove that exposes a portion of the surface of the second metal layer, wherein the first portion of the surface is a portion not covered by the second metal layer, and the portion of the target metal layer including the exposed surface is oxidized to an oxide layer; Under a predetermined environment, reducing the oxide layer with a predetermined gas including a reducing gas, and forming a protective layer at least on the exposed surface of the target metal layer after the reduction to obtain an intermediate structure, wherein the predetermined environment does not contain a gas that can oxidize the target metal layer; Metal material is filled in the first trench and the second trench of the intermediate structure to obtain a lead structure.

2. The method according to claim 1, characterized in that Under a predetermined environment, reducing the oxide layer using a predetermined gas including a reducing gas comprises: Placing the structure formed with the oxide layer in a reaction chamber in a vacuum environment or a protective gas environment; The predetermined gas is introduced into the reaction chamber at a predetermined temperature for a predetermined time period, so that the predetermined gas undergoes a reduction reaction with the oxide layer to reduce the oxide layer.

3. The method according to claim 2, characterized in that The predetermined temperature is 25° C. to 100° C., and the predetermined time is 10 seconds to 40 seconds.

4. The method according to claim 1, characterized in that: A first metal layer, a first insulating layer and a second metal layer are sequentially stacked on the exposed surface of the substrate to obtain a capacitor structure, comprising: A first metal nitride sublayer, a first active metal material sublayer and a second metal nitride sublayer are sequentially stacked on the partially exposed surface of the substrate to obtain the first metal layer; forming the first insulating layer on the first metal layer and the exposed surface of the substrate; A third metal nitride sublayer, a second active metal material sublayer and a fourth metal nitride sublayer are sequentially stacked on the second partial surface of the first insulating layer to obtain the second metal layer, and the projection of the second partial surface on the substrate overlaps with the projection of the first metal layer on the substrate.

5. The method according to claim 4, characterized in that At least a portion of the first dielectric layer is removed to form a first trench that exposes a first portion of the surface of the first metal layer and a second trench that exposes a portion of the surface of the second metal layer, including: Sequentially etching and removing a portion of the first dielectric layer, a portion of the first insulating layer, and a portion of the second metal nitride sublayer, so that the first active metal material sublayer is exposed, thereby obtaining at least one first trench; Part of the first dielectric layer and part of the fourth metal nitride sublayer are sequentially etched away to expose the second active metal material sublayer, thereby obtaining the second trench.

6. The method according to any one of claims 1 to 5, characterized in that Forming a protective layer at least on the exposed surface of the reduced target metal layer, comprising: A first metal nitride material with a first thickness is grown on the exposed surface of the reduced target metal layer, on the exposed inner walls of the first trench and the second trench, and on the exposed surface of the first dielectric layer to obtain the protective layer.

7. The method according to claim 6, characterized in that Before filling the first trench and the second trench of the intermediate structure with metal material to obtain the lead structure, the method further includes: growing a second metal nitride material with a second thickness on the exposed surface of the protective layer, wherein the second thickness is greater than the first thickness.

8. The method according to any one of claims 1 to 5, characterized in that The active metal and the metal material respectively include at least one of the following: aluminum, potassium, calcium, sodium, magnesium, zinc, iron, tin, lead, nickel, hafnium, tantalum, and titanium.

9. The method according to any one of claims 1 to 5, characterized in that The material of the first dielectric layer includes silicon oxide, the reducing gas includes at least one of the following: hydrogen, hydrogen sulfide, methane, sulfur monoxide, carbon monoxide, and the predetermined gas also includes an inert gas.

10. A capacitor, characterized in that: The capacitor is manufactured by the method according to any one of claims 1 to 9.

11. A semiconductor device, characterized in that: Comprising the capacitor as claimed in claim 10.

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