Method for manufacturing a capacitor, capacitor, and semiconductor device

Abstract

The application provides a capacitor manufacturing method, a capacitor and a semiconductor device. The method comprises the following steps: providing a substrate, and sequentially stacking a first metal layer, a first insulating layer and a second metal layer on the substrate to obtain a capacitor structure, wherein the material of a target metal layer comprises a live metal, and the target metal layer comprises at least one of the first metal layer and the second metal layer; forming a first dielectric layer on at least an exposed surface of the capacitor structure, and removing at least part of the first dielectric layer to form a first groove exposing a first part of the surface of the first metal layer and a second groove exposing a part of the surface of the second metal layer, wherein the part of the target metal layer comprising the exposed surface is oxidized into an oxide layer; reducing the oxide layer by using a predetermined gas comprising a reducing gas in a predetermined environment, and forming a protective layer on at least the exposed surface of the target metal layer after reduction; and filling a metal material in the first groove and the second groove to obtain a lead structure.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor, in particular to a capacitor manufacturing method, a capacitor and a semiconductor device. BACKGROUND

[0002] The capacitor is an essential electronic component in the circuit. In the existing capacitor manufacturing process, it is found that when some metals are selected as the plate material, the lead formed will cause a break between the upper and lower plates, thereby affecting the performance of the capacitor. SUMMARY

[0003] The main purpose of the present application is to provide a capacitor manufacturing method, a capacitor and a semiconductor device to at least solve the problem of the risk of break between the upper and lower plates and the lead of the capacitor in the prior art.

[0004] In order to achieve the above-mentioned purpose, according to one aspect of the present application, a capacitor manufacturing method is provided, comprising: 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 capacitor structure, wherein the material of the target metal layer includes a reactive 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 part of the surface of the first metal layer; at least forming a first dielectric layer on the exposed surface of the capacitor structure, and removing part of the first dielectric layer to form a first groove exposing a first part of the surface of the first metal layer and a second groove exposing 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 being oxidized into an oxide layer; under a predetermined environment, reducing the oxide layer by using a predetermined gas containing a reducing gas, and forming a protective layer on at least the exposed surface of the target metal layer after reduction to obtain an intermediate structure, the predetermined environment being free of gas that can oxidize the target metal layer; and filling a metal material in the first groove and the second groove of the intermediate structure to obtain a lead structure.

[0005] Optionally, under a predetermined environment, the oxide layer is reduced by using a predetermined gas containing a reducing gas, comprising: placing a structure formed with the oxide layer in a reaction chamber in a vacuum environment or a protective gas environment; and introducing the predetermined gas into the reaction chamber at a predetermined temperature for a predetermined time, so that the predetermined gas and the oxide layer have a reduction reaction to reduce the oxide layer.

[0006] Optionally, the predetermined temperature is 25℃-100℃, and the predetermined time is 10 seconds-40 seconds.

[0007] Optionally, the method further comprises: 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 capacitor structure, comprising: sequentially stacking a first metal nitride sub-layer, a first active metal material sub-layer and a second metal nitride sub-layer on a part of the 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; and 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 part of the surface of the first insulating layer to obtain the second metal layer, a projection of the second part of the surface on the substrate overlapping a projection of the first metal layer on the substrate.

[0008] Optionally, the method further comprises: removing at least part of the first dielectric layer to form a first groove exposing a first part of the surface of the first metal layer and a second groove exposing a part of the surface of the second metal layer, comprising: etching and removing part of the first dielectric layer, part of the first insulating layer and part of the second metal nitride sub-layer in sequence to expose the first active metal material sub-layer to obtain at least one first groove; and etching and removing part of the first dielectric layer and part of the fourth metal nitride sub-layer in sequence to expose the second active metal material sub-layer to obtain the second groove.

[0009] Optionally, the method further comprises: growing a first metal nitride material of a first thickness on the exposed surface of the target metal layer after reduction, the exposed inner walls of the first groove and the second groove and the exposed surface of the first dielectric layer to obtain a protective layer.

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

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

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

[0013] According to another aspect of the present application, there is provided a capacitor, which is obtained by any of the above methods.

[0014] According to still another aspect of the present application, a semiconductor device is also provided, comprising the capacitor.

[0015] According to the technical solution of the present application, firstly, a substrate, a capacitor structure and a first dielectric layer are provided in sequence, the capacitor structure comprises 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 comprises a reactive metal material, then a first groove exposing the first metal layer and a second groove exposing the second metal layer are formed, the reactive metal material on the exposed surface is oxidized into an oxide layer; afterwards, the oxide layer is reduced in a predetermined environment containing no gas that can oxidize the reactive metal material, thus realizing reduction of the oxide layer and covering a protective layer on the surface of the exposed reactive metal material after reduction, realizing isolation of the reactive metal material from the outside world, avoiding re-oxidation of the reactive metal material after reduction, and ensuring that the first metal layer and the second metal layer serving as the plates of the capacitor are free of the oxide layer on the surface; finally, a lead structure is filled in the first groove and the second groove of the intermediate structure, realizing normal contact and conduction between the lead structure and the plates of the capacitor structure, avoiding contact between the lead structure and the oxide layer of the plates, causing large contact resistance between the lead structure and the plates of the capacitor, and easily leading to open circuit, and ensuring good device performance of the capacitor produced. BRIEF DESCRIPTION OF DRAWINGS

[0016] The accompanying drawings, which form a part of the present application, are intended to provide further understanding of the present application, and are used to interpret the present application together with the description. In the drawings:

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

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

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

[0020] In the above drawings, the following reference signs are used:

[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 DESCRIPTION

[0022] It should be noted that the embodiments and features of the embodiments in the present application can be combined with each other without conflict. The technical solutions in the embodiments of the present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0023] In order for those skilled in the technical field to better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should be within the scope of protection of the present application.

[0024] It should be noted that the terms "first", "second" and the like in the specification and claims of the present application and the accompanying drawings are used to distinguish similar objects, and do not necessarily have to describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented. 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 have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0025] As introduced in the background, there is a risk of disconnection between the upper and lower plates of the capacitor and the lead in the prior art. To solve the above technical problem, the embodiments of the present application provide a capacitor manufacturing method, a capacitor and a semiconductor device.

[0026] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present application.

[0027] In the present embodiment, a capacitor manufacturing method is provided. It should be noted that although the logical sequence is shown in the flowchart, in some cases, the steps shown or described herein can be performed in a different order.

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

[0029] In step S201, a substrate 10 is provided, and a first metal layer 11, a first insulating layer 12 and a second metal layer 13 are sequentially stacked on the exposed surface of the substrate 10, to obtain a capacitor structure as shown in Figure 2 , wherein the material of a target metal layer 14 includes a reactive 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 part of the surface of the first metal layer 11.

[0030] Specifically, the materials of the first metal layer and the second metal layer can be the same or different. In the case where the first metal layer includes a reactive metal, the target metal layer includes the first metal layer. In the case where the second metal layer includes a reactive metal, the target metal layer includes the second metal layer. Generally, in order to ensure good performance of the capacitor structure, the first metal layer and the second metal layer are formed of the same material, i.e., the materials of the first metal layer and the second metal layer both include a reactive metal.

[0031] In step S202, as shown in Figure 2 , a first dielectric layer 15 is formed on at least the exposed surface of the capacitor structure, and as shown in Figure 3 , part of the first dielectric layer 15 is removed to form a first groove 16 exposing a first part of the surface of the first metal layer 11 and a second groove 17 exposing part of the surface of the second metal layer 13, the first part being the part not covered by the second metal layer 13, and as shown in Figure 4 , the part of the target metal layer 14 including the exposed surface is oxidized into an oxide layer 18. Figure 4 The case where both the first metal layer 11 and the second metal layer 13 are target metal layers 14 is shown in

[0032] Specifically, the first partial surface is specifically a portion of the first metal layer that is not covered by a projection of the second metal layer on the first metal layer. In the case where the first insulating layer only covers a portion of the surface of the first metal layer away from the substrate, the first dielectric layer is formed on the capacitor structure and the exposed surface of the substrate, and a portion of the first dielectric layer covers the first partial surface. By removing the portion of the first dielectric layer, the first partial surface is exposed, and the first trench is obtained. In the case where 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 portion of the first dielectric layer and a portion of the first insulating layer, the first partial surface is exposed. In the case where a portion of the surface of the target metal layer is exposed, due to the unstable characteristics of the active metal, the portion of the target metal layer including the exposed surface is oxidized into an oxide layer. The trenching direction of the first trench and the trenching direction of the second trench are both from the surface of the first dielectric layer away from the substrate to the substrate.

[0033] Step S203, reducing the oxide layer 18 in a predetermined environment using a predetermined gas including a reducing gas, and forming 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 FIG. 2B. The predetermined environment does not contain a gas that can oxidize the target metal layer. Figure 5

[0034] Specifically, the gas that can oxidize the target metal layer is specifically an oxidizing gas, such as oxygen, ozone, fluorine, chlorine, etc. It should be noted that the process of forming a 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, filling a metal material in the first trench and the second trench of the intermediate structure, to obtain a lead structure 20 as shown in FIG. 2C. Figure 6

[0036] ​​Through the embodiment, first, a substrate, a capacitor structure and a first dielectric layer are sequentially provided, the capacitor structure comprises 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 comprises a reactive metal material, then a first groove exposing the first metal layer and a second groove exposing the second metal layer are formed, the reactive metal material on the exposed surface is oxidized into an oxide layer; then, the oxide layer is reduced in a predetermined environment containing no oxidizable reactive metal material, so that the reduction of the oxide layer is realized, and a protective layer is covered on the surface of the exposed reactive metal material after reduction, so that the isolation of the reactive metal material from the outside is realized, the oxidized reactive metal material after reduction is avoided, and it is ensured that there is no oxide layer on the surface of the first metal layer and the second metal layer as the capacitor plate; finally, a lead structure is filled in the first groove and the second groove of the intermediate structure, so that normal contact and conduction between the lead structure and the plate of the capacitor structure are realized, the contact between the lead structure and the oxide layer of the plate is avoided, the problem of large contact resistance between the lead structure and the capacitor plate and easy circuit breaking is avoided, and the device performance of the capacitor obtained is ensured to be good.

[0037] In order to further solve the problem of the risk of circuit breaking between the upper and lower plates of the capacitor and the lead, in an optional solution, the oxide layer is reduced by a predetermined gas containing a reducing gas in a predetermined environment, comprising: placing a structure formed with the oxide layer 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 time, so that the predetermined gas and the oxide layer have a reduction reaction to reduce the oxide layer. The semiconductor structure formed with the oxide layer is placed in a reaction chamber in a vacuum environment or a reaction chamber containing a protective gas, and the predetermined gas is introduced into the reaction chamber, so that the predetermined gas bombards the oxide layer to displace the oxygen atoms in the oxide layer, thereby realizing the reduction of the oxide layer and obtaining a reactive metal. Thus, the problem that the exposed part of the plate of the capacitor is oxidized and cannot normally conduct electricity with the lead structure is further solved, thereby further avoiding the problem of circuit breaking of the capacitor.

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

[0039] It should be noted that the protective gas is a gas that does not react with the reactive metal, the predetermined gas and the oxide layer, and can be an inert gas such as an inert gas.

[0040] In actual application, the person skilled in the art can set the specific values of the predetermined temperature and the predetermined time according to the specific predetermined gas to ensure that the predetermined gas can completely reduce the oxide layer. In order to ensure the reduction effect and the reduction efficiency, in an example embodiment of the present application, the predetermined temperature is 25-100°C, and the predetermined time is 10-40 seconds. In order to further accelerate the reduction reaction, some catalysts can be added in the reaction chamber during the reduction of the oxide layer by using the predetermined gas including the reduction gas.

[0041] According to still some optional 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, comprising: Figure 2 As shown in the figure, 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 the exposed surface of the substrate to obtain the first metal layer 11; the first insulating layer 12 is formed on the first metal layer 11 and the exposed surface of 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 the second part of the surface of the first insulating layer 12 to obtain the second metal layer 13, and the projection of the second part of the surface on the substrate 10 overlaps the projection of the first metal layer 11 on the substrate 10. In the embodiment, the first metal layer and the second metal layer both adopt a multi-film layer stacking structure to protect the active metal material and realize the normal conduction of the upper and lower plates of the capacitor using the active metal material.

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

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

[0044] In order to further ensure that the first groove and the second groove are formed more simply and quickly, in actual application, at least part of the first dielectric layer is removed to form a first groove exposing the first part of the surface of the first metal layer and a second groove exposing part of the surface of the second metal layer, comprising: Figure 2 and Figure 3As shown, the first dielectric layer 15, the first insulating layer 12 and the second metal nitride sub-layer 23 are etched in sequence to remove part of them, so that the first active metal material sub-layer 22 is exposed, and at least one first trench 16 is obtained. When there are multiple first trenches 16, the multiple first trenches 16 are arranged at intervals. Then, the first dielectric layer 15 and the fourth metal nitride sub-layer 26 are etched in sequence to remove part of them, so that the second active metal material sub-layer 25 is exposed, and the second trench 17 is obtained.

[0045] In another example, as shown in Figure 3 The first trench 16 has 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 and the second trench, before reducing the oxidation layer in a predetermined environment by using a predetermined gas containing a reducing gas, the method further comprises: cleaning the structure formed with the first trench and the second trench to remove etching residues generated in the process of etching 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 can 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 an 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 comprise 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 tantalum nitride.

[0048] Optionally, at least on the exposed surface of the target metal layer after reduction, a protective layer is formed, comprising: Figures 3 to 5As shown, a first thickness of first metal nitride material is grown on the exposed surface of the target metal layer 14 after reduction, on the exposed inner walls of the first groove 16 and the second groove 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 by the protective layer, further avoiding the target metal layer from being oxidized again. By forming the protective layer on the exposed inner walls of the first groove and the second groove 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 of filling metal material in the first groove and the second groove of the intermediate structure to obtain a lead structure, the method further comprises: growing a second thickness of second metal nitride material (not shown in the figure) on the exposed surface of the protective layer, the second thickness being greater than the first thickness.

[0050] The step S204 of filling metal material in the first groove and the second groove of the intermediate structure to obtain a lead structure comprises: Figure 5 and Figure 6 As shown, the metal material is filled in the remaining first groove and the remaining second groove to obtain the lead structure 20.

[0051] In actual application, the first metal nitride material and the second metal nitride material can be the same or different. Those skilled in the art can select appropriate 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 adopts a twice-growth mode to form a tantalum nitride layer with a required thickness.

[0052] Specifically, those skilled in the art can flexibly set the formation thickness of the first metal nitride material and the second metal nitride material according to actual needs, which is not specifically limited in the present application.

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

[0054] In the present application, aluminum is used as the active metal and the metal material of the lead structure, i.e., aluminum is used as the electrode plate and the lead structure of the capacitor. Compared with copper, which is commonly used, aluminum has a lower cost. By using the manufacturing method of the present application, the manufacturing cost of the capacitor is ensured to be low, and the problem of easy oxidation of the active metal and resulting open circuit is overcome, so that a capacitor structure with good electrical contact is obtained.

[0055] A person 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, carbon silicon oxide compound, nitrogen-doped silicon carbide, etc. In a specific embodiment of the present application, the material of the first insulating layer includes silicon nitride. Similarly, a person skilled in the art can use any suitable material as the first dielectric layer. In the present 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).

[0057] It should be noted that each step in the embodiment of forming the capacitor can be implemented by any feasible method in the prior art. The substrate can be selected according to the actual needs 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 any other substrate structure feasible in the prior art. In the present 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 the present application, the materials of the first dielectric layer and the second dielectric layer are the same.

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

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

[0060] The present embodiment relates to a specific capacitor manufacturing method, comprising the following steps:

[0061] Step S1: providing a substrate, sequentially stacking 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 part of the exposed surface of the substrate to obtain a first metal layer, and forming a first insulating layer SiN on the exposed surface of the first metal layer and the exposed surface of the substrate; sequentially stacking 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 part of the exposed surface of the first insulating layer to obtain a second metal layer, the projection of the second metal layer on the first metal layer covering a part of the surface of the first metal layer, and the part of the surface of the first metal layer not covered by the projection of the second metal layer being a first part of the surface;

[0062] Step S2: sequentially forming 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 being a plane;

[0063] Step S3: etching and removing part of the first dielectric layer silicon oxide, part of the second insulating layer SiN, part of the first insulating layer SiN and part of the second metal nitride sub-layer TaN in sequence to expose the first active metal material sub-layer Al and form a first trench, the exposed part of the first active metal material sub-layer Al being oxidized by air into Al2O3, etching and removing part of the first dielectric layer silicon oxide, part of the second insulating layer SiN, part of the second insulating layer SiN and part of the fourth metal nitride sub-layer TaN in sequence to expose the second active metal material sub-layer Al and obtain the second trench, the exposed part of the second active metal material sub-layer Al being oxidized by air into an oxide layer Al2O3;

[0064] Step S3: placing the semiconductor structure with the oxide layer Al2O3 in a vacuum environment, introducing a predetermined gas 27s including a reducing gas H2, bombarding the oxide layer of the semiconductor structure to break the Al-O chemical bonds in Al2O3, reducing the insulating oxide layer Al2O3 into conductive Al, and the specific reaction formula is as follows, and then depositing a protective layer TaN on the exposed surface of the first dielectric layer silicon oxide, the reduced first trench and the reduced second trench to isolate Al and air, the thickness of the protective layer being

[0065] 2Al2O3+3H2→4Al+3H2O;

[0066] Step S4: re-depositing a second metal nitride material TaN on the exposed surface of the protection layer TaN, the thickness of the second metal nitride material TaN is

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

[0068] According to another aspect of the present application, a capacitor is provided, which is made by any of the above methods.

[0069] The capacitor is made by any of the above methods, which first provides a substrate, a capacitor structure and a first dielectric layer which are 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 a reactive metal material, then a first groove which exposes the first metal layer and a second groove which exposes the second metal layer are formed, the exposed surface of the reactive metal material is oxidized into an oxide layer; then, the oxide layer is reduced in a predetermined environment containing no gas containing the oxidizable reactive metal material, so that the reduction of the oxide layer is achieved, and a protection layer is covered on the surface of the reduced reactive metal material, so that the isolation of the reactive metal material from the outside is achieved, the reduced reactive metal material is prevented from being oxidized again, and the surface of the first metal layer and the second metal layer as the capacitor plate is ensured to be free of the oxide layer; finally, a lead structure is filled in the first groove and the second groove of the intermediate structure, so that the normal contact and conduction between the lead structure and the plate of the capacitor structure are achieved, the contact between the lead structure and the oxide layer of the plate is avoided, the problem of large contact resistance between the lead structure and the capacitor plate and easy circuit breaking is avoided, the device performance of the capacitor is ensured to be good, and the production 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 material of the plate of the capacitor and the lead structure electrically connected to the plate is Al. Compared with Cu, Al has a lower cost, so that the production cost of the capacitor is low.

[0072] Embodiments of the present application also provide a semiconductor device including the capacitor.

[0073] The semiconductor device of the embodiment includes the capacitor, which overcomes the problem of device open circuit caused by using active metal as lead structure and capacitor plate, and ensures good device performance.

[0074] It should also be noted that the terms "comprising", "containing", or any other similar term are intended to encompass non-exclusive inclusions, such that a process, method, article, or apparatus that comprises a list of elements does not necessarily include only those elements, but can include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without more limitations, the element defined by the phrase "comprising a" does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

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

[0076] 1) In the capacitor manufacturing method of the application, first, a substrate, a capacitor structure and a first dielectric layer are provided 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 active metal material, then a first groove exposing the first metal layer and a second groove exposing the second metal layer are formed, the exposed surface of the active metal material is oxidized into an oxide layer; thereafter, the oxide layer is reduced in a predetermined environment containing no oxidizable active metal material, thus realizing reduction of the oxide layer and covering a protective layer on the surface of the exposed active metal material after reduction, realizing isolation of the active metal material from the outside world, avoiding re-oxidation of the active metal material after reduction, and ensuring that the first metal layer and the second metal layer as capacitor plates have no oxide layer on the surface; finally, a lead structure is filled in the first groove and the second groove of the intermediate structure, realizing normal contact and conduction between the lead structure and the plates of the capacitor structure, avoiding contact between the lead structure and the oxide layer of the plates, causing large contact resistance between the lead structure and the capacitor plates, and easily causing open circuit, and ensuring good device performance of the manufactured capacitor.

[0077] 2) The capacitor of the present application is made by any of the methods described above, which first provides a substrate, a capacitor structure and a first dielectric layer stacked in sequence, the capacitor structure comprising 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 comprising a reactive metal material, then forms a first groove exposing the first metal layer and a second groove exposing the second metal layer, the reactive metal material on the exposed surface is oxidized into an oxide layer; then, in a predetermined environment containing no gas that can oxidize the reactive metal material, the oxide layer is reduced, thus achieving the reduction of the oxide layer and covering the surface of the exposed reactive metal material after reduction with a protective layer, achieving the isolation of the reactive metal material from the outside world, avoiding the oxidation of the reactive metal material after reduction, ensuring that there is no oxide layer on the surface of the first metal layer and the second metal layer as the capacitor plate; finally, filling the lead structure in the first groove and the second groove of the intermediate structure, achieving normal contact and conduction between the lead structure and the plate of the capacitor structure, avoiding the contact between the lead structure and the oxide layer of the plate, causing the contact resistance between the lead structure and the capacitor plate to be large, which is prone to cause the problem of circuit breakage, ensuring that the device performance of the capacitor is good and the production yield is high.

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

[0079] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles 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: A substrate is provided, and 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. The material of the target metal layer includes an active metal, and the target metal layer includes at least one of the first metal layer and the second metal layer. The projection of the second metal layer onto the first metal layer covers a portion of the surface of the first metal layer. A first dielectric layer is formed on at least the exposed surface of the capacitor structure, and 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, wherein the first portion of the surface is the portion not covered by the second metal layer, and the portion of the target metal layer including the exposed surface is oxidized into an oxide layer. In a predetermined environment, the oxide layer is reduced using a predetermined gas including a reducing gas, and a protective layer is formed at least on the exposed surface of the reduced target metal layer to obtain an intermediate structure. The predetermined environment does not contain any gas that can oxidize the target metal layer. Metal material is filled into the first and second trenches of the intermediate structure to obtain a lead wire structure. A capacitor structure is obtained by sequentially stacking a first metal layer, a first insulating layer, and a second metal layer on the exposed surface of the substrate, comprising: A first metal nitride sublayer, a first active metal material sublayer, and a second metal nitride sublayer are sequentially stacked on a partially exposed surface of the substrate to obtain the first metal layer; The first insulating layer is formed on the exposed surfaces of the first metal layer and 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 part of the surface of the first insulating layer to obtain the second metal layer. The projection of the second part of the surface on the substrate overlaps with the projection of the first metal layer on the substrate.

2. The method according to claim 1, characterized in that, In a predetermined environment, the oxide layer is reduced using a predetermined gas including a reducing gas, including: The structure with the oxide layer formed thereon is placed in a reaction chamber in a vacuum environment or a protective gas environment; A predetermined gas is introduced into the reaction chamber at a predetermined temperature for a predetermined time, so that the predetermined gas reacts with the oxide layer to reduce the oxide layer.

3. The method according to claim 2, characterized in that, The predetermined temperature is 25℃~100℃, and the predetermined duration is 10 seconds~40 seconds.

4. The method according to claim 1, 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: The first dielectric layer, the first insulating layer, and the second metal nitride sublayer are sequentially etched away to expose the first active metal material sublayer, thereby obtaining at least one first trench. The first dielectric layer and the fourth metal nitride sublayer are sequentially etched away to expose the second active metal material sublayer, thus obtaining the second trench.

5. The method according to any one of claims 1 to 4, characterized in that, A protective layer is formed at least on the exposed surface of the reduced target metal layer, including: A first metal nitride material of 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.

6. The method according to claim 5, characterized in that, Before filling the first and second trenches of the intermediate structure with metal material to obtain the lead structure, the method further includes: growing a second metal nitride material of a second thickness greater than the first thickness on the exposed surface of the protective layer.

7. The method according to any one of claims 1 to 4, characterized in that, The active metal and the metallic material respectively include at least one of the following: aluminum, potassium, calcium, sodium, magnesium, zinc, iron, tin, lead, nickel, hafnium, tantalum, and titanium.

8. The method according to any one of claims 1 to 4, characterized in that, The material of the first dielectric layer includes silicon oxide, and the reducing gas includes at least one of the following: hydrogen, hydrogen sulfide, methane, sulfur monoxide, and carbon monoxide. The predetermined gas also includes an inert gas.

9. A capacitor, characterized in that, The capacitor is manufactured using the method described in any one of claims 1 to 8.

10. A semiconductor device, characterized in that, Includes the capacitor as described in claim 9.

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