Preparation method and application of silicon-doped titanium nitride film material
By using silicon doping technology and a combination of tantalum nitride layer in titanium nitride films, an efficient bottom barrier layer is formed, which solves the problem of performance degradation caused by reduced thickness of titanium nitride films, and improves etching performance and device performance , and reduce process costs.
Patent Information
- Application Number
- CN202411180331.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-26
- Publication Date
- 2024-12-13
AI Technical Summary
The performance of existing titanium nitride films decreases after the thickness decreases, affecting the device performance of high K metal gate structures.
The growth method is to form a silicon-doped titanium nitride film by growing a certain thickness first and then circulating with a silane-doped silicon interlayer, and form a bottom barrier layer with a tantalum nitride layer to improve etching performance and device performance.
Silicon-doped titanium nitride film is more resistant to etching, reduces leakage, improves device performance, silicon atoms absorb oxygen vacancy, increase ion diffusion channels, effectively block metal ions diffusion, and optimize processes to reduce costs.
Smart Images
Figure CN119132937A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of semiconductor technology, and in particular to a preparation method and application of a silicon-doped titanium nitride thin film material. Background Art
[0002] The surface of the high dielectric constant layer (HK layer) in the high-K metal gate (HKMG) is covered with a cap layer, which is usually a titanium nitride (TiN) film. The titanium nitride film can protect the high dielectric constant layer and serve as an etch stop layer in the subsequent etching process. A tantalum nitride (TaN) layer is usually formed on its surface. The two are superimposed to form a bottom barrier metal (BBM). Since it is closest to the high dielectric constant layer, its quality will affect the device performance.
[0003] With the further reduction of semiconductor manufacturing process nodes, from the original gate-first process to the current gate-last process, in order to fill the subsequent metal gate, the titanium nitride film needs to be thinned while ensuring the performance of its etch stop layer / bottom barrier layer, and the requirements for the properties of the film itself are further improved. Summary of the invention
[0004] In view of the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide a method for preparing a silicon-doped titanium nitride thin film material and its application, so as to solve the problem of performance degradation of the titanium nitride thin film due to thickness reduction in the prior art.
[0005] To achieve the above-mentioned purpose and other related purposes, the present application provides an application of a silicon-doped titanium nitride thin film material for preparing a semiconductor device having a high-K metal gate structure, wherein the preparation method of the high-K metal gate structure comprises:
[0006] Step 1, providing a substrate, and forming an interface layer on the substrate;
[0007] Step 2, forming a gate dielectric layer on the interface layer;
[0008] Step 3, forming a silicon-doped titanium nitride film on the gate dielectric layer;
[0009] Step 4, forming a tantalum nitride layer and a metal gate in sequence on the silicon-doped titanium nitride film;
[0010] Among them, in step three, a silicon-doped titanium nitride film is formed by first growing a certain thickness of titanium nitride and then passing a silane-doped silicon interlayer cycle.
[0011] Preferably, the material of the interface layer includes silicon oxide, silicon nitride or silicon oxynitride.
[0012] Preferably, the interface layer is formed by atomic layer deposition, chemical vapor deposition or sputtering.
[0013] Preferably, the gate dielectric layer includes a high-K material layer.
[0014] Preferably, the high-K material layer includes a hafnium-based material layer.
[0015] Preferably, the gate dielectric layer is formed by thermal oxidation, atomic layer deposition or chemical vapor deposition.
[0016] Preferably, the number of cycles of the interlayer cyclic growth is determined according to the performance parameters of the semiconductor device to be manufactured.
[0017] Preferably, the tantalum nitride layer and the silicon-doped titanium nitride film together constitute a bottom barrier layer.
[0018] Preferably, the tantalum nitride layer is formed by atomic layer deposition or chemical vapor deposition.
[0019] Preferably, the metal gate is formed by physical vapor deposition.
[0020] As described above, the preparation method and application of silicon-doped titanium nitride thin film material provided in the present application have the following beneficial effects: silicon-doped titanium nitride film is more resistant to etching, reduces leakage, and improves device performance; silicon atoms can absorb oxygen vacancies in the gate dielectric layer to improve device performance; silicon-doped titanium nitride is more amorphous, increases the channel for ion diffusion, and more effectively blocks the diffusion of metal ions into the gate dielectric layer; optimizes the process and reduces costs. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.
[0022] Figure 1 A flow chart showing a method for preparing a high-K metal gate structure when the silicon-doped titanium nitride thin film material provided by an embodiment of the present application is used to prepare a semiconductor device having a high-K metal gate structure;
[0023] Figure 2 A schematic diagram showing a method for preparing a titanium nitride thin film material in the prior art and the atomic structure of the prepared titanium nitride thin film material;
[0024] Figure 3 A schematic diagram showing a method for preparing a silicon-doped titanium nitride thin film material in the prior art and the atomic structure of the prepared silicon-doped titanium nitride thin film material;
[0025] Figure 4 A schematic diagram showing a method for preparing a silicon-doped titanium nitride thin film material and an atomic structure of the prepared silicon-doped titanium nitride thin film material provided in an embodiment of the present application;
[0026] Figure 5 A data analysis chart showing that the etching resistance of the silicon-doped titanium nitride thin film material provided in an embodiment of the present application is enhanced as the number of interlayer cycle growth increases. DETAILED DESCRIPTION
[0027] The following describes the implementation of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. The present application can also be implemented or applied through other different specific implementations, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.
[0028] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in this application. Obviously, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.
[0029] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating directions or positional relationships, are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.
[0030] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, it can also be the internal connection of two components, it can be a wireless connection, or it can be a wired connection. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.
[0031] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.
[0032] See also Figure 1 , which shows a flow chart of a method for preparing a high-K metal gate structure when the silicon-doped titanium nitride thin film material provided in an embodiment of the present application is used to prepare a semiconductor device with a high-K metal gate structure.
[0033] like Figure 1 As shown, the method for preparing the high-K metal gate structure includes the following steps:
[0034] Step 1, providing a substrate, and forming an interface layer on the substrate;
[0035] Step 2, forming a gate dielectric layer on the interface layer;
[0036] Step 3, forming a silicon-doped titanium nitride film on the gate dielectric layer;
[0037] Step 4: forming a tantalum nitride layer and a metal gate in sequence on the silicon-doped titanium nitride film.
[0038] In step 1, optionally, the substrate is a silicon substrate, a germanium substrate, or a silicon-on-insulator substrate, etc.; or the material of the substrate may also include other materials, such as III-V compounds such as gallium arsenide. Those skilled in the art can select the constituent material of the substrate according to the type of device structure formed on the substrate, so the type of the substrate should not limit the protection scope of the present invention.
[0039] As an example, the interface layer may be silicon oxide (SiO2), or other materials, such as silicon nitride or silicon oxynitride. The interface layer may be formed by atomic layer deposition, chemical vapor deposition, sputtering or other suitable methods.
[0040] In step 2, the gate dielectric layer may include a high-K material layer (a material having a high dielectric constant). As an example, the high-K material layer includes a hafnium-based material layer, such as hafnium oxide (HfO2), hafnium silicon oxide (HfSiO), hafnium silicon oxynitride (HfSiON), hafnium tantalum oxide (HfTaO), hafnium titanium oxide (HfTiO), hafnium zirconium oxide (HfZrO), combinations thereof, or other appropriate materials. The gate dielectric layer may be formed by thermal oxidation, atomic layer deposition, or chemical vapor deposition.
[0041] In step 3, a silicon-doped titanium nitride film is formed by first growing a certain thickness of titanium nitride and then passing silane (SiH4) through a silicon interlayer cycle. The number of interlayer cycle growth cycles depends on the performance parameters of the semiconductor device to be prepared, such as Figure 4 As shown, it shows the growth mode of the interlayer cyclic growth X times and the atomic structure of the silicon-doped titanium nitride film formed accordingly.
[0042] In the prior art, Figure 2As shown, silane is not introduced into the process of forming the titanium nitride film. In order to reduce oxygen vacancies in the gate dielectric layer (PDA annealing for densification of the gate dielectric layer causes oxygen to diffuse into the substrate and form oxygen vacancies) and nitrogen doping of the titanium nitride film to increase its ability to block metal ion diffusion, the prior art adopts a method of first growing amorphous silicon on the surface of the titanium nitride film, then annealing it and then removing it, which results in a cumbersome process and increased cost.
[0043] The silicon atoms in the silicon-doped titanium nitride film provided by the present application can absorb oxygen vacancies in the gate dielectric layer, which can ensure the PMOS performance and reduce device leakage; the film itself is more amorphous, which increases the channel for ion diffusion, and can more effectively block the diffusion of metal ions into the gate dielectric layer. Therefore, compared with the prior art, the preparation method of the silicon-doped titanium nitride film provided by the present application can simplify the process and reduce costs.
[0044] like Figure 3 As shown in FIG. 1 , the prior art is to mix titanium chloride (TiCl 4 ), ammonia (NH 3 ) and silane (SiH 4 ) together to grow a silicon-doped titanium nitride film. Figure 5 As shown, the present application adopts a growth method of first growing titanium nitride of a certain thickness and then passing a silane-doped silicon interlayer cycle, and the formed silicon-doped titanium nitride film can further enhance the etching resistance of the silicon-doped titanium nitride film compared with the prior art.
[0045] In step 4, a tantalum nitride layer can be formed by atomic layer deposition or chemical vapor deposition, and the tantalum nitride layer and the silicon-doped titanium nitride film together constitute a bottom barrier layer.
[0046] As an example, the material of the metal gate includes aluminum. The metal gate may be formed by physical vapor deposition.
[0047] It should be noted that the illustrations provided in this embodiment are only used to illustrate the basic concept of the present application in a schematic manner. Therefore, the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.
[0048] In summary, the preparation method and application of silicon-doped titanium nitride thin film material provided by the present application, the silicon-doped titanium nitride thin film is more resistant to etching, reduces leakage, and improves device performance; silicon atoms can absorb oxygen vacancies in the gate dielectric layer, improving device performance; silicon-doped titanium nitride is more amorphous, increases the channel for ion diffusion, and more effectively blocks the diffusion of metal ions into the gate dielectric layer; optimizes the process and reduces costs. Therefore, the present application effectively overcomes various shortcomings in the prior art and has a high industrial utilization value.
[0049] The above embodiments are merely illustrative of the principles and effects of the present application and are not intended to limit the present application. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by a person of ordinary skill in the art without departing from the spirit and technical ideas disclosed by the present invention shall still be covered by the claims of the present application.
Claims
1. Application of a silicon-doped titanium nitride thin film material for preparing a semiconductor device with a high-K metal gate structure, It is characterized in that The method for preparing the high-K metal gate structure comprises: Step 1, providing a substrate, and forming an interface layer on the substrate; Step 2, forming a gate dielectric layer on the interface layer; Step three, forming a silicon-doped titanium nitride film on the gate dielectric layer; Step 4, sequentially forming a tantalum nitride layer and a metal gate on the silicon-doped titanium nitride film; Wherein, in the step three, the silicon-doped titanium nitride film is formed by first growing a titanium nitride layer of a certain thickness and then passing a silane-doped silicon interlayer cycle.
2. The use according to claim 1, It is characterized in that The material of the interface layer includes silicon oxide, silicon nitride or silicon oxynitride.
3. The use according to claim 1 or 2, It is characterized in that The interface layer is formed by atomic layer deposition, chemical vapor deposition or sputtering.
4. The use according to claim 1, It is characterized in that The gate dielectric layer includes a high-K material layer.
5. The use according to claim 4, It is characterized in that The high-K material layer includes a hafnium-based material layer.
6. The use according to claim 1 or 4, It is characterized in that The gate dielectric layer is formed by thermal oxidation, atomic layer deposition or chemical vapor deposition.
7. The use according to claim 1, It is characterized in that The number of cycles of the interlayer cyclic growth is determined according to the performance parameters of the semiconductor device to be manufactured.
8. The use according to claim 1, It is characterized in that The tantalum nitride layer and the silicon-doped titanium nitride film together form a bottom barrier layer.
9. The use according to claim 1 or 8, It is characterized in that The tantalum nitride layer is formed by atomic layer deposition or chemical vapor deposition.
10. The use according to claim 1, It is characterized in that The metal gate is formed by physical vapor deposition.