Thin film formation method and thin film

Abstract

The present invention relates to a thin film formation method and a thin film, in which a titanium precursor that does not contain a chlorine component is used to deposit an underlayer for a ruthenium (Ru) layer, so as to improve the properties of ruthenium (Ru) in the thin film comprising the ruthenium (Ru) layer. According to the thin film formation method and the thin film of the present invention, the underlayer for the ruthenium (Ru) layer is deposited using a titanium precursor that does not contain a chlorine component, and thus the properties and crystallinity of the ruthenium (Ru) can be improved.

Description

Thin film formation method and thin film

[0001] The present invention relates to a method for forming a thin film and the thin film said, and more particularly, to a method for forming a thin film and the thin film said, which is implemented to improve the characteristics of a ruthenium (Ru)-containing layer by depositing a lower layer of the ruthenium (Ru)-containing layer using a titanium precursor that does not contain a chlorine component in a thin film containing a ruthenium (Ru)-containing layer.

[0002] Various precursors are used to form thin films, and various deposition techniques have been employed. Among these techniques, Chemical Vapor Deposition (CVD) and Atomic Layer Deposition (ALD) processes are increasingly being used due to the advantages of enhanced compositional control, high film uniformity, and effective doping control. Furthermore, CVD and ALD processes provide excellent conformal step coverage for highly non-planar geometries associated with modern microelectronic devices.

[0003] CVD is a chemical process that uses precursors to form thin films on the surface of a substrate. In a typical CVD process, precursors are passed over the surface of a substrate (e.g., a wafer) in a low-pressure or atmospheric-pressure reaction chamber. The precursors react and / or decompose on the substrate surface to produce a thin film of the deposited material. Plasma can be used to aid the reaction of the precursors or to improve material properties. Volatile byproducts are removed by the gas flow through the reaction chamber. The thickness of the deposited film can be difficult to control because it depends on the adjustment of many parameters, such as temperature, pressure, gas flow rate and uniformity, chemical depletion effects, and time.

[0004] ALD is a chemical method for thin film deposition. It is a self-limiting and sequential, unique film growth technique based on surface reactions that provides precise thickness control and enables the deposition of conformal thin films provided by precursors on surface substrates of various compositions.

[0005] In ALD, precursors are separated during the reaction. A first precursor passes over the substrate surface to form a monolayer on the substrate surface. Excess unreacted precursor is pumped out of the reaction chamber. Subsequently, a second precursor or co-reactant passes over the substrate surface and reacts with the first precursor to form a second monolayer film on the first formed film monolayer on the substrate surface. Plasma can be used to aid the reaction of the precursors or co-reactants or to improve material quality. This cycle is repeated to produce a film of the desired thickness.

[0006] Thin films, particularly metal-containing thin films, have various important applications such as nanotechnology and the fabrication of semiconductor devices. Examples of these applications include capacitor electrodes, gate electrodes, adhesive diffusion barriers, and integrated circuits. As the size of microelectronic components continues to decrease, the demand for improved thin film technology has increased. Furthermore, ruthenium (Ru) deposition is required as next-generation metal electrodes, caps, or liners in the manufacturing of logic and memory semiconductors.

[0007] In addition, metal nitride films, such as titanium nitride or tungsten nitride, can be used to improve ruthenium nucleation with reduced surface roughness.

[0008] Conventional titanium nitride (TiN) is formed using a mixture of titanium tetrachloride (TiCl4) gas and ammonia (NH3) gas as titanium precursors. However, during the process of forming titanium nitride (TiN) using titanium tetrachloride (TiCl4) gas, chlorine (Cl) is generated as a byproduct, which may result in residual chlorine (Cl) remaining within the membrane.

[0009] As such, if chlorine (Cl) remains in the film, the resistivity increases rapidly, and consequently, the contact resistance rises. Consequently, when a ruthenium (Ru) layer is deposited on titanium nitride (TiN), there was a problem in that the properties or crystallinity of ruthenium (Ru) changed due to the influence of the titanium nitride (TiN) layer.

[0010] The technical problem that the present invention aims to solve is to provide a method for forming a thin film and the thin film itself, which is implemented to improve the characteristics of a ruthenium (Ru)-containing layer by depositing a lower layer of the ruthenium (Ru)-containing layer using a titanium precursor that does not contain chlorine components in a thin film containing a ruthenium (Ru)-containing layer.

[0011] A thin film forming method according to the present invention for achieving the above technical problem comprises: a step of forming a titanium-containing layer on a substrate; and a step of forming a ruthenium-containing layer on the titanium-containing layer; wherein the step of forming the titanium-containing layer comprises: a step of spraying a titanium precursor that does not contain a halogen component; and a step of spraying a gas containing nitrogen.

[0012] A thin film forming method according to the present invention for achieving the above other technical objectives is a method for forming a thin film in a chamber, comprising the steps of: introducing a substrate having a titanium-containing layer formed thereon into the chamber; and forming a ruthenium-containing layer on the substrate, wherein the titanium-containing layer is a titanium-containing layer that does not contain a halogen component.

[0013] A thin film according to the present invention for achieving the above-mentioned additional technical objective comprises: a titanium-containing layer formed on a substrate; and a ruthenium-containing layer formed on the titanium-containing layer; wherein the titanium-containing layer is formed using a titanium precursor that does not contain a halogen component.

[0014] According to the thin film formation method and the thin film of the present invention, by depositing a lower layer of the ruthenium (Ru) containing layer using a titanium precursor that does not contain chlorine components, the characteristics and crystallinity of the ruthenium (Ru) containing layer can be improved.

[0015] FIG. 1 is a process flow diagram of a thin film formation method according to one embodiment of the present invention.

[0016] FIG. 2 is a process flow diagram of a thin film formation method according to another embodiment of the present invention.

[0017] FIG. 3 is a schematic cross-sectional view of a thin film according to the present invention.

[0018] In order to fully understand the present invention, the operational advantages of the present invention, and the objectives achieved by the implementation of the present invention, reference should be made to the accompanying drawings describing embodiments of the present invention and the contents described in the accompanying drawings.

[0019] The present invention will be described in detail below by explaining preferred embodiments of the invention with reference to the attached drawings. Identical reference numerals in each drawing indicate identical components.

[0020] FIG. 1 is a process flow diagram of a thin film formation method according to one embodiment of the present invention.

[0021] Referring to FIG. 1, the thin film forming method (100) according to the present invention comprises the step of forming a titanium-containing layer (S110) and the step of forming a ruthenium-containing layer (S130).

[0022] In the step of forming a titanium-containing layer (S110), a titanium-containing layer is formed on the upper surface of the substrate.

[0023] The step of forming the titanium-containing layer (S110) comprises a step of spraying a titanium precursor that does not contain a halogen component (S111) and a step of spraying a gas containing nitrogen (S112). The titanium precursor that does not contain a halogen component may, in particular, be a titanium precursor that does not contain a chlorine (Cl) component.

[0024] Meanwhile, the gas containing nitrogen may be ammonia (NH3) gas.

[0025] In this case, the titanium precursor is titanium tetraisopropoxide (Titanium tetraisopropoxide, TTIP, C8H 24 O4Ti), Tetrakis-(dimethylamido)titanium(IV), TDMAT, C8H 24 N4Ti), Tris(methoxy)trimethylcyclopentadienyl titanium(IV), [Ti(CpMe3)(OMe)3], C 11 H 20 O3Ti), Tris(dimethylamido)methylcyclopentadienyl titanium(IV), [Ti(CpMe)(NMe2)3)], C 11 H 35 N3Ti), Tris(isopropoxide)methylcyclopentadienyl titanium(IV), [Ti(CpMe)(iOPr)3)], C 15 H 28 O3Ti), titanium methoxide (Titanium(IV)(methoxide)[Ti(OMe)4)], C4H 12 O4Ti), titanium ethoxide (Titanium(IV)(ethoxide)[Ti(OEt)4)], C8H 20O4Ti), titanium t-butoxide (Titanium(IV)(t-butoxide)[Ti(OtBu)4)], C 16 H 36 O4Ti), Tris(dimethylamido)-mono(N, N' diisopropyl-2-dimethylamidoguanidiato) titanium(IV), TDMAGT, C 15 H 38 N6Ti), bis(dimethylamido)-bis-(dimethylamino-2-propanolato) titanium(IV), BDMABDT, C 14 H 36 N4O2Ti), Tris(dimethylamido)-(dimethylamino-2-propanolato) titanium(IV), TDMADT, C 11 H 30 It is desirable to use at least one selected from N4OTi).

[0026] When using the above-mentioned titanium precursor and a gas containing nitrogen, the titanium-containing layer may be a titanium nitride (TiN) layer, and the titanium nitride (TiN) layer may not contain chlorine (Cl) components that can act as impurities, thereby improving crystallinity and properties.

[0027] A step of forming a plasma (not shown) may be further included between the step of spraying a titanium precursor that does not contain halogen components (S111) and the step of spraying a gas containing nitrogen (S112). In this case, a plasma of hydrogen (H2), helium (He), oxygen (O2), or argon (Ar) gas may be used.

[0028] Meanwhile, the titanium nitride layer can be formed by a sputtering method or a chemical vapor deposition (CVD) method.

[0029] Next, in the step (S130) of forming a ruthenium-containing layer, a ruthenium-containing layer is formed on top of the titanium-containing layer. At this time, the ruthenium-containing layer can be formed by atomic layer deposition (ALD) or chemical vapor deposition (CVD).

[0030] The step of forming the ruthenium-containing layer (S130) comprises a step of spraying a ruthenium precursor (S131) ​​and a step of spraying a gas containing oxygen (S132).

[0031] Meanwhile, a step of forming plasma (S120) may be further included between the step of forming the titanium-containing layer (S110) and the step of forming the ruthenium-containing layer (S130). In the step of forming plasma (S120), plasma is formed on the upper surface of the titanium-containing layer to treat the surface of the titanium-containing layer with plasma. At this time, plasma of hydrogen (H2), helium (He), oxygen (O2), or argon (Ar) gas may be used.

[0032] As in the present invention, when a ruthenium-containing layer is deposited after plasma treating the surface of the titanium-containing layer, the deposition time of the ruthenium-containing layer can be reduced, which has the advantage of allowing the ruthenium-containing layer to be formed using a small amount of ruthenium.

[0033] In addition, the present invention has the effect of determining the crystallinity and characteristics of the titanium-containing layer by using a titanium precursor that does not contain a chlorine (Cl) component when forming the titanium-containing layer, and thereby further improving the crystallinity and characteristics of the ruthenium-containing layer.

[0034] FIG. 2 is a process flow diagram of a thin film formation method according to another embodiment of the present invention.

[0035] Referring to FIG. 2, a thin film forming method (200) according to another embodiment of the present invention is a method for forming a thin film in a chamber, comprising the step (S210) of introducing a substrate having a titanium-containing layer formed thereon into the chamber and the step (S220) of forming a ruthenium-containing layer on the substrate.

[0036] At this time, it is preferable that the titanium-containing layer is a titanium-containing layer that does not contain halogen components. The titanium-containing layer may be a titanium (Ti) layer or a titanium nitride (TiN) layer.

[0037] FIG. 3 is a schematic cross-sectional view of a thin film according to the present invention.

[0038] Referring to FIG. 3, the thin film (300) according to the present invention comprises a substrate (310), a titanium-containing layer (320), and a ruthenium-containing layer (330).

[0039] The substrate (310) may be made of any one of a silicon substrate, a square substrate, and a large-area substrate. A structure such as a transistor having a source and a drain may be formed on the substrate (310), and for convenience of explanation, the detailed structure is not shown.

[0040] The titanium-containing layer (320) is formed in a direction parallel to the upper surface of the substrate (310). At this time, the titanium-containing layer (320) may be a titanium (Ti) layer or a titanium nitride (TiN) layer. The titanium nitride (TiN) layer may be formed by reacting a titanium precursor with a nitrogen-containing gas such as ammonia (NH3) gas.

[0041] In this case, a titanium precursor that does not contain halogen components may be used as the titanium precursor, and it is particularly desirable to use a titanium precursor that does not contain chlorine (Cl) components.

[0042] The above titanium precursor may be a Star-Titanium (Star-Ti) precursor.

[0043] In particular, the above titanium precursor is titanium tetraisopropoxide (TTIP, C8H 24 O4Ti), Tetrakis-(dimethylamido)titanium(IV), TDMAT, C8H 24 N4Ti), Tris(methoxy)trimethylcyclopentadienyl titanium(IV), [Ti(CpMe3)(OMe)3], C 11 H 20 O3Ti), Tris(dimethylamido)methylcyclopentadienyl titanium(IV), [Ti(CpMe)(NMe2)3)], C 11 H 35 N3Ti), Tris(isopropoxide)methylcyclopentadienyl titanium(IV), [Ti(CpMe)(iOPr)3)], C 15 H 28 O3Ti), titanium methoxide (Titanium(IV)(methoxide)[Ti(OMe)4)], C4H 12 O4Ti), titanium ethoxide (Titanium(IV)(ethoxide)[Ti(OEt)4)], C8H 20 O4Ti), titanium t-butoxide (Titanium(IV)(t-butoxide)[Ti(OtBu)4)], C 16 H 36 O4Ti), Tris(dimethylamido)-mono(N, N' diisopropyl-2-dimethylamidoguanidiato) titanium(IV), TDMAGT, C 15 H 38N6Ti), bis(dimethylamido)-bis-(dimethylamino-2-propanolato) titanium(IV), BDMABDT, C 14 H 36 N4O2Ti), Tris(dimethylamido)-(dimethylamino-2-propanolato) titanium(IV), TDMADT, C 11 H 30 It is desirable to use at least one selected from N4OTi).

[0044] When using the above-mentioned titanium precursor, the titanium-containing layer (320) does not contain chlorine (Cl) components that can act as impurities, so crystallinity and properties can be improved.

[0045] The surface of the titanium-containing layer (320) can be plasma treated by a plasma of hydrogen (H2), helium (He), oxygen (O2), or argon (Ar) gas.

[0046] When the surface of the titanium-containing layer (320) is plasma treated, there is an advantage in that the incubation time is reduced when forming a ruthenium-containing layer (330) on top of the titanium-containing layer (220), thereby reducing the consumption of ruthenium.

[0047] A ruthenium-containing layer (330) is formed on top of the titanium-containing layer (320). At this time, the ruthenium-containing layer (330) may be a ruthenium (Ru) layer or a ruthenium oxide (RuO) layer.

[0048] When forming the titanium-containing layer (320), using a titanium precursor that does not contain chlorine (Cl) components results in the crystallinity and characteristics of the titanium-containing layer (320) being determined, and accordingly, the crystallinity and characteristics of the ruthenium-containing layer (330) are improved.

[0049] The present invention has been described with reference to the embodiments illustrated in the drawings, but this is merely illustrative, and those skilled in the art will understand that various modifications and equivalent alternative embodiments are possible therefrom. Accordingly, the true technical scope of protection of the present invention should be determined by the technical spirit of the claims.

Claims

1. As a method for forming a thin film A step of forming a titanium-containing layer on a substrate; and The method comprises the step of forming a ruthenium-containing layer on the titanium-containing layer; wherein The step of forming the titanium-containing layer above A step of spraying a titanium precursor that does not contain halogen components; and A thin film forming method characterized by including the step of injecting a gas containing nitrogen.

2. In claim 1, the titanium precursor that does not contain the halogen component is A thin film forming method characterized by a titanium precursor that does not contain chlorine (Cl) components.

3. In claim 1, the titanium precursor is, C8H 24 O4Ti, C8H 24 N4Ti, C 11 H 20 O3Ti, C 11 H 35 N3Ti, C 15 H 28 O3Ti, C4H 12 O4Ti, C8H 20 O4Ti, C 16 H 36 O4Ti, C 15 H 38 N6Ti, C 14 H 36 N4O2Ti and C 11 H 30 A thin film forming method characterized by at least one selected from N4OTi.

4. In claim 1, after the step of forming the titanium-containing layer, A thin film forming method characterized by further including a step of forming plasma.

5. In claim 4, the step of forming the plasma is, A thin film forming method characterized by forming a plasma with one or more gases selected from hydrogen, helium, oxygen, and argon.

6. In claim 5, the step of forming the ruthenium-containing layer is, Step of spraying a ruthenium precursor; and A thin film forming method characterized by including the step of spraying an oxygen-containing gas.

7. In Paragraph 1, After the step of spraying the titanium precursor that does not contain the above-mentioned halogen component, A thin film forming method characterized by further including a step of forming plasma.

8. In claim 7, the step of forming the plasma is, A thin film forming method characterized by forming a plasma with one or more gases selected from hydrogen, helium, oxygen, and argon.

9. In claim 1, the step of forming the titanium-containing layer A step of spraying a titanium precursor that does not contain halogen components; and A thin film forming method characterized by forming a titanium nitride (TiN) layer, including the step of injecting a gas containing nitrogen.

10. A method for forming a thin film in a chamber, A step of introducing a substrate having a titanium-containing layer formed thereon into the chamber; The method comprises the step of forming a ruthenium-containing layer on the substrate; wherein A method for forming a thin film characterized in that the above titanium-containing layer is a titanium-containing layer that does not contain halogen components.

11. A titanium-containing layer formed on a substrate; and A ruthenium-containing layer formed on the titanium-containing layer; comprising A thin film characterized in that the titanium-containing layer is formed using a titanium precursor that does not contain a halogen component.

12. In claim 11, the titanium precursor A thin film characterized by being Star-Titanium.

13. In claim 11, the titanium precursor C8H 24 O4Ti, C8H 24 N4Ti, C 11 H 20 O3Ti, C 11 H 35 N3Ti, C 15 H 28 O3Ti, C4H 12 O4Ti, C8H 20 O4Ti, C 16 H 36 O4Ti, C 15 H 38 N6Ti, C 14 H 36 N4O2Ti and C 11 H 30 A thin film characterized by being at least one selected from N4OTi.

14. In claim 11, the ruthenium-containing layer A thin film characterized by being a ruthenium (Ru) layer or a ruthenium oxide (RuO) layer.

15. In claim 11, the titanium-containing layer A thin film characterized by being a titanium (Ti) layer or a titanium nitride (TiN) layer.

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