Thin film material, preparation method therefor, interconnect structure, and chip

Abstract

Provided in the present application are a thin film material, a preparation method therefor, an interconnect structure, and a chip. The thin film material comprises tantalum, carbon, and nitrogen, and the thin film material does not contain halogens; the atomic percentage of tantalum in the thin film material is greater than 70%, the atomic percentage of carbon in the thin film material is 0.1-7%, and the atomic percentage of nitrogen in the thin film material is 0.1-4%. The thin film material can be used as an adhesive material for an interconnect layer and a barrier layer of a chip, thus improving the adhesive and barrier properties between the interconnect layer and the barrier layer.

Description

Thin film material and preparation method thereof, interconnection structure, and chip

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on July 28, 2023, with application number 202310949151.0 and application name “Thin film materials, preparation methods thereof, interconnection structures, and chips”, the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the field of semiconductor materials, and specifically to a thin film material, a preparation method thereof, an interconnection structure, and a chip. Background Art

[0004] Tantalum (Ta) is one of the most widely used adhesion materials for Damascus copper interconnects in integrated circuits. Due to its excellent adhesion, Ta effectively improves the adhesion between copper interconnects and tantalum nitride (TaN) barrier layers. Conventional processes deposit tantalum thin films via physical vapor deposition (PVD). However, as chip interconnect line widths continue to shrink, PVD technology is no longer sufficient to meet the demands of advanced interconnect processes.

[0005] Compared to traditional PVD thin film preparation technology, atomic layer deposition (ALD) technology can precisely control the thickness and composition of thin films at the sub-nanometer scale, and the grown films have better conformality and uniformity, making them suitable for the growth of thin film materials on advanced interconnect structures. In addition, in the back-end process of the chip, the temperature of thin film growth cannot exceed 400°C. Since the deposition temperature of the film can be effectively reduced in a plasma-assisted atmosphere, plasma enhanced atomic layer deposition (PEALD) technology is more suitable for chip interconnection processes, especially the preparation of barrier and adhesion layer materials in advanced interconnects. However, even with the use of PEALD technology, how to efficiently, quickly and with high quality prepare the metal Ta adhesion layer has not yet been overcome by the industry and academia, which also restricts the application of tantalum metal films in advanced chip processes.

[0006] Summary of the Invention

[0007] The present application provides a thin film material and a preparation method thereof, an interconnection structure, and a chip, in order to provide an adhesive material that is non-corrosive, has a certain barrier property to Cu, and has a high bonding performance with the interconnection layer.

[0008] In a first aspect, the present application provides a thin film material, which includes tantalum, carbon and nitrogen, and the thin film material does not contain halogen, wherein the atomic percentage of the tantalum element in the thin film material is greater than 70%, the atomic percentage of the carbon element in the thin film material is 0.1 to 7%, and the atomic percentage of the nitrogen element in the thin film material is 0.1 to 4%.

[0009] The thin film material of the present application is mainly composed of tantalum. The tantalum in the thin film material has high adhesion to the copper in the interconnect layer, and also has high adhesion to the tantalum nitride barrier layer. The thin film material of the present application does not contain halogens. When the thin film material contacts the metal in the interconnect layer of the chip, it will not corrode the interconnect layer, thereby avoiding the reduction in the connection strength between the thin film material and the interconnect layer due to the corrosion of halogens. In addition, by containing 0.1-7% carbon and 0.1-4% nitrogen, the barrier performance of the thin film material to Cu can be further improved without significantly reducing the conductive properties of the thin film material and while ensuring the adhesion of the thin film material to the interconnect layer.

[0010] In an optional implementation, the total atomic percentage of the carbon and nitrogen elements is less than 10%. The total atomic number of the carbon and nitrogen elements should not be too large, as an excessive amount can easily reduce the conductivity of the thin film material and, when used in an interconnect structure, can reduce the electrical performance of the semiconductor device.

[0011] Exemplarily, the atomic ratio of the carbon element to the tantalum element may be less than 0.1, such as less than or equal to 0.08. Exemplarily, the atomic ratio of the nitrogen element to the tantalum element may be less than 0.06, such as less than or equal to 0.05. When the atomic ratio of the carbon element to the tantalum element is too high, and when the atomic ratio of the nitrogen element to the tantalum element is too high, the conductive properties of the film material will decrease. Therefore, by limiting the ratio of the number of atoms of the carbon element and the nitrogen element to tantalum in the film material, the barrier properties of the film material can be effectively improved while ensuring that the film material has good adhesion and good conductivity.

[0012] In a second aspect, the present application provides a method for preparing a thin film material, wherein the method uses organic tantalum as a precursor to perform plasma deposition to prepare the thin film material; wherein the organic tantalum contains carbon and nitrogen.

[0013] The thin film material obtained by the preparation method of the present application may have the same performance as the thin film material of the first aspect of the present application. The corresponding effect description in the first aspect above can be referred to, and the performance of the thin film material obtained by using this method will not be repeated here. In addition, the preparation method of the present application uses organic tantalum as a precursor and is obtained by plasma deposition, such as plasma enhanced atomic layer deposition. This preparation method can significantly improve the preparation rate of tantalum metal film, and the prepared thin film material can have high uniformity and conformality. This preparation method is compatible with the current chip manufacturing process, for example, it is compatible with the preparation process of TaN, without the need to add additional process equipment, reducing the manufacturing difficulty and processing cost.

[0014] In an optional implementation, in at least one of Ta(NR1R2)5 or R3N=Ta(NR4R5)3, R1 to R5 are each independently selected from a C1 to C5 alkyl group. For example, R1 to R5 are each independently selected from a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, or a tert-amyl group or one of their isomers.

[0015] In an optional implementation, a discharge gas is introduced as a co-reactant during the plasma deposition, and the discharge gas includes hydrogen and argon, with a flow ratio of the hydrogen to the argon being greater than 0 and less than 3. Since the preparation method of the present application uses organic matter as a precursor, experiments have shown that when a mixture of hydrogen and argon is used as a co-reactant to generate plasma, the carbon and nitrogen contents in the thin film material can be effectively reduced to within the range defined in the present application.

[0016] During the plasma deposition process, the organic tantalum can be heated to 70-100°C. Using argon as the carrier gas, the saturated vapor of the organic tantalum is loaded into the reaction chamber of the deposition equipment for more than 2 seconds. A mixture of hydrogen and argon is used as the discharge gas, with gas flow rates of 25-100 sccm and 0-75 sccm, respectively. The discharge mode is capacitively coupled plasma, the discharge duration is 5-30 seconds, the discharge power is 50-200W, and the frequency is less than 15MHz. The above process is repeated to obtain a thin film material of the desired thickness after several deposition cycles.

[0017] In a third aspect, the present application provides an interconnect structure comprising an interconnect layer, an adhesion layer, and a barrier layer, wherein the adhesion layer is located between the interconnect layer and the barrier layer, the interconnect layer being a copper layer, and the adhesion layer being the thin film material described in the first aspect and any optional implementation thereof. The adhesion layer is used to enhance the bonding strength between the interconnect layer and the barrier layer and prevent the interconnect layer from peeling off.

[0018] In an optional implementation, the thickness of the adhesion layer may be less than or equal to 20 nm.

[0019] In a fourth aspect, the present application provides a chip, which includes the interconnection structure in the above-mentioned third aspect and any optional implementation thereof.

[0020] The technical effects that can be achieved in the third to fourth aspects mentioned above can be described with reference to the corresponding effects in the first aspect mentioned above, and will not be repeated here.

[0021] Among them, the data in the above-mentioned possible implementation methods of the present application, such as the atomic number ratio of tantalum element, the atomic number ratio of carbon element, the atomic number ratio of nitrogen element, the thickness of the adhesion layer, etc., when measuring, the values ​​within the engineering measurement error range should be understood to be within the range specified in the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] FIG1 is a schematic diagram of a Damascus interconnect structure according to an embodiment;

[0023] FIG2 is a schematic diagram of a process flow during a deposition process;

[0024] FIG3 is a graph showing the XPS test results of samples from different embodiments;

[0025] FIG4 is a diagram of a TDDB test model of samples of the embodiment and the comparative example;

[0026] FIG5 is a graph showing the time taken for breakdown of different samples of Example 1 and Comparative Example 2 under constant voltage conditions;

[0027] FIG6 is a SEM image of the groove of the sample of Example 1.

[0028] Reference numerals: 11 - interconnection layer; 12 - adhesion layer; 13 - barrier layer; 21 - Si substrate; 22 - SiO 2 dielectric layer; 23 - Ta thin film layer; 24 - copper layer. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of this application clearer, this application will be further described in detail below with reference to the accompanying drawings.

[0030] The terms used in the following embodiments are only for the purpose of describing specific embodiments and are not intended to limit the present application. As used in the specification and appended claims of this application, the singular expressions "a", "an", "above", "the", and "this" are intended to also include expressions such as "one or more", unless the context clearly indicates otherwise.

[0031] References to "one embodiment" or "some embodiments" in this specification mean that a particular feature, structure, or characteristic described in conjunction with that embodiment is included in one or more embodiments of the present application. Thus, phrases such as "in one embodiment," "in some embodiments," "in other embodiments," and "in yet other embodiments" appearing in various places in this specification do not necessarily refer to the same embodiment, but rather mean "one or more but not all embodiments," unless otherwise specifically emphasized. The terms "including," "comprising," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0032] As the size of integrated circuits continues to decrease, the metal traces within the chip are becoming thinner and thinner, and the layers are becoming more and more numerous. In order to reduce signal crosstalk and RC delay in integrated circuits, copper wires with lower resistivity are often used instead of traditional aluminum wires to form metal interconnect layers to form Damascus interconnect structures. Figure 1 is a schematic diagram of a Damascus interconnect structure of an embodiment. As shown in Figure 1, the Damascus interconnect structure includes a copper layer as an interconnect layer 11. In order to prevent the diffusion of copper in the dielectric layer of the chip, a barrier layer 13 is usually covered on the surface of the copper layer to prevent copper atoms and copper ions from diffusing into the dielectric layer and causing chip failure. Since tantalum nitride is relatively stable, tantalum nitride is usually used as the barrier layer 13 of the copper layer. In order to improve the adhesion between the interconnect layer 11 and the barrier layer 13, a tantalum metal layer is usually provided between the two as an adhesion layer 12.

[0033] The present application provides a thin film material primarily comprising tantalum, carbon, and nitrogen. This thin film material can be used in a chip's Damascene interconnect structure, for example, positioned between a copper interconnect layer and a tantalum nitride barrier layer. This thin film material enhances the bond strength between the copper layer and the tantalum nitride, and improves the barrier to the copper layer, preventing it from penetrating the thin film material and entering the chip's dielectric layer. This improves the stability and reliability of the metal wiring in the interconnect structure. This thin film material is described in further detail below.

[0034] The thin film material of the embodiment of the present application includes tantalum, carbon and nitrogen. Carbon can form tantalum carbide with tantalum, and nitrogen can form tantalum nitride with tantalum. In addition, the thin film material may also include oxygen. The atomic percentage of tantalum in the thin film material is greater than 70%. The atomic percentage refers to the percentage of atomic number. Tantalum metal, due to its good adhesion, can effectively improve the adhesion performance between the copper interconnect layer and the tantalum nitride barrier layer, which mainly improves the bonding strength between the two and prevents the copper layer from falling off. For example, the atomic percentage of tantalum in the thin film material may be 70%, 75%, 80%, 85% or 90% or more.

[0035] The atomic percentage of carbon in the film material is 0.1-7%. For example, the atomic percentage of carbon in the film material can be 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, or 7%, or any value between any two of the above values.

[0036] The atomic percentage of nitrogen in the film material is 0.1-4%. The addition of nitrogen can further improve the film material's barrier properties to copper, thereby further enhancing the stability of the chip structure. For example, the atomic percentage of nitrogen in the film material can be 0.1%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, or 4%, or any value between these two values.

[0037] The film material does not contain halogens. The presence of halogens makes the film material very susceptible to moisture in the air, causing it to slowly decompose, thereby shortening the life of the film material.

[0038] In an optional embodiment, the total atomic content of carbon and nitrogen in the thin film material is less than 10%. The atomic ratio of carbon to tantalum is less than 0.1. The atomic ratio of nitrogen to tantalum is less than 0.06. If the total atomic content of carbon and nitrogen is too high, or if the atomic ratio of either carbon or nitrogen to tantalum is too high, it will affect the conductivity of the thin film material and thus the electrical performance of the chip. For example, in the thin film material, the total atomic content of carbon and nitrogen can be, for example, 9%, 8%, 7%, 6%, 5%, 4%, 3%, or 2%, or any value between any two of the above values. The atomic ratio of carbon to tantalum can be, for example, 0.09, 0.08, 0.07, 0.06, 0.05, 0.04, 0.03, 0.02, 0.01, or any value between any two of the above values. The atomic ratio of nitrogen to tantalum can be, for example, 0.05, 0.04, 0.03, 0.02, 0.01, or any value between the above two values.

[0039] The thin film material of the embodiment of the present application can be prepared by plasma deposition using organic tantalum as a precursor, wherein the organic tantalum contains carbon and nitrogen.

[0040] The organic tantalum may include at least one of Ta(NR1R2)5 or R3N=Ta(NR4R5)3, R1, R2, R3, R4, and R5 are each independently selected from a C1 to C5 alkyl group. For example, R1, R2, R3, R4, and R5 are each independently selected from a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, or a tert-amyl group, or one of the isomers of the tert-amyl group. For example, the organic tantalum includes, but is not limited to, at least one of the compounds represented by the following structural formulas:

[0041] The plasma deposition used in the preparation method of the embodiment of the present application may be plasma enhanced atomic layer deposition, and the discharge mode of the plasma deposition may be a capacitively coupled plasma mode.

[0042] During the deposition process, in addition to introducing organic tantalum as a precursor for the thin film material, a mixture of hydrogen and argon can also be introduced as a co-reactant. The hydrogen and argon gases generate a plasma, providing free radicals and energy for the deposition reaction, thereby promoting the chemical reaction of the organic tantalum to form tantalum metal. During this process, since organic tantalum contains a certain amount of carbon and nitrogen, these elements are deposited in the thin film material after plasma deposition.

[0043] In the mixed gas of hydrogen and argon, the flow ratio of the hydrogen to the argon is greater than 0 and less than 3. By introducing a certain amount of argon, the C and N contents in the thin film material can be reduced to maintain the C and N contents within a desired range.

[0044] FIG2 is a schematic diagram of a deposition process. For example, referring to FIG2 , the method for preparing the thin film material of an embodiment of the present application includes the following steps:

[0045] S1. Heating the organic tantalum to 70-100° C., using argon as a carrier gas, loading the saturated vapor of the organic tantalum into the reaction chamber of the deposition equipment for more than 2 seconds to deposit the organic tantalum on the surface of the substrate;

[0046] S2, using a mixture of hydrogen and argon as a purge gas for more than 10 seconds to remove organic tantalum and by-products that are not deposited on the deposition surface;

[0047] S3, using a mixture of hydrogen and argon as the discharge gas, with gas flow rates of 25-100 sccm and 0-75 sccm respectively, the discharge mode is capacitively coupled plasma, the discharge duration is 5-30 s, the discharge power is 50-200 W, and the frequency is less than 15 MHz;

[0048] S4, again using a mixture of argon and hydrogen as a purge gas for 20 to 40 seconds to remove reaction by-products;

[0049] S5. Repeat steps S1 to S4 for several deposition cycles to obtain a thin film material of a desired thickness.

[0050] The thin film material of the present application is used as an adhesion layer between the interconnection layer and the barrier layer, and its thickness can be less than or equal to 20 nm.

[0051] The preparation method of the present application will be further described in detail below with reference to examples and comparative examples.

[0052] Example 1

[0053] The method for preparing the thin film material of this embodiment comprises the following steps:

[0054] S11, using TBTDET as a precursor, heating the precursor to 90° C., using argon as a carrier gas, loading saturated vapor of the TBTDET precursor into the reaction chamber for 5 seconds to deposit the TBTDET precursor on the surface of the substrate;

[0055] S12, using a mixture of hydrogen and argon as a purge gas for 30 seconds to remove the undeposited precursors and byproducts;

[0056] S13, using a mixture of hydrogen and argon as the discharge gas, with gas flow rates of 50 sccm and 10 sccm respectively, the discharge mode is capacitively coupled plasma, the discharge duration is 20 s, the discharge power is 110 W, and the frequency is 13.56 MHz;

[0057] S14, again using argon-hydrogen mixed gas as purge gas for 30 seconds to remove reaction by-products;

[0058] S15, repeating steps S11 to S14 for several deposition cycles to obtain a tantalum metal film of a desired thickness.

[0059] The thickness of the thin film material grown after 100, 300 and 600 cycles was tested, and the test results are listed in Table 1.

[0060] Table 1

[0061] The growth rate is fitted according to the film thickness corresponding to 100, 300 and 600 growth cycles, and the fitting results are shown in Figure 2. Referring to Figure 2, according to the fitting results, it can be seen that in the preparation method of this application, the growth rate of the film is approximately

[0062] Example 2

[0063] The method for preparing the thin film material of this embodiment differs from that of Example 1 in that the flow rates of hydrogen and argon are different. In this embodiment, the flow rates of hydrogen and argon are 50 sccm and 50 sccm, respectively, and the deposition cycle is 100 times. All other conditions are the same as those of Example 1.

[0064] X-ray electron spectroscopy (XPS) was used to analyze the elements of the samples from Example 1 and Example 2. Three samples were tested in Example 1, while one sample was tested in Example 2. The test results are shown in FIG3 .

[0065] As shown in Figure 3, the compositional characterization data for thin films prepared using TBTDET as a precursor and an H2:Ar ratio of 50 sccm:10 sccm show that the atomic percentages of Ta are all greater than 70%. For sample 1, the atomic percentage of Ta is 78.46%, N is 1.11%, C is 4.47%, and O is 15.97%. For sample 2, the atomic percentage of Ta is 75.42%, N is 2.13%, C is 4.03%, and O is 18.42%. For sample 3, the atomic percentage of Ta is 70.84%, N is 1.84%, C is 2.58%, and O is 24.74%. For sample 4, the atomic percentage of Ta is 74.24%, N is 1.70%, C is 4.89%, and O is 19.18%. Among them, all samples contain oxygen. In addition to the possibility that some oxygen may be introduced during the reaction process, the main reason is that the prepared Ta metal film is easily oxidized by air after being taken out of the reaction chamber of the deposition equipment. Therefore, the atomic percentage of oxygen element in the XPS characterization results is relatively high.

[0066] Example 3

[0067] The method for preparing the thin film material of this embodiment comprises the following steps:

[0068] S11, using PDEAT as a precursor, heating the precursor to 90°C, and using argon as a carrier gas, loading the saturated vapor of the PDEAT precursor into the reaction chamber for 5 seconds;

[0069] S12, using a mixture of hydrogen and argon as a purge gas for 30 seconds to remove unreacted precursors and by-products;

[0070] S13, using a mixture of hydrogen and argon as the discharge gas, with gas flow rates of 50 sccm and 10 sccm respectively, the discharge mode is capacitively coupled plasma, the discharge duration is 20 s, the discharge power is 110 W, and the frequency is 13.56 MHz;

[0071] S14, again using argon-hydrogen mixed gas as purge gas for 30 seconds to remove reaction by-products;

[0072] S15, repeating steps S11 to S14 for 100 deposition cycles to obtain a tantalum metal film of a desired thickness.

[0073] Comparative Example 1

[0074] Tantalum pentachloride (TaCl5) was used as a precursor to prepare thin film materials by plasma deposition.

[0075] Specifically, TaCl5 is used as a precursor and hydrogen plasma as a co-reactant. At a certain deposition temperature, Ta metal thin films are deposited in the interconnect process via plasma-enhanced atomic layer deposition (PEALD). The reaction formula is: TaCl5(s) + 5H(g) → Ta(s) + 5HCl(g).

[0076] Through testing, when TaCl5 is used as a precursor to prepare thin film materials, the growth rate of the thin film material is about This is mainly because the TaCl5 precursor can react with the deposited Ta film, and the by-product HCl is easily adsorbed on the Ta film, so the growth rate of the Ta film prepared by this method is relatively low.

[0077] By comparing the growth rates of Example 1 and Comparative Example 1, it can be seen that the use of organic tantalum to prepare tantalum thin films can significantly increase the growth rate of the thin films. Even under growth conditions that do not exceed the interconnection process temperature of 400°C, the rate of preparing tantalum thin films with organic precursors is faster, thereby improving the efficiency of thin film preparation. In addition, the use of inorganic TaCl5 as a precursor is highly corrosive and can easily damage the chambers and valves of the deposition equipment, making it difficult to apply to large-scale industrial production. In order to avoid damage, the gas path and pipelines need to be heated and precious metal electroplated, which increases the difficulty and cost of manufacturing.

[0078] The preparation method in this application example uses organic tantalum as a precursor, which is non-corrosive to the equipment and can prevent damage to the cavity and valves. Since TaN thin films are typically prepared using plasma deposition in chip manufacturing, the preparation method in this application can be integrated with the chip manufacturing process, avoiding the introduction of new processing equipment.

[0079] Comparative Example 2

[0080] Tantalum thin films were prepared by PVD method.

[0081] Among them, multi-source integrated PVD equipment is used for deposition. During the deposition process, metal tantalum is directly used as the target material to deposit tantalum on the substrate. The deposition power is 300W, the deposition rate is 10.4nm / min, the deposition pressure is 4mtorr, and the deposition time is 18s to obtain a tantalum film.

[0082] The films of Example 1 and Comparative Example 2 were subjected to time dependent dielectric breakdown (TDDB) tests, respectively. The sample model diagram of the TDDB test is shown in FIG4 . The Ta film 23 was deposited on the surface of the SiO2 dielectric layer 22 using the methods of each embodiment, respectively. The SiO2 dielectric layer 22 was provided on the surface of the Si substrate 21. A copper layer 24 was provided on the surface of the Ta film 23. The test method is as follows: voltage was applied to the copper layer 24 and the Si substrate 21, and the time to failure (TTF) at breakdown was detected under a constant electric field stress of 6.8 MV / cm. The TTF of multiple samples can be obtained by testing the TTF. 50％ .TTF 50％ is the median failure time of different samples, indicating that the number of samples with a failure time less than this value is 50%, and the number of samples with a failure time greater than this value is also 50%.

[0083] FIG5 shows the breakdown time of different samples in Example 1 and Comparative Example 2 under the above electric field. As shown in FIG5 , the TTF corresponding to the sample in Example 1 is 50％ The TTF of the sample of comparative example 2 is 33.2s. 50％ It is 19.4s. It is said that the tantalum metal film of the embodiment of the present application has significantly better barrier performance against copper interconnects than the tantalum metal film prepared by traditional PVD. This is mainly because the tantalum metal film of the embodiment of the present application contains trace amounts of C and N elements, and C and N exist in the film in the form of TaC and TaN compounds, respectively. TaC and TaN have good barrier performance against copper metal. Therefore, the barrier performance of the film of the embodiment of the present application against copper metal is better than that of the Ta metal film prepared by PVD.

[0084] In addition, the thin film material is deposited on the groove surface of the substrate using the preparation method of Example 1. The groove width of the groove is less than 20 nm. The substrate slices after deposition are subjected to SEM observation to observe whether there is metal tantalum deposition in the groove structure of the substrate. The SEM test diagram is shown in Figure 6. Figure 6 (a) is a schematic diagram of the structure in the groove of the substrate, Figure 6 (b) is a local enlarged view of the groove bottom of (a), and Figure 6 (c) is a local enlarged view of the groove wall of (a). Referring to Figure 6, a tantalum metal film with good uniformity and high conformality is formed at both the bottom of the groove and the sidewall of the groove. This shows that the preparation method of the present application can be used to uniformly deposit thin film materials in the grooves of the substrate. However, after depositing a tantalum film in the grooves of the substrate using the method of Comparative Example 2, it was found that a tantalum film could not be formed in the grooves of the substrate. This shows that the method of Comparative Example 2 cannot be used to deposit a tantalum film in an advanced groove.

[0085] The above are only specific embodiments of the present application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A thin film material, characterized in that: The thin film material includes tantalum, carbon and nitrogen, and the thin film material does not contain halogen, wherein the atomic percentage of the tantalum in the thin film material is greater than 70%, the atomic percentage of the carbon in the thin film material is 0.1-7%, and the atomic percentage of the nitrogen in the thin film material is 0.1-4%.

2. The film material according to claim 1, characterized in that: In the thin film material, the total atomic proportion of the carbon element and the nitrogen element is less than 10%.

3. The thin film material according to claim 1 or 2, characterized in that: The atomic ratio of the carbon element to the tantalum element is less than 0.08; the atomic ratio of the nitrogen element to the tantalum element is less than 0.

05.

4. A method for preparing a thin film material according to any one of claims 1 to 3, characterized in that: include: The thin film material is prepared by plasma deposition using organic tantalum as a precursor; wherein the organic tantalum contains carbon and nitrogen.

5. The method according to claim 4, characterized in that The organic tantalum includes at least one of Ta(NR1R2)5 or R3N=Ta(NR4R5)3, and R1 to R5 are each independently selected from C1 to C5 alkyl groups.

6. The method according to claim 4 or 5, characterized in that: A discharge gas is introduced into the plasma deposition, wherein the discharge gas includes hydrogen and argon, and a flow ratio of the hydrogen to the argon is greater than 0 and less than 3.

7. The method according to any one of claims 4 to 6, characterized in that: During the plasma deposition process, the organic tantalum is heated to 70-100° C., argon is used as a carrier gas, and the saturated vapor of the organic tantalum is loaded into the reaction chamber of the deposition equipment for a time greater than 2 seconds; a mixed gas of hydrogen and argon is used as a discharge gas, and the gas flow rates are 25-100 sccm and 0-75 sccm respectively, the discharge mode is capacitively coupled plasma, the discharge duration is 5-30 seconds, the discharge power is 50-200 W, and the frequency is less than 15 MHz.

8. An interconnect structure, characterized in that: comprising an interconnection layer, an adhesion layer and a barrier layer, wherein the adhesion layer is located between the interconnection layer and the barrier layer; The interconnection layer is a copper layer, and the adhesion layer is the thin film material according to any one of claims 1-3.

9. The interconnection structure according to claim 8, characterized in that: The thickness of the adhesion layer is less than or equal to 20 nm.

10. A chip, characterized in that: Comprising the interconnection structure as claimed in claim 8 or 9.

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