Tantalum nitride selective deposition method and application thereof
By using organic tantalum and nitrogen-containing precursors to perform selective deposition of tantalum nitride in the range of 250℃~300℃, the complex problem of barrier layer preparation in traditional methods is solved, and the selective deposition of tantalum nitride on different surfaces is achieved. and process simplification, improving device reliability and circuit performance.
Patent Information
- Application Number
- CN202411327088.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-23
- Publication Date
- 2024-12-13
AI Technical Summary
The traditional tantalum nitride deposition method requires additional preparation of barrier layers when achieving patterned thin film deposition, and the operation process is complicated and it is difficult to achieve selective deposition.
By performing at least one deposition cycle on the substrate within the range of 250°C to 300°C, selective deposition of tantalum nitride is performed using organic tantalum precursor and nitrogen-containing precursor, and temperature is controlled within the metal region and the dielectric oxide region. The growth rate difference enables selective deposition of tantalum nitride, avoiding the need for additional preparation of barrier layers.
The selective deposition of tantalum nitride on different surfaces is realized, the operation process is simplified, the simplicity and efficiency of the process is improved, the subsequent etching and cleaning steps are reduced, and the long-term reliability and circuit performance of the device are enhanced.
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Figure CN119121188A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of atomic layer deposition, and in particular to a tantalum nitride selective deposition method and application thereof. Background Art
[0002] Atomic layer deposition (ALD) technology is a thin film preparation technology that grows atomically layer by layer. During the atomic layer deposition process, different precursors are adsorbed on the surface of the substrate and reacted to form a deposited film. By performing a certain number of ALD cycles, the target film thickness can be obtained. In the preparation process of metal interconnect semiconductor devices, it is usually necessary to prepare a tantalum nitride barrier layer. In the traditional tantalum nitride deposition method, in order to achieve patterned thin film deposition, it is usually necessary to use photoresists, self-assembled monolayers, organic molecular barrier materials, etc. to form a barrier layer to control the selective deposition of tantalum nitride in the target area, and the operation process is relatively complicated. Summary of the invention
[0003] Based on this, it is necessary to provide a tantalum nitride selective deposition method and its application. The tantalum nitride selective deposition method of the present application can realize the selective deposition of tantalum nitride on different surfaces, and the tantalum nitride selective deposition method does not require additional preparation of a barrier layer, and the operation process is simple.
[0004] In a first aspect, the present application provides a method for selectively depositing tantalum nitride, comprising the following steps:
[0005] At least one deposition cycle is performed on a substrate, wherein the substrate has a metal region and a dielectric oxide region on a surface thereof, wherein a single deposition cycle comprises the following steps:
[0006] Placing the substrate in a gas atmosphere including an organic tantalum precursor and performing a first treatment at 250° C. to 300° C.;
[0007] The substrate after the first treatment is placed in a gas atmosphere including a nitrogen-containing precursor, and a second treatment is performed at 250° C. to 300° C.
[0008] In some embodiments, the material of the metal region includes copper.
[0009] In some embodiments, the material of the dielectric oxide region includes SiO2.
[0010] In some of the embodiments, in a single deposition cycle, the organic tantalum precursor is introduced for a time period of 0.1 s to 60 s.
[0011] In some embodiments, the flow rate of the organic tantalum precursor is 50 sccm to 150 sccm.
[0012] In some embodiments, the vacuum degree of the first treatment is 100Pa~150Pa.
[0013] In some embodiments, the organic tantalum precursor includes at least one of Ta(NtBu)(NEt2)3, Ta(OEt)5 and Ta(NMe2)5.
[0014] In some of the embodiments, in a single deposition cycle, the introduction time of the nitrogen-containing precursor is 0.1s to 60s.
[0015] In some embodiments, the nitrogen-containing precursor has an inlet flow rate of 50 sccm to 150 sccm.
[0016] In some embodiments, the nitrogen-containing precursor includes a mixed plasma of ammonia and an inert gas, and the volume percentage of the ammonia in the nitrogen-containing precursor is 5% to 20%.
[0017] In some embodiments, the vacuum degree of the second treatment is 200Pa~500Pa.
[0018] In some embodiments, before placing the substrate after the first treatment in a gas atmosphere including a nitrogen-containing precursor, the method further includes the following step: performing a first purge on the organic tantalum precursor using an inert gas.
[0019] In some embodiments, the second treatment further comprises the following steps:
[0020] The nitrogen-containing precursor is purged for a second time using an inert gas.
[0021] In some embodiments, the first purge time is 5s to 60s.
[0022] In some embodiments, the flow rate of the inert gas in the first purge is 50 sccm to 200 sccm.
[0023] In some embodiments, the second purge time is 5s to 60s.
[0024] In some embodiments, the flow rate of the inert gas in the second purge is 50 sccm to 200 sccm.
[0025] In some embodiments, the deposition cycle is performed for 2 to 300 times.
[0026] In a second aspect, the present application provides an application of a tantalum nitride selective deposition method according to any one of the above items in the preparation of a copper interconnect structure.
[0027] In the above-mentioned selective deposition method of tantalum nitride, the temperature of the first treatment and the second treatment is controlled within the range of 250°C to 300°C, and tantalum nitride is prepared by an organic tantalum precursor and a nitrogen-containing precursor. Within this temperature range, it is possible to achieve a large difference in the growth rate of tantalum nitride in the metal region and the dielectric oxide region, thereby achieving selective deposition of tantalum nitride. The selective deposition method of tantalum nitride of the present application does not require the additional preparation of a barrier layer, and the operation process is simple. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] Figure 1 Schematic diagram comparing the growth rates of tantalum nitride in Example 1, Example 2 and Comparative Example 1 of the present application;
[0029] Figure 2 Schematic diagram of the growth thickness of tantalum nitride in Example 2 of the present application;
[0030] Figure 3 Schematic diagram of the application of the tantalum nitride selective deposition method of the present application in the preparation of a copper interconnect structure. DETAILED DESCRIPTION
[0031] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.
[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.
[0033] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.
[0034] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "plurality" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.
[0035] An embodiment of the present application provides a method for selectively depositing tantalum nitride, comprising the following steps:
[0036] At least one deposition cycle is performed on a substrate, wherein the substrate has a metal region and a dielectric oxide region on a surface thereof, and the single deposition cycle comprises the following steps:
[0037] placing the substrate in a gas atmosphere including an organic tantalum precursor and performing a first treatment at 250° C. to 300° C.;
[0038] The substrate after the first treatment is placed in a gas atmosphere including a nitrogen-containing precursor and subjected to a second treatment at 250° C. to 300° C.
[0039] In the above-mentioned selective deposition method of tantalum nitride, the temperature of the first treatment and the second treatment is controlled within the range of 250°C to 300°C, and tantalum nitride is prepared by an organic tantalum precursor and a nitrogen-containing precursor. Within this temperature range, it is possible to achieve a large difference in the growth rate of tantalum nitride in the metal region and the dielectric oxide region, thereby achieving selective deposition of tantalum nitride. The selective deposition method of tantalum nitride of the present application does not require the additional preparation of a barrier layer, and the operation process is simple.
[0040] Optionally, the temperature for the first treatment is 250° C., 255° C., 260° C., 265° C., 270° C., 275° C., 280° C., 285° C., 290° C., 295° C. or 300° C. Alternatively, the temperature for the first treatment may also be within a range between any two of the above temperatures.
[0041] Optionally, the temperature for the second treatment is 250° C., 255° C., 260° C., 265° C., 270° C., 275° C., 280° C., 285° C., 290° C., 295° C. or 300° C. Alternatively, the temperature for the second treatment may also be within a range between any two of the above temperatures.
[0042] In some embodiments, the material of the metal region includes copper.
[0043] In some embodiments, the material of the metal region is copper.
[0044] In some embodiments, the material of the dielectric oxide region includes SiO 2 .
[0045] In some embodiments, the material of the dielectric oxide region is SiO2.
[0046] In some of the embodiments, in a single deposition cycle, the organic tantalum precursor is introduced for a time period of 0.1 s to 60 s.
[0047] Optionally, in a single deposition cycle, the time for the organic tantalum precursor to be introduced is 0.1s to 30s. Further optionally, in a single deposition cycle, the time for the organic tantalum precursor to be introduced is 0.1s to 10s. Further optionally, in a single deposition cycle, the time for the organic tantalum precursor to be introduced is 0.1s, 0.2s, 0.5s, 0.8s, 1s, 1.2s, 1.5s, 1.8s, 2s, 2.5s, 3s, 3.5s, 4s, 4.5s, 5s, 5.5s, 6s, 6.5s, 7s, 7.5s, 8s, 8.5s, 9s, 9.5s or 10s. Alternatively, in a single deposition cycle, the time for the organic tantalum precursor to be introduced can also be within the range between any two of the above times.
[0048] In some embodiments, the flow rate of the organic tantalum precursor is 50 sccm to 150 sccm.
[0049] Optionally, the flow rate of the organic tantalum precursor is 50 sccm, 55 sccm, 60 sccm, 65 sccm, 70 sccm, 75 sccm, 80 sccm, 85 sccm, 90 sccm, 95 sccm, 100 sccm, 105 sccm, 110 sccm, 115 sccm, 120 sccm, 125 sccm, 130 sccm, 135 sccm, 140 sccm, 145 sccm or 150 sccm. Alternatively, the flow rate of the organic tantalum precursor may also be within the range between any two of the above flow rates.
[0050] In some embodiments, the organotantalum precursor is brought into the deposition chamber by a carrier gas.
[0051] In some of these embodiments, the carrier gas includes at least one of an inert gas.
[0052] In some embodiments, the flow rate of the carrier gas is 50 sccm to 150 sccm.
[0053] Optionally, the flow rate of the carrier gas is 50 sccm, 55 sccm, 60 sccm, 65 sccm, 70 sccm, 75 sccm, 80 sccm, 85 sccm, 90 sccm, 95 sccm, 100 sccm, 105 sccm, 110 sccm, 115 sccm, 120 sccm, 125 sccm, 130 sccm, 135 sccm, 140 sccm, 145 sccm or 150 sccm. Alternatively, the flow rate of the carrier gas may also be within a range between any two of the above flow rates.
[0054] In some embodiments, the vacuum degree of the first treatment is 100Pa~150Pa.
[0055] It is understood that the vacuum degree of the first treatment refers to the gas pressure in the deposition chamber after the organic tantalum precursor is introduced. Optionally, the vacuum degree of the first treatment is 100Pa, 105Pa, 110Pa, 115Pa, 120Pa, 125Pa, 130Pa, 135Pa, 140Pa, 145Pa or 150Pa. Alternatively, the vacuum degree of the first treatment may also be within the range between any two of the above vacuum degrees.
[0056] In some embodiments, the organic tantalum precursor includes at least one of Ta(NtBu)(NEt2)3, Ta(OEt)5, and Ta(NMe2)5.
[0057] In some of the embodiments, before performing at least one deposition cycle on the substrate, the method further includes cleaning the substrate.
[0058] In some embodiments, the cleaning comprises the following steps: ultrasonically cleaning the substrate with anhydrous ethanol and deionized water respectively.
[0059] In some embodiments, the cleaning further comprises the following step: performing plasma cleaning on the substrate after ultrasonic cleaning.
[0060] By cleaning the substrate, a large number of non-uniform nucleation sites that may exist on the substrate surface can be reduced, making the process of precursor adsorption on the substrate surface smoother.
[0061] In some embodiments, the ultrasonic cleaning time is 10 min to 20 min.
[0062] Optionally, the time of ultrasonic cleaning is 10 min, 11 min, 12 min, 13 min, 14 min, 15 min, 16 min, 17 min, 18 min, 19 min or 20 min. Alternatively, the time of ultrasonic cleaning can also be within the range between any two of the above times.
[0063] In some embodiments, the organic tantalum precursor is stored in a source bottle and introduced into the deposition chamber through a pipe.
[0064] In some embodiments, the source bottle and the pipeline are kept warm during the process of introducing the organic tantalum precursor.
[0065] In some of the embodiments, the insulation temperature of the source bottle is 25°C~150°C.
[0066] In the above-mentioned insulation temperature range of the source bottle, the carrier gas has a better effect of bringing the organic tantalum precursor into the deposition chamber. Optionally, the insulation temperature of the source bottle is 25°C, 30°C, 35°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C or 150°C. Alternatively, the insulation temperature of the source bottle can also be in the range between any two of the above-mentioned temperatures.
[0067] In some of the embodiments, the insulation temperature of the pipeline is 100°C to 150°C.
[0068] In the above-mentioned insulation temperature range of the pipeline, condensation of the organic tantalum precursor in the pipeline can be reduced. Optionally, the insulation temperature of the pipeline is 100° C., 105° C., 110° C., 115° C., 120° C., 125° C., 130° C., 135° C., 140° C., 145° C. or 150° C. Alternatively, the insulation temperature of the pipeline can also be in the range between any two of the above-mentioned temperatures.
[0069] In some of the embodiments, in a single deposition cycle, the time for introducing the nitrogen-containing precursor is 0.1s to 60s.
[0070] Optionally, in a single deposition cycle, the time for the nitrogen-containing precursor to be introduced is 0.1s to 30s. Further optionally, in a single deposition cycle, the time for the nitrogen-containing precursor to be introduced is 0.1s to 10s. Further optionally, in a single deposition cycle, the time for the nitrogen-containing precursor to be introduced is 0.1s, 0.2s, 0.5s, 0.8s, 1s, 1.2s, 1.5s, 1.8s, 2s, 2.5s, 3s, 3.5s, 4s, 4.5s, 5s, 5.5s, 6s, 6.5s, 7s, 7.5s, 8s, 8.5s, 9s, 9.5s or 10s. Alternatively, in a single deposition cycle, the time for the nitrogen-containing precursor to be introduced may also be within the range between any two of the above times.
[0071] In some embodiments, the flow rate of the nitrogen-containing precursor is 50 sccm to 150 sccm.
[0072] Optionally, the flow rate of the nitrogen-containing precursor is 50 sccm, 55 sccm, 60 sccm, 65 sccm, 70 sccm, 75 sccm, 80 sccm, 85 sccm, 90 sccm, 95 sccm, 100 sccm, 105 sccm, 110 sccm, 115 sccm, 120 sccm, 125 sccm, 130 sccm, 135 sccm, 140 sccm, 145 sccm or 150 sccm. Alternatively, the flow rate of the nitrogen-containing precursor may also be within the range between any two of the above flow rates.
[0073] In some embodiments, the nitrogen-containing precursor includes a mixed plasma of ammonia and an inert gas, and the volume percentage of ammonia in the nitrogen-containing precursor is 5% to 20%.
[0074] Optionally, the nitrogen-containing precursor includes ammonia and an inert gas, and the volume percentage of ammonia in the nitrogen-containing precursor is 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19% or 20%. Alternatively, the volume percentage of ammonia in the nitrogen-containing precursor may also be within the range between any two of the above volume percentages.
[0075] In some embodiments, the vacuum degree of the second treatment is 200Pa~500Pa.
[0076] It is understood that the vacuum degree of the second treatment refers to the gas pressure in the deposition chamber after the nitrogen-containing precursor is introduced. Optionally, the vacuum degree of the second treatment is 200Pa, 220Pa, 240Pa, 260Pa, 280Pa, 300Pa, 320Pa, 340Pa, 360Pa, 380Pa, 400Pa, 420Pa, 440Pa, 460Pa, 480Pa or 500Pa. Alternatively, the vacuum degree of the second treatment may also be within the range between any two of the above vacuum degrees.
[0077] In some embodiments, before placing the first processed substrate in a gas atmosphere including a nitrogen-containing precursor, the method further includes the step of first purging the organic tantalum precursor with an inert gas.
[0078] In some embodiments, the second treatment further includes the following step: performing a second purge on the nitrogen-containing precursor using an inert gas.
[0079] In some embodiments, the first purge time is 5s to 60s.
[0080] Optionally, the first purge time is 5s, 10s, 15s, 20s, 25s, 30s, 35s, 40s, 45s, 50s, 55s or 60s. Alternatively, the first purge time may also be within the range between any two of the above times.
[0081] In some embodiments, the flow rate of the inert gas in the first purge is 50 sccm-200 sccm.
[0082] Optionally, the flow rate of the inert gas in the first purge is 50 sccm, 60 sccm, 70 sccm, 80 sccm, 90 sccm, 100 sccm, 110 sccm, 120 sccm, 130 sccm, 140 sccm, 150 sccm, 160 sccm, 170 sccm, 180 sccm, 190 sccm or 200 sccm. Alternatively, the flow rate of the inert gas in the first purge may also be within the range between any two of the above flow rates.
[0083] In some embodiments, the second purge time is 5s to 60s.
[0084] Optionally, the second purge time is 5s, 10s, 15s, 20s, 25s, 30s, 35s, 40s, 45s, 50s, 55s or 60s. Alternatively, the second purge time may also be within the range between any two of the above times.
[0085] In some embodiments, the flow rate of the inert gas in the second purge is 50 sccm-200 sccm.
[0086] Optionally, the flow rate of the inert gas in the second purge is 50 sccm, 60 sccm, 70 sccm, 80 sccm, 90 sccm, 100 sccm, 110 sccm, 120 sccm, 130 sccm, 140 sccm, 150 sccm, 160 sccm, 170 sccm, 180 sccm, 190 sccm or 200 sccm. Alternatively, the flow rate of the inert gas in the second purge may also be within the range between any two of the above flow rates.
[0087] In some embodiments, the number of deposition cycles is between 2 and 300.
[0088] Optionally, the number of deposition cycles is 2, 5, 10, 20, 30, 50, 75, 100, 125, 150, 175, 200, 225, 250, 275 or 300. Alternatively, the number of deposition cycles may also be within a range between any two of the above numbers.
[0089] In some embodiments, the inert gas includes at least one of argon and helium.
[0090] In some embodiments, a method for selectively depositing tantalum nitride comprises the following steps:
[0091] (1) A substrate is provided, wherein a metal region and a dielectric oxide region are provided on a surface of the substrate. The substrate is ultrasonically cleaned and plasma cleaned in sequence. The cleaned substrate is placed in a deposition chamber, and the deposition chamber is evacuated to a temperature below 5 Pa.
[0092] (2) Maintaining the temperature in the deposition chamber at 250°C~300°C, introducing an organic tantalum precursor into the deposition chamber using an inert gas as a carrier gas, the flow rate of the carrier gas is 50sccm~150sccm, the introduction time of the organic tantalum precursor is 0.1s~60s, and the vacuum degree of the deposition chamber after the introduction of the organic tantalum precursor is 100Pa~150Pa.
[0093] (3) Use inert gas to purge the deposition chamber. The flow rate of the inert gas is 50 sccm~200 sccm, and the purge time is 5s~60s.
[0094] (4) Maintaining the temperature in the deposition chamber at 250°C~300°C, introducing a nitrogen-containing precursor into the deposition chamber. The nitrogen-containing precursor includes ammonia and an inert gas. The volume percentage of ammonia in the nitrogen-containing precursor is 5%~20%. The time for introducing the nitrogen-containing precursor is 0.1s~60s. After introducing the nitrogen-containing precursor, the vacuum degree of the deposition chamber is 200Pa~500Pa.
[0095] (5) Use inert gas to purge the deposition chamber. The flow rate of the inert gas is 50 sccm~200 sccm, and the purge time is 5s~60s.
[0096] (6) Repeat the above steps (2) to (5) for the preset number of cycles.
[0097] Yet another embodiment of the present application provides an application of any of the above-mentioned methods for selectively depositing tantalum nitride in preparing a copper interconnect structure.
[0098] Reference Figure 3 As shown, the application of the tantalum nitride selective deposition method in preparing a copper interconnect structure includes the following steps:
[0099] A semiconductor structure is provided, comprising a copper layer, a seed layer, a first dielectric layer, and a second dielectric layer stacked in layers, an interconnection groove is opened on the surface of the semiconductor structure, the interconnection groove penetrates the second dielectric layer, the first dielectric layer, and the seed layer, and the surface of the copper layer is exposed in the interconnection groove;
[0100] Using any of the above tantalum nitride selective deposition methods to prepare a tantalum nitride barrier layer in the interconnection groove, the tantalum nitride barrier layer covers the sidewalls of the interconnection groove and the surface of the second dielectric layer;
[0101] A seed layer is prepared in the interconnection groove, wherein the seed layer covers the surface of the copper layer exposed in the interconnection groove and the surface of the tantalum nitride barrier layer;
[0102] A copper interconnect structure is filled in the interconnect trench.
[0103] Depositing a tantalum nitride barrier layer by a tantalum nitride selective deposition method can reduce additional steps, and selective deposition of tantalum nitride can eliminate subsequent etching and cleaning steps. In the traditional tantalum nitride deposition method, tantalum nitride is non-selectively deposited on the entire surface, including the copper surface, so an additional etching step is required to remove the unwanted tantalum nitride layer. This not only increases manufacturing costs, but may also introduce additional defects. Selective deposition of tantalum nitride can deposit tantalum nitride directly in the required area, simplifying the process flow.
[0104] It is understood that tantalum nitride, as a diffusion barrier, can prevent copper atoms from diffusing into silicon oxide and avoid the formation of high-resistance copper compounds, thereby maintaining the low resistance performance of the interconnect. If tantalum nitride is deposited on copper, it will affect its conductivity. Through selective deposition, tantalum nitride can be deposited only in the required silicon oxide areas, avoiding the formation of unnecessary layers on the copper surface. In metal interconnect structures, the selective deposition of tantalum nitride can reduce electromigration and thermal effects and increase the long-term reliability of the device. At the same time, by selectively depositing tantalum nitride, the distribution of the material in the interconnect structure can be precisely controlled, thereby optimizing the electrical and thermal performance of the circuit.
[0105] The following are specific embodiments
[0106] Example 1
[0107] Tantalum Nitride Selective Deposition Method:
[0108] (1) A silicon substrate is provided, wherein a metal region and a dielectric oxide region are provided on the surface of the silicon substrate, wherein the material of the metal region is copper, and the material of the dielectric oxide region is SiO2. The substrate is sequentially ultrasonically cleaned with ethanol for 10 minutes, ultrasonically cleaned with deionized water for 10 minutes, and then cleaned with helium plasma. The cleaned substrate is placed in a deposition chamber, and the deposition chamber is evacuated to below 5 Pa.
[0109] (2) Maintain the temperature in the deposition chamber at 250°C, use Ta(NtBu)(NEt2)3 stored in a source bottle as the organic tantalum precursor, maintain the temperature of the source bottle at 60°C, maintain the temperature of the pipeline at 100°C, use argon as a carrier gas to introduce the organic tantalum precursor into the deposition chamber, the flow rate of the carrier gas is 100 sccm, the introduction time of the organic tantalum precursor is 2 s, and the vacuum degree of the deposition chamber after the introduction of the organic tantalum precursor is 100 Pa~150 Pa.
[0110] (3) Use argon gas to purge the deposition chamber. The flow rate of the inert gas is 100 sccm and the purge time is 10 s.
[0111] (4) The temperature in the deposition chamber is maintained at 250°C, and a nitrogen-containing precursor is introduced into the deposition chamber. The nitrogen-containing precursor includes ammonia and an inert gas, and the volume percentage of ammonia in the nitrogen-containing precursor is 10%. The nitrogen-containing precursor is introduced for 2 seconds. After the nitrogen-containing precursor is introduced, the vacuum degree of the deposition chamber is 200Pa~500Pa.
[0112] (5) Use argon gas to purge the deposition chamber. The flow rate of the inert gas is 100 sccm and the purge time is 10 s.
[0113] (6) Repeat the above steps (2) to (5) for a total of 250 cycles, and record the growth of the tantalum nitride film after each cycle.
[0114] Example 2
[0115] (1) A silicon substrate is provided, wherein a metal region and a dielectric oxide region are provided on the surface of the silicon substrate, wherein the material of the metal region is copper, and the material of the dielectric oxide region is SiO2. The substrate is sequentially ultrasonically cleaned with ethanol for 10 minutes, ultrasonically cleaned with deionized water for 10 minutes, and then cleaned with helium plasma. The cleaned substrate is placed in a deposition chamber, and the deposition chamber is evacuated to below 5 Pa.
[0116] (2) The temperature in the deposition chamber is maintained at 300°C, Ta(NtBu)(NEt2)3 stored in a source bottle is used as the organic tantalum precursor, the temperature of the source bottle is maintained at 60°C, the temperature of the pipeline is maintained at 100°C, the organic tantalum precursor is introduced into the deposition chamber using argon as the carrier gas, the flow rate of the carrier gas is 100 sccm, the introduction time of the organic tantalum precursor is 2 s, and the vacuum degree of the deposition chamber after the introduction of the organic tantalum precursor is 100 Pa~150 Pa.
[0117] (3) Use argon gas to purge the deposition chamber. The flow rate of the inert gas is 100 sccm and the purge time is 10 s.
[0118] (4) The temperature in the deposition chamber is maintained at 300°C, and a nitrogen-containing precursor is introduced into the deposition chamber. The nitrogen-containing precursor includes ammonia and an inert gas, and the volume percentage of ammonia in the nitrogen-containing precursor is 10%. The nitrogen-containing precursor is introduced for 2 seconds. After the nitrogen-containing precursor is introduced, the vacuum degree of the deposition chamber is 200Pa~500Pa.
[0119] (5) Use argon gas to purge the deposition chamber. The flow rate of the inert gas is 100 sccm and the purge time is 10 s.
[0120] (6) Repeat the above steps (2) to (5) for a total of 250 cycles, and record the growth of the tantalum nitride film after each cycle.
[0121] Comparative Example 1
[0122] (1) A silicon substrate is provided, wherein a metal region and a dielectric oxide region are provided on the surface of the silicon substrate, wherein the material of the metal region is copper, and the material of the dielectric oxide region is SiO2. The substrate is sequentially ultrasonically cleaned with ethanol for 10 minutes, ultrasonically cleaned with deionized water for 10 minutes, and then cleaned with helium plasma. The cleaned substrate is placed in a deposition chamber, and the deposition chamber is evacuated to below 5 Pa.
[0123] (2) The temperature in the deposition chamber is maintained at 200°C, Ta(NtBu)(NEt2)3 stored in a source bottle is used as the organic tantalum precursor, the temperature of the source bottle is maintained at 60°C, the temperature of the pipeline is maintained at 100°C, the organic tantalum precursor is introduced into the deposition chamber using argon as the carrier gas, the flow rate of the carrier gas is 100 sccm, the introduction time of the organic tantalum precursor is 2 s, and the vacuum degree of the deposition chamber after the introduction of the organic tantalum precursor is 100 Pa~150 Pa.
[0124] (3) Use argon gas to purge the deposition chamber. The flow rate of the inert gas is 100 sccm and the purge time is 10 s.
[0125] (4) The temperature in the deposition chamber is maintained at 200°C, and a nitrogen-containing precursor is introduced into the deposition chamber. The nitrogen-containing precursor includes ammonia and an inert gas, and the volume percentage of ammonia in the nitrogen-containing precursor is 10%. The nitrogen-containing precursor is introduced for 2 seconds. After the nitrogen-containing precursor is introduced, the vacuum degree of the deposition chamber is 200Pa~500Pa.
[0126] (5) Use argon gas to purge the deposition chamber. The flow rate of the inert gas is 100 sccm and the purge time is 10 s.
[0127] (6) Repeat the above steps (2) to (5) for a total of 250 cycles, and record the growth of the tantalum nitride film after each cycle.
[0128] Reference Figure 1As shown, Figure 1 The figure is a comparative diagram of the growth rate of tantalum nitride in Example 1, Example 2 and Comparative Example 1. In Example 1 and Example 2, the deposition process is controlled to be carried out at 250°C and 300°C respectively. It can be seen that the growth rate of tantalum nitride film on the copper surface and the SiO2 surface shows a large difference, that is, the selective deposition of tantalum nitride film on the metal area and the dielectric oxide area can be achieved. In Comparative Example 1, the deposition process is carried out at 200°C. It can be seen that at this temperature, there is no obvious difference in the growth rate of tantalum nitride film on the copper surface and the SiO2 surface. Figure 2 As shown, Figure 2 Schematic diagram of the growth thickness of tantalum nitride in Example 2. That is, when tantalum nitride is deposited at 300° C., after multiple ALD cycles, it can be seen that the growth thickness of tantalum nitride on the SiO2 surface is significantly higher than that on the Cu surface.
[0129] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0130] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims, and the description and drawings may be used to interpret the contents of the claims.
Claims
1. A method for selectively depositing tantalum nitride, characterized in that: The steps include: At least one deposition cycle is performed on a substrate, wherein the substrate has a metal region and a dielectric oxide region on a surface thereof, wherein a single deposition cycle comprises the following steps: Placing the substrate in a gas atmosphere including an organic tantalum precursor and performing a first treatment at 250° C. to 300° C.; The substrate after the first treatment is placed in a gas atmosphere including a nitrogen-containing precursor, and a second treatment is performed at 250° C. to 300° C.
2. The method for selectively depositing tantalum nitride according to claim 1, characterized in that: The material of the metal region includes copper; and / or the material of the dielectric oxide region includes SiO2.
3. The method for selectively depositing tantalum nitride according to claim 1, characterized in that: In a single deposition cycle, the organic tantalum precursor is introduced for a time period of 0.1s to 60s; and / or, The flow rate of the organic tantalum precursor is 50 sccm to 150 sccm; and / or, The organic tantalum precursor includes at least one of Ta(NtBu)(NEt2)3, Ta(OEt)5 and Ta(NMe2)5; and / or, The time for introducing the nitrogen-containing precursor is 0.1s to 60s; and / or, The nitrogen-containing precursor has an inlet flow rate of 50 sccm to 150 sccm.
4. The method for selectively depositing tantalum nitride according to claim 1, characterized in that: The vacuum degree of the first treatment is 100Pa~150Pa.
5. The method for selectively depositing tantalum nitride according to claim 1, characterized in that: The nitrogen-containing precursor comprises a mixed plasma of ammonia and an inert gas, and the volume percentage of the ammonia in the nitrogen-containing precursor is 5% to 20%.
6. The method for selectively depositing tantalum nitride according to claim 1, characterized in that: The vacuum degree of the second treatment is 200Pa~500Pa.
7. The method for selectively depositing tantalum nitride according to any one of claims 1 to 6, characterized in that: Before placing the substrate after the first treatment in a gas atmosphere including a nitrogen-containing precursor, the method further includes the following steps: performing a first purge on the organic tantalum precursor using an inert gas; and / or, The second process further comprises the following steps: The nitrogen-containing precursor is purged for a second time using an inert gas.
8. The method for selectively depositing tantalum nitride according to claim 7, characterized in that: The first purge time is 5s to 60s; and / or, The flow rate of the inert gas in the first purge is 50 sccm to 200 sccm; and / or, The second purge time is 5s to 60s; and / or, The flow rate of the inert gas in the second purge is 50 sccm-200 sccm.
9. The method for selectively depositing tantalum nitride according to any one of claims 1 to 6, characterized in that: The number of cycles of the deposition cycle is 2 to 300.
10. Use of the tantalum nitride selective deposition method according to any one of claims 1 to 9 in preparing a copper interconnect structure.