Nitride coating of titanium material for improved barrier properties

Abstract

Methods and apparatus for nitride capping of titanium materials via chemical vapor deposition techniques are provided. The methods include forming a titanium nitride layer on a titanium material layer formed on a substrate. The titanium nitride layer is formed by exposing the titanium material layer to a hydrogen-rich nitrogen-containing plasma, followed by exposing the titanium material layer to a nitrogen-rich nitrogen-containing plasma. The titanium nitride layer is then exposed to an argon plasma, followed by exposing the titanium nitride layer to a halide soak process.

Description

Technical Field

[0001] The embodiments of this disclosure generally relate to semiconductor substrate processing, and more specifically to nitride coating of titanium materials via chemical vapor deposition. Background Technology

[0002] Semiconductor manufacturing processes often involve the deposition of titanium or titanium-containing films. Titanium and titanium silicide (TiSix) films are widely used in semiconductor manufacturing to form ohmic contacts and reduce contact resistance between transistor connections. After depositing titanium or titanium silicide films, air leakage or oxygen exposure may occur before additional processing. Once the film is exposed to air, the titanium and titanium silicide films can easily oxidize. This oxidation increases the contact resistance of the titanium-containing films, and this increased contact resistance cannot meet the requirements of next-generation technology nodes.

[0003] Therefore, there is a need to provide improved methods for titanium and titanium silicide films with reduced contact resistance. Summary of the Invention

[0004] The embodiments of this disclosure generally relate to semiconductor substrate processing, and more specifically to nitride coating of titanium materials via chemical vapor deposition.

[0005] In one aspect, a method for forming a nitride capping layer is provided. The method includes forming a titanium nitride layer on a titanium material layer formed on a substrate. The titanium nitride layer is formed by exposing the titanium material layer to a hydrogen-rich nitrogen-containing plasma, followed by exposing the titanium material layer to a nitrogen-rich nitrogen-containing plasma. The titanium nitride layer is then exposed to an argon plasma, followed by exposing the titanium nitride layer to a halide immersion process.

[0006] The implementation may include one or more of the following embodiments: A hydrogen-rich nitrogen-containing plasma is formed by flowing hydrogen and nitrogen at a first ratio of hydrogen volume flow rate to nitrogen volume flow rate greater than about 1:1. A nitrogen-rich nitrogen-containing plasma is formed by flowing hydrogen and nitrogen at a second ratio of hydrogen volume flow rate to nitrogen volume flow rate less than about 1:1. A hydrogen-rich nitrogen-containing plasma is formed by flowing hydrogen and nitrogen at a first ratio of hydrogen volume flow rate to nitrogen volume flow rate of about 4:3 to about 8:1. A nitrogen-rich nitrogen-containing plasma is formed by flowing hydrogen and nitrogen at a second ratio of hydrogen volume flow rate to nitrogen volume flow rate of about 1:8 to about 1:6. The substrate includes a high aspect ratio feature, wherein a silicon surface is disposed at the bottom of the high aspect ratio feature, and a dielectric surface is disposed on one or more sidewalls of the high aspect ratio feature. A titanium material layer is formed on the silicon surface. The titanium material layer includes titanium silicide. A titanium nitride capping layer includes TiSiN.

[0007] In another aspect, a method for forming a nitride coating is provided. The method includes forming a titanium nitride layer on a titanium material layer formed on a substrate. Forming the titanium nitride layer includes creating a direct plasma reaction between a spray head and a substrate in a process chamber, involving nitrogen (N2), hydrogen (H2), and argon (Ar), wherein a first ratio of hydrogen volume flow rate to nitrogen volume flow rate is greater than about 1:1. Forming the titanium nitride layer further includes increasing the nitrogen volume flow rate and decreasing the hydrogen volume flow rate, wherein a second ratio of a second hydrogen volume flow rate to a second nitrogen volume flow rate is less than about 1:1. The method further includes exposing the titanium nitride layer to argon plasma. The method further includes exposing the titanium nitride layer to a chlorine immersion process.

[0008] Implementation may include one or more of the following embodiments. Exposing the titanium nitride layer to argon plasma includes stopping the flow of nitrogen and hydrogen. The chlorine immersion process is a plasma-free process. Forming a direct plasma reaction includes flowing hydrogen and nitrogen at a first ratio of hydrogen volume flow rate to nitrogen volume flow rate of about 4:3 to about 8:1. Increasing the volume flow rate further includes flowing hydrogen and nitrogen at a second ratio of hydrogen volume flow rate to second nitrogen volume flow rate of about 1:8 to about 1:6. The substrate includes a high aspect ratio feature, wherein a silicon surface is disposed at the bottom of the high aspect ratio feature, and a dielectric surface is disposed on one or more sidewalls of the high aspect ratio feature. A titanium material layer is formed on the silicon surface. The titanium material layer includes titanium, titanium silicide, or substantially pure titanium.

[0009] In another aspect, a method for forming a nitride capping layer is provided. The method includes forming a titanium silicon nitride capping layer on a titanium silicide layer formed on a substrate. Forming the titanium silicon nitride capping layer includes exposing the titanium silicide layer to a hydrogen-rich nitrogen-containing plasma to form a first portion of the titanium silicon nitride capping layer. Forming the titanium silicon nitride capping layer further includes exposing the first portion of the titanium silicon nitride capping layer to a nitrogen-rich nitrogen-containing plasma to form a second portion of the titanium silicon nitride capping layer. The method further includes exposing the titanium silicon nitride capping layer to an argon plasma to form a plasma-treated titanium silicon nitride capping layer. The method further includes exposing the plasma-treated titanium silicon nitride capping layer to a chlorine immersion process to reduce the thickness of the plasma-treated titanium silicon nitride capping layer.

[0010] The implementation may include one or more of the following embodiments. A hydrogen-rich nitrogen-containing plasma is formed by flowing hydrogen and nitrogen at a first ratio of hydrogen volume flow rate to nitrogen volume flow rate of about 4:3 to about 8:1. A nitrogen-rich nitrogen-containing plasma is formed by flowing hydrogen and nitrogen at a second ratio of hydrogen volume flow rate to nitrogen volume flow rate of about 1:8 to about 1:6.

[0011] In another aspect, instructions are stored on a non-transitory computer-readable medium, which, when executed by a processor, cause the device to perform the operations of the method described above. Attached Figure Description

[0012] To gain a more detailed understanding of the features described above in this disclosure, a more specific description of the embodiments briefly outlined above can be obtained by referring to the embodiments, some of which are illustrated in the accompanying drawings. However, it should be noted that the drawings illustrate only typical embodiments of this disclosure and should therefore not be considered as limiting the scope of this disclosure, as other equivalent embodiments are permissible.

[0013] Figure 1 The diagram shows a schematic of an apparatus suitable for practicing the method disclosed herein.

[0014] Figure 2 The diagram illustrates a flowchart of the nitride coating process sequence according to one or more embodiments of this disclosure.

[0015] Figures 3A to 3D The illustrations are based on one or more embodiments of this disclosure. Figure 2 A schematic cross-sectional view of the substrate during different stages of the processing sequence.

[0016] For ease of understanding, the same reference numerals have been used to indicate common elements in the figures where possible. It is contemplated that elements and features of one embodiment may be advantageously included in other embodiments without further description. Detailed Implementation

[0017] The following disclosure describes the nitride coating on titanium materials. The following description and... Figures 1 to 3D Certain details are elaborated to provide a thorough understanding of the various embodiments of the disclosed invention. The following disclosure does not elaborate on other details describing known structures and systems typically associated with chemical vapor deposition and titanium deposition, in order to avoid unnecessarily obscuring the description of the various embodiments.

[0018] The many details, dimensions, angles, and other features shown in the figures are merely illustrative of specific embodiments. Therefore, other embodiments may have different details, components, dimensions, angles, and features without departing from the spirit or scope of this disclosure. Furthermore, other embodiments of this disclosure may be practiced without some of the details described below.

[0019] This disclosure relates to a method for forming a nitride capping layer with improved oxidation-barrier properties. Titanium and titanium silicide can be readily oxidized upon exposure to air. Currently, nitride capping is used to protect deposited titanium and titanium silicide films from oxidation. However, currently available nitride capping often fails to minimize oxidation, and therefore the contact resistance of the capped titanium film does not meet the requirements of next-generation technology nodes. One or more embodiments of this disclosure provide a method for forming a nitride capping material with improved barrier properties, advantageously addressing the problem of resistivity reduction despite the need for node reduction. In some embodiments, the method of this disclosure includes exposure to a nitrogen-rich gas mixture plasma to increase the nitrogen concentration in the nitride capping layer. Following nitriding, exposure to an inert gas plasma and halide immersion are used to remove unstable titanium and silicon bonds. This removal of unstable bonds is believed to reduce the oxidation of the underlying titanium material upon exposure to air. Due to the reduced oxidation, the contact resistance of the formed integrated circuit device can be lower.

[0020] Figure 1 This is a schematic diagram of an apparatus such as a substrate processing system 10 suitable for practicing the methods of this disclosure. In an embodiment, the substrate processing system 10 includes a process chamber 100, a control unit 110, a gas panel 130, and other hardware components such as a power supply and a vacuum pump. Exemplary process chambers may include any of a number of process chambers configured for the remote and direct chemical vapor deposition (CVD) reactions described herein, and are available from Applied Materials, Inc., Santa Clara, California. Other suitable process chambers from other manufacturers may be similarly used and modified according to this disclosure.

[0021] In an embodiment, the process chamber 100 typically includes a cover heater 131 for heating a processing volume 101, which includes a region, for example, an air chamber space within the process chamber 100 between the cover heater 131 and the spray head 165. Depending on the specific process, the processing volume 101 in the region between the cover heater 131 and the spray head 165 may be heated to a target temperature before or during the processing according to this disclosure. In an embodiment, the cover heater 131 is heated by an embedded heating element, such as a heating element 171. For example, the cover heater 131 may be resistively heated by applying current from an AC power source (not shown) to the heating element 171. The region of the processing volume 101 between the cover heater 131 and the spray head 165 is then heated by the cover heater 131, and the processing volume 101 may be maintained in a process temperature range, for example, from 200 to 800 degrees Celsius, or at a first temperature of about 550 degrees Celsius. In some embodiments, the area between the cover heater 131 and the spray head 165 of the process chamber 100 is maintained at a first temperature of 200 to 800 degrees Celsius. In some embodiments, a cover heater at 200 to 800 degrees Celsius, or in some embodiments about 550 degrees Celsius, a spray head at about 500 degrees Celsius (heated by radiant heat from the cover heater), a wafer temperature of about 425 degrees Celsius, and a base heated to about 450 degrees Celsius can heat the area between the cover heater 131 and the spray head 165 to a temperature of 200 to 800 degrees Celsius, or in some embodiments about 550 degrees Celsius. In some embodiments, the area between the cover heater 131 and the spray head 165 is an air chamber space.

[0022] In an embodiment, a temperature sensor, such as a thermocouple (not shown), may be embedded in the cover heater 131 to monitor its temperature. For example, the measured temperature may be used in a feedback loop to control the power supply to the cover heater 131, such that the temperature of the processing volume 101 in the region between the cover heater 131 and the spray head 165 can be maintained or controlled at a target temperature suitable for a particular process application. In an embodiment, the cover heater 131 is configured to provide sufficient heat to promote remote plasma formation in the processing volume 101 between the cover heater 131 and the spray head 165, or within the spray head 165, and to prevent condensation from occurring in or on the spray head 165. For example, a control unit 110 may be communicated with the cover heater 131, allowing a user to adjust the heat of the cover heater 131 and maintain sufficient heat for remote plasma formation. In an embodiment, depending on processing requirements, the cover heater 131 may be configured not to heat or to promote remote plasma formation in the processing volume 101 in the region between the cover heater 131 and the spray head 165. For example, the cover heater 131 may be turned off by the control unit 110 depending on the user's needs.

[0023] In one embodiment, an RF electrode 181 may be embedded in a cover heater 131 to configure the cover heater 131 to provide an amount of RF sufficient to form plasma in the vicinity of the cover heater 131. In another embodiment, the cover heater 131 is configured to provide sufficient RF to promote plasma formation in the processing volume 101 and / or within the spray head 165 in the region between the cover heater 131 and the spray head 165. For example, a control unit 110 may be communicated with the cover heater 131, allowing a user to adjust the RF emitted from the cover heater 131 and maintain an RF signal sufficient for plasma formation. In another embodiment, depending on processing needs, the cover heater 131 may be configured not to emit an RF signal or to promote plasma formation in the processing volume 101 between the cover heater 131 and the spray head 165. For example, the cover heater 131 may be turned off via the control unit 110 to eliminate the RF generated from the cover heater 131 if the user requires it.

[0024] In an embodiment, the process chamber 100 typically includes a support base 150 having a support surface 192 for supporting a substrate (which may be a semiconductor substrate), such as a substrate 190, within the process chamber 100. The support base 150 is coupled to a base rod 160, which can be moved vertically within the process chamber 100 using a displacement mechanism (not shown). Depending on the specific process, the substrate 190 may be heated to a target temperature prior to processing. In an embodiment, the support base 150 is heated by an embedded heating element, such as a heating element 170. For example, the support base 150 may be resistively heated by applying current from an AC power supply 106 to the heating element 170. The substrate 190 is then heated by the support base 150 and maintained within a process temperature range, for example, 200 to 800 degrees Celsius or 300 to 700 degrees Celsius. In one embodiment, a temperature sensor 172, such as a thermocouple, may be embedded in the support base 150 to monitor the temperature of the support base 150 in a conventional manner. For example, a measured temperature control power supply, such as AC power 106 for the heating element 170, may be used in the feedback loop to maintain or control the temperature of the substrate 190 at a target temperature suitable for a particular process application. In one embodiment, the support base includes a ground at 182.

[0025] In this embodiment, the airflow through the process chamber 100 and the gas panel 130 is properly controlled and regulated by a mass flow controller (not shown) and a control unit 110 such as a computer. The spray head 165 allows for the uniform distribution and introduction of process gases from the gas panel 130 into the process chamber 100. In this embodiment, the spray head 165 is configured to allow reaction products (e.g., reaction products suitable for forming a titanium material layer such as titanium or titanium silicide and nitride capping layers as described herein) to flow into the process chamber to form a nitride capping layer (e.g., TiN or TiSiN) on the titanium material layer formed on the silicon surface of the substrate.

[0026] Illustratively, the control unit 110 includes a central processing unit (CPU) 112, support circuitry 114, and a memory containing associated control software 116. The control unit 110 is used for automated control of numerous operations performed on the substrate 190, such as wafer transfer, airflow control, temperature control, and chamber evacuation. Bidirectional communication between the control unit 110 and various components of the substrate processing system 10 is handled via a large number of signal cables collectively referred to as signal buses 118. Some of the signal cables in signal buses 118... Figure 1 As shown.

[0027] In some embodiments, this disclosure relates to a non-transitory computer-readable medium, such as a memory storing instructions thereon that, when executed, enable a method for selectively depositing a nitride capping layer on a titanium material layer formed on a substrate having a silicon surface and a dielectric surface, the method comprising: forming a plasma reaction between nitrogen (N2), hydrogen (H2), and argon (Ar) in a region between a cap heater and a spray head in a process chamber at a first temperature of 200 to 800 degrees Celsius; and allowing the reaction products to flow into the process chamber to selectively form a nitride capping layer on a titanium material layer formed on a silicon surface of substrate 190.

[0028] In some embodiments, an RF electrode 181 may be embedded in a spray head 165 to configure the spray head 165 to provide an amount of RF energy sufficient to form plasma in the vicinity of the spray head 165. In an embodiment, the spray head 165 is configured to provide RF sufficient to facilitate plasma formation in the processing volume 101. For example, a control unit 110 may be communicated with the spray head 165 so that a user can adjust the RF emitted from the spray head 165 and maintain an RF signal sufficient for plasma formation. In an embodiment, the spray head 165 may be selectively grounded via ground 183 depending on the user's need for plasma positioning in the processing volume 101. In an embodiment, when the spray head 165 is grounded, remote plasma can be formed in the region between the cover heater 131 and the spray head 165 in the processing volume 101. In an embodiment, when the spray head 165 is not grounded, direct plasma is formed in the region between the spray head 165 and the substrate 190 in the processing volume 101. Switch 184 is communicatively connected to ground 183, RF electrode 180, and spray head 165, and is configured to control remote and direct plasma formation according to this disclosure and depending on user needs. In embodiments, switch 184 is communicatively connected to spray head 165 and is configured to control remote and direct plasma formation according to this disclosure and depending on user needs. In some embodiments, when switch 184 is in a first position, a power source, such as an RF or VHF power source, is electrically coupled to the chamber cover via switch 184. When switch 184 is in a second position (not shown), the power source is electrically coupled to spray head 165. When switch 184 is in the first position, a first plasma located at the distal end of substrate 190, such as a remote plasma located directly in the gas chamber space or region between the cover heater and the spray head, is ignited and maintained using the power source. In some embodiments, the remote plasma consists of a process gas flowing into the gas chamber and is maintained as plasma via capacitive coupling of electricity from the power source. In some embodiments, when the switch 184 is in the second position, a second plasma (not shown) is ignited and maintained in the processing volume 101 between the spray head 165 and the substrate 190 disposed on the support base 150 using a power source.

[0029] In one embodiment, the process chamber 100 includes a vacuum pump 102 that evacuates the process chamber 100 and maintains appropriate airflow and pressure within the process chamber 100. A spray head 165 is located above the support base 150 and introduces process gases into the process chamber 100 via the spray head 165. In one embodiment, the spray head 165 may be configured as a multi-gas spray head with two or more separate paths, allowing two or more gases to be introduced into the process chamber 100 individually without premixing. In some embodiments, the spray head 165 is connected to a gas panel 130, which is controlled by a mass flow controller (not shown) and supplies various gases used in different steps of the processing sequence. During wafer processing, a purge gas supplier 104 also provides purge gas, such as an inert gas, around the bottom of the support base 150 to minimize unwanted deposits formed on the support base 150.

[0030] In an embodiment, the control unit 110 is used to control the airflow from the gas panel 130 to the processing volume 101, for example, by controlling the airflow to the region between the cover heater 131 and the spray head 165 via a first airflow line 162, or by controlling the airflow to the spray head 165 via a second airflow line 163. In some embodiments, the process chamber 100 is configured such that the gas panel 130 provides nitrogen (N2), hydrogen (H2), and / or argon (Ar) within the process chamber 100 and the processing volume 101. For example, in an embodiment, the processing volume 101 is configured to receive approximately 1,000 to 6,000 sccm of nitrogen (N2). In an embodiment, the processing volume 101 is configured to receive approximately 1,000 to 6,000 sccm of hydrogen (H2). In an embodiment, the processing volume 101 is configured to receive approximately 6,000 sccm of argon. In some embodiments, one or more gases may be directed from the gas panel 130 to the processing volume 101 via a second gas flow line 163. For example, in an embodiment, hydrogen (H2) or an inert gas such as argon (Ar) may be added to the processing volume 101 via the second gas flow line 163. In some embodiments, such as when the process chamber 100 is configured for remote plasma applications, for example when plasma is ignited in the region between the cover heater 131 and the spray head 165 or within the spray head 165, one or more gases such as nitrogen (N2), hydrogen (H2), and / or argon (Ar) may be directed from the gas panel 130 to the processing volume 101 via a first gas flow line 162, and one or more gases such as nitrogen (N2), hydrogen (H2), or argon (Ar) may be directed to the processing volume 101 via the second gas flow line 163.

[0031] In embodiments, the volumetric flow rate, temperature, and pressure of the processing volume 101 can be adjusted to values ​​sufficient to induce a reaction according to this disclosure. In some embodiments, such as when the process chamber 100 is configured for direct plasma applications, for example, when plasma is ignited in the region between the spray head 165 and the substrate 190, one or more gases such as nitrogen (N2), hydrogen (H2), and / or argon (Ar) can be directed from the gas panel 130 into the processing volume 101 via a first gas flow line 162, and one or more gases such as nitrogen (N2), hydrogen (H2), and / or argon (Ar) can be directed into the processing volume 101 via a second gas flow line 163. In embodiments, the volumetric flow rate, temperature, and pressure of the processing volume 101 can be adjusted to values ​​sufficient to induce a reaction according to this disclosure.

[0032] In an embodiment, process chamber 100 includes RF electrodes 180 sufficient to ignite plasma within processing volume 101 according to this disclosure. In an embodiment, RF electrodes 180 may be coupled to one or more power sources (not shown) via one or more separate matching networks (matching networks are illustrated). The one or more power sources are capable of generating 3,000 watts of RF energy at a frequency of about 350 kHz to about 60 MHz (e.g., about 350 kHz, about 13.56 MHz, or about 60 MHz). In an embodiment, about 200 watts to about 600 watts of RF energy are applied to a remote plasma reaction within processing volume 101. In some embodiments, the RF energy is about 300 watts to about 600 watts or about 500 watts. In some embodiments, pulsed RF energy or continuous wave RF is applied. In some embodiments, the RF power is about 500 watts, the pulse frequency is about 1 kHz, and the duty cycle is about 50%. In some embodiments, process chamber 100 may use capacitively coupled RF energy for plasma processing. For example, process chamber 100 may have a top plate made of dielectric material and spray head 165 at least partially conductive to provide RF electrodes (or may provide individual RF electrodes). Spray head 165 (or other RF electrodes) may be coupled to one or more RF power sources (one RF power source not shown) via one or more separate matching networks (matching networks not shown). One or more plasma sources are capable of generating up to about 3,000 watts of RF energy, or in some embodiments up to about 5,000 watts of RF energy.

[0033] Figure 2 The illustration shows a flowchart of a nitride coating method 200 according to one or more embodiments of this disclosure. Figures 3A to 3D The illustrations are based on one or more embodiments of this disclosure. Figure 2Schematic cross-sectional views of the substrate during different stages of method 200. The methods of this disclosure can be performed in a process chamber configured for thermal deposition techniques (e.g., chemical vapor deposition (CVD)), such as those referenced above. Figure 1 The process chamber 100 is under discussion.

[0034] In the embodiments, for example, Figure 3A The depicted substrate 190 performs method 200. The substrate 190 has a silicon surface 302 extending across a bottom surface 315 of feature 304 and one or more dielectric surfaces such as a dielectric surface 306. In embodiments, the substrate 190 may include a silicon material 308, such as crystalline silicon (e.g., Si). <100> or Si <111> Silicon material 308 may comprise or be composed of a material, such as crystalline silicon (e.g., Si), germanium, doped or undoped polycrystalline silicon, doped or undoped silicon wafers, patterned or unpatterned wafers, silicon-on-insulator (SOI), or combinations thereof. In embodiments, silicon material 308 may comprise or be composed of a material, such as crystalline silicon (e.g., Si). <100> or Si <111> The substrate 190 may be pure silicon, substantially pure silicon (with less than 1% or less than 0.5% impurities), or exposed silicon, such as pretreated silicon with the native oxide layer removed. In embodiments, the substrate 190 may have various sizes, such as 200 mm, 300 mm, 450 mm, or other diameters for a circular substrate. The substrate 190 may also be any polygonal, square, rectangular, curved, or other non-circular object, such as a polygonal glass substrate used in flat panel display manufacturing. Unless otherwise indicated, the embodiments and examples described herein may be performed on substrates such as substrate 190, for example, substrates having a diameter of 200 mm, 300 mm, or 450 mm.

[0035] In some embodiments, silicon material 308 is deposited via any suitable atomic layer deposition (ALD) or chemical layer deposition (CLD) process. In some embodiments, silicon material 308 may comprise any silicon material suitable for semiconductor device fabrication. Reference Figure 3A A silicon oxide layer (not shown) may be present on the silicon surface 302. The silicon oxide layer may be a native oxide layer or formed when the silicon surface 302 is exposed to oxygen, such as in air or water. In some embodiments, the silicon oxide layer may be problematic because it offers less selectivity for titanium materials compared to an exposed silicon surface. In some embodiments, method 200 may include pretreating the silicon surface 302 to form an exposed silicon surface. In some embodiments, method 200 includes contacting the silicon surface 302 with one or more etchants to expose the silicon surface 302. In some embodiments, the silicon oxide layer is removed before depositing titanium material onto or directly onto the silicon surface 302 to expose the silicon surface 302. Non-limiting examples of materials for exposed silicon surfaces include substantially pure (e.g., substantially oxide-free) silicon and the like.

[0036] In embodiments, dielectric layer 310 includes one or more features 304, such as vias or trenches formed in dielectric layer 310. One or more features 304 can be formed by etching dielectric layer 310 using any suitable etching process. In some embodiments, one or more features 304 are defined by one or more sidewalls 314, a bottom surface 315, an opening 318, and a top corner 316. In some embodiments, one or more features 304 may have a high aspect ratio, for example, between about 5:1 and about 20:1. As used herein, aspect ratio is the ratio of the depth of a feature to the width of the feature. In embodiments, one or more features 304 have a width 320 of less than or equal to about 20 nanometers, less than or equal to about 10 nanometers, or about 5 to about 10 nanometers.

[0037] In some embodiments, the dielectric layer 310, including the dielectric surface 306, differs from the silicon material 308, including the silicon surface 302. In some embodiments, the dielectric layer 310 is deposited via any suitable atomic layer deposition (ALD) or chemical layer deposition (CLD) process. In some embodiments, the dielectric layer 310 may include a low-k dielectric layer deposited on the silicon material 308. In some embodiments, the dielectric material 310 may include any low-k dielectric material suitable for semiconductor device fabrication. Non-limiting materials suitable as low-k dielectric materials may include, for example, silicon-containing materials, such as silicon oxide (SiO2), silicon nitride, silicon oxynitride (SiON), combinations thereof, or combinations of the aforementioned layers. In some embodiments, the low-k dielectric material may have a low-k value of less than about 3.9 (e.g., about 2.5 to about 3.5). In some embodiments, the dielectric layer 310 may include hafnium oxide, such as HfOx. In some embodiments, the dielectric layer 310 and the dielectric surface 306 comprise silicon oxide (SiO2), silicon nitride, silicon oxynitride (SiON), or combinations thereof, or a combination thereof.

[0038] In some embodiments, the substrate 190 may be pretreated to improve the selectivity of the exposed silicon surface 302 relative to the dielectric layer 310. In one example, the dielectric layer 310 is pretreated by contacting it with only silane or with silane combined with an inert gas such as argon.

[0039] refer to Figure 3B A titanium material layer 330 is selectively formed on or therein on the exposed silicon surface 302. The titanium material layer 330 comprises titanium, titanium silicide (TiSix), or substantially pure titanium, or is composed of all of the above. In some embodiments, titanium silicide or TiSix refers to titanium silicide, where x is a number between 0.4 and 2.2. In some embodiments, TiSix refers to one or more of Ti5Si3, TiSi2, TiSi, or combinations thereof.

[0040] Titanium material layer 330 can be deposited using any suitable technique (including but not limited to PVD, CVD, and ALD processes). In one example, titanium material layer 330 is formed via a plasma reaction between titanium tetrachloride (TiCl4), hydrogen (H2), and argon (Ar), and TiSix is ​​formed due to the migration of titanium and silicon atoms. The wafer temperature can be maintained at a temperature of approximately 200 to 800 degrees Celsius (e.g., approximately 450 degrees Celsius) during the plasma reaction. The thickness of titanium material layer 330 can be approximately... to approximately The range or approximate to approximately The range or approximate to approximately The range or approximate to approximately Within the range, or approximately In some embodiments, approximately [missing information] are deposited via CVD deposition. A titanium silicide film of a certain thickness.

[0041] In some embodiments, prior to performing method 200, substrate 190 is exposed to a pretreatment process to remove any residues remaining after the formation of the titanium material layer 330, such as TiCl4 residues. In one example, the pretreatment process includes exposing substrate 190 to a remotely formed hydrogen plasma. The exposure to the hydrogen plasma process can last for a period ranging from about 5 seconds to about 20 seconds, for example, from about 10 seconds to about 15 seconds. During the pretreatment process, the wafer temperature can be maintained at a temperature of about 200 to 800 degrees Celsius (e.g., about 450 degrees Celsius). In another example, the pretreatment process includes pretreating the substrate by contacting it with hydrogen and argon at a temperature above room temperature (e.g., 200 to 800 degrees Celsius) while simultaneously contacting the substrate with argon and silane.

[0042] In an embodiment, method 200 includes operation 210, wherein the titanium material layer 330 is exposed to a hydrogen-rich nitrogen-containing plasma to, as Figure 3C At least a portion of a titanium nitride capping layer 340 is formed on or within a titanium material layer 330 on the silicon surface 302 of the substrate 190 shown. The titanium nitride capping layer 340 may be a TiN capping layer or a TiSiN capping layer. As used herein, "hydrogen-rich" refers to a ratio where the volumetric flow rate of hydrogen is greater than the volumetric flow rate of nitrogen, for example, a ratio of hydrogen volumetric flow rate to nitrogen volumetric flow rate greater than about 1:1. In some embodiments, operation 210 includes a process chamber (e.g., Figure 1 In the process chamber 100) in the spray head (e.g. Figure 1A direct plasma reaction is formed between the spray head 165 and the substrate 190 in nitrogen (N2), hydrogen (H2), and argon (Ar) to form a titanium nitride capping layer 340. In some embodiments, a direct plasma nitrogen-hydrogen reaction is provided to form the titanium nitride capping layer 340. In some embodiments, the direct plasma reaction is performed after the post-processed titanium material layer 330 described above. In some embodiments, the direct plasma reaction includes 4 to 8 standard liters per minute (slpm) or about 6 slpm of hydrogen. In some embodiments, 0.5 to 2 slpm or about 1 slpm of nitrogen is provided to the direct plasma reaction. In an embodiment, 4 to 8 standard liters per minute (slpm) or about 6 slpm of argon is provided to the direct plasma reaction. In an embodiment, the process chamber during the direct plasma reaction has a pressure of about 1 to 8 Torr (e.g., 4 Torr). In an embodiment, about 500 watts of RF power is applied during the direct plasma reaction. In some embodiments, the wafer temperature is maintained at about 200 to 800 degrees Celsius (e.g., about 425 degrees Celsius) during the direct plasma reaction. In some embodiments, the cap heater is heated to about 200 to 800 degrees Celsius (e.g., about 550 degrees Celsius) during the direct plasma reaction. In some embodiments, the base temperature is maintained at about 200 to 800 degrees Celsius, or about 450 degrees Celsius, during the direct plasma reaction.

[0043] In some embodiments, the nitriding process sequence or direct plasma reaction provides nitrogen at a volumetric flow rate of about 0.5 to 2 slpm and hydrogen at an amount of 0.1 to 6 slpm. In embodiments, the pressure in the process chamber is maintained at 1 Torr to 8 Torr during the direct plasma reaction. In embodiments, about 100 watts to 1000 watts of RF power is applied during the direct plasma reaction.

[0044] In embodiments, the ratio of hydrogen volumetric flow rate to nitrogen volumetric flow rate during operation 210 is greater than about 1:1, 4:3, 5:2, 6:1, or 8:1. In one example, the ratio of hydrogen volumetric flow rate to nitrogen volumetric flow rate during operation 210 is about 4:3 to about 8:1, for example, about 4:3 to about 6:1, for example, about 5:2 to about 6:1.

[0045] Exposure to a hydrogen-rich nitrogen-containing plasma process can be for a duration ranging from about 30 seconds to about 90 seconds. In some embodiments, exposure to a hydrogen-rich nitrogen-containing plasma process can be for a duration ranging from about 30 seconds to about 70 seconds, or from about 40 seconds to about 60 seconds, or about 50 seconds. In some embodiments, exposure to a hydrogen-rich nitrogen-containing plasma process can be for more than or equal to about 35 seconds, 40 seconds, 50 seconds, 60 seconds, 70 seconds, or 80 seconds. In some embodiments, exposure to a hydrogen-rich nitrogen-containing plasma process can be for less than or equal to about 90 seconds, or 80 seconds, or 70 seconds, or 60 seconds, or 50 seconds, or 40 seconds.

[0046] The initial titanium nitride capping layer 340 can be approximately [thickness value missing]. to approximately Within a range, for example, approximately to approximately For example, about to approximately

[0047] In an embodiment, method 200 further includes operation 220, in which the titanium nitride capping layer 340 is exposed to a nitrogen-rich nitrogen-containing plasma to form a portion of the titanium nitride capping layer 340. While not theoretically limited, it is believed that the nitrogen-rich nitrogen-containing plasma of operation 220 increases the oxidation resistance of the deposited titanium nitride capping layer 340. As used herein, “nitrogen-rich” refers to a ratio where the volumetric flow rate of hydrogen is less than the volumetric flow rate of nitrogen, for example, a ratio of hydrogen volumetric flow rate to nitrogen volumetric flow rate less than about 1:1. In some embodiments, a nitrogen-rich nitrogen-containing plasma can be achieved by increasing the nitrogen flow rate and decreasing the hydrogen flow rate from operation 210. In some embodiments, operation 220 includes a process chamber (e.g., Figure 1 The process chamber 100 is located inside the spray head (e.g. Figure 1A direct plasma reaction is formed between the spray head 165 and the substrate 190 in the presence of nitrogen (N2), hydrogen (H2), and argon (Ar) to form at least a portion of the titanium nitride capping layer 340. In some embodiments, a direct plasma nitrogen-hydrogen reaction is provided to form said portion of the titanium nitride capping layer 340. In some embodiments, the direct plasma reaction is performed after operation 210. In some embodiments, the direct plasma reaction includes an amount of nitrogen of 4 to 8 standard liters per minute (slpm) or about 6 slpm. In some embodiments, hydrogen is provided to the direct plasma reaction in an amount of 0.5 to 2 slpm, or about 1 slpm. In an embodiment, argon is provided to the direct plasma reaction at 4 to 8 standard liters per minute (slpm) or about 6 slpm. In an embodiment, the process chamber during the direct plasma reaction has a pressure of about 1 to 8 Torr (e.g., 4 Torr). In an embodiment, about 500 watts of RF power is applied during the direct plasma reaction. In some embodiments, the wafer temperature is maintained at 200 to 800 degrees Celsius (e.g., about 425 degrees Celsius) during the direct plasma reaction. In some embodiments, the cap heater is heated to 200 to 800 degrees Celsius (e.g., about 550 degrees Celsius) during the direct plasma reaction. In some embodiments, the base temperature is maintained at 200 to 800 degrees Celsius, or about 450 degrees Celsius, during the direct plasma reaction.

[0048] In some embodiments, the nitrogen-rich plasma processing sequence or direct plasma reaction provides hydrogen at a volumetric flow rate of approximately 0.5 to 2 slpm and nitrogen at an amount of 0.1 to 6 slpm. In an embodiment, the pressure in the process chamber during the direct plasma reaction in operation 220 is maintained at 1 Torr to 8 Torr. In an embodiment, during operation 220, approximately 100 watts to 1000 watts of RF power is applied during the direct plasma reaction.

[0049] In embodiments, the ratio of hydrogen volumetric flow rate to nitrogen volumetric flow rate during operation 220 is less than about 1:1, 3:4, 1:2, 2:5, 1:6, 1:8, or 1:10. In one example, the ratio of hydrogen volumetric flow rate to nitrogen volumetric flow rate during operation 220 is about 1:10 to about 2:5, for example, about 1:8 to about 1:6, for example, about 1:6.

[0050] Exposure to a nitrogen-rich plasma process can be for a duration ranging from about 10 seconds to about 70 seconds. In some embodiments, exposure to a nitrogen-rich plasma process can be for a duration ranging from about 10 seconds to about 50 seconds, or from about 20 seconds to about 40 seconds, or about 35 seconds. In some embodiments, exposure to a nitrogen-rich plasma process can be for more than or equal to about 15 seconds, 20 seconds, 30 seconds, 40 seconds, 50 seconds, or 60 seconds. In some embodiments, exposure to an immersion process can be for less than or equal to about 70 seconds, or 60 seconds, or 50 seconds, or 40 seconds, or 30 seconds, or 20 seconds.

[0051] The thickness of the titanium nitride capping layer 340 can be increased during operation 220 relative to the thickness of the titanium nitride layer after operation 210. After operation 220, the thickness of the titanium nitride capping layer 340 can be approximately... to approximately Within a range, for example, approximately to approximately For example, about to approximately

[0052] In an embodiment, method 200 further includes operation 230, in which the formed titanium nitride capping layer 340 is exposed to argon plasma treatment. While not theoretically limited, it is believed that the argon plasma treatment of operation 230 removes unstable bonds and densifies the formed titanium nitride capping layer 340. In some embodiments, exposure to argon plasma treatment can be achieved by stopping the flow rates of nitrogen and hydrogen from operation 220 while allowing argon to continue flowing and maintaining the process conditions of operation 220. In some embodiments, operation 230 includes a process chamber (e.g., Figure 1 In the process chamber 100) in the spray head (e.g. Figure 1A direct argon plasma is formed between the spray head 165 and the substrate 190 to treat the titanium nitride capping layer 340. In other embodiments, the argon plasma is formed remotely and delivered to the process chamber. In some embodiments, the argon plasma treatment of operation 230 is performed after operation 220. In some embodiments, argon gas at a rate of 4 to 8 standard liters per minute (slpm) or about 6 slpm is supplied to the direct plasma. In some embodiments, the process chamber exposed to the argon plasma treatment has a pressure of about 1 to 8 Torr (e.g., 4 Torr). In some embodiments, about 500 watts of RF power is applied during the argon plasma treatment. In some embodiments, the wafer temperature is maintained at a temperature of 200 to 800 degrees Celsius (e.g., about 425 degrees Celsius) during the argon plasma treatment. In some embodiments, the cap heater is heated to a temperature of 200 to 800 degrees Celsius (e.g., about 550 degrees Celsius) during the argon plasma treatment. In some embodiments, the base temperature is maintained at 200 to 800 degrees Celsius, or about 450 degrees Celsius, during exposure to argon plasma treatment.

[0053] In some embodiments, the argon plasma treatment of operation 230 provides an argon gas volumetric flow rate of about 4 to 8 slpm (e.g., about 4 slpm to about 6 slpm). In embodiments, the pressure in the process chamber is maintained at 1 Torr to 8 Torr during operation 230. In embodiments, about 100 watts to 1000 watts of RF power is applied during operation 230.

[0054] Exposure to argon plasma treatment can last for a period ranging from about 5 seconds to about 60 seconds. In some embodiments, the argon plasma exposure lasts for a period ranging from about 5 seconds to about 20 seconds, or from about 5 seconds to about 15 seconds, or for about 10 seconds. In some embodiments, the plasma exposure lasts for more than or equal to about 5 seconds, 10 seconds, 20 seconds, 30 seconds, 40 seconds, or 50 seconds. In some embodiments, the plasma exposure lasts for less than or equal to about 60 seconds, or 50 seconds, or 40 seconds, or 30 seconds, or 20 seconds, or 10 seconds.

[0055] In some embodiments, a purge can be performed after the argon plasma treatment in operation 230. In the purge operation, argon plasma species and effluents are removed from the process chamber. This can be achieved by purging and / or evacuating the process chamber to remove any remaining argon plasma species. Species generated in the argon plasma can be removed by stopping the plasma and allowing argon gas to continue flowing to purge and / or evacuate the process chamber.

[0056] In an embodiment, method 200 further includes operation 240, in which the formed titanium nitride capping layer 340 is treated with an immersion process having a halide precursor. While not theoretically limited, it is believed that the halide immersion process removes unstable bonds, such as unstable titanium bonds, and reduces the thickness of the titanium nitride capping layer 340. The halide precursor may be a chlorine-containing precursor or a fluorine-containing precursor. In one example, the halide precursor is chlorine. The halide precursor may be flowed in with a carrier gas, such as helium (He), argon (Ar), nitrogen (N2), other suitable gases, or combinations thereof. In some embodiments, exposure to immersion can be achieved by allowing chlorine to flow into the process chamber while maintaining the flow rate of argon in operation 230 and maintaining the process conditions of operation 230 without applying RF power. In some embodiments, the immersion of operation 240 is performed after operation 230. In an embodiment, an amount of argon of 4 to 8 standard liters per minute (slpm) or about 6 slpm is supplied to the process chamber. In some embodiments, a halide precursor (e.g., Cl2) is supplied to the process chamber in an amount of 50 sccm to approximately 500 sccm or approximately 100 sccm. In some embodiments, the process chamber exposed to the halide immersion process has a pressure of approximately 1 to 8 Torr (e.g., 4 Torr). In some embodiments, the immersion process is a plasma-free process. In some embodiments, the wafer temperature is maintained at a temperature of 200 to 800 degrees Celsius (e.g., approximately 425 degrees Celsius) during the immersion process. In some embodiments, the cap heater is heated to a temperature of 200 to 800 degrees Celsius (e.g., approximately 550 degrees Celsius) during the immersion process. In some embodiments, the base temperature is maintained at a temperature of 200 to 800 degrees Celsius, or approximately 450 degrees Celsius, during exposure to the immersion process.

[0057] In some embodiments, the immersion process provides chlorine gas at a volumetric flow rate of about 50 to 200 sccm and argon gas in an amount of 0.1 slpm to 6 slpm. In an embodiment, the pressure in the process chamber during the immersion process in operation 240 is maintained at 1 Torr to 8 Torr.

[0058] The exposure to the immersion process can be for a duration ranging from about 5 seconds to about 60 seconds. In some embodiments, the exposure to the immersion process can be for a duration ranging from about 5 seconds to about 20 seconds, or from about 5 seconds to about 15 seconds, or about 10 seconds. In some embodiments, the exposure to the immersion process can be for more than or equal to about 5 seconds, 10 seconds, 20 seconds, 30 seconds, 40 seconds, or 50 seconds. In some embodiments, the exposure to the immersion process can be for less than or equal to about 60 seconds, or 50 seconds, or 40 seconds, or 30 seconds, or 20 seconds, or 10 seconds.

[0059] The thickness of the titanium nitride capping layer 340 can be reduced during operation 240, relative to the thickness of the titanium nitride layer after operation 220. After operation 240, the thickness of the titanium nitride capping layer 340 can be approximately... to approximately Within a range, for example, approximately to approximately For example, about to approximately

[0060] It has been found that exposure to argon plasma treatment in operation 230 and halide immersion in operation 240 can reduce the oxygen content of the titanium nitride capping layer 340. As used herein, reduced oxygen content can mean a reduction in oxygen concentration from the oxygen content of the titanium nitride capping layer 340 to have an oxygen content of less than or equal to about 14 atomic percent, 13.7 atomic percent, 13.5 atomic percent, or 13 atomic percent.

[0061] In some embodiments, after operation 240, method 200 further includes filling feature 304 with a metal filler 350 such as cobalt or tungsten, as... Figure 3D As shown.

[0062] Example:

[0063] The following non-limiting examples are provided to further illustrate the implementations described herein. However, these examples are not intended to be exhaustive or to limit the scope of the implementations described herein.

[0064] A silicon substrate on which a TiSix layer is formed is provided. For operation 210, the TiSi layer is exposed to a hydrogen-rich nitrogen-containing plasma as described herein for 50 seconds to form an initial TiSiN capping layer on the TiSi layer. For operation 220, the initial TiSiN capping layer is exposed to a nitrogen-rich nitrogen-containing plasma as described herein for 35 seconds. Subsequently, the TiSiN capping layer is exposed to argon plasma treatment for a period of 10 seconds, followed by a chlorine immersion for a period of 10 seconds.

[0065] The oxygen content of the deposited capping film was determined using X-ray photoelectron spectroscopy (XPS), and the results are shown in Table 1.

[0066]

[0067] Table 1.

[0068] It was observed that argon plasma treatment followed by chlorine immersion reduced the thickness and oxygen content of the final TiSiN capping layer.

[0069] Implementations may include one or more of the following potential advantages. One or more embodiments of this disclosure advantageously address the problem of resistivity reduction while requiring smaller nodes by providing a method for forming a nitride capping material with improved barrier properties. In some embodiments, the method of this disclosure includes exposure to a nitrogen-rich gas mixture plasma to increase the nitrogen concentration in the nitride capping layer. After nitriding, unstable titanium and silicon bonds are removed using exposure to an inert gas plasma and halide immersion. This removal of unstable bonds is believed to reduce the oxidation of the underlying titanium material upon exposure to air. Due to the reduced oxidation, the contact resistance of the formed integrated circuit device can be reduced.

[0070] The embodiments and all functional operations described herein may be implemented using digital electronic circuit systems, or using computer software, firmware, or hardware, or a combination thereof, including the structural components disclosed herein and their structural equivalents. The embodiments described herein may be implemented as one or more non-transitory computer program products, i.e., one or more computer programs tangibly embodied in a machine-readable storage device, for execution by or control of a data processing device (e.g., a programmable processor, a computer, or multiple processors or computers).

[0071] The process and logic flow described herein can be executed by one or more programmable processors, which execute one or more computer programs to perform functions by manipulating input data and generating outputs. The process and logic flow can also be executed by a dedicated logic circuit system (e.g., an FPGA (Field-Programmable Gate Array) or an ASIC (Application-Specific Integrated Circuit)), and the device can also be implemented as a dedicated logic circuit system.

[0072] The term "data processing apparatus" includes all means, devices, and machines for processing data, including, for example, programmable processors, computers, multiple processors, or computers. In addition to hardware, the apparatus may include code that creates an execution environment for the computer program in question, such as code that constitutes processor firmware, a protocol stack, a database management system, an operating system, or a combination thereof. Processors suitable for executing computer programs include, for example, general-purpose and special-purpose microprocessors, and any one or more processors of any type of digital computer.

[0073] Computer-readable media suitable for storing computer program instructions and data include all forms of non-volatile memory, media, and storage devices, including, for example, semiconductor memory devices (e.g., EPROM, EEPROM) and flash memory devices; magnetic disks, such as internal hard disks or removable disks; magneto-optical disks; and CD-ROMs and DVD-ROMs. Processors and memory may be supplemented by or incorporated into dedicated logic circuitry systems.

[0074] When describing an element of this disclosure or an exemplary aspect or implementation thereof, the articles “a,” “an,” “the,” and “said” are intended to refer to the presence of one or more of that element.

[0075] The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that additional elements may exist in addition to the listed elements.

[0076] While the foregoing describes embodiments of this disclosure, other and additional embodiments of this disclosure may be devised without departing from the basic scope of this disclosure, and the scope of this disclosure is defined by the appended claims.

Claims

1. A method for forming a nitride coating, comprising: A titanium nitride layer is formed on a titanium material layer formed on a substrate, comprising: The titanium material layer was exposed to a hydrogen-rich nitrogen-containing plasma; and The titanium material layer was exposed to nitrogen-rich nitrogen-containing plasma; The titanium nitride layer was exposed to argon plasma; and The titanium nitride layer is exposed to a halide immersion process. The substrate includes a high aspect ratio feature, wherein a silicon surface is disposed at the bottom of the high aspect ratio feature, and a dielectric surface is disposed on one or more sidewalls of the high aspect ratio feature.

2. The method of claim 1, wherein the hydrogen-rich nitrogen-containing plasma is formed by flowing hydrogen and nitrogen at a first ratio of hydrogen volume flow rate to nitrogen volume flow rate greater than 1:

1.

3. The method of claim 2, wherein the nitrogen-rich nitrogen-containing plasma is formed by flowing hydrogen and nitrogen at a second ratio of a second hydrogen volume flow rate to a second nitrogen volume flow rate of less than 1:

1.

4. The method of claim 1, wherein the hydrogen-rich nitrogen-containing plasma is formed by flowing hydrogen and nitrogen at a first ratio of hydrogen volume flow rate to nitrogen volume flow rate of 4:3 to 8:

1.

5. The method of claim 4, wherein the nitrogen-rich nitrogen-containing plasma is formed by flowing hydrogen and nitrogen at a second ratio of a second hydrogen volume flow rate to a second nitrogen volume flow rate of 1:8 to 1:

6.

6. The method of claim 1, wherein the titanium material layer is formed on the silicon surface.

7. The method of claim 1, wherein the titanium material layer comprises titanium silicide.

8. The method of claim 7, wherein the titanium nitride layer comprises TiSiN.

9. A method for forming a nitride coating, comprising: A titanium nitride layer is formed on a titanium material layer formed on a substrate, comprising: In the process chamber, a direct plasma reaction is formed between the spray head and the substrate between nitrogen (N2), hydrogen (H2) and argon (Ar), wherein the first ratio of hydrogen volume flow rate to nitrogen volume flow rate is greater than 1:1; Increase the nitrogen volume flow rate and decrease the hydrogen volume flow rate, wherein the second ratio of the second hydrogen volume flow rate to the second nitrogen volume flow rate is less than 1:1; The titanium nitride layer was exposed to argon plasma; and The titanium nitride layer is exposed to a chlorine immersion process. The substrate includes a high aspect ratio feature, wherein a silicon surface is disposed at the bottom of the high aspect ratio feature, and a dielectric surface is disposed on one or more sidewalls of the high aspect ratio feature.

10. The method of claim 9, wherein the step of exposing the titanium nitride layer to argon plasma comprises: stopping the flow of nitrogen and hydrogen.

11. The method of claim 10, wherein the chlorine immersion process is a plasma-free process.

12. The method of claim 9, wherein the first ratio of the hydrogen volume flow rate to the nitrogen volume flow rate is 4:3 to 8:

1.

13. The method of claim 12, wherein the second ratio of the second hydrogen volume flow rate to the second nitrogen volume flow rate is 1:8 to 1:

6.

14. The method of claim 9, wherein the titanium material layer is formed on the silicon surface.

15. The method of claim 14, wherein the titanium material layer comprises titanium, titanium silicide, or substantially pure titanium.

16. A method for forming a nitride coating, comprising: A titanium silicon nitride capping layer is formed on a titanium silicide layer formed on a substrate, comprising: The titanium silicide layer is exposed to a hydrogen-rich nitrogen-containing plasma to form a first portion of the titanium silicon nitride capping layer; and The first portion of the silicon titanium nitride capping layer is exposed to a nitrogen-rich nitrogen-containing plasma to form the second portion of the silicon titanium nitride capping layer; The silicon titanium nitride capping layer is exposed to argon plasma to form a plasma-treated silicon titanium nitride capping layer; and The plasma-treated silicon-titanium nitride capping layer is exposed to a chlorine immersion process to reduce the thickness of the plasma-treated silicon-titanium nitride capping layer. The substrate includes a high aspect ratio feature, wherein a silicon surface is disposed at the bottom of the high aspect ratio feature, and a dielectric surface is disposed on one or more sidewalls of the high aspect ratio feature.

17. The method of claim 16, wherein the hydrogen-rich nitrogen-containing plasma is formed by flowing hydrogen and nitrogen at a first ratio of hydrogen volume flow rate to nitrogen volume flow rate of 4:3 to 8:

1.

18. The method of claim 17, wherein the nitrogen-rich nitrogen-containing plasma is formed by flowing hydrogen and nitrogen at a second ratio of a second hydrogen volume flow rate to a second nitrogen volume flow rate of 1:8 to 1:6.

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