Molybdenum deposits

Abstract

This invention provides a method for filling pattern features with molybdenum (Mo). [Solution] This method involves selectively depositing a Mo film on a metal-containing surface at the bottom of a feature including a dielectric sidewall. Selective growth of Mo at the bottom surface enables bottom-up growth and allows for high-quality, void-free filling. Related apparatus is also provided. The steps include providing a substrate including a feature having a feature bottom and a feature sidewall, wherein the feature bottom comprises a metal-containing surface and the feature sidewall comprises an oxide surface or a nitride surface, and performing a multi-cycle atomic layer deposition (ALD) process to selectively deposit a molybdenum film on the metal-containing surface relative to the oxide surface or nitride surface, wherein the ALD process includes exposing the feature to alternating pulses of a molybdenum-containing oxyhalide precursor and a reducing agent at a first substrate temperature.

Description

[Background technology]

[0001] [References] As part of this application, a PCT application is filed concurrently with this specification. Each application in which this application claims any benefit or priority granted in a concurrently filed PCT application is incorporated herein by reference for all purposes.

[0002] The background art described herein is for the purpose of providing a general overview of the contents of this disclosure. The inventions of the inventors named herein are not, expressly or implicitly, considered prior art to this disclosure to the extent described in the background art section and in the manner of descriptions that do not constitute prior art at the time of filing.

[0003] Metal deposition is an essential part of many semiconductor manufacturing processes. These materials may be used for horizontal interconnects, vias between adjacent metal layers, and contacts between metal layers and devices. However, as devices shrink and more complex patterning techniques are used in the industry, uniform deposition of low-resistivity metal films has become challenging. [Overview of the Initiative]

[0004] A method for filling pattern features with molybdenum (Mo) is provided. This method involves selectively depositing a Mo film on the bottom metal-containing surface of a feature, including dielectric sidewalls. Selective growth of Mo at the bottom surface enables bottom-up growth and allows for high-quality, void-free filling. Related apparatus is also provided.

[0005] One aspect of the present disclosure is a method comprising the steps of: providing a substrate including a feature having a feature bottom and a feature sidewall, wherein the feature bottom comprises a metal-containing surface and the feature sidewall comprises an oxide surface or a nitride surface; and performing a multi-cycle atomic layer deposition (ALD) process to selectively deposit a molybdenum (Mo) film on the metal-containing surface relative to the oxide surface or nitride surface, wherein the ALD process exposes the feature to alternating pulses of a molybdenum-containing oxyhalide precursor and a reducing agent at a first substrate temperature.

[0006] In some embodiments, the method also includes the step of exposing a metal-containing surface to a hydrogen-containing plasma before carrying out a multi-cycle ALD deposition process. In some embodiments, the reducing agent is thermohydrogen (H2). In some embodiments, the reducing agent is supplied to a plasma generated from hydrogen (H2). In some embodiments, the partial pressure of the reducing agent is at least 10 Torr. In some embodiments, the molybdenum-containing precursor is molybdenum oxychloride. In some embodiments, the first temperature is 600°C or less. In some embodiments, the first temperature is 450°C or less. In some embodiments, the first temperature is 400°C or less. In some embodiments, the molybdenum-containing precursor is molybdenum oxyfluoride. In some embodiments, the method further includes the step of partially filling the features while the substrate is at the first temperature and completely filling the features (or filling a second portion of the features) while the substrate is at a second temperature higher than the first temperature. In some such embodiments, partial filling of the feature is performed at a first station of the processing chamber, and complete filling of the feature (or filling of a second portion of the feature) is performed at a second station of the processing chamber. In some embodiments, the metal-containing surface is one of the materials from the group including cobalt, ruthenium, copper, tungsten, molybdenum, titanium, tin, tantalum, nickel, iridium, and rhodium. In some embodiments, the metal-containing surface is one of the materials from the group including titanium nitride, molybdenum nitride, tungsten nitride, tungsten carbonitride, titanium aluminum carbide, titanium silicide, and tantalum nitride. In some embodiments, the metal-containing surface is a metallic element surface. In some embodiments, the sidewalls include oxides. Examples of oxides include polyethylene oxide, tetraethyl orthosilicate, fluid oxides, and carbon-doped oxides. In some embodiments, the Mo film on the metal-containing film has a greater thickness than the Mo film on the oxide or nitride surface of the sidewall (e.g., at least about 20 Å greater than the Mo film on the oxide or nitride surface).

[0007] Another aspect of the present disclosure relates to a method comprising the steps of: providing a substrate including a feature having a feature bottom and a feature sidewall, wherein the feature bottom comprises a metal-containing surface and the feature sidewall comprises an oxide surface or a nitride surface; and carrying out a deposition process for selectively depositing molybdenum (Mo) on the metal-containing surface relative to the oxide surface or nitride surface, the deposition process comprising the steps of exposing the feature to a molybdenum-containing oxyhalide precursor and a reducing agent at a first substrate temperature.

[0008] In some embodiments, the method also includes the step of exposing the metal-containing surface to a hydrogen-containing plasma before carrying out the deposition process. In some embodiments, the metal-containing surface may be exposed to other treatments using halogen-containing plasmas, such as chlorine (Cl-) plasmas. In some embodiments, the reducing agent is thermohydrogen (H2). In some embodiments, the reducing agent is supplied to a plasma generated from hydrogen (H2). In some embodiments, the partial pressure of the reducing agent is at least 10 Torrell. In some embodiments, the molybdenum-containing precursor is molybdenum oxychloride. In some embodiments, the first temperature is 600°C or less. In some embodiments, the first temperature is 450°C or less. In some embodiments, the first temperature is 400°C or less. In some embodiments, the molybdenum-containing precursor is molybdenum oxyfluoride. In some embodiments, the method further includes the step of partially filling the features while the substrate is at the first temperature and completely filling the features (or filling a second portion of the features) while the substrate is at a second temperature higher than the first temperature. In some embodiments, partial filling of the feature is performed at a first station of the processing chamber, and complete filling of the feature (or filling of a second portion of the feature) is performed at a second station of the processing chamber. In some embodiments, the metal-containing surface is one material from the group including cobalt, ruthenium, copper, tungsten, molybdenum, titanium, tin, tantalum, nickel, iridium, and rhodium. In some embodiments, the metal-containing surface is one material from the group including titanium nitride, molybdenum nitride, tungsten nitride, tungsten carbonitride, titanium aluminum carbide, titanium silicide, and tantalum nitride. In some embodiments, the metal-containing surface is a metallic element surface. In some embodiments, the sidewalls include oxides. Examples of oxides include polyethylene oxide, tetraethyl orthosilicate, fluid oxides, and carbon-doped oxides. In some embodiments, the Mo film on the metal-containing film has a greater thickness than the Mo film on the oxide surface or nitride surface of the sidewall.

[0009] These and further embodiments are described below with reference to the drawings. [Brief explanation of the drawing]

[0010] [Figure 1] Exemplary molybdenum (Mo) interconnects in various embodiments.

[0011] [Figure 2] Exemplary pattern features in which selective deposition of Mo films can be carried out by various embodiments.

[0012] [Figure 3] Exemplary selective deposition methods for filling features with molybdenum, according to various embodiments.

[0013] [Figure 4] Figure 3 is an illustrative cross-sectional schematic diagram of a pattern feature after a specific operation of the method according to a specific embodiment. [Figure 5] Figure 3 is an illustrative cross-sectional schematic diagram of a pattern feature after a specific operation of the method according to a specific embodiment.

[0014] [Figure 6A] An exemplary apparatus equipped with a gas manifold system, which can be used in various embodiments.

[0015] [Figure 6B] Exemplary methods for selectively depositing Mo layers by ALD according to various embodiments.

[0016] [Figure 7] Image (a) shows selective partial Mo filling, and image (b) shows complete Mo filling without seams or voids, in images of Mo gap filling development in via structures with deposition on Cu.

[0017] [Figure 8] A schematic diagram of an exemplary processing chamber for carrying out a particular embodiment of the disclosure.

[0018] [Figure 9] Schematic diagram of an exemplary processing tool for implementing a particular disclosed embodiment. **DETAILED DESCRIPTION OF THE INVENTION**

[0019] A method of filling a pattern feature with molybdenum (Mo) is provided. The method includes a step of selectively depositing a Mo film on a bottom metal-containing surface of a feature including a dielectric sidewall. Selective growth of Mo on the bottom surface enables bottom-up growth and enables high-quality void-free filling.

[0020] FIG. 1 represents an example of a feature 100 according to various embodiments. The feature 100 includes a bottom surface 102 and one or more sidewall surfaces 104. An etch stop layer (ESL) 106 is also shown. The bottom surface 102 may be a metal-containing surface. The structure 100 is filled with molybdenum to form a Mo interconnect 108 that provides an electrical connection to underlying contacts.

[0021] In some embodiments, the bottom surface 102 is a metal-containing surface. The metal-containing surface may include any suitable metal such as cobalt (Co), ruthenium (Ru), copper (Cu), tungsten (W), molybdenum (Mo), nickel (Ni), iridium (Ir), rhodium (Rh), tantalum (Ta), and titanium (Ti). In some embodiments, the metal-containing surface 102 is a metal element surface. Some oxide may be formed on the metal-containing surface upon exposure to moisture. In some embodiments, the metal-containing surface is titanium nitride (TiN), molybdenum nitride (MoN x ), tungsten nitride (WN), tungsten carbonitride (WC x N y ), titanium aluminum carbide (TiAl x C yExamples of metal compounds include those with surfaces of titanium silicide (TiSi2) or tantalum nitride (TaN). These surfaces may exhibit selectivity for dielectric oxides.

[0022] The oxide surfaces used herein include alkoxides such as tetraethoxysilane (TEOS), silicate glass fluoride (FSG), fluid oxides, spin-on glass, and carbon-doped oxides. In some embodiments, the oxide surface is a silicon-based oxide using the examples described above.

[0023] One or more sidewall surfaces 104 are dielectric surfaces. Such surfaces include alkoxides such as poly(2-ethyl-2-oxazoline) (PEOX), and silicon oxides such as tetraethoxysilane (TEOS) oxide, fluid silicon oxide, and carbon-doped silicon oxide. These surfaces may be part of the main dielectric layer surrounding the feature. Selectivity refers to the preference for deposition on a metallic surface, such as a Co, W, or Cu surface, over a dielectric surface. Selectivity may be quantified as a deposition rate ratio or a ratio of deposition thickness after a certain number of deposition cycles.

[0024] In some embodiments, the sidewall surface is made of nitride (e.g., Si) rather than oxide. x N y ) may be. The nitride may be a silicon-based nitride or a silicon-based oxynitride. The selectivity for Mo film formation with respect to nitrides of metal elements is similar to the selectivity for oxides.

[0025] The Mo interconnect 108 may be part of any suitable portion of a semi-finished semiconductor device, including a source / drain (S / D) connection, a middle-of-line (MOL) structure, or a back-end-line (BEOL) structure.

[0026] Figure 2 shows an exemplary embodiment of a pattern feature in which selective deposition of a Mo film can be performed. The pattern feature may be a via, trench, or other suitable feature formed as a result of a patterning operation in a dielectric layer. Feature 210 shows an example of a pattern feature having an aperture profile that gradually widens from the bottom of the feature toward the feature aperture 214.

[0027] Feature 220 shows an example of a pattern feature having a reentrant profile that narrows from the bottom of the feature toward the feature opening 214. The reentrant profile may have a projection toward the feature opening 214. Feature 230 shows a feature having a metallic undercut profile. In various embodiments, this profile has a metal-containing surface beneath the sidewall base 218 of feature 230. There may be a void between the bottom surface 202 and the sidewall base 218. In each of the above profiles, the bottom surface 202 may be a metal-containing surface. A metal oxide 216 may be formed on the bottom surface 202.

[0028] Figure 3 is a flowchart showing an example of a selective deposition method 300 for filling features with a Mo film. Figures 4 and 5 show schematic cross-sectional views of exemplary pattern features after a specific operation of an embodiment of the method in Figure 3. Specifically, at 410 in Figure 4, the pattern feature before the application of the selective deposition method 300 is shown. The pattern feature may be, for example, an etching feature. The pattern feature comprises a bottom surface 402 and side walls 404 which may be an oxide or nitride. In some embodiments, the bottom surface 402 may have a metal oxide 416.

[0029] In operation 305 of Figure 3, features, including metal-containing and dielectric surfaces, are pre-treated as needed. The pre-treatment may include exposing the features to a reducing agent, such as a hydrogen species, as it is used to reduce any metal oxides on the metal-containing surface. The feature pre-treatment may include exposing the features to a hydrogen-containing plasma. In some embodiments, the hydrogen-containing plasma is generated from hydrogen gas (H2). For some surfaces, H2-based plasma may not be effective in reducing metal oxides or preparing the surface. In such cases, other treatments may be used. For example, a halogen-based plasma may be used to treat silicide surfaces, such as TiSi2 surfaces. Examples include plasmas generated from chlorine (Cl2) and / or boron trichloride (BCl3).

[0030] The pretreatment, if performed, may be plasma treatment, or in some embodiments, heat treatment. Heat treatment may involve exposing the surface to a gas in a non-plasma environment. For example, hydrogen fluoride (HF) may be used to treat metal silicides such as TiSi2, and other metal compounds or metal surfaces. If plasma treatment is performed, it may be remote plasma or in-situ plasma. In-situ plasma means plasma generated within a chamber containing the substrate, generally without a filter placed between the substrate and the generated plasma, and may contain ions and radicals. Remote plasma means plasma generated far away from the substrate, and may be generated in a dome or other space that is part of the chamber where the substrate is located, or connected to that chamber, or in a separate, independent device. A showerhead or other filter is generally placed between the generator and the substrate. In some embodiments, the remote plasma contains only radicals or other neutral species and does not contain ions. Figure 420 in Figure 4 is an embodiment of feature 410 after operation 305 has been performed. In this embodiment, the metal-containing surface 402 no longer has metal oxides.

[0031] Returning to block 315 of FIG. 315, selective growth of the Mo film is performed on the metal-containing surface. Selective deposition means selective deposition on the metal-containing surface with respect to the oxide surface or nitride surface. Therefore, the filled portion formed on the metal-containing surface is thicker than the filled portion formed on the oxide surface or nitride surface. This is shown in 430 of FIG. 4 indicating the start of selective deposition of the Mo film 408. Nucleation of the Mo film 408 starts at the metal-containing bottom surface 402. In the example of FIG. 4, there is no growth of the Mo film on the oxide or nitride of the sidewall surface 404. Growth on the metal-containing bottom surface 402 may result in coarsening and / or lower resistance. Selective deposition may be used during ALD (described further below with reference to FIG. 6) or chemical vapor deposition (CVD).

[0032] To selectively deposit Mo, the Mo precursor, temperature, and reactant partial pressure may be controlled. The Mo precursor is a oxyhalide such as Mo x O x H z where H is a halogen (fluorine (F), chlorine (Cl), bromine (Br), or iodine (I)) (x, y, z are numbers greater than zero that can form a stable molecule). Examples of Mo precursors are molybdenum oxyfluoride (MoOF4), molybdenum oxychloride (MoOCl4), molybdenum dioxychloride (MoO2Cl2), molybdenum dioxybromide (MoO2Br2), and molybdenum oxyiodide MoO2I and Mo4O 11 I. The reducing agent reacts with the molybdenum oxyhalide to form molybdenum element. In some embodiments, the reducing agent is hot hydrogen or plasma hydrogen (H2).

[0033] Temperature affects selectivity, particle size, and resistance. High temperatures reduce the selectivity of the Mo film and can lead to growth not only on the sidewall surface 404 but also on the metal-containing bottom surface 402, as well as on the oxide or nitride. However, if the temperature is too low, the impurity levels increase, the particle size decreases, and the resistance increases. The substrate temperature may be within the range of 350–600°C to selectively deposit Mo using chlorine-containing chemicals. As described above, selectivity can be improved as the temperature decreases. Therefore, in some embodiments, the substrate temperature may be about 350–550°C or 350–450°C for chlorine-containing precursors. The substrate temperature for fluorine-containing chemicals may be lower (e.g., 150–350°C).

[0034] In block 325 of Figure 3, the feature is filled with Mo. The start of the Mo filling process is shown at 430 in Figure 4. The Mo film 408 may continue to grow on the metal-containing surface 402. At 404, the Mo film may begin nucleation in oxides or nitrides on the sidewall surface 404. The Mo film 408 fills the feature and has a greater thickness from the metal-containing bottom surface 402 than the Mo film 408 grown from the sidewall 404.

[0035] In some embodiments, multi-stage Mo deposition is performed. In Figure 4, the initial stages where selective deposition is performed are represented by 430 and 440. The second stage, where the deposition conditions are modified to increase deposition rate and throughput, is represented by 450. At 450, co-formation length occurs (not bottom-up or non-co-formation length). By increasing the substrate temperature, the growth rate of the Mo film 408 from both the bottom and sidewalls is increased, and the time to fill features is reduced. In the example in Figure 4, the temperature is increased after some amount of film has been nucleated on the sidewalls. In other embodiments, there may be no nucleated Mo on some or all of the sidewalls above the portion of film growth by bottom-up. The temperature increase enables nucleation on these sidewalls. This may be appropriate once features are sufficiently filled so that co-formation length is used to obtain good feature filling without the risk of voids. The temperature may rise to at least 50°C, at least 100°C, or at least 150°C, and may be as high as at least 500°C and even 800°C, as long as the thermal budget is permissible in the device structure.

[0036] In some embodiments, the substrate temperature or other processing parameters are not modified to increase the deposition rate while the features are filled under selective deposition conditions. This is illustrated in Figure 5, where 510 shows a feature having sidewalls 504 and a bottom surface 502. The bottom surface 502 has a metal oxide 516. 520 shows the feature after the metal oxide has been removed. 530 shows the feature after the Mo deposition has filled the feature. In a single-step deposition without modification of process conditions, the deposition may remain selective, with bottom-up filling used to fill the features, or it may transition from selective deposition to more conformal deposition, as some Mo begins to nucleate at the sidewalls, reducing selectivity.

[0037] Deposition of pure metal films using oxygen-containing precursors is difficult because oxygen is easily incorporated into the film during the deposition process. When oxygen is incorporated, resistance increases. The methods and apparatus described herein may, in some embodiments, be used to deposit pure metal films containing less than 1 atomic percent oxygen. The ratio of the reducing agent to the metal oxyhalide precursor is significantly greater than 1, and the deposited film contains less than 1 atomic percent oxygen. A molar ratio of at least 100:1 may be used. In some embodiments, the deposited film contains 1E18 atoms / cm³. 3 The following halogen concentrations are present. To deposit a pure film containing less than 1 atomic percent oxygen, the reducing agent to metal precursor ratio is significantly greater than 1 (e.g., at least 20:1, or at least 50:1). Examples of temperatures are 350-600°C for chlorine-containing precursors and 150-500°C for fluorine-containing precursors. Examples of chamber pressure are 1-100 Torr. The reducing agent:precursor ratio used to obtain a pure film may decrease as the temperature increases. In some embodiments, the temperature of the chlorine-containing precursor is at least 400°C. Higher pressures may be used to reduce the reducing agent:precursor ratio as the partial pressure of the reducing agent increases.

[0038] In pulsed ALD processes, the number of reducing agent pulses may be greater than the number of precursor pulses in some embodiments. This method may be carried out using multiple packed containers. Figure 6A schematically shows an exemplary apparatus in which three gas sources (precursor, H2, and purge gas) are connected to fill containers. This apparatus includes a gas manifold system that provides line filling to various gas distribution lines. The manifold supplies the precursor gas, reducing gas, and purge gas to the deposition chamber through valved packed containers. Various valves open and close to provide line filling, i.e., pressurize the distribution lines. In various embodiments, the number of reducing agent packed containers (total filling volume) may be greater than the number of containers for the precursor and / or purge gas. Multiple pulses of reducing agent per precursor pulse allow for a rapid reduction of the oxygen-containing precursor, resulting in the deposition of a high-purity, low-resistance metal film. In some embodiments, multiple packed containers may be used not only for the precursor but also for the reducing agent. This introduces multiple pulses and enables the complete reduction of the oxygen-containing precursor.

[0039] The ratio of reducing agent to precursor can be characterized as the ratio of molecules that can react when the substrate is exposed.

number

number

[0040] The above formulas represent molar ratios, and example molar ratios are 50:1 to 10000:1, 50:1 to 2000:1, 100:1 to 10000:1, or 100:1 to 2000:1.

[0041] The ratio of reducing agent to precursor can be characterized as a volume ratio.

number

[0042] The volume ratio can be, for example, 50:1 to 2000:1.

[0043] In some embodiments, the ALD method is used to selectively deposit Mo. Figure 6B is a flow chart showing the operation in the ALD method. In 605, the Mo precursor is pulsed. As described above, the Mo precursor is a molybdenum-containing oxyhalide precursor adsorbed onto the substrate. After the Mo precursor is pulsed, a purge 615 may occur as needed. Argon or any inert gas may be used to purge any unadsorbed precursors from the chamber. The substrate is exposed to a co-reactant 625, which is a reducing agent for reducing the Mo precursor. The reactant may be a hydrogen-containing reactant. In some embodiments, the hydrogen-containing reactant may be thermohydrogen (H2). A remote plasma or in-situ plasma is generated from H2. For thermal (non-plasma) processes, the partial pressure of the co-reactant may be controlled by at least 10 Torr to adjust selectivity. Lower reactant partial pressures increase selectivity by increasing the nucleation delay on the dielectric. High pressure may be used for short exposure times, and low pressure may be used for long exposure times. An optional purge may be performed at 635, after which operations 605–635 may be repeated until the film is fully grown. As described above, this may include fully filling the features and may include appropriately increasing the temperature to transition to a process with a higher deposition rate after the film has grown sufficiently from the bottom.

[0044] Figure 7 shows transmission electron microscope (TEM) images illustrating the results of selective ALD deposition using MoO2Cl2 at 400°C. Image 710 shows Mo selectively deposited on the Cu surface relative to the oxide sidewalls, and Image 720 shows the resulting excellent gap filling.

[0045] Device Figure 8 shows a schematic diagram of an embodiment of an ALD processing station 800 having a processing chamber 802 for maintaining a low-pressure environment. Multiple ALD processing stations may be provided in a common low-pressure processing tool environment. For example, Figure 9 shows an embodiment of a multi-station processing tool 900. In some embodiments, one or more hardware parameters of the ALD processing station 800, including those described in detail below, may be programmed by one or more computer controllers 850.

[0046] The ALD processing station 800 is in fluid communication with a reactant supply system 801a for supplying the process gas to a distribution showerhead 806. The reactant supply system 801a includes a mixing vessel 804 for mixing and / or adjusting the process gas, such as a Mo precursor-containing gas or a hydrogen-containing gas, for supply to the showerhead 806. One or more mixing vessel inlet valves 820 may control the introduction of the process gas into the mixing vessel 804. In various embodiments, selective deposition of the Mo film is performed in the processing station 800, and in some embodiments, other operations such as pretreatment may be performed in the same station or another station of the multi-station processing tool 900, as will be further described below with reference to Figure 9.

[0047] As an example, the embodiment in Figure 8 includes an evaporation point 803 for vaporizing the liquid reactants supplied to the mixing vessel 804. In some embodiments, the evaporation point 803 may be a heated vaporizer. In some embodiments, the liquid precursor or liquid reactants may be vaporized in a liquid injector (not shown). For example, the liquid injector may inject pulses of the liquid reactants into the carrier gas flow upstream of the mixing vessel 804. In one embodiment, the liquid injector may vaporize the reactants by rapidly changing the liquid from high pressure to low pressure. In another example, the liquid injector may atomize the liquid into dispersed droplets, which are then vaporized in a heated supply pipe. Small droplets vaporize faster than large droplets, which may reduce the delay between the liquid injector and complete evaporation. Rapid evaporation may reduce the length of piping downstream from the evaporation point 803. In one scenario, the liquid injector may be directly attached to the mixing vessel 804. In another scenario, the liquid injector may be directly attached to the showerhead 806.

[0048] In some embodiments, a liquid flow control device (LFC) may be provided upstream of the evaporation point 803 to control the liquid mass flow rate for supply to the evaporation and processing chamber 802. For example, the LFC may include a thermal mass flow meter (MFM) installed downstream thereof. The plunger valve of the LFC may then be adjusted in response to a feedback control signal provided by a proportional-integral-derivative action (PID) controller electrically connected to the MFM. However, stabilizing the liquid flow using feedback control may take more than one second. This may extend the time for dosing the liquid reactants. Therefore, in some embodiments, the LFC may be dynamically switched between a feedback control mode and a direct control mode. In some embodiments, this may be done by shutting down the LFC's sensing tube and PID controller.

[0049] The showerhead 806 distributes the processing gas toward the substrate 812. In the embodiment shown in Figure 8, the substrate 812 is located below the showerhead 806 and rests on a base 808. The showerhead 806 may have any suitable shape and may have any suitable number and arrangement of ports for distributing the processing gas toward the substrate 812.

[0050] In some embodiments, the base 808 may be raised and lowered to expose the substrate 812 to the space between the substrate 812 and the shower head 806. In some embodiments, the base 808 may be temperature-controlled by a heater 810. The base 808 may be set to any suitable temperature (e.g., about 350°C to about 450°C) during operation to carry out various embodiments of the disclosure. In some embodiments, the height of the base may be programmed to adjust by a suitable computer controller 850. At the end of the processing stage, the base 808 may be lowered during the transport stage of another substrate so that the substrate 812 can be removed from the base 808.

[0051] In some embodiments, the position of the shower head 806 may be adjusted relative to the base 808 so as to change the volume between the substrate 812 and the shower head 806. Furthermore, it will be found that the vertical position of the base 808 and / or the shower head 806 may be changed by any suitable mechanism within the scope of this disclosure. In some embodiments, the base 808 may have a pivot axis for rotating the orientation of the substrate 812. In some embodiments, it will be found that one or more of these exemplary adjustments may be programmed by one or more suitable computer controllers 850. The computer controllers 850 may include any of the features described below with respect to the controller 950 in Figure 9.

[0052] In some embodiments in which plasma may be used as described above, the showerhead 806 and base 808 are electrically connected to a radio frequency (RF) power supply 814 and a matching network 816 to power the plasma. In some embodiments, the plasma energy may be controlled by controlling one or more of the processing station pressure, gas concentration, RF source power, RF source frequency, and plasma power pulse timing. For example, the RF power supply 814 and the matching network 816 may be operated at any suitable power to form a plasma having radical species of a desired composition. Similarly, the RF power supply 814 may provide RF power at any suitable frequency. In some embodiments, the RF power supply 814 may be configured to control high-frequency and low-frequency RF power supplies independently of each other. Exemplary low-frequency RF frequencies may include, but are not limited to, frequencies between 0 and 900 kHz. Exemplary high-frequency RF frequencies may include, but are not limited to, frequencies between 1.8 MHz and 2.45 GHz, frequencies greater than approximately 13.56 MHz, frequencies greater than 27 MHz, frequencies greater than 80 MHz, or frequencies greater than 60 MHz. It will be found that any suitable parameters may be tuned individually or sequentially to provide the plasma energy for the surface reaction.

[0053] In some embodiments, the plasma may be monitored in-situ by one or more plasma monitors. In one scenario, plasma power may be monitored by one or more voltage-current sensors (e.g., VI probes). In another scenario, plasma density and / or process gas concentration may be measured by one or more emission spectroscopy (OES) sensors. In some embodiments, one or more plasma parameters may be programmed to adjust based on measurements from such in-situ plasma monitors. For example, OES sensors may be used in a feedback loop to provide programmed control of plasma power. In some embodiments, other monitors may be used to monitor plasma and other process characteristics. Such monitors may include, but are not limited to, infrared (IR) monitors, acoustic monitors, and pressure transducers.

[0054] In some embodiments, instructions for the controller 850 may be provided by input / output control (IOC) sequence instructions. For example, instructions for setting conditions for a processing stage may be included in the corresponding recipe stage of the process recipe. In some cases, process recipe stages may be arranged sequentially so that all instructions for a processing stage are executed simultaneously with that processing stage. In some embodiments, instructions for setting one or more reactor parameters may be included in the recipe stage. For example, a first recipe stage may include instructions for setting the flow rate of an inert gas and / or a reaction gas (e.g., a first precursor such as a Mo precursor), instructions for setting the flow rate of a carrier gas (e.g., argon), and a time delay instruction for the first recipe stage. A subsequent second recipe stage may include instructions for adjusting or stopping the flow rate of the inert gas and / or reaction gas, instructions for adjusting the flow rate of a carrier gas or purge gas, and a time delay instruction for the second recipe stage. A third recipe step may include instructions to adjust the flow rate of a second reaction gas, such as H2; instructions to adjust the flow rate of a carrier gas or purge gas; instructions to ignite the plasma; and instructions to delay the third recipe step. A subsequent fourth recipe step may include instructions to adjust or stop the flow rate of an inert gas and / or reaction gas; instructions to adjust the flow rate of a carrier gas or purge gas; and instructions to delay the fourth recipe step. These recipe steps may be further subdivided and / or repeated by any suitable means within the scope of this disclosure.

[0055] Furthermore, in some embodiments, pressure control of the processing station 800 may be provided by a butterfly valve 818. As shown in the embodiment of Figure 8, the butterfly valve 818 regulates the vacuum provided by a downstream vacuum pump (not shown). However, in some embodiments, pressure control of the processing station 800 may be regulated by changing the flow rate of one or more gases introduced into the processing station 800.

[0056] As described above, a multi-station processing tool may be equipped with one or more processing stations. Figure 9 shows a schematic diagram of an embodiment of a multi-station processing tool 900 comprising an input load lock 902 and an output load lock 904, either or both of which may be equipped with a remote plasma source (not shown). A robot 906 is configured to move a wafer at atmospheric pressure from a cassette loaded through a pod 908 to the input load lock 902 via an air inlet 910. The wafer (not shown) is placed on a pedestal 912 in the input load lock 902 by the robot 906, the air inlet 910 is closed, and the input load lock 902 is pumped down. If the input load lock 902 is equipped with a remote plasma source, the wafer may be exposed to remote plasma processing in the input load lock 902 before being introduced into the processing chamber 914. Furthermore, the wafer may be heated in the input load lock 902, for example, to remove moisture and adsorbed gases. Next, the chamber transport port 916 to the processing chamber 914 opens, and another robot (not shown) places the wafer for processing on the base of the first station shown inside the reactor. The embodiment shown in Figure 9 includes a load lock, but it will be seen that in some embodiments, direct loading of the wafer into the processing station may be provided.

[0057] The processing chamber 914 in the figure comprises four processing stations numbered 1 to 8 in the embodiment shown in Figure 9. Each station has a heating base (shown as 918 for station 1) and a gas line inlet. In some embodiments, each processing station may have different or more purposes. For example, in some embodiments, a processing station may be switchable between an ALD processing mode and a plasma-enhanced ALD processing mode. In some embodiments, exposure to the deposition precursor and exposure to the second reactant and plasma are carried out at the same station. In addition, or / or, in some embodiments, the processing chamber 914 may comprise one or more corresponding pairs of ALD processing stations and plasma-enhanced ALD processing stations. Furthermore, exposure to pretreatment gas or plasma and the ALD process may occur at the same station or different stations. Although the processing chamber 914 in the figure comprises four stations, it will be understood that the processing chamber according to this disclosure may have any suitable number of stations. For example, in some embodiments, the processing chamber may have five or more stations, while in other embodiments, the processing chamber may have three or fewer stations. Furthermore, in some embodiments, partial gap filling may be performed at the first station at the first pedestal temperature while the substrate has moved to the second station at the second pedestal temperature.

[0058] Figure 9 shows an embodiment of a wafer transport system 990 for transporting wafers within a processing chamber 914. In some embodiments, the wafer transport system 990 may transport wafers between various processing stations and / or between processing stations and load locks. It will be seen that any suitable wafer transport system may be used. Non-limiting examples include wafer carousels and wafer transport robots. Figure 9 also shows an embodiment of a system controller 950 used to control the process conditions and hardware state of the processing tool 900. The system controller 950 may comprise one or more memory devices 956, one or more mass storage devices 954, and one or more processors 952. The processor 952 may comprise a CPU or computer, analog and / or digital input / output connections, a stepper motor controller board, and the like.

[0059] In some embodiments, the system controller 950 controls all operations of the processing tool 900. The system controller 950 executes system control software 958, which is stored in a mass storage device 954, loaded into a memory device 956, and executed in the processor 952. Alternatively, the control logic may be hardcoded in the controller 950. For these purposes, application-specific integrated circuits, programmable logic devices (e.g., field-programmable gate arrays (FPGAs)), etc., may be used. Wherever the following description uses "software" or "code," functionally equivalent hardcoded logic may be used. The system control software 958 may include instructions for controlling timing, gas mixing, gas flow rate, chamber pressure and / or station pressure, chamber temperature and / or station temperature, plasma exposure period, ultraviolet period, wafer temperature, target power level, RF power level, substrate pedestal, chuck position and / or susceptor position, and other parameters of a particular process performed by the processing tool 900. The system control software 958 may be composed of any suitable means. For example, subroutines or control objects of various processing tool components may be written to control the operation of processing tool components used to execute processes of various processing tools. The system control software 958 may be coded in any suitable computer-readable programming language.

[0060] In some embodiments, the system control software 958 may include input / output control (IOC) sequence instructions for controlling the various parameters described above. In some embodiments, other computer software and / or programs stored in the mass storage device 954 and / or memory device 956 associated with the system controller 950 may be used. Examples of programs or program sections for this purpose include a substrate positioning program, a processing gas control program, a pressure control program, a heater control program, and a plasma control program.

[0061] The substrate positioning program may include program code for processing tool components used to place the substrate on the base 918 and to control the volume between the substrate and other components of the processing tool 900.

[0062] The processing gas control program may include code for controlling the gas composition (e.g., the organotungsten compound-containing gas described herein, the co-reaction gas, the gas for pretreatment, and the purge gas) and flow rate, and may optionally include code for flowing gas into one or more processing stations before loading in order to stabilize the pressure in the processing stations. The pressure control program may include code for controlling the pressure in the processing stations, for example, by controlling the throttle valves of the processing station's exhaust system, the gas flow to the processing stations, etc.

[0063] The heater control program may include code for controlling the current to a heating device used to heat the substrate. Alternatively, the heater control program may control the supply of a heat transfer gas (such as helium) to the substrate.

[0064] The plasma control program may, according to embodiments herein, include code for setting RF power levels to be applied to processing electrodes in one or more processing stations.

[0065] The pressure control program may include code for maintaining the pressure in the reaction chamber, according to the embodiments herein.

[0066] In some embodiments, there may be a user interface associated with the system controller 950. The user interface may include a display screen, an image software screen of the device and / or process conditions, and a user input device (such as a pointing device, keyboard, touch screen, microphone, etc.).

[0067] In some embodiments, the parameters adjusted by the system controller 950 may relate to process conditions. Non-limiting examples include the composition and flow rate of the process gas, temperature, pressure, and plasma conditions (e.g., RF bias power level). These parameters may be provided to the user in the form of a recipe that can be input using a user interface.

[0068] Signals for monitoring the process may be provided from various processing tool sensors via analog and / or digital input connections to the system controller 950. Signals for controlling the process may be outputs at analog and digital output connections to the processing tool 900. Non-limiting examples of processing tool sensors that can be monitored include mass flow controllers, pressure sensors (such as pressure gauges), and thermocouples. Appropriately programmed feedback and control algorithms may be used in conjunction with data from these sensors to maintain process conditions.

[0069] The system controller 950 may provide program instructions for carrying out the above deposition process. These program instructions may control various processing parameters such as DC power level, RF bias power level, pressure, and temperature. These instructions may control parameters for operating in-situ deposition of film layers according to various embodiments described herein.

[0070] The system controller 950 will typically include one or more memory devices and one or more processors configured to execute instructions so that the device carries out the method according to the embodiments of the disclosure. Instructions including a machine-readable medium for controlling processing operations according to embodiments of the disclosure may be coupled to the system controller 950.

[0071] In some embodiments, the system controller 950 is part of a system which may be part of the examples described above. Such a system may comprise a semiconductor processing apparatus including processing tools, chambers, processing platforms, and / or specific processing components (such as wafer pedestals and gas flow systems). These systems may be integrated with electronic equipment for controlling pre-processing, in-processing, and post-processing operations of semiconductor wafers or substrates. These electronic devices may be referred to as “controllers” that can control various components or sub-components of the system. Depending on the process conditions and / or the type of system, the system controller 950 may be programmed to control any of the processes disclosed herein, including the supply of processing gases, temperature settings (e.g., heating and / or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow rate settings, fluid supply settings, position operation settings, and wafer loading and unloading to and from tools and other transport tools and / or load locks connected to or coupled to a particular system.

[0072] Generally, the system controller 950 may be defined as an electronic device having various integrated circuits, logic, memory, and / or software that receive and issue instructions, control operations, enable cleaning operations, enable endpoint measurements, etc. The integrated circuit may include a firmware-type chip that stores program instructions, a chip defined as a digital signal processor (DSP), an application-specific integrated circuit (ASIC), and / or one or more microprocessors or microcontrollers that execute program instructions (e.g., software). Program instructions are instructions that are transmitted to the system controller 950 in the form of various individual settings (or program files) and may define operating parameters for executing a particular process on or for a semiconductor wafer or for the system. In some embodiments, the operating parameters may be part of a recipe defined by a process engineer to realize one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or one or more processing steps during the manufacturing of a wafer die.

[0073] In some embodiments, the system controller 950 may be part of a computer integrated with or coupled to the system, or otherwise networked to or a combination thereof. For example, the system controller 950 may be in a “cloud” that enables remote access to wafer processing, or it may be all or part of a fab host computer system. The computer may enable remote access to the system to monitor the progress of manufacturing operations, investigate the history of past manufacturing operations, investigate trends or performance criteria from multiple manufacturing operations, modify the parameters of the current operation, set up subsequent processing steps for the current operation, or start a new process. In some examples, a remote computer (e.g., a server) may provide process recipes to the system via a network that may include a local network or the internet. The remote computer may include a user interface that enables the entry or programming of parameters and / or settings that are then transmitted from the remote computer to the system. In some examples, the system controller 950 receives instructions in data format that specify the parameters of each processing step performed during one or more operations. It should be understood that the parameters may be specific to the type of process being performed and the type of tools configured to be connected to or controlled by the system controller 950. Thus, as described above, the system controller 950 may be distributed, for example, by including one or more separate controllers networked together and cooperating toward a common purpose, such as the processes and controls described herein. An example of controllers distributed toward such a purpose would be one or more integrated circuits on a chamber, which are located remotely (for example, at the platform level or as part of a remote computer) and communicate with one or more integrated circuits that cooperate to control the processes in the chamber.

[0074] Figures 8 and 9 provide examples of chambers and tools that may be used to carry out the methods disclosed herein, although various modifications may be made. These include the use of a CCP plasma generator or an ICP plasma generator, or the use of a remote plasma generator.

[0075] Rather than being limiting, the exemplary systems may include plasma etching chambers or modules, deposition chambers or modules, spin rinse chambers or modules, metal plating chambers or modules, cleaning chambers or modules, bevel edge etching chambers or modules, physical vapor deposition (PVD) chambers or modules, chemical vapor deposition (CVD) chambers or modules, atomic layer deposition (ALD) chambers or modules, atomic layer etching (ALE) chambers or modules, ion implantation chambers or modules, track chambers or modules, and other semiconductor processing systems that may be related to or used in the fabrication and / or manufacture of semiconductor wafers.

[0076] As described above, the system controller 950 may communicate with one or more of the following, depending on the processing steps performed by the tool: other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, nearby tools, tools installed throughout the factory, a main computer, another controller, or tools used for material transport to load and unload wafer containers to and from tool locations and / or load ports in a semiconductor manufacturing plant.

[0077] knot While the embodiments described above have been explained in some detail for clarity, it will be apparent that certain changes and modifications may be made within the scope of the appended claims. It should be noted that there are many other means of carrying out the processes, systems, and apparatus of these embodiments. Therefore, these embodiments should be considered illustrative rather than restrictive and should not be limited to the details described herein.

Claims

1. It is a method, A step of providing a substrate having a feature having a feature bottom and a feature sidewall, wherein the feature bottom includes a metal-containing surface and the feature sidewall includes an oxide surface or a nitride surface, A step of selectively depositing a molybdenum (Mo) film on a metal-containing surface on an oxide surface or a nitride surface by performing a multi-cycle atomic layer deposition (ALD) process, wherein the ALD process includes a step of exposing the feature to alternating pulses of a molybdenum-containing oxyhalide precursor and a reducing agent at a first substrate temperature. Methods that include...

2. The method according to claim 1, further, A method comprising the step of exposing the metal-containing surface to a hydrogen-containing plasma before carrying out the ALD deposition process for multiple cycles.

3. The method according to claim 1, The reducing agent is thermohydrogen (H 2 ) a method.

4. The method according to claim 1, The reducing agent is hydrogen (H 2 A method provided to plasma generated from ).

5. The method according to claim 1, A method wherein the partial pressure of the reducing agent is at least 10 Torr.

6. The method according to claim 1, The method wherein the molybdenum-containing precursor is molybdenum oxychloride.

7. The method according to claim 6, The first temperature is 600°C or lower, in this method.

8. The method according to claim 6, A method wherein the first temperature is 450°C or lower.

9. The method according to claim 6, A method wherein the first temperature is 400°C or lower.

10. A method according to any one of claims 7 to 9, A method wherein the first temperature is at least 350°C.

11. The method according to claim 1, The method wherein the molybdenum-containing precursor is molybdenum oxyfluoride.

12. The method according to claim 1, further, A method comprising the steps of partially filling the features while the substrate is at a first temperature, and completely filling the features while the substrate is at a second temperature, wherein the second temperature is higher than the first temperature.

13. A method according to claim 12, A method wherein the partial filling step is performed at a first station of the processing chamber, and the complete filling step is performed at a second station of the processing chamber.

14. The method according to claim 1, The metal-containing surface is one of the materials from the group consisting of cobalt, ruthenium, copper, tungsten, molybdenum, titanium, tin, tantalum, nickel, iridium, and rhodium, in a method.

15. The method according to claim 1, The metal-containing surface is one of the materials from the group consisting of titanium nitride, molybdenum nitride, tungsten nitride, tungsten carbonitride, titanium aluminum carbide, titanium silicide, and tantalum nitride, in a method.

16. The method according to claim 1, The method wherein the metal-containing surface is a metal element surface.

17. The method according to claim 1, The method wherein the sidewall comprises an oxide selected from polyethylene oxide, tetraethyl orthosilicate, a fluid oxide, and a carbon-doped oxide.

18. The method according to claim 1, A method wherein the Mo film on the metal-containing film is at least about 20 Å thicker than the Mo film on the oxide surface or nitride surface of the side wall.

19. It is a method, A step of providing a substrate having a feature having a feature bottom and a feature sidewall, wherein the feature bottom includes a metal-containing surface and the feature sidewall includes an oxide surface or a nitride surface, A step of performing a deposition process to selectively deposit a molybdenum (Mo) film on the metal-containing surface of the oxide surface or the nitride surface, wherein the deposition process includes a step of exposing the feature to a molybdenum-containing oxyhalide precursor and a reducing agent at a first substrate temperature. Methods that include...

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