Molybdenum Deposition

Abstract

A method for filling pattern features with molybdenum (Mo) is provided. The method includes selectively depositing a Mo film on the bottom metal-containing surfaces of the feature, including dielectric sidewalls. The selective growth of Mo on the bottom surface enables bottom-up growth, resulting in high-quality, void-free filling. Related apparatus is also provided.

Description

[Background technology]

[0001] [Incorporated by reference] PCT applications are filed concurrently herewith as part of this application. Each application to which this application claims the benefit of or priority to a concurrently filed PCT application is hereby incorporated by reference in its entirety for all purposes.

[0002] The Background Art set forth herein is intended to present the contents of the present disclosure generally, and the inventions of the presently named inventors are not admitted expressly or impliedly as prior art to the present disclosure to the extent that they are described in this Background Art section and in a descriptive manner that does 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 methods are used in the industry, uniform deposition of low-resistivity metal films becomes more challenging. Summary of the Invention

[0004] A method for filling pattern features with molybdenum (Mo) is provided. The method includes selectively depositing a Mo film on the bottom metal-containing surfaces of the feature, including dielectric sidewalls. The selective growth of Mo on the bottom surface enables bottom-up growth, resulting in high-quality, void-free filling. Related apparatus is also provided.

[0005] One aspect of the present disclosure relates to a method that includes providing a substrate including a feature having a feature bottom and feature sidewalls, wherein the feature bottom comprises a metal-containing surface and the feature sidewalls comprise an oxide or nitride surface; and performing a multiple cycle atomic layer deposition (ALD) process to selectively deposit a molybdenum (Mo) film on the metal-containing surface relative to the oxide or nitride surface, the ALD process exposing 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 exposing the metal-containing surface to a hydrogen-containing plasma before performing the multiple cycles of the ALD deposition process. In some embodiments, the reducing agent is hot hydrogen (H). In some embodiments, the reducing agent is provided to the plasma generated from hydrogen (H). In some embodiments, the reducing agent has a partial pressure of 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 partially filling the feature while the substrate is at the first temperature and completely filling the feature (or filling a second portion of the feature) while the substrate is at a second temperature higher than the first temperature. In some such embodiments, partial filling of the feature occurs in a first station of the processing chamber, and complete filling of the feature (or filling of a second portion of the feature) occurs in a second station of the processing chamber. In some embodiments, the metal-containing surface is one of a 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 of a 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 an elemental metal surface. In some embodiments, the sidewall comprises an oxide. Examples of oxides include polyethylene oxide, tetraethyl orthosilicate, flowable oxide, and carbon-doped oxide. In some embodiments, the Mo film on the metal-containing film has a thickness greater 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: providing a substrate including a feature having a feature bottom and feature sidewalls, wherein the feature bottom comprises a metal-containing surface and the feature sidewalls comprise an oxide or nitride surface; and performing a deposition process to selectively deposit molybdenum (Mo) on the metal-containing surface relative to the oxide or nitride surface, the deposition process comprising 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 exposing the metal-containing surface to a hydrogen-containing plasma before performing the deposition process. In some embodiments, the metal-containing surface may be exposed to other treatments, examples of which include a halogen-containing plasma, such as a chlorine (Cl-)-based plasma. In some embodiments, the reducing agent is hot hydrogen (H2). In some embodiments, the reducing agent is provided in a plasma generated from hydrogen (H2). In some embodiments, the reducing agent has a partial pressure of 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 partially filling the feature while the substrate is at a first temperature and completely filling the feature (or filling a second portion of the feature) while the substrate is at a second temperature higher than the first temperature. In some embodiments, partial filling of the feature is performed in a first station of the processing chamber, and complete filling of the feature (or filling of a second portion of the feature) is performed in 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 an elemental metal surface. In some embodiments, the sidewall comprises an oxide. Examples of oxides include polyethylene oxide, tetraethyl orthosilicate, flowable oxide, and carbon-doped oxide. In some embodiments, the Mo film on the metal-containing film has a thickness greater than the Mo film on the oxide or nitride surface of the sidewall.

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

[0010] [Figure 1] 1 illustrates an exemplary molybdenum (Mo) interconnect according to various embodiments.

[0011] [Figure 2] 1A-1C are exemplary pattern features upon which selective deposition of Mo films may be performed according to various embodiments.

[0012] [Figure 3] 1 illustrates an exemplary selective deposition method for filling a feature with molybdenum, according to various embodiments.

[0013] [Figure 4] 4A-4C are exemplary cross-sectional schematic views of pattern features after certain operations of a method according to certain embodiments of FIG. 3. [Figure 5] 4A-4C are exemplary cross-sectional schematic views of pattern features after certain operations of a method according to certain embodiments of FIG. 3.

[0014] [Figure 6A] 1 is an exemplary apparatus that includes a gas manifold system and may be used in accordance with various embodiments.

[0015] [Figure 6B] 1 illustrates an exemplary method for selectively depositing a Mo layer by ALD, according to various embodiments.

[0016] [Figure 7] Images of Mo gap-fill development in a via structure with deposition over Cu, where image (a) shows selective partial Mo filling and image (b) shows complete Mo filling without seams or voids.

[0017] [Figure 8] 1 is a schematic diagram of an exemplary processing chamber for practicing certain disclosed embodiments.

[0018] [Figure 9] 1 is a schematic diagram of an exemplary processing tool for implementing certain disclosed embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0019] A method for filling pattern features with molybdenum (Mo) is provided. The method includes selectively depositing a Mo film on the bottom metal-containing surfaces of the feature, including dielectric sidewalls. The selective growth of Mo on the bottom surface enables bottom-up growth, resulting in high-quality, void-free filling.

[0020] 1 depicts an example feature 100 according to various embodiments. The feature 100 comprises 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 electrical connection to an underlying contact.

[0021] In some embodiments, the bottom surface 102 is a metal-containing surface. The metal-containing surface may comprise 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 an elemental metal surface. Exposure to moisture may result in the formation of some oxides on the metal-containing surface. In some embodiments, the metal-containing surface may be titanium nitride (TiN), molybdenum nitride (MoN), or other suitable oxides. x ), tungsten nitride (WN), tungsten carbonitride (WC x N y ), titanium aluminum carbide (TiAl x C yExamples include titanium silicide (TiSi2), or tantalum nitride (TaN) surfaces. These surfaces may exhibit selectivity to dielectric oxides.

[0022] As used herein, oxide surfaces include alkoxides such as tetraethoxysilane (TEOS), fluorosilicate glass (FSG), flowable oxides, spin-on glass, carbon-doped oxides, etc. In some embodiments, the oxide surface is a silicon-based oxide, using the examples 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-based oxides, including tetraethoxysilane (TEOS) oxides, flowable silicon-based oxides, carbon-doped silicon-based oxides, and the like. These surfaces may be part of the main dielectric layer surrounding the feature. Selectivity refers to the preference of deposition on a metal surface, such as a Co, W, or Cu surface, relative to a dielectric surface. Selectivity may be quantified as a deposition rate ratio or a ratio of deposition thicknesses after a certain number of deposition cycles.

[0024] In some embodiments, the sidewall surface may be a nitride (e.g., Si) rather than an oxide. x N y The nitride may be a silicon-based nitride or a silicon-based oxynitride. The selectivity of Mo deposition over nitrides in metal elements is similar to the selectivity over 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-the-line (MOL) structure, or a back-end-of-the-line (BEOL) structure.

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

[0027] Feature 220 illustrates an example of a pattern feature having a re-entrant profile that narrows from the bottom of the feature toward the feature opening 214. The re-entrant profile may include a protrusion into the feature opening 214. Feature 230 illustrates a feature having a metal undercut profile. According to various embodiments, this profile has a metal-containing surface below 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] FIG. 3 is a flow diagram illustrating an example of a selective deposition method 300 for filling a feature with a Mo film. FIGS. 4 and 5 illustrate cross-sectional schematic views of an exemplary pattern feature after certain operations of the method embodiment of FIG. 3. Specifically, at 410 in FIG. 4, the pattern feature is shown before application of the selective deposition method 300. The pattern feature may be, for example, an etched feature. The pattern feature comprises a bottom surface 402 and sidewall surfaces 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 FIG. 3, pretreatment of features, including metal-containing and dielectric surfaces, is performed as needed. Pretreatment may include exposing the feature to a reducing agent, such as a hydrogen species, to reduce any metal oxides on the metal-containing surface. Pretreatment of the feature may include exposing the feature to a hydrogen-containing plasma. In some embodiments, the hydrogen-containing plasma is generated from hydrogen gas (H). For some surfaces, an H-based plasma may not be effective in reducing metal oxides or preparing the surface. In such cases, other treatments may be used. In one example, a halogen-based plasma may be used to treat a silicide surface, such as a TiSi surface. Examples include plasmas generated from chlorine (Cl) and / or boron trichloride (BCl).

[0030] If performed, the pretreatment may be a plasma treatment or, in some embodiments, a thermal treatment. Thermal treatment may involve exposing the surface to a gas in a non-plasma environment. In one example, hydrogen fluoride (HF) may be used to treat metal silicides, such as TiSi2, and other metal compounds or metal surfaces. If a plasma treatment is performed, it may be a remote plasma or an in-situ plasma. In-situ plasma refers to plasma generated within the chamber containing the substrate, generally without a filter interposed between the substrate and the generated plasma, and may include ions and radicals. Remote plasma refers to plasma generated remotely from the substrate, and may be generated in a dome or other space that is part of or connected to the chamber in which the substrate resides, or in a separate, stand-alone device. A showerhead or other filter is generally interposed between the generator and the substrate. In some embodiments, the remote plasma contains only radicals or other neutral species, but no ions. 420 in FIG. 4 is an embodiment of feature 410 after operation 305 is performed. In this embodiment, metal-containing surface 402 no longer contains metal oxide.

[0031] Figure 3Returning to block 315, selective growth of a Mo film on the metal-containing surface is performed. Selective deposition refers to deposition on the metal-containing surface preferentially relative to an oxide or nitride surface. Therefore, the infill formed on the metal-containing surface is thicker than the infill formed on the oxide or nitride surface. This is shown at 430 in FIG. 4 , which illustrates the initiation of selective deposition of a Mo film 408. Nucleation of the Mo film 408 begins 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 can result in large grains and / or low resistivity. Selective deposition may be used during ALD (further described 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. x O y H z where H is a halogen (fluorine (F), chlorine (Cl), bromine (Br), or iodine (I)) (x, y, and z are numbers greater than zero that can form a stable molecule). Examples of Mo precursors are molybdenum oxide tetrafluoride (MoOF4), molybdenum oxide tetrachloride (MoOCl4), molybdenum dioxide dichloride (MoO2Cl2), molybdenum dioxide dibromide (MoO2Br2), and molybdenum oxyiodides MoO2I and Mo4O 11 I. The reducing agent reacts with the molybdenum oxyhalide to form elemental molybdenum. In some embodiments, the reducing agent is hot hydrogen or plasma hydrogen (H).

[0033] Temperature affects selectivity, grain size, and resistivity. High temperatures can reduce the selectivity of the Mo film, potentially resulting in growth of oxides or nitrides on the sidewall surfaces 404 as well as on the metal-containing bottom surface 402. However, too low a temperature can increase impurity levels, reduce grain size, and increase resistivity. Substrate temperatures can range from 350 to 600°C for selectively depositing Mo using chlorine-containing chemistries. As noted above, selectivity can improve as the temperature decreases. Thus, in some embodiments, the substrate temperature can be about 350 to 550°C, or 350 to 450°C, for chlorine-containing precursors. For fluorine-containing chemistries, the substrate temperature can be lower (e.g., 150 to 350°C).

[0034] At block 325 of Figure 3, the feature is filled with Mo. The start of the Mo filling process is shown at 430 of Figure 4. A Mo film 408 may continue to grow on the metal-containing surface 402. At 404, the Mo film may begin to nucleate on oxides or nitrides on the sidewall surfaces 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 sidewalls 404.

[0035] In some embodiments, a multi-step Mo deposition is performed. In FIG. 4 , the initial stages, where selective deposition is performed, are represented by 430 and 440. A second stage, where deposition conditions are changed to increase deposition rate and throughput, is represented by 450. In 450, conformal growth occurs (rather than bottom-up or non-conformal growth). By increasing the substrate temperature, the growth rate of the Mo film 408 from both the bottom and the sidewalls increases, shortening the time to fill the feature. In the example of FIG. 4 , the temperature is increased after some amount of film nucleation on the sidewall surfaces. In other embodiments, no Mo may nucleate on some or all of the sidewall surfaces above the bottom-up film growth portion. The increased temperature allows nucleation on these sidewall surfaces. This may be appropriate once the feature is sufficiently filled so that conformal growth can be used to obtain good feature fill without risk of voids. The temperature may be increased to at least 50° C., at least 100° C., or at least 150° C., and may be at least 500° C., and as high as 800° C., provided the thermal budget in the device structure allows.

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

[0037] Deposition of pure metal films from oxygen-containing precursors is challenging due to the ease with which oxygen is incorporated into the film during the deposition process. When oxygen is incorporated, resistance increases. The methods and apparatus described herein may be implemented in some embodiments to deposit pure metal films with less than 1 atomic % oxygen. The ratio of reducing agent to metal oxyhalide precursor is significantly greater than 1, and the deposited film contains 1 atomic % or less oxygen. A molar ratio of at least 100:1 may be used. In some embodiments, the deposited film has a 1E18 atom / cm 3 The halogen concentration is: 0.01 to 0.1; 0.02 to 0.1; 0.03 to 0.1; 0.04 to 0.2; 0.05 to 0.1; 0.06 to 0.2; 0.07 to 0.1; 0.08 to 0.2; 0.09 to 0.3; 0.10 to 0.2; 0.11 to 0.1; 0.12 to 0.2; 0.13 to 0.2; 0.14 to 0.2; 0.15 to 0.3; 0.16 to 0.2; 0.17 to 0.3; 0.18 to 0.2; 0.19 to 0.3; 0.20 to 0.2; 0.21 to 0.2; 0.22 to 0.2; 0.23 to 0.2; 0.24 to 0.2; 0.25 to 0.3; 0.26 to 0.27; 0.27 to 0.3; 0.28 to 0.3; 0.29 to 0.3; 0.30 to 0.3; 0.31 to 0.3; 0.32 to 0.3; 0.33 to 0.3; 0.34 to 0.3; 0.35 to 0.3; 0.36 to 0.37; 0.38 to 0.3; 0.39 to 0.4; 0.40 to 0.4; 0.41 to 0.4; 0.42 to 0.4; 0.43 to 0.4; 0.44 to 0.4; 0.45 to 0.4; 0.46 to 0.4; 0.47 to 0.

[0038] In processes such as pulsed ALD, the number of reducing agent pulses can be greater than the number of precursor pulses in some embodiments. This method can be implemented using multiple fill vessels. FIG. 6A shows a schematic of an exemplary apparatus in which three gas sources (precursor, H, and purge gas) are connected to fill vessels. The apparatus includes a gas manifold system that provides line fill to various gas distribution lines. The manifold provides precursor, reducing, and purge gases to the deposition chamber through valved fill vessels. Various valves open and close to provide the line fill, i.e., pressurize the distribution lines. In various embodiments, the number of reducing agent fill vessels (total fill volume) can be greater than the number of precursor and / or purge gas fill vessels. Multiple pulses of reducing agent per precursor pulse enable rapid reduction of the oxygen-containing precursor to deposit high-purity, low-resistivity metal films. In some embodiments, multiple fill vessels can be used for not only the precursor but also the reducing agent. This allows multiple pulses to be introduced to fully reduce the oxygen-containing precursor.

[0039] The reducing agent to precursor ratio may be characterized as the ratio of molecules to which the substrate is exposed and available to react;

number

number

[0040] The above formula is a molar ratio, and exemplary 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 may be characterized as a volume ratio:

number

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

[0043] In some embodiments, an ALD process is used to selectively deposit Mo. FIG. 6B is a flow diagram illustrating operations in an ALD process. In 605, a Mo precursor is pulsed. As described above, the Mo precursor is a molybdenum-containing oxyhalide precursor that adsorbs onto the substrate. After the Mo precursor is pulsed, an optional purge 615 may occur. Argon or any inert gas may be used to purge any non-adsorbed precursor 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 thermal hydrogen (H). A remote plasma or in-situ plasma is generated from H. For thermal (non-plasma) processes, the co-reactant partial pressure may be controlled at least 10 Torr to adjust selectivity. A low reactant partial pressure increases selectivity by increasing nucleation delay on the dielectric. High pressures may be used with short exposure times, and low pressures may be used with long exposure times. An optional purge may be performed in 635, after which operations 605-635 may be repeated until the film is fully grown. As noted above, this may include completely filling the feature, and may include appropriately increasing the temperature to transition to a higher deposition rate process after the film has fully grown from the bottom.

[0044] 7 shows transmission electron microscope (TEM) images showing 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 FIG. 8 depicts 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, FIG. 9 depicts 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 programmatically adjusted by one or more computer controllers 850.

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

[0047] As an example, the embodiment of FIG. 8 includes an evaporation point 803 for vaporizing a liquid reactant 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 reactant may be vaporized in a liquid injector (not shown). For example, the liquid injector may inject pulses of the liquid reactant into a carrier gas stream upstream of the mixing vessel 804. In one embodiment, the liquid injector may vaporize the reactant 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 may then be vaporized in a heated feed tube. Small droplets may vaporize faster than large droplets, reducing the delay between the liquid injector and full evaporation. Faster evaporation may reduce the length of tubing downstream from the evaporation point 803. In one situation, the liquid injector may be attached directly to the mixing vessel 804. In another situation, the liquid injector may be attached directly to the showerhead 806.

[0048] In some embodiments, a liquid flow controller (LFC) may be provided upstream of the evaporation point 803 to control the liquid mass flow rate for evaporation and delivery to the processing chamber 802. For example, the LFC may include a thermal mass flow meter (MFM) located 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 in electrical communication with the MFM. However, stabilizing the liquid flow using feedback control can take more than one second, which may extend the time to dose the liquid reactant. Thus, 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 accomplished by shutting down the sensing tube and PID controller of the LFC.

[0049] 8, the substrate 812 is shown positioned below the showerhead 806 and resting on a pedestal 808. The showerhead 806 may have any suitable shape and may have any suitable number and arrangement of ports for distributing the process gases to the substrate 812.

[0050] In some embodiments, the pedestal 808 may be raised or lowered to expose the substrate 812 to the space between the substrate 812 and the showerhead 806. In some embodiments, the pedestal 808 may be temperature controlled by a heater 810. The pedestal 808 may be set to any suitable temperature (e.g., about 350° C. to about 450° C.) during operation to perform various disclosed embodiments. It will be appreciated that in some embodiments, the height of the pedestal may be programmatically adjusted by a suitable computer controller 850. At the end of a processing step, the pedestal 808 may be lowered during another substrate transfer step to allow removal of the substrate 812 from the pedestal 808.

[0051] In some embodiments, the position of the showerhead 806 may be adjusted relative to the pedestal 808 to change the volume between the substrate 812 and the showerhead 806. Furthermore, it will be appreciated that the vertical position of the pedestal 808 and / or the showerhead 806 may be changed by any suitable mechanism within the scope of the present disclosure. In some embodiments, the pedestal 808 may include a rotation axis for rotating the orientation of the substrate 812. It will be appreciated that in some embodiments, one or more of these exemplary adjustments may be programmatically implemented by one or more suitable computer controllers 850. The computer controller 850 may include any of the features described below with respect to the controller 950 of FIG. 9.

[0052] In some embodiments where a plasma may be used as described above, the showerhead 806 and pedestal 808 are in electrical communication with a radio frequency (RF) power source 814 and matching network 816 to power the plasma. In some embodiments, the plasma energy may be controlled by controlling one or more of the process station pressure, gas concentration, RF source power, RF source frequency, and plasma power pulse timing. For example, the RF power source 814 and matching network 816 may be operated at any suitable power to form a plasma having a desired composition of radical species. Similarly, the RF power source 814 may provide RF power at any suitable frequency. In some embodiments, the RF power source 814 may be configured to control high-frequency and low-frequency RF power 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 about 13.56 MHz, frequencies greater than 27 MHz, frequencies greater than 80 MHz, or frequencies greater than 60 MHz. It will be appreciated that any suitable parameters may be adjusted individually or continuously to provide plasma energy for surface reactions.

[0053] In some embodiments, the plasma may be monitored in situ by one or more plasma monitors. In one situation, plasma power may be monitored by one or more voltage and current sensors (e.g., VI probes). In another situation, plasma density and / or process gas concentration may be measured by one or more optical emission spectroscopy (OES) sensors. In some embodiments, one or more plasma parameters may be programmatically adjusted based on measurements from such in-situ plasma monitors. For example, OES sensors may be used in a feedback loop to provide programmatic control of plasma power. It will be appreciated that in some embodiments, other monitors may be used to monitor the 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. In one example, instructions for setting conditions for a process step may be included in a corresponding recipe step of a process recipe. In some cases, process recipe steps may be arranged sequentially so that all instructions for a process step are executed simultaneously with that process step. In some embodiments, instructions for setting one or more reactor parameters may be included in a recipe step. For example, a first recipe step may include instructions for setting the flow rate of an inert gas and / or a reactive 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 step. A subsequent second recipe step may include instructions for adjusting or stopping the flow rate of an inert gas and / or a reactive gas, instructions for adjusting the flow rate of a carrier gas or purge gas, and a time delay instruction for the second recipe step. The third recipe step may include instructions to adjust the flow rate of a second reactant gas, such as H2, instructions to adjust the flow rate of a carrier or purge gas, instructions to ignite a plasma, and a time delay instruction for 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 a reactant gas, instructions to adjust the flow rate of a carrier or purge gas, and a time delay instruction for the fourth recipe step. It will be appreciated that these recipe steps may be further subdivided and / or repeated in any suitable manner within the scope of the present disclosure.

[0055] Additionally, 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 adjusted by changing the flow rate of one or more gases introduced into the processing station 800.

[0056] As noted above, a multi-station processing tool may include one or more processing stations. FIG. 9 shows a schematic diagram of an embodiment of a multi-station processing tool 900 including an input load lock 902 and an output load lock 904, either or both of which may include a remote plasma source (not shown). A robot 906 is configured to move wafers at atmospheric pressure from a cassette loaded via a pod 908 to the input load lock 902 through an atmospheric vent 910. The wafer (not shown) is placed on a pedestal 912 in the input load lock 902 by the robot 906, the atmospheric vent 910 is closed, and the input load lock 902 is pumped down. If the input load lock 902 includes a remote plasma source, the wafer may be exposed to a remote plasma treatment in the input load lock 902 before being introduced into the processing chamber 914. Additionally, the wafer may be heated in the input load lock 902, for example, to remove moisture and adsorbed gases. A chamber transfer port 916 to the processing chamber 914 then opens, and another robot (not shown) places the wafer on a pedestal in the first station shown in the reactor for processing. It will be appreciated that although the embodiment shown in Figure 9 includes a load lock, some embodiments may provide for direct wafer entry into the processing stations.

[0057] The illustrated processing chamber 914 is shown in the embodiment shown in FIG. From 4The illustrated processing chamber 914 includes four processing stations, numbered 918-919. Each station has a heated pedestal (shown at 918 for station 1) and a gas line inlet. It will be appreciated that in some embodiments, each processing station may have a different or multiple purposes. For example, in some embodiments, the processing station may be switchable between an ALD processing mode and a plasma-enhanced ALD processing mode. In some embodiments, exposure to a deposition precursor and exposure to a second reactant and plasma are performed in the same station. Additionally or alternatively, in some embodiments, the processing chamber 914 may include one or more matched pairs of ALD processing stations and plasma-enhanced ALD processing stations. Furthermore, exposure to a pre-treatment gas or plasma and the ALD process may occur in the same station or in different stations. While the illustrated processing chamber 914 includes four stations, it will be understood that a processing chamber according to the present 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. Additionally, in some embodiments, partial gap filling may be performed at a first pedestal temperature in the first station, with the substrate being moved to a second station at a second pedestal temperature.

[0058] FIG. 9 illustrates an embodiment of a wafer transport system 990 for transporting wafers within the 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 appreciated that any suitable wafer transport system may be used. Non-limiting examples include a wafer carousel and a wafer transport robot. FIG. 9 also illustrates an embodiment of a system controller 950 used to control the process conditions and hardware states of the processing tool 900. The system controller 950 may include one or more memory devices 956, one or more mass storage devices 954, and one or more processors 952. The processor 952 may include a CPU or computer, analog and / or digital input / output connections, a stepper motor controller board, etc.

[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 on the mass storage device 954, loaded into the memory device 956, and executed on the processor 952. Alternatively, the control logic may be hard-coded 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. In the following description, where "software" or "code" is used, functionally equivalent hard-coded logic may be used. The system control software 958 may include instructions for controlling the timing, mixture of gases, gas flow rates, chamber and / or station pressures, chamber and / or station temperatures, plasma exposure duration, UV duration, wafer temperature, target power levels, RF power levels, substrate pedestal, chuck and / or susceptor position, and other parameters of a particular process performed by the processing tool 900. The system control software 958 may be configured by any suitable means. For example, various processing tool component subroutines or control objects may be written to control the operation of the processing tool components used to perform the various processing tool processes. 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 on 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 process 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 the processing tool components used to load the substrate onto the pedestal 918 and control the volume between the substrate and other components of the processing tool 900 .

[0062] The process gas control program may include code for controlling the composition and flow rates of gases (e.g., organotungsten compound-containing gases described herein, co-reactant gases, gases for performing pretreatment, and purge gases), and may include code for flowing gases to one or more process stations prior to deposition, as needed, to stabilize the pressure within the process stations. The pressure control program may include code for controlling the pressure within the process stations, for example, by controlling throttle valves in the exhaust systems of the process stations, gas flows to the process stations, etc.

[0063] The heater control program may include code for controlling the current to a heating device used to heat the substrate, or 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 include code for setting RF power levels applied to process electrodes in one or more process stations according to embodiments herein.

[0065] The pressure control program may include code for maintaining pressure within the reaction chamber according to 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, software screens with images of equipment and / or process conditions, and user input devices (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 process gas composition and flow rates, temperature, pressure, plasma conditions (e.g., RF bias power levels), etc. These parameters may be provided to the user in the form of a recipe, which may be input using a user interface.

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

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

[0070] System controller 950 will typically include one or more memory devices and one or more processors configured to execute instructions such that the device performs methods according to embodiments of the disclosure. Machine-readable media containing instructions for controlling processing operations according to embodiments of the present disclosure may be coupled to system controller 950.

[0071] In some embodiments, the system controller 950 is part of a system that may be part of the examples described above. Such systems may include semiconductor processing equipment, 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 electronics for controlling operations before, during, and after semiconductor wafer or substrate processing. These electronics may be referred to as "controllers" that can control various components or subcomponents of the system. Depending on the process conditions and / or the type of system, the system controller 950 may be programmed to control any process disclosed herein, including supply of process 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, wafer transfer to and from the tool and other transfer tools and / or load locks connected or coupled to the specific system.

[0072] Generally, system controller 950 may be defined as electronic equipment having various integrated circuits, logic, memory, and / or software that receive instructions, issue instructions, control operations, enable cleaning operations, enable endpoint measurements, etc. Integrated circuits may include chips in firmware format that store program instructions, digital signal processors (DSPs), chips defined as application-specific integrated circuits (ASICs), and / or one or more microprocessors or microcontrollers that execute program instructions (e.g., software). Program instructions may be instructions communicated to system controller 950 in the form of various personalizations (or program files) that define operational parameters for performing particular processes on or for semiconductor wafers or for the system. In some embodiments, the operational parameters may be part of a recipe defined by a process engineer to achieve one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or one or more processing steps during the fabrication of wafer dies.

[0073] In some embodiments, the system controller 950 may be part of or coupled to a computer integrated with, coupled to, or otherwise networked to the system. For example, the system controller 950 may be in the “cloud” to enable remote access of wafer processing, or 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, examine the history of past manufacturing operations, examine trends or performance metrics from multiple manufacturing operations, and modify parameters of a current process, set up processing steps following a current process, or initiate a new process. In some examples, a remote computer (e.g., a server) may provide process recipes to the system over a network, which may include a local network or the Internet. The remote computer may include a user interface that enables entry or programming of parameters and / or settings, which are then communicated to the system from the remote computer. In some examples, the system controller 950 receives instructions in the form of data specifying parameters for each processing step to be 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 that the system controller 950 is configured to connect to or control. 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 process or control described herein. An example of a distributed controller for such a purpose would be one or more integrated circuits on the chamber that are located remotely (e.g., at the platform level or as part of a remote computer) and communicate with one or more integrated circuits that cooperate to control the process in the chamber.

[0074] 8 and 9 provide examples of chambers and tools that may be used to practice the methods disclosed herein, although various modifications may be made, including the use of CCP or ICP plasma generators, or the use of remote plasma generators.

[0075] Without being limited thereto, example systems may include plasma etch chambers or modules, deposition chambers or modules, spin rinse chambers or modules, metal plating chambers or modules, cleaning chambers or modules, bevel edge etch 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 etch (ALE) chambers or modules, ion implantation chambers or modules, track chambers or modules, and other semiconductor processing systems related to or usable in the fabrication and / or manufacturing of semiconductor wafers.

[0076] As described above, depending on the processing steps being performed by the tool, the system controller 950 may be in communication with one or more of other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, nearby tools, tools located throughout the factory, a main computer, another controller, or tools used to transport materials to and from tool locations and / or load ports in a semiconductor fabrication factory to transport wafer containers.

[0077] Conclusion Although the foregoing embodiments have been described in some detail for clarity of understanding, 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 alternative ways of implementing the processes, systems, and apparatus of the present embodiments. Accordingly, the present embodiments should be regarded as illustrative rather than restrictive, and should not be limited to the details set forth herein. The present invention can be realized, for example, in the following manner. Application example 1: 1. A method comprising: providing a substrate comprising a feature having a feature bottom and feature sidewalls, the feature bottom comprising a metal-containing surface and the feature sidewalls comprising an oxide or nitride surface; performing a multiple-cycle atomic layer deposition (ALD) process to deposit a molybdenum (Mo) film selectively on the metal-containing surface relative to the oxide or nitride surface, the ALD process comprising exposing the feature to alternating pulses of a molybdenum-containing oxyhalide precursor and a reducing agent at a first substrate temperature; A method comprising: Application example 2: The method according to Application Example 1, further comprising: exposing the metal-containing surface to a hydrogen-containing plasma prior to performing the multiple cycles of the ALD deposition process. Application example 3: The method according to Application Example 1, The reducing agent is hot hydrogen (H 2 ) is a method. Application example 4: The method according to Application Example 1, The reducing agent is hydrogen (H 2 ) to the plasma generated from the method. Application example 5: The method according to Application Example 1, The method wherein the partial pressure of the reducing agent is at least 10 Torr. Application example 6: The method according to Application Example 1, The method wherein the molybdenum-containing precursor is molybdenum oxychloride. Application example 7: The method according to Application Example 6, The method wherein the first temperature is 600°C or less. Application example 8: The method according to Application Example 6, The method wherein the first temperature is 450°C or less. Application example 9: The method according to Application Example 6, The method wherein the first temperature is 400°C or less. Application example 10: The method according to any one of Application Examples 7 to 9, The method wherein the first temperature is at least 350°C. Application example 11: The method according to Application Example 1, The method wherein the molybdenum-containing precursor is a molybdenum oxyfluoride. Application example 12: The method according to Application Example 1, further comprising: partially filling the feature while the substrate is at the first temperature and completely filling the feature while the substrate is at a second temperature, the second temperature being greater than the first temperature. Application example 13: The method according to Application Example 12, The method, wherein the partially filling step occurs in a first station of a processing chamber and the fully filling step occurs in a second station of the processing chamber. Application 14: The method according to Application Example 1, The method wherein 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. Application example 15: The method according to Application Example 1, The method wherein 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. Application 16: The method according to Application Example 1, The method wherein the metal-containing surface is an elemental metal surface. Application 17: The method according to Application Example 1, The method, wherein the sidewall comprises an oxide selected from polyethylene oxide, tetraethyl orthosilicate, flowable oxide, and carbon-doped oxide. Application 18: The method according to Application Example 1, The method, wherein the Mo film on the metal-containing film is at least about 20 Å thicker than the Mo film on the oxide or nitride surfaces of the sidewalls. Application 19: 1. A method comprising: providing a substrate comprising a feature having a feature bottom and feature sidewalls, the feature bottom comprising a metal-containing surface and the feature sidewalls comprising an oxide or nitride surface; performing a deposition process to deposit a molybdenum (Mo) film selectively on the metal-containing surface relative to the oxide surface or the nitride surface, the deposition process comprising exposing the feature to a molybdenum-containing oxyhalide precursor and a reducing agent at a first substrate temperature; A method comprising:

Claims

1. 1. A method comprising: providing a substrate comprising a feature having a feature bottom and feature sidewalls, the feature bottom comprising a metal or metal nitride surface and the feature sidewalls comprising an oxide surface; performing a multiple-cycle atomic layer deposition (ALD) process to deposit a molybdenum (Mo) film selectively on the metal or metal nitride surface relative to the oxide surface, the ALD process including exposing the feature to alternating pulses of a molybdenum-containing oxyhalide precursor and a reducing agent at a first substrate temperature to partially fill the feature while the substrate is at the first substrate temperature and completely fill the feature while the substrate is at a second temperature; A method comprising:

2. 10. The method of claim 1 further comprising: The method includes exposing the metal or metal nitride surface to a hydrogen-containing plasma prior to performing the multiple cycles of the ALD process.

3. 10. The method of claim 1, The reducing agent is hot hydrogen (H 2 ) a method.

4. 10. The method of claim 1, The method wherein the reducing agent partial pressure is at least 10 Torr.

5. 10. The method of claim 1, The method wherein the molybdenum-containing oxyhalide precursor is molybdenum oxychloride.

6. 6. The method of claim 5, The method, wherein the first substrate temperature is 600° C. or less.

7. 6. The method of claim 5, The method, wherein the first substrate temperature is 450° C. or less.

8. 6. The method of claim 5, The method, wherein the first substrate temperature is 400° C. or less.

9. 9. A method according to any one of claims 6 to 8, comprising: The method, wherein the first substrate temperature is at least 350°C.

10. 10. The method of claim 1, The method wherein the molybdenum-containing oxyhalide precursor is molybdenum oxyfluoride.

11. The method of claim 1, The method, wherein the partially filling step occurs in a first station of a processing chamber and the fully filling step occurs in a second station of the processing chamber.

12. 10. The method of claim 1, The method wherein the metal or metal nitride surface is one of the materials from the group consisting of cobalt, ruthenium, copper, tungsten, molybdenum, titanium, tin, tantalum, nickel, iridium, and rhodium.

13. 1. A method comprising: providing a substrate comprising a feature having a feature bottom and feature sidewalls, the feature bottom comprising a metal or metal nitride surface and the feature sidewalls comprising an oxide surface; performing a multiple-cycle atomic layer deposition (ALD) process to deposit a molybdenum (Mo) film selectively on the metal or metal nitride surface relative to the oxide surface, the ALD process comprising exposing the feature to alternating pulses of a molybdenum-containing oxyhalide precursor and a reducing agent at a first substrate temperature; Including, The method wherein the metal or metal nitride surface is one of the materials from the group consisting of titanium nitride, molybdenum nitride, tungsten nitride, tungsten carbonitride, and tantalum nitride.

14. 10. The method of claim 1, The method wherein the metal or metal nitride surface is a metal element surface.

15. 1. A method comprising: providing a substrate comprising a feature having a feature bottom and feature sidewalls, the feature bottom comprising a metal or metal nitride surface and the feature sidewalls comprising an oxide surface; performing a multiple-cycle atomic layer deposition (ALD) process to deposit a molybdenum (Mo) film selectively on the metal or metal nitride surface relative to the oxide surface, the ALD process comprising exposing the feature to alternating pulses of a molybdenum-containing oxyhalide precursor and a reducing agent at a first substrate temperature; Including, The method, wherein the sidewall comprises an oxide selected from polyethylene oxide, tetraethyl orthosilicate, flowable oxide, and carbon-doped oxide.

16. 10. The method of claim 1, The method wherein the Mo film on the metal or metal nitride surface is at least about 20 Å thicker than the Mo film on the oxide surface of the sidewall.

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