Tuning the work function of P metal work function films via vapor deposition

Abstract

The present disclosure relates to a method for forming a p-metal work function nitride film having a desired p-work function on a substrate, comprising: adjusting one or more of the substrate temperature, the duration of one or more time-separated gas phase pulses, the ratio of a tungsten precursor to a titanium precursor, or the pressure of a reaction to tune the work function of the p-metal work function nitride film to the desired p-work function; and contacting the substrate with a tungsten precursor, a titanium precursor, and time-separated gas phase pulses of a reaction gas to form a p-metal work function nitride film having the desired p-work function on the substrate.

Description

Technical Field

[0001] Embodiments of the present disclosure relate generally to the field of semiconductor manufacturing processes, and more particularly, to vapor deposition methods for work function tuning of p-metal films. Background Art

[0002] P-metal films are increasingly used in metal-oxide-semiconductor field-effect-transistors (MOSFETs) such as finfield-effect transistors (FinFETs) in the 10nm technology node and beyond, however the inventors have observed that there are still numerous challenges in this area. For example, the advancement of transistor technology to more advanced nodes (n<10nm) requires the development of low-resistivity work function metals (e.g., p-metals) in transistor devices. In addition, due to the limited space available in the gate structure, the threshold voltage (Vt) tuning range is greatly limited by traditional film thickness scaling. Therefore, for work function control of p-metal films, the ability to tune the work function (such as multi-Vt tuning) without changing the film thickness becomes important.

[0003] Furthermore, the inventors have observed that although some metal carbide nitride films have desirable work functions, these metal carbide nitride films may have high resistivity, which limits the application of metal carbide nitride films as work function materials in FinFET devices.

[0004] Accordingly, the inventors have observed that for FinFET devices with smaller dimensions, the ability to obtain desired p-work function tuning and low resistivity without thickness scaling is important.

[0005]

[0013] Thus, the inventors have provided a method of forming one or more p-metal work function films and tuning the work function of the one or more p-metal work function films. Summary of the invention

[0006] Methods of forming a p-metal work function film having a desired p-work function are provided herein. In some embodiments, a method for forming a p-metal work function nitride film having a desired p-work function on a substrate includes: adjusting one or more of a substrate temperature, a duration of one or more time-separated gas phase pulses, a ratio of a tungsten precursor to a titanium precursor, or a reaction pressure to tune the work function of the p-metal work function nitride film to a desired p-work function; and contacting the substrate with the time-separated gas phase pulses of a tungsten precursor, a titanium precursor, and the time-separated gas phase pulses of a reaction gas to form a p-metal work function nitride film having a desired p-work function on the substrate.

[0007] In some embodiments, a method of forming one or more p-metal work function films having a desired p-work function above a substrate in a reaction includes: adjusting one or more processing parameters of the reaction to tune the work function of the one or more p-metal work function nitride films to the desired p-work function; and alternatingly and continuously contacting the substrate with time-separated gas phase pulses of one or more metal source chemicals and one or more reactant gases to form the one or more p-metal work function nitride films having the desired work function.

[0008] In some embodiments, the present disclosure relates to a non-transitory computer-readable medium having instructions stored thereon, which when executed, produce a method of forming a p-metal work function nitride film having a desired p-work function on a substrate in a processing chamber, the method comprising: adjusting one or more of a substrate temperature, a duration of one or more time-separated gas phase pulses, a ratio of a tungsten precursor to a titanium precursor, or a reaction pressure to tune the work function of the p-metal work function nitride film to the desired p-work function; and contacting the substrate with the time-separated gas phase pulses of a tungsten precursor, a titanium precursor, and a reaction gas to form a p-metal work function nitride film having the desired p-work function on the substrate.

[0009] Other and further embodiments of the disclosure are described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The embodiments of the present disclosure, briefly summarized above and discussed in more detail below, can be understood by reference to the illustrative embodiments of the present disclosure depicted in the accompanying drawings. However, the accompanying drawings depict only typical embodiments of the present disclosure and are therefore not to be considered as limiting the scope of the invention, as the present disclosure may admit of other equally effective embodiments.

[0011] Figure 1 A flow chart of a method of forming a p-metal work function nitride film having a desired work function on a substrate is depicted, according to some embodiments of the present disclosure.

[0012] Figure 2 A flow chart of a method of forming a p-metal work function nitride film having a desired work function on a substrate is depicted, according to some embodiments of the present disclosure.

[0013] Figure 3 A flow chart of a method of forming a p-metal work function nitride film having a desired work function on a substrate is depicted, according to some embodiments of the present disclosure.

[0014] Figure 4 A PMOS transistor including a substrate and a p-metal work function nitride film suitable for use in accordance with the present disclosure is depicted.

[0015] Figure 5 Depicted is a deposition chamber suitable for forming a p-metal work function nitride film having a desired work function on a substrate according to some embodiments of the present disclosure.

[0016] For ease of understanding, the same reference numerals are used as much as possible to indicate the same elements that are common in the drawings. The drawings are not drawn to scale and may be simplified for clarity. Elements and features of one embodiment may be advantageously incorporated into other embodiments without further description. DETAILED DESCRIPTION

[0017] Embodiments of the present disclosure provide a method for forming one or more p-metal work function films above a substrate, which advantageously tunes the work function of one or more p-metal work function nitride films. The work function tuned according to the present disclosure can be used to obtain a desired threshold voltage (Vt) in a semiconductor device. Therefore, embodiments of the present disclosure can be advantageously used during different chemical vapor deposition (CVD) and atomic layer deposition (ALD) processes on devices that can undergo further processing. In some embodiments, the method of the present disclosure advantageously provides a p-metal work function nitride film with a desired or predetermined p-work function suitable for use in fin field effect transistors (FinFETs) in technology nodes at and above 10nm technology nodes. In an embodiment, the desired work function of the p-metal film of the present disclosure is predetermined. For example, the desired work function of the p-metal film of the present disclosure may be targeted to be 4.8 eV or greater, or greater than 4.8 eV to about 5.0 eV, 4.9 eV to 5.0 eV, about 4.9 eV to about 5.0 eV, about 5.0 eV, or 5.0 eV.

[0018] Figure 1 is a flow chart of a method 100 for forming a p-metal work function nitride film having a desired work function on a substrate according to some embodiments of the present disclosure. The method 100 is described below with respect to various stages of processing a substrate and may be performed, for example, in a suitable wafer processing system. Exemplary processing systems that may be used to perform the methods disclosed herein may include, but are not limited to, any of the following systems available from Applied Materials, Inc. of Santa Clara, California: or Brand processing systems. One example of a suitable ALD wafer processing system is shown and described in U.S. Patent No. 7,238,552, entitled Method and Apparatus for Depositing Tungsten After Surface Treatment to Improve Film Characteristics, issued to Applied Materials Inc. on July 3, 2007. Other processing chambers, including processing chambers available from other manufacturers, may also be suitably used in conjunction with the teachings provided herein.

[0019] Method 100 is typically performed on a substrate such as a semiconductor substrate and a glass substrate and layers formed above the substrate, such as a dielectric layer (e.g., SiO2) and a barrier layer (e.g., titanium, titanium nitride, and the like). In some embodiments, the substrate may be a high dielectric constant dielectric layer provided to a processing volume of a processing chamber. The high dielectric constant dielectric layer may be any suitable layer having a high dielectric constant compared to silicon dioxide (3.9). Non-limiting examples of high dielectric constant dielectric materials include materials having a dielectric constant greater than 7. The high dielectric constant dielectric layer may include a metal oxide. Non-limiting examples of suitable metal oxides used in accordance with the present disclosure include oxides containing metals such as hafnium (Hf). For example, the metal oxide may include hafnium oxide or HfO2. Non-limiting examples of high dielectric constant dielectric materials suitable for use as substrates in accordance with the present disclosure may further include HfO2, TiO2, Ta2O5, CeO2, BaZrTiO3, Al2O3, and combinations thereof. In an embodiment, the substrate has a thickness of 1 to 5 nm. In an embodiment, the substrate is formed by one of physical vapor deposition, chemical vapor deposition, and atomic layer deposition.

[0020] In an embodiment of the present disclosure, a p-metal work function nitride film is formed or deposited on top of and in contact with a substrate such as that described above by an ALD process, a CVD process, or a derivative process thereof. Figure 1 At 102, the process includes adjusting one or more of a substrate temperature, a duration of one or more time-separated gas phase pulses, a ratio of a tungsten precursor to a titanium precursor, or a pressure of a reaction to tune the work function of the p-metal work function nitride film. The process described at 102 may be performed before, after, or during 104, which is further described below. In an embodiment, a suitable p-metal work function nitride film includes a film including tungsten (W), titanium (Ti), and combinations thereof, such as, for example, a WTiNC film, or a W x Ti y NC membrane membrane.

[0021] In embodiments, depending on the specific deposition process, such as, for example, ALD, the substrate temperature may be set during deposition. In embodiments, the temperature of one or more time-separated gas phase pulses of the reaction may be adjusted to tune the work function of the p-metal work function nitride film. The substrate may be heated to a desired temperature prior to layer deposition via a heater embedded in a susceptor in a reaction chamber, such as, Figure 5 The wafer support pedestal is provided in a processing chamber 16 in the wafer support pedestal. For example, the pedestal can be resistively heated by applying an electric current from a power supply to a heater assembly disposed in the pedestal. The substrate is then heated and can be maintained within a desired processing temperature range, for example, from about 250° C. to about 500° C. In some embodiments, the substrate temperature is between about 375° C. and about 400° C. A temperature sensor, such as a thermocouple, can also be embedded in the wafer support pedestal to monitor the pedestal temperature in a conventional manner.

[0022] In an embodiment, the duration of one or more time-separated gas phase pulses of the reaction may be adjusted to tune the work function of the p-metal work function nitride film. For example, a first gas phase pulse including a metal organic precursor, such as a first gas phase pulse including a precursor including tungsten, nitrogen, carbon, and hydrogen, may be deposited on a substrate in a deposition process such as ALD. Other non-limiting examples of the first precursor include a tungsten precursor such as one or more of WCl5, WCl6, WF6, bis(tert-butylimido)-bis(dimethylamido)tungsten-(VI), or the like. The first precursor may be supplied in an amount sufficient to form a first layer above the top surface of the substrate, such as an amount sufficient to facilitate the formation of one or more p-metal work function nitride films having a thickness between about 10 angstroms and about 50 angstroms. In an embodiment, the duration of the gas phase pulse is between about 0.1 seconds and 10 seconds. In some embodiments, the duration of the first gas phase pulse or the duration of one or more temporally separated gas phase pulses is tuned to change the film work function of the p-metal work function nitride film to a desired work function. In an embodiment, the duration of the gas phase pulse is changed by an amount between about 0.2 seconds and 9.9 seconds.

[0023] In an embodiment, the duration of the second time-separated gas phase pulse of the reaction can be adjusted to tune the work function of the p-metal work function nitride film to a desired value. For example, in a deposition process such as ALD, a second gas phase pulse comprising a metal precursor, such as a second gas phase pulse comprising a titanium precursor, can be deposited on the substrate. Other non-limiting examples of the second precursor include one or more of the following substances: a titanium precursor, such as TiCl4, tetrakis (dimethylamido) titanium (TDMAT), tetrakis (diethylamido) titanium (TDEAT), or the like, or a combination of the above. In an embodiment, a suitable second precursor is TiCl4. The second precursor can be supplied in an amount sufficient to form a layer above the layer formed by the first precursor above the top surface of the substrate, such as an amount sufficient to help form one or more p-metal work function nitride films having a thickness between about 10 angstroms and about 50 angstroms. In an embodiment, the duration of the second gas phase pulse is between about 0.1 seconds and 10 seconds. In some embodiments, the duration of the second gas phase pulse is adjusted to tune the work function of the p-metal work function nitride film. In an embodiment, the duration of the second gas phase pulse is varied by an amount between about 0.2 seconds and 9.9 seconds.

[0024] In an embodiment, the ratio of the reacted tungsten precursor to the titanium precursor can be adjusted to tune the work function of the p-metal work function nitride film to a desired value. For example, in the case where the first precursor is a tungsten precursor and the second precursor is a titanium precursor, the amount of each precursor forming the film can be adjusted to tune the work function of the p-metal work function nitride film to a desired value. In an embodiment, a tungsten rich film is formed when the percentage of tungsten present in the film is significantly greater than the amount of titanium in the film. In an embodiment, tungsten is present in an amount greater than 1, 2, 5, 10 to 20 times greater than titanium in the film. Similarly, the formation of a Ti-rich film can tune the work function of a p-metal work function nitride film. In an embodiment, titanium is present in an amount greater than 1, 2, 5, 10 to 20 times greater than tungsten in the film. In an embodiment, a tungsten precursor is applied to titanium at a ratio of tungsten precursor to titanium precursor between 1:99 and 99:1. The selected ratio is suitable for tuning the work function of a p-metal work function nitride film. In an embodiment, increasing tungsten or tungsten content will provide a higher p work function film and can reduce the Vt in a semiconductor device having a p work function film disposed therein or thereon, such as a transistor. In an embodiment, increasing titanium or titanium content will provide a lower p work function film and can increase the Vt in a semiconductor device having a p work function film disposed therein or thereon, such as a transistor.

[0025] In an embodiment, the reaction pressure can be adjusted to tune the work function of the p-metal work function nitride film to a desired p-work function. A vacuum pump can also be used to evacuate the process chamber and help maintain appropriate gas flow and pressure within the process chamber. In an embodiment, the pressure of the reaction is between about 1 Torr and 50 Torr, or between about 5 Torr and 25 Torr.

[0026] Return to see Figure 1 , 104 includes contacting a substrate with time-separated gas phase pulses of a tungsten precursor, a titanium precursor, and a reactant gas (each added independently) to form a p-metal work function nitride film having a desired p-work function on the substrate.

[0027] In an embodiment, the reactant gas is provided in an amount sufficient to react the first and second precursors described above to form a p-metal nitride film. In an embodiment, the reactant gas comprises ammonia, hydrazine, or a combination thereof in a gas phase and supplied to the substrate and into the substrate opening in a reactant gas pulse.

[0028] In an embodiment, after sufficient tungsten precursor, titanium precursor, and reactant gases have been supplied to at least reach all surfaces upon which deposition is desired, excess tungsten precursor, titanium precursor, and reactant gases (and any reactant byproducts) are removed in one or more purge or removal processes, such as and including a purge with an inert gas, following each time-separated gas phase pulse.

[0029] Figure 2 Flowchart of method 200 for forming a p-metal work function nitride film having a desired work function on a substrate according to some embodiments of the present disclosure. Method 200 is similar to method 100 with respect to the stages of processing the substrate, and, for example, method 200 may be performed in an appropriate wafer processing system. In addition, method 200 may utilize the precursors and reactive gases mentioned above. However, the process in method 200 may also be applied to processes employing three or more reactants in alternating and temporally separated pulses, and other additional reactants or conditions may be employed, so that processing parameters may generally be adjusted to tune the work function of the p-metal nitride film according to the present disclosure. For example, for some applications, it may be advantageous to supply two consecutive pulses of the same reactant separated only by removal, such as by purging. Additionally, in some applications, it may be advantageous to supply a titanium precursor pulse before applying a reactive gas as described above to form a p-metal film of the present disclosure, and before a tungsten precursor pulse separated only by removal, such as by purging. See also Figure 2, method 200 involves forming one or more p-metal work function films having a desired p-work function over a substrate. At process sequence 202, method 200 includes adjusting one or more processing parameters of a reaction to tune the work function of the one or more p-metal work function nitride films to the desired p-work function. Further at 204, method 200 includes alternatingly and continuously contacting the substrate with one or more metal source chemicals and one or more time-separated gas phase pulses of a reaction gas to form one or more p-metal work function nitride films having the desired work function. In some embodiments, the one or more processing parameters are one or more of a substrate temperature, a duration of the time-separated gas phase pulses, or a pressure of the reaction to tune the work function of the one or more p-metal work function nitride films. In one embodiment, a processing parameter is a substrate temperature that is suitable for preselection or adjustment according to the present disclosure. In one embodiment, a processing parameter is a duration of the time-separated gas phase pulses that is suitable for preselection or adjustment according to the present disclosure. In one embodiment, a reaction pressure is a processing parameter that is suitable for preselection or adjustment according to the present disclosure. In one embodiment, suitable metal source chemistries for use herein include a tungsten precursor and a titanium precursor, wherein the tungsten precursor and the titanium precursor are applied in a ratio between 1:99 and 99:1.

[0030] Figure 3 A flow chart generally illustrates an alternating and continuous deposition process according to an embodiment of the present disclosure. In an embodiment, a process parameter is adjusted at 302 by adjusting one or more of the following: substrate temperature, duration of one or more temporally separated gas phase pulses, ratio of tungsten precursor to titanium precursor, or pressure of the reaction to tune the work function of the p-metal work function nitride film to achieve a desired p-work function value. In an embodiment, a first precursor is supplied to a substrate and into an opening in the substrate in a first precursor pulse 304. After sufficient precursor, such as a tungsten precursor, has been supplied to at least reach all surfaces desired to be deposited thereon, excess first reactant (and any reactant byproducts) is removed in a first removal or purge 305. Removal or purge 305 may include evacuation to vacuum; however, removal may also be achieved as a purge by supplying an inert gas. Undesirable gas phase reactions between the first and second precursors in the reaction space above the substrate are avoided by removal, which is optimized to be as short as possible while ensuring that the reactants that react with each other are spatially and temporally separated. The first precursor pulse 304 and the first removal or purge 305 together represent the first reactant stage.

[0031] Subsequently, a second precursor, such as a titanium precursor in a vapor phase, is supplied to the substrate and into the substrate openings in a second precursor pulse 306. After sufficient second precursor has been supplied to at least reach all surfaces desired to be deposited thereon, excess second precursor (and any reactant byproducts) is removed in a second removal 307, which may include purging with an inert gas. The second precursor pulse 306 and the second removal 307 together represent the second stage. Figure 3 The second precursor pulse 306 in FIG. 3 is shown in dashed lines to illustrate that the second precursor pulse 306 and the reactive gas pulse 308 are optionally interchangeable embodiments. For example, the reactive gas pulse 308 described below may be after the purge 305, and the second precursor pulse 306 may be after the second removal 307 as appropriate.

[0032] A reactant gas, such as ammonia, hydrazine, or a combination thereof in the gas phase, is supplied to the substrate and into the substrate opening in a reactant gas pulse 308. After sufficient reactant gas has been supplied to at least reach all surfaces above which deposition is desired, excess reactant gas (and any reactant byproducts) is removed in a third removal 309, which may include purging with an inert gas. The reactant gas pulse 308 and the third removal 309 together represent the third stage, and the first, second, and third stages together represent a cycle of alternating and continuous deposition processes. The cycle is then repeated as many times as desired until a film of desired thickness is formed. In addition, as described above, the process parameters 302 may be varied in accordance with the present disclosure to tune the work function of the p-metal work function nitride to a desired threshold voltage.

[0033] In embodiments, the first and second precursors may be plasma activated. For example, the plasma activated precursors are activated in situ in a reactor directly above the upper surface of the substrate to provide a uniform supply of activated species across the substrate.

[0034] See also Figure 4 In an embodiment, the tungsten nitride film 402 of the present disclosure is suitable for use in a PMOS transistor 400, for example, the PMOS transistor 400 includes: a substrate 404 suitable for nodes less than 10 nanometers including a first surface; and a work function metal having a thickness of 10 to 50 angstroms disposed above the top surface of the substrate, wherein the work function metal includes a predetermined desired work function. In an embodiment, the PMOS transistor includes a p-metal work function nitride film, the p-metal work function nitride film including a film including tungsten (W), titanium (Ti), and combinations thereof, for example, such as a WTiNC film or a W x Ti yIn an embodiment, the p-metal work function nitride film has a predetermined desired work function. For example, the desired work function of the p-metal film of the present disclosure may be indexed and predetermined to be 4.8 eV or more, or greater than 4.8 eV to about 5.0 eV, 4.9 eV to 5.0 eV, about 4.9 eV to about 5.0 eV, about 5.0 eV, or 5.0 eV.

[0035] See now Figure 5 , shows a processing chamber 16 suitable for forming a p-metal work function nitride film having a desired work function on a substrate according to the present disclosure. In an embodiment, the processing chamber 16 can be configured to operate in both a CVD mode or a cyclic deposition mode (ALD). See Figure 5 , a heater / lifting assembly 46 is disposed within the processing chamber 16, the heater / lifting assembly including a support base 48 connected to a support shaft 48a adapted to support a wafer. When the lid assembly 20 is in a closed position, the support base 48 is positioned between the support shaft 48a and the lid assembly 20. The support shaft 48a extends from the support base 48 away from the lid assembly 20 through a passage formed in the housing 14. A bellows 50 is attached to a portion of the housing 14 disposed opposite the lid assembly 20 to prevent leakage from between the support shaft 48a and the housing 14 into the processing chamber 16. The heater / lifting assembly 46 is movable vertically within the processing chamber 16 so that the distance between the support base 48 and the lid assembly 20 can be controlled. A sensor (not shown) provides information about the position of the support base 48 within the processing chamber 16.

[0036] The support base 48 includes an embedded thermocouple 50a that can be used to monitor its temperature. For example, the signal from the thermocouple 50a can be used in a feedback loop to control the power applied to the heater element 52a by the power supply 52. ​​The heater element 52a can be a resistive heater element or other heat transfer device disposed within or in contact with the support base 48, which is used to control the temperature of the support base 48. Optionally, the support base 48 can be heated using a heat transfer fluid (not shown).

[0037] The support base 48 may be formed of any process compatible material including aluminum nitride and aluminum oxide, and may also be configured to employ a vacuum holding substrate (not shown) thereon, i.e., the support base 48 may be a vacuum chuck. To this end, the support base 48 may include a plurality of vacuum holes (not shown) placed in fluid communication with a vacuum source (such as a pump system) via vacuum tubes routed through the support shaft 48a.

[0038] The liner assembly is disposed in the processing chamber 16 and includes a cylindrical portion 54 and a planar portion. The cylindrical portion 54 and the planar portion may be formed of any suitable material such as aluminum, ceramic, and the like. The cylindrical portion 54 surrounds the support base 48. The cylindrical portion 54 additionally includes a hole 60 that is aligned with the slit valve opening 44 disposed in the side wall 14b of the housing 14 to allow the substrate to enter and exit the processing chamber 16.

[0039] The pumping channel 62 is disposed along the sidewall 14b of the processing chamber 16 adjacent to the lid assembly 20. The pumping channel 62 includes a plurality of holes, one of which is shown as a first hole 62a. The pumping channel 62 includes a second hole 62b, which is coupled to the pump system 18 by a conduit 66. A throttle valve 18a is coupled between the pumping channel 62 and the pump system 18. The pumping channel 62, the throttle valve 18a, and the pump system 18 control the amount of flow from the processing chamber 16. The size and number and location of the holes, such as the size and number and location of the first hole 62a in communication with the processing chamber 16, are configured to achieve uniform flow of gas exiting the lid assembly 20 over the support pedestal 48 and the substrate when disposed on the support pedestal 48. A plurality of supplies 68a, 68b and 68c of process and / or other fluids are in fluid communication with one of valves 32a, 32b or 32c through a series of conduits (not shown) formed through housing 14, cover assembly 20 and gas manifold 34.

[0040] Controller 70 coordinates the operation of the various components of system 10. Controller 70 includes a processor 72 in data communication with memory, such as random access memory 74 and hard drive 76, and communicates with at least pump system 18, power source 52, and valves 32a, 32b, and 32c.

[0041] Although any type of processing fluid may be employed, one example of a processing fluid is a tungsten precursor, a titanium precursor, and a reactive gas as described above, and optionally a purge fluid. The chamber pressure may be in the pressure range as described above, and the support pedestal 48 is heated so that the substrate may be maintained at a set temperature, such as a substrate at the temperature described herein above. In an embodiment, a processing fluid such as a tungsten precursor, a titanium precursor, and a reactive gas may flow into the processing chamber 16 with a carrier fluid such as Ar. However, the purge fluid may be different from the carrier fluid or the precursor, or the co-reactant.

[0042] In a vapor deposition embodiment according to the present disclosure, a method includes performing a chemical vapor deposition (CVD) process in a processing chamber, such as processing chamber 16, by adjusting one or more of substrate temperature, duration of one or more time-separated vapor phase pulses, ratio of tungsten precursor to titanium precursor, or pressure of the reaction to tune the work function of the p-metal work function nitride film to a desired p-work function. In an embodiment, the processing chamber is adapted to contact a substrate with time-separated vapor phase pulses of one or more tungsten precursors, one or more titanium precursors, and a reactant gas to form a p-metal work function nitride film having a desired p-work function on the substrate.

[0043] In some embodiments, vapor deposition embodiments according to the present disclosure include methods that include performing a chemical vapor deposition (CVD) process in a processing chamber, such as processing chamber 16, by adjusting one or more processing parameters of the reaction to tune the work function of one or more p-metal work function nitride films to a desired p-work function. In embodiments, the processing chamber is configured to alternately and sequentially contact a substrate with time-separated vapor phase pulses of one or more metal source chemicals and one or more reactant gases to form one or more p-metal work function nitride films having a desired work function.

[0044] In another embodiment, a non-transitory computer readable medium having instructions stored thereon is provided, which when executed, produce a deposition method, such as, for example, substrate processing according to the present disclosure. For example, in an embodiment, a non-transitory computer readable medium having instructions stored thereon is provided, which when executed, produce a substrate processing method processed in or through a deposition chamber, the method comprising: adjusting one or more of a substrate temperature, a duration of one or more time-separated gas phase pulses, a ratio of a tungsten precursor to a titanium precursor, or a pressure of a reaction to tune the work function of a p-metal work function nitride film to a desired p-work function; and contacting a substrate with the time-separated gas phase pulses of a tungsten precursor, a titanium precursor, and a reactant gas to form a p-metal work function nitride film having a desired p-work function on the substrate.

[0045] In another embodiment, a non-transitory computer readable medium having stored thereon instructions, when executed, produces a deposition method, such as, for example, substrate processing according to the present disclosure. For example, in an embodiment, a non-transitory computer readable medium having stored thereon instructions, when executed, produces a substrate processing method processed in or through a deposition chamber, the method comprising: adjusting one or more processing parameters of a reaction to tune the work function of one or more p-metal work function nitride films to a desired p-work function; and alternatingly and continuously contacting the substrate with time-separated gas phase pulses of one or more metal source chemicals and one or more reactant gases to form one or more p-metal work function nitride films having the desired work function.

[0046] The above embodiments are described by way of example only and variations are possible without departing from the scope of protection defined by the appended claims.

Claims

1. A method for forming a p-metal work function nitride film having a desired p-work function on a substrate, comprising the following steps: adjusting one or more of the temperature of the substrate, the duration of one or more time-separated gas phase pulses, the ratio of the tungsten precursor to the titanium precursor, or the pressure of the reaction to tune the work function of the p-metal work function nitride film to a desired p-work function; and The substrate and the tungsten precursor, The titanium precursor and the time-separated gas phase pulses of the reaction gas are contacted to form a p-metal work function nitride film having the desired p work function on the substrate, wherein the p-metal work function nitride film having the desired p work function is a WTiNC film or a W x Ti y NC membrane. 2 . The method of claim 1 , wherein the temperature of the substrate is between 250° C. and 500° C.

3. The method of claim 1 or 2, wherein the temperature of the substrate is between 375°C and 400°C.

4. The method of claim 1 or 2, wherein the temporally separated gas phase pulses have a duration between 0.1 seconds and 10 seconds.

5. The method of claim 1 or 2, wherein the duration of one or more temporally separated gas phase pulses is between 1 second and 5 seconds.

6. The method of claim 1 or 2, wherein the pressure of the reaction is between 1 Torr and 50 Torr.

7. The method of claim 1 or 2, wherein the pressure of the reaction is between 5 Torr and 25 Torr.

8. The method of claim 1 or 2, wherein the temperature of the substrate is between 375°C and 400°C, wherein the duration of the temporally separated gas phase pulses is between 1 second and 5 seconds, and wherein the pressure is between 5 Torr and 25 Torr.

9. The method of claim 1 or 2, further comprising the step of removing excess tungsten precursor, titanium precursor, and reactive gas after each gas phase pulse.

10. The method of claim 9, wherein the step of removing further comprises the step of purging the reaction space with an inert gas.

11. The method of claim 1 or 2, wherein the tungsten precursor comprises one or more of WCl5, WCl6, WF6, and bis(tert-butylimide)-bis(dimethylamido)tungsten-(VI).

12. The method of claim 1 or 2, wherein the titanium precursor comprises TiCl4, TDMAT, TDEAT, or a combination thereof.

13. A method of forming one or more p metal work function films having a desired p work function over a substrate in a reaction, comprising the steps of: adjusting one or more processing parameters of the reaction to tune the work function of the one or more p-metal work function nitride films to a desired p-work function; and The substrate is contacted with one or more metal source chemicals and one or more reactant gases in time-separated gas phase pulses alternately and continuously to form one or more p-metal work function nitride films having a desired work function, wherein the one or more p-metal work function nitride films having the desired work function are WTiNC films or W x Ti y NC membrane.

14. A non-transitory computer readable medium having instructions stored thereon, which when executed, produce a method of forming a p-metal work function nitride film having a desired p-work function on a substrate in a processing chamber, the method comprising the steps of: adjusting one or more of a temperature of the substrate, a duration of one or more time-separated gas phase pulses, a ratio of a tungsten precursor to a titanium precursor, or a pressure of a reaction to tune the work function of the p-metal work function nitride film to a desired p-work function; and contacting the substrate with the time-separated gas phase pulses of the tungsten precursor, the titanium precursor, and a reactant gas to form a p-metal work function nitride film having the desired p-work function on the substrate, wherein the p-metal work function nitride film having the desired p-work function is a WTiNC film or a W x Ti y NC membrane.

Images