Remote plasma-assisted chemical vapor deposition of silicon nitride

Abstract

Examples are disclosed relating to low-damage deposition of silicon nitride films using chemical vapor deposition (CVD). One example provides a method (300) for forming a silicon nitride film on a substrate in a processing chamber by chemical vapor deposition. The method includes introducing (302) a nitrogen-containing precursor into a remote plasma formed in a remote plasma chamber of the processing tool. The method further includes forming (308) radical nitrogen species in the remote plasma. The method further includes flowing (312) an oxygen-free silicon-containing precursor into the processing chamber of the processing tool. The method further includes introducing (316) radical nitrogen species into the processing chamber from the remote plasma chamber while flowing the oxygen-free silicon-containing precursor. The method further includes reacting the oxygen-free silicon-containing precursor with the radical nitrogen species to form a silicon nitride film on the substrate.

Description

[Background technology]

[0001] Semiconductor fabrication processes can include many steps of material deposition, patterning, and removal to form integrated circuits on a substrate. For example, silicon nitride can be deposited and patterned to form various structures within an integrated circuit. Atomic layer deposition (ALD) can be used to form highly conformal films of silicon nitride. ALD forms films in one or more discrete film layers by sequentially adsorbing precursors on a substrate and then reacting the adsorbed precursors to form the film layers. Summary of the Invention

[0002] This Summary is provided to introduce a selection of concepts in a simplified form, further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Moreover, the claimed subject matter is not limited to implementations that solve any or all disadvantages noted in any part of this disclosure.

[0003] Examples are disclosed relating to low-damage chemical vapor deposition (CVD) of silicon nitride films using a remote plasma. One example provides a method for forming a silicon nitride film on a substrate in a processing chamber by chemical vapor deposition. The method includes introducing a nitrogen-containing precursor into a remote plasma formed in a remote plasma chamber of a processing tool. The method further includes forming radical nitrogen species in the remote plasma. The method further includes flowing an oxygen-free silicon-containing precursor into the processing chamber of the processing tool. The method further includes introducing radical nitrogen species from the remote plasma chamber into the processing chamber while flowing the oxygen-free silicon-containing precursor. The method further includes reacting the oxygen-free silicon-containing precursor with the radical nitrogen species to form a silicon nitride film on the substrate.

[0004] In some such examples, forming the silicon nitride film includes forming a conformal silicon nitride film.

[0005] In some such instances, flowing the oxygen-free silicon-containing precursor additionally or alternatively includes flowing a silane-based precursor.

[0006] In some such examples, forming the silicon nitride film additionally or alternatively includes forming the silicon nitride film on one or more of an amorphous silicon mandrel or an amorphous carbon mandrel.

[0007] In some such examples, forming the silicon nitride film additionally or alternatively includes forming the silicon nitride film in one or more gaps on the substrate.

[0008] In some such examples, the method additionally or alternatively includes performing atomic layer deposition to deposit additional silicon nitride on the silicon nitride film.

[0009] In some such examples, forming the nitrogen radical species additionally or alternatively includes forming a remote plasma using radio frequency power in the range of 300 to 2000 watts.

[0010] In some such examples, the method additionally or alternatively includes controlling the pressure of the processing chamber within a range of 2 to 8 Torr while forming the silicon nitride film.

[0011] In some such examples, introducing a nitrogen-containing precursor into the remote plasma additionally or alternatively includes introducing nitrogen, nitrogen / hydrogen, ammonia, hydrazine, or an amine into the remote plasma.

[0012] Another example provides a method for forming a silicon nitride film on a substrate in a processing chamber of a chemical vapor deposition (CVD) tool. The method includes introducing a nitrogen-containing precursor into a remote plasma formed in a remote plasma chamber of the CVD tool. The method further includes forming radical nitrogen species in the remote plasma. The method further includes introducing an oxygen-free silicon-containing precursor into the processing chamber of the CVD tool. The method further includes introducing the radical nitrogen species into the processing chamber from the remote plasma chamber. The method further includes reacting the oxygen-free silicon-containing precursor with the radical nitrogen species to form a silicon nitride film on the substrate. The method further includes performing atomic layer deposition to form one or more additional layers of silicon nitride on the silicon nitride film.

[0013] In some such examples, forming the silicon nitride film on the substrate includes forming the silicon nitride film on one or more mandrels.

[0014] In some such examples, one or more mandrels comprise amorphous silicon.

[0015] In some such examples, one or more mandrels additionally or alternatively comprise amorphous carbon.

[0016] In some such examples, forming the silicon nitride film on the substrate additionally or alternatively includes forming the silicon nitride film in one or more gaps on the substrate.

[0017] In some such instances, introducing the oxygen-free silicon-containing precursor into the processing chamber additionally or alternatively includes introducing a silane-based precursor into the processing chamber.

[0018] In some such examples, introducing the nitrogen-containing precursor into the remote plasma additionally or alternatively includes introducing one or more of nitrogen, nitrogen / hydrogen, ammonia, hydrazine, or an amine into the remote plasma.

[0019] In another example, a chemical vapor deposition (CVD) tool is provided. The CVD tool includes a process chamber and a remote plasma chamber. The CVD tool further includes a radio frequency power source configured to form a plasma in the remote plasma chamber. The CVD tool further includes a nitrogen precursor source including a nitrogen-containing precursor. The CVD tool further includes an oxygen-free silicon-containing precursor source including an oxygen-free silicon-containing precursor. The CVD tool further includes flow control hardware configured to introduce the nitrogen-containing precursor into the remote plasma chamber and introduce the oxygen-free silicon-containing precursor into the process chamber. The CVD tool further includes a controller configured to operate the flow control hardware to introduce the nitrogen-containing precursor into the remote plasma chamber. The controller is further configured to operate the radio frequency power source to form a plasma from the nitrogen-containing precursor, the plasma including radical nitrogen species. The controller is further configured to operate the flow control hardware to flow the oxygen-free silicon-containing precursor into the process chamber. The controller is further configured to operate the flow control hardware to introduce the radical nitrogen species from the remote plasma chamber into the process chamber to react with the oxygen-free silicon-containing precursor and form a silicon nitride film on the substrate.

[0020] In some such examples, the nitrogen-containing precursor source includes one or more of nitrogen, nitrogen / hydrogen, ammonia, hydrazine, or an amine.

[0021] In some such examples, the CVD tool additionally or alternatively includes a hydrogen-containing precursor source including hydrogen gas, and the controller is configured to operate the radio frequency power source to form a plasma from the nitrogen-containing precursor and the hydrogen gas.

[0022] In some such examples, the CVD tool additionally or alternatively includes an exhaust system, and the controller is configured to operate the exhaust system and flow control hardware to generate a pressure within the range of 2 to 8 Torr within the processing chamber during formation of the silicon nitride film on the substrate. [Brief explanation of the drawings]

[0023] [Figure 1A] FIG. 1A shows a schematic representation of the structure formed in an exemplary atomic layer deposition (ALD) of a silicon nitride film on an amorphous silicon mandrel and the subsequent etching step that results in material loss. [Figure 1B] FIG. 1B shows a schematic representation of the structure formed in an exemplary atomic layer deposition (ALD) of a silicon nitride film on an amorphous silicon mandrel and the subsequent etching step that results in material loss. [Figure 1C] FIG. 1C shows a schematic representation of the structure formed in an exemplary atomic layer deposition (ALD) of a silicon nitride film on an amorphous silicon mandrel and the subsequent etching step that results in material loss.

[0024] [Figure 2A] FIG. 2A schematically illustrates the expansion of an exemplary amorphous carbon mandrel resulting from the ALD deposition of a silicon nitride film. [Figure 2B] FIG. 2B schematically illustrates the expansion of an exemplary amorphous carbon mandrel resulting from the ALD deposition of a silicon nitride film.

[0025] [Figure 3] FIG. 3 shows a flow diagram illustrating an exemplary method for chemical vapor deposition (CVD) of silicon nitride films using radical nitrogen species formed in a remote plasma.

[0026] [Figure 4A] FIG. 4A shows a schematic representation of the structure formed in an exemplary CVD deposition of a silicon nitride film on a substrate including mandrels. [Figure 4B] FIG. 4B shows a schematic representation of the structure formed in an exemplary CVD deposition of a silicon nitride film on a substrate including mandrels. [Figure 4C] FIG. 4C illustrates a schematic of the structure formed in an exemplary CVD deposition of a silicon nitride film on a substrate including mandrels.

[0027] [Figure 5A] FIG. 5A shows a schematic diagram of a structure formed in an exemplary CVD deposition of a silicon nitride film in a gap on a substrate. [Figure 5B] FIG. 5B shows a schematic representation of the structure formed in an exemplary CVD deposition of a silicon nitride film in a gap on a substrate. [Figure 5C] FIG. 5C illustrates a schematic of the structure formed in an exemplary CVD deposition of a silicon nitride film in a gap on a substrate.

[0028] [Figure 6] FIG. 6 shows a schematic diagram of an exemplary CVD tool configured to deposit silicon nitride films using radical nitrogen species generated in a remote plasma.

[0029] [Figure 7] FIG. 7 illustrates a block diagram of an exemplary computing system. DETAILED DESCRIPTION OF THE INVENTION

[0030] The term "alkylamine" may generally refer to a nitrogen-containing compound having one to three alkyl substituents and zero to two hydrogen (H) substituents. Alkylamines include primary amines, secondary amines, tertiary amines, and cyclic amines. Examples of alkylamines include methylamine, dimethylamine, trimethylamine, and piperidine.

[0031] The term "aspect ratio" may generally refer to the ratio of the depth of a feature to the average width of the feature.

[0032] The term "atomic layer deposition" (ALD) may generally refer to a process of forming a film on a substrate in one or more discrete layers by sequentially adsorbing precursors onto the substrate and reacting the adsorbed precursors to form a film layer. Examples of ALD processes include plasma-enhanced ALD (PEALD) and thermal ALD (TALD). PEALD utilizes a plasma of reactive gases to promote the chemical conversion of precursors adsorbed on the substrate into a film on the substrate. TALD utilizes heat to promote the chemical conversion of precursors adsorbed on the substrate into a film on the substrate. The terms "growth" and "deposition," and variations thereof, may also be used to refer to film formation.

[0033] The term "ALD cycle" may generally refer to the sequence of processes used to form a single layer of film on a substrate in an ALD process.

[0034] The term "chemical vapor deposition" (CVD) may generally refer to a process of forming a solid-phase film on a substrate by directing a continuous flow of one or more precursor gases over the substrate surface under conditions configured to cause chemical conversion of the precursor gases into the film. The term "plasma-enhanced chemical vapor deposition" (PECVD) may generally refer to a CVD process that uses a plasma to facilitate the chemical conversion of one or more precursor gases into a solid-phase film on the substrate.

[0035] The term "CVD tool" may generally refer to a machine that includes a processing chamber and other hardware configured to perform CVD.

[0036] The term "conformal film" may generally refer to a film that includes a thickness that varies by 10% or less. A conformal film may include a thickness at a first location that is 90% to 110% of the thickness of the film at a second location.

[0037] The term "gap" may generally refer to a recess formed in the surface of a substrate.

[0038] The term "mandrel" may generally refer to a raised structure in a patterning process having sidewalls that define the location of spacers. Mandrels may be formed from, for example, any of polycrystalline silicon, amorphous silicon, and amorphous carbon.

[0039] The term "nitrogen-containing precursor" may generally refer to any material that can be introduced into a plasma to form radical nitrogen species and react with one or more other precursors to form a silicon nitride film. Examples of suitable nitrogen-containing precursors may include nitrogen (N), ammonia (NH), hydrazine (NH), and amines, such as diamines and alkylamines. Examples of nitrogen-containing precursors may further include mixtures of gases. Examples of gas mixtures include nitrogen / hydrogen and ammonia / hydrogen.

[0040] The term "oxygen-free silicon-containing precursor" may generally refer to any molecule that does not contain oxygen and that can be introduced into a process chamber in the gas phase to react with nitrogen radical species to form a silicon-containing nitride film on a substrate. An example of a silicon-containing nitride is silicon nitride (Si3N4). Examples of oxygen-free silicon-containing precursors for forming silicon-containing nitride films may include materials having the general structure: [ka] wherein R1, R2, and R3 may be the same or different substituents and may include organic groups such as silane, amine, halide, hydrogen, or alkylamine, alkyl, alkenyl, alkynyl, and aromatic groups.

[0041] More specific examples of oxygen-free silicon-containing precursors include silane-based precursors (silane and polysilanes ((H3Si-(SiH2) nExamples of oxygen-free silicon-containing precursors include trisilylamine (TSA). In a further example, the oxygen-free silicon-containing precursor may be an aminosilane, such as bis(diethylamino)silane, diisopropylaminosilane, bis(t-butylamino)silane (BTBAS), di-sec-butylaminosilane, or tris(dimethylamino)silane (3DMAS). Aminosilane precursors have the general formula: H x -Si-(NR) y , where x=1 to 3, and x+y=4, and R is a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted aromatic group, or a hydride group.

[0042] The term "patterning process" may generally refer to a process used to create topography on a substrate.

[0043] The term "plasma" may generally refer to a gas containing positive ions and free electrons. Plasma can be used to generate reactive species from precursor molecules introduced into the plasma. The term "in situ plasma" may generally refer to a plasma to which a substrate is directly exposed during processing. The term "remote plasma" may generally refer to a plasma located remotely from the substrate being processed.

[0044] The term "processing chamber" may generally refer to an enclosure in which chemical and / or physical processes are performed on a substrate. The pressure, temperature, and atmospheric composition within the processing chamber can be controlled to perform the chemical and / or physical processes.

[0045] "Purge" and its variations may generally refer to the process of removing unwanted species from a processing chamber.

[0046] The term "radical" may generally refer to a chemical species that has an unpaired electron.

[0047] The term "radical nitrogen species" may generally refer to a nitrogen-containing atom or molecule with an unpaired electron. Examples include N, NH, NH, and NH radicals.

[0048] The term "radio frequency (RF) power source" may generally refer to a power source configured to supply RF power to an electrode to form a capacitively coupled plasma or to supply RF power to a coil to form an inductively coupled plasma.

[0049] The term "remote plasma generator" may generally refer to one or more components of a processing tool configured to form a remote plasma. The remote plasma generator includes an RF power source and a remote plasma chamber in which the remote plasma is formed.

[0050] The term "silane-based precursors" generally refers to silanes and polysilanes ((H3Si-(SiH2) n It may also represent —SiH3), where n≧0. Examples of polysilanes include disilane, trisilane, and tetrasilane.

[0051] The term "spacer" may generally refer to structures formed in a patterning process that define spacing between features formed in subsequent processing steps.

[0052] The term "substrate" may generally refer to any object onto which a film can be deposited.

[0053] The term "substrate support" may generally refer to any structure for supporting a substrate within a processing chamber. Examples include pedestals, electrostatic chuck pedestals, and showerhead pedestals used in backside deposition processes.

[0054] As described above, silicon nitride is used to form many structures in integrated circuits. Conformal silicon nitride films can be deposited by plasma-enhanced ALD (PEALD). In a silicon nitride PEALD cycle, a silicon-containing precursor gas is introduced into a processing chamber. The silicon-containing precursor gas adsorbs onto the substrate in the processing chamber. Excess film precursor is purged from the processing chamber. A nitrogen-containing precursor is then introduced into the processing chamber. A plasma is then formed by applying radio frequency power to electrodes in the processing chamber. The plasma forms reactive species, such as radical nitrogen species. The radical nitrogen species react with the adsorbed silicon-containing precursor to form a silicon nitride layer. One or more PEALD cycles can be used to grow a highly conformal film of a desired thickness.

[0055] However, silicon nitride deposition by PEALD may not be suitable for some applications. For example, some substrates are vulnerable to plasma damage. Examples of such substrates include amorphous silicon, amorphous carbon, and chalcogenides. Film precursors for PEALD of silicon nitride may include halosilanes, such as dichlorosilane or diiodosilane. Radical halogen species formed from halosilanes in the plasma may etch some substrate materials. Furthermore, PEALD processes may utilize relatively high-power in-situ plasmas containing nitrogen and hydrogen. These conditions may cause nitridation of the substrate.

[0056] Nitridation of the substrate can result in unwanted material loss during subsequent etching processes. This is illustrated in FIGS. 1A-1C. FIG. 1A shows a substrate 100 including silicon mandrels 102A and 102B. The silicon mandrels 102A and 102B include amorphous silicon (α-Si). FIG. 1B shows a silicon nitride film 104 deposited on the silicon mandrels 102A and 102B using PEALD. Because the ALD process uses a direct plasma to promote the growth of the silicon nitride film 104, reactive species formed within the direct plasma impinge on the silicon mandrels 102A and 102B. This results in nitridation of the α-Si. This nitridation forms nitride layers 106A and 106B on the silicon mandrels 102A and 102B, respectively.

[0057] FIG. 1C shows substrate 100 after an etching process to remove silicon nitride film 104. The etching process also removes at least a portion of nitride layers 106A, 106B. This results in material loss from sidewalls 110, 111 of silicon mandrel 102A and sidewalls 112, 113 of silicon mandrel 102B. Due to the material loss, silicon mandrels 102A, 102B shown in FIG. 1C are thinner than those shown in FIG. 1A. Material loss in the mandrels can affect patterning transfer.

[0058] Additionally, the use of direct plasma during PEALD deposition of silicon nitride can result in expansion of carbon substrate features. This is illustrated in Figures 2A-2B. Figure 2A shows a substrate 200 including carbon mandrels 202A and 202B. The carbon mandrels 202A and 202B include amorphous carbon. Figure 2B shows silicon nitride layers 206A and 206B deposited on the carbon mandrels 202A and 202B, respectively. The silicon nitride layers 206A and 206B are deposited using PEALD. Due to the use of direct plasma and high power during PEALD, energetic species in the plasma bombard the carbon mandrels 202A and 202B and react with the carbon, causing the mandrels to expand. As a result, the carbon mandrels 202A and 202B of Figure 2B may not be suitable for patterning applications.

[0059] Additionally, energetic species directly within the plasma can cause halogenation and etching of chalcogenide substrate materials when using halogen-containing precursors. Advanced memory architectures, such as magnetoresistive random access memory (MRAM) and phase-change random access memory (PRAM), may utilize chalcogenides, such as selenium and tellurium. However, such materials may be sensitive to water vapor, oxygen, other gases, and / or plasma. For example, plasma species used in PEALD deposition of silicon nitride can react with chalcogenides to form H2Te or H2Se. Because H2Te and H2Se have relatively low boiling points, the generation of H2Te or H2Se can cause etching.

[0060] Accordingly, examples are disclosed relating to the formation of silicon nitride films by CVD using radical nitrogen species formed in a remote plasma. As described in more detail below, examples of the present disclosure may provide for the growth of conformal films suitable for serving as protective layers prior to conformal atomic layer deposition of silicon nitride. Furthermore, examples of the present disclosure may be substituted for PEALD silicon nitride deposition processes when relatively thin silicon nitride films are desired. Briefly, a nitrogen-containing precursor is introduced into a remote plasma formed in a remote plasma chamber. Radical nitrogen species are formed in the remote plasma. The radical nitrogen species are introduced into a processing chamber containing a substrate. An oxygen-free silicon-containing precursor is introduced into the processing chamber. The radical nitrogen species and the oxygen-free silicon-containing precursor react to form a silicon nitride film on the substrate. By using radical species formed in the remote plasma to activate the oxygen-free silicon-containing precursor, examples of the present disclosure may help avoid direct plasma damage, such as nitridation, expansion, halogenation, and etching. In some examples, relatively high pressures and / or relatively low power may be used compared to other CVD processes, providing a low bombardment energy suitable for the substrate surface. Additionally, using silicon-containing precursors that are oxygen-free and / or halogen-free for CVD deposition can help avoid oxidation and / or etching of the substrate material.

[0061] According to the present disclosure, deposition of silicon nitride films by CVD may be performed using precursors that are relatively inexpensive compared to other methods, such as PEALD. For example, silane-based precursors, such as silane and polysilane, may be used. These materials may be less expensive than other silicon-containing film precursors, such as trisilylamine (TSA). Therefore, examples of the present disclosure may offer cost savings compared to forming nitride films by PEALD. Examples of the present disclosure may also help avoid the above-mentioned issues related to substrate damage, swelling, halogenation, and / or etching due to nitridation.

[0062] As noted above, according to the present disclosure, CVD-deposited silicon nitride films may be used as a stand-alone film in place of PEALD silicon nitride films. This is because the CVD deposition methods of the present disclosure form relatively conformal silicon nitride films. Some such conformal CVD-deposited silicon nitride films may include thicknesses of 50 Å or less. Other conformal CVD-deposited silicon nitride films according to the present disclosure may include thicknesses greater than 50 Å.

[0063] In another example, according to the present disclosure, a silicon nitride film deposited by CVD may be used as an interface layer. For example, according to the present invention, a silicon nitride film deposited by CVD may be used to form a protective silicon nitride film on a substrate surface vulnerable to PEALD damage. PEALD may then be performed to deposit an additional layer of silicon nitride on the silicon nitride film. In this manner, the CVD-deposited silicon nitride film serves as an interface layer between the substrate material and the ALD silicon nitride layer. Due to the conformal nature of the CVD-deposited silicon nitride interface layer, the overall silicon nitride can be as conformal as if the silicon nitride film were deposited using PEALD alone. Furthermore, according to examples disclosed herein, substrate damage may be avoided by depositing the silicon nitride film first.

[0064] FIG. 3 shows a flow diagram of an exemplary method 300 for forming a silicon nitride film on a substrate. At 302, the method 300 includes introducing a nitrogen-containing precursor into a remote plasma formed in a remote plasma chamber. The nitrogen-containing precursor may include any suitable gas capable of forming radical nitrogen species within the plasma. Examples include nitrogen (N), ammonia (NH), hydrazine (NH), and amines, such as diamines and alkylamines. In some examples, introducing the nitrogen-containing precursor in 302 includes introducing a mixture of nitrogen and hydrogen. In such examples, at 304, the method 300 includes introducing one or more of nitrogen, nitrogen / hydrogen, ammonia, hydrazine, or amines into the remote plasma. Additionally, hydrogen can be mixed with ammonia, hydrazine, and other nitrogen-containing precursors. In some examples, an inert gas may be flowed into the remote plasma. Examples of inert gases include helium (He) and argon (Ar).

[0065] At 308, the method 300 includes forming radical nitrogen species in the remote plasma. Examples of radical nitrogen species include N radicals, NH radicals, NH radicals, and NH radicals. In some examples, the radical nitrogen species may be formed by generating an inductively coupled plasma. In other examples, the radical nitrogen species may be formed by generating a capacitively coupled plasma. As a further example, a microwave plasma may be used. Any suitable radio frequency (RF) power may be used to form the plasma. In some examples, the method 300 includes forming the remote plasma at 310 using radio frequency power in the range of 300 to 2000 watts (W). In other examples, RF power outside this range may be used.

[0066] Continuing, the method 300 includes flowing an oxygen-free silicon-containing precursor into the processing chamber at 312. Examples of oxygen-free silicon-containing precursors may include materials having the general structure: [ka] wherein R1, R2, and R3 may be the same or different substituents and may include organic groups such as silane, amine, hydrogen, or alkylamine, alkyl, alkenyl, alkynyl, and aromatic groups.

[0067] More specific examples of oxygen-free silicon-containing precursors include silane-based precursors (silane and polysilanes ((H3Si-(SiH2))) as shown in 314). n -SiH3), where n≧0). Also, an example of an oxygen-free silicon-containing precursor is trisilylamine (TSA). As a further example, the oxygen-free silicon-containing precursor may include an aminosilane, such as bis(diethylamino)silane, diisopropylaminosilane, bis(t-butylamino)silane (BTBAS), di-sec-butylaminosilane, or tris(dimethylamino)silane (3DMAS). Aminosilane precursors have the general formula: H x -Si-(NR) y , where x=1 to 3, and x+y=4, and R is a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted aromatic group, or a hydride group.

[0068] The use of silane-based precursors can offer cost savings compared to examples using more expensive precursors such as trisilylamine or halosilane, although trisilylamine and / or halosilane precursors may be used in other examples.

[0069] In some instances, the oxygen-free silicon-containing precursor is also halogen-free. The use of oxygen-free and halogen-free silicon-containing precursors can help avoid etching. Halogen-containing precursors can be used when etching of halides is less of a concern.

[0070] In some examples, an inert gas is flowed into the processing chamber as a carrier gas along with the oxygen-free silicon-containing precursor. Examples include nitrogen, helium, and argon.

[0071] The method 300 further includes, at 316, introducing radical nitrogen species into the processing chamber from the remote plasma chamber while flowing the oxygen-free silicon-containing precursor, such that the radical nitrogen species can react with the oxygen-free silicon-containing precursor, thereby forming a silicon nitride film on the substrate.

[0072] In some examples, the substrate may include one or more mandrels. Thus, in such examples, a silicon nitride film is formed on one or more mandrels at 318. In some examples, the mandrels include amorphous silicon mandrels at 320. In some examples, the mandrels include amorphous carbon mandrels at 322. In some examples, a silicon nitride film may be deposited over the mandrels to form a protective interface layer.

[0073] Because method 300 uses a remote plasma rather than a direct plasma, the method may help avoid plasma damage, deformation, and / or nitridation of substrate features. The deposition of silicon nitride over the mandrels is described in more detail below with reference to FIG.

[0074] In other examples, method 300 may be used to form a silicon nitride film on any other suitable substrate feature. For example, a silicon nitride film may be formed in a gap on a substrate at 324. In some such examples, the gap may include a relatively high aspect ratio, such as an aspect ratio in the range of 10:1 to 30:1.

[0075] The method 300 may utilize any suitable processing conditions for forming a silicon nitride film. In some examples, the substrate is heated during the formation of the silicon nitride film. In some such examples, the substrate may be heated to a temperature within a range of 25° C. to 400° C. In other examples, the substrate may be heated to a temperature above this range.

[0076] Furthermore, any suitable pressure may be used during the deposition of the silicon nitride. In some examples, at 326, the method 300 includes controlling the pressure of the process chamber within a range of 2 Torr to 8 Torr during the formation of the silicon nitride film. Such a pressure may help avoid substrate damage from reactive species formed in the remote plasma compared to lower pressures. For example, using a relatively high pressure may shorten the mean free path of radical nitrogen species compared to relatively low pressures. The shorter mean free path may reduce the collision rate of radical nitrogen species impinging on the substrate surface. The reduced collision rate may help avoid plasma damage.

[0077] Furthermore, any suitable RF power may be used to form the remote plasma. Examples include RF powers in the range of 300 W to 2000 W. Using a relatively low RF power may reduce the collision energy of radical nitrogen species impinging on the substrate surface compared to using a relatively high power. The reduced collision energy may make it easier to avoid plasma damage.

[0078] In some examples, process conditions may be controlled to achieve a desired degree of conformality for the silicon nitride film. For example, using a relatively high pressure together with a relatively low RF power may facilitate achieving a relatively conformal silicon nitride film. Thus, at 328, in some examples, the method 300 includes forming a conformal silicon nitride film. Film conformality refers to the thickness of the film at the top of the feature relative to the thickness of the film at another location in the feature, such as the bottom or mid-sidewalls. In some examples, the thickness of the silicon nitride film near the bottom of the feature is within a range of 90% to 110% of the thickness of the silicon nitride film at the top of the feature. In examples where a silicon nitride film is formed in one or more gaps at 324, conformal deposition may facilitate filling the gaps without forming voids. In other examples, a less conformal silicon nitride film may be formed. A less conformal film may be formed using a relatively high RF power and / or a relatively low pressure.

[0079] In some examples, the silicon nitride film formed in 316 may be a single film. In some examples, the single film may include a thickness within a range of 3 Å to 50 Å. In other examples, the film may have a thickness outside this range.

[0080] In other examples, the silicon nitride film formed in 316 may be an interfacial film. In such examples, at 330, the method 300 further includes performing PEALD to deposit additional silicon nitride on the silicon nitride film. As discussed above, PEALD of silicon nitride can be damaging to the substrate if an interfacial layer is not present. However, the silicon nitride film formed in 316 can protect the substrate from plasma damage during PEALD, as shown in 330.

[0081] In some examples, the silicon nitride film may be formed as part of a patterning application. For example, a silicon nitride film may be deposited over the mandrels to protect them during subsequent processing steps. The protective silicon nitride film may then be removed, allowing the mandrels to be used for patterning. In other examples, the silicon nitride film may be deposited to form spacers on the sidewalls of the mandrels.

[0082] 4A-4C schematically illustrate an exemplary silicon nitride film formed on mandrels using CVD. First, FIG. 4A illustrates a substrate 400 including mandrels 402A and 402B. The mandrels 402A and 402B may comprise any suitable material, such as carbon or α-Si. Next, FIG. 4B illustrates a silicon nitride film 404 deposited above the mandrels 402A and 402B. Method 300 is an example of a method for forming the silicon nitride film 404. The silicon nitride film 404 may have any suitable thickness. Examples include thicknesses in the range of 3 Å to 50 Å. In some examples, the silicon nitride film 404 can be deposited relatively conformally by using relatively high pressure and / or relatively low RF power.

[0083] By introducing radical nitrogen species from a remote plasma and reacting with the oxygen-free silicon-containing precursor, plasma damage to the mandrels 402A, 402B can be avoided. This can help prevent material loss and / or expansion. In contrast to FIG. 1B, the silicon nitride film 404 can be deposited while avoiding nitridation of the mandrels 402A, 402B. In contrast to FIG. 2B, the silicon nitride film 404 can be deposited while avoiding expansion of the mandrels 402A, 402B. In this way, in the example where the silicon nitride film 404 is removed by etching, the shape of the mandrels 402A, 402B can be preserved. This can be useful for patterning applications.

[0084] FIG. 4C illustrates an example of conformal deposition of additional silicon nitride using ALD. The additional silicon nitride 406 is deposited above the silicon nitride film 404. The deposition of the additional silicon nitride 406 may be performed using any suitable ALD process, such as PEALD or thermal ALD (TANDE). In a PEALD cycle, a silicon-containing precursor is introduced into the processing chamber and adsorbed onto the substrate 400. The silicon-containing precursor may include any suitable precursor capable of reacting to form a silicon nitride film. Examples include silane-based precursors, TSA, alkylsilanes, and halosilanes. Excess silicon-containing precursor is purged from the processing chamber. A nitrogen-containing precursor is then introduced. Examples of nitrogen-containing precursors include nitrogen (N), nitrogen / hydrogen, ammonia (NH), hydrazine (NH), and amines, such as diamines and alkylamines. A plasma is struck into the processing chamber to form radical nitrogen species that react with the adsorbed silicon-containing precursor to form the additional silicon nitride 406. In an ALD cycle, thermal energy may be used to drive the reaction. One or more ALD cycles may be performed to form a conformal silicon nitride film of a target thickness.

[0085] FIG. 5 schematically illustrates an exemplary structure formed during a CVD process to deposit silicon nitride in gaps on a substrate 500. The substrate 500 may represent an intermediate structure in the fabrication of a trench isolation region, a memory structure, or one or more logic gates. As shown in FIG. 5A, the substrate 500 includes gaps 510, 511, 512, 513, and 514. The gaps may include any suitable aspect ratio(s). In some examples, the gaps 510, 511, 512, 513, and 514 may have an aspect ratio or ratio within a range of 10:1 to 30:1. In other examples, the gaps may have an aspect ratio or ratio outside of this range.

[0086] Next, FIG. 5B shows a silicon nitride film 520 formed on the substrate 500, including gaps 510, 511, 512, 513, and 514. The silicon nitride film 520 is deposited using CVD by reacting an oxygen-free silicon-containing precursor with radical nitrogen species formed in a remote plasma. As noted above, conformal deposition of a film into a gap using CVD can be challenging. During CVD, the growth rate of a film toward the top of the gap may differ from the growth rate of a film toward the bottom of the gap. However, examples of the present disclosure can successfully grow a conformal silicon nitride film using CVD. For example, the silicon nitride film 520 can be deposited using the method 300 under conditions that favor conformal film growth. As noted above, relatively high pressure and relatively low RF power can favor a conformal silicon nitride film. Therefore, the thickness 522 of the silicon nitride film 520 at the top of the gap 514 can be similar to the thickness 524 at the bottom of the gap 514. In some examples, thickness 524 is within a range of 90% to 120% of thickness 522. Further, in some examples, thickness 524 is within a range of 100% to 110% of thickness 522. In some examples, a relatively low RF power may make it easier to achieve a thickness 524:thickness 522 ratio closer to 1:1 compared to examples using a relatively high RF power. Conformal deposition of silicon nitride film 520 may make it easier to avoid the formation of re-entrant features, which narrow relative to the substrate surface in a direction extending from the bottom of the gap to the top of the gap. Such re-entrant features may be subject to closure in subsequent conformal ALD processes.

[0087] In some examples, the silicon nitride film 520 may comprise a single film. In other examples, the silicon nitride film 520 may function as an interfacial layer. FIG. 5C shows an additional silicon nitride 530 deposited above the silicon nitride film 520. In this figure, the silicon nitride film 520 is an interfacial layer. In the illustrated example, the silicon nitride 530 layer fills the gaps 510, 511, 512, 513, and 514. The silicon nitride 530 layer may be deposited using ALD (e.g., PEALD or TALLD). As discussed above, if an interfacial layer is not present, PEALD of the silicon nitride may cause damage to the substrate. However, the silicon nitride film 520 can protect the substrate 500 from plasma damage during PEALD. Furthermore, the conformality of the silicon nitride film 520 allows additional silicon nitride to be deposited by ALD to fill the gaps 510, 511, 512, 513, 514 without forming voids (hollow cavities) in the substrate. The voids are hollow cavities formed in the substrate. Thus, examples disclosed herein may facilitate filling gaps on a substrate, including high aspect ratio gaps, while avoiding substrate damage.

[0088] 6 shows an exemplary CVD tool 600 that can be used to deposit a silicon nitride film on a substrate using a remote plasma. The CVD tool 600 includes a processing chamber 602 and a substrate support 604 within the processing chamber. The substrate support 604 is configured to support a substrate 606 disposed within the processing chamber 602. In some examples, the substrate support 604 includes a substrate heater 608. The substrate support 604 may include a pedestal, an electrostatic chuck pedestal, a showerhead pedestal, or any other suitable structure.

[0089] The CVD tool 600 further includes a process gas inlet 610. The process gas inlet 610 is configured to introduce radical species into the process chamber 602 from a remote plasma chamber 612. In some examples, the process gas inlet 610 may be configured to filter ions and / or radiation generated in the remote plasma chamber 612. In some examples, the process gas inlet 610 includes a showerhead.

[0090] CVD tool 600 further comprises flow control hardware 614, 616. Flow control hardware 614 is connected to a nitrogen-containing precursor source 620, an optional hydrogen source 622, and an inert gas source 623. Flow control hardware 616 is connected to an oxygen-free silicon-containing precursor source 624 and an inert gas source 623.

[0091] The nitrogen-containing precursor source 620 may include any suitable nitrogen-containing precursor that is oxygen-free. Examples include nitrogen, ammonia, hydrazine, and amines such as diamines and alkylamines. The optional hydrogen source 622 includes hydrogen gas. In other examples, the hydrogen source may be omitted. In some such examples, the nitrogen-containing precursor source may include a mixture of nitrogen-containing molecules (e.g., N2 or NH3) and hydrogen (H2).

[0092] The oxygen-free silicon-containing precursor source 624 includes any suitable oxygen-free silicon-containing precursor. Examples include silane-based precursors, TSAs, and aminosilanes, as described above. The use of silane-based precursors can facilitate cost reduction compared to other precursors, such as TSAs. However, in some examples, TSAs may be used. In some examples, the oxygen-free silicon-containing precursor may be halogen-free. The inert gas source 623 may include any suitable inert gas, and may include two or more different inert gases that may be flowed separately. Examples include helium, nitrogen, and argon.

[0093] The flow control hardware 614 is configured to control the flow of a nitrogen-containing precursor from a nitrogen-containing precursor source 620 into the remote plasma chamber 612. The flow control hardware 614 is further configured to control the flow of hydrogen from an optional hydrogen source 622 into the remote plasma chamber 612. The flow control hardware 614 is further configured to control the flow of an inert gas (e.g., He, Ar) from an inert gas source 623 into the remote plasma chamber 612. Similarly, the flow control hardware 616 is configured to control the flow of an oxygen-free silicon-containing precursor into the processing chamber 602. The flow control hardware 616 is also configured to control the flow of an inert gas (e.g., He, N, Ar) into the processing chamber 602. In some examples, the inert gas flowing through the flow control hardware 616 is different from the inert gas flowing through the flow control hardware 614. The flow control hardware 614, 616 may comprise one or more mass flow controllers and / or valves to control the flow rates of the gases.

[0094] The remote plasma chamber 612 is configured to generate a remote plasma from the nitrogen-containing precursor to generate radical nitrogen species. In some examples, the remote plasma chamber 612 may be configured to generate an inductively coupled plasma. In other examples, the remote plasma chamber 612 may be configured to generate a capacitively coupled plasma. In further examples, a microwave plasma may be used. The radical nitrogen species may flow into the processing chamber 602 through the process gas inlet 610. The radical nitrogen species may facilitate reaction with the oxygen-free silicon-containing precursor to form a silicon nitride film on the substrate 606. By forming the radical nitrogen species in the remote plasma chamber, the CVD tool 600 may be more likely to avoid plasma damage to the substrate 606.

[0095] CVD tool 600 further comprises an exhaust system 632. Exhaust system 632 is configured to receive gases exiting process chamber 602. In some examples, exhaust system 632 is configured to actively remove gases and / or apply a partial vacuum from process chamber 602. Exhaust system 632 may comprise any suitable hardware, including one or more pumps.

[0096] The CVD tool 600 further includes an RF power supply 634 electrically connected to a plasma generation circuit within the remote plasma chamber 612. Examples of the plasma generation circuit include a capacitor plate for generating a capacitively coupled plasma or a coil for generating an inductively coupled plasma. The CVD tool 600 may further include a matching network 636 for impedance matching of the RF power supply 634. The RF power supply 634 may be configured to provide an appropriate frequency and power to form a plasma within the remote plasma chamber 612. Examples of appropriate frequencies include frequencies within the range of 0.3 MHz to 10 GHz. Examples of appropriate power include power within the range of 300 W to 2000 W. In some examples, the radio frequency power supply 634 is configured to operate at multiple different frequencies and / or powers. In other examples, a microwave plasma may be used.

[0097] The controller 650 is operably coupled to the substrate heater 608, the flow control hardware 614, 616, the remote plasma chamber 612, the exhaust system 632, and the RF power supply 634. Additionally, the controller 650 may be operably coupled to any other suitable components of the CVD tool 600. The controller 650 is configured to control various functions of the CVD tool 600 to deposit a silicon nitride film on a substrate. For example, the controller 650 is configured to operate the substrate heater 608 to heat the substrate. The controller 650 is also configured to operate the flow control hardware 614 to flow a nitrogen-containing precursor into the remote plasma chamber 612 at a selected flow rate. In some examples, the controller 650 is also configured to control the flow control hardware 614 to flow hydrogen into the remote plasma chamber 612. In some examples, the controller 650 is also configured to control the flow control hardware 614 to flow an inert gas into the remote plasma chamber 612. Additionally, the controller 650 is configured to cause the RF power source 634 to form a remote plasma for introducing radical nitrogen species into the processing chamber 602 .

[0098] The controller 650 is also configured to operate the flow control hardware 616 to introduce the oxygen-free silicon-containing precursor into the process chamber 602. The controller 650 is also configured to operate the flow control hardware 616 to flow an inert gas along with the oxygen-free silicon-containing precursor into the process chamber 602. In this manner, the controller 650 can introduce the oxygen-free silicon-containing precursor and radical nitrogen species into the process chamber 602. The radical nitrogen species react with the oxygen-free silicon-containing precursor to form a silicon nitride film on a substrate 606 disposed in the process chamber 602.

[0099] The controller 650 is also configured to operate the exhaust system 632 to remove gases from the process chamber 602. The controller 650 is further configured to operate the flow control hardware 614, 616 and the exhaust system 632 to maintain a selected pressure within the process chamber 602. In some examples, the controller 650 is configured to maintain a pressure within a range of 2 to 8 Torr while flowing an oxygen-free silicon-containing precursor into the process chamber 602.

[0100] The controller 650 is further configured to control the process conditions (e.g., pressure, RF power, gas flow) to control conformality, thickness, and other film properties, and any other functions of the CVD tool 600.

[0101] The controller 650 may comprise any suitable computing system. Figure 7 illustrates a schematic, non-limiting embodiment of a computing system 700 capable of performing one or more of the methods and processes described above. The computing system 700 is illustrated in simplified form. The computing system 700 may take the form of one or more personal computers, workstations, computers integrated into a substrate processing tool, and / or networkable server computers.

[0102] Computing system 700 includes a logic machine 702 and a storage machine 704. Computing system 700 may optionally include a display subsystem 706, an input subsystem 708, a communication subsystem 710, and / or other components not shown in Figure 7. Controller 650 is an example of computing system 700.

[0103] The logical machine 702 includes one or more physical devices configured to execute instructions. For example, the logical machine may be configured to execute instructions that are part of one or more applications, services, programs, routines, libraries, objects, components, data structures, or other logical constructs. Such instructions may be implemented to perform a task, implement a data type, transform the state of one or more components, achieve a technical effect, or otherwise arrive at a desired result.

[0104] A logical machine may include one or more processors configured to execute software instructions. Additionally or alternatively, a logical machine may include one or more hardware or firmware logical machines configured to execute hardware or firmware instructions. The processors of a logical machine may be single-core or multi-core, and the instructions executed thereon may be configured for sequential, parallel, and / or distributed processing. Individual components of a logical machine may optionally be distributed across two or more separate devices, which may be remotely located and / or configured for cooperative processing. Aspects of a logical machine may be virtualized and executed by remotely accessible, networked computing devices arranged in a cloud computing configuration.

[0105] The storage machine 704 includes one or more physical devices configured to hold instructions 712 executable by a logical machine to implement the methods and processes described herein. When such methods and processes are implemented, the state of the storage machine 704 may be transformed, for example, to hold different data.

[0106] The storage machine 704 may include removable and / or internal devices. The storage machine 704 may include optical memory (e.g., CD, DVD, HD-DVD, Blu-ray disc, etc.), semiconductor memory (e.g., RAM, EPROM, EEPROM, etc.), and / or magnetic memory (e.g., hard disk drive, floppy disk drive, tape drive, MRAM, etc.). The storage machine 704 may include volatile, non-volatile, dynamic, static, read / write, read-only, random access, sequential access, position addressable, file addressable, and / or content addressable devices.

[0107] It should be understood that storage machine 704 includes one or more physical devices, although aspects of the instructions described herein may alternatively be propagated by a communication medium (e.g., electromagnetic signals, optical signals, etc.) that is not retained for a finite period by a physical device.

[0108] Aspects of the logic machine 702 and storage machine 704 may be integrated into one or more hardware logic components, which may include, for example, field programmable gate arrays (FPGAs), program and application specific integrated circuits (PASICs / ASICs), program and application specific standard products (PSSPs / ASSPs), systems on a chip (SOCs), and complex programmable logic devices (CPLDs).

[0109] If included, display subsystem 706 can be used to display a visual representation of the data maintained by storage machine 704. This visual representation may take the form of a graphical user interface (GUI). When the methods and processes described herein modify the data maintained by the storage machine, and thus transform the state of the storage machine, the state of display subsystem 706 may be similarly transformed to visually represent the changes to the underlying data. Display subsystem 706 may include one or more display devices utilizing virtually any type of technology. Such display devices may be incorporated into a common enclosure with logic machine 702 and / or storage machine 704, or such display devices may be peripheral display devices.

[0110] If included, the input subsystem 708 may comprise or interface with one or more user input devices, such as a keyboard, mouse, or touchscreen. In some embodiments, the input subsystem may comprise or interface with selected natural user input (NUI) components. Such components may be integrated or peripheral, and translation and / or processing of input actions may be handled on-board or off-board. Examples of NUI components may include microphones for speech and / or voice recognition, and infrared, color, stereo, and / or depth cameras for machine vision and / or gesture recognition.

[0111] If included, the communications subsystem 710 may be configured to communicatively connect the computing system 700 with one or more other computing devices. The communications subsystem 710 may include wired and / or wireless communication devices compatible with one or more different communications protocols. As a non-limiting example, the communications subsystem may be configured for communication over a wireless telephone network, or a wired or wireless local area network or wide area network. In some embodiments, the communications subsystem may enable the computing system 700 to send and / or receive messages to other devices over a network, such as the Internet.

[0112] It will be understood that the configurations and / or approaches described herein are exemplary in nature and are susceptible to numerous variations, and therefore, these specific embodiments or examples should not be construed in a limiting sense. The particular routines or methods described herein may represent one or more of any number of processing strategies. As such, various operations shown and / or described may be performed in the order shown and / or described, in other orders, in parallel, or omitted. Similarly, the order of the processes described above may be changed.

[0113] The subject matter of the present disclosure includes all novel and non-obvious combinations and subcombinations of the various processes, systems, and configurations, and other features, functions, operations, and / or properties disclosed herein, and any and all equivalents thereof.

Claims

1. A method (300) of forming a silicon nitride film on a substrate in a processing chamber by chemical vapor deposition, comprising: Introducing (302) a nitrogen-containing precursor into a remote plasma formed in a remote plasma chamber (612) of a processing tool (600); forming radical nitrogen species within the remote plasma (308); flowing an oxygen-free silicon-containing precursor into a processing chamber of the processing tool (312); introducing (316) the radical nitrogen species into the processing chamber from the remote plasma chamber while flowing the oxygen-free silicon-containing precursor; reacting the oxygen-free silicon-containing precursor with the radical nitrogen species to form the silicon nitride film on the substrate (316); A method comprising:

2. 10. The method of claim 1, The method, wherein forming the silicon nitride film comprises forming a conformal silicon nitride film.

3. 10. The method of claim 1, The method, wherein flowing the oxygen-free silicon-containing precursor comprises flowing a silane-based precursor.

4. 10. The method of claim 1, The method, wherein forming the silicon nitride film comprises forming the silicon nitride film on one or more of an amorphous silicon mandrel or an amorphous carbon mandrel.

5. 10. The method of claim 1, The method, wherein forming the silicon nitride film includes forming the silicon nitride film in one or more gaps on the substrate.

6. 10. The method of claim 1, The method further comprising performing atomic layer deposition to deposit additional silicon nitride on the silicon nitride film.

7. 10. The method of claim 1, The method, wherein forming nitrogen radical species comprises forming the remote plasma using radio frequency power in the range of 300 to 2000 watts.

8. 10. The method of claim 1, The method further comprising controlling the pressure of the processing chamber within a range of 2 to 8 Torr while forming the silicon nitride film.

9. 10. The method of claim 1, The method, wherein introducing the nitrogen-containing precursor into the remote plasma comprises introducing nitrogen, nitrogen / hydrogen, ammonia, hydrazine, or an amine into the remote plasma.

10. 1. A method of forming a silicon nitride film on a substrate in a processing chamber of a chemical vapor deposition (CVD) tool (600), comprising: introducing (302) a nitrogen-containing precursor into a remote plasma formed in a remote plasma chamber (612) of the CVD tool; forming radical nitrogen species within the remote plasma (308); introducing (312) an oxygen-free silicon-containing precursor into the processing chamber of the CVD tool; introducing (316) the radical nitrogen species into the processing chamber from the remote plasma chamber; reacting the oxygen-free silicon-containing precursor with the radical nitrogen species to form the silicon nitride film on the substrate (316); performing atomic layer deposition to form one or more additional layers of silicon nitride on the silicon nitride film (330); A method comprising:

11. 11. The method of claim 10, The method, wherein forming the silicon nitride film on the substrate includes forming the silicon nitride film on one or more mandrels.

12. 12. The method of claim 11, The method, wherein the one or more mandrels comprise amorphous silicon.

13. 12. The method of claim 11, The method, wherein the one or more mandrels comprise amorphous carbon.

14. 11. The method of claim 10, The method, wherein forming the silicon nitride film on the substrate includes forming the silicon nitride film in one or more gaps on the substrate.

15. 11. The method of claim 10, The method, wherein introducing the oxygen-free silicon-containing precursor into the processing chamber comprises introducing a silane-based precursor into the processing chamber.

16. 11. The method of claim 10, The method, wherein introducing the nitrogen-containing precursor into the remote plasma comprises introducing one or more of nitrogen, nitrogen / hydrogen, ammonia, hydrazine, or an amine into the remote plasma.

17. A chemical vapor deposition (CVD) tool (600) comprising: a processing chamber (602); a remote plasma chamber (612); a radio frequency power source (634) configured to form a plasma in the remote plasma chamber; a nitrogen precursor source (620) comprising a nitrogen-containing precursor; an oxygen-free silicon-containing precursor source (624) comprising an oxygen-free silicon-containing precursor; flow control hardware (614, 616) configured to introduce the nitrogen-containing precursor into the remote plasma chamber and the oxygen-free silicon-containing precursor into the process chamber; A controller (650, 700) comprising: Operate the flow control hardware to introduce the nitrogen-containing precursor into the remote plasma chamber (302); operating the radio frequency power source to form a plasma comprising radical nitrogen species from the nitrogen-containing precursor (308); Operate the flow control hardware to flow the oxygen-free silicon-containing precursor into the processing chamber (312); Operate the flow control hardware to introduce the radical nitrogen species from the remote plasma chamber into the processing chamber to react with the oxygen-free silicon-containing precursor and form a silicon nitride film on a substrate (316). A controller (650, 700) configured as follows: A chemical vapor deposition (CVD) tool comprising:

18. 18. The CVD tool of claim 17, A CVD tool, wherein the nitrogen-containing precursor source comprises one or more of nitrogen, nitrogen / hydrogen, ammonia, hydrazine, or an amine.

19. 18. The CVD tool of claim 17, further comprising a hydrogen-containing precursor source comprising hydrogen gas; The CVD tool, wherein the controller is configured to operate the radio frequency power source to form the plasma from the nitrogen-containing precursor and the hydrogen gas.

20. 18. The CVD tool of claim 17, It also has an exhaust system, 10. The CVD tool, wherein the controller is configured to operate the exhaust system and the flow control hardware to generate a pressure within a range of 2 to 8 Torr within the processing chamber during formation of the silicon nitride film on the substrate.

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