Pulsed ALD sequence for low fluorine WN deposition

Abstract

Provided herein is a method of forming a tungsten nitride (WN) barrier layer in a feature, the method comprising forming a tungsten sub-layer by dosing diborane to a chamber and sweeping the diborane from the chamber one or more times, and after dosing and sweeping the diborane, dosing tungsten hexafluoride to the chamber and sweeping the tungsten hexafluoride from the chamber multiple times; after forming the tungsten sub-layer, dosing diborane into the chamber and sweeping the diborane from the chamber; and after dosing and purging the diborane, dosing a nitriding agent to the chamber to convert the tungsten sub-layer into a tungsten nitride sub-layer and purging the nitriding agent from the chamber.

Description

Related Applications

[0001] The PCT application form is filed simultaneously with this specification as part of this application. Each application identified in the PCT application form filed simultaneously that this application claims the benefit of or priority to is incorporated herein by reference in its entirety and for all purposes. Background Art

[0002] Depositing materials containing tungsten-containing materials is an integral part of many semiconductor manufacturing processes. These materials can be used for horizontal interconnects, vias between adjacent metal layers, and contacts between metal layers and devices. As devices are scaled down and more complex patterning schemes are used in the industry, the deposition of tungsten films has become a challenge. The continuous reduction of feature sizes and film thicknesses has presented various challenges, including the relatively high resistivity of the film and the difficulty of achieving void-free filled features. Deposition in complex high aspect ratio structures such as 3D NAND structures is particularly challenging.

[0003] The background description provided here is for the purpose of generally presenting the background of the present disclosure. The work of the currently named inventors within the scope described in this background art section and aspects of the specification that were not determined to be prior art at the time of filing the application are neither expressly nor impliedly admitted to be prior art against the present disclosure. Summary of the Invention

[0004] Methods for forming tungsten nitride (WN) barrier layers in features are provided herein. The methods include an atomic layer deposition (ALD) pulse sequence using tungsten hexafluoride (WF6) as a reactant to form a low fluorine concentration in the deposited WN barrier layer. The methods also include methods of loading wafers into a multi-station tool to reduce non-uniformity of tungsten-containing layers between stations.

[0005] One aspect of the present disclosure relates to a method that includes: providing a 3-D structure of a partially fabricated semiconductor substrate to a chamber, the 3-D structure including sidewalls, a plurality of openings in the sidewalls leading to a plurality of features, the features having a plurality of internal regions that can be fluidly accessed via the openings; depositing a tungsten nitride film in the plurality of features using one or more deposition cycles, each deposition cycle including (a)-(c): (a) Forming a tungsten sublayer by: i) Dispensing diborane into the chamber and purging diborane from the chamber one or more times; ii) After (i), dispensing tungsten hexafluoride into the chamber and purging tungsten hexafluoride from the chamber multiple times; (b) After (a), dispensing diborane into the chamber and purging diborane from the chamber; and (c) After (b), introducing a nitriding agent into the chamber to convert the tungsten sub-layer into a tungsten nitride sub-layer and purging the nitriding agent from the chamber.

[0006] In some embodiments, the nitriding agent is ammonia. In some embodiments, the tungsten nitride film is deposited on an alumina film among the plurality of features. In some embodiments, 2, 3, or 4 deposition cycles are used to deposit the tungsten nitride film having to the thickness of.

[0007] In some embodiments, each deposition cycle includes performing two or more repetitions of (i) before the first repetition of (ii) in the deposition cycle. In some embodiments, each deposition cycle includes at least 3 repetitions of (ii). In some embodiments, each deposition cycle includes at least 3 repetitions of (ii). In some embodiments, each deposition cycle includes at least 5 repetitions of (ii).

[0008] In some embodiments, each of (b) and (c) is performed only once in each deposition cycle. In some embodiments, the number of repetitions of (ii) in each deposition cycle is greater than the number of repetitions of (i). In some embodiments, the duration of each introduction in (i) is from 1 second to 2 seconds. In some embodiments, the duration of each purge in (i) is less than 5 seconds. In some embodiments, the duration of each introduction in (ii) is less than 1 second. In some embodiments, the duration of each purge in (i) is between 1 second and 2 seconds. In some embodiments, the duration of the introduction in (b) is 2 to 10 times the duration of each introduction in (i). In some embodiments, the overall volume ratio of B2H6 to WF6 in (a) is at least 2:1.

[0009] In some embodiments, the concentration of fluorine (F) in the tungsten nitride film is less than 1.0E21. In some embodiments, the concentration of fluorine (F) in the tungsten nitride film is less than 1.0E20. In some embodiments, the concentration of fluorine (F) in the tungsten nitride film is less than 1.0E19. In some embodiments, the concentration of fluorine (F) in the tungsten nitride film is less than 5E18.

[0010] In some embodiments, the method further includes filling the plurality of features with a metal after depositing the tungsten nitride film.

[0011] Another aspect of the present disclosure relates to an apparatus including: a processing chamber including one or more showerheads for guiding gases in the processing chamber and one or more substrate supports; A controller configured to execute machine-readable instructions for depositing a tungsten nitride film using one or more deposition cycles, each deposition cycle including (a)-(c): (a) Causing a tungsten sublayer to be formed by: i) Causing diborane to be dispensed into the processing chamber and purging the diborane from the processing chamber one or more times; ii) After (i), causing tungsten hexafluoride to be dispensed into the processing chamber and purging the tungsten hexafluoride from the processing chamber multiple times; (b) After (a), causing diborane to be dispensed into the processing chamber and purging the diborane from the processing chamber; and (c) After (b), causing a nitriding agent to be dispensed into the processing chamber to convert the tungsten sublayer into a tungsten nitride sublayer and purging the nitriding agent from the processing chamber.

[0012] In another aspect of the embodiments herein, a method of depositing a tungsten-containing layer is provided, the method comprising: providing a processing chamber comprising a plurality of stations; positioning each of a plurality of substrates to a corresponding one of the plurality of stations; after positioning all of the plurality of substrates to the corresponding stations, reducing the pressure in the processing chamber to below a first pressure; after reducing the pressure in the processing chamber to below the first pressure, increasing the pressure in the processing chamber to a second pressure higher than the first pressure; and after increasing the pressure to the second pressure, depositing a tungsten-containing layer on each of the plurality of substrates.

[0013] In some embodiments, each of the plurality of substrates has a three-dimensional (3-D) structure, the 3-D structure including sidewalls and a plurality of openings in the sidewalls leading to a plurality of features, the features having a plurality of internal regions that are fluidly accessible via the openings. In some embodiments, the method further comprises filling the plurality of features with a metal after depositing the tungsten-containing layer. In some embodiments, the first pressure is less than about 100 mTorr. In some embodiments, the second pressure is at least about 3 Torr. In some embodiments, reducing the pressure in the processing chamber is performed for about 10 seconds to about 30 seconds. In some embodiments, the tungsten-containing layer is deposited on an alumina film. In some embodiments, the thickness of the tungsten-containing layer is about to In some embodiments, depositing a tungsten-containing layer includes performing a first set of cycles, and the first set of cycles is performed at each station. In some embodiments, depositing a tungsten-containing layer includes performing a first set of cycles, and each cycle includes (a)-(c): (a) causing a tungsten sublayer to be formed by: i) causing diborane (B2H6) to be dispensed into the processing chamber and purging the diborane from the processing chamber one or more times; ii) after (i), causing a fluorine-containing tungsten precursor to be dispensed into the processing chamber and purging the fluorine-containing tungsten precursor from the processing chamber one or more times; (b) after (a), causing diborane to be dispensed into the processing chamber and purging the diborane from the processing chamber; and (c) after (b), causing a nitriding agent to be dispensed into the processing chamber to convert the tungsten sublayer into a tungsten nitride sublayer and purging the nitriding agent from the processing chamber. In some embodiments, the nitriding agent is ammonia. In some embodiments, each deposition cycle includes two or more repetitions of (i) before the first repetition of (ii) in the deposition cycle. In some embodiments, each deposition cycle includes at least 3 repetitions of (ii). In some embodiments, each deposition cycle includes at least 5 repetitions of (ii). In some embodiments, each deposition cycle performs (b) and (c) only once. In some embodiments, the number of repetitions of (ii) in each deposition cycle is greater than the number of repetitions of (i). In some embodiments, the duration of each dispense in (i) is 1 to 2 seconds. In some embodiments, the duration of each purge in (i) is less than 5 seconds. In some embodiments, the duration of each dispense in (ii) is less than 1 second. In some embodiments, the duration of each purge in (ii) is between 1 and 2 seconds. In some embodiments, the duration of the dispense in (b) is 2 to 10 times the duration of each dispense in (i). In some embodiments, the total volume ratio of diborane to the fluorine-containing tungsten precursor in (a) is at least 2:1. In some embodiments, the fluorine-containing tungsten precursor is WF6.

[0014] In another aspect of the embodiments herein, a system is provided that includes: a processing chamber including a plurality of stations; and a controller configured to execute machine-readable instructions for: positioning each of a plurality of substrates to a corresponding one of the plurality of stations; after positioning all of the plurality of substrates to the corresponding stations, reducing the pressure in the processing chamber to below a first pressure; after reducing the pressure in the processing chamber to below the first pressure, increasing the pressure in the processing chamber to at least a second pressure higher than the first pressure; and performing a first set of cycles, each cycle including (a)-(c): (a) causing a tungsten sublayer to be formed by: i) causing diborane (B2H6) to be dispensed into the processing chamber and purging the diborane from the processing chamber one or more times; ii) after (i), causing a fluorinated tungsten precursor to be dispensed into the processing chamber and purging the fluorinated tungsten precursor from the processing chamber one or more times; (b) after (a), causing diborane to be dispensed into the processing chamber and purging the diborane from the processing chamber; and (c) after (b), causing a nitriding agent to be dispensed into the processing chamber to convert the tungsten sublayer into a tungsten nitride layer and purging the nitriding agent from the processing chamber.

[0015] These and other features of the present disclosure are further described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figures 1A-1E Different views and aspects of an exemplary 3-D NAND structure are shown.

[0017] Figure 2A and 2B A schematic diagram showing features with a conformal barrier layer is shown.

[0018] Figure 3 and Figure 4 A process flow diagram illustrates certain operations in a method of depositing a tungsten nitride layer.

[0019] Figure 5 Individual pulse sequences for depositing tungsten nitride are shown graphically.

[0020] Figure 6 A process flow diagram illustrates certain operations in a method of filling features with metal.

[0021] Figure 7A -B shows indexing a wafer according to various embodiments herein graphically.

[0022] Figures 8-9 A schematic diagram of an apparatus that can be used to perform the methods described herein is shown. DETAILED DESCRIPTION

[0023] In the following description, numerous specific details are set forth to provide a thorough understanding of the presented embodiments. The disclosed embodiments may be practiced without some or all of these specific details. In other instances, well-known processing operations are not described in detail to avoid unnecessarily obscuring the disclosed embodiments. While the disclosed embodiments will be described in conjunction with specific embodiments, it should be understood that they are not intended to limit the disclosed embodiments.

[0024] Methods are provided herein for forming a tungsten-containing layer in a feature, including forming a tungsten nitride (WN) barrier layer in the feature. In certain embodiments, these methods are used to fill word line features in a 3D NAND structure. However, these methods can also be used to form a WN barrier layer in other features including tungsten vias and other vertical features.

[0025] The methods described herein are performed on a substrate (which may be housed in a chamber). The substrate can be a silicon or other semiconductor wafer, such as a 200 mm wafer, a 300 mm wafer, or a 450 mm wafer, which includes a wafer having one or more layers of material (such as dielectric, conductive, or semiconductive material) deposited thereon.

[0026] The substrate can have features such as vias or contact holes, which can be characterized by narrow and / or recessed openings, constrictions within the feature, and / or high aspect ratios. The features can be formed in one or more of the aforementioned layers. For example, the features can be formed at least partially in a dielectric layer. In some embodiments, the features can have an aspect ratio of at least about 2:1, at least about 4:1, at least about 6:1, at least about 10:1, at least about 25:1, or higher. An example of a feature is a hole or via in a semiconductor substrate or a layer on the substrate.

[0027] For some metallization schemes, an adhesion layer and / or a barrier layer can be formed prior to filling the metal to line the feature. A diffusion barrier layer is a layer that prevents the diffusion of substances between layers. An adhesion layer is a layer that promotes adhesion of a layer to the underlying layer.

[0028] In some tungsten metallization applications, tungsten nitride (WN) diffusion barriers can be used. The WN barrier has several advantages compared to the barrier of a titanium adhesion / titanium nitride bilayer (Ti / TiN). These advantages include the ability to conformally deposit a thin WN layer and the ability to deposit WN directly on the dielectric without an adhesion layer. These advantages allow more space to be filled with W, thereby reducing the overall contact resistance. In addition, the deposition of the WN layer can be performed at a much lower temperature than Ti / TiN, which makes it advantageous for low thermal budget applications.

[0029] In some embodiments, these methods are used to deposit a WN barrier layer prior to word line filling in a 3-D NAND structure.Figure 1A A cross-sectional side view of a 3D NAND structure 110 (formed on a silicon substrate 102) is presented, having VNAND stacks (left 125 and right 126), a central vertical structure 130, and multiple stack horizontal features 120, where the horizontal features 120 have multiple openings 122 on opposite sidewalls 140 of the central vertical structure 130. It should be noted that Figure 1A The shown 3D NAND structure 110 of two stacks is shown, which together form a trench-like central vertical structure 130. As Figure 1A shown, there can be more than two stacks arranged in sequence and spatially parallel to each other, and the gaps between adjacent pairs of stacks form the central vertical structure 130. The horizontal features 120 are 3D memory word line features that can be fluidly accessed from the central vertical structure 130 through the openings 122. Present in Figure 1A the shown 3D NAND stacks 125 and 126 (i.e., the left 3D NAND stack 125 and the right 3D NAND stack 126) the horizontal features 120 can also be accessed from other sides of these stacks (the leftmost and the rightmost respectively) through similar vertical structures formed by additional 3D NAND stacks (on the leftmost and on the rightmost, but not shown). In other words, each 3D NAND stack 125, 126 has word line features of the stack that can be fluidly accessed from both sides of the 3D NAND stack through the central vertical structure 130. In the specific example as Figure 1A shown, each 3D NAND stack has 6 pairs of stacked word lines. However, in other embodiments, the 3D NAND memory layout can have any number of vertically stacked word line pairs.

[0030] The word line features in the 3D NAND stack can be formed by depositing alternating stacks of silicon oxide layers and silicon nitride layers, and then selectively removing the nitride layers to leave a stack of oxide layers with gaps therebetween. These gaps are the word line features. As long as there are techniques available for forming word lines and techniques available for successfully achieving (substantially) void-free filling of vertical features, any number of word lines can be vertically stacked in such a 3D NAND structure. Thus, for example, the 3D NAND stack can include 2 to 512 horizontal word line features, 2 to 256 horizontal word line features, 8 to 128 horizontal word line features, or 16 to 64 horizontal word line features, etc. (the listed ranges should be understood to include the enumerated endpoints).

[0031] Figure 1B Presented Figure 1A is a cross-sectional top view of the same 3D NAND structure 110 as shown in the side view, where the cross-section is taken along a horizontal section 160 such as the horizontal dashed line in Figure 1A shown. Figure 1BA cross-section shows several rows of pillars 155 that extend vertically from the bottom of the semiconductor substrate 102 to the top of the 3D NAND structure 110. In some embodiments, these pillars 155 are formed of polysilicon material. The polysilicon pillars can serve as gate electrodes for the memory cells stacked within the pillars. Figure 1B A top view shows that the pillars 155 form a constriction in the opening 122 for the horizontal feature 120, i.e., the fluid accessibility of the horizontal feature 120 from the central vertical structure 130 through the opening 122 (as indicated by the arrow in FIG. 1G) is inhibited by the pillars 155. This reduction in fluid accessibility increases the difficulty of uniformly filling the horizontal feature 120 with material. Figure 1C , 1D FIG. 1E further illustrates the structure of the horizontal feature 120 and the challenge of uniformly filling them with material due to the presence of the pillars 155.

[0032] Figure 1C FIG. Figure 1A shows a vertical cross-section of a 3D NAND structure similar to that shown in FIG. 1G, but here focused on a pair of horizontal features 120. Figure 1C It also schematically illustrates voids 175 in the filled horizontal feature 120. Figure 1D It also schematically illustrates the voids 175, but in this figure they are illustrated by a horizontal cross-section through the pillars 155, which is similar to the horizontal cross-section shown in FIG. 1G. Figure 1E FIG. 1H illustrates the accumulation of tungsten or other metal around the pillars 155 that form the constriction, and this accumulation causes pinching off of the opening 122 such that no additional metal can be deposited in the region of the voids 175. It can be seen from Figure 1C and Figure 1D that void-free word line filling depends on the migration of a sufficient amount of deposition precursor downward through the vertical structure 130, through the opening 122, past the pillars 155 of the constriction, and into the outermost extent of the horizontal feature 120 before the accumulation of metal deposits around the pillars 155 causes pinching off of the opening 122 and prevents further migration of the precursor to the horizontal feature 120. Similarly, Figure 1E FIG. 1I shows a single word line feature 120 viewed from an upper cross-section and illustrates how the general conformal deposition of material begins to pinch off the interior of the word line feature 120 because the significant width of the pillars 155 serves to partially block and / or narrow and / or restrict what would otherwise be an open path through the word line feature 120. (It should be noted that the example in Figure 1E can be understood as a two-dimensional rendering of the 3D features of the pillar constriction structure in Figure 1D , thus illustrating the constriction as presented in a plan view rather than a cross-sectional view.)

[0033] The challenges posed by reduced fluid accessibility also affect the deposition of the WN barrier layer. Although the deposited layer may be thin enough to avoid pinching off, achieving a WN barrier layer with uniform thickness is challenging. These challenges increase as the 3D NAND structure becomes more complex. For example, in some embodiments, reactants may diffuse through at least 5, at least 10, at least 15, at least 20, at least 25, or at least 30 pillars to reach the innermost word line feature. As the number of pillars increases, the opportunity for non-uniform deposition arises.

[0034] Another challenge in depositing the WN layer is preventing fluorine incorporation into the film and the underlying dielectric. Tungsten hexafluoride (WF6) is a useful precursor because it is a gas under standard conditions, unlike many tungsten halide compounds. However, using WF6 in typical tungsten depositions results in unacceptably high fluorine content. Methods for depositing WN using WF6 that result in a WN film with extremely low fluorine content are described below. Thus, the WN layer is an excellent diffusion barrier. Since the WN barrier layer prevents fluorine diffusion, WF6 can also be used for subsequent processing of filling features with tungsten.

[0035] Examples of depositions in features in the horizontal and vertical directions are described herein. It should be noted that, at least in most cases, these examples apply to both horizontal and vertical features. Additionally, it should be noted that in the following description, the term "vertical" may be used to refer to a direction that is generally orthogonal to the plane of the substrate, while the terms "lateral" or "horizontal" may be used to refer to a direction that is generally parallel to the plane of the substrate.

[0036] Figure 2A A schematic example of a word line feature 220 in a 3D NAND structure is depicted. In Figure 2A a 2-D rendering of 3-D features of a partially fabricated 3D NAND structure before tungsten filling is shown, including word line feature 220 and a conformal WN barrier layer 221. The pillar shrinkage shown in the figure refers to shrinkage seen in a plan view rather than a cross-sectional view. The conformal WN barrier layer 221 can be deposited on a dielectric layer (not shown), such as alumina or other dielectrics.

[0037] Figure 2B An example of a vertical feature 270 formed in a dielectric layer 280 is depicted. The dielectric layer 280 can be silicon oxide, alumina, or any other suitable dielectric material. The conformal WN barrier layer 221 lines the inside of the feature 270.

[0038] To achieve conformal deposition of the WN layer, an atomic layer deposition (ALD) sequence can be used. Such a sequence can employ the following operations (performed in various orders): (i) providing a layer of reducing agent on the substrate surface, (ii) contacting the substrate surface with a tungsten precursor to form a tungsten layer on the substrate, and (iii) nitriding the tungsten layer to form tungsten nitride. Each of these operations can involve delivering the dispensed reactants (reducing agent, tungsten precursor, and / or nitriding agent) to a chamber containing the substrate including the features. A purge is performed between these deliveries to purge the reactants from the chamber.

[0039] For a diborane (B2H6) reducing agent, a WF6 precursor, and an ammonia (NH3) nitriding agent, a B / W / N sequence can be represented, where B represents B2H6 delivery + purge, W represents WF6 delivery + purge, and N represents NH3 delivery + purge. This sequence can be repeated for multiple cycles to deposit the WN layer. However, this can result in an excessive fluorine content. Although long delivery / long purge sequences are often used, they also increase the fluorine content. In other embodiments, hydrogen (H2) can be used as a reducing agent to replace diborane or as a supplement to diborane. Using H2 to replace diborane or as a supplement to diborane can reduce the boron concentration in the resulting WN film.

[0040] Another challenge in depositing the WN layer is to reduce surface humidity and to evacuate unwanted substances from the chamber, particularly nitriding agents such as NH3, which may react adversely with the wafer. In some embodiments, a "pump to base" operation can be performed, during which the pressure in the processing chamber can be reduced below the pressure used for processing the wafer. After performing the pump to base operation, the pressure in the processing chamber can be increased before the deposition operation. Performing the pump to base operation can improve the evacuation of unwanted substances and enhance the uniformity of deposition in the 3D NAND structure. This will be further discussed in connection with Figure 7A -B and Figure 8 Various embodiments of the pump to base operation will be further discussed.

[0041] This document provides a WN ALD sequence that uses WF6 but has a low fluorine content. Figure 3 and Figure 4 An example of a WN ALD sequence according to certain embodiments is shown. Although Figure 3 and Figure 4 WN nitride deposition using WF6 and B2H6 is discussed, other deposition materials and reducing agents can be used, including hydrogen-containing materials and boron-free reducing agents.

[0042] First, in Figure 3In [the process], optional processing can be performed in optional operation 300 to reduce the pressure in the processing chamber to a base pressure. Reducing the pressure in the processing chamber before the deposition operation can evacuate the reactants remaining from the existing processing, especially the nitriding agent, as further discussed below. During operation 300, the pressure can be reduced to a base pressure that is lower than the pressure at which other deposition processes can be performed. Then, in operation 302, B2H6 is dispensed and purged one or more times. Then, in operation 304, WF6 is dispensed and purged multiple times. Operations 302 and 304 are repeated one or more times to form a W sublayer in operation 306. In some other embodiments, one repetition of operations 302 and 304 is sufficient to form the W sublayer. In operation 308, the W sublayer is nitrided. Operation 308 can include NH3 dispensing and purging. In other embodiments, other nitriding agents can be used, such as hydrazine dispensing or exposure to a plasma generated by N2. Then operations 302 to 308 are repeated one or more times to form a WN layer in operation 310. In some embodiments, one repetition of operations 302 to 308 can be used to form the WN layer. In Figure 3 the example of, at least the dispensing of B2H6 and WF6 can be pressurized to improve the reaction efficiency.

[0043] Figure 4 Another example of the process is shown. In optional operation 400, the pressure in the processing chamber can be selectively reduced to a base pressure. Then, in operation 402, B2H6 is dispensed and purged one or more times. Then, in operation 404, WF6 is dispensed and purged one or more times. Operations 402 and 404 are repeated one or more times to form a W sublayer in operation 406. In some other embodiments, one repetition of operations 402 and 404 is sufficient to form the W sublayer. Before nitriding, in operation 408, B2H6 is dispensed and purged. Before nitriding, no subsequent WF6 dispensing is performed and no more W is formed. In operation 410, the W sublayer is nitrided. Operation 410 can include the dispensing and purging of NH3. In other embodiments, other nitriding agents can be used, such as hydrazine dispensing or exposure to a plasma generated by N2 as an example. Then operations 402 to 410 are repeated one or more times to form a WN layer in operation 412. At least the dispensing of B2H6 and WF6 can be pressurized to improve the reaction efficiency.

[0044] Examples of these sequences and other sequences will be further described below.

[0045] According to various embodiments, the sequence can be represented as ((BP) x / (WP) y ) zB / P / N / P, where "B" refers to diborane pulse, "P" refers to purge, "W" refers to tungsten hexafluoride dispense, and "N" refers to ammonia dispense. For simplicity, a sequence without a purge operation can be represented as (B x W y ). z BN. In these expressions, x is the number of consecutive B2H6 dispenses, y is the number of consecutive WF6 dispenses, and z is the number of B2H6 and WF6 cycles. A purge is performed between all dispenses, but in some embodiments, the purge may be omitted between consecutive dispenses of the same reactant.

[0046] In some embodiments, x is an integer greater than or equal to 1, y is an integer greater than or equal to 5, and z is an integer greater than or equal to 1. In the same or other embodiments, x is an integer greater than or equal to 1, y is an integer greater than x, and z is an integer greater than or equal to 1.

[0047] According to each embodiment, the duration of x or more B2H6 dispenses in the (B x W y ) cycle can be between 1 and 2 seconds. The duration of x or more purges after the B2H6 dispense can be less than 5 seconds, or less than 3 seconds.

[0048] According to each embodiment, the duration of x or more B2H6 dispenses in the (B x W y ) cycle can be greater than the duration of each or more purges after the B2H6.

[0049] According to each embodiment, the duration of y or more WF6 dispenses in the (B x W y ) cycle can be less than 1 second. The duration of y or more purges after the WF6 dispense can be between 1 and 2 seconds.

[0050] According to each embodiment, the duration of y or more WF6 dispenses in the (B x W y ) cycle can be less than the purge duration after the WF6.

[0051] The diborane dispense after the (B x W y ) cycle and before the NH3 dispense can be much longer than each diborane dispense of x diboranes. For example, it can be 2 - 10 times longer than each diborane dispense in the (B x W y ) cycle. In some embodiments, it can be 10 seconds or shorter.

[0052] According to various embodiments, prior to each dosing, the reactants can be pressurized using a charge volume (also known as a linechanger). Using multiple short pressurized dosing can promote an efficient reaction between B2H6 and WF6, thereby reducing the incorporation of fluorine. It also improves the yield.

[0053] Using a B2H6 pulse prior to the NH3 pulse allows B2H6 to react with the incorporated fluorine to form boron trifluoride (BF3), which can be purged prior to nitridation. In some embodiments, H2 dosing can be used to replace or supplement B2H6 to form hydrogen fluoride (HF). For example, the pulse sequence can be represented as (B x W y ) z HN or (B x W y ) z (B + H)N, where H is the dosing of H2.

[0054] The above (B x W y ) z BN, (B x W y ) z HN or (B x W y ) z (B + H)N sequence can be repeated one or more times to deposit WN with the desired thickness. According to various embodiments, a total of 2 to 4 sequences are used to form 10 to In addition, as described above, the diborane or hydrogen dosing immediately prior to ammonia dosing can be omitted.

[0055] According to various embodiments, the overall volume ratio of B2H6 to WF6 in the (B x W y ) cycle can be about 2:1 or higher.

[0056] The ratio of the reducing agent to the precursor can be characterized as the ratio of the molecules to which the substrate is exposed and available for reaction. Its calculation formula is as follows: The line charge is a pressurized distribution. The dosing time refers to the duration of dosing. This can be simplified to the case where there is no line charge time: In some embodiments, this ratio can be between 1.5:1 and 4:1. In some embodiments, the ratio can be 2:1.

[0057] The reduction of fluorine is demonstrated as follows. As shown in the table below, WN was deposited on the surface of Al2O3 alumina using different ALD sequences of B2H6 and WF6. The fluorine concentration in the deposited WN film and at the WN:Al2O3 surface was measured.

[0058] Figure 5 Graphical representations of the BWN and (B3W5)2BN sequences used are provided. As can be seen from Figure 5 , the dosing time in the BWN sequence is significantly greater than that in the (B3W5)2 sequence. The results show that Figure 3 and Figure 4 in the treatment can significantly reduce fluorine.

[0059] According to various embodiments, Figure 3 each of the operations 302, 304, and 308 in Figure 4 and each of the operations 402, 404, 408, and 410 in

[0060] can be performed in the same processing chamber or different processing chambers. If performed in the same processing chamber, it can be performed in a single-station or multi-station processing chamber. In a multi-station processing chamber, various operations can be performed at each station. For example, operation 302 can be performed at the first station, operation 304 at the second station, and operation 308 at the third station. Figure 6 Figure 1A is a flowchart illustrating the operation of filling a structure with a metal according to various embodiments. First, in operation 602, a WN film is deposited into the structure. This can be performed as described above and is generally a conformal deposition, lining the exposed surfaces of the structure. For example, in a 3D NAND structure as shown in

[0061] , the film is lined on the horizontal feature 120. In some embodiments, the conformal deposition operation of W in the structure can be referred to as Dep1. This can involve ALD deposition of W. In some embodiments, it includes ALD deposition of a nucleation layer, followed by ALD bulk deposition. Further description of the ALD process is as follows. Next, in operation 604, the structure is treated non-conformally with a boron-containing compound. Non-conformal treatment herein refers to a treatment that is preferentially applied at least in narrow channels or feature openings compared to further inside the feature. In many embodiments, the boron-containing compound is diborane (B2H6). Treating the feature with a boron-containing chemical increases the inhibitory effect of the subsequently applied inhibitory treatment, which may be due to the formation of elemental boron on the surface, adsorption of diborane (or other compounds) on the surface, or some combination of these factors.

[0062] According to various embodiments, the processing in operation 604 can be performed directly on the WN film formed in operation 602, or on the formed Dep1 W film.

[0063] Examples of other boron-containing compounds include B n H n+4 , B n H n+6 , B n H n+8 , B n H m boranes, where n is an integer from 1 to 10 and m is an integer different from m. Other boron-containing compounds can be used, such as alkylboranes, alkylborons, aminoboranes (such as (CH3)2NB(CH2)2), carboranes (such as C2B n H n+2 ) and borane halides (such as B2F4).

[0064] The structure is non-conformally exposed to the boron-containing gas. Diborane is a self-decomposing gas. If the amount of diborane is limited (e.g., due to one or more of diborane concentration, flow rate, and dose time), the gas will decompose near the feature opening and will not further diffuse into the feature. For 3D NAND structures, this processing in the vertical direction may be conformal, such that the bottom word line feature and the top word line feature are processed to approximately the same extent, and non-conformal means that the inside of the word line feature is not exposed to this processing or is exposed to this processing to a significantly lower degree than the narrow channels or feature openings.

[0065] In a 3D NAND structure, for example, diborane will decompose in the outer word lines and will not diffuse into the innermost word lines. Since the diffusion of diborane is easier to control than the diffusion of the inhibition gas (NF3) and diborane increases the inhibition effect of NF3, it can be used to control the inhibition profile.

[0066] Operation 604 can include continuous dosing or multiple dosing of boron-containing chemicals, which are separated from each other by sweeping. Using multiple short doses can help prevent diffusion into features that are farther than expected.

[0067] According to various embodiments, diborane can be provided with a nitrogen carrier gas (e.g., 5% / 95% B2H6 / N2), and argon can be used to further dilute diborane, such as 1:1 Ar:(B2H6 / N2) or 2:1 (B2H6 / N2).

[0068] The substrate temperature during operation 604 can be limited to control the degree of inhibition. In some embodiments, it does not exceed 300 °C or does not exceed 250 °C.

[0069] In some embodiments, diborane can flow co-currently with hydrogen gas (H2). Hydrogen gas can be used as a parameter to control the diborane exposure profile. Diborane decomposes more slowly in the presence of hydrogen gas than in another carrier gas such as nitrogen gas (N2). Thus, in order to decompose more quickly in the external word line (or other feature opening), hydrogen gas can be omitted. For complex structures into which diborane treatment penetrates, hydrogen gas can be added. For example, in some 3D NAND structures having multiple pillars, hydrogen gas can be added to allow diborane to pass through one or more pillars before decomposing or otherwise treating the film.

[0070] After non-conformal treatment with a boron-containing compound, in operation 606, nucleation within the structure is non-conformally inhibited. As in operation 604, non-conformal treatment herein refers to treatment preferentially applied at least in narrow channels or feature openings compared to further inside the feature. For a 3-D NAND structure, the treatment in the vertical direction may be conformal such that the bottom word line feature and the top word line feature are treated to about the same extent, and non-conformal is that the inside of the word line feature is not exposed to the treatment or is exposed to the treatment to a significantly lower extent than the narrow channel or feature opening.

[0071] The nucleation inhibition treatment inhibits subsequent metal nucleation on the treated surface, which can include inhibiting one or more of deposition of a film, reaction of a treatment substance with a metal film to form a compound film, and adsorption of a substance. During a subsequent deposition operation, there is a nucleation delay on the inhibited portion of the underlying film relative to the non-inhibited portion or the lower inhibited portion.

[0072] In some embodiments, NF3 is used for thermal inhibition treatment. Other nitrogen-containing gases (such as ammonia (NH3) or hydrazine (N2H4)) can be used for thermal inhibition treatment. The inhibition can also be plasma inhibition, where a nitrogen-containing gas (such as N2) is used to generate a plasma in a remote or in-situ chamber.

[0073] To adjust the lateral non-conformality in the word line, the pressure and the flow rate of the treatment gas can be adjusted. Higher chamber pressure and lower treatment gas flow rate (and / or concentration) promote treatment of the word line feature opening preferentially over the inside of the word line feature. Thus, in some embodiments, the chamber pressure can be decreased from operation 602 to 606. An example range of chamber pressure is from 3 Torr to 40 Torr. And because diborane increases the inhibition effect, the non-conformality of the inhibition can be controlled by the parameters of operation 604 as well as operation 606.

[0074] In some embodiments, the processing gas is pressurized to a level significantly higher than the chamber pressure before being introduced into the chamber. This helps the gas reach the bottommost part of the vertical structure. In the example of NF3 gas, the NF3 gas can be pressurized to a pressure between 10 Torr and 1000 Torr in the fill volume. In some embodiments, the pressure is 400 Torr to 500 Torr.

[0075] Operation 606 can be a continuous flow or a pulsed process, in the latter case, different gases can be pulsed in sequence to adjust the process.

[0076] After operation 606, W deposition is performed in operation 608. Operation 608 can involve ALD or CVD processing. To deposit into the 3D NAND structure, ALD processing can be used to achieve good step coverage across the entire structure. Due to the effect of this process, the gas can more easily reach the interior of the features. After the etch process, the film deposited near the feature entrance is removed, so that there is more space for the gas to reach the interior of the feature and prevent pinching. In some embodiments, enough metal film can be removed such that the underlying surface is fully or partially exposed to increase the nucleation delay in these areas. After the suppression process, the nucleation delay increases, allowing for a fill process from the inside out. In some embodiments, operation 608 can complete the filling of the structure. In other embodiments, one or more additional processing / deposition operations can be performed again.

[0077] According to various embodiments, each of operation 602, operation 604, operation 606, and operation 608 can be performed in the same processing chamber or different processing chambers. If performed in the same chamber, they can be carried out in a single-station or multi-station chamber. In a multi-station chamber, the various operations can be performed at different stations. For example, operation 602 can be performed at the first station, operation 604 at the second station, operation 606 at the third station, and operation 608 at the fourth station. Additionally, operation 602 can be carried out at multiple stations.

[0078] In some embodiments, although various operations are performed at different stations within a single chamber, only a single operation can be performed at a time, namely operation 602 (depositing WN in the structure). In another embodiment, when multiple substrates are being processed, different operations can occur simultaneously. For example, in the same multi-station chamber, a first substrate is undergoing operation 602 at station one while a second substrate is undergoing operation 606 at station two. Operations 604 and 606 can occur simultaneously in the same multi-station chamber. In some embodiments, the chamber pressure can be low to prevent any cross-contamination or safety issues. In one example, in operation 604, a boron-containing compound (e.g., B2H6) can be used at station one to process the structure on the first substrate. A second substrate can undergo operation 604 using NF3 at the second station. The B2H6 treatment at station one and the NF3 treatment at station two can occur simultaneously in the same multi-station chamber. To achieve this, the chamber pressure is set to a lower pressure such as a pressure below 25 Torr.

[0079] In the above example, the deposition of the conformal layer can include the deposition of a nucleation layer. Although in some embodiments the nucleation layer can serve as the initial conformal layer, a conformal bulk layer can be deposited on the nucleation layer to form a conformal layer for the initial metal deposition.

[0080] The nucleation layer is a layer that promotes the subsequent deposition of the bulk metal-containing material thereon. It is typically thin and conformal. According to various implementations, the metal nucleation layer can be deposited before any filling of the feature and / or at a subsequent point during the feature filling process.

[0081] In certain implementations, the nucleation layer is deposited using a cyclic process that sequentially adds reactants for reaction in the feature. This can be an atomic layer deposition (ALD) process and / or a pulsed nucleation layer (PNL) technique. In such techniques, a reducing agent pulse, an optional purge gas, and a metal-containing precursor are sequentially injected and purged from the reaction chamber. The process is repeated in a cyclic manner until the desired thickness is reached. The PNL technique for depositing a tungsten nucleation layer is described in U.S. Patent Nos. 6,635,965; 7,005,372; 7,141,494; 7,589,017, 7,772,114, 7,955,972, and 8,058,170, as well as U.S. Patent Publication No. 2010-0267235, all of which are hereby incorporated by reference in their entirety.

[0082] The nucleation layer thickness can depend on the nucleation layer deposition method and the desired quality of the bulk deposition. Generally, the nucleation layer thickness is sufficient to support high-quality, uniform bulk deposition. Examples can be in the range of, for example

[0083] In some implementations, the body layer can be deposited directly in the feature without using a nucleation layer. For example, in some implementations, the feature surface and / or an already-deposited under-layer support body deposition.

[0084] Tungsten nucleation layer deposition can include exposure to alternating pulses of a tungsten precursor (also referred to as a tungsten source) and a reducing agent separated by an inert purge gas. For tungsten deposition, examples of precursors include tungsten hexafluoride (WF6). Chlorine-containing tungsten precursors (WCl x ) can be used, such as tungsten pentachloride (WCl5) and tungsten hexachloride (WCl6). These precursors can be reduced to elemental tungsten (W) by reaction with a reducing agent such as silane (SiH4) and diborane (B2H6).

[0085] In an alternative embodiment, the metal precursor and the reducing agent can be co-flowed. If co-flowed, a sequence can be used in which the metal precursor and the reducing agent are co-flowed in a pulsed manner. During reactant dosing, the metal precursor and the reducing agent co-flow into the chamber. Co-flowing reactants is more similar to a CVD reaction, which results in a higher deposition rate and a rougher nucleation layer. Various adjustments can be made to this sequence. For example, the metal precursor and reducing agent reactant pulses can be offset but overlapping, where one reactant is delayed relative to the other. In another example, an inert gas can be pulsed for the purge phase.

[0086] Examples of reducing agents can include boron-containing reducing agents (including B2H6 and other boranes), silicon-containing reducing agents (including SiH4 and other silanes), hydrazine, and germane. In some implementations, pulses of the tungsten precursor can be alternated with pulses of one or more reducing agents, such as S / W / S / W / B / W, etc., where W represents the tungsten precursor, S represents the silicon precursor, and B represents the boron precursor. In some implementations, a separate reducing agent may not be used, for example an organometallic tungsten precursor can undergo thermal decomposition or plasma-assisted decomposition.

[0087] According to various implementations, hydrogen may or may not be present in the background environment. Additionally, in some implementations, after deposition of the tungsten nucleation layer, one or more processing operations can be performed before deposition of the tungsten body. For example, processing the deposited tungsten nucleation layer to reduce resistivity is described in U.S. Patent Nos. 7,772,114 and 8,058,170 and U.S. Patent Publication No. 2010-0267235, which are incorporated herein by reference.

[0088] The body deposition can be carried out by ALD or CVD processes. In the CVD process, a reducing agent and a metal precursor are co-fed into a deposition chamber to deposit a body fill layer in the feature. An inert carrier gas can be used to transport one or more reaction streams, which may or may not be pre-mixed. The operation typically includes continuously supplying the reactants until the desired amount of deposition. In some implementations, the CVD operation can be carried out in multiple stages, where multiple periods of continuous and simultaneous supply of reactants are separated by multiple periods of one or more diverted reactants.

[0089] For conformal deposition and deposition into complex structures such as 3D NAND structures, ALD deposition of the body layer can be used. The ALD deposition of the body layer includes exposure to alternating pulses of a metal precursor and a reducing agent separated by an inert purge gas, using the metal precursor described above with reference to the nucleation layer deposition. The same or different metal precursors used for nucleation layer deposition can be used for body deposition. Hydrogen is typically the reducing agent used for body deposition compared to nucleation layer deposition using strong reducing agents such as diborane or silane.

[0090] The deposition can be carried out according to various implementations until a specific feature profile is obtained and / or a specific amount of metal is deposited. In some implementations, the deposition time and other relevant parameters can be determined by building models and / or trial and error. In some implementations, the processing chamber can be equipped with various sensors to perform in-situ metrology measurements for endpoint detection of the deposition operation. Examples of in-situ metrology include optical microscopy and X-ray fluorescence (XRF) for confirming the deposited film thickness.

[0091] In some embodiments, the conformal tungsten layer can be characterized by low resistivity and, in some embodiments, by low stress and / or low fluorine. Since the word line feature is unfilled (unless a nucleation layer is deposited), relatively fast deposition techniques can be used. In some embodiments, this includes alternating pulses of a tungsten-containing precursor such as tungsten hexafluoride (WF6) and hydrogen gas (H2) or other reducing agents to deposit a first tungsten layer in an ALD process. A purge operation can separate the multiple pulses. Relatively short pulse times can be used for deposition to increase throughput. Metal-containing precursor

[0092] As described above, WF6 is used for depositing the WN layer. WF6 is a useful precursor because it is in the gas phase under deposition conditions. WF6 can also be used for depositing the W nucleation and body layers. In some embodiments, other tungsten-containing precursors can be suitable for implementing the disclosed embodiments. For example, metal-organic tungsten-containing precursors can be used. Organometallic precursors and fluorine-free precursors such as MDNOW (methylcyclopentadienyl-dicarbonylnitrosyl-tungsten) and EDNOW (ethylcyclopentadienyl-dicarbonylnitrosyl-tungsten) can also be used. Chlorine-containing tungsten precursors (WClx ) such as tungsten pentachloride (WCl5) and tungsten hexachloride (WCl6).

[0093] Other metals can be deposited on the WN layer. These metals include molybdenum, ruthenium, and cobalt. To deposit molybdenum (Mo), molybdenum precursors can be used, including molybdenum hexafluoride (MoF6), molybdenum pentachloride (MoCl5), molybdenum dioxydichloride (MoO2Cl2), molybdenum oxychloride (MoOCl4), and molybdenum hexacarbonyl (Mo(CO)6).

[0094] To deposit ruthenium (Ru), Ru-precursors can be used. Examples of ruthenium precursors for oxidation reactions include (ethylbenzyl)(1-ethyl-1,4-cyclohexadienyl)Ru(0), (1-isopropyl-4-methylbenzyl)(1,3-cyclohexadienyl)Ru(0)), (2,3-dimethyl-1,3-butadienyl)Ru(0) tricarbonyl, (1,3-cyclohexadienyl)Ru(0) tricarbonyl, and (cyclopentadienyl)(ethyl)Ru(II) dicarbonyl. Examples of ruthenium precursors for reaction with non-oxidizing reactants are bis(5-methyl-2,4-hexanediketonato)Ru(II) dicarbonyl and bis(ethylcyclopentadienyl)Ru(II).

[0095] To deposit cobalt (Co), cobalt precursors can be used, which include cyclopentadienylcobalt(I) dicarbonyl, cobalt carbonyl, various amidinato cobalt precursors, diazadienyl cobalt complexes, cobalt amidinate / guanidinate precursors, and combinations thereof.

[0096] The metal-containing precursors can react with the reducing agent as described above. In some embodiments, H2 is used as the reducing agent for the deposition of the bulk layer to deposit a high-purity film. Nucleation layer deposition

[0097] In some implementations, the methods described herein involve depositing a nucleation layer before depositing the bulk layer. In various implementations, the deposition of the nucleation layer can involve exposure to the metal precursors and reducing agents as described above. Examples of reducing agents can include boron-containing reducing agents (which include diborane (B2H6) and other boranes), silicon-containing reducing agents (which include silane (SiH4) and other silanes), hydrazine, and germane. In some implementations, pulses of the metal-containing can be alternated with pulses of one or more reducing agents, such as S / W / S / W / B / W, etc., where W represents a tungsten-containing precursor, S represents a silicon-containing precursor, and B represents a boron-containing precursor. In some implementations, a separate reducing agent may not be used. For example, the tungsten-containing precursor can undergo thermal decomposition or plasma-assisted decomposition. Body deposition

[0098] As described above, bulk deposition can be performed across the entire wafer. In some implementations, bulk deposition can occur via a CVD process, where a reducing agent and a metal-containing precursor flow into a deposition chamber to deposit a bulk fill layer in the features. An inert carrier gas can be used to transport one or more of the reactant streams, which may or may not be premixed. Unlike PNL or ALD processes, this operation typically involves continuously flowing the reactants until the desired amount is deposited. In certain implementations, the CVD operation can occur in multiple stages, where multiple consecutive and simultaneous flow periods of the reactants are separated by periods of diversion of one or more of the reactant flows. ALD processes can also be used for bulk deposition, where the metal-containing precursor is alternated with a reducing agent such as H2. In some implementations, ALD can be used to deposit an initial bulk layer in a Dep1 process, and CVD is used for filling other features after inhibition. In some implementations, ALD can be used for feature fill, and CVD is used for the capping layer. In some implementations, ALD can be used for all bulk layer depositions.

[0099] It should be understood that the metal films described herein can include a certain amount of other compounds, dopants, and / or impurities, such as nitrogen, carbon, oxygen, boron, phosphorus, sulfur, silicon, germanium, etc., depending on the specific precursors and processes used. The metal content in the film can be from 20% to 100% (atomic) metal. In many implementations, the film is metal-rich, having at least 50% (atomic) metal, or even at least about 60%, 75%, 90%, or 99% (atomic) metal. In some implementations, the film can be a mixture of a metal or elemental metal (e.g., W, Mo, Co, or Ru) and other metal-containing compounds (e.g., tungsten carbide (WC), tungsten nitride (WN), molybdenum nitride (MoN), etc.). CVD and ALD depositions of these materials can include using any suitable precursors as described above. Inhibit metal nucleation

[0100] The plasma inhibition process involves exposure to a plasma generated from a nitrogen-containing compound (e.g., N2). In some embodiments, the plasma power, chamber pressure, and / or process gas can be pulsed.

[0101] Thermal inhibition treatment generally involves exposing features to nitrogen-containing compounds such as ammonia (NH3) or hydrazine (N2H4) to non-conformally inhibit features near the feature openings. In some embodiments, the thermal inhibition treatment is carried out in the temperature range of 250 °C to 450 °C. At these temperatures, exposure of previously formed tungsten or other layers to NH3 produces an inhibitory effect. Other potential inhibitory chemicals such as nitrogen (N2) or hydrogen (H2) can be used for thermal inhibition at higher temperatures (e.g., 900 °C). However, for many applications, these high temperatures are beyond the thermal budget. In addition to ammonia, other hydrogen-containing nitriding agents (such as hydrazine) can also be used at lower temperatures suitable for back-end-of-line (BEOL) applications. During thermal inhibition, the metal precursor can flow with the inhibitory gas or flow in an alternating pulse form with the gas.

[0102] Nitriding of the surface can passivate it. Deposition of tungsten or other metals (such as molybdenum or cobalt) subsequently on the nitrided surface is significantly delayed compared to on a conventional bulk tungsten film. In addition to NF3, fluorocarbons such as CF4 or C2F8 can also be used. However, in some implementations, the inhibitory substance does not contain fluorine to prevent etching during inhibition.

[0103] In addition to the above surfaces, nucleation can be inhibited on liner / barrier layer surfaces such as TiN and / or WN surfaces. Any chemical substance that passivates these surfaces can be used. The inhibitory chemical can also be used to adjust the inhibition curve, where different ratios of active inhibitory substances are used. For example, for the inhibition of W surfaces, nitrogen may have a stronger inhibitory effect than hydrogen; adjustment of the ratio of N2 and H2 gases in the forming gas can be used to adjust the profile.

[0104] In some implementations, the substrate can be heated or cooled before inhibition. The predetermined temperature of the substrate can be selected to induce a chemical reaction between the feature surface and the inhibitory substance and / or to promote the adsorption of the inhibitory substance, as well as to control the rate of the reaction or adsorption. For example, the temperature can be selected to have a high reaction rate so that more inhibition occurs near the gas source.

[0105] After inhibition, the inhibitory effect can be adjusted as described above. In the same or other embodiments, it can also be modulated by soaking it in a reducing agent or a metal precursor, exposing it to a hydrogen (H-) plasma, performing a thermal annealing, or exposing it to air, which can reduce the inhibitory effect. Wafer loading and pumping down to base value

[0106] In various embodiments of the present disclosure, processes for depositing tungsten nitride (WN) barrier layers and other layers are described. These deposition processes can be performed in a processing chamber or tool having two, three, four, five, or even more deposition stations disposed within a single processing chamber or tool. In some embodiments, each station performs one operation simultaneously, while in other embodiments, each station can perform a different operation.

[0107] As described above, in various embodiments, a pressure pumping operation to a base value is performed. As described in operations 300 and 400 above, this operation can be referred to as a "pump to base" operation. During the "pump to base" operation, the pressure in the processing chamber can be reduced below the pressure used for processing the wafers. After performing the pump to base operation, the pressure in the processing chamber can be increased to a higher pressure prior to the deposition operation.

[0108] In some embodiments, reducing the pressure helps to reduce surface moisture or expel undesirable substances from the chamber, particularly nitriding agents such as NH3, which may react adversely with the wafers. For example, as Figure 4 shown, the nitriding operation can be performed after multiple cycles of B2H6 and WF6 dispense. When the processed wafers are removed from the chamber and new wafers are loaded into the chamber, nitrogen-containing reactants such as NH3 may remain and then react with the wafers prior to the new nitriding operation during repeated Figure 4 processing. Such an unexpected interaction of the nitrogen-containing reactants with the wafers is undesirable, and thus the pump to base operation can be performed to evacuate these substances. Additionally, reducing the pressure in the chamber to a base pressure less than the operating pressure at which deposition processing can be performed increases the evacuation rate, increases throughput, and improves film uniformity.

[0109] In some embodiments, the pump to base operation can improve the film deposition rate. Generally, when the pump to base operation is performed, the film growth rate increases. Thus, the pump to base operation can be used prior to the deposition operation to improve the efficiency of the deposition process and increase throughput.

[0110] In some embodiments, the pump to base operation is performed when the wafers are loaded into the stations of the tool. The tool can have multiple stations, and the wafers can be loaded into the stations by placing each wafer in the first station and then positioning the wafer to a different station while placing another wafer in the first station. This process can continue until each station has a wafer. Then, the operations described herein can be performed to deposit layers on the wafers at each station. It should be noted that although each station has its own pedestal and showerhead, the vacuum pump can be connected to the entire processing chamber such that the pressure at each station is the same as that of the other stations.

[0111] In some embodiments, the wafer loading and positioning operations are performed concurrently with the pumping to base operation to improve efficiency and reduce the total time for positioning the wafer and performing the pumping to base operation. Figure 7A FIG. shows a schematic diagram of loading wafers A - D into stations 1 - 4. Each wafer can be initially loaded into station 1, and then one or more of the existing loaded wafers can be positioned either before or concurrently with loading subsequent wafers into station 1. For example, wafer A is loaded into station 1 and then positioned to station 2. During or after wafer A is positioned to station 2, wafer B is loaded into station 1, and then wafers A and B are respectively positioned to stations 2 and 3 to facilitate subsequent loading of wafer C. During these positioning operations, the pumping to base operation can be performed to reduce the pressure in the tool and thus the pressure at each station. After each wafer is loaded, the pumping to base operation can be completed and subsequent deposition processing can be carried out.

[0112] While this method of loading wafers and performing the pumping to base operation increases throughput, it may also increase the non - uniformity of deposition between stations. As Figure 7A shown, the deposition processing performed after the positioning and pumping to base operations results in different film thicknesses. For example, the film growth rates of wafer A and wafer D are different. The difference in film growth rates is related to the order in which the wafers are loaded into the tool and the time each wafer is exposed to the pumping to base operation. This wafer - to - wafer (W2W) non - uniformity is undesirable.

[0113] This W2W non - uniformity may be particularly evident in embodiments where the same process is performed at each station. As described in other parts of this document, in various embodiments, the processes described herein can be performed in the same station / processing chamber or different stations / processing chambers. In embodiments where different operations are performed at each station, two stations can be used to respectively perform B2H6 and WF6 dosing. In embodiments where different operations are performed at different stations, the W2W non - uniformity caused by different exposure times to the pumping to base operation can be reduced. For example, a wafer can enter the tool on station 1, undergo a first process, be positioned to station 2, undergo a second process, be positioned to station 3, undergo a third process, be positioned to station 4, undergo a fourth process, and then be removed from the chamber for further processing elsewhere. During these positioning operations, the processing chamber can be pumped to the base pressure. However, since each wafer is processed at each station before being positioned to the subsequent station, the difference in exposure to the base pressure between wafers is reduced.

[0114] Alternatively, in some embodiments, the same series of operations are performed at each station. In such embodiments, the wafers can be loaded / positioned onto each station, and the operations described herein can be performed simultaneously at each station, e.g., the same or similar processing can be performed at each station. Thereafter, each wafer can be removed from the tool for further processing elsewhere. In such embodiments, when pumping to the base pressure operation is performed during wafer positioning, each wafer can have different exposure conditions (e.g., duration) to the base pressure.

[0115] To reduce this W2W non-uniformity, pumping to the base operation can be performed after the wafers are placed on each station. Figure 7B A diagram showing loading a wafer onto a station in a processing chamber and performing pumping to the base operation after the wafer is placed on each station is presented. In some embodiments, this significantly reduces the W2W non-uniformity. The following table lists the film thicknesses based on loading the wafers, performing Figure 7A and 7B the pumping to the base operation described herein and performing the deposition process described herein. As shown in the following table, performing the pumping to the base operation after the wafers are positioned on each station can improve the W2W non-uniformity to less than 1 angstrom.

[0116] Performing the pumping to the base operation after positioning reduces the throughput compared to performing the pumping to the base operation during positioning, but can significantly improve the W2W uniformity. In some embodiments, the pumping to the base operation performed after positioning can be at least about 15 seconds, at least about 20 seconds, at least about 30 seconds, at least about 40 seconds, between about 10 seconds and about 30 seconds, between about 20 seconds and about 40 seconds, about 30 seconds, about 40 seconds, or between about 20 seconds and about 60 seconds. In some embodiments, the W2W non-uniformity may improve with an increase in the duration of the pumping to the base operation until a saturation point within the above durations. Although performing the pumping to the base operation after positioning reduces the throughput, as shown in the above table, it can significantly improve the uniformity of film deposition.

[0117] In some embodiments, the pump-down-to-base operation can reduce the chamber pressure to less than about 1 Torr, less than about 500 mTorr, less than about 300 mTorr, less than about 200 mTorr, between about 100 mTorr and about 1 Torr, or less than about 100 mTorr. In some embodiments, the chamber pressure can be reduced to the minimum pressure that the vacuum pump can achieve during the pump-down-to-base operation, e.g., during a 30-second period or any other period described above. In some embodiments, the vacuum pump is configured to reduce the pressure at the maximum rate during the pump-down-to-base operation. After the pump-down-to-base operation, the processing chamber pressure can be increased to each of the pressures described herein for performing the deposition operation, e.g., a pressure of at least about 3 Torr. Apparatus

[0118] Any suitable chamber can be used to implement the disclosed embodiments. Exemplary deposition apparatuses include a variety of systems, such as and Max, which is available from Lam Research Corp. (Fremont, California), or any of a variety of other commercially available processing systems.

[0119] In some embodiments, the tool can have two, three, four, five, or even more deposition stations disposed within a single deposition chamber or tool. In some embodiments, each station can perform the same operation or different operations. Thus, for example, an independent gas supply system that forms a local environment on the substrate surface can be used at each station to introduce hydrogen (H2) and tungsten hexafluoride (WF6) onto the surface of the semiconductor substrate in an alternating pulse manner. The same station can be used for boron treatment and NF3 treatment. In some embodiments, the same station or different stations or tools can be used for subsequent ALD bulk fill.

[0120] Figure 8Schematic diagram of a processing system suitable for deposition processing according to an embodiment. System 800 includes a transfer module 803. The transfer module 803 provides a clean pressurized environment to minimize the risk of contamination of the substrate being processed when moving between individual reactor modules. The multi-station reactor 809 mounted on the transfer module 803 is capable of performing ALD deposition, processing, and CVD of WN and / or other metal films according to various embodiments. The multi-station reactor 809 may include a plurality of stations 811, 813, 815, and 817, which may be operated sequentially or simultaneously according to the disclosed embodiments. For example, the multi-station reactor 809 may be configured such that station 811 deposits a W sublayer using WF6 and B2H6, station 813 performs nitridation using NH3, and station 815 performs ALD tungsten bulk deposition of a conformal layer using H2 as a reducing agent. In another example, station 811 may deposit a WN layer, station 813 may perform ALD deposition of a conformal layer, station 815 may perform an NF3 processing operation, and station 817 may perform bulk ALD filling after treatment using H2 as a reducing agent.

[0121] As described above, in some embodiments, the wafers are positioned at each of stations 811, 813, 815, and 817 before performing the deposition operations described herein. As shown in FIG. 7, each station is labeled with numbers 1-4. The labels 1-4 may correspond to Figure 6 stations 1-4 therein. Thus, during the wafer loading operation, wafer A may be placed on station 1, and when wafer A is positioned at station 2, wafer B may be placed on station 1. This is repeated, positioning each wafer at subsequent stations until each station has a wafer. Although Figure 8 stations 811, 813, 815, and 817 therein are labeled 1-4, station 811 is not necessarily station 1, and other methods may be used to position the wafers at the stations.

[0122] The stations may include a heating pedestal or substrate support, one or more gas inlets or showerheads or dispersion plates.

[0123] One or more single or multi-station modules 807 capable of performing plasma or chemical (non-plasma) pre-cleaning, other deposition operations, or etching operations may be mounted on the transfer module 803. The modules may also be used for various processes, for example, preparing the substrate for deposition processing. System 800 also includes one or more wafer source modules 800 where the wafers are stored before and after processing. An atmospheric manipulator (not shown) in the atmospheric transfer chamber 819 may first move the wafers from the source module 801 to the load lock 821. The wafer transfer equipment (generally robotic arm equipment) in the transfer module 803 moves the wafers from the load lock 821 into the modules mounted on the transfer module 803 and between the modules.

[0124] In various embodiments, a system controller 829 controls the processing conditions during deposition. The controller 829 will typically include one or more memory devices and one or more processors. The processor may include a CPU or computer, analog and / or digital input / output connections, a stepper motor controller board, etc.

[0125] The controller 829 can control the activities of all deposition devices. The system controller 829 runs system control software, which includes an instruction set for controlling timing, gas mixing, chamber pressure, chamber temperature, wafer temperature, radio frequency (RF) power level, wafer chuck or pedestal position, and other parameters for a particular process. In some embodiments, other computer programs stored on a memory device associated with the controller 829 may be used.

[0126] Typically, there will be a user interface associated with the controller 829. The user interface may include a display screen, a graphical software display of the device and / or processing conditions, and user input devices such as a pointing device, keyboard, touch screen, microphone, etc.

[0127] The system control logic can be configured in any suitable manner. Generally, the logic can be designed or configured in hardware and / or software. Instructions for controlling the drive circuit can be hard-coded or provided as software. The instructions can be provided by "programming". Such programming is understood to include any form of logic, which includes hard-coded logic in a digital signal processor, an application-specific integrated circuit, and other devices having a specific algorithm implemented as hardware. Programming is also understood to include software or firmware instructions that can be executed on a general-purpose processor. The system control software can be encoded in any suitable computer-readable programming language.

[0128] Computer program code for controlling the germanium-containing reductant pulse, hydrogen gas flow, and tungsten-containing precursor pulse in the processing sequence, as well as other processes, can be written in any conventional computer-readable programming language: for example, assembly language, C, C++, Pascal, Fortran, or others. The compiled object code or script is executed by the processor to perform the tasks identified in the program. Also as indicated, the program code can be hard-coded.

[0129] The controller parameters relate to processing conditions such as, for example, processing gas composition and flow rate, temperature, pressure, cooling gas pressure, substrate temperature, and chamber wall temperature. These parameters are provided to the user in the form of a recipe and can be input using the user interface.

[0130] Signals for monitoring the process can be provided through the analog and / or digital input connections of the system controller 829. Signals for controlling the process are output through the analog and digital output connectors of the deposition device 800.

[0131] The system software can be designed or configured in many different ways. For example, multiple chamber component subroutines or control objectives can be written to control the operation of the chamber components required to perform a deposition process according to the disclosed embodiments. Examples of programs or program segments for this purpose include substrate positioning code, process gas control code, pressure control code, and heater control code.

[0132] In some embodiments, the controller 829 is part of a system that can be part of the above-described embodiments. Such systems include semiconductor processing apparatuses that include one or more processing tools, one or more chambers, one or more platforms for processing, and / or particular processing components (wafer pedestals, gas flow systems, etc.). These systems can be integrated with electronics to control the operation of these systems before, during, or after the processing of semiconductor wafers or substrates. The electronics can be referred to as a "controller" that can control various components or sub-parts of one or more systems. Depending on the processing requirements and / or the type of system, the controller 829 can be programmed to control any of the processes disclosed in the present invention, including controlling the delivery of process gases, temperature settings (e.g., heating and / or cooling), pressure settings, vacuum settings, power settings, RF (radio frequency) generator settings in some systems, RF matching circuit settings, frequency settings, flow rate settings, plasma pulse frequency settings, fluid delivery settings, position and operation settings, the loading and unloading of wafers from tools and other transfer tools, and / or the transfer of load locks connected to or interfacing with a particular system.

[0133] Broadly speaking, a controller can be defined as an electronic device having various integrated circuits, logic, memory, and / or software that receives instructions, issues instructions, controls operations, enables cleaning operations, enables endpoint measurements, etc. The integrated circuit can include a chip storing program instructions in firmware form, a digital signal processor (DSP), a chip defined as an application specific integrated circuit (ASIC), and / or one or more microprocessors or microcontrollers that execute program instructions (e.g., software). The program instructions can be instructions delivered to the controller or system in the form of various different settings (or program files), and the different settings (or program files) define operation parameters for performing a particular process on or for a semiconductor wafer. In some embodiments, the operation parameters can be part of a recipe defined by a processing engineer to complete one or more processing steps in the fabrication of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or dies on a wafer.

[0134] In some embodiments, the controller 829 can be part of or coupled to a computer that is integrated with, coupled to, or networked to the system or combinations thereof. For example, the controller 829 can be in the "cloud" or be all or part of a fab main computer system, which can permit remote access to wafer processing. The computer can enable remote access to the system to monitor the current progress of manufacturing operations, review the history of past manufacturing operations, review trends or performance criteria for multiple manufacturing operations, to change parameters of the current process, set processing steps to follow the current process or initiate a new process. In some embodiments, a remote computer (e.g., a server) can provide a processing recipe to the system via a network, which can include a local network or the Internet. The remote computer can include a user interface that permits input or programming of parameters and / or settings, which are then transferred from the remote computer to the system. In some examples, the controller receives instructions in the form of data that specify parameters for each processing step to be performed during one or more operations. These parameters can be specific to the type of process to be performed and the type of tool, and the controller is configured to connect to or control the type of tool. As described above, the controller can be distributed, for example, by including one or more discrete controllers that are connected together via a network and work towards a common goal (e.g., the processes and controls described herein). An example of a distributed controller for these purposes would be one or more integrated circuits within the chamber that communicate with one or more remote integrated circuits (e.g., at the platform level or as part of a remote computer), which combine to control processing within the chamber.

[0135] Exemplary systems can include, but are not limited to, plasma etch chambers or modules, deposition chambers or modules, spin rinse chambers or modules, metal plating chambers or modules, cleaning chambers or modules, bevel edge etch chambers or modules, physical vapor deposition (PVD) chambers or modules, CVD chambers or modules, ALD chambers or modules, atomic layer etch (ALE) chambers or modules, ion implantation chambers or modules, track chambers or modules, and any other semiconductor processing systems that can be associated with or used in the preparation and / or manufacture of semiconductor wafers.

[0136] As described above, depending on the one or more processing steps to be performed by the tool, the controller can communicate with one or more other tool circuits or modules, other tool components, combined tools, other tool interfaces, adjacent tools, neighboring tools, tools located throughout the factory, a host, another controller, or tools used in material handling that transport a container of wafers between tool locations and / or load ports in a semiconductor manufacturing facility.

[0137] The controller 829 may include different programs. The substrate positioning program may include program code for controlling the chamber components for loading a substrate onto a pedestal or chuck and for controlling the spacing between the substrate and other components of the chamber such as gas inlets and / or targets. The process gas control program may include code for controlling gas composition, flow rate, pulse time, and optionally for flowing gas into the chamber prior to deposition to stabilize the pressure in the chamber. The pressure control program may include code for controlling the pressure in the chamber by adjusting, for example, a throttle valve in the exhaust system of the chamber. The heater control program may include code for controlling the current to a heating unit for heating the substrate. Alternatively, the heater control program may control the delivery of a heat transfer gas such as helium to the wafer chuck.

[0138] Examples of chamber sensors that may be monitored during the deposition process include mass flow controllers, pressure sensors such as pressure gauges, and thermocouples located in the pedestal or chuck. Appropriately programmed feedback and control algorithms may be used with data from these sensors to maintain the desired process conditions.

[0139] The foregoing describes embodiments of the present invention implemented in a single-chamber or multi-chamber semiconductor processing tool. The devices and processes described herein may be used in conjunction with lithographic patterning tools or processes, for example, for fabricating or manufacturing semiconductor devices, displays, LEDs, photovoltaic panels, etc. Generally, although not necessarily, these tools / processes will be used or operated together in a common manufacturing facility. Lithographic patterning of a film typically includes some or all of the following steps, each step enabling multiple viable tools: (1) coating a photoresist on a workpiece, i.e., a substrate, using a spin-coating or spraying tool; (2) curing the photoresist using a hot plate or furnace or ultraviolet curing tool; (3) exposing the photoresist to visible light or ultraviolet or X-rays using a tool such as a wafer stepper; (4) developing the resist to selectively remove the resist and thereby pattern it using a tool such as a wet cleaning station; (5) transferring the resist pattern to the underlying film or workpiece by using a dry or plasma-assisted etching tool; and (6) removing the resist using a tool such as a radio frequency or microwave plasma resist stripper.

[0140] Figure 9Schematically shows an embodiment of a processing station 900 that can be used to deposit materials using atomic layer deposition (ALD) and / or chemical vapor deposition (CVD). For simplicity, the processing station 900 is depicted as a stand-alone processing station having a processing chamber body 902 for maintaining a low-pressure environment. However, it can be understood that multiple processing stations 900 can be included in a common processing tool environment. Additionally, it can be understood that in some embodiments, one or more hardware parameters of the processing station 900, including the parameters discussed in detail below, can be programmatically adjusted by one or more computer controllers.

[0141] The processing station 900 is fluidly connected to a reactant delivery system 901 for delivering processing gases to a distribution showerhead 906. The reactant delivery system 901 includes a mixing vessel 904 for mixing and / or conditioning the processing gases for delivery to the showerhead 906. One or more mixing vessel inlet valves 920 can control the introduction of the processing gases into the mixing vessel 904. Similarly, a showerhead inlet valve 905 can control the introduction of the processing gases into the showerhead 906.

[0142] Before being vaporized and subsequently delivered to the processing station, some reactants can be stored in liquid form. For example, Figure 9 the embodiment includes a vaporization point 903 for vaporizing liquid reactants to be supplied to the mixing vessel 904. In some embodiments, the vaporization point 903 can be a heated vaporizer. The reactant vapor generated from such a vaporizer will condense in the downstream delivery pipeline. Exposure of incompatible gases to the condensed reactants can produce small particles. These small particles can clog the pipeline, impede valve operation, contaminate the substrate, etc. Some ways to address these issues involve purging and / or evacuating the delivery pipeline to remove residual reactants. However, purging the delivery pipeline increases the processing station cycle time and reduces the processing station throughput. Therefore, in some embodiments, the delivery pipeline downstream of the vaporization point 903 can be heat traced. In some examples, the mixing vessel 904 can also be heat traced. In a non-limiting example, the pipeline downstream of the vaporization point 903 has a temperature profile that rises from about 100°C to about 150°C at the mixing vessel 904.

[0143] In some embodiments, the reactant liquid can be vaporized at the liquid injector. For example, the liquid injector can inject pulses of the liquid reactant into the carrier gas stream upstream of the mixing vessel. In one case, the liquid injector can vaporize the reactant by flashing the liquid from a higher pressure to a lower pressure. In another case, the liquid injector can atomize the liquid into dispersed droplets that are then vaporized in a heated delivery tube. It should be understood that smaller droplets can vaporize faster than larger droplets, thereby reducing the delay between liquid injection and completion of vaporization. Faster vaporization can reduce the length of the tubing downstream of the vaporization point 903. In one case, the liquid injector can be loaded directly into the mixing vessel 904. In another case, the liquid injector can be loaded directly into the showerhead 906.

[0144] In some embodiments, a liquid flow controller can be provided upstream of the vaporization point 903 to control the mass flow rate of the liquid to be vaporized and delivered to the processing station 900. For example, the liquid flow controller (LFC) can include a thermal mass flowmeter (MFM) located downstream of the LFC. The plunger valve of the LFC can then be adjusted in response to a feedback control signal provided by a proportional-integral-derivative (PID) controller that is in electrical communication with the MFM. However, it can take one second or longer to use the feedback control to stabilize the liquid flow. This can extend the time to dispense the liquid reactant. Thus, in some embodiments, the LFC can dynamically switch between a feedback control mode and a direct control mode. In some embodiments, the LFC can dynamically switch from the feedback control mode to the direct control mode by disabling the sensing line and the PID controller of the LFC.

[0145] The showerhead 906 distributes the processing gas toward the substrate 912. In Figure 9 the illustrated embodiment, the substrate 912 is located below the showerhead 906 and is shown disposed on a pedestal 908. It should be understood that the showerhead 906 can have any suitable shape and can have any suitable number and arrangement of ports for distributing the processing gas to the substrate 912.

[0146] In some embodiments, a microvolume 907 is located below the showerhead 906. Performing ALD and / or CVD processing in the microvolume rather than in the entire volume of the processing station can reduce reactant exposure and purge times, can reduce the time to change processing conditions (e.g., pressure, temperature, etc.), can limit the exposure of the processing station manipulator to the processing gas, etc. Exemplary microvolume sizes include, but are not limited to, volumes between 0.1 liter and 2 liters. This microvolume also affects the productivity yield. When the deposition rate per cycle decreases, the cycle time also decreases simultaneously. In some cases, for a given target film thickness, the effect of the reduced cycle time is significant enough to increase the overall yield of the module.

[0147] In some embodiments, the pedestal 908 can be raised or lowered to expose the substrate 912 to the microvolume 907 and / or to change the volume of the microvolume 907. For example, during the substrate transfer phase, the pedestal 908 can be lowered so that the substrate 912 can be loaded onto the pedestal 908. During the deposition processing phase, the pedestal 908 can be raised to position the substrate 912 within the microvolume 907. In some embodiments, the microvolume 907 can completely surround the substrate 912 and a portion of the pedestal 908 to form a region of high flow impedance during deposition processing.

[0148] Optionally, the pedestal 908 can be lowered and / or raised during portions of the deposition process to adjust the processing pressure, reactant concentration, etc. within the microvolume 907. In one case where the processing chamber 902 is maintained at a base pressure during deposition processing, lowering the pedestal 908 can allow the microvolume 907 to be evacuated. Exemplary ratios of the microvolume to the processing chamber volume include, but are not limited to, volume ratios between 1:800 and 1:10. It should be understood that in some embodiments, the pedestal height can be programmatically adjusted by a suitable computer controller.

[0149] In another scenario, adjusting the height of the pedestal 908 can cause a change in plasma density during the plasma activation and / or processing cycles involved in the deposition process. At the end of the deposition processing phase, the pedestal 908 can be lowered during another substrate transfer phase to allow the substrate 912 to be removed from the pedestal 908.

[0150] Although the exemplary microvolume variations described herein involve a height-adjustable pedestal, it should be understood that in some embodiments, the position of the showerhead 906 can be adjusted relative to the pedestal 908 to change the volume of the microvolume 907. Additionally, it should be understood that the vertical position of the pedestal 908 and / or the showerhead 906 can be changed by any suitable mechanism within the scope of the present disclosure. In some embodiments, the pedestal 908 can include a rotational axis for rotating the orientation of the substrate 912. It should be understood that in some embodiments, one or more of these exemplary adjustments can be performed programmatically by one or more suitable computer controllers.

[0151] In some embodiments, the pedestal 908 can be temperature-controlled via a heater 910. Additionally, in some embodiments, pressure control of the deposition processing station 900 can be provided by a butterfly valve 918. As Figure 9 shown in the embodiment, the butterfly valve 918 can throttle the vacuum provided by a downstream vacuum pump (not shown). However, in some embodiments, pressure control of the processing station 900 can also be adjusted by changing the flow rate of one or more gases introduced into the processing station 900. Conclusion

[0152] Although some detailed descriptions have been made of the foregoing embodiments for the purpose of clear understanding, it is obvious that certain changes and modifications can be practiced within the scope of the appended claims. It should be noted that there are many alternative ways to implement the processes, systems, and devices of the presented embodiments. Therefore, the presented embodiments are considered illustrative rather than restrictive, and the embodiments are not limited to the details given herein.

Claims

1. A method, comprising: Provide a 3-D structure of a partially fabricated semiconductor substrate to a chamber, the 3-D structure including sidewalls and a plurality of openings in the sidewalls leading to a plurality of features having a plurality of internal regions that are fluidly accessible via the openings; Deposit a tungsten nitride film in the plurality of features using one or more deposition cycles, each deposition cycle including (a)-(c): (a) Form a tungsten sublayer by: i) Dispensing diborane into the chamber and purging the chamber of diborane one or more times; ii) After (i), dispensing tungsten hexafluoride into the chamber and purging the chamber of tungsten hexafluoride multiple times; (b) After (a), dispense diborane into the chamber and purge the chamber of diborane; and (c) After (b), dispense a nitriding agent into the chamber to convert the tungsten sublayer to a tungsten nitride sublayer and purge the chamber of the nitriding agent.

2. The method according to claim 1, wherein the nitriding agent is ammonia.

3. The method according to claim 1, wherein the tungsten nitride film is deposited on an alumina film among the plurality of features.

4. The method according to claim 1, wherein 2, 3 or 4 deposition cycles are used to deposit the tungsten nitride film having to the thickness of.

5. The method according to claim 1, wherein each deposition cycle includes performing two or more repetitions of (i) before the first repetition of (ii) in the deposition cycle.

6. The method according to claim 1, wherein each deposition cycle includes at least 3 repetitions of (ii).

7. The method according to claim 1, wherein each deposition cycle includes at least 3 repetitions of (ii).

8. The method according to claim 1, wherein each deposition cycle includes at least 5 repetitions of (ii).

9. The method according to claim 1, wherein each of (b) and (c) is performed only once in each deposition cycle.

10. The method according to claim 1, wherein the number of repetitions of (ii) in each deposition cycle is greater than the number of repetitions of (i).

11. The method according to claim 1, wherein the duration of each dosing in (i) is from 1 second to 2 seconds.

12. The method according to claim 11, wherein the duration of each cleaning in (i) is less than 5 seconds.

13. The method according to claim 11, wherein the duration of each dosing in (ii) is less than 1 second.

14. The method according to claim 12, wherein the duration of each cleaning in (ii) is between 1 second and 2 seconds.

15. The method according to claim 1, wherein the duration of the dosing in (b) is 2 to 10 times the duration of each dosing in (i).

16. The method according to claim 1, wherein the overall volume ratio of B2H6 to WF6 in (a) is at least 2:

1.

17. The method according to claim 1, wherein the concentration of fluorine (F) in the tungsten nitride film is less than 1.0E21.

18. The method according to claim 1, wherein the concentration of fluorine (F) in the tungsten nitride film is less than 1.0E20.

19. The method according to claim 1, wherein the concentration of fluorine (F) in the tungsten nitride film is less than 1.0E19.

20. The method according to claim 1, wherein the concentration of fluorine (F) in the tungsten nitride film is less than 5E18.

21. The method according to claim 1, further comprising filling the plurality of features with a metal after depositing the tungsten nitride film.

22. An apparatus comprising: A processing chamber including one or more showerheads for directing gases in the processing chamber and one or more substrate supports; A controller configured to execute machine-readable instructions for depositing a tungsten nitride film using one or more deposition cycles, each deposition cycle including (a)-(c): (a) Cause a tungsten sublayer to be formed by: i) Cause diborane to be dispensed into the processing chamber and purge the processing chamber of diborane one or more times; ii) After (i), cause tungsten hexafluoride to be dispensed into the processing chamber and purge the processing chamber of tungsten hexafluoride multiple times; (b) After (a), cause diborane to be dispensed into the processing chamber and purge the processing chamber of diborane; and (c) After (b), cause a nitriding agent to be dispensed into the processing chamber to convert the tungsten sublayer to a tungsten nitride sublayer and purge the processing chamber of the nitriding agent.

23. A method comprising: Provide a processing chamber including a plurality of stations; Position each of a plurality of substrates at a corresponding one of the plurality of stations; After positioning all of the plurality of substrates at the corresponding stations, reduce the pressure in the processing chamber to below a first pressure; After reducing the pressure in the processing chamber to below the first pressure, increase the pressure in the processing chamber to a second pressure higher than the first pressure; And After increasing the pressure to the second pressure, deposit a tungsten-containing layer on each of the plurality of substrates.

24. A system comprising: A processing chamber including a plurality of stations; A controller configured to execute machine-readable instructions for: Position each of a plurality of substrates at a corresponding one of the plurality of stations; After positioning all of the plurality of substrates at the corresponding stations, reduce the pressure in the processing chamber to below a first pressure; After reducing the pressure in the processing chamber to below the first pressure, increase the pressure in the processing chamber to at least a second pressure higher than the first pressure; And Execute a first set of cycles, each cycle including (a)-(c): (a) Cause a tungsten sublayer to be formed by: (i) Cause diborane (B2H6) to be dispensed into the processing chamber and diborane to be purged from the processing chamber one or more times; (ii) After (i), cause a fluorine-containing tungsten precursor to be dispensed into the processing chamber and the fluorine-containing tungsten precursor to be purged from the processing chamber one or more times; (b) After (a), cause diborane to be dispensed into the processing chamber and diborane to be purged from the processing chamber; and (c) After (b), cause a nitriding agent to be dispensed into the processing chamber to convert the tungsten sublayer into a tungsten nitride layer and the nitriding agent to be purged from the processing chamber.

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