Pulsed ALD sequences for low-fluorine nucleation layer deposition

Abstract

The method comprises providing a partially manufactured semiconductor substrate 3D structure in a chamber, the 3D structure comprising a side wall and a plurality of openings in the side wall leading to a plurality of features having a plurality of internal regions through which the openings are fluidly accessible, and depositing a tungsten nucleation layer on the plurality of features using one or more deposition cycles, each deposition cycle comprising (a) administering diborane to the chamber two or more times without purging between diborane administrations, (b) purging the chamber after step (a), and (c) administering tungsten hexafluoride to the chamber one or more times after step (b), wherein purging is performed each time tungsten hexafluoride is administered.

Description

Reference

[0001] As part of this application, a PCT application is filed concurrently with this specification. Each application identified in this concurrently filed PCT application, for which this application claims benefit or priority, is incorporated herein by reference in its entirety for all purposes. [Background technology]

[0002] The deposition of tungsten-containing materials is an essential part of many semiconductor fabrication processes. These materials can be used for horizontal interconnects, vias between adjacent metal layers, and contacts between metal layers and devices. As devices shrink and more complex patterning schemes are used in the industry, tungsten film deposition is becoming a challenge. The continuous decrease in feature size and film thickness presents various challenges, including high resistance in thin films and the difficulty of achieving void-free filling in features. Deposition in complex high-aspect-ratio structures such as 3D NAND structures is particularly difficult.

[0003] The background information provided herein is intended to provide a general overview of the contents of this disclosure. Any research by the inventors named at this time, as well as any description that is not otherwise considered prior art at the time of filing, within the scope described in this background information section, shall not be recognized as prior art to this disclosure, whether express or implied. [Overview of the project]

[0004] This specification provides a method for forming a tungsten (W) nucleation layer on a feature. The method includes an atomic layer deposition (ALD) pulse sequence that uses tungsten hexafluoride (WF6) as a reactant to reduce the fluorine concentration in the deposited W nucleation layer.

[0005] One aspect of the present disclosure relates to a method for depositing a tungsten nucleation layer on a 3D structure. The method comprises providing a 3D structure of a partially fabricated semiconductor substrate in a chamber, the 3D structure comprising a side wall and a plurality of openings in the side wall, which lead to a plurality of features having a plurality of internal regions through which the openings are fluidly accessible, and depositing a tungsten nucleation layer on the plurality of features using one or more deposition cycles, each deposition cycle being (a) Administer diboran into the chamber two or more times without purging between diboran administrations. (b) After (a), purge the chamber, (c)(b) is followed by one or more doses of tungsten hexafluoride administered into the chamber, with purging performed each time tungsten hexafluoride is administered.

[0006] In some embodiments, (c) comprises at least 5, 10, or 15 doses of tungsten hexafluoride. In some embodiments, the tungsten nucleation layer is deposited on a tungsten nitride or tungsten carbonitride film at multiple features. In some embodiments, the tungsten nucleation layer is deposited on a titanium nitride film at multiple features. In some embodiments, one or more deposition cycles are used to deposit a tungsten nucleation layer having a thickness of 10–30 Å. In some embodiments, (a) comprises 2, 3, or 4 doses of diborane.

[0007] In some embodiments, the fluorine concentration in the tungsten nucleation layer is 1 × 10⁻¹⁶ 18 atoms / cm 3 The following applies: In some embodiments, the fluorine concentration in the tungsten nucleation layer is 5 × 10⁻¹⁶. 17 atoms / cm 3 The following applies: In some embodiments, the fluorine concentration in the tungsten nucleation layer is 1 × 10⁻¹⁶. 17 atoms / cm 3 The following applies:

[0008] In some embodiments, the substrate temperature is maintained at 170°C to 250°C. In some embodiments, the chamber pressure is 3 to 10 Torr. In some embodiments, the administration time for at least one dose of diborane in (a) is 1 second or less. In some embodiments, the administration time for at least one dose of diborane in (a) is less than 1 second. In some embodiments, the administration time for at least one dose of tungsten hexafluoride in (c) is less than 2 seconds.

[0009] Another aspect of this disclosure relates to an apparatus, the apparatus is A process chamber comprising one or more shower heads for guiding gas within the process chamber, and one or more substrate supports, A controller configured to execute machine-readable instructions for depositing a tungsten nucleation film using one or more deposition cycles, wherein each deposition cycle is ( (a) Administer diboran into the chamber two or more times without purging between diboran administrations. (b) After (a), purge the chamber. (c)(b) is followed by one or more administrations of tungsten hexafluoride into the chamber, with purging performed each time tungsten hexafluoride is administered.

[0010] These and other features of the present disclosure will be further described below with reference to the drawings. [Brief explanation of the drawing]

[0011] [Figure 1A] Figure 1A shows different diagrams and embodiments of an exemplary 3D NAND structure. [Figure 1B] Figure 1B shows different diagrams and embodiments of an exemplary 3D NAND structure. [Figure 1C] Figure 1C shows different diagrams and embodiments of an exemplary 3D NAND structure. [Figure 1D]FIG. 1D is a diagram showing different views and aspects of an exemplary 3D NAND structure. [Figure 1E] FIG. 1E is a diagram showing different views and aspects of an exemplary 3D NAND structure.

[0012] [Figure 2] FIG. 2 is a schematic diagram of a feature having a conformal nucleation layer.

[0013] [Figure 3A] FIG. 3A is a diagram showing an example of a pulse sequence that can be used during deposition of a nucleation layer. [Figure 3B] FIG. 3B is a diagram showing an example of a pulse sequence that can be used during deposition of a nucleation layer.

[0014] [Figure 4] FIG. 4 is a diagram showing a schematic example of a method for filling a 3D-NAND structure with metal.

[0015] [Figure 5] FIG. 5 is a schematic diagram of an apparatus that can be used to implement the methods described herein. [Figure 6] FIG. 6 is a schematic diagram of an apparatus that can be used to implement the methods described herein. [Figure 7] FIG. 7 is a schematic diagram of an apparatus that can be used to implement the methods described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The following description includes numerous specific details to provide a complete understanding of the presented embodiments. The disclosed embodiments can be practiced without some or all of these specific details. In other examples, well-known process behaviors are not described in detail so as not to unnecessarily obscure the disclosed embodiments. The disclosed embodiments are described in conjunction with specific embodiments, but it will be understood that this is not intended to limit the disclosed embodiments.

[0017] This specification provides a method for forming a metallic nucleation layer in a feature. In certain embodiments, the method is used to fill wordline features in a 3D NAND structure. However, the method can also be used to form metallic layers in other features, including vias or other vertically oriented features. In some embodiments, the method is used to fill tungsten (W) features.

[0018] The methods described herein are carried out on a substrate that can be housed in a chamber. The substrate may be a 200 mm, 300 mm, or 450 mm wafer, comprising a silicon or other semiconductor wafer, for example, a wafer having one or more layers of a dielectric, conductive, or semiconducting material deposited thereon.

[0019] The substrate may have features such as vias or contact holes, which may be characterized by narrow and / or concave openings, constrictions within features, and one or more high aspect ratios. Features may be formed in one or more of the aforementioned layers. For example, features may be formed at least partially in a dielectric layer. In some embodiments, features may have aspect ratios 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.

[0020] In some metallization schemes, adhesive and / or barrier layers may be formed to back the features before filling them with metal. A diffusion barrier is a layer that prevents the diffusion of species between layers. An adhesive layer is a layer that promotes the adhesion of the layer to the layer below.

[0021] For certain tungsten metallization applications, tungsten nitride (WN) diffusion barriers can be used. WN barriers offer several advantages over barriers such as titanium adhesive layer / titanium nitride barrier (Ti / TiN) bilayers. These advantages include the ability to deposit thin WN layers conformally and to deposit WN directly onto the dielectric without an adhesive layer. These advantages allow for filling a larger portion of the available space with W, thereby reducing the overall contact resistance. Furthermore, WN layer deposition can be performed at much lower temperatures than Ti / TiN, making it advantageous for applications with low thermal budgets.

[0022] In some embodiments, the method is used to deposit a W nucleation layer on a WN or TiN barrier layer. The method can be used for word line filling in a 3D NAND structure. Figure 1A shows a cross-sectional side view of a 3D NAND structure 110 (formed on a silicon or other semiconductor substrate 102) having VNAND stacks (left 125 and right 126), a central vertical structure 130, and a plurality of stacked horizontal word line features 120 having openings 122 on the side walls 140 of the central vertical structure 130. Note that Figure 1A shows two stacks of the presented 3D NAND structure 110, which together form a trench-like central vertical structure 130. Three or more such stacks may be arranged in sequence and extend spatially parallel to one another, and the gaps between each adjacent pair of stacks form the central vertical structure 130 as shown in Figure 1A. The horizontal word line features 120 are 3D memory word line features that are fluidly accessible from the central vertical structure 130 through the openings 122. The horizontal wordline features 120 present in both 3D NAND stacks 125 and 126 shown in Figure 1A (i.e., the left 3D NAND stack 125 and the right 3D NAND stack 126) are also accessible from other sides of the stacks (left and right ends, respectively) through a similar vertical structure formed by additional 3D NAND stacks (to the left and right ends, though not shown). In other words, each 3D NAND stack 125, 126 contains a stack of wordline features that are fluidly accessible from both sides of the 3D NAND stack through a central vertical structure 130. In the particular example schematically shown in Figure 1A, each 3D NAND stack contains six pairs of stacked wordlines, but in other embodiments, the 3D NAND memory layout may contain any number of vertically stacked pairs of wordlines.

[0023] Wordline features in a 3D NAND stack can be formed by depositing alternating stacks of silicon oxide and silicon nitride layers, then selectively removing the nitride layers to leave stacks of oxide layers with gaps between them. These gaps are the wordline features. Any number of wordlines can be stacked perpendicularly in such a 3D NAND structure, provided that techniques for forming wordlines are available and that techniques are available to successfully achieve (substantially) void-free filling of vertical features. Therefore, for example, a 3D NAND stack may contain 2 to 512 horizontal wordline features, or 2 to 256 horizontal wordline features, or 8 to 128 horizontal wordline features, or 16 to 64 horizontal wordline features, etc. (the listed ranges are understood to include the endpoints described).

[0024] Figure 1B shows a cross-sectional top view of the same 3D NAND structure 110 as shown in the side view of Figure 1A, where the cross-section is taken through the horizontal section 160 as indicated by the horizontal dashed line in Figure 1A. The cross-section in Figure 1B shows several rows of pillars 155 extending vertically from the base of the semiconductor substrate 102 to the top of the 3D NAND structure 110. In some embodiments, these pillars 155 are formed from a polysilicon material. The polysilicon pillars can function as gate electrodes for stacked memory cells formed within the pillars. The top view in Figure 1B shows that the pillars 155 form a constriction at the opening 122 to the word line feature 120, i.e., the fluid accessibility of the word line feature 120 from the central vertical structure 130 through the opening 122 (indicated by the arrow in Figure 1G) is obstructed by the pillars 155. This reduced fluid accessibility increases the difficulty of uniformly filling the word line feature 120 with material. The structure of the wordline feature 120 and the challenges of uniformly filling them with material due to the presence of the pillar 155 are further illustrated in Figures 1C, 1D, and 1E.

[0025] Figure 1C shows a vertical section of a 3D NAND structure similar to that shown in Figure 1A, but here it focuses on a single pair of wordline features 120. Figure 1C also schematically shows a void 175 in the filled wordline feature 120. Figure 1D also schematically shows a void 175, but in this figure it is shown via a horizontal section of a pillar 155, similar to the horizontal section shown in Figure 1G. Figure 1E shows the accumulation of tungsten 133 or other metals around pillar 155 forming a constriction, and this accumulation causes a pinch-off of the opening 122, and therefore prevents the deposition of additional metals in the area of ​​the void 175. Figure 1E also shows a barrier layer 118 on which a tungsten layer, including a nucleation layer and a bulk layer, can be deposited.

[0026] As is evident from Figures 1C and 1D, void-free wordline filling relies on a sufficient amount of deposited precursor passing through the vertical structure 130, through the opening 122, through the constricting pillar 155, and to the furthest extent of the wordline feature 120 before metal accumulates and deposits around the pillar 155, causing a pinch-off of the opening 122 and preventing further precursor movement to the wordline feature 120. Similarly, Figure 1E shows a single wordline feature 120 viewed in a section from above, illustrating how the generally conformal deposition of the material begins to pinch off the interior of the wordline feature 120 due to the fact that the considerable width of the pillar 155 acts to partially block, and / or narrow, and / or constrict what may be an open path through the wordline feature 120. (Note that the example in Figure 1E can be understood as a 2D rendering of the 3D feature of the pillar constriction structure shown in Figure 1D, and therefore shows the constriction as seen in a plan view rather than a section view.)

[0027] As 3D NAND structures become more complex, the challenges associated with reduced fluid accessibility increase. In some embodiments, for example, a reactant 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 wordline features. As the number of pillars increases, the likelihood of non-uniform deposition increases.

[0028] Another challenge in tungsten wordline filling is preventing fluorine contamination of the film and the underlying dielectric. Tungsten hexafluoride (WF6) is a useful precursor because, unlike many tungsten halides, it is a gas under standard conditions. However, using WF6 for typical tungsten deposition results in unacceptably high levels of fluorine. A method for depositing tungsten nucleation layers using WF6 is described below, which yields tungsten nucleation layers with very low fluorine levels and good continuity. Subsequent processing to fill features with tungsten can also utilize WF6.

[0029] Examples of deposition in horizontally and vertically oriented features are described herein. Note that, at least in most cases, the examples are applicable to both horizontally and vertically oriented features. Furthermore, note that in the following description, the term “vertical” may be used to refer to a direction generally perpendicular to the plane of the substrate, while the terms “lateral” or “horizontal” may be used to refer to a direction generally parallel to the plane of the substrate.

[0030] Figure 2 illustrates a schematic example of a wordline feature 220 in a 3D NAND structure. Figure 2 shows a 2D rendering of the 3D features of a partially fabricated 3D NAND structure before tungsten filling, including the wordline feature 220 and the conformal tungsten nucleation layer 221. Pillar constrictions in the figure represent constrictions seen in a plan view, not a cross-sectional view. The conformal tungsten nucleation layer 221 may be deposited on a barrier layer such as titanium nitride (TiN) or tungsten nitride (WN) (not shown). The barrier layer may be deposited on a dielectric layer (not shown), such as aluminum oxide or other dielectrics. In some embodiments, the nucleation layer may be deposited directly on the dielectric layer without an intervening barrier layer.

[0031] Atomic layer deposition (ALD) sequences can be used for conformal deposition of tungsten nucleation layers. Such sequences may involve the following actions: (i) providing a layer of reducing agent on the substrate surface, and (ii) bringing the substrate surface into contact with a tungsten-containing precursor to form a tungsten layer on the substrate. Each of these actions may involve delivering doses of the reactants (reducing agent, tungsten-containing precursor) into a chamber containing the substrate with the features. Purging is performed between these doses to purge the reactants from the chamber.

[0032] In the methods described herein, diborane (B2H6) can be used as a reducing agent. Although B2H6 is an effective reducing agent, it decomposes relatively easily into boron and hydrogen by thermal decomposition. Due to the complexity of the structure and the long diffusion distance, it can be challenging to deliver diborane throughout the structure while minimizing decomposition. Thermal decomposition creates heterogeneity, and diborane decomposes at the first available surface without diffusing throughout the structure. In the methods described herein, multiple consecutive doses of diborane can be used without intervening purging. The dose can be delivered using a charge volume.

[0033] By administering diborane in large amounts multiple times, diborane can diffuse throughout the 3D NAND structure with minimal decomposition. To reduce thermal decomposition, the chamber pressure and substrate temperature can also be controlled. Depending on various embodiments, the pressure can be 3 - 10 Torr and the temperature can be 170°C - 250°C.

[0034] After feeding diborane, a purge is performed. After that, a tungsten-containing precursor is administered one or more times, and a purge operation is performed after each administration.

[0035] In the case of diborane (B2H6) reducing agent and tungsten hexafluoride (WF6) or other tungsten-containing precursors, the sequence can be represented as B x / Purge / (W / Purge) y where B represents the dosage of B2H6 and W represents the dosage of WF6. By repeating this sequence multiple cycles, a W nucleation layer can be deposited. In the formula, "x" is an integer of 2 or more, for example, 2, 3, or 4, and y is an integer of 1 or more. B x / Purge / (W / Purge) y The sequence itself can be repeated one or more times to deposit a nucleation layer.

[0036] In some embodiments, y (the number of tungsten-containing precursor pulses in each cycle of the nucleation layer sequence) is at least 2, or at least 3. By using multiple short-time administrations, the generation of by-products can be minimized. By subsequent purging, the generated by-products are removed before they accumulate. This may enable complete conversion of the adsorbed reducing agent.

[0037] Figure 3A shows an example of a sequence for tungsten nucleation deposition. An exemplary B x / Purge / (W / Purge) yIn the sequence, x=3 and y=3. Each dose is represented by a peak line indicating an increase or decrease in the mass flow rate of diborane or tungsten hexafluoride into the chamber. This is due to the use of a charge volume. The gas is held in the charge volume at high pressure (e.g., 400 Torr to 1000 Torr). At the start of administration, the gas is allowed to flow from the charge volume into the chamber, and the pressure in the charge volume decreases rapidly. The decrease in pressure in the charge volume corresponds to an increase in the mass flow rate of gas into the chamber. As the pressure in the charge volume decreases, the mass flow rate of gas into the chamber also decreases. In the example in Figure 3A, the purging operation is represented by a capital P. However, the purging gas can also be supplied from the charge volume as described above.

[0038] Figure 3A shows three consecutive doses of diborane followed by a purge. According to various embodiments, the diborane doses may be the same or different in length. For example, multiple doses of 0.5 seconds or 1 second can be used. In some embodiments, the number of charge volumes may affect the dose time. For example, if two charge volumes are allocated to diborane doses, in three doses, the second dose may be longer as the first charge volume is filled. In one example, a dose sequence of 0.5s / 2.5s / 0.5s (where s is seconds) can be used. If sufficient charge volume is available, multiple doses of the same duration can be used. The dose duration can be up to 5 seconds, but shorter pulses may be useful to avoid decomposition. In some embodiments, each dose duration is 2 seconds or less or 1 second. In some embodiments, each dose duration may be less than 1 second.

[0039] In Figure 3A, the diborane administrations are shown to be non-repeated. However, as shown in Figure 3B, diborane administrations can be repetitive, and Figure 3B shows two consecutive repetitive diborane administrations. Examples of the number of diborane pulses can be 2 to 5, for example, 2, 3, or 4. In some embodiments, a single short diborane administration may be sufficient.

[0040] According to various embodiments, diborane may be supplied with a nitrogen carrier gas (e.g., 5% / 95% B2H6 / N2). Diborane can be further diluted with argon, for example, Ar:(B2H6 / N2)=1:1 or Ar:(B2H6 / N2)=2:1. In some embodiments, diborane may be co-circulated with hydrogen (H2). Hydrogen can be used as a parameter to control the exposure profile of diborane. Diborane decomposes more slowly in the presence of hydrogen than in another carrier gas such as nitrogen (N2). Hydrogen may be added for complex structures where the diborane treatment extends to deeper parts of the structure. For example, in some 3D NAND structures with multiple pillars, hydrogen may be added so that diborane can pass through one or more pillars without thermal decomposition.

[0041] Returning to Figure 3A, purging is performed after the final dose of diborane and after each dose of tungsten hexafluoride. The number of tungsten hexafluoride doses in each sequence may be significantly more than three, for example, five, nine, fifteen, twenty, or twenty-five doses. In some embodiments, the number of doses is at least three, five, nine, or fifteen. The administration time may be less than five seconds, less than two seconds, or less than one second. In some embodiments, for example, the administration time may be 0.25 seconds, 0.5 seconds, or 0.75 seconds. The purge time is also short, for example, less than two seconds. In some embodiments, the purge time is one second.

[0042] Using multiple short doses of diborane and tungsten hexafluoride improves both tungsten nucleation layer step coverage and fluorine concentration compared to fewer, longer doses. This is illustrated in the table below, which shows step coverage and fluorine concentration in various nucleation layer pulse sequences. The top row, labeled BBW, is an example using several longer sequences with exemplary pulse times of 5 seconds or more. The middle and last rows use pulse durations of 0.5s / 2.5s / 0.5s for boron administration and a dose duration of 0.25s for tungsten hexafluoride administration. [Table 1]

[0043] Resistivity is also significantly improved. For example, for a 100 Å membrane (bulk + approximately 18 Å of nucleation layer), the resistivity for the nucleation layer deposited with a 5-second dose using the BW (diborane / purge / tungsten hexafluoride / purge) sequence was approximately 30 μΩ·cm. In contrast, B x / Purge / (W / Purge) y The resistivity of a 100 Å (bulk + approximately 18 Å of nucleation layer) membrane with a nucleation layer deposited using sequencing at a significantly shorter dose was 26 μΩ·cm.

[0044] B x / Purge / (W / Purge) y The sequence can be repeated to deposit nucleation layers. The total thickness of exemplary nucleation layers ranges from 10 Å to 30 Å.

[0045] After depositing a nucleated layer, bulk deposition can be performed to deposit a bulk layer on top of the nucleated layer. Bulk deposition can be carried out by ALD or CVD processes. In the CVD process, a reducing agent and a metal precursor are co-flowed into the deposition chamber to deposit a bulk packed layer on the feature. One or more reactant streams can be supplied using an inert carrier gas, and these reactant streams may or may not be pre-mixed. This operation generally involves continuously flowing the reactants until a desired amount is deposited. In certain embodiments, the CVD operation may be carried out in multiple stages, with multiple periods of continuous and simultaneous flow of reactants separated by periods of bypassing one or more reactant streams.

[0046] For deposition into conformal deposits and complex structures such as 3D NAND structures, ALD deposition of bulk layers can be used. ALD deposition of bulk layers involves exposure to alternating pulses of a reducing agent and a metal precursor separated by an inert purge gas, using the metal precursors described above for nucleation layer deposition. The same or different metal precursors used for nucleation layer deposition can be used for bulk deposition. In contrast to nucleation layer deposition, where strong reducing agents such as diborane or silane may be used, hydrogen is often the reducing agent for bulk deposition.

[0047] Deposition may proceed according to various embodiments until a specific feature profile is achieved and / or until a specific amount of metal is deposited. In some embodiments, the deposition time and other relevant parameters may be determined by modeling and / or trial and error. In some embodiments, the process chamber may be equipped with various sensors to perform in-situ measurement for detecting the endpoint of the deposition operation. Examples of in-situ measurement include optical microscopy and X-ray fluorescence (XRF) for determining the thickness of the deposited film.

[0048] In some embodiments, conformal tungsten layers can be characterized as having low resistance, and in some embodiments, low stress and / or low fluorine. Since the wordline features are unfilled (except for the nucleation layer), relatively fast deposition techniques can be used. In some embodiments, this involves alternating pulses of a W-containing precursor such as WF6 and hydrogen (H2) or other reducing agent to deposit the first tungsten layer in the ALD process. The pulses can be separated by a purging operation. To improve throughput, relatively short pulse times can be used for deposition.

[0049] In some embodiments, the deposition process may involve one or more inhibiting operations. Figure 4 shows a deposition-inhibition-deposition (DID) sequence for word lines in a 3D NAND structure. At 410, the word line feature 402 after conformal deposition of the metal layer 404 is shown. The deposition of the metal layer 404 may include the deposition of the nucleation layer as described above and may further include a bulk deposition process. At 420, the feature 402 after the inhibiting treatment is shown. The treated surface 465 extends through a constriction formed by the pillar 451. In this example, the treated surface 465 through the constriction of the pillar 451 is inhibited, but the internal surface at 452 is not inhibited. Thus, in the example of Figure 4, the inhibiting treatment is non-conformal in the lateral direction. However, the treatment can be uniform in the vertical direction, and therefore each word line is inhibited in approximately the same area.

[0050] In step 430, a process is carried out to selectively deposit metal according to the inhibition profile. That is, bulk metal 408 is preferentially deposited on the non-inhibiting portion of the metal layer 404, thereby filling the area behind the constriction that is difficult to fill. In step 440, bulk deposition continues, filling the remaining portion of the feature with bulk metal 408.

[0051] In some embodiments, the nucleation process described above can be used to deposit nucleation layers of other metals. In such embodiments, a metal-containing precursor is reacted with diborane. Examples of other metal-containing precursors are shown below. Other metal-containing precursors can also be used for subsequent bulk deposition. For example, a molybdenum-containing precursor can be used for molybdenum ward lines, etc.

[0052] Metal-containing precursors As described above, WF6 can be used to deposit the W nucleation layer. WF6 is a useful precursor because it is present in the gas phase under deposition conditions. WF6 can also be used for depositing the W bulk layer. In some embodiments, other tungsten-containing precursors may be suitable for carrying out the disclosed embodiments. For example, metal-organotungsten-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 such as tungsten pentachloride (WCl5) and tungsten hexachloride (WCl6) can also be used. x ) can also be used.

[0053] The deposition of other metals may be carried out. These include molybdenum, ruthenium, and cobalt. To deposit molybdenum (Mo), Mo-containing precursors including molybdenum hexafluoride (MoF6), molybdenum pentachloride (MoCl5), molybdenum dichloride (MoO2Cl2), molybdenum tetrachloride (MoOCl4), and hexacarbonylmolybdenum (Mo(CO)6) can be used.

[0054] Ruthenium (Ru) precursors can be used to deposit ruthenium (Ru). Examples of ruthenium precursors that can be used in 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 that react with non-oxidizing agents are bis(5-methyl-2,4-hexanediketonate)Ru(II) dicarbonyl and bis(ethylcyclopentadienyl)Ru(II).

[0055] To deposit cobalt (Co), cobalt-containing precursors can be used, including dicarbonylcyclopentadienylcobalt(I), cobalt carbonyl, various cobalt amidinate precursors, cobalt diazadienyl complexes, cobalt amidinate / guanidinate precursors, and combinations thereof.

[0056] The metal-containing precursor can be reacted with a reducing agent as described above. Diborane can be used as a reducing agent for the nucleation layer. In some embodiments, H2 is used as a reducing agent for bulk layer deposition to deposit a high-purity film.

[0057] As described above, bulk deposition can be performed across the entire wafer. In some embodiments, bulk deposition can be performed by a CVD process in which a reducing agent and a metal-containing precursor are flowed into a deposition chamber to deposit a bulk packing layer on the features. One or more reactant flows can be supplied using an inert carrier gas, and these reactant flows may or may not be pre-mixed. Unlike PNL or ALD processes, this operation generally involves continuously flowing the reactant until the desired amount is deposited. In certain embodiments, the CVD operation may be performed in multiple stages, with multiple periods of continuous and simultaneous flow of reactant separated by periods of bypassing one or more reactant flows. Bulk deposition can also be performed using an ALD process in which a metal-containing precursor is alternately used with a reducing agent such as H2. In some embodiments, in the Dep1 process, ALD may be used to deposit the initial bulk layer, and CVD may be used for the remaining feature packing after inhibition. In some embodiments, ALD may be used for feature packing and CVD may be used for the overburden layer. In some embodiments, ALD may be used for all bulk layer deposition.

[0058] The metal films described herein may contain some nitrogen, carbon, oxygen, boron, phosphorus, sulfur, silicon, germanium, and other compounds, dopants, and / or impurities, depending on the specific precursor and process used. The metal content in the film may range from 20% to 100% (atoms) of metal. In many embodiments, the film is heavily metal-containing, having at least 50% (atoms) of metal, or at least about 60%, 75%, 90%, or 99% (atoms) of metal. In some embodiments, the film may be a mixture of metal or elemental metal (e.g., W, Mo, Co, or Ru) and other metal-containing compounds such as tungsten carbide (WC), tungsten nitride (WN), or molybdenum nitride (MoN). CVD and ALD deposition of these materials may involve the use of any suitable precursor as described above.

[0059] For feature filling, inhibition processes may be used after the deposition of the nucleation layer. Plasma inhibition processes involve exposure to a plasma generated from a nitrogen-containing compound such as N2. Plasma power, chamber pressure, and / or process gas may be pulsed in some embodiments. Thermal inhibition processes generally involve exposing features to a nitrogen-containing compound such as ammonia (NH3) or hydrazine (N2H4) to non-conformally inhibit features near feature openings. In some embodiments, thermal inhibition processes are carried out at temperatures in the range of 250°C to 450°C. At these temperatures, the inhibition effect is obtained by exposing a previously formed tungsten layer or other layer to NH3. Other potentially inhibitory chemicals such as nitrogen (N2) or hydrogen (H2) can be used for thermal inhibition at high temperatures (e.g., 900°C). However, in many applications, these high temperatures exceed the thermal budget. In addition to ammonia, other hydrogen-containing nitrides such as hydrazine can be used at lower temperatures suitable for back-end-of-line (BEOL) applications. During thermal inhibition, the metal precursor may be flowed together with the inhibiting gas, or it may be flowed alternately with the inhibiting gas in a pulsed manner.

[0060] By nitriding the surface, it can be passivated. Subsequent deposition of tungsten, or other metals such as molybdenum or cobalt, on the nitrided surface is significantly delayed compared to on a normal bulk tungsten film. In addition to NF3, fluorocarbons such as CF4 or C2F8 may be used. However, in certain embodiments, the inhibitory species does not contain fluorine to prevent etching during inhibition.

[0061] In addition to the surfaces mentioned above, nucleation can also be inhibited on liner / barrier layer surfaces such as TiN and / or WN surfaces. Any chemicals that passivate these surfaces can be used. The inhibition profile can also be modified using the inhibitory chemicals by changing the ratio of the active inhibitory species used. For example, for inhibition on W surfaces, nitrogen may have a stronger inhibitory effect than hydrogen, and the profile can be modified by adjusting the ratio of N2 gas to H2 gas in the formation gas.

[0062] In certain embodiments, the substrate may be heated or cooled before inhibition. A predetermined temperature for the substrate may be selected to induce a chemical reaction between the feature surface and the inhibitory species and / or to promote the adsorption of the inhibitory species, as well as to control the rate of the reaction or adsorption. For example, a temperature may be selected to have a high reaction rate so that more inhibition occurs near the gas source.

[0063] Device Any suitable chamber can be used to carry out the disclosed embodiments. Exemplary deposition systems include any of the various systems, such as ALTUS® and ALTUS® Max, which are available respectively from Lam Research, Inc. in Fremont, California, or any of the various other commercially available processing systems.

[0064] In some embodiments, the first deposition may be carried out in a first station which is one of two, five, or more deposition stations positioned within a single deposition chamber. Thus, for example, by introducing diborane and tungsten hexafluoride as described above, the nucleation layer can be deposited on the surface of a semiconductor substrate in the first station using individual gas supply systems that create a local atmosphere on the substrate surface. The same or a different station can be used for the deposition of conformal layers using ALD. A third station may be used for inhibition treatment, after which another bulk deposition operation may be performed.

[0065] Figure 5 is a schematic diagram of a process system suitable for performing a deposition process according to an embodiment. The system 500 includes a transfer module 503. The transfer module 503 provides a clean pressurized environment to minimize the risk of substrate contamination as the substrate moves between various reactor modules during processing. The transfer module 503 is fitted with a multi-station reactor 509 capable of performing ALD deposition, inhibition operations, and CVD of W nucleation layers and / or other metal films according to various embodiments. The multi-station reactor 509 may include a plurality of stations 511, 513, 515, and 517 that can sequentially perform operations according to the disclosed embodiments. For example, the multi-station reactor 509 may be configured such that station 511 performs W nucleation layer deposition using WF6 and B2H6, station 513 performs conformal layer ALD tungsten bulk deposition using H2 as a reducing agent, station 515 performs nitriding using NH3, and station 517 performs post-processed bulk ALD filling using H2ae as a reducing agent. In another example, station 511 can perform WN layer deposition, station 513 can perform conformal layer ALD deposition including nucleation layers, station 515 can perform NF3 treatment operations, and station 517 can perform post-treatment bulk ALD filling using an H2ae reducing agent. The stations may include heated pedestals or substrate supports, one or more gas inlets, or showerheads or dispersion plates.

[0066] Returning to Figure 5, the transfer module 503 may also be fitted with one or more single or multi-station modules 507 capable of performing plasma or chemical (non-plasma) pre-cleaning, other deposition operations, or etching operations. The modules can also be used for various processes, for example, to prepare substrates for deposition processes. The system 500 also includes one or more wafer source modules 501, where wafers are stored before and after processing. An atmospheric robot (not shown) in the atmospheric transfer chamber 519 can initially move the wafer from the source module 501 to the load lock 521. A wafer transfer device (typically a robotic arm unit) in the transfer module 503 moves the wafer from the load lock 521 to modules attached to the transfer module 503, or moves it between modules.

[0067] In various embodiments, a system controller 529 is used to control process conditions during deposition. The controller 529 typically includes one or more memory devices and one or more processors. The processors may include a CPU or computer, analog and / or digital input / output connections, a stepping motor controller board, and the like.

[0068] The controller 529 can control all the activities of the deposition apparatus. The system controller 529 runs system control software that includes a set of instructions for controlling timing, gas mixing, chamber pressure, chamber temperature, wafer temperature, radio frequency (RF) power level, wafer chuck position or pedestal position, and other parameters of a particular process. In some embodiments, other computer programs stored in a memory device associated with the controller 529 can be used.

[0069] Typically, a user interface is associated with the controller 529. The user interface may include a display screen, a graphical software display of the device and / or process conditions, and user input devices such as a pointing device, keyboard, touchscreen, or microphone.

[0070] System control logic can be configured in any suitable way. Generally, logic can be designed or configured in hardware and / or software. Instructions for controlling drive circuits may be hardcoded or provided as software. Instructions may also be provided by “programming.” Such programming is understood to include all forms of logic, including hardcoded logic of digital signal processors, application-specific integrated circuits, and other devices with specific algorithms implemented as hardware. Programming is also understood to include software or firmware instructions that can be executed on a general-purpose processor. System control software can be coded in any suitable computer-readable programming language.

[0071] Computer program code for controlling germanium-containing reducing agent pulses, hydrogen streams, and tungsten-containing precursor pulses in a process sequence, as well as other processes, can be written in any conventional computer-readable programming language (e.g., assembly language, C, C++, Pascal, Fortran, etc.). The compiled object code or script is executed by the processor to perform the tasks identified by the program. Alternatively, as shown, the program code may be hardcoded.

[0072] Controller parameters relate to process conditions such as process 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 entered using the user interface.

[0073] Signals for monitoring the process may be provided by the analog and / or digital input connections of the system controller 529. Signals for controlling the process are output by the analog and digital output connections of the deposition unit 500.

[0074] System software can be designed or configured in many different ways. For example, various chamber component subroutines or control objects may be written to control the operation of the chamber components necessary to perform the deposition process according to the disclosed embodiments. Examples of programs or sections of programs for this purpose include substrate positioning code, process gas control code, pressure control code, and heater control code.

[0075] In some embodiments, the controller 529 is part of a system, and such a system may be part of the examples described above. Such a system may include semiconductor processing equipment comprising one or more processing tools, one or more chambers, one or more processing platforms, and / or specific processing components (such as wafer pedestals, gas flow systems, etc.). These systems may be integrated with electronic equipment for controlling system operation before, during, and after processing of semiconductor wafers or substrates. Such electronic equipment may be referred to as a “controller” and may control various components or sub-components of one or more systems. Depending on the processing requirements and / or the type of system, the controller 529 may be programmed to control any of the processes disclosed herein. Such processes may include supplying processing gases, setting temperature (e.g., heating and / or cooling), setting pressure, setting vacuum, setting power, setting radio frequency (RF) generators in some systems, setting RF matching circuits, setting frequency, setting flow rates, setting fluid supply, setting position and operation, loading and unloading wafers to and from tools and other transfer tools connected to or interlocked with a particular system, and / or loading and unloading wafers to and from load locks.

[0076] In a broad sense, a controller may be defined as an electronic device having various integrated circuits, logic, memory, and / or software that receive and issue instructions, control operations, enable cleaning operations, enable endpoint measurements, etc. Integrated circuits may include chips in the form of firmware that store program instructions, chips defined as digital signal processors (DSPs), application-specific integrated circuits (ASICs), and / or one or more microprocessors, i.e., microcontrollers that execute program instructions (e.g., software). Program instructions are instructions communicated to the controller in the form of various individual settings (or program files) that may define operating parameters for performing a particular process on or for a semiconductor wafer or for a system. In some embodiments, the operating parameters may be part of a recipe defined by a process engineer to realize one or more processing steps in the fabrication of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or wafer dies.

[0077] In some embodiments, the controller 529 may be part of a computer integrated with or coupled to the system, or otherwise networked to the system, or coupled to such a computer, or a combination thereof. For example, the controller 529 may be in the “cloud” or may be all or part of a fab host computer system. This enables remote access to wafer processing. The computer may enable remote access to the system to monitor the current progress of fabrication operations, review the history of past fabrication operations, review trends or performance criteria from multiple fabrication operations, change parameters for the current process, set processing steps following the current process, or start a new process. In some examples, a remote computer (e.g., a server) can provide process recipes to the system over a network. Such a network may include a local network or the internet. The remote computer may include a user interface that enables entry or programming of parameters and / or settings, which are then communicated from the remote computer to the system. In some examples, the controller receives instructions in the form of data. Such data identifies parameters for each processing step performed during one or more operations. The parameters may be specific to the type of process being performed and the type of tools the controller is configured to interact with or control. As described above, the controller may be distributed, for example, by including one or more separate controllers that are networked together and cooperate toward a common purpose (such as the processes and controls described herein). An example of a distributed controller for such purposes would be one or more integrated circuits on a chamber that communicate with one or more integrated circuits that are remotely located (for example, at the platform level or as part of a remote computer) and combined to control the processes in the chamber.

[0078] Exemplary systems may include, but are not limited to, plasma etching chambers or modules, deposition chambers or modules, spin rinse chambers or modules, metal plating chambers or modules, cleaning chambers or modules, bevel edge etching chambers or modules, physical vapor deposition (PVD) chambers or modules, CVD chambers or modules, ALD chambers or modules, atomic layer etching (ALE) chambers or modules, ion implantation chambers or modules, tracking chambers or modules, and any other semiconductor processing systems that may be used in connection with or for the fabrication and / or manufacture of semiconductor wafers.

[0079] As described above, depending on one or more process steps performed by the tool, the controller may communicate with one or more other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, nearby tools, tools located throughout the factory, a main computer, another controller, or tools used for material handling to load and unload wafer containers to and from tool locations and / or load ports within the semiconductor manufacturing plant.

[0080] The controller 529 may include various programs. A substrate positioning program may include program code for controlling chamber components used to load the substrate onto a pedestal or chuck and to control the distance between the substrate and other parts of the chamber, such as the gas inlet and / or target. A process gas control program may include code for controlling the gas composition, flow rate, pulse time, and optionally code for supplying gas to the chamber before deposition in order to stabilize the pressure in the chamber. A pressure control program may include code for controlling the pressure in the chamber, for example, by adjusting the throttle valve of the chamber's exhaust system. A heater control program may include code for controlling the current to a heating unit used to heat the substrate. Alternatively, the heater control program can control the supply of a heat transfer gas (such as helium) to the wafer chuck.

[0081] Examples of chamber sensors that can be monitored during deposition include mass flow controllers, pressure sensors (such as pressure gauges), and thermocouples located in a pedestal or chuck. Appropriately programmed feedback and control algorithms can be used in conjunction with data from these sensors to maintain desired process conditions.

[0082] Figure 6 illustrates a schematic diagram of one embodiment of a process station 600 having a process chamber 602 for maintaining a low-pressure environment. In some embodiments, multiple process stations may be included in a common low-pressure process tool environment. For example, Figure 5 illustrates one embodiment of a multi-station reactor 509. In some embodiments, one or more hardware parameters of the process station 600 (including those described in detail below) can be programmatically adjusted by one or more computer controllers 650. In some other embodiments, the process chamber may be a single-station chamber.

[0083] The process station 600 is in fluid communication with a reactant delivery system 601a for supplying process gas to a distribution showerhead 606. The reactant delivery system 601a includes a mixing vessel 604 for blending and / or adjusting process gases such as a metal precursor-containing gas, a hydrogen-containing gas, an inhibitor gas, argon or other carrier gas, or other reactant-containing gases to be supplied to the showerhead 606. One or more mixing vessel inlet valves 620 can control the introduction of process gas into the mixing vessel 604.

[0084] As an example, the embodiment in Figure 6 includes a vaporization point 603 for vaporizing a liquid reactant supplied to a mixing vessel 604. In some embodiments, the vaporization point 603 may be a heated vaporizer. In some embodiments, the liquid precursor or liquid reactant may be vaporized in a liquid injector (not shown). For example, a liquid injector can inject pulses of liquid reactant into the carrier gas flow upstream of the mixing vessel 604. In one embodiment, the liquid injector can vaporize the reactant by flashing the liquid from a higher pressure to a lower pressure. In another example, the liquid injector can spray the liquid into dispersed microdroplets, which are then vaporized in a heated supply pipe. Smaller droplets can vaporize faster than larger droplets, reducing the delay between liquid injection and complete vaporization. Faster vaporization can reduce the length of piping downstream from the vaporization point 603. In one scenario, the liquid injector can be directly attached to the mixing vessel 604. In another scenario, the liquid injector can be directly attached to the showerhead 606.

[0085] In some embodiments, a liquid flow controller (LFC) may be located upstream of the vaporization point 603 to control the mass flow rate of the liquid that is vaporized and supplied to the process chamber 602. For example, the LFC may include a thermal mass flow meter (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 via electrical communication with the MFM. However, stabilizing the liquid flow using feedback control may take more than one second. This may extend the time available for administering the liquid reagent. Therefore, in some embodiments, the LFC may be dynamically switched between a feedback control mode and a direct control mode. In some embodiments, this may be accomplished by disabling the sense tubes of the LFC and the PID controller. According to various embodiments, one or more charge volumes may be connected to a process gas supply source.

[0086] In some embodiments, a solid precursor may be supplied to an ampoule box 613 from which the precursor can be delivered.

[0087] In some embodiments, the station may be equipped with one or more charge volumes. Pulsing of the reactant gas, purge gas, and / or inhibitor gas may be accompanied by the charge volume. An exemplary apparatus is shown in Figure 7, in which four gas sources (precursor, B2H6, H2, and purge gas) are each connected to a charge volume 701. According to various embodiments, all or only some of these gas sources may be connected to the charge volume. The charge volume 701 is used to build up a volume of pressurized gas, which is then flowed into the process chamber. The gas from the charge volume 701 is pressurized (e.g., 300 Torr to 700 Torr) and enters the chamber via a showerhead 706. A pedestal 708 for supporting wafers is also shown.

[0088] Returning to Figure 6, the showerhead 606 distributes the process gas toward the substrate 612. In the embodiment shown in Figure 16, the substrate 612 is located below the showerhead 606 and is shown stationary on the base 608. The showerhead 606 may have any suitable shape and may have any suitable number and arrangement of ports for distributing the process gas toward the substrate 612.

[0089] In some embodiments, the base 608 can be raised or lowered to expose the substrate 612 to the volume between the substrate 612 and the shower head 606. In some embodiments, the base 608 may be temperature-controlled via a heater 610. The base 608 can be set to any suitable temperature during operation to carry out various disclosed embodiments. In some embodiments, it will be understood that the height of the base can be programmatically adjusted by a suitable computer controller 650. At the end of a process stage, the base 608 can be lowered during a transfer stage of another substrate, allowing the substrate 612 to be removed from the base 608.

[0090] In some embodiments, the position of the shower head 606 can be adjusted relative to the base 608 to change the volume between the substrate 612 and the shower head 606. Furthermore, it will be understood that the vertical position of the base 608 and / or the shower head 606 may be changed by any suitable mechanism within the scope of this disclosure. In some embodiments, the base 608 may include a pivot axis for rotating the orientation of the substrate 612. In some embodiments, one or more of these exemplary adjustments can be programmed by one or more suitable computer controllers 650. The computer controllers 650 may include any of the features described below with respect to the controller 650 in Figure 6.

[0091] When plasma is used during deposition or inhibition, the showerhead 606 and base 608 electrically communicate with a radio frequency (RF) power supply 614 and a matching network 616 to power the plasma. In some embodiments, plasma energy can be controlled by controlling one or more of the process station pressure, gas concentration, RF source power, RF source frequency, and plasma power pulse timing. For example, the RF power supply 614 and matching network 616 can operate at any suitable power to form a plasma having a desired composition of radical species. Similarly, the RF power supply 614 can provide RF power at any suitable frequency. In some embodiments, the RF power supply 614 may be configured to control high-frequency and low-frequency RF power supplies independently of each other. Exemplary low-frequency RF frequencies may include, but are not limited to, frequencies from 0 kHz to 900 kHz. Exemplary high-frequency RF frequencies may include, but are not limited to, frequencies from 1.8 MHz to 2.45 GHz, or above about 13.56 MHz, or above 27 MHz, or above 80 MHz, or above 60 MHz. It will be understood that any suitable parameters can be adjusted discretely or continuously to provide the plasma energy necessary for the surface reaction.

[0092] In some embodiments, the plasma can be monitored in situ by one or more plasma monitors. In one scenario, plasma power may be monitored by one or more voltage, current sensors (e.g., VI probes). In another scenario, plasma density and / or process gas concentration may be measured by one or more emission spectroscopic sensors (OES). In some embodiments, one or more plasma parameters can be programmed to adjust based on measurements from such in situ plasma monitors. For example, OES sensors may be used in a feedback loop to provide programmed control of plasma power. In some embodiments, it will be understood that other monitors may be used to monitor plasma and other process characteristics. Such monitors may include, but are not limited to, infrared (IR) monitors, acoustic monitors, and pressure transducers.

[0093] In some embodiments, instructions to the controller 650 may be provided via input / output control (IOC) sequence instructions. For example, instructions for setting conditions for process stages may be included in the corresponding recipe stages of the process recipe. In some cases, process recipe stages may be arranged sequentially so that all instructions for process stages are executed simultaneously with those process stages. In some embodiments, instructions for setting one or more reactor parameters may be included in the recipe stages. For example, a first recipe stage may include instructions for setting the flow rates of the inert gas and / or reactant gas (e.g., a metal precursor), instructions for setting the flow rate of the carrier gas (e.g., argon), and a time delay instruction for the first recipe stage. A second subsequent recipe stage may include instructions for adjusting or stopping the flow rates of the inert gas and / or reactant gas, instructions for adjusting the flow rate of the carrier gas or purge gas, and a time delay instruction for the second recipe stage. A third recipe stage may include instructions for adjusting the flow rate of H2, instructions for adjusting the flow rate of the carrier gas or purge gas, and a time delay instruction for the third recipe stage. A fourth subsequent recipe step may include instructions to adjust or stop the flow rates of the inert gas and / or reactant gas, instructions to adjust the flow rates of the carrier gas or purge gas, and a time delay instruction for the fourth recipe step. It will be understood that these recipe steps may be further subdivided and / or repeated in any suitable manner within the scope of this disclosure.

[0094] Furthermore, in some embodiments, pressure control for the process station 600 may be provided by a butterfly valve 618. As shown in the embodiment of Figure 6, the butterfly valve 618 throttles the vacuum provided by a downstream vacuum pump (not shown). However, in some embodiments, pressure control for the process station 600 can also be adjusted by changing the flow rate of one or more gases introduced into the process station 600.

[0095] The implementation of the disclosed embodiments in single or multi-chamber semiconductor processing tools has been described above. The apparatus and processes described herein may be used in conjunction with lithography patterning tools or processes for, for example, the fabrication or manufacture of semiconductor devices, displays, LEDs, solar panels, etc. Typically, although not essential, such tools / processes are used or performed together in a common fabrication facility. Film lithography patterning typically involves some or all of the following steps, each made possible by a variety of available tools: (1) applying photoresist to a workpiece (i.e., substrate) using a spin-on or spray-on tool; (2) curing the photoresist using a hot plate or furnace or UV curing tool; (3) exposing the photoresist with visible light, UV light, or X-ray light using a tool such as a wafer stepper; (4) developing the resist and selectively removing it using a tool such as a wet bench, thereby patterning the resist; (5) transferring the resist pattern to the underlying film or workpiece by using a dry etching tool or plasma-assisted etching tool; and (6) removing the resist using a tool such as an RF or microwave plasma resist stripper.

[0096] Unless otherwise specified, the scope of this disclosure includes the endpoint, for example, 170°C to 250°C.

[0097] The implementation of the disclosed embodiments in single or multi-chamber semiconductor processing tools has been described above. The apparatus and processes described herein may be used in conjunction with lithography patterning tools or processes for, for example, the fabrication or manufacture of semiconductor devices, displays, LEDs, solar panels, etc. Typically, although not essential, such tools / processes are used or performed together in a common fabrication facility. Film lithography patterning typically involves some or all of the following steps, each made possible by a variety of available tools: (1) applying photoresist to a workpiece (i.e., substrate) using a spin-on or spray-on tool; (2) curing the photoresist using a hot plate or furnace or UV curing tool; (3) exposing the photoresist with visible light, UV light, or X-ray light using a tool such as a wafer stepper; (4) developing the resist and selectively removing it using a tool such as a wet bench, thereby patterning the resist; (5) transferring the resist pattern to the underlying film or workpiece by using a dry etching tool or plasma-assisted etching tool; and (6) removing the resist using a tool such as an RF or microwave plasma resist stripper.

[0098] conclusion While the embodiments described above have been described in some detail for clear understanding, it will be apparent that certain changes and modifications may be practiced within the scope of the appended claims. It should be noted that there are many other ways of carrying out the processes, systems, and apparatus of these embodiments. Therefore, these embodiments should be considered illustrative rather than restrictive, and their embodiments should not be limited to the details described herein.

Claims

1. It is a method, A partially manufactured semiconductor substrate 3D structure is provided in a chamber, the 3D structure comprising a side wall and a plurality of openings in the side wall, the openings leading to a plurality of features having a plurality of internal regions that are fluidly accessible through the openings, The process involves depositing a tungsten nucleation layer on the plurality of features using one or more deposition cycles, each deposition cycle being: (a) Diborane is administered into the chamber two or more times without purging between doses of diborane. (b) After (a), the chamber is purged. A method comprising (c) and (b) followed by administering tungsten hexafluoride to the chamber once or more times, wherein purging is performed each time tungsten hexafluoride is administered.

2. The method according to claim 1, (c) A method comprising at least five doses of tungsten hexafluoride.

3. The method according to claim 1, (c) A method comprising at least 10 doses of tungsten hexafluoride.

4. The method according to claim 1, (c) A method comprising at least 15 doses of tungsten hexafluoride.

5. The method according to claim 1, A method comprising depositing the tungsten nucleation layer on a tungsten nitride film or tungsten carbonitride film in the plurality of features.

6. The method according to claim 1, A method wherein the tungsten nucleation layer is deposited on a titanium nitride film in the plurality of features.

7. The method according to claim 1, A method for depositing the tungsten nucleation layer having a thickness of 10 to 30 Å using one or more of the aforementioned deposition cycles.

8. The method according to claim 1, (a) A method comprising two, three, or four administrations of diborane.

9. The method according to claim 1, The fluorine concentration in the tungsten nucleation layer is 1 × 10 18 atoms / cm 3 The method is as follows:

10. The method according to claim 1, The fluorine concentration in the tungsten nucleation layer is 5 × 10 17 atoms / cm 3 The method is as follows:

11. The method according to claim 1, The fluorine concentration in the tungsten nucleation layer is 1 × 10 17 atoms / cm 3 The method is as follows:

12. The method according to claim 1, A method in which the substrate temperature is maintained between 170°C and 250°C.

13. The method according to claim 1, A method using a chamber pressure of 3 to 10 Torr.

14. The method according to claim 1, A method wherein the administration time for at least one dose of diborane in (a) is 1 second or less.

15. The method according to claim 1, (a) A method in which the administration time for at least one dose of diborane is less than 1 second.

16. The method according to claim 1, (c) A method in which the administration time for at least one tungsten hexafluoride dose is less than 2 seconds.

17. It is a device, A process chamber comprising one or more showerheads within the process chamber for introducing gas, and one or more substrate supports, A controller configured to execute machine-readable instructions for depositing a tungsten nucleation film using one or more deposition cycles, wherein each deposition cycle is (a) Diborane is administered to the chamber two or more times without purging between administrations of diborane. (b) After (a), the chamber is purged. The apparatus comprises (c) and (b) followed by the administration of tungsten hexafluoride to the chamber one or more times, with purging being performed each time tungsten hexafluoride is administered.

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