Molybdenum accumulation and void-free filling

Abstract

Provided herein is a method of filling a feature with molybdenum (Mo), which may be used in logic and memory applications. The method includes treating a surface of the feature prior to filling the feature. In some embodiments, the method includes treating the surface of the feature by exposing it to a molybdenum halide. In some embodiments, the method includes treating the surface of the feature by selectively oxidizing, nitriding, or halogenating it. An apparatus for carrying out the method is provided.

Description

[Background technology]

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

[0002] The deposition of conductive materials is an essential component of many semiconductor fabrication processes. These materials may be used for horizontal interconnects, vias between adjacent metal layers, contacts between metal layers and devices, as well as lines in memory devices. In one example of deposition, a tungsten (W) layer is deposited on a titanium nitride (TiN) barrier layer, followed by deposition of tungsten hexafluoride (WF 6 ) can form a TiN / W bilayer. However, as the industry scales down devices and utilizes more complex patterning schemes, deposition of thin tungsten films becomes challenging. The ever-shrinking feature sizes and film thicknesses pose various challenges for TiN / W film stacks. These challenges include higher resistivity of thinner films and degraded TiN barrier properties. Deposition is especially challenging within complex high aspect ratio structures such as 3D NAND structures.

[0003] The background description provided herein is intended to provide a general overview of the contents of the present disclosure. Work by the currently named inventors within the scope of what is described in this Background section, as well as aspects of the description that may not otherwise be regarded as prior art at the time of filing, are not admitted, expressly or impliedly, as prior art against the present disclosure. Summary of the Invention

[0004] Provided herein is a method for filling features with molybdenum (Mo), which may be used in logic and memory applications.

[0005] In some embodiments, the method includes treating a surface of the feature by exposing it to a molybdenum halide prior to filling the feature.

[0006] One aspect of the present disclosure relates to a method that includes providing a substrate including a feature having a metal-containing contact and a dielectric sidewall, treating the feature by exposing the feature to a molybdenum halide, and depositing molybdenum in the feature, where the deposition is selective to the metal-containing contact relative to the dielectric sidewall.

[0007] In some embodiments, the method further comprises exposing the feature to a hydrogen-containing plasma prior to treating the feature. In some embodiments, selectively depositing molybdenum on the metal-containing bottom comprises exposing the feature to a molybdenum oxyhalide. In some embodiments, the treatment inhibits growth of molybdenum on oxide or nitride sidewalls. In some embodiments, the treatment is performed without depositing molybdenum in the feature. In some embodiments, the treatment further comprises exposing the feature to a co-reactant capable of reducing a molybdenum halide to form molybdenum.

[0008] In some embodiments, an amorphous molybdenum-containing layer is on the metal-containing contact. In some embodiments, the treatment removes the amorphous molybdenum-containing layer. In some embodiments, the treatment inhibits molybdenum growth on dielectric sidewalls. In some embodiments, the method further includes removing etch residues from the metal-containing contact prior to processing the feature.

[0009] In some embodiments, the molybdenum halide is molybdenum pentachloride (MoCl 5 In some embodiments, the selective deposition is performed at a substrate temperature between 250°C and 550°C, for example between 300°C and 500°C.

[0010] Another aspect of the disclosure relates to a molybdenum-on-molybdenum stacking scheme. In some embodiments, a method includes providing a substrate including a feature having a dielectric sidewall and a molybdenum contact, the molybdenum contact and the dielectric sidewall, an amorphous molybdenum-containing layer on top of the molybdenum contact, exposing the feature to a molybdenum halide to remove the amorphous molybdenum-containing layer and inhibit deposition of molybdenum on the dielectric sidewall, and depositing molybdenum in the feature, the deposition being selective to the molybdenum contact relative to the dielectric sidewall. In some embodiments, the molybdenum halide is molybdenum pentachloride (MoCl 5 In some embodiments, depositing molybdenum in the feature comprises exposing the feature to a molybdenum oxyhalide.

[0011] A method for bottom-up filling of a feature on a semiconductor substrate with molybdenum (Mo) includes selectively treating a conformal liner layer in the feature. A portion of the liner layer on the field region and / or upper portions of the feature sidewalls is preferentially treated relative to a liner layer on the lower portions of the sidewalls. Molybdenum is selectively deposited on the untreated or less treated portions.

[0012] One aspect of the disclosure relates to a method that includes: (a) providing a substrate including a field region and a feature, the feature including an opening, a sidewall, and a bottom, the field region surrounding the opening, and a liner layer lining the sidewall of the feature, (b) selectively treating the liner layer such that a portion of the liner layer on an upper portion of the field region and / or the sidewall is preferentially treated relative to a liner layer on a lower portion of the sidewall, the selectively treating the liner layer forming a selectively treated portion of the liner layer, and (c) selectively depositing molybdenum at a bottom of the feature, wherein deposition is inhibited on the selectively treated portion of the liner layer.

[0013] In some embodiments, the liner layer is titanium nitride or tungsten nitride. In some embodiments, (a) includes depositing a liner layer in the feature. In some embodiments, the liner layer is a tungsten-containing layer or a molybdenum-containing layer. In some such embodiments, the liner layer is a tungsten layer or a molybdenum layer.

[0014] In some embodiments, (b) includes oxidizing the liner layer on the field region and / or upper portions of the sidewalls. In some embodiments, (b) includes nitriding the liner layer on the field region and / or upper portions of the sidewalls. In some embodiments, (b) includes exposing the substrate to an ion beam plasma. In some such embodiments, (b) further includes rotating and tilting the substrate during exposure to the ion beam plasma.

[0015] Another aspect of the disclosure relates to a method that includes: (a) providing a substrate including a field region and a feature, the feature including an opening, sidewalls, and a bottom, the field region surrounding the opening, and a liner layer lining the sidewalls of the feature, (b) selectively processing the liner layer such that some of the liner layer on the field region and / or upper portions of the sidewalls is preferentially processed relative to the liner layer on lower portions of the sidewalls to form processed regions of the liner layer, (c) selectively etching the processed regions of the liner layer while leaving other portions that are the liner layer on the lower portions of the sidewalls, and (d) selectively depositing molybdenum at the bottom of the feature.

[0016] In some embodiments, the liner layer is titanium nitride or tungsten nitride.

[0017] In some embodiments, (a) includes depositing a liner layer in the feature. In some embodiments, the liner layer is a tungsten-containing layer or a molybdenum-containing layer. In some such embodiments, the liner layer is a tungsten layer or a molybdenum layer. In some embodiments, (b) includes oxidizing the liner layer on the field region and / or upper portions of the sidewalls. In some embodiments, (b) includes nitriding the liner layer on the field region and / or upper portions of the sidewalls. In some embodiments, (b) includes exposing the substrate to an ion beam plasma. In some such embodiments, (b) further includes rotating and tilting the substrate during exposure to the ion beam plasma.

[0018] Another aspect of the disclosure relates to an apparatus comprising a vacuum transfer module, a deposition module connected to the vacuum transfer module, an ion beam etching module connected to the vacuum transfer module, and a controller including machine-readable instructions for selectively treating a liner layer of a feature on the substrate such that a portion of the liner layer on a field region and / or an upper portion of a sidewall of the feature is preferentially treated relative to a liner layer on a lower portion of the sidewall by exposing the substrate to an ion beam plasma in the ion beam etching module, transferring the substrate from the ion beam etching module to a deposition module via the vacuum transfer module, and depositing molybdenum in the feature in the deposition module.

[0019] These and other aspects of the disclosure are further described below with reference to the drawings. [Brief description of the drawings]

[0020] [Figure 1A] FIG. 1A is a schematic example of a material stack including a molybdenum layer, according to various embodiments. [Figure 1B] FIG. 1B is a schematic example of a material stack including a molybdenum layer, according to various embodiments.

[0021] [Figure 2A] FIG. 2A is a schematic example of various structures into which molybdenum may be deposited according to disclosed embodiments. [Figure 2B] FIG. 2B is a schematic example of various structures into which molybdenum may be deposited according to disclosed embodiments. [Figure 2C] FIG. 2C is a schematic example of various structures into which molybdenum may be deposited according to disclosed embodiments. [Figure 2D] FIG. 2D is a schematic example of various structures into which molybdenum may be deposited according to disclosed embodiments. [Figure 2E] FIG. 2E is a schematic example of various structures into which molybdenum may be deposited according to disclosed embodiments. [Figure 2F] FIG. 2F is a schematic example of various structures into which molybdenum may be deposited according to disclosed embodiments. [Figure 2G] FIG. 2G is a schematic example of various structures into which molybdenum may be deposited according to disclosed embodiments. [Figure 2H] FIG. 2H is a schematic example of various structures into which molybdenum may be deposited according to disclosed embodiments. [Figure 2I] FIG. 2I is a schematic example of various structures into which molybdenum may be deposited according to disclosed embodiments. [Figure 2J] FIG. 2J is a schematic example of various structures into which molybdenum may be deposited according to disclosed embodiments. [Figure 2K] FIG. 2K is a schematic example of various structures into which molybdenum may be deposited according to disclosed embodiments. [Figure 2L] FIG. 2L is a schematic example of various structures into which molybdenum may be deposited according to disclosed embodiments. [Diagram 3] FIG. 3 is a schematic example of various structures into which molybdenum may be deposited according to the disclosed embodiments.

[0022] [Figure 4] Figure 4 shows a schematic example of a molybdenum-on-molybdenum integration scheme.

[0023] [Diagram 5] FIG. 5 is a process flow diagram illustrating an exemplary operation of a method for filling a feature with molybdenum.

[0024] [Figure 6A] FIG. 6A shows a schematic example of a feature in which an example process according to FIG. 5 is proceeding. [Figure 6B] FIG. 6B shows a schematic example of a feature through which an example process according to FIG. 5 proceeds. [Figure 6C] FIG. 6C shows a schematic example of a feature through which an example process according to FIG. 5 proceeds.

[0025] [Figure 7] FIG. 7 illustrates an example of a surface treatment sequence, according to various embodiments.

[0026] [Figure 8] FIG. 8 illustrates an example sequence for surface treatment and selective deposition, according to various embodiments.

[0027] [Figure 9] FIG. 9 is a process flow diagram illustrating a method for filling a feature with a molybdenum (Mo) film.

[0028] [Figure 10A] FIG. 10A shows the feature in various stages of filling the feature with Mo. [Figure 10B] FIG. 10B shows the feature in various stages of filling the feature with Mo. [Figure 10C] FIG. 10C shows the feature in various stages of filling the feature with Mo.

[0029] [Figure 11]FIG. 11 is a plot showing film thickness after multiple atomic layer deposition (ALD) cycles of Mo deposition on both TiN and oxidized TiN (TiON).

[0030] [Figure 12] FIG. 12 is a process flow diagram showing how to fill features with a Mo film.

[0031] [Figure 13A] FIG. 13A shows a schematic example of the method according to FIG. [Figure 13B] FIG. 13B shows a schematic example of the method according to FIG. [Figure 13C] FIG. 13C shows a schematic example of the method according to FIG. [Figure 13D] FIG. 13D shows a schematic example of the method according to FIG.

[0032] [Figure 14A] FIG. 14A shows a schematic example of the method according to FIG. [Figure 14B] FIG. 14B shows a schematic example of the method according to FIG. [Figure 14C] FIG. 14C shows a schematic example of the method according to FIG. [Figure 14D] FIG. 14D shows a schematic example of the method according to FIG.

[0033] [Figure 15] FIG. 15 shows an example of the ion beam angle used to reach the sidewall depth.

[0034] [Figure 16] FIG. 16 illustrates an example of a processing system that can be used to implement the methods described herein. [Figure 17A] FIG. 17A illustrates an example of a processing system that can be used to implement the methods described herein. [Figure 17B] FIG. 17B illustrates an example of a processing system that can be used to implement the methods described herein. [Figure 18] FIG. 18 illustrates an example of a processing system that can be used to implement the methods described herein. [Figure 19] FIG. 19 illustrates an example of a processing system that can be used to implement the methods described herein. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] 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 process operations have not been described in detail so as not to unnecessarily obscure the disclosed embodiments. While the disclosed embodiments will be described in conjunction with specific embodiments, it will be understood that it is not intended to be limited to the disclosed embodiments.

[0036] The subscripts "x" and "y" are used throughout this disclosure to indicate numbers greater than 0 that form stable compounds. However, it should be noted that the absence of "x" or other subscripts (e.g., in titanium nitride (TiN) or titanium oxynitride (TiON)) does not imply a specific atomic ratio.

[0037] Provided herein is a method for filling features with molybdenum (Mo), which may be used in logic and memory applications. The Mo film may be deposited in semiconductor substrate features, such as vias and trenches. The Mo film may be deposited to line the feature as a liner layer and / or to fill the feature.

[0038] In some embodiments, the method includes bottom-up deposition of Mo in the feature. Bottom-up deposition refers to growth mostly or entirely from the bottom of the feature compared to the sidewalls of the feature. Filling of a feature using conventional deposition methods can result in nucleation and growth on all surfaces of the feature. This can result in conformal growth and can result in the formation of voids and / or seams in the feature. For example, voids can form because growth at the top of the feature can pinch off the feature. Seams can form in the center of the feature due to the film growing inward from the sidewalls. Bottom-up deposition can avoid the formation of voids and seams in the feature during the filling process.

[0039] Although described primarily in the context of Mo, the method can be used to deposit other metals, including W, Co, and Ru. In some applications, molybdenum offers several advantages over other metals such as cobalt (Co), ruthenium (Ru), and tungsten (W): (i) barrier-less and linerless deposition of molybdenum films is more suitable than cobalt, ruthenium, and tungsten deposition on oxides and nitrides, (ii) resistivity scaling of Mo is better than that of tungsten, (iii) intermixing of Mo with the underlayer Co is not expected compared to intermixing of Ru with Co at temperatures below 450° C., and (iv) integration of Mo into current W schemes is relatively easy compared to copper and ruthenium.

[0040] 1A and 1B are schematic examples of material stacks including a Mo layer, according to various embodiments. 1A and 1B show the order of materials in a particular stack example, which may be used with any suitable architecture and application, as further described below with respect to FIGS. 2A-2L, 3, 4, 6A-6C, 10A-10C, 13A-13D, and 14A-14D. FIG. 1A shows a first material stack 111 featuring a substrate 102 and a molybdenum layer 108 deposited thereon. The substrate 102 may be a silicon or other semiconductor wafer, e.g., a 200 mm wafer, a 300 mm wafer, or a 450 mm wafer, including a wafer having one or more layers of material deposited thereon, such as a dielectric material, a conductive material, or a semiconductive material. In some embodiments, the substrate 102 may be or include silicon (Si) or silicon germanium (SiGe). The method may also be applied to form metallization stack structures on other substrates such as glass, plastic, etc.

[0041] The stack 111 has a dielectric layer 104 on a substrate 102. The dielectric layer 104 may be deposited directly on a semiconductor surface (e.g., a Si or SiGe surface) of the substrate 102, or there may be any number of intervening layers. For example, the substrate 102 may include any number of layers deposited in various arrangements on the semiconductor surface.

[0042] Examples of dielectric layers include doped and undoped silicon oxide layers, silicon nitride layers, and aluminum oxide layers, with specific examples being silicon nitride (SiN), silicon dioxide (SiO 2 ), and aluminum oxide (Al 2 O 3) doped or undoped layers. The stack 111 has a layer 106 disposed between the molybdenum layer 108 and the dielectric layer 104. The layer 106 may be, for example, a diffusion barrier and / or adhesion layer. A diffusion barrier is a layer that prevents diffusion of species between layers. An adhesion layer is a layer that promotes adhesion of one layer to the layer below. Examples of diffusion barriers and adhesion layers include titanium nitride (TiN), titanium / titanium nitride (Ti / TiN), tungsten (W), tungsten nitride (WN), and tungsten carbonitride (WCN). The molybdenum layer 108 is the main conductor of the structure. In some embodiments, the molybdenum layer 108 may include multiple bulk layers deposited in different ways. The molybdenum layer 108 may or may not include a molybdenum nucleation layer. In the example shown in FIG. 1A, the molybdenum layer 108 is deposited directly on the layer 106. In other embodiments (not shown), the molybdenum layer 108 may be deposited on another layer, such as a growth-initiating layer comprising another material, such as tungsten (W) or a W-containing growth-initiating layer. The growth-initiating layer may be used to facilitate nucleation and growth of the molybdenum layer 108.

[0043] FIG. 1B shows another example of a stack 121. In this example, the stack 121 includes a substrate 102 and a dielectric layer 104, with a molybdenum layer 108 deposited directly on the dielectric layer 104, with no intervening diffusion barrier or adhesion layer. The molybdenum layer 108 is similar to that described above with respect to FIG. 1A. By using molybdenum as the primary conductor, thin films with low resistivity are obtained. Examples of thin films with low resistivity include films with resistivity of less than 40 uOhm-cm at a thickness of 60 Angstroms, and films with resistivity of less than 15 uOhm-cm at a thickness of 200 Angstroms.

[0044] In some embodiments, a stack (not shown) may include a substrate, a conductive layer, and a molybdenum layer deposited on the conductive layer. As used herein, a conductive layer is defined as a layer that has a thermal conductivity of at least 10 at room temperature. 4 Ω -1 cm -13A-3C. An example is molybdenum on a metal layer (e.g., a W layer, or another Mo layer). In these embodiments, there is no dielectric layer between the molybdenum layer and the conductive layer. Similarly, the stack may include molybdenum deposited directly on a metal compound layer. An example is molybdenum on a metal nitride layer (e.g., TiN, WN, or MoN). In yet some other embodiments of the stack (not shown), the stack may include a substrate and a molybdenum layer deposited directly on the substrate, including deposition directly on a semiconducting surface, a dielectric surface, or a conductive surface. FIGS. 1A and 1B show examples of material ordering in certain stacks, which may be used with any suitable architecture and application, with examples further described below with respect to FIGS. 2A-2L, 3, 4, 6A-6C, 10A-10C, 13A-13D, and 14A-14D.

[0045] The methods described herein are performed on a substrate that may be contained within a chamber. The substrate may be a silicon or other semiconductor wafer, including wafers having one or more layers of material deposited thereon, such as dielectric, conductive, or semiconductive materials. The methods are not limited to semiconductor substrates and may be performed to fill any feature with molybdenum.

[0046] The substrate may have features such as vias or contact holes, which may be characterized by one or more narrow and / or re-entrant openings, constrictions in the feature, and a high aspect ratio. The features may be formed in one or more of the above-mentioned stacks, or layers in the stacks. For example, the features may be formed at least partially in a dielectric layer. In some embodiments, the features may 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. One example of a feature is a hole or via in a semiconductor substrate or in a layer on the substrate.

[0047] FIG. 2A shows a schematic example of a DRAM architecture, including a Mo buried word line (bWL) 208 in a silicon substrate 202. The Mo bWL is formed in a trench etched in the silicon substrate 202. A conformal barrier layer 206 and an insulating layer 204 line the trench. The conformal barrier layer 206 is disposed between the insulating layer 204 and the silicon substrate 202. In this example, the insulating layer 204 may be a gate oxide layer formed from a high-k dielectric material such as a silicon oxide material or silicon nitride. In some embodiments disclosed herein, the conformal barrier layer 206 is a TiN or tungsten-containing layer, such as a WN or WCN layer. In some embodiments, a conformal tungsten-containing growth-initiating layer (not shown) may be between the conformal barrier layer 206 and the molybdenum bWL 208. Alternatively, the molybdenum bWL 208 may be deposited directly on the TiN or other diffusion barrier. In some embodiments, one or both of layers 204 and 206 may be absent.

[0048] The bWL structure shown in Figure 2A is an example of an architecture that includes a molybdenum fill layer. During bWL fabrication, molybdenum is deposited in features that may be defined by recesses etched into a silicon substrate 202. When layers 206 and / or 204 are present, the silicon substrate 202 is conformally lined by layers 206 and / or 204.

[0049] 2B-2H are further schematic examples of various structures in which molybdenum may be deposited according to disclosed embodiments. FIG. 2B shows an example of a cross-sectional view of a vertical feature 201 filled with Mo. The feature may include a feature hole 205 in a silicon substrate 202. The feature hole 205 may have an underlayer 203 lining the sidewalls or interior of the feature hole 205 forming its interior surface. The feature hole 205 or other features may have a dimension near the opening, for example, an opening diameter or line width, between about 10 nm and 500 nm (e.g., between about 25 nm and about 300 nm). The feature hole 205 may be referred to as an unfilled feature, or simply a feature. The vertical feature 201, as well as any feature, may be characterized in part by an axis 218 that extends through the length of the feature, with vertically oriented features having a vertical axis and horizontally oriented features having a horizontal axis. The underlayer 203 may be, for example, a diffusion barrier layer, an adhesion layer, a nucleation layer, a combination thereof, or any other applicable material. Non-limiting examples of underlayers may include dielectric layers and conductive layers. Examples of dielectric materials include SiO 2 and Al 2 O 3 oxides such as SiN, nitrides such as SiN, carbides such as nitrogen-doped silicon carbide (NDC) and oxygen-doped silicon carbide (ODC), and carbon-doped SiO 2 Low-k dielectrics such as ZnO, ZnSe ...

[0050] In some embodiments, the features are wordline features in a 3D NAND structure. For example, the substrate may include a wordline structure having a vertical channel at least 200 Å deep and including any number of wordlines (e.g., 50-450). Examples of wordline features are described further below. Another example of a feature is a trench in the substrate or layer. The feature may be of any depth. In various embodiments, the feature may have an underlayer, such as a barrier layer or an adhesion layer. Non-limiting examples of underlayers include dielectric and conductive layers, such as silicon oxide, silicon nitride, silicon carbide, metal oxide, metal nitride, metal carbide, and metal layers.

[0051] FIG. 2C illustrates an example of a vertical feature 201 with a re-entrant profile. A re-entrant profile is a profile that narrows from the bottom, closed end, or interior of the feature to the feature opening. According to various implementations, the profile may be gradually narrowed and / or may include an overhang at the feature opening. FIG. 2C illustrates an example of the latter, where an underlayer 213 lines the sidewall or interior surface of the feature hole 205. As in FIG. 2B, the underlayer 213 may be a diffusion barrier layer, an adhesion layer, a nucleation layer, a combination thereof, or any other applicable material. Non-limiting examples of underlayers may include dielectric layers and conductive layers. The underlayer 213 forms an overhang 215 such that the underlayer 213 is thicker near the opening of the vertical feature 201 than inside the vertical feature 201.

[0052] In some implementations, features may be filled that have one or more constrictions within the feature. FIG. 2D shows example diagrams of various filled features with constrictions. Examples (a), (b), and (c) of FIG. 2D each have a constriction 209 at a midpoint within the feature. The constriction 209 may be, for example, between about 15 nm and 20 nm wide. The constriction may cause pinch-off during deposition of molybdenum within the feature using conventional techniques. The deposited metal may block further deposition beyond the constriction before that portion of the feature is filled, resulting in a void within the feature. Example (b) further includes an overhang 215 (such as a liner / barrier overhang) at the opening of the feature. Such an overhang may also be a potential pinch-off point. Example (c) has a constriction 212 that is further away from the field region than the overhang 215 of example (b).

[0053] Horizontal features such as 3D memory structures can also be filled. FIG. 2E shows an example of a horizontal feature 250 that includes a waist 251. For example, the horizontal feature 250 can be a wordline in a 3D NAND (also referred to as vertical NAND or VNAND) structure. In some implementations, the waist can be due to the presence of pillars in the 3D NAND or other structures. FIG. 2F shows a cross-sectional side view of a 3D NAND structure 210 (formed on a silicon substrate 202). The 3D NAND structure 210 has 3D NAND stacks (left 225 and right 226), a central vertical structure 230, and multiple stacked horizontal wordline features 220 with openings 222 on opposing sidewalls 240 of the central vertical structure 230. Note that FIG. 2F shows two "stacks" of the presented 3D NAND structure 210, which together form a "trench-like" central vertical structure 230. However, in certain embodiments, there may be more than one such stack arranged side by side and extending spatially parallel to each other, with the gap between each adjacent pair of stacks forming a central vertical structure 230 as shown explicitly in FIG. 2F. In this embodiment, the horizontal word line features 220 are 3D memory word line features that are fluidically accessible from the central vertical structure 230 through the openings 222. Although not explicitly shown, the horizontal word line features 220 present in both 3D NAND stacks 225 and 226 (i.e., the left 3D NAND stack 225 and the right 3D NAND stack 226) shown in FIG. 2F are also accessible from the opposite side of the stack (the left and right ends, respectively) through similar vertical structures formed by further 3D NAND stacks (formed at the left and right ends, but not shown). Each of the 3D NAND stacks 225 and 226 includes a stack of word line features that are fluidically accessible from both sides of the 3D NAND stack through the central vertical structure 230. In the particular example shown diagrammatically in Figure 2F, the 3D NAND stacks each include six pairs of stacked word lines, but a 3D NAND memory layout may have any number of pairs of vertically stacked word lines.

[0054] Word line features in a 3D NAND stack can be formed by depositing an alternating stack of silicon oxide and silicon nitride layers, followed by selectively removing the nitride layers while leaving a stack of oxide layers with gaps between them. These gaps are the word line features. Any number of word lines may be stacked vertically in such a 3D NAND structure, provided there is technology available for their formation and to successfully achieve (substantially) void-free filling of the vertical features. Thus, for example, a VNAND stack may include between 2 and 512 horizontal word line features, between 2 and 256 horizontal word line features, between 8 and 128 horizontal word line features, or between 16 and 64 horizontal word line features, etc. (it is understood that the recited ranges include the stated endpoints).

[0055] FIG. 2G shows a cross-sectional top view of the same 3D NAND structure 210 shown in the side view of FIG. 2F. The cross section is taken through a horizontal section 260 indicated by a horizontal dashed line in FIG. 2F. The cross section of FIG. 2G shows several columns of pillars 255. The pillars 255 are shown in FIG. 1F to extend vertically from the base of the substrate 202 to the top of the 3D NAND structure 210. In some embodiments, the pillars 255 are formed of polysilicon material and are structurally and functionally important to the 3D NAND structure 210. In some embodiments, such polysilicon pillars may function as gate electrodes of stacked memory cells formed within the pillars. The top view of FIG. 2G shows that the pillars 255 form a waist in the opening 222 for the wordline feature 220. Fluid accessibility of the wordline feature 220 from the central vertical structure 230 through the opening 222 (indicated by the arrow in FIG. 2G) is constrained by the pillars 255. In some embodiments, the horizontal gap size between adjacent polysilicon pillars is between about 1-20 nm. This reduced fluid accessibility makes uniform filling of the wordline features 220 with material more difficult. The structure of the wordline features 220 and the challenge of uniformly filling the wordline features 220 with molybdenum material due to the presence of pillars 255 are further illustrated in Figures 2H, 2I, and 2J.

[0056] FIG. 2H shows a vertical cross section through a 3D NAND structure similar to that shown in FIG. 2F. However, FIG. 2H focuses on a pair of wordline features 220 and further illustrates a filling process that causes the formation of a void 275 within the filled wordline features 220. FIG. 2I also illustrates the void 275 generally, but with a horizontal cross section through the pillar 255, similar to the horizontal cross section shown in FIG. 2G. FIG. 2J shows the accumulation of molybdenum material around the pillar 255 forming a waist. This accumulation causes a pinch-off of the opening 222, disabling the deposition of further molybdenum material in the region of the void 275. 2H and 2I reveal that void-free molybdenum fill relies on a sufficient amount of deposition precursor migrating down central vertical structure 230, through opening 222, and over constricting pillars 255 to reach the farthest wordline feature 220 before the accumulated molybdenum deposits around pillars 255 cause pinch-off of opening 222, thereby preventing further precursor migration into wordline feature 220. Similarly, FIG. 2J shows a single wordline feature 220 in cross-section from above. FIG. 2J also shows how the generally conformal deposition of molybdenum material begins to pinch off the interior of wordline feature 220 due to the fact that the significant width of pillar 255 acts to partially block and / or narrow and / or constrict the open passageway that would otherwise lead to wordline feature 220. (It should be noted that the example of FIG. 2J can be understood as a 2D rendering of the 3D feature of the pillar constriction structure shown in FIG. 2I, and thus shows the constriction as seen in a plan view rather than a cross-sectional view.)

[0057] Three-dimensional structures may require longer and / or more focused exposure to the precursor to allow for filling of the deepest and bottommost regions. Three-dimensional structures may be particularly challenging when employing molybdenum halide and / or molybdenum oxyhalide precursors due to their tendency to etch, with longer focused exposure allowing for more etching as part of the structure.

[0058] 2K and 2L show an example of a DRAM bWL with an asymmetric trench structure. Some filling processes of the trenches of the DRAM bWL can distort the trench such that the final trench width and resistance Rs are significantly non-uniform. FIG. 2K shows an unfilled feature 261 and a filled feature 265 that exhibits line bending after filling. In this example, the feature is a DRAM bWL with an asymmetric narrow trench structure. As shown, a plurality of features 283 are illustrated on a substrate. The features 283 are spaced apart, and in some embodiments, adjacent features have a pitch between about 20 nm and about 60 nm, or between about 20 nm and 40 nm. The pitch is defined as the distance from the central axis of one feature to the central axis of the neighboring feature. The unfilled feature 261, as shown in feature 283, may be generally V-shaped, with sloping sides such that the width of the feature narrows from the top to the bottom of the feature. The feature widens from the feature bottom 273b to the feature top 273a. After several filling operations, line bending may be observed in the filled feature 265. In some circumstances, cohesive forces between the opposing surfaces of the trench may cause the sides of the trench to pull together, as indicated by arrows 267. This phenomenon is illustrated in FIG. 2L and may be characterized as "zipping up" the feature. As the feature 283 is filled, a greater force is exerted from the central axis 299 of the feature 283, causing line bending. For example, molybdenum may be deposited on the sidewalls of the feature 283. Thus, the molybdenum 284a and 284b deposited on the sidewalls of the feature 283 are in close proximity to each other, and the molybdenum-molybdenum bond radius r is small. Thus, cohesive interatomic forces are generated between the smooth growth surfaces of the molybdenum, causing the sidewalls to pull together, resulting in line bending.

[0059] Provided below is a method of filling features with molybdenum. The methods described herein include surface and deposition processes that can be used to fill substrate features as described above. As described above, molybdenum offers several advantages over other metals. Examples of feature filling for horizontally and vertically oriented features are described below. It should be noted that, at least in most cases, the examples are applicable to both horizontally and vertically oriented features. Horizontally oriented features generally refer to features oriented such that the feature axis is parallel to the plane of the substrate surface. Vertically oriented features generally refer to features oriented such that the feature axis is perpendicular to the plane of the substrate surface.

[0060] A method of filling a feature that includes exposing the feature to a molybdenum halide prior to filling the feature is described with reference to Figures 3-8. As described, the molybdenum halide can etch, deposit, and / or otherwise treat material at the feature bottom and / or on the feature sidewalls.

[0061] In some embodiments, the method is used to fill a feature in contact with an underlying metal. An example of such a feature is shown in FIG. 3. 301 shows an unfilled feature 312. The unfilled feature 312 is formed in an oxide layer 305 and is filled with Mo in contact with an underlying metal 303. The unfilled feature 312 is defined by a sidewall surface 315 and a bottom surface 317.

[0062] According to various embodiments, the sidewall surface 315 and the bottom surface 317 may be the same material or different materials. In some embodiments, the oxide layer 305 may be exposed to form the sidewall surface 315. Similarly, the underlying metal 303 may be exposed to form the bottom surface 317. In some embodiments, the bottom surface 317 may be a metal oxide due to oxidation of the surface. In some embodiments, a liner layer (not shown) may be formed on the sidewall and / or bottom of the feature to form the sidewall surface 315 and / or the bottom surface 317. Examples of liner layers include TiN, WN, and WCN. In some embodiments, the liner layer may be a molybdenum-containing liner layer, such as a molybdenum nitride (MoN) layer.

[0063] In some embodiments, the sidewall surface 315 and the bottom surface 317 are different. In a subsequent deposition process, Mo may be deposited under conditions that preferentially nucleate on the bottom surface 317. This may promote bottom-up filling and prevent the formation of voids.

[0064] Examples of underlayer metals and / or bottom surfaces include TiN, titanium aluminum carbide (TiAlC), W, Co, Mo, Ru, Cu, nickel (Ni), iridium (Ir), rhodium (Rh), tantalum (Ta), and titanium (Ti) and tantalum nitride (TaN).

[0065] The methods described herein address various challenges that arise with shrinking feature sizes. For example, void-free gap filling is more difficult in small features due to deeper features, reentrant profiles near the opening of the feature, and / or poor growth selectivity between the metal surface at the bottom of the feature and the dielectric surface at the sidewalls. Smaller features can cause pattern misalignment more frequently. An example of a misaligned feature is shown at 350, where the unfilled feature 312 is not centered on the underlying metal 303. As a result, the bottom surface 317 includes metal and dielectric material.

[0066] In some embodiments, the method may be used in a molybdenum-on-molybdenum integration scheme. An example of such an integration scheme is shown in FIG. 4. Layer 401 includes dielectric 402 and Mo 403. An etch stop layer (ESL) 404 is disposed on layer 401. ESL 404 may be, for example, SiN. Dielectric layer 405 is deposited on ESL 404. Dielectric layer 405 is then patterned and etched, with the etching stopping on ESL 404 (not shown). ESL 404 is then removed from feature 412 forming unfilled feature 412.

[0067] During the preceding processing operations, a Mo-containing layer 410 may be formed on the surface of Mo 403. The Mo-containing layer 410 is generally an amorphous layer. The Mo-containing layer 410 is relatively thin, for example, on the order of 0.5 nm to 3 nm. The Mo-containing layer 410 may contain various impurities, such as oxygen, nitrogen, and / or other halogens. Oxidation of the surface may occur due to the oxidation of hydrogen (H 2 ) plasma, the Mo-containing layer 410 can be removed by H 2 Generally resistant to plasma. If left in the device, it can lead to higher resistance at the interface between Mo403 and the subsequently deposited Mo film.

[0068] Aspects of the present disclosure relate to a surface treatment that occurs prior to deposition of Mo in a feature. According to various embodiments, the surface treatment includes exposure to a molybdenum halide. In some embodiments, the molybdenum halide is provided without a co-reactant and no deposition occurs. In some embodiments, the molybdenum halide is provided with a co-reactant. A thin layer of Mo can be deposited.

[0069] In some embodiments, the feature includes a dielectric surface, such as a dielectric sidewall surface. The surface treatment inhibits growth on the dielectric surface and enhances selectivity during subsequent deposition onto a conductive surface. In some embodiments, the as-provided feature includes a Mo-containing layer, as described above. The surface treatment removes this layer to produce a clean Mo surface for deposition and Mo-Mo interconnect formation.

[0070] 5 is a process flow diagram illustrating exemplary operations of a method for filling a feature with molybdenum. The process begins in operation 501 where a feature having a dielectric sidewall and a metal-containing contact is provided. The metal-containing contact may be at a bottom of the feature, with dielectric sidewalls extending from the feature opening to the metal-containing contact. The feature may be provided in a processing chamber. In some embodiments, one or more processing operations may be performed in the processing chamber to form a feature having a dielectric sidewall and a metal-containing contact.

[0071] Examples of dielectric sidewalls include silicon-containing layers such as oxides and nitrides. Examples of metal-containing contacts include metal and metal compound films. Metal-containing contacts are generally electrically conductive and have a resistance of at least 10 at room temperature. 4 Ω -1 cm -1 Examples include TiN, TiAlC, W, Co, Mo, Ru, Cu, Ni, Rh, Ir, Ta, Ti, and TaN.

[0072] In some embodiments, a surface oxide is present on the metal-containing contact. Additionally, in some embodiments, other impurity-containing layers are present on the metal-containing contact. One example is the amorphous Mo-containing layer described with reference to FIG.

[0073] In some embodiments, an etching operation is performed prior to operation 501 to remove the liner layer from at least the sidewalls of the feature. For example, the feature may include a TiN liner layer conformally coating the bottom and sidewalls. An etch may be performed to remove the TiN layer from the sidewalls and expose the dielectric material. The sidewall surfaces are then a silicon oxide material or other dielectric material.

[0074] Operation 503 optionally includes cleaning. Operation 503 can, for example, remove surface oxides and / or etch residues. Examples of etch residues include fluorocarbons and hydrocarbon polymers. In some embodiments, operation 503 can include removing fluorinated ... 2 In some embodiments, operation 503 includes exposure to a reducing plasma, such as a plasma. In some embodiments, operation 503 treats the dielectric sidewalls. For example, operation 503 may remove organic material and / or reduce oxygen in the dielectric sidewalls, which can improve the selectivity of subsequent Mo growth on metal-containing surfaces.

[0075] In operation 505, a surface treatment is performed. The surface treatment includes exposure to a molybdenum halide gas. This is typically a plasma-free operation. Plasma-free refers to an operation performed without activating a plasma. As discussed further below, operation 505 may or may not include deposition of molybdenum.

[0076] 4, in embodiments where an amorphous Mo-containing layer is present, operation 505 removes all or at least a portion of this layer. In the same or other embodiments, operation 505 inhibits nucleation on the dielectric sidewall surface. In some embodiments, operation 503 is performed after operation 505.

[0077] The process continues with selective deposition of Mo on the metal-containing contacts in operation 507. In some embodiments, this operation includes reaction with a molybdenum halide precursor or a molybdenum oxyhalide precursor. The process may continue with filling of the features with Mo in operation 509. The same or different Mo precursors may be used in operations 507 and 509.

[0078] 6A-6C show a schematic example of a feature 612 undergoing an example process according to FIG. 5. First, in FIG. 6A, at 650, a feature 612 is shown including a metal-containing contact 603 and a dielectric sidewall 615. In this example, the metal-containing contact 603 is a Mo contact. Molybdenum is deposited in the feature 612 in contact with the Mo contact. An amorphous Mo-containing interfacial layer 610 and a surface oxide 611 are shown. In this example, the surface of the dielectric sidewall 615 is silicon oxide. An etch stop layer (ESL) 604 is also shown.

[0079] In 651, the feature is shown after operation 503 has been performed. 2 A plasma is used to remove the surface oxide 611. As mentioned above, this operation also treats the dielectric sidewalls 615 to improve the selectivity of the subsequent Mo growth on the metal-containing contacts 603.

[0080] Turning now to Figure 6B, feature 612 is shown at 652 undergoing a surface treatment as described above with respect to operation 505 of Figure 5. The amorphous Mo-containing interfacial layer 610 is removed. As the arrows indicate, this treatment also affects the oxide surface, suppressing subsequent Mo nucleation.

[0081] Shown in 653 are features after selective deposition as described above with respect to operation 507 of Figure 5. A bottom-up, non-conformal fill is observed. Mo 605 grows from the underlying metal-containing contacts 603 while there is no or significantly less growth from the sidewall surfaces. As a result, the Mo 605 has no seams or voids.

[0082] In Figure 6C, the feature is shown at 654 after filling of the feature is completed as described above with respect to operation 509 of Figure 5. The remaining filling may be bottom-up or conformal. An overburden deposition of Mo 607 is shown at 655.

[0083] According to various embodiments, the surface treatment, as described above with respect to operation 505 in FIG. 5, includes exposure to a molybdenum halide. In some embodiments, a molybdenum chloride compound is used. Molybdenum-containing compounds are also referred to herein as Mo-containing precursors or Mo precursors. Molybdenum chloride is MoCl x where x is 2, 3, 4, 5, or 6, and molybdenum dichloride (MoCl 2 ), molybdenum trichloride (MoCl 3 ), molybdenum tetrachloride (MoCl 4 ), molybdenum pentachloride (MoCl 5 ), and molybdenum hexachloride (MoCl 6 In some embodiments, MoCl 5 or MoCl 6 In the explanation, MoCl is mainly used. x Although the compound is mentioned, in other embodiments, other molybdenum halides may be used. The molybdenum halide precursor is MoX z where X is a halogen (fluorine (F), chlorine (Cl), bromine (Br), or iodine (I)) and z is 2, 3, 4, 5, or 6. MoX z An example of a precursor is molybdenum fluoride (MoF 6 In some embodiments, non-fluorine-containing MoX z The use of precursors prevents etching or incorporation of fluorine. In some embodiments, non-bromine-containing MoX z Precursors and / or non-iodine containing MoX z The use of precursors prevents etching or incorporation of bromine or iodine.

[0084] In some embodiments, operation 505 includes exposing to a molybdenum halide compound without a co-reactant gas. In such embodiments, the precursor is delivered in a pulsed or continuous input. Figure 7 shows two examples of surface treatment sequences. First, MoCl 5 is pulsed for N cycles with argon (Ar) or other inert gas. Second, MoCl 5 A continuous injection of is delivered followed by an Ar purge.

[0085] In some embodiments, operation 505 includes exposing the molybdenum halide compound with a co-reactant gas to deposit Mo. The co-reactant is typically H 2 However, other reducing agents may be used as described below. Figure 8 shows an example of a surface treatment sequence. In the example sequence 801, MoCl 5 Pulses of H with intervening pulses of purge gas 2 In the exemplary sequence 802, MoCl is alternated with a pulse of 5 A pulse of H without an intervening pulse of purge gas 2 In another exemplary sequence (not shown), MoCl is alternated with a pulse of 5 A pulse of H was introduced into the reaction system, with a pulse of purge gas immediately following only one of the reactant gases in each cycle. 2 In the third exemplary sequence 803, a pulse of MoCl 5 H 2 In a further exemplary sequence 804, the co-flowed reactant gases are pulsed with alternating pulses of Ar. In another exemplary sequence 805, H 2 A gas may be flowed into the chamber, MoCl 5 While H is intermittently flowed into the chamber, 2 Gas is continuously flowed into the chamber.

[0086] In Figures 7 and 8, MoCl 5In place of Ar and H, another molybdenum halide and / or another inert gas may be used, respectively.

[0087] In some embodiments, if a metal other than Mo is at the bottom of the feature, a surface treatment as shown in Figure 8 (with a co-reactant for Mo deposition) may be employed. In such embodiments, forming a Mo surface layer may facilitate subsequent Mo growth. For example, if a W, Co, or Ru layer is at the bottom of the feature, a surface treatment as shown in Figure 8 may be used to form a thin Mo surface layer.

[0088] In an exemplary process, molybdenum oxychloride (MoO 2 Cl 2 Mo was deposited on two treated surfaces using a) silicon dioxide deposited by tetraethyl orthosilicate (TEOS oxide) and b) TiN. The deposition was performed after the treatments listed in the table below. The first treatment was a SiO2 deposition using H 2 The second treatment involves only plasma and H 2 The third treatment includes a plasma followed by a molybdenum chloride treatment, and the third treatment includes a H 2 The deposition process included a plasma followed by a molybdenum chloride and hydrogen treatment. The table below shows the total thickness of Mo deposited in Angstroms. [Table 1]

[0089] Both molybdenum halide surface treatments caused a significant delay in nucleation on silicon dioxide compared to TiN. Both surface treatments also increased deposition on Mo. Feature filling with deposition was also evaluated. In the absence of surface treatment (preclean only), voids were observed due to lack of selectivity. Void-free gap filling was observed for both surface treatments.

[0090] Another aspect of the present disclosure relates to methods for filling features with metal that include selectively treating feature sidewalls prior to deposition. These methods are described below with reference to Figures 9-15. The methods may be used in addition to or without the molybdenum halide treatment described above.

[0091] 9 is a process flow diagram illustrating a method of filling a feature with a Mo film, according to certain embodiments. Example applications include middle-of-line (MOL) interconnects and back-end-of-line (BEOL) interconnects. In one example, the method may be used for source / drain contact filling. The method 900 begins in operation 901 by providing a substrate including a feature in which Mo is to be deposited. The substrate may be provided to a semiconductor processing tool.

[0092] The features may be trenches or vias formed in a dielectric layer. Examples of dielectric materials include silicon oxide (SiO 2 ) and aluminum oxide (Al 2 O 3 ), nitrides such as silicon nitride (SiN), carbides such as nitrogen-doped silicon carbide (NDC) and oxygen-doped silicon carbide (ODC), and carbon-doped SiO 2 Examples of low-k dielectrics include Mo, Mo, and low-k dielectrics such as Mo. Mo may be deposited in the feature to electrically connect to the layer below. Examples of the layer below include metals, metal silicides, and semiconductors. Examples of metals include Co, Ru, Cu, W, Mo, nickel (Ni), iridium (Ir), rhodium (Rh), tantalum (Ta), and titanium (Ti). Examples of metal silicides include titanium silicide (TiSi x ), nickel silicide (NiSi x ), molybdenum silicide (MoSi x ), cobalt silicide (CoSi x ), platinum silicide (PtSi x ), ruthenium silicide (RuSi x), and nickel platinum silicide (NiPt y S x Examples of semiconductors include silicon (Si), silicon germanium (SiGe), and gallium arsenide (GaAs), with or without semiconducting dopants such as carbon (C), arsenic (As), boron (B), phosphorus (P), tin (Sn), and antimony (Sb).

[0093] A feature generally has a sidewall having a sidewall surface and a bottom having a bottom surface. The sidewall may be comprised of one or more layers. The sidewall extends from the field region to the bottom. The feature bottom may extend from a first sidewall in the feature to a second sidewall in the feature and may be comprised of one or more layers. The sidewall surface is an exposed area on the sidewall and may change during wafer processing. For example, the sidewall surface may change from a first material to a second material after the second material is deposited on the sidewall. Similarly, the bottom surface is an exposed area on the bottom and may change during wafer processing. In some embodiments, the sidewall surface may be the same material as the bottom surface. For example, in some embodiments, the as-provided sidewall surface and bottom surface are TiN. In some embodiments, the material of the sidewall surface may be different from the material of the bottom surface. For example, the bottom surface may be a metal silicide and the sidewall surface may be SiO. 2 The silicon oxide may be, for example, silicon oxide.

[0094] Prior to any Mo deposition, a liner layer may line the unfilled feature and form the sidewall and / or bottom surfaces. In some embodiments, the liner layer lines the entire feature and forms the sidewall and bottom surfaces. In some other embodiments, the liner layer lines only a portion of the feature. For example, a TiN layer may line the sidewalls and leave the bottom surface unlined. In some embodiments, the liner layer is a diffusion barrier and / or adhesion layer. Examples of liner layer materials include metal nitrides (e.g., TiN or tantalum nitride (TaN) barrier layers) and metals (e.g., Ti adhesion layers).

[0095] In some embodiments, the bottom and sidewall surfaces are oxidized. Oxidation can occur by exposing the surface of the feature to air or other oxidizing conditions. For example, metal silicides (MSi x (wherein M is a metal) surface is oxidized by exposure to air to form metal oxide silicide (MSi x O y ). Other examples of oxide surfaces include metal oxide nitrides (MN x O y ), silicon oxide (SiO x ), and silicon germanium oxide (SiGeO x ) are mentioned.

[0096] In some embodiments, the oxidizing conditions occur incidentally during substrate processing or transfer operations, hi some embodiments, intentional oxidation is performed as further described below.

[0097] In some embodiments, the liner layer is a conformal metal layer, such as a conformal W or Mo layer, as further described below.

[0098] In operation 902, the liner layer is selectively treated such that at least the top portions of the field regions and / or sidewalls are treated, while the bottom surfaces are not or are less treated.

[0099] According to various embodiments, operation 902 may include selective oxidation or nitridation of the field regions and / or top sidewalls of the features, and in some embodiments, operation 902 includes selective halogenation of the field regions and / or top sidewalls of the features.

[0100] In some embodiments, operation 902 includes selectively oxidizing the field regions and / or top sidewalls of the features. For example, a TiN layer may be oxidized to form titanium oxynitride (TiON). In another example, a Mo liner layer or a W liner layer may be oxidized to form MoOx Layer or WO x A layer is formed.

[0101] In some embodiments, operation 902 includes selective nitridation of the field regions and / or top sidewalls of the features. In one example, a Mo liner layer or a W liner layer is treated to form a MoN layer or a WN layer. Other examples of layers that may be formed include tungsten carbonitride (WCN) and molybdenum carbide (MoC).

[0102] In some embodiments, operation 902 includes selective halogenation of the field regions and / or top sidewalls of the features. In one example, a Mo liner layer or a W liner layer is treated to form MoX y Layer or WX y layer, where X is any halogen and y is a number between 0 and 3 (inclusive). Another example is MoN z or WN z By treating MoN z X y Layer or WN z X y In another example, MoC z or W.C. z By processing the MoC z X y Layer or WC z X y layer, where X is any halogen, y is a number between 0 and 3 (inclusive), and z is a number between 0 and 2 (inclusive). z or WO z By treating MoO z X y or WO z X y where X is any halogen, y is a number between 0 and 3 (inclusive), and z is a number between 0 and 2 (inclusive).

[0103] In some embodiments, operation 902 selectively inhibits subsequent deposition on the processed surface. In some embodiments, the processed liner layer is etched following operation 902. These approaches provide different deposition surfaces and promote selective deposition at the bottom of the feature and bottom-up filling.

[0104] The feature is then filled with Mo in operation 903. Deposition of Mo is described further below.

[0105] 10A shows an example of a feature that will be filled with Mo in a particular embodiment. A feature 1001 is shown having a titanium nitride (TiN) liner layer 1015. The feature 1001 is filled with an underlayer metal silicide (MSi x ) 1007. x is connected to a semiconductor layer 1006, for example silicon (Si) or silicon germanium (SiGe). This stack may be used in a transistor junction structure. x An example of a layer is titanium silicide (TiSi x ).

[0106] A TiN liner layer 1015 lines the feature 1001. The TiN liner layer 1015 provides a TiSi x The TiN layer 1015 is a diffusion barrier layer used on top of a metal silicide such as MSi x Another objective is to prevent any potential reaction between the MSi and the overlying metal. x or other layers from fluorine attack. x from oxidizing in air or during subsequent processing. In the example of Figure 10A, a TiN layer 1015 is present on the feature sidewalls 1011, feature bottom 1005, and field region 1017 of feature 1001.

[0107] Deposition of a metal such as molybdenum in feature 1001 can result in Mo nucleation on all areas. As the film grows, it can cause pinch-off at the top of the feature, preventing further diffusion of reactants within the feature and resulting in the formation of voids. This occurs in features such as that illustrated in FIG. 10A, as well as other features with uniform sidewalls and bottom surfaces.

[0108] 10B shows the feature 1001 after selective oxidation to form a TiON layer 1015a on the field region 1017 and upper sidewall portions 1011a. A TiN liner layer 1015 remains on the bottom surface 1005, as well as on the lower sidewall portions 1011b. The oxygen concentration of the TiON layer may be a decreasing gradient with feature depth.

[0109] 10C shows the feature 1001 after deposition of Mo. Nucleation of the Mo film is inhibited on the TiON layer 1015a. This allows Mo to grow from the feature bottom 1005, resulting in bottom-up deposition of bulk Mo 1023. Filling may continue to completely fill the feature 1001.

[0110] Figure 11 is a plot showing film thickness after multiple ALD cycles of Mo deposition on both TiN and TiN oxide (TiON). As can be seen in Figure 11, Mo growth is inhibited on TiON. TiN is deposited by physical vapor deposition (PVD).

[0111] In some embodiments, prior to selective oxidation, a liner layer of a metal or metal-containing film, such as Mo, MoN, W, WCN, or WN, is conformally deposited in the feature. This liner layer may be deposited over a TiN or other liner layer, if present, or may be the initial liner layer in the feature. This liner layer is selectively oxidized to form a metal oxide layer, similar to the TiON layer of FIG. 2B, followed by selective deposition at the bottom portion of the feature. An example is further described below with respect to FIGS. 14A-14D.

[0112] FIG. 12 is a process flow diagram illustrating a method 1200 of filling a feature with a Mo film. In operation 1211, a substrate including a feature is provided. The feature is filled with Mo. Operation 1211 may be similar to that described above with respect to operation 901 in FIG. 9. In operation 1212, a conformal metal-containing liner layer is deposited in the feature. In operation 1213, the field region and / or upper portions of the sidewalls are treated. According to various embodiments, this may include oxidation and / or nitridation of the field region and / or upper regions of the sidewalls. In operation 1214, the treated regions are selectively etched. Operation 1214 may include exposure to a molybdenum halide compound as described further below. As a result, the conformal metal-containing layer is removed from the treated regions. This may expose the dielectric sidewalls. Molybdenum is then deposited in the feature as described above with respect to operation 903 in FIG. 9.

[0113] 13A-13D show schematic examples of a method according to FIG. 12. In FIG. 13A, a feature 1301 is shown formed in a dielectric layer 1313. The feature 1301 includes dielectric sidewalls 1305 and a feature bottom 1304. A field region 1303 surrounds the feature opening. A conformal liner layer 1315 lines the feature 1301, including lining the dielectric sidewalls 1305 and the feature bottom 1304. In some embodiments, the conformal liner layer 1315 may be a diffusion barrier, such as a TiN layer. A metal is deposited in the feature 1301 in contact with a metal silicide layer 1308 in layer 1306. The metal silicide layer may be, for example, titanium (TiSi x ) layer. Layer 1306 may be a semiconductor layer, such as a Si layer or a SiGe layer.

[0114] Figure 13B shows feature 1301 after depositing within the feature a conformal metal-containing liner layer 1317. In the example of Figure 13B, conformal metal-containing liner layer 1317 covers conformal liner layer 1315.

[0115] FIG. 13C shows the feature 1301 after selectively treating the field regions and upper sidewalls of the metal-containing liner layer 1317 to form a treated conformal metal-containing liner layer 1317a on the field regions and upper sidewalls, and an untreated conformal metal-containing liner layer 1317 on the lower sidewalls and bottom of the feature.

[0116] 13D shows the feature 1301 after etching removes the conformal liner layer 1315 and the treated conformal metal-containing liner layer 1317a from the upper sidewalls and field regions. This operation exposes the dielectric sidewalls 1305 of the feature 1301, leaving the liner layer 1315 (e.g., a TiN layer) and metal-containing liner layer 1317 (e.g., a Mo or W layer) on the feature bottom 1304 and lower sidewalls.

[0117] Figures 14A-14D show schematic examples of another method according to Figure 9. Figures 14A-14C are similar to Figures 13A-13C, with deposition of a conformal metal-containing liner layer 1417 on conformal liner layer 1415. In Figure 14B, in some embodiments, layer 1417 may be a conformal Mo or W layer that may be deposited on a TiN layer or other diffusion barrier. Figure 14C shows feature 1401 after selective processing as described above with respect to Figure 14C.

[0118] 14D shows the feature 1401 after metal deposition. Nucleation of the metal film is inhibited on the treated metal-containing liner layer 1417a. This allows the metal to grow from the feature bottom 1404, resulting in bottom-up deposition of bulk metal 1423. Filling may continue to completely fill the feature.

[0119] In some embodiments, the selective oxidation or nitridation of the field regions and upper portions of the features involves bombardment with mild oxygen or nitrogen ions in an ion beam etching system. An example of an ion beam etching system is described below in FIG. 19. In such a system, the substrate may be appropriately tilted and rotated to control the angle of incidence of the ions, and therefore the selective oxidation. With reference to FIG. 15, an example of the ion beam angle to reach the sidewall depth is shown. By appropriately tilting and rotating the substrate, the ion beam can be directed to selectively oxidize or nitridize the sidewalls and / or field regions.

[0120] The field regions and upper sidewalls of the patterned wafer can be selectively oxidized without removing any material. In the case of a TiN film, TiON can be formed in the field and (optionally) upper sidewall regions, while TiN remains unoxidized at the bottom of the feature. In the case of a conformal Mo, W, or other metal film previously deposited on top of the TiN film, MoO x , WO xor other metal oxide may be formed in the field regions and, optionally, on the upper sidewalls, but the Mo, W, or other metal remains unoxidized at the bottom of the feature.

[0121] The field regions and upper sidewalls of the patterned wafer can be selectively halogenated as described above using a halogen gas source. Exemplary gases include chlorine (Cl 2 ), Bromine (Br 2 ), iodine (I 2 ), hydrogen bromide (HBr), and hydrogen iodide (HI), each of which can be oxidized with an inert gas (e.g., Ar) and / or H 2 and Ar / Cl. 2 , Ar / Br 2 , Ar / I 2 , Ar / HBr, Ar / HI, H 2 / Cl 2 , H 2 / Br 2 , H 2 / I 2 , H 2 / HBr, and H 2 When halogenated, the surface is passivated and deposition is inhibited.

[0122] In some embodiments, the growth surface may be restored after the etching or deposition process. For example, the film may be dehalogenated, deoxidized, or denitrified after operation 902 of the drawing or operation 1214 of FIG. 12. For example, to restore the original growth surface, the halogenated layer may be dehalogenated, deoxidized, or denitrified by removing H 2 Can be treated and / or etched by exposure to gases or plasmas. Thermal and plasma O 2 , N 2 , Cl 2 A variety of etching chemistries can be used to restore the original growth surface, including molybdenum halides, and molybdenum halides. These techniques may also be used after selective oxidation or selective nitridation to restore the original growth surface.

[0123] In one example, the process may include selective treatment of the film, followed by Mo deposition or etching, followed by restoration (eg, dehalogenation), followed by Mo deposition or etching.

[0124] In some embodiments, the selective treatment (e.g., oxidation, nitridation, or halogenation) does not involve ion bombardment. For example, exposure to a plasma generated from an appropriate source gas may be used. The plasma may be capacitively coupled or inductively coupled, depending on various embodiments. The plasma may be generated remotely or in situ. Such exposure may be performed without tilting the substrate.

[0125] For example, a low power, biased oxygen, nitrogen, or halogen plasma may be used in a high pressure system without tilting the substrate. If the pressure is high enough (greater than 2 Torr), the bottom of the feature will remain untreated. In some embodiments, an ion beam etching system as described with reference to FIG. 19 provides better control over the depth of treatment. Selective nitridation may be performed by any of the methods described above, but using a mild nitrogen plasma. Selective halogenation may be performed by any of the methods described above, but using a mild halogen plasma.

[0126] In some embodiments, the H in the plasma exposure operation 2 By tuning the ratio of gas to process gas (oxidizing, nitriding, or halogenating gas), a selective process profile is tailored within the feature. Plasma ions are more dominant on the field / upper sidewall, while H 2 The radicals are more prevalent at the bottom, thus allowing selective processing on the feature. Molybdenum Deposition

[0127] In the methods described herein, deposition of molybdenum may occur after the treatments described above with reference to Figures 4-15. Deposition of molybdenum described herein involves reacting a Mo-containing precursor, also referred to as a molybdenum precursor. In some embodiments, a molybdenum halide compound is used, as described above. In methods that include a surface treatment using a molybdenum halide compound, the same or a different compound may be used for deposition.

[0128] In some embodiments, the Mo precursor is a molybdenum chloride precursor or MoCl x Molybdenum chloride (MoCl), also called precursor x ) compound. For example, operation 507 and / or operation 509 of FIG. 5, operation 903 of FIG. 9, or operation 1215 of FIG. 12 may use a molybdenum oxyhalide precursor. The molybdenum chloride precursor is MoCl x where x is 2, 3, 4, 5, or 6, and molybdenum dichloride (MoCl 2 ), molybdenum trichloride (MoCl 3 ), molybdenum tetrachloride (MoCl 4 ), molybdenum pentachloride (MoCl 5 ), and molybdenum hexachloride (MoCl 6 In some embodiments, MoCl 5 or MoCl 6 In the explanation, MoCl is mainly used. x Although the precursor is mentioned, in other embodiments, other molybdenum halide precursors may be used. The molybdenum halide precursor may be MoX z where X is a halogen (fluorine (F), chlorine (Cl), bromine (Br), or iodine (I)) and z is 2, 3, 4, 5, or 6. MoX z An example of a precursor is molybdenum fluoride (MoF 6 In some embodiments, non-fluorine-containing MoX z The use of precursors prevents etching or incorporation of fluorine. In some embodiments, non-bromine-containing MoX z Precursors and / or non-iodine containing MoXz The use of precursors prevents etching or incorporation of bromine or iodine.

[0129] In some embodiments, the features may be filled using a molybdenum oxyhalide precursor. For example, operations 507 and / or 509 of FIG. 5, operation 903 of FIG. 9, or operation 1215 of FIG. 12 may use a molybdenum oxyhalide precursor. The molybdenum oxyhalide precursor may be MoO y X z where X is a halogen (fluorine (F), chlorine (Cl), bromine (Br), or iodine (I)) and y and z are MoO y X z is a number greater than 0 so that a stable compound is formed. An example of a molybdenum oxyhalide is molybdenum dioxide dichloride (MoO 2 Cl 2 ), molybdenum oxide tetrachloride (MoOCl 4 ), molybdenum oxide tetrafluoride (MoOF 4 ), molybdenum dioxide dibromide (MoO 2 Br 2 ), and molybdenum iodide MoO 2 I, and Mo 4 O 11 I. It should be understood that the term molybdenum oxyhalide precursor as used herein may refer to a molybdenum oxyhalide precursor as described above, or a molybdenum-containing oxyhalide precursor that includes molybdenum, oxygen, a halide, and one or more other elements. In some embodiments, the molybdenum oxyhalide or molybdenum-containing oxyhalide may include multiple different halogens (e.g., F and Cl, and / or I, and / or Br). Features include MoCl x Precursor, MoO y X z The molybdenum may be filled using any of the precursors, precursors, or combinations thereof.

[0130] For deposition of molybdenum in the features, the molybdenum precursor may be reacted with a co-reactant. Examples of co-reactants include hydrogen (H 2 ), silane (SiH 4 ), diborane (B 2 H 6 ), German (GeH 4 ), ammonia (NH 3 ), and hydrazine (N 2 H 4 ) are mentioned.

[0131] In some embodiments, deposition of molybdenum may use a plasma-based process. Gases may be provided to a remote plasma generator or an in situ plasma generator to generate plasma species. Examples of gases that may be used to generate the plasma include H 2 Hydrogen-containing gases such as nitrogen (N 2 ), as well as Ar and NH 3 Other gases may be included, such as SiO. The plasma species may be inert or may react with the molybdenum precursor to produce the film.

[0132] The features may be filled with molybdenum using atomic layer deposition (ALD) or chemical vapor deposition (CVD). Thermal ALD or plasma-enhanced ALD (PEALD) may be used. Similarly, thermal or plasma-enhanced CVD (PECVD) may be used.

[0133] ALD is a surface-mediated deposition technique in which precursor and reactant inputs are introduced sequentially into a deposition chamber. One or more cycles of sequential inputs of molybdenum precursor and reactants may be used to deposit Mo. For example, in the deposition of an initial molybdenum layer (e.g., as in operation 505 or 507 of FIG. 5), MoCl 5 is used as the precursor, and H 2 may be used as the reducing agent. 5 and H 2The charges are introduced sequentially into the deposition chamber with a purge gas, such as argon, flowing between them. The temperature of the substrate and the pressure of the chamber may be controlled for ALD. For example, the substrate may be heated to between 200°C and 800°C, such as between 250°C and 550°C, or between 300°C and 500°C, such as between 350°C and 450°C. In some embodiments, the chamber may be pressurized to between 10 Torr and 200 Torr, such as between 50 Torr and 90 Torr. In some embodiments, the temperature and / or pressure may be used to control the reaction rate. In some embodiments, the temperature and / or pressure may be used to control the selectivity.

[0134] In some embodiments, the molybdenum filling may include CVD. In a CVD process, both the molybdenum precursor and the reactant are in the gas phase in the deposition chamber. Generally speaking, CVD processes fill features faster than ALD processes. In one example, the precursor is MoO 2 Cl 2 and the like. 2 In this example, the wafer is exposed to the precursor and reactant simultaneously to react and fill the features with Mo.

[0135] In yet some other embodiments, the features may be filled using a pulsed CVD process, which continuously flows reactants into a chamber while pulses of precursors are flowed into the chamber. For example, H 2 The gas is flowed into the chamber and the molybdenum-containing precursor is intermittently flowed into the chamber while H 2 Gases may be continuously flowed into the chamber, and the temperature of the substrate and the pressure within the chamber may be controlled during the CVD operation.

[0136] Molybdenum may be selectively deposited in features using the methods described herein. Selective deposition refers to preferential deposition on a first material relative to a second material. Molybdenum deposition and growth may be easier on metallic materials compared to molybdenum deposition and growth on dielectric materials. For example, the features may be formed of SiO 2 The sidewall surfaces of the feature may be SiO 2 and a TiN plug at the bottom of the feature. In the selective deposition, molybdenum is deposited in the feature and grows on the TiN plug while SiO 2 is deposited on the TiN plug. 2 There may be no growth (or only a small amount of growth) on the sidewall surfaces.

[0137] Process conditions such as precursor gas, reducing agent, process temperature, process pressure, and exposure time can affect the selectivity of the deposited molybdenum film. Different precursor gases can have different process windows in which molybdenum films can be selectively deposited. Generally speaking, MoCl 5 Gases have a larger process window, i.e., a wide temperature and pressure range over which the precursor gas retains its selectivity. For example, MoCl 5 can be selectively deposited on metal materials with respect to dielectric materials when the process temperature is between 200°C and 800°C, e.g., between 250°C and 550°C, or between 300°C and 500°C. Generally speaking, higher process temperatures and higher process pressures decrease the selectivity of the deposited gas. For example, at higher temperatures, MoCl 5 A precursor gas such as may lose its selectivity and deposit a molybdenum film on both the metal and dielectric surfaces within the feature.

[0138] MoCl 5 may deposit a molybdenum film by reacting with different reactants. The following describes MoCl 5 Examples of depositing molybdenum films in features using precursors and different process controls. In the first example, MoCl 5 The precursor was prepared by deposition of hydrogen (H 2) reactant. As described herein, the metal precursor reacts with H 2 (Hydrogen reactant or H 2 However, instead of hydrogen, it reacts with SiH 4 , B 2 H 6 , N.H. 3 Other reactants may be used as desired, including other hydrogen-containing reactants such as B 2 H 6 and / or SiH 4 Reactants such as H are stronger reducing agents, but they may also result in higher resistivity. Thus, in some embodiments, H 2 It is advantageous to use a molybdenum film deposition process using a TiN plug at the bottom of the feature. The process temperature for selective deposition of the molybdenum film may be between 200°C and 800°C, for example, 250°C to 550°C, or 300°C to 500°C. At these temperatures, the molybdenum film is selectively deposited on conductive metal or metal compound surfaces, such as TiN surfaces, within the feature relative to dielectric surfaces. The molybdenum film grows from wherever in the feature the conductive surface is located. If the conductive surface is a TiN plug at the bottom of the feature, the molybdenum film may be deposited and grown from the bottom of the feature. In a second example, the molybdenum film is deposited using a MoCl 5 Precursors and H 2 Reactants may be used but deposited at higher temperatures, i.e., greater than 800° C. This process window may deposit molybdenum films on both dielectric and conductive surfaces within a feature. Deposition of a molybdenum film on a dielectric surface may be used to form a barrier-less molybdenum layer within the feature.

[0139] In some embodiments, the selective deposition is performed using a molybdenum oxyhalide precursor. As mentioned above, the above-mentioned surface treatment is carried out using a molybdenum oxyhalide precursor such as MoO 2 Cl 2 As shown above, the selectivity of Mo deposition using MoO y X z An example of a precursor is MoO 2 Cl2 , MoOCl 4 , MoOF 4 , MoO 2 Br 2 , MoO 2 I, and Mo 4 O 11 I. The features may be filled using ALD, plasma-enhanced ALD, chemical vapor deposition (CVD), or plasma-enhanced CVD. In ALD or CVD, H 2 The reducing agent may be MoCl, which is used in the surface treatment. x Deposition is faster when using molybdenum oxyhalide precursors than when using molybdenum oxyhalide precursors, e.g., MoO y X z The precursor is MoCl for the non-plasma process. x Molybdenum may be deposited at a deposition rate at least twice that of the precursor. Plasma enhanced processes may be used to fill features at lower temperatures and / or increase deposition rates.

[0140] In some embodiments, filling of the feature may include deposition of a nucleation layer. The nucleation layer is a thin film that supports the bulk deposition. The nucleation layer may be conformal to the feature. In many embodiments, the nucleation layer is deposited by an ALD process. In some embodiments, the Mo nucleation layer is deposited by a boron-containing reducing agent (e.g., B 2 H 6 ) or silicon-containing reducing agents (e.g., SiH 4) as co-reactants. For example, one or more S / Mo or Mo / S cycles may be used to deposit a Mo nucleation layer. In another example, one or more B / Mo or Mo / B cycles may be used to deposit a Mo nucleation layer on which a bulk Mo layer is deposited. B refers to a pulse of diborane or other boron-containing reducing agent, and S refers to a pulse of silane or other silicon-containing reducing agent, so S / Mo refers to a pulse of silane followed by a pulse of another Mo-containing precursor. B / Mo and S / Mo cycles (or Mo / B and / or Mo / S) may be used together to deposit a Mo nucleation layer. The Mo nucleation layer may be, for example, x(B / Mo)+y(S / Mo), where x and y are integers. Examples of boron-containing reactants include diborane (B 2 H 6 ), alkylboranes, alkylborons, aminoboranes (CH 3 ) 2 NB(CH 2 ) 2 , C 2 B n H n+2 Examples of boranes include carboranes such as B n H n+4 , B n H n+6 , B n H n+8 , B n H m where n is an integer from 1 to 10, and m is an integer different from m. Examples of silicon-containing reducing agents include silane (SiH 4 ), and disilane (Si 2 H 6 ) and other silanes.

[0141] In some embodiments, the deposition of the Mo nucleation layer is performed using a non-oxygen-containing precursor, such as molybdenum hexafluoride (MoF 6 ) or molybdenum pentachloride (MoCl 5 The oxygen in the oxygen-containing precursor reacts with the silicon-containing or boron-containing reducing agent to produce an impure, high resistivity film, MoSix O y or MoB x O y In some embodiments, an oxygen-containing precursor may be used to deposit the nucleation layer with minimal oxygen incorporation, which can be minimized by a high reducing agent flow rate (e.g., a volumetric flow rate of reducing agent to oxygen-containing Mo precursor of greater than 100:1).

[0142] In some embodiments, H is used as the reducing gas for the deposition of the Mo nucleation layer instead of a boron-containing reducing gas or a silicon-containing reducing gas. 2 may be used. Exemplary deposition thicknesses for the Mo nucleation layer range from 5 Å to 30 Å. Films at the lower end of this range may not be continuous, but as long as they are thick enough to help initiate continuous bulk Mo growth, the thickness may be sufficient.

[0143] In some embodiments, the reducing agent pulse during deposition of the nucleation layer or bulk Mo layer may be performed at a lower substrate temperature than the Mo precursor pulse. 2 H 6 or SiH 4 (or other boron-containing or silicon-containing reducing agents) may be pulsed at temperatures below 300°C and Mo may be pulsed at temperatures above 300°C.

[0144] In some embodiments, the reducing agent is NH 3 , or hydrazine (N 2 H 4 ) and other nitrogen-containing reducing agents. 3 The chemisorption of H 2 In some embodiments, the reducing agent and precursor are selected such that they react without dissociation of the reducing agent. 3 reacts with metal oxychlorides and metal chlorides without dissociation. This is the case, for example, with H 2 This is in contrast to metal acid chloride ALD, in which H was used as the reducing agent. 2NH dissociates on the surface to form adsorbed atomic hydrogen, thereby resulting in a very low concentration of active species and low surface coverage during the initial nucleation of metal on the dielectric surface. 3 , and H of the same metal precursor by using metal oxychloride precursor or metal chloride precursor. 2 At deposition temperatures up to several hundred degrees lower than those used for reduction, the nucleation delay is reduced or eliminated.

[0145] In some embodiments, the reducing agent is B 2 H 6 or SiH 4 These reducing agents may be used with metal chloride precursors, with metal oxychlorides, but not with B 2 H 6 and SiH 4 reacts with water, which is formed as a by-product during the ALD process, to form solid B 2 O 3 and SiO 2 These are insulating and can remain in the film and increase resistivity. NH 3 The use of Al 2 O 3 B on a specific surface containing 2 H 6 and SiH 4 The resulting nucleation layer is generally a metal nitride or metal oxynitride film rather than a pure elemental film. In some embodiments, residual chlorine or fluorine may be present from the deposition, especially if the deposition is performed at low temperatures. In some embodiments, trace amounts of residual chlorine or fluorine may be present. In some embodiments, the nucleation layer is an amorphous layer. Impurities in the film (e.g., oxygen, NH 3, chlorine, or other halogens) promote the growth of an amorphous microstructure. In some embodiments, the as-deposited nucleation layer is an amorphous molybdenum oxynitride layer or an amorphous molybdenum nitride layer. The amorphous nature allows for templated large grain growth of the subsequently deposited conductor. The surface energy of the nitride or oxynitride relative to an oxide surface is much more favorable than that of a metal on an oxide surface, promoting the formation of a continuous, smooth film on the dielectric. This allows for the formation of a thin, continuous layer. Example thicknesses of the nucleation layer range from 5 to 30 Å immediately after deposition. This may be, for example, about 5 to 50 ALD cycles depending on the temperature. etching

[0146] The etching operation may be used in the method of filling the feature with a Mo film. The etching operation removes metals, such as metals and nitrides, from the feature. For example, the etching process may partially or completely remove a liner layer from the feature. In another example, the etching process may be used to reduce the thickness of a liner layer. The etching operation may, in some embodiments, include soaking the feature soaked in a Mo halide. In some embodiments, the etching operation may include soaking the feature in a Mo halide. 5 MoCl x In some embodiments, the soaking may be performed continuously with a Mo-halide gas. In some embodiments, the soaking may be pulsed, cycling the Mo-halide gas with a purge gas such as argon (Ar).

[0147] MoCl x The precursors may be used in both deposition and etching operations. For example, in certain process windows, MoCl 5The precursor may simultaneously grow a Mo film and etch a metal or metal compound film in the feature. The process is considered a pure etching operation when the rate at which material is removed is greater than the rate at which material is deposited by the precursor. The speed at which the precursor deposits material and the speed at which it etches material can be controlled by a variety of process conditions, including the type of reactants used and the process temperature. Generally speaking, the lower the temperature, the higher the ratio of material etching to material deposition. At higher temperatures, the same precursor and reactants may be used as a pure deposition process, i.e., the amount of material deposited is greater than the material removed. For example, when the process temperature is below 400°C, MoCl 5 Precursors and H 2 The reactants can be used in the etching operation. When the process temperature is higher than 550° C., the same MoCl 5 Precursors of and H 2 The reactants may be used in the deposition process.

[0148] In some embodiments, MoCl x The precursor may continue to etch material at a faster rate than material is deposited at high temperatures (e.g., greater than 550° C.). For example, MoCl 5 The feature may be etched by soaking without reactants using MoCl. In this example, the temperature may be on the order of 700° C. and continue to etch material from the feature. The feature may be etched without reactants using MoCl. 5 In a soaking in operation, the increased temperature can increase the etch rate of material from the feature.

[0149] The features may have surface oxides or contaminants thereon. For example, the surface of an underlying TiN, WN, or W layer may be oxidized. If left, the oxidized surface may result in higher resistivity. A cleaning operation removes such oxides and contaminants. In some embodiments, the cleaning operation involves soaking the features in a Mo precursor gas, typically a Mo halide. Similar to the etching operation described above, the precursor gas is MoCl x In some embodiments, the soaking may be continuous. In some embodiments, the soaking may be pulsed, with MoCl x A purge gas such as Argon (Ar) may be cycled between the precursor and the surface of the feature. The precursor may be an oxygen-free Cl-containing Mo compound capable of removing oxidation from the surface of the feature. MoCl x Examples of compounds are listed above. Cl-containing precursors can be prepared by thermal or plasma H oxidation, such as where surface oxidation is stable on the surface material. 2 Cl-containing precursors are less likely to overetch the liner layer of the feature or attack the surface of the feature than F-containing compounds. Device

[0150] FIG. 16 shows a schematic diagram of one embodiment of an ALD process station 1600 having a process chamber 1602 for maintaining a low pressure environment. In some embodiments, multiple ALD process stations may be included in a common low pressure process tool environment. For example, FIGS. 17A and 17B show an embodiment of a multi-station processing tool 1700. In some embodiments, one or more hardware parameters of the ALD process station 1600, including those discussed in detail below, may be programmatically adjusted by one or more computer controllers 1750. In some other embodiments, the process chamber may be a single station chamber.

[0151] The ALD process station 1600 is in fluid communication with a reactant delivery system 1601a for delivering process gases to a distribution showerhead 1606. The reactant delivery system 1601a includes a mixing vessel 1604 for formulating and / or conditioning process gases for delivery to the showerhead 1606. The process gases may be Mo precursor-containing gases, hydrogen-containing gases, argon or other carrier gases, or other reactant-containing gases. One or more mixing vessel inlet valves 1620 may control the introduction of process gases to the mixing vessel 1604. In various embodiments, deposition of the initial Mo layer is performed at the process station 1600, and in some embodiments, other operations such as in situ cleaning or Mo gap filling may be performed at the same or another station of a multi-station processing tool 1700, as further described below with respect to FIG. 17A.

[0152] As an example, the embodiment of FIG. 16 includes a vaporization point 1603 for vaporizing a liquid reactant that is provided to the mixing vessel 1604. In some embodiments, the vaporization point 1603 may be a heated vaporizer. In some embodiments, the liquid precursor or liquid reactant may be vaporized in a liquid injector (not shown). For example, the liquid injector may inject a pulse of the liquid reactant into the carrier gas flow upstream of the mixing vessel 1604. In one embodiment, the liquid injector may vaporize the reactant by flowing the liquid from a higher pressure to a lower pressure. In another example, the liquid injector may atomize the liquid into spray droplets that are then vaporized in a heated delivery tubing. Smaller droplets may vaporize faster than larger droplets, reducing the delay between injection and complete vaporization of the liquid. Faster vaporization may reduce the length of tubing downstream of the vaporization point 1603. In one scenario, the liquid injector may be attached directly to the mixing vessel 1604. In another scenario, the liquid injector may be attached directly to the showerhead 1606.

[0153] In some examples, a liquid flow controller (LFC) upstream of the vaporization point 1603 may be provided to control the mass flow rate of liquid for vaporization and delivery to the process chamber 1602. For example, the LFC may include a thermal mass flow meter (MFM) located downstream thereof. A plunger valve of the LFC may then be adjusted in response to a feedback control signal provided by a proportional-integral-derivative (PID) controller in electrical communication with the MFM. However, stabilizing the liquid flow using feedback control may take a second or more. This may extend the time to dose the liquid reactant. Thus, in some embodiments, the LFC may be dynamically switched between a feedback control mode and a direct control mode. In some embodiments, this may be done by disabling the sensing tube and PID controller of the LFC.

[0154] The showerhead 1606 distributes process gases towards the substrate 1612. In the embodiment shown in Figure 16, the substrate 1612 is shown positioned below the showerhead 1606 and resting on a pedestal 1608. The showerhead 1606 may have any suitable shape and may have any suitable number and arrangement of ports for distributing process gases to the substrate 1612.

[0155] In some embodiments, the pedestal 1608 may be raised or lowered to expose the substrate 1612 to the volume between the substrate 1612 and the showerhead 1606. In some embodiments, the pedestal 1608 may be temperature controlled via a heater 1610. The pedestal 1608 may be set to any suitable temperature, such as between about 250° C. and about 800° C., during operation to perform various disclosed embodiments. It will be appreciated that in some embodiments, the height of the pedestal may be programmatically adjusted by a suitable computer controller 850. At the end of a process stage, the pedestal 1608 may be lowered to allow the substrate 1612 to be removed from the pedestal 1608 in a stage to transfer another substrate.

[0156] In some embodiments, the position of the showerhead 1606 may be adjusted relative to the pedestal 1608 to change the volume between the substrate 1612 and the showerhead 1606. Further, it will be appreciated that the vertical position of the pedestal 1608 and / or the showerhead 1606 may be changed by any suitable mechanism within the scope of this disclosure. In some embodiments, the pedestal 1608 may include a rotation axis for rotating the orientation of the substrate 1612. It will be appreciated that in some embodiments, one or more of these adjustments may be programmatically performed by one or more suitable computer controllers 1650. The computer controller 1650 may include any of the features described below with respect to the controller 1650 of FIG.

[0157] In some embodiments where a plasma may be used as described above, the showerhead 1606 and pedestal 1608 are in electrical communication with a radio frequency (RF) power supply 1614 and a matching network 1616 to power the plasma. In some embodiments, the plasma energy may be controlled by controlling one or more of the process station pressure, gas concentration, RF source power, RF source frequency, and plasma power pulse timing. For example, the RF power supply 1614 and the matching network 1616 may be operated at any suitable power to generate a plasma having a desired composition of radical species. Similarly, the RF power supply 1614 may provide RF power of any suitable frequency. In some embodiments, the RF power supply 1614 may be configured to control the high frequency RF power source and the low frequency RF power source independently of each other. Examples of low frequency RF frequencies may include, but are not limited to, frequencies between 0 kHz and 900 kHz. Examples of high frequency RF frequencies may include, but are not limited to, frequencies between 1.8 MHz and 2.45 GHz, or greater than about 13.56 MHz, or greater than 27 MHz, or greater than 80 MHz, or greater than 60 MHz. It will be appreciated that any suitable parameters may be discretely or continuously adjusted to provide plasma energy for surface reactions.

[0158] In some embodiments, the plasma may be monitored in situ by one or more plasma monitors. In one scenario, the plasma power may be monitored by one or more voltage, current sensors (e.g., VI probes). In another scenario, the plasma density and / or process gas concentration may be measured by one or more optical emission spectroscopy (OES) sensors. In some embodiments, one or more plasma parameters may be programmatically adjusted based on measurements from such in situ plasma monitors. For example, OES sensors may be used in a feedback loop to provide programmatic control of the plasma power. It will be appreciated that in some embodiments, other monitors may be used to monitor the plasma or other process characteristics. Such monitors may include, but are not limited to, infrared (IR) monitors, acoustic monitors, and pressure transducers.

[0159] In some embodiments, instructions for the controller 1650 may be provided via input / output control (IOC) sequence instructions. In one example, instructions for setting conditions for a process step may be included in a corresponding recipe step of a process recipe. In some cases, process recipe steps may be sequentially arranged such that all instructions for a process step are executed simultaneously with that process step. In some embodiments, instructions for setting one or more reactor parameters may be included in a recipe step. For example, a first recipe step may include instructions for setting the flow rate of an inert gas and / or reactant gas (e.g., Mo precursor), instructions for setting the flow rate of a carrier gas (such as argon), and a time delay instruction for the first recipe step. A second, subsequent recipe step may include instructions for adjusting or stopping the flow rate of an inert gas and / or reactant gas, instructions for adjusting the flow rate of a carrier gas or purge gas, and a time delay instruction for the second recipe step. A third recipe step may include instructions for setting the flow rate of an inert gas and / or reactant gas (e.g., Mo precursor), instructions for setting the flow rate of a carrier gas (such as argon), and a time delay instruction for the second recipe step. 2The recipe step may include instructions to adjust the flow rate of a second reactant gas such as an inert gas, an inert gas flow rate, a carrier gas or a purge gas flow rate, instructions to ignite a plasma, and a time delay instruction for the third recipe step. The fourth, subsequent recipe step may include instructions to adjust or stop the flow rate of an inert gas and / or a reactant gas, instructions to adjust the flow rate of a carrier gas or a 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 the present disclosure.

[0160] Additionally, in some embodiments, pressure control for the process station 1600 may be provided by a butterfly valve 1618. As shown in the embodiment of FIG. 16, the butterfly valve 1618 throttles and regulates the vacuum provided by a downstream vacuum pump (not shown). However, in some embodiments, pressure control of the process station 1600 may be adjusted by varying the flow rate of one or more gases introduced to the process station 1600.

[0161] 17A and 17B show examples of processing systems. FIG. 17A shows an example of a processing system including multiple chambers. System 1700 includes a transfer module 1703. Transfer module 1703 provides a clean vacuum environment to minimize the risk of contamination of the substrate during processing as it moves between various modules. Attached to transfer module 1703 is a multi-station chamber 1709 capable of performing the in situ cleaning and / or ALD processes described above. Surface treatment and / or deposition of an initial Mo layer may be performed in the same or different station or chamber as the subsequent Mo gap fill.

[0162] The chamber 1709 may include multiple stations 1711, 1713, 1715, and 1717 that may perform sequential operations according to the disclosed embodiments. For example, the chamber 1709 may include stations 1711, 1713, 1715, and 1717 that may perform sequential operations according to the disclosed embodiments. xStation 1713 may be configured to selectively treat the field regions and upper sidewalls, and stations 1715 and 1717 may be configured to perform in situ treatment using a molybdenum oxyhalide precursor and H 2 In another example, chamber 1709 may be configured for station 1711 to perform in situ cleaning, station 1713 to perform ALD of an initial Mo layer, station 1714 to selectively process layers, and station 1715 to deposit bulk Mo. In another example, chamber 1709 may be configured for parallel processing of substrates, with each station performing multiple processes sequentially.

[0163] A multi-station chamber may include two or more stations, e.g., 2-6, with appropriate distribution of operations. For example, a two-station chamber may be configured for ALD of an initial Mo layer in a first station, followed by ALD of bulk Mo in a second station. The stations may include a heated pedestal or substrate support, one or more gas inlets or showerheads or distribution plates.

[0164] The transfer module 1703 may also be fitted with one or more single or multi-station modules 1707. In some embodiments, pre-cleaning as described above may take place in module 1707, after which the substrate is transferred under vacuum to another module (e.g., another module 1707 or chamber 1709) for ALD. In another example, a module for selective treatment of films may be fitted to the transfer module. An example is shown in FIG.

[0165] System 1700 also includes one or more wafer source modules 1701 where wafers are stored before and after processing. An atmospheric robot (not shown) in atmospheric transfer chamber 1719 may first remove wafers from source module 1701 to load lock 1721. A wafer transport device (typically a robot arm unit) in transfer module 1703 moves wafers from load lock 1721 to and between modules attached to transfer module 1703.

[0166] In some embodiments, the ALD of Mo is performed in a first chamber that may be part of a system such as system 1700, and the CVD or PVD of W or Mo or other conductive material deposited as an overburden layer is performed in another chamber that may be part of a separate system that is not coupled to a common transfer module.

[0167] FIG. 17B is an embodiment of a system 1700. The system 1700 of FIG. 17B includes a wafer source module 1701, a transfer module 1703, an atmospheric transfer chamber 1719, and a load lock 1721, as described above with reference to FIG. 17A. The system of FIG. 17B includes three single station modules 1757a-1757c. The system 1700 may be configured to perform sequential operations according to disclosed embodiments. For example, the single station modules 1757a-1757c may be configured such that the first module 1757a performs a surface treatment, the second module 957b performs an ALD of an initial Mo layer using a molybdenum halide precursor, and the third module 957c performs an ALD of bulk Mo using a molybdenum oxyhalide precursor. In this example, an in situ clean may be optionally performed in the second module 1757b instead of or in addition to a pre-clean in the first module 1757a. In another example, the single station modules 1757a-1757c may be configured such that a first module 1757a performs deposition of an initial metal layer, a second module 1757b performs selective processing, and a third module 1757c performs ALD of bulk Mo using a molybdenum oxyhalide precursor. In yet another example, one module may be configured for deposition, another for selective processing, and another for etching.

[0168] The station may include a heated pedestal or substrate support, one or more gas inlets or showerheads or distribution plates, as described above with reference to FIG.

[0169] FIG. 18 shows an example of a system including an ion plasma module 1811, a vapor deposition module 1812, and transfer modules 1814, 1816, and 1818. In some embodiments, the apparatus may have more than one transfer module, with the ion plasma module attached to a first transfer module and the vapor deposition module attached to a second transfer module. An intermediate transfer module (such as transfer module 1816) may be employed to transfer the substrate between the ion plasma module and the deposition module. The system may be configured to selectively process the substrate as described above in the ion plasma module 1811, followed by deposition of Mo in the vapor deposition module 1812. Deposition of a Mo liner, W liner, or other liner in the deposition module 1812 may precede the selective processing. In some embodiments, an etching operation as described above with respect to FIG. 12 and FIG. 13D may be performed in the ion plasma module 1811.

[0170] An example of an ion plasma module is shown in FIG. 19. FIG. 19 shows a simplified cross-sectional view of an ion beam etching system 1900 for performing ion beam etching and / or ion beam processing such as oxidation or nitridation according to certain methods. In this example, a wafer 1901 is placed on a substrate support 1903. The substrate support may hold the wafer 1101 on the substrate support 1903 by providing clamping such as mechanical clamping or electrostatic clamping. The ion beam etching system 1900 may include hardware (not shown) for providing electrical and fluidic connections. Electrical connections may be used to provide electricity to the substrate support 1903 or, in some cases, to an electrostatic chuck located on or within the substrate support 1903. Meanwhile, fluidic connections may be used to provide fluids used to control the temperature of the wafer 1901 and the substrate support 1903. The substrate support 1903 may be heated by a heater (not shown) and / or cooled by a cooling mechanism (not shown). Any suitable cooling mechanism may be used. In one example, the cooling mechanism may include flowing a cooling fluid through piping in or adjacent to the substrate support 1903. The substrate support 1903 may be rotatable and tiltable at variable speeds and angles, as described above with respect to FIG. 15. A position controller 1932 may be used to control the tilt and rotation of the substrate support 1903. The substrate support 1903 and wafer 1901 are in a process chamber 1915.

[0171] The processing chamber 1915 is separated from the plasma source chamber 1905 by an ion extractor 1912. In this embodiment, the ion extractor 1912 includes a first electrode 1909, a second electrode 1911, and a third electrode 1913. In this embodiment, the third electrode 1913 is grounded. In other embodiments, the ion extractor 1912 may be other combinations of electrodes to extract ions from the plasma source chamber 1905. In some embodiments, the ion extractor 1912 can provide an ion beam from the plasma source chamber 1905. The plasma source chamber 1905 is surrounded by a coil 1907. The coil 1907 is electrically connected to a matching network 1924 and a radio frequency (RF) source 1920. The coil 1907, the matching network 1924, and the RF source 1920 provide an RF power system for supplying RF power to the plasma source chamber 1905. A gas inlet 1908 is located at the end of the plasma source chamber 1905. The gas inlet 1908 is fluidly connected to the process gas source 1902 and the cleaning gas source 1904 through at least one manifold 1906. The gas inlet 1908 may be one of many different forms. For example, the gas inlet may be a gas distribution plate, a gas diffuser plate, a showerhead, or a gas injector. A turbo pump 1928 may be fluidly connected to the process chamber 1915 to remove gas from the process chamber 1915 and control the pressure within the process chamber 1915.

[0172] In some embodiments, a switch 1916 may be fluidly connected between the process gas source 1902, the cleaning gas source 1904, and the gas inlet 1908. The switch 1916 may be any device, or any group of devices, configured to switch to provide process gas from the process gas source 1902 during wafer processing and to provide cleaning gas from the cleaning gas source 1904 during chamber cleaning.

[0173] As mentioned above, the ion beam etching system 1900 may be used for selective oxidation or selective nitridation using a mild plasma and appropriate rotation and tilt of the substrate. Examples of process gases for oxidation include oxygen (O 2 ), ozone (O 3 ), nitrous oxide (N 2 O), H 2 and O 2 Mixture of N 2 and O 2 Mixture of NH 3 and O 2 Examples of process gases for nitridation include nitrogen (N 2 ) and ammonia (NH 3 ), and H 2 and N 2 Mixture of N 2 and O 2 Mixture of NH 3 and O 2 In some embodiments, the plasma conditions are mild to treat the surface without etching it. Examples of mild plasma conditions include less than 100 V bias voltage, less than 200 mA source current, less than 500 W source power, and 0-20 sccm station O. 2 The ion beam etching system 1900 may be controlled using a controller 1914. The controller 1914 may have similar properties and features as the system controller 1729 of Figures 17A and 17B.

[0174] Returning to Figures 17A and 17B, in various embodiments, a system controller 1729 is employed to control process conditions during deposition. The controller 1729 typically includes 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, stepper motor control boards, etc. Such a system controller may be employed to control any of the processes and apparatus described herein.

[0175] The controller 1729 may control all of the operation of the apparatus. The system controller 1729 executes system control software that includes sets of instructions for controlling the timing, mixture of gases, chamber pressure, chamber temperature, wafer temperature, radio frequency (RF) power levels, wafer chuck or pedestal position, and other parameters of a particular process. In some embodiments, other computer programs stored on memory devices associated with the controller 1729 may be employed.

[0176] Typically, there is a user interface associated with the controller 1729. The user interface may include a display screen, a graphical software display of equipment and / or process conditions, and user input devices such as a pointing device, keyboard, touch screen, microphone, etc.

[0177] The system control logic may be configured in any suitable manner. In general, the logic may be designed or configured in hardware and / or software. The instructions for controlling the drive circuits may be hard-coded or provided as software. The instructions may be provided by "programming". Such programming is understood to include any form of logic, including logic hard-coded into digital signal processors, application specific integrated circuits, and other devices that have specific algorithms implemented as hardware. Programming is also understood to include software or firmware instructions that may be executed on a general purpose processor. The system control software may be coded in any suitable computer readable programming language.

[0178] The computer program code for controlling the Mo precursor pulse, hydrogen pulse, and argon flow, and other processes in the process sequence, can be written in any conventional computer readable programming language, such as assembly language, C, C++, Pascal, Fortran, etc. The compiled object code or script is executed by the processor to perform the tasks specified in the program. Also, as noted, the program code may be hard coded.

[0179] The controller parameters relate to process conditions such as, for example, process gas composition and flow rates, temperature, pressure, cooling gas pressure, substrate temperature, and chamber wall temperature. These parameters may be provided to a user in the form of a recipe or may be entered using a user interface.

[0180] Signals for monitoring the process may be provided by analog and / or digital input connections of the system controller 1729. Signals for controlling the process are output on analog and digital output connections of the deposition device.

[0181] The system software may be designed or configured in many different ways. For example, subroutines or control objects for various chamber components may be written to control the operation of the chamber components necessary to perform a deposition process in accordance with 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.

[0182] In some implementations, the controller 1729 is part of a system, which may be part of the examples described above. Such a system may include semiconductor processing equipment including one or more processing tools, one or more chambers, one or more processing platforms, and / or certain processing components (wafer pedestals, gas flow systems, etc.). These systems may be integrated with electronics to control the operation of the electronics before, during, and after processing of a semiconductor wafer or substrate. The electronics may be referred to as a "controller" that may control various components or subcomponents of one or more systems. The controller 1729 may be programmed to control any of the processes disclosed herein depending on the processing requirements and / or type of system. Such processes may include delivery of process gases, temperature settings (e.g., heating and / or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings in some systems, RF matching circuit settings, frequency settings, flow settings, fluid delivery settings, position and motion settings, wafer transfer to and from the tool, and wafer transfer to and from other transport tools and / or load locks connected or coupled to the particular system.

[0183] In general, a controller may be defined as an electronic device having various integrated circuits, logic, memory, and / or software that, for example, receive instructions, issue instructions, control operations, enable cleaning operations, and enable end-point metrology. Integrated circuits may include chips in the form of firmware that store program instructions, digital signal processors (DSPs), chips defined as application specific integrated circuits (ASICs), and / or one or more microprocessors or microcontrollers that execute program instructions (e.g., software). Program instructions may be instructions communicated to the controller in the form of various individual settings (or program files) that define operational parameters for performing a particular process on or for a semiconductor wafer or for a system. In some embodiments, the operational parameters may be part of a recipe defined by a process engineer to accomplish one or more processing steps during the fabrication of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or wafer dies.

[0184] In some implementations, the controller 1729 may be part of or coupled to a computer integrated with, coupled to, or otherwise networked to the system, or a combination thereof. For example, the controller 1729 may be in the "cloud" or may be all or part of a fab host computer system, thereby enabling remote access of wafer processing. The computer may enable remote access to the system to monitor the current progress of a fabrication operation, review the history of past fabrication operations, review trends or performance criteria from multiple fabrication operations, modify parameters of a current process, set processing steps following a current process, or initiate a new process. In some examples, a remote computer (e.g., a server) may provide process recipes to the system over a network, which may include a local network or the Internet. The remote computer may include a user interface that allows for 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 that specify parameters for each processing step to be performed during one or more operations. The parameters may be specific to the type of process being performed or the type of tool to which the controller is configured to couple or control. Thus, as discussed above, the controller may be distributed, such as by including one or more separate controllers networked together and working toward a common purpose, such as the processes and controls described herein. An example of a controller distributed for such purposes includes one or more integrated circuits on the chamber that are located remotely (such as at the platform level or as part of a remote computer) and communicate with one or more integrated circuits that cooperatively control the process on the chamber.

[0185] Exemplary systems include, but are not limited to, a plasma etch chamber or module, a deposition chamber or module, a spin rinse chamber or module, a metal plating chamber or module, a cleaning chamber or module, a bevel edge etch chamber or module, a PVD chamber or module, a CVD chamber or module, an ALD chamber or module, an atomic layer etch (ALE) chamber or module, an ion implantation chamber or module, a track chamber or module, and any other semiconductor processing system associated with or that may be used in the fabrication and / or manufacturing of semiconductor wafers.

[0186] As described above, depending on the process step or steps being performed by the tool, the controller may communicate with one or more of other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, nearby tools, tools located throughout the factory, a main computer, another controller, or tools used for material transport to and from containers of wafers to and from tool locations and / or load ports within a semiconductor manufacturing factory.

[0187] The controller 1729 may include various programs. A substrate positioning program may include program code for controlling chamber components used to position the substrate on the pedestal or chuck, as well as control the space between the substrate and other parts of the chamber, such as gas inlets. A substrate tilt and rotation program may include those for tilt and rotation. A process gas control program may include code for gas composition, flow rates, pulse times, and optionally flowing gas into the chamber prior to deposition 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 a throttle valve in the exhaust system of the chamber. 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 may control the delivery of a heat transfer gas, such as helium, to the wafer chuck.

[0188] Examples of chamber sensors that may be monitored during deposition include mass flow controllers, pressure sensors such as manometers, and thermocouples located in the pedestal or chuck. Appropriately programmed feedback and control algorithms may be used in conjunction with data from these sensors to maintain desired process conditions.

[0189] The above describes the implementation of the disclosed embodiments in single or multi-chamber semiconductor processing tools. The apparatus and processes described herein may be used in combination with lithographic patterning tools or processes, for example, for the fabrication or manufacture of semiconductor devices, displays, LEDs, solar panels, etc. Typically, but not necessarily, such tools / processes are used or performed together in a common fabrication facility. Lithographic patterning of a film typically includes some or all of the following steps, each of which is provided using a number of possible tools: (1) applying photoresist onto a workpiece or substrate using a spin or spray tool; (2) curing the photoresist using a hotplate or furnace or UV curing tool; (3) exposing the photoresist to visible or ultraviolet light or x-rays using a tool such as a wafer stepper; (4) patterning by developing the resist to selectively remove the resist using a tool such as a wet bench; (5) transferring the resist pattern to the underlying film or workpiece using a dry or plasma-assisted etching tool; and (6) removing the resist using a tool such as an RF or microwave plasma resist stripper.

Claims

1. 1. A method comprising: Providing a substrate including a feature having a metal-containing contact and a dielectric sidewall; treating the feature by exposing the feature to a molybdenum halide; depositing molybdenum in the feature, the deposition being selective to the metal-containing contact relative to the dielectric sidewalls; A method comprising:

2. 10. The method of claim 1, further comprising exposing the feature to a hydrogen-containing plasma prior to processing the feature.

3. 10. The method of claim 1, wherein depositing molybdenum in the feature comprises exposing the feature to a molybdenum oxyhalide.

4. 2. The method of claim 1, wherein the treatment inhibits molybdenum growth on the dielectric sidewalls.

5. 10. The method of claim 1, wherein the processing is performed without depositing molybdenum in the feature.

6. 2. The method of claim 1, wherein the treating further comprises forming molybdenum by exposing the feature to a co-reactant capable of reducing the molybdenum halide.

7. 10. The method of claim 1, wherein an amorphous molybdenum-containing layer is on the metal-containing contact.

8. 8. The method of claim 7, wherein the treatment removes the amorphous molybdenum-containing layer.

9. 1. A method comprising: A method for fabricating a substrate comprising: providing a substrate including a feature having a dielectric sidewall and a molybdenum contact, the feature including the molybdenum contact and the dielectric sidewall, an amorphous molybdenum-containing layer on a surface of the molybdenum contact; removing the amorphous molybdenum-containing layer and inhibiting molybdenum deposition on the dielectric sidewalls by exposing the feature to a molybdenum halide; depositing molybdenum in the feature, the deposition being selective to the molybdenum contact relative to the dielectric sidewalls; A method comprising:

10. 1. A method comprising: (a) providing a substrate including a field region and a feature, the feature including an opening, a sidewall, and a bottom, the field region surrounding the opening, and a liner layer lining the sidewall of the feature; (b) selectively treating the liner layer such that a portion of the liner layer on the field region and / or an upper portion of the sidewall is preferentially treated relative to the liner layer on a lower portion of the sidewall, the selectively treating the liner layer forming a selectively treated portion of the liner layer; (c) selectively depositing molybdenum at the bottom of the feature, wherein deposition is inhibited on the selectively treated portions of the liner layer; and A method comprising:

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