Tungsten Feature Filling with Inhibitory Control

Abstract

Systems and methods are provided for selective inhibition control in semiconductor manufacturing. An exemplary method includes providing a substrate including a feature having one or more feature openings and an interior of the feature. A nucleation layer is formed on a surface of the interior of the feature. A non-conformal bulk layer is selectively formed on the surface of the nucleation layer based on a differential inhibition profile, resulting in regions of the nucleation layer that are covered by the non-conformal bulk layer and regions of the nucleation layer that are not covered. An inhibition layer is selectively formed in the covered and uncovered regions of the nucleation layer. Tungsten is deposited within the feature according to the differential inhibition profile.

Description

Technical Field

[0001] [Claims of Priority] This application claims the benefit of priority of U.S. Patent Application No. 62 / 805,197, filed on February 13, 2019, the entire content of which is incorporated herein by reference.

[0002] The present disclosure generally relates to tungsten feature filling with enhanced suppression control, and more particularly to substrate processing in semiconductor manufacturing.

Background Art

[0003] The description of "Background Art" provided herein is intended to present the context of the present disclosure in a general way. The achievements of the inventors named in this specification within the scope described in the "Background Art" herein, as well as aspects of this specification that may not be regarded as prior art at the time of filing, are not admitted as prior art to the present disclosure, either explicitly or implicitly.

[0004] Tungsten deposition is used to form conductive features such as contacts, vias, plugs, etc. on a chip. These features are small, often narrow, and use only a very small amount of metal, so it can be difficult to minimize the resistance of the device and fill them completely. At the nanoscale, even a slight defect in the feature can affect device performance or cause the chip to malfunction.

[0005] As semiconductor manufacturers transition to smaller technology nodes, the tungsten contact metallization process faces significant challenges in scaling and integration, such as minimizing contact resistance to meet requirements for reducing power consumption and increasing speed in advanced devices. In nanoscale structures, complete filling of tungsten (W) using conventional chemical vapor deposition (CVD) is limited by overhangs resulting from conventional barrier films and deposition techniques. As a result, the feature openings can close before complete filling can occur, leading to voids, higher resistance, and poor contacts. Even in a completely filled small feature, the tungsten content is low, resulting in high contact resistance. Advanced memory and logic features require deposition techniques that enable complete and defect-free tungsten filling while reducing the resistivity of bulk tungsten. For improving contact filling and reducing contact resistance, when the thickness is thin, good step coverage of the barrier and resistance reduction are required (compared to barrier films by physical vapor deposition / CVD).

[0006] The deposition of conductive materials using CVD technology is an essential part of many semiconductor manufacturing processes. These materials may be used for horizontal interconnects, vias between adjacent metal layers, contacts between the first metal layer and devices on a silicon substrate, and high aspect ratio features. In conventional tungsten deposition processes, the substrate is heated to a predetermined process temperature in a deposition chamber, and a thin layer of a tungsten-containing material that functions as a seed layer or nucleation layer is deposited. Subsequently, the remaining tungsten-containing material (bulk layer) is deposited on the nucleation layer. Typically, the tungsten-containing material is formed by reducing tungsten hexafluoride (WF6) with hydrogen (H2). The tungsten-containing material is deposited over the entire exposed surface area of the substrate, including features and field regions.

[0007] When a tungsten-containing material is deposited in small, particularly high aspect ratio features, seams and voids may form inside the filled features. Large seams can lead to high resistance, contamination, loss of the filled material, and in some cases, degradation of the integrated circuit's performance. For example, a seam may extend near the field region after the fill process and then open during chemical mechanical planarization (CMP). SUMMARY OF THE INVENTION

[0008] In some method embodiments, a method for selective inhibition control in substrate processing includes providing a substrate including one or more feature openings and a feature having an interior, forming a nucleation layer on a surface inside the feature, selectively forming a non-conformal bulk layer on a surface of the nucleation layer based on a differential inhibition profile to create a region of the nucleation layer covered by the non-conformal bulk layer and a region of the nucleation layer not covered, selectively forming an inhibition layer on the covered and non-covered regions of the nucleation layer, and selectively depositing tungsten in the feature according to the differential inhibition profile.

[0009] In some examples, the nucleation layer formed on the surface inside the feature is a conformal nucleation layer.

[0010] In some examples, the covered region of the nucleation layer includes an upper region inside the feature.

[0011] In some examples, the upper region inside the feature corresponds to an outer boundary of a non-conformal bulk layer formed between the conformal nucleation layer and the inhibition layer.

[0012] In some examples, the covered region of the nucleation layer is adjacent to an open entrance of the feature.

[0013] In some examples, selectively forming a non-conformal bulk layer on the surface of the nucleation layer includes applying a bulk layer to the nucleation layer before applying a suppression layer to either the covered or uncovered regions of the nucleation layer.

[0014] In some examples, the exemplary method further includes forming a suppression layer on the bulk layer in the upper region within the feature and forming a suppression layer in the covered region of the nucleation layer in the intermediate region within the feature.

[0015] In some examples, the exemplary method further includes not forming a suppression layer in the non-suppression lower region within the feature.

[0016] In some examples, the exemplary method further includes not forming a non-conformal bulk layer in the intermediate region such that the suppression layer lies directly on the nucleation layer in the intermediate region.

[0017] In some examples, the differential effect of the suppression layer on the non-conformal bulk layer is relatively strong, while the differential effect of the suppression layer on the nucleation layer is relatively weak.

[0018] In some system examples, the system includes a memory and at least one processor configured to perform and control operations in a method for selective suppression control in substrate processing according to instructions in the memory. The substrate includes a feature having one or more feature openings and an interior. The operations include at least forming a nucleation layer on the surface within the feature, selectively forming a non-conformal bulk layer on the surface of the nucleation layer based on a differential suppression profile to create regions of the nucleation layer covered and not covered by the non-conformal layer, selectively forming a suppression layer on the covered and uncovered regions of the nucleation layer, and selectively depositing tungsten on the feature according to the differential suppression profile. Further features of the system may include one or more of the operations of the exemplary method summarized above.

[0019] In a further example, the non-transitory machine-readable medium may include instructions that, when read by a machine, cause the machine to perform one or more of the operations of the exemplary methods outlined above or elsewhere in this specification.

[0020] Some embodiments are shown by way of example in the figures of the accompanying drawings and are not shown as limitations.

Brief Description of the Drawings

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DETAILED DESCRIPTION OF THE INVENTION

[0031] The following description includes systems, methods, and technologies that embody exemplary embodiments of the present disclosure. The following description includes numerous specific details for the purpose of explanation to provide a thorough understanding of the exemplary embodiments. However, it will be apparent to those skilled in the art that the subject matter of the present invention may be practiced without these specific details.

[0032] Part of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner does not object to the reproduction by anyone of the patent document or patent disclosure as it appears in the patent file or records of the Patent and Trademark Office, but reserves all copyrights otherwise. The following notice applies to the software and data described below, and to the drawings which form a part of this specification: Lam Research Corporation 2019-2020, All Rights Reserved.

[0033] Described herein are methods for filling features with tungsten, and related systems and apparatuses. Examples of applications include contact filling for logic and memory, DRAM bWL filling, vertical integrated memory gate / word line filling, and three-dimensional (3D) integration by through-silicon vias (TSVs). The methods described herein can be used to fill vertical features such as tungsten vias, and horizontal features such as vertical NAND (VNAND) word lines. The methods may be used for conformal filling, and bottom-up or inside-out filling. As used herein, the terms layer and film are used interchangeably unless the context indicates otherwise.

[0034] According to various embodiments, the feature can be characterized by one or more of a narrow and / or inwardly recessed opening, a constriction within the feature, and a high aspect ratio. Examples of features that can be filled are shown in FIGS. 1A - 1C. FIG. 1A shows an example of a cross - sectional view of a vertical feature 101 filled with tungsten. The feature can include a feature hole 105 within a substrate 103. The substrate can be a silicon wafer, e.g., a 200 mm wafer, a 300 mm wafer, or a 450 mm wafer, and includes a wafer on which one or more material layers, e.g., dielectric, conductive, or semiconductive materials, are deposited thereon. In some embodiments, the feature hole 105 can have an aspect ratio of at least about 2:1, at least about 4:1, at least about 6:1, or more. The feature hole 105 can also have a dimension near the opening, e.g., the diameter or line width of the opening, of about 10 nm to 500 nm (e.g., about 25 nm to 300 nm). The feature hole 105 can be an unfilled feature or simply referred to as a feature. The feature and any feature can be partially characterized by an axis 118 extending along the length of the feature, with a vertical feature having a vertical axis and a horizontal feature having a horizontal axis.

[0035] FIG. 1B shows an example of a feature 101 having an inwardly recessed profile. The inwardly recessed profile is a profile that narrows from the feature bottom, closed end, or interior to the feature opening. According to various embodiments, the profile can gradually narrow and / or can include an overhang at the feature opening. FIG. 1B shows an example of the latter, where a lower layer 113 lines the sidewall or inner surface of the feature hole 105. The lower layer 113 can be, e.g., a diffusion barrier layer, an adhesion layer, a nucleation layer, a combination thereof, or any other applicable material. The lower layer 113 forms an overhang 115 such that the lower layer 113 is thicker closer to the opening of the feature 101 than inside the feature 101.

[0036] In some embodiments, features having one or more constrictions within the feature may be filled. FIG. 1C shows an example drawing of various filled features having constrictions. Each of examples (a), (b), and (c) in FIG. 1C includes a constriction 109 at an intermediate point within the feature. The constriction 109 may, for example, have a width of about 15 nm to 20 nm. During deposition of tungsten into a feature using prior art, before the portion of the feature ahead of the constriction is filled, the deposited tungsten may block further deposition, causing the constriction to pinch off, resulting in voids in the feature. Example (b) further includes a liner / barrier overhang 115 at the feature opening. Such an overhang can also be a potential pinch-off point. Example (c) includes a constriction 112 further away from the field region than the overhang 115 of example (b). As further described below, the methods described herein enable void-free filling as shown in FIG. 1C.

[0037] Horizontal features such as in a 3D memory structure can also be filled. FIG. 1D shows an example of a word line 150 in a VNAND structure 148 including a constriction 151. In some embodiments, the constriction may be due to the presence of pillars in the VNAND or other structures. For example, FIG. 1E shows a plan view of a pillar 125 in a VNAND structure, and FIG. 1F shows a simplified schematic cross-sectional view of the pillar 125. The arrows in FIG. 1E represent the deposition material, and when a pillar 125 is placed between region 127 and a gas inlet or other deposition source, adjacent pillars may cause constrictions, thereby presenting challenges in void-free filling of region 127.

[0038] FIG. 1G provides another example of the drawing of horizontal features of a VNAND or other structure of a pillar, including, for example, a constriction 151. The example of FIG. 1G is open-ended, and as indicated by the arrows, the deposited material can enter laterally from two sides. (The example in FIG. 1G can be viewed as a two-dimensional (2D) rendering of the 3D feature of the structure, and FIG. 1G is a cross-sectional view of the filled area. It should be noted that the constriction of the pillar in the figure represents the constriction that would be seen in a plan view rather than a cross-sectional view.) In some embodiments, the 3D structure can be characterized by a filled area that extends along three dimensions (e.g., the X, Y, and Z directions in the example of FIG. 1F), and can present more challenges with respect to filling than filling a hole or trench that extends along one or two dimensions. For example, it may be difficult to control the filling of the 3D structure because the deposition gas can enter the feature from multiple dimensions.

[0039] Filling a feature with a tungsten-containing material may form voids and seams inside the filled feature. A void is an unfilled region within the feature. Voids can be formed, for example, when the deposited material forms a pinch point within the feature, sealing off the unfilled space within the feature and preventing the ingress and deposition of reactants.

[0040] There are multiple potential causes for the formation of voids and seams. One is an overhang formed near the feature opening during the deposition of a tungsten-containing material, or more typically, other materials such as a diffusion barrier layer or a nucleation layer. An example is shown in FIG. 1B.

[0041] Although not shown in FIG. 1B, another cause of voids or seam formation that can lead to seam formation or seam enlargement is the curved (or bent) sidewalls of the feature holes, which are also referred to as bent features. In a bent feature, the cross-sectional dimensions of the cavity near the opening are smaller than the cross-sectional dimensions inside the feature. The effect of such a narrower opening in a bent feature is somewhat similar to the overhang problem described above. The constrictions within the features as shown in FIGS. 1C, 1D, and 1G also pose challenges for tungsten filling with little or no voids and seams.

[0042] Even when void-free filling is achieved, the tungsten within the feature may include a seam passing through the axis or a seam passing through the center of a via, trench, line, or another feature. This is because the growth of tungsten can start at the sidewalls and continue until the crystal grains meet the tungsten growing from the opposite sidewalls. This seam may allow trapping of impurities including fluorine-containing compounds such as hydrofluoric acid (HF). During CMP, coring may also propagate from the seam. According to various embodiments, the methods described herein can reduce or eliminate the formation of voids and seams. The methods described herein can also address one or more of the following:

[0043] 1) Very challenging profiles: Void-free filling can be achieved for most inwardly recessed features using deposition-etch-deposition cycles as described in U.S. Patent Application No. 13 / 351,970, which is incorporated herein by reference. However, depending on the dimensions and shape, multiple deposition-etch cycles may be required to achieve void-free filling. This can potentially affect the stability and throughput of the process. The embodiments described herein can provide feature filling with reduced or no use of deposition-etch-deposition cycles.

[0044] 2) Influence of small features and liners / barriers: When the size of the feature is very small, it can be very difficult to adjust the etching process without affecting the integrity of the underlying liner / barrier. In some cases, intermittent Ti attack, possibly due to the formation of a passivating TiFx layer during etching, may occur during W selective etching.

[0045] 3) Scattering at W grain boundaries: When multiple W grains are present inside the feature, electron loss may occur due to grain boundary scattering. As a result, the actual device performance will degrade compared to the theoretical prediction and the results of the blanket wafer.

[0046] 4) Reduction of via volume for W filling: In particularly small and new features, a significant portion of the metal contact is occupied by the W barrier (such as TiN, WN, etc.). These films typically have a higher resistivity than W and have an adverse effect on electrical properties such as contact resistance.

[0047] Certain embodiments relate to a method and associated apparatus for forming tungsten word lines within a memory device. FIG. 1H shows a schematic example of a DRAM architecture including bWL11 within a silicon substrate 9. The bWL is formed within a trench etched into the silicon substrate 9. Lining the trench are a conformal barrier layer 12 and an insulating layer 13 disposed between the conformal barrier layer 12 and the silicon substrate 9. In the example of FIG. 1H, the insulating layer 13 may be a gate oxide layer formed from a high-k dielectric material such as a silicon oxide material or a silicon nitride material. Examples of conformal barrier layers include tungsten-containing layers and titanium nitride (TiN). The tungsten-containing conformal barrier layer is described in U.S. Patent Application No. 15 / 051,561, which is incorporated herein by reference.

[0048] Conventional deposition processes for DRAM bWL trenches tend to distort the trenches, making the final trench width and Rs highly non-uniform. FIG. 1I shows unfilled and filled narrow asymmetric trench structures typical of DRAM bWL. The unfilled features are adjacent, generally V-shaped, and have sloped sidewalls. The features widen from the bottom of the feature towards the top of the feature. Severe line bending has been observed after tungsten filling. Without being bound by a particular theory, it is believed that the cohesive forces between the opposing surfaces of the trench cause the sides of the trench to be pulled together. This phenomenon is shown in FIG. 1J and may be characterized as "zipping up" the feature. When the feature is filled, a greater force acts from the central axis of the feature, causing line bending. FIG. 1K shows the interatomic force as a function of the tungsten-tungsten bond radius r. As can be seen from the figure, there is a cohesive force at a particular value of r. In some embodiments, the pitch (distance between features as seen along the central axis of the feature) is less than 50 nm, less than 40 nm, or less than 30 nm.

[0049] Conventional suppression techniques do not completely solve the problem of void formation. For example, FIG. 6 shows an example of a feature hole 105 including a lower layer 113 that can be, for example, a metal nitride or other barrier layer. A tungsten layer 653 is conformally deposited within the feature hole 10, for example, by a pulsed nucleation layer (PNL) method and / or a CVD method. (In the example of FIG. 6, the tungsten layer 653 is conformally deposited within the feature hole 105, but note that in some other embodiments, tungsten nucleation on the lower layer 113 can be selectively suppressed prior to the selective deposition of the tungsten layer 653.) Subsequently, further deposition onto the tungsten layer 653 is selectively suppressed, and a suppressed portion 655 of the tungsten layer 653 is formed near the feature opening. Then, tungsten is selectively deposited by a PNL method and / or a CVD method according to a suppression profile such that tungsten is preferentially deposited near the bottom and middle of the feature. In some embodiments, deposition continues by one or more selective suppression cycles until the feature is filled. As described above, in some embodiments, by making the deposition time long enough, the suppression effect at the top of the feature can be overcome, while in some embodiments, if deposition at the feature opening is desired, additional nucleation layer deposition or other processing may be performed to reduce or remove passivation at the feature opening. Note that in some embodiments, feature filling may still include the formation of a seam, such as the seam 657 shown in FIG. 6. The sequence shown in the example of FIG. 6 may end with relatively small voids still present after CMP.

[0050] Figure 2 shows a schematic view of two features 202 and 204. Feature 202 has an inwardly concave shape, and feature 204 has a V-shaped form. Features 202 and 204 were formed using deposition only under ultra-low stress deposition conditions. At a low flow rate level of tungsten hexafluoride (WF6) and at a high temperature, voids 206 and 208 are generated as shown due to depletion of WF6 in the vicinity of the field. Attempts to address such voids 206 and 208 include suppression and the use of suppression precursor gases. One such technique is known as inhibition chemistry enhancement, or ICE.

[0051] Referring to Figure 3, a schematic view of a feature 302 during feature progression is shown. First, a conformal nucleation layer 304 is formed by a first deposition (dep1). As shown, a conformal suppression (or ICE) layer 306 is formed over an upper region 308 of the nucleation layer 304. A second deposition (or dep2) forms a non-conformal bulk layer 310 to obtain the completed feature 302 shown on the right. The suppression ICE layer 306 is intended to suppress the growth of the bulk layer 310 and keep the inlet (or constriction) 312 of the trench 316 open during filling (e.g., W filling). This effect can also be expressed as a differential ICE effect. Despite the differential effect of the suppression layer 306, voids 314 were still formed.

[0052] Selective suppression, also referred to as selective passivation, differential suppression, or differential passivation, involves suppressing subsequent tungsten nucleation in a portion of a feature while not suppressing (or reducing the degree of suppression of) nucleation in the remaining portion of the feature. For example, in some embodiments, the feature is selectively suppressed at the feature opening while nucleation inside the feature is not suppressed. Selective suppression can include, for example, selectively exposing a portion of the feature to activated species of a plasma. In certain embodiments, for example, the feature opening is selectively exposed to a plasma generated from molecular nitrogen gas. The desired suppression profile in the feature can be formed by appropriately selecting one or more of the suppression species, substrate bias power, plasma power, process pressure, exposure time, and other process parameters. Further aspects regarding the formation of the suppression profile and differential suppression are described in U.S. Patent Application No. 15 / 640,940, which is incorporated herein by reference.

[0053] As described above, when the flow rate level of tungsten hexafluoride (WF6) is low and the temperature is high, WF6 is depleted. In an environment where WF6 is depleted, typically a strong conformal ICE layer 306 is required that can withstand or suppress the rapid formation of the bulk layer 310 at its inlet 312, such that the inlet 312 remains open and can accept fill, enabling the trench 316 to be completely filled. However, in the example of FIG. 3, sufficient suppression (or a desired suppression profile) has not occurred. The illustrated inlet 312 is closed in an insufficient manner and voids 314 are formed, which is due to the fill not reaching the voids. It will be appreciated that such voids can have a significant adverse effect on device performance. Avoiding voids 314 can be particularly problematic in the formation of features having a very large aspect ratio and in the filling of deep trenches, vias, etc.

[0054] A desired suppression profile may be constructed based on several factors. The factors may include, among other things, the effect of a given suppression layer in delaying growth, the nature (e.g., conformality) or state (e.g., stress) of the underlying nucleation layer or deposition layer to which the suppression layer is applied, and the chamber processing conditions.

[0055] For example, referring to graph 400 of FIG. 4, two graph lines 402 and 404 representing the growth profiles of two films may be observed. The y-axis of graph 400 indicates the final stack height or thickness (THK) of the film in angstroms (A) during the deposition operation (e.g., during (dep2)). The x-axis indicates the corresponding CVD time in seconds during deposition. The slope (Δy / Δx) of line 402 or 404 may be regarded as representing the growth rate of the film (i.e., the thickness growth rate over time).

[0056] Line 402 represents the growth profile for an exemplary film formed by applying a thermal suppression layer (ICE) only to the nucleation layer (nuc). The exemplary line 402 may be mathematically represented as y = 29.815x - 2521.5 in graph 400. In contrast, line 404 represents the growth profile for an exemplary film formed by applying a thermal suppression layer (ICE) to the bulk layer (or, cool film (CF)). The exemplary line 404 may be mathematically represented as y = 29.134x - 2829.6 in graph 400.

[0057] It can be seen that the straight line 404 (i.e., representing the film growth profile) is "shifted" to the right (or at least appears so) in the graph 400 compared to the straight line 402. In fact, although the growth rate (gradient) of each film is substantially the same, the film formed in the situation of the straight line 404 took a longer time (there was a "delay") to reach the same height as the film of the straight line 402. In other words, for the same elapsed time on the x-axis, the thickness of the film of the line 404 lags behind the thickness of the film of the line 402. There was a delay or a "difference" in thickness. In the illustrated example, the "difference" may be represented as about 500 - 1000 Å. For example, when a plurality of suppression layers inside a feature face each other, the differential effect (or suppression profile) may increase or be enhanced accordingly. For example, the "difference" (or suppression profile) between two layers facing each other on both sides of a trench may be considered to be doubled (i.e., 1000 - 2000 Å or more) if each layer is subjected to the same suppression.

[0058] Thus, the suppression or "differential effect" of the suppression layer used in the examples of lines 402 and 404 differs in this example primarily based on the properties and type of the film (i.e., nucleation vs. bulk) to which the suppression layer is applied. Improved selective suppression conforming to the embodiments of the present disclosure may be used as appropriate to form high aspect ratio features and growth profiles. Some embodiments include maintaining free passage for the fill material within the feature during a fill operation and, in some embodiments, during complete void removal. Refer to FIG. 5 in this regard. FIG. 5 shows exemplary operations in an exemplary method of the present disclosure. Here, trench 502 is filled to form feature 504 in various phases shown in the figures of operations 506 - 510. First, a conformal nucleation layer 512 is formed on the inner surface of trench 502. Next, in operation 506, a non - conformal bulk layer 514 is formed on nucleation layer 512 in the upper region 516 of trench 502 as shown. The upper region 516 is adjacent to the open inlet of trench 502, which, as described above, may typically tend to close, thereby not allowing complete filling and causing voids to form within feature 504. The formation of the non - conformal bulk layer 514 may occur in the first non - conformal deposition phase (dep1, operation 506). A slight degree of overburden 518 may appear on the substrate field adjacent to the open inlet of trench 502. The non - conformal bulk layer 514 is applied on the nucleation layer 512 before applying the suppression layer.

[0059] In operation 508, as shown, a suppression layer 520 is applied on the non - conformal bulk layer 514 and on the inner surface of trench 502. In the example shown, the suppression layer 520 is applied to the non - conformal bulk layer 514 in the upper region 516 of the trench and to the nucleation layer 512 in the middle region 522 of the trench, but not to the nucleation layer 512 in the non - suppression required lower region 524 of trench 502.

[0060] As shown, the upper region 516 of the trench 502 corresponds to the outer surface boundary of the non-conformal bulk layer 514 sandwiched between the conformal nucleation layer 512 and the suppression layer 520. In the intermediate region 522, no non-conformal bulk layer 514 (or any layer) is formed, and the suppression layer 520 lies directly on the nucleation layer 512. As can be seen from FIG. 4 described above, the differential effect of the suppression layer on the bulk layer is strong, but the suppression effect of the suppression layer on the nucleation layer is relatively weak.

[0061] In operation 510, the trench is then filled in a subsequent deposition operation (e.g., non-conformal dep2). In the illustrated example, due to the strong suppression effect of the suppression layer 520 in the upper region 516 adjacent to the entrance of the trench, the entrance remains open. During (e.g.) dep2, in that region, the non-conformal bulk film grows slowly, but in the zone with weak suppression below the intermediate region 522, the film grows relatively fast. The growth of the film adjacent to the entrance is "delayed" in the manner further described above. The differential suppression (or growth profile) enables the fill to reach the bottom of the trench 502 and form a substantially void-free integral feature 504. Thus, in at least some examples, selective formation of the first non-conformal bulk layer inside the feature before the suppression layer is applied enhances the suppression or differential effect within the feature and can provide void-free filling.

[0062] Accordingly, in some embodiments, the method may include providing a substrate including one or more feature openings and a feature having an interior, forming a nucleation layer on the surface inside the feature, selectively forming a non-conformal bulk layer on the surface of the nucleation layer based on a differential suppression profile to have regions of the nucleation layer covered by the non-conformal bulk layer and regions of the nucleation layer not covered, selectively forming a suppression layer on the covered and non-covered regions of the nucleation layer, and selectively depositing tungsten on the feature according to the differential suppression profile.

[0063] While the embodiments have been described with reference to specific exemplary embodiments, it will be apparent that various changes and modifications may be made to these embodiments without departing from the broader scope of the disclosure and the claims of the present invention. Accordingly, the specification and drawings are intended to be regarded as illustrative rather than limiting in nature. The accompanying drawings, which form a part of this specification, illustrate specific embodiments in which the subject matter may be practiced, by way of example and not of limitation. The embodiments shown are described in sufficient detail to enable those skilled in the art to practice the teachings disclosed herein. Other embodiments may be utilized and derived therefrom without departing from the scope of the disclosure, such that structural and logical substitutions and changes may be made. Accordingly, this "Mode for Carrying Out the Invention" should not be construed in a limiting sense, and the scope of the various embodiments is defined only by the appended patent claims and the full scope of equivalents to which such patent claims are entitled.

[0064] Such embodiments of the subject matter of the present invention may, in this specification, for convenience only, be referred to individually and / or collectively by the term "invention," and when one or more inventions or inventive concepts are disclosed, it is not intended to voluntarily limit the scope of the present application to any single invention or inventive concept. Accordingly, while specific embodiments have been illustrated and described herein, it should be understood that any configuration contemplated for achieving the same purpose may be used in place of the specific embodiments shown. The present disclosure is intended to cover any and all adaptations or variations of the various embodiments. Combinations of the above embodiments, and other embodiments not specifically described herein, will be apparent to those skilled in the art upon review of the above specification. The present disclosure includes the following application examples. [Application Example 1] A method for selective suppression control in substrate processing, providing a substrate including one or more feature openings and a feature having an interior of the feature, forming a nucleation layer on a surface within the feature, selectively forming a non-conformal bulk layer on a surface of the nucleation layer based on a differential suppression profile to create a region of the nucleation layer covered by the non-conformal bulk layer and a region of the nucleation layer not covered, selectively forming a suppression layer on the covered and non-covered regions of the nucleation layer, selectively depositing tungsten within the feature according to the differential suppression profile. A method including these steps. [Application Example 2] The method according to Application Example 1, wherein the nucleation layer formed on the surface within the feature is a conformal nucleation layer. [Application Example 3] The method according to Application Example 2, wherein the covered region of the nucleation layer includes an upper region within the feature. [Application Example 4] The method according to Application Example 3, wherein the upper region within the feature corresponds to a boundary of an outer surface of the non-conformal bulk layer formed between the conformal nucleation layer and the suppression layer. [Application Example 5] The method according to Application Example 1, wherein the covered region of the nucleation layer is adjacent to an open entrance of the feature. [Application Example 6] The method according to Application Example 1, wherein selectively forming the non-conformal bulk layer on the surface of the nucleation layer includes applying the bulk layer to the nucleation layer before applying the suppression layer to the covered or non-covered region of the nucleation layer. [Application Example 7] The method according to Application Example 1, further including forming the suppression layer on the bulk layer in an upper region within the feature and forming the suppression layer on the covered region of the nucleation layer in an intermediate region within the feature. [Application Example 8] The method according to Application Example 7, further comprising not forming a suppression layer in the unnecessary lower region inside the feature. [Application Example 9] The method according to Application Example 7, further comprising not forming the non-conformal bulk layer in the intermediate region such that the suppression layer lies directly on the nucleation layer in the intermediate region. [Application Example 10] The method according to Application Example 1, wherein the differential effect of the suppression layer on the non-conformal bulk layer is relatively strong, and the differential effect of the suppression layer on the nucleation layer is relatively weak. [Application Example 11] A system including a memory and at least one processor, wherein the processor is configured to perform and control operations in a method for selective suppression control in substrate processing according to instructions in the memory, the substrate including features having one or more feature openings and an interior of the feature, and the operations including at least forming a nucleation layer on a surface inside the feature, selectively forming a non-conformal bulk layer on the surface of the nucleation layer based on a differential suppression profile to provide a region of the nucleation layer covered by the non-conformal bulk layer and a region of the nucleation layer not covered, selectively forming a suppression layer on the covered and non-covered regions of the nucleation layer, and selectively depositing tungsten in the feature according to the differential suppression profile. [Application Example 12] The system according to Application Example 11, wherein the nucleation layer formed on the surface inside the feature is a conformal nucleation layer. [Application Example 13] The system according to Application Example 12, wherein the covered region of the nucleation layer includes an upper region inside the feature. [Application Example 14] The system according to Application Example 13, wherein the upper region inside the feature corresponds to a boundary of an outer surface of the non-conformal bulk layer formed between the conformal nucleation layer and the suppression layer. [Application Example 15] The system according to Application Example 11, wherein the covered region of the nucleation layer is adjacent to an open inlet of the feature. [Application Example 16] The system according to Application Example 11, wherein selectively forming the non-conformal bulk layer on the surface of the nucleation layer includes applying the bulk layer to the nucleation layer before applying the suppression layer to the covered or uncovered area of the nucleation layer. [Application Example 17] The system according to Application Example 11, wherein the operation further includes forming the suppression layer on the bulk layer in the upper region inside the feature and forming the suppression layer in the covered area of the nucleation layer in the middle region inside the feature. [Application Example 18] The system according to Application Example 17, further including not forming a suppression layer in the lower region inside the feature where suppression is not required. [Application Example 19] The system according to Application Example 17, further including not forming the non-conformal bulk layer in the middle region such that the suppression layer lies directly on the nucleation layer in the middle region. [Application Example 20] The system according to Application Example 11, wherein the differential effect of the suppression layer on the non-conformal bulk layer is relatively strong. The differential effect of the suppression layer on the nucleation layer is relatively weak.

Claims

Claim 1 A method for selective suppression control in substrate processing, comprising: providing a substrate including one or more features having feature openings and an interior of the feature; forming a nucleation layer on a surface within the feature; depositing a non-conformal bulk layer on a surface of the nucleation layer to provide a region of the nucleation layer covered by the non-conformal bulk layer and a region of the nucleation layer not covered, wherein the covered region of the nucleation layer includes an upper region within the feature and the covered region of the nucleation layer does not include a lower region within the feature that is located below the upper region; selectively forming a suppression layer on a surface of the non-conformal bulk layer in an upper region within the feature and on a surface of the nucleation layer in an intermediate region within the feature, and not forming a suppression layer in a lower region within the feature; selectively depositing tungsten within the feature according to a differential suppression profile. Claim 2 The method of claim 1, wherein the nucleation layer formed on the surface within the feature is a conformal nucleation layer. Claim 3 The method of claim 2, wherein the upper region within the feature corresponds to a boundary of an outer surface of the non-conformal bulk layer formed between the conformal nucleation layer and the suppression layer. Claim 4 The method of claim 1, wherein the covered region of the nucleation layer is adjacent to the feature opening. Claim 5 The method of claim 1, further comprising not forming the non-conformal bulk layer in the intermediate region such that the suppression layer lies directly on the nucleation layer in the intermediate region. Claim 6 The method of claim 1, wherein the differential effect of the suppression layer on the non-conformal bulk layer is relatively strong, and the differential effect of the suppression layer on the nucleation layer is relatively weak. Claim 7 A system including a memory and at least one processor, wherein the processor is configured to perform and control operations in a method for selective suppression control in substrate processing by instructions in the memory, the substrate includes features having one or more feature openings and an interior of the feature, and the operations at least include forming a nucleation layer on a surface inside the feature; depositing a non-conformal bulk layer on a surface of the nucleation layer to form an area of the nucleation layer covered by the non-conformal bulk layer and an area of the nucleation layer not covered, wherein the covered area of the nucleation layer includes an upper area inside the feature, and the covered area of the nucleation layer does not include a lower area inside the feature that is located below the upper area; selectively forming a suppression layer on a surface of the non-conformal bulk layer in an upper area inside the feature and on a surface of the nucleation layer in an intermediate area inside the feature, and not forming a suppression layer in a lower area inside the feature; selectively depositing tungsten in the feature according to a differential suppression profile.

8. The system according to claim 7, wherein the nucleation layer formed on the surface inside the feature is a conformal nucleation layer.

9. The system according to claim 8, wherein the upper area inside the feature corresponds to a boundary of an outer surface of the non-conformal bulk layer formed between the conformal nucleation layer and the suppression layer.

10. The system according to claim 7, wherein the covered area of the nucleation layer is adjacent to the feature opening.

11. The system according to claim 7, further including not forming the non-conformal bulk layer in the intermediate area such that the suppression layer directly lies on the nucleation layer in the intermediate area.

12. The system according to claim 7, wherein the differential effect of the suppression layer on the non-conformal bulk layer is relatively strong, and the differential effect of the suppression layer on the nucleation layer is relatively weak.

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