System and method for forming metal hard masks in device manufacturing

Abstract

To provide a method of formation of a hard mask.SOLUTION: A method includes performing a first plasma-enhanced surface treatment in a chamber prior to disposal of a substrate, then, subsequently, depositing a season material in the process chamber. After depositing the plurality of season materials in the process chamber, a substrate is disposed in the chamber. The substrate is positioned in the process chamber in contact with the season material. A substrate treatment is performed. The substrate treatment can include one or more of: performing a second plasma-enhanced surface treatment, forming a barrier layer on the substrate, or performing a low frequency RF treatment prior to forming a metal-based hard mask film on the substrate. The metal-based hard mask film includes one or more metals.SELECTED DRAWING: Figure 2

Description

TECHNICAL FIELD

[0001]

[0001] Embodiments of the present disclosure generally relate to the fabrication of integrated circuits (ICs) used in semiconductor technology for both memory applications and logic applications. The fabrication of these ICs can include photolithography as well as a transfer process that transfers the fabricated pattern to a substrate. This transfer process can employ a masking film.

BACKGROUND ART

[0002]

[0002] Semiconductor devices include film stacks in which high aspect ratio features are formed. High aspect ratio features can be formed in various processes. Some high aspect ratio features can be formed using hard mask films to form features within the film stack during processing of advanced logic and memory components. The hard mask film can include various metallic materials, non-metallic materials, or combinations of materials, depending on the type of device being manufactured. Hard mask films are designed to withstand long etching processes without degradation. Hard mask films further exhibit higher mechanical strength and lower stress compared to other masking materials. However, conventional hard masks suffer from peeling issues during processing. Peeling of the hard mask can negatively impact device manufacturing, including etching and downstream processes.

[0003]

[0003] Accordingly, there is a need for improved hard masks and methods of forming hard masks.

SUMMARY OF THE INVENTION

[0004]

[0004] The disclosure generally relates to systems and methods for manufacturing devices using a metal-based hard mask, including the configuration and preparation of a system used to manufacture the device. In one example, a method for forming a hard mask includes performing a first plasma surface treatment in a process chamber, after which a seasoning material is deposited on a plurality of exposed surfaces in the process chamber. Furthermore, in this example, after the seasoning material has been deposited on the plurality of exposed surfaces in the process chamber, a substrate is placed in the process chamber and the substrate is in contact with the seasoning material. At least one process is performed on the substrate, and at least one process includes performing a second plasma surface treatment, forming a barrier layer on the substrate, or performing a low-frequency RF treatment. After performing at least one process, a metal hard mask film is formed on the substrate.

[0005]

[0005] In another example, the substrate manufacturing method includes cleaning a process chamber and then performing a first plasma surface treatment in the process chamber. After performing the first plasma surface treatment, a seasoning material is deposited on a plurality of exposed surfaces of the process chamber, the seasoning material comprising at least two of silicon oxide, silicon nitride, amorphous silicon, or a combination thereof, and a substrate is placed in the process chamber in contact with the seasoning material to form a metal hard mask film on the substrate.

[0006]

[0006] In one example, the device includes a silicon substrate, a plurality of alternating SiN-SiO2 layers arranged on the silicon substrate to form a laminate, a barrier layer formed on the laminate, and a hard mask layer formed on the barrier layer.

[0007]

[0007] To allow for a more detailed understanding of the above-mentioned features of the Disclosure, a more specific description of the Disclosure, which has been briefly summarized above, can be given by reference to embodiments, some of which are shown in the accompanying drawings. However, it should be noted that the accompanying drawings show only exemplary embodiments and therefore should not be considered limiting in scope, as the Disclosure may allow for other equally valid embodiments. [Brief explanation of the drawing]

[0008] [Figure 1] This is a flowchart of a substrate manufacturing method according to an embodiment of the present disclosure. [Figure 2] This is a partial cross-sectional view of a process chamber in which a barrier layer and a metal-based hard mask film are formed according to an embodiment of the present disclosure. [Figure 3A] This is a partial schematic diagram of a shower head according to an embodiment of the present disclosure. [Figure 3B] This is a partial schematic diagram of a shower head according to an embodiment of the present disclosure. [Figure 4] This is a comparison of two defect scanning images of the front surface of a substrate fabricated as discussed herein using a tungsten hard mask film.

[0009] For ease of understanding, identical elements common to the drawings are indicated with the same reference numeral where possible. It is intended that elements and features of one embodiment may be usefully incorporated into other embodiments without further enumeration.

[0010]

[0012] Integrated circuit (IC) manufacturers are advancing semiconductor technologies to reduce the critical dimension (CD) size during processing for both logic and memory device applications, in order to achieve higher capacity and lower costs per device. Non-collapse, highly etching-selective hard masks, such as those discussed herein, are used to transfer patterns from photolithography to the underlying substrate in order to manufacture devices with increasingly smaller critical dimensions.

[0011]

[0013] Embodiments of the systems and methods of this disclosure relate to the formation (deposition) of defect-free metal-based hard masks on a wide variety of substrate types and substrate shapes. In one embodiment, “defect-free” can mean that there are fewer than a predetermined number ("X") of defects of a predetermined diameter (e.g., particulate contaminants) that are acceptable to be present in or on a semiconductor film of a predetermined thickness. In one example, fewer than 10 defects larger than 32 nm may be present in a semiconductor film approximately 200 Å thick on a substrate with a diameter of 200 mm or 300 mm. In another example, fewer than 30 defects larger than 90 nm may be present in a film with a thickness of 5 kÅ.

[0012]

[0014] A substrate discussed herein, on which a metal-based hard mask film is formed, may include a device substrate placed in a process chamber for a process including film formation and patterning. A substrate discussed herein, on which a metal-based hard mask film (or hard mask material) is formed, may further include a process chamber surface and components, including a showerhead, a blocker plate, and other components contained within the process chamber.

[0013]

[0015] The films currently used for hard masking can have various challenges, including poor substrate adhesion, lack or inefficiency of a barrier layer, and undesirable in-film defects, including back-side defects. Conventional metal-containing hard mask films used in logic and memory applications (which may be thicker than those used in logic applications) exhibit poor adhesion, for example, unusable or undesirable, on substrates including silicon oxide, silicon nitride, polysilicon, and amorphous silicon. Poor adhesion may result from the diffusion of fluorine (F) radicals (generated from WF6, a commonly used tungsten precursor) through the hard mask film toward the hard mask-substrate interface. When the hard mask-substrate interface becomes saturated with F radicals, the saturated interface causes the hard mask film to delaminate from the underlying substrate, thus reducing adhesion.

[0014]

[0016] Unlike conventional applications, the hard mask films discussed herein are used in conjunction with a barrier layer. The barrier layer, which may also be referred to herein as an initiation layer, is formed on the substrate before hard mask deposition to prevent fluorine diffusion. The barrier layer further facilitates sufficient adhesion of the metal hard mask film, including the tungsten hard mask film, to the desired substrate. In one example, the hard mask film discussed herein can be formed as a single layer. In another example, the hard mask film discussed herein can be formed as two or more layers. In one example, the hard mask film can be formed on a device substrate and / or on process chamber components in a series of sub-steps.

[0015]

[0017] Furthermore, the barrier layer discussed herein acts as a seed layer to provide sufficient nucleation sites for subsequent bulk amorphous metal-based hard mask ("metal hard mask") film deposition. The barrier layer promotes both the uniform composition and morphology of the metal-based hard mask film, such as a tungsten hard mask film, along (through) the depth of the hard mask film. The barrier layer discussed herein exhibits etching behavior similar to that of a bulk tungsten hard mask film. Similar etching behavior prevents problems such as profile broadening during etching and hard mask residue left after etching. Similar etching behavior can also mitigate other challenges presented by barrier layers of materials that do not behave as similarly to the bulk metal hard mask film used in various embodiments of this disclosure.

[0016]

[0018] The metal-based hard masks discussed herein can be deposited using plasma deposition methods and modified gas flow distribution schemes. Using the systems and methods discussed herein, metal-based hard mask films with a wide range of dopant concentrations (e.g., 10% to 80%) can be formed. The hard mask films discussed herein may include one or more metals or combinations and alloys of metals, such as tungsten (W), cobalt (Co), titanium (Ti), molybdenum (Mo), yttrium (Y), zirconium (Zr), or other metals. The metal-based hard mask films can be formed to contain dopants such as boron, carbon, nitrogen, and silicon, and are deposited on substrates (e.g., oxides, nitrides, amorphous silicon, oxide-nitride laminates, titanium nitride, silicon, polysilicon, etc.).

[0017]

[0019] Metal-based hard mask films manufactured according to embodiments of this disclosure exhibit viable adhesion and are defect-free or substantially defect-free on both the front and back surfaces of the substrate. In various examples, the dopant content may be 10 to 80% by weight of the total weight of the metal hard mask film. In some embodiments, the substrate on which the metal hard mask film is formed includes a Si-based laminate, which may range, for example, from 32 to 256 layers, and includes alternating layers of silicon oxide (SiOx) and silicon nitride (SiNx). The laminate is manufactured to be patterned by a method including etching. These patterns can be formed using masks, including the metal-based hard masks discussed herein. Thus, the metal-based hard masks discussed herein are formed to withstand etching of thicker stacks (e.g., 96 or more silicon oxide / silicon nitride layers) than conventional masks. The metal-based hard masks discussed herein have a reduced possibility and severity of delamination from the surface of the stack. Hard mask delamination can result in substrate defects, undercuts during etching, and / or insufficient or inconsistent etching selectivity between layers of the stack.

[0018]

[0020] Returning to the barrier layer, to suit next-generation node applications, the barrier layer is selected to exhibit thermal and mechanical properties and stoichiometric composition similar to the bulk hard mask material (e.g., tungsten hard mask). The similarity in properties and stoichiometric composition can prevent profile broadening during subsequent etching processes, prevent unexpected hard mask residues, and improve device yield. Similarly, films formed according to embodiments of this disclosure can be used for future generations of applications due to their viable in-film defect (inclusion) performance. The in-film defect performance of the hard mask films discussed herein facilitates the prevention of misaligned profiles during hard mask open etching processes, and therefore mitigates misalignment of subsequent etching profiles, increasing device yield.

[0019]

[0021] During substrate processing, materials used to form metal hard mask films, such as tungsten hard mask films, can accumulate on the upper electrode surface ("showerhead surface") within the process chamber. Poor adhesion of the deposited metal hard mask film during the plasma processing step within the process chamber can result in flaking or peeling of the metal hard mask film from the upper electrode. Conventional metal hard mask films may flak or peel on the substrate, or appear as in-film particle defects within the layers on the processing substrate, potentially interfering with etching or other subsequent processes performed on the substrate. Various methods, either alone or in combination, can be used to form metal-based hard mask films using the systems and methods discussed herein. Silicon substrates with more than 96 layers can be successfully etched while mitigating flaking of the metal-based hard mask material.

[0020]

[0022] The systems and methods described herein may include the following steps: (1) cleaning the chamber before placing a substrate in the chamber using a blocker plate designed to distribute the gas more evenly; (2) performing a plasma treatment of the chamber surface before placing a substrate in the chamber, using, for example, ionized / radicalized nitrogen oxides (e.g., N2O) and ionized / radicalized oxygen and / or helium; (3) performing plasma deposition of a season material, such as a silicon-rich material, in the chamber before placing a substrate in the chamber; (4) performing a hydrogen and / or nitrogen plasma surface treatment after placing a substrate in the chamber; (5) forming a barrier layer, such as a tungsten nitride barrier layer, while the substrate is in the chamber, by performing a cycle that includes, or does not include, process gas ramping, in contrast to maintaining a constant gas flow in the chamber during plasma treatment after precursor soaking, while the substrate is in the chamber, and / or (6) applying low-frequency RF while the substrate is in the chamber and process gas ramping is being used. The above describes one example, but other examples are possible. For example, step (3) can be performed before step (2). In one embodiment, one or more gases used in (1) may include argon, NF3, or oxygen.

[0021]

[0023] Using the systems and methods discussed herein, at least one layer of seasoning (showerhead surface conditioning) material can be used in conjunction with a barrier layer. The barrier layer, which also functions as a seed layer on the showerhead, can provide a fixed site for the deposited metal hard mask material. Furthermore, fluorine diffusion to the showerhead surface that would cause the tungsten hard mask and / or seasoning material to peel off is prevented / suppressed by the barrier layer. In some embodiments, at least silicon oxide and silicon nitride are used in various predetermined ratios to facilitate the protection of the chamber components during seasoning of the chamber, and therefore the showerhead, before the substrate is placed in the chamber. Silicon, oxygen, and nitrogen precursors are utilized to form silicon oxide and / or silicon nitride. The precursors are ionized and / or radicalized using RF power to enhance the adhesion of silicon oxide and silicon nitride to the showerhead, which is a major factor in the AlFx formation described later. The silicon dioxide:silicon nitride percentage ratio used can include 100:0, 90:10, 80:20, 70:30, 60:40, 50:50, or other ratios up to 10:90.

[0022]

[0024] A further challenge to the manufacture and use of metal hard masks is the occurrence of back-side defects that can be caused by aluminum contamination. For example, during the plasma / NF3 cleaning process, the aluminum-containing substrate support or heater surface is partially converted to AlFx. In some cases, the AlFx is carried to the back surface of the substrate, thus causing undesirable aluminum contamination on the back surface of the substrate. Furthermore, the formed AlFx sublimes and deposits on low-temperature chamber inner surfaces such as the showerhead surface.

[0023]

[0025] In contrast to conventional approaches, a layer of seasoning material is deposited on the heater surface immediately after the plasma / NF3 cleaning process. Aluminum diffusion from the heater surface to the substrate backside is blocked by the seasoning layer, eliminating or reducing aluminum backside contamination on the substrate. The seasoning layer can also suppress the sublimation of AlFx onto the showerhead surface, which contributes to reduced adhesion of subsequent layers on the showerhead. Furthermore, the use of silicon oxide and silicon nitride reduces scratches on the backside of the substrate due to the relative softness of the silicon oxide and silicon nitride layers.

[0024]

[0026] Accordingly, using the systems and methods herein, the adhesion of a hard mask film, which may be a tungsten hard mask film, is improved by (1) surface treatment, (2) seasoning material deposition, and (3) barrier / seed layer deposition. In one example, the surface treatment applied to the showerhead removes AlFx residues to enhance the adhesion of the seasoning material. The surface treatment further improves the nucleation of the metal hard mask film on the barrier / seed layer. The seasoning material exhibits low hardness, adheres well to the showerhead surface (to enable further processing), and provides anchoring sites for metal hard mask film deposition on the showerhead and other surfaces having a barrier layer disposed thereon. The desired "low" hardness of the seasoning material discussed herein may be defined herein as a hardness that is less than 50% of the hardness of the substrate so as not to scratch the substrate. In another example, the hardness of the seasoning material is less than 33% of the hardness of the substrate, or less than 25% of the hardness of the substrate. Turning to the barrier layer, in one example, the barrier layer comprises properties and stoichiometric composition similar to the bulk metal hard mask material, including similar behavior during etching processes.

[0025]

[0027] Figure 1 is a flowchart of a substrate manufacturing method 100 according to an embodiment of the present disclosure. In some examples, at step 102, the process chamber is cleaned using, for example, one or more gases containing chlorine. In one example, step 102 is performed before placing a substrate or a batch of substrates into the process chamber. Following the chamber cleaning in step 102, a first plasma surface treatment is performed in the process chamber in step 104. This treatment in step 104 may include nitrogen oxides (e.g., N₂O) and / or a mixture of oxygen and helium gas. A radio frequency (RF) current (e.g., ~13.56 MHz) can be applied to ionize or radicalize the mixture of nitrogen oxides and / or oxygen and helium gas to form a radio frequency plasma. In other embodiments, in step 104, one or more gases such as nitrogen oxides, nitrogen (e.g., N₂), oxygen (e.g., O₂), helium, ammonia (NH₃), diborane (B₂H₆), or propene (C₃H₆) can be used alone or in various combinations with one or more of the aforementioned gases to generate a radio frequency RF plasma.

[0026]

[0028] During the first plasma treatment in step 104, AlFx residue on the surface of the showerhead in the process chamber is converted to aluminum oxide (AlOx). Following the first plasma treatment in step 104, in step 106, with no substrate in the process chamber, one or more layers of seasoning material are deposited on the exposed surfaces inside the process chamber. The one or more layers of seasoning material deposited in step 106 may include silicon oxide, silicon nitride, amorphous silicon (a-Si), one or more alternating layers of silicon oxide and silicon nitride, one or more alternating layers of silicon oxide and amorphous silicon, one or more alternating layers of silicon nitride and amorphous silicon, etc. The exposed surfaces may include the showerhead surface, the substrate support surface, the chamber bottom, and / or the chamber sidewalls. The conversion of AlFx residue to aluminum oxide increases the adhesion of the subsequently deposited seasoning material on the process chamber surface and the showerhead. The season layer deposited in step 106 adheres closely to the showerhead, providing a fixed surface for subsequent hard mask material deposition in step 112, described later. The season layer positioned in step 106 can be less than 50 angstroms, less than 30 angstroms in some examples, or about 20 angstroms or less, to prevent the diffusion of fluorine radicals onto the showerhead when fluorine is subsequently introduced into the process chamber and the showerhead is exposed to it. As described above, the diffusion of fluorine radicals can lead to a reaction between fluorine and the aluminum showerhead, forming AlFx, which can result in delamination or flaking of the material from the showerhead and cause defects on the front surface of the substrate.

[0027]

[0029] The seasoning materials discussed herein are soft in terms of hardness. In one example, the seasoning material discussed herein has a hardness of less than 50% of the hardness of the substrate. In another example, the seasoning material discussed herein has a hardness of less than one-third of the hardness of the substrate. The hardness of the seasoning material compared to the hardness of the substrate contributes to reducing backside scratches on the substrate when the substrate is in contact with it. If a material with a higher hardness (for example, one closer to the hardness of the substrate than the material discussed herein as the seasoning material used in step 106) is used, backside scratches may occur during the subsequent lithography process. The seasoning material deposited in step 106 can further act to suppress the diffusion of AlFx from the substrate support surface to the backside of the substrate, which results in aluminum contamination of the substrate. In step 108, a substrate or batch of substrates is placed in a process chamber, and one or more processing steps, such as deposition, etching, annealing, and lithography, may be performed before the pre-hard masking in substrate processing step 110.

[0028]

[0030] In substrate processing step 110, one or more substrate processing sub-steps can be performed to form a barrier layer. As discussed herein, the formation of the barrier layer facilitates and promotes the formation of a metal hard mask film in step 118 (discussed below). The hard mask film discussed herein can withstand etching and further processing by improving the adhesion of the hard mask film to the substrate through the barrier layer. In one embodiment, in the first sub-step 112 of substrate processing step 110, the initial hydrogen and nitrogen plasma surface treatment is applied to the season layer. One or more sub-steps that can be performed in substrate processing step 110 can be optionally performed alone or in combination, as described below. In some examples, one or more sub-steps in substrate processing step 110 are performed sequentially.

[0029]

[0031] During the hydrogen and nitrogen surface treatment in the first sub-step 112 of the substrate processing step 110, hydrogen (H) bombardment generates surface Si-H bonds. These Si-H bonds function as nucleation sites on the barrier layer for subsequent barrier layer deposition (in sub-steps 114A and 114B) and / or for the hard mask layer in step 118 (described later). Metal precursors such as WF6 interact with these nucleation sites to promote film formation. If 110 is performed as a periodic process, such that the hydrogen and nitrogen treatment occurs on a tungsten-containing layer, the hydrogen bombardment (after sub-steps 114A and 114B) further generates nitrogen vacancies in the treated film, trapping fluorine radicals during metal hard mask deposition or subsequent barrier layer deposition. In examples where the metal hard mask and / or barrier layer contains tungsten, the hydrogen bombardment further increases the hydride content of the tungsten layer when the tungsten layer is converted to a tungsten nitride layer. The tungsten nitride layer acts as a barrier layer for the tungsten hard mask film, or other metal-based hard mask films discussed herein, improving adhesion and nucleation.

[0030]

[0032] In another embodiment, which can be combined with other examples and embodiments herein, a precursor such as WF6 is introduced in a second sub-step 114A of the substrate processing step 110 and adsorbed onto the substrate surface in a (quasi)monolayer. Subsequently, plasma hydrogen and nitrogen surface treatment can be performed in a third sub-step 114B of the substrate processing step 110. The third sub-step 114B exposes the substrate to hydrogen and nitrogen plasma to reduce WF6 to tungsten (W). Furthermore, in the third sub-step 114B, the tungsten layer is converted to tungsten nitride. In one example, which can be combined with other examples herein, the first sub-step 112 can be combined with the second sub-step 114A and the third sub-step 114B.

[0031]

[0033] In the substrate processing step 110, the use of the initial hydrogen and nitrogen surface treatment in the first sub-step 112 eliminates the conventional use of boron (B) or silicon (Si) precursors to form a tungsten layer on the substrate. The use of boron or silicon-containing precursors in conventional processes can cause process flow / device manufacturing problems due to boron or silicon contamination of the material placed on the substrate.

[0032]

[0034] The thickness of the tungsten nitride (WN) layer formed during the substrate processing step 110 can be controlled by adjusting the number of process cycles. A single cycle of the second sub-step 114A and the third sub-step 114B can be repeated multiple times during the substrate processing step 110 until a barrier layer having a thickness within a predetermined range is formed. In one embodiment, multiple nucleation sites are formed on the substrate for tungsten nucleation in order to form a metal-based barrier layer using tungsten in the second sub-step 114A and the third sub-step 114B. In conventional processes, a boron or silicon precursor can be adsorbed onto the substrate surface and then chemically react with tungsten to nucleate tungsten on the substrate. However, this can result in the formation of boron or silicon residues from unreacted precursors. The formation of boron or silicon residues can interfere with the formation of hard mask films and may hinder downstream processes. By using H2 / N2 treatment in the first sub-step 112 of the substrate processing step 110, surface dangling bonds are formed that act as tungsten nucleation sites. In this example, the use of boron or silicon precursors is excluded.

[0033]

[0035] In one example, the cycles of the second sub-step 114A and the third sub-step 114B can form a barrier layer with a thickness of approximately 2 Å to 4 Å. Controlling the barrier layer thickness by the periodic process improves the tunability of the barrier layer properties, in contrast to bulk deposition methods which can be adapted to deposit thicker film layers (e.g., 20 angstroms to 40 angstroms or more). The periodic deposition process used in the second sub-step 114A and the third sub-step 114B can be used alone or in combination with the first sub-step 112 of the substrate processing step 110. In another example, the periodic deposition process used in the second sub-step 114A and the third sub-step 114B can be used alone or in combination with the fourth sub-step 116 of the substrate processing step 110. In this example, the periodic deposition process is independent of the plasma distribution. Rather, one or more parameters of the soaking in the second sub-step 114A of the substrate processing step 110, such as duration, type of precursor, and concentration of precursor, enable angstrom-level control of barrier layer formation. The tunability and control of barrier layer formation allows for consistency in layering, such as hard masks discussed herein, across the entire substrate, independently of the plasma distribution in the process chamber.

[0034]

[0036] In one example, the barrier layer formed by one or more cycles of the second sub-step 114A and the third sub-step 114B can be formed to a thickness of about 5 Å to about 50 Å. In another example, the barrier layer formed by one or more cycles of the second sub-step 114A and the third sub-step 114B can be formed to a thickness of about 15 Å to about 25 Å. In yet another example, the barrier layer formed by one or more cycles of the second sub-step 114A and the third sub-step 114B can have a target thickness of 20 Å. In some embodiments, one or more cycles of the second sub-step 114A and the third sub-step 114B are performed in a high-frequency (RF) environment of about 13.56 MHz or higher.

[0035]

[0037] In some embodiments, gas ramping can be used in one or both of the second sub-step 114A and the third sub-step 114B in the substrate processing step 110. Gas ramping is defined herein as adjusting the flow rate of one or more precursor gases into the process chamber so that the gas flow rate varies over a predetermined gas flow rate range. Depending on the embodiment, the gas flow can be ramped up (increased) and / or ramped down (decreased) during one or both of the second sub-step 114A and the third sub-step 114B in the substrate processing step 110. In contrast to the instantaneous gas flow that has been conventionally used, the gas ramping discussed herein can be configured so that it takes 5 to 30 seconds to achieve the target gas flow rate. During instantaneous gas flow, the start of the gas flow in processing causes the target flow rate or range to be reached as soon as the gas flow is started. This relatively slow ramping according to the embodiments herein can promote and enable increased, and therefore sufficient time for barrier layer nucleation, in contrast to conventional methods. In one example, gas ramping can increase the WF6 flow rate from 0 sccm to 85 sccm within 5 seconds using a ramping rate of 17 sccm / s. In some embodiments, gas ramping is performed in conjunction with the preceding plasma hydrogen-nitrogen surface treatment in a first sub-step 112 of the substrate processing step 110. In this example, the barrier layer formed during the substrate processing step 110 facilitates sufficient adhesion of the hard mask to the different substrates, which would have been reduced in the absence of the barrier layer. The barrier layer deposited during the ramping step exhibits the same composition and / or properties as the hard mask film subsequently formed thereon. The similarity in behavior between the barrier layer and the bulk hard mask film prevents or reduces the exacerbation of problems such as profile broadening after the etching process, or the presence of hard mask residue, or other challenges in hard mask formation discussed herein.

[0036]

[0038] Optionally, a fourth sub-step 116 can be utilized. In the fourth sub-step 116 of the substrate processing step 110, low-frequency RF processing can be used while a plasma formed from nitrogen and / or hydrogen is present in the process chamber. This low-frequency RF processing can be performed at frequencies below 13.56 MHz, e.g., 2 MHz, 350 kHz, or other frequencies appropriate for various embodiments. This can accommodate the application of bias to the substrate support from 200 W to 300 W, compared to high-frequency RF processing which can occur at about 600 W or more. The low-frequency RF processing in the fourth sub-step 116 of the substrate processing step 110 can be used together with the first sub-step 112 or independently. In another example, which can be combined with other examples herein, the fourth sub-step 116 can be performed in addition to the second sub-step 114A and the third sub-step 114B in the substrate processing step 110.

[0037]

[0039] In step 118, a metal hard mask film is formed on the barrier layer. The metal hard mask film is formed to a thickness of, for example, about 0.2 microns to about 2.0 microns. In one example, the metal hard mask film formed in step 118 has a dopant concentration of about 10% to about 80%. One or more dopants contained in the metal hard mask film may include boron, carbon, nitrogen, or silicon. The hard mask film formed in step 118 may contain one or more metals, or combinations and alloys of metals, such as tungsten (W), cobalt (Co), titanium (Ti), molybdenum (Mo), yttrium (Y), zirconium (Zr), or other metals.

[0038]

[0040] As discussed herein, systems used to manufacture film laminates and metal-based hard mask films can be configured in various operating states to execute processes and subprocesses via a controller. The controller transmits programming information to various elements within the system, such as heater elements, pressure elements, gas flow elements, and / or substrate handling elements.

[0039]

[0041] Figure 2 is a cross-sectional view of a process chamber 200 on which a barrier layer and a metal-based hard mask film are formed according to embodiments of the present disclosure. The process chamber 200 includes a shower head 202 positioned parallel to the substrate support assembly 214 and at a distance 216 from the substrate support assembly 214. In one embodiment, the substrate support assembly 214 may include a heater and / or other components, some of which are described below. The substrate support assembly 214 is in contact with a first AlFx residue layer 204A. The shower head 202 is in contact with a second AlFx residue layer 204B. The season layers discussed herein may be formed as a first season layer 206A on the first AlFx residue layer 204A and a second season layer 206B on the second AlFx residue layer 204B.

[0040]

[0042] The substrate 210 is placed on the first season layer 206A, in direct contact with the first season layer 206A. A first barrier layer 208A is formed on the first surface 218 of the substrate 210. A second barrier layer 208B is formed on the second season layer 206B. A first metal hard mask film 212A is formed on the first barrier layer 208A. A metal hard mask material 212B is also formed on the second barrier layer 208B. Various layer thicknesses are shown in Figure 2, but this is done for the sake of clarity and does not limit the thickness of the components shown or their relative thicknesses.

[0041]

[0043] Figure 2 shows one embodiment, but other embodiments are also possible. For example, in another embodiment, the substrate 210 may include an additional barrier layer (not shown) formed on the bottom surface (back surface) 220 of the substrate 210 opposite the first surface 218 of the substrate 210. The additional barrier layer on the back surface 220 of the substrate 210 can be formed in a manner similar to that used to form the barrier layer in the substrate processing step 110, as described in the substrate manufacturing method 100. The additional barrier layer protects the back surface 220 from AlFx contamination.

[0042]

[0044] Figures 3A and 3B are partial schematic diagrams of a shower head according to embodiments of the present disclosure. In the example of Figure 3A, the shower head 202 includes a blocker plate 304 and a face plate 306. Figure 3A further includes a center line 330 that passes through the center of the blocker plate 304 and the face plate 306.

[0043]

[0045] Multiple blocker plate openings 308 are formed in the blocker plate 304. Multiple face plate openings 322 are formed in the face plate 306. In one example, the blocker plate 304 is coupled to the face plate 306 with a gap that defines the plenum. In this example, the position of each of the multiple face plate openings 322 corresponds to the position of each of the multiple blocker plate openings 308 (e.g., aligned axially). Alternatively, some or all of the blocker plate openings 308 are offset from the face plate openings 322. In other examples, there may be no gap or a minimal gap formed between the blocker plate 304 and the face plate 306. In several examples (not shown herein) that can be combined with other examples herein, fewer positions than all of the positions of each of the multiple blocker plate openings 308 correspond to the positions of each of the multiple face plate openings 322. The multiple blocker plate openings 308 may be spaced apart from each other by multiple different distances. Figure 3A shows the first spacing 310, the second spacing 312, and the third spacing 314. Although the multiple blocker plate openings 308 are shown in Figure 3A to be perpendicular to the axis 318 and parallel to the axis 316, in alternative embodiments some or all of the multiple blocker plate openings 308 may be at an angle other than 90 degrees with respect to the axis 318. In one embodiment, some or all of the multiple blocker plate openings 308 may be angled toward or away from the centerline 302.

[0044]

[0046] In one embodiment, a plurality of blocker plate openings 308 have a first spacing 310 between the openings when measured from a first edge 320A of the blocker plate 304. A second edge 320B is also shown for reference on the opposite side of the first edge 320A. Various features shown on the first side of the centerline 302 (e.g., the side closer to the first edge 320A) are mirror images across the centerline 302. In one example, the first spacing 310 between adjacent openings of the plurality of blocker plate openings 308 is smaller than the second spacing 312 between adjacent blocker plate openings of the plurality of blocker plate openings 308. In another example, which can be combined with other examples herein, the second spacing 312 between adjacent blocker plate openings of the plurality of blocker plate openings 308 can be smaller than the third spacing 314 between adjacent blocker plate openings 308. In this example, the relative spacing of the plurality of blocker plate openings 308 can increase toward the centerline 302 of the blocker plate 304. Multiple blocker plate openings 308 can be configured in various ways in different blocker plate designs to evenly distribute gas (indicated by dashed arrows) within the process chamber 300. This design is in contrast to, for example, a blocker plate with equally spaced openings. With equally spaced openings, the gas can be received within the process chamber 300 in the central region of the process chamber 300, for example, at a location within the process chamber coaxial with the centerline 302. Therefore, equally spaced openings may not evenly distribute the gas within the process chamber 300.

[0045]

[0047] Although the multiple blocker plate openings 308 in Figure 3A are shown to have approximately the same diameter, it is intended that the diameter of each opening in the multiple blocker plate openings 308 may differ within the blocker plate. In one example, the blocker plate 304 includes an "opening gradient". In a blocker plate with an opening gradient, the multiple blocker plate openings 308 closer to the edges 320A and 320B of the blocker plate 304 have a larger diameter than the multiple blocker plate openings 308 located closer to the centerline 302 of the blocker plate 304. In some examples, the opening gradient of the blocker plate can be configured such that, in some cases, the degree of contact of the blocker plate openings per unit surface area is higher near the edges 320A and 320B of the blocker plate 304 than near the centerline 302. The opening gradient of the blocker plate 304 can be configured such that the density of the openings per unit surface area of ​​the blocker plate openings 308 is higher near the edges 320A and 320B of the blocker plate 304. This higher density is compared to the blocker plate openings 308 of multiple blocker plate openings 308 located closer to the centerline 302. The opening gradient of the blocker plate 304 can be adjusted to enable and facilitate improved gas flow, including an improved gas flow distribution toward the edges 320A / 320B of the face plate 306.

[0046]

[0048] Using the systems and methods described herein, the overall gas conductance is increased, and the gas distribution of gas and plasma within the process chamber is modified to improve uniformity in order to reduce the total cleaning time. The increased gas conductance acts to suppress AlFx formation. Thus, the increased gas conductance improves the adhesion of the season layer on the showerhead and reduces intra-film defects. In contrast to the process gas distribution at the first edge 320A and the second edge 320B, the process gas distribution, particularly at the centerline 302, can be adjusted via the configuration of the blocker plate 304. Controlling the uniform distribution of the process gas allows for control of the uniformity of the hard mask film and the adhesion behavior of the hard mask film.

[0047]

[0049] Figures 4A and 4B are front-side defect scanning images of substrates fabricated as described herein using a tungsten hard mask film. Figure 4A shows a first defect scanning image of substrate 410A fabricated without plasma and seathing treatment in steps 104 and 106 of Figure 1. The substrate in Figure 4A shows more than 200 in-film defects on the back surface of the substrate. In contrast, Figure 4B shows a second defect scanning image of substrate 410B fabricated according to embodiments of this disclosure. The substrate shown in Figure 4B was fabricated using hydrogen and nitrogen plasma and seathing treatment, which may be similar to those discussed in steps 104 and 106 of Figure 1. The substrate in Figure 4B shows only four defects.

[0048]

[0050] Therefore, using the systems and methods described herein, the adhesion of metal hard mask films is improved, resulting in a longer lifespan for process chamber components and a reduction in the incidence and severity of substrate defects. Hard mask films fabricated on a surface without a barrier layer between the hard mask film and the substrate exhibit poor adhesion and a high likelihood of delamination. In contrast, metal hard mask films formed on a barrier layer according to embodiments of this disclosure exhibit improved adhesion. Thus, metal hard mask films formed on a barrier layer do not exhibit peeling or delamination, or the likelihood and / or severity of peeling or delamination is reduced. The metal hard mask films discussed herein can be formed not only on process chamber components but also on substrates used in semiconductor device components.

[0049]

[0051] The surface treatment applied to the showerhead removes AlFx residue, which enhances the adhesion of the seasoning material to the showerhead and improves the adhesion of the hard mask film and / or subsequent layers containing the material. The seasoning material adheres well to the showerhead surface, reducing the possibility of substrate defects due to flaking. The seasoning material further provides fixed sites for the deposition of the metal hard mask film on the showerhead and other surfaces of the process chamber, on which a barrier layer is placed. When a barrier layer is used, one or more materials selected for the barrier layer may have material properties (e.g., etching selectivity and / or stoichiometric composition) substantially similar to one or more metals contained in the metal hard mask. The selection of materials with similar material properties and / or stoichiometric composition improves the adhesion of the metal hard mask film to the barrier layer.

[0050]

[0052] While the foregoing is directed toward embodiments of the present disclosure, other and further embodiments of the present disclosure may be devised without departing from the fundamental scope of the present disclosure, the scope of which is determined by the following claims.

Claims

1. A method for forming a hard mask, In the process chamber, a first plasma surface treatment is performed for the conversion of AlFx residue to aluminum oxide, After performing the first plasma surface treatment, the season material is deposited on a plurality of exposed surfaces of the process chamber, After depositing the seasoning material onto the plurality of exposed surfaces of the process chamber, the substrate is placed in the process chamber in contact with the seasoning material, The process is performed on the aforementioned substrate, The process includes performing a procedure on the substrate to form a barrier layer as a seed layer for a metal hard mask film, Subsequently, the metal hard mask film is formed on the substrate, Includes, Forming the barrier layer comprises at least one cycle of: soaking the substrate in a precursor for a first period to form a target barrier layer thickness; and then performing plasma treatment for a second period. A method wherein, during the second period, a plurality of gases used in the plasma treatment are ramped up to a target gas flow rate over a predetermined gas flow time.

2. The method according to claim 1, wherein the seasoning material comprises at least two of silicon oxide, silicon nitride, amorphous silicon, and combinations thereof, and the seasoning material has a hardness of less than half the hardness of the substrate.

3. The method according to claim 1, wherein the first plasma surface treatment includes introducing a gas into the process chamber through a blocker plate having openings having unequal spacing.

4. The method according to claim 1, wherein the target barrier layer thickness is 3 angstroms to 50 angstroms.

5. The method according to claim 1, wherein the predetermined gas flow time is 5 to 30 seconds.

6. A method for manufacturing circuit boards, Cleaning the process chamber, Subsequently, a first plasma surface treatment is performed in the process chamber for the conversion of AlFx residue to aluminum oxide. After performing the first plasma surface treatment, a seasoning material comprising at least two of silicon oxide, silicon nitride, amorphous silicon, and combinations thereof is deposited on multiple exposed surfaces of the process chamber. The substrate is placed in the process chamber in contact with the season material, The process is performed on the aforementioned substrate, Perform a second plasma surface treatment, which is a hydrogen and nitrogen plasma surface treatment, and Subsequently, a barrier layer is formed on the substrate as a seed layer for the metal hard mask film. Executing a process that includes, Next, the metal hard mask film is formed on the substrate, During the formation of the barrier layer, a plurality of process gases are introduced into the process chamber, Performing gas ramping during the formation of the barrier layer, The gas ramping includes the following: During the gas ramping, the target gas flow of the plurality of process gases is achieved within the process chamber within a time of 5 to 30 seconds after the plurality of process gases are introduced into the process chamber. method.

7. The method according to claim 6, wherein the metal hard mask film comprises at least one of tungsten (W), cobalt (Co), titanium (Ti), molybdenum (Mo), yttrium (Y), zirconium (Zr), and alloys or combinations thereof, and a dopant comprising at least one of boron, carbon, nitrogen, and silicon.

8. The method according to claim 6, wherein the metal hard mask film comprises a first metal including tungsten (W), cobalt (Co), titanium (Ti), molybdenum (Mo), yttrium (Y), or zirconium (Zr), and the barrier layer comprises the first metal.

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