Systems and methods for forming metal hard masks in device fabrication

Abstract

A method and system for substrate fabrication is disclosed herein. The method includes performing a first plasma enhanced surface treatment in a chamber prior to treating a substrate, and then, subsequently, depositing an aged material in the process chamber. After a plurality of aged materials are deposited in the process chamber, a substrate is disposed in the chamber. The substrate is positioned in contact with the aged material in the process chamber. Substrate processing is performed. The substrate treatment may 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.

Description

[0001] This application is a divisional application of the invention patent application with the application date of March 1, 2019, application number "201980021152.0", and invention name "System and method for forming a metal hard mask in device manufacturing". Technical Field

[0002] Embodiments of the present disclosure generally relate to the fabrication of integrated circuits (ICs) for both memory and logic applications in semiconductor technology. The fabrication of these ICs may include photolithography and a transfer process for transferring the fabricated pattern to a substrate. The transfer process may employ a mask film. Background Art

[0003] Semiconductor devices include film stacks in which high aspect ratio features are formed. High aspect ratio features can be formed in various operations. Some high aspect ratio features can be formed using hard mask films to form features in the film stack during the processing of advanced logic and memory components. The hard mask film can include various metal materials, non-metal materials, or a combination of materials, depending on the type of device being manufactured. The hard mask film is designed to withstand long etching processes without degradation. Compared to other mask materials, hard masks also exhibit higher mechanical strength and lower stress. However, conventional hard masks suffer from delamination problems during processing. Delamination of the hard mask can negatively impact device manufacturing, including etching and downstream operations.

[0004] Therefore, there is a need for improved hard masks and methods of forming hard masks. Summary of the Invention

[0005] The present disclosure generally relates to systems and methods for manufacturing devices using metal-based hard masks, including the configuration and preparation of systems for manufacturing these devices. In one example, a method of forming a hard mask includes: performing a first plasma-enhanced surface treatment in a process chamber; and after performing the first plasma-enhanced surface treatment, depositing an aged material on multiple exposed surfaces of the process chamber. In addition, in this example, after depositing the aged material on the multiple exposed surfaces of the process chamber, positioning a substrate in the process chamber, wherein the substrate is in contact with the aged material. At least one treatment is performed on the substrate, the at least one treatment including: performing a second plasma-enhanced surface treatment; forming a barrier layer on the substrate; or performing a low-frequency RF treatment. After performing the at least one treatment, a metal hard mask film is formed on the substrate.

[0006] In another example, a method for manufacturing a substrate includes: cleaning a process chamber; and then performing a first plasma-enhanced surface treatment in the process chamber. After performing the first plasma-enhanced surface treatment, depositing a seasoning material on a plurality of exposed surfaces in the process chamber, the seasoning material comprising at least two or more of silicon oxide, silicon nitride, amorphous silicon, or a combination thereof; positioning a substrate in the process chamber in contact with the seasoning material; and forming a metal hard mask film on the substrate.

[0007] In one example, a device includes a silicon substrate; a plurality of alternating SiN-SiO2 layers arranged to form a stack on the silicon substrate; a barrier layer formed on the stack; and a hard mask layer formed on the barrier layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In order that the manner in which the above-described features of the present disclosure are understood in detail, a more particular description of the present disclosure, briefly summarized above, may be made by reference to embodiments, some of which are illustrated in the accompanying drawings. It should be noted, however, that the drawings illustrate only exemplary embodiments and are therefore not to be considered limiting of the scope, as the disclosure may admit to other equally effective embodiments.

[0009] Figure 1 is a flow chart of a substrate manufacturing method according to an embodiment of the present disclosure.

[0010] Figure 2 is a partial cross-sectional view of a process chamber in which a barrier layer and a metal-based hard mask film have been formed according to an embodiment of the present disclosure.

[0011] Figures 3A to 3B is a partial schematic diagram of a nozzle according to an embodiment of the present disclosure.

[0012] Figures 4A to 4B is a comparison of two defect scan images of the front side of a substrate fabricated with a tungsten hard mask film as discussed herein.

[0013] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation. DETAILED DESCRIPTION

[0014] To achieve higher device capacity and lower unit cost, integrated circuit (IC) manufacturers are developing semiconductor technologies to reduce the size of critical dimensions (CDs) during processing in logic and memory device applications. Non-collapsing, highly etch-selective hard masks, as discussed herein, are used to transfer patterns to underlying substrates via photolithography to produce devices with increasingly smaller critical dimensions.

[0015] Embodiments of the disclosed systems and methods relate to forming (depositing) defect-free metal-based hardmasks on a variety of substrate types and geometries. In one embodiment, "defect-free" may mean that less than a predetermined number ("X") of defect additives (e.g., particle contamination) of a predetermined diameter are permitted to be present in or on a semiconductor film of a predetermined thickness. In one example, for a substrate of approximately 200 mm or 300 mm diameter, the thickness of the semiconductor film may be approximately 100 mm. For a semiconductor film thicker than 32 nm, there may be fewer than 10 defect additives greater than 32 nm. In another example, for For thick films, there can be fewer than 30 defect additives larger than 90nm.

[0016] The substrate on which the metal-based hard mask film is formed as discussed herein may include a device substrate positioned in a process chamber for operations including film formation and patterning. The substrate on which the metal-based hard mask film (or hard mask material) is formed as discussed herein may further include process chamber surfaces and components, including showerheads, blocking plates, and other components included in the process chamber.

[0017] Currently employed films for hardmasks can present various challenges, including substrate adhesion, nonexistent or ineffective barrier layers, and undesirable intra-film defects, including backside defects. Conventional metal-containing hardmask films used in logic and memory applications (which can be thicker films than those used in logic applications) exhibit poor (e.g., unusable or undesirable) adhesion on substrates, including silicon oxide, silicon nitride, polycrystalline silicon, amorphous silicon, and the like. Poor adhesion can be the result of fluorine (F) radicals (generated from WF6, a common tungsten precursor) diffusing through the hardmask film toward the hardmask-substrate interface. Once the hardmask-substrate interface is saturated with F radicals, the saturated interface can cause the hardmask film to delaminate from the underlying substrate, leading to poor adhesion.

[0018] Unlike conventional applications, the hard mask film discussed herein is used in combination with a barrier layer. The barrier layer may also be referred to herein as an initial layer and is formed on the substrate before the hard mask is deposited to prevent the diffusion of fluorine. The barrier layer further promotes that the metal hard mask film (including the tungsten hard mask film) fully adheres 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 the device substrate and / or on the process chamber components in a series of sub-operations.

[0019] In addition, the barrier layers discussed herein serve as seed layers to provide sufficient nucleation sites for subsequent bulk amorphous metal-based hard mask ("metal hard mask") film deposition. The barrier layers promote both 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 layers discussed herein exhibit similar etching behavior to bulk tungsten hard mask films. The similar etching behavior prevents problems such as profile widening during etching and residual hard mask material left after etching. The similar etching behavior can also alleviate other challenges posed by material barrier layers that behave less similarly to the bulk metal hard mask films employed in various embodiments of the present disclosure.

[0020] The metal-based hard mask discussed herein can be deposited using a plasma enhanced deposition method and an improved gas flow distribution scheme. Using the systems and methods discussed herein, metal-based hard mask films having a wide range of dopant concentrations (e.g., 10% to 80%) are formed. The hard mask films discussed herein may include one or more metals such as tungsten (W), cobalt (Co), titanium (Ti), molybdenum (Mo), yttrium (Y), zirconium (Zr), or other metals, or combinations and alloys of metals. The metal-based hard mask film can be formed to include dopants such as boron, carbon, nitrogen, and silicon and deposited on a substrate (e.g., oxide, nitride, amorphous silicon, oxynitride stack, titanium nitride, silicon, polysilicon, etc.).

[0021] The metal-based hard mask films manufactured according to embodiments of the present disclosure exhibit viable adhesion and are free of or substantially free of defects on both the front and back sides of the substrate. In various examples, the dopant content may be 10 wt % to 80 wt % of the total weight of the metal hard mask film. In some embodiments, the substrate on which the metal hard mask film is formed comprises a silicon-based stack, for example, an alternating silicon oxide (SiO x ) and silicon nitride (SiN x) layers. The stack is manufactured by a method including etching to pattern it. Masks (including the metal-based hard masks discussed herein) can be used to form these patterns. Therefore, the metal-based hard masks discussed herein are formed to withstand etching stacks thicker than conventional masks (e.g., 96 or more silicon oxide / silicon nitride layers). The metal-based hard masks discussed herein have a reduced likelihood and severity of delamination from the surface of the stack. Delamination of the hard mask can result in substrate defects, undercuts during etching, and / or poor or inconsistent etch selectivity in and between layers of the stack.

[0022] Referring back to the barrier layer, to be suitable for next generation node applications, the barrier layer is selected to exhibit thermal and mechanical properties and stoichiometry similar to that of bulk hard mask materials (e.g., tungsten hard mask). The similarity in properties and stoichiometry can prevent profile widening during subsequent etching processes and can prevent unintended hard mask residues, which improves device yield. Similarly, due to feasible intra-film defect (inclusion) performance, the films formed according to embodiments of the present disclosure can be used for future generation applications. The intra-film defect performance of the hard mask films discussed herein contributes to preventing misaligned profiles during hard mask open etching operations, thereby mitigating subsequent etch profile misalignment and improving device yield.

[0023] During substrate processing, material used to form a metal hard mask film (such as a tungsten hard mask film) may accumulate on the top electrode surface ("showerhead surface") within the process chamber. During plasma processing operations within the processing chamber, poor adhesion of the deposited metal hard mask film causes the metal hard mask film to flake or peel off from the top electrode. Conventional metal hard mask films may flake or peel off onto the substrate, or may manifest as intra-film particle defects within the layers on the processed substrate, which may hinder etching or other subsequent processes performed on the substrate. Using the systems and methods discussed herein, various methods may be employed, alone or in combination, to form metal-based hard mask films. Silicon substrates having stacks greater than 96 layers can be successfully etched while mitigating flaking of the layers of metal-based hard mask material.

[0024] The systems and methods discussed herein may include operations such as: (1) cleaning a chamber prior to positioning a substrate in the chamber using a baffle designed to more evenly distribute gases; (2) performing a plasma enhanced chamber surface treatment using, for example, ionized / radicalized nitrogen oxides (e.g., N2O) and ionized / radicalized oxygen and / or helium prior to positioning the substrate in the chamber; (3) performing a plasma enhanced deposition of aged materials, such as silicon-rich materials, in the chamber prior to positioning the substrate in the chamber; (4) performing a plasma enhanced deposition of aged materials, such as silicon-rich materials, in the chamber prior to positioning the substrate in the chamber; and (5) performing a plasma enhanced deposition of aged materials, such as silicon-rich materials, in the chamber prior to positioning the substrate in the chamber. Thereafter, performing a hydrogen and / or nitrogen plasma enhanced surface treatment; (5) independently of or after (4), while the substrate is in the chamber, forming a barrier layer, such as a tungsten nitride barrier layer, by performing a cycle of soaking the substrate in a precursor and then performing the plasma enhanced surface treatment, which may or may not include a process gas ramp, as opposed to maintaining the gas flow in the chamber at a constant rate during the plasma treatment after the precursor soak; and / or (6) applying a low frequency RF while the substrate is in the chamber and employing a process gas ramp. While one example is described above, other examples are contemplated. For example, operation (3) may be performed before operation (2). In one embodiment, the one or more gases employed at (1) may include argon, NF3, or oxygen.

[0025] Using the systems and methods discussed herein, at least one layer of seasoning material (showerhead surface conditioning) may be used in conjunction with a barrier layer. The barrier layer, which may also serve as a seed layer on the showerhead, may provide an anchoring location for the deposited metal hard mask material. Additionally, fluorine is prevented / inhibited from diffusing toward the showerhead surface by the barrier layer, which would otherwise cause flaking (delamination) of the tungsten hard mask and / or seasoning material. In some embodiments, during seasoning of the chamber and, therefore, the showerhead prior to positioning the substrate in the chamber, at least silicon oxide and silicon nitride are employed in various predetermined proportions to facilitate protection of chamber components. To form silicon oxide and / or silicon nitride, silicon, oxygen, and nitrogen precursors are utilized. RF power is used to ionize and / or radicalize the precursors to enhance adhesion of the silicon oxide and silicon nitride to the showerhead to address the AlF discussed below. x The ratio of silicon oxide to silicon nitride percentages employed may include 100:0; 90:10; 80:20; 70:30; 60:40; 50:50, or other ranges of ratios up to and including 10:90.

[0026] Another challenge in the fabrication and use of metal hardmasks is the generation of backside defects that can be caused by aluminum contamination. s3 During the cleaning process, the aluminum-containing substrate support or heater surface is partially converted to AlF x In some examples, AlF xwill be transferred to the back side of the substrate and thus cause undesirable aluminum contamination on the back side of the substrate. In addition, the AlF x Sublimates and deposits on the inner surface of the cold chamber (such as the showerhead surface).

[0027] In contrast to conventional methods, the aged material layer is deposited on the heater surface immediately after the plasma / NF3 cleaning process is completed. The diffusion of aluminum from the heater surface to the back of the substrate is blocked by the aged layer to eliminate or mitigate aluminum back contamination on the substrate. The aged layer can also inhibit AlF x Sublimation onto the showerhead surface, which would otherwise cause poor adhesion of subsequent layers on the showerhead. In addition, due to the relative softness of the silicon oxide layer and the silicon nitride layer, the use of silicon oxide and silicon nitride reduces scratching on the back side of the substrate.

[0028] Thus, using the systems and methods herein, the adhesion of a hard mask film (which may be a tungsten hard mask film) may be improved through the following operations: (1) surface treatment, (2) deposition of an aged material, and (3) deposition of a barrier / seed layer. In one example, the surface treatment applied to the showerhead removes AlF x Residue to enhance the adhesion of the aged material. The surface treatment further improves the nucleation of the metal hard mask film on the barrier layer / seed layer. The aged material exhibits low hardness, good adhesion to the showerhead surface (to enable further processing) and provides anchoring sites for the metal hard mask film to be deposited on the showerhead and other surfaces with the barrier layer. The "low" desired hardness of the aged material discussed herein may be defined herein as less than 50% of the hardness of the substrate to avoid scratching the substrate. In another example, the hardness of the aged 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 includes properties and stoichiometry as a bulk metal hard mask material, including similar behavior during the etching process.

[0029] Figure 11 is a flow chart of a substrate manufacturing method 100 according to an embodiment of the present disclosure. In some examples, at operation 102, a process chamber is cleaned using, for example, one or more gases (including chlorine). In one example, operation 102 is performed before a substrate or a batch of substrates are deposited into the process chamber. After the chamber clean at operation 102, a first plasma surface treatment is performed in the process chamber at operation 104. The treatment at operation 104 may include a mixture of nitrogen oxides (e.g., NO) and / or oxygen and helium. A high-frequency RF current (e.g., approximately 13.56 MHz) may be applied to ionize or radicalize the nitrogen oxides and / or the mixture of oxygen and helium to form a high-frequency plasma. In other embodiments, at operation 104, one or more gases, such as nitrogen oxides, nitrogen (e.g., N), oxygen (e.g., O), helium, ammonia (NH), diborane (BH), or propylene (CH), may be used alone or in various combinations with one or more of the gases discussed above to generate the high-frequency RF plasma.

[0030] During the first plasma treatment at operation 104, AlF x The residue is converted into aluminum oxide (AlO x At operation 106, after the first plasma treatment at operation 104 and without a substrate or substrates in the process chamber, one or more layers of aged material are deposited on exposed surfaces within the process chamber. The one or more layers of aged material deposited at operation 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, and the like. The exposed surfaces may include a showerhead surface, a substrate support surface, a chamber bottom, and / or a chamber sidewall. x The residual conversion to aluminum oxide increases the adhesion of the subsequently deposited aged material to the process chamber surfaces and showerhead. The aged layer deposited at operation 106 adheres to the showerhead to provide an anchoring site for subsequent hard mask material deposition at operation 112 discussed below. When fluorine is subsequently introduced into the process chamber and the showerhead is exposed to fluorine, the aged layer provided at operation 106 (which may be less than 60 angstroms and in some examples less than 30 angstroms or about 20 angstroms or less) prevents fluorine radicals from diffusing into the showerhead. As discussed above, the diffusion of fluorine radicals causes the fluorine to react with the aluminum showerhead to form AlF x , which causes material to delaminate or flake off from the showerhead, potentially leading to defects on the front side surface of the substrate.

[0031] The aged material discussed herein is soft in terms of hardness. In one example, the aged material discussed herein has a hardness less than 50% of the hardness of the substrate. In another example, the aged material discussed herein has a hardness less than 1 / 3 of the hardness of the substrate. When the substrate is placed in contact with the aged material, the hardness of the aged material contributes to reducing scratches on the back side of the substrate compared to the hardness of the substrate. When a higher hardness material is used (e.g., a material closer to the hardness of the substrate than the aged material used at operation 106 discussed herein), back side scratches may occur during subsequent photolithography processes. The aged material deposited at operation 106 can further be used to suppress AlF x Diffusion from the substrate support surface to the back side of the substrate, which would otherwise cause aluminum contamination of the substrate. At operation 108, a substrate or batch of substrates is positioned in a process chamber and one or more processing operations such as deposition, etching, annealing, photolithography, etc. may occur prior to pre-hard mask processing at substrate processing operation 110.

[0032] At substrate processing operation 110, one or more substrate processing sub-operations may 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 at operation 118 (discussed below). Due to the improved adhesion of the hard mask film to the substrate via the barrier layer, the hard mask film discussed herein is able to withstand etching and further processing. In one embodiment, at a first sub-operation 112 at substrate processing operation 110, an initial hydrogen and nitrogen plasma enhanced surface treatment is applied to the aged layer. The one or more sub-operations that may be performed at substrate processing operation 110 may optionally be performed individually or in combination, as discussed below. In some examples, the one or more sub-operations at substrate processing operation 110 are performed sequentially.

[0033] During the hydrogen and nitrogen surface treatment at the first sub-operation 112 at the substrate processing operation 110, hydrogen (H) bombardment generates surface Si-H bonds. The Si-H bonds serve as nucleation sites on the barrier layer for subsequent or barrier layer deposition (at sub-operations 114A and 114B) and / or the hard mask layer at operation 118 (discussed below). A metal precursor (such as WF6) interacts with the nucleation sites to promote film formation. When 110 is performed in a cyclic process such that hydrogen and nitrogen treatment occurs on the tungsten-containing layer, the hydrogen bombardment (after sub-operations 114A and 114B) further generates nitrogen vacancies in the treated film, thereby trapping fluorine radicals during metal hard mask deposition or subsequent barrier layer deposition. In examples where the metal hard mask and / or barrier layer include tungsten, the hydrogen bombardment further increases the hydride content of the tungsten layer when the tungsten layer is converted into a tungsten nitride layer. The tungsten nitride layer serves as a barrier layer for the tungsten hard mask film or other metal-based hard mask films discussed herein to improve adhesion and nucleation.

[0034] In another embodiment that may be combined with other examples and embodiments herein, at the second sub-operation 114A of the substrate processing operation 110, a precursor (such as WF6) is introduced and adsorbed in a (quasi) monolayer on the substrate surface. Subsequently, a plasma-enhanced hydrogen and nitrogen surface treatment may be performed at the third sub-operation 114B of the substrate processing operation 110. The third sub-operation 114B exposes the substrate to a hydrogen and nitrogen plasma and reduces the WF6 to tungsten (W). Additionally, at the third sub-operation 114B, the tungsten layer is converted into tungsten nitride. In an example that may be combined with other examples herein, the first sub-operation 112 may be combined with the second sub-operation 114A and the third sub-operation 114B.

[0035] The use of an initial hydrogen and nitrogen surface treatment in the first sub-operation 112 eliminates the use of conventional boron (B) or silicon (Si) precursors for forming a tungsten layer on the substrate in substrate processing operation 110. The use of boron or silicon containing precursors in conventional processes may cause problems with process flow / device manufacturing due to boron or silicon contamination of materials disposed on the substrate.

[0036] The thickness of the tungsten nitride (WN) layer formed during substrate processing operation 110 can be controlled by adjusting the number of process cycles. A single cycle of the second sub-operation 114A and the third sub-operation 114B can be iteratively repeated multiple times during substrate processing operation 110 until a barrier layer having a thickness within a predetermined thickness range is formed. In one embodiment, to form a metal-based barrier layer using tungsten in the second sub-operation 114A and the third sub-operation 114B, multiple nucleation sites are formed on the substrate for tungsten nucleation. In conventional processes, boron or silicon precursors can be adsorbed on the substrate surface and then chemically reacted with tungsten to nucleate tungsten on the substrate. However, this can result in boron or silicon residues from the unreacted precursors. The formation of boron or silicon residues can hinder the formation of a hard mask film and potentially inhibit downstream operations. By using an H2 / N2 treatment in the first sub-operation 112 of substrate processing operation 110, surface dangling bonds are formed that serve as tungsten nucleation sites. In this example, the use of boron or silicon precursors is eliminated.

[0037] In one example, a loop of the second sub-operation 114A and the third sub-operation 114B may form approximately to Thick barrier layers. Controlling the thickness of the barrier layer via cyclic operation improves the tunability of barrier layer properties compared to bulk deposition methods that can focus on depositing thicker film layers (such as 20 angstroms to 40 angstroms or greater). In substrate processing operation 110, the cyclic deposition process utilized at second sub-operation 114A and third sub-operation 114B can be used alone or in combination with first sub-operation 112. In another example, at substrate processing operation 110, the cyclic deposition process utilized at second sub-operation 114A and third sub-operation 114B can be used alone or in combination with fourth sub-operation 116. In this example, the cyclic deposition process does not rely on plasma distribution. Instead, one or more parameters of the immersion at second sub-operation 114A of substrate processing operation 110, such as duration, precursor type, and precursor concentration, enable angstrom-level control of barrier layer formation. The tunability and control of barrier layer formation enable consistent capping layer formation (such as the hard mask discussed herein) across the substrate, regardless of the plasma distribution in the process chamber.

[0038] In another example, the barrier layer formed by one or more cycles of the second sub-operation 114A and the third sub-operation 114B may be formed to be approximately to about In other examples, the barrier layer formed by one or more cycles of the second sub-operation 114A and the third sub-operation 114B may be formed to a thickness of about to about In yet other examples, the barrier layer formed by one or more cycles of the second sub-operation 114A and the third sub-operation 114B may have a thickness of In some embodiments, one or more cycles of the second sub-operation 114A and the third sub-operation 114B are performed in a high frequency (RF) environment at about 13.56 MHz or greater.

[0039] In some embodiments, a gas ramp may be employed at one or more of the second sub-operation 114A and the third sub-operation 114B of the substrate processing operation 110. Gas ramping is defined herein as adjusting the flow or one or more precursor gases entering the process chamber so that the gas flow rate varies within a predetermined gas flow rate range. Depending on the embodiment, the gas flow may be ramped up (increasing the gas flow) and / or ramped down (decreasing the gas flow) during one or more of the second sub-operation 114A and the third sub-operation 114B of the substrate processing operation 110. Compared to conventionally employed instantaneous gas flow, the gas ramps discussed herein can be configured to achieve a target gas flow rate that may take 5 to 30 seconds to achieve. During instantaneous gas flow, gas flow initiation during processing results in the target flow rate or range being reached upon initiation of gas flow. Compared to conventional methods, this relatively slow ramp according to embodiments herein can facilitate and achieve increased, and therefore sufficient, time for barrier layer nucleation. In one example, a gas ramp can increase the flow rate of WF6 from 0 sccm to 85 sccm in 5 seconds using a ramp rate of 17 sccm / s. In some embodiments, a gas ramp is performed in conjunction with a prior plasma-enhanced hydrogen-nitrogen surface treatment at the first sub-operation 112 of the substrate processing operation 110. In this example, the barrier layer formed during the substrate processing operation 110 facilitates sufficient adhesion of the hard mask to various substrates, which would otherwise result in reduced adhesion in the absence of the barrier layer. The barrier layer deposited during the ramping operation 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 severity of issues such as profile widening after the etching process, the presence of hard mask residue, or other challenges of hard mask formation as discussed herein.

[0040] Optionally, a fourth sub-operation 116 may be utilized. During the fourth sub-operation 116 of the substrate processing operation 110, low-frequency RF treatment may be employed while a plasma formed from nitrogen and / or hydrogen is present in the process chamber. This low-frequency RF treatment may be performed at a frequency below 13.56 MHz (e.g., 2 MHz, 350 kHz, or other frequencies suitable for various embodiments). This may correspond to applying a bias of between 200 W and 300 W to the substrate support, compared to high-frequency RF treatment, which may occur at frequencies above approximately 600 W. The low-frequency RF treatment at the fourth sub-operation 116 of the substrate processing operation 110 may be employed in conjunction with or independently of the first sub-operation 112. In another example, which may be combined with other examples herein, the fourth sub-operation 116 may be performed in addition to the second sub-operation 114A and the third sub-operation 114B of the substrate processing operation 110.

[0041] At operation 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 at operation 118 has a dopant concentration of about 10% to about 80%. The one or more dopants included in the metal hard mask film may include, for example, boron, carbon, nitrogen, or silicon. The hard mask film formed at operation 118 may include one or more metals, such as tungsten (W), cobalt (Co), titanium (Ti), molybdenum (Mo), yttrium (Y), zirconium (Zr), or other metals, or combinations and alloys of metals.

[0042] As discussed herein, a system for fabricating film stacks and metal-based hard mask films can be configured in various operating states to perform operations and sub-operations via a controller. The controller transmits programming information to various elements in the system, such as heater elements, pressure elements, gas flow elements, and / or substrate handling elements.

[0043] Figure 2 FIG2 is a cross-sectional view of a process chamber 200 in which a barrier layer and a metal-based hard mask film have been formed according to an embodiment of the present disclosure. The process chamber 200 includes a showerhead 202 disposed parallel to and separated from a substrate support assembly 214 by a distance 216. In one embodiment, the substrate support assembly 214 may include a heater and / or other components, some of which are discussed below. The substrate support assembly 214 is aligned with the first AlF x The showerhead 202 contacts the second AlF x The aged layer discussed herein may be formed as a first AlF x The first aged layer 206A on the residual layer 204A and the second AlF x A second aged layer 206B is formed on the residual layer 204B.

[0044] The substrate 210 is positioned on and in direct contact with the first aged layer 206A. A first barrier layer 208A is formed on the first side 218 of the substrate 210. A second barrier layer 208B is formed on the second aged 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. Figure 2 Various layer thicknesses are shown in FIG, but this is done for ease of illustration and is not intended to limit the description of the thicknesses or relative thicknesses of the components shown.

[0045] although Figure 2One embodiment is shown, but other embodiments are also contemplated. For example, in other embodiments, the substrate 210 can include an additional barrier layer (not shown) formed on a bottom (back) surface 220 of the substrate 210 opposite the first side 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 at the substrate processing operation 110 as discussed in the substrate manufacturing method 100. The additional barrier layer protects the back surface 220 from AlF x pollute.

[0046] Figure 3A and Figure 3B : is a partial schematic diagram of a nozzle according to an embodiment of the present disclosure. Figure 3A In the example shown in FIG. 3 , the showerhead 202 includes a blocking plate 304 and a face plate 306 . Figure 3A Further included is a centerline 330 that is centrally disposed through the blocking plate 304 and the face plate 306 .

[0047] A plurality of baffle holes 308 are formed in the baffle plate 304. A plurality of panel holes 322 are formed in the panel 306. In one example, the baffle plate 304 is coupled to the panel 306, wherein a gap therebetween defines an air chamber. In this example, the position of each of the plurality of panel holes 322 corresponds to the position of each of the plurality of baffle holes 308 (e.g., is axially aligned therewith). Alternatively, some or all of the baffle holes 308 are offset from the panel holes 322. In other examples, no gap or a minimal gap may be formed between the baffle plate 304 and the panel 306. In some examples (not shown here) that may be combined with other examples herein, not every baffle hole 308 has a position that corresponds to every panel hole 322. The baffle holes 308 may be spaced apart at a plurality of different distances relative to each other. Figure 3A A first spacing 310, a second spacing 312, and a third spacing 314 are shown. Figure 3A 308 are shown as being perpendicular to axis 318 and parallel to axis 316, but in alternative embodiments, some or all of the plurality of baffle holes 308 may be angled other than 90 degrees relative to axis 318. In one example, some or all of the plurality of baffle holes 308 may be angled toward or away from centerline 302.

[0048] In one embodiment, the plurality of barrier plate holes 308 have a first spacing 310 between the holes measured from a first edge 320A of the barrier plate 304. For reference, a second edge 320B opposite the first edge 320A is also shown. The various features shown on a first side of the centerline 302 (e.g., the side closest to the first edge 320A) are mirrored across the centerline 302. In one example, the first spacing 310 between adjacent holes in the plurality of barrier plate holes 308 is less than the second spacing 312 between adjacent barrier plate holes in the plurality of barrier plate holes 308. In another example, which may be combined with other examples herein, the second spacing 312 between adjacent barrier plate holes in the plurality of barrier plate holes 308 may be less than the third spacing 314 between adjacent barrier plate holes 308. In this example, the relative spacing of the plurality of barrier plate holes 308 may increase toward the centerline 302 of the barrier plate 304. The plurality of barrier plate holes 308 may be configured in various ways in different barrier plate designs to evenly distribute gas (indicated by the dashed arrows) within the process chamber 300. This design is in contrast to, for example, a baffle having a uniformly spaced hole distribution. A uniformly spaced hole distribution may result in gas being received in the process chamber 300 in a central region of the process chamber 300 (e.g., at a location coaxial with the centerline 302 of the process chamber). Therefore, a uniformly spaced hole distribution does not uniformly distribute gas within the process chamber 300.

[0049] Although Figure 3A The plurality of baffle plate holes 308 in the barrier plate 304 are shown as having approximately similar diameters, but it is contemplated that the diameter of each hole in the plurality of baffle plate holes 308 may vary within the barrier plate. In one example, the barrier plate 304 includes a "pore gradient." In a barrier plate having a pore gradient, the diameter of the plurality of baffle plate holes 308 closer to the edges 320A and 320B of the barrier plate 304 is larger than the diameter of the plurality of baffle plate holes 308 located closer to the centerline 302 of the barrier plate 304. In some examples, the pore gradient of the barrier plate can be configured such that, in some examples, a higher concentration of baffle plate holes per surface area of ​​the plurality of baffle plate holes 308 are located toward the edges 320A and 320B of the barrier plate 304 than toward the centerline 302. The pore gradient of the barrier plate 304 can be configured such that, per surface area of ​​the plurality of baffle plate holes 308, a higher concentration of holes are located toward the edges 320A and 320B of the barrier plate 304. This higher concentration is relative to those baffle plate holes 308 in the plurality of baffle plate holes 308 that are closer to the centerline 302. The aperture gradient of the baffle 304 may be tuned to achieve and promote improved airflow, including improved airflow distribution toward the edges 320A / 320B of the panel 306 .

[0050] Using the systems and methods discussed herein, the overall gas conductivity is increased and the gas distribution of the gas and plasma in the process chamber is modified to improve uniformity and reduce the overall cleaning time. The increased gas conductivity can suppress AlF x Formation. Thus, increased gas conductivity improves adhesion of the aged layer to the showerhead and reduces defects within the film. The distribution of the process gas (particularly at centerline 302) can be adjusted via the configuration of the blocking plate 304 compared to the distribution of the process gas at the first edge 320A and the second edge 320B. Controlling the uniform distribution of the process gas enables control of the uniformity of the hard mask film and the adhesion behavior of the hard mask film.

[0051] Figures 4A to 4B is a defect scan image of the front side of a substrate fabricated with a tungsten hard mask film as discussed herein. Figure 4A Shown in Figure 1 FIG. 4 is a first defect scan image of a substrate 410A manufactured without plasma and aging treatments at operations 104 and 106 in FIG. Figure 4A The substrate of showed more than 200 intra-film defects on the back side of the substrate. In contrast, Figure 4B A second defect scan image of a substrate 410B manufactured according to an embodiment of the present disclosure is shown. Figure 4B The substrate shown in FIG was fabricated using hydrogen and nitrogen plasma treatments and aging processes similar to those in FIG. Figure 1 The processing discussed at operations 104 and 106 of FIG. Figure 4B The substrate in Figure 4 shows only 4 defects.

[0052] Thus, using the systems and methods herein, metal hard mask film adhesion is improved, resulting in longer life for process chamber components and reduced incidence and severity of substrate defects. Hard mask films fabricated on surfaces without a barrier layer between the hard mask film and the substrate have poor adhesion, thereby increasing the likelihood of delamination. In contrast, metal hard mask films formed on barrier layers according to embodiments of the present disclosure exhibit improved adhesion. Thus, the metal hard mask films formed on barrier layers do not exhibit delamination or delamination, or exhibit a reduced likelihood and / or severity of delamination or delamination. 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.

[0053] Surface treatment applied to printheads to remove AlF xResidue, which enhances the adhesion of the aged material to the showerhead and improves the adhesion of subsequently deposited layers (including hard mask films and / or materials). The aged material can adhere well to the surface of the showerhead, thereby reducing the possibility of substrate defects caused by peeling. The aged material also provides anchor points for depositing the metal hard mask film on other surfaces of the showerhead and process chamber on which the barrier layer is set. When a barrier layer is used, the one or more materials selected for the barrier layer may have material properties that are substantially similar to the one or more metals included in the metal hard mask, such as etching selectivity and / or stoichiometry. Selecting materials with similar material properties and / or stoichiometry improves the adhesion of the metal hard mask film to the barrier layer.

[0054] While the foregoing is directed to embodiments of the present disclosure, other and further embodiments may be devised without departing from the basic scope thereof, and the scope of the embodiments is to be determined by the claims that follow.

Claims

1. A method for forming a hard mask, comprising: performing a first plasma enhanced surface treatment in the process chamber; depositing a seasoning material on a plurality of exposed surfaces of the process chamber after performing the first plasma enhanced surface treatment; After depositing the aged material on the plurality of exposed surfaces of the process chamber, positioning a substrate in the process chamber and in contact with the aged material; performing a process on the substrate, the process comprising: forming a barrier layer on the substrate; and performing low frequency RF processing; and After performing the at least one process, a metal hard mask film is formed on the substrate.

2. The method according to claim 1, wherein The aged material includes at least two of silicon oxide, silicon nitride, amorphous silicon, or a combination thereof, wherein the aged material includes a hardness less than a hardness of the substrate.

3. The method according to claim 1, wherein The first plasma enhanced surface treatment includes introducing a gas into the process chamber through a barrier plate, the barrier plate including holes having unequal spacing therebetween.

4. The method of claim 1, wherein forming the barrier layer comprises at least one cycle of immersing the substrate in a precursor to form a target barrier layer thickness for a first period of time, and subsequently performing a plasma enhanced treatment for a second period of time.

5. The method according to claim 4, wherein The target barrier layer thickness is from about 3 angstroms to about 50 angstroms.

6. The method according to claim 4, wherein During the second time period, a plurality of gases employed in the plasma enhanced process are ramped to target gas flow rates within a predetermined gas flow period.

7. The method according to claim 6, wherein The predetermined gas flow time period is from about 5 seconds to about 30 seconds.

8. A method for manufacturing a substrate, comprising: Cleaning process chambers; Subsequently, a first plasma enhanced surface treatment is performed in the process chamber; After performing the first plasma enhanced surface treatment, depositing a seasoning material 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; positioning a substrate in the process chamber in contact with the seasoning material; performing a process on the substrate, the process comprising: performing a second plasma enhanced surface treatment; and forming a barrier layer on the substrate; and A metal hard mask film is formed on the substrate.

9. The method according to claim 8, wherein The metal hard mask film includes at least one of tungsten (W), cobalt (Co), titanium (Ti), molybdenum (Mo), yttrium (Y), zirconium (Zr) or an alloy or combination thereof and a dopant, wherein the dopant includes at least one of boron, carbon, nitrogen or silicon.

10. The method of claim 8, further comprising: After positioning the substrate in the process chamber and before forming the metal hard mask film, performing a process on the substrate, the process comprising: Perform low frequency RF processing.

11. The method according to claim 10, wherein The metal hard mask film includes a first metal including tungsten (W), cobalt (Co), titanium (Ti), molybdenum (Mo), yttrium (Y), or zirconium (Zr), and the barrier layer includes the first metal.

12. The method of claim 10, further comprising: introducing a plurality of process gases into the process chamber during forming the barrier layer; as well as A gas ramp is performed during the forming of the barrier layer, wherein during the gas ramp, target gas flows of the plurality of process gases are achieved in the process chamber within a time period from 5 seconds to 30 seconds after introducing the plurality of process gases into the process chamber.

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