Improved tribological properties of diamond films

Abstract

A method for manufacturing integrated circuits is described. Nanocrystalline diamond is used instead of amorphous carbon as a hard mold. A method for processing a substrate is provided, wherein nanocrystalline diamond is used as a hard mold, and the processing method produces a smooth surface. The method involves two processing steps. Two separate nanocrystalline diamond formulations are combined, i.e., a first formulation and a second formulation are cycled to achieve a nanocrystalline diamond hard mold with high hardness, high modulus, and a smooth surface. In several other embodiments, an inert gas plasma smoothing process follows the first formulation, and the first formulation is subsequently cycled to achieve high hardness, high modulus, and a smooth surface.

Description

Technical Field

[0001] Several embodiments of this disclosure relate to the field of electronic device manufacturing, and more particularly to integrated circuit (IC) manufacturing. More specifically, several embodiments of this disclosure provide methods for depositing nanocrystalline diamond films. Background Technology

[0002] As the semiconductor industry introduces a new generation of integrated circuits (ICs) with higher performance and greater functionality, the density of the components forming those ICs has increased, while the size, dimensions, and spacing between individual parts or components have decreased. While in the past such reductions were limited only by the ability to define structures using photolithography, device geometries measured in μm or nm have created new constraints, such as the conductivity of metal components, the dielectric constant of the insulating materials used between components, or the challenges in 3D NAND or DRAM processes. These constraints can be mitigated by more durable and rigid hard masks.

[0003] A direct way to reduce the cost per bit and increase chip density in 3D NAND is by adding more layers. One of the key steps in 3D NAND technology is slot etching before the silicon nitride (SiN) recesses used for metal contact deposition. As the number of layers increases across technology nodes, the thickness of the hard mold must be increased proportionally to withstand the high depth and width of the slot etching profile (uniform etching from top to bottom) in order to control the slot etching profile. Traditionally, extremely high-quality hard mold films with high etch selectivity, unparalleled hardness, and high density are used. Current hard mold films include pure or doped plasma-enhanced chemical vapor deposition (PECVD) amorphous carbon (aC:H) substrates due to their high hardness and modulus, film transparency, and ease of removal after slot etching. However, PECVD amorphous carbon hard mold films have problems with delamination / peeling on the slope (a major problem in downstream etching processes), which makes them less transparent in the case of thicker films (light alignment problem) and causes undesirable morphologies such as pillar striation, one-sided bow, and pillar twisting.

[0004] Nanocrystalline diamond is considered a high-hardness material suitable for use as a hard mold in semiconductor device processing. While possessing high hardness and modulus, nanocrystalline diamond hard molds exhibit high surface roughness. Therefore, there is a need for hard molds with high hardness and modulus but low surface roughness. Summary of the Invention

[0005] An apparatus and method for manufacturing integrated circuits are described. In one or more embodiments, a processing method is described. In one embodiment, the processing method includes: depositing a first nanocrystalline diamond layer on a substrate, the first nanocrystalline diamond layer having a first thickness, a first roughness, a first hardness, and a first modulus; and depositing a second nanocrystalline diamond layer on the first nanocrystalline diamond layer, the second nanocrystalline diamond layer having a second thickness and a second roughness, wherein the first thickness is greater than the second thickness, and the second roughness is less than the first roughness.

[0006] In several other embodiments, the processing method includes depositing a first nanocrystalline diamond layer on a seed layer, the first nanocrystalline diamond layer having a first thickness, a first roughness, a first hardness, and a first modulus; and exposing the first nanocrystalline diamond layer to an inert gas plasma to form a smooth nanocrystalline diamond layer.

[0007] In one or more embodiments, an electronic device is described. The memory device includes: a memory stack including a plurality of alternating layers of a first material and a second material on a substrate; a nanocrystalline diamond layer on the memory stack having a roughness of less than about 15 nm; and a memory channel extending from the top surface of the memory stack to the substrate. Attached Figure Description

[0008] To understand the above-described features of this disclosure in a more detailed manner, reference can be made to several embodiments to achieve a more specific description of the disclosure briefly outlined above, some of which are depicted in the accompanying drawings. However, it should be noted that the drawings depict only a few typical embodiments of this disclosure and should therefore not be considered as limiting the scope of this disclosure, as other equivalent embodiments are permissible. The embodiments described herein are depicted in the accompanying drawings by way of example and not limitation, wherein similar reference numerals indicate similar elements.

[0009] Figure 1A A cross-sectional view of a substrate according to one or more embodiments;

[0010] Figure 1B A cross-sectional view of a substrate according to one or more embodiments;

[0011] Figure 1C A cross-sectional view of a substrate according to one or more embodiments;

[0012] Figure 1D A cross-sectional view of a substrate according to one or more embodiments;

[0013] Figure 2A A cross-sectional view of a substrate according to one or more embodiments;

[0014] Figure 2B A cross-sectional view of a substrate according to one or more embodiments;

[0015] Figure 2C A cross-sectional view of a substrate according to one or more embodiments;

[0016] Figure 2D A cross-sectional view of a substrate according to one or more embodiments;

[0017] Figure 3A A cross-sectional view of a substrate according to one or more embodiments;

[0018] Figure 3B A cross-sectional view of a substrate according to one or more embodiments;

[0019] Figure 3C A cross-sectional view of a substrate according to one or more embodiments;

[0020] Figure 4A A cross-sectional view of a substrate according to one or more embodiments;

[0021] Figure 4B A cross-sectional view of a substrate according to one or more embodiments;

[0022] Figure 4C A cross-sectional view of a substrate according to one or more embodiments;

[0023] Figure 4D A cross-sectional view of a substrate according to one or more embodiments;

[0024] Figure 5 A flowchart depicting a method according to one or more embodiments; and

[0025] Figure 6 A flowchart depicting a method according to one or more embodiments. Detailed Implementation

[0026] Before describing several exemplary embodiments of this disclosure, it should be understood that this disclosure is not limited to the details of the construction or process steps set forth in the following description. This disclosure is capable of many other embodiments and can be practiced or implemented in various ways.

[0027] As used herein, “substrate” means any substrate or material surface formed on a substrate on which a film treatment is performed during a manufacturing process. For example, depending on the application, substrate surfaces on which treatments can be performed include materials such as silicon, silicon oxide, strained silicon, silicon-on-insulator (SOI), carbon-doped silicon oxide, amorphous silicon, doped silicon, germanium, gallium arsenide, gallium nitride, glass, sapphire, and any other materials such as metals, metal nitrides, metal alloys, and other conductive materials. Substrates include, but are not limited to, semiconductor wafers. Substrates may be exposed to pretreatment processes to polish, etch, reduce, oxidize, hydroxylate, anneal, and / or bake the substrate surface. In addition to film treatments performed directly on the surface of the substrate itself, as disclosed in more detail below, any of the disclosed film treatment steps may also be performed on an underlayer formed on the substrate, and as indicated by the context, the term “substrate surface” is intended to include such an underlayer. Thus, for example, when a film / layer or a portion of a film / layer has been deposited onto the substrate surface, the exposed surface of the newly deposited film / layer becomes the substrate surface.

[0028] As used in this specification and the appended claims, the terms “precursor,” “reactant,” “reactive gas,” etc., are used interchangeably to refer to any gaseous component that can react with the substrate surface.

[0029] As used herein, the term "nanocrystalline diamond" refers to a diamond solid film typically grown on a substrate such as silicon. Nanocrystallization is the result of an enhanced renucleation reaction during diamond growth, in which the growth of diamond crystals is interrupted by fluctuations in the surrounding environment, such as the amount of free radicals, temperature, and pressure. The formation of the diamond nucleus is determined by hydrogen atoms, which play a crucial role in driving the adsorption of external carbon atoms and etching away the non-diamond phase, and are considered to be competing between diamond growth and etching. Nanocrystalline diamond is primarily composed of small diamond crystals in the shape of nanospheres or nanopillars, with amorphous carbon typically distributed between the surrounding crystals or aggregated at grain boundaries. Due to its chemical inertness, optical transparency, and good mechanical properties, nanocrystalline diamond is used as a hard molding material in semiconductor applications.

[0030] In one or more embodiments, plasma-enhanced chemical vapor deposition (PECVD) is widely used for depositing nanocrystalline diamond films due to its cost-effectiveness and versatility in film properties. In a PECVD process, a hydrocarbon source, such as gaseous hydrocarbons or liquid hydrocarbon vapors already entrained in a carrier gas, is introduced into a PECVD chamber. Plasma is then induced in the chamber to generate excited CH radicals. The excited CH radicals are chemically bonded to the surface of a substrate disposed in the chamber, thereby forming the desired nanocrystalline diamond film on that surface. The various embodiments described herein with reference to the PECVD process can be performed using any suitable thin film deposition system. Examples of suitable systems include those that can be used... Processing chamber System, PRECISION system, system, GTTM system XP Precision TM system, SETM system Processing chambers and Mesa TM The processing chambers, all of which are available from Applied Materials, Inc., Santa Clara, California. Other tools capable of performing PECVD processes can also be adapted to benefit from the various implementations described herein. Additionally, it is beneficial to use any system capable of performing the PECVD processes described herein. Any equipment descriptions herein are illustrative and should not be construed as limiting the scope of the various implementations described herein.

[0031] Device manufacturers using carbon-based hard mold layers need to meet stringent requirements: (1) high selectivity of the hard mold during dry etching of the underlying material, (2) low film roughness, (3) low film stress, and (4) film stripping capability. As used herein, the term “dry etching” generally refers to an etching process in which the material is not dissolved by immersion in a chemical solution, and includes methods such as plasma etching, reactive ion etching, sputtering etching, and vapor phase etching.

[0032] In one or more embodiments, a nanocrystalline diamond layer is formed on a substrate. The process of one or more embodiments advantageously produces a nanocrystalline diamond layer with high density, high hardness, high etch selectivity, low stress, and excellent thermal conductivity.

[0033] Hard dies are used as etch-stop layers in semiconductor processing. Ashable hard dies have a chemical composition that allows them to be removed after they have achieved their purpose through a technique called ashing. Ashable hard dies are generally composed of carbon and hydrogen, along with trace amounts of one or more dopants (e.g., nitrogen, fluorine, boron, silicon). In typical applications, after etching, the hard die achieves its purpose and is removed from the underlying substrate. This is typically accomplished, at least in part, through ashing, also known as “plasma ashing” or “dry stripping.” The substrate with the hard die to be ashed, typically a partially fabricated semiconductor wafer, is placed in a vacuum chamber, and oxygen is introduced and the substrate is subjected to an RF power source, an operation that generates oxygen radicals (plasma). The radicals react with the hard die to oxidize it into water, carbon monoxide, and carbon dioxide. In some cases, such as when the ashable hard die leaves any residue that cannot be removed by ashing alone, complete removal of the hard die can be achieved through an additional wet or dry etching process following ashing.

[0034] Hard-film layers are often used in narrow and / or deep contact etching applications where the photoresist may not be thick enough to shield the underlying layer. This is especially true as critical dimensions shrink.

[0035] V-NAND or 3D-NAND structures are used in flash memory applications. A V-NAND device is a vertically stacked NAND structure with many cells arranged in blocks. As used herein, the term "3D NAND" refers to an electronic (solid-state) non-volatile computer memory where memory cells are stacked in multiple layers. 3D NAND memory typically includes multiple memory cells, each containing a floating-gate transistor. Traditionally, a 3D NAND memory cell comprises multiple NAND memory structures arranged three-dimensionally around a bit line.

[0036] A key step in 3D NAND technology is slot etching. As the number of layers increases across different technology nodes, the thickness of the hard mold must increase proportionally to withstand the high depth and width of the slot etching profile. Currently, amorphous carbon (aC:H) films are used due to their high hardness and ease of peeling after slot etching. However, amorphous carbon hard mold films exhibit delamination at the bevels and poor morphology, resulting in columnar streaks.

[0037] Tribology is the science and engineering of interacting surfaces in relative motion. It encompasses the study and application of the principles of friction, lubrication, and wear. In one or more embodiments, nanocrystalline diamond is advantageously used as a hard mold instead of amorphous carbon. Nanocrystalline diamond hard molds provide high hardness and high modulus, but result in high surface roughness. Therefore, in one or more embodiments, a method of processing a substrate is provided, wherein nanocrystalline diamond is used as a hard mold, and the processing method produces a smooth surface. One or more embodiments of the method involve two processing steps. In one embodiment, two separate nanocrystalline diamond formulations are combined—a first formulation provides high hardness and high modulus, and a second formulation provides a smooth surface. The first and second formulations are cycled to achieve a nanocrystalline diamond hard mold with high hardness, high modulus, and a smooth surface. In other embodiments, an inert gas plasma smoothing process follows the first formulation, and the first formulation is subsequently cycled to achieve high hardness, high modulus, and a smooth surface.

[0038] One or more embodiments of the processing method advantageously retain the hardness and modulus of the nanocrystalline diamond hard mold film while maintaining low surface roughness. With the high hardness, high modulus, and improved surface roughness of the nanocrystalline diamond hard mold film, the film can be used as a hard mold to overcome the challenges faced in amorphous carbon-based films.

[0039] In one or more embodiments, to achieve greater etch selectivity, the density of the nanocrystalline diamond layers 108, 208 is increased, and more importantly, the Young's modulus is improved. One of the main challenges in achieving greater etch selectivity and improving Young's modulus is the high-pressure stress on such films, which can render them unsuitable for applications due to the resulting high wafer bowing. Therefore, a high density and modulus (e.g., higher sp) are required. 3 Nanocrystalline diamond films with high etching selectivity and low stress (e.g., <-500MPa) (content), have high etch selectivity and low stress (e.g., <-500MPa).

[0040] Several embodiments described herein include improved methods for manufacturing nanocrystalline diamond hard films having high density (e.g., >1.8 g / cc), high Young's modulus (e.g., >150 GPa), and low stress (e.g., <-500 MPa). In one or more embodiments, the Young's modulus is measured at room temperature or at ambient temperature or at a temperature ranging from about 22°C to about 25°C. In one or more embodiments, the Young's modulus of the nanocrystalline diamond film may be greater than 250 GPa. In several other embodiments, the Young's modulus of the nanocrystalline diamond film may be greater than 300 GPa or greater than 350 GPa.

[0041] In one or more embodiments, the density of the nanocrystalline diamond film is greater than about 3.0 g / cc.

[0042] Figures 1A to 1D A schematic cross-sectional view of substrate 100 at different stages of the integrated circuit manufacturing process and the first formulation, incorporating a nanocrystalline diamond layer as a hard mold. Figures 1A to 1D In this process, the deposited nanocrystalline diamond layer 108 has a thickness T1, high modulus (E>250 GPa), and high surface roughness (Ra>25 nm). In one or more embodiments, the first nanocrystalline diamond layer 108 has a thickness T1 ranging from about 250 nm to about 650 nm. In one or more embodiments, the roughness of the nanocrystalline diamond layer 108 is greater than 25 nm, as measured by atomic force microscopy (AFM).

[0043] Figures 2A to 2D A schematic cross-sectional view of substrate 200 at different stages of the integrated circuit manufacturing process and the second formulation, incorporating a nanocrystalline diamond layer as a hard mold. Figures 2A to 2D In this process, the deposited nanocrystalline diamond layer 208 has a thickness T2, high modulus (E>250 GPa), and low surface roughness (Ra<15 nm). In one or more embodiments, the second nanocrystalline diamond layer 208 has a thickness T2 ranging from about 5 nm to about 200 nm. In one or more embodiments, the roughness of the nanocrystalline diamond layer 208 is less than about 15 nm, as measured by atomic force microscopy (AFM).

[0044] Figure 1A A cross-sectional view of device 100 is shown. In one or more embodiments, device 100 may be a NAND device. Device 100 includes a substrate 102, a plurality of device layers 104, 106, and a nanocrystalline diamond mask layer 108 formed on the plurality of device layers 104, 106.

[0045] Figure 2A A cross-sectional view of device 200 is shown. In one or more embodiments, device 200 may be a NAND device. Device 200 includes a substrate 202, a plurality of device layers 204, 206, and a nanocrystalline diamond mask layer 208 formed on the plurality of device layers 204, 206.

[0046] In one or more embodiments, substrates 102, 202 may be substrates of any semiconductor known in the art, such as single-crystal silicon, epitaxial layers of IV-IV compounds (such as silicon-germanium (Si-Ge) or silicon-germanium-carbon (Si-Ge-C), III-V compounds, II-VI compounds) on such substrates, or any other semiconductor or non-semiconductor material (such as silicon oxide, glass, plastic, metal, or ceramic substrates). In one or more embodiments, substrates 102, 202 may include integrated circuits fabricated thereon, such as driver circuitry (not shown) for memory devices.

[0047] In one or more embodiments, multiple device layers 104, 106, 204, 206 may be formed on the surfaces of substrates 102, 202. The multiple device layers 104, 106, 204, 206 may be deposition layers for components forming a 3D vertical NAND structure. Components may be formed from all or a portion of the multiple device layers (e.g., dielectric or storage segments for discrete charges). The dielectric portions may be independently selected from any one or more of the same or different electrical insulating materials, such as silicon oxide, silicon nitride, silicon oxynitride, or other high-k insulating materials. In one embodiment, the structure may include silicon oxide / silicon nitride pairs deposited in an alternating manner. The total height of the pairs may be [not specified in the original text]. and Between. The number of pairs can be greater than 10, such as 32 pairs, 64 pairs or more.

[0048] In one or more embodiments, the nanocrystalline diamond layers 108, 208 are high sp2... 3 Crystalline carbon layers with high content and small crystal size. The most common chemical bond in amorphous and nanocrystalline carbon is tris(sp). 2 (key) and four (sp) 3 ) key coordination. In sp 3 In this configuration, carbon atoms form four sp atoms. 3 This creates orbitals, thus generating strong sigma bonds to neighboring atoms. In areas with high sp... 3 In carbon films with high content, sp 3 The content is greater than 80%, such as greater than about 90% or greater than about 95%. Nanocrystalline diamond layers 108 and 208 have high sp2 content. 3 Content (e.g., nanocrystalline diamond grains) and by sp 2 Structure (e.g., graphite) supports this. As used herein, small crystal size is a crystal size less than 6 nm, such as between 2 nm and 5 nm.

[0049] In one or more embodiments, the nanocrystalline diamond layer 108 produced by the first formulation has a highly biased surface roughness with a root mean square greater than 25 nm. In one or more embodiments, the first formulation may comprise a flow of methane (CH4) / carbon dioxide (CO2) / hydrogen (H2) at a flow rate range of 100% total flow. The nanocrystalline diamond film is deposited using microwave power in the range of 2 kW to 12 kW, pressure of 0.1 to 1 Torr, and temperature of 500°C to 650°C.

[0050] In one or more embodiments, the nanocrystalline diamond layer 208 produced by the second formulation has a highly biased root mean square surface roughness of less than about 15 nm. In one or more embodiments, the second formulation may comprise a flow of methane (CH4) / carbon dioxide (CO2) / hydrogen (H2) / argon (Ar) at a flow rate range of 100% total flow. The nanocrystalline diamond film is deposited using microwave power in the range of 2 kW to 12 kW, pulse strength of 10% to 90%, pressure of 0.1 to 1 Torr, and temperature of 500°C to 650°C.

[0051] In one or more embodiments, the nanocrystalline diamond layers 108 and 208 have a density of 2.5 g / cm³ and 3.5 g / cm³, respectively. 3 Density, such as 3g / cm³ 3 The density. In one or more embodiments, the nanocrystalline diamond layers 108, 208 have stresses between -50 MPa and -150 MPa, such as stresses between -80 MPa and -120 MPa. The nanocrystalline diamond layers 108, 208 have cover etch selectivity between 2 and 4.

[0052] In some embodiments, antireflective coatings 110 and 210 are on nanocrystalline diamond layers 108 and 208, and photoresist 112 and 212 are on antireflective coatings 110 and 210. In some embodiments, antireflective coatings 110 and 210 are dielectric antireflective coatings (DARC). Reference Figure 1B and Figure 2B The anti-reflective coatings 110 and 210 are patterned to form openings 113 and 213, which expose a portion of the top surface of the nanocrystalline diamond layers 108 and 208.

[0053] refer to Figure 1C and Figure 1D and Figure 2C and Figure 2DDevices 100 and 200 include channels 114 and 214. Channels 114 and 214 are formed through nanocrystalline diamond layers 108 and 208 and multiple device layers 104, 106, 204, and 206. Channels 114 and 214 may be substantially perpendicular to the top surface of substrates 102 and 202. For example, channels 114 and 214 may have a columnar shape. Channels 114 and 214 may extend substantially perpendicular to the top surface of substrates 102 and 202. In some embodiments, channels 114 and 214 may be filled features. In some other embodiments, channels 114 and 214 may be hollow. In such embodiments, an insulating filler material (not depicted) may be formed to fill the hollow portion surrounded by channels 114 and 214. The insulating filler material may include any electrically insulating material, such as silicon oxide, silicon nitride, silicon oxynitride, or other high-k insulating materials.

[0054] refer to Figure 1D and Figure 2D In one or more embodiments, the anti-reflective coatings 110 and 210 may be removed after the channels 114 and 214 are formed.

[0055] Any suitable semiconductor material can be used for channels 114 and 214, such as silicon, germanium, silicon-germanium, or other compound semiconductor materials, such as III-V, II-VI, or conductive or semiconducting oxides, or other materials. The semiconductor material can be amorphous, polycrystalline, or single-crystal. The semiconductor channel material can be formed by any suitable deposition method. For example, in one embodiment, the semiconductor channel material is deposited by low-pressure chemical vapor deposition (LPCVD). In several other embodiments, the semiconductor channel material can be a recrystallized polycrystalline semiconductor material formed by recrystallizing the initially deposited amorphous semiconductor material.

[0056] In one or more embodiments, the nanocrystalline diamond layer 108 produced according to the first formulation has a thickness T1. In one or more embodiments, the nanocrystalline diamond layer 108 has a thickness of approximately... to approximately The thickness T1 is within the range. Depending on the etching chemistry of the energy-sensitive resist material 112 used in the manufacturing process, an optional sealing layer (not shown) may be formed on the nanocrystalline diamond layer 108 prior to the formation of the energy-sensitive resist material 112. When the pattern is transferred into the nanocrystalline diamond layer, the optional sealing layer acts as a mask for the nanocrystalline diamond layer 108 and protects the nanocrystalline diamond layer 108 from damage by the energy-sensitive resist material 112.

[0057] In one or more embodiments, the nanocrystalline diamond layer 208 produced according to the second formulation has a thickness T2. In one or more embodiments, the nanocrystalline diamond layer 208 has a thickness of approximately... to approximately Thickness T2 within the range.

[0058] like Figure 1A and Figure 2A As depicted, energy-sensitive photoresist materials 112 and 212 can be formed on nanocrystalline diamond layers 108 and 208. Layers of energy-sensitive photoresist materials 112 and 212 can be spin-coated onto the substrate to approximately... to approximately Thickness within the range. Most energy-sensitive resist materials are sensitive to ultraviolet (UV) radiation with wavelengths less than about 450 nm, and for some applications, wavelengths of 245 nm or 193 nm are required. Patterning is introduced into layers of energy-sensitive resist materials 112 and 212. For example... Figure 1A and Figure 2A As shown, after the energy-sensitive resist materials 112 and 212 have been developed, the desired pattern consisting of holes / openings 111 and 211 exists in the energy-sensitive resist materials 112 and 212. Subsequently, refer to... Figure 1B and Figure 2B The pattern defined in the energy-sensitive resist materials 112, 212 is transmitted through the antireflective coatings 110, 210 by using energy-sensitive resist materials 110, 210 as masks and forming openings / holes 113, 213.

[0059] refer to Figure 1C and Figure 2C Patterns defined in antireflective coatings 110 and 210 are transferred through nanocrystalline diamond layers 108 and 208. Using a suitable chemical etchant, the nanocrystalline diamond layers 108 and 208 are selectively etched over energy-sensitive resist materials 110 and 210 and multiple material layers 104, 106, 204, and 206, thereby extending holes 113 and 213 into substrates 102 and 202, forming channels 114 and 214. Suitable chemical etchants include ozone, oxygen, or ammonia plasma.

[0060] Current carbon hard-film deposition processes are performed at extremely high temperatures and have low hydrogen (H) content, but these films are primarily sp. 2 This results in lower density and modulus, leading to lower etch selectivity and pattern integrity. Modulus is a measure of the mechanical strength of a film. Films with low modulus, especially thick films, exhibit line wiggling and other problems.

[0061] Figures 3A to 3C A cross-sectional view of a device 300 processed according to one or more embodiments of the method is shown. Figure 5 A process flow diagram is depicted for method 500 according to one or more embodiments. In some embodiments, a substrate for processing is provided prior to operation 502. As used herein, the term "provided" means placing the substrate in a location or environment for further processing. In one or more embodiments, the substrate is maintained in a range from about 200°C to about 1000°C, including a range from about 500°C to about 650°C.

[0062] In one or more embodiments, the process chamber used can be any CVD process chamber with a plasma source (e.g., remote, microwave, capacitively coupled plasma (CCP), or inductively coupled plasma (ICP)), such as one of the processing chambers described above. In some embodiments, the flow rates and other processing parameters described below are used for 300 mm substrates. It should be understood that these parameters can be adjusted based on the size of the substrate being processed and the type of chamber used without departing from the various embodiments disclosed herein.

[0063] As used herein, "substrate surface" refers to any substrate or material surface formed on a substrate on which a film processing can be performed. For example, depending on the application, substrate surfaces on which processing can be performed include materials such as silicon, silicon oxide, silicon nitride, doped silicon, germanium, gallium arsenide, gallium nitride, glass, sapphire, and any other materials such as metals, metal nitrides, metal alloys, and other conductive materials. Substrate surfaces may also include dielectric materials such as silicon dioxide and carbon-doped silicon oxide. Substrates can have various sizes, such as wafers of 200 mm, 300 mm, or other diameters, and rectangular or square grids.

[0064] The device layer can then be deposited on the processed surface. The device layer can be as shown in the reference... Figures 1A to 1D and Figures 2A to 2D The device layer described. Furthermore, a device layer can be one of multiple device layers. Device layers can work together to form one or more feature structures or components, such as components of a 3D NAND device.

[0065] In operation 502, a first nanocrystalline diamond layer is deposited on a substrate, or in some embodiments, on a device layer. The first nanocrystalline diamond layer may have an average grain size of less than 6 nm. In one example, the first nanocrystalline diamond layer has an average grain size between 2 nm and 5 nm. Small grain sizes, such as below 6 nm, allow for better control of adhesion between the hard mold layer and the underlying layer, and for smaller hard mold layers. Arbitrary placement of larger grain sizes during deposition will increase the number of contactless spaces between the hard mold layer and the underlying layer. Contactless spaces are spaces between the hard mold layer and the underlying layer where the hard mold layer does not directly contact the underlying layer due to the shape and size of the grains in the hard mold layer and due to the roughness of the underlying layer itself. Larger contactless spaces reduce layer adhesion and reduce heat transfer between the hard mold and the underlying layer. The size of the contactless spaces is reduced by smaller grains because smaller grains can be more densely packed than larger grains when deposited as part of a layer. Furthermore, due to the smaller grain size, the layer can be made thinner than a larger grain size layer while maintaining good contact with the underlying layer.

[0066] The deposition of the first nanocrystalline diamond layer at operation 502 can be initiated by delivering a deposition gas into the CVD process chamber at a first pressure using a plasma source (e.g., remote, microwave, CCP, or ICP). The deposition gas includes a carbon-containing precursor and a hydrogen-containing gas. In one or more embodiments, the carbon-containing precursor is an alkane precursor. The alkane precursor can be a saturated unbranched hydrocarbon, such as methane, ethane, propane, and combinations of methane, ethane, and propane. Other alkane precursors include n-butane, n-pentane, n-hexane, n-heptane, n-octane, and combinations of n-butane, n-pentane, n-hexane, n-heptane, and n-octane. The hydrogen-containing gas can include hydrogen (H2), water (H2O), ammonia (NH3), or other hydrogen-containing molecules.

[0067] The deposition gas is then delivered into the CVD process chamber. The deposition gas may be mixed within the chamber or before entering the chamber. The deposition gas is delivered at relatively high pressures, such as greater than 5 Torr. In one embodiment, the deposition gas is delivered between about 10 Torr and 100 Torr, such as about 50 Torr.

[0068] The deposited gas can then be activated to generate activated deposited gas. The deposited gas can be activated by forming plasma using a power source. Any power source capable of activating the gas into reactive components and maintaining the reactive components in the plasma can be used. For example, a power discharge technique based on radio frequency (RF), direct current (DC), or microwave (MW) can be used. The power source generates source plasma power, which is applied to the CVD process chamber by a plasma source (e.g., remote, microwave, CCP, or ICP) to generate and maintain the plasma of the deposited gas. In several embodiments using RF power for the source plasma power, the source plasma power can be delivered at a frequency of about 2 MHz to about 170 MHz and at a power level between 500 W and 12000 W. Several other embodiments include delivering source plasma power from about 2000 W to about 12000 W. The applied power can be adjusted according to the size of the substrate being processed. In one or more embodiments, microwave plasma is applied in the form of a continuous wave at a power range of about 2 kW to about 12 kW.

[0069] Based on the high pressure and other factors in the CVD chamber, the formation of ionized components will be minimized while the formation of free radicals will be maximized. Without being bound by theory, it is assumed that the nanocrystalline diamond layer should primarily consist of sp... 3 Key instead of sp 2 Furthermore, it is believed that more sps can be achieved by increasing the amount of free radical components beyond the ionized components during layer deposition. 3 Bonding. Ionized components are highly reactive and may require more space to move compared to free radicals. Increasing pressure reduces electron energy, increasing the likelihood of collisions with other molecules. The decrease in electron energy and the increase in the number of collisions favor free radical formation over ion formation.

[0070] Once activated, the activated deposition gas is then delivered via a second space with a second pressure. The second space can be a second chamber between the process space and the CVD chamber with the plasma source, or another enclosed region. In one example, the second space is the connection between the CVD chamber with the plasma source and the process space.

[0071] The second pressure is lower than the first pressure. Movement from the remote plasma chamber to the second space, based on flow rate, total space variation, or a combination of flow rate and total space variation, results in a pressure decrease in the activated deposition gas within the second space. This pressure decrease allows for better deposition of radical components while reducing collisions between ionized components and the deposited layer. In one embodiment, the second pressure is between about 0.1 Torr and about 5 Torr. In one or more embodiments, the second pressure is in the range of about 0.1 Torr to about 1 Torr.

[0072] In one or more embodiments, an activated deposition gas comprising methane (CH4) / carbon dioxide (CO2), in a flow rate ranging from about 2 sccm to about 10 sccm, is subsequently delivered to a substrate in the process space of the process chamber. The substrate can be of any composition, such as a crystalline silicon substrate. The substrate may also include one or more feature structures, such as vias or interconnects. The substrate may be supported on a substrate support. The substrate support may be maintained within a specific temperature range. In one embodiment, the substrate support is maintained in a temperature range between about 500°C and about 650°C.

[0073] like Figure 3A As depicted herein, a pre-seeded substrate 302 can be used for the deposition of a nanocrystalline layer. In one embodiment, the substrate 302 is immersed in or otherwise coated in a seed solution to form suspended nanodiamonds 304 on the substrate 302. The seed solution may be an ethanol-based nanodiamond suspension. The substrate 302 may be immersed in the suspension during ultrasonic treatment, which causes a portion of the suspended nanodiamonds 304 to adhere to the surface of the substrate 302. Other pre-seeding techniques may be used without departing from the various embodiments described herein.

[0074] refer to Figure 3B A first nanocrystalline diamond layer 306 is then deposited on the surface of the substrate 302. Free radicals from the previously formed activated deposition gas bombard the substrate surface to form the first nanocrystalline diamond layer 306. Low pressure is considered beneficial to the sp(s) in the first nanocrystalline diamond layer 306 formed from remotely generated free radicals. 3 Bond formation. The higher pressure in the CVD plasma chamber allows for preferential free radical formation, while the lower pressure in the process space allows for more uniform deposition from previously formed free radicals.

[0075] Once the first nanocrystalline diamond layer 306 is deposited, hydrogen-containing gas is delivered into the CVD plasma chamber. The hydrogen-containing gas can be delivered individually or the gas flow from the previous step can be maintained. No alkane precursors are present in this portion. The hydrogen-containing gas can be delivered together with an inert gas or as part of a combination of multiple hydrogen-containing gases. In one or more embodiments, hydrogen (H2) is delivered at a flow rate in the range of about 90 sccm to about 96 sccm.

[0076] The hydrogen-containing gas is then activated to produce activated hydrogen-containing gas. The hydrogen-containing gas can be converted into plasma using the same pressure, temperature, power type, power range, and other parameters discussed for plasma formation, which are used to form activated deposition gases.

[0077] Once activated hydrogen-containing gas is formed, it can be delivered to the substrate in the process space. The process space and the substrate can be maintained at the same pressure, temperature, and other parameters as described above. During the deposition process, it is considered that polymers can form on the surface of the deposited nanocrystalline diamond layer. Polymers can affect further deposition and otherwise degrade the properties of the deposited layer. By delivering activated hydrogen-containing gas to the deposited layer, the polymers are made volatile and can subsequently be removed from the chamber so that they do not affect subsequent deposition processes.

[0078] The above steps can then be repeated to deposit a second nanocrystalline diamond layer 308, which has a lower roughness than the first nanocrystalline diamond layer 306. In operation 504, the second nanocrystalline diamond layer 308 is deposited on the first nanocrystalline diamond layer. The second nanocrystalline diamond layer can have an average grain size of less than 6 nm. In one example, the second nanocrystalline diamond layer has an average grain size between 2 nm and 5 nm. Small grain sizes, such as less than 6 nm, allow for better control of adhesion between the hard mold layer and the underlying layer, and smaller hard mold layers. Arbitrary placement of larger grain sizes during deposition will increase the number of contactless spaces between the hard mold layer and the underlying layer. Contactless spaces are spaces between the hard mold layer and the underlying layer where the hard mold layer does not directly contact the underlying layer due to the shape and size of the grains in the hard mold layer and due to the roughness of the underlying layer itself. Larger contactless spaces reduce layer adhesion and reduce heat transfer between the hard mold layer and the underlying layer. The size of the contactless space is reduced by using smaller grains because smaller grains can be filled more tightly than larger grains when deposited as part of a layer. Furthermore, due to the smaller grain size, layers can be made thinner than larger grain-sized layers while maintaining good contact with the underlying layer.

[0079] The deposition of the second nanocrystalline diamond layer at Operation 504 can be initiated by delivering a deposition gas into the CVD plasma chamber under a first pressure. The deposition gas includes a carbon-containing precursor and a hydrogen-containing gas. In one or more embodiments, the carbon-containing precursor is an alkane precursor. The alkane precursor can be a saturated unbranched hydrocarbon, such as methane, ethane, propane, and combinations of methane, ethane, and propane. Other alkane precursors include n-butane, n-pentane, n-hexane, n-heptane, n-octane, and combinations of n-butane, n-pentane, n-hexane, n-heptane, and n-octane. The hydrogen-containing gas can include hydrogen (H2), water (H2O), ammonia (NH3), or other hydrogen-containing molecules. The deposition gas may further include an inert gas. The inert gas can be a noble gas, such as argon (Ar).

[0080] The deposited gas is then delivered into the CVD plasma chamber. The deposited gas may be mixed within the chamber or before entering the chamber. The deposited gas is delivered at relatively high pressures, such as greater than 5 Torr. In one embodiment, the deposited gas is delivered between about 10 Torr and 100 Torr, such as about 50 Torr.

[0081] The deposited gas can then be activated to generate activated deposited gas. The deposited gas can be activated by forming plasma using a power source. Any power source capable of activating the gas into reactive components and maintaining the reactive components in the plasma can be used. For example, power discharge techniques based on radio frequency (RF), direct current (DC), or microwave (MW) can be used. The power source generates source plasma power, which is applied to the CVD plasma chamber to generate and maintain the plasma of the deposited gas. In several embodiments using RF power for the source plasma power, the source plasma power can be delivered from a frequency of about 2 MHz to about 170 MHz and at power levels between 500 W and 12000 W. Several other embodiments include delivering source plasma power at about 2000 W to about 12000 W. The applied power can be adjusted according to the size of the substrate being processed.

[0082] Based on the high pressure and other factors in the remote plasma chamber, the formation of ionized components will be minimized while the formation of free radicals will be maximized. Without being bound by theory, it is assumed that the nanocrystalline diamond layer should primarily consist of sp... 3 Key instead of sp 2 Furthermore, it is believed that more sps can be achieved by increasing the amount of free radical components beyond the ionized components during layer deposition. 3Bonding. Ionized components are highly reactive and may require more space to move compared to free radicals. Increasing pressure reduces electron energy, increasing the likelihood of collisions with other molecules. The decrease in electron energy and the increase in the number of collisions favor free radical formation over ion formation.

[0083] Once activated, the activated deposition gas, comprising methane (CH4) / carbon dioxide (CO2) / argon (Ar) in a flow rate range of 2-10 / 2-10 / 2-90 sccm, is then delivered via a second space having a second pressure. The second space can be a second chamber between the process space and the CVD plasma chamber, or another enclosed region. In one example, the second space is the connection between the CVD plasma chamber and the process space.

[0084] The second pressure is lower than the first pressure. Movement from the CVD plasma chamber to the second space, based on flow rate, total space variation, or a combination of flow rate and total space variation, results in a pressure decrease in the activated deposition gas within the second space. This pressure decrease allows for better deposition of radical components while reducing collisions between ionized components and the deposited layer. In one embodiment, the second pressure is between about 0.1 Torr and about 5 Torr. In one or more embodiments, the second pressure is in the range of about 0.1 Torr to about 1 Torr.

[0085] The activated deposition gas, a mixture of methane (CH4) / carbon dioxide (CO2) / argon (Ar), is then delivered to the substrate in the process space of the process chamber at flow rates ranging from approximately 2-10 / 2-10 / 2-90 sccm. In one embodiment, the substrate support is maintained at a temperature between approximately 500°C and approximately 650°C.

[0086] A second nanocrystalline diamond layer 308 was subsequently deposited on the surface of the first nanocrystalline diamond layer 306. Free radicals from the previously formed activated deposited gas bombard the surface to form the second nanocrystalline diamond layer 308. Low pressure is considered beneficial for the formation of sp from remotely formed free radicals in the second nanocrystalline diamond layer 308. 3 Bonding. Higher pressure in the remote plasma source allows for preferential radical formation, while lower pressure in the process space allows for more uniform deposition from previously formed radicals. The second nanocrystalline diamond layer 308 has a smooth surface with an AFM of less than about 15 nm.

[0087] Once the nanocrystalline diamond layer is deposited, hydrogen-containing gas is delivered to a remote plasma chamber. The hydrogen-containing gas can be delivered individually or the gas flow from previous steps can be maintained. No alkane precursors are present in this portion. The hydrogen-containing gas can be delivered together with an inert gas or as part of a combination of multiple hydrogen-containing gases. In one or more embodiments, hydrogen (H2) is delivered at a flow rate ranging from about 1 sccm to about 94 sccm, including from about 15 sccm to about 45 sccm.

[0088] The hydrogen-containing gas is then activated to produce activated hydrogen-containing gas. The hydrogen-containing gas can be converted into plasma using the same pressure, temperature, power type, power range, and other parameters discussed for plasma formation, which are used to form activated deposition gases.

[0089] Once activated hydrogen-containing gas is formed, it can be delivered to the substrate in the process space. The process space and the substrate can be maintained at the same pressure, temperature, and other parameters as described above. During the deposition process, it is considered that polymers can form on the surface of the deposited nanocrystalline diamond layer. Polymers can affect further deposition and otherwise degrade the properties of the deposited layer. By delivering activated hydrogen-containing gas to the deposited layer, the polymers are made volatile and can subsequently be removed from the chamber so that they do not affect subsequent deposition processes.

[0090] At decision point 506, it is determined whether the nanocrystalline hard mold 308 has achieved the predetermined roughness and thickness. Each deposition cycle produces approximately... With the agreement The thickness between, such as approximately The thickness. By repeating the above steps, the previous layer acts as a seed layer for the next deposition, thereby allowing the deposition of the total desired thickness. In one embodiment, the nanocrystalline diamond stack is deposited to a thickness of 1 μm.

[0091] If at decision point 506 the nanocrystalline diamond stack is too coarse or not thick enough, then the cycle returns to operations 502 and 504 for further deposition steps.

[0092] If, at decision point 506, the nanocrystalline diamond stack has achieved the desired roughness and thickness, then the process continues. In operation 508, the nanocrystalline diamond layer can then be selectively patterned and etched. Patterning may include the deposition of photoresist 112, 212 on the nanocrystalline diamond layer. The photoresist 112, 212 is then exposed to an appropriate radiation wavelength to create patterns of openings / holes 111, 211. The patterns are then etched into the photoresist 112, 212, and subsequently into the nanocrystalline diamond layer.

[0093] In operation 510, the device can then be etched to form a feature structure or channel. As a pattern is formed in the nanocrystalline diamond layer, the device can then be etched. The device is etched with an etchant that selectively etches the device layers 104, 106, 204, 206 above the nanocrystalline diamond layers 108, 208. The device layers are etched using chemical reactions and techniques well-known in the art. In one embodiment, the etchant is a chlorine-containing etchant.

[0094] In operation 512, the nanocrystalline diamond layer can subsequently be removed from the surface of the device. For example, a plasma ashing process can be used to ashing the nanocrystalline diamond layer from the surface of the device layer. The plasma ashing process may include activating an oxygen-containing gas, such as O2. When using O2, the ashing rate is approximately... / minute or more. Nanocrystalline diamond layers can be ashed using a high aspect ratio etching system.

[0095] Figures 4A to 4D A cross-sectional view of a device 400 processed according to one or more embodiments. Figure 6 A process flow diagram is depicted for method 600 according to one or more embodiments. In some embodiments, a substrate is provided for processing prior to operation 602. As used herein, the term "provided" means placing the substrate in a location or environment for further processing. In one or more embodiments, the substrate is held at a temperature ranging from about 500°C to about 650°C.

[0096] The device layer can then be deposited on the processed surface. The device layer can be as shown in the reference... Figures 1A to 1D and Figures 2A to 2D The device layer described. Furthermore, a device layer can be one of multiple device layers. Device layers can work together to form one or more feature structures or components, such as components of a 3D NAND device.

[0097] In operation 602, a first nanocrystalline diamond layer is deposited on a substrate, or in some embodiments on a device layer. The nanocrystalline diamond layer can have an average grain size of less than 6 nm. In one example, the nanocrystalline diamond layer has an average grain size between 2 nm and 5 nm. Small grain sizes, such as below 6 nm, allow for better control of adhesion between the hard mold layer and the underlying layer, and smaller hard mold layers. Arbitrary placement of larger grain sizes during deposition will increase the number of contactless spaces between the hard mold layer and the underlying layer. Contactless spaces are spaces between the hard mold layer and the underlying layer where the hard mold layer does not directly contact the underlying layer due to the shape and size of the grains in the hard mold layer and due to the roughness of the underlying layer itself. Larger contactless spaces reduce layer adhesion and reduce heat transfer between the hard mold and the underlying layer. Smaller grains reduce the size of the contactless spaces because smaller grains can be more densely packed when deposited as part of a layer compared to larger grains. Furthermore, due to the smaller grain size, the layer can be made thinner than a layer with a larger grain size while maintaining good contact with the underlying layer.

[0098] The deposition of a 602 nm crystalline diamond layer can be initiated by delivering a deposition gas into a CVD chamber (equipped with a plasma source) at a first pressure. The deposition gas includes a carbon-containing precursor and a hydrogen-containing gas. In one or more embodiments, the carbon-containing precursor is an alkane precursor. The alkane precursor can be a saturated, unbranched hydrocarbon, such as methane, ethane, propane, and combinations thereof. Other alkane precursors include n-butane, n-pentane, n-hexane, n-heptane, n-octane, and combinations thereof. The hydrogen-containing gas can include hydrogen (H₂), water (H₂O), ammonia (NH₃), or other hydrogen-containing molecules.

[0099] The deposition gas is then delivered into a CVD chamber (with a plasma source). The deposition gas may be mixed within the chamber or before entering the chamber. The deposition gas is delivered at relatively high pressures, such as greater than 5 Torr. In one embodiment, the deposition gas is delivered between about 10 Torr and 100 Torr, such as about 50 Torr.

[0100] The deposited gas can then be activated to generate activated deposited gas. The deposited gas can be activated by forming plasma using a power source. Any power source capable of activating the gas into reactive components and maintaining the reactive components in plasma can be used. For example, power discharge techniques based on radio frequency (RF), direct current (DC), or microwave (MW) can be used. The power source generates source plasma power, which is applied to the CVD chamber (having a plasma source) to generate and maintain the plasma of the deposited gas. In embodiments using RF power for the source plasma power, the source plasma power can be delivered at frequencies from about 2 MHz to about 170 MHz and at power levels between 500 W and 12000 W. Several other embodiments include delivering source plasma power at about 2000 W to about 12000 W. The applied power can be adjusted according to the size of the substrate being processed. In one or more embodiments, microwave plasma is applied in the form of a continuous wave at a power range from about 2 kilowatts (kW) to about 12 kilowatts (kW).

[0101] Based on the high pressure in the CVD chamber (with a plasma source) and other factors, the formation of ionized components will be minimized while the formation of free radicals will be maximized. Without being bound by theory, it is assumed that the nanocrystalline diamond layer should primarily consist of sp... 3 Key instead of sp 2 Furthermore, it is believed that more sps can be achieved by increasing the amount of free radical components beyond the ionized components during layer deposition. 3 Bonding. Ionized components are highly reactive and may require more space to move compared to free radicals. Increasing pressure reduces electron energy, increasing the likelihood of collisions with other molecules. The decrease in electron energy and the increase in the number of collisions favor free radical formation over ion formation.

[0102] Once activated, the activated deposition gas is then delivered via a second space with a second pressure. The second space can be a second chamber between the process space and the remote plasma chamber, or another enclosed region. In one example, the second space is the connection between the remote plasma chamber and the process space.

[0103] The second pressure is lower than the first pressure. Movement from the remote plasma chamber to the second space, based on flow rate, total space variation, or a combination of flow rate and total space variation, results in a pressure decrease in the activated deposition gas within the second space. This pressure decrease allows for better deposition of radical components while reducing collisions between ionized components and the deposited layer. In one embodiment, the second pressure is between about 0.1 Torr and about 5 Torr. In one or more embodiments, the second pressure is in the range of about 0.1 Torr to about 1 Torr.

[0104] An activated deposition gas of methane (CH4) / carbon dioxide (CO2), comprising a flow rate in the range of about 2 sccm to about 10 sccm, is then delivered to a substrate in the process space of the process chamber. The substrate can have any composition, such as a crystalline silicon substrate. The substrate may also include one or more feature structures, such as through-holes or interconnects. The substrate may be supported on a substrate support. The substrate support may be maintained within a specific temperature range. In one embodiment, the substrate support is maintained in a temperature range between about 500°C and about 650°C.

[0105] like Figure 4A As depicted herein, a pre-seeded substrate 402 can be used for the deposition of a nanocrystalline layer. In one embodiment, the substrate 402 is immersed in or otherwise coated in a seed solution to form suspended nanodiamonds 404 on the substrate 402. The seed solution may be an ethanol-based nanodiamond suspension. The substrate 402 may be immersed in the suspension during ultrasonic treatment, which causes a portion of the suspended nanodiamonds 404 to adhere to the surface of the substrate 402. Other pre-seeding techniques may be used without departing from the various embodiments described herein.

[0106] refer to Figure 4B A nanocrystalline diamond layer 406 is then deposited on the surface of the substrate 402. Free radicals from the previously formed activated deposition gas bombard the substrate surface to form the nanocrystalline diamond layer 406. It is believed that low pressure is beneficial for the formation of sp from remotely formed free radicals in the nanocrystalline diamond layer 406. 3 Bonding. Higher pressure in a remote plasma source allows for preferential radical formation, while lower pressure in the process space allows for more uniform deposition of previously formed radicals.

[0107] Once the nanocrystalline diamond layer 406 is deposited, hydrogen-containing gas is delivered into the CVD chamber (equipped with a plasma source). The hydrogen-containing gas can be delivered individually or the gas flow from the previous step can be maintained. No alkane precursors are present in this section. The hydrogen-containing gas can be delivered together with an inert gas or as part of a combination of multiple hydrogen-containing gases. In one or more embodiments, hydrogen (H2) is delivered at a flow rate in the range of 90 sccm to 96 sccm.

[0108] The hydrogen-containing gas is then activated to produce activated hydrogen-containing gas. The hydrogen-containing gas can be converted into plasma using the same pressure, temperature, power type, power range, and other parameters discussed for plasma formation, which are used to form activated deposition gases.

[0109] Once activated hydrogen-containing gas is formed, it can be delivered to the substrate in the process space. The process space and the substrate can be maintained at the same pressure, temperature, and other parameters as described above. During the deposition process, it is considered that polymers can form on the surface of the deposited nanocrystalline diamond layer. Polymers can affect further deposition and otherwise degrade the properties of the deposited layer. By delivering activated hydrogen-containing gas to the deposited layer, the polymers are made volatile and can subsequently be removed from the chamber so that they do not affect subsequent deposition processes.

[0110] refer to Figure 4C and Figure 6 In operation 604, the nanocrystalline diamond layer 406 is exposed to an inert gas plasma to form a smooth-surfaced nanocrystalline diamond layer 408. In one or more embodiments, the gas flow comprises one or more inert gases selected from helium (He), neon (Ne), and argon (Ar). In one or more specific embodiments, the inert gas plasma comprises argon (Ar), delivered at a flow rate ranging from about 50 sccm to about 200 sccm, pulsed with microwave power ranging from about 2 kW to about 12 kW at 10% to 90%, at pressures ranging from about 0.1 Torr to about 1 Torr, and at temperatures ranging from about 500°C to about 650°C.

[0111] The inert gas is then delivered to a remote plasma chamber. The inert gas is delivered at relatively high pressures, such as greater than 5 Torr. In one embodiment, the inert gas is delivered at pressures between about 10 Torr and 100 Torr, such as about 50 Torr.

[0112] The inert gas can then be activated to generate activated inert gas. The inert gas can be activated by forming plasma using a power source. Any power source capable of activating the gas into a reactive component and maintaining the reactive component in plasma can be used. For example, power discharge techniques based on radio frequency (RF), direct current (DC), or microwave (MW) can be used. The power source generates source plasma power, which is applied to the CVD chamber (having a plasma source) to generate and maintain a plasma of inert gas. In several embodiments using RF power for the source plasma power, the source plasma power can be delivered at frequencies from about 2 MHz to about 170 MHz and at power levels between 500 W and 12000 W. Other embodiments include delivering source plasma power from about 2000 W to about 12000 W. The applied power can be adjusted according to the size of the substrate being processed.

[0113] Based on the high pressure in the CVD chamber (with a plasma source) and other factors, the formation of ionized components will be minimized while the formation of free radicals will be maximized, resulting in the smoothing of the surface of the nanocrystalline diamond layer 406 to form a smooth nanocrystalline diamond layer 408.

[0114] Once activated, an activated inert gas, comprising argon (Ar) at a flow rate ranging from about 50 sccm to about 200 sccm, is subsequently delivered via a second space having a second pressure. The second space can be a second chamber between the process space and the remote plasma chamber, or another enclosed region. In one example, the second space is the connection between the remote plasma chamber and the process space.

[0115] The second pressure is lower than the first pressure. Movement from the remote plasma chamber to the second space, based on flow rate, total space variation, or a combination of flow rate and total space variation, results in a pressure decrease in the activated deposition gas within the second space. This pressure decrease allows for better deposition of radical components while reducing collisions between ionized components and the deposited layer. In one embodiment, the second pressure is between about 0.1 Torr and about 5 Torr. In one or more embodiments, the second pressure is in the range of about 0.1 Torr to about 1 Torr.

[0116] The activated inert gas is then delivered to the nanocrystalline diamond layer 406 within the process space of the process chamber at a flow rate ranging from about 50 sccm to about 200 sccm. In one embodiment, the substrate support is maintained in a temperature range between about 500°C and about 650°C.

[0117] The smooth nanocrystalline diamond layer 408 has a smooth surface with an roughness (AFM) of less than about 15 nm.

[0118] At decision point 606, it is determined whether the smooth nanocrystalline hard mold 408 has achieved the predetermined roughness and thickness. Each deposition cycle produces approximately With the agreement The thickness between, such as approximately The thickness. By repeating the above steps, the previous layer acts as a seed layer for the next deposition, thereby allowing the deposition of the total desired thickness. In one embodiment, the nanocrystalline diamond stack is deposited to a thickness of 1 μm.

[0119] If at decision point 606 the nanocrystalline diamond stack is too coarse or not thick enough, then the cycle returns to operations 602 and 604 for further deposition and smoothing steps to produce a thick and smooth nanocrystalline diamond stack 410 (see...). Figure 4D ).

[0120] If, at decision point 606, the nanocrystalline diamond stack has achieved the desired roughness and thickness, then the process continues. In operation 608, the nanocrystalline diamond layer can then be selectively patterned and etched. Patterning may include depositing photoresist 112, 212 on the nanocrystalline diamond layer. The photoresist 112, 212 is then exposed to an appropriate radiation wavelength to create a pattern of openings / holes 111, 211. The pattern is then etched into the photoresist 112, 212, and subsequently etched into the nanocrystalline diamond layer.

[0121] In operation 610, the device can then be etched to form a feature structure or channel. As a pattern is formed in the nanocrystalline diamond layer, the device can then be etched. The device is etched with an etchant that selectively etches the device layers 104, 106, 204, 206 above the nanocrystalline diamond layers 108, 208. The device layers are etched using chemical reactions and techniques well-known in the art. In one embodiment, the etchant is a chlorine-containing etchant.

[0122] In operation 612, the nanocrystalline diamond layer can subsequently be removed from the surface of the device. For example, a plasma ashing process can be used to ashing the nanocrystalline diamond layer from the surface of the device layer. The plasma ashing process may include activating an oxygen-containing gas, such as O2. When using O2, the ashing rate is approximately... Minutes or longer. Nanocrystalline diamond layers can be ashed using a high aspect ratio etching system.

[0123] In the foregoing description, various embodiments of this disclosure have been described with reference to several specific exemplary embodiments. It will be apparent that various modifications can be made to this disclosure without departing from the broad spirit and scope of the various embodiments set forth in the following claims. Therefore, this specification and the accompanying drawings should be viewed in an illustrative rather than restrictive manner.

[0124] Throughout this specification, the terms "one embodiment," "some embodiments," "one or more embodiments," or "an embodiment" refer to a particular feature, structure, material, or characteristic described in connection with that embodiment, which is included in at least one embodiment of this disclosure. Therefore, expressions such as "in one or more embodiments," "in some embodiments," "in one embodiment," or "in an embodiment" appearing in various places throughout this specification do not necessarily refer to the same embodiment of this disclosure. Furthermore, in one or more embodiments, the particular feature, structure, material, or characteristic may be combined in any suitable manner.

[0125] Although the disclosure herein has been described with reference to several particular embodiments, it should be understood that these embodiments are merely illustrative of the principles and applications of this disclosure. It will be apparent to those skilled in the art that various modifications and variations can be made to the methods and apparatus of this disclosure without departing from the spirit and scope of this disclosure. Therefore, this disclosure is intended to include modifications and variations within the scope of the appended claims and their equivalents.

Claims

1. A processing method, comprising: A first deposition gas comprising methane and carbon dioxide is delivered and activated in a first space having a pressure greater than 5 Torr; The activated first deposition gas is delivered in a second space having a pressure between 0.1 Torr and 5 Torr, wherein the flow rate of the activated first deposition gas is in the range of 2 sccm to 10 sccm. A first nanocrystalline diamond layer is deposited on a substrate using microwave power in the range of 2kW to 12kW, pressure of 0.1 Torr to 1 Torr, and temperature of 500°C to 650°C. The first nanocrystalline diamond layer has a first thickness, a first roughness, a first hardness, and a first modulus. In the first space having a pressure greater than 5 Torr, a second deposition gas comprising methane, carbon dioxide and argon is delivered and activated. The activated second deposition gas is delivered in a second space having a pressure between 0.1 Torr and 5 Torr, wherein the activated second deposition gas comprises methane with a flow rate in the range of 2 sccm to 10 sccm, carbon dioxide with a flow rate in the range of 2 sccm to 10 sccm, and argon with a flow rate in the range of 2 sccm to 90 sccm; and Using microwave power in the range of 2kW to 12kW, and pulse strength of 10% to 90%, A second nanocrystalline diamond layer is deposited on the first nanocrystalline diamond layer using a pressure of 0.1 Torr to 1 Torr and a temperature of 500°C to 650°C. The second nanocrystalline diamond layer has a second thickness and a second roughness. The first thickness is greater than the second thickness, and the second roughness is less than the first roughness.

2. The processing method of claim 1, further comprising depositing a seed crystal layer on the substrate prior to depositing the first nanocrystalline diamond layer.

3. The processing method according to claim 2, wherein the seed crystal layer comprises nanocrystalline diamond.

4. The processing method of claim 1, further comprising exposing the substrate to hydrogen plasma to form the first nanocrystalline diamond layer.

5. The processing method of claim 1, further comprising exposing the first nanocrystalline diamond layer to hydrogen plasma to form the second nanocrystalline diamond layer.

6. The processing method of claim 1, wherein the first thickness is in the range of 250 nm to 650 nm.

7. The processing method of claim 1, wherein the second thickness is in the range of 5 nm to 200 nm.

8. The processing method of claim 1, wherein the first roughness is greater than 25 nm.

9. The processing method of claim 1, wherein the second roughness is less than 15 nm.

10. A processing method, comprising: Deposit gas comprising methane and carbon dioxide is delivered and activated in a first space having a pressure greater than 5 Torr; The activated deposition gas is delivered in a second space having a pressure between 0.1 Torr and 5 Torr, wherein the flow rate of the activated deposition gas is in the range of 2 sccm to 10 sccm. A first nanocrystalline diamond layer is deposited on a substrate, the first nanocrystalline diamond layer having a first thickness, a first roughness, a first hardness and a first modulus; and The first nanocrystalline diamond layer is exposed to an inert gas plasma to form a smooth nanocrystalline diamond layer, wherein the inert gas plasma comprises argon, is pulsed with microwave power ranging from 2 kW to 12 kW at 10% to 90%, pressure ranging from 0.1 Torr to 1 Torr, and temperature ranging from 500°C to 650°C.

11. The processing method of claim 10, further comprising depositing a seed crystal layer on the substrate prior to depositing the first nanocrystalline diamond layer.

12. The processing method of claim 11, wherein the seed crystal layer comprises nanocrystalline diamond.

13. The processing method of claim 10, further comprising exposing the substrate to hydrogen plasma to form the first nanocrystalline diamond layer.

14. The processing method of claim 10, wherein the inert gas plasma further comprises one or more of helium and neon.

15. The processing method of claim 10, wherein the first roughness is greater than 25 nm.

16. The processing method of claim 10, wherein the smooth nanocrystalline diamond layer has a second roughness of less than 15 nm.

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