Amorphous carbon for clearance filling

Abstract

To provide a method for depositing an amorphous carbon layer on a substrate and a method for filling a substrate feature by means of amorphous carbon clearance filling.SOLUTION: A method includes introducing a hydrocarbon source into a processing chamber, introducing a plasma initiation gas into the processing chamber, generating plasma at a temperature exceeding 600°C inside of the processing chamber, forming an amorphous carbon layer on a substrate at a deposition speed exceeding 200 nm / hr, and purging the processing chamber.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE

[0001] Embodiments of the present disclosure relate generally to integrated circuit manufacturing, and more particularly to the deposition of amorphous carbon layers on semiconductor substrates. [Background technology]

[0002]

[0002] Integrated circuits have evolved into complex devices that can contain millions of transistors, capacitors, and resistors on a single chip. Evolution in chip design continually requires faster and denser circuits. The demand for faster circuits with higher circuit density places similar demands on the materials used to fabricate such integrated circuits. In particular, as the dimensions of integrated circuit components have been reduced to sub-micron dimensions, it has become necessary to use not only low-resistivity conductive materials such as copper, but also insulating materials with low dielectric constants, often referred to as low-k dielectric materials, to improve the electrical performance of the devices.

[0003] Fabricating devices with low-k dielectric materials that are free of or have little to no surface defects or feature deformation is challenging. Low-k dielectric materials with a dielectric constant less than about 3.0 are often porous and susceptible to scratching or damage during subsequent process steps, thus increasing the likelihood of defects forming on the substrate surface. Such low-k dielectric materials are often brittle and can deform under conventional polishing processes, such as chemical-mechanical polishing (CMP). One solution to limit or reduce surface defects and deformation of such low-k dielectric materials is to deposit a hard mask over the exposed low-k dielectric material before patterning and etching. The hard mask prevents damage and deformation of the delicate low-k dielectric material. Additionally, the hard mask layer may act as an etch mask in conjunction with conventional lithography techniques to prevent removal of the low-k dielectric material during etching.

[0004] Amorphous hydrogenated carbon (aC:H or α-C:H) is a material that may be used as a hard mask for, among other things, metals, amorphous silicon, and dielectric materials such as silicon dioxide or silicon nitride materials. Amorphous carbon is considered a carbon material that does not have long-range crystalline order and may contain a substantial hydrogen content, for example, on the order of about 10 to 45 atomic % hydrogen. Amorphous carbon has been found to possess chemical inertness, optical transparency, and good mechanical properties. aC:H films can be deposited via a variety of techniques, but plasma-enhanced chemical vapor deposition (PECVD) is widely used due to its cost-effectiveness and film property tunability.

[0005]

[0005] Both logic and memory applications require a carbon gap-fill process. Carbon materials can be removed using plasma etching without affecting the underlying materials. In the fabrication of multi-layer 3D NAND, a sacrificial layer memory hole plug process is desired to protect the bottom-layer memory holes. Such a process must meet the requirements of throughput, dry etch removability, and stability at high temperatures (up to 850°C). Therefore, a gap-fill process that provides amorphous carbon materials that are stable at high temperatures is needed. Summary of the Invention

[0006] One or more embodiments are directed to a method of depositing a film. In one or more embodiments, the method includes performing a deposition cycle. The deposition cycle includes introducing a hydrocarbon source into a process chamber, introducing a plasma-initiating gas into the process chamber, generating a plasma in the process chamber at a temperature greater than 600° C., forming an amorphous carbon layer on a substrate, and purging the process chamber.

[0007] In one or more embodiments, a processing method includes forming an amorphous carbon film on a substrate surface. The substrate surface has at least one feature thereon. The at least one feature extends from the substrate surface to a lower surface by a feature depth. The at least one feature has a width defined by a first sidewall and a second sidewall. The amorphous carbon film is then deposited on the substrate surface, the first sidewall, the second sidewall, and the lower surface of the at least one feature.

[0008] One or more embodiments are directed to a non-transitory computer-readable medium including instructions that, when executed by a controller of a processing chamber, cause the processing chamber to perform operations to perform a deposition cycle, the deposition cycle including introducing a hydrocarbon source into the processing chamber, introducing a plasma-initiating gas into the processing chamber, generating a plasma in the processing chamber at a temperature greater than 600° C., forming an amorphous carbon layer on a substrate, and purging the processing chamber.

[0009]

[0009] In order that the above features of the present disclosure may be understood in detail, a more particular description of the present disclosure briefly summarized above can be made by reference to embodiments, some of which are illustrated in the accompanying drawings. However, it should be noted that the accompanying drawings illustrate only typical embodiments of the present disclosure, and the present disclosure may also admit of other equally effective embodiments, so the accompanying drawings should not be considered to limit the scope of the present disclosure. The embodiments described herein are set forth with the accompanying drawings for purposes of illustration and not limitation, in which like elements are designated by like reference numerals. [Brief explanation of the drawings]

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

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

[0012] 1 illustrates a cross-sectional view of a substrate according to one or more embodiments. [Figure 2A]

[0013] 1 illustrates a cross-sectional view of a substrate according to one or more embodiments. [Figure 2B]

[0014] 1 illustrates a cross-sectional view of a substrate according to one or more embodiments. [Figure 3A]

[0015] 1 illustrates a cross-sectional view of a substrate according to one or more embodiments. [Figure 3B]

[0016] 1 illustrates a cross-sectional view of a substrate according to one or more embodiments. [Figure 4]

[0017] 1 illustrates a cluster tool in accordance with one or more embodiments of the present disclosure. [Figure 5]

[0018] 1 illustrates a flowchart of a processing method in accordance with one or more embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0011]

[0019] Before describing several example embodiments of the present disclosure, it is to be understood that the present disclosure is not limited to the details of construction or process steps set forth in the following description. The present disclosure is capable of other embodiments and of being practiced or carried out in various ways.

[0012]

[0020] As used herein, the term "about" means approximately or approximately, and in the context of a stated numerical value or range, refers to a variation of no more than ±15% of the numerical value. For example, values ​​that vary by ±14%, ±10%, ±5%, ±2%, or ±1% satisfy the definition of about.

[0013]

[0021] As used herein and in the appended claims, the terms "substrate" or "wafer" refer to a surface or a portion of a surface upon which a process acts. Those skilled in the art will also understand that a reference to a substrate may refer to only a portion of a substrate, unless the context clearly dictates otherwise. Furthermore, a reference to deposition on a substrate may refer to both a bare substrate and a substrate having one or more films or features deposited or formed on its surface.

[0014]

[0022] As used herein, "substrate" refers to any substrate or material surface formed on a substrate on which a film treatment is performed during a manufacturing process. For example, substrate surfaces on which treatment may 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, glass, sapphire, and any other materials such as metals, metal nitrides, metal alloys, and other conductive materials, depending on the application. Substrates include, but are not limited to, semiconductor wafers. Substrates may be subjected to pretreatment processes to polish, etch, reduce, oxidize, hydroxylate, anneal, and / or bake the substrate surface. In addition to film treatment directly on the surface of the substrate itself, the present disclosure contemplates that any of the disclosed film treatment steps may be performed on an underlying layer formed on the substrate, as disclosed in more detail below. The term "substrate surface" is intended to include such underlying layers, as the context indicates. Thus, for example, when a film / layer or partial film / layer is deposited on a substrate surface, the exposed surface of the newly deposited film / layer becomes the substrate surface.

[0015]

[0023] As used herein and in the appended claims, the terms "precursor," "reactant," "reactant gas," and the like are used interchangeably to refer to any gas species capable of reacting with the substrate surface.

[0016]

[0024] In one or more embodiments, plasma-enhanced chemical vapor deposition (PECVD) is widely used to deposit amorphous carbon films due to its cost-effectiveness and versatility in film properties. In a PECVD process, a hydrocarbon source, such as a gaseous or liquid hydrocarbon vapor entrained in a carrier gas, is introduced into a PECVD chamber. In one or more embodiments, a plasma is generated by a remote plasma source (RPS) or a capacitively coupled plasma (CCP) or inductively coupled plasma (ICP) with an ambient gas such as argon (Ar), helium (He), ammonia (NH), nitrogen (N), hydrogen (H), or a mixture thereof. A plasma is then initiated in the chamber to generate excited CH radicals. The excited CH radicals chemically bond to the surface of a substrate positioned in the chamber, forming the desired amorphous carbon film thereon.

[0017]

[0025] PECVD techniques involve applying an electric field to a reaction zone near the substrate surface to promote excitation and / or dissociation of reactant gases, creating a plasma of reactive species. The reactivity of the species in the plasma reduces the energy required for a chemical reaction to occur, effectively lowering the temperature required for such PECVD processes.

[0018]

[0026] The embodiments described herein in connection with PECVD processes may be performed using any suitable thin film deposition system. Examples of suitable systems include the DXZ® processing chamber, the PRECISION 5000® system, the PRODUCER® system, the PRODUCER® GT™ system, the PRODUCER® XP Precision™ system, the PRODUCER® SE™ system, the ENDURA® system, the Sym3® processing chamber, and the CENTURA® system, which may use the Mesa™ processing chamber, all of which are commercially available from Applied Materials, Inc., Santa Clara, Calif. Other tools capable of performing PECVD processes may also be adapted to benefit from the embodiments described herein. Additionally, any system capable of enabling the PECVD processes described herein may be advantageously used. Any apparatus described herein is exemplary and should not be understood or interpreted as limiting the scope of the embodiments described herein.

[0019]

[0027] Device manufacturers using amorphous carbon layers require two important requirements to be met: (1) high selectivity of the hard mask during dry etching of the underlying material, and (2) high optical transparency in the visible spectrum for lithographic registration accuracy. As used herein, the term "dry etching" generally refers to etching processes in which the material is not dissolved by immersion in a chemical solution, and includes methods such as reactive ion etching, sputter etching, and gas-phase etching.

[0020]

[0028] Hard mask layers are often used in narrow and / or deep contact etch applications and high aspect ratio (HAR) etch applications, where the photoresist may not be thick enough to mask the underlying layers, especially as critical dimensions shrink.

[0021]

[0029] V-NAND or 3D-NAND structures are used in flash memory applications. V-NAND devices are vertically stacked NAND structures with many cells arranged in blocks. As used herein, the term "3D NAND" refers to a type of electronic (solid-state) non-volatile computer storage memory in which memory cells are stacked in multiple layers. 3D NAND memory generally includes multiple memory cells that include floating gate transistors. Traditionally, 3D NAND memory cells include multiple NAND memory structures arranged in three dimensions around a bit line.

[0022]

[0030] A key step in 3D NAND technology is slit etching. As the number of layers increases at each technology node, the thickness of the hard mask film must increase proportionally to withstand the high-aspect-ratio etch profile in order to control the slit etching profile. Amorphous carbon (aC:H) films can be used due to their high hardness and ease of peeling after slit etching. In the fabrication of multi-layer 3D NAND, a sacrificial layer memory hole plug process is required to protect the memory holes in the bottom layer. Such a process must meet the requirements of throughput, dry etching removability, and stability at high temperatures (e.g., 850°C).

[0023]

[0031] Other approaches include amorphous silicon-based processes or other amorphous carbon-based processes. Amorphous silicon materials require wet removal processes, which can adversely affect the oxide / nitride stack. Other amorphous carbon materials suffer from slow deposition rates, slow throughput, and instability at high temperatures.

[0024]

[0032] In one or more embodiments, methods are provided for depositing amorphous carbon (aC:H) materials with improved conformality in chemical vapor deposition systems, particularly plasma-enhanced chemical vapor deposition (PECVD) systems. Layer conformality is typically quantified by the ratio (which may be expressed as a percentage) of the average thickness of the layer deposited on the sidewalls of a feature to the average thickness of the same deposited layer on the field, or top, surface of the substrate. Layers deposited by the methods described herein have been observed to have conformalities of greater than about 30% (e.g., 70% or greater), about 7:10 or greater (e.g., about 80% or greater), about 4:5 or greater, up to about 100%, about 1:1, or up to about 200% or greater, or about 2:1.

[0025]

[0033] The amorphous carbon material of one or more embodiments can be easily removed via oxygen (O2) plasma, eliminating any impact on the oxide / nitride stack. The process of one or more embodiments advantageously provides deposition rates that are more than 10 times greater than other methods. Furthermore, the process of one or more embodiments advantageously provides tunability of the deposition profile compared to other amorphous carbon materials, while also being stable at high temperatures.

[0026]

[0034] In particular, methods are provided for improving conformal deposition of aC:H layers. Conformal deposition may be improved by using precursors with a carbon to hydrogen ratio of 1:2 or greater (e.g., a carbon to hydrogen ratio of 2:3 or greater). In this case, the plasma-initiating gas is selected from helium, hydrogen, nitrogen, argon, or combinations thereof. In this case, the precursor flow rate is increased relative to the plasma-initiating gas flow rate, the deposition pressure is increased, the deposition temperature is increased, lower RF power is applied, the plasma environment has a reduced deposition rate, amorphous carbon is deposited in multiple layers, and combinations thereof. The deposition processes herein may be performed in a suitable processing system.

[0027]

[0035] For illustrative purposes, deposition of an amorphous carbon film for a gap-fill application is described. However, those skilled in the art will understand that the described precursors and methods are not limited to gap-fill applications and can be used for any PECVD film formation. FIG. 1A shows a partial cross-sectional view of a substrate 100 having a feature 110. While this figure shows a substrate with a single feature for illustrative purposes, those skilled in the art will understand that more than one feature may be present. The shape of the feature 110 may be any suitable shape, including, but not limited to, a trench and a cylindrical via. As used in this context, the term "feature" refers to any intentionally formed surface irregularity. Suitable examples of a feature include, but are not limited to, a trench having a top, two sidewalls, and a bottom, and a peak having a top and two sidewalls. The feature may have any suitable aspect ratio (the ratio of the depth of the feature to the width of the feature). In some embodiments, the aspect ratio is greater than or equal to about 5:1, 10:1, 15:1, 20:1, 25:1, 30:1, 35:1, 40:1, 45:1, or 50:1.

[0028]

[0036] In one or more embodiments, a substrate 100 has a substrate surface 120. At least one feature 110 forms an opening in the substrate surface 120. The feature 110 extends to a depth D from the substrate surface 120 to a bottom surface 112. The feature 110 has a first sidewall 114 and a second sidewall 116 that define a width W of the feature 110. The open area formed by the sidewalls and bottom is also referred to as a gap.

[0029]

[0037] One or more embodiments of the present disclosure are directed to a processing method in which a substrate surface is provided having at least one feature thereon. When used in this context, the term "provided" means that the substrate is placed in a location or environment for further processing.

[0030]

[0038] 1B shows a partial cross-sectional view of a substrate 100 having features 110. As shown in FIG. 1B, an amorphous carbon film 150 is formed on the substrate surface 120 and on the first sidewall 114, the second sidewall 116, and the bottom surface 112 of at least one feature 110. The amorphous carbon film 150 fills the at least one feature 110 such that a substantial seam is not formed. A seam is a gap formed between, but not necessarily in the middle of, the sidewalls of the feature 110. As used in this context, the term "substantially seamless" means that any gap formed in the film between the sidewalls is less than about 1% of the cross-sectional area of ​​the sidewalls.

[0031]

[0039] The amorphous carbon film 150 may be formed by any suitable process. In some embodiments, forming the amorphous carbon film 150 is performed by plasma enhanced chemical vapor deposition (PECVD). In other words, the amorphous carbon film 150 may be deposited by a plasma enhanced chemical vapor deposition process.

[0032]

[0040] 1C shows a partial cross-sectional view of substrate 100 having feature 110, where amorphous carbon film 150 has been planarized so that it is substantially coplanar with substrate surface 120. Planarization may be accomplished by any means known to those skilled in the art, including, but not limited to, chemical mechanical polishing (CMP) or etching.

[0033]

[0041] Aspects of the present invention provide improved conformal deposition of amorphous carbon layers. Improved conformal deposition may be achieved by processes using precursors with a carbon to hydrogen ratio of 1:2 or greater (e.g., a carbon to hydrogen ratio of 2:3 or greater), using a plasma-initiating gas selected from the group consisting of helium, hydrogen, nitrogen, argon, or combinations thereof, increasing the precursor flow rate relative to the plasma-initiating gas flow rate, increasing the deposition pressure, increasing the deposition temperature, applying lower RF power, using a plasma environment with a reduced deposition rate, increasing the spacing between the gas distributor and the substrate surface, depositing the amorphous carbon in multiple layers, and combinations thereof. It is believed that the processes described herein provide increased deposition rates and better thermal stability, thereby providing a more conformal deposition process.

[0034]

[0042] In one or more embodiments of the deposition process, the amorphous carbon layer is formed by a process that includes introducing a hydrocarbon source and a plasma-initiating gas into a processing chamber, such as process chamber 300 described in connection with Figure 4. The hydrocarbon source is a mixture of one or more hydrocarbon compounds and an optional carrier gas (such as argon).

[0035]

[0043] The one or more hydrocarbon compounds may include compounds having a ratio of carbon atoms to hydrogen atoms of 1:2 or greater (e.g., greater than 1:2). For example, a ratio of carbon to hydrogen (or substituents such as fluorine for hydrogen) of 2:3 or greater (e.g., from 2:3 to 2:1 (e.g., from about 2:3 to about 3:2)) has been observed to produce amorphous carbon films with improved conformality. It is believed that hydrocarbon compounds having such a described ratio of carbon atoms to hydrogen atoms result in a more isotropic deposition process.

[0036]

[0044] The hydrocarbon compounds may be partially or fully doped derivatives of hydrocarbon compounds, and they may also benefit from the method of the present invention. The derivatives include nitrogen, fluorine, oxygen, hydroxyl group, and boron-containing derivatives of hydrocarbon compounds.

[0037]

[0045] Generally, the hydrocarbon compounds or their derivatives that may be contained in the hydrocarbon source may be described by the chemical formula C , D , <​​​​​​​​​​​​​​​​​​​​​​​Suitable hydrocarbon compounds include one or more of the following compounds: alkynes such as acetylene (CH), vinyl acetylene, and their derivatives; aromatic hydrocarbons such as benzene, styrene, toluene, xylene, pyridine, ethylbenzene, acetophenone, methyl benzoate, phenyl acetate, phenol, cresol, furan, and the like; α-terpinene, cymene, 1.1.3.3.-tetramethylbutylbenzene, t-butyl ether, t-butyl ethylene, methyl methacrylate, and t-butyl furfuryl ether; compounds having the formulas CH and CH; halogenated aromatic compounds including monofluorobenzene, difluorobenzene, tetrafluorobenzene, hexafluorobenzene, and the like. Further suitable hydrocarbons include alkenes (e.g., ethylene, propylene, butylene, pentene, etc.), dienes (e.g., butadiene, isoprene, pentadiene, hexadiene, etc.), and halogenated alkenes, including monofluoroethylene, difluoroethylene, trifluoroethylene, tetrafluoroethylene, monochloroethylene, dichloroethylene, trichloroethylene, tetrachloroethylene, etc. An example of a precursor having a carbon atom to hydrogen atom ratio of greater than 1:2 is CH, which may be diacetylene.

[0039]

[0047] Additionally, in one or more embodiments, the precursor has a carbon to hydrogen atom ratio of 3:1 or greater (e.g., 5:1, e.g., 10:1 or greater). It is believed that as the carbon to hydrogen ratio increases, carbon atoms bond with neighboring carbon atoms during deposition, forming webs of complex three-dimensional short-order structures, thereby improving the conformality of the deposited film.

[0040]

[0048] The amorphous carbon deposition process involves the use of a hydrocarbon compound and a plasma-initiating gas, which is introduced into the chamber before and / or simultaneously with the plasma initiation to initiate deposition. The plasma-initiating gas may be a high ionization potential gas, including, but not limited to, helium gas, hydrogen gas, nitrogen gas, argon gas, and combinations thereof. The plasma-initiating gas may also be a chemically inert gas, such as helium gas, nitrogen gas, or argon gas. Suitable ionization potentials for the gas are approximately 5 eV (electron potential) to 25 eV. The plasma-initiating gas may be introduced into the chamber before the hydrocarbon source, which allows for a stable plasma to be generated and reduces the possibility of arcing. The use of a plasma-initiating gas with a high ionization potential has been observed to reduce anisotropic etching of the film during deposition, thereby improving conformality in the deposition of amorphous carbon films. An inert gas or a carrier gas, such as argon, may be introduced along with the plasma-initiating gas, the hydrocarbon source, or a combination thereof.

[0041]

[0049] The hydrocarbon compound and plasma initiating gas may be introduced at a gas flow ratio of hydrocarbon compound to plasma initiating gas of about 1:100 or greater (e.g., about 1:100 to 100:1 (e.g., about 1:10 to about 10:1)) for amorphous carbon deposition. In one embodiment, a flow ratio of hydrocarbon compound to plasma initiating gas of about 1:5 or greater (e.g., about 1:5 to about 2:1 (e.g., about 1:2 to about 1:1)) may be used for amorphous carbon deposition. It has been observed that increasing the flow ratio of hydrocarbon compound to plasma initiating gas improves conformality over lower ratios.

[0042]

[0050] Amorphous carbon layers may be deposited from process gases by maintaining a chamber pressure of about 2 Torr or greater (e.g., from about 2 Torr to about 20 Torr, and in one embodiment, about 7 Torr or greater (e.g., from about 7 Torr to about 9 Torr)). Conformality has been observed to improve as pressure increases, and it is believed that ions experience scattering before reaching the substrate, thereby losing some of their etching ability, while radicals experience more scattering and arrive at the substrate surface at more random and isotropic angles, resulting in more isotropic and conformal film growth.

[0043]

[0051] The amorphous carbon layer of one or more embodiments is advantageously deposited from a hydrocarbon source in a chamber that maintains a substrate temperature above 600°C, including a temperature range of about 600°C to about 800°C (e.g., temperatures of about 600°C, about 650°C, about 700°C, about 750°C, and about 800°C). Without intending to be bound by theory, it is believed that deposition at elevated temperatures produces amorphous carbon gap-filling films with improved thermal stability. Surprisingly, it has been observed that depositing amorphous carbon films at elevated temperatures increases the deposition rate and improves conformality. Higher temperatures also increase the diffusivity or mobility of the adsorbed carbon precursor, resulting in a more isotropic deposition and improved conformality.

[0044]

[0052] In one or more embodiments, the amorphous carbon layer has a deposition rate of greater than 200 nm / hr, including greater than 300 nm / hr and greater than 350 nm / hr.

[0045]

[0053] In one or more embodiments, a hydrocarbon source and a plasma-initiating gas are introduced into the chamber, and a plasma is initiated to begin deposition. A dual-frequency RF system can be used to generate the plasma. It is believed that application of dual-frequency RF power provides independent control of flux and ion energy, since the energy of ions impinging on the film surface is believed to affect film density. It is believed that the high-frequency plasma controls the plasma density, while the low-frequency plasma controls the kinetic energy of ions impinging on the substrate surface. A dual-frequency source of mixed RF power provides high-frequency power in the range of about 10 MHz to about 30 MHz (e.g., about 13.56 MHz) and low-frequency power in the range of about 10 kHz to about 1 MHz (e.g., about 350 kHz). When depositing amorphous carbon films using a dual-frequency RF system, the ratio of the second RF power to the total mixed-frequency power is preferably less than about 0.6 to 1.0 (0.6:1). The applied RF power and use of one or more frequencies may vary based on the substrate size and equipment used. A single frequency RF power application may be used, typically the application of high frequency power as described herein.

[0046]

[0054] The plasma may be generated by applying RF power to the substrate surface area at a power density of about 0.01 W / cm to about 5 W / cm (e.g., about 0.01 W / cm to about 1 W / cm (e.g., about 0.1 W / cm)). The power application may be about 1 Watt to about 2000 Watts (e.g., about 10 Watts to about 200 Watts (e.g., about 20 Watts)) for a 300 mm substrate.

[0047]

[0055] Without intending to be bound by theory, it is believed that the plasma process reduces the rate of amorphous carbon growth to improve conformality by reducing the number of energetic ions that drive hydrocarbon compounds (i.e., radicals) onto the substrate surface in a more random deposition pattern, thereby resulting in film growth with a more isotropic deposition pattern. It has also been observed that increasing plasma deposition results in higher deposition rates that allow the adsorbing carbon precursor to diffuse onto the surface of the substrate, providing a more conformal layer.

[0048]

[0056] An exemplary deposition process for a 300 mm circular substrate employs a plasma-initiating gas such as helium and a hydrocarbon source such as acetylene (C2H2). The process may include supplying the plasma-initiating gas, such as helium, at a flow rate of about 400 sccm to about 8000 sccm, supplying the hydrocarbon source, such as acetylene (C2H2), at a flow rate of about 400 sccm to about 8000 sccm, applying dual-frequency RF power of about 10 W to about 2000 W, maintaining a chamber pressure of about 2 Torr to about 20 Torr, and maintaining a chamber temperature above 600°C. This process range provides a deposition rate ranging from about 200 nm / hr to about 1000 nm / hr for the amorphous carbon layer with a conformality (ratio of the average thickness of a layer deposited on the sidewalls of a feature to the average thickness of the same layer deposited on the field, or top, surface of the substrate) of about 30% to about 100%.

[0049]

[0057] In one or more embodiments of the deposition process, multiple separate amorphous carbon depositions are performed to form the amorphous carbon layer. In one aspect of the multiple deposition processes described herein, the deposition step occurs before the etching step. In the etching step, a plasma initiating gas, a dilution gas, and / or precursors may be flowed at a reduced or zero deposition rate. Suitable plasma initiating gases, dilution gases, and / or precursors may be flowed into the chamber at a flow rate of about 100 sccm to about 40,000 sccm. If a plasma initiating gas and / or dilution gas is used, a plasma may be initiated for the etching step. In one or more embodiments, an etching plasma is used to trim the morphology of the carbon layer. After trimming, conformality is improved. In one or more embodiments, the etching gas or etchant includes one or more of hydrogen (H), ammonia (NH), nitrous oxide (NO), oxygen (O), etc. The deposition and etching steps may then be repeated until the desired thickness is obtained, which may be 1 to 100 cycles (e.g., 10 to 50 cycles (e.g., 30 cycles)), or alternatively, between about 1% and about 100% (e.g., about 2% to about 10%) (e.g., 3.3%) of the thickness of the amorphous carbon material. Individual cycles may deposit a thickness of about 1 Å to about 1000 Å of amorphous carbon material per cycle, forming an amorphous carbon layer having a thickness of about 10 Å to about 15000 Å. The cyclic deposition process may use one or more of the process parameter adjustments described above.

[0050]

[0058] In one or more embodiments, a multi-layer deposition scheme improves conformality. Generally, for a given amorphous carbon film thickness, increasing the number of layers (smaller individual layer thicknesses and more repetitions) improves conformality.

[0051]

[0059] One significant advantage of the method of the present invention is its improved conformality over other amorphous carbon deposition processes, as illustrated in Figures 2A-2B. Figure 2A shows a partial cross-sectional view of a substrate 200 having features 210. In one or more embodiments, the substrate 200 has a substrate surface 220. At least one feature 210 forms an opening in the substrate surface 220. The feature 210 extends from the substrate surface 220 to a depth D from the substrate surface 220 to a lower surface 212. f The feature 210 extends to a width W f The open area formed by the sidewalls and the bottom is also referred to as a gap.

[0052]

[0060] FIG. 2B shows a schematic cross-sectional view of a feature 210 and a substrate 200 having an amorphous carbon layer 250 formed thereon. The amorphous carbon layer 250 exhibits a typical appearance of a film deposited using the method of the present invention. Qualitatively, the amorphous carbon layer 250 is highly conformal, completely covering the sidewalls 214, 216 and bottom surface 212 of the feature 210. Quantitatively, the amorphous carbon layer 250 may have a conformality on the order of about 30% to about 100%, for example, about 70% to about 90%. Conformality is then defined as the ratio of the average thickness S of the amorphous carbon layer 250 deposited on the sidewalls 214, 216 to the average thickness T of the amorphous carbon layer 250 on the top surface 220 of the substrate 200.

[0053]

[0061] 3A shows a partial cross-sectional view of a substrate 260 having features 270. The substrate 260 has a substrate surface 280. At least one feature 270 forms an opening in the substrate surface 280. The at least one feature 270 has a feature depth D from the substrate surface 280 to a lower surface 272. f At least one feature 270 extends to a width W of the at least one feature 270. fThe open area formed by the side walls 274, 276 and the bottom portion 272 is also referred to as a gap. In one or more embodiments, the width W f However, at least one feature 270 has a depth D f In other embodiments, the width W f At the top of the at least one feature 270, the width W at the bottom surface 272 of the at least one feature 270 f In still further embodiments, the width W f is the width W at the top of at least one feature 270 in the middle of at least one feature 270 f and a width W at the bottom surface 272 of at least one feature 270 f It is wider than.

[0054]

[0062] In one or more embodiments, the substrate 260 is a film stack including multiple alternating layers of nitride material 264 and oxide material 266 deposited on the semiconductor substrate 260 .

[0055]

[0063] The semiconductor substrate 262 may be any suitable substrate material. In one or more embodiments, the semiconductor substrate 262 comprises a semiconductor material (e.g., silicon (Si), carbon (C), germanium (Ge), silicon germanium (SiGe), gallium arsenide (GaAs), indium phosphide (InP), indium gallium arsenide (InGaAs), indium aluminum arsenide (InAlAs), copper indium gallium selenide (CIGS), other semiconductor materials, or any combination thereof). In one or more embodiments, the semiconductor substrate 262 comprises one or more of silicon (Si), germanium (Ge), gallium (Ga), arsenic (As), indium (In), phosphorus (P), copper (Cu), or selenium (Se). Although some examples of materials from which substrate 262 may be formed are described herein, any material that may serve as a foundation upon which passive and active electronic devices (e.g., transistors, memory, capacitors, inductors, resistors, switches, integrated circuits, amplifiers, optoelectronic devices, or any other electronic device) may be built is within the spirit and scope of the present disclosure.

[0056]

[0064] In one or more embodiments, at least one feature 270 comprises a memory hole or a word line slit. Thus, in one or more embodiments, substrate 260 comprises a memory device or logic device, such as NAND, VNAND, DRAM, etc.

[0057]

[0065] 3B shows a cross-sectional schematic view of a gap-fill process according to one or more embodiments of the present disclosure. In one or more embodiments, an amorphous carbon film 290 is formed on the substrate surface 280 and on the walls 274, 276 and bottom 272 of at least one feature 270. As shown in FIG. 3B, in one or more embodiments, the amorphous carbon film 290 is formed over the width W of the at least one feature 270. f There are no seams inside.

[0058]

[0066] In some embodiments, an amorphous carbon film 290 is conformally formed over at least one feature 270. As used herein, the terms "conformal" or "conformally" refer to a layer that adheres to and uniformly covers an exposed surface at a thickness that varies by less than 1% relative to the average thickness of the film. For example, a 1000 Å thick film will have a thickness variation of less than 10 Å. This thickness and variation includes the edges, corners, sides, and bottom of the recess. For example, in various embodiments of the present disclosure, a conformal layer deposited by PECVD will provide coverage over the deposition area of ​​essentially uniform thickness on a complex surface.

[0059]

[0067] In some embodiments, the amorphous carbon film 290 is a continuous film. As used herein, the term "continuous" refers to a layer that covers the entire exposed surface, such that there are no gaps or bare spots that expose the underlying material of the deposited layer. A continuous layer may have gaps or bare spots that have a surface area of ​​less than about 1% of the total surface area of ​​the film. In some embodiments, the amorphous carbon film 290 is a pinhole-free film. As used herein, the term "pinhole-free" refers to a layer that covers the entire exposed surface, such that there are no gaps, bare spots, holes, pinholes, etc. that expose the underlying material of the deposited layer. A pinhole-free layer may have holes or pinholes that have a surface area of ​​less than about 1% of the total surface area of ​​the film.

[0060]

[0068] 5, one or more embodiments of the present disclosure are directed to a method 500 for depositing a film. In some embodiments, the method 500 includes a pretreatment operation 506. The pretreatment can be any suitable pretreatment known to those skilled in the art. Suitable pretreatments include, but are not limited to, preheating, cleaning, soaking, native oxide removal, or deposition of an adhesion layer (e.g., titanium nitride (TiN)).

[0061]

[0069] In deposition 510, a process cycle is performed to deposit a film on a substrate (or substrate surface). The deposition process may include one or more operations to form a film on a substrate. In operation 512, a hydrocarbon source is introduced into the processing chamber. In operation 514, a plasma-initiating gas is introduced into the processing chamber. In operation 516, a plasma is generated in the processing chamber at a temperature greater than 600°C.

[0062]

[0070] An amorphous carbon layer is formed on the substrate in operation 518. In operation 520, the processing chamber is purged.

[0063]

[0071] The thickness of the deposited film or the number of cycles is considered in decision step 522. If the deposited film reaches a predetermined thickness or a predetermined number of process cycles have been performed, the method 500 moves to an optional post-processing operation 524. If the thickness of the deposited film or the number of process cycles has not reached a predetermined threshold, the method 500 returns to operation 510 and continues by reintroducing the hydrocarbon source in operation 512.

[0064]

[0072] The optional post-treatment operation 524 can be, for example, a process to modify film properties (e.g., annealing) or a further film deposition process (e.g., a further ALD or CVD process) to grow a further film. In some embodiments, the post-treatment operation 524 can be a process to modify the properties of the deposited film. In some embodiments, the post-treatment operation 524 includes annealing the film. In some embodiments, the annealing is performed at a temperature in the range of about 300°C, 400°C, 500°C, 600°C, 700°C, 800°C, 900°C, or 1000°C. The annealing environment in some embodiments includes one or more of an inert gas (e.g., molecular nitrogen (N), argon (Ar)), or a reducing gas (e.g., molecular hydrogen (H) or ammonia (NH)), or an oxidizing agent (e.g., but not limited to, oxygen (O), ozone (O), or peroxide). The annealing can be performed for any suitable length of time. In some embodiments, the film is annealed for a predetermined time ranging from about 15 seconds to about 90 minutes, or from about 1 minute to about 60 minutes. In some embodiments, annealing the as-deposited film increases the density, decreases the resistivity, and / or improves the purity of the film.

[0065]

[0073] Various multi-processing platforms may be utilized, including the Centura®, Dual ACP, Producer® GT, Precision®, and Endura® platforms available from Applied Materials®, as well as other processing systems. Referring to Figure 4, a cluster tool 300 includes at least one central transfer station 314 having multiple sides. A robot 316 is disposed within the central transfer station 314 and configured to move a robot blade and wafer to each of the multiple sides.

[0066]

[0074] Generally, a cluster tool is a modular system with multiple chambers that perform various functions, including substrate center detection and orientation, degassing, annealing, deposition, and / or etching. According to one or more embodiments, a cluster tool includes at least a first chamber and a central transfer chamber. The central transfer chamber may house a robot capable of transferring substrates back and forth between processing chambers and load lock chambers. The transfer chamber is typically maintained at reduced pressure and provides an intermediate stage for transferring substrates back and forth from one chamber to another chamber and / or to the load lock chamber located at the front end of the cluster tool. However, the actual configuration and combination of chambers may be varied for the purpose of performing specific steps of the processes described herein. Other processing chambers that may be used include, but are not limited to, cyclic layer deposition (CLD), atomic layer deposition (ALD), chemical vapor deposition (CVD), physical vapor deposition (PVD), etching, pre-cleaning, chemical cleaning, thermal treatment (such as RTP), plasma nitridation, degassing, orientation, hydroxylation, and other substrate processes. By performing the processing in a chamber on a cluster tool, surface contamination of the substrate with airborne impurities can be avoided without oxidation prior to depositing a subsequent film.

[0067]

[0075] Referring to Figure 4, a cluster tool 300 includes multiple processing chambers 308, 310, and 312 (also referred to as process stations) connected to a central transfer station. The various processing chambers provide separate processing regions isolated from adjacent process stations. The processing chambers may be any suitable chambers, including, but not limited to, pre-clean chambers, deposition chambers, annealing chambers, etch chambers, selective etch chambers, etc. The specific arrangement of process chambers and components may vary depending on the cluster tool and should not be construed as limiting the scope of the present disclosure.

[0068]

[0076] In some embodiments, the cluster tool 300 includes an isotropic etch chamber for selectively etching / trimming the semiconductor material layer 224. In some embodiments, the isotropic etch chamber includes one or more fluorine-based dry etch chambers. In some embodiments, the cluster tool 300 includes a pre-clean chamber connected to a central transfer station.

[0069]

[0077] 4, a factory interface 318 is connected to the front of the cluster tool 300. The factory interface 318 includes a loading and unloading chamber 302 on the front 319 of the factory interface 318.

[0070]

[0078] The size and shape of the loading and unloading chambers 302 can vary depending on, for example, the substrates to be processed in the cluster tool 300. In the illustrated embodiment, the loading and unloading chambers 302 are sized to hold a wafer cassette having multiple wafers disposed within the cassette.

[0071]

[0079] A robot 304 resides within a factory interface 318 and is capable of moving between the loading chamber and the unloading chamber 302. The robot 304 is capable of transferring wafers from a cassette in the loading chamber 302 through the factory interface 318 to a load lock chamber 320. The robot 304 is also capable of transferring wafers from the load lock chamber 320 through the factory interface 318 to a cassette in the unloading chamber 302.

[0072]

[0080] In some embodiments, the robot 316 is a multi-arm robot capable of independently moving multiple wafers at a time. The robot 316 is configured to move wafers between chambers around the transfer chamber 314. Individual wafers are carried on a wafer transfer blade positioned at the distal end of the first robotic mechanism.

[0073]

[0081] A system controller 357 communicates with the robot 316 and the multiple processing chambers 308, 310, and 312. The system controller 357 can be any suitable component capable of controlling the processing chambers and the robot. For example, the system controller 357 can be a computer including a central processing unit (CPU) 392, memory 394, input / output (I / O) 396, and support circuits 398.

[0074]

[0082] The processes may generally be stored in the memory of the system controller 357 as software routines that, when executed by a processor, cause the process chamber to perform the processes of the present disclosure. The software routines may also be stored and / or executed by a second processor (not shown) located remotely from the hardware controlled by the processor. Some or all of the methods of the present disclosure may also be performed in hardware. Thus, the processes may be implemented in software and executed in hardware using a computer system, for example, as an application-specific integrated circuit or other type of hardware implementation, or as a combination of software and hardware. The software routines, when executed by a processor, transform a general-purpose computer into a special-purpose computer (controller) that controls chamber operation to perform the processes.

[0075]

[0083] In some embodiments, the system controller 357 has a configuration for controlling the deposition of amorphous carbon on the substrate.

[0076]

[0084] In one or more embodiments, a processing tool includes a central transfer station including a robot configured to move wafers, a plurality of process stations, each process station connected to the central transfer station to provide a processing region separated from the processing regions of adjacent process stations, the plurality of process stations including deposition chambers, plasma chambers, curing chambers, and etch chambers, and a controller connected to the central transfer station and the plurality of process stations, the controller configured to activate the robot to move wafers between the process stations and to control the processes occurring at each of the process stations.

[0077]

[0085] The present disclosure will now be described with reference to the following examples. Before certain exemplary embodiments of the present disclosure are described, it should be understood that the present disclosure is not limited to the details of construction or process steps set forth in the following description. The present disclosure is capable of other embodiments and of being practiced or carried out in various ways.

[0078]

[0086] Multiple Examples

[0079]

[0087] Example 1

[0080]

[0088] An amorphous carbon layer was deposited at a deposition rate of 1800 nm / hr with a spacing of about 300 mils by providing argon at a flow rate of about 2000 sccm, C2H2 at a flow rate of about 300 sccm, applying high frequency RF power (13.56 MHz) of about 200 W, maintaining a deposition temperature of about 650°C, and maintaining a chamber pressure of about 10 Torr. Conformity was observed to be achieved, ranging from about 83% dense area to about 96% open area step coverage (a measure of conformality).

[0081]

[0089] Example 2 Comparison

[0082]

[0090] An amorphous carbon layer was deposited at a deposition rate of 30 nm / hr with a spacing of about 400 mils by providing helium at a flow rate of about 100 sccm, C3H6 at a flow rate of about 100 sccm, and NH3 at a flow rate of about 100 sccm to the processing chamber, applying a high frequency RF power (13.56 MHz) of about 600 W, maintaining a deposition temperature of about 400°C, and maintaining a chamber pressure of about 9 Torr. Conformity was observed to be achieved, ranging from about 83% dense area to about 96% open area step coverage (a measure of conformality).

[0083]

[0091] Spatially relative terms, such as "below," "belower," "lower side," "up," "above," and "upper," may be used herein to facilitate describing the relationship of one element or feature to another element(s) or feature(s), as shown in the figures. It should be understood that the spatially relative terms are intended to encompass various orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures were turned over, elements described as "below" or "below" other elements or features would then be oriented "above" the other elements or features. Thus, the exemplary term "below" may include both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or to other orientations), and the spatially relative descriptors used herein may be interpreted accordingly.

[0084]

[0092] In the context of describing the materials and methods described herein (particularly in the context of the claims below), use of the terms "a," "an," and "the" and similar referents is intended to cover both the singular and the plural, unless indicated to the contrary herein or clearly contradicted by context. The recitation of ranges of values ​​herein is merely intended to serve as a shorthand method of individually referencing each individual value falling within the range, unless otherwise stated herein, and each individual value is incorporated into the specification as if it were individually recited herein. All methods described herein may be performed in any suitable order, unless indicated to the contrary herein or otherwise clearly contradicted by context. The use of any and all examples or exemplary language (e.g., "such as") provided herein is intended merely to better describe the materials and methods and does not limit the scope unless specifically claimed. No language in the specification should be construed as indicating any element not claimed as essential to the practice of the disclosed materials and methods.

[0085]

[0093] Throughout this specification, references to "one embodiment," "certain embodiment," "one or more embodiments," or "an embodiment" mean that a particular feature, structure, material, or characteristic described in connection with an embodiment is included in at least one embodiment of the present disclosure. Thus, the appearances of phrases such as "in one or more embodiments," "in a particular embodiment," "in one embodiment," or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment of the present disclosure. In one or more embodiments, the particular features, structures, materials, or characteristics may be combined in any suitable manner.

[0086]

[0094] Although the disclosure herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the disclosure. It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed method and apparatus without departing from the spirit and scope of the disclosure. Therefore, it is intended that the present invention cover modifications and variations that come within the scope of the appended claims and their equivalents.

Claims

1. 1. A method of forming a film, comprising: performing a deposition cycle, the deposition cycle comprising: introducing a hydrocarbon source into a processing chamber; introducing a plasma-initiating gas into the processing chamber; generating a plasma in said processing chamber at a temperature greater than 600°C; forming an amorphous carbon layer on a substrate at a deposition rate of greater than 200 nm / hr; and purging the processing chamber.

2. 10. The method of claim 1, wherein the hydrocarbon source has a ratio of carbon atoms to hydrogen atoms greater than 1:

2.

3. The method of claim 1 , wherein the plasma-initiating gas is selected from one or more of hydrogen, helium, argon, and nitrogen.

4. The method of claim 1 , further comprising repeating the deposition cycle between 2 and 50 times.

5. The method of claim 1 , wherein the amorphous carbon layer is a gap-fill layer.

6. The method of claim 1 , wherein the amorphous carbon layer is a conformal layer.

7. The hydrocarbon source may be acetylene, vinyl acetylene, benzene, styrene, toluene, xylene, pyridine, acetophenone, phenol, furan, C 3 H 2 , C 5 H 4 3. The method of claim 2, wherein the fluorobenzene comprises one or more of monofluorobenzene, difluorobenzene, tetrafluorobenzene, and hexafluorobenzene.

8. The method of claim 1 , wherein purging the processing chamber comprises flowing a purge gas into the processing chamber.

9. The method of claim 8 , wherein the purge gas comprises an inert gas or a hydrocarbon source gas.

10. A processing method comprising:

1. A method comprising: forming an amorphous carbon film on a substrate surface, the substrate surface having at least one feature extending from the substrate surface to a lower surface by a feature depth, the at least one feature having a width defined by a first sidewall and a second sidewall, the amorphous carbon film being deposited on the substrate surface, the first sidewall, the second sidewall, and the lower surface of the at least one feature.

11. The method of claim 10 , wherein forming the amorphous carbon film comprises a plasma-enhanced chemical vapor deposition process.

12. 12. The method of claim 11, wherein the plasma enhanced chemical vapor deposition process is carried out at a temperature greater than 600°C and a deposition rate greater than 200 nm / hr.

13. The plasma enhanced chemical vapor deposition process comprises: introducing a hydrocarbon source into the processing chamber; introducing a plasma-initiating gas into the processing chamber; and The method of claim 11 , comprising generating a plasma in the processing chamber at a temperature greater than 600° C.

14. The hydrocarbon source may be acetylene, vinyl acetylene, benzene, styrene, toluene, xylene, pyridine, acetophenone, phenol, furan, C 3 H 2 , C 5 H 4 14. The method of claim 13, wherein the fluorobenzene comprises one or more of monofluorobenzene, difluorobenzene, tetrafluorobenzene, and hexafluorobenzene.

15. The method of claim 13 , wherein the plasma-initiating gas is selected from one or more of hydrogen, helium, argon, and nitrogen.

16. The method of claim 10 , wherein the feature has an aspect ratio of about 10:1 or greater.

17. 11. The method of claim 10, wherein the depth of the at least one feature ranges from about 50 nm to about 100 nm.

18. The method of claim 10 , wherein the substrate comprises a stack of multiple alternating layers of oxide and nitride materials.

19. The method of claim 10 , wherein the at least one feature comprises a memory hole or a word line slit.

20. 1. A non-transitory computer-readable medium containing instructions that, when executed by a controller of a processing chamber, cause the processing chamber to: performing an operation of performing a deposition cycle, the deposition cycle comprising: introducing a hydrocarbon source into the processing chamber; introducing a plasma-initiating gas into the processing chamber; generating a plasma in said processing chamber at a temperature greater than 600°C; forming an amorphous carbon layer on a substrate; and purging the processing chamber.

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