High density low temperature carbon films for hard mask and other patterning applications

Abstract

Embodiments of the present disclosure generally relate to the fabrication of integrated circuits. More specifically, the embodiments described herein provide techniques for depositing high density films for patterning applications. In one embodiment, a method of processing a substrate is provided. The method includes flowing a hydrocarbon-containing gas mixture into a processing volume of a processing chamber having a substrate positioned on an electrostatic chuck. The substrate is maintained at a pressure between about 0.5 mTorr and about 10 Torr. The method also includes generating a plasma at a substrate level by applying a first RF bias to the electrostatic chuck to deposit a diamond-like carbon film on the substrate. The diamond-like carbon film has a density greater than 1.8 g / cc and a stress less than -500 MPa.

Description

[0001] This application is a divisional application of application number 201880030287.9, filed on May 15, 2018, entitled “High Density Low Temperature Carbon Films for Hard Mask and Other Patterning Applications”. TECHNICAL FIELD

[0002] Embodiments of the present disclosure generally relate to the fabrication of integrated circuits. More specifically, the embodiments described herein provide techniques for depositing high density films for patterning applications. BACKGROUND

[0003] Integrated circuits have evolved into complex devices that can include millions of transistors, capacitors, and resistors on a single chip. The evolution of chip design continues to demand faster circuits and greater circuit density. The demand for faster circuits and greater circuit density creates a corresponding demand for materials used to fabricate such integrated circuits. In particular, as the size of integrated circuit components is reduced to submicron dimensions, it is now necessary to use low resistivity conductive materials as well as low dielectric constant insulating materials to obtain suitable electrical properties from such components.

[0004] The demand for greater integrated circuit density also creates a demand for process sequences for integrated circuit component fabrication. For example, in a process sequence using conventional photolithography techniques, an energy-sensitive resist layer is formed over a stack of material layers disposed on a substrate. The energy-sensitive resist layer is exposed to an image of a pattern to form a photoresist mask. Thereafter, an etching process is used to transfer the mask pattern into one or more of the stacked material layers. The chemical etchant used in the etching process is selected to have a greater etch selectivity for the stacked material layers than for the mask of the energy-sensitive resist. That is, the chemical etchant etches one or more layers of the material stack at a substantially faster rate than the energy-sensitive resist. The etch selectivity for the one or more material layers of the stack over the resist prevents the energy-sensitive resist from being depleted before the end of the pattern transfer.

[0005] As the pattern size is reduced, the thickness of the energy-sensitive resist is correspondingly reduced in order to control the pattern resolution. Such thin resist layers can be insufficient to mask the underlying material layers during the pattern transfer step due to erosion by the chemical etchant. An intermediate layer (e.g., silicon oxynitride, silicon carbide, or a carbon film) is typically used between the energy-sensitive resist layer and the underlying material layers, which is referred to as a hard mask, facilitating the pattern transfer due to greater resistance to the chemical etchant. Hard mask materials that combine high etch selectivity and high deposition rate are desirable. As critical dimensions (CDs) are reduced, current hard mask materials lack the desired etch selectivity with respect to the underlying materials (e.g., oxides and nitrides), and are often difficult to deposit.

[0006] Thus, there is a need in the art for improved hard mask layers and methods for depositing improved hard mask layers. SUMMARY

[0007] Embodiments of the present disclosure generally relate to the fabrication of integrated circuits. More specifically, the embodiments described herein provide techniques for depositing high density films for patterning applications. In one embodiment, a method of processing a substrate is provided. The method includes flowing a hydrocarbon-containing gas mixture into a processing volume of a processing chamber having a substrate positioned on an electrostatic chuck. The substrate is maintained at a pressure between about 0.5 mTorr and about 10 Torr. The method further includes generating a plasma at a substrate level by applying a first RF bias to the electrostatic chuck to deposit a diamond-like carbon film on the substrate. The diamond-like carbon film has a density greater than 1.8 g / cc and a stress less than -500 MPa.

[0008] In another embodiment, a method of processing a substrate is provided. The method includes flowing a hydrocarbon-containing gas mixture into a processing volume of a processing chamber having a substrate positioned on an electrostatic chuck. The substrate is maintained at a pressure between about 0.5 mTorr and about 10 Torr, and the hydrocarbon-containing gas mixture includes acetylene (C2H2). The method additionally includes generating a plasma at a substrate level by applying a first RF bias and a second RF bias to the electrostatic chuck to deposit a diamond-like carbon film on the substrate. The diamond-like carbon film has a density from about 1.8 g / cc to about 2.5 g / cc and a stress from about -600 MPa to about -300 MPa.

[0009] In yet another embodiment, a method of processing a substrate is provided. The method includes flowing a hydrocarbon-containing gas mixture into a processing volume of a processing chamber having a substrate positioned on an electrostatic chuck. The processing volume is maintained at a pressure between about 0.5 mTorr and about 10 Torr. The method further includes generating a plasma at a substrate level by applying a first RF bias and a second RF bias to the electrostatic chuck to deposit a diamond-like carbon film on the substrate. The diamond-like carbon film has a density from about 1.8 g / cc to about 2.5 g / cc and a stress from about -1000 MPa to about -100 MPa (e.g., from about -600 MPa to about -300 MPa). The method further includes forming a patterned photoresist layer over the diamond-like carbon film. The method further includes etching the diamond-like carbon in a pattern corresponding to the patterned photoresist layer. The method further includes etching the pattern into the substrate. The method further includes depositing a material into the etched portion of the diamond-like carbon film.

[0010] In yet another embodiment, a film is provided for use as an underlayer for an EUV lithography process. The film has between 40% and 90% sp 3 hybrid carbon atom content; a density between 1.8 g / cc and 2.5 g / cc; and an elastic modulus between 150 GPa and 400 GPa. In some embodiments, the film has a density between 2.0 g / cc and 2.5 g / cc and an elastic modulus between 180 GPa and 200 GPa. In some embodiments, the film has a stress of -600 MPa; an index of refraction between 2.0 and 3.0; and an extinction coefficient between 0.2 and 0.3. BRIEF DESCRIPTION OF DRAWINGS

[0011] So that the manner in which the above-recited features of the present disclosure can be understood in detail, a more particular description, briefly summarized above, can be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this disclosure and are therefore not to be considered limiting of its scope, for the disclosure can admit to other equally effective embodiments.

[0012] FIG. 1A schematic cross-sectional view of a deposition system that can be used in the practice of embodiments described herein;

[0013] FIG. 1B schematic cross-sectional view of another deposition system that can be used in the practice of embodiments described herein;

[0014] FIG. 2 schematic cross-sectional view of a deposition system that can be used in the practice of embodiments described herein; FIG. 1A and FIG. 1B schematic cross-sectional view of an electrostatic chuck that can be used in the apparatus of

[0015] FIG. 3 flow chart depicting a method of forming a diamond-like carbon layer on a film stack disposed on a substrate in accordance with one or more embodiments of the present disclosure;

[0016] FIG. 4A to FIG. 4B depiction of one embodiment of a sequence of forming a diamond-like carbon layer on a film stack formed on a substrate in accordance with one or more embodiments of the present disclosure;

[0017] FIG. 5 is a graph depicting density as a function of bias power for diamond-like carbon layers formed in accordance with one or more embodiments of the present disclosure;

[0018] FIG. 6 is a graph depicting stress as a function of bias power for diamond-like carbon layers formed in accordance with one or more embodiments of the present disclosure; and

[0019] FIG. 7 It is a graph depicting the density and stress of a diamond-like carbon layer formed according to one or more embodiments of the present disclosure as a function of pressure.

[0020] For ease of understanding, the same reference numerals are used to designate common elements in the figures where possible. It is contemplated that elements and features of one embodiment may be advantageously incorporated into other embodiments without further detail. Detailed Implementation

[0021] The following disclosure describes a technique for depositing diamond-like carbon films on a substrate. In the following description and in Figures 1 to 1... FIG. 7 Certain details are set forth in this disclosure to provide a thorough understanding of the various embodiments thereof. Further details describing well-known structures and systems typically associated with plasma processing and diamond-like carbon film deposition are not set forth in the following disclosure to avoid unnecessarily obscuring the description of the various embodiments.

[0022] The numerous details, dimensions, angles, and other features shown in the figures are merely illustrative of specific embodiments. Therefore, other embodiments may have different details, components, dimensions, angles, and features without departing from the spirit or scope of this disclosure. Furthermore, further embodiments of this disclosure may be practiced without the following details.

[0023] The embodiments described herein will be described below with reference to plasma-enhanced chemical vapor deposition (PECVD) processes that can be performed using any suitable thin film deposition system. Examples of suitable systems include those that can be used with... Processing chamber System, PRECISION system, system, GT TM system, XP Precision TM system, SE tm system, Processing chambers and Mesa TM The processing chambers are all available from Applied Materials, Santa Clara, California, USA. Other tools capable of performing PECVD processes are also suitable for benefiting from the embodiments described herein. Furthermore, any system for implementing the PECVD process described herein can be used to gain advantages. The equipment descriptions herein are illustrative and should not be considered or construed as limiting the scope of the embodiments described herein.

[0024] Current hard mask applications for memory and other devices mostly use thick carbon films (e.g., 300 nm to 1.5 microns) that are amorphous in nature, but whose etch selectivity is no longer sufficient to meet the increasingly stringent requirements and high aspect ratio etching of upcoming nodes. To achieve greater etch selectivity, the density and Young's modulus of the film need to be improved. One of the major challenges in achieving greater etch selectivity and improved Young's modulus is the high compressive stress of such films, which causes high wafer bow, making such films unsuitable for applications. Thus, there is a need for carbon (diamond-like) films with high density and modulus (e.g., sp 3 The higher the content, the greater the diamond-like density and modulus, high etch selectivity, and low stress (e.g., <-500 MPa).

[0025] The embodiments described herein include improved methods of making carbon films with high density (e.g., > 1.8 g / cc), high modulus (e.g., > 150 GPa), and low stress (e.g., <-500 MPa). In contrast to current patterning films, carbon films made according to the embodiments described herein are amorphous in nature and have higher etch selectivity and significantly greater modulus (e.g., > 150 GPa) and lower stress (<-500 MPa). Carbon films made according to the embodiments described herein not only have low stress, but also have high sp 3 Carbon content. In general, the deposition processes described herein are also fully compatible with current integration schemes for hard mask applications.

[0026] In some embodiments, the diamond-like carbon films described herein can be formed by a chemical vapor deposition (plasma enhanced and / or thermal) process using hydrocarbon-containing gas mixtures including, such as but not limited to, C2H2, C3H6, CH4, C4H8, 1,3-dimethyladamantane, bicyclo[2.2.1]hepta-2,5-diene (2,5- norbornadiene), diamondoid (C 10 H 16 ), norbornene (C7H 10) or combinations thereof. The deposition process can be performed at temperatures ranging from -50 degrees Celsius to 600 degrees Celsius. The deposition process can be performed in a processing volume at pressures ranging from 0.1 mTorr to 10 Torr. The hydrocarbon-containing gas mixture can additionally include any of He, Ar, Xe, N2, H2, or combinations of any of He, Ar, Xe, N2, H2. The hydrocarbon-containing gas mixture can further include etchant gases such as Cl2, CF4, and / or NF3 to improve film quality. The plasma (e.g., capacitively coupled plasma) can be formed from a top electrode and a bottom electrode or a side electrode. The electrodes can be formed from single pass electrodes, dual pass electrodes, or multiple electrodes having multiple frequencies such as, but not limited to, 350 KHz, 2 MHz, 13.56 MHz, 27 MHz, 40 MHz, 60 MHz, and 100 MHz, which are alternatively or simultaneously used in a CVD system to deposit diamond-like carbon thin films for any or all of the reactive gases listed herein, which are used as hard masks and / or etch stops or any other application requiring a smooth carbon film. By having a high density and high modulus compared to current produced films, a high etch selectivity of the diamond-like carbon film is achieved. Without being bound by theory and believing that the high density and high modulus are a result of a high content of sp 3 hybridized carbon atoms, which in turn can be achieved by a combination of low pressure and low plasma power.

[0027] In some embodiments, hydrogen radicals are fed via the RPS, which causes sp 2 hybridized carbon atoms to be selectively etched, thus increasing the film's distance sp 3 hybridized carbon atom fraction, thus further increasing the etch selectivity.

[0028] In some embodiments, a diamond-like carbon film is deposited in a chamber, where the substrate pedestal is maintained at 10 degrees Celsius and the pressure is maintained at 2 mTorr, a plasma is generated at the wafer level by applying 2500 Watts (13.56 MHz) bias to an electrostatic chuck. In some embodiments, an additional RF of 1000 Watts at 2 MHz is also delivered to the electrostatic chuck, thus generating a dual-bias plasma at the wafer level.

[0029] In some embodiments, a film used as an underlayer for an EUV lithography process can be any of the films described herein.

[0030] In some embodiments, a film used as an underlayer for an EUV lithography process has a content of sp 3 hybridized carbon atoms between 40% and 90% based on the total amount of carbon atoms in the film; a density between 1.8 g / cc and 2.5 g / cc; and an elastic modulus between 150 GPa and 400 GPa.

[0031] In some embodiments, the film used as an underlayer for EUV lithography processes has a density between 2.0 g / cc and 2.2 g / cc; and an elastic modulus between about 180 GPa and about 200 GPa. In some embodiments, the film has a density of about 2.1 g / cc and an elastic modulus of about 195 GPa.

[0032] In some embodiments, used as an underlayer for EUV lithography processes, has a stress of -600 MPa; a refractive index between 2.0 and 3.0; and an extinction coefficient between 0.2 and 0.3.

[0033] FIG. 1A A schematic diagram of a substrate processing system 132 that can be used to perform diamond-like carbon layer deposition according to embodiments described herein is depicted. The substrate processing system 132 includes a processing chamber 100 coupled to a gas panel 130 and a controller 110. The processing chamber 100 generally includes a top wall 124, a sidewall 101, and a bottom wall 122 defining a processing volume 126. A substrate support assembly 146 is provided in the processing volume 126 of the processing chamber 100. The substrate support assembly 146 generally includes an electrostatic chuck 150 supported by a stem 160. The electrostatic chuck 150 can generally be fabricated from aluminum, ceramic, and other suitable materials. The electrostatic chuck 150 can be moved in a vertical direction using a displacement mechanism (not shown) inside the processing chamber 100.

[0034] A vacuum pump 102 is coupled to a port formed in the bottom of the processing chamber 100. The vacuum pump 102 is used to maintain a desired gas pressure in the processing chamber 100. The vacuum pump 102 also evacuates post-processing gases and byproducts from the processing chamber 100.

[0035] The substrate processing system 132 can additionally include additional equipment for controlling the chamber pressure, such as valves (e.g., throttle and isolation valves) positioned between the processing chamber 100 and the vacuum pump 102 to control the chamber pressure.

[0036] A gas distribution assembly 120 having a plurality of holes 128 is disposed on the top of the processing chamber 100 above the electrostatic chuck 150. The holes 128 of the gas distribution assembly 120 are used to direct process gases into the processing chamber 100. The holes 128 can have different sizes, numbers, distributions, shapes, designs, and diameters to facilitate various process gas flows for different process requirements. The gas distribution assembly 120 is connected to the gas panel 130, which allows various gases to be supplied to the processing volume 126 during processing. A plasma is formed from the process gas mixture exiting the gas distribution assembly 120 to enhance thermal decomposition of the process gases, thereby causing material to be deposited on the surface 191 of the substrate 190.

[0037] The gas distribution assembly 120 and the electrostatic chuck 150 can form a pair of spaced apart electrodes in the processing volume 126. One or more RF power sources 140 provide a bias potential to the gas distribution assembly 120 via an optional matching network 138 to facilitate the creation of a plasma between the gas distribution assembly 120 and the electrostatic chuck 150. Alternatively, the RF power source 140 and the matching network 138 can be coupled to the gas distribution assembly 120, to the electrostatic chuck 150, or to both the gas distribution assembly 120 and the electrostatic chuck 150, to an antenna (not shown) disposed outside of the processing chamber 100. In some embodiments, the RF power source 140 can generate power at a frequency of 350 KHz, 2 MHz, 13.56 MHz, 27 MHz, 40 MHz, 60 MHz, or 100 MHz. In one embodiment, the RF power source 140 can provide power between about 100 Watts and about 3000 Watts at a frequency of about 50 kHz to about 13.6 MHz. In another embodiment, the RF power source 140 can provide power between about 500 Watts and about 1800 Watts at a frequency of about 50 kHz to about 13.6 MHz.

[0038] The controller 110 includes a central processing unit (CPU) 112, a memory 116, and support circuits 114 to control the process sequences and regulate the flow of gases from the gas panel 130. The CPU 112 can be of any form of a general purpose computer processor that can be used in an industrial setting. The software routines can be stored in the memory 116, such as a FIG. 1A some of the signal cables are described in

[0039] FIG. 1B A schematic cross-sectional view of another substrate processing system 180 that can be used in the practice of the embodiments described herein is depicted. The substrate processing system 180 is similar to the substrate processing system 132 of FIG. 1A the substrate processing system 132, except that the substrate processing system 180 is configured so that the process gas from the gas panel 130 flows through the surface 191 of the substrate 190 via the sidewall 101. In addition, FIG. 1A the gas distribution assembly 120 depicted in

[0040] FIG. 2Depictions of systems that can be used in the practice of embodiments described herein FIG. 1A and FIG. 1B schematic cross-sectional view of a substrate support assembly 146 used in the processing system of FIG. 2 Referring to FIG. 1, an electrostatic chuck 150 can include a heater assembly 170 adapted to control the temperature of a substrate 190 supported on an upper surface 192 of the electrostatic chuck 150. The heater assembly 170 can be embedded in the electrostatic chuck 150. The electrostatic chuck 150 can be heated in a resistive manner by applying current from a heater power supply 106 to the heater assembly 170. The heater power supply 106 can be coupled via an RF filter 216. The RF filter 216 can be used to protect the heater power supply 106 from RF energy. The heater assembly 170 can be made of nichrome wire encapsulated in a protective sheath of nickel-iron-chromium alloy (e.g., Inconel®), Incoloy®, or similar material. The current supplied from the heater power supply 106 is regulated by the controller 110 to control the amount of heat generated by the heater assembly 170, thus maintaining the substrate 190 and the electrostatic chuck 150 at a substantially constant temperature during film deposition. The current supplied can be adjusted to selectively control the temperature of the electrostatic chuck 150 between about -50 degrees Celsius and about 600 degrees Celsius.

[0041] Referring to FIG. 1, a temperature sensor 172, such as a thermocouple, can be embedded in the electrostatic chuck 150 that monitors the temperature of the electrostatic chuck 150 in a conventional manner. The controller 110 uses the measured temperature to control the power supplied to the heater assembly 170 to maintain the substrate at a desired temperature.

[0042] The electrostatic chuck 150 includes an attraction electrode 210, which can be a grid of electrically conductive material. The attraction electrode 210 can be embedded in the electrostatic chuck 150. The attraction electrode 210 is coupled to an attraction power supply 212 that, when energized, electrostatically clamps the substrate 190 to the upper surface 192 of the electrostatic chuck 150.

[0043] The attraction electrode 210 can be configured as a monopolar or bipolar electrode, or have another suitable configuration. The attraction electrode 210 can be coupled to the attraction power supply 212 via an RF filter 214 that provides direct current (DC) electricity to electrostatically secure the substrate 190 to the upper surface 192 of the electrostatic chuck 150. The RF filter 214 prevents RF power used to form a plasma within the processing chamber 100 from damaging electrical equipment or creating an electrical hazard outside the chamber. The electrostatic chuck 150 can be fabricated from a ceramic material such as AI N or AI2O3. Alternatively, the electrostatic chuck 150 can be fabricated from a polymer such as polyimide, polyether ether ketone (PEEK), polyaryletherketone (PAEK), or the like.

[0044] ​The power application system 220 is coupled to the substrate support assembly 146. The power application system 220 can include a heater power supply 106, an attraction power supply 212, a first radio frequency (RF) power supply 230, and a second RF power supply 240. Embodiments of the power application system 220 can additionally include the controller 110 and a sensor arrangement 250 that is in communication with the controller 110 and in communication with both the first RF power supply 230 and the second RF power supply 240.

[0045] The controller 110 can also be used to control a plasma from a process gas to deposit a layer of material on the substrate 190 by applying RF power from the first RF power supply 230 and the second RF power supply 240.

[0046] As described above, the electrostatic chuck 150 includes an attraction electrode 210 that can be used in one aspect to attract the substrate 190 while also serving as a first RF electrode. The electrostatic chuck 150 can also include a second RF electrode 260 and, together with the attraction electrode 210, can apply RF power to tune a plasma. The first RF power supply 230 can be coupled to the second RF electrode 260 and the second RF power supply 240 can be coupled to the attraction electrode 210. A first matching network and a second matching network for the first RF power supply 230 and the second RF power supply 240, respectively, can be provided. As shown, the second RF electrode 260 can be a solid metal plate of electrically conductive material. Alternatively, the second RF electrode 260 can be a mesh of electrically conductive material.

[0047] The first RF power supply 230 and the second RF power supply 240 can generate power at the same frequency or at different frequencies. In some embodiments, one or both of the first RF power supply 230 and the second RF power supply 240 can independently generate power at a frequency from about 350 KHz to about 100 MHz (e.g., 350 KHz, 2 MHz, 13.56 MHz, 27 MHz, 40 MHz, 60 MHz, or 100 MHz). In some embodiments, the first RF power supply 230 can generate power at a 13.56 MHz frequency and the second RF power supply 240 can generate power at a 2 MHz frequency, or vice versa. The RF power from one or both of the first RF power supply 230 and the second RF power supply 240 can be varied in order to tune a plasma. For example, the sensor arrangement 250 can be used to monitor RF energy from one or both of the first RF power supply 230 and the second RF power supply 240. Data from the sensor arrangement 250 can be communicated to the controller 110 and the controller 110 can be used to vary the power applied by the first RF power supply 230 and the second RF power supply 240.

[0048] sp3 content in as-deposited diamond-like carbon 3The number / percentage of hybridized carbon atoms can vary depending on the application. In various embodiments of the present disclosure, the as-deposited diamond-like carbon film can contain at least 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, or 85% sp 3 hybridized carbon atoms. The as-deposited diamond-like carbon film can contain up to 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, or 90% sp 3 hybridized carbon atoms. The as-deposited diamond-like carbon film can contain from about 50% to about 90% sp 3 hybridized carbon atoms. The as-deposited diamond-like carbon film can contain from about 60% to about 70% sp 3 hybridized carbon atoms.

[0049] Generally, the following exemplary deposition process parameters can be used to form the as-deposited diamond-like carbon layer. The wafer temperature can be in a range from about -50 °C to about 350 °C (e.g., from about 10 °C to about 100 °C; or from about 10 °C to about 50 °C). The chamber pressure can be in a range of chamber pressures from about 0.5 mTorr to about 10 Torr (e.g., from about 2 mTorr to about 50 mTorr; or between about 2 mTorr and 10 mTorr). The flow rate of the hydrocarbon-containing gas mixture can be from about 10 seem to about 1000 seem (e.g., from about 100 seem to about 200 seem, or from about 150 seem to about 200 seem). The flow rate of the dilution gas can individually be in a range from about 50 seem to about 50000 seem (e.g., from about 50 seem to about 500 seem; or from about 50 seem to about 100 seem).

[0050]

[0051] Table I.

[0052] The diamond-like carbon layer can be deposited to a thickness of between about and about (e.g., between about and about ; between about and about , or between about and about . The process parameters depicted above in Table I provide an example of process parameters for a 300 mm substrate in a deposition chamber available from Applied Materials, Inc. of Santa Clara, California, USA.

[0053] The as-deposited diamond-like carbon film can have a refractive index or n-value (n (at 633 nm)) of greater than 2.0, such as from about 2.0 to about 3.0, such as 2.3. The as-deposited diamond-like carbon film can have an extinction coefficient or k-value (K (at 633 nm)) of greater than 0.1, such as from about 0.2 to about 0.3, such as 0.25. The as-deposited diamond-like carbon film can have a stress (MPa) of less than about -100 MPa, such as from about -1000 MPa to about -100 MPa, from about -600 MPa to about -300 MPa, from about -600 MPa to about -500 MPa, such as about -550 MPa. The as-deposited diamond-like carbon film can have a density (g / cc) of greater than 1.8 g / cc, such as from about 2.0 g / cc or more, about 2.5 g / cc or more, such as from about 1.8 g / cc to about 2.5 g / cc. The as-deposited diamond-like carbon film can have an elastic modulus (GPa) of greater than 150 GPa, such as from about 200 GPa to about 400 GPa.

[0054] FIG. 3 A flowchart of a method 300 of forming a diamond-like carbon layer on a film stack disposed on a substrate in accordance with one embodiment of the present disclosure is depicted. The diamond-like carbon layer formed on the film stack can be used as, for example, a hard mask to form a stepped structure in the film stack. FIG. 4A to FIG. 4B is a schematic cross-sectional view illustrating a sequence for forming a diamond-like carbon layer on a film stack disposed on a substrate in accordance with the method 300. While the method 300 is described below with reference to a hard mask layer that can be formed on a film stack to fabricate a stepped structure in a film stack for a three-dimensional semiconductor device, the method 300 can also be used in other device fabrication applications to provide advantages. In addition, it should also be understood that, FIG. 3 The operations depicted in FIG. 3 may be performed simultaneously and / or in an order different than the order depicted in

[0055] The method 300 begins at operation 310, which is positioning a substrate, such as the substrate 400 depicted in FIG. 4A , in a processing chamber, such as the processing chamber 100 depicted in FIG. 1A or FIG. 1B . The substrate 400 can be the substrate 190 depicted in FIG. 1A , FIG. 1B and FIG. 2 . The substrate 400 can be positioned on an electrostatic chuck, for example, on the upper surface 192 of the electrostatic chuck 150. The substrate 400 can be a silicon-like material or any suitable insulating or conductive material as desired, on which a film stack 404 is disposed, which can be used to form a structure 402, such as a stepped structure, in the film stack 404.

[0056] As shown in the exemplary embodiment depicted in FIG. 4A substrate 400 can have a substantially planar surface, an uneven surface, or a substantially planar surface with structures formed on the substrate. A film stack 404 is formed on the substrate 400. In one embodiment, the film stack 404 can be used to form gate structures, contact structures, or interconnect structures in a front end or back end process. The method 300 can be performed on the film stack 404 to form stepped structures in the film stack for use in memory structures such as NAND structures. In one embodiment, the substrate 400 can be a material such as crystalline silicon (e.g., Si<100> or Si<111>), silicon oxide, strained silicon, silicon germanium, doped or undoped polysilicon, doped or undoped silicon substrate, and patterned or unpatterned silicon on insulator (SOI), carbon-doped silicon oxide, silicon nitride, doped silicon, germanium, gallium arsenide, glass, sapphire. The substrate 400 can have various dimensions such as 200 mm, 300 mm, and 450 mm or other diameter substrates, and rectangular or square plates. Unless otherwise noted, the embodiments and examples described herein are performed on a substrate having a 200 mm diameter, a substrate having a 300 mm diameter, or a 450 mm diameter substrate. In embodiments where a SOI structure is used for the substrate 400, the substrate 400 can include an embedded dielectric layer disposed on a silicon crystalline substrate. In the embodiments depicted herein, the substrate 400 can be a crystalline silicon substrate.

[0057] In one embodiment, the film stack 404 disposed on the substrate 400 can have a plurality of vertically stacked layers. The film stack 404 can include pairs of first layers (shown as 408al, 408a2, 408a3,..., 408a n ) and second layers (shown as 408bl, 408b2, 408b3,..., 408b n ) repeatedly formed in the film stack 404. The pairs include alternating first layers (shown as 408al, 408a2, 408a3,..., 408a n ) and second layers (shown as 408bl, 408b2, 408b3,..., 408b n ) repeatedly formed until a desired number of pairs of first layers and second layers are reached.

[0058] The film stack 404 can be part of a semiconductor chip such as a three-dimensional memory chip. Although FIG. 4A to FIG. 4B first layers (408al, 408a2, 408a3,..., 408a n ) and second layers (shown as 408bl, 408b2, 408b3,..., 408b n) three repeating layers, although it should be noted that any desired number of first and second layers of repeating pairs can be utilized as desired.

[0059] In one embodiment, the film stack 404 can be used to form a multi-gate structure for a three-dimensional memory chip. The first layers 408a1, 408a2, 408a3,..., 408a n may be first dielectric layers, and the second layers 408b1, 408b2, 408b3,..., 408b n may be second dielectric layers. Suitable dielectric layers can be used to form the first layers 408a1, 408a2, 408a3,..., 408a n and the second layers 408b1, 408b2, 408b3,..., 408b n including silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, silicon oxycarbide, titanium nitride, a composite of oxide and nitride, at least one or more oxide layers sandwiched by nitride layers, combinations thereof, and the like. In some embodiments, the dielectric layers can be high-k materials having a dielectric constant greater than 4. Suitable examples of high-k materials include hafnium dioxide (Hf02), zirconium dioxide (Zr02), hafnium silicon oxide (HfSi02), hafnium aluminum oxide (HfAlO), zirconium silicon oxide (ZrSi02), tantalum dioxide (Ta02), aluminum oxide, aluminum-doped hafnium dioxide, bismuth strontium titanium, platinum zirconium titanium, and the like.

[0060] In one particular example, the first layers 408a1, 408a2, 408a3,..., 408a n are silicon oxide layers, and the second layers 408b1, 408b2, 408b3,..., 408b n are silicon nitride layers or polysilicon layers disposed on the first layers 408a1, 408a2, 408a3,..., 408a n In one embodiment, the thickness of the first layers 408a1, 408a2, 408a3,..., 408a n may be controlled to be between about and about , such as about and the thickness of each second layer 408b1, 408b2, 408b3,..., 408b n may be controlled to be between about and about , such as The film stack 404 can have a total thickness between about and about In one embodiment, the total thickness of the film stack 404 is about 3 microns to about 10 microns and will vary with technological advances.

[0061] It is noted that the diamond-like carbon layer can be formed on any surface or any portion of the substrate 400, and that the film stack 404 is present or absent on the substrate 400.

[0062] At operation 320, an attraction voltage is applied to the electrostatic chuck to clamp the substrate 400 to the electrostatic chuck. In some embodiments, with the substrate 400 positioned on the upper surface 192 of the electrostatic chuck 150, the upper surface 192 provides support and clamping for the substrate 400 during processing. The electrostatic chuck 150 flattens the substrate 400 against the upper surface 192, thereby preventing backside deposition. An electrical bias is provided to the substrate 400 via the attraction electrode 210. The attraction electrode 210 can be in electronic communication with an attraction power supply 212 that supplies the bias voltage to the attraction electrode 210. In one embodiment, the attraction voltage is between about 10 volts and about 3000 volts. In one embodiment, the attraction voltage is between about 100 volts and about 2000 volts. In one embodiment, the attraction voltage is between about 200 volts and 1000 volts.

[0063] During operation 320, several process parameters of the process can be adjusted. In one embodiment suitable for processing 300 mm substrates, the process pressure in the processing volume can be maintained at about 0.1 mTorr to about 10 Torr (e.g., about 2 mTorr to about 50 mTorr; or about 5 mTorr to about 20 mTorr). In one embodiment suitable for processing 300 mm substrates, the processing temperature and / or the substrate temperature can be maintained at about -50 degrees Celsius to about 350 degrees Celsius (e.g., about 0 degrees Celsius to about 50 degrees Celsius; or about 10 degrees Celsius to about 20 degrees Celsius).

[0064] In one embodiment, a constant attraction voltage is applied to the substrate 400. In one embodiment, the attraction voltage can be pulsed to the electrostatic chuck 150. In some embodiments, a backside gas can be applied to the substrate 400 at the same time as the attraction voltage is applied to control the temperature of the substrate. The backside gas can include, but is not limited to, helium (He), argon (Ar), and the like.

[0065] At operation 330, a plasma is generated at the substrate level by applying a first RF bias to the electrostatic chuck. The plasma generated at the substrate level can be generated in a plasma region between the substrate and the electrostatic chuck. The first RF bias can be from about 10 Watts to about 3000 Watts at a frequency from about 350 KHz to about 100 MHz (e.g., 350 KHz, 2 MHz, 13.56 MHz, 27 MHz, 40 MHz, 60 MHz, or 100 MHz). In one embodiment, the first RF bias is provided at a frequency of about 13.56 MHz with a power between about 2500 Watts and about 3000 Watts. In one embodiment, the first RF bias is provided to the electrostatic chuck 150 via the second RF electrode 260. The second RF electrode 260 can be in electronic communication with the first RF power source 230 that supplies a bias voltage to the second RF electrode 260. In one embodiment, the bias power is between about 10 Watts and about 3000 Watts. In one embodiment, the bias power is between about 2000 Watts and about 3000 Watts. In one embodiment, the bias power is between about 2500 Watts and about 3000 Watts. The first RF power source 230 can generate power at a frequency from about 350 KHz to about 100 MHz (e.g., 350 KHz, 2 MHz, 13.56 MHz, 27 MHz, 40 MHz, 60 MHz, or 100 MHz).

[0066] In some embodiments, operation 330 further includes applying a second RF bias to the electrostatic chuck. The second RF bias can be from about 10 Watts to about 3000 Watts at a frequency from about 350 KHz to about 100 MHz (e.g., 350 KHz, 2 MHz, 13.56 MHz, 27 MHz, 40 MHz, 60 MHz, or 100 MHz). In one embodiment, the second RF bias is provided at a frequency of about 2 MHz with a power between about 800 Watts and about 1200 Watts. In one embodiment, the second RF bias is provided to the substrate 400 via the attraction electrode 210. The attraction electrode 210 can be in electronic communication with the second RF power source 240 that supplies a bias voltage to the attraction electrode 210. In one embodiment, the bias power is between about 10 Watts and about 3000 Watts. In one embodiment, the bias power is between about 500 Watts and about 1500 Watts. In one embodiment, the bias power is between about 800 Watts and 1200 Watts. The second RF power source 240 can generate power at a frequency from about 350 KHz to about 100 MHz (e.g., 350 KHz, 2 MHz, 13.56 MHz, 27 MHz, 40 MHz, 60 MHz, or 100 MHz). In one embodiment, the attraction voltage supplied in operation 320 is maintained during operation 330.

[0067] In some embodiments, during operation 330, a first RF bias is provided to the substrate 400 via adsorption electrode 210, and a second RF bias is provided to the substrate 400 via a second RF electrode 260. In one embodiment, the first RF bias is approximately 2500 watts (13.56 MHz) and the second RF bias is approximately 1000 watts (2 MHz).

[0068] During operation 340, a hydrocarbon-containing gas mixture flows into processing volume 126 to form a diamond-like carbon film on the film stack. The hydrocarbon-containing gas mixture may flow from gas panel 130 via gas distribution assembly 120 or via sidewall 101 into processing volume 126. The hydrocarbon-containing gas mixture may include at least one hydrocarbon compound. The hydrocarbon-containing gas mixture may additionally include inert gases, diluent gases, nitrogen-containing gases, etchant gases, or combinations thereof. The hydrocarbon may be any liquid or gas, but a preferred precursor is vapor at room temperature to simplify the hardware required for material metering, control, and delivery to the chamber. In some embodiments, the adsorption voltage supplied during operation 320 is maintained during operation 340. In some embodiments, the process conditions established during operation 320 and the plasma formed during operation 330 are maintained during operation 340.

[0069] In one embodiment, the hydrocarbon compound is a gaseous hydrocarbon. In one embodiment, the hydrocarbon compound has the general formula C1. x H y Where x ranges from 1 to 20, and y ranges from 1 to 20. Suitable hydrocarbon compounds include, for example, C2H2, C3H6, CH4, C4H8, 1,3-dimethyladamantane, bicyclic [2.2.1]heptavalent-2,5-diene (2,5-norbornene), and adamantine (C 10 H 16 norbornene (C7H) 10 (or combinations thereof) precursors. In one example, C2H2 is attributed to the formation of a more stable intermediate species that allows for greater surface mobility, which is preferable.

[0070] In one embodiment, the hydrocarbon compound is an alkane (e.g., C42-C5 ... n H 2n+2 (where n is between 1 and 20). Suitable hydrocarbon compounds include, for example, alkanes, such as methane (CH4), ethane (C2H6), propylene (C3H6), propane (C3H8), and butane (C4H6). 10 ) and its isomers isobutane and pentane (C5H 12 ), hexane (C6H) 14 ) and its isomers isopentane and neopentane, hexane (C6H 14) and isomers thereof 2-methylpentane, 3-methylpentane, 2,3-dimethylbutane, and 2,2-dimethylbutane, or combinations thereof.

[0071] In one embodiment, the hydrocarbon compound is an alkene (e.g., C n H 2n where n is between 1 and 20). Suitable hydrocarbon compounds include, for example, alkenes such as acetylene, ethylene, propylene, butenes and isomers thereof, pentenes and isomers thereof, and the like, dienes such as butadiene, isoprene, pentadiene, hexadiene, or combinations thereof. Additional suitable hydrocarbons include, for example, halogenated alkenes such as monofluoroethylene, difluoroethylene, trifluoroethylene, tetrafluoroethylene, monochloroethylene, dichloroethylene, trichloroethylene, tetrachloroethylene, or combinations thereof.

[0072] In one embodiment, the hydrocarbon compound is an alkyne (e.g., C n H 2n-2 where n is between 1 and 20). Suitable hydrocarbon compounds include, for example, alkenes such as acetylene, ethylene, propylene, butenes and isomers thereof, pentenes and isomers thereof, and the like, dienes such as butadiene, isoprene, pentadiene, hexadiene, or combinations thereof. Additional suitable hydrocarbons include, for example, halogenated alkenes such as monofluoroethylene, difluoroethylene, trifluoroethylene, tetrafluoroethylene, monochloroethylene, dichloroethylene, trichloroethylene, tetrachloroethylene, or combinations thereof.

[0073] In one embodiment, the hydrocarbon compound is an aromatic compound such as benzene, styrene, toluene, xylene, ethylbenzene, acetophenone, methyl benzoate, phenyl acetate, phenol, cresol, furan, and the like, a-pinene, isopropyltoluene, 1,1,3,3,-tetramethylbutylbenzene, tertiary butyl ether, tertiary butyl ethylene, methyl methacrylate, and tertiary butyl furfuryl ether, compounds having the chemical formula C3H2and C5H4, halogenated aromatic compounds including monofluorobenzene, difluorobenzene, tetrafluorobenzene, hexafluorobenzene, or combinations thereof.

[0074] In some embodiments, the hydrocarbon-containing gas mixture additionally includes one or more diluent gases. Suitable diluent gases such as helium (He), argon (Ar), xenon (Xe), hydrogen (H2), nitrogen (N2), ammonia (NH3), or combinations thereof, and the like, can be added to the gas mixture as desired. Ar, He, and N2are used to control the density and deposition rate of the diamond-like carbon layer. In some cases, as discussed below, the addition of N2and / or NH3may be used to control the hydrogen ratio of the diamond-like carbon layer. Alternatively, no diluent gas can be used during deposition.

[0075] In some embodiments, the hydrocarbon-containing gas mixture additionally includes one or more nitrogen-containing gases. Suitable nitrogen-containing compounds include, for example, pyridine, aliphatic amines, amines, nitriles, ammonia, and similar compounds.

[0076] In some embodiments, the hydrocarbon-containing gas mixture additionally includes an inert gas. In some embodiments, an inert gas such as argon (Ar) and / or helium (He) can be supplied with the hydrocarbon-containing gas mixture into the processing volume 126. Other inert gases such as nitrogen (N2) and nitric oxide (NO) can also be used to control the density and deposition rate of the diamond-like carbon layer. Additionally, various other process gases can be added to the hydrocarbon-containing gas mixture to modify the properties of the diamond-like carbon material. In one embodiment, the other process gas can be a reactive gas such as hydrogen (H2), ammonia (NH3), a mixture of hydrogen (H2) and nitrogen (N2), or combinations thereof. The addition of H2and / or NH3may be used to control the hydrogen ratio (e.g., the ratio of carbon to hydrogen) of the deposited diamond-like carbon layer. The hydrogen ratio present in the diamond-like carbon film provides control over layer properties such as reflectivity.

[0077] In some embodiments, the hydrocarbon-containing gas mixture additionally includes an etchant gas. Suitable etchant gases include chlorine (CI2), carbon tetrafluoride (CF4), nitrogen trifluoride (NF3), or combinations thereof. Without being bound by theory, it is believed that the etchant gas selectively etches sp 2 hybridized carbon atoms, thus increasing the sp 3 a small fraction of the hybridized carbon atoms, thus increasing the etch selectivity of the film.

[0078] In some embodiments, after the diamond-like carbon layer 412 is formed on the substrate during operation 340, the diamond-like carbon layer 412 is exposed to hydrogen radicals. In some embodiments, the diamond-like carbon layer is exposed to hydrogen radicals during the deposition process of operation 340. In some embodiments, the hydrogen radicals are formed in the RPS and delivered to the processing region. Without being bound by theory, it is believed that exposing the diamond-like carbon layer to hydrogen radicals results in selective etching of sp 2 hybridized carbon atoms, thus increasing the sp 3 a small fraction of the hybridized carbon atoms, thus increasing the etch selectivity.

[0079] At operation 350, after the diamond-like carbon layer 412 is formed on the substrate, the substrate is unadsorbed. During operation 350, the adsorption voltage is turned off. The reactive gas is shut off and optionally purged from the processing chamber. In one embodiment, during operation 350, the RF power is reduced (e.g., about 200 W). Optionally, the controller 110 monitors the impedance change to determine whether the electrostatic charge is dissipated to ground via the RF path. Once the substrate is unadsorbed from the electrostatic chuck, the remaining gas is purged from the processing chamber. The processing chamber is pumped down, and the substrate is moved upward on the lift pins and transferred out of the chamber.

[0080] After forming the diamond-like carbon layer 412 on the substrate, the diamond-like carbon layer 412 can be used as a patterning mask in an etching process to form a three-dimensional structure, such as a stepped structure. The diamond-like carbon layer 412 can be patterned using standard photoresist patterning techniques. A patterned photoresist (not shown) can be formed over the diamond-like carbon layer 412. The diamond-like carbon layer 412 can be etched in a pattern corresponding to the patterned photoresist layer, which is subsequently etched into the substrate 400. Material can be deposited into the etched portions of the diamond-like carbon layer 412. The diamond-like carbon layer 412 can be removed using a solution including hydrogen peroxide and sulfuric acid. One exemplary solution including hydrogen peroxide and sulfuric acid is known as a Piranha solution or Piranha etch. The diamond-like carbon layer 412 can also be removed using etching chemicals containing oxygen and halogen (e.g., fluorine or chlorine), such as Cl2 / O2, CF4 / O2, Cl2 / O2 / CF4. The diamond-like carbon layer 412 can be removed by a chemical mechanical polishing (CMP) process.

[0081] Examples:

[0082] The following non-limiting examples are provided to further illustrate the embodiments described herein. However, these examples are not intended to be all-inclusive and are not intended to limit the scope of the embodiments described herein.

[0083] In one embodiment, the low stress, high density diamond-like carbon film of the present disclosure is fabricated by flowing 150 seem C2H2 and 100 seem He as process gases at a temperature of 10 degrees Celsius in a CVD reactor with Ar and / or He as dilution gas, applying 2500 watt RF (13.56 MHz) power and 1000 watt (2 MHz) power via the substrate pedestal (electrostatic chuck). The resulting diamond-like carbon film has a density of 1.94 g / cc and a stress of -350 MPa, as well as an etch selectivity greater than existing amorphous carbon films.

[0084]

[0085]

[0086] Table II.

[0087] FIG. 5 is a graph 500 depicting the density of diamond-like carbon layers formed in accordance with one or more embodiments of the present disclosure as a function of bias power. The graph 500 depicts the density of diamond-like carbon films deposited at a frequency of 2 MHz and a frequency of 13.56 MHz as a function of bias power. The y-axis represents the density of the deposited film (g / cc), and the x-axis represents the bias power (watts). As explained in FIG. 5 in the Background section, the density of the as-deposited film increases substantially as the bias power increases.

[0088] FIG. 6 This is a graph 600 depicting the stress as a function of bias power for a diamond-like carbon layer formed according to one or more embodiments of the present disclosure. Graph 600 depicts the stress as a function of bias power for diamond-like carbon films deposited at frequencies of 2 MHz and 13.56 MHz. The y-axis represents the stress (MPa) of the deposited film, and the x-axis represents the bias power (watts). As in... FIG. 6 As explained in the paper, to a large extent, the stress of the deposited film also increases with the increase of bias power.

[0089] FIG. 7 This is a graph 700 depicting the density and stress of a diamond-like carbon layer formed according to one or more embodiments of the present disclosure as a function of pressure. The y-axis represents the density (g / cc) and stress (MPa) of the deposited film, and the x-axis represents the process pressure (millitorrs). As in FIG. 7 As explained in the text, lower pressure produces slightly higher density, and lower stress and higher pressure produce greater compressive stress.

[0090] Extreme ultraviolet (“EUV”) patterning scheme

[0091] When using metal-containing photoresists in extreme ultraviolet (“EUV”) patterning schemes, the choice of the underlying layer is critical for preventing nanoscale failures (e.g., bridging defects and spacing defects) in semiconductor devices. The conventional underlying layer for EUV patterning (photolithography) schemes is spin-on carbon (SOC) material. However, during patterning, metals (such as tin) diffuse through the SOC material, leading to nanoscale failures in the semiconductor device. These nanoscale failures often reduce, degrade, and impair semiconductor performance.

[0092] The high-density carbon films described in this paper, on the other hand, possess excellent film quality, such as improved hardness and density. This hardness and density allow the high-density carbon films to act as a more robust barrier layer against metal penetration and to prevent and at least reduce nanoscale failures to a greater extent than conventional SOC films.

[0093] In some embodiments, a film is provided as a lower layer for extreme ultraviolet (“EUV”) lithography processes. In some embodiments, the film (and / or the deposited film) has one or more of the following properties:

[0094] 1) Based on at least 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, or 85% of the total carbon atoms in the deposited film, sp 3 The number / percentage of hybrid carbon atoms (i.e., sp) 3 Hybridized carbon atom content). In these or other embodiments, sp3 The number / percentage of hybridized carbon atoms is up to 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85, or 90% based on the total amount of carbon atoms in the as-deposited film. In these or other embodiments, the sp 3 The number / percentage of hybridized carbon atoms is from about 50% to about 90% (such as from about 60% to about 70%) based on the total amount of carbon atoms in the as-deposited film.

[0095] 2) a thickness of between about and about (eg, between about and about , such as between about and about ). Alternatively, a thickness of between about and about .

[0096] 3) an index of refraction or n value (n (at 633 nm)) of greater than 2.0, for example, from about 2.0 to about 3.0, such as 2.3.

[0097] 4) an extinction coefficient or k value (K (at 633 nm)) of greater than 0.1, for example, from about 0.2 to about 0.3, such as 0.25.

[0098] 5) a stress (MPa) of less than about -300 MPa, for example, from about -600 to about -300 MPa, from about -600 MPa to about -500 MPa, such as about -550 MPa.

[0099] 6) a density (g / cc) of greater than 1.8 g / cc, for example, about 2.0 g / cc or higher, about 2.5 g / cc or higher, such as from about 1.8 g / cc to about 2.5 g / cc.

[0100] 7) an elastic modulus (GPa) of greater than 150 GPa, for example, from about 200 GPa to about 400 GPa.

[0101] In some embodiments, the film used as an underlayer for an EUV lithography process can be any of the films described herein.

[0102] In some embodiments, the film used as an underlayer for an EUV lithography process has between 40% and 90% sp 3 hybridized carbon atoms based on the total amount of carbon atoms in the film; a density of between 1.8 g / cc and 2.5 g / cc; and an elastic modulus of between 150 GPa and 400 GPa.

[0103] In some embodiments, the film used as an underlayer for EUV lithography processes has a density between 2.0 g / cc and 2.2 g / cc; and an elastic modulus between about 180 GPa and about 200 GPa. In some embodiments, the film has a density of about 2.1 g / cc and an elastic modulus of about 195 GPa.

[0104] In some embodiments, the film used as an underlayer for EUV lithography processes has a stress of -600 MPa; an index of refraction between 2.0 and 3.0; and an extinction coefficient between 0.2 and 0.3.

[0105] Accordingly, methods and apparatus for forming a diamond-like carbon hard mask layer are provided that can be used to form a stepped structure for a three-dimensional stack of semiconductor devices. By utilizing a diamond-like hard mask layer having desirable robust film properties and etch selectivity, improved dimensions and improved profile control of the resulting structure formed in a film stack can be obtained, and electrical performance of a chip device in applications for three-dimensional stacks of semiconductor devices can be enhanced.

[0106] In summary, some benefits of the present disclosure provide processes for depositing a diamond-like hard mask film on a substrate. Typical PECVD hard mask films have very low hybrid sp 3 atomic percentages, and thus low modulus and low etch selectivity. In some embodiments described herein, low process pressure (millitorr vs. torr) and bottom-driven plasma enable film fabrication with approximately 60% or greater hybrid sp 3 atomic percentages, which results in improved etch selectivity over previously available hard mask films. Additionally, some embodiments described herein are performed at low substrate temperatures, which enables deposition of other dielectric films at significantly lower temperatures than currently possible, opening up applications with low thermal budgets that current CVD cannot address. Additionally, some embodiments described herein can be used as an underlayer for EUV lithography processes.

[0107] When introducing elements of the present disclosure or the exemplary aspects or embodiments thereof, the articles "a," "an," "the," and "said" are intended to mean that there are one or more of the elements. The terms "comprising," "including," and "having" are intended to be inclusive and mean that there can be additional elements other than the listed elements.

[0108] The terms "comprising," "including," and "having" are intended to be inclusive and mean that there can be additional elements other than the listed elements.

[0109] While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure can be devised without departing from the basic scope thereof, and the scope of the present disclosure is determined by the appended claims.

Claims

1. A method of processing a substrate, comprising the steps of: flowing a hydrocarbon-containing gas mixture into a processing volume of a processing chamber having a substrate positioned on an electrostatic chuck, wherein the processing volume is maintained at a pressure between 0.5 mTorr and 10 mTorr and the hydrocarbon-containing gas mixture includes a hydrocarbon-containing precursor and an etchant gas; A plasma is generated within the processing volume by applying a first RF bias to the electrostatic chuck to deposit a carbon film from the hydrocarbon-containing mixture on the substrate, the carbon film comprising at least 50% sp 3 hybridized carbon atoms, wherein the substrate is maintained at a temperature of from -50 degrees Celsius to 350 degrees Celsius.

2. The method of claim 1, wherein the etchant gas comprises one or more of Cl2, CF4, or NF3.

3. The method of claim 2, wherein the hydrocarbon compound is an alkane.

4. The method of claim 1, wherein the hydrocarbon compound includes one or a combination of methane, ethane, propylene, propane, butane, isobutane, pentane, hexane, isopentane, neopentane, 2-methylpentane, 3-methylpentane, 2,3-dimethylbutane, and 2,2-dimethylbutane.

5. The method of claim 1, wherein there is at least 75% sp 3 hybridized carbon atoms.

6. The method of claim 1, wherein the temperature of the substrate is maintained at 0 degrees Celsius to 50 degrees Celsius.

7. The method of claim 1, wherein the first RF bias is provided at a frequency from 350 kHz to 100 MHz and at a power between 10 Watts and 3000 Watts.

8. The method of claim 7, wherein the first RF bias is provided at a frequency from 350 kHz to 100 MHz at a power between 2500 Watts and 3000 Watts.

9. The method of claim 1, wherein the hydrocarbon-containing gas mixture further includes one or more diluent gases.

10. The method of claim 9, wherein the one or more diluent gases include helium, argon, xenon, hydrogen, nitrogen, ammonia, or a combination thereof.

11. A method of processing a substrate, comprising the steps of: flowing a hydrocarbon-containing gas mixture into a processing volume of a processing chamber having a substrate positioned on an electrostatic chuck, wherein the electrostatic chuck has an attraction electrode and an RF electrode separate from the attraction electrode, wherein the processing volume is maintained at a pressure between 0.5 mTorr and 10 mTorr and the hydrocarbon-containing gas mixture includes a hydrocarbon-containing precursor, a diluent gas, and an etchant gas; A plasma is generated within the processing volume by applying a first RF bias to the electrostatic chuck to deposit a carbon film from the hydrocarbon-containing mixture on the substrate, the carbon film comprising at least 50% sp 3 hybridized carbon atoms.

12. The method of claim 11, wherein the substrate is maintained at a temperature from -50 degrees Celsius to 350 degrees Celsius.

13. The method of claim 11, wherein the etchant gas comprises one or more of Cl2, CF4, or NF3.

14. The method of claim 11, wherein the hydrocarbon compound is an alkane.

15. The method of claim 11, wherein the hydrocarbon compound includes one or a combination of methane, ethane, propylene, propane, butane, isobutane, pentane, hexane, isopentane, neopentane, 2-methylpentane, 3-methylpentane, 2,3-dimethylbutane, and 2,2-dimethylbutane.

16. The method of claim 11, wherein there is at least 75% sp 3 hybridized carbon atoms.

17. The method of claim 11, wherein the temperature of the substrate is maintained at 0 degrees Celsius to 50 degrees Celsius.

18. A method of processing a substrate, comprising the steps of: flowing a hydrocarbon-containing gas mixture into a processing volume of a processing chamber having a substrate positioned on an electrostatic chuck, wherein the processing volume is maintained at a pressure between 0.5 mTorr and 10 mTorr and the hydrocarbon-containing gas mixture includes a hydrocarbon-containing precursor and an etchant gas, the hydrocarbon-containing precursor selected from the group consisting of C2H2, C3H6, CH4, C4H8, bicyclo[2.2.1]hepta-2,5-diene (2,5-norbornadiene), norbornene (C7H 10 ), and combinations thereof; A plasma is generated within the processing volume by applying a first RF bias to the electrostatic chuck to deposit a diamond-like carbon film from the hydrocarbon-containing mixture on the substrate, and wherein the substrate is maintained at a temperature of from -50 degrees Celsius to 350 degrees Celsius, wherein the diamond-like carbon film comprises at least 50% sp 3 hybridized carbon atoms, having a density of from 1.8 g / cc to 2.5 g / cc and a stress of from -600 MPa to -300 MPa.

19. The method of claim 18, wherein the etchant gas comprises one or more of Cl2, CF4, or NF3.

20. The method of claim 18, wherein the diamond-like carbon film comprises at least 75% sp 3 hybridized carbon atoms, and a temperature of the substrate is maintained at 0 degrees Celsius to 50 degrees Celsius during deposition of the diamond-like carbon film.

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