High-Density Carbon Films for Patterning Applications

Abstract

Embodiments of the present disclosure generally relate to the deposition of highly transparent, high-density carbon films for patterning applications. In one embodiment, a method of forming a carbon film on a substrate is provided. The method includes: flowing a gas mixture containing hydrocarbons into a process chamber having a substrate positioned on an electrostatic chuck, wherein the substrate is maintained at a temperature of about -10 °C to about 20 °C and a chamber pressure of about 0.5 mTorr to about 10 Torr; and generating a plasma by applying a first RF bias to the electrostatic chuck to deposit a diamond-like carbon film containing about 60% or more hybrid sp<supgt;3< / supgt; atoms on the substrate, wherein the first RF bias is provided at a power of about 1800 W to about 2200 W and a frequency of about 40 MHz to about 162 MHz.

Description

BACKGROUND OF THE DISCLOSURE FIELD OF THE DISCLOSURE

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

[0003] DESCRIPTION OF RELATED ART

[0004] 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 continuously demands faster circuit systems and greater circuit density. The need for faster circuits with greater circuit density places corresponding requirements on the process sequences used in the fabrication of integrated circuit components. For example, in a process sequence using conventional lithography 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 to one or more of the stacked material layers.

[0005] As pattern sizes decrease, the thickness of the energy-sensitive resist correspondingly decreases in order to control pattern resolution. Such thin resist layers may be insufficient to mask underlying material layers during pattern transfer operations due to erosion by chemical etchants. Because hard masks have greater resistance to chemical etchants, hard masks are typically used between the energy-sensitive resist layer and the underlying material layer to facilitate pattern transfer. As critical dimensions (CDs) decrease, current hard mask materials lack the desired etch selectivity relative to underlying materials (e.g., oxides and nitrides) and are generally difficult to deposit.

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

[0007] Embodiments of the present disclosure generally relate to the fabrication of integrated circuits. More specifically, embodiments described herein provide techniques for depositing high density films for patterning applications. In one embodiment, a method of forming a carbon film on a substrate is provided. The method includes flowing a hydrocarbon-containing gas mixture into a process chamber having a substrate positioned on an electrostatic chuck, wherein the substrate is maintained at a temperature of from about -10 °C to about 20 °C and a chamber pressure of from about 0.5 millitorr to about 10 torr; and generating a plasma by applying a first RF bias to the electrostatic chuck to deposit on the substrate a film containing about 60% or more hybridized sp 3A diamond-like carbon film of an atom, wherein a first RF bias is provided at a power of about 1800 watts to about 2200 watts and a frequency of about 40 MHz to about 162 MHz for a 300 mm substrate.

[0008] In another embodiment, the method includes: flowing a hydrocarbon-containing gas mixture into a processing space of a process chamber having a substrate positioned on an electrostatic chuck; and generating a plasma by applying a first RF bias to the electrostatic chuck and a second RF bias to an electrode disposed above and opposite the electrostatic chuck to deposit a diamond-like carbon film on the substrate, wherein the first RF bias is provided at a frequency of about 13.56 MHz or lower, and the second RF bias is provided at a frequency of about 40 MHz or higher, and the substrate is maintained at a temperature of about -10 °C to about 20 °C and a chamber pressure of about 0.5 mTorr to about 10 Torr.

[0009] In yet another embodiment, the method includes: flowing a hydrocarbon-containing gas mixture into a processing space of a process chamber having a substrate positioned on an electrostatic chuck, wherein the substrate is maintained at a chamber pressure between about 5 mTorr and about 10 mTorr, and wherein the hydrocarbon-containing gas mixture includes acetylene (C2H2); generating a plasma at the substrate level by applying a first RF bias to the electrostatic chuck to deposit a diamond-like carbon film on the substrate, wherein the first RF bias is provided at a power of about 2000 watts and a frequency of about 60 MHz; forming a patterned photoresist layer over the diamond-like carbon film; etching the diamond-like carbon film in accordance with the pattern of the patterned photoresist layer; etching the pattern into the substrate; and depositing a material into the etched portion of the diamond-like carbon film. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] For a more particular understanding of the above-described features of the present disclosure, reference may be made to the embodiments described above in more detail with reference to the embodiments, some of which are illustrated in the drawings. However, it should be noted that the drawings only illustrate typical embodiments of the present disclosure and should not be considered as limiting the scope of the present disclosure, as the present disclosure may admit other equivalent embodiments.

[0011] Figure 1A A schematic cross-sectional view depicting a deposition system that can be used to implement the embodiments described herein;

[0012] Figure 1B A schematic cross-sectional view depicting another deposition system that can be used to implement the embodiments described herein;

[0013] Figure 2 Depicted as being usable in Figure 1A and Figure 1BSchematic cross-sectional view of an electrostatic chuck for implementing the embodiments described herein in a device;

[0014] Figure 3 Flowchart depicting a method for forming a diamond-like carbon layer on a film stack disposed on a substrate according to one or more embodiments of the present disclosure;

[0015] Figures 4A to 4B Depicting an embodiment of a sequence for forming a diamond-like carbon layer on a film stack formed on a substrate according to one or more embodiments of the present disclosure;

[0016] For ease of understanding, the same reference numerals are used, where possible, to indicate the same elements common to the figures. It is contemplated that elements and features in one embodiment may be beneficially incorporated into other embodiments without further recitation. Detailed Description

[0017] The following disclosure describes techniques for depositing diamond-like carbon films on substrates. The embodiments described herein will be described below with reference to a PECVD process that can be performed using any suitable thin film deposition system. Examples of suitable systems include systems that can use processing chambers of systems, PRECISION systems, systems, GT TM systems, XP Precision TM systems, SE TM systems, processing chambers, and Mesa TM processing chambers, all of the above systems / chambers are available from Applied Materials, Inc. of Santa Clara, California, USA. Other tools that can perform the PECVD process can also be adapted to benefit from the embodiments described herein. Additionally, any system that can implement the PECVD process described herein can be beneficially used. The device descriptions provided herein are illustrative and should not be construed or interpreted as limiting the scope of the embodiments described herein.

[0018] Figure 1ASchematic diagram depicting a substrate processing system 132 that can be used to perform diamond-like carbon layer deposition according to embodiments described herein. The substrate processing system 132 includes a process chamber 100 that is coupled to a gas panel 130 and a controller 110. The process chamber 100 generally includes a top wall 124, side walls 101, and a bottom wall 122 that define a processing space 126. A substrate support assembly 146 is disposed in the processing space 126 of the process chamber 100. The substrate support assembly 146 generally includes an electrostatic chuck 150 supported by a shaft 160. The electrostatic chuck 150 can generally be made of aluminum, ceramic, and other suitable materials such as stainless steel. A displacement mechanism (not shown) can be used to move the electrostatic chuck 150 vertically within the process chamber 100.

[0019] A vacuum pump 102 is coupled to a port formed in the bottom of the process chamber 100. The vacuum pump 102 is used to maintain a desired gas pressure in the process chamber 100. The vacuum pump 102 also exhausts post-processing gases and by-products of the process from the process chamber 100.

[0020] A gas distribution assembly 120 having a plurality of pores 128 is disposed on top of the process chamber 100, above the electrostatic chuck 150. The pores 128 of the gas distribution assembly 120 are used to introduce process gases into the process chamber 100. The pores 128 can have different sizes, numbers, distributions, shapes, designs, and diameters to facilitate the flow of various process gases for different process requirements. The gas distribution assembly 120 is connected to the gas panel 130, and the gas panel 130 allows various gases to flow into the processing space 126 during processing. A plasma is formed from the process gas mixture exiting the gas distribution assembly 120 to enhance the thermal decomposition of the process gas, thereby causing material to be deposited on the top surface 191 of a substrate 190 positioned on the electrostatic chuck 150.

[0021] The gas distribution assembly 120 and the electrostatic chuck 150 can form a pair of spaced-apart electrodes in the processing space 126. One or more RF power supplies 140 provide a biasing potential to the gas distribution assembly 120 through a matching network 138 (the matching network 138 is optional) to facilitate the generation of a plasma between the gas distribution assembly 120 and the electrostatic chuck 150. Alternatively, the RF power supply 140 and the matching network 138 can be coupled to the gas distribution assembly 120, the electrostatic chuck 150, or both the gas distribution assembly 120 and the electrostatic chuck 150, or to an antenna (not shown) disposed outside the process chamber 100. In some embodiments, the RF power supply 140 can generate power at a frequency of 350 KHz, 2 MHz, 13.56 MHz, 27 MHz, 40 MHz, 60 MHz, 100 MHz, or 162 MHz.

[0022] The controller 110 includes a central processing unit (CPU) 112, a memory 116, and support circuitry 114 for controlling process sequences and regulating the gas flow from the gas panel 130. The CPU 112 can be any form of general-purpose computer processor that can be used in an industrial setting. Software routines can be stored in the memory 116 (such as random access memory, read-only memory, floppy disk, or hard disk drive, or other forms of digital storage). The support circuitry 114 is coupled to the CPU 112 and can include a cache, clock circuitry, input / output systems, power supplies, and the like. Bidirectional communication between the controller 110 and the various components of the substrate processing system 132 is handled by a large number of signal cables collectively referred to as the signal bus 118, some of which are shown in Figure 1A as shown.

[0023] Figure 1B FIG. depicts a schematic cross-sectional view of another substrate processing system 180 that can be used to implement the embodiments described herein. The substrate processing system 180 is similar to Figure 1A the substrate processing system 132, except that the substrate processing system 180 is configured to cause the processing gas from the gas panel 130 to flow radially across the top surface 191 of the substrate 190 via the sidewall 101. Additionally, Figure 1A the gas distribution assembly 120 depicted in

[0024] Figure 2 is replaced by an electrode 182. The electrode 182 can be configured for secondary electron generation. In one embodiment, the electrode 182 is a silicon-containing electrode. Figure 1A and Figure 1B FIG. depicts a schematic cross-sectional view of a substrate support assembly 146 used in the processing systems of Figure 2 that can be used to implement the embodiments described herein. Referring to

[0025] Referring to Figure 1A andFigure 1B , a temperature sensor 172 such as a thermocouple can be embedded in the electrostatic chuck 150 to monitor the temperature of the electrostatic chuck 150. The measured temperature is used by the controller 110 to control the power supplied to the heater element 170 to maintain the substrate at a desired temperature.

[0026] Return reference Figure 2 , the electrostatic chuck 150 includes an adsorption electrode 210, and the adsorption electrode 210 can be a mesh of a conductive material. The adsorption electrode 210 can be embedded in the electrostatic chuck 150. The adsorption electrode 210 is coupled to an adsorption power supply 212, and when energized, the adsorption power supply 212 electrostatically clamps the substrate 190 to the upper surface 192 of the electrostatic chuck 150.

[0027] The adsorption electrode 210 can be configured as a monopole or bipolar electrode, or have another suitable arrangement. The adsorption electrode 210 can be coupled to the adsorption power supply 212 through an RF filter 214, and the adsorption power supply 212 provides direct current (DC) power to electrostatically fix the substrate 190 to the upper surface 192 of the electrostatic chuck 150. The RF filter 214 prevents the RF power used to form a plasma in the process chamber 100 from damaging electrical equipment. The electrostatic chuck 150 can be made of a ceramic material such as AlN or Al2O3.

[0028] 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 adsorption power supply 212, a first radio frequency (RF) power supply 230, and a second RF power supply 240. An embodiment of the power application system 220 can additionally include a controller 110 and a sensor device 250, and the sensor device 250 communicates with both the controller 110 and the first RF power supply 230 and the second RF power supply 240. The controller 110 can also be used to control the plasma from the process gas by applying RF power from the first RF power supply 230 and the second RF power supply 240 to deposit a material layer on the substrate 190.

[0029] As described above, the electrostatic chuck 150 includes an adsorption electrode 210, which can function as an adsorption of the substrate 190 on the one hand and also serve as the first RF electrode. The electrostatic chuck 150 can also include a second RF electrode 260, and together with the adsorption electrode 210, RF power can be applied to tune the plasma. The first RF power supply 230 can be coupled to the second RF electrode 260, while the second RF power supply 240 can be coupled to the adsorption electrode 210. A first matching network and a second matching network can be provided for the first RF power supply 230 and the second RF power supply 240, respectively. The second RF electrode 260 can be a solid metal plate of a conductive material or a mesh of a conductive material.

[0030] The first RF power supply 230 and the second RF power supply 240 may 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 may independently generate power at a frequency ranging from about 350 KHz to about 162 MHz (e.g., 350 KHz, 2 MHz, 13.56 MHz, 27 MHz, 40 MHz, 60 MHz, 100 MHz, or 162 MHz). The RF power from one or both of the first RF power supply 230 and the second RF power supply 240 may be varied in order to tune the plasma.

[0031] Generally, the system described with respect to Figure 1A 、 Figure 1B and Figure 2 can be used to deposit carbon films according to the embodiments described herein. Carbon films (e.g., one or more carbon layers) fabricated according to the embodiments described herein are amorphous in nature and have a high sp 3 carbon content (e.g., diamond-like). As-deposited diamond-like carbon layers have an extinction coefficient or k value (K (at 633 nm)) of less than 0.1 (e.g., 0.09), a density (g / cc) greater than 1.8 g / cc (e.g., 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), a refractive index or n value (n (at 633 nm)) greater than 2.0 (e.g., about 2.0 to about 3.0, such as 2.3), a stress (MPa) less than about -100 MPa (e.g., from about -1000 MPa to about -100 MPa, such as about -550 MPa), and an elastic modulus (GPa) of about 150 GPa or greater (e.g., from about 200 GPa to about 400 GPa). In various embodiments of the present disclosure, as-deposited diamond-like carbon layers may contain at least 40% sp 3 hybridized carbon atoms or more, such as about 60% or more, e.g., about 90% sp 3 hybridized carbon atoms. The thickness of the as-deposited diamond-like carbon layer may be between about 5 angstroms and about 20,000 angstroms.

[0032] A diamond-like carbon layer having the above characteristics can be formed using the exemplary deposition process parameters described below. The substrate temperature can range from about -50°C to about 350°C (e.g., from about -10°C to about 20°C). The chamber pressure can range from about 0.5 mTorr to about 10 Torr (e.g., about 5 mTorr to about 10 mTorr). The flow rate of the hydrocarbon-containing gas mixture can be from about 10 sccm to about 1,000 sccm (e.g., about 100 sccm to about 200 sccm). The flow rate of the dilution gas can individually range from about 50 sccm to about 5,000 sccm (e.g., from about 50 sccm to about 200 sccm). Table I below shows exemplary deposition process parameters, which are performed on a 300 mm substrate in a deposition chamber available from Applied Materials, Inc., Santa Clara, California, USA.

[0033] Table I

[0034]

[0035] Figure 3 A flowchart depicting method 300 for forming a diamond-like carbon layer on a film stack disposed on a substrate according to an embodiment of the present invention. The diamond-like carbon layer formed on the film stack can be used, for example, as a hard mask to form a stepped structure in the film stack. Figures 4A to 4B is a sequence showing the formation of a diamond-like carbon layer on a film stack disposed on a substrate according to method 300. It should also be understood that the operations depicted in Figure 3 can be performed simultaneously and / or in an order different from the order depicted.

[0036] Method 300 begins at operation 310 by positioning a substrate (such as the substrate 400 depicted in Figure 4A ) into a process chamber (such as the process chamber 100 depicted in Figure 1A or Figure 1B ). The substrate 400 can be the substrate 190 depicted in Figure 1A , Figure 1B and Figure 2 . The substrate 400 can be positioned on an electrostatic chuck, for example, on the upper surface 192 of the electrostatic chuck 150. As needed, the substrate 400 can be a silicon-based material or any suitable insulating material, conductive material, or semiconductor material, having a film stack 404 disposed on the substrate 400, and the film stack 404 can be used to form a structure 402 (such as a stepped structure) in the film stack 404.

[0037] As in Figure 4AAs shown in the exemplary embodiments depicted, the substrate 400 may have a substantially flat surface, an uneven surface, or a substantially flat surface with structures formed thereon. A film stack 404 is formed on the substrate 400. In one embodiment, the film stack 404 may be used to form gate structures, contact structures, or interconnect structures in a front-end or back-end process. A method 300 may be performed on the film stack 404 to form a stepped structure (such as a NAND structure) for use in a memory structure in the film stack 404. In one embodiment, the substrate 400 may 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 substrate of silicon-on-insulator (SOI), carbon-doped silicon oxide, silicon nitride, doped silicon, germanium, gallium arsenide, glass, sapphire, etc. The substrate 400 may have various sizes, such as substrates with diameters of 200 mm, 300 mm, and 450 mm or other diameters, as well as rectangular or square panels. Unless otherwise specified, the embodiments and examples described herein are performed on substrates with diameters of 200 mm, 300 mm, or 450 mm. In embodiments where an SOI structure is used for the substrate 400, the substrate 400 may include a buried dielectric layer disposed on a silicon crystalline substrate. In the embodiments depicted herein, the substrate 400 may be a crystalline silicon substrate.

[0038] In one embodiment, the film stack 404 disposed on the substrate 400 may have a number of vertically stacked layers. The film stack 404 may include multiple pairs including a first layer (shown as 408a1, 408a2, 408a3, ……, 408a n ) and a second layer (shown as 408b1, 408b2, 408b3, ……, 408b n ) that are repeatedly formed in the film stack 404. The multiple pairs including the alternating first layer (shown as 408a1, 408a2, 408a3, ……, 408a n ) and the second layer (shown as 408b1, 408b2, 408b3, ……, 408b n ) are repeatedly formed until a desired number of pairs of the first layer and the second layer is reached.

[0039] The film stack 404 may be part of a semiconductor chip (such as a three-dimensional memory chip). Although three repeating layers of the first layer (shown as 408a1, 408a2, 408a3, ……, 408a Figures 4A to 4B ) and the second layer (shown as 408b1, 408b2, 408b3, ……, 408b n ) are shown in n , it should be noted that any desired number of repeating pairs of the first layer and the second layer may be used as needed.

[0040] In one embodiment, the membrane stack 404 can be used to form a plurality of gate structures of a three-dimensional memory chip. The first layers 408a1, 408a2, 408a3, ……, 408a n formed in the membrane stack 404 can be a first dielectric layer, and the second layers 408b1, 408b2, 408b3, ……, 408b n can be a second dielectric layer. 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 carbonitride, titanium nitride, a composite of an oxide and a nitride, at least one or more oxide layers sandwiching a nitride layer, and combinations thereof. In some embodiments, the dielectric layer can be a high-k material with a dielectric constant greater than 4. Suitable examples of high-k materials include hafnium dioxide (HfO2), zirconium dioxide (ZrO2), hafnium silicate (HfSiO2), hafnium aluminate (HfAlO), zirconium silicate (ZrSiO2), tantalum dioxide (TaO2), aluminum oxide, hafnium dioxide doped with aluminum, bismuth strontium titanate (BST), and platinum zirconium titanate (PZT), etc.

[0041] In a specific 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 can be controlled between about 50 angstroms and about 1000 angstroms (such as about 500 angstroms), and the thickness of each of the second layers 408b1, 408b2, 408b3, ……, 408b n can be controlled between about 50 angstroms and about 1000 angstroms (such as about 500 angstroms). The total thickness of the membrane stack 404 can be between about 100 angstroms and about 2000 angstroms and can vary with the development of technology.

[0042] Note that the diamond-like carbon layer can be formed on any surface or any part of the substrate 400 with or without the membrane stack 404 on the substrate 400.

[0043] At operation 320, an adsorption voltage is applied to the electrostatic chuck to hold the substrate 400 to the electrostatic chuck. An electrical bias voltage is provided to the substrate 400 via the adsorption electrode 210. The adsorption electrode 210 may be in electrical communication with an adsorption power supply 212 that supplies a bias voltage to the adsorption electrode 210. In one embodiment, the adsorption voltage is between about 10 volts and about 3000 volts.

[0044] During operation 320, the process pressure in the process chamber can be maintained between about 0.1 mTorr and about 10 Torr (e.g., between about 0.5 mTorr and about 15 mTorr), and the process temperature and / or the substrate temperature can be maintained between about -50°C and about 350°C (e.g., between about -10°C and about 20°C).

[0045] At operation 330, a hydrocarbon-containing gas mixture flows into the process chamber 126. The hydrocarbon-containing gas mixture may flow into the process chamber 126 through the gas distribution assembly 120 or via the sidewall 101 from the gas panel 130. The hydrocarbon-containing gas mixture may include at least one hydrocarbon. The hydrocarbon-containing gas mixture may further include an inert gas, a dilution gas, or any combination thereof. In some embodiments, the adsorption voltage supplied during operation 320 is maintained during operation 330. In some embodiments, the process conditions established during operation 320 are maintained during operation 330.

[0046] In one embodiment, the hydrocarbon is a gaseous hydrocarbon. In one embodiment, the hydrocarbon has the general formula C x H y , where x ranges from 1 to 20, and y ranges from 1 to 20. Suitable hydrocarbons include, for example, C2H2, C3H6, CH4, C4H8, 1,3-dimethyladamantane, bicyclo[2.2.1]hepta-2,5-diene (2,5-norbornadiene), adamantane (C 10 H 16 ), norbornene (C7H 10 ) or combinations thereof.

[0047] In some embodiments, the hydrocarbon-containing gas mixture further includes one or more dilution gases. Suitable dilution gases may include, but are not limited to, helium (He), argon (Ar), xenon (Xe), hydrogen (H2), nitrogen (N2), ammonia (NH3), or any combination thereof. In one embodiment, the dilution gas includes a combination of Ar, He, and N2. In one embodiment, the dilution gas includes a combination of Ar, He, and H2.

[0048] In some embodiments, the hydrocarbon-containing gas mixture further comprises an inert gas. In some embodiments, an inert gas (such as argon (Ar) and / or helium (He)) can be supplied into the processing space 126 together with the hydrocarbon-containing gas mixture. 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.

[0049] At operation 340, as Figure 4B shown, a plasma is generated at the substrate level to form a diamond-like carbon film on the film stack. The plasma can be generated by applying a first RF bias to 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 162 MHz (e.g., 350 KHz, 2 MHz, 13.56 MHz, 27 MHz, 40 MHz, 60 MHz, 100 MHz, or 162 MHz). In one embodiment, the first RF bias is provided at a power between about 1500 watts and about 2500 watts (e.g., 1800 - 2200 watts) and at a frequency of about 40 MHz or higher. 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 electrical communication with a first RF power supply 230 that supplies a bias voltage to the second RF electrode 260. The first RF power supply 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).

[0050] In some embodiments, operation 340 further includes applying a second RF bias to the electrostatic chuck to independently control the ion density and ion energy to adjust the film stress. The second RF bias can be from about 10 watts to about 3000 watts, and at a frequency of 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 power between about 800 watts and about 1200 watts and at a frequency of about 13.56 MHz or lower (e.g., about 2 MHz). In one embodiment, the second RF bias is provided to the substrate 400 via the adsorption electrode 210. The adsorption electrode 210 can be in electrical communication with a second RF power supply 240 that supplies a bias voltage to the adsorption electrode 210. The second RF bias is provided at a power between about 10 watts and about 3000 watts. In one embodiment, the second RF bias is provided at a power between about 800 watts and about 1200 watts. In one embodiment, the adsorption voltage supplied in operation 320 is maintained during operation 340.

[0051] In some embodiments, which can be combined with any other embodiments of the present disclosure, during operation 340, a first RF bias is provided to the substrate 400 via the adsorption electrode 210, and a second RF bias can be provided to the substrate 400 via the second RF electrode 260.

[0052] In some embodiments, which can be combined with any other embodiments of the present disclosure, during operation 340, a first RF bias is provided to the gas distribution assembly 120 or the electrode 182, and a second RF bias can be provided to the substrate 400 via the second RF electrode 260 or the adsorption electrode 210. In this case, the first RF bias applied to the gas distribution assembly 120 or the electrode 182 can have a high frequency, and the second RF bias applied to the second RF electrode 260 or the adsorption electrode 210 can have a low frequency.

[0053] The first RF bias and the second RF bias can use various combinations of power levels and frequencies. In some embodiments, the first RF bias can be about 2000 watts at about 40 MHz, 60 MHz, or 162 MHz, and the second RF bias can be about 1000 watts at 350 KHz. In some embodiments, the first RF bias can be about 2000 watts at 40 MHz, 60 MHz, or 162 MHz, and the second RF bias can be about 1000 watts at 2 MHz. In some embodiments, the first RF bias can be about 2000 watts at about 40 MHz, 60 MHz, or 162 MHz, and the second RF bias can be about 1000 watts at 13.56 MHz.

[0054] In some additional embodiments, which can be combined with any other embodiments of the present disclosure, during operation 340, a first RF bias is provided to the substrate 400 via the adsorption electrode 210, a second RF bias can be provided to the substrate 400 via the second RF electrode 260, and a third RF bias can be provided to the gas distribution assembly 120 or the electrode 182. In this case, the first RF bias and the second RF bias can be any combination of frequencies and powers discussed in the present disclosure, and the third RF bias can be configured to have the same power and frequency as the first RF bias or the second RF bias discussed herein.

[0055] 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, hydrogen radicals are formed in the RPS and are transported to the processing area. 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, thereby increasing the sp 3The proportion of hybrid carbon atoms is thus increased, thereby improving the etching selectivity.

[0056] At operation 350, after forming the diamond-like carbon layer 412 on the substrate, the substrate is desorbed. During operation 350, the adsorption voltage is turned off. The reactive gas is turned off and optionally purged from the processing chamber. In one embodiment, during operation 350, the RF power (e.g., about 200 W) is reduced. Once the substrate is desorbed from the electrostatic chuck, the remaining gas is purged from the processing chamber. The processing chamber is evacuated and depressurized, and the substrate is moved upward on the lift rod and then removed from the process chamber.

[0057] 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.

[0058] The following non-limiting examples are provided to further illustrate the embodiments described herein. However, the examples are not intended to be all-inclusive nor to limit the scope of the embodiments described herein. In one embodiment, the low-stress, high-density diamond-like carbon film of the present disclosure is fabricated by flowing 150 sccm of C2H2 and 100 sccm of He as process gases at a temperature of 10 °C and applying 2000 watts of RF (60 MHz) power through a substrate pedestal (electrostatic chuck) in a CVD reactor with Ar and / or He as dilution gases. A comparison between the resulting diamond-like carbon film, an amorphous carbon reference film, and a diamond-like carbon film formed by PVD is shown in Table II below.

[0059] Table II

[0060]

[0061] Accordingly, methods and apparatuses are provided for forming a diamond-like carbon hard mask layer having high transparency, which can be used to form a stepped structure for manufacturing a three-dimensional stack of semiconductor devices. By utilizing a diamond-like hard mask layer having desired robust film properties and etching selectivity, improved dimensional and profile control of the resulting structures formed in the film stack can be obtained, and the electrical performance of the chip devices can be enhanced in applications of three-dimensional stacks of semiconductor devices.

[0062] Although the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the present disclosure can be designed without departing from the basic scope of the present disclosure, and the scope of the present disclosure is determined by the appended claims.

Claims

1. A method of forming a carbon film on a substrate, comprising: Flowing a hydrocarbon-containing gas mixture into a process chamber having the substrate positioned on an electrostatic chuck, the electrostatic chuck including a first radio frequency (RF) electrode and a second RF electrode disposed within the electrostatic chuck, wherein the substrate is maintained at a temperature of -10°C to 20°C and a chamber pressure of 0.5 mTorr to 10 Torr; and Plasma is generated by applying a first RF bias voltage to the first RF electrode of the electrostatic chuck and a second RF bias voltage to the second RF electrode of the electrostatic chuck to deposit a diamond-like carbon film containing 60% or more of hybrid sp 3 atoms on the substrate, wherein the first RF bias voltage is provided at a power of 1800 W to 2200 W and a frequency of 40 MHz to 162 MHz, and the second RF bias voltage is provided at a power of 800 W to 1200 W and a frequency of 350 KHz to 13.56 MHz.

2. The method of claim 1, wherein the first RF bias is provided at a power of 2000 watts and a frequency of 60 MHz, and the second RF bias is provided at a power of 1000 watts and a frequency of 2 MHz.

3. The method of claim 1, wherein the substrate is maintained at a temperature of 10°C.

4. The method according to claim 1, wherein the hydrocarbon-containing gas mixture comprises a hydrocarbon precursor, and the hydrocarbon precursor comprises: C2H2, C3H6, CH4, C4H8, 1,3 - dimethyladamantane, bicyclo[2.2.1]hepta - 2,5 - diene (2,5 - norbornadiene), adamantane (C 10 H 16 ), norbornene (C7H 10 ), or any combination of the foregoing.

5. The method according to claim 1, wherein the hydrocarbon-containing gas mixture further comprises a dilution gas, and the dilution gas comprises: He, Ar, Xe, N2, H2, or any combination of the foregoing.

6. The method of claim 1, wherein the hydrocarbon-containing gas mixture flows into the process chamber through a gas panel disposed at a sidewall of the process chamber.

7. A method of forming a carbon film on a substrate, comprising: Flowing a hydrocarbon-containing gas mixture into a process chamber having the substrate positioned on an electrostatic chuck; And Generating a plasma by applying a first RF bias to a first electrode disposed in the electrostatic chuck and a second RF bias to a second electrode disposed in the electrostatic chuck to deposit a diamond-like carbon film on the substrate, Wherein the first RF bias is provided at a frequency of 13.56 MHz or lower and a power of 800 watts to 1200 watts, and the second RF bias is provided at a frequency of 40 MHz or higher and a power of 1500 watts to 2500 watts, and the substrate is maintained at a temperature of -10°C to 20°C and a chamber pressure of 0.5 mTorr to 10 Torr.

8. The method of claim 7, wherein the first RF bias is provided at a frequency of 2 MHz.

9. The method of claim 7, wherein the second RF bias is provided at a frequency of 60 MHz.

10. The method according to claim 7, wherein the hydrocarbon-containing gas mixture comprises a hydrocarbon precursor, and the hydrocarbon precursor comprises: C2H2, C3H6, CH4, C4H8, 1,3-dimethyladamantane, bicyclo[2.2.1]hepta-2,5-diene (2,5-norbornadiene), adamantane (C 10 H 16 ), norbornene (C7H 10 ), or any combination of the foregoing.

11. The method according to claim 7, wherein the hydrocarbon-containing gas mixture further comprises a dilution gas, the dilution gas comprising: He, Ar, Xe, N2, H2, or any combination of the foregoing.

12. The method according to claim 7, wherein generating the plasma further comprises: Applying a third RF bias to a third electrode disposed above and opposite the electrostatic chuck.

13. The method of claim 12, wherein the third RF bias is provided at a power of 10 watts to 3000 watts and a frequency ranging from 350 KHz to 162 MHz.

14. A method of processing a substrate, comprising: Flowing a hydrocarbon-containing gas mixture into a processing space of a process chamber having a substrate positioned on an electrostatic chuck, wherein the substrate is maintained at a chamber pressure between 5 mTorr and 10 mTorr, and wherein the hydrocarbon-containing gas mixture includes acetylene (C2H2); Plasma is generated at the substrate level by applying a first RF bias to a first RF electrode disposed in the electrostatic chuck and a second RF bias to a second RF electrode disposed in the electrostatic chuck to deposit a diamond-like carbon film on the substrate, wherein the first RF bias is provided at a power of 2000 watts to 3000 watts and a frequency of 40 MHz to 60 MHz, and the second RF bias is provided at a power of 1000 watts and a frequency of 2 MHz; A patterned photoresist layer is formed over the diamond-like carbon film; The diamond-like carbon film is etched in accordance with the pattern of the patterned photoresist layer to produce an etched portion; And A material is deposited into the etched portion of the diamond-like carbon film.

15. The method of claim 14, wherein the diamond-like carbon film serves as an underlayer in a far ultraviolet ("EUV") lithography process.

16. The method according to claim 14, wherein the hydrocarbon-containing gas mixture further comprises a dilution gas, and the dilution gas comprises: He, Ar, Xe, N2, H2, or any combination thereof.

17. The method of claim 16, wherein the hydrocarbon-containing gas mixture flows into the process chamber through a gas panel disposed at a sidewall of the process chamber.

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