Dense carbon films for patterning applications

Abstract

To provide a method for depositing a high-density carbon film for patterning application.SOLUTION: Flowing a hydrocarbon-containing gas mixture into a processing chamber having a substrate positioned thereon, wherein the substrate is maintained at a temperature of about - 10 °C. to about 20 °C. and a chamber pressure of about 0. 5mTorr to about 10Torr, and generating a plasma by applying a first RF bias to the electrostatic chucks to deposit a diamond-like film comprising about 60% or more hybridized sp3 atoms on the substrate. The first RF bias is provided at a power of about 1800 Watts to about 2200 Watts and a frequency of about 40MHz to about 162MHz.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE Embodiments of the present disclosure relate generally to the fabrication of integrated circuits. More particularly, embodiments described herein provide techniques for the deposition of dense carbon films for patterning applications. [Background technology]

[0002] Integrated circuits have evolved into complex devices capable of incorporating millions of transistors, capacitors, and resistors on a single chip. Evolution in chip design continually requires faster circuits and greater circuit density. The demand for faster circuits with greater circuit density places corresponding demands on the process sequences used to manufacture integrated circuit components. For example, in a process sequence using conventional photolithography techniques, a layer of energy-sensitive resist is formed on a stack of material layers disposed on a substrate. This energy-sensitive resist layer is exposed to an image of a pattern to form a photoresist mask. The mask pattern is then transferred into one or more material layers of the stack using an etching process.

[0003] As feature dimensions shrink, the thickness of energy-sensitive resists decreases accordingly to control pattern resolution. Such thin resist layers may be insufficient to mask the underlying material layer during pattern transfer operations due to attack by chemical etchants. Hard masks are often used between the energy-sensitive resist layer and the underlying material layer to facilitate pattern transfer due to their high resistance to chemical etchants. As critical dimensions (CDs) decrease, current hard mask materials often lack the desired etch selectivity compared to the underlying materials (e.g., oxides and nitrides) and are difficult to deposit.

[0004] Therefore, there is a need in the art for improved hardmask layers and methods for depositing the same. Summary of the Invention

[0005] FIELD OF THE DISCLOSURE Embodiments of the present disclosure generally relate to integrated circuit manufacturing. More particularly, embodiments described herein provide techniques for the deposition of dense films for patterning applications. In one embodiment, a method for forming a carbon film on a substrate is provided. The method includes flowing a hydrocarbon-containing gas mixture into a processing chamber having a substrate positioned on an electrostatic chuck, the substrate being 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 applying a first RF bias to the electrostatic chuck to form a carbon film on the substrate with a hybrid sp of about 60% or more. 3 generating a plasma by depositing a diamond-like carbon film containing atoms, 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 at a 300 mm substrate.

[0006] In another embodiment, the method includes flowing a hydrocarbon-containing gas mixture into a process volume 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 the electrostatic chuck and facing 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 less and the second RF bias is provided at a frequency of about 40 MHz or more, 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.

[0007] In yet another embodiment, the method includes flowing a hydrocarbon-containing gas mixture into a process volume of a process chamber having a substrate positioned on an electrostatic chuck, the substrate being maintained at a pressure of between about 5 mTorr, and the hydrocarbon-containing gas mixture comprising acetylene (C2H2); generating a plasma at the substrate level by applying a first RF bias provided at a power of between about 2000 Watts and a frequency of about 60 MHz to the electrostatic chuck to deposit a diamond-like carbon film on the substrate; forming a patterned photoresist layer on the diamond-like carbon film; etching the diamond-like carbon in a pattern corresponding to the patterned photoresist layer; etching the pattern into the substrate; and depositing material on the etched portion of the diamond-like carbon film.

[0008] So that the above-described features of the present disclosure can be understood in detail, a more particular description of the present disclosure, briefly summarized above, can be had by reference to embodiments, some of which are illustrated in the accompanying drawings. It should be noted, however, that since the present disclosure is open to other equally effective embodiments, the accompanying drawings illustrate only typical embodiments of the disclosure and therefore should not be considered as limiting the scope of the present disclosure. [Brief explanation of the drawings]

[0009] [Figure 1A] 1 is a schematic cross-sectional view of a deposition system that can be used to practice embodiments described herein. [Figure 1B] 1 is a schematic cross-sectional view of another deposition system that can be used to practice embodiments described herein. [Figure 2] FIG. 1C is a schematic cross-sectional view of an electrostatic chuck that can be used in the apparatus of FIGS. 1A and 1B for practicing embodiments described herein. [Figure 3] 1 is a flow diagram of a method for 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. [Figure 4A]1 illustrates one embodiment of a sequence for 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. [Figure 4B] 1 illustrates one embodiment of a sequence for 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. DETAILED DESCRIPTION OF THE INVENTION

[0010] For ease of understanding, wherever possible, like reference numerals are used to designate like elements common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.

[0011] The following disclosure describes techniques for depositing diamond-like carbon films on substrates. The embodiments described herein are described below with reference to PECVD processes that can be performed using any suitable thin film deposition system. Examples of suitable systems include the CENTURA® system (which can use a DXZ® processing chamber), the PRECISION 5000® system, the PRODUCE® system, the PRODUCE® GT™ system, the PRODUCE® XP Precision™ system, the PRODUCE® SE™ system, the Sym3® processing chamber, and the Mesa™ processing chamber, all of which are commercially available from Applied Materials, Inc., Santa Clara, California, USA. Other tools capable of performing PECVD processes can also be adapted to benefit from the embodiments described herein. In addition, any system capable of the PECVD processes described herein can be used advantageously. The apparatus descriptions described herein are exemplary and should not be understood or interpreted as limiting the scope of the embodiments described herein.

[0012] 1A shows a schematic diagram of a substrate processing system 132 that can be used to perform deposition of a diamond-like carbon layer according to embodiments described herein. 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 that define a processing volume 126. A substrate support assembly 146 is disposed within 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 typically be fabricated from aluminum, ceramic, and other suitable materials, such as stainless steel. The electrostatic chuck 150 can be moved vertically within the processing chamber 100 using a displacement mechanism (not shown).

[0013] 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 within the processing chamber 100. The vacuum pump 102 also evacuates post-processing gases and processing by-products from the processing chamber 100.

[0014] A gas distribution assembly 120 having a plurality of apertures 128 is positioned at the top of the processing chamber 100 above the electrostatic chuck 150. The apertures 128 of the gas distribution assembly 120 are utilized to introduce process gases into the processing chamber 100. The apertures 128 may have various sizes, quantities, distribution specifications, shapes, designs, and diameters to facilitate the flow of various process gases for various processing requirements. The gas distribution assembly 120 is connected to a gas panel 130, which allows various gases to flow into the processing volume 126 during processing. A plasma is formed from the process gas mixture exiting the gas distribution assembly 120 to facilitate thermal decomposition of the process gases and result in the deposition of material on an upper surface 191 of a substrate 190 positioned on the electrostatic chuck 150.

[0015] The gas distribution assembly 120 and the electrostatic chuck 150 may form a pair of spaced-apart electrodes within the process 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 generation of a plasma between the gas distribution assembly 120 and the electrostatic chuck 150. Alternatively, the RF power sources 140 and the matching network 138 may 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 may be coupled to an antenna (not shown) located outside the process chamber 100. In some embodiments, the RF power sources 140 may generate power at frequencies of 350 KHz, 2 MHz, 13.56 MHz, 27 MHz, 40 MHz, 60 MHz, 100 MHz, or 162 MHz.

[0016] The controller 110 includes a central processing unit (CPU) 112, memory 116, and support circuits 114 that are utilized to control process sequences and regulate gas flow from the gas panel 130. The CPU 112 may be any form of general-purpose computer processor that can be used in an industrial setting. Software routines may be stored in the memory 116, such as random access memory, read-only memory, floppy or hard disk drive, or other form of digital storage. The support circuits 114 are coupled to the CPU 112 and may include cache, clock circuits, input / output systems, power supplies, etc. Bidirectional communication between the controller 110 and the various components of the substrate processing system 132 is handled via a number of signal cables, some of which are shown in FIG. 1A, collectively referred to as a signal bus 118.

[0017] 1B shows a schematic cross-sectional view of another substrate processing system 180 that can be used to practice embodiments described herein. The substrate processing system 180 is similar to the substrate processing system 132 of FIG. 1A, except that the substrate processing system 180 is configured to flow process gases radially from the gas panel 130 across the top surface 191 of the substrate 190 through the sidewall 101. Additionally, the gas distribution assembly 120 shown in FIG. 1A has been replaced with an electrode 182. The electrode 182 may be configured for secondary electron generation. In one embodiment, the electrode 182 is a silicon-containing electrode.

[0018] 2 shows a schematic cross-sectional view of a substrate support assembly 146 used in the processing system of FIGS. 1A and 1B, which can be used to implement embodiments described herein. Referring to FIG. 2, an electrostatic chuck 150 can include a heater element 170 suitable for controlling the temperature of a substrate 190 supported on an upper surface 192 of the electrostatic chuck 150. The heater element 170 can be embedded in the electrostatic chuck 150. The electrostatic chuck 150 can be resistively heated by applying a current to the heater element 170 from a heater power supply 106. The heater power supply 106 can be coupled through an RF filter 216 to protect the heater power supply 106 from RF energy. The current provided by the heater power supply 106 is adjusted by a controller 110 to control the heat generated by the heater element 170, thus maintaining the substrate 190 and the electrostatic chuck 150 at a substantially constant temperature during film deposition. The supplied current can be adjusted to selectively control the temperature of the electrostatic chuck 150 between about −50° C. and about 350° C. during deposition of the diamond-like carbon film on the substrate.

[0019] 1A and 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.

[0020] 2, the electrostatic chuck 150 includes a chucking electrode 210, which may be a mesh of conductive material. The chucking electrode 210 may be embedded in the electrostatic chuck 150. The chucking electrode 210 is coupled to a chucking power supply 212, which, when energized, electrostatically clamps the substrate 190 to the upper surface 192 of the electrostatic chuck 150.

[0021] The chuck electrode 210 may be configured as a monopolar or bipolar electrode or may have another suitable configuration. The chuck electrode 210 may be coupled to a chuck power supply 212 through an RF filter 214, which provides direct current (DC) power for electrostatically clamping the substrate 190 to the upper surface 192 of the electrostatic chuck 150. The RF filter 214 prevents the RF power utilized to form the plasma within the processing chamber 100 from damaging electrical equipment. The electrostatic chuck 150 may be fabricated from a ceramic material such as AlN or Al2O3.

[0022] The power supply system 220 is coupled to the substrate support assembly 146. The power supply system 220 may include a heater power supply 106, a chuck power supply 212, a first radio frequency (RF) power supply 230, and a second RF power supply 240. An embodiment of the power supply system 220 may further include a controller 110 and a sensor device 250 in communication with the controller 110, and both the first RF power supply 230 and the second RF power supply 240. The controller 110 may also be utilized to control a 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 layer of material on the substrate 190.

[0023] As described above, the electrostatic chuck 150 includes a chucking electrode 210 that can function as a first RF electrode and, in one aspect, to chuck the substrate 190. The electrostatic chuck 150 can also include a second RF electrode 260, which, in conjunction with the chucking electrode 210, can apply RF power to regulate the plasma. A first RF power source 230 can be coupled to the second RF electrode 260, while a second RF power source 240 can be coupled to the chuck electrode 210. First and second matching networks can be provided for the first and second RF power sources 230 and 240, respectively. The second RF electrode 260 can be a solid metal plate of a conductive material or a mesh of a conductive material.

[0024] The first RF power source 230 and the second RF power source 240 can generate power at the same frequency or at different frequencies. In some embodiments, one or both of the first RF power source 230 and the second RF power source 240 can independently generate power 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). The RF power from one or both of the first RF power source 230 and the second RF power source 240 can be varied to tailor the plasma.

[0025] 1A, 1B, and 2 can be used to deposit carbon films according to embodiments described herein. Carbon films (e.g., one or more carbon layers) produced according to embodiments described herein are essentially amorphous and have high sp 3The as-deposited diamond-like carbon layer has an extinction coefficient or k value (K(at 633 nm)) of less than 0.1, e.g., 0.09, a density (g / cc) of greater than 1.8 g / cc, e.g., about 2.0 g / cc or greater, e.g., about 2.5 g / cc or greater, e.g., about 1.8 g / cc to about 2.5 g / cc, a refractive index or n value (n(at 633 nm)) of greater than 2.0, e.g., about 2.0 to about 3.0, e.g., 2.3, a stress (MPa) of less than about -100 MPa, e.g., about -1000 MPa to about -100 MPa, e.g., about -550 MPa, and an elastic modulus (GPa) of greater than about 150 GPa, e.g., about 200 to about 400 GPa. In various embodiments of the present disclosure, the as-deposited diamond-like carbon layer has at least 40 percent sp 3 Hybridized carbon atoms, e.g., greater than about 60 percent, e.g., about 90 percent sp 3 The as-deposited diamond-like carbon layer may have a thickness between about 5 Å and about 20,000 Å.

[0026] Diamond-like carbon layers having the above properties can be formed using the following exemplary deposition process parameters: The substrate temperature can range from about −50° C. to about 350° C. (e.g., 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 range from about 10 sccm to about 1,000 sccm (e.g., about 100 sccm to about 200 sccm). The flow rates of the dilution gases can individually range from about 50 sccm to about 5,000 sccm (e.g., about 50 sccm to about 200 sccm). Table I below shows exemplary deposition process parameters performed on a 300 mm substrate in a deposition chamber available from Applied Materials, Inc., Santa Clara, California, USA. TIFF2026000945000002.tif63170

[0027] 3 shows a flow diagram of a method 300 for forming a diamond-like carbon layer on a film stack disposed on a substrate according to one embodiment of the present disclosure. The diamond-like carbon layer formed on the film stack can be utilized, for example, as a hard mask for forming a stair-like structure in the film stack. FIGS. 4A-4B are schematic cross-sectional views illustrating a sequence for forming 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 shown in FIG. 3 can be performed simultaneously and / or in a different order than that shown.

[0028] Method 300 begins at operation 310 by positioning a substrate, such as substrate 400 shown in FIG. 4A, in a processing chamber, such as processing chamber 100 shown in FIG. 1A or 1B. Substrate 400 may be substrate 190 shown in FIGS. 1A, 1B, and 2. Substrate 400 may be positioned on the top surface 192 of an electrostatic chuck, such as electrostatic chuck 150. Substrate 400 may be a silicon-based material or any suitable insulating, conductive, or conducting material, as desired, and has a film stack 404 disposed thereon that may be utilized to form a structure 402, such as a stepped structure, in film stack 404.

[0029] As shown in the exemplary embodiment depicted in FIG. 4A, the substrate 400 can have a substantially planar surface, an uneven surface, or a substantially planar surface with structures formed thereon. A film stack 404 is formed on the substrate 400. In one embodiment, the film stack 404 can be utilized 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 therein used in memory structures such as NAND structures. In one embodiment, the substrate 400 is made of crystalline silicon (e.g., Si <100> or Si <111> The substrate 400 can be made of materials such as silicon dioxide, strained silicon, silicon germanium, doped or undoped polysilicon, doped or undoped silicon substrates, and patterned or unpatterned substrates, silicon-on-insulator (SOI), carbon-doped silicon dioxide, silicon nitride, doped silicon, germanium, gallium arsenide, glass, sapphire, and the like. The substrate 400 can have a variety of dimensions, such as 200 mm, 300 mm, and 450 mm or other diameter substrates, as well as rectangular or square panels. Unless otherwise specified, the embodiments and examples described herein are performed on substrates with a diameter of 200 mm, 300 mm, or 450 mm. In embodiments in which an SOI structure is utilized for the substrate 400, the substrate 400 can include a buried dielectric layer disposed on a silicon crystalline substrate. In the embodiments depicted herein, the substrate 400 can be a crystalline silicon substrate.

[0030] In one embodiment, the film stack 404 disposed on the substrate 400 may have multiple vertically stacked layers. The film stack 404 may include a first layer (408a1, 408a2, 408a3, . . . , 408a4) formed repeatedly within the film stack 404. n ) and the second layer (408b1, 408b2, 408b3, . . . , 408b nThese pairs may include pairs including a first layer (408a1, 408a2, 408a3, . . . , 408a n ) and the second layer (408b1, 408b2, 408b3, . . . , 408b n (shown as ) and .

[0031] The film stack 404 can be part of a semiconductor chip, such as a three-dimensional memory chip. n ) and the second layer (408b1, 408b2, 408b3, . . . , 408b n It should be noted that although three repeating layers of first and second layer pairs (shown as first and second layer pairs) are shown in Figures 4A-4B, any desired number of repeating first and second layer pairs can be utilized as needed.

[0032] In one embodiment, the film stack 404 can be utilized to form multiple gate structures for a three-dimensional memory chip. n may be the first dielectric layer, and the second layers 408b1, 408b2, 408b3, . . . , 408b n can be the second dielectric layer. Using an appropriate dielectric layer, the first layers 408a1, 408a2, 408a3, . . . , 408a n can be formed, and the second layers 408b1, 408b2, 408b3, . . . , 408b nExamples of high-k materials include silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, silicon oxycarbide, titanium nitride, composites of oxide and 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 having a dielectric constant greater than 4. Suitable examples of high-k materials include hafnium dioxide (HfO), zirconium dioxide (ZrO), hafnium silicon oxide (HfSiO), hafnium aluminum oxide (HfAlO), zirconium silicon oxide (ZrSiO), tantalum dioxide (TaO), aluminum oxide, aluminum-doped hafnium dioxide, bismuth strontium titanium (BST), and platinum zirconium titanium (PZT), among others.

[0033] In one particular example, the first layer 408a1, 408a2, 408a3, . . . , 408a n is a silicon oxide layer, and the second layers 408b1, 408b2, 408b3, . . . , 408b n The first layer 408a1, 408a2, 408a3, . . . , 408a n In one embodiment, the first layers 408a1, 408a2, 408a3, . . . , 408a n The thickness of each of the second layers 408b1, 408b2, 408b3, . . . , 408b4 can be controlled to be between about 50 Å and about 1000 Å, for example, about 500 Å. n The thickness can be controlled between about 50 Å and about 1000 Å, for example, about 500 Å. The film stack 404 can have a total thickness between about 100 Å and about 2000 Å, and can vary with technological advances.

[0034] It should be noted that the diamond-like carbon layer can be formed on any surface or portion of the substrate 400 with or without the film stack 404 present on the substrate 400 .

[0035] In operation 320, a chucking voltage is applied to the electrostatic chuck to clamp the substrate 400 to the electrostatic chuck. An electrical bias is provided to the substrate 400 via the chuck electrode 210. The chuck electrode 210 may be in electronic communication with a chuck power supply 212, which provides the bias voltage to the chuck electrode 210. In one embodiment, the chucking voltage is between about 10 volts and about 3000 volts.

[0036] During operation 320, the process pressure in the processing volume may be maintained between about 0.1 mTorr and about 10 Torr (e.g., between about 0.5 mTorr and about 15 mTorr), and the processing temperature and / or substrate temperature may be maintained between about −50° C. and about 350° C. (e.g., between about −10° C. and about 20° C.).

[0037] In operation 330, a hydrocarbon-containing gas mixture flows into the processing volume 126. The hydrocarbon-containing gas mixture may flow into the processing volume 126 from the gas panel 130 either through the gas distribution assembly 120 or through the sidewall 101. The hydrocarbon-containing gas mixture may include at least one hydrocarbon compound. The hydrocarbon-containing gas mixture may further include an inert gas, a diluent gas, or any combination thereof. In some embodiments, the chuck voltage supplied during operation 320 is maintained during operation 330. In some embodiments, process conditions are established during operation 320 and maintained during operation 330.

[0038] In one embodiment, the hydrocarbon compound is a gaseous hydrocarbon. In one embodiment, the hydrocarbon compound has the general formula C 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, bicyclo[2.2.1]hepta-2,5-diene (2,5-norbornadiene), adamantane (C 10 H 16 ), norbornene (C7H 10 ), or a combination thereof.

[0039] In some embodiments, the hydrocarbon-containing gas mixture further comprises one or more diluent gases. Suitable diluent gases may include, but are not limited to, helium (He), argon (Ar), xenon (Xe), hydrogen (H), nitrogen (N), ammonia (NH), or any combination thereof. In one embodiment, the diluent gas comprises a combination of Ar, He, and N. In one embodiment, the diluent gas comprises a combination of Ar, He, and H.

[0040] 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 process volume 126 along with the hydrocarbon-containing gas mixture. Other inert gases, such as nitrogen (N) and nitric oxide (NO), can also be used to control the density and deposition rate of the diamond-like carbon layer.

[0041] In operation 340, a plasma is generated at the substrate level to form a diamond-like carbon film on the film stack, as shown in FIG. 4B. 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 of 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 of between about 1500 Watts and about 2500 Watts (e.g., 1800-2200 Watts) and a frequency of about 40 MHz or greater. 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 supply 230, which supplies a bias voltage to the second RF electrode 260. The first RF power source 230 may generate power at a frequency from about 350 KHz to about 100 MHz (eg, 350 KHz, 2 MHz, 13.56 MHz, 27 MHz, 40 MHz, 60 MHz, or 100 MHz).

[0042] In some embodiments, operation 340 further includes applying a second RF bias to the electrostatic chuck to independently control ion density and ion energy to adjust film stress. The second RF bias can be from about 10 watts to about 3000 watts at a frequency of 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 power between about 800 Watts and about 1200 Watts and at a frequency of about 13.56 MHz or less, e.g., about 2 MHz. In one embodiment, the second RF bias is provided to the substrate 400 via the chuck electrode 210. The chuck electrode 210 can be in electronic communication with a second RF power supply 2400 that supplies a bias voltage to the chuck electrode 210. In one embodiment, 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 chuck voltage provided in operation 320 is maintained during operation 340.

[0043] In some embodiments, which may be combined with any other embodiment of the present disclosure, during operation 340, a first RF bias may be provided to the substrate 400 via the chuck electrode 210, and a second RF bias may be provided to the substrate 400 via the second RF electrode 260.

[0044] In some embodiments, which can be combined with any other embodiments of the present disclosure, during operation 340, a first RF bias can be 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 chuck electrode 210. In such cases, 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 chuck electrode 210 can have a low frequency.

[0045] Various combinations of power levels and frequencies can be used for the first and second RF biases. 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.

[0046] In some further embodiments, which can be combined with any other embodiments of the present disclosure, during operation 340, a first RF bias can be provided to the substrate 400 via the chuck 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 such cases, the first RF bias and the second RF bias can be any combination of frequency and power discussed in this disclosure, and the third RF bias can be configured to have the same power and frequency as that of the first or second RF bias discussed in this disclosure.

[0047] In some embodiments, the diamond-like carbon layer 412 is exposed to hydrogen radicals after it is formed on the substrate during operation 340. 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 sp 2 Selective etching of the hybridized carbon atoms occurs, thus reducing the sp 3It is believed that the proportion of hybridized carbon atoms increases, improving the etching selectivity.

[0048] In operation 350, after the diamond-like carbon layer 412 is formed on the substrate, the substrate is dechucked. During operation 350, the chucking voltage is turned off. The reactive gases are turned off and optionally purged from the processing chamber. In one embodiment, during operation 350, the RF power is reduced (e.g., to about 200 W). Once the substrate is dechucked from the electrostatic chuck, remaining gases are purged from the processing chamber. The processing chamber is pumped down, and the substrate is moved up on lift pins and transferred out of the process chamber.

[0049] After the diamond-like carbon layer 412 is formed on the substrate, it can be used in an etching process as a patterning mask to form three-dimensional structures, such as stair-like structures. The diamond-like carbon layer 412 can be patterned using standard photoresist patterning techniques.

[0050] The following non-limiting examples are provided to further illustrate the embodiments described herein. However, these examples are not intended to be exhaustive or to limit the scope of the embodiments described herein. In one embodiment, low-stress, high-density diamond-like carbon films disclosed herein were fabricated by applying 2000 watts of RF (60 MHz) power through a substrate pedestal (electrostatic chuck) in a CVD reactor at a temperature of 10° C. using 150 sccm CH and 100 sccm He as process gases and Ar and / or He as diluent gases. A comparison of the resulting diamond-like carbon films, an amorphous carbon reference film, and a diamond-like carbon film formed by PVD is shown in Table II below. TIFF2026000945000003.tif53170

[0051] Thus, a method and apparatus are provided for forming a highly transparent diamond-like carbon hard mask layer that can be utilized to form stepped structures for fabricating three-dimensional stacks of semiconductor devices. By utilizing a diamond-like hard mask layer with desirable robust film properties and etch selectivity, improved dimensional and profile control of the resulting structures formed in the film stack can be obtained, and the electrical performance of chip devices can be enhanced in applications involving three-dimensional stacks of semiconductor devices.

[0052] While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, the scope of which is determined by the claims that follow.

Claims

1. 1. A method for forming a carbon film on a substrate, comprising: flowing a hydrocarbon-containing gas mixture into a processing chamber having a substrate positioned on an electrostatic chuck, the substrate being 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 A first RF bias is applied to the electrostatic chuck to form a mixed sp on the substrate of about 60% or more. ３ generating a plasma by depositing a diamond-like carbon film including atoms, 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; A method comprising:

2. The method of claim 1 , wherein generating the plasma further comprises applying a second RF bias to the electrostatic chuck.

3. 3. The method of claim 2, wherein the second RF bias is provided at a power of about 800 Watts to about 1200 Watts and a frequency of about 350 KHz to about 13.56 MHz.

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

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

6. 1. A method for forming a carbon film on a substrate, comprising: flowing a hydrocarbon-containing gas mixture into a processing chamber having a substrate positioned on an electrostatic chuck; and applying a first RF bias to the electrostatic chuck and a second RF bias to an electrode disposed above the electrostatic chuck and facing the electrostatic chuck, thereby generating plasma and depositing a diamond-like carbon film on the substrate; Including, a first RF bias is provided at a frequency of about 13.56 MHz or less, a second RF bias is provided at a frequency of about 40 MHz or more, 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; method.

7. 7. The method of claim 6, wherein the first RF bias is provided at a frequency of about 2 MHz and at a power of about 800 watts to about 1200 watts.

8. 7. The method of claim 6, wherein the second RF bias is provided at a frequency of about 60 MHz and at a power of about 1500 watts to about 2500 watts.

9. The method of claim 6 , wherein generating the plasma further comprises applying a third RF bias to an electrode disposed on and facing the electrostatic chuck.

10. 7. The method of claim 6, wherein the third RF bias is provided at a power between about 10 watts and about 3000 watts and at a frequency between about 350 KHz and about 162 MHz.

11. 1. A method of processing a substrate, comprising: flowing a hydrocarbon-containing gas mixture into a processing volume of a processing chamber having a substrate positioned on an electrostatic chuck, the substrate being maintained at a pressure of between about 5 mTorr, and the hydrocarbon-containing gas mixture being acetylene (C ２ H ２ ), including shedding; generating a plasma at the substrate level by applying a first RF bias to the electrostatic chuck, the first RF bias being provided at a power of about 2000 watts and a frequency of about 60 MHz to deposit a diamond-like carbon film on the substrate; forming a patterned photoresist layer on the diamond-like carbon film; Etching the diamond-like carbon in a pattern corresponding to the patterned photoresist layer; and Depositing material onto the etched portion of the diamond-like carbon film A method comprising:

12. 12. The method of claim 11, wherein generating the plasma further comprises applying a second RF bias to the electrostatic chuck provided at a power of about 1000 Watts and a frequency of about 2 MHz.

13. 12. The method of claim 11, wherein the diamond-like carbon film is used as an underlayer in an extreme ultraviolet ("EUV") lithography process.

14. The hydrocarbon-containing gas mixture is He, Ar, Xe, N ２ , H ２ 12. The method of claim 11, further comprising a diluent gas comprising:

15. 15. The method of claim 14, wherein the hydrocarbon-containing gas mixture flows into the process chamber through a gas panel disposed in a sidewall of the processing chamber.

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